KR970004931B1 - Polyester block copolymer and elastic yarn composed thereof - Google Patents

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Description

Polyester block copolymers and elastic yarns thereof

The present invention relates to novel polyester block copolymers and elastic yarns composed thereof. More specifically, the present invention relates to a polyester-polyester block copolymer having excellent elastic recovery performance and high light resistance and chlorine resistance, and to an elastic yarn formed using the block copolymer.

Currently polyester block copolymers are used as molding resins, which are elastomers characterized by thermoplastics, and two such polyester elastomers; That is, it is known that it consists of a polyether ester block copolymer and a polyester ester block copolymer.

Polyether ester block copolymers consist of aliphatic polyethers such as polytetramethylene glycol and polybutylene terephthalate aromatic polyesters. Such polymers are thermoplastic and have high crystallinity and high heat resistance and are therefore widely used. Nevertheless, such polymers have the drawback that the resistance to acid reaction is very low. For example, if such polymers are made and molded in the absence of stabilizers, the surface becomes smooth and cracks occur within months. In other words, such polymers can be used as ratios with the help of practical stabilizers.

However, the addition of stabilizers presents several problems; For example, if the molded body held at a high temperature cools, the stabilizer will bleed to the surface and the molded part will sometimes appear cloudy, and its commercial value will decrease. In addition, if the shaped body is used in the presence of NOx, its yellowing sometimes occurs, and its commercial value is reduced again and again. Moreover, in medical applications it is evident that the presence of easily extracted stabilizers is undesirable.

Polyester ester block copolymers are known which consist of aromatic polyesters such as aliphatic polyesters and aromatic polyesters such as polybutylene terephthalate. The oxidation resistance of such polymers is higher than that of polyether ester copolymers, but the polymers have the disadvantage of poor hydrolysis resistance. Stabilizers that can enhance oxidation resistance are known, but it has been thought that it is difficult to enhance hydrolysis resistance because there is no stabilizer that can enhance hydrolysis resistance. In addition, although the oxidation resistance of the polymer is higher than that of the polyether ester copolymer, the oxidation resistance is not yet satisfactory, so a stabilizer should be used.

Spandex yarn has been used as an elastic yarn because it has excellent elastic recovery performance, and elastic yarn composed of polyester block copolymers has recently been used in limited applications. However, because of the poor moisture and heat resistance of spandex yarn, the blended fabric of polyester fiber and spandex yarn is difficult to dye, and yellow discoloration easily occurs under light irradiation, and spandex yarn is not used satisfactorily for swimwear or the like because it has poor chlorine resistance. There is a flaw. Therefore, practical use of spandex yarn is very limited.

In order to overcome these drawbacks, various studies have been conducted on the preparation of elastic yarns using the above-mentioned polyester block copolymers, but only polyether ester copolymerized elastic yarns having improved moisture-heat resistance have been used. There is a bar. This is because all the elastic yarns obtained have inferior spandex performance, especially poor elastic recovery, but if these drawbacks are overcome, the excellent properties of the polyester block copolymers can be utilized and the defect free elastic yarns of spandex Will lose.

The properties of elastic yarns, such as light resistance and chlorine resistance, are determined by the type of actual soft segment, and thus new soft segments other than spandex are needed.

Previously studied polyester ester block copolymers made of polyester as soft segments have never been used as fibers because they are difficult to manufacture of the polymer itself and the performance of the elastic yarn is also poor, and are characterized by polymer formation, but the drawback also It is obvious that this hinders actual use. For example, the specification of US Pat. No. 3,037,960 consists of a polyester having a melting point of 50 ° C. or lower and a polyester having a melting point of 200 ° C. or higher, wherein the general formula— (R′COOROCO) (-R represents an aromatic diol residue. Polyester block copolymers represented by) are described. This US patent teaches that block copolymers are superior to spandex in tonal stability, light stability, and oxidative stability and are superior to polyethers in oxidative stability. Almost thirty years have passed since the publication of this US patent, but no block copolymers have ever been used. The reason for this is interpreted from the examples of the patent specification that (1) the hydrolysis resistance is poor, (2) the tensile recovery is lower than that of the spandex yarn, and (3) the strength is low. In addition, although the specification of US Pat. No. 4,031,165 describes polyester block copolymers composed of aliphatic polyesters and aromatic polyesters, it is believed that problems of low hydrolysis resistance occur when the polymer is used in fibrous form. The specification of US Pat. No. 3,446,779 describes a polyester block copolymer consisting of hexamethylene terephthalate / isophthalate / aliphatic dicarboxylic acid copolyester and polymethylene terephthalate, which is similar to the block copolymer of the present invention. Such block copolymers have also not been used in practice. According to the disclosed method, it is believed that the two polymers are bonded through the chain extender, and since the chain extender is included in the polymer chain, hydrolysis resistance and elastic recovery are lowered.

Another reason that practical use is suppressed is that the elastic recovery and adhesion resistance are inferior in the forming or spinning step. That is, especially when trying to obtain a product having good elastic recovery in the form of fibers, adhesion occurs and the yarn cannot be injected.

As noted above, polyethers, sometimes used as soft components, such as polytetramethylene glycol, have very poor oxidation resistance, low light resistance and chlorine resistance, but these disadvantages are overcome by the use of stabilizers. Can be. Nevertheless, the use of stabilizers causes problems such as discoloration by nitrogen oxides (NOx) or copper ions, and in addition, even when stabilizers are used, satisfactory light resistance or chlorine resistance cannot be obtained. In the case of spandex yarn, aliphatic polyester is used as a soft component to increase chlorine resistance, but in this case, white mold and hydrolysis occur. Therefore, if the problems of mildew and hydrolysis can be solved, the application of such yarn will be expanded, and its durability will be increased.

Conventional techniques and problems have been described above with respect to elastic yarn as an example, but similar problems arise in molded articles and films. Specifically, the film can be considered to be the same as the actual fiber. In many cases, elastic recovery performance is not required for molded products, but since stabilizers are used, problems such as the display of stabilizers are raised. Therefore, the development of elastomers that can be used without the use of stabilizers is desirable.

The primary object of the present invention is to provide a block copolymer having good elastic recovery by using a soft component having excellent oxidation resistance (light resistance, chlorine resistance, etc.) and hydrolysis resistance.

It is still another object of the present invention to provide an elastic yarn having a heat resistance capable of excluding a temperature generally adopted in fabric production and having no property of filament adhesion at such a processing temperature.

When attempting to select polyester as a soft component with good oxidation resistance to achieve the previous object, the present inventors focused their research on this problem, since known aliphatic polyesters are hydrolyzed very quickly and cannot be used in practice. As a result, it has been found that aromatic polyesters can be used. This is useful in that the properties are sometimes unnecessary at low temperatures, for example below freezing point. Based on these findings, repeated studies have found that polyesters consisting of benzenedicarboxylic acid and long chain glycols can be used. Polyester was chosen as a hard component to improve poor moist heat resistance and poor yellowing resistance, i.e., defects of spandex. In addition, a method of increasing the elastic recovery of such a combination has been studied, and as a result, the block copolymer obtained by the reaction between a specific polyester and another specific polyester has high elastic recovery and high heat resistance at the site where the soft segment is increased. It was found that it can have.

According to one embodiment of the invention, 30-90% by weight of polyester segments consisting of 5-12 aliphatic diols of carbon atoms and rigid between benzenedicarboxylic acid as the acid main component of the soft segment (A) and hydroxyl groups as the glycol main component It is composed of 70-10% by weight of polyester consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol or 1,4-cyclohexane dimethanol as the main component of the acid of the component (B) and aromatic dicarboxylic acid and glycol Wherein (i) when the polyester having an intrinsic viscosity of at least 0.6 is formed by polycondensation of a component composed of a polyester segment (A) which is a soft segment, the melting point of the obtained polyester is 50 ° C. or less or the obtained polyester Polyester that is amorphous and (ii) a polyester having an intrinsic viscosity of at least 0.6 is a hard segment When formed by polycondensation of a component composed of segment (B), a polyester block copolymer is provided having a melting point of polyester of at least 180 ° C., having an intrinsic viscosity of at least 0.6.

According to another embodiment of the invention, an elastic yarn formed using such a polyester block copolymer is provided.

The composition of the polyester segment (A) of the present invention is a glycol component composed mainly of an acid component mainly composed of benzenedicarboxylic acid and an aliphatic diol having 5-12 carbon atoms between hydroxyl groups. The term used mainly in the present invention means that the content of an acid or glycol main component is at least 70 mol%; That is, other components may be contained in amounts up to 30 mol%. As benzenedicarboxylic acid, phthalic acid, isophthalic acid and terephthalic acid may be mentioned, but isophthalic acid is most commonly used most frequently. In order to control the crystallinity, isophthalic acid is sometimes copolymerized with terephthalic acid or phthalic acid, and for this control, terephthalic acid is used in amounts up to 30 mol%.

As aliphatic diols having 5-12 carbon atoms between hydroxyl groups, mention may be made of polymethylene glycol having 6-12 carbon atoms and diols in which the hydrogen atom of the methylene chain of the polymethylene glycol is substituted with methyl or ethyl groups. For example, HOCH ₂ CHCH ₃ (CH ₂ ) ₆ OH, HOCH ₂ CH ₂ CHCH ₃ CH ₂ CH ₂ OH and HOCH ₂ CH ₂ CH ₂ CH ₂ CHCH ₃ CH ₂ CH ₂ OH can be used.

In addition to the diol having 5-12 carbon atoms between the benzenedicarboxylic acid and the hydroxy group, the component to be copolymerized is not particularly limited and various components may be copolymerized to improve various properties. For example, an aliphatic dicarboxylic acid or an aliphatic polyether may be copolymerized to improve elastic recovery at low temperatures, or a compound having an affinity functional group with an ionic dye to improve dyeability. This may be copolymerized. As the aliphatic dicarboxylic acid, mention may be made, for example of α, ω-dicarboxylic acids having 6-12 carbon atoms, with 30 mol% of the amount copolymerized in general before being especially 10-30 mol%. In this amount of copolymerization, the decrease in the hydrolysis resistance is insignificant, and the elastic recovery is greatly increased at a temperature close to 0 ° C. As polyethers used for the same purpose, polytetramethylene glycol may be mentioned. The amount of polytetramethylene glycol mixed is preferably up to 30% by weight. If the amount is larger than this, a large amount of stabilizer must be used in the case of the polyether ester block copolymer, and thus the elastic recovery is sometimes poor.

0.5-5 mol% of a sulfonic acid salt compound represented by the following formula based on the dicarboxylic acid component constituting the entire polyester block copolymer with respect to the cationic dye, preferably a compound having a functional group compatible with the ionic dye. May be used in an amount of 1-3 mol%:

In the formula, M represents a metal or quaternary phosphonium group. As the metal M, Na, Li and K are preferable, and as the quaternary phosphonium group, a tetrabutyl phosphonium group, a butyltriphenyl phosphonium group and a tetraphenyl phosphonium group are preferable. More specifically, preferably 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid and its dimethyl ester are used.

For anionic dyes, for example, the diol compound having a quaternary phosphonium group, represented by the following formula, may be used in an amount of 0.5-5 mol%, preferably 1-3 mol%:

Wherein R ₁ , R ₂ and R ₃ each represent a hydrocarbon group, preferably a butyl group or a phenyl group, and X ⁻ represents a sulfonic acid anion, preferably a p-toluene-sulfonic acid anion or a methylsulfonic acid anion.

More specifically, the following compounds are preferably used:

The compound is preferably introduced into the soft segment, but may be introduced only in the hard segment or in both the soft and the hard segment.

The polyester (A ') having an intrinsic viscosity of at least 0.6, obtained by polymerization of the components constituting the polyester segment (A), must have a melting point of 50 ° C or lower or be amorphous. If the melting point is higher than this level, a polymer with the intended elastic recovery cannot be obtained. In view of elastic recovery properties, gum-like amorphous polymers are particularly preferred.

Polyester (A ') is used in the form of a polyester having an intrinsic viscosity of at least 0.6, prepared according to conventional production methods. In view of the subsequent blocking reaction, it is preferred to synthesize the polyester in the presence of a titanium or tin catalyst. This is because after the blocking reaction is performed at a relatively low temperature not exceeding 260 ° C., the reaction can be stopped by phosphoric acid or the like. Preferably, the intrinsic viscosity is 0.8-1.3. If the intrinsic viscosity is too low, the strength of the resultant molded articles or yarns, for example elastic yarns, is sometimes reduced. If the intrinsic viscosity is too high, subsequent blocking reactions do not proceed smoothly. Intrinsic viscosity mentioned in the present invention is measured at 35 ° C. in O-chlorophenol.

Polyester (B ') of intrinsic viscosity of at least 0.6 obtained by polycondensation of the components constituting the polyester segment (B) is produced by a conventional method. Preferably, such polyesters are also synthesized in the presence of titanium or tin catalyst. Polyester (B ') has an intrinsic viscosity of 0.6-1.5, preferably 0.8-1.3. Melting | fusing point of polyester (B ') is at least 180 degreeC, Preferably it is 200-260 degreeC. More specifically, aromatic dicarboxylic acids such as terephthalic acid, naphthalene-2,6-dicarboxylic acid or 4,4'-diphenyl-dicarboxylic acid, and ethylene glycol, trimethylene glycol, tetramethylene glycol or cyclohexane Polyesters of dimethanol may be mentioned. When polyester block copolymers are used in the form of fibers with good resilience, polytrimethylene terephthalate and polytetramethylene terephthalate are chosen and are resistant to heat and elastic recovery at sites where the amount of soft segments is at least 70%. It is used more preferably from another aromatic polyester from a viewpoint.

The polyester block copolymer of the present invention consists of the polyester segment (A) which is the aforementioned soft segment and the polyester segment (B) which is the hard segment.

The weight ratio of polyester segment (A) to polyester segment (B) is 30 / 70-90 / 10, preferably 75 / 25-85 / 15. The ratio of this polyester segment (A) / polyester segment (B) is a polyester block copolymer in the form of a yarn having a single filament fineness of about 20 deniers. It can be determined based on the amount of solid residue remaining upon treatment at 40 ° C. for time.

In the present invention, polyester (A ') and polyester (B') are subjected to a transesterification reaction (blocking reaction). The weight ratio of polyester (A ') to polyester (B') is adjusted to 30 / 70-90 / 10, preferably 50 / 50-85 / 15. If the ratio of polyester (A ') is less than this range, the effect of a block copolymer is low. For example, the elastic recovery performance is not satisfactory and the softening degree is poor. If the proportion of polyester (A ') exceeds the above-mentioned range, the crystallinity is poor and molding becomes difficult. When the block copolymer is used for the fibers, the above-mentioned range is preferably 70 / 30-90 / 10, in particular 75 / 25-85 / 15. Beyond this range, fibers with satisfactory elastic recovery performance cannot be obtained.

In the present invention, polyester (A ') and polyester (B') are melt reacted at the above-mentioned weight ratios. The progress of this melting reaction is very important but simply cannot be measured. Nevertheless, the melting point of the formed polyester block copolymer should be about 2-40 ° C. below the melting point of the starting material high melting point polyester (B ′). Particularly in the case of fibers, the progress of the melting reaction is at least 85%, in particular at least 90%, after 200% elongation of the fibers, and it is preferably determined that no adhesion occurs during the heat treatment performed at 130 ° C. These conditions depend on the polymer composition, the intrinsic viscosity of each polyester, the type of catalyst, the amount of catalyst, the reaction temperature, and the reaction pressure, so these factors are maintained at a constant level, varying the reaction time, and providing the polymers required. Investigate As another means, mention may be made of reactions in the absence of milky bodies of polymers, such as in the absence of deglossants, wherein the point at which the polymer becomes transparent is used to determine the end point. This method is useful in that even when the reaction conditions change, the corresponding end point of the reaction can be measured. In general, the reaction is stopped within 5 minutes from the point where the polymer becomes clear.

The blocking reaction can be carried out in batch or in a continuous manner. For example, a method of forming polyester (A ') by polymerization and adding inherently formed polyester (B') to polyester (A ') and reacting when the intrinsic viscosity is raised, and polyester The method of forming (A ') and (B') separately by polymerization and feeding into a continuous reactor may be adopted. The reaction is generally carried out at 230-260 ° C. under atmospheric pressure or reduced pressure. If the temperature is too low, the polyester (B ') is not readily dissolved and if the temperature is too high, it is difficult to stop the reaction, but if the reaction product can be cooled immediately as in a continuous process, the reaction temperature may be further raised. Can be. In order to suppress the reduction of physical properties in the subsequent spinning step, an acid such as phosphoric acid, phosphorous acid, phenylphosphonic acid or phenyl aphosphonic acid is preferably added to stop the reaction. The acid is generally added in an amount of about 1 to about 10 moles per mole of catalyst metal.

According to another type of the invention, the obtained polyester block copolymer is drawn into fibers. The spinning method is not specifically limited, but in general, the melt spinning method is adopted. According to the melt spinning method, the polymer melted by the usual method is extruded from the spinneret and cooled to obtain a compact. If the ratio of the acquisition rate to the extrusion rate is increased, the elongation rate is reduced. Elongation is reduced. Therefore, the acquisition speed is appropriately determined in accordance with the intended use. In order to suppress deterioration caused by the blocking reaction, the melting point is preferably at most 270 ° C, in particular at most 260 ° C.

In many cases the pulled fibers are used directly, but in many cases the pulled fibers are heat treated or stretched. The heat treatment temperature is generally 130-180 ° C., and stretching is generally performed at room temperature −70 ° C. Elongation of 3-6 is usually adopted.

Preferably, in the obtained elastic yarn, the elastic recovery after 200% elongation is at least 90% and adhesion of the filament does not occur even when the heat treatment is performed at 130 ° C. for 10 minutes. In many cases, elastic recovery is poor or adhesion occurs because of the use of inadequate conditions for the production of block copolymers. For example, if the reaction time is too long, heat resistance is lowered and adhesion occurs in the yarn. If the reaction time is too short, the elastic recovery is poor and the filament of the yarn cannot be released. Also, sometimes the transesterification proceeds excessively in the spinning step, with the same opposite result as the one observed when the reaction time is too long. Nevertheless, the desired fiber can be obtained if the previous factors are properly considered.

The polyester block copolymers of the present invention can be used in various articles as well as the elastic yarns mentioned above. For example, polyester block copolymers are formed into films and used for packaging films or liquid or blood infusion tubes. Moreover, as injection molding resins, polyester block copolymers can be used as shock absorbers such as automobile bumpers, and soft bottles. In the field of extrusion, polyester block copolymerization can be used to mold tubes and electrical wire coatings and the like. When the polyester block copolymers of the present invention are applied in these fields, excellent light stability is obtained, and since the stabilizer is not incorporated, the surface is not expressed, the surface is not blurred, hardly causes white mold, and biological damage is reduced. And excellent hygienic effect is achieved. According to the present invention, it is possible to obtain elastic yarns having excellent light stability and chlorine resistance than known elastic yarns, such as spandex yarns, and elastic recovery performance comparable to known elastic yarns. Even when the stabilizer is not used, the elastic yarn of the present invention has excellent light stability, and therefore, the elastic yarn is useful in that it is not necessary to pay attention to preventing the removal of the stabilizer in the dyeing step or the washing step (especially in the dry washing step). Do.

In particular, when polytrimethylene terephthalate or polytetramethylene terephthalate is used in the hard segments, even when the amount of the soft segments is increased to 70% by weight or more, elastic yarns having non-tacky and high elastic recovery properties can be obtained. have. This is most surprising, and I think this effect is due to the specific combination of polyester segments.

The present invention is characterized in that an ionic dye and a polyester block copolymer readily dyeable can be easily obtained. That is, since the compound having a functional group compatible with the ionic dye can be selectively introduced into the soft segment, the decrease in crystallinity or melting point in the hard segment can be suppressed and the deterioration in heat resistance can be prevented. .

Additives such as pigments, dyes, stabilizers, fillers, modifiers, emitters and flame retardants may be incorporated into the polyester block copolymers of the present invention. Elastic yarn can be used directly or when coated with other nylon or polyester fibers.

The invention will be described in detail with reference to the following examples. In the examples, both parts are by weight.

Example 1

A mixture of 70 parts of dimethyl isophthalate, 12 parts of dimethyl terephthalate, 40 parts of decandicarboxylic acid and 150 parts of hexamethylene glycol was heated together with 0.07 parts of titanium tetrabutoxide and the methanol and water formed as an adduct were removed. Thereafter, the reaction product was placed in a reaction tube capable of reducing pressure, and the reaction was carried out under reduced pressure to obtain polyester (A ') having an intrinsic viscosity of 0.95. Separately, polytetramethylene terephthalate [polyester (B ′)] having an intrinsic viscosity of 0.92 was polymerized in the same manner as described above to prepare from dimethyl tetraphthalate and tetramethylene glycol. Polyester (B ') was added to polyester (A') so that the amount of polyester (A ') might be 80 weight% and the amount of polyester (B') was 20 weight%. The mixture was reacted at 250 ° C. for 15 minutes under reduced pressure of 1 mmHg. First, the reaction mixture became cloudy but became clear when the reaction was performed for about 12 minutes. After 15 minutes, 0.1 part of phosphoric acid was added to the reaction mixture, the reaction mixture was stirred for 5 minutes, and the product was recovered to obtain a polyester block copolymer having an intrinsic viscosity of 0.96.

The obtained polyester block copolymer was extruded from a spinneret having 12 holes at 250 ° C., and the extrudate was wound at a speed of 400 m / min to obtain an elastic yarn having an elongation of 720% and a strength of 0.8 g / de, and an elastic yarn of 200% (first time). The elastic recovery rate of the elastic yarn was 93% when the elastic yarn immediately recovered after being stretched three times the length). When the elastic yarn was immersed at 60 ° C. for 2 hours in an aqueous solution of sodium hypochlorite having a chlorine concentration of 600 ppm and a pH value of 7, the strength was not reduced to an appreciable degree. When the elastic yarn was irradiated with a xenon tester at 60 ° C. for 144 hours, discoloration hardly occurred and the strength retention was higher than 80%. The elastic yarn was kept in tetrachloroethylene for 1 hour at 50 ° C. and dried, and then the thread was irradiated for 24 hours by a xenon tester in the same manner as described above. The strength retention after irradiation was 94%. In addition, when the elastic yarn was treated in hot water at 130 ° C. for 1 hour, the strength retention was 61%.

Example 2

A mixture of 70 parts of dimethyl isophthalate, 12 parts of dimethyl terephthalate, 34 parts of azelaic acid and 150 parts of decamethylene glycol was heated together with 0.02 parts of dibutyltin acetate and methanol and water formed as by-products were removed. Thereafter, the reaction product was placed in a reaction tube capable of reducing pressure, and the reaction was carried out under reduced pressure to obtain polyester (A ') having an intrinsic viscosity of 0.98. Separately, polytetramethylene terephthalate [polyester (B ′)] having an intrinsic viscosity of 0.92 was prepared by polymerization in the same manner as described above from dimethyl terephthalate and tetramethylene glycol. Polyester (B ') was added to polyester (A') so that the amount of polyester (A ') might be 85 weight% and the amount of polyester (B') would be 15 weight%. The mixture was reacted for 10 minutes at 250 ° C. under a reduced pressure of 1 mmHg. First, the reaction mixture was opaque but became clear when the reaction was performed for about 8 minutes. After 10 minutes, 0.1 part of phosphoric acid was added to the reaction mixture, the reaction mixture was stirred for 5 minutes, and the product was recovered to obtain a polyester block copolymer having an intrinsic viscosity of 0.92.

The obtained polyester block copolymer was extruded from a spinneret having 12 holes at 250 ° C., and the extrudate was wound at a speed of 400 m / min to obtain an elastic yarn having an elongation of 690% and a strength of 0.6 g / de, and an elastic yarn of 200% (first time). The elastic recovery rate of the elastic yarn measured after stretching to 3 times the length) was 95%. When the elastic yarn was immersed in an aqueous sodium hypochlorite solution having a chlorine concentration of 600 ppm and a pH of 7 at 60 ° C. for 2 hours, the strength was hardly decreased. When the elastic yarn was irradiated at 60 ° C. for 144 hours by xenon tester, discoloration hardly occurred and the strength retention was higher than 80%.

Comparative Example 1

In the same manner as described in Example 1 except that polyester having an intrinsic viscosity of 1.04 obtained by polymerization of decane-dicarboxylic acid and hexamethylene glycol in the presence of titanium tetrabutoxide as a polymerization catalyst was used as polyester (A '). To prepare a polyester block copolymer.

When the block copolymer was pulled in the same manner as described in Example 1 in the yarn obtained, the filaments adhered to each other and the yarn product could not be released from the bobbin. When the wound body was heat-treated at 130 ° C. for 10 minutes in a heated air dryer, fusion bonding of filaments occurred.

When the yarn was treated at 130 ° C. for 1 hour in hot water, the yarn became very weak.

From the previous results, if the above-mentioned aliphatic polyester is used as the polyester (A '), it is known that (1) the obtained block copolymer is very viscous and has poor heat resistance, and (2) hydrolysis resistance is very low.

Example 3-8 and Comparative Example 2

A mixture of 70 parts of dimethyl isophthalate, 12 parts of dimethyl terephthalate, 40 parts of dimethyl sebacate and 150 parts of decamethylene glycol was heated together with 0.02 parts of dibutyltin diacetate and methanol and water were removed as by-products. Thereafter, the reaction product was placed in a reaction tube capable of reducing pressure, and the reaction was carried out halfway under reduced pressure to obtain polyester (A ') having an intrinsic viscosity of 0.96. Separately, polytetramethylene terephthalate [polyester (B ′)] having an intrinsic viscosity of 0.92 was prepared by polymerization in the same manner as described above from dimethyl terephthalate and tetramethylene glycol. Polyester (B ') was added to polyester (A') and reacted at various ratios. Thereafter, phosphoric acid was added in the same manner as described in Example 1, and spinning was performed. The results are shown in the following table.

If the amount of polyester (B ') is too small from the result of the comparative example 2, it is known that heat resistance is low and moldability or spin property is inferior.

Example 9

Polyester block copolymers were prepared in the same manner as described in Example 1 except that polytrimethylene terephthalate (high viscosity 0.8), which was similarly formed by polymerization, was used instead of polytetramethylene terephthalate. The elastic recovery rate (after 200% elongation) of the yarn obtained by spinning was 91%. When the yarn was treated at 130 ° C. for 10 minutes, no adhesion occurred in the yarn.

Example 10

The synthesis of polyester block copolymers was attempted in the same manner as described in Example 1 using polytetramethylene-2,6-naphthalene-dicarboxylate instead of polytetramethylene terephthalate. Various reaction times were adopted and tested for heat resistance and elastic recovery. The results are shown in the following table.

When polytetramethylene-2,6-naphthalene-dicarboxylate is used compared to the case where polytetramethylene terephthalate is used, the range of conditions that provide optimum results is relatively narrow and the physical properties are relatively poor, It is known that elastic yarns can be formed.

Example 11

Dimethyl isophthalate, 1,12-dodecane-diol and ethylene glycol were subjected to ester ion exchange in the presence of titanium tetrabutoxide (40 mmol% on the basis of dimethyl isophthalate) as a catalyst and polymerized under high vacuum according to a conventional method. Polyester (A ') having an intrinsic viscosity of 1.10 was obtained. After hydrolyzing the obtained polyester, the copolymerization rate of the glycol component was measured by gas chromatography. It was found that the 1,12-dodecane-diol / ethylene glycol molar ratio 81/19.

Thereafter, 35 parts by weight of the same polyester (B ') as used in Example 1 was melted at 250 ° C., and then 65 parts by weight of the polyester (A ′) were added and the mixture was reduced at 250 ° C. under a reduced pressure of less than 1 mmHg for 1 hour 40 minutes. Stirring was carried out. When the reaction mixture became slightly transparent, phosphoric acid was added in an amount of 1.5 moles per mole of titanium.

The intrinsic viscosity of the obtained block copolymer was 1.12 and the melting point was 195 ° C (measurement was performed at a temperature rising rate of 20 ° C / min using a differential scanning calorimeter and the endothermic peak temperature was measured). The block copolymer was extruded at 250 ° C. from a nozzle hole having a diameter of 0.5 mm, and the extrudate was wound at a speed of 200 m / min to obtain a fiber. When the fibers were stretched 50% at 25 ° C. and recovered immediately, the recovery rate (measured after 1 minute; elastic recovery after 50% elongation) was higher than 95%. When the fibers were kept at 120 ° C. for 15 days in a heated air dryer, the elastic recovery after 50% elongation was higher than 95%. Thus, it was confirmed that the fibers have very high durability.

Comparative Example 3

A polyether ester block copolymer having a polytetramethylene glycol component content of 65% by weight was prepared from polytetramethylene glycol, dimethyl terephthalate and tetramethylene glycol having an average molecular weight of 2,000 according to a conventional method. This polymer had an intrinsic viscosity of 1.35 and a melting point of 189 ° C.

The polymer obtained was formed into fibers in the same manner as described in Example 1. When the elastic recovery rate was measured after 50% elongation, the elastic recovery rate was higher than 95% and was good. If the fibers were kept in a heated air dryer at 120 ° C., the fibers deteriorated and comminuted within about a week. Thus, it was confirmed that the polyether ester block copolymer has very good oxidation resistance.

Examples 12-22 and Comparative Example 4

The polyester (A ') and polyester (B') shown in the following table, prepared using titanium tetrabutoxide (40 mmol% based on the total dicarboxylic acid component), were melt mixed under the conditions shown in the table. . In the same manner as described in Example 1, when the reaction mixture became slightly transparent, phosphoric acid was added to the reaction mixture to obtain a polyester block copolymer.

The properties of the obtained polymer were evaluated in the same manner as described in Example 11. The results are shown in the following table.

week

DMI: Dimethyl Isophthalate

DMP: Dimethyl Phthalate

C _n G: n-alkane-diol having n carbon atoms

DMT: Dimethyl Terephthalate

DMN: Dimethyl 2,6-naphthalene-dicarboxylate

DMD: Dimethyl 4,4'-diphenyldicarboxylate

CHDM: 1,4-cyclohexane-dimethanol

MOD: 2-methyl-1,8-octane-diol

Example 23

In the presence of titanium tetrabutoxide (40 mmol% based on dimethyl isophthalate) as catalyst with dimethyl isophthalate and 5-tetrabutyl phosphonium sulfoisophthalic acid dimethyl ester (4 mol% based on dimethyl isophthalate), 1 It was transesterified with, 10-decane-diol and ethylene glycol, and polymerization was carried out at 260 ° C. under high vacuum according to a conventional method to obtain polyester (A ′) having an intrinsic viscosity of 1.05. The obtained polyester was hydrolyzed and the copolymerization rate of the glycol component was measured by gas chromatography, and it was found that the 1,10-decane-diol / ethylene glycol mole ratio was 81/19.

Thereafter, 35 parts by weight of the same polyester (B ') as used in Example 1 was melted at 250 ° C, and then 65 parts of the polyester (A') were added to the melt and stirred for 40 minutes at 250 ° C under a high vacuum of 1 mmHg or less. Was performed. When the reaction mixture became slightly transparent, phosphorous acid was added to the reaction mixture in an amount of 1.5 mol per mole of titanium.

The intrinsic viscosity of the obtained polyester block copolymer was 1.10 and the melting point was 193 ° C (measured at an endothermic peak temperature using a differential scanning calorimeter at a temperature rise of 20 ° C / min).

The polymer was dried and then melted at 260 ° C. and the melt was extracted from the cap with three-hole nozzles at an extrusion rate of 3.9 g / min. The extract was wound through two godet rolls at a speed of 1500 m / min to obtain an elastic yarn. The physical properties of the elastic yarn are shown in the following table. The elastic yarn was kept at 120 ° C. for 150 days in a heated air dryer, and then the recovery rate after 50% elongation was measured. The results are shown in the following table. It is known that the elastic yarn has excellent heat resistance. The elastic yarn was dyed at 120 ° C. for 60 minutes with a cationic dye (Cathilon Blue CD-FRLH / Cathion Blue CD-FBLH 1/1; supplied by Hodogaya Kagaku) 2% owf (Glauber salt 3g / l and acetic acid 0.3g / additional l)). The sharpness of the dyed fabric is shown in the following table.

Example 24

Dimethyl isophthalate and a compound of formula (a) (5 mol% based on dimethyl isophthalate) are transesterified with 1,10-decane-diol and ethylene glycol in the presence of titanium tetrabutoxide as catalyst, The polymerization reaction was carried out at 260 ° C. under high vacuum, thereby obtaining polyester (A ′) having an intrinsic viscosity of 1.02.

When the obtained polyester was hydrolyzed and the copolymerization rate of the glycol component was measured by gas chromatography, it was found that the molar ratio of 1,10-decane-diol / diethylene glycol was 86/14.

Thereafter, 35 parts by weight of the same polyester (B ') as used in Example 1 was melted at 250 ° C, and then 65 parts by weight of the polyester (A') was added to the melt and 40 minutes at 250 ° C under a high vacuum of 1 mmHg or less. The stirring reaction was carried out. When the reaction mixture became slightly transparent, phosphorous acid (1.5 mol per mole of titanium) was added to the reaction mixture.

The intrinsic viscosity of the obtained polyester block copolymer was 1.08, and melting | fusing point was 191 degreeC (blood absorption peak temperature was measured at 20 degree-C / min of temperature rise with the differential scanning calorimeter).

The polymer was evaluated in the same manner as described in Example 23. The results are shown in the following table. From the results presented, it was found that the elastic performance of the obtained block copolymer was excellent.

The elastic yarn was formed into a cylindrical knitted fabric, and the fabric was a dye solution containing an acid dye, Alizarin Light Blue AA 2% owf (pH value 3, acetic acid 3ml / l, bath ratio 1/50) Was stained at 120 ° C. for 60 minutes. The fabric was dyed very dark blue.

The present invention can provide a block copolymer having good elastic recovery by using a soft component having excellent oxidation resistance (light resistance, chlorine resistance, etc.) and hydrolysis resistance.

In addition, it is possible to provide an elastic yarn having a heat resistance that can exclude the temperature generally adopted in the fabrication, and the adhesion of the filament does not occur at this processing temperature.

Claims (9)

It consists of 30-90 wt% of the soft segment (A) and 70-10 wt% of the hard segment (B), and (A) 5-12 carbon atoms between the benzenedicarboxylic acid as the main acid component and the hydroxyl group as the main component of the glycol. Polyester segment consisting of two aliphatic diols and (B) an acidic component of the polyester segment consisting of aromatic dicarboxylic acid and a glycol major component of ethylene glycol, trimethylene glycol, tetramethylene glycol or 1,4-cyclohexane dimethanol Wherein (i) when the polyester having an intrinsic viscosity of at least 0.6 is formed by polycondensation of the component consisting of the polyester segment (A), the melting point of the polyester obtained is 50 ° C. or less or the polyester obtained is amorphous (ii) a polyester having an intrinsic viscosity of at least 0.6 by polycondensation of the component consisting of the polyester segment (B) Than when formed, has a melting point of the polyester, the inherent viscosity less than 180 ℃ at least 0.6 in the polyester block copolymer. The polyester block copolymer according to claim 1, wherein at least one component selected from the compounds represented by the following general formula is copolymerized in an amount of 0.1-5 mol% based on the entire acid component consisting of the polyester block copolymer: Wherein M represents an alkali metal or PR ₁ R ₂ R ₃ R ₄ , R ₁ , R ₂ , R ₃ and R ₄ are the same or different and represent a hydrocarbon group of 1-8 carbon atoms, X ⁻ Represents a sulfonic acid anion. The polyester block copolymer according to claim 2, wherein the compound to be copolymerized is selected from 5-sodium sulfoisophthalic acid, 5-tetrabutyl phosphonium sulfoisophthalic acid and dimethyl esters thereof. The polyester block copolymer according to claim 2, wherein the compound to be copolymerized is selected from the following formulas. The polyester block copolymer according to claim 1, wherein the polyester block copolymer has an intrinsic viscosity of 0.6-1.5, a melting point of 50 ° C. or lower, or an amorphous substance, and has a carbon number of 5 -C atoms between the benzenedicarboxylic acid as an acid main component and a hydroxyl group as a glycol main component. 30-90% by weight of polyester (A '), a soft segment composed of 12 aliphatic diols, has a melting point of 180 ° C. or higher, an intrinsic viscosity of 0.6-1.5, and an aromatic dicarboxylic acid and glycol as a main component of ethylene glycol, tri Polyester block copolymer obtained by melt-mixing and transesterifying with 70-10% by weight of polyester (B '), a hard segment having a high melting point composed of methylene glycol, tetramethylene glycol or 1,4-cyclohexane dimethanol Polyester block air characterized in that the melting point of the block copolymer is 2-40 ℃ lower than the polyester (B ') melting point coalescence. The polyester block copolymer according to claim 5, wherein the amount of polyester (A ') used is 50-85% by weight and the amount of polyester (B') used is 50-15% by weight. Elastic yarn composed of the polyester block copolymer of claim 1. 8. The aliphatic of claim 7, wherein the polyester block copolymer has an intrinsic viscosity of 0.6-1.5, a melting point of 50 ° C. or less, or an amorphous, aliphatic having 5-12 carbon atoms between the benzenedicarboxylic acid as an acid main component and a hydroxyl group as a glycol main component. 70-90% by weight of a soft segment polyester (A ') consisting of diol, having a melting point of 180 ° C. or higher, an intrinsic viscosity of 0.6-1.5, and a hard segment consisting of ethylene glycol, trimethylene glycol or tetramethylene glycol as main components of acid and terephthalic acid It is a polyester block copolymer obtained by melt-mixing together with 30-10 weight% of polyester (B '), and the melting point of this block copolymer is 2-40 degreeC lower than melting point of polyester (B'). , The elastic recovery rate is at least 90% after 200% tension of the elastic yarn, and when the elastic yarn is heat-treated at 130 ℃ for 10 minutes, Elastic yarn characterized by no adhesion. The elastic yarn according to claim 8, wherein the amount of polyester (A ') used is 75-85% by weight and the amount of polyester (B') used is 25-15% by weight.