JP2009298923A - Thermoplastic polyester elastomer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester elastomer having excellent heat resistance in addition to elastic characteristics. <P>SOLUTION: A polyester elastomer wherein its hard segment comprises a dicarboxylic acid component and a 2-10C glycol component, 5-100 mol% of the dicarboxylic acid component is a 6, 6'-(alkylenedioxy)di-2-naphthoic acid component, its soft segment is a poly(alkylene oxide) glycol component of a number-average molecular weight of 500-5,000, and the weight ratio between the hard segment component and the soft segment component is 20/80-80/20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyester elastomer having excellent heat resistance in addition to elastic properties.

  As thermoplastic polyester elastomers, polyether ester elastomers (patent document 1, patent document 2) having polybutylene terephthalate (PBT) units as hard segments and polytetramethylene glycol (PTMG) as soft segments have been used. Polyester ester elastomers with segments, polycaprolactone (PCL) units as soft segments (Patent Document 3, Patent Document 4, Patent Document 5), and polyester ester elastomers with PBT units as hard segments and dimer fatty acids as soft segments ( Patent document 6) etc. are known and put into practical use. However, when PBT is used for the hard segment, since the melting point of PBT is 230 ° C. or less, the melting point as an elastomer does not exceed 230 ° C.

  Recently, attempts have been made to apply molded articles of thermoplastic polyester elastomers to parts that are used in very hot atmospheres, such as, for example, automotive engine rooms. Therefore, further heat resistance is required for the molded article of the thermoplastic polyester elastomer. It is possible to obtain a thermoplastic polyester elastomer having a melting point exceeding 240 ° C. by increasing the ratio of the hard segment having a higher melting point than that of the conventionally proposed thermoplastic elastomer. However, as described above, when the ratio of the hard segment is increased, it becomes difficult to obtain the elasticity inherent to the elastomer. In addition, even if it exhibits a certain degree of elasticity, there is a large decrease in elasticity due to thermal degradation, and the molded product does not show proper stretchability in a high-temperature atmosphere. This causes problems such as

  Patent Document 7 describes the use of a hard segment having a high melting point (290 ° C.) such as polycyclohexanedimethylene terephthalate for the purpose of improving these points. However, even in this elastomer, even when the hard segment contained 40 wt%, the melting point was as low as 220 ° C., and there was still a problem in heat resistance.

  Furthermore, these thermoplastic polyester elastomer molded products can be processed using a general-purpose molding machine because the melting point of the polymer is low when the polyalkylene glycol component, which is a soft segment, is increased in order to improve the elastic recovery rate. It was difficult. In order to form a sufficiently strong physical crosslink using PBT in a conventional hard segment, as much as 40 wt% PBT is required. Furthermore, it is inferior in flexibility and rubberiness. As a means for solving the problems of the polyester elastomer, a method for improving the elastic properties by increasing the crystallinity of the hard segment has been proposed.

  Patent Document 7 discloses a polyester elastomer using naphthalenedicarboxylic acid or biphenyldicarboxylic acid as an acid component constituting a hard segment and 1,3-propanediol as a diol component constituting a hard segment. However, with this elastomer, the elastic properties at the time of large elongation cannot be greatly improved.

  Patent Documents 8 and 9 disclose a composition in which a crystal nucleating agent is blended with a polyester elastomer. However, the polymer composition having such a high degree of crystallinity still has insufficient elastic recovery properties for use as an elastic body.

Japanese Patent Publication No.49-48195 Japanese Patent Publication No.49-31558 Japanese Patent Publication No. 48-4116 JP 59-12926 A JP 59-15117 A JP 54-127955 A JP-A-5-202176 JP-A-4-370219 JP 59-45349 JP 59-45350 A

  An object of the present invention is to provide a polyester elastomer that maintains good heat resistance and excellent elasticity.

（Ｒは炭素数２から１０のアルキレン基）
で表されるポリエステル成分であり、ソフトセグメントは数平均分子量が５００〜５０００のポリ（アルキレンオキシド）グリコール成分であって、ハードセグメント成分とソフトセグメント成分の重量比が２０／８０〜８０／２０であるポリエステルエラストマーである。 The present inventors have found that the above problems can be solved by a polyester elastomer having a specific polyester component as a hard segment, and have reached the present invention. That is, in the present invention, the hard segment is composed of a dicarboxylic acid component and a glycol component having 2 to 10 carbon atoms, and 5 to 100 mol% of the dicarboxylic acid component is represented by the following formula (1).

(R is an alkylene group having 2 to 10 carbon atoms)
The soft segment is a poly (alkylene oxide) glycol component having a number average molecular weight of 500 to 5000, and the weight ratio of the hard segment component to the soft segment component is 20/80 to 80/20 It is a certain polyester elastomer.

  The polyester elastomer of the present invention has excellent heat resistance in addition to elastic properties. The polyester elastomer of the present invention has a practical melting point even if a large amount of a soft segment component such as polytetramethylene glycol is used for the purpose of increasing the elastic recovery rate, has excellent elastic recoverability, and is easy to process. Can provide polyester elastomers with excellent operability during processing.

（Ｒは炭素数２から１０のアルキレン基）
で表されることを特徴とするポリエステル成分であり、ソフトセグメントは数平均分子量が５００〜５０００のポリ（アルキレンオキシド）グリコール成分であって、ハードセグメント成分とソフトセグメント成分の重量比が２０／８０〜８０／２０であるポリエステルエラストマーである。 In the present invention, the hard segment is composed of a dicarboxylic acid component and a glycol component having 2 to 10 carbon atoms, and 5 to 100 mol% of the dicarboxylic acid component is represented by the following formula (1).

(R is an alkylene group having 2 to 10 carbon atoms)
The soft segment is a poly (alkylene oxide) glycol component having a number average molecular weight of 500 to 5000, and the weight ratio of the hard segment component to the soft segment component is 20/80. A polyester elastomer that is ˜80 / 20.

（ｎは１〜３）
で表される。さらに具体的には下記式（１）−２

で表される６，６’−（エチレンジオキシ）ジ−２−ナフトエ酸成分である事が好ましい。 In the 6,6 ′-(alkylenedioxy) di-2-naphthoic acid component represented by the above formula (1), the alkylene group represented by R is preferably a linear aliphatic hydrocarbon group, Furthermore, the number of methylene groups is preferably an even number. More preferably, the following formula (1) -1

(N is 1-3)
It is represented by More specifically, the following formula (1) -2

It is preferable that it is a 6,6'- (ethylenedioxy) di-2-naphthoic acid component represented by these.

  The polyester constituting the hard segment preferably has a melting point of 260 to 300 ° C. When using such a high melting point polyester, it has a practical melting point even if a large amount of soft segment components such as polytetramethylene glycol is used for the purpose of increasing the elastic recovery rate, has excellent elastic recovery properties, and is processed. A polyester elastomer having excellent properties can be obtained. In particular, poly {ethylene 6,6 ′-(ethylenedioxy) di-2-naphthoate} polymerized from 6,6 ′-(ethylenedioxy) di-2-naphthoic acid and ethylene glycol has a melting point of 300 ° C. It has good crystallinity and can be suitably used as a hard segment.

  On the other hand, when a polyester having a melting point exceeding 300 ° C. is used for the hard segment, the polymerization reaction temperature becomes high, so that the polytetramethylene glycol as the soft segment component is thermally decomposed during the reaction, which is not preferable.

  In addition to the 6,6 ′-(alkylenedioxy) di-2-naphthoic acid component represented by the above formula (1), the polyester constituting the hard segment in the present invention includes an aromatic dicarboxylic acid, an alicyclic carboxylic acid, It is possible to copolymerize the main constituents of aliphatic carboxylic acid or diol within a range that does not impair the object of the present invention.

  The 6,6 ′-(alkylenedioxy) di-2-naphthoic acid component represented by the above formula (1) is 5 to 100 mol% of the dicarboxylic acid component, preferably 30 to 100 mol%, More preferably, it is 50-100 mol%.

  The dicarboxylic acid component other than the 6,6 ′-(alkylenedioxy) di-2-naphthoic acid component constituting the polyester component is, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4- Naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, benzophenone dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 3,3'-diphenyldicarboxylic acid, 4,4'-diphenyl ether Terdicarboxylic acid, 4,4′-diphenylsulfone dicarboxylic acid and the like can be used, and among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid can be preferably used. As the alicyclic dicarboxylic acid component, for example, hexahydroterephthalic acid, 1,3-adamantane dicarboxylic acid, cyclohexane dicarboxylic acid, or the like can be used. As the aliphatic dicarboxylic acid component, for example, adipic acid, succinic acid, azelaic acid, suberic acid, sebacic acid, dodecanedioic acid and the like can be used. These acid components may be used alone or in combination of two or more, and further, a part of an oxyacid such as hydroxyethoxybenzoic acid may be copolymerized.

  Examples of the glycol component having 2 to 10 carbon atoms constituting the polyester component include chlorohydroquinone, methylhydroquinone, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenylsulfone, and 4,4′-dihydroxydiphenyl. Aromatic diols such as sulfide, 4,4'-dihydroxybenzophenone and p-xylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1 , 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol And the like, and 2,2′-bis (4′-β-hydroxyethoxyphenyl) propane and the like can be used. Among them, ethylene glycol, 1,4-butanedio- , 1,4-cyclohexanedimethanol, diethylene glycol, and particularly preferably ethylene glycol can be used. These diol components may be used alone or in combination of two or more. The polyester of the present invention includes a polymonofunctional compound such as trimellitic acid, pyromellitic acid, glycerol, pentaerythritol, 2,4-dioxybenzoic acid, lauryl alcohol, and phenyl isocyanate. Other compounds may be copolymerized as long as the polymer is substantially linear. In addition to the glycol component, p-hydroxybenzoic acid, m-hydroxybenzoic acid, aromatic hydroxycarboxylic acids such as 2,6-hydroxynaphthoic acid, p-aminophenol, p-aminobenzoic acid and the like are not impaired. If it is a small amount, it can be further copolymerized.

  The polyester component includes polyesters mainly composed of ethylene terephthalate units, such as polyethylene terephthalate (PET) and polybutylene terephthalate, polyesters mainly composed of ethylene naphthalate units, such as polyesters such as polyethylene naphthalate (PEN). May be blended. In this case, the ratio of the 6,6 ′-(ethylenedioxy) di-2-naphthoic acid component is not particularly limited, but 6,6 ′-(ethylenedioxy) di-2-naphthoic acid relative to the total dicarboxylic acid component. The ratio of a component is 5-100 mol%, Preferably it is 30-100 mol%, More preferably, it is 50-100 mol%.

  In this way, by introducing various copolymer components or blending with other polyesters for the polyester constituting the hard segment, it is possible to produce elastomers having various heat resistance temperatures. The aromatic polyester component constituting the hard segment of the polyester elastomer is mainly composed of a dicarboxylic acid component and a glycol component represented by the above formula (1), but other repeating units are 50 mol% or less, preferably 40 It may be contained in a proportion of not more than mol%, more preferably not more than 30 mol%, still more preferably not more than 20 mol%, particularly preferably not more than 10 mol%.

  The poly (alkylene oxide) glycol component used as the soft segment must have an average molecular weight of 500 to 5,000, particularly 1,000 to 3,000. When the molecular weight is less than 500, sufficient elastic properties cannot be obtained. Conversely, when the molecular weight exceeds 5,000, the compatibility with the hard segment deteriorates and the elastic recovery rate decreases. As for the ratio of the hard segment and the soft segment, the weight ratio of the hard segment / soft segment is preferably in the range of 20/80 to 80/20 in order to maintain an excellent elastic recovery rate and physical properties. When the amount of the soft segment is less than 20% by weight, the elastic performance and the elastic recovery rate are unfavorable, and when the amount of the soft segment exceeds 80% by weight, the melting point becomes too low. This is not preferable because it deteriorates the operability. Preferable examples of the poly (alkylene oxide) glycol component include poly (alkylene oxide) glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Further, the poly (alkylene oxide) glycol component may be not only a homopolymer of the above component, but also a random copolymer or a block copolymer composed of two or more of the above components. It may be a polymer or a mixed polymer in which two or more of the copolymers are mixed.

  The polyester elastomer used in the present invention has a component other than the poly (alkylene oxide) glycol component having a number average molecular weight of 500 to 5000, for example, an aliphatic polyester component, as a soft segment, not more than 20% by weight, preferably not more than 10% by weight. It may be included in proportions.

  The polyester elastomer of the present invention can be identified by melting point measurement, elemental analysis, infrared absorption spectrum (IR), nuclear magnetic resonance spectrum (NMR) analysis and the like.

  The intrinsic viscosity (IV) of the polyester elastomer of the present invention (measurement solvent: P-chlorophenol / 1,1,2,2-tetrachloroethane = 4/6 (weight ratio), measurement temperature: 35 ° C.) is 1.0. It is preferable that it is -3.5 when maintaining the outstanding mechanical characteristics (for example, intensity | strength, elastic recovery rate). The thing of 1.5-3.0 is especially preferable.

  The polyester elastomer production method of the present invention includes, for example, an aromatic dicarboxylic acid ester which is a polyester component constituting a hard segment, or a diol derivative of an aromatic dicarboxylic ester and a poly (alkylene which is a component for constituting a soft segment. A method of performing a polymerization reaction by a conventionally known melt polymerization method using (oxide) glycol can be preferably employed. The polyester component constituting the hard segment can also employ a transesterification reaction between a diol derivative of an aromatic dicarboxylic acid ester and a diol derivative of an aromatic dicarboxylic ester.

  More specifically, each raw material described above is placed in a reaction vessel, subjected to a transesterification reaction or esterification reaction in the presence or absence of a catalyst, and further subjected to polycondensation in a high vacuum in the presence of a catalyst. A method of increasing the degree of polymerization can be used. A conventionally known transesterification catalyst or polycondensation catalyst can be used as the catalyst. Titanium compounds, antimony compounds, tin compounds, calcium compounds, manganese compounds, and germanium compounds are preferably used. Of these, titanium compounds and antimony compounds are particularly preferable. Further, other various stabilizers, pigments and the like can be arbitrarily used as necessary.

  The polyester elastomer described above can be melt-spun and melt-molded by conventional methods. Under the present circumstances, it can be set as a molded article of a fiber, a film, and other shapes according to the melt spinning method and melt molding processing method of a general thermoplastic polymer. Moreover, like normal polyester, molding process conditions can be arbitrarily set. That is, the polyester elastomer can be easily processed and molded into a fiber, a film, a molded product, etc., so that it can be used in various shapes, and its industrial significance is extremely great.

For the polyester elastomer used in the present invention, other thermoplastic polymers, heat stabilizers, light stabilizers, matting agents, pigments, antioxidants, ultraviolet absorbers, plasticizers, lubricants, difficulty, and the like as necessary. A flame retardant, mold release agent, nucleating agent, filler, elongation improver, chain extender, and the like can be added.
In particular, examples of the heat stabilizer include hindered phenols, amines, sulfurs, phosphoruss, carbodiimides, imides, amides, and the like, and hindered phenols, amines, and sulfurs are preferably used. The addition amount of the heat stabilizer is 5% by weight or less, preferably 0.01 to 5% by weight with respect to the polyester elastomer.

  The polyester elastomer may be used by mixing other thermoplastic polymers such as polyester as a modifier in a small amount, for example, 20 wt% or less, preferably 10 wt% or less. Examples of other thermoplastic polymers include polyester, polyamide, polycarbonate, and polystyrene.

  As a method for molding the polyester elastomer of the present invention, a normal injection molding method, melt extrusion molding method, or melt spinning method can be employed.

  Since the polyester elastomer of the present invention uses a crystalline polyester having a high melting point for the hard segment, even if a large amount of the polytetramethylene glycol of the soft segment is copolymerized, the melting point as a polyester elastomer is high, so that it is a general-purpose molding machine. Can be processed sufficiently.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
The intrinsic viscosity of the polyester elastomer was measured using a P-chlorophenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 4/6) at a concentration of 12 mg / ml and a temperature of 35 ° C.
The melting point was measured using a DSC under nitrogen at a heating rate of 20 ° C./min.

[Reference Example 1]
A 10 L autoclave was charged with 400 parts by weight of 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, 6169 parts by weight of ethylene glycol, and 0.067 parts by weight of tetrabutoxy titanium, and a nitrogen pressure of 0.3 MPa was applied at a temperature of 230 ° C. For 6 h. After the reaction temperature was lowered to room temperature, the reaction product was taken out and filtered. Thereafter, 2375 parts by weight of methanol was added to the filtrate and washed and filtered. This operation was repeated three times and dried with a vacuum dryer at 120 ° C. White solid bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid having a melting point of 240 ° C. was obtained.

[Example 1]
In the reactor, 150 parts by weight of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid obtained in Reference Example 1 and polytetramethylene glycol (Hodogaya Chemical, average molecular weight 2000) 237 parts by weight was charged, 0.05 part by weight of tetrabutyl titanate was added as a catalyst, and a transesterification reaction was performed at 280 ° C. for 1 hour under normal pressure. The obtained reaction product was transferred to a polymerization can and once completely melted at a temperature of 320 ° C., then the temperature was lowered to 280 ° C., and a polycondensation reaction was performed under a reduced pressure of 1.33 × 10 ⁻⁴ MPa or less. . Perform polycondensation reaction for about 1 hour, add 0.6 parts by weight of Sumilizer GA-80 (manufactured by Sumitomo Chemical) and 1.4 parts by weight of Sumitizer TP-D (manufactured by Sumitomo Chemical) as antioxidants, and stir and mix for 10 minutes. A polyester elastomer was obtained. The obtained polymer had an intrinsic viscosity of 1.6 and a melting point of 237 ° C. The resin was dried at 120 ° C. A molded product was obtained at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. by Nissei Corporation (model: PS-20). The measurement results of polymer properties are shown in Table 1.

[Example 2]
A polyester elastomer was obtained in the same manner as in Example 1 except that the charging ratio of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) g-2-naphthoic acid and polytetramethylene glycol was changed as shown in Table 1. It was. The results are shown in Table 1.
A polyester elastomer was obtained in the same manner as in Example 1, except that 150 parts by weight of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid and 68 parts by weight of polytetramethylene glycol were used. It was. The results are shown in Table 1.

[Example 3]
A polyester elastomer was obtained in the same manner as in Example 1 except that the catalyst was changed from 0.05 parts by weight of tetrabutyl titanate to 0.042 parts by weight of antimony oxide. The results are shown in Table 1.

[Example 4]
The bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid obtained in Reference Example 1 was 150 parts by weight, the polytetramethylene glycol was 102 parts by weight, and the catalyst was tetrabutyl. A polyester elastomer was obtained in the same manner as in Example 1 except that 0.05 parts by weight of titanate was changed to 0.042 parts by weight of antimony oxide. The results are shown in Table 1.

[Example 5]
150 parts by weight of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid obtained in Reference Example 1, 22 parts by weight of dimethylterephthalic acid, and 21 of 1,4-butanediol A polyester elastomer was obtained in the same manner as in Example 1 with 127 parts by weight of polytetramethylene glycol and 0.042 parts by weight of antimony oxide. The results are shown in Table 1.

[Comparative Example 1]
The reactor was charged with 200 parts by weight of dimethyl terephthalate, 186 parts by weight of 1,4-butanediol, and 340 parts by weight of polytetramethylene glycol (Hodogaya Chemical, average molecular weight 2000), and 0.08 parts by weight of tetrabutyl titanate as a catalyst. In addition, methanol was distilled off by carrying out a transesterification reaction at 210 ° C. under normal pressure. After confirming that a predetermined amount of methanol was distilled off, the temperature was raised to 240 ° C., and a polycondensation reaction was performed under a reduced pressure of 1.33 × 10 ⁻⁴ MPa or less. The polycondensation reaction is performed for about 2 hours, 1.14 parts by weight of Sumilizer GA-80 (manufactured by Sumitomo Chemical) and 2.27 parts by weight of Sumitizer TP-D (manufactured by Sumitomo Chemical) are added as an antioxidant, and the mixture is stirred and mixed for 10 minutes. An elastomer was obtained. The obtained polymer had an intrinsic viscosity of 1.50 and a melting point of 194 ° C. The resin was dried at 120 ° C. A molded product was obtained at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. by Nissei Corporation (model: PS-20).
The measurement results of polymer properties are shown in Table 1.

[Comparative Example 2]
A polyester elastomer was obtained in the same manner as in Comparative Example 1 except that 100 parts by weight of dimethyl terephthalate, 97 parts by weight of 1,4-butanediol, and 170 parts by weight of polytetramethylene glycol were used. The measurement results of polymer properties are shown in Table 1.

ＰＴＭＧ：ポリテトラメチレングリコール成分
ＰＢＴ：ポリブチレンテレフタレート成分

PTMG: Polytetramethylene glycol component PBT: Polybutylene terephthalate component

Claims (4)

The hard segment is composed of a dicarboxylic acid component and a glycol component having 2 to 10 carbon atoms, and 5 to 100 mol% of the dicarboxylic acid component is represented by the following formula (1).

(R is an alkylene group having 2 to 10 carbon atoms)
The soft segment is a poly (alkylene oxide) glycol component having a number average molecular weight of 500 to 5000, and the weight ratio of the hard segment component to the soft segment component is 20/80 to 80/20 Some polyester elastomers.   2. The polyester elastomer according to claim 1, wherein the poly (alkylene oxide) glycol component is polytetramethylene glycol.   The polyester elastomer according to claim 1, which has a melting point of 200 ° C. to 300 ° C.   The polyester according to any one of claims 1 to 3, wherein the 6,6 '-(alkylenedioxy) di-2-naphthoic acid component represented by the formula (1) is 50 to 100 mol% of the dicarboxylic acid component. Elastomer.