KR20160089977A - Thermoplastic cellulose through a cellulose plasticizing and preparation of oxo-biodegradable additive using the plasticized cellulose. - Google Patents

Abstract

The present invention relates to an eco-friendly and plasticized cellulose raw material pellet having improved biodegradability and mechanical properties, to a manufacturing method thereof, and to an oxo-biodegradable additive raw material pellet using the same. More specifically, the present invention relates to plasticized cellulose used for manufacturing an oxo-biodegradable plastic raw material pellet, to a manufacturing method thereof, and an oxo-biodegradable additive raw material pellet manufactured by using the same. The oxo-biodegradable raw material pellet increases mechanical properties such as the strength or the like by using the sodium-based plasticized cellulose, prevents carbonization, increases the biodegradability, and provides oxo-biodegradable functions for generally used polymers.

Description

TECHNICAL FIELD [0001] The present invention relates to a thermoplastic cellulose by plasticizing cellulose, an oxidative biodegradation additive using the same, and a preparation method thereof.

The present invention relates to a process for producing a raw material pellet of oxo-biodegradable additive by plasticizing cellulose by using a plasticizer, and more particularly, a thermoplastic cellulose improved in physical properties is a general purpose polymer such as polypropylene (PP) ), PE (polyethylene), etc., And biodegradability is increased, plasticized cellulose and metal salts, metal ion activator, auto oxidizer, peroxide. A raw material pellet for oxidative biodegradation additive manufactured by combining a compatibilizing agent, a lubricant, an inorganic filler and the like, and a production method thereof.

The annual amount of plastic packaging materials used in Korea is 1,369,000 tons per year as of 2013. Since the recycling rate of plastic packaging materials is less than 70%, 410,000 tons of plastic packaging materials per year are discarded, buried and incinerated, which causes environmental hormones, dioxins and air pollution.

In Korea, plastic waste including waste packaging accounts for about 11% of the total waste, and the amount of plastic waste discarded per day is about 44,000 tons, reaching about 16 million tons per year. The best method is to recycle 100% of the used plastic, but it is difficult to collect, separate, and dispose of it, and the number of recycling is also limited.

Therefore, biodegradable plastics such as PLA (poly lactic acid), PHA (polyhydroxyalkanoate), poly-hydroxybutyrate (PHB), poly-hydrolyvalerate (PHV) and poly-caprolactone It was used in this market. However, these biodegradable plastics have limited use due to low physical properties, high price, risk of early biodegradation during distribution, and difficulty in recycling.

In addition, degradable plastics were produced and used as the concepts of oxidative decomposition, photodegradation, and photodegradation. However, these plastics were completely decomposed into water and carbon dioxide at the final stage, which took about 50 to 100 years. Bio-based plastics, which have been attracting attention since 2010, are not carbon neutral because they are focused on carbon reduction and do not biodegrade. In addition, bio-based plastics having excellent physical properties are disadvantageous in that they are expensive, and inexpensive ones are poor in physical properties.

Oxidized biodegradable plastics were produced in the United States as a standard for ASTM D 6954, which was expected to be marketed for biodegradable plastics, but the company did not specify the final biodegradation period and was treated with expensive photodegradation products. However, in 2009 UAE S 5009: 2009 in the United Arab Emirates ESMA stipulated that the final biodegradation period of oxidized biodegradable plastics should be degraded by more than 60% within 36 months. We have enacted laws to use biodegradable plastics in 2012. In addition, the United Arab Emirates granted ECAS certification for biodegradable plastic products and enacted legislation that prohibits the distribution of biodegradable plastics from January 1, 2014. This ECAS certification covers most packaging materials and disposable items, and if not ECAS certified, it will impose a penalty of about 8.5 million won per product.

Currently, not only in the United Arab Emirates but also in France, Italy, UK, India, Pakistan and other countries, biodegradable plastics can replace the plastic oxide biodegradable plastic, and is preparing legislation.

The core technology of such oxidative biodegradable plastics is a method for preparing oxidative biodegradation additives. Up to now, oxidative biodegradation additives that partially substitute binder polymers and increase biodegradability by plasticizing cellulose have not been developed yet.

Therefore, we have developed oxidative biodegradation additive which can reduce biodegradation time by using low-cost cellulose and excellent compatibility with general polymer, and produce oxidized biodegradable plastics by using additives to minimize environmental problems and treatment costs You can do it.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the problems of the prior art as described above, and it is an object of the present invention to provide a plasticized cellulose which can be used as a biodegradable polymer enhanced in physical properties by plasticizing inexpensive cellulose, An oxidizing agent, an oxidizing agent, and the like are added so that the general polymer resin is spontaneously decomposed into water and carbon dioxide in the final stage, and a manufacturing method thereof.

To achieve the above object, the present invention provides a cellulose plasticized with a sodium-based plasticizer. A binder polymer to the plasticized cellulose prepared; Metal salts; Metal ion activators; Auto oxidizer; peroxide; Compatibilizers; Lubricant; Inorganic filler; Is mixed and extrusion-molded, and the raw material pellets for oxidative biodegradation additive are provided.

According to another aspect of the present invention, there is provided a method for producing a cellulose powder, comprising the steps of: (A) pulverizing at least one of rice hull, buckwheat, buckwheat, large scalp and pulp with fine particles of 50 to 300 mesh to prepare a cellulose powder; (B) drying the cellulose powder at 50 to 150 DEG C for 0.5 to 24 hours to remove moisture; (C) adding wax to the dried cellulose powder and stirring at a stirring speed of 300 to 800 RPM to coat the surface of the cellulose powder; (D) adding a sodium-based plasticizer to the coated cellulose powder to form a plasticizer-cellulose composition; (E) adding a metal salt, a metal ion activator, an oxidizing agent, a peroxide, a compatibilizing agent, a lubricant, and an inorganic filler to the cellulose composition and stirring to produce a mixture; (F) The mixture of the above item (E) is subjected to a cellulose plasticizing reaction and a graft coupling of the binder polymer and plasticized cellulose using a twin-screw extruder, discharging the mixture through a discharge port, Drying and then cutting or die face hot cutting to form oxidative biodegradable additive pellets.

The plasticized cellulose according to the present invention plasticizes cellulose with a sodium-based plasticizer. This plasticizer of the soda-lime series can be expected to have an oxidizing effect together with a plasticizer effect. In addition, since biodegradable cellulose is basically used, the biodegradation efficiency of the oxidized biodegradable plastic produced by mixing the present oxidative biodegradable additive can be increased.

Generally, cellulose contains a component called lignin. This lignin has a function of strongly attracting ultraviolet rays generated from carbon, and is easily denatured by heat. Cellulose had many dark lignin components with such color, and it was difficult to produce a transparent product, and a transparent additive was prepared using relatively expensive starch.

However, since the sodium-based plasticizer used in the present invention has the function of binding to the lignin in addition to the effect of the plasticizer and the oxidizer, the dark color due to lignin can be masked, so that the inexpensive cellulose can be applied to the transparent product .

In addition, according to the present invention, the cellulose is plasticized into fine particles, and the reaction area is increased, so that a small effect can be obtained even with a small amount of the graft coupling agent. Further, the dispersibility is increased and the mechanical properties such as strength and tensile ratio And can be efficiently increased to a required level.

In addition, plasticized cellulose can be used singly as a substitute for general-purpose plastic depending on its use, and it can be used more independently because of improved physical properties such as strength when a polymer and a graft are bonded. In the case of microfabricated plasticized cellulose, The strength can be maintained even with a small amount of graft coupling agent, which is advantageous in cost reduction.

Further, the present invention is greatly helpful in shortening the biodegradation period of general oxidative biodegradation additive products by suitably mixing the plasticized cellulose with a metal salt, an oxidative decomposition activator, an automatic oxidizer, and the like.

The present invention can use various types of cellulose, and when the plastic is produced by using the oxidative biodegradation additive having an increased biodegradation rate, the plastic can be spontaneously decomposed into water and carbon dioxide, .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electron micrograph (SEM) photograph showing the shape of cellulosic powder used in the present invention, after powdering, and after polarization filtering.
FIG. 2 is an electron microscope (SEM) photograph showing the shape of a film produced from an additive using plasticized cellulose and a film produced from an oxidative biodegradation additive without plasticizing cellulose. FIG.
Fig. 3 is a schematic diagram showing the grafting of plastics resin and plasticized cellulose according to the present invention. Fig.
Fig. 4 is an explanatory view showing the principle of improving mechanical properties such as strength according to the present invention.
FIG. 5 is a view showing a die discharge part for producing cellulose plasticizing and oxidative biodegradation additives according to the present invention.
FIG. 6 is a view showing production of a cellulose plasticizing and oxidative biodegradation additive by a strand air-cooling method according to the present invention.

Hereinafter, the present invention will be described in detail.

Oxidation biodegradation additive using plasticized cellulose

The present invention utilizes a plasticizer of the sodium series to plasticize the cellulose. Higher amounts of cellulose in the final product can increase the biodegradation efficiency, solve environmental problems through carbon reduction, and reduce cost. However, general cellulose has disadvantages in that it can not add a large amount to finished products because of its physical properties such as elongation and strength.

Therefore, the plasticization of cellulose is very important, and in particular, the sodium group used in plasticizing the sodium system in the production of the oxidative biodegradation additive can also act as an oxidizing agent, thereby accelerating the decomposition rate of the oxidative biodegradable plastic.

The cellulosic material may be any of those including cellulosic materials such as chaff, opium, large scalp, wheat bran, cornstarch, peanut bark, wood powder, wood pulp, peanut bark, coconut shell, In the present invention, the fine powder is coated with wax after using at least one of rice hull, oak, coriander, large scalp and pulp.

The wax has a function of preventing reabsorption of moisture by coating of a cellulose powder, and also acts as a lubricant auxiliary agent due to a low molecular weight and a low melting point. Further, the wax has an advantage that it can be biodegraded as a low-molecular substance.

Examples of the wax include those commonly used in the art such as paraffin wax, liquid paraffin wax, wax, mold wax, emulsifying wax, candelilla wax, PE wax, and PP wax.

The wax is preferably used in an amount of 1 to 20 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the cellulose powder. When the content of the wax is less than 1 part by weight, the function of the coating function and the lubrication aid may be insufficient. If the amount of the wax is more than 20 parts by weight, debris such as foreign matters may be generated in the production facility dice.

Sodium hydrogensulfite (NaHSO ₃ ), sodium percarbonate (2Na ₂ CO ₃ ), sodium bicarbonate (NaHCO ₃ ), calcium chloride (NaCl) and soda ash were added to the coated cellulose. the Na ₂ CO ₃₎ was plasticized using one or more. 1 to 5 parts by weight of soybean bran, 2 to 6.5 parts by weight of rice husks, corn and bean sprouts, 3 to 8 parts by weight of pulp, It is preferable that the content is included in the content. This is because the higher the content of cellulose and lignin, the more plasticizer is needed. (Table 1 shows the cellulosic and lignin content of each plant.)

When the rice husk is contained in an amount of less than 2.0 parts by weight, plasticization may be difficult, and if it exceeds 6.5 parts by weight, an unnecessary increase in cost may be caused.

Said cellulosic and plasticizer composition; Binder polymer; Metal salts; Metal ion activators; Auto oxidizer; peroxide; Compatibilizers; Lubricant; An inorganic filler is mixed and extruded to produce oxidized biodegradable additive pellets.

The cellulosic and plasticizer compositions can be expected to improve the biodegradation efficiency and the oxidizing effect of sodium, and they are preferably contained in an amount of 5 to 40 parts by weight.

The binder polymer may be selected from linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA) and polypropylene (PP), PLA, PHA, , PCL, PBAT, and copolymer, may be used. The binder polymer is preferably contained in an amount of 5 to 75 parts by weight. If the content of the binder polymer is less than 5 parts by weight, the resulting pellet may be broken or powder may be formed due to insufficient binding force. If the content of the binder polymer exceeds 75 parts by weight, the biodegradation function of the additive may be degraded.

The metal salt may be at least one of acetic acid anhydride, ammonium metal sulfate, metal naphthenate, metal sulfate, metal silicate, sulfonium salt, acetylacetonate and tetrabutylammonium acetate.

 The metal ions contained in the metal salt repeatedly react with the peroxide and the redox reaction to generate energy, and the radical reaction is initiated by this energy. This reaction causes the carbon chain of the polymer to be cleaved and oxidative decomposition to occur, so that the molecular weight of the polymer is reduced. The low molecular weight oxidized low molecular weight material is finally decomposed and absorbed by the microorganisms in the natural environment and converted into water and carbon dioxide, and the decomposition can be completed.

The metal salt is preferably contained in an amount of 0.01 to 5 parts by weight, and if it is less than 0.01 part by weight, the oxidative decomposition function of the plastic resin may be weakened, and if it exceeds 5 parts by weight, the production cost may increase.

The metal ion of the metal salt may be at least one selected from iron, copper, manganese, vanadium, zinc, cerium and scandium.

The metal ion activator may be at least one selected from the group consisting of citric acid, malic acid, maleic acid, propionic acid, and para-nitrobenzoic acid. The metal ion activator serves as an intermediate for binding the cellulose to the end group of the polymer in which the peroxide is cleaved and to release the antioxidant.

The metal ion activator is preferably contained in an amount of 0.2 to 5 parts by weight. If the content of the metal ion activator is less than 0.2 parts by weight, the oxidative decomposition function of the plastic resin may be weakened, and if it exceeds 5 parts by weight, unnecessary manufacturing cost may be increased beyond the required level.

The autoxidizing agent may be one or more of misteroolioleic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid and palmitoleic acid, preferably two or more kinds thereof. The autooxidizer has a structure with double bonds. It generates energy by cutting off double bonds due to catalytic action of heat and light, and the generated energy breaks the bond of the polymer resin, thereby accelerating decomposition and promoting thermal decomposition and photolysis do.

The autoxidizing agent is preferably contained in an amount of 0.2 to 6 parts by weight. If the content is less than 0.1 part by weight, it may be difficult to expect a good decomposition of the polymer material. If the content is more than 3 parts by weight, unnecessary manufacturing cost may be increased beyond the required level.

The peroxide is selected from the group consisting of azo-bis-isobutylonitrile, tributyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, di-tributyl peroxide, 2,5 dimethyl- Butyl peroxy) hexane, 1,3-bis (t-buthyl peroxy-isopropyl) benzene, 2,5- isopropylbenzene) may be used.

The peroxide may react with the metal salt by repeating redox reaction to activate a radical reaction and to smoothly produce a graft-bonded structure of the plasticized cellulose and the binder polymer.

The peroxide is preferably 0.01 to 1 part by weight, or 0.01 to 5 parts by weight based on the weight of the binder polymer. If the content of the peroxide is less than 0.01 part by weight based on 100 parts by weight of the total mixture, it is difficult to expect a graft-linking function with the polymer or a cellulose content of the final product is decreased, The natural decomposition and oxidizing effect of the natural decomposition may be reduced and the final natural decomposition period may be long. If the amount exceeds 1 part by weight, decomposition may occur too fast and the unnecessary manufacturing cost may be increased.

 The compatibilizer is a component that imparts compatibility to remove the dissociation between the polar cellulose and the non-polar binder and mix them well.

Examples of the compatibilizing agent include glycidyl methacrylate, ethylene vinyl alcohol, polyvinyl alcohol and ethylene vinyl acetate, which are conventionally used in the art. Preferably, a polyolefin-based polymer represented by the following formula (3) or a polyolefin derived polymer represented by the following formula (4) is used, and for example, ADPOLY PH-200, EM-200 and SMS-554 (Lotte Chemical Co., Ltd.)

(3)

(R은 H 또는 CH₃)

(R is H or CH ₃₎

[Chemical Formula 4]

(R은 H 또는 CH₃)

(R is H or CH ₃₎

The compatibilizer is preferably contained in an amount of 0.5 to 5 parts by weight. When the content of the compatibilizing agent is less than 0.5 parts by weight, compatibility is not sufficient and delamination may occur. If the amount of the compatibilizing agent is more than 5 parts by weight, unnecessary manufacturing cost may be increased.

The lubricant may be one or more of zinc stearate and calcium stearate. The lubricant is a natural substance having a high environmental friendliness as a component enabling smooth production of pellets by improving the flowability of a plant biomass raw material.

The lubricant is preferably contained in an amount of 0.5 to 5 parts by weight. If the content of the lubricant is less than 0.5 parts by weight, it may be difficult to achieve a desired effect depending on the addition of the lubricant. If the amount of the lubricant is more than 5 parts by weight, foreign matters such as foreign matters may be generated in the dies.

The inorganic filler is a component contributing to enhancement of durability of the pellet, and includes at least one of calcium carbonate, clay, talc, loess, talc, and kaolin.

 As the inorganic filler, nano-sized powder is preferably contained in an amount of 1 to 50 parts by weight in view of improvement in physical properties. More specifically, the inorganic filler is contained in an amount of 10 to 30 parts by weight of 80 to 100 nano- .

The inorganic filler is preferably contained in an amount of 5 to 65 parts by weight. If the content of calcium carbonate is less than 5 parts by weight, it may be difficult to enhance the durability and the cost reduction effect according to the addition thereof. If the content of calcium carbonate exceeds 65 parts by weight, properties such as tensile strength and elongation of the product may deteriorate.

On the other hand, it has been confirmed that the plasticizing reaction of cellulose through the sodium based plasticizer occurs particularly well at extruder temperatures of 100 to 300 DEG C and 300 to 800 RPM.

Ingredient table of used cellulose
division

moisture

Starch
Cellulose (lignin)
Other
Remarks
Scalp

11
2 to 5
65 to 70 (5 to 10)
12 to 22
chaff

7 ~ 9
2 to 5
50 to 60 (10 to 15)
25 to 30
Oxy

8-10
10-16
55 to 60 (10 to 15)
15 ~ 18
Cornice

8-10
2 to 5
55 to 60 (10 to 15)
12-14
pulp

8-10
-
85 to 96 (20 to 40)
4 to 10

Manufacturing method of oxidative biodegradation additive using plasticized cellulose

According to another aspect of the present invention,

(A) preparing a cellulose powder by pulverizing cellulose selected from the group consisting of rice hulls, oats, cornstalks, large scalp and pulp into fine particles of 80 to 300 mesh;

(B) heating and drying the plant cellulose powder at 50 to 150 DEG C for 0.5 to 24 hours to remove moisture;

(C) adding wax to the heat-dried cellulose powder and stirring at a stirring speed of 300 to 800 RPM to coat the surface of the cellulose powder;

(D) Sodium hydrogensulfite (NaHSO ₃ ), sodium percarbonate (2Na ₂ CO ₃ ), sodium bicarbonate (NAH CO ₃ ), calcium chloride (NaCl ) And soda ash (Na ₂ CO ₃ ), and stirring to produce a plasticized cellulose mixture;

(E) adding a binder polymer, a metal salt, a metal ion activator, an oxidizing agent, a peroxide, a compatibilizing agent, a lubricant, and an inorganic filler to the cellulose mixture and stirring to produce a mixture; And

(F) The above mixture is subjected to a cellulose plasticization reaction and a graft coupling of a binder polymer-plasticized cellulose using a twin-screw extruder, and discharged through a discharge port. Then, the discharged strand is conveyed through a conveyor belt, Drying, and then cutting or die face hot cutting to form oxidative biodegradable additive pellets.

The step (A) is a step of pulverizing at least one of rice hull, oak, corn, large scalp, pulp, which is cellulose, into small particles and pulverizing.

In this step, the cellulose is pulverized into fine particles of 80 to 300 mesh. When the size is less than 80 mesh, the mean particle size of the fine particles becomes too large to about 100 탆, which causes poor flowability and poor productivity during production of the pellets. If the particle size is larger than the thickness, the surface becomes uneven and the strength and elongation of the product may be deteriorated. If the particle size exceeds 300 mesh, it takes a long time for the pulverization process to lower the overall productivity and increase the manufacturing cost. Due to the nature of the binding to cellulose, can have a bad influence on the dispersibility of cellulose.

In the step (B), the obtained cellulose powder is heated and dried to remove water.

In this step, the moisture content is adjusted to 10% or less by drying for 0.5 to 24 hours while heating and stirring at 50 to 150 ° C. using a conventional drying apparatus. If the drying temperature is lower than 50 캜, sufficient drying may not be performed or the drying time may become longer. If the drying temperature is higher than 150 캜, the possibility of carbonization of the cellulose or the like increases, which may lead to deterioration of the product quality. If the drying time is less than 0.5 hour, the drying is not sufficient and the product quality may be deteriorated due to the moisture problem when the product is manufactured by applying the finished product. If it exceeds 24 hours, the energy is wasted without additional drying effect, It can fall.

In the step (C), the dried cellulose powder is coated with wax to produce a coated cellulose powder.

In this step, the wax is added to the dried cellulose powder and the coating is performed at a stirring speed of 300 to 800 RPM (suitably, 500 RPM) to perform coating. Such self-heating by the high-speed stirring allows the wax to naturally melt, And is coated on the surface.

The coating time in this step is not particularly limited. For example, coating may be completed at a time when the coated cellulose powder becomes a lump shape. Generally, it takes about 10 ~ 30 minutes to form a lump and complete the coating.

The step (D) comprises adding sodium sodium hydrogen carbonate (NaHSO ₃ ), sodium percarbonate (2Na ₂ CO ₃ ), sodium bicarbonate (NAHCO ₃ ) calcium chloride NaCl) and soda ash (Na ₂ CO ₃ ), and stirring to produce a mixture; And manufacturing.

The step (E) is a step of preparing a mixture of a binder polymer, a binder polymer, a metal salt, a metal ion activator, an automatic oxidizer, a peroxide, a compatibilizer, a lubricant, and an inorganic filler in the cellulose mixture.

The steps (C), (D), and (E) may be performed sequentially or simultaneously.

In the step (F), the resulting mixture is discharged through a discharge port while being graft bonded between the cellulose plasticization reaction and the binder polymer-plasticized cellulose using a twin-screw extruder (twin extruder), and the discharged strand is conveyed to a conveyor belt Drying and then die-face hot-cutting to finally produce a raw material pellet of oxidative biodegradation additive which is a binder polymer-plasticized cellulosic graft-bonded structure composition.

Particularly, when the reaction is carried out at a reaction temperature of 100 to 300 ° C through extruder and a screw rotating speed of 300 to 800 RPM, the coupling reaction is smoothly performed. If the reaction temperature is less than 100 ° C., the added materials may not be melted and the reaction may not proceed. If the temperature exceeds 300 ° C., carbonization may occur or the temperature may be too high to melt the resin as water, . If the screw rotation speed is less than 300 RPM, productivity may be poor and sufficient mixing and reaction may be difficult. If the screw rotation speed is higher than 800 RPM, the internal pressure of the screw may increase and the carbonization of the cellulose may occur due to the pressure increase.

In addition, in order to improve processability, product stability, product performance and the like, various well known components that can be used as additives for the production of plastics may be added in predetermined amounts to produce the oxidized biodegradable additive pellets of the present invention. For example, a surface treatment agent may be added in a predetermined amount to enhance the bonding force and reduce the repulsive force. Also, in order to maintain the physical and chemical properties of the resin during use of the plastic product, Can be added.

In addition, a linear organic thermal stabilizer and an antioxidant (irganox 1010 or 1076 series) having a molecular weight of less than 2,000 are added in a predetermined amount according to a conventional method in order to prevent deformation and carbonization of the compound to maintain mechanical properties and processing stability It is also preferred.

Hereinafter, the present invention will be described more specifically by way of examples. However, these examples are provided only for the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

Hereinafter, the present invention will be described more specifically by way of examples. However, these examples are provided only for the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

Example 1: Production of oxidative biodegradation additive using plasticized cellulose

The rice husks were pulverized to about 200 mesh to produce rice husk powder. The rice husk powder was heated and dried at 100 ° C for 30 minutes to prepare dry rice husk powder.

1.5 parts by weight (based on 100 parts by weight of the whole composition) of ELISA Wax 102N (manufactured by Lion Chemical Co., Ltd.) was added to the dried rice husk powder and stirred at 500 RPM at high speed to coat the rice husk powder surface.

96 parts by weight of the surface-coated rice husk powder and 4 parts by weight of sodium hydrogen sulfite as a sodium-based plasticizer were added to a high-speed stirrer, and stirred at 400 RPM to prepare a mixture based on 100 parts by weight of the plasticized cellulose composition.

* An electron microscope (SEM) photograph showing the shape of the cellulose after the pulverization, the pulverization and the polarization filter is shown in Fig.

* An electron microscope (SEM) photograph showing the film shape after plasticization and plasticization of cellulose is shown in Fig.

45 parts by weight of the cellulose mixture prepared in Example 1, 40 parts by weight of linear low density polyethylene (LLDPE), 0.5 part by weight of acetic acid anhydride ammonium iron sulfate (III), 100 parts by weight of oxidative biodegradation additive using plasticized cellulose, 1 part by weight of maleic acid, 1 part by weight of palmitoleic acid, 0.05 part by weight of dicumyl peroxide, 1 part by weight of a polyolefin derived polymer (EM-200, manufactured by Lotte Chemical), 1 part by weight of glycidyl methacrylate, 2.0 parts by weight and the remainder as calcium carbonate was added to a high-speed stirrer and stirred at 400 RPM to produce a mixture.

Next, oxidative biodegradable additive pellets having a plastic resin-plasticized cellulose graft bond were prepared using a twin-screw extruder.

Example 2: Preparation of oxidative biodegradation additive using plasticized cellulose

The oxidative biodegradation additive pellets were prepared in the same manner as in Example 1, except that cellulose was used in an amount of 100 parts by weight of the plasticized cellulose composition.

Example 3: Preparation of oxidative biodegradation additive using plasticized cellulose

The oxidative biodegradation additive pellets were prepared in the same manner as in Example 1, except that cellulose was used in 100 parts by weight of the plasticized cellulose composition.

Example 4: Preparation of oxidative biodegradation additive using plasticized cellulose

Raw material pellets for oxidative biodegradation additive were prepared in the same manner as in Example 1, except that 97 parts by weight of surface-coated large-sized scalp powder and 3 parts by weight of sodium hydrogen sulfite as a sodium-based plasticizer were used for 100 parts by weight of the plasticized cellulosic composition.

Example 5: Preparation of oxidative biodegradation additive using plasticized cellulose

Raw material pellets for oxidative biodegradation additive were prepared in the same manner as in Example 1, except that 93 parts by weight of surface-coated pulp powder and 7 parts by weight of sodium hydrogen sulfite as a sodium plasticizer were used for 100 parts by weight of the plasticized cellulose composition.

Comparative Example 1: Production of oxidative biodegradation additive excluding plasticized cellulose

40 parts by weight of rice husk coating powder, 45 parts by weight of linear low density polyethylene (LLDPE), 0.5 part by weight of ammonium acetic anhydride (III) sulfate, 1 part by weight of maleic acid 1 part by weight of palmitoleic acid, 0.05 part by weight of dicumyl peroxide, 1 part by weight of a polyolefin derived polymer (EM-200, manufactured by Lotte Chemical Co., Ltd.), 1 part by weight of glycidyl methacrylate, 2.0 parts by weight of calcium stearate, And the remainder as calcium carbonate. The mixture was then added to a high-speed stirrer and stirred at 400 RPM to produce a mixture.

Next, raw material pellets for oxidative biodegradation additive were prepared using a twin-screw extruder.

Example 6: Preparation of oxidative biodegradable plastic film using plasticized cellulose

20 parts by weight of the oxidative biodegradable additive pellets prepared in Example 1, and 80 parts by weight of a polymer resin (PE) were mixed, and then an oxidative biodegradable plastic film was produced by using a conventional film production facility.

Example 7: Preparation of oxidative biodegradable plastic film using plasticized cellulose

20 parts by weight of the oxidative biodegradable additive pellets prepared in Example 2 and 80 parts by weight of a polymer resin (PE) were mixed, and then an oxidative biodegradable plastic film was prepared using a conventional film production facility.

Example 8: Preparation of oxidative biodegradable plastic film using plasticized cellulose

20 parts by weight of the oxidative biodegradable additive pellets prepared in Example 3 and 80 parts by weight of the polymer resin (PE) were mixed, and then an oxidative biodegradable plastic film was prepared using a conventional film production facility.

Example 9: Preparation of oxidative biodegradable plastic film using plasticized cellulose

20 parts by weight of the oxidative biodegradable additive pellets prepared in Example 4 and 80 parts by weight of a polymer resin (PE) were mixed, and then an oxidative biodegradable plastic film was produced using a conventional film production facility.

Example 10: Preparation of oxidative biodegradable plastic film using plasticized cellulose

20 parts by weight of the oxidative biodegradable additive pellets prepared in Example 5 and 80 parts by weight of a polymer resin (PE) were mixed, and then an oxidative biodegradable plastic film was prepared using a conventional film production facility.

Comparative Example 2: Production of oxidative biodegradable plastic film excluding plasticized cellulose

20 parts by weight of the pellets prepared in Comparative Example 1 and 80 parts by weight of the polymer resin (PE) were mixed and then an oxidative biodegradable plastic film was prepared using a conventional film production facility.

Experimental Example: Mechanical properties and degradability test of the produced film

(1) Mechanical properties

Tensile strength and elongation of the biodegradable plastic film prepared in Examples 6 to 10 and the biodegradable plastic film prepared in Comparative Example 2 were measured for each sample cut to 25 X 102 mm according to the ASTM D 3826 method. The number of samples per film was measured 10 times for each measurement item to reduce the error per film, and the average value except the maximum and minimum values was taken. The load cell was 50 kg, the UTM (Universal Testing Machine, Daekyung Tech, Korea) machine was used, and the tensile speed of the machine was set at 50 mm / min. The results are shown in Table 2 below.

Mechanical property test result
division

Tensile strength (kg / cm2)
Elongation (%)
Example 6

345
246
Example 7

343
244
Example 8

348
249
Example 9

338
242
Example 10

334
240
Comparative Example 2

280
223

As shown in Table 2, the oxidized biodegradable plastic film produced using plasticized cellulose according to the present invention had better mechanical properties than cellulose without plasticization.

(2) Photodegradability

The oxidized biodegradable plastic films prepared in Examples 6 to 10 and Comparative Example 2 were irradiated with ultraviolet rays for 200 hours using a QUV Accelerated Weathering Tester according to the ASTM D 15 UV treatment test method, Tensile strength and elongation were measured and converted into strength retention ratio and elongation retention ratio. The ultraviolet (UV) lamp type was UVB 313 and the Irradiance was 0.60 w / nf (310 nm). The results are shown in Table 3 below.

Photodegradation test result
division

Strength Retention Rate (%)
Shinto hold ratio (%)
Example 6

1.4
0.5
Example 7

1.3
0.4
Example 8

1.1
0.3
Example 9

0.8
0.1
Example 10

0.6
0.1
Comparative Example 2

2.5
1.4

As shown in Table 3, the oxidized biodegradable plastic film using plasticized cellulose according to the present invention had a remarkable decrease in the strength retention ratio and elongation retention ratio after UV irradiation. Thus, it can be seen that the oxidized biodegradable plastic film using the plasticized cellulose of the present invention can be decomposed to a considerable degree in a natural state by light such as ultraviolet rays.

(3) Biodegradability

The biodegradability of the biodegradable plastic films prepared in Examples 6 to 10 and Comparative Example 2 was tested according to the ASTM G 21 method. In other words, after cutting the sample to a certain size, a solid agar medium without carbon source as a medium was used to remove Aspergillus niger , Penicillium pinophilum , The mixture suspension of Chaetomium globosum , Gliocladium virens and Aureobasidium pullulans was sprayed in an aseptic condition and the degree of fungus covered in the sample for 60 days was measured by ASTM G 21 method to measure biodegradability.

In addition, biodegradability evaluation by bacteria was carried out according to ASTM G 22 method. The cell mixture suspension of Pseudomonas aeruginosa and Baccllus subtillus was applied to the sample in a sterile state on a solid agar medium without carbon source and the degree of growth of bacteria in the sample for 60 days was measured according to ASTM G 22 method And the biodegradability was measured.

Biodegradation marking method
Growth in the observed specimens

Rating
none

0
Growth trail (less than 10%)

One
Some growth (10-30%)

2
Medium growth (30-60%)

3
Overgrown growth (60% ~ completely covering the surface)

4

At the same time, the sample was taken out every 20 days while being kept for 60 days in a thermo-hygrostat fixed at a relative humidity of 85% and an internal temperature of 30 ° C, and the degree of weight loss of the sample according to the degree of growth of the mold was measured Respectively.

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

The results are shown in Tables 5 and 6 below.

Evaluation of degree of biodegradation by mold and weight loss test result
division
Degree of biodegradation (%)

Weight loss rate (%) ^*
10 days

20 days
30 days
40 days
50 days
60 days
20 days
40 days
60 days
Example 6

One
2
2
3
4
4
91.7
71.0
54.2
Example 7

One
2
2
2
3
4
92.5
71.7
53.4
Practical example 8

One
2
2
2
3
4
92.3
73.1
61.7
Example 9

One
2
2
2
3
4
92.4
73.3
60.5
Example 10

One
2
2
2
3
4
92.9
73.5
61.8
Comparative Example 2

One
One
2
2
3
3
95.4
78.4
68.2

* Weight loss rate (%) = Weight after sample collection / Weight of raw sample X 100

Evaluation of degree of biodegradation by bacteria and weight loss test result
division
Degree of biodegradation (%)

Weight loss rate (%) ^*

10 days

20 days
30 days
40 days
50 days
60 days
20 days
40 days
60 days
Example 6

One
2
2
3
4
4
90.5
69.4
52.4
Example 7

One
2
2
2
3
4
91.5
72.4
56.3
Example 8

One
2
2
2
3
4
91.7
71.2
55.8
Example 9

One
2
2
2
3
4
91.6
71.4
56.5
Example 10

One
2
2
2
3
4
92.2
72.3
57.7
Comparative Example 2

One
One
2
2
3
3
96.2
81.2
73.1

* Weight loss rate (%) = Weight after sample collection / Weight of raw sample X 100

As shown in Tables 5 and 6, it can be seen that the oxidized biodegradable plastic film produced using the plasticized cellulose according to the present invention rapidly decomposed by bacteria and fungi over time.

(4) Pyrolysis

In order to evaluate the thermal decomposition properties of the cellulose biodegradable plastic films prepared in Examples 6 to 10 and the biodegradable plastic films prepared in Examples 16 to 20 and Comparative Example 3, the specimens were cut into a size of 13 X 90 mm, Tensile strength and elongation were measured using a UTM (Universal Testing Machine, Daekyung Tech, Korea) apparatus. The specimens were taken at intervals of 7 days while being kept for 49 days in a thermostatic chamber at 85% Respectively.

The results are shown in Table 7 below.

Pyrolysis test result
division

Strength Retention Rate (%)
Shinto hold ratio (%)
Example 6

4.7
2.8
Example 7
5.5
2.1

Example 8

5.1
1.9
Example 9

5.4
2.1
Example 10

5.2
2.3
Comparative Example 2

9.2
4.3

As shown in Table 7, the oxidized biodegradable plastic film according to the present invention exhibited remarkably reduced strength retention ratio and elongation retention ratio after being treated under heat. That is, it can be seen that the oxidized biodegradable plastic film of the present invention can be decomposed to a considerable extent under high temperature conditions such as a landfill.

Comprehensively, the oxidized biodegradable plastic film using plasticized cellulose according to the present invention was found to have excellent degradability, and the mechanical properties of the plasticized biodegradable plastic film using unplasticized cellulose were greatly improved.

The oxidative biodegradation additive using the plasticized cellulose of the present invention is excellent in degradability and mechanical properties and can be applied to various products requiring plastic such as films, articles, industrial products, and packaging materials as a basic material in the field of environmentally friendly plastics It is expected that the business impact will also be significant.

Claims (10)

In a cellulose composition in which a powder of rice hull, jade, oak, large scalp or pulp is surface-coated with wax and plasticized with a sodium-based plasticizer; Binder polymer, metal salt, metal ion activator, auto oxidizer, peroxide, compatibilizer, Lubricant; And an inorganic filler, wherein the raw material pellet is an extruded oxidized biodegradable additive,
The cellulose is plasticized,
The binder polymer penetrates into micropores of the plasticized cellulose and forms graft bonds with each other,
The oxidative biodegradation additive using the plasticized cellulose is used as an additive in general plastics and has a strong mechanical property,
Wherein the oxidized biodegradable additive using the plasticized cellulose is used as an additive in general plastics and has an oxidative biodegradation action.
Oxidation biodegradation additive raw material pellets.
The method according to claim 1,
Cellulose plasticizers use one or more of sodium hydrogensulfite (NaHSO3), sodium percarbonate (2Na2CO3), sodium bicarbonate (NaHCO3), calcium chloride (NaCl) and soda ash (Na2CO3) A sodium-based plasticizer
The method according to claim 1,
10 to 70 parts by weight of plasticized cellulose, 5 to 75 parts by weight of a binder polymer, 0.1 to 10 parts by weight of a metal salt, 0.2 to 5 of a metal ion activator, 0.2 to 6 of an oxidizing agent, 0.2 to 6 of a peroxide 0.01 to 1, compatibilizing agent 0.5 to 5, lubricant 0.5 to 5, inorganic filler 5 to 65,
(A) pulverizing a cellulose selected from rice hull, oak, corn, large scalp and pulp into fine particles of 80 to 300 mesh to produce a cellulose powder;
(B) heating and drying the cellulose powder at 50 to 150 DEG C for 0.5 to 24 hours to remove moisture;
(C) adding wax to the heat-dried cellulose powder and stirring at a stirring speed of 300 to 800 RPM to coat the surface of the cellulose powder;
(D) adding a sodium-based plasticizer to the surface-coated cellulose powder and stirring to produce a plasticized cellulose mixture; And
(E) a binder polymer in the cellulose mixture, a metal salt, a metal ion activator, an auto oxidizer, a peroxide, a compatibilizer, Lubricant; And an inorganic filler to form a mixture,
(B) the mixture is subjected to graft bonding of the binder polymer-plasticized cellulose by using a twin-screw extruder and discharged through a discharge port, and then the discharged strand is conveyed through a conveyor belt, Hot-cutting to form oxidative biodegradable additive pellets;
Wherein the oxidized biodegradation additive is a polylactic acid.
The method according to claim 1,
The binder polymers include linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA) and polypropylene (PP), PLA, PHA, PHB, PHV, PCL, PBAT, and other biodegradable polymers. The polymer resin is characterized in that at least one of the polymer and the biodegradable polymer is used.
The method according to claim 1,
The metal salt may be at least one selected from the group consisting of acetic acid anhydride, ammonium metal sulfate, metal naphthenate, metal sulfate, metal silicate, sulfonium salt, acetylacetonate, tetrabutylammonium acetate, and metal ions selected from iron, copper, manganese, vanadium, zinc , Cerium, and scandium.
The method according to claim 1,
Wherein the metal ion activator is at least one selected from the group consisting of citric acid, malic acid, maleic acid, propionic acid, and para-nitrobenzonic acid.
The method according to claim 1,
Wherein the autoxidizing agent is at least one selected from the group consisting of myristoleic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid and palmitoleic acid.
An oxidative biodegradation additive pellet according to claim 4; And a polymer resin.
A product made from the biodegradable plastic raw material pellets according to claim 9.

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