JPH0768376B2 - Polyester elastomer sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester elastomer sheet (including a film and a plate-like body) formed of a polyester copolymer having rubber-like elasticity.

(Prior Art) As a method for producing a polyester elastomer sheet, for example, in Japanese Examined Patent Publication No. 1-49741, a crystalline polyester elastomer having a melting point of 140 ° C. or higher is melt-formed into a sheet, and then, in the width direction. A method has been proposed in which rolling is performed in the longitudinal direction at the same time as rolling, and then heat treatment is performed. According to such a method, a sheet having higher tensile strength and tear strength than an unstretched sheet can be obtained.

(Problems to be Solved by the Invention) In the sheet obtained in the above publication, polyester having a relatively high melting point and crystallinity is used. However, since an aromatic polyester such as polyethylene terephthalate or polybutylene terephthalate is used as the hard segment of the elastomer,
The physical properties such as tensile breaking strength and elongation of the sheet were insufficient.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to provide a polyester elastomer sheet in which physical properties such as tensile breaking strength and elongation are further improved as compared with conventional sheets. .

(Means for Solving the Problems) The polyester elastomer sheet of the present invention comprises (A) ethylene glycol and / or butylene glycol as a main diol component and terephthalic acid as a main dicarboxylic acid component, and the general formula is represented by the following formula [I]. A polyester copolymer obtained by reacting an aromatic polyester containing the dihydroxy compound represented by 0.1 mol% to 30 mol% of the diol component with a lactone (B) was melt-molded into a sheet. After that, the sheet is rolled or stretched, and then obtained by heat treatment, whereby
The above object is achieved.

(In the formula, R ¹ and R ² independently represent —H or —CH ₂ CH ₂ OH.) The aromatic polyester used in the present invention mainly contains ethylene glycol and / or butylene glycol. A diol component containing a dihydroxy compound represented by the formula [I] and a dicarboxylic acid component mainly containing terephthalic acid are used as constituent components.

As the butylene glycol, either 1,4-butanediol or 1,3-butanediol can be used. The dihydroxy compound [I] is a low molecular weight compound exhibiting liquid crystallinity, and is, for example, 4,4-dihydroxy-p-quaterphenyl or 4,4-di (2-hydroxyethoxy).
-P-quaterphenyl and the like are preferably used.

The transition temperature from the crystalline state of 4,4-dihydroxy-p-quaterphenyl to the liquid crystal state is 336 ° C., and 4,4
That of -di (2-hydroxyethoxy) -p-quaterphenyl is 403 ° C. In addition, 4,4-dihydroxy-p-quaterphenyl is, for example, Journal of Che
It can be synthesized according to the method described in mical Society, 1379-85 (1940). Further, the liquid crystal state refers to a state in which the compound is in a molten state and the molecules maintain the alignment state. The above dihydroxy compounds [I] may be used alone or in combination.

Liquid crystal molecules generally have high crystallinity, and as described above, 4,
4-dihydroxy-p-quaterphenyl and 4,4
-Di (2-hydroxyethoxy) -p-quarterphenyl has a high transition point from the crystal to the liquid crystal state,
When these dihydroxy compounds [I] are incorporated into the polymer chain, the polymer shows unique properties. That is, since the dihydroxy compound [I] exhibits crystallinity and its transition point is high, the dihydroxy compound [I]
Even if the compounding amount of is small, it forms a strong and heat-resistant physical crosslink. As a result, it is presumed that a thermoplastic elastomer having high heat resistance can be obtained without impairing the flexibility derived from the soft segment.

An aromatic polyester composed of at least one of ethylene glycol and butylene glycol, a dihydroxy compound [I], and terephthalic acid is added to a glycol other than the above, polyalkylene oxide, and a polysilicone having two hydroxyl groups, a formula [ I], an aromatic diol component other than I], an aromatic dicarboxylic acid other than terephthalic acid, an aromatic hydroxycarboxylic acid, and an aliphatic dicarboxylic acid may be contained as constituent components, but these are the total of the diol component and the dicarboxylic acid component. The amount is preferably 10 mol% or less. .

Examples of the glycol include propylene glycol, trimethylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10. -Decanediol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,3-diol,
Cyclohexane-1,4-diol, cyclohexane-1,4
-Dimethanol and the like can be mentioned, and these may be used alone or in combination of two or more kinds.

Examples of the polyalkylene oxide include polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyhexamethylene oxide, and the like.
These may be used alone or in combination of two or more. The number average molecular weight of polyalkylene oxide is
When it becomes smaller, the ability to impart flexibility to the aromatic polyester produced decreases, and when it becomes too large, physical properties such as thermal stability of the obtained aromatic polyester deteriorate, so 10
It is preferably 0 to 20,000, more preferably 500 to 5,000.

Examples of the above-mentioned polysilicone include dimethylpolysiloxane, diethylpolysiloxane, diphenylpolysiloxane and the like. The number average molecular weight of polysilicone is
When it becomes smaller, the ability to impart flexibility to the polyester produced decreases, and when it becomes larger, it becomes difficult to produce the polyester, so 100 to 20,000 is preferable, and 500 to 5,000 is more preferable.

Examples of the aromatic diol include hydroquinone, resorcin, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′- Dihydroxydiphenyl sulfide, 4,
4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, bisphenol A, 1,1-di (4-hydroxyphenyl) cyclohexane, 1,2-bis (4-hydroxyphenoxy) Examples thereof include ethane, 1,4-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene.

Examples of the aromatic dicarboxylic acid include isophthalic acid, 5-
Metal salts of sulfoisophthalic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether,
4,4'-dicarboxydiphenyl sulfide, 4,4'-
Dicarboxydiphenyl sulfone, 3,3′-dicarboxybenzophenone, 4,4′-dicarboxybenzophenone, 1,2-bis (4-carboxyphenoxy) ethane,
Examples include 1,4-dicarboxynaphthalene and 2,6-dicarboxynaphthalene.

The aromatic hydroxycarboxylic acid imparts rigidity and liquid crystallinity to the polyester, and includes salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, and 3-bromo-4-hydroxy. Benzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4'-carboxy Biphenyl and the like can be mentioned, with preference given to parahydroxybenzoic acid, 2-hydroxy-6-naphthoic acid and 4-hydroxy-4'-carboxybiphenyl.

The aliphatic dicarboxylic acid is preferably a dicarboxylic acid having 10 or less carbon atoms, for example, oxalic acid, malonic acid,
Examples include succinic acid, glutaric acid, adipic acid, suberic acid, and sebacic acid.

The aromatic polyester composed of the dihydroxy compound [I], at least one of ethylene glycol and butylene glycol, and a dicarboxylic acid component mainly containing terephthalic acid is resistant to heat when the content of the dihydroxy compound [I] decreases. When the amount of the dihydroxy compound [I] is 0.1 to 30% of that of the diol component constituting the polyester, the content of the dihydroxy compound [I] is not suitable as a thermoplastic elastomer. Mol%, more preferably 0.5 to 20 mol%, still more preferably 1.0 to 10 mol%.
When polyalkylene oxide or polysilicone is used as the diol component other than aromatic, the constitutional unit is counted as one monomer. That is, polyethylene oxide having a degree of polymerization of 10 is counted as 10 monomers.

The aromatic polyester used in the present invention may be a mixture of a plurality of aromatic polyesters such as a combination of two or more aromatic polyesters having different soft segments.
Also, a small amount of a branched component such as trimellitic acid or glycerin may be copolymerized, or an aromatic polyester in which a terminal carboxy group of the aromatic polyester is blocked and stabilized with epoxy or the like may be used. .

Aromatic polyester composed of the above components,
It can be produced using any generally known polycondensation method. For example, a method of directly reacting a dicarboxylic acid component with a diol component, a method of reacting a lower ester of the dicarboxylic acid component with a diol component by transesterification, a method of reacting a halide of the dicarboxylic acid component with a diol component such as pyridine Various solvents, a method of reacting a metal alcoholate of a diol component with a halide of a dicarboxylic acid component, a method of reacting an acetylated product of a diol component with a dicarboxylic acid component by transesterification, and the like. .

In the polycondensation, a catalyst generally used in producing polyester may be used. As the catalyst, lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium,
Examples thereof include metals such as tin, lead, antimony, arsenic, cerium, boron, cadmium and manganese, organometallic compounds thereof, organic acid salts, metal alkoxides and metal oxides.

Particularly preferred catalysts are calcium acetate, diacyl stannous, tetraacyl stannic acid, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate, tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanate, germanium dioxide, and tris. It is antimony oxide. Two or more kinds of these catalysts may be used in combination. In addition, water, alcohol, glycol, etc., which are by-products of the polymerization, are efficiently distilled off,
In order to obtain a high molecular weight polymer, the reaction system is
It is preferable to reduce the pressure to 1 mmHg or less. The reaction temperature is generally 150 to 350 ° C.

The lactone used in the present invention is a compound that opens a ring and reacts with an acid and a hydroxyl group to add an aliphatic chain, and imparts flexibility to the polyester copolymer. Those having 4 or more carbon atoms are preferable, and 5-membered ring to 8-membered ring is more preferable. Examples thereof include ε-caprolactone, δ-valerolactone, γ-butyrolactone, enanthlactone and caprylolactone. Two or more lactones may be used in combination.

The composition ratio of the aromatic polyester and the lactone is preferably 30/70 to 80/20 in terms of the weight ratio of the aromatic polyester / lactone from the viewpoint of the elastic properties of the resulting polyester copolymer, and a particularly preferred range is 30/70 to 70/30.

For the reaction between the aromatic polyester and the lactones, the above catalyst used for producing the aromatic polyester may be used. When the reaction is carried out in a solvent-free system, the reaction temperature is usually a temperature at which the mixture of the aromatic polyester and the lactone is uniformly melted and a temperature equal to or higher than the melting point of the block copolymer produced. When the aromatic polyester and the lactone are reacted in a solvent system, the reaction temperature can be appropriately selected. Generally, the range of 180 ° C to 300 ° C is preferable. 180 ° C
If it is less than 300 ° C, it is difficult for the aromatic polyester to be easily and uniformly dissolved with the lactone, and if it exceeds 300 ° C, decomposition or other undesirable side reaction occurs. Further, the solvent when the above reaction is carried out in a solvent system needs to be a common solvent with the aromatic polyester and the lactone. For example, α-methylnaphthalene can be adopted.

The aromatic polyester-polylactone polyester copolymer thus obtained is usually formed into a sheet by melt extrusion, and the obtained sheet is rolled or stretched. The rolling or stretching may be uniaxial or biaxial. When the sheet is rolled, it can be performed mainly by using a rolling roll and, if necessary, a take-up roll, and the rolling ratio is preferably about 2 to 7 times in the longitudinal direction and about 1 to 2 times in the lateral direction. The temperature of the sheet during rolling is
Usually, it is a temperature range not lower than the glass transition point of the polyester copolymer and lower than the melting point thereof by at least 30 ° C., preferably from room temperature to at least 50 ° C. lower than the melting point.

Stretching of the sheet can be usually carried out using a take-up roll, the stretching ratio is preferably 2 to 10 times, and the temperature during stretching can be set in the same manner as in the above rolling.

The rolled or stretched sheet needs to be heat-treated so that the sheet does not undergo dimensional change when used in a high temperature atmosphere and the performance is not deteriorated. The heat treatment temperature is preferably higher than the use temperature in consideration of the use environment of the sheet, but if the heat treatment is performed at a temperature too close to the melting point of the polyester copolymer, the rolling or stretching effect will be alleviated. It is preferable to keep the temperature at about 20 ° C or lower.

(Example) Hereinafter, the present invention will be described with reference to Comparative Examples and Examples.

Comparative Example (A) Synthesis of Aromatic Polyester Dimethyl terephthalate was placed in a glass flask having an internal volume of 1 equipped with a stirrer, a thermometer, a gas blowing port and a distillation port.
194g (1.0mol), ethylene glycol 138g (2.24mo
l), small amounts of calcium acetate and acid or antimony as a catalyst were added. After replacing the inside of the flask with nitrogen, the inside of the flask was heated and reacted at 180 ° C. for 3 hours. With the reaction, methanol began to distill out from the flask, and bis (2-hydroxyethyl) terephthalate was obtained.

To this flask, 50.7 g (0.15 mol) of 4,4-dihydroxy-p-quaterphenyl was added, and the flask was heated to 280 ° C.
The temperature was raised to, and the reaction was carried out at this temperature for about 2 hours. Next, the distillation port was connected to a vacuum vessel, and the reaction was carried out for 1 hour while the pressure inside the flask was reduced to 1 mmHg. With the reaction, ethylene glycol was distilled out, and an extremely viscous liquid was produced in the flask. After allowing the flask to cool, the glass flask was broken and the product was taken out.

(B) Synthesis of polyester copolymer Internal volume 1 equipped with stirring blade, gas blowing port and distillation port
250 g of the aromatic polyester obtained in the above (A), 250 g of ε-caprolactone, 1.0 g of tetrabutyl titanate as a catalyst, and 1,3,5-trimethyl-2,4, as a heat stabilizer, in a glass flask. 6-Tris (3,5-di-t-
1.0 g of butyl-4-hydroxybenzyl) benzene was charged, and the inside of the flask was replaced with nitrogen, and then heated to 250 ° C. in an oil bath while stirring. The reaction system became a uniform viscous liquid.

Then, after reacting under a nitrogen stream for 1 hour, the gas blowing port was connected to a vacuum pump, and the inside of the flask was further reacted for 1 hour under a reduced pressure of 1 torr or less.

Next, the polyester copolymer obtained is melt extruded from a T die at a temperature of 240 ° C. to obtain a film-like product, and the film-like product is passed through a cooling roll kept at 20 ° C.
A 3 mm unstretched sheet was obtained.

The obtained sheet was punched out into JIS K6301 No. 3 dumbbells and molded, and according to ASTM D638 Shimadzu Autograph AGB-
A tensile test was conducted at 5000 to determine the tensile breaking strength, tear strength and elongation at tensile breaking. The results are shown in Table 1.

The tensile rupture strength and the elongation at tensile rupture are the values obtained by pulling the sheet in the longitudinal direction, and the tear strength is the value obtained by pulling the sheet in a direction orthogonal to it.

Example 1 An unrolled sheet (thickness 3 m obtained in the same manner as in Comparative Example)
m) was rolled under the following conditions and then heat treated to obtain a polyester elastomer sheet.

The unstretched sheet was heated through a preheating chamber set at 80 ° C., and then stretched 1.2 times in the width direction between a pair of rolls heated at 100 ° C. and rolled 2.5 times in the longitudinal direction.

The longitudinal (feeding direction) ratio was adjusted by changing the peripheral speed ratio of the rolling roll and the take-up roll, and the width direction ratio was adjusted by the pressing pressure of the rolling roll.

Next, the rolled sheet was heat set by passing it at a constant speed through a heating chamber at 160 ° C. adjacent to the take-up roll. At this time, the sheet feeding speed was 15 m / min, and the heat setting time was 2 minutes.

The physical properties of the obtained rolled and heat-treated sheet (polyester elastomer sheet) were measured by the same method as in Comparative Example. The results are shown in Table 1.

Example 2 In Example 1, an unrolled sheet (thickness 3 mm) was heated to 100 ° C.
After being uniaxially stretched by 5 times, a heat-treated sheet was obtained in the same manner as in Example 1.

The physical properties of the obtained sheet were measured by the same method as in Comparative Example. The results are shown in Table 1.

(Effects of the Invention) The polyester elastomer sheet of the present invention has higher crystallinity than conventional polyesters, and is rolled or stretched with a polyester copolymer having a hard segment based on a quaterphenyl compound having a high melting point introduced, and then rolled. Since it is obtained by heat treatment, the hard segment is oriented and a strong physical crosslink is formed during rolling or stretching and then heat treatment. In addition, since polylactones are introduced as a soft segment into the polyester copolymer, it also has rubber elasticity. Therefore, for example, it is possible to provide an elastomer sheet excellent in heat resistance, mechanical properties and the like, which does not cause a creep phenomenon even when used at a place where a heavy load acts or at a high temperature.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // C08L 67:00 (72) Inventor Daishiro Kishimoto 2-11-20 Mishimaoka, Ibaraki City, Osaka Prefecture Umeyama Mansion 102

Claims (1)

[Claims] 1. A dihydroxy compound represented by the general formula [I] below is used in an amount of 0.1 mol% of (A) ethylene glycol and / or butylene glycol as a main diol component and terephthalic acid as a main dicarboxylic acid component. A polyester copolymer obtained by reacting an aromatic polyester contained in an amount of up to 30 mol% with (B) a lactone is melt-formed into a sheet, and then the sheet is rolled or stretched and then heat treated. Polyester elastomer sheet obtained by: (In the formula, R ¹ and R ² independently represent —H or —CH ₂ CH ₂ OH).