JP2012107155A - Polyester elastomer composition and molded article comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polyester elastomer composition, which has superior thermal aging resistance and water resistance, hardly causes gelation and reduction in the melt viscosity during melt retention although it has a high melt viscosity, and is superior in molding processability in extrusion molding, blow molding or the like.SOLUTION: The polyester elastomer composition is obtained by reacting 100 pts.wt of a thermoplastic polyester elastomer (A) in which hard segments comprising a polyester composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol and soft segments comprising an aliphatic polycarbonate are bonded, 3-20 pts.wt of an epoxy group-containing ethylenic copolymer compound (B), 0.3-1.0 pts.wt of a bifunctional or higher epoxy compound (C), and 1-5 pts.wt of a carbodiimide compound (D).

Description

  The present invention relates to a polyester elastomer composition excellent in heat resistance, light resistance, heat aging resistance, water resistance, low temperature characteristics, and the like, and a blow molded article made of the composition. Specifically, polyester elastomers that are blow molded products such as air conditioning ducts, intake ducts, exhaust ducts, etc., and are useful in fields requiring heat aging resistance, water resistance, low temperature characteristics, heat resistance, etc. A composition and a blow molded article made of the composition.

  Thermoplastic polyester elastomers have long been made of crystalline polyesters such as polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN) as hard segments, and polyoxyalkylene glycols such as polytetramethylene glycol (PTMG) and / or Or what uses polyester, such as a polycaprolactone (PCL) and a polybutylene adipate (PBA), as a soft segment, is known, and is utilized (for example, patent document 1, 2).

  However, polyester polyether type elastomers that use polyoxyalkylene glycols in the soft segment are superior in water resistance and low temperature properties, but are inferior in heat aging resistance, and polyester polyester type elastomers that use polyester in the soft segment are Although it is excellent in heat aging resistance, it is known to be inferior in water resistance and low temperature characteristics.

  In order to solve the above drawbacks, polyester polycarbonate type elastomers using polycarbonate as a soft segment have been proposed (see, for example, Patent Documents 3 to 9).

  Although the above problems are solved, the polyester polycarbonate type elastomers disclosed in these patent documents have a problem that the retention of melt viscosity is poor when held in a molten state.

  There is no problem with extrusion blow molding, which has a short residence time in the molding machine. However, in a molding machine with an accumulator or a two-layer blow molding machine that extrudes together with a high-melting-point material, the viscosity drop at the time of melting is large, and a good blow There is a problem that moldability cannot be obtained.

Japanese Patent Laid-Open No. 10-17657 JP 2003-192778 A Japanese Patent Publication No. 7-39480 JP-A-5-295049 JP-A-6-306202 Japanese Patent Laid-Open No. 10-182784 JP 2001-206939 A JP 2001-240663 A JP 2008-150540 A

  The present invention has excellent heat resistance, heat aging resistance, water resistance, light resistance, low temperature characteristics, etc. in view of the problems of the above-mentioned conventional thermoplastic polyester elastomer, and has excellent residence stability during melting. It is an object to provide a polyester elastomer composition.

  The inventor of the present invention provides a thermoplastic polyester elastomer (A) 100 weight obtained by bonding a hard segment composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol and a soft segment composed of an aliphatic polycarbonate. Parts, 3 to 20 parts by weight of an epoxy group-containing ethylene copolymer (B), 0.3 to 1.0 parts by weight of a bifunctional or higher epoxy compound (C), and 1 to 5 parts by weight of a carbodiimide compound (D) It has been found that the above-mentioned problems are solved by a polyester elastomer composition obtained by reacting with the above, and the present invention has been completed.

  In this case, the thermoplastic polyester elastomer (A) was heated from room temperature to 300 ° C. at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter and held at 300 ° C. for 3 minutes, and then the temperature falling rate was 100 ° C. The melting point difference (Tm1-Tm3) between the melting point (Tm1) obtained by the first measurement and the melting point (Tm3) obtained by the third measurement when the cycle of lowering the temperature to room temperature at 3 times / min is 0 It is preferably a thermoplastic polyester elastomer having a temperature of 50 ° C. and a tensile strength at cutting of 15 to 100 MPa.

  In this case, the composition preferably has a tensile elongation of 30% or more with respect to the initial tensile elongation after being exposed to an atmosphere of 1 atm and 180 ° C. for 1000 hours. .

In this case, when the thermoplastic polyester elastomer (A) is the hard chain average chain length (x) and soft segment average chain length (y) calculated using the nuclear magnetic resonance (NMR) method, The segment is preferably a thermoplastic polyester elastomer having an average chain length (x) of 5 to 20 and a block property (B) calculated by the following formula (1) of 0.11 to 0.45.
B = 1 / x + 1 / y (1)

In this case, it is preferable that the hard segment is composed of a polybutylene terephthalate unit, and the melting point of the obtained thermoplastic polyester elastomer is 200 to 225 ° C.
Or it is preferable that a hard segment consists of a polybutylene naphthalate unit, and melting | fusing point of the thermoplastic polyester elastomer obtained is 215-240 degreeC.

  In this case, the carbodiimide compound (D) is preferably an aliphatic or alicyclic carbodiimide compound having 2 to 50 carbodiimide groups and an isocyanate group content of 0.5 to 4% by mass.

  In this case, the composition preferably has a melt flow rate (according to JIS K7210: 230 ° C.) of 3 g / 10 min or less.

  The present invention is also a blow molded product or an extrusion molded product formed from the polyester elastomer composition.

  The polyester elastomer composition of the present invention is excellent in heat resistance, heat aging resistance, low temperature characteristics, etc. while maintaining the characteristics of the polyester polycarbonate type elastomer, and has extrusion moldability, blow moldability, etc. The molding processability of has been dramatically improved. In addition, the deterioration of the polymer properties of the thermoplastic polyester elastomer can be prevented as much as possible by molding and recycling.

Hereinafter, the thermoplastic polyester elastomer used in the present invention will be described in detail.
In the thermoplastic polyester elastomer used in the present invention, a normal aromatic dicarboxylic acid is widely used as the aromatic dicarboxylic acid constituting the hard segment polyester, and is not particularly limited, but the main aromatic dicarboxylic acid is terephthalic acid or naphthalene. A dicarboxylic acid is desirable. Other acid components include diphenyl dicarboxylic acid, isophthalic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid, cycloaliphatic dicarboxylic acid, alicyclic dicarboxylic acid such as tetrahydrophthalic anhydride, succinic acid, glutaric acid, adipine Examples thereof include aliphatic dicarboxylic acids such as acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and hydrogenated dimer acid. These are used within a range that does not significantly lower the melting point of the resin, and the amount thereof is less than 30 mol%, preferably less than 20 mol% of the total acid component.

  Further, in the thermoplastic polyester elastomer used in the present invention, the aliphatic or alicyclic diol constituting the hard segment polyester is widely used as a general aliphatic or alicyclic diol, and is not particularly limited. It is desirable to be an alkylene glycol having a number of 2 to 8. Specific examples include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. Most preferred are 1,4-butanediol and 1,4-cyclohexanedimethanol.

  The component constituting the hard segment polyester is preferably a butylene terephthalate unit or a butylene naphthalate unit from the viewpoint of physical properties, moldability, and cost performance.

  Moreover, the aromatic polyester suitable as polyester which comprises the hard segment in the thermoplastic polyester elastomer used by this invention can be easily obtained according to the manufacturing method of a normal polyester. Moreover, what has the number average molecular weight 10000-40000 is desirable for this polyester.

  Moreover, it is preferable that the aliphatic polycarbonate which comprises the soft segment in the thermoplastic polyester elastomer used by this invention mainly consists of a C2-C12 aliphatic diol residue. Examples of these aliphatic diols include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2, 2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,9-nonanediol, 2-methyl-1,8- Examples include octanediol. In particular, aliphatic diols having 5 to 12 carbon atoms are preferable from the viewpoint of flexibility and low temperature characteristics of the obtained thermoplastic polyester elastomer. These components may be used alone or in combination of two or more as required, based on the case described below.

  As the aliphatic polycarbonate diol having good low-temperature characteristics constituting the soft polyester elastomer segment in the present invention, those having a low melting point (for example, 70 ° C. or less) and a low glass transition temperature are preferable. In general, an aliphatic polycarbonate diol composed of 1,6-hexanediol used to form a soft segment of a thermoplastic polyester elastomer has a low glass transition temperature of around -60 ° C and a melting point of around 50 ° C. Good low temperature characteristics. In addition, an aliphatic polycarbonate diol obtained by copolymerizing an appropriate amount of, for example, 3-methyl-1,5-pentanediol with the above aliphatic polycarbonate diol has a glass transition point with respect to the original aliphatic polycarbonate diol. Although the melting point is slightly increased, the melting point is lowered or becomes amorphous, so that it corresponds to an aliphatic polycarbonate diol having good low-temperature characteristics. Moreover, for example, an aliphatic polycarbonate diol composed of 1,9-nonanediol and 2-methyl-1,8-octanediol has a melting point of about 30 ° C. and a glass transition temperature of about −70 ° C., which is sufficiently low. Corresponds to aliphatic polycarbonate diol with good low-temperature properties.

  The above-mentioned aliphatic polycarbonate diol is not necessarily composed of only the polycarbonate component, and may be obtained by copolymerizing a small amount of other glycol, dicarboxylic acid, ester compound or ether compound. Examples of copolymer components include, for example, dimer diols, hydrogenated dimer diols and glycols such as modified products thereof, dicarboxylic acids such as dimer acid and hydrogenated dimer acid, aliphatic, aromatic, and alicyclic dicarboxylic acids Examples thereof include polyesters or oligoesters composed of glycol, polyesters or oligoesters composed of ε-caprolactone, polyalkylene glycol such as polytetramethylene glycol, polyoxyethylene glycol, or oligoalkylene glycol.

  The copolymer component can be used to such an extent that the effect of the aliphatic polycarbonate segment is not substantially lost. Specifically, it is 40 parts by mass or less, preferably 30 parts by mass or less, more preferably 20 parts by mass or less with respect to 100 parts by mass of the aliphatic polycarbonate segment. When the amount of copolymerization is too large, the resulting thermoplastic polyester elastomer has poor heat aging resistance and water resistance.

  As long as the thermoplastic polyester elastomer used in the present invention does not lose the effect of the invention, as a soft segment, for example, polyalkylene glycol such as polyethylene glycol and polyoxytetramethylene glycol, polyester such as polycaprolactone and polybutylene adipate, etc. The copolymer component may be introduced. The content of the copolymer component is usually 40 parts by mass or less, preferably 30 parts by mass or less, and more preferably 20 parts by mass or less with respect to 100 parts by mass of the soft segment.

  In the thermoplastic polyester elastomer used in the present invention, the mass part ratio of the polyester constituting the hard segment and the aliphatic polycarbonate and copolymer component constituting the soft segment is generally hard segment: soft segment = 30: 70 to 95: 5, preferably 40:60 to 90:10, more preferably 45:55 to 87:13, and most preferably 50:50 to 85:15.

The thermoplastic polyester elastomer used in the present invention is composed of a hard segment composed of polyester composed of the above aromatic dicarboxylic acid and an aliphatic or alicyclic diol and a soft segment composed mainly of aliphatic polycarbonate. A polyester elastomer. Here, the term “bonded” means that the hard segment and the soft segment are not bonded by a chain extender such as an isocyanate compound, but the units constituting the hard segment and the soft segment are directly bonded by an ester bond or a carbonate bond. The state is preferable.
For example, it is preferable to obtain the polyester constituting the hard segment, the polycarbonate constituting the soft segment, and if necessary, various copolymerization components while melting and repeating the transesterification reaction and depolymerization reaction for a certain period of time (hereinafter referred to as blocking reaction). Sometimes called).

  The blocking reaction is preferably performed at a temperature within the range of the melting point of the polyester constituting the hard segment to the melting point + 30 ° C. In this reaction, the concentration of the active catalyst in the system is arbitrarily set according to the temperature at which the reaction is carried out. That is, since the transesterification and depolymerization proceed rapidly at higher reaction temperatures, it is desirable that the active catalyst concentration in the system be low, and that there is some concentration of active catalyst at lower reaction temperatures. It is desirable that

  The catalyst may be an ordinary catalyst such as titanium compounds such as titanium tetrabutoxide and potassium oxalate titanate, or one or more tin compounds such as dibutyltin oxide and monohydroxybutyltin oxide. The catalyst may be pre-existing in the polyester or polycarbonate, in which case it need not be added anew. Furthermore, the catalyst in the polyester or polycarbonate may be partially or substantially completely deactivated in advance by any method. For example, when titanium tetrabutoxide is used as a catalyst, for example, phosphorous acid, phosphoric acid, triphenyl phosphate, tristriethylene glycol phosphate, orthophosphoric acid, carbethoxydimethyl diethyl phosphonate, triphenyl phosphite, trimethyl phosphate, trimethyl phosphite, etc. The deactivation is performed by adding a phosphorus compound or the like, but is not limited thereto.

  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 optimum value of the reaction conditions is, for example, when the melting point of the obtained chain extension polymer and the melting point of the polyester used as the hard segment are compared, and the difference is 2 ° C to 60 ° C. When the difference in melting point is less than 2 ° C., both segments are not mixed or / and reacted, and the resulting polymer exhibits inferior elastic performance. On the other hand, when the difference in melting point exceeds 60 ° C., the block property of the obtained polymer is lowered due to the remarkable progress of the transesterification reaction, and crystallinity, elastic performance and the like are lowered.

  It is desirable that the remaining catalyst in the molten mixture obtained by the above reaction is deactivated as completely as possible by any method. When the catalyst remains more than necessary, it is considered that the transesterification further proceeds during compounding or molding, and the physical properties of the obtained polymer fluctuate.

  This deactivation reaction is carried out in the above-described manner, for example, phosphorous acid, phosphoric acid, triphenyl phosphate, tristriethylene glycol phosphate, orthophosphoric acid, carboxydimethyl diethyl phosphonate, triphenyl phosphite, trimethyl phosphate, trimethyl phosphite, etc. Although it is carried out by adding a phosphorus compound or the like, it is not limited to this.

  The thermoplastic polyester elastomer used in the present invention may contain a trifunctional or higher polycarboxylic acid or polyol only in a small amount. For example, trimellitic anhydride, benzophenone tetracarboxylic acid, trimethylolpropane, glycerin and the like can be used.

  Hereinafter, the epoxy group-containing ethylene copolymer (B), bifunctional or higher functional epoxy compound (C), and carbodiimide compound (D) used in the present invention will be described.

The epoxy group-containing ethylene copolymer (B) is 3 to 20 parts by weight with respect to 100 parts by weight of the thermoplastic polyester elastomer (A). 5 to 15 parts by weight is preferred.
The epoxy group-containing ethylene copolymer (B) is an ethylene-vinyl acetate copolymer or ethylene-methyl acrylate copolymerized with glycidyl acrylate or glycidyl methacrylate. There are various grades of name bond first. Alternatively, ethylene is a copolymer of acrylic acid. Specifically, there are various grades under the trade name Yucaron of Mitsubishi Chemical.

The bifunctional or higher functional epoxy compound (C) is 0.3 to 1.0 part by weight with respect to 100 parts by weight of the thermoplastic polyester elastomer (A). 0.35-0.7 weight part is preferable and 0.4-0.6 weight part is more preferable.
The bifunctional or higher functional epoxy compound (C) may be any compound having two or more epoxy groups or glycidyl groups in the molecule. For example, bisphenol A / epichloro epoxy resin, sorbitol polyglycidyl ether, polyglycerol Polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trityrolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol glycidyl ether, polyethylene glycol glycidyl ether Ether, propylene glycol glycidyl ether, polypyrene glycol diglycidyl ether, tris (2,3-epoxy Shipuropiru) isocyanurate and the like.

The carbodiimide compound (D) is 1 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic polyester elastomer (A). 1.5 to 3 parts by weight is preferred.
The carbodiimide compound (D) may be any compound containing at least two carbodiimide groups in the molecule, such as aromatic polycarbodiimide (for example, Stabuzol P, Stabuzol P-100 manufactured by Rheinhemy), Aliphatic (alicyclic) polycarbodiimides (for example, LA-1 manufactured by Nisshinbo Industries, Inc.) can be mentioned. These carbodiimide compounds may be used alone or in combination of two or more.

  Furthermore, the thermoplastic polyester elastomer 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, metal deactivators, organic and inorganic nucleating agents, neutralizing agents, antacids, antibacterial agents, fluorescent brighteners, fillers, flame retardants, difficult Flame retardants, organic and inorganic pigments and the like can be added.

  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 thermoplastic polyester elastomer.

  The thermoplastic polyester elastomer used in the present invention was heated from room temperature to 300 ° C. at a heating rate of 20 ° C./min using a differential scanning calorimeter of the thermoplastic polyester elastomer, and held at 300 ° C. for 3 minutes. The melting point difference (Tm1−Tm3) between the melting point (Tm1) obtained by the first measurement and the melting point (Tm3) obtained by the third measurement when the cycle of lowering the temperature to room temperature at a temperature lowering rate of 100 ° C./min is repeated three times. ) Is 0 to 50 ° C. The melting point difference is more preferably 0 to 40 ° C, further preferably 0 to 30 ° C. The melting point difference is a measure of the blockability retention of the thermoplastic polyester elastomer. The smaller the temperature difference, the better the blockability retention. When the difference in melting point exceeds 50 ° C., the blockability retention is deteriorated, the quality fluctuation at the time of molding is increased, and the uniformity of the quality of the molded product is deteriorated and the recyclability is deteriorated.

  By satisfy | filling the said characteristic, the effect of the outstanding block property which the thermoplastic polyester elastomer used by the below-mentioned this invention has can be utilized effectively.

  In the thermoplastic polyester elastomer used in the present invention, it is preferable that the hard segment is composed of a polybutylene terephthalate unit and the melting point is 200 to 225 ° C. 205-225 degreeC is more preferable.

  Moreover, in the thermoplastic polyester elastomer used by this invention, it is preferable that a hard segment consists of a polybutylene naphthalate unit and melting | fusing point of the thermoplastic polyester elastomer obtained is 215-240 degreeC. 220-240 degreeC is more preferable.

  When the hard segment is a polybutylene terephthalate unit or a polybutylene naphthalate unit, a commercially available polyester such as polybutylene terephthalate or polybutylene naphthalate can be used, which is advantageous in terms of economy.

  Moreover, when the melting point of the thermoplastic polyester elastomer used in the present invention is less than the above lower limit, the block property is lowered, and the heat resistance and mechanical properties of the thermoplastic polyester elastomer are deteriorated. On the other hand, when the above upper limit is exceeded, the compatibility between the hard segment and the soft segment is lowered, and the mechanical properties of the thermoplastic polyester elastomer are deteriorated, which is not preferable.

  The thermoplastic polyester elastomer used in the present invention has a polyester unit as a hard segment and an aliphatic polycarbonate unit as a ft segment. The average value of the number of repeating units constituting one homopolymer structural unit is an average chain. In the present specification, unless otherwise indicated, values calculated using a nuclear magnetic resonance method (NMR method) are shown.

When the average chain length (x) of the hard segment and the average chain length (y) of the soft segment calculated using the nuclear magnetic resonance method (NMR method) are used, the average chain length (x) of the hard segment is 5 to 20 It is preferable that the block property (B) calculated by the following formula (1) is 0.11 to 0.45.
B = 1 / x + 1 / y (1)

  As for the thermoplastic polyester elastomer used by this invention, the average chain length of the polyester unit which is a hard segment structural component has preferable 5-20. More preferably, it is 7-18, More preferably, it is the range of 9-16.

  In the thermoplastic polyester elastomer used in the present invention, the average chain length (x) of the polyester unit of the hard segment is an important factor that determines the block property of the thermoplastic polyester elastomer, and is determined by the melting point of the thermoplastic polyester elastomer. It has a big impact. Generally, as the average chain length (x) of the polyester units increases, the melting point of the thermoplastic polyester elastomer also increases. Further, the average chain length (x) of the polyester units of the hard segment is a factor that affects the mechanical properties of the thermoplastic polyester elastomer. When the average chain length (x) of the polyester unit of the hard segment is less than 5, it means that randomization has progressed, and the mechanical properties such as the decrease in heat resistance due to the decrease in melting point, hardness, tensile strength, elastic modulus, etc. Degradation of properties is large. When the average chain length (x) of the polyester unit of the hard segment is large, the compatibility with the aliphatic carbonate diol constituting the soft segment is lowered, causing phase separation, greatly affecting the mechanical properties, and its strength. , Reduce the elongation.

Moreover, it is preferable that block property (B) is 0.11-0.45. 0.13-0.40 is more preferable and 0.15-0.35 is still more preferable. As the value increases, the block property decreases. When the block property exceeds 0.4, the polymer properties such as the melting point of the thermoplastic polyester elastomer being lowered due to the block property decline are not preferable. On the other hand, if it is less than 0.10, the compatibility between the hard segment and the soft segment is lowered, causing deterioration of mechanical properties such as strong elongation and bending resistance of the thermoplastic polyester elastomer and an increase in fluctuation of the properties. Therefore, it is not preferable.
Here, the block property is calculated by the following equation (1).
B = 1 / x + 1 / y (1)

From the above relationship, the average chain length (y) of the soft segment is preferably 4-15.
Only when the above block property is satisfied, it is possible to achieve both high heat resistance and mechanical properties.

In the thermoplastic polyester elastomer used in the present invention, the method for bringing the above-described blockability retention and blockability into the above ranges is not limited, but it is preferable to optimize the molecular weight of the polycarbonate diol as a raw material. That is, it is preferably produced by reacting the polyester constituting the hard segment in the thermoplastic polyester elastomer used in the present invention with an aliphatic polycarbonate diol having a molecular weight of 5000 to 80000 in a molten state. The larger the molecular weight of the aliphatic polycarbonate diol, the higher the block property retention and the block property. The polycarbonate diol has a number average molecular weight of preferably 5000 or more, more preferably 7000 or more, and still more preferably 10,000 or more. The upper limit of the molecular weight of the polycarbonate diol is preferably 80000 or less, more preferably 70000 or less, and even more preferably 60000 or less, from the viewpoint of compatibility between the hard segment and the soft segment. If the molecular weight of the polycarbonate diol is too large, the compatibility is lowered, phase separation occurs, the mechanical properties are greatly affected, and the strength and elongation are lowered.
The tensile strength at the time of cutting of the thermoplastic polyester elastomer used in the present invention is 15 to 100 MPa, preferably 20 to 60 MPa.

  The thermoplastic polyester elastomer used in the present invention preferably has a flexural modulus of 1000 MPa or less. The flexural modulus is more preferably 800 MPa or less, and further preferably 600 MPa or less. When the flexural modulus exceeds 1000 MPa, the flexibility of the thermoplastic polyester elastomer is insufficient, which is not preferable. The lower limit is preferably 50 MPa or more, more preferably 80 MPa or more, and further preferably 100 MPa or more. If the pressure is less than 50 MPa, the thermoplastic polyester elastomer is too soft to ensure the strength of the product.

  In addition, what has the number average molecular weight 10000-40000 is desirable for the aromatic polyester suitable as polyester which comprises the hard segment in the thermoplastic polyester elastomer used by this invention.

  The method for optimizing the molecular weight of the polycarbonate diol is not limited. An optimal molecular weight may be purchased or prepared, or a molecular weight adjusted by increasing the molecular weight in advance with a low molecular weight polycarbonate diol and a chain extender such as diphenyl carbonate or diisocyanate may be used. .

  For example, as a method for producing the above high molecular weight aliphatic polycarbonate diol, the above aliphatic diol and the following carbonates, that is, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, dimethyl carbonate, diphenyl carbonate It can obtain by making it react.

  Another method for producing a high molecular weight aliphatic polycarbonate diol is to react a low molecular weight aliphatic polycarbonate diol with dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, dimethyl carbonate, diphenyl carbonate, etc. This is also possible.

The present invention will be illustrated by the following examples, but the present invention is not limited thereto.
The thermoplastic polyester elastomer used in the present invention is formed from a melt by a usual molding technique such as injection molding, flat film extrusion, extrusion blow molding, or coextrusion.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but is not limited thereto. In this specification, each measurement was performed according to the following method.
(1) Reduced viscosity of thermoplastic polyester elastomer used in the present invention 0.05 g of thermoplastic polyester elastomer was dissolved in 25 mL of a mixed solvent (phenol / tetrachloroethane = 60/40) and measured at 30 ° C. using an Ostwald viscometer. did.

(2) Melting point (Tm) of the thermoplastic polyester elastomer used in the present invention
Thermoplastic polyester elastomer dried under reduced pressure at 50 ° C. for 15 hours was measured by using a differential scanning calorimeter DSC-50 (manufactured by Shimadzu Corporation) at a rate of 20 ° C./min from the room temperature. did.
In addition, 10 mg of a measurement sample was weighed in an aluminum pan (TA Instruments, product number 900793.901), sealed with an aluminum lid (TA Instruments, product number 900794.901), and measured in an argon atmosphere. .

(3) Tensile strength and elongation at the time of cutting of the thermoplastic polyester elastomer composition of the present invention The tensile strength and elongation at the time of cutting of the thermoplastic polyester elastomer composition of the present invention were measured according to JIS K 6251. The test piece was injection-molded into a 100 mm × 100 mm × 2 mm flat plate at a cylinder temperature (Tm + 20 ° C.) and a mold temperature of 30 ° C. using an injection molding machine (model-SAV, manufactured by Yamashiro Seiki Co., Ltd.), and then a dumbbell shape. A No. 3 test piece was punched from a flat plate.

(4) Melt viscosity (MFR)
Based on the test method (Method A) described in JIS K7210, the melt flow rate (MFR: g / 10 minutes) at a measurement temperature of 230 ° C. and a load of 2160 g was measured. Further, the difference (ΔMFR: MFR ₃₅ −MFR ₅ ) between the MFR value (MFR ₃₅ ) 35 minutes after the resin was added and the MFR value (MFR ₅ ) after 5 minutes was measured. For the measurement, a composition having a moisture content of 0.1 parts by weight or less was used.

[Evaluation by direct blow molding]
The cylinder temperature of a direct blow molding machine (single screw extruder: L / D = 25, full flight screw, screw diameter 65 mm) was set to 180 to 230 ° C. to produce a direct blow molding bottle. A parison forming die lip was attached to the tip of the cylinder, and blow air was sealed in the mold to continuously produce bottles. At this time, the parison holding state and product dimensional accuracy were evaluated according to the following criteria.

(5) Parison holding state:
○: The drawdown is very small and the shape is maintained. △: The drawdown is large and the shape collapses, but it can be blown somehow. ×: The drawdown is large and the shape collapses and cannot be blown.

(6) Gelled product generation test In the direct blow molding, after stopping for 20 minutes in a state where the molten resin was retained in the accumulator, the parison was extruded again, and the presence or absence of the gelled product of the parison was determined according to the following criteria.
○: No gelled product is observed Δ: Gelated product is slightly observed ×: Gelated product is remarkably recognized

(7) Average chain length and block property of hard segment and soft segment (when the glycol component of the polyester is butanediol and the glycol in the aliphatic polycarbonate diol is an aliphatic diol having 5 to 12 carbon atoms)
[NMR measurement]
Apparatus: Fourier transform nuclear magnetic resonance apparatus (AVANCE500 manufactured by BRUKER)
Measuring solvent: Deuterated chloroform Sample solution concentration: 3-5 vol%
¹ H resonance frequency: 500.13 MHz
Detection pulse flip angle: 45 °
Data acquisition time: 4 seconds Delay time: 1 second Integration count: 50-200 times Measurement temperature: Room temperature

〔Method of calculation〕
The H-NMR integrated value (in arbitrary units) of the methylene peak adjacent to oxygen in the aromatic dicarboxylic acid-butanediol-butanediol of the aromatic dicarboxylic acid chain is defined as A.
The H-NMR integrated value (unit is arbitrary) of the peak of the methylene adjacent to oxygen closer to carbonic acid of butanediol of the aromatic dicarboxylic acid-butanediol-carbonic acid chain is defined as C.
H-NMR integrated value (unit is arbitrary) of the peak of methylene adjacent to oxygen closer to the aromatic dicarboxylic acid of aromatic dicarboxylic acid-C5-C12 aliphatic diol-carbonic acid chain hexanediol And
The H-NMR integrated value (unit is arbitrary) of the methylene peak adjacent to oxygen of the carbonic acid-aliphatic diol having 5 to 12 carbon atoms-aliphatic diol having 5 to 12 carbon atoms in the carbonic acid chain is defined as D.
Hard segment average chain length (x) is
x = ((((A / 4) + (C / 2)) / ((B / 2) + (C / 2)))) × 2.
Soft segment average chain length (y) is
y = (((D / 4) + (B / 2)) / ((B / 2) + (C / 2)))) × 2.
The block property (B) was calculated by the following equation (1) from the values of x and y obtained by the above method. The smaller the value of B, the higher the block property.
B = 1 / x + 1 / y (1)

(8) Retainability of block property 10 mg of the thermoplastic polyester elastomer used in the present invention dried under reduced pressure at 50 ° C. for 15 hours in an aluminum pan (TA Instruments, product number 900793.901), and an aluminum lid (TA After making a sealed state with Instruments, product number 900794.901) and adjusting the measurement sample, using a differential scanning calorimeter DSC-50 (manufactured by Shimadzu Corporation), a heating rate of 20 ° C./min under a nitrogen atmosphere The temperature was raised from room temperature to 300 ° C. and held at 300 ° C. for 3 minutes, and then the measurement sample pan was taken out, immersed in liquid nitrogen and rapidly cooled. Thereafter, the sample was taken out from the liquid nitrogen and left at room temperature for 30 minutes. The measurement sample pan is set on a differential scanning calorimeter and allowed to stand at room temperature for 30 minutes, and then the temperature is raised again from room temperature to 300 ° C. at a temperature rising rate of 20 ° C./min. The melting point difference (Tm1−Tm3) between the melting point (Tm1) obtained by the first measurement when this cycle is repeated three times and the melting point (Tm3) obtained by the third measurement is obtained, and the melting point difference is determined as a block property. Retainability. The smaller the temperature difference, the better the blockability retention.
Based on the melting point difference evaluated by the above method, the blockability retention was determined and displayed according to the following criteria.
A: Melting point difference 0 to less than 30 ° C. ○: Melting point difference 30 to less than 40 ° C. Δ: Melting point difference 40 to less than 50 ° C. ×: Melting point difference 50 ° C. or more

(9) Molecular weight of aliphatic polycarbonate diol An aliphatic polycarbonate diol sample was dissolved in deuterated chloroform (CDCl ₃ ), and the end group was determined by measuring H-NMR in the same manner as described in (7) above. It calculated and calculated | required with the following formula.
Molecular weight = 1000000 / ((Terminal group weight (equivalent / ton)) / 2)
(10) Number average molecular weight (Mn) of aromatic polyester
The value was calculated according to the following formula using the value of reduced viscosity (ηsp / c) determined by the same method as that for measuring the reduced viscosity of the thermoplastic polyester elastomer.
ηsp / c = 1.919 × 10 ⁻⁴ × Mn ^0.8929 −0.0167

[Method for producing aliphatic polycarbonate diol]
Method for producing aliphatic polycarbonate diol (molecular weight 10,000):
Aliphatic polycarbonate diol (Ube Industries, Ltd. carbonate diol UH-CARB200, molecular weight 2000, 1,6-hexanediol type) 100 parts by mass and diphenyl carbonate 8.6 parts by mass were respectively charged and reacted at a temperature of 205 ° C. and 130 Pa. It was. After 2 hours, the contents were cooled and the polymer was removed. The molecular weight was 10,000.

Method for producing aliphatic polycarbonate diol (molecular weight 20000):
Aliphatic polycarbonate diol (Ube Industries, Ltd. carbonate diol UH-CARB200, molecular weight 2000, 1,6-hexanediol type) 100 parts by mass and diphenyl carbonate 9.6 parts by mass were respectively charged and reacted at a temperature of 205 ° C. and 130 Pa. It was. After 2 hours, the contents were cooled and the polymer was removed. The molecular weight was 20000.

Method for producing aliphatic copolymer polycarbonate diol (molecular weight 10,000):
Aliphatic copolymer polycarbonate diol (Asahi Kasei Chemicals carbonate diol T5652, molecular weight 2000, copolymer of 1,6-hexanediol and 1,5-pentanediol, amorphous) 100 parts by mass and diphenyl carbonate 8.6 Each mass part was charged and reacted at a temperature of 205 ° C. and 130 Pa. After 2 hours, the contents were cooled and the polymer was removed. The molecular weight was 10,000.

Production method of aliphatic polycarbonate diol (molecular weight 85000) Aliphatic polycarbonate diol (Ube Industries, Ltd. carbonate diol UH-CARB200, molecular weight 2000, 1,6-hexanediol type) and diphenyl carbonate were each 100 parts by mass and 10.7. Polymerization was advanced at a temperature of 205 ° C. and 130 Pa by charging a mass part. After 2 hours and 45 minutes, the contents were cooled and the polymer was removed. The molecular weight was 85000.

[Method for producing thermoplastic polyester elastomer]
Method for producing thermoplastic polyester elastomer A:
100 parts by mass of polybutylene terephthalate (PBT) having a number average molecular weight of 30000 and 43 parts by mass of a polycarbonate diol having a number average molecular weight of 10,000 prepared by the above method are stirred at 230 ° C. to 245 ° C. under 130 Pa for 1 hour, After confirming that it became transparent, the content was taken out and cooled to obtain a polymer (thermoplastic polyester elastomer A).

Method for producing thermoplastic polyester elastomer B:
100 parts by weight of polybutylene terephthalate (PBT) having a number average molecular weight of 30000 and 43 parts by weight of a polycarbonate diol having a number average molecular weight of 20000 prepared by the above method were stirred at 230 ° C. to 245 ° C. under 130 Pa for 1.5 hours, After confirming that the resin became transparent, the contents were taken out and cooled to obtain a polymer (thermoplastic polyester elastomer B). It had the same quality as the thermoplastic polyester elastomer A and was of high quality.

Production method of thermoplastic polyester elastomer C:
100 parts by mass of polybutylene terephthalate (PBT) having a number average molecular weight of 30,000 and 43 parts by mass of an aliphatic copolymer polycarbonate diol having a number average molecular weight of 10,000 prepared by the above method are stirred at 230 ° C. to 245 ° C. under 130 Pa for 1 hour. After confirming that the resin became transparent, the contents were taken out and cooled to obtain a polymer (thermoplastic polyester elastomer C). It had the same quality as the thermoplastic polyester elastomer A and was of high quality. Moreover, compared with the case where the polycarbonate diol which consists of 1, 6- hexanediol is used as a soft segment, it is excellent in the low temperature characteristic.

Production Method of Thermoplastic Polyester Elastomer D 245 ° C. to 260 ° C., 130 Pa, 100 parts by mass of polybutylene naphthalate (PBN) having a number average molecular weight of 30000 and 43 parts by mass of a polycarbonate diol having a number average molecular weight of 10,000 prepared by the above method. Under stirring for 1 hour, it was confirmed that the resin became transparent, and the contents were taken out and cooled to obtain a polymer (thermoplastic polyester elastomer D). The thermoplastic polyester elastomer A had the same blockability and blockability retention, and had a higher melting point than the thermoplastic polyester elastomer A, and was of higher quality.

[Examples 1-8, Comparative Examples 1-6]
The obtained thermoplastic polyester elastomer was dried under reduced pressure at 100 ° C. for 8 hours, and then pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4) with respect to 100 parts by mass of the thermoplastic polyester elastomer pellets. -Hydroxyphenyl) propionate], 0.5 parts by weight of pentaerythritol tetrakis (3-laurylthiopropionate), 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) ) 0.50 parts by weight of benzotriazole, 0.2 parts by weight of 2-phenylimidazoline, and the compounds shown in Tables 1 and 2 were blended and granulated using a twin screw extruder to obtain a polyester elastomer composition. Obtained.

  As can be seen from Tables 1 and 2, the polyester elastomer compositions of the examples have improved melt viscosity reduction and parison drawdown, which are problems in blow molding, and high quality blow molding with less gelation. Goods can be obtained.

  The polyester elastomer composition of the present invention is excellent in heat resistance, heat aging resistance, low temperature characteristics, etc. while maintaining the characteristics of the polyester polycarbonate type elastomer, and has extrusion moldability, blow moldability, etc. The molding processability of has been dramatically improved. Therefore, since the thermoplastic polyester elastomer composition of the present invention has the above-mentioned excellent characteristics and advantages, it is useful for blow molding products such as automobiles and home appliance parts that require heat resistance, heat aging resistance, and low temperature characteristics. is there. In particular, the present invention is useful for blow molded product applications that require flexibility such as constant velocity joint boots, suspension boots, rack and pinion boots, air ducts, and the like, which have excellent durability under high temperature environments.

Claims (10)

100 parts by weight of a thermoplastic polyester elastomer (A) formed by bonding a hard segment composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol, a soft segment composed of an aliphatic polycarbonate, and an epoxy group 3 to 20 parts by weight of the ethylene-based copolymer compound (B), 0.3 to 1.0 part by weight of a bifunctional or higher functional epoxy compound (C), and 1 to 5 parts by weight of a carbodiimide compound (D) are reacted. A polyester elastomer composition characterized by comprising: The thermoplastic polyester elastomer (A) was heated from room temperature to 300 ° C. at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter, held at 300 ° C. for 3 minutes, and then cooled to room temperature at a temperature falling rate of 100 ° C./min. The melting point difference (Tm1−Tm3) between the melting point (Tm1) obtained by the first measurement and the melting point (Tm3) obtained by the third measurement when the cycle of lowering the temperature to 3 times is repeated is 0 to 50 ° C. The polyester elastomer composition according to claim 1, which is a thermoplastic polyester elastomer having a tensile strength at the time of cutting of 15 to 100 MPa. The tensile elongation after being exposed to a normal atmosphere of 1 atm and 180 ° C for 1000 hours has a retention rate of 30% or more with respect to the initial tensile elongation. Polyester elastomer composition. When the thermoplastic polyester elastomer (A) has an average chain length (x) of hard segments and an average chain length (y) of soft segments calculated using a nuclear magnetic resonance method (NMR method), the average chain of hard segments 2. A thermoplastic polyester elastomer having a length (x) of 5 to 20 and a block property (B) calculated by the following formula (1) of 0.11 to 0.45. The polyester elastomer composition in any one of -3.
B = 1 / x + 1 / y (1) The polyester elastomer composition according to any one of claims 1 to 4, wherein the hard segment comprises a polybutylene terephthalate unit, and the thermoplastic polyester elastomer obtained has a melting point of 200 to 225 ° C. The polyester elastomer composition according to any one of claims 1 to 4, wherein the hard segment comprises a polybutylene naphthalate unit, and the thermoplastic polyester elastomer obtained has a melting point of 215 to 240 ° C.   The carbodiimide compound (D) is an aliphatic or alicyclic carbodiimide compound having 2 to 50 carbodiimide groups and an isocyanate group content of 0.5 to 4% by mass. 7. The polyester elastomer composition according to any one of 6. The polyester elastomer composition according to any one of claims 1 to 7, wherein a melt flow rate (conforming to JIS K7210: 230 ° C) is 3 g / 10 min or less. A blow molded product molded from the polyester elastomer composition according to claim 1. The extrusion molded product shape | molded from the polyester elastomer composition in any one of Claims 1-8.