KR101789724B1 - Improved compatibility for biodegradable compound composition - Google Patents

Abstract

The present invention relates to a resin composition comprising a resin mixture (A) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer and a compatibilizer,
Wherein the compatibilizer is a blend obtained by chain-exchanging a resin mixture (B) of a polylactic acid and a polybutylene adipate-terephthalate copolymer with an amino alcohol, wherein the biodegradable compound And to provide a film having bubble stability and excellent mechanical properties using a resin composition.

Description

Improved compatibility for biodegradable compound composition < RTI ID = 0.0 >

The present invention relates to a biodegradable compound resin composition.

Plastic products are widely used in various fields in real life because they are lightweight, have excellent mechanical properties and durability, are easy to process and can be mass-produced. However, as the use of plastic products is increased and the service life is shortened, a large amount of waste is generated, which causes social pollution and environmental problems. In addition, since plastic products are difficult to decompose in a natural state, domestic and overseas industries have been actively developed for application to various fields such as various packaging containers and electronic product cases by using biodegradable resin which can be decomposed in nature. In order to put the packaging container using the biodegradable resin into practical use, it is required to have high hardness in order to maintain the shape after molding, and it should not be damaged by external impact during use.

The biodegradable resin can be divided into a resin mixture by synthesis and a starch resin polymerized by fermenting natural product. These resins can be degraded into biodegradable or low-molecular substances and eventually decomposed into water and carbon dioxide due to the action of enzymes produced by environmentally-existing microorganisms. However, polyester biodegradable resins by synthesis have lower hardness and higher flexibility than conventional plastic products, and thus they have many limitations in practical use as packaging containers.

On the other hand, polylactic acid made by fermenting starch is an environmentally friendly biodegradable resin that has good transparency and harmless degradation by microorganisms. It can also be used as a packaging container for food products after approval by the US Food and Drug Administration (FDA). However, the polylactic acid has a low elongation of 10% or less, breakage due to impact easily occurs, and holes are formed in the thinned portion in the process of blow molding to produce the film. The blow molding is a process widely used because of high production speed and low cost in producing articles such as films and bags. However, polylactic acid has a low limit of thermal deformation temperature and poor stability of bubbles due to a slow cooling rate, and thus there are many limitations in the part for producing a film by blow molding.

To solve these problems, it is necessary to improve bubble stability, elongation at break, tear strength and thermal fusion strength during blow molding of polylactic acid. Therefore, in order to improve the physical properties of the polylactic acid, a method of adding a low molecular weight softener or plasticizer or introducing a copolymer by using other monomers has been proposed. However, it has been attempted to improve the physical properties of the polylactic acid film, It is still necessary to develop related technologies to overcome these problems.

Korean Patent Publication No. 2011-0130029 (December 5, 2011)

It is an object of the present invention to provide an environmentally friendly biodegradable compound resin composition having improved mechanical strength and improved elongation, tear strength and thermal fusion strength during film forming by improving bubble stability during blow molding.

 The present invention also provides a method for producing a film using the biodegradable compound resin composition and a film produced using the method.

In order to achieve the above object, the present invention provides a resin composition comprising a resin mixture (A) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer and a compatibilizer,

Wherein the compatibilizer is a blend of resin mixtures (B) of polylactic acid and polybutylene adipate-terephthalate copolymer chain-exchanged with aminoalcohol.

In one embodiment of the present invention, the resin mixture (A) and the resin mixture (B) may contain 50 to 90% by weight of polylactic acid and 10 to 50% by weight of polybutylene adipate-terephthalate copolymer.

In one embodiment of the present invention, from 2 to 15 parts by weight of the compatibilizing agent may be included per 100 parts by weight of the resin mixture (A).

In one embodiment of the present invention, the compatibilizing agent may include 5 to 15 parts by weight of amino alcohol with respect to 100 parts by weight of the resin mixture (B).

In one embodiment of the present invention, the compatibilizer may further comprise 0.1 to 2.5 parts by weight of a viscosity modifier based on 100 parts by weight of the resin mixture (B).

In one embodiment of the present invention, the amino alcohol may include any one or two or more selected from C ₁ to C ₈ amino alcohols.

In one embodiment of the present invention, the biodegradable compound resin composition may further include any one or two or more selected from carbodiimide-based additives and diisocyanates.

In one embodiment of the present invention, the biodegradable compound resin composition may further comprise 0.5 to 10 parts by weight of a carbodiimide-based additive and 0.1 to 2.5 parts by weight of a diisocyanate based on 100 parts by weight of the resin mixture (A).

In one embodiment of the present invention, the carbodiimide additive may include any one or two or more selected from aliphatic carbodiimide type, alicyclic carbodiimide type and aromatic carbodiimide type.

In one embodiment of the present invention, the diisocyanate may include any one or two or more selected from aliphatic diisocyanates and aromatic diisocyanates.

In one embodiment of the present invention, the biodegradable compound resin composition may further include any one or two or more additives selected from a plasticizer, a viscosity modifier, an inorganic filler, an antioxidant, an amide wax and a pigment.

In one embodiment of the present invention, 5 to 20 parts by weight of a plasticizer, 0.1 to 2.5 parts by weight of a viscosity modifier, 1 to 30 parts by weight of an inorganic filler, 0.1 to 0.5 parts by weight of an antioxidant, 0.1 to 1 part by weight of an amide wax and 0.1 to 1 part by weight of a pigment.

The present invention provides a film using the biodegradable compound resin composition.

The biodegradable compound resin composition according to the present invention has improved bubble stability and excellent blow moldability, and has an improved elongation, tensile strength, tear strength, tear growth resistance and heat fusion strength during film formation, And can have excellent mechanical strength.

Further, since the present invention contains polylactic acid, which is a biodegradable resin, it can be used as an environmentally friendly film that can be decomposed in a natural state, a molded product such as a packaging container, a sheet, and a packaging material.

Hereinafter, the biodegradable compound composition of the present invention having improved compatibility will be described in detail.

The present invention relates to a resin composition comprising a resin mixture (A) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer and a compatibilizer,

The compatibilizing agent is a biodegradable compound resin composition characterized in that the resin mixture (B) of polylactic acid and polybutylene adipate-terephthalate copolymer is a chain-exchanged product by amino alcohol. The chain exchange means one or more selected from a transesterification reaction and a transamidation reaction.

The present invention relates to a process for producing a polylactic acid copolymer by blending an amino alcohol with polylactic acid (PLA) and a polybutylene adipate-terephthalate copolymer (PBAT) having incompatibility and chain-exchanging the polylactic acid and the polybutylene adipate-terephthalate copolymer And is used as a compatibilizing agent capable of imparting compatibility by causing a reaction to be used in a biodegradable compound resin composition.

In order to further improve the reactivity between the compatibilizing agent and the polymer, a biodegradable compound resin composition was prepared using a carbodiimide additive and a diisocyanate.

Accordingly, the biodegradable compound resin composition produced by the present invention can improve the bubble stability during blow molding, which is a conventional problem, and improve the elongation, tear strength and thermal fusion strength upon film molding, A biodegradable compound resin composition can be provided.

Hereinafter, the present invention will be described in detail.

Polylactic acid (PLA) used in the present invention is excellent in heat resistance and strength among biodegradable resins and excellent in transparency after molding, and can be used in various fields such as films, packaging containers, sheets, packaging materials, coating agents, . In addition, polylactic acid is a resin that is eco-friendly plastic product instead of PE (Polyethylene) and PVC (Polyvinyl chloride).

The polylactic acid used in the present invention may have a weight average molecular weight (Mn) of 50,000 to 150,000 g / mol. Further, polylactic acid has an isomer and is produced by polymerizing monomers derived from D-lactide and L-lactide or DL-lactide, The content of the monomer can be controlled to be used as the homopolymer and the polylactic acid of the copolymer.

The polylactic acid to be used in the present invention may be selected from amorphous polylactic acid having a D-lactide content of 9 to 15% by weight and crystalline (D-lactide) having a D-lactide content of 1 to 5% The polylactic acid may be used singly or in combination, but it is preferable to use crystalline polylactic acid. This is because the crystalline polylactic acid has impact resistance and heat resistance, and the shape change of the molded article can be minimized as it is used singly.

In the present invention, a polybutylene adipate-terephthalate copolymer (PABT) is used together with the polylactic acid. The polybutylene adipate-terephthalate copolymer may also be represented by polybutylene adipate-co-terephthalate (PBAT). Since the polybutylene adipate-terephthalate copolymer has a low cooling rate and a high flexibility, it can be mixed with the polylactic acid to improve the flexibility of the resin composition and to improve the limitations in molding due to the hardness of the polylactic acid have. The weight average molecular weight (Mn) of the polybutylene adipate-terephthalate copolymer (PABT) used in the present invention may be 20,000 to 100,000 g / mol.

Specifically, in the present invention, a resin mixture (A) and a resin mixture (B) containing 50 to 90% by weight of polylactic acid and 10 to 50% by weight of polybutylene adipate-terephthalate copolymer can be used. It is possible to improve the fragility of polylactic acid within the above-mentioned range, to have excellent long-term storage property, and to improve the deformation due to the load.

In the present invention, since a compatibilizing agent is used, there is a feature that a biodegradable compound resin composition having improved compatibility can be produced. Specifically, the compatibilizing agent is a compatibilizing agent characterized in that the resin mixture (B) of the polylactic acid and the polybutylene adipate-terephthalate copolymer is a blend chain-exchanged by amino alcohol. The chain exchange means one or more selected from a transesterification reaction and a transamidation reaction. The biodegradable compound resin composition having improved compatibility by using the compatibilizing agent can stably produce a film without shaking in a state where the bubble is expanded when the film is formed by blow molding, .

In the present invention, the compatibilizing agent may be a form in which a polylactic acid and a polybutylene adipate-terephthalate copolymer are formed in the form of a block in a block form by chain exchange.

Concretely, it is preferable to use 5 to 15 parts by weight, more preferably 8 to 13 parts by weight, of the amino alcohol with respect to 100 parts by weight of the resin mixture (B) as the compatibilizing agent. Chain exchange of amino alcohols can be effectively carried out within the above-mentioned range, and thus it may be suitable for improving the compatibility.

Specifically, the amino alcohol may be any one selected from C ₁ to C ₈ aminoalcohols, or two or more thereof. More specifically, the aminoalcohol may be selected from the group consisting of C ₁ methanolamine, C ₂ ethanolamine, monoethanolamine (MEA), C ₃ methylethanolamine, and 1- Amino-2-propanol and C ₄ 4-amino-1-butanol, C _{5 5} -amino-1-pentanol (5- Amino-1-pentanol, C ₆ 6-amino-1-hexanol, C ₇ 7-amino-1-heptanol, C ₈ -amino-1-octanol, heptaminol, and the like, preferably ethanolamine (MEA) But is not limited thereto.

Specifically, the compatibilizing agent is preferably used in an amount of 2 to 15 parts by weight, more preferably 5 to 10 parts by weight, based on 100 parts by weight of the resin mixture (A). The compatibility can be effectively imparted to the biodegradable compound resin composition within the above range and it may be suitable to improve the bubble stability at the time of blow molding.

In addition, the compatibilizing agent may further include a viscosity controlling agent to facilitate processing. The viscosity adjusting agent is preferably used in an amount of 0.1 to 2.5 parts by weight, more preferably 0.2 to 1.5 parts by weight, based on 100 parts by weight of the resin mixture (B). The viscosity control agent is described in detail below again.

In the present invention, one or more selected from carbodiimide-based additives and diisocyanates may be used in order to further improve the reactivity between the compatibilizing agent and the resin mixture (A).

Specifically, the carbodiimide additive is an additive that reacts with the carboxyl moiety during the reaction of the compatibilizing agent and the resin mixture (A), and at the same time induces bonding between the resin mixture. The carbodiimide-based additives can be used to control the molecular weight and improve mechanical properties such as tensile strength and elongation of the film produced from the biodegradable compound resin composition.

Specifically, the carbodiimide-based additive may be used either alone or in combination of two or more selected from aliphatic carbodiimide type, alicyclic carbodiimide type and aromatic carbodiimide type .

More specifically, the carbodiimide-based additive is an aliphatic carbodiimide compound such as N, N'-Diisopropylcarbodiimide (DIC) and 1-ethyl-3- (3- (N, N'-dicyclohexylcarbodiimide, DCC) based on an alicyclic carbodiimide such as 1-ethyl-3- (3- dimethylaminopropyl) carbodiimide Bis (2,6-diisopropylphenyl) carbodiimide (CDI) based on an aromatic carbodiimide, and the like, and preferably one or more selected from the group consisting of But not limited to, N, N'-dicyclohexylcarbodiimide (DCC).

 More specifically, the carbodiimide-based additive may be used in an amount of 0.5 to 10 parts by weight, more preferably 3 to 7 parts by weight, per 100 parts by weight of the resin mixture (A). In the above range, the reactivity between the compatibilizing agent and the resin mixture (A) can be improved remarkably. If it exceeds the above range, the cost may be increased rather than improving the reactivity.

The diisocyanate is an additive that reacts with the alcohol moiety upon reaction of the compatibilizing agent and the resin mixture (A), and at the same time, induces bonding between the resin mixture. The diisocyanate inhibits the hydrolysis by removing the alcohol group generated by the amino alcohol can do. Also, it is possible to produce a biodegradable compound resin composition having various flexibility and stiffness by forming a hard segment which is a hard part of the polymer.

Specifically, the diisocyanate may be selected from among aliphatic diisocyanates and aromatic diisocyanates and may be used alone or in combination.

More specifically, the aliphatic diisocyanate is at least one or more selected from hexamethylene diisocyanate (HDI), 4,4'-methylene-bis (cyclohexyl isocyanate) (HMDI) and isophorone diisocyanate (IPDI) Mixtures may be used, but are not limited thereto.

More specifically, the aromatic diisocyanate may be at least one selected from toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and the like, preferably diphenylmethane diisocyanate (MDI) But is not limited thereto.

More specifically, it is preferable to use 0.1 to 2.5 parts by weight, more preferably 0.2 to 1.5 parts by weight, of diisocyanate relative to 100 parts by weight of the resin mixture (A). It is possible to induce proper bonding and rigidity of the biodegradable compound resin composition within the above range and to improve the tensile strength and heat resistance of the film produced from the biodegradable compound resin composition.

In the present invention, when 3 to 7 parts by weight of the carbodiimide additive and 0.2 to 1.5 parts by weight of the diisocyanate are simultaneously contained in 100 parts by weight of the resin mixture (A), the film produced from the biodegradable compound resin composition The tensile strength, the elongation, the tear strength, the tear growth resistance, and the heat fusion strength of the steel sheet can be improved at the same time.

In the present invention, the biodegradable compound resin composition may further include any one or two or more additives selected from plasticizers, viscosity regulators, inorganic fillers, antioxidants, amide waxes, and pigments.

The plasticizer may be selected from the group consisting of triacetin, citrate-based plasticizers, high-molecular plasticizers, and the like, but not limited thereto.

Specifically, the citrate based plasticizer is selected from the group consisting of tributyl citrate, triethyl citrate (TEC), triethylhexyl citrate, and acetyl tributyl citrate citrate, and the like. Preferably, tributyl citrate is used. However, the present invention is not limited thereto. The polymer type plasticizer may be selected from the group consisting of polyethyleneglycol (PEG), polycaprolactone, polyglycerin acetate, and the like, but not limited thereto.

The amount of the plasticizer is preferably 5 to 20 parts by weight, more preferably 6 to 15 parts by weight, based on 100 parts by weight of the resin mixture (A). The plasticization of the biodegradable compound resin composition can be controlled within the above range, so that the elongation and tear strength during film formation can be preferably improved.

The viscosity adjusting agent may be selected from organic peroxides and cross-linking agents, and the like, but not limited thereto.

Specifically, the organic peroxide is selected from the group consisting of dibenzoyl peroxide, 2,5-dimethyl-2,5 di (t-butylperoxy) butylperoxy-hexane, di- (2-t-butylperoxyisopropyl) benzene, and the like, or mixtures of two or more thereof, Di- (2-t-butylperoxyisopropyl) benzene is preferably used, but not limited thereto.

Specifically, the cross-linking agent is selected from the group consisting of triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), trimethylolpropane triacrylate (TMPTA) And trimethylolpropane trimethacrylate (TMPTMA), or a mixture of two or more of them may be used, but the present invention is not limited thereto.

More specifically, the content of the viscosity modifier is preferably 0.1 to 2.5 parts by weight, more preferably 0.2 to 1.5 parts by weight, based on 100 parts by weight of the resin mixture (A). The biodegradable compound resin composition which is finally molded within the above range can have a suitable viscosity and thus the film thickness can be controlled and the moldability can be maintained.

The inorganic filler can increase the degree of crystallization of the biodegradable compound resin composition and improve rigidity, transparency and gloss. The particle size of the inorganic filler is preferably from 0.5 to 10 mu m, more preferably from 1 to 7 mu m, but is not limited thereto. The particles of the inorganic filler are preferably dispersed in the biodegradable compound resin composition within the above range.

Specifically, the inorganic filler is calcium carbonate (CaCO _3), talc (talc), wollastonite (wollastonite), magnesium carbonate (magnesium Carbonate), clay (clay), bentonite (bentonite), silica (SiO ₂₎ and alumina (Al ₂ O ₃ ), and mixtures of two or more thereof. Preferably, calcium carbonate (CaCO ₃ ) is used, but not limited thereto.

More specifically, the content of the inorganic filler is preferably 1 to 30 parts by weight, more preferably 3 to 15 parts by weight, based on 100 parts by weight of the resin mixture (A). It is preferable that the specific gravity of the biodegradable compound resin composition can be controlled within the above range.

The antioxidant may include a primary antioxidant and a secondary antioxidant. The primary antioxidant acts as a radical scavenger to stabilize the plastic by reacting with the radicals produced in the plastic. The secondary antioxidant serves as a primary antioxidant and acts as a release of peroxide.

Specifically, the representative materials of the primary antioxidant are phenol-based and aromatic-amine-based, preferably (3,5-di-t-butyl-4- hydrocycinnamate) methane ((3,5- di -t-butyl-4-hydroxyhydrocinnamate) methane). As the second antioxidant, tris (2,4-di-t-butylphenyl) phosphite may be preferably used, but is not limited thereto.

More specifically, the content of the antioxidant is preferably 0.1 to 0.5 parts by weight, more preferably 0.2 to 0.4 parts by weight, based on 100 parts by weight of the resin mixture (A). Within the above range, the biodegradable compound resin composition has good heat resistance and processability and can be used as an excellent stabilizer.

Amide-based wax is used to prevent stickiness between the surface of a mold or extruder and resin during processing, molding and extrusion, and is used to control the friction force. The amide-based wax lowers the melt viscosity of the resin, As the machining time is shortened, the deterioration during machining can be reduced and the quality of the product can be improved.

Specifically, the amide-based wax may include one or more selected from among Erucamide, Oleamide, and Stearamide. Preferably, the amide wax may include Erucamide, But it is not limited thereto and can be used.

More specifically, the content of the amide wax is preferably 0.1 to 1 part by weight, more preferably 0.3 to 0.7 part by weight, based on 100 parts by weight of the resin mixture (A). The frictional force can be effectively controlled during processing, molding and extrusion within the above-mentioned range, and the adhesion and the adhesive force of the biodegradable compound resin composition may not be affected.

Pigments can be used to blend in resin to develop color, gloss or prevent corrosion. Specifically, the pigment is titanium dioxide (TiO _2), zinc oxide (ZnO), zinc sulfide (ZnS), yellow iron oxide _{(FeO (OH), Fe 2} O 3 and H ₂ O), and cobalt blue (CoO and Al ₂ O ₃ ) or the like, or a mixture of two or more of them. Preferably, titanium dioxide (TiO ₂ ) is used, but not limited thereto.

More specifically, the content of the pigment is preferably 0.1 to 1 part by weight, more preferably 0.3 to 0.7 part by weight, based on 100 parts by weight of the resin mixture (A). It can be used within the above range without deteriorating the physical properties of the biodegradable compound resin composition.

The biodegradable compound resin composition of the present invention may contain various additives such as stabilizers, lubricants, flame retardants, antistatic agents, antimicrobial agents, biodegradation accelerators, heat stabilizers, light stabilizers, weathering stabilizers, ultraviolet absorbers and anti- And can be compounded within a range that does not impair the purpose.

The present invention can provide a film using the biodegradable compound resin composition.

As a method for producing a film using the biodegradable compound resin composition according to the present invention,

Preparing a compatibilizing agent comprising a resin mixture (B) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer, an amino alcohol and a viscosity controlling agent, or

(A) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer, a compatibilizer, a carbodiimide additive, a plasticizer, a viscosity modifier, an inorganic filler, an antioxidant, an amide-based wax and a pigment After performing the step of preparing the biodegradable compound resin composition,

And a step of preparing a biodegradable film using the biodegradable compound resin composition.

In the present invention, a super mixer or a ribbon blender may be used to homogeneously mix the compatibilizer or the biodegradable compound resin composition. At this time, the number of revolutions is preferably 300 to 700 rpm.

Concretely, mixing of the biodegradable compound resin composition is carried out by mixing the resin mixture (A), the compatibilizer, the carbodiimide additive, the viscosity adjusting agent, the antioxidant, the amide wax and the pigment except for the plasticizer and the inorganic filler in the super mixer super mixer) or a ribbon blender.

 The mixed compatibilizer or biodegradable compound resin composition may be fed into a main feeder of an extruder. At this time, the mixture of the biodegradable compound resin composition except for the plasticizer and the inorganic filler was firstly introduced, and then, on the cylinder side at the 1/3 to 2/3 point of the cylinder, the plasticizer and the inorganic The filler can be injected.

Specifically, the extruder may be a single-screw extruder, a co-rotating twin-screw extruder, a bi-directional twin-screw extruder, or the like, preferably a co-rotating twin-screw extruder.

At this time, the temperature of the cylinder of the extruder is preferably in the range of 160 to 200 DEG C because the molten state of the resin is uniformly maintained. The number of revolutions of the screw is preferably 150 to 400 rpm. If the number of revolutions is too fast, the residence time of the mixture in the extruder may be reduced and excessive shearing stress may be generated to reduce plasticity.

Extruded by the extruder, cooled using a cooling water tank, and a pellet-type compatibilizer or biodegradable compound resin composition can be obtained by a rotary knife. The pellet-type compatibilizing agent or biodegradable compound resin composition is preferably dried and used until the final moisture content is less than 500 ppm.

The pellet-shaped biodegradable compound resin composition obtained after extrusion can be formed into a film through blow molding using a circular dice having a gap of 0.5 to 2.5 mm. The BUR may be in the range of 0.8 to 3.0, and may be manufactured at a rate of 10 to 25 m / min to produce a blown film having a thickness of 10 to 50 μm.

Hereinafter, the biodegradable compound resin composition according to the present invention will be described in more detail. It should be understood, however, that the following Preparation Examples and Examples are only illustrative and not restrictive, and that the present invention can be embodied in various forms.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The physical properties of the biodegradable compound resin compositions prepared through the following Production Examples, Examples and Comparative Examples were measured as follows.

How to measure property

1. Glass transition temperature (Tg): Measured at a heating rate of 10 캜 / min using a dynamic mechanical analyzer (DMA).

2. Melt flow index (MI): measured according to ASTM D 1238 at 190 占 폚 at a load of 2.16 kg / cm2.

3. Tensile strength and elongation: Measured by KS M 3001.

4. Tear strength: Measured after machining at 1 mm notch by KS M 3503.

5. Tear Growth Resistance: Measured according to ASTM D 1922.

6. Thermal Melt Strength: Measured by KS M 7132.

Bubble stability evaluation method

When the film is formed, the bubble must be kept in an expanded state and produced without shaking from side to side. At this time, the degree of the bubble size being unsteady or shaking to the left and right was evaluated as follows.

◎: Very stable

○: Slightly to the left and right (less than 2 cm), but stable production

△: The state that can be corrected by using a bubble guide roll while rocking more than 2 cm to the left and right

X: The size is changed while swinging more than 2 cm to the left and right, so that it can not be continuously produced.

In the following Production Examples, Examples and Comparative Examples, polylactic acid (PLA) was a crystalline polylactic acid having a D-lactide content of 1.4% with a weight average molecular weight of 100,000 g / mol and polybutylene adipate- (PBAT) is a polybutylene adipate-terephthalate copolymer having a weight average molecular weight of 40,000 g / mol and a melt flow index (MI) of 3 g / 10 min (190 ° C, 2.16 kg / Coalescence was used.

[Preparation Example 1] Preparation of compatibilizer

100 parts by weight of a resin mixture (B) containing 80% by weight of polylactic acid (PLA) and 20% by weight of polybutylene adipate-terephthalate copolymer (PBAT) in 100% by weight of the whole, (MEA) and 0.5 part by weight of di- (2-t-butylperoxyisopropyl) benzene as an organic peroxide as a viscosity modifier were added to the mixture, followed by the use of a super mixer 1 hour by Respectively.

The mixed compatibilizer was prepared in the form of pellets using a co-axial twin-screw extruder (diameter 48 mm, L / D 40). At this time, the cylinder temperature condition of the extruder was 160-200 ° C., compounding was carried out at a screw rotation speed of 150 rpm at a rate of 50 kg / hr, and a screen mesh was pelletized using a 200 mesh screen. The compatibilizer obtained in the form of pellets was dried in an oven at 80 DEG C for 24 hours to prepare a pellet having a water content of 500 ppm or less. The content of the prepared compatibilizer is shown in Table 1

[Preparation Example 2] Preparation of compatibilizer

100 parts by weight of a resin mixture (B) obtained by mixing 60% by weight of polylactic acid (PLA) and 40% by weight of polybutylene adipate-terephthalate copolymer (PBAT) in 100% by weight of the whole, Except that 0.5 part by weight of di- (2-t-butylperoxyisopropyl) benzene, which is an organic peroxide, was used as a viscosity modifier, . The contents of the prepared compatibilizer are shown in Table 1.

[Example 1] Production of biodegradable compound resin composition

100 parts by weight of a resin mixture (A) comprising 60% by weight of polylactic acid (PLA) and 40% by weight of polybutylene adipate-terephthalate copolymer (PBAT) , 0.3 part by weight of diphenylmethane diisocyanate (MDI) as a diisocyanate, 0.05 part by weight of di- (2-t-butylperoxyisopropyl) benzene as an organic peroxide as a viscosity modifier, 0.2 part by weight of (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane ((3,5-di-t-butyl-4-hydroxyhydrocinnamate) 0.2 part by weight of tris (2,4-di-t-butylphenyl) phosphite, which is an antioxidant, 0.6 part by weight of erucamide as an amide wax, 0.6 part by weight of titanium dioxide (TiO ₂ ) as a pigment was added and mixed for about 1 hour using a super mixer.

The mixture was first introduced into an extruder, and then, on the cylinder side at 1/3 to 2/3 of the cylinder, using tributyl citrate, which is a plasticizer, and inorganic filler particles (CaCO ₃ ) surface-coated with a fatty acid having a size of 1 탆. At this time, the extruder was extrusion-molded using a twin-screw extruder (diameter 48 mm, L / D 40) in the same direction to produce a biodegradable compound resin composition in the form of a pellet. The cylinder temperature condition of the extruder was 160-200 ° C., compounding was carried out at a screw rotation speed of 350 rpm at a rate of 100 kg / hr, and a screen mesh was pelletized using a 200 mesh screen.

The biodegradable compound resin composition in the form of a pellet was dried in an oven at 80 DEG C for 24 hours to prepare a pellet having a water content of 500 ppm or less, The film was prepared in the following manner. The film was formed into a film having a thickness of 35 mu m using a 55 mm single screw extruder (die diameter 100 mm, dies gap 1 mm). At this time, the temperature of the dies was 170 ° C, the burr (BUR) was 2.8, the film production speed was 15 m / min, and the film forming temperature was 150-170 ° C. For thermal bonding of the film, the film was bonded at a temperature of 180 to 220 DEG C at a rate of 45 times / min. The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 2]

All the steps were carried out in the same manner as in Example 1, except that 10 parts by weight of the compatibilizer prepared in Preparation Example 2 was used for 100 parts by weight of the resin mixture (A). The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 3]

All the steps were carried out in the same manner as in Example 1, except that 7 parts by weight of the compatibilizer prepared in Preparation Example 1 was used for 100 parts by weight of the resin mixture (A). The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 4]

All the steps were carried out in the same manner as in Example 1, except that 7 parts by weight of the compatibilizer prepared in Preparation Example 2 was used for 100 parts by weight of the resin mixture (A). The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 5]

All the steps were carried out in the same manner as in Example 1, except that 5 parts by weight of the compatibilizer prepared in Preparation Example 1 was used for 100 parts by weight of the resin mixture (A). The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 6]

All the steps were carried out in the same manner as in Example 1, except that 5 parts by weight of the compatibilizer prepared in Preparation Example 2 was used for 100 parts by weight of the resin mixture (A). The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 7]

To 100 parts by weight of the resin mixture (A), 10 parts by weight of the compatibilizer prepared in Preparation Example 1 and 10 parts by weight of N, N'-dicyclohexylcarbodiimide (hereinafter referred to as " DCC) was used as the initiator in the same manner as in Example 1. The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Example 8]

Except that 7 parts by weight of the compatibilizer prepared in Preparation Example 1 and 5 parts by weight of N, N'-dicyclohexylcarbodiimide (DCC), which is a carbodiimide additive, were used for 100 parts by weight of the resin mixture (A) And all the steps were carried out in the same manner as in Example 1. The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Comparative Example 1]

All processes were carried out in the same manner as in Example 1 except that compatibilizers and carbodiimide additives were not used. The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Comparative Example 2]

Except that no compatibilizing agent is used and 5 parts by weight of N, N'-dicyclohexylcarbodiimide (DCC), which is a carbodiimide additive, is added to 100 parts by weight of the resin mixture (A) Was carried out in the same manner as in Example 1. The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

[Comparative Example 3]

All the steps were carried out in the same manner as in Example 1 except that 7 parts by weight of the compatibilizing agent prepared in Preparation Example 2 was used for 100 parts by weight of the resin mixture (A), and no carbodiimide additive and diisocyanate were used . The content of the prepared biodegradable compound resin composition is shown in Table 2, and the physical properties and bubble stability of the film prepared using the same are shown in Table 3.

Compatibilizer Glass transition temperature (Tg) (占 폚) PLA PBAT MEA abandonment
peroxide PLA PBAT weight% Weight portion Production Example 1 80 20 13 0.5 51 -23 Production Example 2 60 40 10 0.5 55 -27

Table 1 shows the contents of the compatibilizing agent prepared in Production Examples 1 and 2 and the glass transition temperature (Tg) of polylactic acid (PLA) and polybutylene adipate-terephthalate copolymer (PBAT) Tg).

PLA PBAT Compatibilizer Carbodiimide additive Diisocyanate Organic peroxide Inorganic filler Plasticizer Primary antioxidant Secondary antioxidant Amide wax TiO ₂ Production Example 1 Production Example 2 weight% Weight portion Example 1 60 40 10 0 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 2 60 40 0 10 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 3 60 40 7 0 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 4 60 40 0 7 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 5 60 40 5 0 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 6 60 40 0 5 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 7 60 40 10 0 5 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Example 8 60 40 7 0 5 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Comparative Example 1 60 40 0 0 0 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Comparative Example 2 60 40 0 0 5 0.3 0.05 5 6.5 0.2 0.2 0.6 0.6 Comparative Example 3 60 40 0 7 0 0 0.05 5 6.5 0.2 0.2 0.6 0.6

Table 2 shows the contents of the biodegradable compound resin compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3.

Melting
flow
Index (g / 10 min) Bubble stability
(????>?> X) The tensile strength
(kgf / cm2) Elongation
(%) Phosphorus strength
(kgf / cm) Tear Growth Resistance
(N / mm) Heat fusion strength
(N) Length
direction width
direction Length
direction width
direction Length
direction width
direction Length
direction width
direction Example 1 6.8 △ 330 298 383 352 118 95 33 32 10.3 Example 2 7.5 △ 326 300 337 355 118 102 33 30 9.2 Example 3 4.9 △ 357 351 384 364 138 119 38 40 10 Example 4 4.3 ○ 332 363 325 363 140 115 35 42 10.2 Example 5 3.5 ○ 312 339 350 318 118 96 34 38 10.7 Example 6 3 ○ 325 312 353 318 115 113 32 38 10.2 Example 7 1.5 ◎ 444 378 403 372 138 105 43 55 12.3 Example 8 2.3 ◎ 412 351 395 417 140 119 45 50 13 Comparative Example 1 2.7 ○ 321 300 250 290 100 95 27 30 9.2 Comparative Example 2 8.5 × 304 318 332 312 100 97 27 37 10 Comparative Example 3 12 × 321 335 364 303 110 92 30 32 9.8 ≪ Bubble stability evaluation method &
◎: Very stable
○: Slightly to the left and right (less than 2 cm), but stable production
△: The state that can be corrected by using a bubble guide roll while rocking more than 2 cm to the left and right
X: The size is changed while swinging more than 2 cm to the left and right, so that it can not be continuously produced.

Table 3 shows the physical properties and bubble stability of the films prepared using the biodegradable compound resin compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3. As shown in Table 3, Examples 7 to 8 including both the compatibilizing agent, the carbodiimide additive and the diisocyanate had a low melt flow index, and the bubble stability was not only very stable, but also tensile strength, elongation, The tear strength, the tear strength, the tear strength, the tear strength, and the thermal bonding strength. Further, in Example 7, 3 parts by weight of a compatibilizing agent was further contained than in Example 8, indicating that it exhibited more excellent physical properties.

In addition, in Comparative Example 1, both the compatibilizer and the carbodiimide additive are not included, and the elongation percentage is the lowest. Comparative Example 2 does not include a compatibilizing agent, but a carbodiimide-based additive is included and the elongation percentage is higher than Comparative Example 1, but it can not be continuously produced because the bubble stability is poor. In Comparative Example 3, the compatibilizer was included, but it was confirmed that the carbodiimide-based additive and the diisocyanate were not included, and the bubble stability was poor as in Comparative Example 2, so that the continuous production was not possible.

Therefore, it is possible to produce the biodegradable compound resin composition containing the compatibilizing agent, the carbodiimide type additive and the diisocyanate according to the present invention stably without bending in the expanded state of the bubble when the film is formed, It is possible to shorten the processing time due to the low flow index, and it can be confirmed that the produced film has excellent mechanical properties by improving tensile strength, elongation, tear strength, tear growth resistance and heat bonding strength.

Claims (13)

A resin mixture (A) comprising a polylactic acid and a polybutylene adipate-terephthalate copolymer, a compatibilizer, a carbodiimide additive and a diisocyanate,
Wherein the compatibilizer is a blend in which the resin mixture (B) of polylactic acid and polybutylene adipate-terephthalate copolymer is chain-exchanged with amino alcohol. The method according to claim 1,
Wherein the resin mixture (A) and the resin mixture (B) comprise 50 to 90 wt% of polylactic acid and 10 to 50 wt% of polybutylene adipate-terephthalate copolymer. The method according to claim 1,
And 2 to 15 parts by weight of a compatibilizer based on 100 parts by weight of the resin mixture (A). The method according to claim 1,
Wherein the compatibilizer comprises 5 to 15 parts by weight of an amino alcohol based on 100 parts by weight of the resin mixture (B). The method according to claim 1,
Wherein the compatibilizer further comprises 0.1 to 2.5 parts by weight of a viscosity modifier based on 100 parts by weight of the resin mixture (B). The method according to claim 1,
Wherein the amino alcohol comprises any one or two or more selected from C ₁ to C ₈ amino alcohols. delete The method according to claim 1,
0.5 to 10 parts by weight of a carbodiimide additive and 0.1 to 2.5 parts by weight of a diisocyanate are added to 100 parts by weight of the resin mixture (A). The method according to claim 1,
Wherein the carbodiimide-based additive comprises any one or two or more selected from the group consisting of an aliphatic carbodiimide type, an alicyclic carbodiimide type, and an aromatic carbodiimide type. The method according to claim 1,
Wherein the diisocyanate comprises any one or two or more selected from aliphatic diisocyanate and aromatic diisocyanate. The method according to claim 1,
Wherein the biodegradable compound resin composition further comprises any one or two or more additives selected from a plasticizer, a viscosity modifier, an inorganic filler, an antioxidant, an amide wax and a pigment. 12. The method of claim 11,
5 to 20 parts by weight of a plasticizer, 0.1 to 2.5 parts by weight of a viscosity modifier, 1 to 30 parts by weight of an inorganic filler, 0.1 to 0.5 parts by weight of an antioxidant, 0.1 to 1 part by weight of an amide wax And 0.1 to 1 part by weight of a pigment. A film using the biodegradable compound resin composition according to any one of claims 1 to 6 and 8 to 12.