JPH0544128A - Copolyester spun yarn with shape memory capacity - Google Patents

Abstract

(57) [Summary] [Problem] To provide a copolyester spun yarn that has a shape memory ability and can be a cloth that returns to the shape after being typed at a high temperature even if it loses its shape by mild heating. [Structure] Polyethylene terephthalate having a melting point of 150 ° C. or higher, which is obtained by copolymerizing a long-chain aliphatic dicarboxylic acid having 6 or more carbon atoms, such as dodecanedioic acid, and has a single fiber strength of 2.5 g.
/ A spun yarn composed of a copolyester fiber having a shape memory ability of denier or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spun yarn made of synthetic fiber, and more particularly to a spun yarn made of copolyester having a shape memory ability.

[0002]

2. Description of the Related Art In recent years, synthetic resins having shape memory ability have been developed and put on the market. This resin has a large change in elastic modulus before and after the glass transition point. The function is, for example, to first form an arbitrary shape A, heat in the state of the shape A and crystallize (entanglement of crystal parts) or intermolecular cross-linking to generate a fixed point and store the shape. Then, an external force is applied in an atmosphere having a glass transition temperature or higher and lower than the above heating temperature to deform into shape B, and the temperature is maintained below the glass transition point as it is, so that shape B can be fixed. By further heating this above the glass transition point, it has a function of recovering the shape A without applying an external force, that is, it has a "shape memory ability".

As a resin material having a shape memory ability, a polytransisoprene resin (Japanese Patent Laid-Open No. 55-93806) is used.
No.), polynorbornene-based resin (JP-A-59-5352)
No. 8), consisting of a mixture of vinyl resin and acrylic acid resin or synthetic rubber (JP-A-63-17952).
No.) etc. are known. Further, a polyurethane-based shape memory polymer yarn (Japanese Patent Laid-Open No. 2-169713) is disclosed.

However, conventionally known resin materials have poor spinnability, and it is difficult to produce a fiber having a fineness of about 1 to 3 denier and a strength capable of being spun with good productivity, which is used as a spun yarn. ， It was almost impossible.

[0005]

The present invention is intended to solve such a problem. That is, it is intended to provide a spun yarn using a copolyester having a shape memory ability, which is capable of melt-spinning fibers having high fineness with high productivity as in the case of ordinary polyester.

[0006]

The present inventor has arrived at the present invention as a result of extensive studies to solve the above-mentioned problems.

That is, the first invention of the present application comprises a copolyester fiber having a glass transition point of 80 ° C. or lower, a melting point of 150 ° C. or higher, and a single fiber strength of 2.5 g / denier or more and a shape memory ability. The second invention of the present application is a copolymerized long-chain aliphatic dicarboxylic acid having 6 or more carbon atoms, having a glass transition point of 80 ° C. or lower and a melting point of 150. Above ℃,
The gist of the present invention is a copolyester spun yarn characterized by comprising a polyethylene terephthalate fiber having a shape memory ability of a single fiber strength of 2.5 g / denier or more.

The present invention will be described in detail below.

The copolyester having shape memory ability used in the present invention has the following characteristics. (a) The shape is memorized when it is crystallized in a heating atmosphere after melt molding. (b) When an external force is applied in a temperature range higher than the glass transition point and lower than the temperature at which the shape is memorized, it deforms relatively easily. (c) If the temperature is below the glass transition temperature while maintaining the deformed shape, the deformed shape is fixed. (Shape-fixing ability) (d) Furthermore, if a temperature higher than the glass transition point is applied to this without applying an external force, the shape remembered in (a) is restored. (Shape recovery ability)

The glass transition point of the copolyester must be 80 ° C. or lower. If the glass transition point exceeds 80 ° C, the temperature required for shape recovery is too high, which is not practical. When the glass transition point is about 45 ° C. or higher, the spun yarn of the present invention has a firm texture similar to that of a normal polyethylene terephthalate spun yarn up to room temperature or near body temperature. ， Return to the memorized state. If the glass transition point is lower than room temperature or body temperature, the temperature will be higher than the glass transition point during normal use.
Since the body is soft and has a property of always returning to a memorized state, for example, when the cloth made of the spun yarn of the present invention is preliminarily memorized at a high temperature in a wrinkle-free state before use, Wrinkles are more difficult.

The melting point of the copolyester must be 150 ° C. or higher. If the melting point is less than 150 ° C., it becomes difficult to perform hot set or high temperature dyeing for preventing shrinkage of the spun yarn upon heating, which is not practical.

Further, the single fiber strength of the copolyester fiber must be 2.5 g / denier or more. If the strength of the single fiber is less than 2.5 g / denier, the spinning property and the yarn quality are deteriorated due to the breakage of the single fiber in the spinning process, which is not practical.

Next, as a method of obtaining a copolyester having a shape memory ability, a method of copolymerizing an aromatic polyester segment (hard segment) and an aliphatic polyester segment (soft segment) at an appropriate ratio to obtain a polymer Another example is a method of copolymerizing an aromatic polyester segment (hard segment) and a polyalkylene glycol segment (soft segment) at an appropriate ratio to obtain a polymer, but the former is preferable.

The aromatic polyester segment means a polyester segment having at least one aromatic ring in the polyester repeating unit, and the aliphatic polyester segment means a polyester segment in which the polyester repeating unit is composed only of an aliphatic compound. Say that.

Examples of the aromatic monomer component constituting the hard segment include terephthalic acid, isophthalic acid, bisphenol A, dicarboxylic acids such as p-oxybenzoic acid, diols and hydroxycarboxylic acids.

Examples of the aliphatic monomer component which constitutes the hard segment with the aromatic monomer or the soft segment itself includes adipic acid,
Azelaic acid, dodecanedioic acid, eicosanedioic acid, ethylene glycol, butanediol, hexanediol, ε
-Dicarboxylic acids such as caprolactone, diols and oxycarboxylic acids (or lactones). Polyalkylene glycols such as polyethylene glycol and polytetramethylene glycol can also function as the soft segment component.

As the hard segment, polyester of ethylene terephthalate unit or butylene terephthalate unit is preferable, but ethylene terephthalate unit is most preferable in view of economy and physical properties.

The soft segment is preferably a long-chain aliphatic dicarboxylic acid such as azelaic acid, sebacic acid or dodecanedioic acid, and particularly an ester unit of an aliphatic dicarboxylic acid having 6 or more carbon atoms and ethylene glycol.

In the copolyester used in the present invention, it is considered that the soft segment acts as an intramolecular plasticizer to promote the crystallization of the polymer and causes the entanglement of the crystallized portions to give a fixed point. .. Even a copolyester consisting of only these hard and soft segments can be made into a polyester having sufficient shape memory capacity, but even if a molecular structure capable of intermolecular cross-linking is introduced, the rubber remembers its shape by vulcanization. Similar to the principle described above, it can function as a fixing point for fixing the shape to be memorized by cross-linking the polyester molecules at important points. Specific examples of the molecular structure capable of intermolecular crosslinking include a structure in which a monomer component having an unsaturated bond is copolymerized and an unsaturated bond is introduced into the main chain of polyester. Intermolecular cross-linking becomes possible by cleaving this unsaturated bond by an appropriate means when the shape is fixedly memorized.

Examples of monomer components which can be copolymerized with polyester and have an unsaturated bond include, for example, maleic anhydride, maleic acid, chloromaleic acid, itaconic acid, fumaric acid, citraconic acid, hettic acid, hettic anhydride, 2-
Examples thereof include unsaturated dicarboxylic acids or unsaturated diols such as butene-1,4-diol and 3-butene-1,2-diol.

Copolymerization of a polyester with a trifunctional or higher functional monomer component is also an effective means. In this case, when the shape is fixedly stored, intermolecular crosslinking can be performed by adding and reacting a crosslinking agent having a hydroxyl group or a carboxyl group of polyester, an isocyanate group, an amino group or the like.

If desired, the polyester of the present invention may be copolymerized with other auxiliary raw materials as long as the object of the present invention is not impaired, and various additives are included. Good.

The constituent components of the monomers constituting the polyester used in the present invention and the copolymerization ratio thereof can be selected within a wide range, but in consideration of economical efficiency, versatility, physical properties, etc., for example, the following are preferable. .. That is, terephthalic acid as a dicarboxylic acid is 50 to 95 mol%, preferably 60 to 90 mol%, dodecanedioic acid is 5 to 50 mol%, preferably 10 to 40 mol%, and ethylene glycol is 100 mol% as a diol. It is a polyester used in proportion. In this example, the repeating unit consisting of ethylene glycol and terephthalic acid is the hard segment,
Repeating units consisting of ethylene glycol and dodecanedioic acid share the function of soft segment.

The polyester fiber used in the present invention may be produced by a melt spinning method and a drawing method, like the general-purpose polyester fiber. Spinning conditions and drawing conditions differ depending on the physical properties of the shape-memory polyester used, but can generally follow conventional techniques. That is, spinning may be performed using a general-purpose spinning device or a composite spinning device. The spun fibers are
If necessary, it may be stretched or heat treated continuously or in a separate process.
It is subjected to high-level processing such as crimping and chemical treatment. In addition, additives such as stabilizers, fluorescent agents, pigments, and reinforcing materials may coexist during spinning.

The fiber shape of the copolyester fiber may be a round cross section, an irregular shape such as a triangular cross section, or a hollow fiber.

The obtained copolyester fiber can be formed into a spun yarn with high productivity by a conventional method, and can be subjected to a weaving / weaving process and a dyeing process in the same manner as ordinary polyethylene terephthalate.

The spun yarn of the present invention contains polyester fibers such as ordinary polyethylene terephthalate and polybutylene terephthalate which do not have a shape memory ability, nylon fibers, rayon fibers, wool, cotton, etc. within a range that does not impair the shape memory ability. It may be a blend of synthetic fibers such as hemp, recycled fibers and natural fibers.

[0028]

As in the spun yarn of the present invention, if the shape is memorized in the heat treatment process in which a fixed point is generated, when the temperature exceeds the glass transition point, the shape is restored. The action works and it becomes possible to return to the original shape.

[0029]

EXAMPLES Next, the present invention will be described with reference to examples. In the examples, the characteristic values of polyester are measured as follows. (1) Intrinsic viscosity An equal weight mixture of phenol and ethane tetrachloride was used as a solvent, and measurement was performed at a temperature of 20 ° C. (2) Melting point and glass transition point Differential scanning calorimeter (Perkin Elmer, DSC-2)
Type) was used and the temperature was raised at a rate of 20 ° C./min.

Example 1 Bis (β-hydroxyethyl terephthalate) obtained by the esterification reaction of terephthalic acid with ethylene glycol and 45.0 kg of its oligomer were mixed with dodecanedioic acid.
5.8kg, maleic acid 0.4kg, ethylene glycol 9.0k
g, add 26 g of tetrabutyl titanate as a catalyst,
The esterification reaction was carried out at 250 ° C. under a nitrogen gas pressure of 3.6 kg / cm ² for 2 hours. The copolymerization amount of dodecanedioic acid was 10 mol% and the copolymerization amount of maleic acid was 1.5 mol%.

The obtained esterified product was transferred to a polycondensation reactor and subjected to polycondensation reaction at 280 ° C. and 0.4 torr for 3 hours to obtain a copolyester A. The obtained copolyester A has a glass transition point of 49 ° C, a melting point of 232 ° C and an intrinsic viscosity of 0.
It was 65.

After the chips of copolyester A were dried under reduced pressure, they were melted by using a usual melt spinning device, and the number of spinning holes was 4
Through 15 spinnerets, spinning temperature 270 ℃, total discharge 3
Melt spun at 00 g / min. After cooling the spun fiber yarn, it was taken out at a take-up speed of 1000 m / min to obtain an undrawn fiber yarn. The obtained filaments are bundled, made into a tow of 100,000 denier, and drawn at a draw ratio of 3.4 and a draw temperature of 60 ° C, and then drawn at 150 ° C.
After heat-treating with a heat drum, the crimp was applied using a push-in crimper. Subsequently, it was cut into a length of 51 mm to obtain a copolyester fiber having a single yarn fineness of 2 denier, a single fiber strength of 6.0 g / denier and an elongation of 57% and a shape memory ability. Using this fiber, a spun yarn of the present invention of 20th count was obtained through card, drawing, roving, and spinning.

This spun yarn was woven with a design of 103 warps / inch, 87 wefts / inch, and a width of 93 cm, and desizing and scouring were carried out according to a conventional method. Further, using a high-pressure beam dyeing machine, high temperature dyeing was carried out with a disperse dye and a dispersant at 130 ° C. for 1 hour to obtain a blue cloth. The 40 cm square of this cloth was folded in two and heat-set with an iron heated to 175 ° C. to memorize the creases. Further, after washing this with a home washing machine, the cloth was hung in a drying room at 60 ° C with one side of the cloth facing upward and dried. When it was taken out after drying, the creases that were memorized were clearly recognized as compared with those obtained by ironing ordinary polyethylene terephthalate cloth under the same conditions.
The shape memory ability was good.

Examples 2 to 3 and Comparative Example 1 Copolyesters B to D were prepared in the same manner as in Example 1 except that maleic acid was not added and the copolymerization amount of dodecanedioic acid was changed. Obtained. Table 1 shows the physical properties of these copolyesters. Further, Examples 2 to 3 and Comparative Example 1 were performed in the same manner as in Example 1 except that these copolyesters were used instead of the copolyester A in Example 1 and the heat drum temperature in the stretching step was changed.
I got a spun yarn. Using these spun yarns, weaving and dyeing were performed in the same manner as in Example 1 except that the iron heat setting temperature for storing the crease was changed, and the shape memory ability was evaluated. The results are also shown in Table 1.

[0035]

[Table 1]

The shape memory abilities of Examples 2 and 3 were good, as in Example 1, and could be visually judged by the memory condition of the folds, but the copolyester having a large amount of copolymerization of dodecanedioic acid and a low melting point. In the case of Comparative Example 1 which is a fiber, a light fusion between the fibers occurred during dyeing, resulting in a rough texture, and the shape memory ability was also poor.

Comparative Example 2 In Example 1, a copolyester E having an intrinsic viscosity of 0.44 was obtained by setting the polycondensation reaction time to 1.5 hours. The glass transition point of this copolyester E is 47 ° C, and the melting point is 230 ° C.
Met. Except for using this copolyester E,
The same procedure as in Example 1 was carried out to obtain a copolyester fiber having a single fiber strength of 2.3 g / denier and an elongation of 50%. Spinning was carried out using this fiber, but since the spinning performance was poor due to the occurrence of cotton wool and yarn breakage, the subsequent tests were cancelled.

[0038]

According to the present invention, a polyester spun yarn having a shape memory ability can be obtained. Once the fabric using this is modeled, even if it loses its shape when used, it returns to its original modeled state by light heating. That is, the fabric obtained by weaving and knitting the spun yarn of the present invention is wrinkled, heat-pressed or heat-treated into a three-dimensional shape, and if the crystallization or the crosslinking reaction is promoted in that state, the shape is memorized. And
Even if the memorized shape collapses due to use or washing,
The original shape is restored by light heating above the glass transition point. Therefore, it can be applied to bedding materials such as futon side cloths, bedding materials such as pillow covers, or clothing such as cuter shirts, polo shirts, trousers, ties, etc., to prevent wrinkles and creases by press working for a long time, or to make cloth centering materials and hat materials. It can be applied to and promote the shape prevention effect. Further, the spun yarn of the present invention can be applied to piles such as mockets and carpets to bring about an effect of correcting pile collapse.

Claims (2)

[Claims] 1. A glass transition point of 80 ° C. or lower and a melting point of 15
A spun yarn comprising a copolyester fiber having a shape memory capacity of 0 ° C or higher and a single fiber strength of 2.5 g / denier or higher. 2. A glass transition point of 80 ° C. or lower and a melting point of 15 which is obtained by copolymerizing a long-chain aliphatic dicarboxylic acid having 6 or more carbon atoms.
A copolyester spun yarn comprising a polyethylene terephthalate fiber having a shape memory capacity of 0 ° C. or higher and a single fiber strength of 2.5 g / denier or higher.