TWI649370B - Alloy resin composition of polylactic acid/acrylonitrile-butadiene-styrene copolymer - Google Patents

Abstract

An alloy resin composition of polylactic acid / acrylonitrile-butadiene-styrene copolymer is disclosed, comprising 30 to 90 parts by weight of a polylactic acid resin and 10 to 70 parts by weight of an ABS resin, wherein the polylactic acid The resin includes a hard segment and a soft segment. The hard segment includes a polylactic acid repeating unit. The soft segment includes a polyolefin-based polyol repeating unit. In the polyolefin-based polyol repeating unit, the polyolefin-based repeating unit The polyol structural units are connected in a linear or branched manner through a monocarbamate bond or an ester bond, wherein the organic carbon content of the biomass carbon is at least 60%, which not only has improved impact resistance, but also It also has excellent general properties such as heat resistance, moisture resistance, mechanical properties and injection moldability, and therefore can be effectively used to manufacture a molded product, and because of its eco-friendly nature, it is important for avoiding environmental pollution contribution.

Description

Alloy resin composition of polylactic acid / acrylonitrile-butadiene-styrene copolymer Field of invention

The invention relates to an alloy resin composition of polylactic acid (PLA) / acrylonitrile-butadiene-styrene copolymer (ABS). In particular, the present invention relates to an alloy resin composition including a polylactic acid resin and an ABS-based resin. This alloy resin composition has eco-friendly properties, and due to improved impact resistance and excellent general properties such as heat resistance, moisture resistance, mechanical properties, injection moldability, etc., it can be effectively used as a molding material.

Background of the invention

Petroleum-based resins such as polyethylene terephthalate (PET), nylon, polyolefin and plasticized polyvinyl chloride (PVC) are widely used today in a wide range of applications, for example, as a packaging material. However, these petroleum-based resins are not biodegradable, and therefore, cause environmental pollution, for example, excessive emission of greenhouse gases such as carbon dioxide during waste disposal. Recently, due to the depletion of petroleum sources, biomass-based resins, typically polylactic acid resins, are widely regarded as a substitute.

However, compared with petroleum-based resins, polylactic acid resins have unsatisfactory heat resistance, moisture resistance, or mechanical properties; therefore, their application fields and applications are limited. In particular, although attempts have been made to use polylactic acid resins as packaging materials such as packaging films, they have failed due to the poor flexibility of polylactic acid resins.

To overcome the limitations of polylactic acid resin, an alloy composition of polylactic acid resin and other traditional resins and / or engineering plastics has been used. Although molded products containing a polylactic acid resin have been prepared from these alloy compositions, due to the incompatibility between the two resins, there are limitations in improving their heat resistance and mechanical properties.

Furthermore, in order to solve the above problems, it has recently been suggested to add a graft copolymer compatibilizer such as glycidyl methacrylate and the like during the preparation of an alloy composition containing a polylactic acid resin and an ABS resin (see early Korean (Patent Announcement No. 2012-0041626 and 2011-0000247 cases). However, these polylactic acid resin compositions and products prepared from them have the disadvantage of high cost. Furthermore, since it overcomes the limitation of low compatibility between polylactic acid resin and ABS resin, the improvement in its properties is not significant. Therefore, it is not feasible to use these compositions for automotive interior materials that require high durability. Furthermore, because the polylactic acid resin composition has a wide molecular weight distribution and poor melting characteristics, it cannot be injection molded well, resulting in products having poor appearance, mechanical properties, heat resistance, and impact resistance. The compatibilizer also emits a large amount of total volatile organic compounds (TVOC) derived from residual solvents, monomers and other volatile organic compounds generated by thermal decomposition during the mixing process. In particular, such as toluene, xylene, styrene, and having 5 to 12 carbon atoms These volatile organic compounds release strong irritating odors. When humans are exposed to the air containing these volatile organic compounds for a long time, they will suffer from headache, drowsiness, nausea, difficulty breathing, pain in eyes, nose, and throat.

Moreover, due to the hydrolysis reaction caused by the moisture contained therein, the polylactic acid resin is extremely vulnerable to moisture. Therefore, the resin is partially degraded into lactic acid, monomers, or oligomers, thus causing molecular weight degradation.

Furthermore, the resulting lactic acid, monomers and oligomers evaporate during a molding process and can cause equipment contamination or corrosion, or damage the quality of the finished product. In particular, in the case where a sheet is produced by extrusion molding, residual lactic acid, monomers, and oligomers are volatilized during the sheet extrusion method, thus causing a change in thickness. In the case where a sheet is produced by injection molding, the hydrolysis reaction occurs continuously, and even after the manufacturing method is completed, it depends on the environment in which the product is used, and therefore, its mechanical properties deteriorate. Furthermore, because the polylactic acid resin easily absorbs water in nature, the water is easily absorbed during the cooling treatment performed in a water bath after extrusion or when the kneaded product is stored in pellet form. When these pellets are injection molded, due to the moisture contained in them, the resulting product will suffer from poor appearance, for example, silver streaks, or deterioration in physical properties.

Therefore, there is a need for a polylactic acid resin having improved impact resistance and excellent moisture resistance, excellent general properties such as mechanical properties, heat resistance and outflow resistance properties, and a reduction in the total amount produced from a resin during the mixing method It is a technology of volatile organic compounds while maintaining the unique characteristics of a polylactic acid resin.

Summary of the invention

Therefore, an object of the present invention is to provide a PLA / ABS alloy resin composition having eco-friendly properties, due to improved impact resistance and excellent properties such as moisture resistance, mechanical properties, transparency, heat resistance, General properties such as anti-blocking and moldability can be effectively used for plastic molding.

According to one aspect of the present invention, there is provided an alloy resin composition of polylactic acid (PLA) / acrylonitrile-butadiene-styrene copolymer (ABS), comprising: 30 to 90 parts by weight of a polylactic acid resin, and 10 Up to 70 parts by weight of an ABS-based resin, wherein the polylactic acid resin includes a hard segment and a soft segment, the hard segment includes a polylactic acid repeating unit of Chemical Formula 1, the soft segment includes a polyolefin-based ( polyolefin-based) polyol repeating unit, in the polyolefin-based polyol repeating unit, the polyolefin-based polyol structural units of Chemical Formula 2 are connected in a linear or branched manner through a monocarbamate bond or an ester bond , Wherein the organic carbon content (% C _bio ) of the biomass carbon defined by Equation 1 is at least 60%, and wherein, in Chemical Formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is from Integer from 5 to 200:

[Equation 1]% C _bio = (weight ratio of ¹⁴ C isotope to ¹² C weight of total carbon content in polylactic acid resin) / (weight ratio of ¹⁴ C to ¹² C weight of total carbon content in primary carbon standard materials ) x100.

The PLA / ABS alloy resin composition according to the present invention not only has improved impact resistance, but also has excellent general properties such as heat resistance, moisture resistance, mechanical properties, and injection moldability. Therefore, the alloy resin composition of the present invention can be effectively used to manufacture a molded product, and at the same time has a significant contribution to the prevention of environmental pollution due to its eco-friendly nature.

Brief description

The above and other objects and features of the present invention will become apparent from the following description when combined with the attached drawings: FIGS. 1 to 3 are scanning electron microscope (SEM) photographs of the pellets prepared in Examples 1 to 3.

Detailed description of the invention

Hereinafter, a PLA / ABS alloy resin composition according to an embodiment of the present invention will be explained in detail.

An alloy resin composition of polylactic acid (PLA) / acrylonitrile-butadiene-styrene copolymer (ABS) of the present invention contains (A) 30 to 90 parts by weight of one polylactic acid resin, and (B) 10 to 70 parts by weight of an ABS-based resin, wherein the polylactic acid resin includes a hard segment and a soft segment, the hard segment includes a polylactic acid repeating unit of Chemical Formula 1, the soft segment includes a polyolefin-based multicomponent Alcohol repeating units. In the polyolefin-based polyol repeating unit, the polyolefin-based polyol structural units of Chemical Formula 2 are connected in a linear or branched manner through a monocarbamate bond or an ester bond, in which, the equation 1 The organic carbon content (% C _bio ) of the defined biomass carbon is at least 60%, and in formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is an integer from 5 to 200 :

[Equation 1]% C _bio = (weight ratio of ¹⁴ C isotope to ¹² C weight of total carbon content in polylactic acid resin) / (weight ratio of ¹⁴ C to ¹² C weight of total carbon content in primary carbon standard materials ) x100.

(A) Polylactic acid resin

The polylactic acid resin contained in the PLA / ABS alloy resin composition according to the present invention basically contains a polylactic acid weight represented by Chemical Formula 1 The complex unit serves as a hard segment. Furthermore, the polylactic acid resin contains a polyolefin-based polyol repeating unit as a soft segment. In this polyolefin-based polyol repeating unit, the polyolefin-based polyol structural unit represented by Chemical Formula 2 is through a monocarbamate bond (-C (= O) -NH-) or an ester bond (-C ( = O) -O-) connected in a linear or branched manner.

The polylactic acid resin exhibits characteristics such as eco-friendly properties and biodegradability, which are unique to the biomass-based resin system because the polylactic acid repeating unit serves as a hard segment. In addition, according to the experimental data obtained by the inventors of the present case, it was confirmed that the polylactic acid resin shows a greatly improved flexibility due to the polyolefin-based polyol repeating unit as a soft segment, and can produce a molding with high transparency and low haze product. In particular, due to the combination of the hard segment and the soft segment, the polylactic acid resin reduces the possibility of the soft segment flowing out due to reduced stability or flexibility. One molded product containing this polylactic acid resin is less likely to suffer from high turbidity or low transparency. Furthermore, this polylactic acid resin can achieve the above benefits without using a large amount of soft segments that cause flexibility; therefore, it can contain a relatively large amount of a biomass resin, for example, derived from a polylactic acid resin A hard segment.

At the same time, this polylactic acid resin contains a non-polar soft segment, and therefore, it has excellent moisture resistance compared to conventional polylactic acid resins.

The polylactic acid resin contained in the alloy resin composition of PLA / ABS, the organic carbon content (% C _bio ) of the biomass-based carbon as defined in Equation 1 may be at least about 60%, at least about 70%, at least about 80 %, At least about 85%, at least about 90%, or at least about 95%.

Compared with the polylactic acid resin contained in the PLA / ABS alloy resin composition of the present invention, it uses a polyolefin-based polyol repeating unit, when a polyester-based (polyester-based) repeating unit is used as a soft segment At this time, it may be difficult to obtain an organic carbon content (% C _bio ) of about 60% because it requires the use of a larger amount of other resins, such as a polyester-based polyol repeating unit derived from a petroleum-based source.

The organic carbon content (% C _bio ) of the biomass carbon represented by Equation 1 can be measured by a standard test method based on, for example, the ASTM D6866 standard. In the following, the technical significance and the method of measuring the organic carbon content (% C _bio ) of biomass carbon are explained in detail.

Generally, unlike organic materials derived from petroleum-based resins, organic materials derived from autotrophic (or living source) resins are known to contain ¹⁴ C isotopes within them. In particular, all organic materials taken from living organisms such as animals or plants contain three isotopes in a fixed ratio: ¹² C (about 98.892% by weight), ¹³ C (about 1.108% by weight) and ¹⁴ C (about 1.2 x 10 ^-10 % by weight). This ratio is the same as in the atmosphere, and it remains fixed because carbon is continuously exchanged with the environment through the metabolic action in living organisms.

At the same time, ¹⁴ C is a radioisotope, the amount of which decreases with time according to the following equation 2: [Equation 2] n = no‧exp (-at)

Among them, no is the number of ¹⁴ C atoms in the initial stage, n is the number of ¹⁴ C atoms left after time t, and a is a decay constant (or radioactive decay constant), which is related to the half-life.

In Equation 2, the half-life of ¹⁴ C is about 5,730 years. Considering this half-life, organic materials derived from living organisms that continuously interact with their surroundings, ie, biomass-based (living resource-based) resins, can sustain a fixed amount of ¹⁴ C and a fixed isotope. The content ratio, for example, one of ¹⁴ C / ¹² C fixed content ratio (weight ratio) = about 1.2 x 10 ^-12 , even if the isotope content is slightly reduced.

In comparison, fossil fuel systems such as coal or petroleum cannot exchange carbon atoms with the atmosphere for at least 50,000 years. According to Equation 2 above, the ¹⁴ C isotope content of organic materials derived from fossil fuel-based resins is at most 0.2% of the initial content; therefore, these materials do not substantially contain ¹⁴ C isotopes.

Equation 1 is based on the above technical significance. In Equation 1, the denominator may be the weight ratio of ¹⁴ C / ¹² C in primary biomass carbon, for example, about 1.2 x 10 ^-12 , and the numerator may be the weight ratio of ¹⁴ C / ¹² C in a resin sample. As explained above, based on the fact that the weight ratio of carbon atom isotopes derived from primary biomass is maintained at about 1.2 x 10 ^-12 and the weight ratio of carbon atom isotopes derived from fossil fuels is essentially 0, biomass is carbon organic The carbon content (% C _bio ) can be measured from one of the polylactic acid resins contained in a PLA / ABS alloy resin composition using Equation 1. The content and ratio of each carbon isotope can be determined by one of the three methods described in the standard ASTM D6866-06 (Standard Test Method for Determination of the Biosystem Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis)者 测。 Measurement. Preferably, the measurement can be carried out by mass spectrometry, in which a resin sample is reduced to graphite or carbon dioxide gas, which is then analyzed in a mass spectrometer or by scintillation spectroscopy. In mass spectrometry technology, an accelerator and a mass spectrometer are used to separate ¹⁴ C ions from ¹² C ions to measure the content and ratio of each carbon isotope. Alternatively, those skilled in the art can use liquid scintillation spectroscopy to measure the content and ratio of each carbon isotope to calculate the value in Equation 1.

When the organic carbon content (% C _bio ) of the biomass carbon measured by Equation 1 is at least about 60%, a polylactic acid resin and an alloy resin composition containing one of the resins PLA / ABS may contain a relatively large amount of biomass The resin and carbon of the system can therefore enhance the eco-friendly nature and biodegradability.

In particular, a polylactic acid resin having such a high organic carbon content (% C _bio ) and an alloy resin composition including PLA / ABS including this resin can exhibit eco-friendly properties as explained below.

Biochemical products such as polylactic acid resins are biodegradable and release a small amount of carbon dioxide; according to the current technological level, the amount of carbon dioxide released can be reduced by up to 108% compared with petrochemical products, and it is Energy can be saved up to 50%. In addition, when a biomass material is used in the manufacture of a bioplastic instead of fossil fuels, the CO ₂ emissions calculated by ISO 14000 conforming to life cycle analysis (LCA, life cycle assessment procedures) can be reduced by up to about 70%.

As a special example, according to NatureWorks, when manufacturing 1 kg of PET resin, 3.4 kg of CO _{2 is} released, and every 1 kg of polylactic acid resin (ie, a bioplastic) releases 0.77 kg of CO ₂ , this shows About 77% reduction in CO ₂ emissions. Furthermore, in terms of energy consumption, this bioplastic requires only 56% of energy compared to the energy consumption for PET. However, conventional polylactic acid resins are limited due to low flexibility, and it is observed that when other ingredients such as plasticizers are used to solve this problem, the above-mentioned advantages of bioplastics are significantly impaired.

However, a polylactic acid resin that satisfies the above-mentioned high organic carbon content (% C _bio ) and an alloy resin composition containing PLA / ABS of this resin can exhibit the advantages of bioplastics, and can be used in various applications because a polylactic acid The problem of low flexibility of the resin is solved.

Therefore, a polylactic acid resin satisfying the above-mentioned high organic carbon content (% C _bio ) and an alloy resin composition including PLA / ABS of this resin have the advantages of bioplastics, and therefore can significantly reduce CO ₂ emissions and Energy consumption shows the nature of being friendly to the environment. These eco-friendly properties can be measured by, for example, life cycle assessment (LCA) of a PLA / ABS alloy resin composition.

The polylactic acid resin in the alloy resin composition of PLA / ABS may contain about 7.2 × 10 ^-11 to 1.2 × 10 ^-10 % by weight, about 9.6 × 10 ^-11 to 1.2 × 10 ^-10 % by weight, or about 1.08 × 10 ¹⁴ C isotope in an amount of ^-10 to 1.2 × 10 ^-10 % by weight. The polylactic acid resin containing ¹⁴ C isotope of this content may have a relatively large amount of resin and carbon derived from the biomass, or substantially the entire resin and carbon are derived from the biomass, therefore, exhibit more improved biodegradability and Eco-friendly nature.

In the polylactic acid resin, the polylactic acid repeating unit of the hard segment and the polyolefin-based polyol structural unit of the soft segment can be derived from a single biomass. This polyolefin-based polyol structural unit can be obtained, for example, from a polyolefin-based polyol resin derived from a biomass. The biomass can be of any plant or animal origin, for example, one of plant origin such as corn, sugar cane or cassava. Therefore, an alloy resin composition containing a polylactic acid resin containing a polyolefin polyol structural unit derived from a biomass and a PLA / ABS containing the resin may contain a relatively large amount of organic carbon content (% C _bio ), for example, at least About 90% or at least about 95%.

In the polylactic acid resin, the hard segment derived from the biomass has at least about 90%, preferably about 95 to 100% of the organic carbon content (% C _bio ) as defined by Equation 1; and the soft segment derived from the biomass The segment has at least about 70%, preferably about 75 to 95%, organic carbon content (% C _bio ) as defined in Equation 1.

The PLA / ABS alloy resin composition containing this biomass-based polylactic acid resin has a high organic carbon content (% C _bio ) of at least about 60%, or at least about 80% of the biomass-based carbon, therefore, it complies with JBPA ’s “ Boimass Pla ”certification (one certification based on the standard ASTM D6866). Therefore, the alloy resin composition of PLA / ABS can properly bear the label of "Biomass" of JORA.

In the polylactic acid resin, the polylactic acid repeating unit of Chemical Formula 1 contained in the hard segment may be referred to as a polylactic acid homopolymer or a repeating unit of this homopolymer. The polylactic acid repeating unit can be obtained according to the conventional method for preparing polylactic acid homopolymer known in the art. For example, it can be formed by forming an L- or D-lactide from L- or D-lactic acid (ie, a cyclic dimer) and performing a ring-opening polymerization reaction, or by L- or D -Obtained by direct polycondensation of lactic acid. Among them, the ring-opening polymerization method is preferred because it can provide a higher degree of polymerization of polylactic acid repeating units. Furthermore, the polylactic acid repeating unit can be prepared by copolymerizing L-lactide and D-lactide at a specific ratio to make the copolymer non-crystalline, but the polylactic acid repeating unit is preferably It is prepared by homopolymerization of L-lactide or D-lactide in order to increase the heat resistance of one molded product containing this polylactic acid resin. In particular, A L- or D-lactide material with an optical purity of at least 98% can be subjected to a ring-opening polymerization reaction to obtain this polylactic acid repeating unit. Lower optical purity will lower the melting point of polylactic acid resin.

Meanwhile, the polyolefin-based polyol repeating unit included in the soft segment of the polylactic acid resin has a polyolefin-based polyol structural unit having the chemical formula 2 via a monourethane bond (-C (= O) -NH -) Or an ester bond (-C (= O) -O-) connected in a linear or branched manner. In particular, the polyolefin-based polyol structural unit may refer to a polymer prepared from a monomer such as butadiene (for example, poly 1,2-butadiene or poly 1,3-butadiene), or this polymer One of the structural units, especially a liquid phase hydroxyl-terminated polybutadiene (HTPB) prepared from a hydrogenation reaction and having a hydroxyl group at its terminal with a number average molecular weight of 1,000 to 5,000.

The terminal hydroxyl group of the polyolefin-based polyol structural unit, or a prepolymer prepared by an addition polymerization reaction between the terminal hydroxyl group of the polyolefin-based polyol structural unit and the lactide can be combined with a prepolymer The diisocyanate compound or one or more functional isocyanate compound reacts to form a monocarbamate bond. At the same time, the terminal hydroxyl group of polyolefin polyol structural unit can react with lactide or a lactic acid derivative compound to form an ester bond (-C (= O) -O-). The polyolefin-based polyol structural unit is connected through a urethane or ester bond in a linear or branched manner to form a polyolefin-based polyol repeating unit.

The molar ratio of the terminal hydroxyl group of the polyolefin-based polyol structural unit to the isocyanate group of the diisocyanate compound or the isocyanate compound of two or more functionalities may be 1: 0.50 to 1: 0.99. Preferably, polyene The molar ratio of the terminal hydroxyl group of the hydrocarbon-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 polyolefin-based polyol structural unit is a polymer linearly connected via a monourethane bond, or a repeating unit of this polymer, can be called a polyurethane polyol repeating unit, and can have The hydroxyl group at the terminal. Therefore, the polyolefin-based polyol repeating unit can be used as one of the initiators for forming the polylactic acid repeating unit in the polymerization reaction method. If the molar ratio of the terminal hydroxyl group to the isocyanate group is significantly higher than 0.99, the number of terminal hydroxyl groups of the repeating unit of the polyurethane polyol will be insufficient (OHV <1); therefore, it may not be suitable as One starter. Furthermore, if the molar ratio of hydroxyl groups to isocyanate groups is too low, the number of terminal hydroxyl groups of the polyolefin-based polyol repeat unit will be too large (OHV> 35); therefore, it may be difficult to obtain high molecular weight Polylactic acid repeating unit and 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 number average molecular weight of the polymer having a polyolefin-based polyol repeating unit is too large or too small, one of the molded products prepared from the polylactic acid and the PLA / ABS alloy resin composition containing polylactic acid may not have satisfactory Flexibility, moisture resistance and mechanical properties. Furthermore, the polylactic acid resin may not have suitable molecular weight properties, resulting in reduced processability of the PLA / ABS alloy resin composition, or deterioration of flexibility, moisture resistance, and mechanical properties of a molded product.

The isocyanate compound may be a diisocyanate compound, or Any compound having at least three isocyanate groups as long as it can form a monocarbamate bond with the terminal hydroxyl group of the polyolefin-based polyol repeating unit. It can 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-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4 ' -Bisphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated diphenylmethane diisocyanate. The multifunctional isocyanate compound can be selected from oligomers of diisocyanate compounds, polymers of diisocyanate compounds, cyclic polymers of diisocyanate compounds, hexamethylene diisocyanate isocyanurate, triisocyanate compounds, and A group of these isomers. In addition, various other diisocyanate compounds known to those skilled in the art can be used without particular restrictions. Considering the ability to impart flexibility to the polylactic acid resin, 1,6-hexamethylene diisocyanate is preferred.

Meanwhile, the polylactic acid resin contained in the composition may include a block copolymer, in which the terminal carboxyl group of the polylactic acid repeating unit contained in the hard segment is linked to the polyolefin contained in the soft segment via an ester bond It is connected to the terminal hydroxyl group of the polyol structural unit; or another block copolymer, in which these block copolymers are connected in a linear or branched manner through a carbamate bond.

In particular, the terminal carboxyl group of the repeating unit of the polylactic acid can be linked to the terminal of the repeating unit of the polyolefin polyol via an ester bond in the block copolymer The hydroxyl group is connected. For example, the chemical structure of the block copolymer can be represented by the following general formulas 1 and 2: [Formula 1] Polylactic acid repeating unit (L)-(E) -Polyolefin repeating unit (OUOUO)-(E)- Polylactic acid repeating unit (L)

[Formula 2] Polylactic acid repeating unit (L)-(E) -Polyolefin structural unit (O)-(E) -Polylactic acid repeating unit (L)-(U) -Polylactic acid repeating unit (L )-(E) -polyolefin polyol structural unit (O)-(E) -polylactic acid repeating unit (L)

Among them, O refers to a polyolefin polyol structural unit, U refers to a urethane bond, and E refers to an ester bond.

Since the polylactic acid resin includes a block copolymer in which the polylactic acid repeating unit and the polyolefin-based polyol structure or repeating unit are connected together, it suppresses the outflow of the polyolefin-based polyol structure or repeating unit that causes flexibility. Therefore, one of the molded products prepared therefrom may have excellent moisture resistance, transparency, mechanical properties, heat resistance, or anti-blocking properties. In addition, because at least some polylactic acid structures or repeating units and polyolefin polyol repeating units are monoblock copolymer types, the molecular weight distribution, glass transition temperature (Tg), and melting point (Tm) of the polylactic acid resin may be optimal The mechanical properties, flexibility, heat resistance, etc. of one of the molded products manufactured from it can be improved.

However, it is not necessary to connect all the polylactic acid repeating units contained in the polylactic acid resin to the polyolefin polyol structure or repeating units to form a monoblock copolymer. At least some of the polylactic acid repeating units may be one of polylactic acid homopolymers that are not bonded to the polyolefin-based polyol structure or repeating units. In this case, The polylactic acid resin may be a mixture containing one of the following: (i) The terminal carboxyl group of the polylactic acid repeating unit contained in the hard segment is linked to the polyolefin polyol structure contained in the soft segment via an ester bond A block copolymer connected to the terminal hydroxyl group of the unit, or a block copolymer prepared by connecting these block copolymers in a linear or branched manner through a monocarbamate bond; and (ii) A polylactic acid homopolymer that is not coupled with polyolefin-based polyol repeat units.

Meanwhile, based on 100 parts by weight of the total polylactic acid resin (when the polylactic acid homopolymer is selectively included, 100 parts by weight is the sum of the weights of the block copolymer and the homopolymer), the polylactic acid resin may contain Hard segments in an amount of about 65 to 95% by weight, about 80 to 95% by weight, or about 82 to 92% by weight; and about 5 to 35% by weight, about 5 to 20% by weight, or about 8 to 18% by weight The amount of soft segments.

If the content of the soft segment is too high, one of the polylactic acid resins with a high molecular weight cannot be easily provided. Therefore, a molded product prepared therefrom may have insufficient mechanical properties, for example, strength. The sliding properties, processability, or dimensional stability of a molded product during a packaging process will also decrease because the glass transition temperature of the resin decreases. On the contrary, if the content of the soft segment is too low, the flexibility and moisture resistance of the polylactic acid resin and one of the molded products prepared therefrom cannot be sufficiently improved. In particular, the glass transition temperature of the polylactic acid resin will be too high; therefore, the flexibility of a molded product will deteriorate. Furthermore, the polyolefin polyol structure of the soft segment or the repeating unit may not be used as an initiator. Therefore, the polymerization conversion rate may not be reduced or a polylactic acid resin having a high amount of mandarin ducks may not be prepared.

The polylactic acid resin in the alloy resin composition of PLA / ABS may have a number average molecular weight of about 50,000 to 200,000, preferably about 50,000 to 150,000. Furthermore, the polylactic acid resin may have a weight average molecular weight of about 100,000 to 400,000, preferably about 100,000 to 320,000. The molecular weight will affect the processability of the PLA / ABS alloy resin composition and the mechanical properties of a molded product. When the number average molecular weight is too small, the melt viscosity of the resin will be too small during a melting method such as extrusion, resulting in deterioration of the resin processability and mechanical properties of the product including strength during product preparation. Furthermore, when the number average molecular weight is too high, the resin may have significantly poorer processability and productivity due to its high melt viscosity.

In addition, the polylactic acid resin may have a molecular weight distribution (MWD) of about 1.60 to 3.0, preferably about 1.80 to 2.15, which is defined by the ratio of the weight average molecular weight (Mw) to the log average molecular weight (Mn) (Mw / Mn). When the molecular weight of the polylactic acid resin is distributed in this range, the resin has a suitable melt viscosity and melt processability during a melting method such as extrusion, so that it can be efficiently processed and extruded into a molded product, and contains this One of the molded products of polylactic acid resin shows good mechanical properties including strength. Conversely, when the molecular weight distribution of the polylactic acid resin is too narrow, the melt viscosity becomes too high, which makes it difficult to process and extrude the composition into a molded product. If the molecular weight distribution is too wide, the mechanical properties such as strength of a molded product will be damaged, and its melting properties will deteriorate, for example, resulting in too low a melt viscosity. Therefore, it may be difficult to extrude the composition into a molded product, or the product may be formed under poor extrusion conditions.

Furthermore, the polylactic acid resin may have about 145 to 178 ° C, about 160 Melting point (Tm) to 178 ° C, or about 165 to 175 ° C. When the melting point is too low, one molded product containing this polylactic acid resin will have poor heat resistance. If the melting point is too high, the polylactic acid resin will have poor moldability due to its high viscosity or high temperature molding.

In addition, the polylactic acid resin, for example, the block copolymer contained therein, has a glass transition temperature (Tg) of about 20 to 55 ° C, about 25 to 55 ° C, or about 30 to 55 ° C. When the polylactic acid resin has a glass transition temperature falling within this range, a molded product prepared from the PLA / ABS alloy resin composition can have appropriate flexibility and stiffness. If the glass transition temperature of the polylactic acid resin is too low, a molded product will have improved flexibility, but it will have poor sliding properties, processability, dimensional stability, or anti-blocking properties, when the molded product accepts a combination method Time, it will contribute to a significant low stiffness. Conversely, if a molded product has too high a glass transition temperature, the molded product shows poor flexibility and high stiffness, so that when a combination method is accepted, it cannot be closely adhered to a target product.

Meanwhile, based on the total weight of the polylactic acid resin contained therein, the PLA / ABS alloy resin composition may contain less than about 1% by weight, preferably about 0.01 to 0.5% by weight of residual monomers ( For example, lactide monomers used to form polylactic acid repeat units). Because the alloy resin composition of PLA / ABS includes a block copolymer with a special structural feature and a polylactic acid resin containing the block copolymer, and optionally an antioxidant, most of the lactic acid used in the preparation method The ester monomer precipitates in the polymerization reaction to form a polylactic acid repeating unit; and the depolymerization reaction or degradation of the polylactic acid resin does not actually occur. Therefore, the alloy resin composition of PLA / ABS can make residual monomers, For example, residual lactide monomers, etc., are kept to a minimum.

If the content of the residual monomer is about 1% by weight or more, the odor will be released in the method of forming a product using the alloy resin composition of PLA / ABS. The strength of a final molded product will also be impaired because the molecular weight of the polylactic acid resin will decrease during the molding process. In particular, when a molded product is applied to food packaging, safety problems arise due to residual monomers flowing out.

The polylactic acid resin may be included in an amount of, for example, 30 to 90% by weight based on the total weight of the alloy resin composition of PLA / ABS.

(B) Acrylonitrile-butadiene-styrene copolymer (ABS) resin

The ABS resin contained in the PLA / ABS alloy resin composition according to the present invention can strengthen the properties of the polylactic acid resin. The ABS resin contains an acrylonitrile-butadiene-styrene copolymer (ABS) as a main component in order to improve the properties of the polylactic acid resin such as impact resistance, stiffness, durability, and heat resistance.

The ABS-based resin contains acrylonitrile-butadiene consisting of 10 to 30% by weight of acrylonitrile, 10 to 30% by weight of butadiene, and 40 to 70% by weight of styrene. Styrene copolymer (ABS). At least 10% by weight of acrylonitrile results in suitable stiffness, oil resistance, and chemical resistance; and 30% by weight or less of acrylonitrile can have desirable properties such as moldability and impact resistance. At least 10% by weight of butadiene produces suitable impact resistance; and 30% by weight or less of butadiene can have desirable properties such as stiffness, oil resistance, and chemical resistance. Furthermore, at least 40% by weight of styrene leads to suitable moldability; and 70% by weight or less of styrene can have desirable properties such as strength Degree, oil resistance, chemical resistance and impact resistance.

The ABS-based resin may further include a styrene-acrylonitrile copolymer (SAN), which may be one of graft copolymers containing styrene in an amount of 60 to 80% by weight and acrylonitrile in an amount of 20 to 40% by weight. If styrene is within this amount, a SAN has good compatibility with an ABS, giving the composition the desired physical properties.

Furthermore, based on 100 parts by weight of the ABS-based resin, SAN may be included in an amount of 30 to 70 parts by weight. Based on 100 parts by weight of the ABS-based resin, 30 parts by weight or more of SAN results in suitable compatibility; and 70 parts by weight or less can have desirable properties such as impact resistance.

The ABS tree and the polylactic acid resin can be used as the matrix resin of the composition of the present invention.

For example, based on the total weight of the PLA / ABS alloy resin composition, the ABS-based resin may be included in an amount of 10 to 70% by weight, preferably 30 to 60% by weight. When the content is within this range, desired properties such as good compatibility with a polylactic acid resin, heat resistance, appearance, and impact resistance can be achieved.

The alloy resin composition of PLA / ABS may further contain an impact modifier.

The impact modifier may be selected from an olefin-based impact modifier, an acrylic-based impact modifier, a methacrylate / butadiene / styrene (MBS) -based impact modifier, a styrene / ethylene / Butadiene / styrene (SEBS) impact modifiers, at least one of silicon-based impact modifiers, and a polyester elastomer impact modifiers. Preferably, the impact modifier can It is an olefin-based impact modifier, more preferably an ethylene-δ-olefin copolymer.

The olefin-based impact modifier is economical, and has excellent impact resistance, elasticity, flexibility, and good compatibility with ABS resins. The ethylene-δ-olefin copolymer is preferably prepared using a metallocene catalyst.

The polylactic acid resin in the PLA / ABS alloy resin composition of the present invention incorporates a polyolefin-based polyol component into its polymer structure. Because it shows an impact modifier with an acrylic impact modifier, a methacrylic acid / butadiene / styrene (MBS) impact modifier, and a styrene / ethylene / butadiene / styrene (SEBS) impact modifier The quality agent, a silicon-based impact modifier and a polyester elastomer impact modifier have good compatibility, which can be used with any impact modifier without restriction.

Based on 100 parts by weight of the combined polylactic acid resin and ABS resin, the impact modifier can be used 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. If the impact modifier is within this content, the compatibility between the polylactic acid resin and the ABS resin is good, and one of the PLA / ABS alloy resin compositions prepared therefrom has significantly improved impact resistance, elongation and heat resistance Sex. Because the impact modifier reduces the heat resistance and injection moldability by reducing the crystallization rate and crystallinity of the PLA / ABS alloy resin composition, if the amount of the impact modifier exceeds 20 parts by weight, a molded product will have improvements Heat resistance and poor appearance.

Meanwhile, the alloy resin composition of PLA / ABS may contain an antioxidant. The antioxidant suppresses the yellowing of the polylactic acid resin, and therefore, improves the appearance of the PLA / ABS alloy resin composition and one of the molded products prepared therefrom. Furthermore, antioxidants can inhibit the oxidation or thermal degradation of soft segments.

For this purpose, based on the content of the monomer (for example, lactic acid or lactide) used to form the polylactic acid repeating unit of the polylactic acid resin, the PLA / ABS alloy resin composition may contain about 100 to 3,000 ppmw, about Antioxidants in amounts of 100 to 2,000 ppmw, about 500 to 1,500 ppmw, or about 1,000 to 1,500 ppmw.

If the amount of antioxidant used is too low, the flexing components such as soft segments will be oxidized, resulting in yellowing of the polylactic acid resin and PLA / ABS alloy resin composition and a poor appearance of a molded product. On the other hand, if the amount of the antioxidant used is too high, the polymerization reaction rate of lactide decreases, thus hindering the formation of segments containing polylactic acid repeating units. Therefore, the mechanical properties of the polylactic acid resin will be damaged.

If the antioxidant is used in an optimal amount, for example, the polylactic acid resin and the PLA / ABS alloy resin composition are produced by adding the antioxidant in the optimal amount during the polymerization reaction The degree of responsiveness is increased and therefore productivity is increased. Furthermore, since the alloy resin composition of PLA / ABS can have better thermal stability in a molding method exceeding 180 ° C, it can suppress the low of monomers such as lactide or lactic acid or chains such as cyclic oligomers Molecular weight materials are formed.

Therefore, by suppressing the reduction in molecular weight and the color change (yellowing) of the molded product, it can provide not only a better appearance of T but also improved flexibility and general properties such as mechanical properties, heat resistance, anti-blocking properties, etc. Molded products.

In particular, the PLA / ABS alloy resin composition may have a monoester repeating unit, which may be added by adding an antioxidant, a heat stabilizer, or a polymerization reaction Stabilizer to avoid oxidation or thermal degradation during a high temperature polymerization reaction, a high temperature extrusion method, or a high temperature molding method.

The PLA / ABS alloy resin composition is selected from one or more antioxidants of the group consisting of a hindered phenol-based antioxidant, a amine-based antioxidant, a sulfur-based antioxidant, and a phosphite-based antioxidant. Various other known antioxidants that can be applied to the PLA / ABS alloy resin composition can also be used.

Specific examples of antioxidants include phosphoric acid-based thermal stabilizers, such as phosphoric acid, trimethyl phosphate, and triethyl phosphate; hindered phenol-based primary antioxidants, such as 2,6-di-third-butyl-p-cresol , Octadecyl-3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate, tetrabis [benzyl-3- (3,5-di-tert-butyl-4- (Hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,5 -Di-tert-butyl-4-hydroxybenzyl phosphite diethyl ester, 4,4'-butylene-bis (3-methyl-6-tert-butylphenol), 4,4'-sulfur Bis (3-methyl-6-tert-butylphenol), and bis [3,3-bis- (4'-hydroxy-3'-tert-butylphenyl) butyric acid] diol ester; amine Secondary antioxidants, such as phenyl-α-naphthylamine, phenyl-β-naphthylamine, N, N'-diphenyl-p-phenylenediamine, and N, N'-di-β-naphthalene -P-phenylenediamine; thio-based secondary antioxidants, such as dilauryl disulfide, dilauryl thiopropionate, distearyl thiopropionate, mercaptobenzothiazole, and tetramethyl Tetraram disulfide tetrabis [methylidene-3- (laurylthio) propionate] methane; and phosphite series Grade antioxidants, such as triphenyl phosphite, tri (nonylphenyl) phosphite, triisodecyl phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, And (1,1'-diphenyl) -4,4'-diylbisphosphonic acid tetra [2,4-bis (1,1-dimethylethyl) phenyl] ester. most The best system uses one of the phosphite antioxidants in combination with other antioxidants.

In addition to the above-mentioned impact modifiers and antioxidants, the PLA / ABS alloy resin composition may contain various known additives, such as an anti-hydrolysis agent, a nucleating agent, an organic or inorganic filler, a plasticizer, a Chain extender, an ultraviolet stabilizer, a color blocker, an anti-glare agent, a deodorant, a flame retardant, an anti-weathering agent, an antistatic agent, a release agent, an oxidation inhibitor, a The ion exchanger, a coloring pigment, and inorganic or organic particles, as long as they have no adverse impact on the general properties of the PLA / ABS alloy resin composition.

The anti-hydrolysis agent is a reactive compound that can react with the terminal hydroxyl group or carboxyl group of polylactic acid. The anti-hydrolysis agent can increase the anti-hydrolysis property and durability of the PLA / ABS alloy resin composition. That is, the anti-hydrolysis agent can be applied to an ester-based resin such as polyester, polyamide, polyurethane, etc., to prevent the resin composition from passing through a seal that occurs at the end of the polymer chain by water or acid The lid reacts and hydrolyzes. The anti-hydrolysis agent can be carbodiimides, for example, modified phenylcarbodiimide, poly (tolylcarbodiimide), poly (4,4'-diphenylmethane carbodiimide (Imide), poly (3,3'-dimethyl-4,4'-biphenylenecarbodiimide), poly (p-phenylenecarbodiimide), poly (m- Phenylcarbodiimide), or poly (3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide). The anti-hydrolysis agent can be used in an amount of about 5 parts by weight based on 100 parts by weight of polylactic acid and ABS resin.

Based on 100 parts by weight of the PLA / ABS alloy resin composition (including the nucleating agent), the nucleating agent can be used in an amount of about 10% by weight, preferably 5% by weight. If the resin composition contains this content of nucleating agent, its heat resistance and Injection moldability can be improved. The nucleating agent may be a metal salt of a sorbitol, a metal salt of a phosphate, a quinacridone, a calcium carboxylate, and an organic compound of a amide series, preferably a metal salt of a phosphate series.

Examples of plasticizers include phthalate plasticizers, such as diethyl phthalate, dioctyl phthalate, and dicyclohexyl phthalate; aliphatic dibasic acid ester plasticizers, such as adipic acid dibasic -1-butyl, di-n-octyl adipate, di-n-butyl sebacate, and di-2-ethylhexyl azelate; phosphate plasticizers, such as diphenyl-2-ethyl phosphate Hexyl, and diphenyloctyl phosphate; polyhydroxycarboxylic acid ester plasticizers, such as, tributyl acetyl citrate, tri-2-ethylhexyl acetyl citrate, and tributyl citrate ; Aliphatic ester plasticizers, such as acetyl ricinoleic acid methyl, and stearic acid amide; polyhydric alcohol ester plasticizers, such as glycerol triacetate; and epoxy plasticizers , Such as, epoxidized soybean oil, epoxidized linseed oil fatty acid butyl ester, and epoxidized octyl stearate.

Furthermore, examples of coloring pigments may include inorganic pigments, such as carbon black, titanium oxide, zinc oxide, and iron oxide; and organic pigments, such as cyanine pigments, phosphorus, quinones, pyrenones, isoindolinone Category, and sulfur indigo.

When the PLA / ABS alloy resin composition is used to prepare a molded product, inorganic or organic particles can be used to improve the anti-blocking properties of the molded product. Based on the total weight of the PLA / ABS alloy resin composition, the amount of inorganic or organic particles may be about 30% by weight, preferably about 10% by weight. Examples of inorganic or organic particles may include silica, colloidal silica, alumina, alumina sol, talc, titanium dioxide, mica, calcium carbonate, polystyrene, polymethyl methacrylate, silicon, and the like. The surface treatment of the silicon dioxide, titanium dioxide, or talc is not particularly limited. However, if you use The reason is that titanium dioxide or talc, which gives molded products a balance of overall properties including stiffness and impact resistance, also improves properties such as reduced specific gravity, heat resistance and injection moldability. The surface treatment can be carried out by a chemical or physical method such as a silane coupling agent, a higher fatty acid, a fatty acid metal salt, an unsaturated fatty acid, an organic titanate, a resin acid, and polyethylene glycol Implementation. The average particle size of the inorganic particles may be 1 to 30 μm, preferably 1 to 15 μm. If the average particle size is within this range, one of the molded products containing the same shows improved heat resistance and stiffness.

Furthermore, various additives that can be applied to the PLA / ABS alloy resin composition or molded products prepared therefrom can be used, and the types and purchase paths are known to those skilled in the art.

At the same time, the PLA / ABS alloy resin composition in a sliced form may have a color-b value of less than 15, preferably 10 or less. Because the yellowing of the polylactic acid resin can be reduced by one of the antioxidants included in the alloy resin composition, the alloy resin composition can have a color-b value of less than 15. If the color-b value of the alloy resin composition is 15 or greater, the appearance of one of the molded products prepared from the alloy resin composition will be poor, resulting in low product value.

Hereinafter, the preparation method of the PLA / ABS alloy resin composition of the present invention will be explained in detail.

<Preparation of polyolefin polyol structural unit>

First, a hydroxyl group is introduced to the terminal of a polymer (poly1,2-butadiene or poly1,3-butadiene) prepared by copolymerization of butadiene monomer. Then, by forming a hydroxyl terminated polybutadiene (HTPB) having a number average molecular weight of 1,000 to 3,000, a monohydrogenation reaction is performed to obtain a polyolefin It is one (co) polymer of polyol structural unit. This method can be carried out by one of the conventional methods for preparing polyolefin polyol (co) polymers.

<Preparation of Polyolefin-based Polyol Repeating Unit A>

A (co) polymer containing polyolefin polyol structural units, a multifunctional isocyanate compound, and a monocarbamate reaction catalyst are charged into a reactor, and receive monocarbamate when heated and stirred reaction. This reaction combines the two isocyanate groups of the isocyanate compound with the terminal hydroxyl group of the (co) polymer, thus forming a monourethane bond. Therefore, one (co) polymer containing repeating units of a polyurethane polyol is formed, in which the polyolefin-based polyol structural units are connected in a linear or branched manner via a monourethane bond, etc. The unit system is one of the soft segments in a polylactic acid resin. The polyurethane polyol (co) polymer can be in the form of OUOUO or OU (-O) -OUO, in which the repeating units (O) of the polyolefin polyol are via a urethane bond (U ) Connected in a linear or branched manner, and both ends are polyolefin-based polyol repeating units.

<Preparation of Polyolefin-based Polyol Repeating Unit B>

Furthermore, (co) polymers containing polyolefin-based polyol structural units, lactic acid (D- or L-lactic acid), lactide (D- or L-lactide), and a condensation catalyst or a ring-opening The polymerization catalyst is loaded into a reactor and undergoes a polyesterification reaction or a ring-opening polymerization reaction. This reaction binds lactic acid (D- or L-lactic acid) or lactide (D- or L-lactide) to the hydroxyl group of the (co) polymer, thus forming an ester bond. Therefore, a (co) polymer comprising a polylactic acid resin repeating unit (L) and a polyolefin-based polyol (O) is formed, in which the polyolefin-based polyol structural unit is connected through Sex or branching. The (co) polymer may be in the form of L-E-O-E-L, in which the polyolefin-based polyol repeating unit (O) is linearly connected via an ester bond (E), and both ends are polylactic acid resin repeating units.

The two or more isocyanate groups of the isocyanate compound and the terminal hydroxyl group of the (co) polymer are combined in a linear or branched manner to form a urethane bond (U). Therefore, a polylactic acid resin can be obtained in the final form of L-E-O-E-L-U-L-E-O-E-L.

Polyolefin-based polyol repeat units prepared from butadiene can be derived from biomass, for example, a plant source; therefore, polyolefin-based polyol (co) polymers can have an extremely high organic carbon content of at least about 70% (% C _bio ).

The carbamate reaction can be carried out in the presence of a tin catalyst, for example, tin octoate, dibutyltin dilaurate, dioctyltin dilaurate, and the like. In addition, the urethane reaction can be carried out under typical reaction conditions used to prepare polyurethane resins. For example, the isocyanate compound and polyolefin polyol (co) polymer are accepted in the presence of a monocarbamate reaction catalyst, and the reaction at 70 to 80 ° C under a nitrogen atmosphere lasts for 1 to 5 hours, resulting in One (co) polymer of polyol repeating units.

Thereafter, the PLA / ABS alloy resin composition containing the block copolymer (or the polylactic acid resin containing the block copolymer) and an antioxidant may be composed of a polyolefin-based polyol repeating unit due to the antioxidant and In the presence of this (co) polymer, the polycondensation reaction of lactic acid (D- or L-lactic acid) or the ring-opening polymerization reaction of lactide (D- or L-lactide) is prepared. That is, according to these polymerization reactions, a polylactic acid resin having a polylactic acid repeating unit as a hard segment is formed, and at the same time, yellowing of the resin due to oxidation of the soft segment can be achieved by Dad antioxidant inhibition. During this method, the polyurethane polyol repeating unit is bonded to at least some terminal groups of the polylactic acid repeating unit to produce a block copolymer.

Furthermore, a prepolymer can be prepared by combining a polyolefin polyol and lactide. The prepolymer can be reacted with one of the diisocyanate compounds to obtain a known polylactic acid-based copolymer, or with one of the isocyanate compounds having at least two functional groups to obtain a known branched block copolymerization Thing.

Meanwhile, the ring-opening polymerization of lactide can be carried out in the presence of a metal catalyst, such as an alkaline earth metal, a rare earth metal, a transition metal, aluminum, germanium, tin, and antimony. In particular, the metal catalyst may be of the carbonate type, alkoxide type, halide type, oxide type, or carbonate type. Tin octoate, titanium tetraisopropoxide, or aluminum triisopropoxide are preferred as metal catalysts.

Furthermore, the formation of polylactic acid repeat units through the ring-opening polymerization of lactide can be carried out continuously in the same reactor where the urethane reaction has occurred. That is, a polyolefin-based polyol polymer and an isocyanate compound undergo a monocarbamate reaction to produce a polymer containing polyolefin-based polyol repeating units, and then, monomers such as lactide and a catalyst are continuous To the same reactor in order to obtain a polylactic acid repeating unit. Therefore, a polymer containing a polyolefin-based polyol repeating unit as an initiator can continuously produce a polylactic acid repeating unit and a polylactic acid resin containing the polylactic acid repeating unit with high productivity and productivity. In a similar manner, a polyolefin polyol receives a ring-opening polymerization reaction with one of a lactide starter, and then, A monoisocyanate compound is continuously added to the same reactor, and a chain elongation reaction is performed to obtain a polylactic acid repeating unit and a polylactic acid resin containing the polylactic acid repeating unit with high yield and productivity.

Therefore, the prepared polylactic acid resin is mixed with an ABS resin and other components to obtain a PLA / ABS alloy resin composition.

Because the PLA / ABS alloy resin composition includes a block copolymer (a polylactic acid resin) in which special hard segments and soft segments are combined, it can have improved flexibility and at the same time show that it can be attributed to polymer Biodegradability of lactic resin. Furthermore, this resin composition can minimize the outflow of soft segments that cause flexibility, and can largely avoid the moisture resistance, mechanical properties, heat resistance, and transparency of a molded product that may be caused by the formation of soft segments Or the anti-turbidity property is reduced.

In addition, the polylactic acid resin thus prepared has a specific glass transition temperature and a specific melting point (Tm) of selectivity. Therefore, a molded product prepared therefrom has optimized flexibility and stiffness as a packaging material, and also has good melt processability, anti-blocking property, and heat resistance. Therefore, the polylactic acid resin and the PLA / ABS alloy resin composition containing the polylactic acid resin can be preferably used as a packaging material such as a molded product.

Furthermore, in the preparation method or in the user, due to the presence of antioxidants, the yellowing of the polylactic acid resin can be suppressed, and the PLA / ABS alloy resin composition containing these components can be manufactured with flexible modifications such as significant improvements. It is one of the better general properties of good mechanical properties and excellent mechanical properties, and at the same time can have a better appearance and product quality.

That is, the PLA / ABS alloy resin composition of the present invention contains polyene The hydrocarbon-based polyol repeating unit serves as a soft segment; therefore, one of the molded products prepared from the PLA / ABS alloy resin composition has significantly improved flexibility.

Furthermore, the polyolefin polyol in the soft segment (which is non-polar compared to the polylactic acid resin, ie, the hard segment) can reduce the moisture content of the resin, and the moisture resistance of the resin can be significantly improved.

Hereinafter, the functions and effects of the present invention will be more clearly explained by the following examples. However, these examples are provided for illustrative purposes only, and the present invention is not limited to these examples.

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

1. Polyolefin-based polyol repeating unit and its counterpart

-HTPB 1.0: hydroxyl-terminated polybutadiene (HTPB) with a molecular weight of 1,000, which is a conjugated polymer (poly1,2-butadiene) by introducing a hydroxyl group to one of the butadiene monomers Or poly 1,3-butadiene) terminal, followed by a hydrogenation reaction to prepare.

-HTPB 2.0: a hydroxyl terminated polybutadiene (HTPB) with a molecular weight of 2,000, which is a conjugated polymer (poly1,2-butadiene) by introducing a hydroxyl group to one of the butadiene monomers Or poly 1,3-butadiene) terminal, followed by a hydrogenation reaction to prepare.

-HTPB 3.0: hydroxyl-terminated polybutadiene (HTPB) with a molecular weight of 3,000, which is a conjugated polymer (poly1,2-butadiene) by introducing a hydroxyl group to one of the butadiene monomers Or poly 1,3-butadiene) terminal, followed by a hydrogenation reaction to prepare.

-HTPB 5.0: hydroxyl terminated polybutadiene (HTPB) with a molecular weight of 5,000, which is conjugated by introducing hydroxyl groups to one of the butadiene monomers Compound (poly 1,2-butadiene or poly 1,3-butadiene) terminal, followed by a hydrogenation reaction to prepare.

-PEG 8.0: polyethylene glycol with an average molecular weight of 8,000.

-PPDO 2.4: Poly (1,3-propanediol) with an average molecular weight of 2,400.

-PBSA 11.0: An aliphatic polyester polyol prepared by polycondensation reaction of 1,4-butanediol, succinic acid, and adipic acid, and having a number average molecular weight of 11,000.

2. Diisocyanate compounds and isocyanate compounds with at least three functional groups

-HDI: hexamethylene diisocyanate

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

-D-L75: Bayer, Desmodur L75 (trimethylolpropane + 3 toluene diisocyanate)

3. Lactide monomer

-L- or D-lactide: manufactured by Purac and containing organic carbon derived from autogenous substance with only 99.5% higher optical purity

4. Antioxidants, etc.

-TNPP: tris (nonylphenyl) phosphite

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

-S412: Tetra [methane-3- (laurylthio) propionate] methane

-PEPQ: (1,1'-biphenyl) -4,4'-diylbisphosphonic acid tetra [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'-third butyl-phenyl) butyric acid] glycol ester

5. Acrylonitrile-butadiene-styrene copolymer (ABS) resin

-ABS745: one part of 40 parts by weight of acrylonitrile-butadiene-styrene copolymer (ABS) (which contains 20% by weight of acrylonitrile, 25% by weight of butadiene, and 55% by weight of styrene), and 60 parts by weight of a mixture of styrene-acrylonitrile copolymer (SAN), manufactured by Kumho Petrochemical Co., Ltd., and having a melt index of 10 g / 10 min (220 ° C, 10 kg), of 84 ° C Heat distortion temperature, impact strength (6.4mm, 23 ℃) 35kgf. cm / cm

6. Impact modifier, etc.

-G1701: block copolymer of styrene / ethylene / propylene, with 37% by weight of styrene and manufactured by KRAPTON, with a stiffness of 72 HD (Shore A, 30s)

-MB838A: Methyl methacrylate / butadiene / styrene (MBS) block copolymer manufactured by LG Chem. With a stiffness of 71 HD (Shore A, 30S)

-Biostrength150: acrylic core / shell impact modifier made by ARKEMA

7. Inorganic fillers and nucleating agents, etc.

-SP-3000: Talc manufactured by Dawon Chem. Has an average particle size of 2.5 μm and a bulk density of 0.32 g / cm ²

-EMforce ^TM Bio: CaCO ₂ manufactured by Special Mineral, with an average particle size of 1.0 μm and an aspect ratio of 5.4

-TF-1: N, N ', N "-tricyclohexyl-1,3,5-benzenetricarboxamide manufactured by NJC Co., Ltd.

-NA-11: 2,2'-Methylbis 4,6-di-tert-butylphenol) sodium phosphate manufactured by Asahi Denka

8. Anti-hydrolysis agent and chain extender

-BioAdimide 100: carbodiimide polymer manufactured by Rhein Chemie

-ADR 4368: Styrene / acrylic polymer made by BASF

9. Compatibilizer, etc.

-AX8840: ethylene-maleic anhydride grafted-glycidyl methacrylate copolymer made by Arkema, with a graft ratio of 8.0%

-PH-200: Propylene-maleic anhydride graft copolymer manufactured by Honam Petrochemical Corp. with a graft ratio of 3.9%

Preparation Examples 1 to 6: Preparation of polylactic acid resins A to F

According to the ingredients and contents in Table 1 below, the reactants and a catalyst were filled into an 8-liter reactor equipped with a nitrogen tube, a stirrer, a catalyst inlet, a first-class output condenser, and a vacuum system. Based on the total weight of the reactants, dibutyltin dilaurate is used as a catalyst in an amount of 130 ppmw. Under a nitrogen atmosphere, the monocarbamate reaction was carried out at 70 ° C for 2 hours. Then, 4 kg of L- (or D-) lactide was fed into the reactor, and then flushed with nitrogen five times.

Thereafter, the reaction mixture was heated to 150 ° C to completely dissolve the L- (or D-) lactide. Based on the total weight of the reactants, a 120 ppmw tin 2-ethylhexanoate catalyst was diluted with 500 ml of toluene. The solution thus obtained is fed into the reactor via the catalyst inlet. Under a nitrogen pressure of 1 kg, the reaction was carried out at 185 ° C for 2 hours. Then, phosphoric acid was added to the reaction mixture through the catalyst inlet in an amount of 200 ppmw, and mixed with it for 15 minutes to deactivate the catalyst. After the catalyst is deactivated, a vacuum condition is applied until the pressure reaches 0.5 Torr to remove unreacted L- (or D-) lactide (about 5 wt% of the initial distillation weight). The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 7: Preparation of polylactic acid resin G

As shown in Table 1 below, 865 grams of HTPB 2.0 and 3.9 kilograms of L-lactide and 0.1 kilograms of D-lactide are charged to the installation of a nitrogen tube, a stirrer, a catalyst inlet, and first-class effluent condensation And an 8-liter reactor in a vacuum system, followed by nitrogen flushing five times. Thereafter, the reaction mixture was heated to 150 ° C to completely dissolve the lactide. Based on the total weight of the reactants, a 120 ppmw tin 2-ethylhexanoate catalyst was diluted with 500 ml of toluene. The solution thus obtained is fed into the reactor via the catalyst inlet. Under a pressure of 1 kg of nitrogen, the reaction was carried out at 185 ° C for 2 hours. Then, phosphoric acid was added to the reaction mixture in an amount of 200 ppmw via the catalyst inlet, and mixed with it for 15 minutes to deactivate the catalyst. After the catalyst is deactivated, a vacuum condition is applied until the pressure reaches 0.5 Torr to remove unreacted L-lactide (about 5 wt% of the initial feed weight). Then, a solution of HDI as shown in Table 1 and 120 ppmw of dibutyltin dilaurate catalyst in 500 ml of toluene was introduced into the reactor through the catalyst inlet. Under a nitrogen atmosphere, a polymerization reaction was carried out at 190 ° C. for 1 hour, and the molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 8: Preparation of polylactic acid resin H

A polylactic acid resin was prepared according to the same procedure as Preparation Example 7, except that 885 g of HTPB 2.0, 3.8 kg of L-lactide, and 0.2 kg of D-lactide were used as shown in Table 1 below, Thereafter, HDI and D-L75 were introduced. The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 9: Preparation of polylactic acid resin I

As shown in Table 1 below, polyethylene glycol and 4 kg of L-lactide are charged to one of a nitrogen pipe, a stirrer, a catalyst inlet, a first-class effluent condenser, and a vacuum system Within the 8-liter reactor, nitrogen was flushed five times thereafter. Thereafter, the reaction mixture was heated to 150 ° C to completely dissolve the lactide. Based on the total weight of the reactants, 120 ppmw of tin 2-ethylhexanoate catalyst was diluted with 500 ml of toluene. The solution thus obtained is fed into the reactor via the catalyst inlet. Under a nitrogen pressure of 1 kg, a reaction was carried out at 185 ° C for 2 hours. Then, phosphoric acid was added to the reaction mixture in an amount of 200 ppmw via the catalyst inlet, and mixed with it for 15 minutes to deactivate the catalyst. After the catalyst is deactivated, a vacuum condition is applied until the pressure reaches 0.5 Torr to remove unreacted L-lactide. The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 10: Preparation of Polylactic Acid Resin J

A polylactic acid resin was prepared according to the same procedure as Preparation Example 9, except that 378.8 g of poly (1,3-propanediol) (PPDO) having a number average molecular weight of 2,400 was used as shown in Table 1. The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 11: Preparation of polylactic acid resin K

A polylactic acid resin was prepared according to the same procedure as Preparation Example 9, except that 6 grams of 1-dodecyl alcohol was used in place of the polyol as shown in Table 1. The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Preparation Example 12: Preparation of polylactic acid resin L

As shown in Table 1 below, PBSA 11.0 (polyester polyol) and HDI were charged to an 8-liter reaction equipped with a nitrogen tube, a stirrer, a catalyst inlet, a first-class effluent condenser, and a vacuum system Afterwards, flush with nitrogen five times. Based on the total weight of the reactants, dibutyltin dilaurate is used as a catalyst in an amount of 130 ppmw. Under a nitrogen atmosphere, the monocarbamate reaction was carried out at 190 ° C for 2 hours. Then, 4 kg of L-lactide was fed into the reactor and completely dissolved in a nitrogen atmosphere at 190 ° C. The amount of 120 ppmw as an addition polymerization catalyst of tin 2-ethylhexanoate and the amount of 1,000 ppmw as an ester and / or ester amide exchange catalyst of dibutyltin dilaurate were diluted with 500 ml of toluene and passed through the catalyst Entrance is introduced. Under a nitrogen pressure of 1 kg, a reaction was carried out at 190 ° C for 2 hours. Then, phosphoric acid was added to the reaction mixture in an amount of 200 ppmw via the catalyst inlet, and mixed with it for 15 minutes to deactivate the catalyst. After the catalyst is deactivated, a vacuum condition is applied until the pressure reaches 0.5 Torr to remove unreacted L-lactide (about 5 wt% of the initial feed weight). The molecular weight, Tg, Tm,% C _bio, etc. of the obtained resin were measured and shown in Table 1.

Examples 1 to 8 and Comparative Examples 1 to 8: Preparation of molded products

The polylactic acid resins prepared in Preparation Examples 1 to 12 were dried under reduced pressure under a low vacuum of 1 Torr at 80 ° C for 6 hours, and mixed with polypropylene and other materials as shown in Table 2 or 3 in an ultra mixer . The mixture thus obtained was kneaded and extruded into a strand type at an extrusion temperature of 220 to 250 ° C with a 19 mm twin screw extruder. (In addition, various known devices such as a single screw extruder, a roll mill, a kneader, or a Banbury mixer can be used). The strands thus formed are cooled in a water bath and cut into pellets with a granulator. The pellets thus prepared were dried in a hot air dryer at 80 ° C for 4 hours, and subjected to injection molding to obtain product samples. The molded product samples were evaluated, and the results are shown in Tables 2 and 3.

Experimental example

(1) NCO / OH: isocyanate group of diisocyanate compound (for example, hexamethylene diisocyanate) / polyether-based polyol repeating unit (or (common ) The molar ratio of the terminal hydroxyl groups of the polymer).

(2) OHV (KOH mg / g): By dissolving a polyolefin-based polyol repeating unit (or (co) polymer) in dichloromethane, the repeating unit is acetylated to make the acetyl group The repeated units of hydrolysis hydrolyze to produce acetic acid, which is measured by titrating acetic acid with 0.1 N KOH in methanol. It indicates the number of terminal hydroxyl groups of the polyolefin-based polyol repeating unit (or (co) polymer).

(3) Mw and Mn (g / mol), and molecular weight distribution (Mw / Mn): by subjecting a 0.25% by weight solution of polylactic acid resin in chloroform to a gel permeation chromatography (Viscotek TDA 305 , Column: Each is measured by Shodex LF804 x 2). Polystyrene is used as a standard material to determine the weight average molecular weight (Mw) and number average molecular weight (Mn). The molecular weight distribution (MWD) is calculated from Mw and Mn.

(4) Tg (glass transition temperature, ° C): After quenching a molten sample, and then increasing the sample temperature at a rate of 10 ° C / min, it was measured with a differential scanning calorimeter (TA Instruments). Tg is determined from the median value of a tangent line on an endothermic curve and a baseline.

(5) Tm (melting point, ℃): after quenching a molten sample, then, When the sample temperature was increased at a rate of 10 ° C / min, it was measured with a differential scanning calorimeter (TA Instruments). Tm is determined from the maximum value of the melting endothermic peak of one of the crystals.

(6) Residual monomer (lactide) content (wt%): by dissolving 0.1 g of one resin in 4 ml of chloroform, adding 10 ml of hexane to this, and filtering the resulting mixture, followed by A GC analysis and measurement.

(7) Content of polyolefin-based polyol repeating unit (% by weight): The content of polyolefin-based polyol repeating unit in each polylactic acid resin is measured using a 600 MHz nuclear magnetic resonance (NMR) spectrometer.

(8) Slice color-b: The color-b value of a resin slice is measured using a color difference meter CR-410 manufactured by Konica Minolta Sensing Co. and indicated by the average value of five measurements.

(9) Organic carbon content (% C _bio ) of biomass carbon: It is one of the test measurements to measure the content of primary biomass materials according to ASTM D6866 from the amount of organic radioactive carbon (percent modern; ¹⁴ C).

(10) Extrudability: A PLA / ABS alloy resin is extruded into a strand at 220 to 250 ° C with a 30 mm twin screw extruder equipped with a hole die. The extruded strands were cured in a water bath at 20 ° C. At this time, the melt viscosity and uniformity of the extrudate were visually observed. The uniformity of melt viscosity (extrusion) is evaluated according to the following criteria: ●: due to the good compatibility between the two resins and the uniform melt viscosity, the strands are easily prepared without cracking; O: due to the low compatibility and low The melt viscosity is uniform and the strand is prepared with some cracks; and X: Due to the extremely low compatibility between the two resins and the poor uniformity of the melt viscosity, the strand is not prepared and has cracks and die expansion.

(11) Melt index (MI): measured according to ASTM D1238 at 220 ° C, 2.16 kgf, and indicated by the average of three measurements.

(12) Compatibility: A polylactic acid resin PLA / ABS alloy resin is extruded at 220 to 250 ° C using a 30-mm twin-screw extruder equipped with a one-hole die. The extrudate was cured in a water bath at 20 ° C to obtain a strand sample. The strand sample is immersed in a liquid nitrogen and cut. The cut surface was observed using a scanning electron microscope (SEM) and evaluated according to the following criteria: ●: the two resins were well dispersed, and the particle size of the undispersed resin was 0.2 μm or less; O: acceptable phase between the two resins Capacitive, and the particle size of the undispersed resin is 1.0 μm or less; and X: poor dispersibility between the two resins, and the particle size of the undispersed resin is 1.0 μm or more.

(13) Appearance: The appearance of a sample is visually inspected to check flow marks, bonding lines, and reduce gloss. These are caused by reduced fluidity, as follows: ●: No flow marks and bonding lines, which are due to good melting Viscosity, and good surface gloss; O: no flow marks and bonding lines, which is due to a slightly higher melt viscosity, but the gloss is reduced; and X: flow marks, bonding lines and gloss are reduced, which is due to extremely high melt viscosity.

(14) Initial tensile strength (kgf / cm ² ): A sample was prepared according to ASTM D638, and was adjusted at a temperature of 20 ° C and a humidity of 65% RH for 24 hours. The initial tensile strength was measured using a universal testing machine (UTM, manufactured by INSTRON) and indicated by the average of five measurements.

(15) Elongation (%): judged when a sample is broken under the same conditions as those used for the initial tensile strength of (14) above. The average of five measurements is provided.

(16) Impact strength (kgf.cm/cm): tested according to ASTM D256 using a cantilever impact tester.

(17) Flexural strength (kgf / cm ² ) and flexural modulus (kgf / cm ² ): A test sample was prepared according to ASTM D790. The flexural strength and flexural modulus are measured using a UTM (INSTRON). The average of five measurements is provided.

(18) Heat resistance (° C): A test sample was prepared in accordance with ASTM D648, and the heat resistance of the sample was tested using a UMT.

i) High temperature mold: a high temperature mold is used at 110 ° C, and the cooling duration is about 30 seconds.

ii) Low temperature mold: use a low temperature mold at room temperature, and the cooling duration is about 30 seconds.

(19) Outflow resistance: The surface of a molded product is observed, and the outflow of low molecular weight plasticizer on the surface of the molded product is tactilely evaluated on an A4 size film sample and evaluated according to the following criteria: ●: No outflow; O: outflow, but not severe; and X: severe outflow.

(20) Tensile strength retention rate (%): A film sample with a length of 150mm and a width of 10mm was prepared and at a temperature of 40 ° C and a humidity of 90% RH Adjust for 30 days. The tensile strength is measured and compared with the initial tensile strength value.

(21) Malodor: After the mixing method, highly volatile malodor from a discharge extrusion mixture was checked:

●: Malodor was detected.

X: No malodor was detected.

(22) Total Volatile Organic Compounds (TVOC): Headspace (HS) -GC / MS analysis

1) A 2 gram sample is placed in a sealed glass vial and subjected to HS-GC / MS.

2) STD: A series of 250, 500, and 1,000 ppm toluene standard solutions (50 μL) were prepared, sealed in a small glass bottle, and subjected to HS-GC / MS analysis.

3) HS-GC / MS

-HS: heating at 180 ° C (30 minutes), and performing headspace gas analysis.

-Column DB-5 (60m × 0.32mm × 1.0μm)

-80 ℃ (5 minutes) -10 ℃ / min-320 ℃ (16 minutes), injection 280 ℃, 1:30 split

(23) Chemical resistance: Gasoline and a solvent (each of which is 10 ml) are led to a 20 ml small glass bottle, and each sample (10 mm × 30 mm × 2 mm) is added to this small glass bottle. After 2 hours, the chemical resistance of each sample was evaluated according to the following criteria: ●: no whitening and swelling were detected; O: whitening was detected; but no swelling was detected; and X: whitening and swelling were detected.

Referring to Table 2, Examples 1 to 5 and 7 to 8 represent from PLA / ABS alloy Molded product made of resin composition. These compositions contain a soft segment (ie, polyolefin-based polyol repeating unit) in an amount of 5 to 35% by weight in a polylactic acid resin, have a low color-b value, and contain one of the appropriate amounts The antioxidant has a weight average molecular weight of 100,000 to 400,000 and a molecular weight distribution of 1.60 to 3.0, a Tg of 20 to 60 ° C, and a Tm of 145 to 178 ° C. Furthermore, Example 6 shows a molded product prepared from a polylactic acid / ABS alloy resin composition, which includes a conventional polylactic acid resin (Resin K) and one polylactic acid resin (Resin F) of the present invention.

The molded products of Examples 1 to 8 have excellent mechanical properties, such as an initial tensile strength of 300 kgf / cm ² or more, and 15 kgf. Impact strength of cm / cm or more. They have good heat resistance expressed by high temperature mold HDT of 75 ° C or more. Furthermore, when the sample is adjusted at a temperature of 40 ° C and a humidity of 90% RH for 30 days, the molded product has a retention rate of tensile strength of 80% or more, due to the absence of styrene or an acrylic compatibilizer and a plastic TVOC of 200ppm or less of chemical agent, and no outflow, therefore, effectively reduce the total volatile organic compounds harmful to the human body. Furthermore, they are eco-friendly materials with a total organic carbon content of 25% or more.

On the contrary, although the molded product prepared from the PLA / ABS alloy resin containing one of the conventional polylactic acid resins of Comparative Example 1 has good general properties, it has a total organic carbon content of 25% or less, so The global standard of environmentally friendly plastics. Furthermore, the molded product prepared from the PLA / ABS alloy resin composition containing one of the polylactic acid resin K of Comparative Example 2 lacks compatibility between the polylactic acid resin and the ABS-based resin, and the melt viscosity between the resins is large Difference. Therefore, the final product is not suitable as a molded product because it has poor extrudability, which can be attributed to the die expansion when the molten composition is discharged, the tensile strength of less than 200kgf / cm ² is less than 5kgf‧cm / cm impact strength, and poor moisture resistance. For the molded products of Comparative Examples 3 and 4 prepared from the PLA / ABS alloy resin composition containing the polylactic acid resin K combined with a compatibilizer, the compatibilizer has good extrudability. However, the compatibility between the two resins is insufficient to give the final molded product sufficient mechanical properties, moisture resistance, and heat resistance. Furthermore, the compatibilizer releases severe malodors and causes run-off problems.

The molded product of Comparative Example 5 consists of polylactic acid resin K lacking a polyolefin-based polyol repeating unit (a soft segment) and poly (1,3 having a number average molecular weight of 2,400 as a plasticizer -Propylene glycol) is simply mixed and kneaded, and then the mixture thus obtained is prepared by injection molding. Due to the unsatisfactory dispersibility of the plasticizer in the resin, it has high turbidity, poor extrudability and appearance. Furthermore, after a period of time has elapsed, the plasticizer flows out of the shaped product. Molded products also have poor moisture resistance and TVOC properties.

The molded products of Comparative Examples 6 and 7 prepared from the PLA / ABS alloy resin composition containing each of the polylactic acid resins I and J lacked compatibility between the two resins, and the melt viscosity between these resins involved Large difference; therefore, the final product is not suitable as a molded product because it has poor extrudability, which can be attributed to die expansion when the molten composition is discharged.

The molded product of Comparative Example 8 was prepared from a PLA / ABS alloy resin containing a polylactic acid resin having a wide molecular weight distribution and a polyester polyol repeating unit. Because the molded product has as a soft The polyamine carbamate, which is randomly introduced in the form of small segments, has relatively good bleeding resistance and TVOC properties. However, due to the relatively small size of the polylactic acid repeating unit, the molded product has poor heat resistance such as low Tm, and also has poor mechanical properties due to compatibility issues. Due to the poor compatibility between the polyester polyol used to form a soft segment and the polylactic acid resin, it also lacks uniformity. It has poor extrudability, mechanical properties, and moisture resistance.

Meanwhile, the pellets prepared in Examples 1 to 3 were observed using a scanning electron microscope, and the results are individually illustrated in FIGS. 1 to 3.

In FIGS. 1 to 3, it is noted that there is no clear distinction between the polylactic acid resin and the ABS resin, regardless of the ratio between them. This indicates that the compatibility between the two resins is enhanced, even if there is no specific compatibilizer, this also indicates improved flexural modulus and impact strength.

In summary, the polylactic acid resin or ABS resin in the PLA / ABS alloy resin composition improves the compatibility between the two resins. Therefore, the properties known to be insufficient for a polylactic acid resin system, such as heat resistance, The crystallization rate and impact resistance balance the overall properties of the resin composition.

Claims (16)

A polylactic acid (PLA) / acrylonitrile-butadiene-styrene copolymer (ABS) alloy resin composition, comprising: 30 to 90 parts by weight of polylactic acid resin, and 10 to 70 parts by weight of ABS resin , Wherein the polylactic acid resin includes a hard segment and a soft segment, the hard segment includes a polylactic acid repeating unit of Chemical Formula 1, the soft segment includes a polyolefin-based polyol repeating unit, in the polyolefin In the polyol repeating unit, the polyolefin polyol structural units of Chemical Formula 2 are connected in a linear or branched manner through a carbamate bond or an ester bond, wherein the biomass carbon defined by Equation 1 The organic carbon content (% C _bio ) is at least 60%, and in formulas 1 and 2, n is an integer from 700 to 5,000, and m + l is an integer from 5 to 200:

[Equation 1]% C _bio = (weight ratio of ¹⁴ C isotope to ¹² C in the total carbon content of the polylactic acid resin) / (weight of ¹⁴ C to ¹² C in the total carbon content of the primary carbon standard material Ratio) x100. According to the PLA / ABS alloy resin composition of claim 1, based on the combination of 100 parts by weight of the polylactic acid resin and the ABS-based resin, it further contains an impact modifier in a content of 0.1 to 20 parts by weight. The PLA / ABS alloy resin composition according to claim 1, wherein the ¹⁴ C isotope content in the polylactic acid resin is 7.2 × 10 ^-11 to 1.2 × 10 ^-10 % by weight. The PLA / ABS alloy resin composition according to claim 1, wherein the soft segment has an organic carbon content (% C _bio ) of at least 70% of the biomass carbon defined in Equation 1 above. The PLA / ABS alloy resin composition according to claim 1, wherein 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. The PLA / ABS alloy resin composition according to claim 1, wherein the polylactic acid resin has a glass transition temperature (Tg) of 20 to 55 ° C and a melting point (Tm) of 145 to 178 ° C. The PLA / ABS alloy resin composition according to claim 1, wherein the urethane bond is through the terminal hydroxyl group of the polyolefin-based polyol structural unit, or through the polyolefin-based polyol structural unit The prepolymer prepared by the addition polymerization reaction between the terminal hydroxyl group and the lactide is formed by the reaction between a diisocyanate compound or an isocyanate compound with one or two or more functionalities. The PLA / ABS alloy resin composition according to claim 1, wherein the polylactic acid resin includes a block copolymer, and in the block copolymer, the terminals of the polylactic acid repeating unit included in the hard segment The carboxyl group is connected to the terminal hydroxyl groups of the polyolefin polyol structural unit contained in the soft segment via an ester bond; or another block copolymer in which the inter-block copolymer is Connected in a linear or branched manner via a monocarbamate bond. The PLA / ABS alloy resin composition according to claim 8, wherein the polylactic acid resin further includes a polylactic acid homopolymer that is not coupled to the polyolefin-based polyol repeating unit. The PLA / ABS alloy resin composition according to claim 1, wherein the polyolefin-based polyol repeating unit has a number average molecular weight of 1,000 to 100,000. The PLA / ABS alloy resin composition according to claim 7, wherein the terminal hydroxyl groups of the polyolefin-based polyol structural unit are the isocyanates of the diisocyanate compound or the di- or higher-functionality isocyanate compound The molar ratio of groups is 1: 0.50 to 1: 0.99. The PLA / ABS alloy resin composition according to claim 1, wherein the polylactic acid resin contains 65 to 95% by weight of the hard segment and 5 to 35% by weight based on the total weight of the polylactic acid resin The soft segment. The PLA / ABS alloy resin composition according to claim 1, wherein the ABS-based resin contains acrylonitrile in a content of 10 to 30% by weight, butadiene in a content of 10 to 30% by weight, and a content of 40 to 70% by weight One of styrene is acrylonitrile-butadiene-styrene copolymer (ABS). The PLA / ABS alloy resin composition according to claim 1, wherein, based on 100 parts by weight of the ABS-based resin, the ABS-based resin further contains 30 to 70 parts by weight of a styrene-acrylonitrile copolymer (SAN ). The PLA / ABS alloy resin composition according to claim 1, which has a color-b value of less than 10. According to the PLA / ABS alloy resin composition of claim 1, based on the total weight of the polylactic acid resin, it contains less than 1% by weight of residual monomers.