JPS6117946B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for efficiently producing an elastic fabric with improved elastic properties and thermal stability by weaving and weaving single filament yarns of elastic fibers in the same manner as ordinary inelastic fibers. A polyester polyether block copolymer, which has a hard segment of polyester such as polyethylene terephthalate and a soft segment of polyalkylene ether glycol such as polyethylene glycol or polytetramethylene glycol, has rubber-like elasticity. It is already known that elastic fibers can be obtained from coalescence (for example, Japanese Patent Publication No. 14054/1983, Japanese Patent Application Laid-open No. 1983-14054).
10346, JP-A-48-10350, etc.). However, the methods for producing elastic fabrics described in these publications involve blending or blending elastic fibers made from polyester polyether block copolymers with other fibers, and then knitting and weaving them. This manufacturing method was insufficiently efficient in that it required a process of blending and blending fibers. In addition, elastic fibers using polyethylene terephthalate have the disadvantage of poor thermal stability, so fabrics obtained by mixing them with other inelastic fibers,
In practice, it has been difficult to increase the stability of the fabric shape by heat setting without impairing its elastic properties.
That is, heat-setting at temperatures high enough to heat-set inelastic fibers (e.g., over 150°C in dry heat) will impair their elastic properties, whereas lowering the heat-setting temperature will cause inelastic fibers to become sufficiently heat-set. There were disadvantages in that the elastic fabric could not be set, had poor shape stability, and had irregular dimensions (dimensional irregularities due to poor heat fixability). In addition, it was previously thought that elastic copolymers containing polybutylene terephthalate as hard segments lacked the flexibility and advanced elastic recovery properties necessary for elastomers, and were unsuitable for use as elastic fibers (Japanese Patent Laid-Open No. 52 -57292). The purpose of the present invention is to overcome the drawbacks of such conventional methods, to be able to produce elastic fabrics with excellent elastic recovery characteristics and excellent thermal stability with high efficiency, and to be able to produce elastic fabrics with high efficiency after relaxation heat treatment. The object of the present invention is to produce an excellent fabric that can be set to form an elastic fabric with excellent shape stability. In order to achieve this object, the present invention uses a polyester consisting essentially of polybutylene terephthalate as a hard segment, and a polyester polyester consisting of a polyalkylene ether glycol whose main component is at least polytetramethylene glycol as a soft segment. After the ether block copolymer is melt-spun, it is stretched to twice or more to obtain a latent shrinkable elastic fiber. The filament yarn consisting only of the latent shrinkable elastic fibers is inter-knitted or interwoven with other non-shrinkable fiber yarns without using an active yarn feeding device, and then subjected to a relaxing heat treatment. The term "latent shrinkage" as used in the present invention refers to the ability and property of shrinking by heat treatment, and specifically refers to a boiling water shrinkage rate defined by the following formula of 30% or more. Boiling water shrinkage rate = lo-l/lo x 100 [%] (lo = length of fiber measured with a load of 3 mg per denier, l = length of fiber measured under no tension in boiling water for 30 minutes, then taken out. Fiber length measured after cooling and applying a load of 3 mg per denier) Hereinafter, the method for producing the elastic fabric of the present invention will be specifically described. The polyester polyether block copolymer can be produced by the following method. For example, a method in which a lower alcohol diester of a dicarboxylic acid, an excess amount of a low molecular weight glycol, and a polyalkylene ether glycol is transesterified in the presence of a catalyst, and the resulting reaction product is polycondensed; and polyalkylene ether glycol in the presence of a catalyst, and the resulting product is polycondensed, or polyalkylene terephthalate is prepared in advance and dicarboxylic acid, diol, or polyalkylene ether glycol is added to it. Alternatively, other copolymerized polyesters may be added and randomization may be performed by transesterification. The polyester polyether block copolymer obtained by the above method is formed into chips, melt-spun using a normal melt-spinning device, and air-cooled. Therefore, it can be used as a latent shrinkable elastic fiber. In the above manufacturing method, the hard segment of the polyester polyether block copolymer consists essentially of polybutylene terephthalate. As this hard segment, it is preferable to use polybutylene terephthalate alone that does not contain other polyester components, but polybutylene isophthalate, polybutylene sebacate, polybutylene adipate, polybutylene paraoxyethoxybenzoate, polybutylene dodecanate, polybutylene Other polyester components such as butylene orthophthalate may be included within a range (for example, 10 wt% or less) that does not impede the properties of polybutylene terephthalate. As the soft segment, polytetramethylene ether glycol alone is most suitable, but other polyalkylene ether glycols (for example, polyethylene ether glycol, polytrimethylene ether glycol, etc.) may be used as necessary.
Copolymerized polyalkylene ether glycols such as poly(tetramethylene ether/ethylene ether) glycol may also be used. However, in the case of mixing or copolymerization,
In terms of heat resistance, light resistance, chemical resistance, etc., the content of polytetramethylene ether glycol is 80wt.
% or more. The copolymerization ratio (weight) of the above-mentioned polyester as a hard segment and the above-mentioned polyalkylene ether glycol as a soft segment is preferably 70:30 to 20:80 from the viewpoint of elastic properties, strength, melting point, etc., and more preferably 60:80. :40-25:75 is good. The number average molecular weight of the polyalkylene ether glycol is preferably 1000 to 4000, more preferably 2000 to 3000, from the viewpoint of raising the melting point of the fiber and improving elastic properties at high temperatures. In addition, the above-mentioned polyester polyether block copolymer may be added with an optional quenching agent or various other stabilizers during polymerization, before forming into chips after polymerization, or before melt spinning after forming into chips. A small amount may be added. After melt spinning, polybutylene terephthalate, which is the hard segment (or main component) of the copolymer, has a high crystallization rate and is highly crystalline, so it is cooled in air without cooling with water or other solvents. The bottom can be easily made into fibers. It is necessary to draw the obtained fiber twice or more. If this stretching ratio is less than 2 times, the boiling water shrinkage rate of the fiber obtained by stretching is 30%.
It is small and does not show sufficient latent contractility. It is preferable to stretch it three times or more. The latent shrinkable elastic fibers produced in this way have a high strength modulus and almost no tension unevenness during winding, so they can be formed into a pirn shape similar to non-elastic fibers such as general polyamide fibers and polyester fibers. It can also be rolled up. Next, this latent shrinkable elastic fiber is knitted or interwoven with other inelastic fibers in the form of a single filament yarn, then subjected to relaxation heat treatment, and further heat set as necessary to make it elastic. Manufacture fabric. At this time, the latent shrinkable elastic fibers can be treated in the same way as other inelastic fibers, so there is no need to combine them (covering, twisting, etc.), blend them, or blend them with other fibers. Since there is no need to use an active yarn feeding device, it is possible to inter-knit or mix-weave with a single filament yarn in the same manner as other inelastic fibers, making it possible to knit and weave elastic fabrics with high efficiency. can do. The relaxation heat treatment after knitting and weaving may be carried out using either dry heat or wet heat, and must be carried out at a temperature below the melting point of the latent shrinkable elastic fibers.
It is desirable to carry out the heating at 70 to 130°C from the viewpoint of the heat setting effect when heat setting is performed later and the elastic properties of the fabric. As other inelastic fibers, inelastic synthetic fibers such as general polyamide fibers and polyester fibers are usually used, and natural fibers may also be used. After the relaxation heat treatment, a heat setting similar to that of ordinary fabrics is performed, if necessary. In the case of dry heat treatment,
A sufficient heat setting effect can be obtained if the temperature is 150°C or higher. The elastic fabric of the present invention obtained in this manner can be heat-set without loss of elasticity under temperature conditions (for example, dry heat of 150°C or higher) that can sufficiently heat-set the inelastic fibers. Since it has as excellent thermal stability as possible, it can also be made into an elastic fabric that does not have irregular dimensions and has good shape stability. Furthermore, the obtained elastic fabric is excellent in its elastic properties. As explained above, the important requirements for the method of the present invention are, firstly, that latent shrinkage elastic fibers obtained by melt-spinning a specific polybutylene terephthalate-based elastic copolymer and drawing it twice or more; , knitted or interwoven with other non-shrinkable fiber yarns as a filament yarn on its own, without compounding, mixing or blending with other fibers, and without using an active yarn feeding device, followed by relaxation heat treatment. However, if necessary, heat set at 150°C or higher. This requirement is compatible with the next application, which uses an elastic copolymer with a hard segment of polybutylene terephthalate, which was previously thought to be unsuitable for elastic fibers because it lacks the flexibility and high elastic recovery properties required for an elastomer. This is a condition that could only be achieved by taking the condition. The second important requirement is that the polyester polyether block copolymer constituting the elastic fiber
The purpose of this invention is to use a specific polymer whose block components are a hard segment consisting essentially of polybutylene terephthalate and a soft segment consisting of polyalkylene ether glycol whose main component is at least polytetramethylene glycol. In this way, the present invention has such good thermal stability that sufficient heat setting can be achieved only by combining the above two requirements, and
An excellent elastic fabric with improved elastic properties can be efficiently produced using a single filament yarn using a simple method similar to the weaving and weaving method of ordinary inelastic fibers. Hereinafter, the effects of the method of the present invention will be specifically explained with reference to Examples. [Example 1] 3490 parts of terephthalic acid, 1,4-butanediol
A polyester polyether block copolymer (polybutylene (using terephthalate as a hard segment and polytetramethylene ether glycol as a soft segment) was obtained. The melting point (endothermic peak determined by differential thermal spectroscopy) of the obtained copolymer was 207°C;
Intrinsic viscosity (in orthochlorophenol at 25℃) is
It was 4.10. This copolymer was melt-spun using a screw-type extruder (spinning temperature 250℃, nozzle diameter 0.5mm, 8 holes, output rate 38g/min), and cooled and solidified by blowing cooling air at 15℃ (30m/min). After letting
The fiber was wound for 8 minutes at a speed of 600 m/min. The spinning state was extremely stable, there was no sticking, and fiber division was easy. This fiber was stretched five times at room temperature (30°C) and wound into a pirn shape on a bobbin. The wound package had a good form and had excellent unwinding properties. Latently shrinkable elastic fiber A obtained in this way
Table 1 shows the properties of Fiber A and the properties of Fiber B obtained by subjecting Fiber A to boiling water shrinkage treatment.

【table】

[Example 2]

Polyester polyether copolymers with different hard and soft segment compositions and copolymerization ratios,
Obtained by polymerization in the same manner as in Example 1 (Second
table).

[Table] In Table 2, samples a1 to a3 are copolymers according to the production method of the present invention, and c to e are control samples. These copolymers were each spun in the same manner as in Example 1 (each fiber was A1, A2, A3,
C, D, E) and evaluated its characteristics (3rd
table).

[Example 3]

The properties of the fiber obtained by changing only the stretching conditions in the manufacturing method of Example 1 were evaluated (4th
table). In the table, A4 to A8 are latent shrinkable elastic fibers produced by the production method of the present invention, and F is a control fiber.

[Example 4]

The heat fixability of the latent shrinkable elastic fiber A obtained in Example 1 was compared with that of commercially available spandex fiber S (Table 5). In order to make the conditions consistent, fiber A was subjected to boiling water shrinkage treatment.

[Table] As is clear from Table 5, although the heat fixation rate of spandex fibers is 0 at 150°C and 160°C, the heat fixation rate of the fibers according to the present invention is extremely high at 90% or more. Next, the chemical resistance (especially against chlorine-based chemicals, which is the most problematic) of the fiber A and the spandex fiber S after the boiling water treatment was evaluated (Table 6).

【table】

[Table] As shown in Table 6, after being immersed in a 0.1% calcium hypochlorite solution, the strength retention rate and elongation retention rate of the spandex fibers were extremely low. All fibers have a high retention rate of 80% or more. Needless to say, yellowing was clearly visible in spandex fibers, but yellowing was not noticeable in the fibers of the present invention, and the YI (yellowness index) value was not a problem. low. [Example 5] The latent shrinkable elastic fibers obtained in Example 2 and Example 3 were inter-knitted with nylon yarn to knit a half tricot in the same manner as in Example 1, and then subjected to relaxation heat treatment, Heat set at 160°C. The method of the present invention using fibers A1, A2, and A3 of Example 2 had good elastic properties even after heat setting, whereas polyethylene terephthalate elastic fibers of fibers C, D, and E had good elastic properties. When used, the elastic properties were greatly impaired during heat setting, and only fabrics with poor elastic properties could be obtained.
The elastic properties of the fabric using the fiber C were as follows. Elongation rate Elongation recovery rate Vertical direction 76.0% 72.1% Horizontal direction 146.7% 67.6% Furthermore, in the case of the method of the present invention using fibers A4 to A8 in Example 3, it had good elastic properties even after heat setting. On the other hand, when fibers F which were insufficiently stretched and had insufficient latent shrinkage properties were used, only a fabric with poor elastic properties could be obtained as shown below. Using fiber F: Elongation rate Elongation recovery rate Vertical direction 43.0% 45.0% Horizontal direction 86.4% 42.0% Furthermore, since the spandex fiber obtained in Example 4 is extremely easy to stretch even with a small force, it is difficult to warp and The yarn could not be knitted, and after being made into a covering yarn, it had to be interknitted with nylon yarn. [Comparative Example] A polyester copolymer was polymerized in the same manner as in Example 1, except that polybutylene terephthalate and polybutylene phthalate were used as hard segments at a molar ratio of 70:30, followed by melt spinning, stretching, and cross-linking. A fabric was prepared by knitting, relaxing heat treatment and heat setting. Even if the heating temperature during heat setting was lowered to 140°C, the elastic properties of the fabric were lost, so heat setting could not be performed without losing the elastic properties.

Claims (1)

[Claims] 1 Using polyester consisting essentially of polybutylene terephthalate as the hard segment,
A polyester polyether block copolymer made of polyalkylene ether glycol whose main component is at least polytetramethylene glycol is melt-spun as a soft segment, and then stretched to twice or more to obtain a latent shrinkable elastic fiber, A method for producing an elastic fabric, characterized in that the filament yarn consisting only of the latent shrinkable elastic fibers is knitted or interwoven with other non-shrinkable fiber yarns without using an active yarn feeding device, and then subjected to relaxation heat treatment. .