JP5991312B2 - Polyester block copolymer composition for flexible boots - Google Patents

Description

  The present invention relates to a polyester block copolymer composition having excellent mechanical properties despite its high flexibility. Specifically, a polyester block copolymer composition having excellent bending fatigue resistance under a high temperature environment, excellent flexibility under a low temperature environment, and excellent moldability, particularly extrudability and blow moldability. It is about. The present invention also relates to a blow molded product molded from the polyester block copolymer composition. More specifically, the present invention relates to a molded article that requires flexibility such as a constant velocity joint boot of an automobile having excellent bending fatigue resistance under a high temperature environment, flexibility under a low temperature environment, and excellent chemical resistance.

  Polyester block copolymers have been used as an alternative to conventional rubber because of the environmental advantages of recyclability, the performance of bending fatigue resistance, and the cost advantages of productivity. Its applications are wide, and the performance required for it varies widely, including high chemical resistance, high heat resistance, and high bending fatigue resistance.

  Constant velocity joint boots made of a polyester block copolymer with polybutylene terephthalate, a crystalline aromatic polyester, as a hard segment and aliphatic polyester or polyalkylene glycols as a soft segment, have excellent rubber-like elasticity and resistance. Has bending fatigue. However, the use environment temperature of constant velocity joint boots has risen due to high performance of automobiles and downsizing of functional parts, and the bending fatigue resistance under the required high temperature environment is not good for conventional polyester block copolymers. It was enough.

  As a means of improving the bending fatigue resistance of the polyester block copolymer, the bending fatigue resistance can be increased by increasing the molecular weight of the polyalkylene glycols contained in the soft segment or by increasing the molecular weight of the polyester block copolymer itself. It is known to improve the properties. As a means corresponding to the use environment at high temperature, there is Patent Document 1. For the purpose of improving bending fatigue resistance at 100 ° C., a bifunctional or higher functional glycidyl ester is blended. However, no mention is made of bending fatigue resistance at high temperatures exceeding 100 ° C.

Japanese Patent No. 4038742

  Polyester block copolymer composition for flexible boots that exhibits good flex fatigue resistance when used in higher temperature environments, which has not been solved by conventional techniques, and maintains flexibility in use under low temperature environments It is an issue to provide. In particular, the object is to exhibit good bending fatigue resistance at 140 ° C. and sufficient flexibility at −30 ° C.

In order to solve the above-mentioned problems, the present inventors have intensively studied and studied, and finally completed the present invention.
Bending fatigue resistance in a high temperature environment (140 ° C.) is excellent in a polyester block copolymer having polybutylene naphthalate as a hard segment (hereinafter sometimes referred to as an N-based block copolymer). Below (−30 ° C.), the hardness increases and the flexibility tends to decrease. On the other hand, a polyester block copolymer having polybutylene terephthalate as a hard segment (hereinafter sometimes referred to as a T-based block copolymer) can satisfy flexibility in a low temperature environment (−30 ° C.), but is It has been found that the bending fatigue resistance in the environment (140 ° C.) tends to be insufficient. As a result of the study by the present inventors, it is surprisingly expected that the N-based block copolymer having a specific configuration and the T-based block copolymer having a specific configuration are included in a specific ratio. The present inventors have found that excellent effects exceeding the bending fatigue resistance under a high temperature environment (140 ° C.) and the flexibility under a low temperature environment (−30 ° C.) depending on the blending ratio are exhibited.

The present invention is as follows.
[1] Polyester block containing a polybutylene naphthalate component as a hard segment, a polyoxytetramethylene glycol component having a number average molecular weight of 1100 to 1400 as a soft segment, and a soft segment content of 30 to 60% by mass Copolymer [A] and a polybutylene terephthalate component as a hard segment, a polyoxytetramethylene glycol component having a number average molecular weight of 1200 to 1800 as a soft segment, and a soft segment content of 30 to 60% by mass The polyfunctional epoxy compound [C] with respect to 100 parts by mass of the resin component containing the polyester block copolymer [B] of [A] / [B] (mass ratio) of 65/35 to 35/65 0.05 to 3 parts by mass of Polyester block copolymer composition for flexible boots.

[2] The polyester block copolymer composition for flexible boots according to [1], wherein the polyfunctional epoxy compound [C] is a polyfunctional epoxy compound having naphthalene or triazine as a skeleton.

[3] A flexible boot formed using the polyester block copolymer composition according to [1] or [2].

  The polyester block copolymer composition of the present invention exhibits good flexural fatigue resistance in a further high temperature environment (140 ° C.) required by the market, and is excellent in flexibility in a low temperature environment. It can be used optimally for boots.

Hereinafter, the present invention will be described in detail.
(Polyester block copolymer [A])
The polyester block copolymer [A] according to the present invention is composed of a hard segment and a soft segment. The hard segment is a polyester having butylene naphthalate as a repeating unit. From the viewpoint of physical properties and availability, polybutylene naphthalate composed of 2,6-naphthalenedicarboxylic acid (or an alkyl ester thereof) and 1,4-butanediol is preferable. The soft segment includes polyoxytetramethylene glycol.
The polyester block copolymer [A] according to the present invention preferably contains 70 mol% or more of butylene naphthalate units as hard segments, more preferably 80 mol% or more, and still more preferably 90 mol% or more.
The polyester block copolymer [A] according to the present invention preferably contains 70% by mass or more of polyoxytetramethylene glycol as a soft segment, more preferably 80% by mass or more, and still more preferably 90% by mass or more.

  In the polyester block copolymer [A] according to the present invention, terephthalic acid, isophthalic acid or the like may be used as a copolymerization component in addition to naphthalene dicarboxylic acid as the dicarboxylic acid constituting the hard segment polyester. The amount is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less of the total dicarboxylic acid component.

  In addition, in the polyester block copolymer [A] according to the present invention, ethylene glycol, 1,3-propylene glycol, 1,6 in addition to 1,4-butanediol as the low molecular weight glycol constituting the hard segment polyester. -Hexanediol, 1,4-cyclohexanedimethanol, dimer glycol or the like may be used as a copolymerization component. The amount is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less of the total low molecular weight glycol component.

  Moreover, the number average molecular weights of the polyoxytetramethylene glycol of the component which comprises the soft segment in the polyester block copolymer [A] used for this invention are 1100-1400. If the number average molecular weight is 1100 or more, the cohesion of the hard segment is increased to improve heat resistance, and if the number average molecular weight is 1400 or less, phase separation between the hard segment and the soft segment does not occur. A range is desirable. Other poly (oxyalkylene) glycols, aliphatic polyester glycols, and the like may be used as part of the soft segment as long as the characteristics of the present invention are not impaired. The number average molecular weight of the desired polyoxytetramethylene glycol may be achieved by mixing high molecular weight polyoxytetramethylene glycol and low molecular weight polyoxytetramethylene glycol.

  The polyester block copolymer [A] according to the present invention is obtained by reacting a hard segment and a soft segment. The mass ratio of the soft segment is 30 to 60% by mass in order to maintain the shape in a high temperature environment without impairing flexibility as an elastomer, and is 35 to 55%. Mass% is preferred. The above reaction can be carried out by arbitrarily determining a combination of reaction temperature, catalyst concentration, and reaction time. That is, the appropriate values of the reaction conditions vary depending on various factors such as the types and amount ratios of the hard segments and soft segments to be used, the shape of the apparatus to be used, and the stirring conditions.

  The polyester block copolymer [A] used in the present invention may contain a tri- or higher functional polycarboxylic acid or polyol only in a small amount. For example, trimellitic anhydride, benzophenone tetracarboxylic acid, trimethylolpropane, glycerin and the like can be used.

  The solution viscosity of the polyester block copolymer [A] is preferably 1.4 to 2.6 dl / g. The solution viscosity of [A] is more preferably 1.6 to 2.4 dl / g, still more preferably 1.7 to 2.3 dl / g. The solution viscosity is measured by the method described in the item of Examples described later. If the solution viscosity is less than 1.4 dl / g, it is difficult to maintain the shape during heating, and if it exceeds 2.6 dl / g, the fluidity is significantly lowered.

Next, as a method for obtaining the polyester block copolymer [A] according to the present invention, any known method can be employed. For example, any of a melt polymerization method, a solution polymerization method, a solid phase polymerization method and the like can be appropriately used. In the case of a melt polymerization method, a transesterification method or a direct polymerization method may be used. In order to improve the viscosity of the resin, it is of course desirable to perform solid phase polymerization after melt polymerization.
As the catalyst used for the reaction, an antimony catalyst, a germanium catalyst, and a titanium catalyst are preferable. In particular, a titanium catalyst is preferable. Specifically, tetraalkyl titanates such as tetrabutyl titanate and tetramethyl titanate, and metal oxalates such as potassium titanium oxalate are preferable. The other catalyst is not particularly limited as long as it is a known catalyst, and examples thereof include tin compounds such as dibutyltin oxide and dibutyltin dilaurate, and lead compounds such as lead acetate.

(Polyester block copolymer [B])
The polyester block copolymer [B] according to the present invention is composed of a hard segment and a soft segment. The hard segment is a polyester having butylene terephthalate as a repeating unit. From the viewpoint of physical properties and availability, polybutylene terephthalate comprising terephthalic acid (or an alkyl ester thereof) and 1,4-butanediol is preferred. The soft segment includes polyoxytetramethylene glycol.
The polyester block copolymer [B] according to the present invention preferably contains 70 mol% or more of butylene terephthalate units as hard segments, more preferably 80 mol% or more, and still more preferably 90 mol% or more.
The polyester block copolymer [B] according to the present invention preferably contains 70% by mass or more of polyoxytetramethylene glycol as a soft segment, more preferably 80% by mass or more, and still more preferably 90% by mass or more.

  In the polyester block copolymer [B] according to the present invention, naphthalenedicarboxylic acid, isophthalic acid or the like may be used as a copolymerization component in addition to terephthalic acid as the dicarboxylic acid constituting the hard segment polyester. The amount is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less of the total dicarboxylic acid component.

  In addition, in the polyester block copolymer [B] according to the present invention, ethylene glycol, 1,3-propylene glycol, 1,6 in addition to 1,4-butanediol as the low molecular weight glycol constituting the hard segment polyester. -Hexanediol, 1,4-cyclohexanedimethanol, dimer glycol or the like may be used as a copolymerization component. The amount is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less of the total low molecular weight glycol component.

  Moreover, the number average molecular weights of the polyoxytetramethylene glycol of the component which comprises the soft segment in the polyester block copolymer [B] used for this invention are 1200-1800. If the number average molecular weight is 1200 or more, the cohesion of the hard segment is increased for improving heat resistance, and if the number average molecular weight is 1800 or less, the hardness change at low temperature due to the aggregation of the hard segment is excellent. This range is desirable. Other poly (oxyalkylene) glycols, aliphatic polyester glycols, and the like may be used as part of the soft segment as long as the characteristics of the present invention are not impaired. The number average molecular weight of the desired polyoxytetramethylene glycol may be achieved by mixing high molecular weight polyoxytetramethylene glycol and low molecular weight polyoxytetramethylene glycol.

  The polyester block copolymer [B] according to the present invention is obtained by reacting a hard segment and a soft segment. The mass ratio of the soft segment is 30 to 60% by mass in order to maintain the shape in a high temperature environment without impairing flexibility as an elastomer, and is 35 to 55%. Mass% is preferred. The above reaction can be carried out by arbitrarily determining a combination of reaction temperature, catalyst concentration, and reaction time. That is, the appropriate values of the reaction conditions vary depending on various factors such as the types and amount ratios of the hard segments and soft segments to be used, the shape of the apparatus to be used, and the stirring conditions.

  The polyester block copolymer [B] used in the present invention may contain a tri- or higher functional polycarboxylic acid or polyol only in a small amount. For example, trimellitic anhydride, benzophenone tetracarboxylic acid, trimethylolpropane, glycerin and the like can be used.

  The solution viscosity of the polyester block copolymer [B] is preferably 1.4 to 2.6 dl / g. The solution viscosity of [B] is more preferably 1.6 to 2.4 dl / g, still more preferably 1.7 to 2.3 dl / g. The solution viscosity is measured by the method described in the item of Examples described later. If the solution viscosity is less than 1.4 dl / g, it is difficult to maintain the shape during heating, and if it exceeds 2.6 dl / g, the fluidity is significantly lowered.

Next, as a method for obtaining the polyester block copolymer [B] according to the present invention, any known method can be employed. For example, any of a melt polymerization method, a solution polymerization method, a solid phase polymerization method and the like can be appropriately used. In the case of a melt polymerization method, a transesterification method or a direct polymerization method may be used. In order to improve the viscosity of the resin, it is of course desirable to perform solid phase polymerization after melt polymerization.
As the catalyst used for the reaction, an antimony catalyst, a germanium catalyst, and a titanium catalyst are preferable. In particular, a titanium catalyst is preferable. Specifically, tetraalkyl titanates such as tetrabutyl titanate and tetramethyl titanate, and metal oxalates such as potassium titanium oxalate are preferable. The other catalyst is not particularly limited as long as it is a known catalyst, and examples thereof include tin compounds such as dibutyltin oxide and dibutyltin dilaurate, and lead compounds such as lead acetate.

(Polyfunctional epoxy compound [C])
In the present invention, the polyfunctional epoxy compound [C] refers to a compound having two or more epoxy groups. Specific examples of the polyfunctional epoxy compound [C] include 1,6-dihydroxynaphthalenediglycidyl ether and 1,3-bis (oxiranylmethoxy) benzene having two epoxy groups, and 1 having three epoxy groups. , 3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, diglycerol triglycidyl ether, with four epoxy groups Examples thereof include 1-chloro-2,3-epoxypropane, formaldehyde, 2,7-naphthalenediol polycondensate and pentaerythritol polyglycidyl ether. Among these, a polyfunctional epoxy compound having heat resistance in the skeleton is preferable. In particular, an epoxy compound having a naphthalene structure as a skeleton or an epoxy compound having a triazine structure as a skeleton is preferable. A bifunctional or trifunctional epoxy compound is preferred from the degree of increase in the solution viscosity of the polyester elastomer resin itself and the degree of gelation caused by aggregation and solidification of the epoxy itself.

(Polyester block copolymer composition)
In the present invention, the polyester block copolymer composition is a mixture of the polyester block copolymer [A], the polyester block copolymer [B], and the polyfunctional epoxy compound [C].
The polyester block copolymer composition of the present invention is a polyfunctional epoxy compound [C] with respect to 100 parts by mass of resin component [A] / [B] (mass ratio) contained in a ratio of 65/35 to 35/65. ] In an amount of 0.05 to 3 parts by mass. [A] / [B] (mass ratio) is preferably a ratio of 60/40 to 40/60. When the content ratio of [A] is smaller than the above ratio, the bending fatigue resistance under a high temperature environment deteriorates, which is not preferable. When the content ratio of [B] is smaller than the above ratio, flexibility in a low temperature environment is deteriorated, which is not preferable.
When the blending amount of the polyfunctional epoxy compound [C] is less than 0.05 parts by mass with respect to 100 parts by mass of the resin component, it is difficult to maintain the shape at the time of blow molding, and resistance to bending fatigue in a high temperature environment is also achieved. It becomes unsatisfactory and not preferable. When the compounding amount of the polyfunctional epoxy compound [C] exceeds 3.0 parts by mass, the polyfunctional epoxy itself is not preferable because the surface of the molded product obtained from the composition is uneven due to cohesive curing (gelation). .

  The number of times until the break in the dematcher bending fatigue test at 140 ° C. of the polyester block copolymer composition of the present invention is preferably 4 million times or more. By being 4 million times or more, it can be said that the bending fatigue resistance under a high temperature use environment can be satisfied. The dematcher bending fatigue test is measured by the method described in the item of an example described later.

  Furthermore, the ratio of (tensile stress at 23 ° C.) / (Tensile stress at −30 ° C.) in the polyester block copolymer composition of the present invention is preferably 2 or less. When this ratio is 2 or less, it can be said that the flexibility in a low temperature environment is satisfactory. The tensile stress test is measured by a method described in the item of an example described later.

Furthermore, the polyester block copolymer or polyester block copolymer composition used in the present invention can be blended with various additives depending on the purpose to obtain a composition. Additives include known hindered phenol-based, sulfur-based, phosphorus-based, amine-based antioxidants, hindered amine-based, triazole-based, benzophenone-based, benzoate-based, nickel-based, salicyl-based light stabilizers, antistatic agents, etc. Agents, lubricants, molecular modifiers such as peroxides, epoxy compounds, isocyanate compounds, compounds having reactive groups such as carbodiimide compounds, metal deactivators, organic and inorganic nucleating agents, neutralizing agents, control agents Acid agents, antibacterial agents, fluorescent brighteners, fillers, flame retardants, flame retardant aids, organic and inorganic pigments, and the like can be added.
10 mass% or less is preferable in a polyester block copolymer composition, and, as for the compounding quantity of these additives, 5 mass% or less is more preferable.

  As a method for blending these additives, they can be blended using a kneader such as a heating roll, an extruder, or a Banbury mixer. Moreover, it can add and mix in the oligomer before the transesterification reaction or polycondensation reaction at the time of manufacturing a polyester block copolymer.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited thereto.
(Measurement method)
Solution viscosity:
0.05 g of the polyester block copolymer was dissolved in 25 mL of a mixed solvent (phenol / tetrachloroethane = 60/40) and measured at 30 ° C. using an Ostwald viscometer.

Dematcher bending fatigue test:
A test piece having a shape in accordance with JIS K6260 was repeatedly bent at 140 ° C. at 70 mm when stretched and at 18 mm when compressed at 140 ° C., and the number of times until the test piece broke was measured.

Phase separation:
The polyester block copolymer composition was observed with an extruder for the transparency of the strand before cooling during melting and kneading. Evaluation was made according to the following criteria.
○: The strand is transparent by visual inspection. ×: White turbidity is confirmed by visual inspection.

Gelation:
A sheet having a width of 150 mm and a thickness of 200 μm was prepared from the polyester block copolymer composition melted and kneaded by an extruder using a uniaxial sheet extruder, and the unevenness of the sheet surface was observed. Evaluation was made according to the following criteria.
○: Less than 10 irregularities in a 150 mm square sheet ×; 10 or more irregularities in a 150 mm square sheet

Low temperature characteristics (tensile stress test):
The stress was measured when a test piece having a shape according to ASTM D638 was stretched to 75 mm with a tensile speed of 50 mm / min and a chuck distance of 50 mm using a tensile tester.
Evaluation was made according to the following criteria.
○; (Stress at −30 ° C.) / (Stress at 23 ° C.) ≦ 2
×; (Stress at −30 ° C.) / (Stress at 23 ° C.)> 2

(Preparation of polyester block copolymer [A1])
Dimethyl 2,6-naphthalenedicarboxylate (NDCM) 380 g, 1,4-butanediol (BD) 280 g, polytetramethylene glycol (PTMG, number average molecular weight 1250) 240 g, Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [A1] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [A2])
390 g of dimethyl 2,6-naphthalenedicarboxylate (NDCM), 250 g of 1,4-butanediol (BD), 300 g of polytetramethylene glycol (PTMG, number average molecular weight 1100), Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [A2] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [A3])
Dimethyl 2,6-naphthalenedicarboxylate (NDCM) 380 g, 1,4-butanediol (BD) 250 g, polytetramethylene glycol (PTMG, number average molecular weight 1400) 310 g, Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [A3] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [A4])
Dimethyl 2,6-naphthalenedicarboxylate (NDCM) 420 g, 1,4-butanediol (BD) 280 g, polytetramethylene glycol (PTMG, number average molecular weight 1250) 240 g, Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [A4] had a soft segment mass ratio of 35%.

(Preparation of polyester block copolymer [A5])
Dimethyl 2,6-naphthalenedicarboxylate (NDCM) 340 g, 1,4-butanediol (BD) 210 g, polytetramethylene glycol (PTMG, number average molecular weight 1250) 370 g, Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [A5] had a soft segment mass ratio of 55%.

(Preparation of polyester block copolymer [A6])
Except for adjusting the polymerization reaction time, the polymerization reaction was performed until the solution viscosity became 1.5 dl / g in the same manner as in the production of the polyester block copolymer [A1], and the polymer was taken out into a pellet form. The collected polyester block copolymer [A6] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [B1])
340 g of dimethyl terephthalate (DMT), 300 g of 1,4-butanediol (BD), 320 g of polytetramethylene glycol (PTMG, molecular weight 1500), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [B1] had a soft segment mass / weight ratio of 45%.

(Preparation of polyester block copolymer [B2])
350 g of dimethyl terephthalate (DMT), 290 g of 1,4-butanediol (BD), 310 g of polytetramethylene glycol (PTMG, molecular weight 1200), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [B2] had a soft segment mass / weight ratio of 45%.

(Preparation of polyester block copolymer [B3])
340 g of dimethyl terephthalate (DMT), 300 g of 1,4-butanediol (BD), 330 g of polytetramethylene glycol (PTMG, molecular weight 1800), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [B3] had a soft segment mass / weight ratio of 45%.

(Preparation of polyester block copolymer [B4])
390 g of dimethyl terephthalate (DMT), 330 g of 1,4-butanediol (BD), 250 g of polytetramethylene glycol (PTMG, molecular weight 1500), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [B4] had a soft segment mass / weight ratio of 35%.

(Preparation of polyester block copolymer [B5])
300 g of dimethyl terephthalate (DMT), 240 g of 1,4-butanediol (BD), 390 g of polytetramethylene glycol (PTMG, molecular weight 1500), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [B5] had a soft segment mass-to-weight ratio of 55%.

(Preparation of polyester block copolymer [B6])
Except for adjusting the polymerization reaction time, the polymerization reaction was carried out until the solution viscosity became 1.5 dl / g in the same manner as in the production of the polyester block copolymer [B1], and the polymer was taken out in a pellet form. The collected polyester block copolymer [B6] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [C1])
390 g of dimethyl 2,6-naphthalenedicarboxylate (NDCM), 250 g of 1,4-butanediol (BD), 290 g of polytetramethylene glycol (PTMG, number average molecular weight 1000), Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [C1] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [C2])
370 g of dimethyl 2,6-naphthalenedicarboxylate (NDCM), 260 g of 1,4-butanediol (BD), 310 g of polytetramethylene glycol (PTMG, number average molecular weight 1500), Irganox-1330 (manufactured by Ciba Japan) 8 g and 1.0 g of tetrabutyl titanate (TBT) were charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Furthermore, a polymerization reaction was performed until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out in a pellet form. The collected polyester block copolymer [C2] had a soft segment mass ratio of 45%.

(Preparation of polyester block copolymer [D1])
360 g of dimethyl terephthalate (DMT), 290 g of 1,4-butanediol (BD), 300 g of polytetramethylene glycol (PTMG, molecular weight 1000), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [D1] had a soft segment mass / weight ratio of 45%.

(Preparation of polyester block copolymer [D2])
340 g of dimethyl terephthalate (DMT), 290 g of 1,4-butanediol (BD), 330 g of polytetramethylene glycol (PTMG, molecular weight 2000), 1.8 g of Irganox-1330 (manufactured by Ciba Japan), tetrabutyl titanate (TBT) 1.0 g was charged into a 4 L autoclave, and the temperature was increased from room temperature to 220 ° C. over 3 hours to conduct a transesterification reaction. Next, the inside of the can was gradually depressurized and further heated, and an initial condensation reaction was performed at 250 ° C. and 1 torr or less over 45 minutes. Further, a polymerization reaction was conducted for 2 hours until the solution viscosity became 2.0 dl / g at 250 ° C. and 1 torr or less, and the polymer was taken out into a pellet form. The collected polyester block copolymer [D2] had a soft segment mass-to-weight ratio of 45%.

Example 1
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 2)
60 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in the extruder with respect to 40 parts by mass of the polyester block copolymer [A1] obtained as described above. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 3)
For 60 parts by mass of the polyester block copolymer [A1] obtained above, 40 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

Example 4
For 50 parts by mass of the polyester block copolymer [A2] obtained above, 50 parts by mass of the polyester block copolymer [B2] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 5)
Polyester block copolymer [B3] 50 parts by mass and 1,6-dihydroxynaphthalenediglycidyl ether 0.3 part by mass are melted in an extruder with respect to 50 parts by mass of the polyester block copolymer [A2] obtained above. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 6)
For 50 parts by mass of the polyester block copolymer [A3] obtained above, 50 parts by mass of the polyester block copolymer [B2] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 7)
For 50 parts by mass of the polyester block copolymer [A3] obtained above, 50 parts by mass of the polyester block copolymer [B3] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 8)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.05 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

Example 9
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 3.0 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 10)
For 50 parts by mass of the polyester block copolymer [A4] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 11)
For 50 parts by mass of the polyester block copolymer [A5] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 12)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B4] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 13)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B5] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 14)
50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1], 1,3,5-tris (2,3-epoxypropyl) -1,3, A polyester block copolymer composition is obtained by melting and kneading 0.3 parts by mass of 5-triazine-2,4,6 (1H, 3H, 5H) -trione in an extruder and passing through cold water to form a cooling strand. It was. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 15)
For 50 parts by mass of the polyester block copolymer [A6] obtained above, 50 parts by mass of the polyester block copolymer [B6] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Example 16)
50 parts by mass of the polyester block copolymer [A1] obtained as described above, 50 parts by mass of the polyester block copolymer [B1], 1-chloro-2,3-epoxypropane / formaldehyde / 2 having 4 epoxy groups , 7-Naphthalenediol polycondensate 0.3 parts by mass was melted and kneaded in an extruder, then passed through cold water to form a cooled strand to obtain a polyester block copolymer composition. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 1)
For 100 parts by mass of the polyester block copolymer [A1] obtained above, 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether was melted and kneaded in the extruder, and then passed through cold water to form a cooled strand. A polyester block copolymer composition was obtained. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 2)
For 100 parts by mass of the polyester block copolymer [B1] obtained above, 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether is melted and kneaded in an extruder, and then passed through cold water to form a cooled strand. A polyester block copolymer composition was obtained. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 3)
For 30 parts by mass of the polyester block copolymer [A1] obtained above, 70 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 4)
For 70 parts by mass of the polyester block copolymer [A1] obtained above, 30 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 5)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.03 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 6)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 3.2 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 7)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [D1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 8)
For 50 parts by mass of the polyester block copolymer [A1] obtained above, 50 parts by mass of the polyester block copolymer [D2] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 9)
For 50 parts by mass of the polyester block copolymer [C1] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

(Comparative Example 10)
For 50 parts by mass of the polyester block copolymer [C2] obtained above, 50 parts by mass of the polyester block copolymer [B1] and 0.3 parts by mass of 1,6-dihydroxynaphthalenediglycidyl ether are melted in an extruder. -After kneading, a polyester block copolymer composition was obtained by passing through cold water to form a cooling strand. Various measurements and evaluations were performed. The results are shown in Table 1.

  The polyester block copolymer composition obtained in the examples has a bending fatigue resistance of at least 4 million times by a Dematcher bending fatigue tester at 140 ° C, and a tensile stress at -30 ° C is 23 ° C. It became 2 or less with respect to the tensile stress.

  The polyester block copolymer composition of the present invention suppresses a change in hardness at a low temperature while achieving good bending fatigue resistance under a high temperature environment, and is optimal for, for example, a constant velocity joint boot.

Claims (3)

It comprises polybutylene naphthalate component as a hard segment and a number average molecular weight comprises a polyoxytetramethylene glycol component of 1100 to 1400 as a soft segment, and Ri is 30 to 60% by mass content of the soft segment, solution viscosity 1.4~2.6dl / g der Ru polyester block copolymer [a], include polybutylene terephthalate component as a hard segment and a number average molecular weight of polyoxytetramethylene glycol component of 1200 to 1800 as a soft segment wherein, and Ri is 30 to 60% by mass content of the soft segment, a polyester block copolymer solution viscosity Ru 1.4~2.6dl / g der the [B], [a] / [B] (Mass ratio) with respect to 100 parts by mass of resin component contained at a ratio of 65/35 to 35/65 , A polyfunctional epoxy compound [C] were blended 0.05 to 3 parts by weight, the polyfunctional epoxy compound [C] is an epoxy compound having two epoxy groups, an epoxy compound having three epoxy groups, or four A polyester block copolymer composition for flexible boots , which is an epoxy compound having an epoxy group . The polyfunctional epoxy compound [C] is naphthalene or triazine flexible boot for polyester block copolymer composition according to claim 1 is di cane epoxy compound in the backbone.   The flexible boot shape | molded using the polyester block copolymer composition of Claim 1 or 2.