KR20120025864A - Biodegradable film composition - Google Patents

Abstract

PURPOSE: A biodegradable film composition is provided to shorten manufacturing time, prevent decrease of biodegradation, and improve mechanical property. CONSTITUTION: A biodegradable film composition comprises aliphatic polyester-based polymer which is reformed to reactive modifier, thermoplastic starch, peroxide, and antioxidant. The aliphatic polyester-based polymer which is reformed to reactive modifier includes 0.5-2.5 parts by weight of reactive modifier, 0.1-0.6 parts by weight of peroxide, and 0.3-0.5 parts by weight of antioxidant based on 100.0 parts by weight aliphatic poly ester based polymer. The aliphatic polyester-based polymer has a melt index(2.16kg/cm^2, 190deg.C) of 5-30g/10min.

Description

Biodegradable film composition

The present invention relates to an environment-friendly biodegradable film composition, and to a composition of a biodegradable film with improved economic properties by using an aliphatic polyester-based polymer modified with a polar reactive modifier.

Synthetic resins such as polyethylene, polystyrene, polypropylene and polyvinyl chloride have been widely used in garbage 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 a conventional polyolefin. Although the price is similar to that of resin, it can secure economic feasibility, but it is difficult to apply to products due to the lack of rigidity and flexibility.

In addition, aliphatic polyester resins based on chemical synthesis, such as aliphatic polyester polymers, are somewhat more flexible than polylactic acid, but are not sufficient yet, and their hydrolysis rate is too fast. This product is not only a big defect, but also has high manufacturing cost, which is poor in economic feasibility.

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 a biodegradable film composition excellent in biodegradability and improved mechanical properties. In addition, the present invention is to provide a biodegradable film using the composition.

The present invention for solving the above problems provides a biodegradable film composition comprising an aliphatic polyester-based polymer modified with a polarized reactive modifier, thermoplastic starch, peroxidant and antioxidant.

The aliphatic polyester polymer according to the present invention is a polybutylene succinate (PBS), polybutylene adipate / terephthalate (PBAT), polybutylene succinate adipate (Polybutylene succinate adipate) (PBSA)) or polybutylene succinate / butylene terephthalate (PBST).

The aliphatic polyester system modified with the reactive modifier includes 0.5 to 2.5 parts by weight of reactive modifier, 0.05 to 0.5 parts by weight peroxidant and 0.1 to 0.8 parts by weight of antioxidant based on 100 parts by weight of aliphatic polyester.

The reactive modifier is copolymerized by aliphatic polyester and extruder to increase the compatibility and to improve the mechanical properties such as tensile strength, impact strength, if the content is less than 0.5 to improve the mechanical properties It is difficult to anticipate the effect, 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, which may reduce the quality of the product and further reduce the 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 0.1 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 0.05 parts by weight, it is difficult to achieve the object of the present invention because there is little modification effect by the reactive modifier, if the content is more than 0.6 parts by weight excessive gelation due to networking between the main chain (Networking) occurs 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 0.5 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 0.5 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].

As described above, the aliphatic polyester polymer modified with the reactive modifier has a melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) of 5 to 30 g / 10 min, which is advantageous for mixing with thermoplastic starch.

The biodegradable film composition according to the present invention is capable of maintaining biodegradability while improving mechanical properties by mixing aliphatic polyester polymer modified with a reactive modifier and thermoplastic starch, and the mixing ratio of the modified aliphatic polyester polymer and thermoplastic starch is It is preferable that it is 5: 5-9: 1. If the amount of starch used exceeds 50%, the hygroscopicity of the starch during storage is too high, resulting in decreased storage stability and deterioration of physical properties. When used less than 10%, price competitiveness is ensured by starch filling and biodegradation rate is increased. It is difficult to achieve the purpose of use, such as increase and workability improvement.

The thermoplastic starch contains glycerin, inorganic particles and a plasticizer, preferably 10 to 50 parts by weight of glycerin, and the inorganic particles include talc, calcium carbonate, bauxite, glass beads, silica, alumina, magnesium carbonate and calcium hydroxide. At least one selected from titanium dioxide and pozzolan. The inorganic particles may help improve mechanical properties such as tensile strength and tear strength, and more preferably, having a particle size of 100 to 1000 nm may smoothly form a film surface while preventing cracking.

The plasticizer is selected from water, alcohols, aldehydes, ketones, amines, esters, amides, imides and mixtures thereof.

The plasticizer preferably contains 5 to 25 parts by weight based on 100 parts by weight of starch, and when the content is less than 5 parts by weight, the workability is lowered, and when it exceeds 25 parts by weight, mechanical properties may be deteriorated.

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, anti-blocking agents, etc. It can mix | blend in the range which does not impair.

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, to compensate for the mechanical properties that were conventionally weak while not reducing the biodegradability of the biodegradable film And it can be extended to extend its use throughout the industry as an advantage to improve.

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.

(Tear strength)

According to the 7.7 tear strength test method of KS M 3503, the MD and TD tear strengths (kg / cm) of the samples were measured and the lowest values were taken.

(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

Preparation of Aliphatic Polyester Polymer Modified with Reactive Modifier

(Production Example 1)

1 part by weight of Alkenyl succinic anhydride, Albemarle (hereinafter referred to as 18ASA) per 100 parts by weight of poly (butylene succinate-co-butylene terephthalate) (hereinafter referred to as PBST) dried at 80 ° C. for 12 hours or more, peroxide 0.1 parts by weight of dicumyl peroxide and 0.3 parts by weight of antioxidant were premixed and extruded in an 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.

(Manufacture example 2)

2 parts by weight of 18ASA, 0.1 parts by weight of peroxide, and 0.3 parts by weight of antioxidant were premixed with 100 parts by weight of PBST dried at 80 ° C. for 12 hours or more, and extruded in an 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.

(Production Example 3)

1 part by weight of 18ASA, 0.1 part by weight of peroxide, and 0.4 part by weight of antioxidant were premixed with 100 parts by weight of PBST dried at 80 ° C. for 12 hours or more, followed by extrusion in an extruder. At this time, an antioxidant was used by mixing 0.2 parts by weight of Anox 20 (Chemtura Corporation) and 0.2 parts 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.

(Production Example 4)

2 parts by weight of 18ASA, 0.1 parts by weight of peroxide, and 0.4 parts by weight of antioxidant were premixed with 100 parts by weight of PBST dried at 80 ° C. for 12 hours or more, and extruded in an extruder. At this time, an antioxidant was used by mixing 0.2 parts by weight of Anox 20 (Chemtura Corporation) and 0.2 parts 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.

Thermoplastic starch ( TPS Manufacturing

(Manufacture example 5)

To 100 parts by weight of starch, 30 parts by weight of glycerin, 10 parts by weight of talc, and 7 parts by weight of water were premixed and extruded in an extruder. The temperature condition of the extruder is 80/100 / 110/125/135/120/120/110 ℃, the screw rpm was extruded by feeder 50rpm, main motor 250 ~ 300rpm.

(Production Example 6)

To 100 parts by weight of starch, 30 parts by weight of glycerin, 10 parts by weight of talc, and 10 parts by weight of ethanolamine were premixed and extruded in an extruder. The temperature condition of the extruder is 80/100 / 110/125/135/120/120/110 ℃, the screw rpm was extruded by feeder 50rpm, main motor 250 ~ 300rpm.

Biodegradable Film Composition

(Example 1)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of modified PBST of Preparation Example 1 and TPS of Preparation Example 5, followed by mixing the modified PBST and TPS in a weight ratio of 8: 2. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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.

(Example 2)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of modified PBST of Preparation Example 1 and TPS of Preparation Example 5, followed by mixing the modified PBST and TPS in a weight ratio of 7: 3. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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.

(Example 3)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of the modified PBST of Preparation Example 2 and the TPS of Preparation Example 5, followed by mixing the modified PBST and TPS in a weight ratio of 7: 3. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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.

(Example 4)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of the modified PBST of Preparation Example 3 and the TPS of Preparation Example 5, followed by mixing the modified PBST and TPS in a weight ratio of 7: 3. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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.

(Example 5)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of modified PBST of Preparation Example 4 and TPS of Preparation Example 5, followed by mixing the modified PBST and TPS in a weight ratio of 7: 3. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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.

(Example 6)

0.15 parts by weight of Anox 20 (Chemtura Corporation) and Alkanox based on 100 parts by weight of the modified PBST of Preparation Example 1 and TPS of Preparation Example 6, followed by mixing the modified PBST and TPS in a weight ratio of 7: 3. 0.15 parts by weight of 240 (Chemtura Corporation) were used as antioxidants and premixed, followed by extrusion on an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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 1)

After sufficiently drying pure PBST and TPS of Preparation Example 5, 0.15 part of Anox 20 (Chemtura Corporation) and 0.15 part of Alkanox 240 (Chemtura Corporation) to 100 parts by weight of PBST and TPS mixed at a weight ratio of 7: 3. The parts were premixed using antioxidants and extruded in an extruder. The temperature condition of the extruder is 100/120/150/160/170/160/150/150/140/150 ℃, the rpm of the screw was extruded by feeder 70 ~ 80rpm, main motor 450rpm. 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 6 according to the present invention was confirmed that the mechanical properties of tensile strength, modulus and elongation rate is excellent compared to Comparative Example 1 without lowering the biodegradability.

Claims (10)

A biodegradable film composition comprising an aliphatic polyester-based polymer modified with a reactive modifier, thermoplastic starch, peroxidant and antioxidant.
The method of claim 1,
The aliphatic polyester-based polymer modified with the reactive modifier is a biodegradable film including 0.5 to 2.5 parts by weight of a reactive modifier, 0.1 to 0.6 parts by weight of peroxide, and 0.3 to 0.5 parts by weight of antioxidant, based on 100 parts by weight of aliphatic polyester-based polymer. Composition.
The method of claim 1,
The aliphatic polyester-based polymer modified with the reactive modifier has a melt index (ASTM D 1238, 2.16 kg / cm 2, 190 ° C.) of 5-30 g / 10 min.
The method according to claim 1 or 2,
The antioxidant is biodegradable 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 thermoplastic starch is a biodegradable film composition comprising 10 to 50 parts by weight of glycerin, 1 to 20 parts by weight of inorganic particles and 5 to 25 parts by weight of a plasticizer, based on 100 parts by weight of starch.
The method of claim 5,
The inorganic particles are talc, calcium carbonate, bauxite, glass beads, silica, alumina, magnesium carbonate, calcium hydroxide, titanium dioxide and pozzolan.
The method of claim 5,
Wherein said plasticizer is selected from water, alcohols, aldehydes, ketones, amines, esters, amides, imides, and mixtures thereof.
The method according to claim 1 or 2,
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 The biodegradable film composition which is any one. The method according to claim 1 or 2,
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)).
The method according to claim 1 or 2,
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, fumaric acid, citraconic anhydride, maleic anhydride or alkenyl succinic anhydride Film composition.