KR20120047431A - Eco-friendly biodegradable film composition - Google Patents

Abstract

PURPOSE: A biodegradable film composition is provided to reduce process time, to reduce manufacturing cost, and to improve physical properties without decreasing biodegradability, because of melt-flowability suitable for processing. CONSTITUTION: A biodegradable film composition comprises an aliphatic polyester-based polymer modified by a reactive modifier, a polylactic acid, a peroxidase, an antioxidant, and inorganic filler. The mixing weight ratio of the aliphatic polyester-based polymer and the polylactic acid is 1:9 - 9:1. The aliphatic polyester-based polymer modified by a reactive modifier comprises 0.5-2.5 parts by weight of a reactive modifier, 0.06-0.6 parts by weight of peroxidase, 0.3-0.8 parts by weight of an antioxidant.

Description

Eco-friendly biodegradable film composition

The present invention relates to an environment-friendly biodegradable film composition, and more particularly, to improve mechanical properties and economics, including aliphatic polyester-based polymer and polylactic acid (PLA) modified with a polar reactive modifier It relates to a composition of this excellent eco-friendly biodegradable film.

Synthetic resins such as polyethylene, polystyrene, polypropylene, and polyvinyl chloride have been widely used in trash bags, rollbacks, shopping bags, food packaging, building materials and home appliances in various fields throughout the industry, and are indispensable in everyday life. Occupies. Although these synthetic resins are very durable, they have a weak degradability in the natural state, which adversely affects the ecosystem and causes environmental destruction when disposed of after use, and is a social problem as the resins are increasingly being used in disposable products. And economic cost increases.

A solution to this is to use a biodegradable resin. Examples of the biodegradable resins include starch resins, biodegradable polyester resins, and the like. Such resins can be degraded into biodegradation, ie, low molecular weight substances, and finally into water and carbon dioxide due to the action of the enzymes produced by environmentally existing microorganisms.

As eco-friendly awareness is emerging throughout the industry, the use of biodegradable resins discussed above has been extensively researched and developed, and research and development for higher utilization in one-time products that are difficult to recover by recycling in agricultural materials or packaging materials. It is becoming.

Of the aforementioned biodegradable resins, starch-based resins are excellent in economic efficiency, but have the disadvantage of extremely weak mechanical properties such as rigidity. On the other hand, biodegradable polyester resins include polyglycolic acid, polyhydroxybutyl acid, polylactic acid, and aliphatic polyester. Polyglycolic acid and polyhydroxybutyl acid obtained by biosynthesis have high manufacturing costs, while polylactic acid is conventionally used. Although the price is similar to that of polyolefin-based resin, it is possible to secure economic feasibility, but it is difficult to apply to products due to the lack of flexibility and tear characteristics.

In addition, aliphatic polyester resins based on chemical synthesis, such as aliphatic polyester polymers, are more flexible than polylactic acid, but have less mechanical strength, are expensive than polylactic acid, and are too expensive to be hydrolyzed, making them into bags. As a result, there is a big defect as a product, such as a sudden drop in the heat seal property when it is stored, and the economical cost is high due to the high manufacturing cost.

As a remedy for this, as in the Republic of Korea Patent Application No. 1992-0027027, a composition in which inexpensive inorganic particles such as calcium carbonate was added to an aliphatic polyester resin was used, but the economic efficiency was improved, but the stiffness was insufficient. Due to this problem, the stiffness worsened and the hydrolysis was promoted, and the improvement was not sufficient. In Korean Patent Application No. 10-2006-0008907, the hydrolysis rate decreases when the surface characteristics of inorganic particles are neutral, and the composition is obtained by adding a neutral surface oil with a relatively cheap mica (including oil) to the aliphatic polyester resin. As a result, the economic and hydrolysis resistance were slightly improved, but the mechanical properties are very weak, and the emergence of breakthrough new technologies that can improve them is urgently required. In other words, there is an urgent need for a breakthrough alternative to solve eco-friendly biodegradability and excellent mechanical properties while securing economic feasibility.

The present invention is to solve the problems of the prior art is to provide an eco-friendly biodegradable film composition with excellent biodegradability and improved mechanical properties. In addition, the present invention is to provide an eco-friendly biodegradable film using the composition.

The present invention for solving the above problems include an aliphatic polyester-based polymer, polylactic acid, peroxidant, antioxidant and inorganic filler modified with a reactive reactive modifier, the aliphatic polyester-based polymer and polylactic acid By adjusting the mixing weight ratio of to provide a good mechanical properties and environmentally friendly biodegradable film composition.

Eco-friendly biodegradable film composition according to the present invention comprises an aliphatic polyester-based polymer, polylactic acid, peroxidant, antioxidant and inorganic filler modified with a reactive modifier.

In this case, the mixing of the aliphatic polyester-based polymer and the polylactic acid modified with the reactive modifier is to maintain the biodegradability while improving the mechanical properties, characterized in that the mixing weight ratio is 1: 9-9: 1. . Outside the above range, it is difficult to expect an increase in the economics expected by mixing and complementary mechanical properties.

The aliphatic polyester modified with the reactive modifier includes 0.5 to 2.5 parts by weight of reactive modifier, 0.1 to 0.6 parts by weight of peroxidant and 0.3 to 0.8 parts by weight of antioxidant based on 100 parts by weight of aliphatic polyester.

The reactive modifier increases the compatibility while copolymerizing by aliphatic polyester and extruder in the extruder and can improve the mechanical properties such as tensile strength, impact strength when mixed with polylactic acid, the content is 0.5 If less than one, it is difficult to expect the effect of improving mechanical properties, and if it is more than 2.5, it may cause an increase in cost, discoloration of raw materials, and an increase in side reactions, thereby reducing the quality of the product and further reducing biodegradability.

Reactive modifiers that can be used in the present invention include vinyl silane, glycidyl methacrylate, styrene-acrylonitrile, acrylic acid, fumaric acid, Citric acid anhydride (Citraconic Anhydride), maleic anhydride (Alkenyl succinic anhydride) or any one selected from among the polar (Acid) of the molecular structure (polar) Or in the anhydride, the thing of the low molecular weight of 1000 or less can be used, and can be used individually or in mixture as needed.

The aliphatic polyester-based polymer modified with the reactive modifier contains 0.06 to 0.6 parts by weight of the peroxidant based on 100 parts by weight of the aliphatic polyester-based polymer. If the content is less than 0.06 parts by weight of the modification effect by the reactive modifier is difficult to achieve the object of the present invention, if the content is more than 0.6 parts by weight due to excessive reaction due to excessive gelation due to networking (Networking) between the main chain (Networking) Damage to the appearance of the film and severely damage the film during the molding process may result in the unmolding result. At this time, the peroxidant dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t- butyl peroxy isopropyl carbonate, t- butyl peroxy laurate, t- butyl peroxy acetate, di-t -Butyl diperoxy phthalate, t-dibutyl peroxy maleic acid, t-butyl cumyl peroxide, t-butyl hydroperoxide, 1, 3-bis (t-butyl peroxy isopropyl) benzene, methyl ethyl ketone peroxide, di -(2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (benzoylperoxy ) Hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, and n-butyl-4,4-bis (t-butylperoxy) valerate It includes any one selected from among.

The aliphatic polyester polymer modified with the reactive modifier contains 0.3 to 0.8 parts by weight of antioxidant based on 100 parts by weight of aliphatic polyester polymer. When the content is less than 0.3 parts by weight, it is difficult to achieve structural protection of the aliphatic polyester polymer from the heat history generated during processing, and when the content is more than 0.8 parts by weight, excessive use may result in a transition phenomenon in the process of using the film. Deterioration of mechanical properties can also result. At this time, the antioxidant is pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) [pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) ] And tris 2,4-di-tert-butylphenylphosphite [Tris (2,4-di-tert-butylphenyl) phosphite].

Melt index (ASTM D 1238, 2.16kg / ㎠, 190 ℃) of the biodegradable film composition according to the invention is characterized in that 3 ~ 30g / 10min, more preferably 5 ~ 20g / 10min. By adjusting the melt index of the above range can improve the processability of the composition, it is possible to improve the mechanical properties such as tensile strength, elongation.

The present invention includes an aliphatic polyester-based polymer modified with the polar reactive modifier, polylactic acid, peroxidant and antioxidant, and is environmentally friendly by controlling the mixed weight ratio of the aliphatic polyester-based polymer and polylactic acid. Phosphorus biodegradable film compositions can be provided to improve melt flow and simplify the process to reduce production costs. The composition can sufficiently express excellent processability and mechanical properties.

More preferably, the present invention may further include an inorganic filler having an average particle size of 0.5 μm to 5 μm in order to increase the moldability by increasing the crystallization rate in the molding process. The inorganic filler is selected from one or a mixture of two or more of hard or heavy calcium carbonate, silica, talc, barium sulfate, clay or calcium oxide, and 2 to 13% of the total composition is used. If the average particle size of the inorganic filler is less than 0.5 μm, it becomes difficult to disperse the particles. If the average particle size is more than 5 μm, the size of the particles becomes too large, and it is difficult to achieve the intention of the present invention. In addition, when the content of the inorganic filler is less than 2% of the total composition, the effect of contributing to the crystallization rate is small, and when the content of the inorganic filler exceeds 13%, it is difficult to disperse the inorganic filler, resulting in deterioration of mechanical properties.

The biodegradable film composition of the present invention, if necessary, various additives such as stabilizers, lubricants, flame retardants, antistatic agents, antibacterial agents, biodegradation accelerators, heat stabilizers, light stabilizers, weathering stabilizers, ultraviolet absorbers, antiblocking agents, etc., impair the object of the present invention. It can mix | blend in the range which does not make it.

As the extruder that can be used in the present invention, any known mixing property, such as a single screw extruder, a co-rotating twin screw extruder, a bi-directional rotary twin screw extruder, may be used, but preferably a co-rotating twin screw extruder is used. .

As described above, the biodegradable film composition according to the present invention is suitable for processing the melt flow rate can shorten the process time and can reduce the production cost. In addition, it is possible to supplement and improve the mechanical properties without reducing the biodegradability of the biodegradable film has the advantage that can be widely applied to the application throughout the industry.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

Tensile strength, elongation, tear strength and biodegradability of the films prepared according to the following Examples and Comparative Examples were measured as follows.

Property evaluation

(Tensile strength and elongation)

The strength (kg / cm 2) and elongation (%) at break of the sample were measured according to the 7.6 tensile strength and tensile elongation test method of KS M 3503. The lowest value was taken after each measurement was made for the travel direction MD and the width direction TD perpendicular to the travel direction.

(Biodegradable)

The aerobic biodegradability of plastics under KS M 3100-1 composting conditions was measured and evaluated by measuring the amount of carbon dioxide generated from the standard sample (cellulose) and the test sample.

Biodegradability (%) = (quantity of generated carbon dioxide / theoretical amount of carbon dioxide) * 100

As a reactive modifier Modified  Aliphatic polyester Of polymer  Produce

(Production Example 1)

1 part by weight of Alkenyl succinic anhydride, Albemarle (hereinafter referred to as 18ASA) with respect to 100 parts by weight of poly (butylene succinate-co-butyleneterephthalate) (hereinafter referred to as PBST) dried at 80 ° C. for 12 hours or more, as a peroxide. 0.1 parts by weight of dicumyl peroxide and 0.3 parts by weight of antioxidant were premixed and extruded in a coaxial twin screw extruder. At this time, the antioxidant used was a mixture of 0.15 parts by weight of Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation).

The temperature condition of the extruder is 130/140/150/160/160/170/160/160/170/170 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm.

Biodegradable Film Composition

(Example 1)

0.1 parts by weight of dicumyl peroxide, 100 parts by weight of the modified PBST and polylactic acid of Preparation Example 1, mixed at a weight ratio of 7: 3, Anox 20 as an antioxidant (Chemtura Corporation) After premixing them using 0.15 parts by weight and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation), the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) showed 6.8 g / 10 min, which was extruded in an extruder. . The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the screw rpm was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a width of 300 mm and a thickness of 30 μm by appropriately adjusting the extruder cylinder and the die temperature in a range of 130 to 170 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1 below. .

(Example 2)

To 100 parts by weight of the modified PBST and polylactic acid of Preparation Example 1 was mixed in a weight ratio of 3: 7, 0.06 parts by weight of dicumyl peroxide, Anox 20 (Chemtura Corporation) as an antioxidant After premixing them using 0.15 parts by weight and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation), the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) showed 8.3 g / 10 min, which was extruded in an extruder. . The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a width of 300 mm and a thickness of 30 μm by properly adjusting the extruder cylinder and the die temperature in the range of 130 to 170 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1 below. .

(Example 3)

0.1 parts by weight of dicumyl peroxide, 100 parts by weight of the modified PBST and polylactic acid of Preparation Example 1, mixed at a weight ratio of 6: 4, Anox 20 as an antioxidant (Chemtura Corporation) After premixing them using 0.15 parts by weight and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation), the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) showed 10.9 g / 10 min, which was extruded in an extruder. . The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a width of 300 mm and a thickness of 30 μm by properly adjusting the extruder cylinder and the die temperature in the range of 130 to 170 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1 below. .

(Example 4)

To 100 parts by weight of the modified PBST and polylactic acid of Preparation Example 1 was mixed in a weight ratio of 2: 8, 0.06 parts by weight of dicumyl peroxide, Anox 20 (Chemtura Corporation) as an antioxidant After premixing them using 0.15 parts by weight and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation), the melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) showed 5.5 g / 10 min, which was extruded in an extruder. . The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a thickness of 300 mm and a thickness of 30 μm by appropriately adjusting the extruder cylinder and the die temperature in the range of 130 to 170 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1. .

(Example 5)

0.1 parts by weight of dicumyl peroxide, 100 parts by weight of the modified PBST and polylactic acid of Preparation Example 1, mixed at a weight ratio of 7: 3, Anox 20 as an antioxidant (Chemtura Corporation) 0.15 parts by weight and 0.15 parts by weight of Alkanox 240 (Chemtura Corporation) were used, and calcium carbonate having an average particle diameter of 1 탆 was premixed so that 4.3% of the total composition was included and then extruded in an extruder. At this time, the temperature conditions of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a width of 300 mm and a thickness of 30 μm by appropriately adjusting the extruder cylinder and the die temperature in a range of 130 to 170 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1 below. .

(Comparative Example 1)

0.15 parts of Anox 20 (Chemtura Corporation) and Alkanox 240 (Chemtura Corporation) as antioxidants based on 100 parts by weight of unmodified PBST and polylactic acid, which were mixed at a weight ratio of 7: 3 after drying. These were premixed using 0.15 parts by weight and then extruded in an extruder. The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a thickness of 30 μm by properly adjusting the extruder cylinder and the die temperature in the range of 170 to 190 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1.

(Comparative Example 2)

0.15 parts of Anox 20 (Chemtura Corporation) and Alkanox 240 (Chemtura Corporation) as antioxidants based on 100 parts by weight of unmodified PBST and polylactic acid, which were mixed at a weight ratio of 3: 7 after drying. These were premixed using 0.15 parts by weight and then extruded in an extruder. The temperature condition of the extruder is 150/160/170/180/160/170/170/180/180/180 ℃, the rpm of the screw was extruded by feeder 60 rpm, main motor 370 rpm. The biodegradable film composition thus prepared was a tubular film having a thickness of 30 μm by properly adjusting the extruder cylinder and the die temperature in the range of 170 to 190 ° C. using a circular die molding machine, and the physical properties thereof are shown in Table 1.

As shown in Table 1, Examples 1 to 4 according to the present invention is confirmed that the mechanical properties are better due to the increase in the interfacial adhesion of the modified fatty acid polyester to increase the compatibility with PLA compared to the comparative example Could.

The present invention is not limited to the above embodiments, and various modifications and variations are possible to those skilled in the art from this description. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later will belong to the scope of the present invention. .

Claims (10)

Eco-friendly biodegradable film composition comprising an aliphatic polyester-based polymer modified with a reactive modifier, polylactic acid, peroxidant, antioxidant and inorganic filler.
The method of claim 1,
Eco-friendly biodegradable film composition, characterized in that the mixing weight ratio of the aliphatic polyester-based polymer and polylactic acid modified with the reactive modifier is 1: 9 ~ 9: 1.
The method of claim 1,
The aliphatic polyester-based polymer modified with the reactive modifier is environmentally-friendly biodegradable, including 0.5-2.5 parts by weight of reactive modifier, 0.06-0.6 parts by weight of peroxide, and 0.3-0.8 parts by weight, based on 100 parts by weight of aliphatic polyester-based polymer. Film composition.
The method according to claim 1, wherein
Melt index of the composition (ASTM D 1238, 2.16kg / ㎠, 190 ℃) is 3 ~ 30g / 10min eco-friendly biodegradable film composition.
The method of claim 1,
The antioxidant is environmentally friendly biodegradation including pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) and tris 2,4-di-tert-butylphenylphosphite Film composition.
The method of claim 1,
The peroxidant may be dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxy laurate, t-butylperoxy acetate, di-t-butyl Diperoxyphthalate, t-dibutyl peroxymaleic acid, t-butyl cumyl peroxide, t-butyl hydroperoxide, 1,3-bis (t-butylperoxyisopropyl) benzene, methylethylketone peroxide, di- ( 2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane , 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, and n-butyl-4,4-bis (t-butylperoxy) valerate Any one of which is an eco-friendly biodegradable film composition.
The method of claim 1,
The aliphatic polyester-based polymer may be polybutylene succinate (PBS), polybutylene adipate / terephthalate (PBAT), polybutylene succinate adipate (PBSA) ) Or polybutylene succinic acid / butylene terephthalate (Polybutylene succinate / butylene terephthalate (PBST)) is any one of the environmentally-friendly biodegradable film composition.
The method of claim 1,
The reactive modifier is a low molecular weight of 1,000 or less in a polar acid or its anhydride in molecular structure, vinyl silane, glycidyl methacrylate, styrene-acrylonitrile (Styrene-acrylonitrile), acrylic acid, fumaric acid, citraconic anhydride (Citraconic Anhydride), maleic anhydride or alkenyl succinic anhydride are selected from Biodegradable Film Compositions.
The method of claim 1,
The inorganic filler is selected from one or two or more of hard or heavy calcium carbonate, silica, talc, barium sulfate, clay or calcium oxide having an average particle size of 0.5 to 5 μm, and using 2 to 13% of the total composition. Eco-friendly biodegradable film composition, characterized in that.
Eco-friendly biodegradable film comprising any one of the compositions selected from claim 1 to claim 9.