TW201326300A - Blend of polylactic acid resin and copolyester resin and articles using the same - Google Patents

Abstract

A blend of polylactic acid resin and copolyester resin, which has excellent impact resistance and heat resistance, and a molded article manufactured using the same are disclosed. The blend of polylactic acid resin and copolyester resin, comprises a polylactic acid resin; and a copolyester comprising a dicarboxylic acid residue which contains a terephthalic acid residue and a diol component which contains 3 to 99 mol% of a cyclohexanedimethanol residue and 1 to 60 mol% of an isosorbide residue, wherein the sum of content of polylactic acid resin and the content of the isosorbide residue contained in the copolyester is 20 to 60 wt% with respect to total content of the blend.

Description

Mixture of polylactic acid resin and copolyester resin and articles using the same (2)

The present application claims priority to Korean Patent Application No. 10-2011-0120864, filed on Nov. 18, 2011. All disclosures of this Korean Patent Application are hereby incorporated by reference.

The present invention relates to a mixture of a polylactic acid resin and a copolyester resin, and more particularly to a mixture of a polylactic acid resin and a copolyester resin and a molded article produced using the mixture, the mixture having excellent Impact resistance and heat resistance.

The polylactic acid (PLA) resin is a plant-derived resin obtained from a plant such as corn, and the polylactic acid (PLA) resin is biodegradable. Unlike conventional petroleum-based resins such as polystyrene resins, polyvinyl chloride (PVC) resins or polyethylene resins, polylactic acid (PLA) resins are not derived from petroleum and emit less carbon dioxide gas and inhibit petroleum-based resources. Consumption, and therefore, unlike petroleum-based plastic products, polylactic acid (PLA) resins are produced. Less environmental pollution. Since environmental pollution caused by waste plastics has caused social problems, efforts have been made to extend the application of polylactic acid to various fields where ordinary plastics (oil-based resins) have been applied, including food packaging materials and containers, boxes for electronic products, etc. . However, polylactic acid has poor impact resistance and heat resistance as compared with conventional petroleum-based resins, and thus polylactic acid is used in limited applications.

In order to overcome this problem of polylactic acid resins, a method of mixing a polylactic acid resin with a resin selected from conventional petroleum-based plastic resins has been reported. For example, Korean Patent Application Laid-Open No. 10-2005-0056021 discloses a method of improving the impact resistance of polylactic acid by mixing polylactic acid with a polycarbonate resin. However, in this case, if the content of the polycarbonate resin (the petroleum-based plastic resin) is increased to improve the impact resistance and heat resistance of the polylactic acid, the content of the dangerous bisphenol A in the mixture will increase. Therefore, the purpose of using the polylactic acid resin will not be achieved. Therefore, when mixing with a polylactic acid resin, it is necessary to be able to improve heat resistance and impact strength while being environmentally friendly by maintaining the content of the biomaterial at 20% by weight to 60% by weight.

Accordingly, it is an object of the present invention to provide a mixture of a polylactic acid resin and a copolyester resin and a molded article produced using the mixture, which is environmentally friendly and has excellent heat resistance and impact resistance.

In order to achieve the above objects, the present invention provides a mixture of a polylactic acid resin and a copolyester resin, the mixture comprising: a polylactic acid resin; and a copolyester comprising a dicarboxylic acid residue and a glycol component, The dicarboxylic acid residue Containing a terephthalic acid residue containing from 3 moles to 99 mole % of cyclohexane dimethanol residue and from 1 mole % to 60 mole % of isosorbide residues. Here, the sum of the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester is from 20% by weight to 60% by weight based on the total amount of the mixture.

Further, the present invention provides a molded article produced by molding a mixture of a polylactic acid resin and a copolyester resin.

As described above, a mixture of a polylactic acid resin and a copolyester resin according to the present invention is prepared by mixing polylactic acid, a copolyester resin containing a residue of isosorbide (bio-monomer), and even When the content of the copolyester resin in the mixture is increased, the content of the biomaterial (polylactic acid resin and isosorbide) is also maintained at a specific level (20% by weight to 60% by weight), which indicates the mixture of the present invention. Environmentally friendly. Further, the mixture of the present invention improves the low impact resistance and heat resistance of the polylactic acid resin, and thus the mixture has improved impact resistance and heat resistance. Further, unlike other mixtures of petroleum-based resins, the mixture of the present invention does not contain a hazardous substance such as bisphenol A and does not generate bubbles upon hot molding, which indicates that in the process of manufacturing a molded article from the mixture. No separate drying process is required. Furthermore, the mixture of the invention can be molded at relatively low temperatures, and thus the mixture has advantages in terms of time and cost. Further, the mixture of the polylactic acid resin and the copolyester resin according to the present invention can be used as an environment-friendly molded article (sheet, packaging material, container, internal and external materials of an electronic product, internal materials of an automobile, and external parts). Materials such as materials, interior materials and exterior materials of buildings, etc., are especially useful as materials for beverages and food containers, medical containers, and the like.

The mixture of the polylactic acid resin and the copolyester resin according to the present invention comprises a polylactic acid (PLA) resin and a copolyester resin containing isosorbide (biomonomer) as a glycol component. The content of the biomaterial (polylactic acid resin and isosorbide) is maintained at 20% by weight to 60% by weight, which indicates that the mixture of the present invention is environmentally friendly. The mixture according to the invention has a good notched Izod impact strength of 80 J/m or more, as measured according to ASTM D256 at 23 ° C, and the mixture has a good heat distortion temperature of 80 ° C or above, such as at 0.455 Measured according to ASTM D648 at MPa.

The polylactic acid used in the present invention is not particularly limited and the polylactic acid may be a commercially available polylactic acid resin. The polylactic acid resin is generally prepared from a monomer derived from L lactic acid and/or D lactic acid, and in addition to L lactic acid and D lactic acid, the polylactic acid resin may contain a monomer in an amount which does not impair the effect of the present invention. The polylactic acid resin can be produced by various methods, but the polylactic acid resin is usually prepared by ring-opening polymerization of lactide prepared from lactic acid. Further, a polylactic acid resin can also be prepared by directly polycondensing lactic acid. The polylactic acid resin prepared from a monomer derived from each of L lactic acid and D lactic acid is crystalline and has a high melting point. However, when the polylactic acid resin is prepared from L lactide, D lactide and meso lactide derived from L lactic acid and D lactic acid, the crystallinity and melting point of the polylactic acid may be based on L lactide and D lactic acid. The content of lactide and meso lactide is easily controlled The content of each lactide in the lactide may also be controlled according to the intended use of the polylactic acid resin.

The polylactic acid resin has a number average molecular weight of 10,000 to 500,000, and preferably 30,000 to 300,000. If the number average molecular weight of the polylactic acid resin is less than 10,000, the resulting mixture will lack mechanical properties such as impact resistance; and if the number average molecular weight is more than 500,000, it will be difficult to prepare (polymerize) the polylactic acid resin, and the polylactic acid resin The treatment becomes difficult due to the excessively high molecular weight of the polylactic acid resin.

The copolyester resin used in the present invention is for improving the impact resistance and heat resistance of a mixture of a polylactic acid resin and a copolyester resin and for maintaining the biomaterial content of the mixture at a specific level (60% by weight) or higher. A copolyester resin is prepared by copolymerizing a dicarboxylic acid component and a glycol component, the dicarboxylic acid component containing a terephthalic acid residue containing 3 mol% to 99 mol% a cyclohexanedimethanol residue and an isosorbide residue of 1 mol% to 60 mol%, and the isosorbide residue is represented by the following formula 1. Further, the copolyester resin has a structure in which an acid portion derived from a dicarboxylic acid component and a glycol portion derived from a glycol component are repeated.

As used herein, the term "copolyester resin" means a synthetic polymer prepared by polycondensation of one or more difunctional carboxylic acids with one or more difunctional hydroxy compounds. Generally, the difunctional carboxylic acid is a dicarboxylic acid and the difunctional hydroxy compound is a divalent alcohol such as ethylene glycol or a glycol. As used herein, the term "residue" means a moiety or unit derived from a product of a chemical reaction of a particular compound and derived from that particular compound. For example, each of the "dicarboxylic acid residue" and the "diol (ethylene glycol) residue" means a portion derived from a dicarboxylic acid component of a polyester formed by esterification or copolymerization. Or a fraction derived from the glycol component of the polyester. Specifically, the term "residue" means a residue remaining after removal of a hydrogen, a hydroxyl group or an alkoxy group from a common polyester comprising a dicarboxylic acid and a glycol (ethylene glycol) component. Thus, the dicarboxylic acid residue may be derived from an acid halide or ester of a dicarboxylic acid monomer or a dicarboxylic acid monomer (for example, a lower alkyl ester having 1 to 4 carbon atoms (C _1-4 low carbon) Alkyl esters, such as monomethyl, monoethyl, dimethyl, diethyl or dibutyl), salts, anhydrides or mixtures of the foregoing. Thus, as used herein, the terms "dicarboxylic acid", "terephthalic acid" and the like are intended to include any derivatives of dicarboxylic acids and dicarboxylic acids (including related acid halides, esters of dicarboxylic acids, a half-ester, a salt, a half-salt, an acid anhydride, a mixed acid anhydride, and a mixture of the foregoing, the dicarboxylic acid and derivatives of the same are useful for reacting with a glycol To produce polyester.

The dicarboxylic acid component of the copolyester resin contains terephthalic acid residues, and the amount of the terephthalic acid residues is from 50 mol% to 100 mol% based on the total number of moles of the dicarboxylic acid component (for example, 60) Mohr% to 99.9 mol%, specifically 90 mol% to 99.9 mol%), and in order to improve the physical properties of the polyester resin, the dicarboxylic acid component may contain 0 mol% to 50 mol% ( For example, from 0.1 mol% to 40 mol%, specifically from 0.1 mol% to 10 mol%) of dicarboxylic acid residues, including _C8-14 aromatic dicarboxylic acid residues (except terephthalic acid) A residue other than a residue), a C _4-12 aliphatic acid residue or a mixture of the above. Examples of the aromatic dicarboxylic acid capable of forming an aromatic dicarboxylic acid residue include an aromatic dicarboxylic acid which is generally used for preparing a polyester resin, for example, isophthalic acid (other than terephthalic acid), naphthalene Dicarboxylic acid (such as 2,6-naphthalenedicarboxylic acid), dicarboxylic acid, and the like. Examples of the aliphatic dicarboxylic acid capable of forming an aliphatic dicarboxylic acid residue include a linear, branched or cyclic aliphatic dicarboxylic acid component generally used for producing a polyester resin, for example, cyclohexanedicarboxylic acid (such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid), phthalic acid, azelaic acid, succinic acid, isoindole succinic acid, maleic acid, antibutene Acid, adipic acid, glutaric acid, sebacic acid, and the like. In the case where the copolyester resin contains a dicarboxylic acid residue (comonomer) other than the terephthalic acid residue, if the content of the dicarboxylic acid residue is too low or too high, the physical properties of the mixture are improved. The effect will be insufficient, or the physical properties of the polyester resin may be lowered rather than increased.

The glycol component of the copolyester resin comprises: 3 mol% to 99 mol%, preferably 5 mol% to 91 mol% of cyclohexanedimethanol relative to the glycol component (i) (1) a residue of 2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, or the like, and (ii) 1 mol% to 60 mol%, preferably 4 mole% to 40% by mole of isosorbide residue, wherein the content of the cyclohexanedimethanol residue and the content of the isosorbide residue are within the range of the following Equation 1: [Equation 1] 0.0012 (CHDM Mo %) ² -0.2401 (CHDM Mo %) + 11.136 ≦ ISB Molar % ≦ -0.0122 (CHDM Mo %) ² + 0.0243 (CHDM Mo %) + 79.846 where ISB More % means different yam The content of the alcohol residue, and the % by mole of CHDM represents the content of the cyclohexanedimethanol residue.

Further, the resin comprises a diol component 0 mole% to 94 mole% copolyester, preferably 0.1 mole% to 88 mole%, more preferably 0.1 mole% to 80 mole% of C _{2 -20} aliphatic diol residue, preferably C _2-12 aliphatic diol residue (except cyclohexane dimethanol residue and isosorbide residue). Examples of the diol capable of forming an aliphatic diol residue include linear and branched cyclic aliphatic diols including ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol (1, 2). -propylene glycol, 1,3-propanediol, etc.), 1,4-butanediol, pentanediol, hexanediol (1,6-hexanediol, etc.), neopentyl glycol (2,2-dimethyl- 1,3-propanediol), 1,2-cyclohexanediol, 1,4-cyclohexanediol, and tetramethylcyclohexanediol, preferably including ethylene glycol.

If the content of the cyclohexanedimethanol residue in the glycol component of the copolyester resin is less than 3 mol% based on the total weight of the glycol component, the impact resistance of the copolyester resin will be insufficient; If the content is more than 99 mol%, the heat resistance of the copolyester resin will be insufficient because the content of the isosorbide residue is less than 1 mol%. If the content of the isosorbide residue is less than 1 mol% based on the total amount of the glycol component, the heat resistance of the obtained copolyester resin will be insufficient; and if the content is more than 60 mol%, copolymerization may occur. Yellowing of the ester resin. Further, if the content of the diol residue (except the cyclohexane dimethanol residue and the isosorbide residue) is more than 94 mol% based on the total amount of the diol component, the physics of the copolyester resin The nature will be bad.

A 3.2-mm thick sample prepared from a copolyester resin preferably exhibits a notched Izod impact strength of 50 J/m or more, as measured at 23 ° C according to the ASTM D256 method. . On the other hand, the polyester resin obtained by copolymerizing only ethylene glycol and isosorbide substantially exhibits a notched Izod impact strength of 50 J/m or less. When the copolyester resin is annealed at 300 ° C for 5 minutes and the copolyester resin is cooled to room temperature, followed by scanning at a heating rate of 10 ° C / min, the copolyester resin preferably has 90 ° C or higher. Glass transition temperature (Tg). Further, the copolyester resin has an intrinsic viscosity of 0.35 d l /g or more, preferably 0.40 d l /g or more, more preferably 0.45 d l /g or more, such as at 35 ° C in the vicinity Measured at a concentration of 1.2 g/d l in chlorophenol (OCP). The copolyester resin is environmentally friendly and has excellent heat resistance and impact resistance. Therefore, when the copolyester resin is mixed with the above polylactic acid resin, the copolyester resin can improve the impact resistance and heat resistance of the polylactic acid resin.

The weight average molecular weight (Mw) of the copolyester resin is, for example, 10,000 to 200,000 (g/mol), preferably 20,000 to 100,000 (g/mol). If the weight average molecular weight (Mw) of the copolyester resin exceeds the above range, the processability or physical properties of the mixture can be lowered.

The copolyester resin can be prepared according to a conventional method. For example, a copolyester resin can be prepared by a process comprising the steps of: (1) esterifying a dicarboxylic acid with a glycol compound; and (2) subjecting the esterified product to polycondensation. Specifically, the step of esterifying the dicarboxylic acid with a glycol compound can be carried out by using a glycol ester ester at a pressure of from 0 kg/cm ² to 10.0 kg/cm ² and at a temperature of from 150 ° C to 300 ° C. The transesterify dicarboxylic acid is carried out for from 1 hour to 24 hours. The conditions of the esterification reaction can be appropriately controlled depending on the specific properties of the obtained copolyester, the molar ratio between the dicarboxylic acid component and the glycol (ethylene glycol) component, the process conditions, and the like. Specifically, the esterification reaction is preferably carried out under the following conditions: a pressure of from 0 kg/cm ² to 5.0 kg/cm ² , more preferably from 0.1 kg/cm ² to 3.0 kg/cm ² , and a temperature of 200 ° C To 270 ° C, more preferably 240 ° C to 260 ° C, and the reaction time is from 1 hour to 15 hours, more preferably from 2 hours to 8 hours. The molar ratio between the dicarboxylic acid component and the glycol component participating in the esterification reaction may be from 1:1.05 to 1:3.0. For example, a dicarboxylic acid component and a glycol component may be added so that the content of cyclohexanedimethanol is 10 parts by weight to 90 parts by weight, based on 100 parts by weight of the dicarboxylic acid component. The ground weight ranges from 20 parts to 80 parts. The molar ratio of the glycol component to the dicarboxylic acid component is less than 1.05, the unreacted dicarboxylic acid will remain after polymerization and reduce the transparency of the resin; and if the molar ratio is greater than 3.0, the polymerization rate will be lowered or will be lowered The productivity of the resin. In order to increase the rate of the esterification reaction and the productivity of the resin, a catalyst may be used as appropriate. Further, the esterification reaction may be carried out batchwise or continuously, and the raw material may be separately added, but it is preferred to add a raw material in the form of a slurry obtained by adding a dicarboxylic acid component to the glycol component. Further, for the second polyester, the glycol component (such as solid isosorbide) can be dissolved in water or ethylene glycol at room temperature and the solution and the dicarboxylic acid component (such as terephthalic acid) can be used. The slurry was prepared by mixing. Further, water may be additionally added to a slurry composed of a mixture of a dicarboxylic acid component, a glycol component (such as isosorbide) and ethylene glycol to increase the solubility of isosorbide. Further, the slurry may be prepared at a temperature of 60 ° C or higher to provide a slurry containing isosorbide dissolved therein.

Meanwhile, the step of subjecting the esterified product to the polycondensation can be carried out by subjecting the esterification product of the dicarboxylic acid component and the glycol component to a condensation reduction at a temperature of from 150 ° C to 300 ° C under a reduced pressure of from 400 mmHg to 0.01 mmHg. It is implemented in hours to 24 hours. Preferably, the polycondensation reaction can be carried out at a temperature of from 200 ° C to 290 ° C, more preferably from 260 ° C to 280 ° C, under a reduced pressure of from 100 mmHg to 0.05 mmHg, more preferably from 10 mmHg to 0.1 mmHg. When the polycondensation reaction is carried out under reduced pressure, ethylene glycol (a by-product of the polycondensation reaction) may be removed, but if the polycondensation reaction is carried out under a pressure exceeding a range of 400 mmHg to 0.01 mmHg, by-product Removal of the object may not be sufficient. Further, if the polycondensation reaction is carried out at a temperature exceeding the range of 150 ° C to 300 ° C, the physical properties of the obtained polyester may be deteriorated. The polycondensation reaction can be carried out for a sufficient period of time (e.g., an average residence time of from 1 hour to 24 hours) until the intrinsic viscosity of the final reaction product reaches a suitable level. Preferably, the polycondensation reaction can be carried out until a vacuum level of less than 2.0 mmHg is reached, and the esterification reaction and the polycondensation reaction can be carried out in an inert gas atmosphere.

In the preparation of the polyester, an additive such as a polycondensation catalyst, a stabilizer or a colorant may be used. Such additives, such as polycondensation catalysts or stabilizers, can be added to the esterification or reverse esterification product prior to the start of the polycondensation reaction. Alternatively, such additives may be added to the slurry comprising the dicarboxylic acid and the diol compound prior to or during the esterification reaction.

The polycondensation catalyst which can be used in the present invention may be selected from the group consisting of a titanium-based compound, a mercapto compound, a mercapto compound, an aluminum-based compound, a tin-based compound, and a mixture of the above. Examples of the titanium-based compound include tetraethyl titanate, tripropyl acetate titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, and bismuth titanate Alcohol ester, titanyl lactate, triethanolamine titanate, acetamidine acetone titanate, titanyl ethyl acetate, isostearyl titanate, titanium dioxide, titanium dioxide/cerium dioxide co-precipitate, Titanium dioxide / zirconia co-precipitate and the like. Examples of the mercapto compound include germanium dioxide (GeO ₂ ), germanium tetrachloride (GeCl ₄ ), germanium ethyleneglycoxide, barium acetate, co-precipitates of the above, and the like. a mixture of people.

The stabilizer which can be used in the present invention may be a phosphorus-based compound such as phosphoric acid, trimethyl phosphate or triethyl phosphate and may be relative to the obtained polymer (total The polyester resin is added in an amount of 10 ppm to 100 ppm (based on elemental phosphorus). If the amount of stabilizer added is less than 10 ppm, the stabilizing effect will be insufficient and yellowing of the final product may be caused. On the other hand, if the amount of the stabilizer added is more than 100 ppm, a highly polymerized polymer cannot be obtained.

A coloring agent usable in the present invention is added to improve the color of the polymer, and the coloring agent may be a conventional coloring agent such as cobalt acetate or cobalt propionate. An organic compound-based color former can also be used if necessary. The colorant may be added in an amount of from 0 ppm to 100 ppm based on the weight of the final polymer (copolyester resin).

The mixture of the polylactic acid resin and the copolyester resin according to the present invention may be, for example, 1 part to 30 parts by weight, preferably 3 parts to 20 parts by weight, based on 100 parts by weight of the mixture, if necessary. The amount contains one or more other resin components (for example, polycarbonate, polyethylene, polypropylene, polymethacrylate, etc.) and additive components.

Examples of additives that may be added to the mixture include stabilizers having the ability to maintain the physical properties of the mixture during handling, storage, and use, for example, oxidative stabilizers, heat stabilizers, light stabilizers, or UV stabilizers. In addition, nucleating agents, chain extenders, lubricants, impact modifiers, colorants, waxes, mold release agents, fragrances, foaming agents, plasticizers, hydrolysis inhibitors, non-reactive materials and reactivity Materials can be used for the handling, storage and use of the mixture. The compatibilizer used in the present invention contains at least one reactive functional group selected from the group consisting of epoxy propyl, maleic anhydride, epoxy, Isocyanate, amine, carboxylic acid and oxazoline groups and mixtures of the above, for example 6% by weight to 8% by weight of vinyl reactivity Copolymer or terpolymer. The compatibilizer can react with the ends of the polylactic acid resin and the copolyester resin (ie, the carboxylic acid (-COOH) and the hydroxyl group (-OH)) to improve the compatibility between the polylactic acid resin and the copolyester resin. . Further, the compatibilizer enhances the impact resistance of the mixture depending on the molecular structure bonded to the functional group or the structure of the main chain. Any compound can be used as a compatibilizer without limitation as long as the compound contains the above-mentioned reactive functional group. Examples of compatibilizers include, but are not limited to, adipic acid, hexamethylene diamine, epoxy compounds, PPDI (p-phenylene diisocyanate), HDI (1,6-extended hexyl diisocyanate), TDI (diisocyanate). Toluene ester), NDI (1,5-naphthalene diisocyanate), IPDI (isoporon diisocyanate), MDI (4,4-diphenylmethane diisocyanate), H12MDI (cyclohexyl diisocyanate), Ethyl methacrylate propyl acrylate, ethyl acrylate propylene propyl ester, ethyl acrylate-glycidyl acrylate, ethyl acrylate-glycidyl methacrylate, reaction Polystyrene, oxazoline-based highly reactive polymer (epocros) and mixtures of the foregoing. The above additives may be selected depending on the intended use of the mixture and are not limited to the examples mentioned above.

The mixture of the polylactic acid resin and the copolyester resin according to the present invention can be prepared by any conventional mixing process, and the mixture can be molded by a molding process such as injection, extrusion or compounding. Specifically, the molding mixture can be extrusion molded or shot immediately after mixing. Alternatively, the mixture can be compounded, extruded, cooled and granulated, followed by crystallization, and the obtained granule mixture fragments can be used for extrusion molding or injection molding applications.

In the mixture of the polylactic acid resin and the copolyester resin according to the present invention, the content of the biomaterial (polylactic acid resin) relative to the total content of the mixture The content of the sum of the isosorbide residues in the copolyester resin is from 20% by weight to 60% by weight, preferably from 20% by weight to 45% by weight, more preferably from 21% by weight to 38% by weight, Optimum 21% to 35% by weight. The content of the polylactic acid resin and the copolyester resin can be adjusted within the above-mentioned content of the biological material. For example, the content of the polylactic acid resin is from 3% by weight to 60% by weight, preferably from 4% by weight to 40% by weight, more preferably from 5% by weight to 30% by weight, most preferably from 6% by weight to 20% by weight And the content of the copolyester resin is from 40% by weight to 97% by weight, preferably from 60% by weight to 96% by weight, more preferably from 70% by weight to 95% by weight, most preferably from 80% by weight to 94% by weight. Further, the content of the additive is from 1 part by weight to 30 parts by weight relative to 100 parts by weight of the total mixture. If the content of the biomaterial (the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester resin) is less than 20% by weight, the biodegradability is not exhibited, and the biodegradability is polylactic acid. The advantages of resin. If the content of the biomaterial (the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester resin) is more than 60% by weight, the heat resistance may be lowered below the reference point, indicating that the mixture cannot be used. For the manufacture of various molded items.

A 3.0-mm thick sample prepared from a mixture of a polylactic acid resin and a copolyester resin according to the present invention exhibits 80 J/m or more, preferably 85 J/m or more, more preferably 90 J/m or The above, optimally 110 J/m or more notched Izod impact strength, as measured at 23 ° C according to the ASTM D256 method.

A 127 mm × 13 mm × 3 mm to 13 mm sample prepared from a mixture of a polylactic acid resin and a copolyester resin according to the present invention is displayed at 80 ° C or The heat distortion temperature above, preferably 82 ° C or above, more preferably 90 ° C or above, optimally 100 ° C or above, as measured at 0.455 MPa according to the ASTM D648 method. It is known that the mixture of the present invention has good impact strength and good heat resistance (high heat distortion temperature) because the compatibility of the polylactic acid resin with the copolyester is good in the mixing step, and the copolyester resin is not lowered. In the case of the content, the high content of the copolyester resin exhibits heat resistance and impact resistance.

The mixture of the polylactic acid resin and the copolyester resin according to the present invention may be subjected to a conventional molding process known in the art (for example, injection, extrusion, extrusion blowing, injection blowing or profile injection) and post-treatment (such as heat). The molding process is molded and, if desired, the mixture can be prepared into a suitable molded article, such as a fiber, an injection molded article, a sheet or a film.

Hereinafter, the present invention will be described in further detail with reference to comparative examples and comparative examples. However, it is to be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the invention. In the following examples and comparative examples, the performance of the polymer (mixture) was evaluated in the following manner.

(1) Heat resistance (heat distortion temperature (HDT)): A sample having a size of 127 mm × 13 mm × 3 to 13 mm was prepared using the above mixture, and the test sample was measured according to the ASTM D648 method under a pressure of 0.455 MPa. Heat distortion temperature or heat deflection temperature (HDT).

(2) Notched Izod impact strength: A 3.0 mm thick sample was prepared using the above mixture, and the notched Izod impact strength of the sample was tested according to ASTM D256 at 23 °C.

(3) Checking whether the mixture contains harmful substances: The presence and content of dangerous substances (bisphenol A, etc.) in the mixture are checked by nuclear magnetic resonance (NMR).

Preparation Example 1: Preparation of Copolyester Resin

6 g of terephthalic acid as a dicarboxylic acid component and 138 g of 1,4-cyclohexane methanol and 313 g of ethylene glycol based on 6 mol of terephthalic acid as a glycol component 105 g of isosorbide was mixed with each other while slowly heating to 255 ° C in a 3-L reactor to subject the materials to esterification, and the reactor was equipped with a stirrer and a reflux condenser. The generated water is discharged from the system, and after completion of the formation and discharge of water, the reaction product is transferred to a polycondensation reactor equipped with a stirrer, a cooling condenser, and a vacuum system. A suitable amount of catalyst, stabilizer and color former is added to the esterification product, after which the internal temperature of the reactor is raised to 240 ° C to 275 ° C while the internal pressure of the reactor is reduced from atmospheric pressure to 50 mmHg for 40 hours. The ethylene glycol was discharged in minutes and the internal pressure was then slowly lowered to a high vacuum level of 0.1 mmHg. The esterified product is subjected to polycondensation at a temperature and pressure until the esterified product reaches a desired intrinsic viscosity, thereby preparing a copolyester resin. The prepared resin had a weight average molecular weight (Mw) of 63,000 (g/mol) and an intrinsic viscosity of 0.76 (dl/g).

Preparation Example 2: Preparation of Copolyester Resin

A copolyester resin was prepared in the same manner as in Example 1 except that 6 mol of terephthalic acid was used as the acid component and 565 g of 6 mol based terephthalic acid was used as the glycol component. 1,4-cyclohexane methanol, 96 g of ethylene glycol and 789 g of isosorbide. The prepared copolyester resin has a weight average molecular weight (Mw) of 37,000 (g/mol) and an inherent value of 0.65 (dl/g). Viscosity.

Example 1: Preparation and Evaluation of Polylactic Acid Resin/Copolyester Resin Mixture

3 wt% of the polylactic acid resin chips having a number average molecular weight of 100,000 and 97 wt% of the copolyester resin chips prepared in Preparation Example 2 were placed in a Haake laminating machine at 220 ° C. The cylinder temperature and the mold temperature of 210 ° C and the screw rotation speed of 200 rpm were mixed with each other, thereby preparing a granular mixture of the polylactic acid resin and the copolyester resin. Using the above method, the heat distortion temperature of the mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Example 2: Preparation and evaluation of polylactic acid resin/copolyester resin mixture

A granular mixture of a polylactic acid resin and a copolyester resin was prepared in the same manner as in Example 1 except that 17% by weight of a polylactic acid resin pellet having a number average molecular weight of 100,000 and 75% by weight were used for the preparation. The copolyester resin chips prepared in Example 2 and 8 wt% of a vinyl reactive terpolymer having about 8% of a glycidyl reactive group in the main chain. The heat distortion temperature of the prepared mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Example 3: Preparation and evaluation of polylactic acid resin/copolyester resin mixture

A granular mixture of a polylactic acid resin and a copolyester resin was prepared in the same manner as in Example 1 except that 25% by weight of a polylactic acid resin having a number average molecular weight of 100,000 and 65% by weight were used. The copolyester resin chips prepared in Example 2 and 10% by weight of a vinyl reactive terpolymer containing about 6% of the epoxypropyl reactive groups in the main chain were prepared. The heat distortion temperature of the prepared mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Example 4: Preparation and evaluation of polylactic acid resin/copolyester resin mixture

A granular mixture of a polylactic acid resin and a copolyester resin was prepared in the same manner as in Example 1 except that 35 wt% of a polylactic acid resin pellet having a number average molecular weight of 100,000 and 52% by weight were used for the preparation. The copolyester resin chips prepared in Example 1 and 13% by weight of a vinyl reactive terpolymer containing about 6% of the epoxypropyl reactive groups in the main chain. The heat distortion temperature of the prepared mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Example 5: Preparation and evaluation of polylactic acid resin/copolyester resin mixture

A granular mixture of a polylactic acid resin and a copolyester resin was prepared in the same manner as in Example 1 except that 43% by weight of a polylactic acid resin pellet having a number average molecular weight of 100,000 and 42% by weight were used for the preparation. The copolyester resin chips prepared in Example 2 and 15% by weight of a vinyl reactive terpolymer having about 8% of a epoxypropyl reactive group in the main chain. The heat distortion temperature of the prepared mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Example 6: Preparation and evaluation of polylactic acid resin/copolyester resin mixture

A granular mixture of a polylactic acid resin and a copolyester resin was prepared in the same manner as in Example 1 except that 55 wt% of a polylactic acid resin pellet having a number average molecular weight of 100,000 and 30% by weight were used for the preparation. The copolyester resin chips prepared in Example 1 and 15% by weight of a vinyl reactive terpolymer having about 8% of a glycidyl reactive group in the main chain. The heat distortion temperature of the prepared mixture, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Comparative Example 1: Preparation and evaluation of granular polylactic acid resin

A particulate polylactic acid resin was prepared in the same manner as in Example 1 except that the copolyester resin was not used. The heat distortion temperature of the prepared resin, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

Comparative Example 2: Preparation and evaluation of granular polylactic acid resin

30% by weight of polylactic acid resin chips having a number average molecular weight of 100,000 and 70% by weight of the copolyester resin chips were placed in a Hacker laminating machine at a cylinder temperature of 260 ° C and a mold temperature of 255 ° C and A particle type mixture of a polylactic acid resin and a copolyester resin was prepared by mixing with each other at a screw rotation speed of 50 rpm. The heat distortion temperature of the prepared resin, the notched Izod impact strength, and the presence or absence of harmful substances were measured, and the results of the measurement are shown in Table 1 below.

[Table 1]

As seen in Table 1 above, the mixture of the polylactic acid resin and the copolyester resin according to the present invention exhibits a high heat distortion temperature of from 80 ° C to 110 ° C and a high notched Izod impact strength of from 80 J/m to 600 J/m. Further, the mixture of the present invention does not contain a hazardous substance (bisphenol A or the like), but the mixture contains 20% by weight to 60% by weight of the biomaterial (polysorbate resin and isosorbide residue in the copolyester resin), The situation indicates that the mixture is environmentally friendly.

Claims (14)

a mixture of a polylactic acid resin and a copolyester resin, the mixture comprising: a polylactic acid resin; and a copolyester comprising a dicarboxylic acid residue and a glycol component, the dicarboxylic acid residue Containing a pair of phthalic acid residues containing from 3 moles to 99 mole% of one cyclohexanedimethanol residue and from 1 mole% to 60 mole% of one isosorbide residue, The sum of the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester is from 20% by weight to 60% by weight based on the total amount of the mixture. The mixture of claim 1, wherein the mixture of the polylactic acid resin and the copolyester resin has a notched Izod impact strength of 80 J/m or more, as measured according to ASTM D256 at 23 ° C, and The mixture has a heat distortion temperature of 80 ° C or higher, as measured according to ASTM D648 at 0.455 Mpa. The mixture according to claim 1, wherein the sum of the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester is from 20% by weight to 45% by weight based on the total amount of the mixture. %, the mixture of the polylactic acid resin and the copolyester resin has a notched Izod impact strength of 85 J/m or more, as measured according to ASTM D256 at 23 ° C, and the mixture has a temperature of 82 ° C or more. Heat distortion temperature, such as at 0.455 MPa according to ASTM D648 Measured. The mixture according to claim 1, wherein the sum of the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester is from 21% by weight to 38% by weight based on the total amount of the mixture. %, the mixture of the polylactic acid resin and the copolyester resin has a notched Izod impact strength of 90 J/m or more, as measured according to ASTM D256 at 23 ° C, and the mixture has a temperature of 90 ° C or more. The heat distortion temperature is measured according to ASTM D648 at 0.455 MPa. The mixture according to claim 1, wherein the sum of the content of the polylactic acid resin and the content of the isosorbide residue contained in the copolyester is from 21% by weight to 35 parts by weight based on the total amount of the mixture. %, the mixture of the polylactic acid resin and the copolyester resin has a notched Izod impact strength of 110 J/m or more, as measured according to ASTM D256 at 23 ° C, and the mixture has 100 ° C or more. The heat distortion temperature is measured according to ASTM D648 at 0.455 MPa. The mixture of claim 1, wherein the polylactic acid resin has a number average molecular weight of 10,000 to 500,000. The mixture of claim 1, wherein the dicarboxylic acid component further contains from 0 mol% to 50 mol% of at least one dicarboxylic acid residue, the at least one dicarboxylic acid residue being selected from the group consisting of Group: C _8-14 aromatic dicarboxylic acid residue, C _4-12 aliphatic dicarboxylic acid residue, and mixtures of the foregoing. The mixture of claim 1, wherein the cyclohexanedimethanol residue is selected from the group consisting of 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4 a mixture of cyclohexanedimethanol and each of the above. The mixture according to claim 1, wherein the content of the isosorbide residue (% by weight of ISB) and the content of the cyclohexanedimethanol residue (% by weight of CHDM) are in accordance with the following Equation 1 Within the range: [Equation 1] 0.0012 (CHDM Mo %) ^{2 -} 0.2401 (CHDM Mo %) + 11.136 ≦ ISB Mo % ≦ - 0.0122 (CHDM Mo %) ² + 0.0243 (CHDM Mo %) + 79.846. The mixture of claim 1, wherein the glycol component contains from 8 mol% to 91 mol% of the cyclohexane dimethanol residue and from 4 mol% to 40 mol% of the isosorbide residue. base. The mixture of claim 1, wherein the glycol component further contains from 0 mol% to 94 mol% of one or more C _2-20 aliphatic diol residues (except the cyclohexane dimethanol residue) And the isosorbide residue). The mixture of claim 11, wherein the aliphatic diol residue is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol. Alcohol, 1,4-butanediol, pentanediol, hexanediol, neopentyl glycol (2,2-dimethyl-1,3-propanediol), 1,2-cyclohexanediol, 1,4 a mixture of cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, tetramethylcyclobutanediol, and the like. The mixture of claim 1, wherein the content of the cyclohexanedimethanol residue is from 10 parts by weight to 90 parts by weight based on 100 parts by weight of the dicarboxylic acid component. A molded article manufactured by molding a mixture of a polylactic acid resin and a copolyester resin according to any one of claims 1 to 13.