JP2001002764A - Ester-based elastomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject elastomer having excellent high-temperature mechanical characteristics and durability in spite of having flexibility, useful for boots, control cable, or the like, of automobile by making the Durometer hardness and compression set of an ester-based elastomer have specific values. SOLUTION: This elastomer comprises a bond crystalline aromatic polyester (e.g. polyethylene naphthalate) in the structure and has 40-50 Durometer hardness (23 deg.C) and <=83% compression set (120 deg.C, 72 hours) by a constitution composed of preferably (A) 100 pts.wt. of a polyester-based copolymer, (B) 25-250 pts.wt. of a polymer containing hydroxyl groups at both ends (e.g. polytetramethylene glycol) (C) 10-60 pts.wt. of a urethane component composed of formula I (R1 is a 2-15C alkylene, or the like) or formula II (R2 is a 2-15 alkylene, or the like) as a constituent unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ester elastomer.

[0002]

2. Description of the Related Art In recent years, due to increasing awareness of environmental issues,
The replacement of recyclable materials in various industrial fields is accelerating. As a rubber material, thermoplastic elastomer (TPE) has been attracting attention for a long time, and has been used for various applications in fields such as automobiles and various industries.

[0003] However, at present, a thermoplastic elastomer having an appropriate flexibility, while being excellent in various physical properties such as mechanical strength, heat resistance, abrasion resistance and bending fatigue resistance, has not been obtained. For example, polyester-based elastomer (TPEE) is excellent in mechanical strength, heat resistance, abrasion resistance and bending fatigue resistance, but it is difficult to obtain a flexible material,
In order to obtain a flexible TPEE, a method has been proposed in which the ratio of the hard segment component responsible for physical crosslinking is reduced (for example, Japanese Patent Application Laid-Open No. 2-88632), but the blockability of the hard segment component is reduced. As a result, there is a problem that the melting point is lowered and the mechanical properties at a high temperature are lowered, and a material satisfying flexibility and mechanical strength has not been obtained.

Further, TPEE also has a problem that the compression set at the time of large deformation and high temperature is large, and the creep resistance is lacking. A technique of improving the creep resistance by increasing the degree of polymerization is disclosed in, for example, Showa 52-12
Although proposed in Japanese Patent No. 1699, the improvement in creep resistance is not sufficient, and further, this method cannot achieve compatibility with flexibility.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ester elastomer which is flexible and has excellent mechanical properties at high temperatures in view of the above-mentioned problems of the conventional thermoplastic elastomer. In particular, the present invention provides an ester-based elastomer suitable for applications requiring long-term durability at high temperatures.

[0006]

In order to achieve the above object, the present invention comprises a crystalline aromatic polyester in the structure and a durometer hardness (HDD) at 23 ° C. of 40.
To provide an ester-based elastomer having a compression set of 83% or less under the condition of more than 50 and 120 ° C. for 72 hours.

The durometer hardness at 23 ° C. (H
When D D) is 40 or less, the strength is reduced, and the abrasion resistance and heat resistance are inferior. When D D) is more than 50, the material becomes too hard and becomes difficult to use as a flexible material. The ester-based elastomer of the present invention has a durometer hardness (HDD) of more than 40 and 5
When it is 0 or less, appropriate flexibility and mechanical strength are compatible. The durometer hardness (HDD) is more preferably more than 40 and 47 or less, particularly preferably 40 or less.
And 43 or less. The durometer hardness (H
D D) was measured at 23 ° C. based on JIS K 7215.

[0008] When the compression set under the conditions of 120 ° C. for 72 hours exceeds 83%, the mechanical strength at high temperatures decreases, and the creep resistance becomes poor. The compression set is 1 based on JIS K6301.
It was measured under the conditions of 20 ° C. and 72 hours.

Even if the durometer hardness (HDD) is in the range of more than 40 and less than 50, the compression set is 8
If it exceeds 3%, the mechanical strength at high temperatures becomes inferior, and it becomes difficult to use it for applications requiring long-term durability at high temperatures. Further, even if the compression set is 83% or less, if the durometer hardness (HDD) is 40 or less or exceeds 50, the bending resistance is poor and the durability at high temperature is required. It cannot be used for the intended use. Only those satisfying these two physical properties can be suitably used, for example, in applications such as automobile boots and control cables, and soft combs for dryers in the electric field.

[0010] Since the ester-based elastomer of the present invention has a crystalline aromatic polyester in its structure, the mechanical strength, heat resistance, abrasion resistance and bending fatigue resistance are improved. In order to improve these physical properties, the crystalline aromatic polyester is preferably at least one of polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate, and polybutylene terephthalate.

The ester elastomer of the present invention preferably comprises a block copolymer of a crystalline aromatic polyester and a polyether. Further, the melting point of the block copolymer of the crystalline aromatic polyester and the polyether is preferably 170 to 240 ° C, more preferably 180 to 220 ° C. 170 ° C melting point
If it is less than 80%, the compression set tends to exceed 83%. If it exceeds 240 ° C., there is a problem in moldability and it becomes difficult to use the material. The melting point is measured by differential scanning calorimetry, and can be evaluated by the endothermic peak temperature caused by crystal melting. The measurement was performed in a heating process at a heating rate of 10 ° C./min. As the apparatus, for example, “DSC 2920” manufactured by TA Instruments Inc. can be used.

The ester type elastomer having a durometer hardness (HDD) of more than 40 and 50 or less and the compression set of 83% or less is specifically described as a block copolymer as described below. It is preferred that
The block copolymer having such a structure can provide an elastomer having a soft segment component and a hard segment component (crystalline aromatic polyester) in a flexible ratio, while the blockability of the crystalline aromatic polyester component is low. It is kept well and makes the above properties compatible.

That is, in the above block copolymer, the polyester copolymer (A) and the polymer (B) having hydroxyl groups at both terminals are represented by the general formula (c1):
Or a component bonded by a urethane component (C) having (c2) as a structural unit,

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Embedded image The polyester-based copolymer (A) is 50 to 95% by weight of the short-chain polyester component (A1) represented by the general formula (a1).
And 50 to 5% by weight of a long-chain polyester component (A2) represented by the general formula (a2), and the long-chain polyester component (A2) has a glass transition temperature of 20 in its constituent unit.
C. or less, having an oligomer component (L) having a number average molecular weight of 500 to 5000,

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Embedded image The polymer (B) having a hydroxyl group at both ends has a glass transition temperature of 20 ° C. or lower, a number average molecular weight of 500 to 5000, and a solubility parameter δB of the polymer (B) and the long-chain polyester component (a2). Absolute value | δB− of difference between oligomer component (L) and solubility parameter δL
It is preferable that δL | is 0.5 or less.

The polyester-based copolymer (A) is a short-chain polyester component (A) represented by the general formula (a1).
1) and a repetition of the long-chain polyester component (A2) represented by the general formula (a2).

As the short-chain polyester component (A1), an ester-based elastomer having good creep resistance at a high temperature can be obtained, so that polybutylene terephthalate, polyethylene terephthalate, and polybutylene-2,6 are used.
-Naphthalate and polyethylene-2,6-naphthalate are preferred. In particular, when polybutylene-2,6-naphthalate or polyethylene-2,6-naphthalate is used, the creep resistance at high temperatures is greatly improved.

The long-chain polyester component (A2) has an oligomer component (L) having a glass transition temperature of 20 ° C. or less and a number average molecular weight of 500 to 5,000 in its constituent units.

The oligomer component (L) has a hydroxyl group at both ends when (L) alone is present, and both ends form an ester bond in the long-chain polyester component (A2). Specific examples of the oligomer component (L) include:
Examples include polyether, aliphatic polyester, polylactone, polycarbonate, polyolefin, polybutadiene, polyisoprene, polyacrylate, and polysiloxane. Among these, because of its good reactivity, especially polyether, aliphatic polyester,
Polylactone and polycarbonate are preferred.

When the glass transition temperature of the oligomer component (L) exceeds 20 ° C., the degree of polymerization of the ester elastomer does not increase due to a decrease in compatibility with the polymer (B), resulting in insufficient strength. More preferably, the glass transition temperature is 0.
° C or lower, more preferably -20 ° C or lower.

When the number average molecular weight of the oligomer component (L) is less than 500, the polyester copolymer (A)
Of the ester-based elastomer becomes insufficient due to a decrease in the blockability of the polyester elastomer. If it exceeds 5,000, the degree of polymerization of the ester-based elastomer will not be increased due to a decrease in compatibility with the polymer (B), and the strength will be insufficient. Preferably, the number average molecular weight is from 500 to 2,000.

The polyester copolymer (A) is a short-chain polyester component (A1) represented by the general formula (a1)
50 to 95% by weight and 50 to 5% by weight of a long-chain polyester component (A2) represented by the general formula (a2). If the content of the short-chain polyester component (A1) is less than 50% by weight, the melting point of the polyester copolymer (A) is low, which adversely affects the mechanical strength of the ester elastomer at high temperatures. On the other hand, if it exceeds 95% by weight, the compatibility with the polymer (B) becomes low, so that the degree of polymerization of the ester-based elastomer does not increase, and a sufficient strength cannot be obtained. Preferably, the short-chain polyester component (A1) is 70 to 90% by weight.
It is.

The polyester-based copolymer (A) may be an aromatic dicarboxylic acid or an ester-forming derivative thereof,
It can be obtained by reacting a low molecular weight diol and an oligomer component (L). The oligomer component (L) reacts to form the oligomer component (L), and specifically, as described later in detail, polyether, aliphatic polyester, polylactone, polycarbonate and the like are preferably used.

The aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid and the like. Examples of the ester-forming derivative of the aromatic dicarboxylic acid include dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, dimethyl naphthalenedicarboxylate, dimethyl paraphenylenedicarboxylate, and the like.

Examples of the low molecular weight diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentane Diol, 1,6-hexanediol and the like. These may be used alone or in combination of two or more.

As the oligomer component (L), a polyether, an aliphatic polyester, a polylactone or a polycarbonate having a structural unit represented by a specific general formula is preferably used together with the polymer (B). Can be That is, as the polyether used as the oligomer component (L), a polyether (M) having a structural unit represented by the following general formula (m) is preferable, and polyethylene glycol, poly-1,3-propylene glycol, poly1,2- Examples include propylene glycol, polytetramethylene glycol, polyhexamethylene glycol, and the like. Among these, polytetramethylene glycol is preferable in terms of excellent mechanical properties and weather resistance, and BASF
Commercial products such as "PTHF" manufactured by Mitsubishi Chemical Corporation and "PTMG" manufactured by Mitsubishi Chemical Corporation can be used as they are.

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As the aliphatic polyester used as the oligomer component (L), an aliphatic polyester (N) having a structural unit represented by the following general formula (n) is preferable, and “Nipporan 4009” and “Nipporan 4010” manufactured by Nippon Polyurethane Industries, Ltd. , And Nipporan 4070.

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The polylactone used as the oligomer component (L) is a polylactone (O) having a structural unit represented by the following general formula (o), for example, having 3 to 3 carbon atoms.
Those obtained by ring-opening polymerization of 10 lactones are preferred, and particularly preferred are ε-caprolactone polymers. Commercially available polylactones include, for example,
"TONE polyol" manufactured by Union Carbide and the like.

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The polycarbonate used as the oligomer component (L) is a polycarbonate (P) having the following general formula (p) as a constitutional unit. For example, an aliphatic carbonate having 4 to 10 carbon atoms is subjected to ring-opening polymerization. And propylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. Examples of commercially available products of such polycarbonate include "Nipporan 981" manufactured by Nippon Polyurethane Co., Ltd.

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The above polyester copolymer (A) can be polymerized by a known method. Specifically, terephthalic acid dimethyl ester is heated at 200 ° C. in the presence of a catalyst together with a polyether and an excess of a low molecular weight diol at 200 ° C. to perform a transesterification reaction, followed by a polycondensation reaction at 240 ° C. under reduced pressure. Thereby, a polyester copolymer (A) can be obtained. Instead of polyether, aliphatic polyester,
The same applies to the use of polylactone and polycarbonate.

The intrinsic viscosity of the polyester copolymer (A) is preferably from 0.05 to 1.0, more preferably from 0.2 to 0.6. When the intrinsic viscosity is less than 0.05, the blockiness of the ester elastomer becomes low, which adversely affects the mechanical strength at high temperatures. Further, when the intrinsic viscosity exceeds 1.0, the degree of polymerization of the ester elastomer does not increase because of low compatibility with the polymer (B),
An ester elastomer having sufficient strength cannot be obtained.
The intrinsic viscosity is a value measured at 30 ° C. using orthochlorophenol as a solvent.

The ester elastomer of the present invention comprises a block copolymer comprising a polyester copolymer (A) and a polymer (B) having hydroxyl groups at both ends bonded by the urethane component (C), As described in claim 4, the absolute value | δB−δL | of the difference between the solubility parameter δB of the polymer (B) and the solubility parameter δL of the oligomer component (L) is preferably 0.5 or less. Preferably, | δB−δL | is 0, and more preferably, the polymer (B) and the oligomer component (L) are of the same type (both are polyethers, etc.).

The polymer (B) is not particularly limited as long as it satisfies the above conditions. In particular,
Examples include polyether, aliphatic polyester, polylactone, polycarbonate, polyolefin, polybutadiene, polyisoprene, polyacrylate, and polysiloxane. Among these, because of its good reactivity, especially polyether, aliphatic polyester,
Polylactone and polycarbonate are preferred.

The above polyethers, aliphatic polyesters,
As the polylactone and the polycarbonate, the same ones as those exemplified as the oligomer component (L) can be used.

The glass transition temperature of the polymer (B) is 2
When the temperature exceeds 0 ° C., the compatibility with the polyester copolymer (A) decreases, the degree of polymerization of the ester elastomer does not increase, the strength becomes insufficient, and the obtained ester elastomer has poor flexibility. Becomes More preferably, the glass transition temperature is 0 ° C. or lower, still more preferably −20 ° C.
These are:

The polymer (B) has a number average molecular weight of 5
If it is less than 00, the obtained ester-based elastomer is inferior in flexibility, and if it exceeds 5,000, the crystallinity becomes too high, and the flexibility in the low-temperature region becomes poor. More preferably 500-3000, even more preferably 500-100
0.

The absolute value | δB−δL | of the difference between the solubility parameter δB of the polymer (B) and the solubility parameter δL of the oligomer component (L) is preferably 0.5 or less. In the present invention, the solubility parameter is generally a quantity (ΔE /
V) ^1/2 is the value with respect to the polymer. ΔE is the molar evaporation energy of the solvent. In the case of a polymer, a unit capable of dividing the molecular chain into partial chains (segments) having substantially the same volume as the solvent molecule and evaporating is assumed. Calculate using energy. V represents a volume, and here, the volume of the segment is used.

The above-mentioned solubility parameters include a solvent and a polymer,
In addition, in the present invention, the polymer (B) and the oligomer component (L) are selected so that | δB−δL | is 0.5 or less. (B) and oligomer component (L)
And the compatibility between the polymer (B) and the polyester-based copolymer (A) is improved, so that the reaction between the two proceeds quickly, and an ester-based elastomer having high flexibility and high mechanical strength can be obtained.

The solubility parameter of the polymer can be experimentally determined by the method described in “Polymer Data Book”, edited by the Society of Polymer Chemistry, pp. 592 (published in 1989, Baifukan). In this method, a polymer is immersed in a series of solvents having known different solubility parameters δS, and the solubility parameter of the polymer is calculated from the range of δS of the solvent in which the polymer is dissolved.

Further, as a method of obtaining a solubility parameter by calculation, for example, the Fedor method is known. Fedor's method is described in Journal of the Adhesion Society of Japan, No. 22,
Vol. 10, No. 564, (1986). In this way the solubility parameter [delta] P of the polymer _{is, δP = (ΣΔe i / ΣΔv} i) can be obtained by ^1/2. ΣΔe _i , ΣΔv _i are
With respect to the repeating unit of the polymer, the values in the table described on page 564 of the above-mentioned Journal of the Adhesion Society of Japan can be applied to each of the constituent components of the polymer, and can be determined from the sum of the values and the basic values in the table.

As an example, when δP is calculated for polytetramethylene glycol (—C ₄ H ₈ —O—), the result is as follows. _{ΣΔe i = 1180 × 4 + 800} = 5520 ΣΔv i = 16.1 × 4 + 3.8 = 68.2 δP = (5520 / 68.2) 1/2 = 8.996 It should be noted that, according to the description of the Journal of the Adhesion Society of Japan, methylene each group and is .DELTA.e _i and Delta] v _i of oxygen, a methylene group (.DELTA.e _i =
1180, Δv _i = 16.1), oxygen (Δe _i = 80)
0, Δv _i = 3.8).

Further, δP of a copolymer composed of 80 parts by weight of a polymer α having a δP of 10 and 20 parts by weight of a polymer β having a δP of 12 represents a weight fraction of each polymer. It is calculated as follows in consideration of the above.

ΔP = 10 × 0.8 + 12 × 0.2 = 1
0.4

In the ester elastomer of the present invention, the polyester copolymer (A) and the polymer (B) having hydroxyl groups at both terminals are represented by the general formula (c1):
Or a block copolymer bonded by a urethane component (C) having (c2) as a structural unit,

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Embedded image The polyester-based copolymer (A) is 50 to 95% by weight of the short-chain polyester component (A1) represented by the general formula (a1).
And 50 to 5% by weight of a long-chain polyester component (A2) represented by the general formula (a2), and the long-chain polyester component (A2) has a glass transition temperature of 20 in its constituent unit.
C. or less, having an oligomer component (L) having a number average molecular weight of 500 to 5000,

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Embedded image The polymer (B) having hydroxyl groups at both ends has a glass transition temperature of 20 ° C. or lower, a number average molecular weight of 500 to 5,000, and a solubility parameter δA of the polyester copolymer (A) and a solubility of the polymer (B). It is preferable that the absolute value | δA−δB | of the difference from the parameter δB is 3.5 or less.

In the fifth aspect of the present invention, | │δ
When A-δB | is larger than 3.5, the compatibility between the polyester copolymer (A) and the polymer (B) decreases,
The reaction between the two becomes difficult, and an ester elastomer having sufficient strength cannot be obtained. A preferred range of the absolute value of the difference between the solubility parameters is that | δA−δB | is 3 or less, more preferably 2.5 or less. In this case, since the compatibility between the polyester copolymer (A) and the polymer (B) is very good, the reaction between the polyester copolymer (A) and the polymer (B) proceeds rapidly, and A sufficient ester-based elastomer can be obtained.

In order to obtain an ester elastomer in which the polyester copolymer (A) and the polymer (B) are bonded by a urethane component (C), the polyester copolymer (A) and the polymer (B) must be combined. , Preferably a diisocyanate compound (C ') represented by the general formula (i)
And may be reacted.

[0045]

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When the terminal functional group of the polyester-based copolymer (A) is a hydroxyl group, the urethane component (C) has the above-mentioned general formula (c1) as a constitutional unit, and when the terminal functional group is a carboxyl group, it mainly has the general formula (c2) ) Are linked by a urethane component (C) having a constitutional unit. In the case where the terminal functional group of the polyester-based copolymer (A) is a carboxyl group, it is considered that a small amount of a portion bonded with the general formula (c3) as a constituent unit is also included.

[0047]

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The structure of the isocyanate compound (C ′) is not particularly limited as long as it has two isocyanate groups in the same molecule.

Examples of the isocyanate compound (C ′) include aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; 1,2-ethylene diisocyanate, 1,3-propylene Aliphatic diisocyanates such as diisocyanate, 1,4-butane diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate, and hydrogenated 4,4'-diphenylmethane diisocyanate Is mentioned.

The above isocyanate compound (C ′)
May be substituted with a compound having a trifunctional or higher isocyanate group. Since the polyester elastomer produced by the reaction with the compound having a trifunctional or higher isocyanate group has a high molecular weight and a high melt viscosity, the moldability is improved.

When a part of the isocyanate compound (C ′) is used by substituting it with a compound having three or more isocyanate groups, the average number of isocyanate groups, that is, 1
The value divided by the number of molecules should be 2.2 or less.
If the average number of isocyanate groups exceeds 2.2, the melt viscosity becomes too high, and conversely, the moldability decreases. When the number of the isocyanate groups is 2.2, the use of a difunctional and a trifunctional isocyanate compound is equivalent to the use of the difunctional: trifunctional = 4: 1.

The average number of isocyanate groups is 2 to 2.2.
As the isocyanate compound described above, those which are commercially available by mixing compounds having different isocyanate groups can be used. For example, “Millionate MR200” manufactured by Nippon Polyurethane Co., Ltd. is a mixture of compounds represented by the following general formula (c4) in which the number of n is 0, 1, 2, or 2 or more, and the average number of isocyanate groups is 2. 8 has been set. In the present invention, a diisocyanate compound may be added to the composition so that the average number of isocyanate groups becomes 2.2 or less as a whole.

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The polyester elastomer of the present invention comprises:
It is obtained by melt-mixing and reacting the polyester copolymer (A), polyether (B) and isocyanate compound (C ′). Examples of the melt mixing method include a method of melt mixing in an extruder.

In the above reaction, it is preferable to add the isocyanate compound (C ′) after melt-mixing the polyester copolymer (A) and the polyether (B). It is more preferable to add the isocyanate compound (C ′) after the polyester copolymer (A) and the polyether (B) are mixed and melted, and the solution becomes transparent.

In order to obtain an ester elastomer satisfying the conditions of the present invention, the polyester copolymer (A)
The amount of the polymer (B) is 25 to 25 per 100 parts by weight.
0 parts by weight, and the amount of the urethane component (C) is 10 to 60.
It is preferred that the amount is by weight.

When the amount of the polymer (B) is less than 25 parts by weight, the durometer hardness exceeds 50, and when it exceeds 250 parts by weight, the durometer hardness becomes 40 or less. The permanent set also exceeds 83%. Preferably it is 500 to 200 parts by weight.

When the amount of the urethane component (C) is less than 10 parts by weight, the ester elastomer does not become a high molecular weight substance, and as a result, the durometer hardness becomes 40 or less and the mechanical strength becomes low. Would. Also, 60
When the amount is more than 50 parts by weight, the durometer hardness exceeds 50, and the flexibility of the polyester elastomer becomes poor. Preferably it is 20 to 50 parts by weight.

In the polyester elastomer of the present invention, in order to satisfy the amounts of the polyester copolymer (A), the polymer (B) and the urethane component (C), the polyester copolymer (A), the polymer When reacting (B) and the isocyanate compound (C ′),
Melt and mix so that the amount of the polymer (B) is 25 to 250 parts by weight and the amount of the isocyanate compound (C ') is 10 to 60 parts by weight with respect to 100 parts by weight of the polyester-based copolymer (A). Thus, the reaction may be performed.

The polyester-based copolymer (A), polymer (B) and isocyanate compound (C ′) can be reacted by melt-mixing using an extruder. The extrusion temperature is preferably from 180 to 260C, more preferably from 200 to 240C. Extrusion temperature is 180 ° C
If it is less than 1, the polyester-based copolymer (A) does not melt and the reaction is difficult, so that a high molecular weight polymer cannot be obtained. If it exceeds 260 ° C, the polyester-based copolymer (A) and isocyanate Compound (C ') is decomposed, and a polymer having sufficient strength cannot be obtained.

As the extruder, a single-screw or twin-screw extruder is used, but is not particularly limited. Preferably,
A co-rotating twin-screw extruder and a co-rotating twin-screw extruder are used, and more preferably a co-rotating mesh twin-screw extruder is used from the viewpoint of the efficiency of stirring and mixing.

When the polyester-based copolymer (A), polymer (B) and diisocyanate compound (C ′) are reacted, by adding a compound having two or more reactive functional groups in the molecule, The molecular weight of the obtained elastomer can be increased, and the moldability and the bending resistance can be improved. Examples of the reactive functional group include an epoxy group, an alcohol group, and a hydrogen group in an NH bond. Examples of the compound include a polyfunctional epoxy compound, a polyfunctional alcohol compound, and an amine compound having at least one amino group. And amine compounds having two or more imino groups, compounds having an epoxy group and an alcohol group in the molecule, compounds having an epoxy group and an amino group in the molecule, and the like.

The compounds having two or more reactive functional groups in the molecule can be used in combination of two or more. In particular, it is preferable to use a polyfunctional epoxy compound and a polyfunctional amine compound in combination.

When a compound having two or more reactive functional groups is added, the polyester-based copolymer (A), the polymer (B) and the diisocyanate compound (C ′) are melt-kneaded, and then the reactive functional group is added. It is preferable to add a compound having two or more groups and knead the mixture. For example, in a method of simultaneously supplying and melt-mixing four components of a polyester-based copolymer (A), a polymer (B), an isocyanate compound (C ′), and an epoxy compound, a polyester-based copolymer (A) and a polymer (B) are used. In addition, an uneven reaction occurs due to a difference in reactivity between the epoxy compound and the isocyanate compound (C), and an elastomer having sufficient mechanical strength cannot be obtained. Similarly, in a method of melt-kneading the polyester-based copolymer (A), the polymer (B), and the epoxy compound, and then supplying and melt-mixing the isocyanate compound (C ′), an elastomer having sufficient mechanical strength can be obtained. Absent.

The compound having two or more reactive functional groups is preferably added in an amount of 0.01 to 20 parts by weight based on 100 parts of the polyester copolymer (A). 0.0
If the amount is less than 1 part by weight, a sufficient melt viscosity of the polyester-based elastomer cannot be obtained. If the amount is more than 20 parts by weight, gelation may progress and the melt fluidity may be lost. Preferably, it is 0.1 to 10 parts by weight.

In the present invention, a catalyst can be used at the time of melt-mixing the above-mentioned polyester-based copolymer (A) and polymer (B) with the isocyanate compound (C ′). As the above catalyst, for example, diacyl stannous, tetraacyl stannic, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate, tin dioctanoate, tin tetraacetate, triethyleneamine, diethyleneamine, triethylamine, metal naphthenate, Metal octylate, triisobutylaluminum, tetrabutyltitanate, calcium acetate, germanium dioxide, antimony trioxide and the like may be used, and these may be used alone or in combination of two or more.

In the present invention, a catalyst can be used at the time of melt-mixing the polyester copolymer (A) and the polymer (B) with the isocyanate compound (C ′). As the above catalyst, for example, diacyl stannous, tetraacyl stannic, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate, tin dioctanoate, tin tetraacetate, triethyleneamine, diethyleneamine, triethylamine, metal naphthenate, Metal octylate, triisobutylaluminum, tetrabutyltitanate, calcium acetate, germanium dioxide, antimony trioxide and the like may be used, and these may be used alone or in combination of two or more.

A stabilizer may be used in the above-mentioned ester-based elastomer, for example, 1,3,5-trimethyl-2,4,6-
Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis {2- [3- (3-t-butyl-4-hydroxybenzyl)
-5-methylphenyl) -propionyloxy] -1,1-dimethylethyl {-2,4,8,10-tetraoxaspiro [5,5] undecane and other hindered phenolic antioxidants; tris (2 , 4-di-t-butylphenyl) phosphite, trilauryl phosphite, 2-t-butyl-α- (3-t-butyl-4-
(Hydroxyphenyl) -p-cumenylbis (p-nonylphenyl) phosphite, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate,
And heat stabilizers such as pentaerythryltetrakis (3-laurylthiopropionate) and ditridecyl-3,3'-thiodipropionate.

The ester-based elastomer of the present invention may be a fiber, an inorganic filler, an inorganic substance, a flame retardant, an ultraviolet absorber, an antistatic agent, or the like, within a range that does not impair the utility during or after the production.
An additive such as a higher fatty acid salt may be added.

Examples of the fiber include glass fiber,
Examples include inorganic fibers such as carbon fiber, boron fiber, silicon carbide fiber, alumina fiber, amorphous fiber, and silicon / titanium / carbon fiber; and organic fibers such as aramid fiber. Examples of the inorganic filler include calcium carbonate, titanium oxide, mica, and talc, and examples of the inorganic substance include barium sulfate, alumina, and silicon oxide. Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, and pentabromophenyl allyl ether.

As the above-mentioned ultraviolet absorber, for example, p-
tert-butylphenyl salicylate, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-methoxy-
2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like.

Examples of the antistatic agent include N, N
-Bis (hydroxyethyl) alkylamine, alkylallyl sulfonate, alkyl sulfanate and the like. Examples of the higher fatty acid salt include sodium stearate, barium stearate, sodium palmitate and the like.

The ester-based elastomer of the present invention may be mixed with other thermoplastic resins and rubber components to modify its properties before use. Examples of the thermoplastic resin include polyolefin, modified polyolefin, polystyrene, polyvinyl chloride, polyamide, polycarbonate, polysulfone, and polyester.

Examples of the rubber component include natural rubber, styrene-butadiene copolymer, polybutadiene,
Polyisoprene, acrylonitrile-butadiene copolymer, ethylene-propylene copolymer (EPM, EPD
M), polychloroprene, butyl rubber, acrylic rubber,
Examples include silicone rubber, urethane rubber, olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, PVC-based thermoplastic elastomer, ester-based thermoplastic elastomer, and amide-based thermoplastic elastomer.

The ester-based elastomer of the present invention can be formed into a molded product by a generally used molding method such as press molding, extrusion molding, injection molding, blow molding and the like. Although the molding temperature varies depending on the melting point of the ester elastomer and the molding method, 160 to 260 ° C is suitable. If the molding temperature is lower than 160 ° C., a uniform molded product cannot be obtained because the fluidity of the ester elastomer is low. If the molding temperature is higher than 260 ° C., the ester elastomer is decomposed, and a sufficient strength of the ester elastomer is obtained. I can't get it.

The molded article obtained by using the ester-based elastomer of the present invention is suitably used for, for example, automobile parts, electric and electronic parts, industrial parts, sports goods, medical goods and the like.

Examples of the automotive parts include boots such as constant velocity joint boots and rack and opinion boots; ball joint seals; safety belt parts; bumper fascia; emblem;
As the electric and electronic components, for example, a wire covering material,
Gears, rubber switches, membrane switches, tact switches, O-rings, and the like. Examples of the industrial component include a hydraulic hose, a coil tube, a sealing material, a packing, a V-belt, a roll, a vibration damping material, a shock absorber, a coupling, a diaphragm, and the like.

Examples of the sporting goods include shoe soles and ball for ball games. Examples of the medical supplies include a medical tube, a blood transfusion pack,
Catheters and the like. In addition to the above applications, elastic fibers,
It can be suitably used as an elastic sheet, a composite sheet, a hot melt adhesive, a material for alloying with other resins, and the like.

(Effect) The ester-based elastomer of the present invention has a crystalline aromatic polyester in its structure and has the above-mentioned durometer hardness and permanent compression set. Excellent properties and durability at high temperatures. In particular, the ester elastomer of the present invention according to claim 4 or 5 is obtained by copolymerizing a short-chain polyester component (A1) as a hard segment and a long-chain polyester component (A2) as a soft segment. Using the polyester-based copolymer (A) and the polymer (B) as a soft segment component, a solubility parameter δB of the polymer (B) and a solubility parameter δA of the polyester-based copolymer (A), or Since the absolute value | δA-δB | or | δB-δL | of the difference from the solubility parameter δL of the oligomer component (L) in the structural unit of the long-chain polyester component (A2) was set to a specific value or less, the polymer (B ) And polyester copolymer (A)
Alternatively, an ester elastomer having good compatibility of the oligomer component (L) and high blockability of the hard segment component and the soft segment component is formed, and a portion having a high ratio of the hard segment component and a portion having a high ratio of the soft segment component , The short-chain polyester component is easier to crystallize than conventional ester-based elastomers that exhibit the same degree of flexibility, resulting in high flexibility and excellent long-term durability at high temperatures. I do.

[0079]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example 1) Dimethyl terephthalate 100
Parts by weight, 102 parts by weight of 1,4-butanediol, and polytetramethylene glycol having a number average molecular weight of about 1000 as oligomer component (L) (“PTHF1” manufactured by BASF).
000 ", δ value: 9.0), 12 parts by weight, 0.3 parts by weight of tetrabutyl titanate as a catalyst, and 1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene 0.3 parts by weight and tris (2,4-di-t-butylphenyl) phosphite 0.3 parts by weight were added, and the reaction system was added under nitrogen. The mixture was kept at 200 ° C. for 3 hours to carry out a transesterification reaction. The progress of the transesterification reaction was confirmed by measuring the amount of methanol distilled off. After the transesterification proceeded, the temperature was raised to 240 ° C. for 20 minutes, and the pressure was reduced. The polymerization system reached a reduced pressure of 2 mmHg or less in 20 minutes. As a result of a polycondensation reaction in this state for 20 minutes, 120 parts by weight of a white polyester-based copolymer (A ₁ ) was obtained. The intrinsic viscosity of the obtained polyester copolymer (A ₁ ) was 0.36.

This polyester copolymer (A1) 10
0 parts by weight, 80 parts by weight of polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000” manufactured by BASF, δ value: 9.0) as a polymer component (B),
Then, 35 parts by weight of 4,4′-diphenylmethane diisocyanate was used as an isocyanate compound (C ′) by using a twin-screw extruder (L / D = 25, manufactured by Berstorf Co., Ltd.) to obtain 2 parts.
The mixture was kneaded (residence time: 200 seconds) at 20 ° C. to obtain ester elastomer pellets.

Example 2 1,4-butanediol 10
70 parts by weight of ethylene glycol was used instead of 2 parts by weight, and polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000” manufactured by BASF, δ
Polyester copolymer (A ₂ ) was obtained in the same manner as in Example 1 except that 15 parts by weight of the compound (value: 9.0) was used. The intrinsic viscosity of the obtained polyester copolymer (A ₂ ) was 0.32.

The above polyester copolymer (A ₂ ) 10
0 parts by weight, 75 parts by weight of polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000” manufactured by BASF, δ value: 9.0) having a number average molecular weight of about 1000 as a polymer component (B),
Then, 30 parts by weight of 4,4′-diphenylmethane diisocyanate was used as an isocyanate compound (C ′) by using a twin-screw extruder (L / D = 25 manufactured by Berstorf Co., Ltd.) to obtain 2 parts.
The mixture was kneaded (residence time: 200 seconds) at 20 ° C. to obtain ester elastomer pellets.

Example 3 100 parts by weight of dimethyl naphthalenedicarboxylate, 81 parts by weight of 1,4-butanediol, and a number average molecular weight of about 65 as an oligomer component (L)
0 polytetramethylene glycol (“P
THF650, 12 parts by weight of δ value: 9.0), 0.3 parts by weight of tetrabutyl titanate as a catalyst, and 1,3,5-trimethyl-2,4,6-tris (3,5- Di-t-butyl-4-hydroxybenzyl)
0.3 parts by weight of benzene and tris (2,4-di-t
-Butylphenyl) phosphite 0.3 parts by weight,
The reaction system was maintained at 210 ° C. for 3 hours under nitrogen to carry out a transesterification reaction. The progress of the transesterification reaction was confirmed by measuring the amount of methanol distilled off. After the transesterification reaction proceeded, the temperature was raised to 250 ° C. in 20 minutes, and a pressure reduction operation was performed. The polymerization system reached a reduced pressure of 2 mmHg or less in 20 minutes. As a result of a polycondensation reaction for 20 minutes in this state, 130 parts by weight of a white polyester-based copolymer (A ₃ ) was obtained. The obtained polyester copolymer (A
The intrinsic viscosity of ₃ ) was 0.31.

This polyester copolymer (A3) 10
0 parts by weight, 75 parts by weight of polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000” manufactured by BASF, δ value: 9.0) having a number average molecular weight of about 1000 as a polymer component (B),
Then, 25 parts by weight of 4,4′-diphenylmethane diisocyanate was used as the isocyanate compound (C ′) using a twin-screw extruder (L / D = 40 manufactured by Berstorf Co.) to obtain 2 parts by weight.
The mixture was kneaded (residence time: 200 seconds) at 20 ° C. to obtain ester elastomer pellets.

Example 4 In place of 1,4-butanediol, 56 parts by weight of ethylene glycol were used, and polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000” manufactured by BASF, δ value: 9) .0)
Was used in the same manner as in Example 3 except that 28 parts by weight of was used to obtain a polyester copolymer (A4). The intrinsic viscosity of the obtained polyester copolymer (A4) was 0.07.

The above polyester copolymer (A4) 10
0 parts by weight, 65 parts by weight of polytetramethylene glycol having a number average molecular weight of about 1000 (“PTHF1000”, δ value: 9.0, manufactured by BASF) having a number average molecular weight of about 1000 as a polymer component (B);
Then, 25 parts by weight of 4,4′-diphenylmethane diisocyanate was used as an isocyanate compound (C ′) by using a twin-screw extruder (L / D = 25 manufactured by Berstorf Co., Ltd.) to obtain 2 parts by weight.
The mixture was kneaded (residence time: 200 seconds) at 20 ° C. to obtain ester elastomer pellets.

Comparative Example 1 Dimethyl Terephthalate 100
Parts by weight, 102 parts by weight of 1,4-butanediol, 170 parts by weight of polytetramethylene glycol having a number average molecular weight of about 1000 ("PTHF100" manufactured by BASF), 0.3 parts by weight of tetrabutyl titanate as a catalyst, and as a stabilizer 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
0.3 parts by weight of benzene and tris (2,4-di-t
-Butylphenyl) phosphite 0.3 parts by weight,
The reaction system was maintained at 200 ° C. for 3 hours under nitrogen to carry out a transesterification reaction. The progress of the transesterification reaction was confirmed by measuring the amount of methanol distilled out. After the transesterification proceeded, the temperature was raised to 240 ° C. for 20 minutes, and the pressure was reduced. The polymerization system reached a reduced pressure of 2 mmHg or less in 20 minutes. As a result of performing a polycondensation reaction in this state for 6 hours,
283 parts by weight of a white ester elastomer were obtained.

Comparative Example 2 "Hytrel 4767", a commercially available ester elastomer, manufactured by Du Pont-Toray Co., Ltd.
Was used.

* The pellets obtained in the above Examples and Comparative Examples were press-molded to produce 2 mm thick sheets. The pressing temperature was 23 in Examples 1, 2, and 5 and Comparative Examples 1 and 2.
The temperature was set to 0 ° C, and to 240 ° C for Examples 3 and 4. The following items were evaluated using this sheet, and the results are shown in the table.

(1) Durometer Hardness (Share D) Measured at 23 ° C. in accordance with JIS K 7215. (2) Compression set In accordance with JIS K 6301, the compression set was measured at 120 ° C. with a compression set of 25%. (3) Tensile properties Tensile strength and tensile elongation at room temperature (23 ° C.) were evaluated according to JIS K6301. (3) Storage elastic modulus It was measured under the following conditions using a viscoelastic spectrometer (“RSA-II” manufactured by Rheometric Scientific Effey).

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[Table 1]

[0093]

The ester elastomer of the present invention has specific durometer hardness and permanent compression set, and as a result, is excellent in mechanical properties at high temperature and durability at high temperature while being flexible. The ester-based elastomer of the present invention is suitable as a material for automobile boots, control cables, and soft combs for dryers in the electric field.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Nakatani 2-1 Shimomoto-cho, Mishima-gun, Osaka Sekisui Chemical Co., Ltd. (72) Inventor Shigeichi Fukaya 2-1 Shimomoto-cho, Mishima-gun, Osaka F-term in Sekisui Chemical Co., Ltd. (reference) 4J029 AB01 AC03 AD01 AD07 AD10 AE01 AE02 AE03 AE06 AE14 BA02 BA03 BA04 BA05 BA08 BA09 BA10 BF25 CA00 CB04A CB05A CB06A CB10A CC06A EG00 EG09 J02J03 J02E03 J02J02E KH01 4J034 DF01 DF02 DF11 DG01 DM01 DP18 DP19 HA01 HA07 HC03 HC12 HC17 HC22 HC64 HC66 HC67 HC71 HC73 JA06 JA44 KB04 QB14 QB15 RA12

Claims (8)

[Claims] 1. It has a crystalline aromatic polyester in its structure and has a durometer hardness (HDD) at 23 ° C. of 40.
An ester elastomer having a compression set of not more than 50 and not more than 50 and a compression set of not more than 83% at 120 ° C. for 72 hours. 2. The ester-based elastomer according to claim 1, wherein the crystalline aromatic polyester is at least one of polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate, and polybutylene terephthalate. 3. The ester elastomer according to claim 1, comprising a block copolymer of a crystalline aromatic polyester and a polyether. 4. A polyester-based copolymer (A) and a polymer (B) having hydroxyl groups at both terminals are bonded by a urethane component (C) having a structural unit represented by the general formula (c1) or (c2). Consisting of a block copolymer, Embedded image The polyester-based copolymer (A) is 50 to 95% by weight of the short-chain polyester component (A1) represented by the general formula (a1).
And 50 to 5% by weight of a long-chain polyester component (A2) represented by the general formula (a2), and the long-chain polyester component (A2) has a glass transition temperature of 20 in its constituent unit.
Having an oligomer component (L) having a number average molecular weight of 500 to 5000 at a temperature of not more than ℃, Embedded image The polymer (B) having a hydroxyl group at both ends has a glass transition temperature of 20 ° C. or lower and a number average molecular weight of 500 to 5000, and has a solubility parameter δB of the polymer (B) and the long-chain polyester component (A2). Absolute value | δB− of difference between oligomer component (L) and solubility parameter δL
The ester-based elastomer according to claim 1, wherein δL | is 0.5 or less. 5. A polyester-based copolymer (A) and a polymer (B) having hydroxyl groups at both terminals are bonded by a urethane component (C) having a structural unit represented by the general formula (c1) or (c2). Consisting of a block copolymer, Embedded image The polyester-based copolymer (A) is 50 to 95% by weight of the short-chain polyester component (A1) represented by the general formula (a1).
And 50 to 5% by weight of a long-chain polyester component (A2) represented by the general formula (a2), and the long-chain polyester component (A2) has a glass transition temperature of 20 in its constituent unit.
Having an oligomer component (L) having a number average molecular weight of 500 to 5,000 at a temperature of not more than ℃, Embedded image The polymer (B) having hydroxyl groups at both ends has a glass transition temperature of 20 ° C. or lower, a number average molecular weight of 500 to 5,000, and a solubility parameter δA of the polyester copolymer (A) and a solubility of the polymer (B). The ester elastomer according to claim 1, wherein the absolute value | δA-δB | of the difference from the parameter δB is 3.5 or less. 6. A polymer (B) having hydroxyl groups at both ends with respect to 100 parts by weight of the polyester copolymer (A).
25 to 250 parts by weight and urethane component (C) 10 to 60
6. The method according to claim 4, wherein the parts are composed of parts by weight.
The ester-based elastomer according to 1. 7. A polymer (B) having hydroxyl groups at both ends
And the oligomer component (L) is a polyether (M) having the general formula (m) as a structural unit, an aliphatic polyester (N) having a general formula (n) as a structural unit, and a general formula (o).
The ester-based elastomer according to any one of claims 4 to 6, which is any one of a polylactone (O) having a structural unit of: and a polycarbonate (P) having a general formula (p) as a structural unit. Embedded image Embedded image Embedded image Embedded image 8. R ₃ in the short-chain polyester component (A1)
Is a phenylene group or a naphthalene group, and R ₄ is an ethylene group or a butylene group.
7. The ester elastomer according to 5 or 6.