JP2009097012A - Polyester resin composition, molding body obtained from resin composition thereof, and fiber obtained from resin composition thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition with excellent molding ability in addition to heat resistance and shock resistance (toughness), a molding body obtained from the resin composition, and fiber obtained from the resin composition. <P>SOLUTION: This polyester resin composition contains an aliphatic polyester resin (A) containing more than 70 mol% α- and β-hydroxycarboxylic acid units, an aromatic copolyester resin (B) with the fusing point of 140-220 °C, and a compatilizer (C). This composition exhibits a sea-island type polymer alloy structure with the resin (A) as a sea component and the resin (B) as an island component. The domain size of the resin (B) of the island component is below 0.5 μm in average diameter and below 1.0 μm in maximum diameter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyester resin composition, a molded body obtained from the resin composition, and fibers obtained from the resin composition.

  In recent years, with increasing awareness of the environment on a global scale, various aliphatic polyesters that can be decomposed in a natural environment and that have biodegradability typified by polylactic acid have attracted attention. Polylactic acid is a resin having a relatively high melting point, but because of its low glass transition temperature (Tg), the operating conditions such as mold temperature and molding cycle time are limited during injection molding in order to control crystallinity. In addition, there are technical limitations in order to develop heat resistance. Furthermore, polylactic acid has a drawback that it has low impact resistance (toughness) and is brittle, and it cannot be said that durability is sufficient.

  A composition made of 100% aliphatic polyester other than polylactic acid is restricted in physical properties and production when used as a molding material. For this reason, it has come to be considered that it is difficult to spread it alone. On the other hand, even if it is a mixture with a non-biodegradable resin, if the aliphatic polyester resin is derived from a plant such as polylactic acid, it is widely used to reduce the amount of petroleum-derived resin used. As a result, it is possible to contribute to the saving of petroleum resources, and the idea that it is favorable for the environment has permeated.

  In applications where durability is required for resins and fibers, the above-mentioned tendency is intensifying. For example, a combination of a general-purpose resin such as a polyolefin resin and a polylactic acid resin has been studied.

  For example, in Patent Document 1, the impact strength is improved while maintaining transparency by mixing an aliphatic polyester mainly composed of polylactic acid and syndiotactic polyprene having low crystallinity among polypropylene. Has been proposed.

Patent Documents 2, 3, and 4 disclose those in which impact properties and flexibility are improved by using an alloy resin of polylactic acid and another thermoplastic polyester.
JP 2006-321988 A JP 2007-023189 A JP 2007-009053 A JP 2006-283033 A

  However, in the thing of patent document 1, there is room for improvement in physical properties, such as heat resistance, durability, and a moldability, as a result of crystallinity falling focusing on the transparency of a resin composition.

  In the ones described in Patent Documents 2 and 3, other flexible resins are added to improve the impact resistance of the polylactic acid resin. However, since the two resins are not compatible, they cannot withstand rapid draft deformation such as high-speed spinning, and are not resins with high-speed spinning.

  The thing of patent document 4 copolymerizes the structural component of polylactic acid with aromatic polyester, in order to improve the compatibility of polylactic acid and aromatic polyester. Thereby, a certain high-speed spinnability is also obtained.

  The present invention provides a resin composition having excellent moldability in addition to heat resistance and impact resistance (toughness), a molded product obtained from the resin composition, and a fiber obtained from the resin composition. Objective.

  As a result of intensive studies to solve such problems, the present inventors have achieved a resin composition by achieving nanoalloying of a sea-island structure in which a polyester resin is a sea component and an aromatic polyester resin is an island component. It has been found that a resin composition can be obtained in which the island component does not peel off or drop off from the sea component on the surface of the object, thereby solving the above problem, and the present invention has been achieved.

  That is, the gist of the present invention is as follows.

  (1) an aliphatic polyester resin (A) containing 70 mol% or more of α- and / or β-hydroxycarboxylic acid units, a copolymer aromatic polyester resin (B) having a melting point of 140 ° C. to 220 ° C., and A compatibilizing agent (C), a resin alloy (A) is a sea component and a resin (B) is an island component, and has a sea-island type polymer alloy structure, and the island component resin (B) has a domain size of A polyester resin composition having an average diameter of less than 0.5 μm and a maximum diameter of less than 1.0 μm.

  (2) The polyester resin composition according to (1), wherein the α- and / or β-hydroxycarboxylic acid unit is D-lactic acid, L-lactic acid, or a mixture thereof.

  (3) The copolymerized aromatic polyester (B) is one of terephthalic acid, ethylene glycol, and butanediol as constituent components, or one of terephthalic acid, isophthalic acid, and ethylene glycol as constituent components. The polyester resin composition according to (1) or (2), wherein

  (4) The blend ratio of the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B) is, by mass ratio, aliphatic polyester resin (A) / copolymerized aromatic polyester resin (B) = 95 / It is 5-70 / 30, The polyester resin composition in any one of (1) to (3) characterized by the above-mentioned.

  (5) The compatibilizer (C) is one or more selected from an epoxy chain extender, an isocyanate chain extender, a carbodiimide chain extender, and a glycidyl ether chain extender. The polyester resin composition according to any one of (1) to (3), wherein:

  (6) A molded article characterized by using any of the polyester resin compositions (1) to (5).

  (7) A polyester fiber using the polyester resin composition according to any one of (1) to (5) above, wherein the domain size of the copolymerized aromatic polyester resin (B) by spinning draft deformation is 0.001 to 0.001. A polyester fiber characterized by being in the range of 0.1 μm.

  According to the present invention, by dispersing the copolymerized aromatic polyester resin (B) in the aliphatic polyester resin (A), it has practical mechanical strengths such as impact resistance and toughness, and has excellent moldability. An excellent biodegradable resin composition, which is a polyester resin composition that can express specific fiber characteristics without impairing the appearance of molded articles and fibers using the resin composition. In addition, it can be manufactured at a low cost. Moreover, the molded object excellent in the external appearance quality without a spot can be provided using this resin composition.

  The polyester resin composition of the present invention comprises an aliphatic polyester resin (A) containing 70 mol% or more of α- and / or β-hydroxycarboxylic acid units, and a copolymerized aromatic polyester having a melting point of 140 ° C to 220 ° C. It is a composition obtained by melt-kneading resin (B) and further adding a compatibilizer (C).

  The melting point of the aliphatic polyester resin (A) is preferably 120 ° C. or higher, preferably 150 ° C. or higher, from the relationship between the heat resistance and mechanical strength of products such as fibers and molded articles obtained using the polyester resin composition of the present invention. Is even better. For the same reason, the content of the α- and / or β-hydroxycarboxylic acid unit needs to be 70 mol% or more, preferably 80 mol% or more.

  The copolymerization aromatic polyester resin (B) needs to have a melting point of 140 ° C to 220 ° C. This is to prevent the melting point difference from the aliphatic polyester resin (A) from becoming large. That is, when the polyester resin composition of the present invention is obtained, it is necessary to melt and mix both resins (A) and (B), and a molded body and fibers are obtained using the polyester resin composition of the present invention. In some cases, it is necessary to melt the resin composition. At that time, if the melting point of the copolymerized aromatic polyester resin (B) exceeds 220 ° C., the difference between the melting points of the two resins (A) and (B) increases, so that the aliphatic polyester resin (A) is thermally decomposed. become. On the other hand, when the melting point of the copolymerized aromatic polyester resin (B) is less than 140 ° C., practical heat resistance cannot be obtained. For this reason, the preferable range of melting | fusing point of a copolymer aromatic polyester resin (B) is 150 to 210 degreeC, and a more preferable range is 180 to 200 degreeC. In addition, when resin (B) does not show clear melting | fusing point, the softening point is considered as melting | fusing point.

  In the polyester resin composition of the present invention and fibers and molded bodies using the same, the resin composition exhibits a sea-island type polymer alloy structure in which the resin (A) is a sea component and the resin (B) is an island component. . In addition, the domain size of the resin (B) of the island component needs to have an average diameter of less than 0.5 μm and a maximum diameter of less than 1.0 μm. That is, the copolymerized aromatic polyester resin (B) needs to be dispersed in islands in the sea-island structure with the compatibilizing agent (C), and is finely dispersed to a nano size. is required. Because the copolyester resin (B) is finely dispersed in the resin composition with the compatibilizer (C), there is no segment peeling in the matrix, and the smaller this segment, the more the impact force is dispersed and absorbed. As a result, the toughness of the resin composition is improved. Moreover, it is because the operativity at the time of manufacturing a molded object and a fiber improves by setting it as fine dispersion.

  The dispersion state of the copolymerized aromatic polyester resin (B) can be observed by TEM. As described above, the domain size of the copolymerized aromatic polyester resin (B) has an average diameter of less than 0.5 μm and a maximum diameter. It must be less than 1.0 μm.

  When the average diameter is 0.5 μm or more, not only the take-up property when producing pellets made of the resin composition is inferior, but also the moldability is poor, and the high-speed spinnability when spinning fibers (spinning speed 3500 m / min) The object of the present invention is not achieved. A more preferable average diameter is 0.4 μm or less. The lower limit of the average diameter is preferably 0.001 μm. If average diameter is less than 0.001 micrometer, it will become compatible with aliphatic polyester resin (A), and toughness will not improve.

  The reason why the maximum domain size diameter of the copolymerized aromatic polyester resin (B) is less than 1.0 μm is the same as the reason why the average diameter is less than 0.5 μm, thereby producing pellets. This is because the take-up property at the time and the moldability at the time of obtaining a molded article are good, and high-speed spinning is possible. More preferably, the maximum diameter is less than 0.65 μm. The lower limit of the maximum diameter is preferably 0.001 μm.

  Thus, the copolymer aromatic polyester resin (B) as the island component is finely dispersed in the aliphatic polyester resin (A) as the sea component, and the domain size of the copolymer aromatic polyester resin (B) is determined as the average diameter. In order to obtain a polyester resin composition of the present invention by mixing the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B), in order to obtain a polyester resin composition of the present invention by mixing less than 0.5 μm and less than 1.0 μm in maximum diameter It is necessary to add an appropriate amount of the compatibilizer (C) and perform melt mixing.

  The blending amount of the copolymerized aromatic polyester resin (B) is preferably, as a mass ratio, aliphatic polyester resin (A) / copolymerized aromatic polyester resin (B) = 95/5 to 70/30. When the blending amount of the copolymerized aromatic polyester resin (B) is less than 5% by mass, the toughness of the resin composition is not improved, and the effect of improving the impact resistance does not appear. Moreover, when the compounding quantity exceeds 30 mass%, the intensity | strength of the resin composition obtained will fall extremely and a physical property sufficient as a molded article or a fiber cannot be obtained. Further, it is not preferable from the viewpoint of cost.

  As described above, the compatibilizer (C) is used to finely disperse the copolymerized aromatic polyester resin (B) as an island component in the aliphatic polyester resin (A) as a sea component with a specific domain size. .

  The aliphatic polyester resin (A) will be described in detail. Examples of α- and / or β-hydroxycarboxylic acid units include D-lactic acid, L-lactic acid, glycolic acid, 3-hydroxybutyric acid, 3-hydroxyvaleric acid, 3-hydroxycaproic acid and the like. A mixture thereof may be used.

  Accordingly, examples of the aliphatic polyester resin (A) that can be used in the present invention include poly (D- and / or L-lactic acid), poly (glycolic acid), poly (3-hydroxybutyric acid), and poly (3-hydroxybutyrate). Herbic acid), poly (3-hydroxycaproic acid), copolymers thereof, and mixtures thereof.

  Of the above resins, poly (D- and / or L-lactic acid) can be preferably used from the viewpoint that industrial mass production is possible. For poly (D- and / or L-lactic acid), the copolymerization ratio of the monomer components may be determined so that the melting point of the copolymer is 150 ° C or higher. The copolymerization ratio of L-lactic acid and D-lactic acid is (L-lactic acid) / (D-lactic acid) = 5/95 to 0/100, or (L-lactic acid) / (D-lactic acid) in molar ratio. = 95/5 to 100/0, the melting point of the copolymer is 150 ° C. or higher, and the crystallinity of the copolymer is increased, which is preferable from the viewpoint of heat resistance.

  The aliphatic polyester resin (A) can be produced by a generally known melt polymerization method or by further using a solid phase polymerization method. In addition, poly (3-hydroxy entangling acid), poly (3-hydroxyvaleric acid), and the like can be produced by microorganisms.

  The aliphatic polyester resin (A) may be copolymerized with other aliphatic polyester resin components as necessary within a range that does not significantly impair the heat resistance of poly (α- and / or β-hydroxycarboxylic acid). Or they can be mixed. Other aliphatic polyester resins mentioned here include aliphatic polyesters composed of diols and dicarboxylic acids typified by poly (ethylene succinate) and poly (butylene succinate); and poly (ε-caprolactone). Poly (ω-hydroxyalkanoates); poly (butylene succinate-co-butylene terephthalate) and (butylene adipate-co-butylene terephthalate); polyesteramide; polyester Carbonate; polysaccharides such as starch;

  The lactic acid polymer can be produced by polymerizing lactic acid by a conventionally known method. Examples of the polymerization method include a method of directly dehydrating condensation of lactic acid, a method of ring-opening polymerization of lactide which is a cyclic dimer of lactic acid, and the like. These polymerization reactions may be performed in a solvent, and if necessary, the reaction may be efficiently performed using a catalyst or an initiator. These methods may be appropriately selected in consideration of the molecular weight and melt viscosity necessary for the obtained resin.

  The weight average molecular weight of the aliphatic polyester resin (A) is not particularly limited, but is preferably 50,000 to 200,000, and more preferably 80,000 to 180,000. A weight average molecular weight of less than 50,000 is not preferable because the melt viscosity of the resin composition is too low. On the contrary, if this exceeds 200,000, the moldability and high-speed spinnability of the resin composition may decrease rapidly, which is not preferable.

  Next, the copolymerized aromatic polyester resin (B) will be described. The copolymerized aromatic polyester resin (B) is obtained by polymerizing an ester of a glycol component and a dicarboxylic acid component, and may be any one as long as the melting point is 140 ° C to 220 ° C. The melting point may be within this range by adjusting the copolymerization ratio. Examples of the glycol component include ethylene glycol, propylene glycol, butylene glycol, pentyl glycol, and 1,4 butanediol. As the dicarboxylic acid component, a dicarboxylic acid having 4 to 20 carbon atoms is preferable. Examples of such dicarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, and dodecanedioic acid, terephthalic acid, isophthalic acid, sulfoisophthalic acid, oxalic acid, naphthalene-dicarboxylic acid, 1,4 -Cyclohexane dicarboxylic acid etc. are mentioned.

  Next, the compatibilizer (C) will be described. As the compatibilizing agent (C), a generally known chain extender can be most effectively applied. It is essential that the compatibilizer (C) has reactivity with chain extension, such as an epoxy group, a carbodiimide group, an isocyanate group, and a maleic anhydride group.

  Examples of the compound as the compatibilizer (C) include an epoxy group-containing compound, a glycidyl ether compound, a glycidyl ester compound, a glycidyl imide compound, and an oxazoline compound.

Specific examples of the epoxy group compound include Joncryl ADR4300, 4368 (manufactured by BASF).
Specific examples of glycidyl ether compounds include glycidyl methacrylate, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, polypropylene glycol diglycidyl ether. Examples include ether. Of these, polyglycerol polyglycidyl ether is particularly preferred.

  Specific examples of the glycidyl ester compound include glycidyl methacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, polypropylene glycol diester. Methacrylate, polypropylene glycol diacrylate, polytetramethylene glycol dimethacrylate, polytetramethylene glycol diacrylate, poly (ethylene glycol-tetramethylene glycol) dimethacrylate, poly (ethylene glycol-tetramethylene glycol) diacrylate, poly (propylene glycol- Tetramethylene glyco Le) dimethacrylate, poly (propylene glycol - tetramethylene glycol) diacrylate, polyethylene glycol - polypropylene glycol dimethacrylate, polyethylene glycol - and polypropylene glycol diacrylate.

  Polymers having these glycidyl group-containing compounds as monomer units, compounds in which a glycidyl group is graft-copolymerized to a polymer as a main chain, specifically, Modeler A4200 (manufactured by NOF Corporation) are also included. . In addition to these monomer units, a long-chain alkyl acrylate can be copolymerized to control the reactivity of the glycidyl group.

  Specific examples of the glycidyl imide compound include N-glycidyl phthalimide.

  Examples of the oxazoline compound include oxazoline compounds such as N, N′-di-m-phenylenebis (2-oxazoline) and N, N′-di-p-phenylenebis (2-oxazoline).

  Examples of the carbodiimide group compounds include diphenylcarbodiimide, di-cyclohexylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, dioctyldecylcarbodiimide, diisopropylcarbodiimide, N, N′-di-p-aminophenylcarbodiimide, N, N′-dioctyl. Decylcarbodiimide, N, N'-di-2,6-dimethylphenylcarbodiimide, N, N'-di-2,6-diisopropylphenylcarbodiimide, 2,6,2 ', 6'-tetraisopropyldiphenylcarbodiimide, N, N′-di-p-hydroxyphenylcarbodiimide, N, N′-di-cyclohexylcarbodiimide, N, N′benzylcarbodiimide, N, N′-di-p-ethylphenylcarbodiimide, N, N′-di- o-Isop Pyrphenylcarbodiimide, N, N'-di-2,6-diethylphenylcarbodiimide, N, N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N, N'-di-2-isobutyl-6-isopropyl Examples thereof include phenyl carbodiimide, N, N′-di-2,4,6-trimethylphenyl carbodiimide, N, N′-di-2-isobutyl-6-isopropylphenyl carbodiimide, and the like. Of these, N, N′-di-2,6-diisopropylphenylcarbodiimide and 2,6,2 ′, 6′-tetraisopropyldiphenylcarbodiimide are preferable. Specific examples thereof include Stavacsol I (manufactured by Line Hemy), EN-160 (manufactured by Matsumoto Yushi Co., Ltd.), LA-1 (manufactured by Nisshinbo Co., Ltd.), and the like.

  As an isocyanate compound, C6-C20 aromatic diisocyanate, C2-C18 aliphatic diisocyanate, C4-C15 alicyclic diisocyanate, C-carbon (excluding carbon in NCO group, the same applies hereinafter) 8-15 araliphatic diisocyanates, modified products of these diisocyanates and mixtures of two or more of these can be used. Specific examples of the isocyanate include phenylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, ethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), Examples include lysine triisocyanate. Of these, lysine triisocyanate, TDI, HDI, and IPDI are preferable. Particularly preferred is lysine triisocyanate.

It is preferable that the compatibilizing agent (C) in the present invention is an arbitrarily selected one or more compounds selected from the above.
The amount of the compatibilizer (C) added is in the range of 0.01 to 10 parts by mass, with the total of the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B) being 100 parts by mass.

  The impact resistance and toughness of the polyester resin composition of the present invention and a molded article using the same can be evaluated by Izod impact strength. The Izod impact strength is preferably 28 J / m or more, more preferably 30 J / m or more, and further preferably 32 J / m or more.

  A crystal nucleating agent is preferably added to the polyester resin composition of the present invention. The crystal nucleating agent promotes crystallization of the polyester resin composition, and is an important factor for retaining heat resistance and dimensional stability. Crystal nucleating agents include inorganic fillers and compounds that are effective in promoting crystallization among organic compounds, and any nucleating agent may be used or may be used in combination. For example, examples of the inorganic filler include layered silicate, talc, titanium oxide, and silicon oxide. Examples of the organic compound include erucic acid amide, ethylene bis-12-hydroxystearyl amide, ethylene bis stearic acid amide, citric acid, and ethylene bis oleic acid amide.

  In the polyester resin composition of the present invention, pigments, fragrances, dyes, matting agents, heat stabilizers, antioxidants, plasticizers, lubricants, mold release agents, light-proofing agents, as long as the properties are not significantly impaired. It is also possible to add a weathering agent, a flame retardant, an antibacterial agent, a surfactant, a surface modifier, an antistatic agent, a filler, a terminal blocking agent, and the like.

  As the heat stabilizer or antioxidant, for example, hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, or mixtures thereof can be used.

  Inorganic fillers include zinc carbonate, wollastonite, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, zinc oxide, antimony trioxide, zeolite, Examples thereof include hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, glass fiber, and carbon fiber.

  Examples of the organic filler include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, and modified products thereof.

  Examples of the terminal blocking agent include carbodiimide compounds, oxazoline compounds, and epoxy compounds.

  The method of mixing the aliphatic polyester resin of the present invention with a compatibilizer, additive, or other thermoplastic resin is not particularly limited, but after normal heating and melting, for example, a single-screw extruder or a twin-screw extruder It is preferable to add using a roll mixer, a Brabender, etc., and knead to such an extent that the viscosity of the resin does not decrease extremely. It is more effective to use a dynamic mixer or a static mixer together if necessary. Moreover, you may add at the time of superposition | polymerization of biodegradable resin.

  The molded product obtained using the polyester resin composition of the present invention preferably has a crystallinity of 10 to 35% of the polyester resin constituting the molded product. When the degree of crystallinity is less than 10%, thermal shrinkage tends to be large and heat resistance tends to be poor. When the degree of crystallinity exceeds 35%, it is good from the viewpoint of heat resistance, but impact strength and toughness tend to be lowered. Therefore, the more preferable range of crystallinity is 15 to 30%.

  In the molded product of the present invention, in order to increase the crystallinity of the polyester resin to 10% or more, the above-described crystal nucleating agent is added, heat treatment is performed after molding, and the temperature conditions at the time of manufacturing the molded product are set. It is necessary to control. Control of the temperature conditions during the production of the molded body includes, for example, the drawing temperature and mold temperature, the glass transition temperature of the polyester resin composition used as Tg, and the melting point as Tm, and (Tg + 20 ° C.) to (Tm− It is possible to cite cooling to Tg or less after maintaining for a predetermined time in the range of 20 ° C.). In order to further promote the crystallization of the resin, it is more preferable to set the crystallization temperature of the resin to Tc and the mold temperature in the range of (Tc−20 ° C.) to (Tc + 20 ° C.). Since the time to hold at the temperature of (Tg + 20 ° C.) to (Tm−20 ° C.) depends on the crystallization rate index of the polyester resin composition to be used, it cannot be defined unconditionally, but it is precisely controlled within a predetermined temperature within the above range. It is preferable to hold for at least 3 seconds, preferably 5 seconds, more preferably 10 seconds or more in the mold. When the time is shorter than 3 seconds, the crystallinity cannot be sufficiently increased.

A molded body using the resin composition of the present invention can be obtained by a known molding method such as injection molding, blow molding, extrusion molding, fiber molding or the like.
As the injection molding method, in addition to a general injection molding method, a gas injection molding method, an injection press molding method, or the like can be employed. The cylinder temperature at the time of injection molding needs to be equal to or higher than the melting point Tm or the flow start temperature of the resin composition, and is preferably in the range of (Tm or flow start temperature + 5 ° C.) to (Tm or flow start temperature + 100 ° C.). More preferably, it is in the range of (Tm or flow start temperature + 5 ° C.) to (Tm or flow start temperature + 50 ° C.). If the molding temperature is too low, a short circuit may occur during molding, resulting in instability of the molding or a tendency to overload. On the other hand, when the molding temperature is too high, the resin component is decomposed, resulting in problems such as the strength of the resulting molded product being reduced or being colored. On the other hand, when the mold temperature is set to a glass transition temperature Tg or less of the resin composition and when heat resistance is obtained by crystallization in the mold, the mold temperature with respect to the crystallization temperature Tc of the resin composition. The method is selected according to the purpose from the method of setting the temperature to (Tc ± 20 ° C.), preferably (Tc ± 10 ° C.) or less. Molding with the mold temperature in the range of (Tc ± 20 ° C.) is very useful because the heat resistance can be improved by crystallizing the resin within the injection molding cycle. Moreover, you may heat-process after shaping | molding with the low temperature metal mold | die below Tg. Since the resin composition of the present invention has a very high crystallization rate, the heat treatment time is relatively short. The heat treatment temperature is preferably (Tc ± 20 ° C.). This principle of crystallization works similarly in various molding methods other than injection molding.

  Examples of the blow molding method include a direct blow method in which molding is performed directly from raw material chips, an injection blow molding method in which a preformed body (bottom parison) is first molded by injection molding, and then blow molding is performed, and further, stretch blow molding is performed. Law. In addition, any of a hot parison method in which blow molding is continuously performed after molding of a preformed body and a cold parison method in which the preform is once cooled and taken out and then heated again to perform blow molding can be employed. Also in the blow molding method, it is possible to improve the heat resistance by crystallizing the resin within the molding cycle by selecting the blow mold temperature, and even if heat treatment is performed after molding in a low temperature mold of Tg or less. It is possible to improve heat resistance.

  As the extrusion molding method, a T-die method, a round die method, or the like can be applied. The extrusion molding temperature needs to be equal to or higher than the melting point Tm or the flow start temperature of the resin composition, and is preferably in the range of (Tm or flow start temperature + 5 ° C.) to (Tm or flow start temperature + 100 ° C.), More preferably, it is the range of (Tm or flow start temperature +5 degreeC)-(Tm or flow start temperature +50 degreeC). If the molding temperature is too low, the molding becomes unstable or is easily overloaded. On the other hand, when the molding temperature is too high, the resin component is decomposed, resulting in problems such as a decrease in strength and coloring of the obtained extruded product. Sheets, pipes and the like can be produced by extrusion molding.

  In the above, the melting point Tm and the glass transition temperature Tg of the resin composition are values measured as described below. On the other hand, the crystallization temperature Tc is a value measured as follows. That is, using a DSC apparatus (for example, Pyrisl DSC manufactured by Perkin Elmer), the temperature was raised from 25 ° C. to 200 ° C. at + 20 ° C./min, then held at 200 ° C. for 10 minutes, and then 200 ° C. at −20 ° C./min. After the temperature is lowered from 0 ° C. to 0 ° C., the temperature is held at 0 ° C. for 5 minutes, and the temperature is raised again from 0 ° C. to 200 ° C. as a second scan at + 20 ° C./min. In such a case, the crystallization temperature Tc is a value measured from an exothermic peak when the temperature is lowered.

  The molded body produced by the molding method is molded into various forms and used for various purposes. Specific examples include dishes such as dishes, bowls, bowls, chopsticks, spoons, forks, knives; containers for fluids; caps for containers; rulers, writing instruments, clear cases, CD cases, and other office supplies; Daily items such as trash cans, washbasins, toothbrushes, combs, hangers, etc .; agricultural and horticultural materials such as flower pots and nursery pots; various toys such as plastic models; for electrical appliances such as various cases such as air conditioner panels, personal computers and copiers Resin parts; automotive resin parts such as bumpers, instrument panels and door trims.

  The form of the fluid container is not particularly limited, but is preferably molded to a depth of 20 mm or more in order to accommodate the fluid. Although the thickness of a container is not specifically limited, From a strong point, it is preferable that it is 0.1 mm or more, and it is more preferable that it is 0.1-5 mm. Specific examples of fluid containers include beverage cups and beverage bottles such as dairy products, soft drinks and alcoholic beverages; containers for temporarily storing seasonings such as soy sauce, sauces, mayonnaise, ketchup, and edible oils; shampoos and rinses Containers for cosmetics; containers for agricultural chemicals, and the like.

  Specific applications of the sheet or pipe obtained by the extrusion method include: raw sheet for deep drawing, cards such as credit cards, underlays, clear files, straws, rigid pipes for agriculture and horticulture, personal computer parts, automobiles Examples include parts. In addition, the sheet is further subjected to vacuum forming, pressure forming, vacuum drawing, vacuum drawing, etc., so that food containers, agricultural / horticultural containers, blister pack containers, press-through pack containers, PC parts, Auto parts can be manufactured. The molding temperature and the heat treatment temperature are preferably (Tg + 20 ° C.) to (Tg + 100 ° C.). If the squeezing temperature is less than (Tg + 20 ° C.), it becomes difficult to squeeze, and conversely if the squeezing temperature exceeds (Tg + 100 ° C.), the resin component is decomposed and uneven thickness occurs, or the orientation of the biodegradable resin is lost and resistance is increased. The impact property may be reduced. Further, heat resistance can be imparted by molding at Tc ± 20 ° C. Further, heat resistance is improved even after heat treatment after molding with a low-temperature mold of Tg or less.

  Forms of food containers, agricultural / horticultural containers, blister pack containers, press-through pack containers, container-shaped parts among automobile parts, and container-shaped parts among personal computer parts are not particularly limited, but food, goods, medicines In order to accommodate miscellaneous goods and the like, it is preferable that the drawing is deeply drawn to a depth of 2 mm or more. Although the thickness of a container is not specifically limited, From a strong point, it is preferable that it is 50 micrometers or more, and it is more preferable that it is 150-500 micrometers. Specific examples of food containers include fresh food trays, instant food containers, fast food containers, lunch boxes and the like. Specific examples of the agricultural / horticultural containers include seedling pots. Specific examples of blister pack containers include a variety of product groups such as office supplies, toys, dry batteries, automobile interior parts, personal computer parts, etc. in addition to food.

  The resin composition of this invention can exhibit the effect more by making it into a fiber especially. The production method is not particularly limited, but a method of melting, spinning at high speed and stretching is preferred. The melt spinning temperature is preferably in the range of (Tm or flow start temperature + 5 ° C.) to (Tm or flow start temperature + 100 ° C.), (Tm or flow start temperature + 5 ° C.) to (Tm or flow start temperature + 50 ° C.). A range is more preferred. When the melt spinning temperature is lower than the lower limit value, melt extrusion tends to be difficult. On the other hand, when the upper limit value is exceeded, decomposition of the resin component becomes remarkable and it becomes difficult to obtain fibers having practical strength. It is in. In melt spinning, for example, it is possible to take up with a roller at a spinning speed of 3500 m / min or more. Moreover, you may apply the spin draw method which extends | stretches the taken fiber yarn continuously. That is, it is preferable to draw the fiber yarn by pulling it at a temperature equal to or higher than Tg so as to obtain a target fiber diameter. The draw ratio is preferably about 1 to 20 times. The obtained yarn can be processed into various fibers such as multifilaments and monofilaments. For example, by applying the drawn false twist method to the obtained fiber to obtain a draw textured yarn, it is possible to obtain a fiber that can be developed for use in clothing, industrial materials, daily life materials and the like. Also in this case, crystallization easily occurs by stretching or heat treatment in a subsequent process, and heat resistance can be improved.

  Further, a fiber web is formed by drawing melt-spun fiber yarns by pulling with air, and a non-woven fabric, that is, a so-called spunbonded non-woven fabric can exhibit a very good effect.

  The melt flow rate of the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B) will be described. For the aliphatic polyester resin (A), a melt flow rate (hereinafter referred to as “MFR1”) measured under the conditions of a temperature of 190 ° C. and a load of 21.2 N (2.16 kgf), a temperature of 210 ° C. and a load of 21.2 N Both the melt flow rate (hereinafter referred to as “MFR2”) measured under the condition of (2.16 kgf) are defined. On the other hand, MFR2 is defined for the copolymerized aromatic polyester resin (B).

  When shape | molding a fiber using the resin composition of this invention, it is preferable that MFR1 of an aliphatic polyester resin (A) is 5-20 g / 10min. Moreover, it is preferable that MFR2 of an aliphatic polyester resin (A) is 15-30 g / 10min. When MFR1 is less than 5 g / 10 minutes or when MFR2 is less than 15 g / 10 minutes, the high-speed spinnability tends to be inferior. On the other hand, when MFR1 exceeds 20 g / 10 min, or when MFR2 exceeds 30 g / 10 min, the melt tension decreases and it is difficult to form fibers, and it is difficult to cool when obtaining a molded product. The formed body tends to be brittle. For this reason, about an aliphatic polyester resin (A), the more preferable range of MFR1 is 8-12 g / 10min, and the more preferable range of MFR2 is 18-24 g / 10min.

  The MFR2 of the copolymerized aromatic polyester resin (B) is preferably 2 to 35 g / 10 minutes. When MFR2 is less than 2 g / 10 min, a tendency to be inferior in high-speed spinnability occurs. On the other hand, when MFR2 exceeds 35 g / 10 min, the melt tension is lowered and it is difficult to form a fiber, and it is difficult to cool when obtaining a molded product, and the obtained molded product tends to be brittle. For this reason, the more preferable range of MFR2 of a copolymerization aromatic polyester resin (B) is 3-30 g / 10min, and a more preferable range is 5-25 g / 10min.

  The resin composition of the present invention exhibits a sea-island type polymer alloy structure in which the aliphatic polyester resin (A) is a sea component and the copolymerized aromatic polyester resin (B) is an island component, and the resin (B ) Has an average diameter of less than 0.5 μm and a maximum diameter of less than 1.0 μm. When this resin composition is used for fiberization, so-called spinning draft deformation occurs in the spinning draft process at that time. The domain size of the resin (B), which is an island component, is reduced. The domain size of the resulting resin (B) is preferably in the range of 0.001 to 0.1 μm. By being in this range, it is possible to obtain a fiber having a very soft feel.

  In order to make the domain size of the copolymerized aromatic polyester resin (B) in the above range in the obtained fiber, the spinning draft is preferably 150 or more. More preferably, it is 200 or more, More preferably, it is 300 or more. The spinning draft is a value obtained by dividing the spinning speed by the discharge linear speed, and is an index used as a standard for thinning the fiber in the process from discharging the molten polymer to taking it up as a fiber. The discharge speed refers to a value obtained by further dividing the value obtained by dividing the single hole discharge amount by the melt density of the polymer by the single hole area. In order to obtain the polyester fiber of the present invention, the spinning speed is preferably 3500 m / min or more.

  The resin composition of the present invention is alloyed so that it can be used when producing a fiber structure including a process of spinning and fiberizing at high speed using air soccer, such as the above spunbond nonwoven fabric. It is a resin composition. That is, in the resin composition of the present invention, in the alloyed resin, the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B) are uniformly blended, and the resin ( When the domain size of B) is less than 0.5 μm in average diameter and less than 1.0 μm in maximum diameter, it can sufficiently withstand high-speed spinning by air soccer with a spinning speed of 3500 m / min or more and withstand the stretching tension at the time of spinning. Therefore, the spunbonded nonwoven fabric can be produced while maintaining high productivity with few yarn breaks. The fiber obtained by such high-speed spinning is a fiber having a very soft feel because the domain size of the copolymerized aromatic polyester resin (B) is in the range of 0.001 to 0.1 μm as described above. In addition, the heat resistance of the fibers is improved.

  The fiber constituting the spunbonded nonwoven fabric may be a fiber composed only of the resin composition of the present invention, or a fiber having a composite cross section obtained by combining the resin composition of the present invention and another resin composition. Also good. In this case, in consideration of compatibility with the resin composition of the present invention, a polylactic acid polymer that is not alloyed, a copolymerized aromatic polyester resin (B), or the like is used. Is preferred.

  A specific form of the composite cross section includes a side-by-side composite cross section in which the resin composition of the present invention and another resin composition are bonded together. Moreover, the core-sheath-type composite cross section by which the resin composition of this invention and the other resin composition were compounded by the core-sheath type is mentioned. Specific combinations of core and sheath include polylactic acid polymer (core) / resin composition of the present invention (sheath), resin composition of the present invention (core) / polylactic acid polymer (sheath), Polymerized aromatic polyester resin (core) / resin composition (sheath) of the present invention, resin composition (core) of the present invention / copolymerized aromatic polyester resin (sheath) are mentioned.

  As a form of the spunbonded nonwoven fabric, at least a resin located on the fiber surface is melted or softened so that the fibers are thermally bonded to each other and the shape is maintained, but the constituent fibers are retained by entanglement. It may be a thing.

  As a form of thermal bonding, it may be one in which the fibers are thermally bonded via a polymer melted or softened on the fiber surface at the contact point between the fibers, or partially formed by passing the web through a hot embossing device. It may have a thermal bonding part and other non-thermal bonding parts.

  As another form, it is also possible to adopt a form in which entanglement is integrated by three-dimensional entanglement processing such as needle punching after provisional thermocompression bonding using a heat embossing device. Furthermore, if a predetermined amount of binder resin is adhered to the entangled nonwoven fabric, a nonwoven fabric in which the constituent fibers are firmly adhered at the bonded portion can be obtained.

  The fibers obtained by the above method can be used as clothing fibers, industrial material fibers, and the like. Specific examples of use include multifilaments, various clothing fibers, ropes and various nets, industrial fibers such as reinforcing fibers for resins and rubbers used in personal computers and automobiles, etc., flags and posting nets, etc. For advertising purposes. The monofilament can be applied to various nets, guts, fishing lines, and polishing applications. Further, it can be applied to a composite compounded with a resin.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited only to the following examples.

  In addition, measurement and evaluation of various characteristics in the following examples and comparative examples were performed by the following methods.

(1) Relative viscosity and limiting viscosity of polyester resin Solvent: phenol / tetrachloroethane (1: 1 weight ratio), concentration: 0.5 g / 100 ml, dissolution temperature: 120 ° C., measurement temperature: 20 ° C.

(2) Molecular weight Using a gel permeation chromatography (GPC) apparatus (manufactured by Shimadzu Corporation) equipped with a differential refractive index detector, the molecular weight was determined in terms of standard polystyrene in terms of 40 ° C. using tetrahydrofuran or chloroform as an eluent. Polylactic acid was dissolved in a small amount of chloroform and then tetrahydrofuran was added to prepare a sample.

(3) Melting point / softening point Tm
Using a DSC device (Perkin Elmer, Pyrisl DSC), the temperature of the resin to be measured was raised from 25 ° C. to 200 ° C. at + 20 ° C./min, then held at 200 ° C. for 10 minutes, and then −20 ° C./min. The temperature was lowered from 200 ° C. to 0 ° C., held at 0 ° C. for 5 minutes, and again at + 20 ° C./minute, the temperature was raised from 0 ° C. to 200 ° C. as a second scan. From the endothermic peak during this second scan, the melting point Asked.

  The resin composition of the present invention is a polymer alloy of two types of resins, resin (A) and resin (B). Therefore, in principle, two endothermic peaks appear. In that case, the endothermic peak on the low temperature side is present. And a melting point Tm2 based on an endothermic peak on the high temperature side.

  The softening point is determined by placing a molded piece made of the resin to be measured on a slide glass under a microscope with a hot stage and observing the state of the molded piece while raising the temperature at 2 ° C./min. The starting point was taken as the softening point.

(4) Glass transition temperature Tg, crystallization temperature Tc
The glass transition temperature Tg was measured by the second scan of (3) above. The crystallization temperature Tc was measured when the temperature was lowered in (3) above.

(5) Melt flow rate (MFR1)
Measured according to JIS K7210 (temperature 190 ° C., load 21.2 N (2.16 kgf)).

(6) Melt flow rate (MFR2)
The measurement was performed according to JIS K7210 (temperature 210 ° C., load 21.2 N (2.16 kgf)).

(7) Flexural modulus and flexural strength A test piece of 127 mm × 12.7 mm × 3.2 mm was produced according to ASTM-D-790, and measured by applying a load at a deformation rate of 1 mm / min.

(8) DTUL (thermal deformation temperature)
According to ASTM-D-648 standard, the load was measured at 0.45 MPa.

(9) Izod impact strength A test piece with a notch of 64 mm × 12.7 mm × 3.2 mm was prepared and measured according to ASTM-D-256.

(10) Take-up property The take-up property when the resin melted and kneaded with a biaxial kneader was immersed in a water bath from a 4 mm diameter die at 10 m / min and passed through the pelletizer was evaluated according to the following criteria. .

A: The strand travels in a very good state. ○: The strand travels in a good state. Δ: The strand travels with variations in thickness in the length direction. Thickness variation is large in the vertical direction and stable running is not possible

(11) Formability
Thickness spots due to sink marks, which are defects during injection molding, were measured and evaluated according to the following criteria.

◎: When the thickness variation of the molded piece is less than 0.01 mm ○: When the thickness variation of the molded piece is 0.01 mm or more and less than 0.1 mm ×: Deformed when the molded piece is taken out, or the thickness variation is 0.1 mm or more If it is

(12) Appearance of molded piece Sample pieces at the time of injection molding were observed and evaluated according to the following criteria.

◎: No surface spots ○: Most surface spots are not observed △: Surface spots are slightly observed ×: Surface spots are observed

(13) Observation of island component domains:
Cut the sample in the TD direction (horizontal direction) or cut it in the direction perpendicular to the fiber axis, halve the thickness, immerse it in a visible curable resin (epoxy embedding material) for several hours, and then cure it. Sections were collected. Using the slice, a photograph was taken (20,000 times) by transmission measurement with an acceleration voltage of 100 kV, a current of 58 μA, and an irradiation aperture 3 using a JEM-1230 TEM apparatus manufactured by JEOL. The length of 100 island domains at that time was measured, and the average value and the maximum value were obtained.

(14) Fiber strength and elongation Using a constant speed tensile tester “Tensilon DSS-200” manufactured by Baldwin, the sample (polymer alloy fiber) is stretched at a constant speed as shown in JIS L1013 (chemical fiber filament yarn test method). The measurement was performed under the conditions (grip interval 25 cm, tensile speed 30 cm / min). The elongation was determined from the elongation at the point showing the maximum strength in the SS curve.

(15) Young's modulus It calculated | required based on JISL1013 (initial tensile resistance degree) from the SS curve obtained by the same method as said (14).

(16) Shrinkage ratio of hot water A sample (polymer alloy fiber) was immersed in boiling water for 15 minutes, and was determined from the dimensional change before and after immersion according to the following equation.

Hot water shrinkage (%) = [(L0−L1) / L0] × 100
However, L0: A sample was taken, and the case length measured under an initial load of 0.088 cN / dtex. L1: The case where L0 was measured was treated with boiling water in a load-free state, air-dried, and then an initial load of 0.088 cN / Case length measured under dtex

(17) Fiber state It was determined as follows according to the feeling when the fiber was bundled and grasped by hand and the smooth state of the fiber surface observed with a microscope.

High soft: extremely soft to touch and smooth fiber surface
Soft: soft touch and smooth fiber surface Slightly soft: soft touch but slightly lying on the fiber surface
Hard: It has a rough feeling as a touch, or a large number of recumbent can be seen on the fiber surface.

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

Aliphatic polyester resin (A):
A-1: Polylactic acid (manufactured by Nature Works, weight average molecular weight: 134,000, MFR 1: 12 g / 10 min, MFR 2: 25 g / 10 min, L-form: 99 mol%, D-form: 1 mol%, (Glass transition temperature Tg: 57 ° C, melting point Tm: 167 ° C)
A-2: Polylactic acid (manufactured by Nature Works, weight average molecular weight: 116,000, MFR: 38 g / 10 min, MFR 2: 84 g / 10 min, L form: 99 mol%, D form: 1 mol%, (Glass transition temperature Tg: 57 ° C, melting point Tm: 166 ° C)
A-3: Polylactic acid (weight average molecular weight: 125,000, MFR1: 10 g / 10 min, MFR2: 23 g / 10 min, L-form: 99.9 mol%, D-form: 0.1 mol%, glass transition (Tg: 59 ° C, melting point Tm: 179 ° C)

Copolymerized aromatic polyester resin (B):
B-1: Copolyester having a relative viscosity of 1.40 and a melting point of 180 ° C. (acid component: terephthalic acid, diol component: 1,4 butanediol 50 mol%, ethylene glycol 50 mol%)
B-2: Copolyester having a relative viscosity of 1.30 and a melting point of 180 ° C. (acid component: terephthalic acid, diol component: 1,4 butanediol 50 mol%, ethylene glycol 50 mol%)
B-3: Copolyester having a relative viscosity of 1.38 and a softening point of 170 ° C. (acid component: 67 mol% terephthalic acid, 33 mol% isophthalic acid, diol component: ethylene glycol)
B-4: Copolyester having an intrinsic viscosity of 0.67 and a melting point of 190 ° C. (obtained by adding and polymerizing 80 mol% terephthalic acid, 100 mol% ethylene glycol, 18 mol% glutaric acid, 2 mol% sulfoisophthalic acid)
B-5: Copolyester having a relative viscosity of 1.44 and a melting point of 200 ° C. (acid component: terephthalic acid, diol component: 1,4 butanediol 82 mol%, ethylene glycol 18 mol%)

Compatibilizer (C):
C-1: Epoxy compound (manufactured by BASF, trade name “JONCRYL-ADR-4300”)
C-2: Epoxy compound (manufactured by BASF, trade name “JONCRYL-ADR-4368”)
C-3: Polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name “Danacol EX-521”)
C-4: Lysine ester triisocyanate (manufactured by Kyowa Hakko)
C-5: Polycarbodiimide (Nisshinbo Co., Ltd., trade name “LA-1”)
C-6: Polyethylene glycidyl methacrylate-graft-polymethyl methacrylate = 70/30 (mass%) (manufactured by NOF Corporation, trade name “Modiper A4200”)

Examples 1-3
Using a biaxial extrusion kneader (Ikegai PCM-30, melting temperature-extrusion head temperature: 210 ° C., screw rotation 170 rpm, discharge rate 7.5 kg / h), polylactic acid (A) as aliphatic polyester resin (A) A-1) and the copolymerized aromatic polyester resin (B-1) were mixed at different rates as shown in Table 1. In the mixing, as a compatibilizing agent (C), JONCRYL-ADR-4300 (0.2 parts by mass) (C-1) manufactured by BASF, which is an epoxy compound, (A-1) and ( B-1) was added in the amount shown in Table 1 as 100 parts by mass.

  The screw used for kneading is a strong kneading dimension (a screw configuration in which a normal lead screw is combined with one reverse lead screw, three normal lead kneading disks, two reverse lead kneading disks, and three neutral kneading disks). Applied.

  The melt-kneaded resin was discharged from 3 holes, cooled in a water bath, and cut into pellets with a pelletizer. After drying the obtained pellets of the alloy resin composition, using an injection molding machine IS-80G manufactured by Toshiba Machine Co., Ltd., injection molding under the conditions of a cylinder set temperature of 190 ° C., an injection pressure of 100 MPa, and an injection time of 20 seconds, Various physical properties were evaluated. The mold temperature at this time was set in three stages of 15 ° C., 85 ° C., and 105 ° C., and the cooling time was 20 seconds at 15 ° C. and 80 seconds at 85 ° C. and 105 ° C.

  On the other hand, the dried pellets of the alloy resin compositions of Example 1 and Example 2 obtained above were supplied to a high-speed spinning machine base. The spinning machine is a spinning device having a 40 mm diameter single-screw extruder (manufactured by Barmag), discharged from a 36 hole spinneret with a spinning temperature of 220 ° C. and a hole diameter of 0.3 mm, and a yarn by annular blowing. Was cooled, and the oil agent was sprayed at a position 1500 mm below the spinneret while being taken up with a roller and spun at the maximum speed at which no yarn breakage occurred, to obtain 83 dtex / 36f brand fiber. The alloy resin composition of Example 3 was not subjected to fiberization.

  The results are shown in Table 1.

Examples 4-5
The type of copolymerized aromatic polyester resin (B) was changed to B-2 and B-3, and the amount added was changed as shown in Table 1. Otherwise by performing the same operations as in Example 1, a resin composition was obtained. Subsequent injection molding and fiber forming were performed under the same conditions as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Examples 6-10
The type and amount of the compatibilizer (C) were changed as shown in Table 1. Otherwise by performing the same operations as in Example 1, a resin composition was obtained. Subsequent injection molding and fiber forming were performed under the same conditions as in Example 1, and various evaluations were performed. The results are shown in Table 1.

  As is clear from Table 1, Examples 1 to 3 are resin compositions excellent in Izod strength, and were found to be applicable to various moldings. It was found that the resins of Examples 1 and 2 had sufficient high-speed spinnability by melt spinning. However, it has been found that when the content of the copolymerized polyester component, which is an alloy component, is increased, the maximum spinning speed at which yarn breakage does not occur tends to decrease slightly.

  Examples 4 to 10 were all confirmed to have a practical heat resistance and to obtain a molded article having sufficient impact strength. Furthermore, when the resins of Examples 4 to 10 were formed into fibers, no yarn breakage occurred even at a spinning speed of 5000 m / min, and it was confirmed that the operability was good. It was confirmed that the domain size of the copolymerized aromatic polyester resin (B) in the obtained fiber was in the range of 0.001 to 0.1 μm, and the fiber state was also high soft.

Example 11
To 90% by mass of polylactic acid (A-2), 10% by mass of copolymerized aromatic polyester resin (B-4) was added. Moreover, 0.2 mass part of compatibilizer (C-1) was added with respect to a total of 100 mass parts of polylactic acid (A-2) and a copolymer aromatic polyester resin (B-4). And it melt-mixed similarly to Example 1 and obtained the alloy resin composition. After drying, injection molding was performed in the same manner as in Example 1, and molding evaluation was performed. The average size of the island components was 0.19 μm, DTUL 55 ° C., Izod impact strength 27 J / m, MFR-1: 6 g / 10 minutes, MFR-2: 13 g / 10 minutes, and the moldability was good.

On the other hand, the obtained dried pellets of the alloy resin composition were supplied to a spinning machine table for spunbond nonwoven fabric. That is, the spinning machine has a 65 mm diameter single screw extruder (manufactured by Nippon Steel Co., Ltd.), uses two nozzles having a spinning temperature of 220 ° C., a hole diameter of 0.3 mm and 72H, and a single hole discharge rate of 1 The yarn was discharged from the spinneret at 4 g / min / hole, the yarn was cooled by horizontal spraying, and the filament was pulled by air soccer at a position of 2000 mm below the spinneret to obtain a 2.0 dtex fiber web. . The spinning speed was examined from the fiber diameter of this fiber web. As a result, the spinning speed was 5300 m / min, the spinning draft was 294, and the fiber was high-soft and excellent in fiber opening. This fiber web was passed through an embossing roll at 130 ° C. to obtain a 75 g / m ² spunbond nonwoven fabric.

Example 12
Copolymer aromatic polyester resin (B-5) 15 mass% was added with respect to polylactic acid (A-3) 85 mass%. Moreover, 0.2 mass part of compatibilizer (C-2) was added with respect to a total of 100 mass parts of polylactic acid (A-3) and copolymerization aromatic polyester resin (B-5). And it melt-mixed similarly to Example 1 and obtained the alloy resin composition. After drying, injection molding was performed in the same manner as in Example 1, and molding evaluation was performed. The average size of the island component is 0.34 μm, DTUL is 57 ° C., Izod impact strength is 37 J / m, MFR-1 is 6.1 g / 10 min, MFR-2 is 13 g / 10 min, and the moldability is good. there were.

  Using the obtained pellets of the alloy resin composition, the single-hole discharge rate was 1.67 g / min / hole, the spinning speed was 4400 m / min, and the fineness was 3.7 dtex. Similarly, a spunbond nonwoven fabric was obtained. The spinning draft was 204. The domain size of the copolymerized aromatic polyester resin (B-5) in the fibers constituting the obtained nonwoven fabric is in the range of 0.001 to 0.1 μm, and the fibers are high-soft and excellent in openability. there were.

Comparative Examples 1-2
In Comparative Example 1, only an aliphatic polyester resin was used, and in Comparative Example 2, only a copolymerized aromatic polyester resin was used. Other than that, injection molding and fiber forming were performed under the same methods and conditions as in Example 1, and various evaluations were performed. The results are shown in Table 1.

  Although both of these Comparative Examples 1 and 2 have good moldability, Comparative Example 1 is slightly inferior in impact resistance, and when used as a fiber, Comparative Example 1 is hard, and Comparative Example 2 is that of each Example. It was inferior in flexibility compared to the fiber.

Comparative Examples 3-5
In Comparative Example 3, the compatibilizing agent was not added when the alloy resin of polylactic acid (A-1) and copolymerized aromatic polyester (B-1) was produced, and the other methods were the same as in Example 1. An attempt was made to obtain a resin composition. However, at the time of kneading and discharging the polymer, the ballast increased, the spinnability was almost lost, the pelletizer could not be passed through, and pellets could not be obtained. That is, a resin composition could not be obtained with good operability.

  In Comparative Example 4, as shown in Table 1, an excessive amount of the compatibilizer (C) was used and subjected to kneading to obtain an alloy resin composition under the same conditions as in Example 2. In addition, various evaluations were performed by performing injection molding and fiber molding under the same method and conditions as in Example 2. The results are shown in Table 1.

  As is clear from Table 1, in Comparative Example 4, the melt viscosity of the resin was very high, and the fluidity of the resin was greatly reduced. Therefore, when the domain of the resin was investigated, it was found that the average diameter of the island component was larger than the range of the present invention, and the spinning property was inhibited. An attempt was made to produce this alloy resin composition under the same spinning conditions as in Example 2, but the melt viscosity was high and high-speed spinning was not possible.

  In Comparative Example 5, since the addition amount of the copolymerized aromatic polyester was excessive, even if the addition amount of the compatibilizing agent was optimized, the island component domain average diameter was large and the moldability was not good. When fibers were molded using this resin composition, it was confirmed that spinning performance with a spinning speed of about 1000 m / min was obtained, but high-speed spinning performance exceeding 3000 m / min could not be obtained. The average island component domain diameter of the fiber was smaller than that of the resin composition, but it was not the domain diameter following high-speed spinning.

Comparative Examples 6 and 7
The screw of the twin screw extruder kneader is a normal dimension (one reverse lead screw, one normal lead kneading disk, two reverse lead kneading disks, one neutral kneading disk combined with a normal lead screw) Configuration) was applied, the screw rotation speed was 100 rpm, and strong kneading was not performed. And it was going to obtain the resin composition according to Example 1 except having changed the addition amount of the copolymer aromatic polyester (B-1) and the compatibilizing agent (C) as shown in Table 1. However, in Comparative Example 6, when kneading and discharging the polymer, the ballast increased, the take-off property was poor, and the pelletizer stopped many times. When the obtained resin composition was molded, the injection moldability was not good.

  When the domain diameter of the island component of the resin composition was measured in order to investigate this cause, the average diameter was larger than the range of the present invention, and the maximum diameter exceeded 1 μm which was the upper limit of the range of the present invention. . Further, this alloy resin was applied to spinning in the same manner as in Example 2. However, there was no high-speed spinning property, and the maximum spinning speed was as low as 50 m / min. The fiber state of the obtained fiber was quite hard.

  In Comparative Example 7, the amount of copolymerized aromatic polyester resin (B-1) added was reduced. As in Comparative Example 6, strong kneading was not performed. As a result, although the average diameter of the island component domains was relatively small, the maximum domain diameter exceeded 1 μm. Due to this, the take-up property and the moldability were not so good. This alloy resin was applied to spinning in the same manner as in Example 2. However, there was no high-speed spinnability, and the maximum spinning speed was remarkably low at 200 m / min. The fiber state of the obtained fiber was also quite hard.

Claims (7)

  Aliphatic polyester resin (A) containing 70 mol% or more of α- and / or β-hydroxycarboxylic acid units, copolymerized aromatic polyester resin (B) having a melting point of 140 ° C. to 220 ° C., and a compatibilizing agent (C), the resin (A) is a sea component and the resin (B) is an island component, and has a sea-island type polymer alloy structure, and the domain size of the island component resin (B) is an average diameter. A polyester resin composition having a diameter of less than 0.5 μm and a maximum diameter of less than 1.0 μm.   The polyester resin composition according to claim 1, wherein the α- and / or β-hydroxycarboxylic acid unit is D-lactic acid or L-lactic acid or a mixture thereof.   The copolymerized aromatic polyester (B) is either one comprising terephthalic acid, ethylene glycol and butanediol as constituents, or one comprising terephthalic acid, isophthalic acid and ethylene glycol as constituents. The polyester resin composition according to claim 1 or 2.   The blend ratio of the aliphatic polyester resin (A) and the copolymerized aromatic polyester resin (B) is, by mass ratio, aliphatic polyester resin (A) / copolymerized aromatic polyester resin (B) = 95/5 to 70. The polyester resin composition according to any one of claims 1 to 3, wherein the polyester resin composition is / 30.   The compatibilizer (C) is one or more selected from an epoxy chain extender, an isocyanate chain extender, a carbodiimide chain extender, and a glycidyl ether chain extender. The polyester resin composition according to any one of claims 1 to 4, wherein the polyester resin composition is any one of claims 1 to 4.   A molded body comprising the polyester resin composition according to any one of claims 1 to 5.   It is a polyester fiber using the polyester resin composition according to any one of claims 1 to 5, wherein the domain size of the copolymerized aromatic polyester resin (B) by spinning draft deformation is 0.001 to 0.00. A polyester fiber characterized by being in the range of 1 μm.