KR100584905B1 - Biodegradable plastic composition containing biodegradable powders - Google Patents

Abstract

The present invention relates to a biodegradable plastic composition, comprising: (a) 100 parts by weight of a biodegradable thermoplastic base resin having a carboxyl group; (b) 5 to 400 parts by weight of a powder made of a biodegradable material having a hydroxyl group; And (c) 0.1 to 10 parts by weight of an amine compound containing at least two or more amine groups. The biodegradable plastic composition of the present invention is an economical composition having a property of biodegradation after a predetermined period of time, and increases the compatibility between the base resin and the powder to not only have excellent physical properties such as tensile strength and tensile elongation, but also have good workability. It can be easily prepared in various formulations such as injection molded articles, sheet molding and blow molded products.

Biodegradable * Resin * Hydroxyl * Powder * Amine

Description

Biodegradable Plastic Composition {BIODEGRADABLE PLASTIC COMPOSITION CONTAINING BIODEGRADABLE POWDERS}

The present invention relates to a biodegradable plastic composition, and more particularly, to a biodegradable plastic composition containing a base resin and powder having biodegradability, and having good physical properties and processability.

Synthetic polymers, represented by plastics, are one of the important materials to lead a convenient and comfortable modern life together with metals and ceramics. Such synthetic polymer products are used in various industries, such as household goods, construction, medical, agriculture, the amount of use is increasing significantly. However, unlike natural polymers, most synthetic polymers are not easily decomposed, so the disposal and management of waste products made of these synthetic polymers has become a major social problem in many countries around the world.

Such waste plastics are processed by recycling, incineration, landfilling, etc. However, recycled products are limited in their use and cause many problems such as excessive cost and pollution during the recycling process. Research on degradable plastics has been actively conducted in various countries.

In general, a degradable polymer (or resin) refers to a polymer that is rotted or degraded by microorganisms, moisture, or light. Degradable polymers are classified into four types according to their decomposition: biodegradable, hydrolyzable, photodegradable and oxidatively degradable polymers. According to ASTM definition in the United States, biodegradable polymer refers to a polymer that is degraded by the action of microorganisms such as bacteria, fungi and algae, and hydrolyzable polymer refers to a polymer that is degraded by hydrolysis. Photodegradable polymer refers to a polymer that is decomposed by natural light, especially ultraviolet light, oxidatively decomposable polymer is a polymer that is decomposed by oxidation. Among these, biodegradable polymers are completely decomposed into water and carbon dioxide, and circulate in nature, so there is no pollution and harmless to human body.

However, biodegradable polymers have the advantage that they do not cause environmental pollution by being fully decomposed, while having a disadvantage of expensive manufacturing costs, commercialization is delayed. In order to overcome this disadvantage, a so-called biodegradable plastic composition in which a biodegradable material such as starch is mixed with a non-degradable resin has been proposed. Therefore, there is a problem that the non-degradable resin remains in the soil in the form of small pieces. In addition, a technique for providing an economical biodegradable plastic composition by lowering the ratio of expensive biodegradable polymers is disclosed in Korean Patent Laid-Open No. 2001-28686. The biodegradable plastic composition disclosed in the above document consists of a mixture of various natural fine powders such as flour, rice husk, sawdust, rice flour and melamine resin. In general, since natural fine powder is inexpensive and biodegradable, there is an advantage that the possibility of commercialization is increased when mixed with the biodegradable base polymer. However, in order to maintain the physical properties such as tensile strength and tensile elongation of the plastic composition more than a predetermined degree, the base resin and the powder must be uniformly mixed, but it is not easy to obtain a uniform mixture due to the difference in density between the two components, There is a problem that many processes must be accompanied to increase the compatibility.

Therefore, the technical problem to be solved by the present invention is to solve the above problems, as an economical composition having a property of biodegradation after a predetermined period of time, by increasing the compatibility between the base resin and the powder to be excellent in physical properties such as tensile strength, tensile elongation In addition, the present invention provides a biodegradable plastic composition having good processability, which can be easily manufactured in various formulations such as various injection molded articles, sheet molding, blow molded products, and the like.

In order to achieve the above technical problem, the biodegradable plastic composition of the present invention (a) 100 parts by weight of the biodegradable thermoplastic base resin having a carboxy group; (b) 5 to 400 parts by weight of a powder made of a biodegradable material having a hydroxyl group; And (c) 0.1 to 10 parts by weight of an amine compound containing at least two or more amine groups.

In the biodegradable plastic composition of the present invention, the two or more amine groups contained in the amine compound each react with the carboxy group of the base resin and the hydroxyl group of the powder, thereby increasing the compatibility between the base resin and the powder. Accordingly, since the base resin and the powder are uniformly mixed without a separate complicated mixing process, physical properties such as tensile strength and tensile elongation are maintained well.

Hereinafter, the biodegradable plastic composition according to the present invention will be described in detail.

The biodegradable plastic composition according to the present invention contains a biodegradable thermoplastic base resin having a carboxyl group. As described above, the biodegradable thermoplastic base resin having a carboxyl group may be used as the base resin of the present invention as long as it contains a carboxyl group capable of reacting with the amine group contained in the amine compound and is biodegradable and has excellent extrusion processability. .

Such base resins include aliphatic polyesters prepared from aliphatic dibasic acids and diols, and polybutylene succinate (hereinafter referred to as PBS) is typical, and polylactic acid (hereinafter referred to as PLA). ), Polyglycolic acid (hereinafter referred to as PGA) and many aliphatic polyesters are known. In particular, polybutylene succinate (hereinafter referred to as PBS) has a relatively low manufacturing cost in synthetic biodegradable polymers and a higher melting point (110-120 ° C.) than other aliphatic polyesters. Among the biodegradable synthetic polymers, it is the polymer material that attracts the most attention (co-authored by Industrial Textiles, Ryu Dong-il, 1999, Chonnam National University Press).

In addition, the biodegradable plastic composition of the present invention contains a powder made of a biodegradable material having a hydroxyl group in order to compensate the economic disadvantages of the base resin described above. As a biodegradable material having a hydroxyl group, it is preferable from the economical point of view to use a powder of a natural material such as corn powder or wood powder (wood powder) alone or in combination thereof. The smaller the particle size of the powder to be mixed, the better the physical properties of the composition. If wood flour is used, a series of treatments may be included, followed by bleaching and drying prior to grinding. This wood bleaching process is because the various colors included in the natural wood powder may adversely affect the result in color. Therefore, this bleaching process is not necessarily an essential component of the present invention. On the other hand, the bleach used in the bleaching process is preferably treated with ozone in order to prevent the biodegradable product does not have a harmful effect on the human body.

In the biodegradable plastic composition of the present invention, the powder content of the biodegradable material having a hydroxyl group is 5 to 400 parts by weight, preferably 20 to 80 parts by weight based on 100 parts by weight of the biodegradable thermoplastic base resin having a carboxyl group. Suitable. When the content of wood powder is 5 parts by weight or less, the processability of the product is increased, but the manufacturing cost is increased, which is uneconomical. When it is more than 400 parts by weight, the heat resistance of the product is weak and carbonization occurs, and mechanical properties such as strength and elongation will be poor. There is concern.

The biodegradable plastic composition of the present invention contains an amine compound containing at least two or more amine groups in order to increase the compatibility of a powder composed of a biodegradable thermoplastic base resin having a carboxyl group and a biodegradable material having a hydroxy group. The reaction mechanism when the aliphatic polyester and wood powder were used as a base resin and powder, respectively, and the amine compound containing two amine groups as an amine compound was illustrated in following Reaction Scheme 1 below.

Referring to Scheme 1, one of the amine groups in the mixed amine compound reacts with the carboxy group of the base resin, and the other amine groups react with the hydroxyl group contained in the powder, thereby increasing the compatibility between the base resin and the powder. Therefore, the amine compound should contain at least two amine groups to achieve the above object, and if such amine compounds are aliphatic amines, ring aliphatic amines, aromatic amines, etc. You can use both. Aliphatic amines include ethyl diamine, diethylene triamine, triethylene tetratramine, methane diamine, isoprene diamine, and the like. Examples of the aliphatic amines include M-xylene diamine, and examples of the aromatic amines include, but are not limited to, meta phenylene diamine, and the like. Two or more kinds can be mixed and used. In the biodegradable plastic composition of the present invention, the content of the amine compound containing at least two or more amine groups is suitably 0.1 to 10 parts by weight based on 100 parts by weight of the biodegradable thermoplastic base resin having a carboxyl group.

To the biodegradable plastic composition of the present invention, various resins, such as polyolefin resins such as polyethylene, ethylene vinyl acetate resins copolymerized with polyethylene acetate, polystyrene, ABS resins, and the like, may be added to the biodegradable plastic composition in a predetermined amount without impairing the object of the present invention. Can be.

In addition, in the biodegradable plastic composition of the present invention, in order to improve physical properties, processability and film forming property in sheet molding, 0.1 to 10 parts by weight of a plasticizer may be further added. As such plasticizers, calcium-stearate, zinc-stearate, barium-stearate, aluminum-stearate, magnesium-stearate, paraffin wax or polyethylene wax can be used alone or in combination, respectively.

In addition, various additives can be further mixed in the range without departing from the object of the present invention. For example, surfactants may be added to increase biodegradability and physical properties. In particular, nonionic surfactants are known to accelerate biodegradability more than anionic or cationic surfactants. In addition, as the biodegradable agent, unsaturated fatty acids and derivatives thereof which are autocalcinates may be further added. These biodegradants are substances that can be transformed into peroxides that can break down the carbon-carbon bonds of the base resin by contacting microorganisms such as bacteria, fungi and enzymes under natural conditions. Any material can be used as long as it is made and meets biodegradability and is commercially widely available.

The biodegradable plastic compositions according to the invention described above can be used as injection molded articles, sheet moldings and blow molding articles. For example, aliphatic polyester resins, wood flour and / or corn powder, amine compounds, and plasticizers are mixed in a constant ratio, and then melted and extruded using a twin screw extruder, and then processed into pellets by pelletizers. An injection molding machine, an extruder for sheet manufacture, etc. can be used to manufacture injection molded articles, sheet molding products and the like.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, embodiments according to the present invention can be modified in many different forms, the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example 1

100 parts by weight of aliphatic polyester resin, 20 parts by weight of wood powder having a particle diameter of 200 to 300 µm, 3.5 parts by weight of ethyl diamine, 1 part by weight of antioxidant and 1 part by weight of a release agent, and then mixed in a high speed mixer for 3 to 4 minutes, The extruder was used to extrude at a temperature of 140 ° C. to process chips.

Screw speed: 130rpm

Extruder barrel temperature: 130 ℃ / 140 ℃ / 140 ℃ / 140 ℃ / 140 ℃ / 140 ℃ / 140 ℃ / 140 ℃ / 130 ℃ / 120 ℃

Examples 2-9

It was prepared in the same manner as in Example 1 except for changing according to the components and contents shown in Table 1.

Polyester resin (parts by weight) Wood powder (parts by weight) Ethyl diamine (parts by weight) Antioxidant (parts by weight) Release agent (parts by weight) Example 1 100 20 3.5 One One Example 2 100 40 3.5 One One Example 3 100 60 3.5 One One Example 4 100 80 3.5 One One Example 5 100 100 3.5 One One Example 6 100 150 3.5 One One Example 7 100 200 3.5 One One Example 8 100 250 3.5 One One Example 9 100 300 3.5 One One

In Table 1, the polyester resin used G4460 grade of the polybutylene succinate (PBS) of the chemical since then, the antioxidant Hindered Phenolic Antioxidant (manufacturer: Miwon Commersial co., Ltd. trade name: ANOX 20) The release agent is Y 200 purchased from Yeohwa Corporation.

Examples 10-18

It was prepared in the same manner as in Example 1 except for changing according to the components and contents shown in Table 2.

Screw speed: 130rpm

Extruder Barrel Temperature: 150 ℃ / 160 ℃ / 160 ℃ / 160 ℃ / 160 ℃ / 160 ℃ / 160 ℃ / 160 ℃ / 150 ℃ / 120 ℃

Polyester resin (parts by weight) Wood powder (parts by weight) Meta phenylene diamine (by weight) Antioxidant (parts by weight) Release agent (parts by weight) Example 10 100 20 3.5 One One Example 11 100 40 3.5 One One Example 12 100 60 3.5 One One Example 13 100 80 3.5 One One Example 14 100 100 3.5 One One Example 15 100 150 3.5 One One Example 16 100 200 3.5 One One Example 17 100 250 3.5 One One Example 18 100 300 3.5 One One

Examples 19-25

It was prepared in the same manner as in Example 2 except for changing according to the ingredients and contents shown in Table 3 below.

Polyester resin (parts by weight) Wood powder (parts by weight) Jade powder (parts by weight) Antioxidant (parts by weight) Release agent (parts by weight) Meta phenylene diamine (by weight) Calcium-stearate (parts by weight) Polyethylene Wax (parts by weight) Example 19 100 50 One One 5 Example 20 100 50 One One 5 5 Example 21 100 50 One One 5 5 Example 22 100 50 One One 5 Example 23 100 50 One One 5 Example 24 100 100 One One 5 5 Example 25 100 50 50 One One 5 5

Comparative Examples 1 to 9

For comparison with the above-described embodiment of the present invention and a biodegradable plastic composition containing a commonly used silane coupling agent, in the following comparative example, by adding vinyl trimethoxy silane (VTS) Biodegradable plastic compositions were prepared. It was prepared in the same manner as in Example 1 except for changing according to the components and contents shown in Table 4.

Polyester resin (parts by weight) Wood powder (parts by weight) Vinyl trimethoxysilane (by weight) Antioxidant (parts by weight) Release agent (parts by weight) Comparative Example 1 100 20 3.5 One One Comparative Example 2 100 40 3.5 One One Comparative Example 3 100 60 3.5 One One Comparative Example 4 100 80 3.5 One One Comparative Example 5 100 100 3.5 One One Comparative Example 6 100 150 3.5 One One Comparative Example 7 100 200 3.5 One One Comparative Example 8 100 250 3.5 One One Comparative Example 9 100 300 3.5 One One

After the chip of the biodegradable plastic composition according to the above Examples and Comparative Examples was injected through an injection machine under conditions of temperature 160 ~ 180 ℃, pressure 700 psi to obtain a specimen with a thickness of 3.26㎜, tensile strength, tensile elongation, extrudability , Biodegradability was evaluated and shown in Tables 7 to 10 below. The extrudability of the product is 32 mm of screw diameter and the screw L / D is 40 and the temperature and screw rotation speed are set using an extruder, and then the extrudate extruded from the nozzle is connected to the pelletizer. The amount of pellet produced per hour during production without any additional work was measured and evaluated as good, normal, or poor according to the following criteria.

30 ㎏ / hr or more: excellent extrudability

Less than 10 ~ 30 kg / hr: Extrudeable Moderate

Less than 10 kg / hr: Poor extrudability

On the other hand, biodegradability was carried out according to the degradability accelerated evaluation method (Composting Method). The measurement process of the degradable acceleration evaluation method is as follows.

The medium was composed as shown in Table 5 in accordance with the composition ratio of garbage generated in Korea, and the internal environment was adjusted as shown in Table 6 and maintained for 10 weeks to measure the weight loss of the sample to evaluate the degree of decomposition. Was calculated by the following equation.

Resolution (%) = (sample weight before treatment-10 weeks after sample weight) / sample weight before treatment × 100

ingredient content(%) Food (white rice cake, Chinese cabbage, pork, fish cake) 39.8 Paper (computer paper, newspaper) 20.7 sawdust 5.3 Superfluous 7.3 Plastics 7.7 Rubber 4.5 leaf 14.7 sum 100

Item Condition PH 7.0 Water content of the medium 60% Initial value of the carbon / nitrogen component of the medium 23 Air supply 100ml / min Internal holding temperature 55 ℃

Tensile Strength (㎏f / ㎠) Tensile Elongation (%) Extrudability Biodegradability (% of weight loss) Example 1 55.421 35 Great 89.3 Example 2 52.734 34 Great 88.4 Example 3 50.596 33 Great 89.1 Example 4 43.834 32 Great 88.7 Example 5 42.347 31 Great 88.6 Example 6 40.912 30 Great 89.2 Example 7 33.184 27 usually 87.9 Example 8 27.593 25 usually 89.1 Example 9 24.785 22 usually 89.6

Tensile Strength (㎏f / ㎠) Tensile Elongation (%) Extrudability Biodegradability (% of weight loss) Example 10 50.674 42 Great 85.8 Example 11 49.832 40 Great 87.2 Example 12 47.268 39 Great 86.9 Example 13 45.337 36 Great 88.1 Example 14 45.239 35 Great 82.6 Example 15 41.559 32 Great 87.4 Example 16 40.634 31 Great 83.6 Example 17 35.951 29 Great 82.7 Example 18 32.691 26 usually 85.3

Tensile Strength (㎏f / ㎠) Tensile Elongation (%) Extrudability Biodegradability (% of weight loss) Example 19 48.555 32 Great 87.6 Example 20 40.171 33 Great 88.8 Example 21 44.256 29 Great 89.7 Example 22 41.263 32 Great 89.7 Example 23 47.113 31 Great 87.4 Example 24 40.921 24 usually 88.2 Example 25 39.658 25 usually 89.4

Tensile Strength (㎏f / ㎠) Tensile Elongation (%) Extrudability Biodegradability (% of weight loss) Comparative Example 1 31.272 20 Great 88.7 Comparative Example 2 27.654 18 Great 88.5 Comparative Example 3 24.123 17 Great 86.2 Comparative Example 4 22.384 15 usually 87.4 Comparative Example 5 19.675 14 usually 87.1 Comparative Example 6 17.239 13 usually 89.1 Comparative Example 7 15.120 11 Bad 88.2 Comparative Example 8 13.526 7 Bad 87.5 Comparative Example 9 11.137 6 Bad 86.4

Referring to Tables 7 to 10, the samples of the embodiment prepared from the biodegradable plastic composition according to the present invention are excellent in physical properties such as tensile strength, tensile elongation, extrudability than the physical properties of the comparative example using a silane coupling agent. Able to know. In addition, the experimental results according to all the above embodiments is excellent in biodegradation can minimize the problems of soil, air, marine pollution due to landfill, incineration of waste.

 As described above, the biodegradable plastic composition according to the present invention is an economical composition that can be commercialized and has excellent physical properties such as tensile strength and tensile elongation since the compatibility between the base resin and the powder is increased and uniformly mixed without any additional mixing process. . In addition, the biodegradable plastic composition of the present invention can be easily manufactured in a variety of formulations such as various injection molded articles, sheet molding and blow molding products, such as good processability, biodegradation of waste products by natural microorganisms within a certain period after use By doing so, problems of soil, air, and marine pollution due to landfill and incineration of waste can be minimized.

Claims (4)

(a) 100 parts by weight of a biodegradable thermoplastic base resin having a carboxyl group; (b) 5 to 400 parts by weight of a powder made of a biodegradable material having a hydroxyl group; And (c) 0.1 to 10 parts by weight of an amine compound containing at least two or more amine groups; biodegradable plastic composition containing. The biodegradable thermoplastic base resin of claim 1, wherein the biodegradable thermoplastic base resin is an aliphatic polyester resin, and the powder made of the biodegradable material is any one selected from the group consisting of wood powder, corn powder, and mixtures thereof. Plastic composition. The biodegradable plastic composition according to claim 1 or 2, wherein the amine compound containing two or more amine groups is any one selected from the group consisting of ethyl diamine, meta phenylene diamine, and mixtures thereof. The biodegradable plastic composition according to claim 1 or 2, further comprising 0.1 to 10 parts by weight of a plasticizer.