Thermoplastic polyester elastomer resin composition, method of preparing the resin composition, and molded article comprising the resin composition

Abstract

The present invention relates to a thermoplastic polyester elastomer resin composition, a method of preparing the same, and a molded article comprising the same. More particularly, the present invention relates to a thermoplastic polyester elastomer resin composition, a method of preparing the same, and a molded article comprising the same, the thermoplastic polyester elastomer resin composition comprising: 89 to 96 wt% of a thermoplastic polyester elastomer resin (A); 1.5 to 5.5 wt% of a glycidyl-modified olefin-based rubber polymer (B); and 1.5 to 5.5 wt% of an ionomer resin (C). The present invention has the effect of providing a high-quality thermoplastic polyester elastomer resin composition, a method of preparing the same, and a molded article comprising the same, the thermoplastic polyester elastomer resin composition having excellent mechanical properties and molding properties; being capable of inhibiting the generation of flow marks on the inner surface of the molded article; and thus being suitable for use in constant-velocity universal joint boots.

Description

TECHNICAL FIELD

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims priority to Korean Patent Application No. 10-2021-0144938 filed on October 27, 2021, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2022-0099866 filed on August 10, 2022, based on the priority of the above-mentioned patent, the disclosures of each of which are incorporated herein by reference.

[0003] The present invention relates to a thermoplastic polyester elastomer resin composition, a method of preparing the same, and a molded article comprising the same. More particularly, the present invention relates to a high-quality thermoplastic polyester elastomer resin composition, a method of preparing the same, and a molded article comprising the same, the thermoplastic polyester elastomer resin composition having excellent hardness and mechanical properties; having excellent molding properties due to high melt tension; being capable of inhibiting the generation of flow marks on the inner surface of a molded article; and thus being suitable for automobile parts, in particular, constant velocity joint boots (CVJBs). BACKGROUND

[0004] With the development of automobile technology, the modularization of automobile parts is being actively pursued. In particular, in the case of automobiles having a front engine / front drive wheel (FF) system, the front wheel module is responsible for various functions such as acceleration / deceleration, impact absorption, and steering. When the force generated by the automobile engine acts directly on the wheel, the impact absorbed by the wheel is transmitted to the engine, resulting in deterioration of durability. In this case, the automobile part required is a constant velocity joint (CVJ). By the action of the constant velocity joint, the force generated by the engine is transmitted to the transmission through the output shaft, and the force transmitted to the transmission is uniformly transmitted through the shafts of the respective wheels, so that both wheels rotate at a constant velocity. In order to ensure constant velocity, the internal components of the constant velocity joint are arranged to be placed in a predetermined position. In order to ensure the function of the constant velocity joint, that is, in order to prevent the internal heat generated due to the continuous friction between the internal components of the constant velocity joint from increasing above a certain temperature, and in order to facilitate the predetermined movement of the internal components, a lubricating grease is applied to the constant velocity joint as a lubricant.

[0005] A constant velocity joint (CVJ) boot is an internal component that resists heat generated by a constant velocity joint, prevents leakage of lubricating grease, and protects the constant velocity joint from foreign substances. The constant velocity joint boot rotates together in the process of transmitting force to a wheel. At this time, noise is generated due to friction between the wrinkled surfaces of the boot. In addition, when various foreign substances such as water, salt water (e.g., calcium chloride), and sand are introduced from the road surface into the lower part of the car and the constant velocity joint boot is contaminated, a huge noise of 90 decibels or more can be generated.

[0006] Meanwhile, conventionally, crosslinked rubber such as chloroprene rubber has been used as a material for a constant velocity joint boot. Recently, with the trend of lightening and environmental protection of automobiles, a thermoplastic polyester elastomer resin having a low specific gravity and being easily recycled is mainly used. The constant velocity joint boot is manufactured by mixing the polyester elastomer resin with a lubricant to secure friction resistance, scratch resistance, and noise resistance.

[0007] In order to manufacture a constant velocity joint boot by molding using a thermoplastic polyester elastomer resin, it is necessary to increase the viscosity of the resin by increasing the molecular weight of the resin. In this case, a chain extender is added to the resin to increase the viscosity thereof by forming a chemical bond. As the amount of the chain extender added to the resin increases, the viscosity of the resin increases. However, when an excessive amount of the chain extender is added, due to a gelation phenomenon, the discharge pressure of a nozzle rises during molding, and an excessive load is applied to a molding machine. In addition, the inner surface of the boot becomes rough, resulting in poor appearance, and due to uneven molecular weight, weight variation and batch-to-batch difference increase. On the other hand, when the viscosity of the resin is low, since the melt viscosity of a parison is reduced, molding cannot be performed, or the thickness deviation of the boot increases, resulting in reduced durability or leakage of lubricating grease.

[0008] Therefore, there is a need to develop a material capable of improving molding performance and internal appearance.

[0009] [Related Art Documents]

[0010] [Patent Documents]

[0011] KR10-1242686B1 SUMMARY

[0012] TECHNICAL PROBLEM

[0013] Therefore, the present application has been made in view of the above problems, and it is an object of the present application to provide a high-quality thermoplastic polyester elastomer resin composition having excellent hardness and mechanical properties; excellent molding performance due to high melt tension; capable of suppressing the generation of flow marks on the inner surface of a molded article; and thus, suitable for automobile parts, particularly, a constant velocity joint boot (CVJB).

[0014] Another object of the present application is to provide a method of preparing the thermoplastic polyester elastomer resin composition.

[0015] Still another object of the present application is to provide a molded article manufactured using the thermoplastic polyester elastomer resin composition.

[0016] The above and other objects can be achieved by the present application described below.

[0017] Technical Solution

[0018] According to one aspect of the present application, there is provided a thermoplastic polyester elastomer resin composition, comprising: 89 to 96% by weight of a thermoplastic polyester elastomer resin (A); 1.5 to 5.5% by weight of a glycidyl-modified olefin-based rubber polymer (B); and 1.5 to 5.5% by weight of an ionomer resin (C).

[0019] Further, the present application can provide a thermoplastic polyester elastomer resin composition, comprising: 89 to 96% by weight of a thermoplastic polyester elastomer resin (A); 1.5 to 5.5% by weight of a glycidyl-modified olefin-based rubber polymer (B); and 1.5 to 5.5% by weight of an ionomer resin (C), wherein, when the thermoplastic polyester elastomer resin composition pellets are discharged in the form of a sheet using a single-screw extruder (screw diameter: 30Φ, screw length: 1 m) at 60 rpm and a barrel temperature of 230℃ through a T-die (die width: 150 mm, die thickness: 1.5T), and the time required for the sheet discharged from the T-die to fall from a height of 120 cm, i.e., the falling time, is measured, the falling time of the thermoplastic polyester elastomer resin composition is 60 to 120 seconds.

[0020] The melt flow rate of the thermoplastic polyester elastomer resin composition, measured according to ISO 1133 at 230℃ and a load of 10 kg, can preferably be 5 to 16 g / 10 min.

[0021] The melt flow rate of the thermoplastic polyester elastomer resin (A), measured according to ISO 1133 at 230℃ and a load of 2.16 kg, can preferably be 0.5 to 10 g / 10 min.

[0022] The thermoplastic polyester elastomer resin (A) can preferably be an elastomer resin comprising an aromatic dicarboxylic acid or an ester-forming derivative thereof; an aliphatic diol; and a polyalkylene oxide.

[0023] The aromatic dicarboxylic acid can preferably include one or more selected from terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, and 1,4-cyclohexane dicarboxylic acid.

[0024] The ester-forming derivative of the aromatic dicarboxylic acid can preferably include one or more selected from dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalene dicarboxylate, and dimethyl 1,4-cyclohexane dicarboxylate.

[0025] The aliphatic diol can preferably include one or more selected from ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexane dimethanol.

[0026] The polyalkylene oxide can preferably include one or more selected from polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, a copolymer of ethylene oxide and propylene oxide, an ethylene oxide addition polymer of polypropylene glycol, and a copolymer of ethylene oxide and tetrahydrofuran.

[0027] The glycidyl-modified olefin-based rubber polymer (B) can preferably be a polymer obtained by graft polymerization of glycidyl (meth)acrylate to a polyolefin-based rubber copolymer ((meth)acrylate-grafted polyolefin elastomer).

[0028] The glycidyl-modified olefin-based rubber polymer (B) can preferably include 6 to 20% by weight of glycidyl (meth)acrylate, based on the total weight of the glycidyl-modified olefin-based rubber polymer (B).

[0029] The ionomer resin (C) can preferably include a carboxyl group or a sulfonic acid group in which a hydrogen ion is substituted with a metal cation.

[0030] The thermoplastic polyester elastomer resin composition can preferably include one or more selected from an antioxidant, a light stabilizer, a lubricant, and a black master batch.

[0031] According to another aspect of the present application, there is provided a method of preparing a thermoplastic polyester elastomer resin composition, the method including: preparing a pellet by kneading and extruding 89 to 96% by weight of a thermoplastic polyester elastomer resin (A), 1.5 to 5.5% by weight of a glycidyl-modified olefin-based rubber polymer (B), and 1.5 to 5.5% by weight of an ionomer resin (C) at 200 to 300°C and 150 to 350 rpm.

[0032] Further, the present application can provide a method of preparing a thermoplastic polyester elastomer resin composition, the method including: preparing pellets by kneading and extruding 89 to 96 wt% of a thermoplastic polyester elastomer resin (A), 1.5 to 5.5 wt% of a glycidyl-modified olefin-based rubber polymer (B), and 1.5 to 5.5 wt% of an ionomer resin (C) at 200 to 300°C and 150 to 350 rpm, wherein, when the prepared pellets are discharged in the form of a sheet using a single-screw extruder (screw diameter: 30Φ, screw length: 1 m) at 60 rpm and a barrel temperature of 230°C through a T-die (die width: 150 mm, die thickness: 1.5T), and the time required for the sheet discharged from the T-die to fall from a height of 120 cm, i.e., the falling time, is measured, the falling time is 60 to 120 seconds.

[0033] According to still another aspect of the present application, there is provided a molded article including the thermoplastic polyester elastomer resin composition.

[0034] Advantageous Effects

[0035] The present application has the effect of providing a thermoplastic polyester elastomer resin composition, a method of preparing the thermoplastic polyester elastomer resin composition, and a molded article including the thermoplastic polyester elastomer resin composition, the thermoplastic polyester elastomer resin composition having excellent hardness and mechanical properties; having excellent molding properties due to high melt tension; and being capable of achieving excellent appearance by minimizing the generation of flow marks on the inner surface of a molded article.

[0036] Further, the thermoplastic polyester elastomer resin composition of the present application can satisfy the physical properties required for automotive parts, particularly constant velocity joint boot (CVJB), and can provide more excellent molding properties and surface appearance than conventional resin compositions. Accordingly, when the thermoplastic polyester elastomer resin composition of the present application is applied to a constant velocity joint boot, a rack and pinion boot, a propeller shaft boot, a dust boot, or a bellows, the quality thereof can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 An image including whether flow marks are generated on the inner surface of a molded article when resin compositions of Example 3 and Comparative Example 6 are blow-molded to manufacture a constant velocity joint boot, respectively, is included.

[0038] Figure 2 A method of measuring a falling time is schematically illustrated. DETAILED DESCRIPTION

[0039] Hereinafter, the thermoplastic polyester elastomer resin composition according to the present application, the method of preparing the same, and the molded article comprising the same will be described in detail.

[0040] The present inventors have confirmed that when a certain amount of glycidyl-modified olefin-based rubber polymer is combined with an ionomer resin in a thermoplastic polyester elastomer resin, a thermoplastic polyester elastomer resin composition having excellent hardness and mechanical properties; excellent molding properties due to high melt tension; and capable of inhibiting the generation of flow marks on the inner surface of a molded article can be obtained. Based on these results, the present inventors have conducted further research to complete the present application.

[0041] The thermoplastic polyester elastomer resin composition according to the present application will be described in detail as follows.

[0042] The thermoplastic polyester elastomer resin composition of the present application comprises: 89 to 96 wt% of a thermoplastic polyester elastomer resin (A); 1.5 to 5.5 wt% of a glycidyl-modified olefin-based rubber polymer (B); and 1.5 to 5.5 wt% of an ionomer resin (C). In this case, the hardness and mechanical properties can be excellent, the molding properties can be excellent due to high melt tension, the generation of flow marks on the inner surface of a blow molded article can be minimized, and thus, a high quality thermoplastic polyester elastomer resin composition can be applied to automobile parts, in particular, constant velocity universal joint boot.

[0043] Hereinafter, each component of the thermoplastic polyester elastomer resin composition of the present application will be described in detail.

[0044] A) thermoplastic polyester elastomer resin

[0045] For example, the content of the thermoplastic polyester elastomer resin (A) can be 89 to 96 wt%, preferably 89 to 95 wt%, more preferably 90 to 95 wt%, still more preferably 91 to 95 wt%, still more preferably 93 to 95 wt%, based on the total weight of components (A) to (C). Within this range, the hardness, mechanical properties, and flowability can be excellent.

[0046] For example, the thermoplastic polyester elastomer resin (A) can be an elastomer resin comprising an aromatic dicarboxylic acid or an ester-forming derivative thereof; an aliphatic diol; and a polyalkylene oxide. In this case, the flexibility, mechanical strength, and heat resistance can be increased, and an excellent balance can be achieved.

[0047] The crystalline hard segment can be formed from an aromatic dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol, and the soft segment can be formed from a polyalkylene oxide. For example, the crystalline hard segment and the soft segment can be arranged arbitrarily.

[0048] For example, the aromatic dicarboxylic acid can include one or more selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, and 1,4-cyclohexane dicarboxylic acid, preferably terephthalic acid, isophthalic acid, or a mixture thereof.

[0049] For example, the ester-forming derivative of the aromatic dicarboxylic acid can include one or more selected from the group consisting of dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalene dicarboxylate, and dimethyl 1,4-cyclohexane dicarboxylate, preferably dimethyl terephthalate, dimethyl isophthalate, or a mixture thereof.

[0050] The content of the aromatic dicarboxylic acid or the ester-forming derivative thereof can be 25 to 70% by weight, preferably 30 to 62% by weight, more preferably 35 to 55% by weight, based on the total weight of the thermoplastic polyester elastomer resin. Within this range, the reaction can be easily performed due to an excellent reaction equilibrium.

[0051] The aliphatic diol can preferably include one or more selected from the group consisting of ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexane dimethanol, more preferably 1,4-butanediol.

[0052] For example, the aliphatic diol can be a diol having a number average molecular weight of 300 g / mol or less, preferably 60 to 300 g / mol.

[0053] In the present disclosure, unless otherwise defined, the number average molecular weight can be measured using gel permeation chromatography (GPC, Waters Breeze). As a specific example, the number average molecular weight can be measured by gel permeation chromatography (GPC, Waters Breeze) using tetrahydrofuran (THF) as an eluent. In this case, the number average molecular weight is obtained as a relative value for polystyrene (PS) standard samples. As a specific measurement example, the number average molecular weight can be measured under the following conditions: solvent: THF, column temperature: 40°C, flow rate: 0.3 ml / min, sample concentration: 20 mg / ml, injection amount: 5 μl, column type: 1 x PLgel 10 μm MiniMix-B (250 x 4.6 mm) + 1 x PLgel 10 μm MiniMix-B (250 x 4.6 mm) + 1 x PLgel 10 μm MiniMix-B Guard (50 x 4.6 mm), instrument name: Agilent 1200 series system, refractive index detector: Agilent G1362 RID, RI temperature: 35°C, data processing: Agilent ChemStation S / W, test method (Mn, Mw, and PDI): OECD TG 118.

[0054] For example, the content of the aliphatic diol can be 19 to 40% by weight, preferably 22 to 35% by weight, more preferably 24 to 35% by weight, based on the total weight of the thermoplastic polyester elastomer resin. Within this range, the reaction can proceed smoothly, and the balance of physical properties between flexibility and mechanical strength can be excellent.

[0055] The polyalkylene oxide is an aliphatic polyester that serves as a soft segment, and can include, for example, one or more selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, a copolymer of ethylene oxide and propylene oxide, an ethylene oxide addition polymer of polypropylene glycol, and a copolymer of ethylene oxide and tetrahydrofuran, preferably polytetramethylene glycol.

[0056] For example, the content of the polyalkylene oxide can be 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 40% by weight, based on the total weight of the thermoplastic polyester elastomer resin. Within this range, flexibility, mechanical strength, and heat resistance can be excellent, and thus the balance of physical properties can be excellent.

[0057] For example, the number average molecular weight of the polyalkylene oxide can be 600 g / mol to 3,000 g / mol, preferably 1,000 g / mol to 2,000 g / mol. Within this range, the polymerization reaction can proceed stably, and a thermoplastic polyester elastomer resin having an excellent balance of physical properties can be obtained.

[0058] The polyalkylene oxide can preferably be polypropylene glycol having end groups capped with ethylene oxide. In this case, the polymerization reactivity can be excellent.

[0059] The thermoplastic polyester elastomer resin can preferably contain a branching agent. In this case, the melt viscosity and the melt tension of the elastomer resin can increase.

[0060] For example, the branching agent can contain one or more selected from the group consisting of glycerol, pentaerythritol, trimellitic anhydride, trimellitic acid, trimethylolpropane, and neopentyl glycol, preferably trimellitic anhydride.

[0061] For example, the content of the branching agent can be 0.05% by weight to 0.1% by weight, preferably 0.05% by weight to 0.09% by weight, more preferably 0.06% by weight to 0.09% by weight, based on 100% by weight of the total thermoplastic polyester elastomer resin. Within this range, since the melt viscosity increases, the melt viscosity of the elastomer resin can be controlled, and thus the intrinsic viscosity thereof can be easily controlled during the melt polymerization process.

[0062] For example, the thermoplastic polyester elastomer resin can be prepared by melt polymerization of an aromatic dicarboxylic acid or an ester-forming derivative thereof, an aliphatic diol, and a polyalkylene oxide. In this case, the balance of physical properties between flexibility, mechanical strength, and heat resistance can be excellent, and the molding properties can be further improved.

[0063] The thermoplastic polyester elastomer resin can preferably be prepared by solid state polymerization of a resin prepared by using melt polymerization. In this case, the balance of physical properties between flexibility, mechanical strength, and heat resistance can be excellent, and the molding properties can be further improved.

[0064] Preferably, the thermoplastic polyester elastomer resin can be prepared by obtaining bis(4-hydroxybutyl) terephthalate (BHBT) oligomers by transesterification of an aromatic dicarboxylic acid, an aliphatic diol, and a polyalkylene oxide at 140°C to 215°C for 110 minutes to 130 minutes in the presence of a tetrabutyl titanate (TBT) catalyst, adding the TBT catalyst again, and then performing melt polymerization at 215°C to 245°C for 110 minutes to 130 minutes while gradually reducing the pressure from 760 Torr to 0.3 Torr.

[0065] The melt polymerization reaction can be performed until the melt flow rate (MFR) measured according to ASTM D1238 at 230°C and a load of 2.16 kg is 20 g / 10 min. After the reaction ends, the product can be discharged from the reactor by nitrogen pressure, and can be obtained in the form of a pellet by a strand pelletizing line.

[0066] Then, the pellet can be subjected to solid state polymerization at 140°C to 200°C in a solid state polymerization reactor or a rotatable vacuum dryer under an inert atmosphere such as a nitrogen atmosphere for 10 hours to 24 hours.

[0067] The solid state polymerization can be performed until the melt flow rate (MFR) measured according to ASTM D1238 at 230°C and a load of 2.16 kg is 10 g / 10 min or less, preferably 1 g / 10 min to 10 g / 10 min, more preferably 3 g / 10 min to 8 g / 10 min.

[0068] The degree of vacuum applied during the solid state polymerization can be selected within the degree of vacuum generally used in the field to which the present application pertains, without particular limitation.

[0069] The solid state polymerization reactor can be a vessel vacuum dryer connected to a rotatable high vacuum pump, and the inert atmosphere can be a nitrogen atmosphere.

[0070] The melt flow rate of the thermoplastic polyester elastomer resin according to ASTM D1238, measured at 230°C and a load of 2.16 kg, can be 0.5 g / 10 min to 10 g / 10 min, preferably 0.5 g / 10 min to 6 g / 10 min. In this range, the molding properties can be excellent.

[0071] For example, the Shore hardness of the thermoplastic polyester elastomer resin can be 30D to 50D, preferably 35D to 47D, more preferably 37D to 42D. In this range, a composition having excellent flexibility and mechanical strength can be obtained.

[0072] In the present disclosure, unless otherwise stated, the Shore hardness can be measured according to the method specified in ISO 868 (type D).

[0073] B) glycidyl-modified olefinic rubber polymer

[0074] The glycidyl-modified olefin-based rubber polymer (B) serves to increase the melt viscosity and the melt strength, and to elongate the chain, i.e., to increase the molecular weight, during the extrusion process.

[0075] For example, the content of the glycidyl-modified olefin-based rubber polymer (B) can be 1.5 to 5.5% by weight, preferably 2 to 5.5% by weight, more preferably 2.5 to 5% by weight, still more preferably 2.5 to 4.5% by weight, still more preferably 2.5 to 3.5% by weight, based on the total weight of components (A) to (C). Within this range, a high-quality product can be applied to a constant velocity joint boot requiring excellent molding properties due to excellent hardness, mechanical properties, and flowability.

[0076] For example, the glycidyl-modified olefin-based rubber polymer (B) can be prepared by graft polymerization of 6 to 20% by weight, preferably 6 to 15% by weight, more preferably 6 to 10% by weight of glycidyl (meth)acrylate, based on the total weight of the glycidyl-modified olefin-based rubber polymer (B). Within this range, the molding properties can be excellent due to an increase in melt viscosity and melt tension.

[0077] For example, the (meth)acrylate can be an acrylate, a methacrylate, or a mixture thereof.

[0078] For example, the glycidyl-modified olefin-based rubber polymer (B) contains units represented by the following Chemical Formula 1. In this case, the impact resistance can be excellent.

[0079] [Chemical Formula 1]

[0080]

[0081] In Chemical Formula 1, R is an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, still more preferably an alkyl group having 1 to 2 carbon atoms. In this case, the impact strength can be excellent.

[0082] In the units represented by Chemical Formula 1, the number of repetitions (n) of the units is preferably an integer of 1 to 2,000, more preferably an integer of 1 to 1,000, still more preferably an integer of 1 to 20. Within this range, the impact strength can be excellent.

[0083] Preferably, the glycidyl-modified olefin-based rubber polymer (B) can be a polyethylene-based copolymer on which a compound represented by Chemical Formula 1 and glycidyl (meth)acrylate are grafted. In this case, the impact strength can be excellent.

[0084] More preferably, the glycidyl-modified olefin-based rubber polymer (B) can be a polymer obtained by grafting a (meth)acrylic acid glycidyl ester onto a polyolefin-based rubber copolymer, and still more preferably a polymer obtained by grafting a (meth)acrylic acid glycidyl ester onto an ethylene-octene rubber. In this case, the impact resistance can be excellent.

[0085] For example, the olefin-based rubber copolymer can be a rubber obtained by copolymerizing two or more olefins, preferably a rubber obtained by polymerizing ethylene and an α-olefin containing 3 to 12 carbon atoms, and more preferably a rubber obtained by polymerizing ethylene and an α-olefin containing 4 to 8 carbon atoms. In this case, the melt viscosity and the melt tension can increase.

[0086] For example, the α-olefin can include one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornadiene, ethylidenenorbornene, phenylnorbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, α-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.

[0087] The polyolefin-based rubber polymer can preferably include one or more selected from the group consisting of ethylene-1-butene rubber, ethylene-butene rubber, ethylene-1-pentene rubber, ethylene-1-hexene rubber, ethylene-1-heptene rubber, ethylene-1-octene rubber, and ethylene-4-methyl-1-pentene rubber, and more preferably ethylene-1-octene rubber (EOR). In this case, the melt viscosity and the melt tension can increase.

[0088] For example, the glycidyl-modified olefin-based rubber polymer (B) can have a melt flow rate of 1 g / 10 min to 5 g / 10 min, preferably 2 g / 10 min to 4 g / 10 min, measured at 190°C and a load of 2.16 kg according to ASTM D1238. In this range, the melt viscosity and the melt tension can increase.

[0089] In the present disclosure, the content of a monomer in a polymer can refer to the weight (wt%) of a monomer added during the preparation of the polymer or the weight (wt%) of units from the monomer.

[0090] C) ionomer resin

[0091] For example, the content of the ionomer resin (C) can be 1.5 to 5.5% by weight, preferably 2 to 5.5% by weight, more preferably 2.5 to 5% by weight, still more preferably 2.5 to 4.5% by weight, still more preferably 2.5 to 3.5% by weight, based on the total weight of components (A) to (C). Within this range, the molding properties can be improved due to the increase in the melt viscosity and the melt tension, and the appearance can be excellent.

[0092] The ionomer resin (C) serves to increase the melt viscosity of the thermoplastic polyester elastomer resin (A) by inducing entanglement between the chains of the thermoplastic polyester elastomer resin (A).

[0093] For example, the ionomer resin (C) can contain a carboxyl group or a sulfonic acid group in which a hydrogen ion is substituted with a metal cation. In this case, the melt viscosity and the melt tension of the thermoplastic polyester elastomer resin can be increased.

[0094] For example, the metal cation can contain one or more selected from the group consisting of Zn, Na, Mg, and Li, preferably Zn, Na, or a mixture thereof. In this case, the processability can be excellent.

[0095] The ionomer resin (C) can preferably be a resin in which a hydrogen contained in a carboxyl group contained in a copolymer composed of an α-olefin and a (meth)acrylic acid or a derivative thereof is substituted with a metal ion. The ionomer can be obtained by preparing an olefin containing a functional group by copolymerizing an α-olefin with a (meth)acrylic acid or a derivative thereof, and then substituting a part of the functional groups contained in the resulting copolymer, such as a carboxyl group, with a metal ion.

[0096] For example, the α-olefin can include one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornadiene, ethylidenenorbornene, phenylnorbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, α-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.

[0097] For example, the (meth)acrylic acid can be acrylic acid, methacrylic acid, or a mixture thereof.

[0098] For example, the derivative of the (meth)acrylic acid can be a derivative of acrylic acid, a derivative of methacrylic acid, or a mixture thereof.

[0099] The ionomer resin (C) can preferably be a resin in which the carboxylic acid of the methacrylic acid in the ethylene-methacrylic acid copolymer is substituted with a metal ion, more preferably a resin in which the carboxylic acid of the methacrylic acid in the ethylene-methacrylic acid copolymer is substituted with a sodium ion, as shown in Chemical Formula 2 below. In this case, the molding properties and surface appearance can be improved due to an increase in the melt viscosity and the melt tension.

[0100] [Chemical Formula 2]

[0101]

[0102] In Chemical Formula 2, m and n represent average polymerization degrees, and are each independently an integer of 2 to 30,000, preferably an integer of 10 to 28,000, more preferably an integer of 100 to 12,000.

[0103] For example, the melt flow rate of the ionomer resin (C) can be 0.1 g / 10 min to 5 g / 10 min, preferably 0.3 g / 10 min to 3 g / 10 min, more preferably 0.5 g / 10 min to 2 g / 10 min, still more preferably 0.7 g / 10 min to 1.5 g / 10 min, measured at 190°C and a load of 2.16 kg according to ASTM D1238. In this range, the molding properties and surface appearance can be excellent due to an increase in the melt viscosity and the melt tension.

[0104] According to the present application, by the combination of the glycidyl-modified olefin-based rubber polymer (B) and the ionomer resin (C), a synergistic effect of increasing the melt viscosity and the melt tension and reducing the melt flow rate can be obtained, thereby improving the molding properties and suppressing the occurrence of flow marks in the interior of a molded article. Accordingly, a high-quality molded article can be manufactured, and the molded article can be applied to automobile parts, particularly, a constant-velocity universal joint boot.

[0105] The weight ratio (B:C) of the glycidyl-modified olefin-based rubber polymer (B) to the ionomer resin (C) can preferably be 4:6 to 6:4, more preferably 4.5:5.5 to 5.5:4.5. In this range, the synergistic effect of increasing the melt viscosity and the melt tension and reducing the melt flow rate can be maximized.

[0106] For example, the total weight of the glycidyl-modified olefin-based rubber polymer (B) and the ionomer resin (C) can be 4.5% by weight to 11% by weight, preferably 4.5% by weight to 9% by weight, more preferably 5% by weight to 7% by weight, based on the total weight of components (A) to (C). In this range, the hardness and the mechanical properties can be excellent, and the synergistic effect of increasing the melt viscosity and the melt tension and reducing the melt flow rate can be maximized.

[0107] Thermoplastic polyester elastomer resin composition

[0108] When the thermoplastic polyester elastomer resin composition pellets are discharged in the form of a sheet using a single screw extruder (screw diameter: 30Φ, screw length: 1 m) through a T-die (die width: 150 mm, die thickness: 1.5T) at 60 rpm and a cylinder temperature of 230°C, the time taken for the sheet discharged from the T-die to fall from a height of 120 cm, i.e., the fall time, can preferably be 60 seconds to 120 seconds, more preferably 70 seconds to 110 seconds, still more preferably 70 seconds to 100 seconds. Within this range, the molding properties and surface appearance can be excellent, and the generation of flow marks can be inhibited. Thus, a high-quality composition can be manufactured, and the composition can be applied to a constant velocity universal joint boot. When the fall time exceeds the range, the molding properties and surface appearance can be poor, and flow marks can be generated.

[0109] The fall time is an index for evaluating the melt tension. That is, as the fall time increases, the melt tension increases.

[0110] In the present disclosure, the fall time can be measured at room temperature.

[0111] In the present disclosure, room temperature can be in the range of 20±5°C.

[0112] The melt flow rate of the thermoplastic polyester elastomer resin composition measured according to ISO 1133 at 230°C and a load of 10 kg can preferably be 5 g / 10 min to 16 g / 10 min, more preferably 6 g / 10 min to 15 g / 10 min, still more preferably 8 g / 10 min to 15 g / 10 min, still more preferably 8 g / 10 min to 13 g / 10 min. Within this range, the molding properties and physical property balance can be excellent.

[0113] When two square test pieces each having a size of 100 mm x 100 mm x 2T are arranged so as to overlap, and the hardness thereof is measured after contacting a durometer thereto for 15 seconds according to ISO 868, the hardness of the thermoplastic polyester elastomer resin composition can preferably be 35 or more, more preferably 37 to 43, still more preferably 37 to 40. Within this range, the mechanical properties and physical property balance can be excellent.

[0114] The tensile strength of the thermoplastic polyester elastomer resin composition can preferably be 15 MPa or more, more preferably 20 MPa or more, and still more preferably 20 MPa to 30 MPa, when a test piece having a size of 100 mm x 100 mm x 2T is punched into a dumbbell shape according to ISO 527-2-5A, and its tensile strength is measured according to ISO 527-2 at a crosshead speed of 200 mm / min. In this range, the mechanical and physical property balance can be excellent.

[0115] The elongation of the thermoplastic polyester elastomer resin composition can be 370% or more, more preferably 400% or more, and still more preferably 400% to 520%, and still more preferably 450% to 500%, when a test piece having a size of 100 mm x 100 mm x 2T is punched into a dumbbell shape according to ISO 527-2-5A, and its tensile strength is measured according to ISO 527-2 at a crosshead speed of 200 mm / min. In this range, the mechanical and physical property balance can be excellent.

[0116] In the present disclosure, the tensile strength and elongation can be measured according to ISO 527-2 using a UTM device (Zwick Z050) at a crosshead speed of 200 mm / min.

[0117] The cycle time of the thermoplastic polyester elastomer resin composition can preferably be 20 seconds to 60 seconds, more preferably 20 seconds to 50 seconds, and still more preferably 25 seconds to 40 seconds, when the thermoplastic polyester elastomer resin composition pellets are fed into a cylinder of a blow molding machine set to 220°C to 240°C and melted and discharged in the form of a parison, and then the time taken for the discharged material to be blow molded and hardened in a mold set to 20°C to 40°C, i.e., the cycle time, is measured. In this range, the molding property, surface appearance, and physical property balance can be excellent, and the productivity can be improved.

[0118] In the present disclosure, when one product is manufactured by blow molding, pellets are fed into a cylinder of a blow molding machine set to 220°C to 240°C and melted and discharged in the form of a parison. Then, the discharged material is blow molded and hardened in a mold set to 20°C to 40°C. In this case, the time required for blow molding and hardening is referred to as the cycle time. The cycle time of one product is considered to be one cycle.

[0119] In the present disclosure, a pressure blower (model name: DSE150, OSSBURGER Co.) is used as the blow molding machine.

[0120] Additives

[0121] For example, the thermoplastic polyester elastomer resin composition can include one or more selected from the group consisting of an antioxidant, a hindered amine-based light stabilizer (HALS), a lubricant, and a black master batch. In this case, the desired physical properties can be effectively achieved without deteriorating the inherent physical properties of the thermoplastic polyester elastomer resin composition of the present application.

[0122] For example, the antioxidant can include one or more selected from the group consisting of a phosphorus antioxidant, a sulfur antioxidant, a hindered phenol-based antioxidant, and a diphenylamine antioxidant, preferably a hindered phenol-based antioxidant, a diphenylamine antioxidant, or a mixture thereof. In this case, oxidation caused by heat can be prevented during extrusion, and mechanical properties and heat resistance can be excellent.

[0123] For example, the content of the antioxidant can be 0.1 to 2% by weight, preferably 0.3 to 1.5% by weight, more preferably 0.3 to 1.2% by weight, based on the total weight of components (A) to (C) and the antioxidant. In this range, oxidation caused by heat can be prevented during extrusion, and mechanical properties and heat resistance can be excellent.

[0124] For example, the phosphorus antioxidant can include one or more selected from the group consisting of tris(mixed, mono, and di-nonylphenyl) phosphite, tris(2,3-di-tert-butylphenyl) phosphite, 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl-ditridecyl) phosphite, 1,1,3-tris(2-methyl-4-ditridecylphosphite-5-tert-butylphenyl) butane, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tetra(2,4-di-tert-butylphenyl)-4,4'-biphenylene phosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)-2-ethylhexyl phosphite, bis(2,4,6-di-tert-butylphenyl) pentaerythritol-diphosphite, triphenyl phosphite, diphenyl decyl phosphite, dodecyl phenyl phosphite, tridecyl phosphite, trioctyl phosphite, tridodecyl phosphite, triostearyl phosphite, and tridodecyl trithiophosphite.

[0125] For example, the sulfur antioxidant can include one or more selected from the group consisting of dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, lauryl stearyl-3,3'-thiodipropionate, and pentaerythritol tetra(3-laurylthiopropionate).

[0126] For example, the hindered phenolic antioxidant can be [3-[3-(4-hydroxy-3,5-di-tert-butyl- phenyl)propionyloxy]-2,2-bis[3-(4-hydroxy-3,5-di-tert-butyl-phenyl)propionyloxymethyl]propyl] 3-(4-hydroxy-3,5-di-tert-butyl-phenyl)propionate.

[0127] For example, the diphenylamine antioxidant can include one or more selected from the group consisting of phenyl naphthyl amine, 4,4'-dimethoxydiphenylamine, 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine, and 4-isopropoxydiphenylamine, preferably 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine.

[0128] When the hindered phenolic antioxidant and the diphenylamine antioxidant are included, the mechanical properties and the molding properties can be further improved due to the synergistic effect of the combination thereof.

[0129] The light stabilizer can preferably be a hindered amine light stabilizer (HALS).

[0130] For example, the hindered amine light stabilizer (HALS) can include one or more selected from the group consisting of poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidyl)imino]], bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, decane-2-oic acid bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidyl) ester, 1,1-dimethylethyl hydroperoxide, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]propanediol butyl, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-sebacate, and methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, preferably poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidyl)imino]]. In this case, the mechanical strength can be maintained, the heat resistance can be further improved, and discoloration can be prevented.

[0131] For example, the content of the light stabilizer can be 0.05 to 2% by weight, preferably 0.1 to 1% by weight, more preferably 0.1 to 0.5% by weight, based on the total weight of components (A) to (C) and the light stabilizer. In this range, the mechanical strength can be maintained, the heat resistance can be further improved, and discoloration can be prevented.

[0132] For example, the lubricant can include one or more selected from the group consisting of fatty acid amide-based compounds, montan-based waxes, and olefin-based waxes, preferably one or more selected from the group consisting of fatty acid amide-based compounds and montan-based waxes. In this case, the compatibility with the elastomer resin can be increased, thereby reducing surface defects.

[0133] For example, the fatty acid amide-based compounds can include one or more selected from the group consisting of stearamide, behenamide, ethylene bis (stearamide), N,N'-ethylene bis (12-hydroxystearamide), erucamide, oleamide, and ethylene bisoleamide.

[0134] For example, the montan-based waxes can be montan wax, montan ester wax, or a mixture thereof.

[0135] For example, the olefin-based waxes can be polyethylene wax, polypropylene wax, or a mixture thereof.

[0136] For example, the montan ester wax can include one or more selected from the group consisting of a wax obtained by esterifying a montan-based wax with ethylene glycol and montanic acid, a wax obtained by esterifying a montan-based wax with glycerol and montanic acid, calcium montanate containing a montanic acid ester, and a montanic acid-based ester mixed wax.

[0137] For example, the content of the lubricant can be 0.1 to 3% by weight, preferably 0.3 to 2.5% by weight, and more preferably 0.5 to 2% by weight, based on the total weight of components (A) to (C) and the lubricant. In this range, the compatibility with the elastomer resin can be increased, thereby reducing surface defects. In addition, the mechanical properties can be excellent.

[0138] For example, the black masterbatch can be a carbon black masterbatch, preferably a carbon black masterbatch using a thermoplastic polyester elastomer resin as a carrier resin. In this case, the compatibility with the thermoplastic polyester elastomer resin can be excellent. Accordingly, the carbon black can be uniformly dispersed, and mixing can be easily performed.

[0139] For example, the content of the black masterbatch can be 0.1 to 3% by weight, preferably 0.3 to 2.5% by weight, and more preferably 0.5 to 2% by weight, based on the total weight of components (A) to (C) and the black masterbatch. In this range, the compatibility with the elastomer resin can be excellent. Accordingly, the carbon black can be uniformly dispersed, and mixing can be easily performed.

[0140] The thermoplastic polyester elastomer resin composition can further include one or more additives selected from the group consisting of ultraviolet absorbers, heat stabilizers, antistatic agents, antibacterial agents, processing aids, friction reducing agents, anti-wear agents, metal deactivators, and coupling agents. In this case, the content of each additive can be 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, and still more preferably 0.2 to 1.5 parts by weight, based on 100 parts by weight in total of components (A) to (C). Within this range, the desired physical properties can be effectively achieved without deteriorating the inherent physical properties of the thermoplastic polyester elastomer resin composition of the present application.

[0141] Method of preparing a thermoplastic polyester elastomer resin composition

[0142] The method of producing a thermoplastic polyester elastomer resin composition according to the present application includes the step of producing pellets by kneading and extruding 89 to 96 parts by weight of a thermoplastic polyester elastomer resin (A), 1.5 to 5.5 parts by weight of a glycidyl-modified olefin-based rubber polymer (B), and 1.5 to 5.5 parts by weight of an ionomer resin (C) at 200 to 300°C and 150 to 350 rpm. In this case, the hardness and mechanical properties can be excellent, the molding properties can be excellent due to an increase in melt tension, and the occurrence of flow marks on the inner surface of a molded article can be inhibited. Thus, a high-quality thermoplastic polyester elastomer resin composition can be manufactured, and can be applied to automotive parts, in particular, constant-velocity universal joint boot covers.

[0143] For example, kneading and extrusion can be performed using a single-screw extruder, a twin-screw extruder, or a Banbury mixer. In this case, the compatibility can be excellent due to uniform dispersion of the composition.

[0144] Kneading and extrusion can be performed at a barrel temperature of preferably 200 to 260°C, more preferably 210 to 240°C. In this case, the production amount per unit time can be appropriate, melt kneading can be sufficiently performed, and thermal decomposition of the resin components can be inhibited.

[0145] For example, kneading and extrusion can be performed at a screw rotation speed of 150 to 350 rpm, preferably 200 to 300 rpm, and more preferably 230 to 270 rpm. In this case, the production amount per unit time can be appropriate, and the process efficiency and physical properties of the composition can be excellent.

[0146] The resin composition can be used to manufacture molded articles for use in various industrial fields by molding processes such as a blow molding process and an injection molding process.

[0147] The description of the method of producing the thermoplastic polyester elastomer resin composition includes the description of the above thermoplastic polyester elastomer resin composition, and the repeated description thereof is omitted.

[0148] Shaped article

[0149] For example, the molded article of the present application contains the thermoplastic polyester elastomer resin composition of the present application. In this case, the moldability can be excellent, and the occurrence of flow marks on the inner surface of the molded article can be suppressed.

[0150] The molded article can be an automobile part, preferably a constant velocity universal joint boot, a rack and pinion boot, a propeller shaft boot, a dust boot, or a bellows.

[0151] The method of manufacturing the molded article preferably includes a step of melt-kneading and extruding 89 to 96% by weight of the thermoplastic polyester elastomer resin (A), 1.5 to 5.5% by weight of the glycidyl-modified olefin-based rubber polymer (B), and 1.5 to 5.5% by weight of the ionomer resin (C) at 200 to 300°C and 150 to 350 rpm to produce a pellet; and a step of blow molding the produced pellet using a blow molding machine. In this case, the melt tension of the thermoplastic polyester elastomer resin composition can be increased, thereby improving the moldability and minimizing the occurrence of flow marks on the inner surface of the molded article. Accordingly, a high-quality molded article can be manufactured, and can be applied to a constant velocity universal joint boot of an automobile.

[0152] The description of the method of manufacturing the molded article includes the description of the above thermoplastic polyester elastomer resin composition, and the repeated description is omitted.

[0153] In the description of the thermoplastic polyester elastomer resin composition of the present application, the method of producing the same, and the molded article containing the same, it should be noted that other conditions or apparatuses not explicitly described herein can be appropriately selected within the range generally practiced in the art, without being particularly limited.

[0154] Hereinafter, the present application will be described in greater detail with reference to the following preferred examples. However, these examples are provided for illustrative purposes only, and should not be construed as limiting the scope and concept of the present application. Furthermore, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the concept and scope of the present application, and such changes and modifications are also within the scope of the appended claims.

[0155] [Examples]

[0156] The materials used in the examples and comparative examples are as follows.

[0157] * TPEE (A): KEYFLEX BT2140D (LG Chemical Co.), having a melt flow rate (230°C, 2.16 kg) of 5 g / 10 min and a Shore D hardness of 40D

[0158] * Glycidyl-modified olefin-based rubber polymer (B): EOR-GMA (KT20, glycidyl methacrylate content: 6 to 9 wt%, K&A TRADD Co.)

[0159] * Ionomer resin (C): Surlyn 8920 (melt flow rate (190°C, 2.16 kg): 0.9 g / 10 min, substituted metal: Na; Dupont Co.)

[0160] * Hindered phenol-based antioxidant: IR1010 (BASF Co.)

[0161] * Diphenylamine antioxidant: Naugard 445 (SUNFINE GLOBAL Co.)

[0162] * Hindered amine-based light stabilizer (HALS): CHIMASSORB 944 (BASF Co.)

[0163] * Lubricant: OP-WAX (Clariant Co.), Incroslip G (Croda Co.)

[0164] * Black masterbatch: M40C (LG Chemical Co.)

[0165] Examples 1 to 6 and Comparative Examples 1 to 6

[0166] The components were kneaded and extruded using a twin-screw extruder at an extrusion temperature of 230°C and a screw rotation speed of 250 rpm to prepare pellets according to the contents and components shown in Tables 1 and 2 below. The melt flow rate of the prepared pellets was measured. In addition, the prepared pellets were injected to prepare injection test samples using an injection machine (ENGEL 80MT) at an injection temperature of 230°C, a mold temperature of 40°C, and an injection speed of 20 mm / min, and the physical properties of the injection test samples were measured.

[0167] [Experimental Examples]

[0168] The properties of the test samples prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were measured according to the following method, and the results are shown in Tables 1 and 2 below.

[0169] Measurement methods

[0170] * Melt flow rate: The melt flow rate was measured according to ISO 1133 at 230°C under a load of 10 kg for 10 minutes. Here, the unit of the melt flow rate is g / 10 min.

[0171] * Hardness (Shore D): Two square test pieces of 100 mm x 100 mm x 2T were arranged so as to overlap, and the hardness thereof was measured after contacting with a durometer for 15 seconds according to ISO 868.

[0172] * Tensile strength (MPa) and elongation (%) : Test pieces of 100 mm x 100 mm x 2T were punched into dumbbell shapes according to ISO 527-2-5A, and the tensile strength and elongation thereof were measured according to ISO 527-2 using a UTM device (Zwick Z050) at a crosshead speed of 200 mm / min.

[0173] * Drop time (sec): As shown below Figure 2 , a thermoplastic polyester elastomer resin composition pellet was discharged in the form of a sheet through a T-die (die width: 150 mm, die thickness: 1.5T) at 60 rpm and a cylinder temperature of 230°C using a single screw extruder (screw diameter: 30Φ, screw length: 1 m), and the time taken for the sheet discharged from the T-die to drop from a height of 120 cm was measured.

[0174] * Whether or not flow marks are generated on the inner surface: A CVJ boot was manufactured by blow molding a thermoplastic polyester elastomer resin composition pellet at a molding temperature of 220°C to 240°C using a blow molding machine (Pressblower, model name: DSE150, OSSBURGER Co.). The inside of the molded article was visually observed, and the degree of generation of flow marks was evaluated as follows.

[0175] ◎: No flow marks and excellent appearance

[0176] O: Flow marks are fine and the appearance is good

[0177] Δ: Flow marks are observed intermittently and the appearance is normal

[0178] X: Flow marks are apparent and the appearance is deteriorated

[0179] XX: A large amount of flow marks and poor appearance

[0180] * Cycle time (sec): Thermoplastic resin composition pellets were fed into a cylinder of a blow molder (Pressblower, Model name: DSE150, OSSBURGER Co.) set to 220 to 240°C, and melted and discharged in the form of a parison. Then, the time taken for the discharged material to be blow-molded and hardened in a mold set to 20 to 40°C was measured.

[0181] [Table 1]

[0182]

[0183]

[0184] [Table 2]

[0185]

[0186]

[0187] As shown in Tables 1 and 2, in the case of Examples 1 to 6 of the present application, the hardness, tensile strength, and elongation were excellent compared to Comparative Examples 1 to 6, which were outside the scope of the present application. In addition, since the melt flow rate was in the range of 5 to 16 g / 10 min, and the drop time was in the range of 60 to 120 seconds, the molding performance was excellent. In addition, since no flow marks were generated on the inner surface of the molded article, the appearance was excellent.

[0188] Specifically, in the case of Comparative Example 1, which contained only EOR-GMA (B), and Comparative Example 2, which contained only ionomer resin (C), the molding performance was poor due to the short drop time.

[0189] In addition, Comparative Example 3, which contained a small amount of ionomer resin (C), had a high melt flow rate and a short drop time, resulting in poor molding performance. In the case of Comparative Example 4, which contained an excessive amount of ionomer resin (C), the melt flow rate was very low and the drop time was long, resulting in a large number of flow marks on the inner surface of the molded article. Therefore, the molded article did not have commercial value.

[0190] In addition, in the case of Comparative Example 5, which contained a small amount of EOR-GMA (B), the molding performance was poor due to the shortened drop time. Comparative Example 6, which contained an excessive amount of EOR-GMA (B), had a very low melt flow rate and a very long drop time, resulting in poor molding performance and a large number of flow marks on the inner surface of the molded article, resulting in poor appearance.

[0191] When the resin compositions prepared in Comparative Example 6 and Example 3 were applied to actual products, whether flow marks were generated inside the molded article was observed, and the resulting images are shown inFigure 1 In the case of Example 3, no flow marks were observed, and the appearance was excellent. Thus, the resin composition of Example 3 was suitable for use in automobile parts. In the case of Comparative Example 6, a large number of flow marks were observed, and thus, the resin composition of Comparative Example 6 could not be applied to products.

[0192] As described above, the thermoplastic polyester elastomer resin composition according to the present application, which comprises a thermoplastic polyester elastomer resin (A), a glycidyl-modified olefin-based rubber polymer (B), and an ionomer resin (C) in predetermined content ratios, has excellent mechanical properties and molding properties, and can inhibit the generation of flow marks on the inner surface of a molded article. Thus, a high-quality thermoplastic polyester elastomer resin composition can be applied to a constant-velocity universal joint boot.

Claims

1. A thermoplastic polyester elastomer resin composition comprising: 89% to 96% by weight of thermoplastic polyester elastomer resin (A); 1.5% to 5.5% by weight of polymer (B) obtained by grafting glycidyl (meth)acrylate onto ethylene-octene rubber; and 1.5% to 5.5% by weight of ionomer resin (C), in, According to ISO 1133, the melt flow rate of the thermoplastic polyester elastomer resin (A), measured at 230°C and a load of 2.16 kg, is 0.5 g / 10 min to 10 g / 10 min, and the Shore hardness, according to the method specified in ISO 868 (Type D), is 30 D to 50 D. Wherein, based on the total weight of the polymer (B), the polymer (B) contains 6% to 10% by weight of glycidyl (meth)acrylate, and The total weight of the polymer (B) and the ionomer resin (C) is 4.5 to 9% by weight, based on the total weight of components (A) to (C).

2. The thermoplastic polyester elastomer resin composition according to claim 1, wherein, When using a single-screw extruder with a screw diameter of 30Φ and a screw length of 1m, thermoplastic polyester elastomer resin composition granules are discharged in sheet form through a T-die with a die width of 150mm and a die thickness of 1.5T at a barrel temperature of 60rpm and 230°C. The time taken for the sheet discharged from the T-die to fall from a height of 120cm is measured, i.e., the fall time of the thermoplastic polyester elastomer resin composition is 60 seconds to 120 seconds.

3. The thermoplastic polyester elastomer resin composition according to claim 1, wherein, According to ISO 1133, the melt flow rate of the thermoplastic polyester elastomer resin composition, measured at 230°C and a load of 10 kg, is from 5 g / 10 min to 16 g / 10 min.

4. The thermoplastic polyester elastomer resin composition according to claim 1, wherein, The thermoplastic polyester elastomer resin (A) is an elastomer resin comprising an aromatic dicarboxylic acid or its ester-formed derivative; an aliphatic diol; and a polyepoxide.

5. The thermoplastic polyester elastomer resin composition according to claim 4, wherein, The aromatic dicarboxylic acid comprises one or more selected from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

6. The thermoplastic polyester elastomer resin composition according to claim 4, wherein, The ester-forming derivatives of the aromatic dicarboxylic acid comprise one or more selected from dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalenedicarboxylate, and dimethyl 1,4-cyclohexanedicarboxylate.

7. The thermoplastic polyester elastomer resin composition according to claim 4, wherein, The aliphatic diol comprises one or more selected from ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanediol.

8. The thermoplastic polyester elastomer resin composition according to claim 4, wherein, The polyepoxide comprises one or more selected from polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition polymers of polypropylene glycol, and copolymers of ethylene oxide and tetrahydrofuran.

9. The thermoplastic polyester elastomer resin composition according to claim 1, wherein, The ionomer resin (C) contains carboxyl or sulfonic acid groups in which hydrogen ions are replaced by metal cations.

10. The thermoplastic polyester elastomer resin composition according to claim 1, wherein, The thermoplastic polyester elastomer resin composition comprises one or more selected from antioxidants, light stabilizers, lubricants, and black masterbatches.

11. A method for preparing a thermoplastic polyester elastomer resin composition, comprising preparing granules by kneading and extruding 89% to 96% by weight of a thermoplastic polyester elastomer resin (A), 1.5% to 5.5% by weight of a polymer (B) obtained by grafting glycidyl (meth)acrylate onto ethylene-octene rubber, and 1.5% to 5.5% by weight of an ionomer resin (C) at 200°C to 300°C and 150 rpm to 350 rpm. in, According to ISO 1133, the melt flow rate of the thermoplastic polyester elastomer resin (A), measured at 230°C and a load of 2.16 kg, is 0.5 g / 10 min to 10 g / 10 min, and the Shore hardness, according to the method specified in ISO 868 (Type D), is 30 D to 50 D. Wherein, based on the total weight of the polymer (B), the polymer (B) contains 6% to 10% by weight of glycidyl (meth)acrylate, and The total weight of the polymer (B) and the ionomer resin (C) is 4.5 to 9% by weight, based on the total weight of components (A) to (C).

12. A molded article comprising the thermoplastic polyester elastomer resin composition according to any one of claims 1 to 10.

Images