JP2019006993A - Thermoplastic elastomer resin and molding thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer resin composition having excellent bending fatigue resistance and injection moldability. SOLUTION: The thermoplastic elastomer resin composition is measured according to ASTM D1238-1990 under the conditions of a temperature of 240 ° C., a load of 2160 g, and a residence time of 5 minutes. It is composed of a polyester elastomer (B) having an MFR of 15 g / 10 minutes or more measured under the conditions of a temperature of 240 ° C., a load of 2160 g, and a residence time of 5 minutes according to D1238-1990. [Selection diagram] None

Description

  The present invention relates to a thermoplastic elastomer resin (composition) and a molded body thereof.

  Polyester block copolymer having a crystalline aromatic polyester unit such as a polybutylene terephthalate unit as a hard segment and an aliphatic polyester unit such as a poly (alkylene oxide) glycol unit and / or a polylactone unit as a soft segment (heat Plastic polyester elastomers) are superior in mechanical properties such as strength, impact resistance, elastic recovery, flexibility, and low temperature and high temperature characteristics, and are thermoplastic and easy to mold. It is widely used in fields such as parts and consumer goods, and in a specific example, it is used for a cover boot, an air duct, a fuel tube, etc. of a constant velocity joint drive device.

  Resin compositions containing thermoplastic elastomers have also been developed for the purpose of improving the physical properties of such thermoplastic elastomers. For example, Patent Document 1 discloses a technique of adding a bifunctional or higher functional epoxy compound and a specific antioxidant at a specific ratio to a polyether ester block copolymer.

JP-A-11-323110

  An object of the present invention is to provide a novel thermoplastic elastomer resin (or resin composition) and a molded body thereof.

  According to the study of the present inventor, a molded article formed of a thermoplastic elastomer (such as a cover boot material of a constant velocity joint drive device of an automobile) may require bending fatigue resistance, but in the case of a conventional thermoplastic elastomer, In some cases, the bending fatigue resistance is not sufficient.

  Of the molding methods, injection molding is an excellent molding method that enables mass production of molded products. Unlike conventional molding methods such as blow molding, injection molding is difficult with conventional thermoplastic elastomers due to insufficient filling. In particular, such a problem may be conspicuous in a molded product having a complicated shape or a long flow length.

  As a result of intensive studies to achieve the above object, the present inventor can obtain a novel thermoplastic elastomer resin (or resin composition) by combining thermoplastic elastomers having different specific MFRs, etc. The present inventors have found that such a resin has characteristics such as excellent bending fatigue resistance and injection moldability, and completed the present invention.

  That is, the thermoplastic elastomer resin (or composition thereof) of the present invention includes an elastomer having a specific value in MFR and / or a specific value in MFR.

  Typically, the thermoplastic elastomer resin (composition) of the present invention is a polyester elastomer having an MFR of less than 15 g / 10 minutes measured under conditions of a temperature of 240 ° C., a load of 2160 g and a residence time of 5 minutes in accordance with ASTM D1238-1990. (A) and a polyester elastomer (B) having an MFR measured at a temperature of 240 ° C., a load of 2160 g, and a residence time of 5 minutes in accordance with ASTM D1238-1990 of 15 g / 10 minutes or more.

  In such a resin (composition), the polyester elastomer (A) and the polyester elastomer (B) may contain a polyether ester elastomer.

  In the resin (composition) of the present invention, the polyester elastomer (A) and the polyester elastomer (B) are polyester block copolymers having a hard segment containing an aromatic polyester unit and a soft segment containing an aliphatic polyether unit. It may be. In such polyester elastomer (A) and polyester elastomer (B), even if the ratio of a hard segment and a soft segment is a hard segment / soft segment (mass ratio) = about 70 / 30-40 / 60, for example. Good.

  In the resin (composition) of the present invention, the hard segment of the polyester elastomer (A) and the polyester elastomer (B) may contain a butylene terephthalate unit and / or a butylene isophthalate unit.

  The soft segment of the polyester elastomer (A) and the polyester elastomer (B) was selected from poly (tetramethylene oxide) glycol, an ethylene oxide adduct of poly (propylene oxide) glycol, and a copolymer glycol of ethylene oxide and tetrahydrofuran. At least one kind may be included.

  In the resin (composition) of the present invention, the ratio of the polyester elastomer (A) to the polyester elastomer (B) is, for example, polyester elastomer (A) / polyester elastomer (B) (mass ratio) = 95 / 5-5 / It may be about 95.

  According to ASTM D1238-1990 of the resin (composition) of the present invention, the MFR measured under conditions of a temperature of 240 ° C., a load of 2160 g, and a residence time of 5 minutes may be, for example, 3.5 to 50 g / 10 minutes.

Representative resins (compositions) of the present invention include
The polyester elastomer (A) and the polyester elastomer (B) include a polyether ester elastomer,
According to ASTM D1238-1990, the MFR when measured under the conditions of a temperature of 240 ° C., a load of 2160 g and a residence time of 5 minutes is 5 g / 10 minutes or less in the polyester elastomer (A), and 20 g / 10 minutes or more in the polyester elastomer (B). 4-30 g / 10 min in the composition,
The composition etc. whose ratio of a polyester elastomer (A) and a polyester elastomer (B) is polyester elastomer (A) / polyester elastomer (B) (mass ratio) = 90/10-10/90 are contained.

  The resin (composition) of the present invention may be used particularly for injection molding.

  The present invention includes a molded body (molded article) containing the resin (composition). Such a molded body may in particular be an injection molded body and may be a cover boot, an air duct, a fuel tube or a hinge part.

  According to the present invention, a novel thermoplastic elastomer resin (or resin composition) and a molded body thereof are provided.

  Such a resin (or resin composition) is often excellent in injection moldability and can be suitably used for injection molding.

  In addition, the resin (or resin composition) of the present invention is often excellent in bending fatigue resistance, and in particular, can achieve both excellent injection moldability and excellent bending fatigue resistance.

  Furthermore, the resin (or resin composition) of the present invention improves or improves the injection moldability and bending fatigue resistance as described above while maintaining the physical properties (for example, flexibility) as a thermoplastic elastomer. sell.

<Thermoplastic elastomer resin (composition)>
The thermoplastic elastomer resin (composition) of the present invention contains a specific polyester elastomer. In a preferred embodiment, the polyester elastomer contains a specific polyester elastomer (A) and a polyester elastomer (B) in combination. Also good.

[Polyester elastomer]
The polyester elastomer (particularly, the polyester elastomer (A) and the polyester elastomer (B)) is usually composed of a hard segment (or hard block, high melting crystalline polymer segment) and a soft segment (or soft block, low melting point weight). Merged segments).

(Hard segment)
The high-melting crystalline polymer segment may be a polyester unit having a dicarboxylic acid component containing an aromatic dicarboxylic acid component and a diol component as a polymerization component.

  Examples of the aromatic dicarboxylic acid component include at least one selected from aromatic dicarboxylic acids and ester-forming derivatives thereof.

  Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid (for example, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid), anthracene dicarboxylic acid, 4, Examples include 4'-diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, 4,4'-diphenylether dicarboxylic acid, 5-sulfoisophthalic acid, sodium 3-sulfoisophthalate, and the like. These may be used alone or in combination of two or more.

  The aromatic dicarboxylic acid is preferably terephthalic acid or isophthalic acid.

Examples of the ester-forming derivatives of aromatic dicarboxylic acids include lower alkyl esters (C _1-4 alkyl esters such as methyl esters and ethyl esters), aryl esters, carbonates, and acid halides. These may be used alone or in combination of two or more.

  The dicarboxylic acid component may contain at least one selected from non-aromatic dicarboxylic acids and ester-forming derivatives thereof, if necessary.

  Non-aromatic dicarboxylic acids include, for example, alicyclic dicarboxylic acids (eg, cycloalkane dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and cyclopentanedicarboxylic acid; 4,4′-dicyclohexyldicarboxylic acid, etc.), aliphatic Examples thereof include dicarboxylic acids (for example, adipic acid, succinic acid, oxalic acid, sebacic acid, dodecanedioic acid, dimer acid, etc.). These may be used alone or in combination of two or more.

Examples of ester-forming derivatives of non-aromatic dicarboxylic acids include, for example, lower alkyl esters (C _1-4 alkyl esters such as methyl esters and ethyl esters), aryl esters, carbonates, acid halides, and the like. May be. These may be used alone or in combination of two or more.

  Examples of the diol component include at least one selected from diol and ester-forming derivatives thereof.

Examples of the diol include aliphatic diols (for example, alkane diols such as 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, preferably C _{2− 12} alkanediols), alicyclic diols (for example, cycloalkanedimethanols such as 1,1-cyclohexanedimethanol and 1,4-cyclohexanedimethanol; tricyclodecanedimethanol, etc.), aromatic diols (for example, xylene glycol) Bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) propane, 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4- (2-hydroxy) phenyl] sulfur Hong, 1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane, 4,4′-dihydroxy-p-terphenyl, 4,4′-dihydroxy-p-quaterphenyl, etc.). These diols may be used alone or in combination of two or more.

  The diol may be, for example, a diol having a molecular weight of 400 or less.

  The diol is particularly preferably an alkanediol (particularly 1,4-butanediol).

  Examples of the diol ester-forming derivatives include acetyl diols and alkali metal salts of diols. These may be used alone or in combination of two or more.

  The high-melting crystalline polymer segment preferably includes an alkylene arylate unit (for example, a butylene terephthalate unit and / or a butylene isophthalate unit), and more preferably includes at least a butylene terephthalate unit. Such a high-melting crystalline polymer segment having at least a butylene terephthalate unit may be formed of only a butylene terephthalate unit, or may be formed of a butylene terephthalate unit and a butylene isophthalate unit.

  In the polyester elastomer (particularly, the polyester elastomers (A) and (B)), the butylene terephthalate unit and the butylene isophthalate unit may be randomly copolymerized or block copolymerized.

  In addition, when combining a polyester elastomer (A) and a polyester elastomer (B), these hard segments may be the same and may differ. In particular, the hard segments of the polyester elastomer (A) and the polyester elastomer (B) are preferably the same type of segments (for example, alkylene arylate units, butylene terephthalate units and / or butylene isophthalate units), and are the same. May be.

(Soft segment)
Examples of the low melting point polymer segment of the polyester elastomer (particularly, the polyester elastomers (A) and (B)) include polyether units and polyester units. The low melting point polymer segment may have one unit alone or two or more units, and may contain both a polyether unit and a polyester unit.

  In many cases, the polyether unit is usually an aliphatic polyether unit.

  Aliphatic polyethers include, for example, polyalkylene glycols [eg, poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol], Polymer glycol (for example, copolymer glycol of ethylene oxide and propylene oxide, copolymer glycol of ethylene oxide and tetrahydrofuran, etc.), alkylene oxide adduct of polyalkylene glycol [for example, ethylene oxide adduct of poly (propylene oxide) glycol, etc.] Etc. The low melting polymer segment is preferably poly (tetramethylene oxide) glycol, an ethylene oxide adduct of poly (propylene oxide) glycol, and a copolymer glycol of ethylene oxide and tetrahydrofuran. An aliphatic polyether may be used independently or may be used in mixture of 2 or more types.

  The polyester unit is usually an aliphatic polyester unit in many cases.

  Examples of the aliphatic polyester include polylactones [for example, poly (ε-caprolactone), polyenantlactone, polycaprylolactone, and the like]. These may be used alone or in combination of two or more.

  In addition, the low melting point polymer segment may contain other components (or units derived from other components) as long as the physical properties and the like as the thermoplastic elastomer are not impaired.

  The soft segment preferably includes at least a polyether unit. That is, preferred polyester elastomers (particularly polyester elastomers (A) and (B)) include polyether ester elastomers. The polyether ester elastomer is usually a polyester elastomer containing polyether units as a low melting polymer segment.

  In addition, polyester elastomer (especially polyester elastomer (A) and (B)) is a block copolymer (polyester block copolymer) which has a hard segment and a soft segment normally. The number of blocks of such a block copolymer is not particularly limited, but may be a polyblock body such as a di to decablock body.

  In the polyester elastomer (particularly, the polyester elastomers (A) and (B)), the ratio of the hard segment to the soft segment is, for example, hard segment / soft segment (mass ratio) = 95/5 to 5/95 (for example, 93 / 7 to 7/93), preferably 90/10 to 10/90 (e.g. 85/15 to 15/85), 80/20 to 30/70 (e.g. 75/25 to 35 / 65), 75/25 to 40/60 (for example, 70/30 to 40/60, 70/30 to 43/57).

  The thermoplastic elastomer resin (composition) of the present invention may contain a polyester elastomer (A) having a specific MFR (melt flow rate) and a polyester elastomer (B) as the resin component or the thermoplastic elastomer. Good.

(Polyester elastomer (A))
The MFR measured under the conditions of a polyester elastomer (A) temperature of 240 ° C. and a load of 2160 g can be selected from a range of less than 15 g / 10 minutes, for example, 12 g / 10 minutes or less (for example, 10 g / 10 minutes or less), preferably It may be 8 g / 10 min or less (for example, 6 g / 10 min or less), 5 g / 10 min or less, 4 g / 10 min or less, 3.5 g / 10 min or less, or the like.

  It seems that it is easy to obtain a thermoplastic elastomer resin that is advantageous in terms of resistance to bending fatigue and the like within the above range.

  The lower limit of the MFR measured under the conditions of a temperature of 240 ° C. and a load of 2160 g of the polyester elastomer (A) is not particularly limited, but for example, 0.1 g / 10 min, 0.2 g / 10 min, 0.3 g / It may be 10 minutes, 0.5 g / 10 minutes, 0.6 g / 10 minutes, 0.7 g / 10 minutes, 0.8 g / 10 minutes, 1 g / 10 minutes, 1.5 g / 10 minutes, and the like.

  The MFR may be measured according to ASTM D1238-1990, or the residence time may be measured as a predetermined time (for example, 5 minutes).

(Polyester elastomer (B))
The MFR measured at a temperature of 240 ° C. and a load of 2160 g of the polyester elastomer (B) can be selected from a range of 15 g / 10 min or more, for example, 16 g / 10 min or more (for example, 18 g / 10 min or more), preferably It may be 20 g / 10 min or more (for example, 22 g / 10 min or more), 25 g / 10 min or more, 30 g / 10 min or more, 35 g / 10 min or more.

  It seems that it is easy to obtain a thermoplastic elastomer resin advantageous in terms of injection moldability and the like within the above range.

  The upper limit value of MFR measured under the conditions of a temperature of 240 ° C. and a load of 2160 g of the polyester elastomer (B) is not particularly limited, but for example, 120 g / 10 minutes, 100 g / 10 minutes, 90 g / 10 minutes, 80 g / 10 Minutes, 70 g / 10 minutes, 65 g / 10 minutes, 60 g / 10 minutes, and the like.

  The MFR may be measured according to ASTM D1238-1990, or the residence time may be measured as a predetermined time (for example, 5 minutes).

  When combining the polyester elastomer (A) and the polyester elastomer (B), the ratio of the polyester elastomer (A) to the polyester elastomer (B) is, for example, polyester elastomer (A) / polyester elastomer (B) (mass ratio) = 95 / 5-5 / 95 (e.g. 93 / 7-7 / 93), preferably 90 / 10-10 / 90 (e.g. 85 / 15-15 / 85), 95 / 5-15 / 85 (for example, 95/5 to 20/80), 93/7 to 25/75 (for example, 90/10 to 25/75, 85/15 to 30/70).

  By setting the ratio as described above, it seems that it is easy to obtain a thermoplastic elastomer resin (composition) that is advantageous in terms of bending fatigue resistance and injection moldability.

  In addition, you may adjust these ratios so that MFR in the whole thermoplastic elastomer resin (composition) may become the below-mentioned range.

(Method for producing polyester elastomer)
Polyester elastomers (particularly polyester elastomers (A) and (B)) can be produced by known methods.
For example, a method in which a lower alcohol diester of a dicarboxylic acid, an excessive amount of a low molecular weight glycol, and a low melting point polymer segment component are transesterified in the presence of a catalyst, and the resulting reaction product is polycondensed; Glycol and low-melting polymer segment components are esterified in the presence of a catalyst, and the resulting reaction product is polycondensed. A high-melting-point crystalline segment is prepared in advance, and a low-melting-point segment component is added to this. Any method may be employed, such as a method of randomizing by a transesterification reaction, a method of connecting a high melting point crystalline segment and a low melting point polymer segment with a chain linking agent.

  The MFR of the polyester elastomer (particularly, the polyester elastomer (A) and the polyester elastomer (B)) is determined by selecting a polymerization method (for example, solid phase polymerization), whether or not an additive (for example, a thickener) is added, It can be adjusted (controlled) as appropriate depending on the ratio.

(Additives, etc.)
The thermoplastic elastomer resin (composition) of the present invention may contain other components (for example, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, softeners, dyes, pigments, etc.) as necessary. Additives) and the like. The kind of such other components and the blending ratio thereof are not particularly limited.

(Physical properties)
The MFR of the thermoplastic elastomer resin (composition) of the present invention measured under conditions of a temperature of 240 ° C. and a load of 2160 g is from about 3.2 to 57 g / 10 minutes (for example, 3.5 to 55 g / 10 minutes). For example, it may be 3.5 to 50 g / 10 min, preferably 4 to 45 g / 10 min, more preferably about 4.5 to 40 g / 10 min, and 3.5 to 35 g / min. It may be 10 minutes, 4 to 30 g / 10 minutes, 4.2 to 25 g / 10 minutes, 4.5 to 20 g / 10 minutes, 5 to 15 g / 10 minutes, and the like.

  It seems that it is easy to obtain a thermoplastic elastomer resin advantageous in terms of bending fatigue resistance, injection moldability, etc. within the above range.

  The MFR may be measured according to ASTM D1238-1990, or the residence time may be measured as a predetermined time (for example, 5 minutes).

  Moreover, said MFR is MFR of a thermoplastic elastomer resin, for example, when combining polyester elastomer (A) and (B), it is MFR of a thermoplastic elastomer resin (composition) containing these.

The surface hardness (durometer D hardness) of the thermoplastic elastomer resin (composition) of the present invention may be, for example, 30 to 80, preferably 35 to 77, and more preferably about 40 to 75.
In addition, surface hardness (durometer D hardness) can be measured at 23 degreeC according to JISK7215-1986, for example.

(Method for producing thermoplastic elastomer resin (composition))
The method for producing the thermoplastic elastomer resin of the present invention is not particularly limited, and a conventional method can be used.
For example, when a polyester elastomer (A), a polyester elastomer (B) (and other components) are mixed to obtain a thermoplastic elastomer resin (composition), the mixing method is not particularly limited. In many cases, mixing is performed by kneading (for example, melt kneading).
In particular, when melt-kneading, it is preferable to perform vacuum deaeration treatment from the vent port of the extruder cylinder.

[Uses and molded products]
The present invention also includes a molded body containing the thermoplastic elastomer resin (composition).
The molded body can be obtained by molding the thermoplastic elastomer resin (composition) of the present invention.
Although it does not specifically limit as a shaping | molding method, Especially injection molding is preferable.

  The shape of the molded body is not particularly limited, and can be selected according to a molding method, for example, a one-dimensional form (for example, a linear shape, a rod shape), a two-dimensional form (for example, a sheet shape, a film shape, etc.). Any of a three-dimensional form (for example, a form having a concave part, a convex part, and a concave-convex part) may be used.

  The molded body may be a molded body made of only a thermoplastic elastomer resin (composition), or a member formed of a thermoplastic elastomer resin (composition) (hereinafter sometimes simply referred to as “member 1”). Further, it may be a composite molded body in which a member formed of another resin (D) (hereinafter sometimes simply referred to as “member 2”) is bonded (or joined). In the composite molded body, the member 1 and the member 2 may be directly bonded without interposing an adhesive layer.

  Although it does not specifically limit as a molded object (especially injection molded object or an injection molded product), For example, a motor vehicle, an electronic device, an electric device, a precision device, general consumer materials (or these components) is mentioned.

  In particular, according to the thermoplastic elastomer resin (composition) of the present invention, even a molded product having a complicated shape or a long flow length can be efficiently produced.

  From this point of view, the thermoplastic elastomer resin (composition) of the present invention produces cover boots (for example, cover boots for constant velocity joint drive devices for automobiles), air ducts, fuel tubes, hinges (hinge parts), and the like. You may use suitably as resin (composition) etc. for doing.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. All percentages and parts in the examples are based on weight unless otherwise specified. The physical properties shown in the examples were measured as follows.

[Surface hardness (Durometer D)]
It measured at 23 degreeC according to JISK7215-1986.

[Melt viscosity index (MFR)]
MFR was measured according to ASTM D1238-1990 under conditions of a temperature of 240 ° C., a load of 2160 g, and a residence time of 5 minutes.

[Mechanical properties]
Using a dumbbell test piece obtained by injection molding, the tensile strength at break, tensile elongation at break and tensile elastic modulus at 23 ° C. were measured according to JIS K7113-1995.

[Bending fatigue resistance]
A strip of length 75 mm × width 20 mm × thickness 2 mm was cut out from a square plate 75 mm long × 125 mm wide × 2 mm thick obtained by injection molding, and 80 ° C. using a Dematcher bending fatigue tester manufactured by Toyo Seiki Seisakusho. Under the atmosphere, the distance between chucks of 25 mm to 5 mm was stroked at a cycle of 300 times / minute, and the number of flexing until a crack occurred was measured.

[Injection molding (fluidity)]
A square plate having a length of 75 mm × width of 125 mm × thickness of 2 mm is injected into an injection molding machine (manufactured by Nissei Plastic Industries, “NEX1000”), cylinder temperature 240 ° C., mold temperature 50 ° C., injection speed 30 mm / second, injection time 10 seconds, The cooling time was 15 seconds, the VP switching position was set to 0, and the limit pressure required for complete filling of the mold was measured by the first-speed limit pressure.
And fluidity | liquidity was determined with the following references | standards.
○: Limit pressure required for complete filling is 65 MPa or less ×: Limit pressure required for complete filling exceeds 65 MPa

[Polyester elastomer (A1)]
42.0 parts of terephthalic acid, 40.0 parts of 1,4-butanediol and 47.5 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.03 part of titanium tetrabutoxide and mono-n-butyl -It charged to the reaction container provided with the helical ribbon type stirring blade with 0.01 part of monohydroxytin oxides, and it heated at 200-235 degreeC for 3 hours, and esterification was performed, making reaction water flow out of a system. After adding 0.15 part of tetra-n-butyl titanate to the reaction mixture and adding 0.05 part of a hindered phenolic antioxidant (Ciba Geigy, “Irganox 1098”), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was carried out for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of a strand and pelletized by cutting. The obtained pellets were charged into a rotatable reaction vessel, the pressure inside the system was reduced to 27 Pa, heated while rotating at 170 to 180 ° C. for about 50 hours to perform solid phase polymerization, and polyester elastomer (A1) ( Hard segment / soft segment (mass ratio) = 65/35).
MFR of the obtained polyester elastomer (A1) was 3 g / 10 min.

[Polyester elastomer (A2)]
50.5 parts of terephthalic acid, 43.8 parts of 1,4-butanediol and 35.4 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.04 part of titanium tetrabutoxide and mono-n-butyl -An esterification reaction was performed while charging 0.02 part of monohydroxytin oxide and a reaction vessel equipped with a helical ribbon type stirring blade, heating at 190 to 225 ° C for 3 hours, and allowing reaction water to flow out of the system. After adding 0.2 parts of tetra-n-butyl titanate to the reaction mixture and adding 0.05 parts of a hindered phenol antioxidant (“Irganox 1098” manufactured by Ciba Geigy), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of a strand and pelletized by cutting. The obtained pellets are charged into a rotatable reaction vessel, the pressure inside the system is reduced to 27 Pa, and heated at 170 to 180 ° C. for about 25 hours to perform solid phase polymerization, and polyester elastomer (A2) ( Hard segment / soft segment (mass ratio) = 70/30) was obtained.
MFR of the obtained polyester elastomer (A2) was 3 g / 10 min.

[Polyester elastomer (A3)]
42.0 parts of terephthalic acid, 40.0 parts of 1,4-butanediol and 47.5 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.03 part of titanium tetrabutoxide and mono-n-butyl -It charged to the reaction container provided with the helical ribbon type stirring blade with 0.01 part of monohydroxytin oxides, and it heated at 200-235 degreeC for 3 hours, and esterification was performed, making reaction water flow out of a system. After adding 0.15 part of tetra-n-butyl titanate to the reaction mixture and adding 0.05 part of a hindered phenolic antioxidant (Ciba Geigy, “Irganox 1098”), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was carried out for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of a strand and pelletized by cutting. The obtained pellets were charged into a rotatable reaction vessel, the pressure inside the system was reduced to 27 Pa, and heated at 170 to 180 ° C. for about 60 hours to perform solid phase polymerization, and polyester elastomer (A3) ( Hard segment / soft segment (mass ratio) = 65/35).
MFR of the obtained polyester elastomer (A3) was 1 g / 10 min.

[Polyester elastomer (B1)]
42.0 parts of terephthalic acid, 40.0 parts of 1,4-butanediol and 47.5 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.03 part of titanium tetrabutoxide and mono-n-butyl -It charged to the reaction container provided with the helical ribbon type stirring blade with 0.01 part of monohydroxytin oxides, and it heated at 200-235 degreeC for 3 hours, and esterification was performed, making reaction water flow out of a system. After adding 0.15 part of tetra-n-butyl titanate to the reaction mixture and adding 0.05 part of a hindered phenolic antioxidant (“Irganox 1098” manufactured by Ciba Geigy), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of strands and pelletized by cutting to obtain a polyester elastomer (B1) (hard segment / soft segment (mass ratio) = 65/35).
MFR of the obtained polyester elastomer (B1) was 28 g / 10 min.

[Polyester elastomer (B2)]
50.5 parts of terephthalic acid, 43.8 parts of 1,4-butanediol and 35.4 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.04 part of titanium tetrabutoxide and mono-n-butyl -An esterification reaction was performed while charging 0.02 part of monohydroxytin oxide and a reaction vessel equipped with a helical ribbon type stirring blade, heating at 190 to 225 ° C for 3 hours, and allowing reaction water to flow out of the system. After adding 0.2 parts of tetra-n-butyl titanate to the reaction mixture and adding 0.05 parts of a hindered phenol antioxidant (“Irganox 1098” manufactured by Ciba Geigy), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of a strand and pelletized by cutting. The obtained pellets were charged into a rotatable reaction vessel, the pressure in the system was reduced to 27 Pa, and solid phase polymerization was carried out by rotating at 170 to 180 ° C. for about 15 hours.
MFR of the obtained polyester elastomer (B2) (hard segment / soft segment (mass ratio) = 70/30) was 24 g / 10 min.

[Polyester elastomer (B3)]
50.5 parts of terephthalic acid, 43.8 parts of 1,4-butanediol and 35.4 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400, 0.04 part of titanium tetrabutoxide and mono-n-butyl -An esterification reaction was performed while charging 0.02 part of monohydroxytin oxide and a reaction vessel equipped with a helical ribbon type stirring blade, heating at 190 to 225 ° C for 3 hours, and allowing reaction water to flow out of the system. After adding 0.2 parts of tetra-n-butyl titanate to the reaction mixture and adding 0.05 parts of a hindered phenol antioxidant (“Irganox 1098” manufactured by Ciba Geigy), the temperature was raised to 245 ° C. Then, the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was performed for 1 hour and 50 minutes under the conditions.
The obtained polymer was discharged into water in the form of a strand and pelletized by cutting to obtain a polyester elastomer (B3) (hard segment / soft segment (mass ratio) = 70/30).
MFR measured at 240 degreeC of the obtained polyester elastomer (B3) was 58 g / 10min.

[Example 1]
The polyester elastomer (A1) and the thermoplastic polyester elastomer (B1) were dry blended at a blending ratio (mass ratio) shown in Table 1. The dry blended compound was melt-kneaded at 250 ° C. using a twin screw extruder having a cylinder diameter of 26 mm and vacuum degassing from one vent port near the cylinder discharge port, and then pelleted Turned into.
The obtained pellets were charged into a shelf-type hot air dryer and dried at 80 ° C. for 4 hours to obtain a thermoplastic elastomer resin composition, and various properties were evaluated.
Further, the obtained thermoplastic elastomer resin composition was subjected to JIS No. 2 dumbbell test at a mold temperature (mold cavity surface) of 50 ° C. using an in-line screw type injection molding machine set to the melting point of the composition + 30 ° C. A piece and a square plate molded product having a length of 75 mm, a width of 125 mm, and a thickness of 2 mm were injection molded.
Various characteristics were evaluated using the obtained dumbbell test pieces and injection molded articles.

[Examples 2 to 9 and Reference Examples 1 to 4]
Thermoplastic elastomer resin (composition) in the same manner as in Example 1 except that polyester elastomers (A1) to (A3) and polyester elastomers (B1) to (B3) were used at the blending ratios shown in Table 1. A dumbbell test piece and an injection molded product were obtained, and various properties were evaluated.

  The composition and properties are summarized in Table 1 below.

  As is apparent from the results in Table 1, the thermoplastic elastomer resin compositions obtained in the examples were excellent in bending fatigue resistance and injection moldability. In addition, physical properties such as flexibility and strength were not inferior.

In the present invention, a novel thermoplastic elastomer resin (composition) can be obtained. In particular, in the present invention, a resin (composition) having excellent bending resistance and injection moldability can also be obtained.
Such a thermoplastic elastomer resin (composition) of the present invention can be suitably used in various applications such as automobiles, electronic / electric equipment, precision equipment, and general consumer goods.

Claims (12)

  According to ASTM D1238-1990, a polyester elastomer (A) having an MFR of less than 15 g / 10 minutes measured at a temperature of 240 ° C., a load of 2160 g and a residence time of 5 minutes, and a temperature of 240 ° C., a load of 2160 g according to ASTM D1238-1990 A thermoplastic elastomer resin composition comprising a polyester elastomer (B) having an MFR of 15 g / 10 min or more measured under a residence time of 5 minutes.   The composition according to claim 1, wherein the polyester elastomer (A) and the polyester elastomer (B) comprise a polyether ester elastomer.   The polyester elastomer (A) and the polyester elastomer (B) have a hard segment containing an aromatic polyester unit and a soft segment containing an aliphatic polyether unit, and the ratio of the hard segment to the soft segment is hard segment / The composition according to claim 1 or 2, which is a polyester block copolymer having a soft segment (mass ratio) of 70/30 to 40/60.   The composition in any one of Claims 1-3 in which the hard segment of a polyester elastomer (A) and a polyester elastomer (B) contains a butylene terephthalate unit and / or a butylene isophthalate unit.   The soft segment of the polyester elastomer (A) and the polyester elastomer (B) is at least one selected from poly (tetramethylene oxide) glycol, an ethylene oxide adduct of poly (propylene oxide) glycol, and a copolymer glycol of ethylene oxide and tetrahydrofuran. The composition in any one of Claims 1-4 containing.   The ratio of the polyester elastomer (A) to the polyester elastomer (B) is polyester elastomer (A) / polyester elastomer (B) (mass ratio) = 95/5 to 5/95. The composition as described.   The composition according to any one of claims 1 to 6, wherein the MFR measured under conditions of a temperature of 240 ° C, a load of 2160 g, and a residence time of 5 minutes is 3.5 to 50 g / 10 minutes according to ASTM D1238-1990. The polyester elastomer (A) and the polyester elastomer (B) include a polyether ester elastomer,
According to ASTM D1238-1990, the MFR when measured under the conditions of a temperature of 240 ° C., a load of 2160 g and a residence time of 5 minutes is 5 g / 10 minutes or less in the polyester elastomer (A), and 20 g / 10 minutes or more in the polyester elastomer (B). 4-30 g / 10 min in the composition,
The ratio of a polyester elastomer (A) and a polyester elastomer (B) is either polyester elastomer (A) / polyester elastomer (B) (mass ratio) = 90/10 to 10/90, A composition according to 1.   It is an object for injection molding, The composition in any one of Claims 1-8.   The molded object containing the composition in any one of Claims 1-9.   The molded article according to claim 10, which is an injection molded article.   The molded body according to claim 10 or 11, which is a cover boot, an air duct, a fuel tube or a hinge part.