KR20070118834A - The biodegradable vessel using starch and the manufacturing method of that - Google Patents

Abstract

A biodegradable container using starch is provided to maximize the content of starch, to increase water resistance, oil resistance, acid resistance and compression strength, and to ensure excellent biodegradability, thereby solving the problem of environmental pollution caused by disposable plastic containers. A biodegradable container using starch comprises a starch structure, and a coating sheet attached to at least one surface of the starch structure. The biodegradable container comprises 86.21-97.10 wt% of the starch structure and 2.90-13.79 wt% of the coating sheet. Particularly, the starch structure comprises 79.17-79.72 wt% of starch, 2.84-5.71 wt% of pulp fibers, 0.08-0.99 wt% of polyvinyl alcohol. At least one starch selected from modified and non-modified starch having an amylose content of 40 wt% or less is used.

Description

Biodegradable vessel using starch and the Manufacturing method of that}

The present invention relates to a biodegradable starch container and a method for producing the same, wherein a paper (hereinafter referred to as coated paper) composed of a coating layer of a biodegradable emulsion resin is formed on at least one side of a starch structure manufactured using starch as a main raw material. The present invention relates to a biodegradable starch container which realizes the same physical properties as a plastic container such as polyethylene (PE), polyethylene terephthalate (PET), styrofoam, and which does not cause environmental problems due to rapid biodegradation in a landfill process and a method of manufacturing the same. .

Due to the development of science and technology and the improvement and convenience of quality of life culture, the use of disposable products of various materials is rapidly increasing. In particular, plastics having advantages such as low specific gravity, convenience of processing, stabilized process, excellent physical properties and durability are processed into various disposable products and are widely used in daily life. However, due to the nature of disposable products discarded after use, plastic disposable products are causing serious environmental pollution. Disposable products are treated after use, such as landfill or incineration. However, due to the nature of plastics that are not decomposed, such treatment process causes soil pollution and decreases the lifespan of landfills, and toxic gases generated from waste plastics are not only increased in air pollution but also environmental hormones and various Carcinogens are generated, causing direct damage to the human body. In order to solve the above problems through recycling, campaigns by country and region are underway, but the recovery rate is still low.

As a solution to this, various materials have been proposed to replace plastics in the field of disposable products. As a representative example, disposable product containers based on pulp have emerged, but considering the forests that cause air and water pollution and damaged for smooth supply of raw materials, it is not a sustainable solution. Not favorable In addition, the development of disposable products using photodegradable / microbial degradable plastics is also in progress. However, photodegradable resin has its own toxicity and does not decompose when landfilled, and problems such as expensive raw material price remain to be solved.

Meanwhile, the development of disposable product containers based on starch, which is capable of continuous supply, excellent biodegradability, practical price, and nontoxic natural polymer, has already been trying to launch products by many domestic and foreign companies. These products are different from each company, but to distinguish them, Korean Patent Publication No. 10-2005-0030306 can produce a container by mixing and thermoforming starch and acrylate resin, and Korean Patent Publication No. 10-2004 -0076150 consists of a starch-based component composed of starch and its crosslinking agent, acid / salts or anhydrides thereof, and a coating layer of silicon or polycaprolactone formed on one side thereof, and in Korean Utility Model Registration No. 20-0366379, one of the starch containers. A method such as laminating a polylactic acid film or a polycaprolactone film on the side is known.

However, containers manufactured by conventional methods require a large amount of chemicals to increase the water resistance of the starch, and even if a separate water-resistant coating layer is formed on the starch component, the water content of the starch component does not dissolve in the coating solution. Alternatively, since alcohol treatment is required, a number of chemicals must be added to improve the water resistance of starch. There is no guarantee of final consumer health as a container. Alternatively, when the biodegradable film is lined, the film must exceed 100 µm to allow continuous processing. Thus, thick films of more than 100 μm, even if they are biodegradable, not only delay the decomposition period but are also quite disadvantageous for the cost of expensive biodegradable films. In addition, since the methods must go through two processes, a starch-based structure fabrication process and a coating or laminating process, considerable process costs are expected. For this reason, containers through existing methods doubt the potential for market introduction of disposable containers.

In order to solve the problems described above, the present invention is attached to the starch structure containing the starch as the main raw material and the coated paper on at least one side of the structure, the final biodegradable starch container has a starch content based on the solid content of the container 79.17 To 97.10% by weight, to increase the water resistance, oil resistance, acid resistance, and compressive strength to meet the end-user's diversified consumption, and to realize excellent biodegradability, thereby expanding the range of use of biodegradable disposable devices It is an object of the present invention to provide a biodegradable starch container and a method of manufacturing the same, which fundamentally solve various environmental pollution problems generated from waste plastic by replacing plastic disposable containers.

In order to achieve the above object, the present invention is characterized by providing a biodegradable starch container with a coated paper attached to at least one side of the starch structure and starch structure produced by heating / compression using the starch as a main raw material.

In addition, the starch structure may be made of only starch and distilled water, or in addition to the starch and distilled water, pulp fiber, which is a flexible reinforcing agent of the starch structure, may be added as needed, and may include polyvinyl alcohol, which is an adhesive reinforcing agent of the starch structure and coated paper. It is characterized by.

In addition, the base paper of the coated paper is characterized by using a processed paper of a single or two or more kinds of raw paper of royal ivory paper, ivory paper, tracing paper, Korean paper, white paper.

In addition, as a coating agent for forming a coating layer of the coated paper, using a single or two or more of latex emulsion, silicone emulsion, fluorine emulsion, polyester aqueous solution, polyvinylacetate (PVAc) aqueous solution, rosin emulsion, wax emulsion, or the At least one emulsion is characterized in that 50% by weight of the acrylate-based emulsion to reduce the cost.

In addition, in preparing a biodegradable starch container, characterized in that the biodegradable starch container is produced through a single heating and pressing process after the coating paper and the starch mixture is added in parallel, the coated paper and the starch mixture to each nose Starch structure through the process of inputting into the mold frame consisting of the upper and lower parts of the heating presser through a sieving machine and a starch injector and operating the heating presser under the conditions of temperature of 180 to 250 ° C and pressure of 10 to 12 kg / cm 2. It characterized in that the biodegradable starch container is formed on one side or both sides of the coated paper.

The starch mixture of the present invention is a raw material of the starch structure, by heating and pressing the starch mixture to produce a starch structure. The composition of the starch mixture is prepared by stirring 50% by weight of starch and 50% by weight of distilled water as a solvent for 2 hours or more, or 41.79 to 50% by weight of starch, 1.70 to 3.16% by weight of pulp fiber as a strength reinforcing agent, and polyvinyl as a biodegradable adhesive. 1.02 to 10.45% by weight of an alcoholic 5% aqueous solution and 44.78 to 50.63% by weight of distilled water as a solvent are prepared by stirring for 2 hours or more.

At this time, the solvent distilled water is suitable to include 44.78 to 50.63% by weight based on the starch mixture, less than 44.78% by weight, the high viscosity of the dough of the starch mixture resulting in the aggregation of pulp fibers, resulting in 50.63 weight This is because when the dough content of the starch mixture of low viscosity is exceeded, it is difficult to control the amount of the starch mixture to be added to the heating pressurizer.

Starch, which is the main raw material of the starch mixture, is not particularly limited, but is preferably a biodegradable container using natural starch extracted from sweet potato, potato, wheat, tapioca, rice, corn, and the like, and physical / chemical modified starch thereof and esterified starch thereof. In consideration of the strength, flexibility, foaming rate and recovery rate suitable for the application, single or two or more kinds of mixed starches may be used.

The longer the pulp fibers, the more favorable the flexibility and compressive strength of the starch structure, so the pulp fibers of the conifers are preferred.

The polyvinyl alcohol aqueous solution is added to increase the adhesion between the starch structure and the base of the coated paper, in addition to the polyvinyl ether aqueous solution, polyvinylpyrrolidone aqueous solution, rosin emulsion, polyvinyl acetate emulsion, acrylic emulsion, styrene emulsion, It is possible to use solely or two or more kinds of a urethane emulsion and a melanin emulsion, and in particular, it is preferable to use an aqueous polyvinyl alcohol solution.

The distilled water is for forming the dough of the starch mixture, in addition to the higher or lower alcohol, an aqueous alkali solution or two or more kinds of mixtures can be used, in particular, it is preferable to use distilled water.

The starch mixture consisting of the above components is added 30 to 40g in the center of the mold frame consisting of the upper / lower preheated to 180 to 250 ℃. At this time, the coated paper is introduced so that the coated paper is positioned on the upper or upper / lower portion of the starch mixture.

In addition, the mold can be applied simultaneously to the starch mixture and one or more coated papers located between the mold mold and a pressure of 10 to 12 kg / ㎠. An appropriate time for the pressing process is 180 to 210 seconds.

At this time, all the distilled water, which is a solvent of the starch mixture, is evaporated through the heating / pressing process to form a starch structure composed of starch or starch, pulp fiber, and polyvinyl alcohol, and at one side of the starch structure. Coated paper is bonded to the above, and a biodegradable starch container is completed.

The coating paper, which is added to the heating pressurizer in parallel with the starch mixture, is to impart water resistance, oil resistance and acid resistance of the biodegradable starch container of the present invention and at the same time increase the compressive strength of the starch structure. However, raw paper of a single or two or more types of coated paper among royal ivory paper, ivory paper, tracing paper, Hanji paper, and white paper can be used, and in particular, it is possible to use press paper and royal ivory paper for food packaging. It is preferable.

The coating layer formed on one side of the coated paper is a part implementing water resistance, oil resistance, and acid resistance. As the coating agent for forming the coating layer, a single or two or more of latex emulsion, silicone emulsion, fluorine emulsion, polyester aqueous solution, polyvinylacetate (PVAc) aqueous solution, rosin emulsion, wax emulsion, or one or more of the emulsions is used. In order to reduce the cost, the acrylate-based emulsion is characterized in that the 50% by weight.

There is no particular limitation in attaching the starch structure and the coated paper, but it is advantageous in the process to simultaneously feed the starch mixture and the coated paper into the heating pressurizer. In more detail, it is possible to control the temperature in the range of 50 to 350 ℃, and a heating press produced to apply a pressure of 5 to 20 kg / ㎠ to the upper / lower mold, and the upper / lower of the heating press The three apparatuses of the coated paper feeder capable of continuously supplying coated paper to the upper and lower ends of the mold frame and the starch feeder capable of injecting the starch mixture were manufactured by themselves. The three devices are organically linked so that one starch container is produced in one process. In other words, the starch mixture is introduced into the lower mold. The coated paper is introduced so that the base of the coated paper faces the upper portion of the starch mixture. In some cases, the coated paper may be added to the lower portion of the starch mixture with the original surface of the coated paper facing the starch mixture. After the input of such raw material is finished, the pressure is 10 to 12 kg / cm 2. At this time, the mold of the heating press is preheated to a temperature of 180 to 210 ℃, the moisture of the starch mixture is removed to complete the final biodegradable starch container.

Hereinafter, a biodegradable starch container according to the present invention and a manufacturing method thereof will be described in detail.

In the present invention, the starch structure serving as the main body of the biodegradable starch container may include pulp fibers to reinforce the compressive strength, and may include polyvinyl alcohol (PVA) for smooth adhesion with coated paper. 5% aqueous solution can be used, and it is characterized by including distilled water as a solvent.

In addition, the coating paper is produced by coating / drying an emulsion-type coating agent on one side of the base paper, and is put into a heating pressurizer and bonded to one side or both sides of the biodegradable starch container. At this time, the starch structure is formed by removing the water of the starch mixture continuously introduced into the coated paper by heating and pressing the heating presser, and forming the starch structure, wherein the starch structure of the produced starch structure or the adhesive force of starch / polyvinyl alcohol Due to this, the surface of the coated paper and the starch structure have a very strong adhesion. This process produces a biodegradable starch container.

At this time, the solid content of the biodegradable starch container comprises 86.21 to 97.10% by weight starch and 2.90 to 13.79% by weight coated paper, or 79.17 to 79.54% by weight starch, 2.84 to 5.71% by weight pulp fiber and 0.08 to polyvinyl alcohol (PVA) It is preferred to include 0.99% by weight and 14.21 to 17.54% by weight coated paper.

As the starch, corn, waxy corn, potato, tapioca, sweet potato, rice, glutinous rice, wheat, barley, and other seeds having an amylose content of 40% by weight or less may be used. In particular, corn, potato, wheat, rice, tapioca, It is appropriate to use one or two or more starches selected from the group consisting of sweet potatoes.

The starch preferably contains 79.17 to 97.10% by weight, based on the solids of the biodegradable starch container. In addition to the cost of the product, according to the Ministry of Environment's national notice, starch containers must not exceed 70% by weight because the starch content must be greater than 70% by weight. If the content exceeds 98% by weight, it is unsuitable for use by the end consumer due to deterioration of the physical properties of the container.

Next, the pulp fibers are suitably contained in the biodegradable starch container or contain 2.84 to 5.71 wt% based on the biodegradable starch container solids. Even biodegradable starch containers of the same specifications differ in their flexibility and compressive strength. When it does not contain pulp fibers it is suitable for flexible biodegradable starch containers and when it contains 5.00% by weight pulp fibers it is suitable for biodegradable starch containers with high compressive strength. When the pulp fiber exceeds 5.71% by weight, it is not only difficult to produce a uniform starch mixture due to the agglomeration of the pulp fibers in producing a starch mixture, which is one of the materials of the biodegradable starch container, but also a problem of increasing the cost of raw materials. Because of this.

Next, a 5% aqueous solution of polyvinyl alcohol (PVA) is added for smooth adhesion of the starch structure and the coated paper. In preparing the starch mixture, in mixing starch or starch and pulp fibers, 5% aqueous solution was used in consideration of defects such as agglomeration of starch or agglomeration of starch and pulp and proper viscosity of the final starch mixture. . The polyvinyl alcohol was selected from fully saponified polyvinyl alcohol having excellent water resistance and strength. If a 5% aqueous solution of polyvinyl alcohol is not included in the biodegradable starch container or 0.08 to 0.99% by weight based on the solids of the biodegradable starch container, it is appropriate to use a coated paper when it does not include a 5% aqueous solution of polyvinyl alcohol. When the adhesion between the starch structure and the starch structure alone is sufficient, when the 5% aqueous solution of polyvinyl alcohol exceeds 0,99% by weight, the adhesion of the dough of the final starch mixture increases, making it difficult to properly add the starch mixture. This is because the agglomeration of pulp fibers increases the difficulty in producing a uniform starch mixture.

Next, in the production of coated paper imparting water resistance and oil resistance, the base paper is not particularly limited, but a single or two or more types of paper products among royal ivory paper, ivory paper, tracing paper, Hanji paper, and white paper can be used. Preferably, it is preferably presserine (20 to 40 g / m 2) and royal ivory (50 to 200 g / m 2), which are types of tracing paper for food packaging. More precisely, it is preferable that the paper is a food packaging paper having a thickness of 25 to 70 g / m 2 and conforming to the standards and standards of the Food Code No. 6. Apparatus, Container, and Packaging.

Coated paper is suitable to use 2.90 to 17.54% by weight based on the solids of the biodegradable starch container, but less than 2.90% by weight is too small in terms of increased flexibility and compressive strength of the biodegradable starch container, 17.54% by weight If it exceeds the ratio of paper in the biodegradable starch container is too high because there is a problem accompanying the increase in the cost of the biodegradable starch container.

Water-soluble resins such as latex emulsion, silicone emulsion, fluorine emulsion, polyester aqueous solution, polyvinylacetate (PVAc) aqueous solution, rosin emulsion, wax emulsion, and acrylate emulsion may be used as a coating agent to directly form the coated surface of the coated paper. Do. The coating layer formed through the water-soluble resin is a coating layer is formed through the superimposition of the resin particles of the micron unit, it is easier to permeate the atmospheric gas than the coating layer produced through the laminating process. Accordingly, a biodegradable water-soluble resin is prepared by mixing three emulsions of a wax emulsion, a biodegradable emulsion, and a silicone emulsion, and an acrylate emulsion, a disintegratable resin, in the emulsion. The acrylate-based emulsions reduce the cost of water-soluble resins, while reinforcing water and oil resistance. The biodegradable water-soluble resin is used to form a coating layer on one side of the base paper for food packaging using a coater equipped with a four-stage mesh coater. At this time, the final coating layer is advantageous in terms of biodegradability to form a thin film of 4 to 8㎛ that is the critical point at which the desired physical properties appear.

For example, a process of preparing a biodegradable starch container by attaching a starch structure composed of starch as the main component and starch structure to one or more sides of the starch structure may be coated with water, oil, and acid resistant treatments.

A starch mixture is prepared by mixing about 20 minutes at a ratio of 1 weight of distilled water to 1 weight of unmodified corn starch.

On the other hand, for the purpose of increasing the high strength and bending resistance and adhesion to the coated paper to be laminated in the future, 1.04 to 1.14 weight of distilled water, 0.04 to 0.07 weight of pulp fiber, 5% of polyvinyl alcohol, per 1 weight of unmodified corn starch. A starch mixture is prepared by mixing for about 20 minutes at a rate of 0.02 to 0.25 weight of the aqueous solution.

The mold of the upper and lower plates of the heating presser capable of temperature control of 50 to 350 ° C. and pressure control of 5 to 20 kg / cm 2 is preheated to an appropriate temperature. Insert the coated paper with the coating surface of the coated paper facing the upper plate and the lower plate of the mold. 30 to 40 g of one starch mixture selected from the two kinds of starch mixtures were introduced into the base paper of the coated paper of the lower die mold, and then the water of the starch mixture was subjected to a pressure of 10 to 12 kg / cm 2 over 180 to 210 seconds. Along with the removal, the coating paper and the starch are attached. At this time, the coated paper attached to the lower side of the biodegradable starch container can be removed in the operation of the heating pressurizer according to the required physical properties such as the strength and flexibility of the final product of the biodegradable starch container. Also within the range possible.

Hereinafter, the present invention will be described in detail through examples. However, the scope of the present invention is not limited by the embodiment.

Example 1 Preparation of Coating

Silicone Emulsion Preparation Example 1

70 g of silicon was added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, a cooler, and a nitrogen injector, stirred at 500 rpm, heated to 80 ° C., 300 g of distilled water prepared in advance, and 6.33 g of emulsifier SPAN23. 14.67 g of TWEEN60 was slowly added. Thereafter, the mixture was cooled to room temperature over 180 minutes to terminate the reaction, thereby preparing a silicone emulsion having a composition as shown in Table 1 below.

Silicone Emulsion Preparation Example 2

70 g of silicon was added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, a cooler, and a nitrogen injector, stirred at 500 rpm, and heated to 80 ° C., 300 g of distilled water and 2.12 g of emulsifier SPAN23 prepared in advance over 180 minutes. SPAN40 1.08g, TWEEN60 15.80g, P-24 5g was slowly added. Thereafter, the mixture was cooled to room temperature over 180 minutes to terminate the reaction, thereby preparing a silicone emulsion having a composition as shown in Table 1 below.

silicon emulsion Preparation Example 3

70 g of silicon was added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, a cooler, and a nitrogen injector, stirred at 500 rpm, heated to 80 ° C., and 300 g of distilled water and 1.04 g of emulsifier SPAN23 prepared in 180 minutes. SPAN40 0.56g, TWEEN60 16.40g, P-24 10g was slowly added. Thereafter, the mixture was cooled to room temperature over 180 minutes to terminate the reaction, thereby preparing a silicone emulsion having a composition as shown in Table 1 below.

silicon Emulsifier Distilled water SPAN 23 SPAN 40 TWEEN 60 P-24 (5%, aq) Preparation Example 1 70 g 6.33 g - 14.67 g - 300 g Preparation Example 2 70 g 2.12 g 1.08g 15.80 g 5.0 g 300 g Preparation Example 3 70 g 1.04 g 0.56 g 16.40 g 10.00 g 300 g

P-24: fully saponified polyvinyl alcohol (PVA) of Dongyang Steel Chemical

Evaluation of physical properties of silicone emulsion

After coating three kinds of the silicone emulsion prepared in Examples 1 to 3 of the silicone emulsion on one side of the presserol, a 6 μm coating film was formed through a drying process to prepare a 30 cm 2 size coated paper. 200 ml of pure water, edible oil, and 5% glacial acetic acid were contacted with the coating surface of the coated paper through a jig made to contact 200 ml of liquid to 10 cm 2 paper for 3 hours to evaluate water resistance, oil resistance, and acid resistance. Releasability was evaluated by stacking 20 coated papers and applying a pressure of 2 kg per cm 2 in a thermostat at 80 ° C. The results for water resistance, acid resistance, oil resistance, and releasability of the silicone emulsion Preparation Examples 1 to 3 are shown in Table 2 below.

Water resistance Oil resistance Acid resistance Dysplasia Preparation Example 1 ○ × × ◎ Preparation Example 2 ◎ △ × ◎ Preparation Example 3 ◎ △ △ ◎

* Reference 1. Evaluation criteria for water resistance, oil resistance and acid resistance

◎: no wet at all, ○: less than 1/10 wet area, △: less than 1/5 wet area

×: 1/5 wet area

* Reference 2. Based on Releasable Funga

◎: No paper at all, ○: Less than 1 sheet of paper (including partial paper)

(Triangle | delta): Two sheets of paper (including partial paper), x: Two or more sheets of paper (including partial paper)

Preparation Example 4 of Acrylate Emulsion

1000 ml flask equipped with stirrer, thermometer, monomer emulsion inlet, cooler, nitrogen injector 10g monomer MMA, EAM 23g, BA 112g, SM 53g, AAc 2g, emulsifier NPES-930 4g, polymerization initiator APS 1.2g, distilled water 244g After the addition, the mixture was stirred at 60 rpm and gradually increased to 84 ° C. over 120 minutes at room temperature, and then maintained at 80 ㅁ 5 ° C. over 180 minutes, and then cooled to room temperature over 120 minutes to terminate the reaction. An acrylate emulsion was prepared with the same composition.

Preparation Example 5 of Acrylate Emulsion

Into a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, a cooler, and a nitrogen injector, a monomer BA 112g, SM 86g, AAc 2g, an emulsifier NPES-930 4g, a polymerization initiator APS 1.2g, distilled water 244g were charged, and at 60 rpm. After stirring, the mixture was gradually increased to 84 ° C. over 120 minutes, and then maintained at 80 ± 5 ° C. over 180 minutes, and then cooled to room temperature over 120 minutes to terminate the reaction. An emulsion was prepared.

MMA * EAM * BA * SM * AAc * NPES-930 * APS * Distilled water Preparation Example 4 10 g 23 g 112 g 53 g 2 g 4 g 1.2 g 244 g Preparation Example 5 - - 112 g 86 g 2 g 4 g 1.2 g 244 g

The abbreviations or product names of the monomers and initiators indicated by * in Table 3 are as follows.

MMA: Methyl methacrylate, EAM: Ethyl acrylate monomer, BA: Butyl acrylate monomer, SM: Styrene monomer, AAc: Acrylic acid, NPES-930: CYTEC's nonyl phenol ether sulfates, APS: Ammonium persulfate

Physical property evaluation of acrylate emulsion

The two acrylate emulsions prepared in Preparation Examples 4 and 5 of the acrylic emulsion were subjected to physical property evaluation in the same manner as in the physical property evaluation method of the silicone emulsion. The results of evaluation of physical properties for water resistance, acid resistance, oil resistance, and releasability of Preparation Examples 4 and 5 are shown in Table 4 below.

Water resistance Oil resistance Acid resistance Dysplasia Preparation Example 4 ◎ ◎ × △ Preparation Example 5 ◎ ◎ × ×

Preparation Example 6 of Wax Emulsion

60 g of distilled water and 1.5 g of catalyst (potassium hydroxide) were added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, and a cooler, and 32.5 g of PE oxide wax and an emulsifier under constant temperature (100 ° C.) and stirring (500 rpm) conditions. 4 g of OT-75 and 2 g of LE-15 were added while maintaining at 140 ° C. The wax mixture was cooled to room temperature over 10 minutes at the time when the wax mixture was added, thereby preparing a wax emulsion having the composition shown in Table 5.

Preparation Example 7 of Wax Emulsion

60 g of distilled water and 1.5 g of catalyst (potassium hydroxide) were added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, and a cooler, and beeswax (mp: 62 ° C.) under constant temperature (100 ° C.) and stirring (500 rpm). 16 g, 16.5 g of PE oxide wax, and 12 g of emulsifier OT-75 and 2 g of LE-15 were added at 140 ° C. The wax mixture was cooled to room temperature over 10 minutes at the time when the wax mixture was added, thereby preparing a wax emulsion having the composition shown in Table 5.

Preparation Example 8 of Wax Emulsion

60 g of distilled water and 1.5 g of catalyst (potassium hydroxide) were added to a 1000 ml flask equipped with a stirrer, a thermometer, a monomer emulsion inlet, and a cooler, and beeswax (mp: 62 ° C.) under constant temperature (100 ° C.) and stirring (500 rpm). 24g, 8.5g PE wax and 30g of emulsifier OT-75 and 2g of LE-15 were added at 140 ° C. The wax mixture was cooled to room temperature over 10 minutes at the time when the wax mixture was added, thereby preparing a wax emulsion having the composition shown in Table 5.

Beeswax Oxide PE Wax Distilled water OT-75 LE-15 KOH Preparation Example 6 - 32.5 g 60 g 4 g 2 g 1.5 g Preparation Example 7 16 g 16.5 g 60 g 12 g 2 g 1.5 g Preparation Example 8 24 g 8.5 g 60 g 30 g 2 g 1.5 g

Physical property evaluation of wax emulsion

Preparation of Wax Emulsion Three wax emulsions prepared in Examples 6 to 8 were subjected to physical property evaluation in the same manner as the physical property evaluation method of the silicone emulsion. The results are shown in Table 6 below.

Water resistance Oil resistance Acid resistance Dysplasia Preparation Example 6 ○ △ ◎ ◎ Preparation Example 7 ○ ○ ◎ ◎ Preparation Example 8 ◎ △ ◎ ◎

<Example 2. Preparation of biodegradable coated paper>

Preparation Example 9 of Biodegradable Coated Paper

Silicone Emulsion of Preparation Example 3 Acrylic Emulsion of Preparation Example 4 Wax emulsion of Preparation Example 7 was mixed and stirred at a weight ratio of 1: 2: 1, and then a coating agent designed to rapidly decompose after thin film coating treatment Was prepared. The coating agent was coated by using a comma coating device on one side of the roe deer (25㎛) fabric that can be used as food packaging paper. After the coating, the hot air was dried at 130 ° C. for 5 minutes to form a thin film having a thickness of about 4 μm to prepare a coated paper having a composition as shown in Table 7 below.

Preparation Example of Biodegradable Coated Paper 10

Silicone emulsion of Preparation Example 3: The wax emulsion of Preparation Example 7 was mixed and stirred at a weight ratio of 1: 1, thereby preparing a coating agent designed to rapidly decompose after thin film coating treatment. The coating was coated using a comma coating device on one side of the Royal Ivory (70 ㎛) fabric that can be used as food packaging paper. After the coating, the hot air was dried at 130 ° C. for 5 minutes to form a thin film having a thickness of about 8 μm to prepare a coated paper having a composition as shown in Table 7 below.

Silicone emulsion Acrylic emulsion Wax emulsion Use base Preparation Example 9 25 wt% 50 wt% 25 wt% Roe deer Preparation Example 10 50 wt% - 50 wt% Royal Ivory

Evaluation of Properties of Biodegradable Coated Paper

The physical properties of the two biodegradable coated papers prepared in Preparation Examples 9 and 10 of the biodegradable coated paper were evaluated in the same manner as in the physical property evaluation method of the silicone emulsion, and were excellent in water resistance, oil resistance, acid resistance and release property. In addition, as a result of applying 10 cm 2 of the coated paper to 30 cm of soil, it was confirmed that biodegradation over 16 days and 24 days, respectively. The results are shown in Table 8 below.

Water resistance Oil resistance Acid resistance Dysplasia Biodegradation period Preparation Example 9 ◎ ◎ ◎ ◎ 16th Preparation Example 10 ◎ ◎ ◎ ◎ 24 days

Example 3. Preparation of Starch Mixture

Preparation Example 11 of Starch Mixture

7 kg of unmodified corn starch (water 12.3) and 7 kg of distilled water were added thereto, followed by stirring for about 30 minutes to prepare a biodegradable starch mixture. The composition thereof is shown in Table 9 below.

Preparation of Starch Mixture Example 12

7 kg of unmodified corn starch (water 12.3), 0.15 kg of a 5% aqueous solution of polyvinyl alcohol (PVA), and 7.3 kg of distilled water were added and stirred for about 30 minutes. Then, 0.25 kg of pulp fiber was added to the mixture and stirred for 2 hours. Biodegradable starch mixtures were prepared. The composition thereof is shown in Table 9 below.

Preparation Example 13 of Starch Mixture

7 kg of unmodified corn starch (moisture 12.3), 0.3 kg of 5% aqueous solution of polyvinyl alcohol (PVA), 8 kg of distilled water were added and stirred for about 30 minutes, and 0.5 kg of pulp fiber was added to the mixture. A starch mixture was prepared. The composition thereof is shown in Table 9 below.

Preparation of Starch Mixture Example 14

7 kg of unmodified corn starch (water 12.3), 1.75 kg of 5% aqueous solution of polyvinyl alcohol (PVA), and 7.5 kg of distilled water were added and stirred for about 30 minutes, and 0.5 kg of pulp fiber was added to the mixture. Biodegradable starch mixtures were prepared. The composition thereof is shown in Table 9 below.

Starch Distilled water P-25 (5% aq) Pulp Fiber Preparation Example 11 7.00 kg 7.00 kg - - Preparation Example 12 7.00 kg 7.30 kg 0.15 kg 0.25 kg Preparation Example 13 7.00 kg 8.00 kg 0.30 kg 0.50 kg Preparation Example 14 7.00 kg 7.50 kg 1.75 kg 0.50 kg

Example 4 Preparation of Starch Container

Preparation Example 15 of Biodegradable Starch Container

It is possible to adjust the temperature of 50 to 350 ℃, the heating press produced to apply a pressure of 5 to 20 kg / ㎠ to the upper / lower mold, and coated paper on the upper and lower ends of the upper / lower mold The three machines of the coated paper feeder which can continuously supply the feeder, and the feeder which can feed the starch mixture were manufactured. The upper and lower frames of the molding machine are designed to produce a rectangular tray No. 18 having a size of 23.5 * 16.8 * 2.4 cm. Into the lower plate preheated to 190 ° C of the molding machine, one sheet of coated presserine (0.8 g) prepared in Preparation Example 9 was introduced with the coating surface facing the lower plate. 30 g of the starch mixture prepared in Preparation Example 11 was added to the raw surface of the coating presser that was previously added to the lower plate. One sheet (1.2 g) of the coating presser prepared in Preparation Example 9 was added to the upper side of the previously added starch mixture. At this time, the base of the coating presser is faced in the direction of the starch mixture. After completion of the feeding process as described above, a pressure of 10 kg / cm 2 was applied for 180 seconds to prepare 100 biodegradable starch containers of No. 18 tray standard. The components for this are specified in Table 10 below.

Preparation Example of Biodegradable Starch Container 16

The same instrument used in Preparation Example 15 was used. Into the lower plate preheated to 210 ° C. of the molding machine, 1 sheet (1.8 g) of the coated royal ivory produced in Preparation Example 10 was added with the coating surface facing the lower plate. 40 g of the starch mixture prepared in Preparation Example 12 was added to the base of the coated royal ivory paper, which was previously added to the lower plate. One sheet (2.4 g) of the coated royal ivory prepared in Preparation Example 10 was added to the upper side of the previously added starch mixture. The base of the coated royal ivory is then directed in the direction of the starch mixture. After completing the feeding process as described above, a pressure of 12 kg / cm 2 was applied for 210 seconds to prepare 100 biodegradable starch containers of No. 18 tray standard. The components for this are specified in Table 10 below.

Preparation Example of Biodegradable Starch Container 17

The same instrument used in Preparation Example 15 was used. Into the lower plate preheated to 200 ℃ of the molding machine is injected one sheet (0.8 g) of the coating presser prepared in Preparation Example 9 with the coating surface facing the lower plate. 40 g of the starch mixture prepared in Preparation Example 13 is added to the raw surface of the coating presser that was previously added to the lower plate. One sheet of coated royal ivory (2.4 g) prepared in Preparation Example 10 was added to the upper side of the previously added starch mixture. The base of the coated royal ivory is then directed in the direction of the starch mixture. After completing the feeding process as described above, a pressure of 11 kg / cm 2 was added for 190 seconds to prepare 100 biodegradable starch containers of No. 18 tray standard. The components for this are specified in Table 10 below.

Preparation Example of Biodegradable Starch Container 18

The same instrument used in Preparation Example 15 was used. Into the lower plate preheated to 200 ° C of the molding machine, 1 sheet (1.8 g) of the coated royal ivory produced in Preparation Example 10 was added with the coating surface facing the lower plate. 40 g of the starch mixture prepared in Preparation Example 14 was added to the original surface of the coated royal ivory loaded into the lower plate. One sheet (1.2 g) of the coating presser prepared in Preparation Example 9 was added to the upper side of the previously added starch mixture. At this time, the base of the coating presser is faced in the direction of the starch mixture. After completing the feeding process as described above, a pressure of 11 kg / cm 2 was added for 190 seconds to prepare 100 biodegradable starch containers of No. 18 tray standard. The components for this are specified in Table 10 below.

Preparation Example of Biodegradable Starch Container 19

The same instrument used in Preparation Example 15 was used. 4g of soybean oil is applied to the lower plate preheated to 200 ° C of the molding machine to facilitate the release of the starch mixture to be added later. 40 g of the starch mixture prepared in Preparation Example 11 was added to a lower plate coated with soybean oil. 1 sheet (0.6 g) of the coating presser prepared in Preparation Example 9 was added to the upper side of the previously added starch mixture. At this time, the base of the coating presser is faced in the direction of the starch mixture. After completion of the feeding process as described above, a pressure of 10 kg / cm 2 was applied for 180 seconds to prepare 100 biodegradable starch containers of No. 18 tray standard. The components for this are specified in Table 10 below.

Preparation Example of Biodegradable Starch Container 20

The same instrument used in Preparation Example 15 was used. 4 g of soybean oil is applied to the lower plate preheated to 190 ° C. of the molding machine to facilitate the release of the starch mixture to be added later. 30 g of the starch mixture prepared in Preparation Example 11 was added to a lower plate coated with soybean oil. One sheet (2.4 g) of the coated royal ivory prepared in Preparation Example 10 was added to the upper side of the previously added starch mixture. At this time, the base of the coated royal ivory is directed toward the starch mixture. After finishing the above charging step, the biodegradable starch containers of 100 No. 18 tray standards were prepared by applying a pressure of 11 kg / cm 2 for 180 seconds. The components for this are specified in Table 10 below.

Starch Pulp Fiber Polyvinyl Alcohol (PVA) Coated paper Preparation Example 15 88.24% by weight - - 11.76 wt% Preparation Example 16 79.54 wt% 2.84 wt% 0.08% by weight 17.54 wt% Preparation Example 17 79.72% by weight 5.71% by weight 0.17% by weight 14.40 wt% Preparation Example 18 79.17% by weight 5.63% by weight 0.99% by weight 14.21 wt% Preparation Example 19 97.10% by weight - - 2.90 wt% Preparation Example 20 86.21% by weight - - 13.79 wt%

Evaluation of Properties of Biodegradable Starch Containers

The physical properties and appearance of the water-repellent, oil-resistant, acid-resistant, etc. of the rectangular tray starch container prepared for each production example over the production examples 15 to 20 of the biodegradable starch container was confirmed. The physical properties were evaluated in the same manner as the physical property evaluation method of the silicone emulsion, and the biodegradability was measured by the time required to completely decompose 10 cm 2 of the biodegradable starch container in 30 cm of soil. Compressive strength was measured by compressing both sides of the container using a load cell of the speed of 2mm / s to measure the strength when the container is broken. The results are shown in Table 11.

Water resistance Oil resistance Acid resistance Compressive strength Exterior Biodegradation period Preparation Example 15 ◎ ◎ ◎ 6.5㎏㎨ No peeling 21st Preparation Example 16 ◎ ◎ ◎ 8.0㎏㎨ No peeling 25 days Preparation Example 17 ◎ ◎ ◎ 7.2 kg No peeling 26 days Preparation Example 18 ◎ ◎ ◎ 6.9 kg No peeling 22 days Preparation Example 19 ◎ ◎ ◎ 4.7㎏㎨ No peeling 20 days Preparation Example 20 ◎ ◎ ◎ 5.6㎏㎨ No peeling 22 days

The present invention forms a starch container suitable for the notice of the Ministry of Environment by maximizing the starch content by forming a biodegradable coated paper on at least one side of the starch container, and at the same time, water resistance, oil resistance and acid resistance which are problems of other starch containers. In addition to solving this problem, the process of the starch container is drastically reduced by an easy process, thereby enabling the popularization of the biodegradable starch container and maximizing the biodegradability.

Claims (9)

Biodegradable starch container, characterized in that the coated paper is attached to one or more of the starch structure and the starch structure. The biodegradable starch container according to claim 1, wherein the starch structure comprises 86.21 to 97.10 wt% of starch and 2.90 to 13.79 wt% of the coated paper. The starch structure of claim 1, wherein the starch structure comprises 79.17 to 79.72 wt% starch, 2.84 to 5.71 wt% pulp fiber, 0.08 to 0.99 wt% polyvinyl alcohol (PVA) and the coated paper contains 14.21 to 17.54 wt%. Biodegradable starch container. The starch according to claim 2 or 3, wherein the starch has an amylose content of 40% by weight or less of corn, waxy corn, potato, tapioca, sweet potato, rice, glutinous rice, wheat, barley and other seeds of unmodified starch and its denaturation. Biodegradable starch container, characterized in that to use one or two or more starches selected from starch. The biodegradable starch according to claim 2 or 3, wherein, as the base paper of the coated paper, a single or two or more kinds of laminated papers of royal ivory paper, ivory paper, tracing paper, Korean paper, and white paper are processed. Vessel. The coating agent for forming a coating layer of the coated paper according to claim 2 or 3, alone or two in a latex emulsion, silicone emulsion, fluorine emulsion, polyester aqueous solution, polyvinylacetate (PVAc) aqueous solution, rosin emulsion, wax emulsion Biodegradable starch container characterized by using the above. According to claim 2 or 3, wherein the coating agent for forming a coating layer of the coated paper any one selected from latex emulsion, silicone emulsion, fluorine emulsion, polyester aqueous solution, polyvinylacetate (PVAc) aqueous solution, rosin emulsion, wax emulsion The biodegradable starch container, which is used by adding 50% by weight of an acrylate emulsion. The method of manufacturing a biodegradable starch container according to claim 1, wherein the heating / pressing process of the starch structure and the bonding process of the coated paper are simultaneously performed. The method according to claim 8, wherein the starch mixture and the coated paper, which are raw materials of the starch structure, are injected into upper and lower molds of the heating pressurizer using respective starch feeders and coated paper feeders, and the starch mixture and coated paper are heated. Operating the pressurizer at a temperature of 180 to 250 ° C. and a pressure of 10 to 12 kg / cm 2 for 180 to 210 seconds so that the coated paper is formed on one side or both sides of the starch structure through the process of heating / pressing the starch mixture and the coated paper. Biodegradable starch container manufacturing method characterized in that.