JPH06157884A - Polyester elastomer composition - Google Patents

Abstract

PURPOSE:To obtain an elastomer composition excellent in moldability, whether resistance, low-temperature properties, etc., by melt-mixing a polyether ester elastomer with a polyester ester elastomer. CONSTITUTION:This elastomer composition is prepared by melt-mixing 5-95 pts.wt. polyether ester elastomer mainly consisting of a polytetramethylene glycol component, terephthalic acid and tetramethylene glycol and 95-5 pts.wt. polyester elastomer comprising a polyester having a soft component mainly consisting of isophthalic acid and/or phthalic acid and a 5C or higher diol and a polyester having a hard component mainly consisting of terephthalic acid and tetramethylene glycol. This melt mixing is desirably carried out under such conditions that no reaction occurs between the two block copolymers. To inhibit such a reaction, for example, phosphoric acid, phosphorous acid, a phosphonic acid, phosphinic acid or their derivatives can be used. The mixing temperature is usually in the range of 200-260 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyester elastomer composition obtained by mixing two kinds of polyester elastomers. More specifically, a polyester elastomer composition having excellent heat resistance, weather resistance, low temperature characteristics, etc. obtained by mixing a polyether ester elastomer which has been widely used from the past with a polyester / polyester elastomer having an aromatic polyester as a soft component. Regarding things.

[0002]

2. Description of the Related Art Polyether ester elastomers are
It is well known that it has been widely used in recent years by utilizing its moldability, heat resistance, cold resistance and the like. However, this elastomer has a problem in heat deterioration resistance and cannot be used without a stabilizer. Of course, a stabilizer solves this problem for the time being, but there is a point that it is difficult to use in an environment such as an engine room of a car exposed to a high temperature for a long time.

On the other hand, the present inventors have previously proposed an elastomer using an aromatic polyester as a soft component.
However, although this elastomer has high heat resistance, it has poor cold resistance and has a problem.

[0004]

The present inventors need an elastomer having both heat deterioration resistance and cold resistance in parts requiring resistance to both hot and cold conditions such as automobiles. Therefore, this is a problem to be solved.

[0005]

As a method for solving the above problems, the inventors have found that both performances can be achieved in addition to mixing two kinds of elastomers, and have reached the present invention.

That is, the present invention provides polytetramethylene glycol, 5 to 95 parts by weight of a polyether ester elastomer (A) containing terephthalic acid and tetramethylene glycol as main components, and isophthalic acid and / or phthalic acid and 5 or more carbon atoms. A polyester elastomer composition obtained by mixing 95 to 5 parts by weight of a polyester / polyester elastomer (B) containing as a soft component a polyester mainly composed of the diol and a polyester mainly comprising terephthalic acid and tetramethylene glycol as a hard component. Is.

To explain the present invention, a polyether ester elastomer containing terephthalic acid, tetramethylene glycol and polytetramethylene glycol as main components is terephthalic acid or its ester-forming derivative and tetramethylene glycol or its ester. A block copolymer obtained from a forming derivative and polytetramethylene glycol or an ester forming derivative thereof.
The composition of the block copolymer in which the effect of the present invention is remarkably preferable is in a block copolymer which accounts for at least 50% by weight, preferably 50 to 80% by weight.

[0008] Further, terephthalic acid and tetramethylene glycol are not only used alone, but may be copolymerized with other third component, for example, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc. Any of the aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used as the copolymerization component. Further, other than tetramethylene glycol, ethylene glycol, aliphatic diol such as hexamethylene glycol, alicyclic diol such as cyclohexanedimethanol, and aromatic diol such as 2,2-bis (4-hydroxyphenyl) propane and hydroquinone are also copolymerized. It can be used as an ingredient. The copolymerization ratio of these is 30 mol% or less, preferably 20%, based on the dicarboxylic acid component.
It is not more than mol%. If the copolymerization ratio is higher than this range, the melting point is low and the tackiness during molding becomes high, which is not preferable.

The polytetramethylene glycol having an average molecular weight of 500 to 3000 is used.
Such a block copolymer is produced by a method similar to the usual polyester polymerization method.

On the other hand, the polyester-ester elastomer is a polyester having isophthalic acid and / or phthalic acid and a diol having 5 or more carbon atoms as a main component as a soft component, and a polyester containing terephthalic acid and tetramethylene glycol as a hard component. Block polyester. Here, isophthalic acid and / or phthalic acid constituting the polyester used as the soft component means, in addition to isophthalic acid and / or phthalic acid, an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid other than the above, and an alicyclic dicarboxylic acid. An acid or the like may be copolymerized, and the copolymerization ratio is less than 50 mol%, particularly preferably less than 40 mol%. This is because when the copolymerization rate is 50 mol% or more, the hydrolysis resistance is deteriorated and the properties are unfavorably hardened.

As the dicarboxylic acid component which can be copolymerized here, an aliphatic dicarboxylic acid having 6 to 12 carbon atoms can be mentioned, and it is a preferred copolymerized product in the case of improving the characteristics at low temperature, 5 to 40 Often mole percent copolymerized.

Further, a carbonate component can also be used as a copolymerization component, and in this case also, it is effective in improving the characteristics at low temperatures, and in many cases, it is preferable in that it has better hydrolysis resistance than an aliphatic dicarboxylic acid. .

On the other hand, the diol component is particularly preferably an aliphatic diol having 5 or more carbon atoms, preferably 6 to 12, such as hexamethylene glycol, decamethylene glycol, 3-methylpentanediol and 2-methyloctanediol. Is exemplified. This diol may also contain a copolymerization component, and in addition to the above, an aliphatic diol such as ethylene glycol and tetramethylene glycol, an alicyclic diol such as cyclohexanedimethanol, and a diol having an ether group in the molecule such as diethylene glycol. , Aromatic diols and the like. These also have a copolymerization ratio of less than 50 mol%, preferably less than 40 mol%.

A polyester containing terephthalic acid and tetramethylene glycol as main components is used as the hard component, and other dicarboxylic acids, diols and the like may be copolymerized in an amount of less than 30 mol%.

The block copolymer of the present invention is a block copolymer comprising the above-mentioned soft and hard components, and the ratio of the soft component and the hard component is 80/20 to 30/7.
0, preferably 75/25 to 50/50.

The block copolymer is produced, for example, by a method of obtaining a block copolymer by reacting a polyester as a soft component and a polyester as a hard component by melt-mixing to react them. At this time, the melting point of the resulting block copolymer is 2 to more than the melting point of the hard component polyester.
It is preferably about 30 ° C. lower. The intrinsic viscosity of this block copolymer is 0.6 or more, preferably 0.8 or more.

In the present invention, the composition of the present invention is obtained by melt-mixing the two block copolymers, but at this time, the two block copolymers are prevented from reacting with each other. Is desirable. For this,
It is preferable to contain a compound that deactivates the transesterification catalyst. For example, phosphoric acid, phosphorous acid, phosphonic acids, phosphinic acids, or derivatives thereof are used. The mixing temperature is usually in the range of 200 to 260 ° C.

The composition of the present invention is a mixture of such two kinds of block copolymers, and the mixing ratio is 95 to 5.
/ 5 to 95. The mixing ratio may be appropriately changed depending on the application to be used. However, when the effect of the present invention is to emphasize the flexibility at low temperature and the prevention of deterioration at high temperature, the ratio of the polyester ester elastomer is 50.
% Or more, and for example, the polyester ester elastomer component is preferably 90 to 50% by weight.

However, even if the ratio of the polyester ester elastomer is small, there is an effect of improving heat resistance and weather resistance, and the composition is not necessarily limited to the above.

The composition of the present invention thus obtained contains, in addition to the above two block copolymers, a filler, a stabilizer, a pigment and the like, which are generally used as modifiers for resins. There is no problem, and a mixture with another resin may be added as long as it does not affect the intended improvement item.

[0021]

EFFECTS OF THE INVENTION By carrying out the present invention, both the properties of flex fatigue resistance at low temperature and heat deterioration resistance at high temperature, which cannot be obtained by a polyether ester elastomer or a polyester ester elastomer alone, are satisfied. A possible composition is obtained.

[0022]

EXAMPLES The present invention will be described in detail below with reference to examples. In addition, "part" in an Example shows a "weight part."

[0023]

Example 1 62 parts of polytetramethylene glycol having a molecular weight of about 1500, 34 parts of dimethyl terephthalate and 28 parts of tetramethylene glycol were melt-polymerized by an ordinary method using titanium tetrabutoxide as a catalyst to give an intrinsic viscosity ( A polyether ester elastomer of 1.52 was obtained at 35 ° C. in orthochlorophenol and the same hereinafter. 1 g of Irganox 1010 manufactured by Ciba-Geigy was used as a stabilizer at the end of the polymerization reaction.
Part, 0.3 parts of TINUVIN 327 were added (polyether ester elastomer A).

Polytetramethylene terephthalate (intrinsic viscosity 1.02) was obtained from 194 parts of dimethyl terephthalate and 135 parts of tetramethylene glycol by a conventional method using 0.1 part of titanium tetrabutoxide as a catalyst.

After transesterification of 116 parts of dimethyl isophthalate, 19 parts of dimethyl terephthalate, 69 parts of dimethyl sebacate and 142 parts of hexamethylene glycol with 0.4 part of titanium tetrabutoxide, 240 ° C.
Was subjected to a polycondensation reaction under reduced pressure to obtain a polymer having an intrinsic viscosity of 1.05. After adding 110 parts of the above polytetramethylene terephthalate to this polymer and reacting for 40 minutes,
0.2 part of phenylphosphonic acid was added and stirred for another 15 minutes. This product has an intrinsic viscosity of 1.01 and a melting point of 193 ° C., which clearly shows that it is a block copolymer (polyester ester elastomer B).

Polyetherester elastomer A30
Part and 2 parts of polyester ester elastomer B
Melt kneading was carried out by an extruder at 40 ° C. 23 of this mixture
Injection molding was performed at 0 ° C. to obtain a flat plate having a thickness of 2 mm.

From this, according to JIS6301, the No. 3 dumbbell was punched out, and the gear aging tester at 150 ° C. was used for 200
As a result of conducting a tensile test after the time treatment, the breaking strength was kept at 55% and the elongation was kept at 52% as compared with before the test.

A strip-shaped test piece having a width of 1 cm was prepared from this flat plate, and was held by two grippers at an interval of 5 mm. The grip tool on one side was bent so that the left and right 90-degree test pieces were bent. A bending test was performed at -40 ° C. Even after 200 tests, the test piece did not break and did not crack.

[0029]

COMPARATIVE EXAMPLE 1 Only the polyether ester elastomer A and the polyester ester elastomer B used in Example 1 were subjected to the same gear aging tester as in Example 1 and a bending test at -40 ° C. As a result, in the case of the polyether ester elastomer A, neither breaking nor cracking was observed in the bending test, but it was broken before the measurement in the gear aging test, while in the case of the polyester ester elastomer, the breaking strength and the breaking elongation were measured in the gear aging test. The degree of retention was 65% and 80%, respectively, but the bending test at −30 ° C. also broke 25 times.

[0030]

Example 2 In the polyester ester elastomer of Example 1, 2 was used instead of hexamethylene glycol.
-Methyl octamethylene glycol is used, and a polymer obtained by polymerizing only dimethyl isophthalate as a dicarboxylic acid component is melt-mixed with a polymer of dimethyl terephthalate and tetramethylene glycol in a weight ratio of 75/25, A block polymer having a melting point of 185 ° C. and an intrinsic viscosity of 0.97 was obtained.

This polymer and the polyetherester elastomer of Example 1 were mixed in a chip state at a weight ratio of 50/50, injection-molded in the same manner as in Example 1, and subjected to a gear aging test and -40 ° C. A bending test was performed. As a result of the gear aging test, the strength retention rate was 39% and the elongation retention rate was 54%, and in the bending test at -40 ° C, no cracks were formed after 200 cycles.

Claims (1)

[Claims] 1. A polytetramethylene glycol component,
Polyether ester elastomer (A) 5 containing terephthalic acid and tetramethylene glycol as main components
Polyester ester elastomer (B) 95 comprising 95 parts by weight and a polyester having isophthalic acid and / or phthalic acid and a diol having 5 or more carbon atoms as a main soft component, and a polyester having terephthalic acid and tetramethylene glycol as a main hard component A polyester elastomer composition obtained by mixing 5 to 5 parts by weight.