KR20120037206A - Injection molded article by using corn stalk powder and method of the same - Google Patents

Abstract

PURPOSE: An injection molded product is provided to have excellent natural degradability, and to reduce carbon dioxide, by using a large amount of corn stalk powder. CONSTITUTION: A manufacturing method of an injection molded product comprises: a step of generating corn stalk powder; a step of heating and drying the corn stalk powder, and generating coated corn stalk powder by putting wax into the dried corn stalk powder; a step of forming a mixture by mixing a plastic resin polymer, organic acid, and peroxide into the coated stalk powder ; a step of graft combining the plastic resin-plant body by putting the mixture into the extruder; a step of outputting the plastic resin-plant body grafted material, and manufacturing pellets by cutting the outputted stands; and a step of injection molding by adding the pellets into the plastic resin.

Description

Injection molded article using corn flake powder and manufacturing method {Injection molded article by using corn stalk powder and Method of the same}

The present invention relates to an eco-friendly injection molded product using a plant biomass such as corn stalk and a manufacturing method thereof, and more specifically, to prepare a biodegradable biomass pellet using corn stalk, powder, oxidant, starch, inorganic filler, etc. The present invention relates to an eco-friendly injection molded article containing biomass powder, such as corn stalks, which is processed to facilitate the production of food packaging materials, baby products, bathroom products, kitchenware and industrial packaging materials using the pellets.

Biomass plastics are plastics containing 25% or more of so-called biomass derived from plants such as corn, which suppresses the increase in the concentration of carbon dioxide in the atmosphere by using a plant resource in which atmospheric carbon is fixed by photosynthesis. It is effective, can reduce the consumption of petroleum, a limited resource, and since it is decomposed by microorganisms after disposal, has recently attracted attention as an environmentally friendly degradable material.

Natural decomposition involving biomass occurs in three stages. The first step is the step of microbial decomposition and oxidative decomposition of the biodegradable components, and the physical breakdown of the polymer occurs as the biomass components contained in the final product such as food containers are microbially degraded. As the first step proceeds, the surface area increases, the physical strength and the elongation decrease, and the polymer proceeds to a porous state. The second step is a chemical decomposition (molecular weight reduction) step, the automatic oxidation reaction proceeds by the carboxylic acid, ketones, aldehydes, etc. generated due to the natural decomposition, the surface gradually becomes hydrophilic to promote thermal and chemical decomposition, Chemical decomposition occurs due to peroxides, organic acids and the like, and the molecular weight of the polymer decreases. The third stage is a microbial decomposition (final biodegradation) stage, in which the molecular weight is lowered and the plastic is made into a low molecular weight, changed into alcohol, aldehyde, fatty acid, etc., and then further decomposed into water, carbon dioxide and biomass.

Various bacteria, bacteria, enzymes, etc. present in the soil act on the low molecular weight polymer and finally biodegrade in nature. When the molecular weight falls below 40,000, decomposition by the microorganisms proceeds actively without the action of additives or the like. In a real natural environment, the three decompositions proceed simultaneously and complementarily. What is needed is a biodegradable composition to contribute to the decomposition of the first and second stages above.

Corn is a perennial crop belonging to the flower family, which varies from region to region, but grows globally because it grows well in 45 to 60 days without being affected by drought or rainy season and without being soiled.

The cornstalk is one of the biomasses that forms the outer part of the cornstalk except for the sorghum cores. Unlike corn cores, it contains a lot of fiber, can be purchased at a low price, it is easy to reduce carbonization during processing, and has an excellent decomposition effect. However, cornstalks, like other plant powders, had poor flowability during injection molded products, so the cornstalk content was hard to exceed 5%. Therefore, there is a demand for developing an effective method for increasing cornstalk content and using cornstalk powder in a large amount in an eco-friendly injection molding product using biodegradable cornstalk biomass pellets used for injection molding.

The first problem to be solved by the present invention is to disclose a method for producing an environment-friendly injection molded article with increased use of cornstalk, one of the plant biomass.

Another problem to be solved by the present invention is to disclose an environmentally friendly injection molded article with increased use of corncobs.

In order to achieve the object of the present invention, (A) pulverizing cornstalks with fine particles of 80 to 400 mesh or less to produce cornstalk powder; (B) heat-drying the cornstalk powder at 50 to 150 ° C. to remove moisture, and adding wax to the heat-dried cornstalk powder and stirring to produce a coated cornstalk powder; (C) preparing a mixture by adding and mixing the plastic resin polymer and organic acid and peroxide which serve as a binder to the coated cornstalk powder; (D) Injecting the mixture into a twin extruder to achieve a plastic resin-plant graft bond, and discharge the material made of the plastic resin-plant graft bond through the discharge port, the discharged strands to the conveyor belt Manufacturing a biodegradable biomass pellet composition, which is a plastic resin-plant graft bonding structure composition, by cutting or face-cutting after drying with air blowing while being transported through; It provides a manufacturing method of an environmentally-friendly injection molded article comprising a; (E) the production of an injection-molded article after injection molding the added pellet to the plastic resin.

In the step (C), the starch and starch plasticizer is further added before mixing the input, and the starch is preferably 5 to 50 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition.

In the step (C), prior to mixing the input is to add any one or more of the lubricant, oxidant and inorganic filler, the lubricant is 0.5 to 5 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition The oxidizing agent is preferably 0.2 to 6 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition.

The inorganic filler is preferably 10 to 65 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition.

The peroxide is any one of dicumyl peroxide, benzoyl peroxide, di-tributyl peroxide, and the content of the peroxide is preferably 0.01 to 5.0 parts by weight based on 100 parts by weight of the plastic resin.

The organic acid is any one or more of citric acid, citric acid, malic acid, maleic acid, acetic acid, and the amount of the organic acid is 100 parts by weight of the biodegradable biomass pellet composition. It is preferable that it is 0.2-5 weight part.

The glidants may be used without limitation, those generally known, and specifically, one or more of zinc stearate and calcium stearate, and the oxidizing agent is any one or more of oleic acid, linoleic acid, linolenic acid, arachidonic acid, and palmitoleic acid, The inorganic filler is preferably one or more of calcium carbonate, clay, talc and loess.

The starch plasticizer is any one or more of glycerin and sorbitol, the content of the starch plasticizer is preferably 10 to 30 parts by weight based on 100 parts by weight of the starch based on the starch content.

The cornstalk powder content is 10 to 50 parts by weight with respect to 100 parts by weight of the biodegradable biomass pellet composition, the combined content of the cornstalk and starch is increased as the content of the plastic resin increases, The content of the peroxide increases as the content of the plastic resin increases, and the content of the organic acid is preferably increased as the combined content of the corn stalk and starch increases.

The binder resin of step (C) is any one of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polystyrene (PS) and acrylonitrile butadiene styrene (ABS) It is preferable that it is above.

The binder resin is preferably a pellet having a melt index of 3.0 or more.

Preferably, the coating step of step (B) and the step (C) are performed at the same time.

In order to achieve the object of the present invention, it proposes an environment-friendly injection molded article manufactured by the above-described manufacturing method.

Eco-friendly injection molded article prepared according to the present invention is not only excellent in the biodegradability of the injection molded article manufactured by using a large amount of cornstalk powder, it can produce an eco-friendly injection molded article for reducing carbon dioxide.

1 is an exemplary flow chart of a method for manufacturing an eco-friendly injection molded article of the present invention.
FIG. 2 is a schematic diagram in which a plastic resin-plant graft bonding structure is produced. FIG.
3 is a schematic diagram of the reaction point of the plastic resin-plant graft bond.

Hereinafter, it demonstrates in detail, referring drawings.

1 is an exemplary flow chart of a method for manufacturing an eco-friendly injection molded article of the present invention.

Eco-friendly injection molded article of the present invention is divided into five stages. Step A is a step of crushing the cornstalk to produce cornstalk powder. Corn cob is pulverized into fine powder so that it is about 80 to 400 mesh. If the size is less than 80 mesh, the particle size is so large that the productivity is poor due to poor flowability during pellet production, the surface is rough, and the quality of the final product, such as film, is deteriorated, the strength of the product is worsened, Due to the very small size, the product quality is excellent, but the grinding time is too long, which lowers the price competitiveness due to lower overall productivity and higher costs.

Subsequently, in step B, the cornstalk powder is coated with wax to produce coated cornstalk powder. In the coating step, the cornstalk powder is dried by heating at 50 to 150 degrees to remove moisture, and the wax is added to the heat-dried cornstalk powder and stirred to produce a coated cornstalk powder. Drying is carried out for 0.5 hours to 24 hours with heating and stirring at 50 to 150 degrees using a conventional drying apparatus to dry to 10% or less moisture content. If the drying temperature is less than 50 degrees, there is a problem that not enough drying or drying takes a long time, and if the drying temperature is higher than 150 degrees, there is a problem of increasing the likelihood of carbonization of corn stalks, etc., resulting in poor product quality. If the drying time is less than 0.5 hours, there is a problem that the product quality is bad due to moisture problems when producing the product by applying the finished product is not enough, and if more than 24 hours there is a problem that only energy is wasted without additional drying effect. Wax was added to the dried cornstalk powder, and the cornstalk powder surface was coated by high speed agitation at 300 to 800 rpm. The added wax is dissolved by self heating (self-heating) and coated on the surface of the cornstalk powder. The coated corn cob powder is prevented from reabsorbing moisture. Wax has the advantage of low molecular weight and low melting point can also function as a lubricant aid when preparing the additive composition using an extruder, and also has the advantage of being biodegradable into a low molecular weight material. Waxes may be used paraffin wax, liquid paraffin wax, beeswax, drive wax, emulsion wax, candelilla wax, PE wax, PP wax and the like. The wax content is suitably 1% to 20% of the corn cob content. When used less than 1%, the lubricant has a weak role, and when used more than 20%, debris such as debris occurs in the die, the cost increases. If a lot of wax is used, the coating for water resistance is excellent, but 1 ~ 5 parts by weight is used for 100 parts by weight of the biodegradable biomass pellet composition because debris is generated in the production equipment die in injection, extrusion, film production, etc. Better to do.

In the coating step, the wax is added and then stirred at high speed at 300-800rpm. Thus, the wax naturally melts by self-heating due to the high-speed stirring and is coated on the surface of the cornstalk powder. The coating time is not specified, and the coated cornstalk powder is finished in the form of lumps to some extent. In general, the coating is completed in a little lump form in about 10 to 30 minutes.

Subsequently, the step of forming a mixture by adding and mixing the plastic resin polymer, organic acid and peroxide serving as a binder to the cornstalk powder coated in step C. Peroxides chemically cut the polymer chains of plastic resins. The organic acid functions as an intermediate for bonding plants such as corn stalks to the terminal portion of the cut plastic resin polymer. 2 shows this schematic diagram. Peroxides and organic acids allow plastic resin-plant graft bonding structures such as those of FIG. 2 to be produced. The organic acid binds to the polymer terminal group cut by the peroxide. The peroxide is preferably the peroxide is any one of dicumyl oxide, benzoyl peroxide, di- triple butyl peroxide. Peroxides include azo-bis-isobutylnitrile, tributyl hydroperoxide, dicumyl peroxide, 2,5 dimethyl-2,5 di (thibutylperoxy) hexane (2,5-Dimethyl-2,5- di (t-butyl peroxy) hexane), 1,3-bis (ti-butylperoxy-isopropyl) benzene (1,3-Bis (t-buthyl peroxy-isoproply) benzene), etc. may also be used, but the experimental results Mill oxide, benzoyl peroxide, and di-triple butyl peroxide were good, and the effect of producing graft-bonded structures of corn cob powder and plastic polymer of dicumyl oxide was the most preferable, and the productivity of finished products such as injection molded products was the best.

The content of the peroxide may be 0.01 to 5 parts by weight based on 100 parts by weight of the plastic resin based on the plastic resin. However, if it is 0.01 parts by weight or less, it is difficult to expect graft bonding, that is, commercialization function, there is a problem that the content of corn stalks of the final product is reduced, and the natural decomposition period of the plastic resin is reduced and the final natural decomposition period is long. There is. On the other hand, if you use more than 5 parts by weight, the cost increases a lot, there is a problem that the economy is insufficient. Preferably, 0.01 part by weight or more and less than 0.5 part by weight based on 100 parts by weight of the biodegradable biomass pellet composition may be used.

The organic acid binds to the polymer terminal group cut by the peroxide and serves as an oxidative decomposition agent. The organic acid is preferably at least one selected from citric acid, malic acid, maleic acid, and acetic acid, and the content of the organic acid is 100 wt% of the biodegradable biomass pellet composition. It is preferable to use 0.2 weight part or more and less than 5 weight part with respect to a part. When the content of the organic acid is less than 0.2 parts by weight, the oxidative decomposition function of the plastic resin is weakened, and when it exceeds 5 parts by weight, there is a burden of cost increase.

Corn cob powder, like other plant powders, had poor flowability, making it difficult to exceed 5% of corn cob powder in the manufacture of injection molded articles. If graft bonding is sufficient, the productivity of finished products such as sheet production and extrusion molding as well as injection molding can be improved, and the content of poor physical and flowable substances such as cornstalk powder can be increased.

Graft bonding occurs well when extruders such as twin extruders react at screw speeds of 200 to 600 rpm at temperatures of 100 to 200 ° C. If the reaction temperature is 100 ℃ or less, the added raw materials are not melted and can not be reacted. If the temperature is higher than 200 ℃, carbonization occurs, or the temperature is too high, so that the resin melts like water and cannot be pelletized.

Meanwhile, starch may be further added to the input as one of the biodegradable plants. The reason for adding more starch is 1) the highest biodegradability among vegetable biomass, 2) cheaper than other raw materials, 3) resource abundance and ease of supply, 4) non-toxicity of raw materials, 5) plasticization This is because it is easy to paint and has excellent physical properties such as plastic. When starch is added, it is preferable to add an additional starch plasticizer. When the starch plasticizer is added, the starch plasticizer is modified at high temperature and high pressure to change the properties of the starch into thermoplastic starch, thereby improving molding processability when producing a finished product (injection, extrusion, film product). If the starch plasticizer is not added, even if the finished product is produced, the physical properties of the product deteriorate due to flowability, moldability, and carbonization. Starch is a naturally degradable plant, such as cornstalk, so that the plastic resin-plant graft bond structure as shown in FIG. 2 is generated by the peroxide and the organic acid like cornstalk powder. The plastic resin-corn to powder graft bond structure and the plastic resin-starch graft bond structure are collectively referred to as a plastic resin-plant graft bond structure. It will be apparent that corn starch powder and starch may be simultaneously bound to the plastic resin chain, and a schematic diagram of the plastic resin-plant graft bonding structure is shown in FIG. 2. The starch plasticizer is suitably 10% to 30% by weight of the starch weight. If it is less than 10%, starch denaturation is not easy, and if it exceeds 30%, the price is high and economic efficiency is low.

Higher plant biomass content in the final product is desirable in terms of lower carbon dioxide emissions. Corn bran has high physical properties such as elongation, strength, and flowability, so it is not possible to add a large amount to the finished product, thus increasing the amount of insufficient plant biomass. As is the position of the starch is important. The particle size of the starch is fine because the starch can be plasticized and used as a thermoplastic starch. Starch materials can vary, but the properties of underground starch (starch sweet potatoes, potatoes, Taupica, etc.) are better. However, there is a problem that the price is too expensive in Korea. As an alternative to this, ground starch (corn, wheat, rice starch, etc.) may be used. Corn is preferable because of various conditions.

In addition, an oxidant is additionally added to accelerate decomposition of the polymer material such as plastic resin and the like and to promote thermal decomposition and photolysis. The oxidizing agent may be used as oleic acid, linoleic acid, linolenic acid, arachidonic acid, palmitoleic acid, etc. as an unsaturated fatty acid series. The amount of the oxidizing agent added may be 0.2 to 6 parts by weight or more based on 100 parts by weight of the biodegradable biomass pellet composition. If the amount of the oxidizing agent is less than 0.2 parts by weight, the oxidative decomposition function of the polymer material such as plastic resin is weakened, and when used in excess of 6 parts by weight, there is a problem in that the product properties are lowered and the productivity deteriorates during production.

Natural plants have a high molecular weight and are not melted by heat, and thus have poor flowability in the production of pellets. The biodegradable biomass pellet composition may further include a lubricant as it is necessary to improve the flowability when using the natural product / plant raw material to enable the smooth production of the pellets. Suitable lubricants are zinc stearate and calcium stearate. The lubricant is preferably used in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition. When the amount is less than 0.5 parts by weight, the lubricant has a weak role, and when used in excess of 5 parts by weight, debris such as debris occurs in the die, and the cost increases.

The biodegradable biomass pellet composition may further include an inorganic filler. The content of the inorganic filler may be 10 to 65 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition. When the inorganic filler is used in less than 10 parts by weight, the cost reduction is less affected, and when using more than 65 parts by weight, the physical properties such as tensile strength, elongation of the product.

The powdery mixture produced through the above process is completed. Since such a composition is in a powder state, a material that serves as a binder for tangling the powder is required. The plastic resin used as the binder material may be linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polystyrene (PS) and acrylonitrile butadiene styrene (ABS). . The binder may be used in an amount of 15 parts by weight to 60 parts by weight based on 100 parts by weight of the biodegradable biomass pellet composition. If the content of the binder is less than 15 parts by weight, there is a risk that the finished pellets are fragile or cracked, and if the content of the binder exceeds 60 parts by weight, the economical efficiency of the finished pellets is lost.

Subsequently, in step D, the mixture containing the above-mentioned materials is discharged through a discharge port while the plastic resin-plant graft is bonded using an extrusion apparatus such as a twin screw extruder, and the blown strand is blown dry while conveying the discharged strand through the conveyor belt. The biodegradable biomass pellet composition, which is a plastic resin-plant graft bonding structure composition, is prepared by cutting or face cutting.

The biodegradable biomass pellet composition according to the present invention may be molded into a product to be manufactured, such as an injection molded article or an extruded article, by immediately mixing a conventional thermoplastic polymer resin such as plastic and other composition components according to the use. 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 in advance, and then may be molded back into a desired product if necessary.

In the final step E, the pellet is mixed with the thermoplastic resin, which is a normal thermoplastic, on the fly, to injection molding, thereby completing the eco-friendly injection molded article of the present invention. The blending ratio of the pellets and the plastic resin in step D is not particularly limited, but preferably the pellets may be added in an amount of 10 to 200 parts by weight based on 100 parts by weight of the plastic resin. When the addition amount of the pellet is added less than 10 parts by weight, there is a disadvantage in that the degradation of the environmentally-friendly injection molded article manufactured is poor, and when the addition amount exceeds 200 parts by weight, the physical properties such as the initial tensile strength, elongation rate, etc. There is a problem falling.

Hereinafter, the present invention will be described in more detail by way of examples. The following examples are intended to illustrate the invention and are not intended to limit the invention thereto.

<Examples 1-8>

Degradable Corn stand Biomass  Manufacture of pellets

&Lt; Example 1 >

Corn bar was pulverized to about 150 mesh to produce a corn bar powder, and then dried by heating at 100 ° C. for 30 minutes to prepare a dry corn bar powder. 1.5 parts by weight of LC wax 102N (from Lion Chemical) was added to the dried cornstalk powder, and the cornstalk powder surface was coated by high speed stirring at 500 rpm. 100 parts by weight of the plastic resin-biomass pellet composition, 25 parts by weight of surface-coated cornstalk powder, 25 parts by weight of polypropylene, 10 parts by weight of linear low density polyethylene (LLDPE), 20 parts by weight of corn starch, 4 parts by weight of sorbitol , 0.3 part by weight of linoleic acid, 1.0 part by weight of zinc stearate, 0.5 part by weight of maleic acid, 0.01 part by weight of dicumyl peroxide and the remainder were added to a high speed stirrer with calcium carbonate, followed by stirring at 400 rpm to produce a mixture. Biodegradable biomass pellets were prepared using a plastic resin-plant graft bond.

<Example 2>

Except for adding 30 parts by weight of cornstalk powder in Example 1, and 0.02 parts by weight of dicumyl peroxide to produce the same composition for pellets as in Example 1, to prepare a pellet.

<Example 3>

Except 35 parts by weight of corn cob powder in Example 1, 0.03 parts by weight of dicumyl peroxide was added to produce the same composition for pellets as in Example 1, to prepare a pellet.

 <Example 4>

Except for adding 40 parts by weight of cornstalk powder in Example 1, 0.04 parts by weight of dicumyl peroxide to produce the same composition for pellets as in Example 1, to prepare a pellet.

Example 5

In Example 1, 0.5 parts by weight of citric acid was added instead of 0.5 parts by weight of maleic acid, and 0.02 parts by weight of benzoyl peroxide was added instead of 0.01 parts by weight of dicumyl peroxide to produce the same composition for pellets as in Example 1. To prepare pellets.

 <Example 6>

In Example 5, except that 30 parts by weight of cornstalk powder and 0.03 parts by weight of benzoyl peroxide, the same composition for pellets as in Example 6 was produced to prepare pellets.

 <Example 7>

In Example 5, 35 parts by weight of cornstalk powder was added, except that 0.04 parts by weight of benzoyl peroxide to produce the same composition for pellets as in Example 6, to prepare a pellet.

 <Example 8>

  In Example 5, except that 40 parts by weight of cornstalk powder, and 0.05 parts by weight of benzoyl peroxide, the same composition for pellets as in Example 6 was produced to prepare a pellet.

Comparative Example 1

In Example 1, except that 0.5 parts by weight of maleic acid, 0.01 parts by weight of dicumyl peroxide was produced to produce the same pellet composition as in Example 1, to prepare a pellet.

Comparative Example 2

In Example 5, except that 0.5 parts by weight of citric acid and 0.02 parts by weight of benzoyl peroxide was removed, the same composition for pellets as in Example 5 was produced to prepare pellets.

<Examples 9-16>

Eco-Friendly Injection Molding

Example 9

 30 parts by weight of the pellets prepared in Example 1 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Hunan Petrochemical products

<Example 10>

 30 parts by weight of the pellets prepared in Example 2 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Hunan Petrochemical products

<Example 11>

 30 parts by weight of the pellets prepared in Example 3 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Hunan Petrochemical products

<Example 12>

30 parts by weight of the pellets prepared in Example 4, 70 parts by weight of polypropylene (PP), and 15 parts by weight of homo polypropylene were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Hunan Petrochemical products

Example 13

30 parts by weight of the pellets prepared in Example 5 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Hunan Petrochemical products

<Example 14>

 30 parts by weight of the pellets prepared in Example 6 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Honam Petrochemical.

<Example 15>

 30 parts by weight of the pellets prepared in Example 7 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Honam Petrochemical.

<Example 16>

 30 parts by weight of the pellets prepared in Example 8 and 70 parts by weight of polypropylene (PP) were mixed, and then injection molded products were manufactured using a conventional injection molding machine. PP used Honam Petrochemical.

<Example 17>

 30 parts by weight of the pellets prepared in Comparative Example 1 and 70 parts by weight of polypropylene (PP) were mixed, and then a film was prepared using a conventional injection molding machine. PP used Honam Petrochemical.

&Lt; Example 18 >

 30 parts by weight of the pellets prepared in Comparative Example 2 and 70 parts by weight of polypropylene (PP) were mixed, and then a film was prepared using a conventional injection molding machine. PP used Honam Petrochemical.

Experimental Example 1

Example  Mechanical property test of eco-friendly injection molded parts manufactured according to 9 ~ 18

Tensile strength and elongation were measured for samples cut to 25 × 102 mm according to ASTM D 3826 for the injection molded articles prepared in Examples 9-18. In order to reduce the measurement error, the number of injection molded samples was measured 10 times for each measurement item and the average value was taken out of the maximum and minimum values. Load cell was used 50kg and UTM (Universal Testing Machine, Daekyung Tech, Korea) machine was used, the tensile speed of the machine was set to 50mm / min and the experiment was carried out, the results are summarized in Table 1 below.

Mechanical property test result division Tensile Strength (㎏ / ㎠) Elongation (%) PP products 280 200 Example 9 283 200 Example 10 279 197 Example 11 274 195 Example 12 272 193 Example 13 281 199 Example 14 277 196 Example 15 273 192 Example 16 272 191 Example 17 269 179 Example 18 268 177

As can be seen from Table 1, the injection molded product using the cornstalk, one of the plant biomass according to the present invention, even though the cornstalk powder, organic acid, and peroxide are contained, the tensile strength and elongation are similar to the existing products. Can be. In Examples 17 and 18 corresponding to Comparative Examples 1 and 2, it can be seen that the tensile strength and the elongation are lower than those of Examples 9 to 16, which correspond to the existing products or examples of the present invention.

Experimental Example 2

Example  Of eco-friendly injection molded products manufactured according to 9 ~ 18 Photodegradable  evaluation

Photodegradability was achieved by irradiating UV light for 200 hours using a QUV Accelerated Weathering Tester according to ASTM D15 UV treatment test method, and then measuring the tensile strength and elongation of the film. At this time, the type of ultraviolet (UV) lamp was UVB 313, the light intensity (Irradiance) was 0.60w / nf (310nm) and the results are shown in Table 2 below.

Photodegradability Test Results division Strength retention rate (%) % Retention PP products 97.8 97.2 Example 9 2.4 1.4 Example 10 0.8 0.5 Example 11 0.6 0.0 Example 12 0.2 0.0 Example 13 2.9 1.5 Example 14 1.4 0.8 Example 15 1.0 0.2 Example 16 0.5 0.0 Example 17 36.1 30.7 Example 18 37.0 32.2

  As can be seen from Table 2, compared with the conventional PP products, the strength retention and elongation retention are hardly reduced even after UV irradiation, whereas the injection molded articles to which the biodegradable biomass pellets according to the present invention are applied have strength retention and elongation retention. Significantly reduced. In Examples 17 to 18 without using an organic acid and a peroxide, strength and elongation were reduced by more than 60% compared to the PP product. That is, it can be seen that the injection molded article of the present invention can be decomposed to a considerable extent in a natural state by light such as ultraviolet rays. It can also be seen that as the cornstalk content is increased, the degree of decomposition increases.

<Experimental Example 3>

Example  Eco-friendly manufactured according to 9-18 Of injection molded products  Biodegradability Assessment

Evaluation of the biodegradability by the fungus of injection molded articles made from pellets using corn cobs in the plant biomass of the present invention was tested according to the ASTM G 21 method. That is, the AAS that after cutting the sample to a predetermined size by using a solid agar medium without a carbon source as a medium commonly found in the soil and this switch Aspergillus (Aspergillus niger ), Penicillium piniphilum), while tomyum Globo Island (Chaetomium globosum), glycidyl Eau radium by lances (Gliocladium The biodegradability was determined by spraying a mixed mycelium suspension of virens ) and Aureobasidium pullulans in a sterile state and evaluated the extent of mold cover on the samples for 60 days in accordance with ASTM G 21 method at intervals of 10 days.

In addition, the biodegradability evaluation by bacteria was tested according to the ASTM G 22 method. A cell mixture suspension of Pseudomonas aeruginosa and Baccllus subtillus was applied to the sample in a sterile state on a solid agar medium without a carbon source. The biodegradability was measured according to the evaluation.

Biodegradation Notation Method

Class 0: no growth in observed samples

Level 1: Growth less than 10% in observed samples

Level 2: Growth is more than 10% and less than 30% in observed samples (slight growth)

Level 3: Growth is more than 30% and less than 60% in the observed sample (medium growth)

Level 4: Growth is more than 60% in observed samples (Dense growth

 At the same time, the sample of the eco-friendly injection molded product is taken out every 20 days while being kept in a constant temperature and humidity chamber fixed at a relative humidity of 85% and an internal temperature of 30 ° C. It was measured by the ratio.

In the case of bacteria, the relative humidity was fixed at 85% and the internal temperature of 37 ° C., and the weight loss was measured in the same manner as described above.

In order to reduce the measurement error, the number of injection molded samples was measured 10 times for each measurement item and the average value was taken out of the maximum and minimum values.

The results are shown in Tables 3 and 4 below.

Evaluation of biodegradation by mold and weight loss test results division Biodegradation degree (%) Weight loss rate (%) ^* 10 days 20 days 30 days 40 days 50 days 60 days 20 days 40 days 60 days PP products 0 0 0 0 0 0 99.9 99.9 99.9 Example 9 One 2 2 3 4 4 94.1 73.1 57.2 Example 10 One 2 3 4 4 4 92.9 70.5 52.2 Example 11 One 2 3 4 4 4 91.8 67.4 49.9 Example 12 2 3 3 4 4 4 91.4 63.1 46.8 Example 13 One 2 2 3 4 4 94.6 73.7 60.5 Example 14 One 2 3 3 4 4 93.7 72.2 55.7 Example 15 One 2 3 4 4 4 92.5 69.8 51.4 Example 16 2 3 3 4 4 4 91.7 67.6 50.5 Example 17 One 2 2 2 3 3 95.3 77.3 66.9 Example 18 One 2 2 2 3 3 95.8 77.4 67.1

^* Weight loss rate (%) = weight after sampling / weight of original sample × 100

Evaluation of the degree of biodegradation by bacteria and weight loss test results division Biodegradation degree (%) Weight loss rate (%) ^* 10 days 20 days 30 days 40 days 50 days 60 days 20 days 40 days 60 days PP products 0 0 0 0 0 0 99.9 99.9 99.9 Example 9 One 2 2 3 4 4 94.3 72.5 55.1 Example 10 One 2 3 3 4 4 93.2 71.5 52.6 Example 11 One 2 3 4 4 4 92.0 68.7 50.4 Example 12 2 3 3 4 4 4 90.8 63.2 47.6 Example 13 One 2 2 3 4 4 95.2 74.7 61.8 Example 14 One 2 3 3 4 4 94.1 72.8 55.9 Example 15 One 2 3 4 4 4 92.5 69.8 52.2 Example 16 2 3 3 4 4 4 92.0 68.0 51.0 Example 17 One 2 2 2 3 4 95.8 78.3 67.7 Example 18 One 2 2 2 3 3 96.1 77.9 67.9

As can be seen from Tables 3 and 4, the existing PP products are hardly decomposed by bacteria or molds over time, and only partially dissolve in Examples 17 to 18 without using organic acids and peroxides. It was a progress. Eco-friendly injection molded article according to the present invention can be seen that significantly progressed by the bacteria and mold over time. In addition, a large amount of biomass such as corn stalks can be seen that the growth of bacteria and fungi faster.

The present invention can be used in various manufacturing industries, such as carbon dioxide reduction, biomass plastics industry by replacing plastics.

Claims (11)

(A) grinding corncob into fine particles of 80 to 400 mesh or less to produce corncob powder;
(B) the cornstalk powder is dried by heating at 50 degrees to 150 ° C for 0.5 hours to 24 hours to remove moisture, and the wax is added to the heat-dried cornstalk powder and coated by stirring at a stirring speed of 300 to 800 RPM. Producing corn cob powder;
(C) a plastic resin polymer serving as a binder and the organic acid and a peroxide are added to the coated cornstalk powder and mixed to form a mixture;
(D) Injecting the mixture into the extruder to form a plastic resin-plant graft bond, discharge the material made of the plastic resin-plant graft bond through the discharge port, and discharged the strand through the conveyor belt Pellet manufacturing step of producing a pellet by cutting or face-cut after blowing air while conveying;
(E) injection molding by adding the prepared pellets to the plastic resin manufacturing step of eco-friendly injection molded article; manufacturing method of eco-friendly injection molded article, characterized in that it comprises a The method of claim 1,
In the step (C), the starch and starch plasticizer is further added before mixing the input,
The starch is 5 to 50 parts by weight based on 100 parts by weight of the pellet composition,
The starch plasticizer is one or more of glycerin and sorbitol,
The starch plasticizer content is 10 to 30 parts by weight with respect to 100 parts by weight of the starch, based on the starch content manufacturing method of the injection-molded article.
The method of claim 1,
In the step (C), it is to add any one or more of the lubricant, oxidant and inorganic filler before mixing the input,
The lubricant is 0.5 to 5 parts by weight based on 100 parts by weight of the pellet composition,
The oxidizing agent is 0.2 to 6 parts by weight based on 100 parts by weight of the pellet composition,
The inorganic filler is 10 to 65 parts by weight based on 100 parts by weight of the pellet composition,
The lubricant is one or more of zinc stearate and calcium stearate,
The oxidizing agent is any one or more of oleic acid, linoleic acid, linolenic acid, arachidonic acid and palmitoleic acid,
The inorganic filler is a method for producing an environmentally-friendly injection molded article, characterized in that any one or more of calcium carbonate, clay and loess.
The method of claim 1,
The peroxide is any one of dicumyl oxide, benzoyl peroxide, di- triple butyl peroxide,
The content of the peroxide is 0.01 to 5 parts by weight based on 100 parts by weight of the plastic resin manufacturing method of eco-friendly injection molding.
The method of claim 1,
The organic acid is any one or more of citric acid (Citric acid), malic acid (Malic acid), maleic acid (Maleic aicd), acetic acid (acetic acid),
The amount of the organic acid is 0.2 to 5 parts by weight based on 100 parts by weight of the pellet composition.
The method of claim 1,
The wax is any one or more of paraffin wax, liquid paraffin wax, beeswax, drive wax, emulsifying wax, candelilla wax, P. wax, P. wax.
The content of the wax is a method for producing an injection-molded article, characterized in that 1.0 to 5.0 parts by weight based on 100 parts by weight of the pellet composition.
The method of claim 1,
The cornstalk content is 10 to 50 parts by weight based on 100 parts by weight of the pellet composition,
The combined content of cornstalk and starch is increased as the content of the plastic resin increases,
The content of the peroxide is increased as the content of the plastic resin increases,
The content of the organic acid is a method of producing an environmentally-friendly injection molded article, characterized in that it increases as the combined content of the cornstalk and starch increases.
The method of claim 1,
The plastic resin of the binder role is at least one of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polystyrene (PS) and acrylonitrile butadiene (ABS). Eco-friendly injection molded product manufacturing method.
The method of claim 1,
The coating step of step (B) and the step (C) is an environmentally-friendly injection molding method, characterized in that is carried out at the same time.
The method of claim 1,
When the injection molding of the step (E) (D) the pellet is a method for producing an injection-molded article, characterized in that 10 to 200 parts by weight based on 100 parts by weight of the plastic resin.
Eco-friendly injection molded article prepared by the method of any one of claims 1 to 10.

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