KR102103524B1 - Polylactic acid-polyamide alloy resin composition - Google Patents

Abstract

The present invention is a polylactic acid-polyamide alloy resin composition comprising 30 to 90 parts by weight of a polylactic acid resin and 10 to 70 parts by weight of a polyamide resin, wherein the polylactic acid resin is a hard segment comprising a repeating unit of polylactic acid, and polyolefin Polylactic acid-poly, wherein the polyol-based structural units include a soft segment comprising a polyolefin-based polyol repeating unit connected in a linear or branched form via a urethane bond or an ester bond, and the organic carbon content of biomass origin is 60% or more. Regarding an amide alloy resin composition, the polylactic acid-polyamide alloy resin composition according to the present invention not only exhibits improved impact resistance, but also has excellent physical properties such as heat resistance, moisture resistance, mechanical properties, and injection processability, thereby forming a molded article material. As it can be usefully used, it has eco-friendly properties It can greatly contribute to the prevention of environmental pollution.

Description

Polylactic acid-polyamide alloy resin composition {POLYLACTIC ACID-POLYAMIDE ALLOY RESIN COMPOSITION}

The present invention relates to a polylactic acid-polyamide resin composition, and more specifically, not only exhibits improved impact strength, but also has excellent physical properties such as heat resistance, moisture resistance, mechanical properties, and injection processability, and is usefully used as a molded article material. May, and relates to an alloy resin composition comprising a polylactic acid resin and a polyamide resin having environmentally friendly properties.

Crude oil-based resins such as polyethylene terephthalate, nylon, polyolefin, or soft polyvinyl chloride (PVC) are still widely used as materials for various purposes such as packaging materials. However, these crude oil-based resins do not have biodegradability, and thus have a problem of causing environmental pollution, such as discharging large amounts of carbon dioxide, which is a global warming gas, upon disposal. In addition, as oil resources are gradually depleted, the use of biomass-based resins, typically polylactic acid resins, has been widely studied in recent years.

However, since these polylactic acid resins do not have sufficient heat resistance, moisture resistance, and mechanical properties as compared to crude oil-based resins, it is true that there are limits to the fields or applications to which they can be applied. In particular, attempts have been made to apply a polylactic acid resin as a packaging material such as a packaging film, but due to the low flexibility of the polylactic acid resin, these applications are facing limitations.

To overcome the limitations of the polylactic acid resin, a composition in the form of an alloy of a polylactic acid resin and other general-purpose resins and / or engineering plastics is used. However, even if a molded article including a polylactic acid resin is obtained using the alloy-type composition, it is true that in most cases, there is a limit in improving heat resistance and mechanical properties due to compatibility problems between the two resins.

In addition, in order to solve the above problems, a method of introducing a polyamide resin into a polylactic acid resin and introducing a clay and an impact modifier has been proposed (Republic of Korea Patent Publication No. 2009-0073847). However, these polylactic acid-polyamide alloy resin compositions and products have limitations in overcoming the low compatibility of polylactic acid resins and polyamide resins, so the effect of improving physical properties is not sufficient, and thus, application as an interior material for automobiles requiring high durability Have difficulties. In addition, the polylactic acid-based resin composition is poor in meltability due to lack of compatibility, resulting in poor extrusion, poor injection molding, poor product appearance, and insufficient mechanical properties, heat resistance, and impact resistance.

In addition, polylactic acid resins are generally very vulnerable to moisture resistance, which is mainly due to the hydrolysis reaction by moisture contained in the resin, and as a result, part of the polymer is decomposed into lactic acid, monomers or oligomers, and Deterioration occurs.

Moreover, the produced lactic acid, monomers and oligomers volatilize during the molding process of the resin, causing contamination and corrosion of mechanical devices, and also causing quality problems of the molded product. Specifically, in the case of sheet production by extrusion molding, the residual lactic acid, monomers and oligomers in the resin volatilize during sheet extrusion to generate a thickness variation of the produced sheet. Hydrolysis may occur and deterioration of mechanical properties may occur. In addition, because of the nature of the polylactic acid resin, water absorption is very easy, and thus water absorption increases in a pellet state when working in a water bath for cooling after passing through the extruder or when storing these compounding products. When the molded product is injected using the resin, moisture may cause problems such as appearance defects or deterioration in properties such as silver streak due to moisture in the resin.

Accordingly, there is a continuing need to develop a polylactic acid resin exhibiting improved impact resistance, excellent moisture resistance, and excellent physical properties such as mechanical properties, heat resistance, or bleed-out properties.

The present invention not only exhibits improved impact resistance, but also has excellent physical properties such as moisture resistance, mechanical properties, transparency, heat resistance, blocking resistance, and molding processability, and can be usefully used as plastic molding materials, and has environmentally friendly poly It is to provide a lactic acid-polyamide alloy resin composition.

According to the above object, the present invention

A polylactic acid-polyamide alloy resin composition comprising 30 to 90 parts by weight of polylactic acid resin and 10 to 70 parts by weight of polyamide resin,

The polylactic acid resin is a hard segment comprising a polylactic acid repeating unit represented by the following Chemical Formula 1, and a polyolefin-based polyol repeated in which the polyolefin-based polyol structural units represented by the following Chemical Formula 2 are linearly or branchedly connected via a urethane bond or an ester bond. Includes a soft segment containing units,

Provided is a polylactic acid-polyamide alloy resin composition having an organic carbon content (% C _bio ) of biomass origin of 60% or more as defined by Equation 1 below:

[Formula 1]

[Formula 2]

[Equation 1]

% C = _bio ⁽¹⁴ C isotope ratio by weight of the ¹² C isotope of the biomass origin standard carbon atoms) (poly (lactic acid) ¹⁴ C isotope ratio by weight of the ¹² C isotope of carbon atoms of the resin) / 100 ×

In Chemical Formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is an integer from 5 to 200.

The polylactic acid-polyamide alloy resin composition according to the present invention not only exhibits improved impact resistance, but also has excellent physical properties such as heat resistance, moisture resistance, mechanical properties, and injection processability, and can be usefully used as molded article materials, and is environmentally friendly. Since it has characteristics, it can greatly contribute to the prevention of environmental pollution.

1 to 3 is an electron microscope (SEM) photograph of the pellets prepared in Examples 1 to 3.
4 is an electron microscope (SEM) photograph of the pellets prepared in Comparative Example 4.

Hereinafter, a polylactic acid-polyamide alloy resin composition according to a specific embodiment of the present invention will be described.

The polylactic acid-polyamide alloy resin composition according to the present invention includes 30 to 90 parts by weight of polylactic acid resin and 10 to 70 parts by weight of polyamide resin,

The polylactic acid resin is a hard segment comprising a polylactic acid repeating unit represented by the following Chemical Formula 1, and a polyolefin-based polyol repeated in which the polyolefin-based polyol structural units represented by the following Chemical Formula 2 are linearly or branchedly connected via a urethane bond or an ester bond. Includes a soft segment containing units,

The organic carbon content (% C _bio ) of biomass origin as defined by the following Equation 1 is 60% or more:

[Formula 1]

[Formula 2]

[Equation 1]

% C = _bio ⁽¹⁴ C isotope ratio by weight of the ¹² C isotope of the biomass origin standard carbon atoms) (poly (lactic acid) ¹⁴ C isotope ratio by weight of the ¹² C isotope of carbon atoms of the resin) / 100 ×

In Chemical Formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is an integer from 5 to 200.

(1) Polylactic acid resin

The polylactic acid resin included in the polylactic acid-polyamide alloy resin composition according to the present invention basically includes a polylactic acid repeating unit represented by Chemical Formula 1 as a hard segment. In addition, the polylactic acid resin includes a polyolefin-based polyol repeating unit as a soft segment. In the polyolefin-based polyol repeating unit, the polyolefin-based polyol structural units represented by Formula 2 are urethane bonds (-C (= O) -NH-). ) Or ester bonds (-C (= O) -O-) through a linear or branched structure.

These polylactic acid resins can exhibit biodegradability and eco-friendly characteristics peculiar to biomass-based resins by basically including a polylactic acid repeating unit as a hard segment. In addition, as a result of the experiments of the present inventors, as the polyolefin-based polyol repeating unit is included as a soft segment, it is possible to manufacture a molded article exhibiting not only excellent flexibility but also excellent transparency and low haze value using the polylactic acid resin. It turned out. In particular, as the soft segment is introduced into the polylactic acid resin itself in a form combined with the hard segment, there is less possibility that the soft segment for improving flexibility bleeds out or exhibits low stability, and molded products containing the polylactic acid resin, etc. It was also confirmed that the risk of increased haze or reduced transparency was reduced. In addition, the polylactic acid resin may exhibit the above-described effect without increasing the content of the soft segment for improving flexibility, and thus, a relatively high content of biomass-based resin, such as a hard segment derived from a polylactic acid resin, It can contain.

On the other hand, since the polylactic acid resin contains a non-polar soft segment, it has excellent moisture resistance compared to an ordinary polylactic acid resin.

The polylactic acid resin included in the polylactic acid-polyamide alloy resin composition has an organic carbon content (% C _bio ) of biomass origin as defined by Equation 1 above about 60%, about 70%, about 80 % Or more, about 85% or more, about 90% or more, or about 95% or more.

Compared to the polylactic acid resin included in the polylactic acid-polyamide alloy resin composition of the present invention, when a polyester-based repeating unit other than a polyolefin-based polyol repeating unit is included as a soft segment, in order to achieve excellent flexibility Since it is necessary to introduce another resin such as a polyester-based polyol repeating unit of higher fossil fuel origin, it may be difficult to achieve the organic carbon content (% C _bio ) of about 60% described above.

The method for measuring the organic carbon content (% C _bio ) of biomass origin by Equation 1 may be, for example, according to the method described in ASTM D6866 standard. More specifically about the technical meaning and measurement method of the organic carbon content (% C _bio ) is as follows.

In general, unlike organic materials such as resins derived from fossil raw materials, organic materials such as resins derived from biomass (biological resources) are known to contain the isotope ^14C . More specifically, all organic materials taken from living organisms such as animals or plants are ¹² C (about 98.892 wt%), ¹³ C (about 1.108 wt%) and ¹⁴ C (about 1.2 x 10 ^-10 wt%) as carbon atoms. It contains three isotopes of, and the proportion of each isotope is also known to be kept constant. This is the same as the ratio of each isotope in the atmosphere, so that the isotope ratio remains constant because living organisms continue to exchange carbon atoms with the external environment while continuing to metabolize.

Meanwhile, ¹⁴ C is a radioactive isotope, and its content may decrease over time ( t ) according to Equation 2 below.

[Equation 2]

In Equation 2, the no represents the initial number of atoms of the ¹⁴ C isotope, the n represents the number of atoms of the ¹⁴ C isotope remaining after t time, and the a decay constant associated with the half life (or radioactive constant) ).

In Equation 2, the half-life of the ¹⁴ C isotope is about 5,730 years. Considering these half-life, the environment and continuously to each other organic material such as a resin derived from the organic material, i.e. biomass (biological resources), taken from a living organism acting despite fine content reduction of the isotope, and a substantially constant ¹⁴ It is possible to maintain a constant content ratio (weight ratio) of a C isotope content and a constant content ratio with other isotopes, such as ¹⁴ C / ¹² C = about 1.2 × 10 ^-12 .

In contrast, fossil fuels such as coal or petroleum have been blocked from exchanging carbon atoms with the external environment for over 50,000 years. Accordingly, organic materials such as resins derived from fossil raw materials include ¹⁴ C isotopes as 0.2% or less of the initial content (number of atoms) when estimated according to Equation 2 above, and substantially include ¹⁴ C isotopes. I never do that.

Equation 1 is considering the above points, the denominator may be a weight ratio of the isotope ¹⁴ C / ¹² C derived from biomass, for example, about 1.2 × 10 ⁻¹² , and the molecule is ¹⁴ C included in the resin to be measured. / ¹² C may be a weight ratio. As described above, the carbon atom derived from biomass maintains an isotope weight ratio of about 1.2 × 10 ⁻¹² , whereas the carbon atom derived from fossil fuels has a substantially zero isotope weight ratio. In the polylactic acid resin included in the polylactic acid-polyamide alloy resin composition, the organic carbon content (% C _bio ) of biomass origin among all carbon atoms can be measured by Equation 1 above. At this time, the content of each carbon isotope and their content ratio (weight ratio) are described in the ASTM D6866-06 standard (a standard test method for determining the biobased content of natural substances using radiometric carbon and isotope ratio mass spectrometry analysis). It can be measured according to one of the three methods. Suitably, the carbon atom contained in the resin to be measured may be formed in the form of graphite or carbon dioxide gas and measured by a mass spectrometer or according to liquid scintillation spectroscopy. At this time, the two isotopes can be separated using an accelerator for separating ¹⁴ C ions from ¹² C ions together with the mass spectrometer, and the content and content ratio of each isotope can be measured with a mass spectrometer. Optionally, the content and content ratio of each isotope may be obtained by using liquid scintillation spectroscopy, which is apparent to those skilled in the art, through which measurement values of Equation 1 may be derived.

When the organic carbon content (% C _bio ) of Equation 1 derived as described above is about 60% or more, the polylactic acid resin and the polylactic acid-polyamide alloy resin composition containing the same are derived from a higher content of biomass. It contains resin and carbon, and can exhibit unique eco-friendly properties and biodegradability.

More specifically, the polylactic acid resin that satisfies such high organic carbon content (% C _bio ) and the polylactic acid-polyamide alloy resin composition comprising the same may exhibit eco-friendly characteristics described below.

Biochemical products, such as polylactic acid resins, are biodegradable, have less carbon dioxide emissions, and can reduce carbon dioxide emissions by up to 108% compared to petrochemical products at the current technology level, and reduce energy for resin production by up to 50%. can do. In addition, if bio-plastics are produced using biomass raw materials, carbon dioxide emissions calculated by ISO 14000 compliant life cycle analysis (LCA) compared to fossil raw material use may be reduced by up to 70%.

As a specific example, according to NatureWorks, when PET resin is manufactured, 3.4 kg of carbon dioxide is emitted per kg, whereas polylactic acid resin, which is a kind of bioplastic, generates only 0.77 kg of carbon dioxide per kg. It can achieve carbon dioxide reduction effect, and it is known that the energy consumption is only 56% compared to PET. However, previously known polylactic acid resins have limitations in application due to low flexibility and the like, and when other components such as plasticizers are included in order to solve them, there is a problem in that the advantages as bioplastics described above are greatly reduced.

However, the polylactic acid resin and the polylactic acid-polyamide alloy resin composition comprising the polylactic acid resin may satisfy the above-described high organic carbon content (% C _bio ), while sufficiently utilizing the advantages as a bioplastic, It can be applied to more various fields by solving problems such as low flexibility.

Accordingly, the polylactic acid resin that satisfies the high organic carbon content (% C _bio ) described above and the polylactic acid-polyamide alloy resin composition containing the same have eco-friendly properties that significantly reduce the amount of carbon dioxide generated and energy consumption by utilizing the advantages as bioplastics. Can be represented. Such eco-friendly characteristics can be measured, for example, through a life cycle assessment of a polylactic acid-polyamide alloy resin composition.

In the polylactic acid-polyamide alloy resin composition, the polylactic acid resin has a content of ¹⁴ C isotopes in carbon atoms of about 7.2 × 10 ^-11 to 1.2 × 10 ^-10 % by weight, and about 9.6 × 10 ^-11 to 1.2 X 10 ^-10 wt%, or about 1.08 x 10 ^-10 to 1.2 x 10 ^-10 wt%. In the polylactic acid resin having a content of the ¹⁴ C isotope, more resin and carbon, or substantially all of the resin and carbon may be derived from biomass, and may exhibit superior biodegradability and eco-friendly characteristics.

In the polylactic acid resin, not only is the polylactic acid repeating unit of the hard segment derived from biomass, but the polyolefin-based polyol constituent unit of the soft segment may also be derived from biomass. Such a polyolefin-based polyol structural unit can be obtained, for example, from a polyolefin-based polyol resin derived from biomass. The biomass can be any plant or animal resource, such as corn, sugarcane, or plant resources such as tapioca. As described above, a polylactic acid resin comprising a polyolefin-based polyol structural unit derived from biomass and a polylactic acid-polyamide alloy resin composition comprising the same have a higher organic carbon content (% C _bio ), such as about 90% or more, Or it may represent an organic carbon content of about 95% or more (% C _bio ).

In this case, in the polylactic acid resin, the hard segment derived from biomass has an organic carbon content (% C _bio ) of biomass origin as defined by Equation 1 above, about 90% or more, preferably about 95% to 100 %, And the soft segment derived from the biomass may have an organic carbon content (% C _bio ) of biomass origin as defined by Equation 1 above about 70% or more, preferably about 75% to 95% have.

Since the polylactic acid resin contained in the polylactic acid-polyamide alloy resin composition has a high organic carbon content (% C _bio ) of biomass origin of about 60% or more, or about 80% or more, it is based on standard ASTM D6866. The criteria for obtaining the "Biomass Pla" certification of JBPA, a certifier, can be met. Thus, the polylactic acid resin can legitimately attach JORA's "Biomass-based" label.

In the polylactic acid resin, the polylactic acid repeating unit of Formula 1 included in the hard segment may refer to a polylactic acid homopolymer or a repeating unit constituting the same. Such a polylactic acid repeating unit can be obtained according to a method for preparing a polylactic acid homopolymer well known to those skilled in the art. For example, a method for producing L-lactide or D-lactide which is a cyclic 2 monomer from L-lactic acid or D-lactic acid and obtaining it by ring-opening polymerization, or by direct dehydration condensation polymerization of L-lactic acid or D-lactic acid It is possible to obtain a polylactic acid repeating unit having a higher degree of polymerization through a ring-opening polymerization method. In addition, the polylactic acid repeating unit may be prepared to copolymerize L-lactide and D-lactide at a certain ratio to exhibit an amorphous property, in order to further improve the heat resistance of a molded article containing the polylactic acid resin, the It is preferable to prepare by a single polymerization method using either L-lactide or D-lactide. More specifically, the polylactic acid repeating unit can be obtained by ring-opening polymerization using an L-lactide or D-lactide raw material having an optical purity of 98% or more, and if the optical purity is less than this, the melting temperature (Tm) of the polylactic acid resin Can be lowered.

Meanwhile, in the polyolefin-based polyol repeating unit included in the soft segment of the polylactic acid resin, the polyolefin-based polyol structural units of Formula 2 are urethane bonds (-C (= O) -NH-) or ester bonds (-C (= O ) -O-) may have a structure connected in a linear or branched form, and specifically, the polyolefin-based polyol structural unit is a polymer obtained by radical polymerization of a monomer such as butadiene (poly 1,2-butadiene or poly 1,3-butadiene) or a structural unit constituting the same, which imparts a hydroxy group to its ends, and refers to a liquid polybutadiene (HTPB) having a molecular weight of 1,000 to 5,000 obtained through a hydrogenation reaction.

At this time, the urethane bond may be formed by reaction of a prepolymer obtained by addition polymerization of lactide to a hydroxyl group at the terminal of the polyolefin-based polyol constituent unit or a hydroxyl group at the terminal of the polyolefin-based polyol constituent unit, and an isocyanate compound having two or more isocyanate groups. On the other hand, when the hydroxyl group at the end of the polyolefin-based polyol structural unit reacts with the lactide or lactic acid derivative compound, an ester bond (-C (= O) -O-) may be formed. The polyolefin-based polyol constituent units may be linearly or branched to each other through the urethane bond or the ester bond to form the polyolefin-based polyol repeating unit.

The reaction molar ratio of the hydroxy group at the terminal of the polyolefin-based polyol structural unit and the isocyanate group of the isocyanate compound having two or more isocyanate groups may be 1: 0.50 to 1: 0.99. Preferably, the reaction molar ratio of the terminal hydroxy group of the polyolefin-based polyol structural unit to the isocyanate group of the isocyanate compound may be about 1: 0.60 to about 1: 0.95, more preferably about 1: 0.70 to about 1: 0.90.

The polymer formed by the polyolefin-based polyol structural units being linearly connected via a urethane bond or a repeating unit constituting the same may be referred to as a polyurethane polyol repeating unit, and may have a hydroxyl group at its terminal. Accordingly, the polyolefin-based polyol repeating unit may act as an initiator in a polymerization process for forming a polylactic acid repeating unit. However, if the reaction molar ratio of the hydroxy group: isocyanate group exceeds 0.99 and becomes too high, the number of terminal hydroxyl groups of the polyurethane polyol repeating unit becomes insufficient (OHV <1), and may not function properly as an initiator. In addition, when the reaction molar ratio of the hydroxy group: isocyanate group is too low, the number of terminal hydroxy groups in the polyolefin-based polyol repeating unit becomes too large (OHV> 35), making it difficult to obtain a high molecular weight polylactic acid repeating unit and a polylactic acid resin.

The polyolefin-based polyol repeating unit may have a number average molecular weight of about 1,000 to 100,000, preferably about 10,000 to 50,000. If the molecular weight of the polyolefin-based polyol repeating unit is too large or small, the flexibility, moisture resistance, mechanical properties, etc. of the molded article obtained from the polylactic acid resin and the polylactic acid-polyamide alloy resin composition containing the polylactic acid resin will not be sufficient. You can. In addition, since the polylactic acid resin may be difficult to meet appropriate molecular weight properties, etc., the processability of the polylactic acid-polyamide alloy resin composition may be deteriorated, or the flexibility, moisture resistance, or mechanical properties of the molded article may be deteriorated.

The isocyanate compound capable of forming a urethane bond by combining with the terminal hydroxy group of the polyolefin-based polyol repeating unit may be a diisocyanate compound or any isocyanate compound having three or more isocyanate groups in a molecule, and may be derived from fossil fuels.

Examples of the diisocyanate compound include 1,6-hexamethylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1 , 5-naphthalene diisocyanate, m-phenylenediisocyanate, p-phenylenediisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-bisphenylene diisocyanate, hexamethylene diisocyanate Isocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like, and the isocyanate compounds having three or more isocyanate groups include oligomers of the diisocyanate compounds, polymers of the diisocyanate compounds, and rings of the diisocyanate compounds. Type multimer, hexamethylene diisocyanate isocyanurate and isocyanate compounds selected from the group consisting of cyanate isocyanurates, triisocyanate compounds, and isomers thereof. In addition, various diisocyanate compounds well known to those skilled in the art can be used without particular limitation. However, 1,6-hexamethylene diisocyanate is preferable from the viewpoint of providing flexibility to the polylactic acid resin film.

On the other hand, the polylactic acid resin, the block copolymer in which the terminal carboxyl group of the polylactic acid repeating unit included in the hard segment is connected by an ester bond with the terminal hydroxy group of the polyolefin-based polyol constituent unit included in the soft segment, or the block copolymer It may include a block copolymer connected linearly or branched via a urethane bond.

Specifically, in such a block copolymer, the terminal carboxy group of the polylactic acid repeating unit may form an ester bond with the terminal hydroxy group of the polyolefin-based polyol repeating unit. For example, the chemical structure of this block copolymer can be represented by the following general formula (1):

[Formula 1]

Polylactic acid repeating unit (L)-(E) -polyolefin-based polyol repeating unit (O-U-O-U-O)-(E) -polylactic acid repeating unit (L)

[Formula 2]

Polylactic acid repeating unit (L)-(E) -polyolefin-based polyol structural unit (O)-(E) -polylactic acid repeating unit (L)-(U) -polylactic acid repeating unit (L)-(E) -polyolefin System Polyol Constituent Unit (O)-(E) -Polylactic Repeat Unit (L)

In the general formulas 1 and 2, O represents a polyolefin-based polyol structural unit, U represents a urethane bond, and E represents an ester bond.

As the polylactic acid repeating unit and the polyolefin-based polyol structural unit or repeating unit include a block copolymer, the polyolefin-based polyol structural unit or repeating unit for imparting flexibility can be prevented from being bleeded out. A polylactic acid resin molded article comprising a polylactic acid resin may have various properties such as excellent moisture resistance, transparency, mechanical properties, heat resistance, or blocking resistance. In addition, as at least a portion of the polylactic acid structural unit or repeating unit and polyolefin-based polyol repeating unit have a block copolymer form, molecular weight distribution, glass transition temperature (Tg) and melting temperature (Tm) of the polylactic acid resin, etc. This optimization can further improve the mechanical properties, flexibility and heat resistance of the molded article.

However, all of the polylactic acid repeating units included in the polylactic acid resin need not be in the form of a block copolymer combined with the polyolefin-based polyol structural unit or repeating unit, and at least some of the polylactic acid repeating units are polyolefin-based. It may also be in the form of a polylactic acid homopolymer that is not bound to a polyol structural unit or repeat unit. In this case, the polylactic acid resin is a block copolymer in which the terminal carboxyl group of the polylactic acid repeating unit included in the hard segment is connected to the terminal hydroxy group and ester bond of the polyolefin-based polyol constituent unit included in the soft segment, or the block copolymer It may be in the form of a mixture further comprising a polylactic acid repeating unit, i.e., a polylactic acid homopolymer, which is not bound to the polyolefin-based polyol repeating unit to a block copolymer connected linearly or branched via a urethane bond.

On the other hand, the polylactic acid resin is based on the total 100 parts by weight (the weight of the above-mentioned block copolymer, and optionally, if the polylactic acid homopolymer is included, 100 parts by weight of the total weight of such a single polymer), Hard segment about 65 to 95 parts by weight, about 80 to 95 parts by weight, or about 82 to 92 parts by weight, soft segment about 5 to 35 parts by weight, about 5 to 20 parts by weight, or about 8 to 18 parts by weight You can.

When the content of the soft segment is excessively high, it may be difficult to provide a high molecular weight polylactic acid resin, and as a result, mechanical properties such as strength of a molded article including the same may be deteriorated. In addition, when the glass transition temperature is low, slipping, handling, or shape retention characteristics may be deteriorated during packaging using a molded article. Conversely, when the content of the soft segment is too low, there is a limit in improving the flexibility and moisture resistance of the polylactic acid resin and the polylactic acid molded product. In particular, the glass transition temperature of the polylactic acid resin may be excessively high, so that the flexibility of the molded product may be deteriorated, and the polyolefin-based polyol structural unit or repeating unit of the soft segment may not properly function as an initiator, resulting in poor polymerization conversion rate or high molecular weight polylactic acid Resin may not be manufactured properly.

The polylactic acid resin in the aforementioned polylactic acid-polyamide alloy resin composition may have a number average molecular weight of about 50,000 to 200,000, preferably a number average molecular weight of about 50,000 to 150,000. In addition, the polylactic acid resin may have a weight average molecular weight of about 100,000 to 400,000, preferably a weight average molecular weight of about 100,000 to 320,000. These molecular weights may affect the processability of the polylactic acid-polyamide alloy resin composition described above, mechanical properties of molded articles, and the like. When the molecular weight is too small, when melt-processed by a method such as extrusion, the melt viscosity is too low, so that workability to a molded article may be deteriorated, and mechanical properties such as strength may be deteriorated even when processing to a molded article is possible. Conversely, when the molecular weight is too large, the melt viscosity during melt processing is too high, and thus productivity and processability to a molded product may be greatly reduced.

In addition, the polylactic acid resin may have a molecular weight distribution (Mw / Mn) defined as a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of about 1.60 to 3.0, preferably about 1.80 to 2.15. As the polylactic acid resin exhibits such a narrow molecular weight distribution, it exhibits proper melt viscosity and melt properties when melt-processed by a method such as extrusion, and can exhibit excellent molded product extrusion state and processability, and includes the polylactic acid resin. The molded article to be exhibited can exhibit mechanical properties such as excellent strength. On the other hand, if the molecular weight distribution is too narrow, the melt viscosity at the processing temperature for extrusion or the like is too large, and processing as a molded product may be difficult. Conversely, when the molecular weight distribution is too wide, mechanical properties such as strength of the molded product may be reduced or Molding itself may be difficult due to poor melt characteristics such as too low a melt viscosity, or the molding extrusion may be poor.

In addition, the polylactic acid resin may have a melting temperature (Tm) of about 145 to 178 ° C, about 160 to 178 ° C, or about 165 to 175 ° C. If the melting temperature is too low, the heat resistance of the molded article containing the polylactic acid resin may be lowered, and if it is too high, high temperature is required during melt processing by extrusion or the like, or the viscosity is too high, thereby deteriorating the processing characteristics of the molded article. You can.

And, the polylactic acid resin, for example, the block copolymer contained therein has a glass transition temperature (Tg) of about 20 to 55 ° C, or about 25 to 55 ° C, or about 30 to 55 ° C. As such a polylactic acid resin exhibits such a glass transition temperature range, the flexibility or stiffness of the molded article containing the polylactic acid-polyamide alloy resin composition is properly maintained and can be preferably used as a molded article. If, when the glass transition temperature of the polylactic acid resin is too low, the flexibility of the molded article may be improved, but as the strength is too low, slipping, handling, shape retention properties, or anti-blocking properties during assembly processing using the molded article The property and the like may become poor, and therefore, application to a molded product may be unsuitable. Conversely, if the glass transition temperature is too high, the flexibility of the molded article is low and the strength is too high, and thus, when assembling the molded article, adhesion to a target product may be poor.

On the other hand, the polylactic acid-polyamide alloy resin composition, based on the weight of the polylactic acid resin contained therein, less than about 1% by weight of monomer (eg, lactide monomer used for the production of polylactic acid repeating units) May remain, and more preferably, about 0.01 to 0.5% by weight of monomer may remain. The polylactic acid-polyamide alloy resin composition includes a block copolymer having specific structural properties and a polylactic acid resin containing the same, and an antioxidant, and thus, most of the lactide monomers used during the manufacturing process participate in polymerization. It forms a polylactic acid repeating unit, and depolymerization or decomposition of the polylactic acid resin also does not occur substantially. For this reason, the polylactic acid-polyamide alloy resin composition may include a minimum amount of residual monomer, such as residual lactide monomer.

If the residual monomer content is about 1% by weight or more, an odor problem occurs during molding using the polylactic acid-polyamide alloy resin composition, and the strength of the final molded product decreases due to a decrease in the molecular weight of the polylactic acid resin according to the molding process. In particular, when applied to food packaging, residual monomers may be bleed-out, causing stability problems.

(2) Polyamide resin

The polyamide resin contained in the polylactic acid-polyamide alloy resin composition according to the present invention is used for reinforcing the physical properties of the polylactic acid resin, and maximizes physical properties such as impact strength, stiffness, durability and heat resistance of the polylactic acid resin In order to do so, it may be a high stiffness polymer based on a polyamide resin.

The polyamide resin is PA 6, PA 66, PA 11, PA 46, PA 12, PA 1012, PA 610, PA 69, PA 6T, PA 6I, PA 10T, PA 12I, polyphthalamide (PPA), or PA MXD 6 (Poly-m-xylene-adipamide) is a homo- or copolyamide selected from the group comprising copolymers or mixtures thereof based on the monomers used in (Poly-m-xylene-adipamide).

Specific examples of the polyamide resin include polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene nonanediamide (nylon 69), poly Hexamethylene sebacamide (nylon610), polycaproamide / polyhexamethyleneadipamide copolymer (nylon 6/66), polyhexamethylenedodecanediamide, polyhexamethylenedodecaramide (nylon612), polyunde Canoamide (nylon 11), polydodecaamide (nylon 12), polyhexamethylene isophthalamide (nylon 61), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), Polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polybis (4-aminocyclohexyl) methanedodecamide (nylon PACM12), polyundecamethylene terephthalamide ( Nylon may be 11T), poly undeca-methylene-hexahydro-terephthalamide (nylon 11T (H)), mixtures thereof or copolymers (where, I is an isophthalic acid, T means terephthalic acid). These compounds may be used alone or as a mixture or copolymer of two or more. More preferably, the polyamide resin may be selected from the group consisting of PA 6, PA 610, PA 1010, PA 1012, mixtures and copolymers thereof using monomers derived from biomass, and most preferably PA 1010 can be used.

The polyamide resin preferably has a viscosity number (ISO 307) of 120 to 220, and more preferably 120 to 160. When the viscosity (ISO 307) is within the above range, the melt viscosity of the polyamide resin is low, so it can be effectively melt-mixed with the polylactic acid resin, and is excellent in balance in formability, heat resistance, and mechanical properties.

This polyamide resin becomes a matrix resin of a composite material together with a polylactic acid resin, and the content of the polyamide resin may be 10 to 70% by weight based on the total weight of the polylactic acid-polyamide alloy resin composition, and is preferable. It may be 30 to 60% by weight, it can exhibit excellent compatibility with the polylactic acid resin within the above range, heat resistance, appearance characteristics and impact strength.

The polylactic acid-polyamide alloy resin composition may further include an impact modifier.

The impact modifiers include polyether polyol-polyamide copolymer impact modifiers, acrylic impact modifiers, methyl methacrylate-butadiene-styrene (MBS) based impact modifiers, styrene-ethylene-butadiene-styrene (SEBS) based impact modifiers, silicone based And at least one selected from the group consisting of impact modifiers and polyester-based elastomeric impact modifiers, preferably a polyamide copolymer impact modifier, and more preferably a polyetherpolyol-polyamide copolymer. You can.

The polyether polyol-polyamide impact modifier is excellent in compatibility with polyamide and expressed impact resistance, and is economical. In particular, the polyether polyol-polyamide copolymer has excellent elasticity, flexibility and impact resistance, and the polyether. It is preferable that the polyol-polyamide copolymer is prepared using a biomass raw material.

In the polylactic acid resin of the polylactic acid-polyamide alloy resin composition of the present invention, a polyolefin-based polyol component is introduced into the polylactic acid resin polymer structure, and thus, a polyether polyol-polyamide impact modifier, an acrylic impact modifier, and methyl methacrylate- Since it exhibits excellent compatibility with butadiene-styrene (MBS) -based impact modifiers, styrene-ethylene-butadiene-styrene (SEBS) impact modifiers, silicone-based impact modifiers, and polyester-based elastomeric impact modifiers, any specific impact modifier is used. Is not limited to

The impact modifier may be included in an amount of 20 parts by weight or less, preferably 0.1 to 20 parts by weight, and more preferably 5 to 10 parts by weight based on 100 parts by weight of the total polylactic acid resin and polyamide resin.

Within the above range, the compatibility with the polylactic acid resin and the polyamide resin is excellent, and the impact resistance, elongation and heat resistance of the produced polylactic acid-polyamide alloy resin composition are greatly improved. Since the impact modifier lowers the crystallization rate and crystallization content of the polylactic acid-polyamide alloy resin composition, thereby deteriorating heat resistance and injection moldability, when the amount of the impact modifier exceeds 20% by weight, heat resistance and appearance of the injection molded product There may be a problem that the back is lowered.

Meanwhile, the polylactic acid-polyamide alloy resin composition may include an antioxidant. The antioxidant can suppress the yellowing of the polylactic acid resin to improve the appearance of the polylactic acid-polyamide alloy resin composition and molded article, and can suppress the soft segment or the like from being oxidized or thermally decomposed.

To this end, the polylactic acid-polyamide alloy resin composition is about 100 to 3,000 ppmw, about 100 to 2,000 with respect to the amount of monomer (eg, lactic acid or lactide) added for the formation of a polylactic acid repeating unit of the polylactic acid resin. antioxidants in an amount of ppmw, about 500 to 1,500 ppmw, or about 1,000 to 1,500 ppmw.

When the content of the antioxidant is too low, polylactic acid resin may be yellowed by oxidation of a softening component such as the soft segment, and the appearance of the polylactic acid-polyamide alloy resin composition and molded article may be poor. On the other hand, if the content of the antioxidant is too high, the antioxidant may lower the polymerization rate of lactide and the like and the hard segment containing the polylactic acid repeating unit may not be properly generated, and the mechanical properties of the polylactic acid resin The back may deteriorate.

When the antioxidant is included in an optimized amount, for example, in the case of polymerization for the production of a polylactic acid resin, the antioxidant is added in an optimized amount to obtain the polylactic acid resin and the polylactic acid-polyamide alloy resin composition. , It is possible to increase the productivity of the polylactic acid resin by improving the polymerization yield (conversion of polymerization) and the degree of polymerization (degree of polymerization). In addition, since the polylactic acid-polyamide alloy resin composition may exhibit excellent thermal stability in a molding process that requires heating of 180 ° C. or higher for the polylactic acid-polyamide alloy resin composition, such as lactide or lactic acid It is possible to suppress the production of low-molecular substances in a monomeric or cyclic oligomer chain state.

Therefore, as a result of the molecular weight reduction of the polylactic acid resin or the color change (yellowing) of the molded product is suppressed, it not only has an excellent appearance, but also exhibits greatly improved flexibility, and also has excellent physical properties such as mechanical properties, heat resistance, and blocking resistance. It becomes possible to provide molded products that are expressed.

As the antioxidant, one or more selected from the group consisting of hindered phenol-based antioxidants, amine-based antioxidants, thio-based antioxidants, and phosphite-based antioxidants may be used, and other polylactic acid-polyamides Various antioxidants known to be usable in the alloy resin composition can be used.

However, since the polylactic acid-polyamide alloy resin composition may have an ester repeating unit, it tends to be easily oxidized or thermally decomposed during high-temperature polymerization reaction, high-temperature extrusion processing or molding. Therefore, as the antioxidant, it is preferable to use a thermal stabilizer, polymerization stabilizer or antioxidant of the series listed above. Specific examples of such antioxidants include phosphoric acid-based thermal stabilizers such as phosphoric acid, trimethylphosphate or triethylphosphate; 2,6-di-t-butyl-p-cresol, octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrabis [methylene-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy Benzyl) benzene, 3,5-di-t-butyl-4-hydroxybenzylphosphite diethyl ester, 4,4'-butylidene-bis (3-methyl-6-t-butylphenol), 4, Stereo as such as 4'-thiobis (3-methyl-6-t-butylphenol) or bis [3,3-bis- (4'-hydroxy-3'-tert-butyl-phenyl) butanoic acid] glycol ester Hindered phenolic primary antioxidants; Amines such as phenyl-α-naphthylamine, phenyl-β-naphthylamine, N, N'-diphenyl-p-phenylenediamine or N, N'-di-β-naphthyl-p-phenylenediamine Secondary antioxidants; Thio, such as dilauryl disulfide, dilaurylthiopropionate, distearylthiopropionate, mercaptobenzothiazole or tetramethylthiuramdisulfide tetrabis [methylene-3- (laurylthio) propionate] methane (thio) -based secondary antioxidants; Or triphenyl phosphite, tris (nonylphenyl) phosphite, triisodecylphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite or (1,1'-biphenyl) -4, And phosphite-based secondary antioxidants such as 4'-diylbisphosphoneric acid tetrakis [2,4-bis (1,1-dimethylethyl) phenyl] ester. Among them, it is most preferable to use a combination of a phosphite-based antioxidant and another antioxidant.

In addition to the above-mentioned impact modifiers and antioxidants, the polylactic acid-polyamide alloy resin composition has various known hydrolysis inhibitors, nucleating agents, organic or inorganic fillers, plasticizers, chain extenders, UV rays Stabilizers, colorants, matte agents, deodorants, flame retardants, weathering agents, antistatic agents, mold release agents, antioxidants, ion exchangers, coloring pigments, inorganic or organic particles may further include various additives.

The hydrolysis-resistant agent is a reactive compound capable of reacting with a hydroxyl group or a carboxyl group, which is a terminal component of polylactic acid, and can improve durability as well as hydrolysis resistance of the polylactic acid-polyamide resin composition. That is, the hydrolysis-resistant agent is applied to an ester-based resin such as polyester, polyamide, and polyurethane to prevent an hydrolysis of the resin composition by water or acid by performing an endcapping reaction at the end of the polymer chain. Plays a role. The hydrolysis-resistant agent may be a carbodiimide-based compound, for example, modified phenylcarbodiimide, poly (tolylcarbodiimide), poly (4,4'-diphenylmethanecarbodiimide), poly (3,3 ') -Dimethyl-4,4'-biphenylenecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (3,3'-dimethyl-4,4'-di Phenylmethane carbodiimide). The hydrolysis-resistant agent may be used within 5% by weight based on the total weight of the polylactic acid resin and the polyamide resin.

The nucleating agent may be included within 10% by weight, preferably within 5% by weight relative to the total 100% by weight of the polylactic acid-polyamide alloy resin composition (including the nucleating agent), and within the above range, heat resistance and injection There is an effect that the moldability is improved. The nucleating agent may be a sorbitol-based metal salt, a phosphate-based metal salt, quinacridone, calcium carboxylate, and an amide-based organic compound, and may preferably be a phosphate-based metal salt.

Examples of the plasticizer include phthalic acid ester plasticizers such as diethyl phthalate, dioctyl phthalate, and dicyclohexyl phthalate; Aliphatic dibasic acid ester plasticizers such as di-1-butyl adipic acid, di-n-octyl adipic acid, di-n-butyl sebacic acid, and di-2-ethyl hexyl azeraline; Phosphoric acid ester plasticizers such as diphenyl-2-ethyl hexyl phosphate and diphenyl octyl phosphate; Hydroxy polyvalent carboxylic acid ester plasticizers such as acetyl tributyl citrate, tri-2-ethyl hexyl acetyl citrate, and tributyl citrate; Fatty acid ester plasticizers such as methyl acetyl ricinoleate and imyl stearate; Polyhydric alcohol ester plasticizers such as glycerin triacetate; And epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil fatty acid butyl ester, and epoxy stearic acid octyl.

In addition, examples of the coloring pigments include inorganic pigments such as carbon black, titanium oxide, zinc oxide, and iron oxide; And organic pigments such as cyanine, phosphorus, quinone, perinone, isoindolinone, and thioindigo.

Meanwhile, when a molded article is manufactured using a polylactic acid-polyamide alloy resin composition, inorganic or organic particles may be included in order to improve mold releasability, etc. of the molded article, and the inorganic or organic particles are the polylactic acid. -The polyamide alloy resin composition may be included within 30% by weight based on the total weight, and preferably within 10% by weight. Examples of the inorganic or organic particles include silica, colloidal silica, alumina, alumina sol, talc, titanium dioxide, mica, calcium carbonate, polystyrene, poly methyl methacrylate, or silicon. The silica, titanium dioxide or talc is not limited to surface treatment, but when using the surface-treated titanium dioxide or talc, the overall physical properties including stiffness and impact strength are excellent, as well as specific gravity reduction, heat resistance and injection. There is an effect that the moldability is improved. Specifically, the surface treatment may be carried out by a chemical or physical method using a treatment agent such as a silane coupling agent, a higher fatty acid, a fatty acid metal salt, an unsaturated fatty acid, organic titanate, resin acid or polyethylene glycol. The inorganic particles may have an average particle size of 1 to 30 μm, preferably 1 to 15 μm, and have an effect of improving heat resistance and rigidity within the range.

In addition, various additives known to be usable for polylactic acid-polyamide alloy resin compositions or molded articles thereof may be included, and specific types and methods of obtaining them are obviously known to those skilled in the art.

Meanwhile, the polylactic acid-polyamide alloy resin composition may have a color-b value of less than 15 in a chip state, and preferably 10 or less. Since the polylactic acid-polyamide alloy resin composition contains an antioxidant, yellowing of the polylactic acid resin may be suppressed, and thus a color-b value of less than 15 may be exhibited. If the color-b value of the polylactic acid-polyamide alloy resin composition is 15 or more, the appearance of a molded article may be poor when used for molding purposes, and product value may be deteriorated.

Hereinafter, a method for producing the polylactic acid-polyamide copolymer alloy resin composition of the present invention will be described in more detail, for example.

<Production of polyolefin-based polyol structural units>

First, a hydroxyl group is added to the end of a polymer (poly 1,2-butadiene or poly 1,3-butadiene) obtained by radical polymerization of a butadiene monomer, and a liquid polybutadiene having a molecular weight of 1,000 to 3,000 ranges through a hydrogenation reaction (hydroxyl) -terminated polybutadiene (HTPB) is formed to obtain a (co) polymer having a polyolefin-based polyol structural unit. This can be performed according to a conventional polyolefin-based polyol (co) polymer production method.

<Production of polyolefin-based polyol repeating unit A>

Then, the (co) polymer having the polyolefin-based polyol structural unit, a polyfunctional isocyanate compound, and a urethane reaction catalyst are charged in a reactor, and heated and stirred to perform a urethane reaction. By this reaction, two or more isocyanate groups of the isocyanate compound and terminal hydroxy groups of the (co) polymer are combined to form a urethane bond. As a result, a (co) polymer having a polyurethane polyol repeating unit in which polyolefin-based polyol constituent units are linearly or branched connected via the urethane bond may be formed. This is included as a soft segment of the polylactic acid resin described above. At this time, the polyurethane polyol (co) polymer is a polyolefin-based polyol structural unit (O) is a OUOUO or OU (-O) -OUO in the form of OUOUO or OU (-O) -OUO via a urethane bond (U), and is coupled at both ends. It may be formed in a form having a polyolefin-based polyol repeating unit.

<Production of polyolefin-based polyol repeating unit B>

In addition, the (co) polymer having the polyolefin-based polyol structural unit, lactic acid (D or L-lactic acid) or lactide (D or L-lactide) compound and a condensation reaction or ring-opening reaction catalyst are charged in a reactor and heated and stirred. To perform a polyester reaction or a ring-opening polymerization reaction. By this reaction, the hydroxy group (D or L-lactic acid) or lactide (D or L-lactide) is combined with the terminal hydroxy group of the (co) polymer to form an ester bond. As a result, a (co) polymer in which polyolefin-based polyol constituent units are linearly or branchedly connected to the polylactic acid repeating unit through the ester bond may be formed. At this time, the (co) polymer is a polyolefin-based polyol structural unit (O) is a linear bond in the form of a polylactic acid repeating unit (L) and LEOEL via an ester bond (E) as a form having a polylactic acid repeating unit at both ends. It can be formed of.

Two or more isocyanate groups of the isocyanate compound and terminal hydroxy groups of the (co) polymer may be combined to form urethane bonds to form linear or branched bonds in the form of L-E-O-E-L-U-L-E-O-E-L to produce a final polylactic acid resin.

At this time, the polyolefin-based polyol repeating units obtained from the butadiene may be derived from biomass such as plant resources, and accordingly, the polyolefin-based polyol (co) polymer has an organic carbon content (% C _bio ) of biomass origin of about It can be a fairly high value, above 70%.

The urethane reaction may be carried out in the presence of a conventional tin-based catalyst, for example, stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, and the like. In addition, the urethane reaction may be performed under reaction conditions for the production of a conventional polyurethane resin. For example, after adding an isocyanate compound and a polyolefin-based polyol (co) polymer under a nitrogen atmosphere, the urethane reaction catalyst is added to react at a reaction temperature of 70 to 80 ° C. for 1 to 5 hours to obtain a (co) polymer having a polyolefin polyol repeating unit. Can be produced.

Subsequently, in the presence of the (co) polymer having the polyolefin-based polyol repeating unit and an antioxidant, polycondensation of lactic acid (D or L-lactic acid) or ring-opening polymerization of lactide (D or L-lactide) is described above. A block copolymer (or a polylactic acid resin including the same) and a polylactic acid-polyamide alloy resin composition including an antioxidant may be prepared. That is, when this polymerization reaction is performed, yellowing due to oxidation of a soft segment is suppressed by an antioxidant, and a polylactic acid repeating unit included as a hard segment is formed, whereby the polylactic acid resin is prepared, and at least some polylactic acid is produced. The polyurethane polyol repeating unit may be bonded to the end of the repeating unit to form a block copolymer.

In addition, after preparing a prepolymer in which a polyolefin-based polyol and lactide are first combined, these prepolymers have a known polylactic acid-based copolymer in which chains are extended with diisocyanate compounds, or the prepolymers have two or more isocyanate groups. A branched block copolymer reacted with an isocyanate compound and a polylactic acid-polyamide alloy resin composition comprising the same may be formed.

Meanwhile, the lactide ring-opening polymerization reaction may be performed in the presence of a metal catalyst including an alkaline earth metal, rare earth metal, transition metal, aluminum, germanium, tin or antimony. Specifically, these metal catalysts may be in the form of carboxylates, alkoxides, halides, oxides or carbonates of these metals. Preferably, as the metal catalyst, tin octylate, titanium tetraisopropoxide or aluminum triisopropoxide may be used.

In addition, the steps of forming a polylactic acid repeating unit such as the lactide ring-opening polymerization reaction described above may be continuously performed in the same reactor in which the urethane reaction is performed. That is, after the polyolefin-based polyol polymer and the isocyanate compound are urethane-reacted to form a polymer having a polyolefin-based polyol repeating unit, a polylactic acid repeating unit can be formed by continuously adding monomers and catalysts such as lactide to the reactor. . As a result, while the polymer having the polyolefin-based polyol repeating unit acts as an initiator, the polylactic acid repeating unit and the polylactic acid resin containing the same can be continuously produced with high yield and productivity. Likewise, after the ring-opening polymerization of a polyolefin-based polyol with an initiator of lactide, chain extension polymerization is performed by continuously adding an isocyanate compound in the same reactor, so that the polylactic acid repeating unit and the polylactic acid resin containing the same have high yield and productivity. It can be produced continuously.

As the polylactic acid-polyamide alloy resin composition described above includes a block copolymer (polylactic acid resin) in which a specific hard segment and a soft segment are combined, it exhibits biodegradability of the polylactic acid resin and may exhibit improved flexibility. have. In addition, the bleed-out of the soft segment for imparting flexibility may be minimized, and the addition of such a soft segment may greatly reduce the moisture resistance, mechanical properties, heat resistance, transparency, or haze characteristics of the molded article.

In addition, as the polylactic acid resin is manufactured to have a predetermined glass transition temperature and, optionally, a predetermined melting temperature, a molded article obtained therefrom can exhibit optimized flexibility and stiffness as a packaging material, as well as melt processability. It becomes excellent, and the blocking resistance and heat resistance are further improved. Therefore, such a polylactic acid resin and the polylactic acid-polyamide alloy resin composition including the same can be very preferably applied to packaging materials such as molded articles.

And, the polylactic acid resin is included with an antioxidant, yellowing during manufacturing or use can be suppressed, and the polylactic acid-polyamide alloy resin composition containing these components exhibits excellent appearance and product, while greatly It is possible to provide a molded article exhibiting various properties such as improved flexibility and excellent mechanical properties.

That is, as the polylactic acid-polyamide alloy resin composition of the present invention includes a polyolefin-based polyol repeating unit as a soft segment, flexibility of a molded article manufactured using the polylactic acid-polyamide alloy resin composition is greatly improved. You can.

In addition, the moisture content in the entire resin is lowered by the resin component composed of the polyolefin-based polyol of the non-polar soft segment compared to the polylactic acid resin which is the hard segment, so that the moisture resistance can be greatly improved.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are only presented as examples of the invention, and the scope of the invention is not thereby determined.

The raw materials used in the following examples and comparative examples are as follows:

One. Polyolefin system Polyol  Repeat units and their counterparts

-HTPB 1.0: A liquid polybutadiene having a molecular weight of 1,000 obtained through a hydrogenation reaction is imparted with a hydroxyl group at the end of a polymer (poly 1,2-butadiene or poly 1,3-butadiene) obtained by radical polymerization of a butadiene monomer. -terminated polybutadiene: HTPB)

-HTPB 2.0: Liquid polybutadiene (HTPB) having a molecular weight of 2,000 obtained through a hydrogenation reaction by imparting a hydroxyl group to the end of a polymer (poly 1,2-butadiene or poly 1,3-butadiene) obtained by radical polymerization of a butadiene monomer )

-HTPB 3.0: Liquid polybutadiene (HTPB) having a molecular weight of 3,000 obtained by adding a hydroxyl group to the end of a polymer (poly 1,2-butadiene or poly 1,3-butadiene) obtained by radical polymerization of a butadiene monomer )

-HTPB 5.0: Liquid polybutadiene (HTPB) having a molecular weight of 5,000 obtained through a hydrogenation reaction by imparting a hydroxyl group to the end of a polymer (poly 1,2-butadiene or poly 1,3-butadiene) obtained by radical polymerization of a butadiene monomer )

-PTMG 3.0: polytetramethylene glycol; Number average molecular weight 3,000

-PPDO 2.4: Poly (1,3-propanediol): number average molecular weight 2400

-PBSA 11.0: 1,4-butanediol and an aliphatic polyester polyol made of a condensate of succinic acid and adipic acid; Number average molecular weight 11,000

2. Isocyanate compounds having two or more isocyanate groups

-HDI: hexamethylene diisocyanate

-TDI: 2,4- or 2,6-tolylene diisocyanate (toluene diisocyanate: TDI)

-D-L75: Bayer's desmodur L75 (trimethylolpropane + 3 toluene diisocyanate)

3. Lactide  Monomer

-L-lactide or D-lactide: Purac, optical purity of 99.5% or more

Monomer consisting only of organic carbon of biomass origin

4. Antioxidants, etc.

-TNPP: tris (nonylphenyl) phosphite

-U626: bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite

-S412: tetrakis [methane-3- (rorylthio) propionate] methane

-PEPQ: (1,1'-biphenyl) -4,4'-diylbisphosphoneric acid tetrakis [2,4-bis (1,1-dimethylethyl) phenyl] ester

-I-1076: Octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate

-O3: bis [3,3-bis- (4'-hydroxy-3'-tert-butyl-phenyl) butanoic acid] glycol ester

5. Polyamide resin, etc.

-PA1010: polyamide resin made from polycondensation reaction of 1,10-decamethylene diamine and 1,10-decanedioic acid (sevasic acid) derived from biomass, viscosity number 120 cm ³ / g, bio Content 100%

-PA610: polyamide resin made by polycondensation reaction of petroleum-based 1,6-hexamethylene diamine and 1,10-decanedioic acid (sebacetic acid) derived from biomass, viscosity of 160 cm ³ / g, bio content 63 %

-PA66: polyamide resin made by polycondensation reaction of petroleum-based 1,6-hexamethylene diamine and 1,6-hexanedioic acid (adipic acid), viscosity of 200 cm ³ / g, bio content 0%

6. Impact modifier  Etc

-Pebax 63R53 SP01: poly 1,3-propanediol-polyamide block copolymer, Arkema, hardness 56 HD (Shore D, 15s), bio content 80%

-AX8840: Ethylene-maleic anhydride graft-glycidyl methacrylate copolymer, Akema, Graft rate 8.0%

-Biostrength 150: acrylic core-shell impact modifier, Arkema

7. Weapon filler  And Nuclear  Etc

-SP-3000: Talc, Dawon Chemical, average particle size 2.5μm, specific gravity 0.32g / cm2

-EMforce ™ Bio: CaC0 ₂ , Specialty Minerals, average particle size 1.0 μm, average aspect ratio 5.4

-TF-1: N, N ', N' '-tricyclohexyl-1,3,5-benzenetricarboxamide, NJC Corporation

-NA-11: 2,2'-methylene bis (4,6-di-tert-butylphenol) sodium phosphate, Asahi Denka

8. Hydrolysis agent  And chain extenders

-BioAdimide 100: Carbodiimide-based polymer, Rhein Chemie

-ADR 4368: Styrene-acrylic polymer, BASF

Manufacturing example  1 to 6: Polylactic acid  Preparation of resins A to F

In an 8L reactor equipped with a nitrogen gas introduction tube, a stirrer, a catalyst inlet, an outlet condenser, and a vacuum system, reactants of components and contents as shown in Table 1 below were charged together with a catalyst. As a catalyst, dibutyltin dilaurate of 130 ppmw compared to the total reactant content was used. The urethane reaction was carried out for 2 hours at a reactor temperature of 70 ° C. under nitrogen flow, and nitrogen flushing was performed 5 times by adding 4 kg of L- (or D-) lactide.

Thereafter, the temperature was raised to 150 ° C to completely dissolve L- (or D-) lactide, and toluene was used to make the catalyst, tin 2-ethylhexanoate, 120 ppmw compared to the total reactant content through the catalyst inlet. Diluted to 500 ml and added into the reaction vessel. The reaction proceeded for 2 hours at 185 ° C. under 1 kg nitrogen pressure, and 200 ppmw of phosphoric acid was added to the catalyst inlet, followed by mixing for 15 minutes to inactivate the residual catalyst. Subsequently, unreacted L- (or D-) lactide (about 5% by weight of the initial dose was removed through a vacuum reaction until 0.5 torr was reached. Molecular weight properties of the obtained resin, Tg, Tm and% C _bio Table 1 was measured and the like.

Manufacturing example  7: Polylactic acid  Preparation of resin G

In an 8L reactor equipped with a nitrogen gas inlet tube, agitator, catalyst inlet, outlet condenser and vacuum system, 865 g of HTPB2.0 and 3.9 kg of L-lactide and 0.1 kg of D-lactide as shown in Table 1 below. Was added and nitrogen flushing was performed 5 times. The lactide was completely dissolved by heating to 150 ° C., and 120 ppmw of tin 2-ethylhexanoate as a catalyst was diluted with 500 ml of toluene through a catalyst inlet and added into the reaction vessel. Subsequently, the reaction was performed for 2 hours at 185 ° C under 1 kg nitrogen pressure, and 200 ppmw of phosphoric acid was added to the catalyst inlet, followed by mixing for 15 minutes to inactivate the residual catalyst. Unreacted L-lactide (about 5 parts by weight of the initial dose) was removed through a vacuum reaction until 0.5 torr was reached. Thereafter, 120 ppmw of HDI and catalyst dibutyltin dilaurate as shown in Table 1 below were diluted with 500 ml of toluene through a catalyst inlet and added into the reaction vessel. The reaction was carried out for 1 hour at 190 ° C under a nitrogen atmosphere, and the molecular weight characteristics, Tg, Tm, and% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Manufacturing example  8: Polylactic acid  Preparation of resin H

As shown in Table 1 below, 885 g of HTPB2.0 and 3.8 kg of L-lactide and 0.2 kg of D-lactide were used, followed by HDI and D-L75 as shown in Table 1 below through the catalyst inlet. It was manufactured in the same manner as in Production Example 7, except that was used together. The molecular weight characteristics of the obtained resin, Tg, Tm, and% C _bio are measured and are shown in Table 1.

Manufacturing example  9: Polylactic acid  Preparation of resin I

Into an 8 L reactor equipped with a nitrogen gas introduction pipe, agitator, catalyst inlet, outlet condenser and vacuum system, 386.9 g of PTMG3.0 and 4 kg of L-lactide were added and nitrogen flushing was performed 5 times as shown in Table 1 below. Was conducted. The temperature was raised to 150 ° C to completely dissolve L-lactide, and 120 ppmw of catalyst tin 2-ethylhexanoate was diluted with 500 ml of toluene through a catalyst inlet and added into the reaction vessel. Subsequently, the reaction was carried out at 185 ° C for 2 hours under 1 kg nitrogen pressure, and 200 ppmw of phosphoric acid was added to the catalyst inlet, followed by mixing for 15 minutes to inactivate the residual catalyst. Unreacted L-lactide was removed through a vacuum reaction until 0.5 torr was reached. The molecular weight characteristics of the obtained resin, Tg, Tm, and% C _bio are measured and are shown in Table 1.

Manufacturing example  10: Polylactic acid  Preparation of resin J

Into an 8 L reactor equipped with a nitrogen gas inlet tube, agitator, catalyst inlet, outlet condenser and vacuum system, 378.8 g of PPDO2.4 and 4 kg of L-lactide were added and nitrogen flushing was performed 5 times as shown in Table 1 below. Was conducted. The temperature was raised to 150 ° C to completely dissolve L-lactide, and 120 ppmw of catalyst tin 2-ethylhexanoate was diluted with 500 ml of toluene through a catalyst inlet and added into the reaction vessel. Subsequently, the reaction was carried out at 185 ° C for 2 hours under 1 kg nitrogen pressure, and 200 ppmw of phosphoric acid was added to the catalyst inlet, followed by mixing for 15 minutes to inactivate the residual catalyst. Unreacted L-lactide was removed through a vacuum reaction until 0.5 torr was reached. The molecular weight characteristics of the obtained resin, Tg, Tm, and% C _bio are measured and are shown in Table 1.

Manufacturing example  11: Polylactic acid  Preparation of resin K

It was prepared in the same manner as in Production Example 10, except that the raw material was added as shown in Table 1 below. The molecular weight characteristics of the obtained resin, Tg, Tm, and% C _bio are measured and are shown in Table 1.

Manufacturing example  12: Polylactic acid  Preparation of resin L

To an 8L reactor equipped with a nitrogen gas introduction tube, agitator, catalyst inlet, outlet condenser, and vacuum system, PBSA 11.0 (polyester polyol) and HDI were introduced as shown in Table 1 below, and nitrogen flushing was performed 5 times. As a catalyst, dibutyltin dilaurate of 130 ppmw compared to the total reactant content was used. The urethane reaction was carried out for 2 hours at a reactor temperature of 190 ° C under a nitrogen stream, 4 kg of L-lactide was added, and the L-lactide was completely dissolved at 190 ° C in a nitrogen atmosphere, and the total reactant content through the catalyst inlet. Contrast addition polymerization catalyst tin 2-ethylhexanoate 120 ppmw and 1,000 ppmw of dibutyltin dilaurate as an ester and / or ester amide exchange catalyst were diluted with 500 ml of toluene and added into the reaction vessel. The reaction was carried out for 2 hours at 190 ° C under 1 kg nitrogen pressure, and 200 ppmw of phosphoric acid was added to the catalyst inlet and mixed for 15 minutes to inactivate the residual catalyst. Subsequently, unreacted L-lactide (about 5 weight of the initial dose) was removed through a vacuum reaction until 0.5 torr was reached. The molecular weight characteristics of the obtained resin, Tg, Tm, and% C _bio are measured and are shown in Table 1.

Example  1 to 8, and Comparative example  1 to 8: Preparation of molded articles

The polylactic acid resins prepared in Preparation Examples 1 to 12 were dried under reduced pressure at 80 ° C. for 6 hours under a vacuum of 1 torr, followed by supermixing the polyamide resin and other materials as described in Tables 2 or 3. Using a mixture, and using a 19 mm diameter twin screw extruder (single screw extruder, roll mill, kneader or Banbury mixer can use one of a variety of blending and processing machines) with a extrusion temperature of 230 to 260 ° C. to strand It was melt-kneaded and extruded. The strand cooled through the water bath was prepared in pellet form using a pelletizer. This was dried at 80 ° C. for 4 hours or more with a dehumidifying dryer or a hot air dryer, followed by injection processing to prepare a specimen. Table 2 or 3 shows the evaluation results of the obtained molded article.

Experimental example

(1) NCO / OH: Reaction of "terminal hydroxyl group of isocyanate group / polyether-based polyol repeating unit (or (co) polymer) of diisocyanate compound (eg hexamethylene diisocyanate)" for formation of polyolefin-based polyol repeating unit " Molar ratio was indicated.

(2) OHV (KOHmg / g): Polyolefin-based polyol repeating unit (or (co) polymer) was dissolved in dichloromethane and acetylated, and acetic acid generated by hydrolysis was measured by titration with 0.1N KOH methanol solution. . This corresponds to the number of hydroxyl groups present at the end of the polyolefin-based polyol repeating unit (or (co) polymer).

(3) Mw and Mn (g / mol) and molecular weight distribution (Mw / Mn): polylactic acid resin was dissolved in chloroform at a concentration of 0.25% by weight, and gel permeation chromatography (manufacturer: Viscotek TDA 305, column: Shodex LF804 * 2ea) was measured, and polystyrene as a standard material was calculated by weight average molecular weight (Mw) and number average molecular weight (Mn), respectively. The molecular weight distribution (MWD) was calculated from the Mw and Mn thus calculated.

(4) Tg (glass transition temperature, ℃): using a differential scanning calorimeter (manufacturer: TA Instruments), the sample was melt-quenched and then heated to 10 ° C / min to measure. The midline of the baseline and each tangent near the endothermic curve was taken as Tg.

(5) Tm (melting temperature, ° C): Using a differential scanning calorimeter (manufacturer: TA Instruments), the sample was melt-quenched and then heated to 10 ° C / min to measure. The maximum temperature of the melting endothermic peak of the crystal was taken as Tm.

(6) Residual monomer (lactide) content (% by weight): 0.1 g of the resin was dissolved in 4 ml of chloroform, filtered by adding 10 ml of hexane, and analyzed by GC analysis to quantify.

(7) Content of polyolefin-based polyol repeating unit (wt%): Using a 600 Mhz nuclear magnetic resonance (NMR) spectrometer, the content of the polyolefin-based polyol repeating unit contained in each prepared polylactic acid resin was quantified.

(8) Chip color-b: After obtaining a value using a color difference meter (CR-410, Konica Minolta Sensing Co., Ltd.) for the resin chip, the average value of five tests in total was displayed.

(9) Organic carbon content of biomass origin (% C _bio ): Based on ASTM D6866, from the biomass origin material content test by radioactive carbon concentration (Percent Modern Carbon; C14), the organic carbon content of biomass origin It was measured.

(10) Extrusion state: A polylactic acid resin-polyamide alloy resin was extruded into a strand at an extrusion temperature of 230 to 260 ° C. in a 30 mm diameter twin screw extruder equipped with a hole die. Then, it solidified in a cooling water bath at 20 ° C. At this time, the melt viscosity and the uniformity of the melt on the strand discharge were visually evaluated to evaluate the state of the melt viscosity (extrusion state) according to the following criteria.

◎: The compatibility between the two resins is good, and the melt viscosity and uniformity are good.

○: It is difficult because the compatibility between the two resins is slightly insufficient and the melt viscosity and uniformity are slightly low, but strands can be formed and broken.

×: The compatibility between the two resins is too low, and the melt viscosity and uniformity are also poor, so die swelling occurs and strands are cut off, making it impossible to generate.

(11) MI (melting index): According to ASTM D1238, the average value of three tests in total at a temperature of 220 ° C. and a load of 2.16 kgf was expressed as a result.

(12) Compatibility: Polylactic acid resin polylactic acid-polyamide alloy resin in a 30 mm diameter twin screw extruder equipped with a hole die was extruded at an extrusion temperature of 230 to 260 ° C., followed by 20 ° C. After solidifying in a cooling water bath, a strand specimen was obtained, immersed in liquid nitrogen and fractured, and then the cut surface was observed with a scanning electron microscope (SEM) and visually evaluated according to the following criteria.

◎: The phase separation between the two resins was good, and the particle size of the undispersed resin was 0.2 µm or less.

(Circle): The powdery state between two resins is favorable, and the particle size of undispersed resin is 1.0 µm or less

X: The phase separation between the two resins was poor, and the undispersed resin particle size was 1.0 µm or more.

(13) Appearance characteristics: The appearance was judged visually, and flow marks, weld lines, and gloss deterioration caused by a lack of flowability of the resin melt were determined.

◎: Good melt viscosity, no flow mark, weld line, excellent gloss

○: There is no flow mark or weld line because the melt viscosity is slightly high, but the gloss is poor.

×: Very high melt viscosity, resulting in flow marks, weld lines and deterioration of gloss

(14) Initial Tensile Strength (kgf / ㎠): Test specimens in accordance with ASTM D638 at a temperature of 20 ° C and a humidity of 65% RH for 24 hours, and test 5 times in total using the UTM (manufacturer: INSTRON) universal tester After that, the average value was expressed as a result.

(15) Elongation (%): Under the same conditions as the initial tensile strength of (14), the elongation until the specimen fractured was measured, and the average value of five tests in total was expressed as a result.

(16) Impact strength (kgf · cm / cm): A specimen for measurement was made according to ASTM D 256, and the impact strength value was measured using an Izod impactor.

(17) Flexural strength ((kgf / ㎠) and flexural modulus ((kgf / ㎠): Prepare a test specimen according to ASTM D790 and use the UTM (manufacturer: INSTRON) universal tester to obtain the average value of 5 tests in total. It was denoted as.

(18) Heat resistance (℃): A test specimen was prepared according to ASTM D648, and the heat resistance was measured using a universal tester.

i) High temperature mold: 110 ℃ high temperature mold was used during injection, and cooling time is within 30 seconds.

ii) Low temperature mold: A normal temperature mold was used during injection, and the cooling time was within 30 seconds.

(19) Anti bleed-out: The degree of low molecular weight plasticizer component bleed out to the surface of the molded article by tactile observation by observing the surface of the molded article was evaluated according to the following criteria using an A4 sized film sample.

◎: No bleed out

○: Bleed out occurred but not severe

×: severe bleed out

(20) Moisture resistance tensile strength retention rate (%): The film sample having a length of 150 mm and a width of 10 mm was measured for 30 days in an atmosphere at a temperature of 40 ° C. and a humidity of 90% RH, and the initial tensile strength change was measured.

Suzy
A Suzy
B Suzy
C Suzy
D Suzy
E Suzy
F Suzy
G Suzy
H Suzy
I Suzy
J Suzy
K Suzy
L HTPB 2.0 (g) 475 104 865 885 HTPB 1.0 (g) 231 208 HTPB 3.0 (g) 490 HTPB 5.0 (g) 1607 PTMG 3.0 (g) 386.9 PPDO 2.4 (g) 378.8 PBSA 11.0 (g) 800 HDI (g) 17 32 19 2 122 55 3 13.1 21.2 9.5 TDI (g) 36 D-L75 (g) 3 NCO / OH 0.65 0.85 0.92 0.55 0.5 0.96 0.8 0.6 0.8 0.8 OHV (KOHmg / g) 9 6 7 29 7 2 4 4 10 6 3 TNPP (g) 4 2 U626 (g) 2 3 6 9.6 0.8 3 PEPQ (g) 4 4 4 S412 (g) 2 I-1076 (g) One 2 2 O3 (g) 2 L-lactide (g) 4000 4000 4000 4000 3900 3800 4000 4000 4000 4000 D-lactide (g) 4000 4000 100 200 Antioxidant content (ppmw) 1000 1000 1000 1500 1500 2400 200 500 1500 1500 750 0 Mn (× 1,000, g / mol) 75 120 145 62 70 61 129 121 70 105 128 65 Mw (× 1,000, g / mol) 165 240 320 108 152 110 280 340 148 245 295 185 MWD 2.2 2.0 2.2 1.7 2.2 1.8 2.2 2.7 2.01 2.1 2.3 2.8 Tg (℃) 50 49 54 55 46 30 40 42 49 42 65 18 Tm (℃) 171 168 174 174 164 145 155 153 170 168 176 85, 165 Color b 3 2 2 3 5 8 8 7 14 13 4 13 Polyolefin-based polyol repeating unit content (% by weight) 11 11 6 5 15 30 19 18 10 10 0 18 Residual monomer content (% by weight) 0.45 0.4 0.3 0.65 0.55 0.78 0.92 0.88 0.5 0.4 0.3 2.5 Organic carbon content (ASTM D6866) 88% 90% 92% 94% 85% 69% 79% 81% 90% 90% 97% 78%

Example
One Example
2 Example
3 Example
4 Example
5 Example
6 Example
7 Example
8 Polylactic acid
(Parts by weight) Resin 1 A 27 B 45 C 63 D 40 E 40 F 20 G 35 H 36 Resin 2 K 20 L 2 Polyamide
(Parts by weight) PA1010 63 45 27 32 39 PA610 39 36 30 PA66 Impact modifier
(Parts by weight) PEBAX 10 10 10 10 5 5 5 10 AX8840 10 10 Biostrength150 10 Weapon filler
(Parts by weight) SP3000 20 Emforce Bio 5 10 18 Nuclear
(Parts by weight) TF-1 One 3 One NA-11 2 4 Hydrolysis resistance (parts by weight) BioAdimide
100 One Chain extender (parts by weight) ADR4368 One Extrusion state ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Compatibility ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ MI (220 ℃ * 2.16kg) 26 25 30 45 38 12 10 15 Appearance characteristics ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Tensile strength (kgf / cm ² ) 370 339 410 362 388 389 391 329 Elongation (%) 43.0 7.0 4.0 30.0 5.0 18.0 25.0 3.5 Impact strength (kgf ㆍ cm / cm) 38.0 35.0 25.0 100.0 56.0 75.0 95.0 26.0 Flexural strength (kgf / cm ² ) 810 802 762 768 726 723 745 809 Flexural modulus (kgf / cm ² ) 26000 23000 22000 29000 30000 21000 20000 27000 Low temperature mold heat resistance (℃) 46 45 46 50 53 52 72 80 High temperature mold heat resistance (℃) 105 97 88 90 145 122 132 141 My bleed out ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Moisture resistance tensile strength retention rate (%) 90 88 86 84 90 89 91 92 Organic carbon content (%) 95 94 92 70 94 79 65 73

Comparative example
One Comparative example
2 Comparative example
3 Comparative example
4 Comparative example
5 Comparative example
6 Comparative example
7 Comparative example
8 Polylactic acid
(Parts by weight) Resin 1 A 20 K 50 K 25 I 20 J 30 PPDO 5 PBSA 5 L 40 Resin 2 K 45 K 45 Polyamide
(Parts by weight) PA1010 50 PA610 50 50 60 PA66 80 65 80 60 Impact modifier
(Parts by weight) PEBAX 10 10 5 10 AX8840 10 Biostrength150 Weapon filler
(Parts by weight) SP3000 Emforce Bio Nuclear
(Parts by weight) TF-1 NA-11 Hydrolysis resistance (parts by weight) BioAdimide
100 Chain extender (parts by weight) ADR4368 Extrusion state ◎ X X X O O O Compatibility ◎ X X X X X X MI (210 ℃ * 2.16kg) 14 Lack of compatibility

Die swelling occurs

Not extruded Lack of compatibility

Die swelling occurs

Not extruded
Lack of compatibility

Die swelling occurs

Not extruded
Lack of compatibility

Die swelling occurs

Not extruded
> 100 > 100 > 100 Appearance characteristics ◎ X X X Tensile strength (kgf / cm ² ) 440 175 189 197 Elongation (%) 10.2 7.7 8.2 9.5 Impact strength (kgf ㆍ cm / cm) 33.8 3.1 6.6 5.1 Flexural strength (kgf / cm ² ) 700 330 366 345 Flexural modulus (kgf / cm ² ) 27000 24000 25000 26000 Low temperature mold heat resistance (℃) 58 44 43 43 High temperature mold heat resistance (℃) 138 55 49 48 My bleed out ◎ X X Moisture resistance tensile strength retention rate (%) 90 63 71 55 Organic carbon content (%) 17 71 78 90

Referring to Table 2, Examples 1 to 5 and Examples 7 to 8 have a content of the softening component (polyolefin-based polyol repeating unit) in the polylactic acid resin of 5 to 35% by weight, a low color b value, and an appropriate content. It is obtained from a polyamide alloy resin composition comprising an antioxidant, and a polylactic acid resin having physical properties such as weight average molecular weight 100,000 to 400,000, molecular weight distribution 1.60 to 3.0, Tg 20 to 60 ° C and Tm 145 to 178 ° C It is a molded product. In addition, Example 6 is a polylactic acid-polyamide comprising a polylactic acid resin (resin F) and a general polylactic acid resin (resin K) corresponding to the polylactic acid resin contained in the polylactic acid-polyamide alloy resin composition of the present invention. It was produced using an amide alloy resin composition.

All of the injection molded products of Examples 1 to 8 have an initial tensile strength of 300 kgf / cm ² or more, an impact strength of 25 kgf · cm / cm or more, as well as excellent mechanical properties, and a high temperature mold HDT of 85 ° C or more. It showed excellent heat resistance. And, after 30 days in an atmosphere of 40 ° C. and a humidity of 90% RH, the moisture proof tensile strength retention was excellent at 80% or more, and no bleed out occurred. In addition, it can be said that the organic carbon content of the resin is 60% or more, which is an eco-friendly material.

On the other hand, the injection molded article of Comparative Example 1 made of a polylactic acid-polyamide alloy resin containing a polylactic acid resin A contained in the polylactic acid-polyamide alloy resin composition of the present invention has good various properties, The organic carbon content was less than 25%, which did not meet the world's eco-friendly plastic standards. In addition, the extrusion and kneading resins of Comparative Examples 2 and 3 prepared from the polylactic acid-polyamide alloy resin composition containing the general polylactic acid resin K lack the compatibility between the polylactic acid resin and the polyamide resin and the melt viscosity between the two resins. The difference was so large that it was difficult to be used as an injection molded product due to poor extrusion conditions such as die swelling when discharging extrusion kneading.

In addition, compatibility with the injection molded products of Comparative Examples 4 and 5 prepared from polylactic acid-polyamide alloy resin compositions using polylactic acid resin I and polylactic acid J, respectively, containing a polyether-based urethane polyol as a soft segment. The lack and the difference in melt viscosity between the two resins was so large that it was difficult to be used as an injection molded product due to poor extrusion conditions such as die swelling during extrusion kneading.

In addition, Comparative Examples 6 and 7 did not contain a polyolefin-based polyol repeating unit, which is a softening component, in the polylactic acid resin, and as plasticizer components, poly (1,3-propanediol) having a number average molecular weight of 2,400 and 11,000 having a number average molecular weight of 11,000, respectively. It is injection molded by simply compounding and mixing an aliphatic polyester polyol made of, 4-butanediol and a condensate of succinic acid and adipic acid in polylactic acid resin K. The injection molded products of Comparative Examples 6 and 7 had poor compatibility, and the degree of dispersion of the plasticizer component in the resin was not perfect, so that the extrusion state and appearance characteristics of the melt during extrusion kneading were poor, and plasticizer in the injection molded products after a lapse of time. The phenomenon that the component bleed out was found.

In addition, in the injection molded product of Comparative Example 8, a polyester polyol repeating unit was introduced and the molecular weight distribution was wide. It is produced from a polylactic acid-polyamide alloy resin comprising a polylactic acid resin. Although the injection molded article of Comparative Example 8 exhibited relatively excellent bleed-out properties as the softening component polyurethane was randomly introduced in a small segment size, as the polylactic acid repeating unit was introduced in a relatively small segment size, low Tm It exhibited poor heat resistance due to and the like, and overall mechanical strength was poor due to compatibility problems. In addition, it was confirmed that the extrusion kneaded product was non-uniform due to the low compatibility of the polyester polyol and polylactic acid used for the formation of the softening component, leading to poor extrusion state of the molded product and deterioration of mechanical properties, and very low moisture resistance. .

On the other hand, the pellets prepared in Examples 1 to 3 and Comparative Example 4 were observed using a microscope (SEM), and the results are shown in FIGS. 1 to 4, respectively. 1 to 4, the white portion is a polylactic acid resin, and the black portion is a polyamide resin.

In the case of FIGS. 1 to 3, it can be seen that, regardless of the ratio of the polylactic acid resin and the polyamide resin, the distinction between the white portion of the polylactic acid resin and the black portion of the polyamide resin was not apparent. This means that the compatibility between the two resins increased without the use of a special compatibilizer, showing that the physical properties of the flexural modulus and impact strength were improved. However, FIG. 4 shows that the distinction between the polylactic acid resin and the polyamide resin is clear, and the compatibility is poor, so that die swelling occurs during melt-kneading between the two resins, and an air layer (void) is generated on the end face of the alloy resin. You can. This makes it difficult to manufacture strands and pellets by itself because a uniform extrudate cannot be obtained.

Summarizing the above results, in the polylactic acid resin-polyamide alloy resin composition, the polylactic acid resin increases the dispersibility in the polyamide resin or the polyamide resin in the polylactic acid resin, thereby increasing the dispersibility in the polylactic acid resin. , It can be seen that the overall physical property balance of the resin composition can be achieved by improving the crystallization rate and heat resistance.

Claims (16)

A polylactic acid-polyamide alloy resin composition comprising 30 to 90 parts by weight of polylactic acid resin and 10 to 70 parts by weight of polyamide resin,
The polylactic acid resin is a hard segment comprising a polylactic acid repeating unit represented by the following Chemical Formula 1, and a polyolefin-based polyol repeated in which the polyolefin-based polyol structural units represented by the following Chemical Formula 2 are linearly or branchedly connected via a urethane bond or an ester bond. Includes a soft segment containing units,
A polylactic acid-polyamide alloy resin composition having an organic carbon content (% C _bio ) of 60% or more originating from biomass defined by the following Equation 1:
[Formula 1]

[Formula 2]

[Equation 1]
% C = _bio ⁽¹⁴ C isotope ratio by weight of the ¹² C isotope of the biomass origin standard carbon atoms) (poly (lactic acid) ¹⁴ C isotope ratio by weight of the ¹² C isotope of carbon atoms of the resin) / 100 ×
In Chemical Formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is an integer from 5 to 200.
According to claim 1,
A polylactic acid-polyamide alloy resin composition further comprising 0.1 to 20 parts by weight of an impact modifier with respect to 100 parts by weight of the total polylactic acid resin and polyamide resin.
According to claim 1,
A polylactic acid-polyamide alloy resin composition having a content of ¹⁴ C isotopes in carbon atoms of the polylactic acid resin of 7.2 × 10 ^-11 wt% to 1.2 × 10 ^-10 wt%.
According to claim 1,
A polylactic acid-polyamide alloy resin composition in which the soft segment has an organic carbon content (% C _bio ) of 70% or more defined by Equation 1.
According to claim 1,
A polylactic acid-polyamide alloy resin composition in which the polylactic acid resin has a number average molecular weight of 50,000 to 200,000, and a weight average molecular weight of 100,000 to 400,000.
According to claim 1,
A polylactic acid-polyamide alloy resin composition in which the polylactic acid resin has a glass transition temperature (Tg) of 20 ° C to 55 ° C and a melting temperature (Tm) of 145 ° C to 178 ° C.
According to claim 1,
The urethane bond is a polylactic acid formed by the reaction of an isocyanate compound having two or more isocyanate groups with a prepolymer obtained by addition polymerization of lactide to a hydroxyl group at the end of the polyolefin-based polyol constituent unit or a hydroxyl group at the end of the polyolefin-based polyol constituent unit. -Polyamide alloy resin composition.
According to claim 1,
The polylactic acid resin is a block copolymer in which the terminal carboxyl group of the polylactic acid repeating unit included in the hard segment is connected by an ester bond to the terminal hydroxy group of the polyolefin-based polyol structural unit included in the soft segment, or
A polylactic acid-polyamide alloy resin composition in which the block copolymer comprises a block copolymer connected linearly or branched via a urethane bond.
The method of claim 8,
A polylactic acid-polyamide alloy resin composition in which the polylactic acid resin further comprises a polylactic acid homopolymer not bound to the polyolefin-based polyol repeating unit.
According to claim 1,
The polyolefin-based polyol repeating unit has a polylactic acid-polyamide alloy resin composition having a number average molecular weight of 1,000 to 100,000.
The method of claim 7,
A polylactic acid-polyamide alloy resin composition having a hydroxy group at the terminal of the polyolefin-based polyol structural unit and a reaction molar ratio of the isocyanate group of the isocyanate compound having two or more isocyanate groups in a range from 1: 0.50 to 1: 0.99.
According to claim 1,
The polylactic acid resin, a polylactic acid-polyamide alloy resin composition comprising 65 to 95 parts by weight of the hard segment and 5 to 35 parts by weight of the soft segment relative to 100 parts by weight of the polylactic acid resin.
According to claim 1,
The polyamide resin is polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene nonanediamide (nylon 69), polyhexamethylene three Bacamide (nylon 610), polycaproamide / polyhexamethylene adipamide copolymer (nylon 6/66), polyhexamethylenedodecanediamide, polyhexamethylenedodecaramide (nylon612), polyundecanoamide ( Nylon 11), polydodecaamide (nylon 12), polyhexamethylene isophthalamide (nylon 61), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene Adiphamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polybis (4-aminocyclohexyl) methanedodecamide (nylon PACM12), polyundecamethylene terephthalamide (nylon 11T), polyun Car-methylene-hexahydro-terephthalamide (nylon 11T (H)), a mixture thereof or a copolymer of polylactic acid-polyamide alloy resin composition.
According to claim 1,
A polylactic acid-polyamide alloy resin composition having a Viscosity Number (ISO 307) of 120 to 220.
According to claim 1,
A polylactic acid-polyamide alloy resin composition exhibiting a color-b value of less than 15.
According to claim 1,
A polylactic acid-polyamide alloy resin composition in which less than 1% by weight of the monomer remains, based on the total weight of the polylactic acid resin.

Images