JP2558322B2 - Cationic dyeable polyester fiber having good texture and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester fiber having a texture similar to that of natural silk fiber and having an easily dyeable property in cationic dyeing, and a method for producing the same. Is.

(Prior Art) Conventionally, fibers made of filaments of synthetic fibers such as polyester and polyamide have a large single yarn fineness and a simple cross-sectional shape, and therefore are compared with natural fibers such as silk, cotton, and hemp. The texture and luster were monotonous, and because it was plastic, it felt cold and of low quality.

In recent years, various attempts have been made to modify the cross section of the fiber, crimp processing, composite fibers, etc. in order to improve these drawbacks, but at present, the objective has not yet been sufficiently achieved.
For example, JP-A-56-165015, JP-A-57-5921, and JP-A-
58-98425 and JP-A-61-239010 are used to form a composite fiber of an easily soluble polymer and a polyester, which is then post-processed to give a dry touch and a texture with a squeaky feeling and a unique gloss. It may be applied to a knitted fabric, or Japanese Patent Publication No. 51-7207, JP-A-58-70711, JP-A-62-13311.
No. 8, etc., a method for improving the feeling by imparting spots in the fiber length direction, or Japanese Patent Publication No.
As disclosed in Japanese Patent No. 3 and Japanese Patent Publication No. 56-16231, etc., a method for improving the feeling by fibrillating synthetic fibers has been proposed. However, it is not sufficient in providing synthetic fibers with a texture similar to that of natural fibers, and in particular, imparts a texture and surface appearance and retains natural spots that have a soft feeling similar to that of natural silk fibers. It was not enough to say. Further, since the cationic dye-easily dyed polyester fiber is copolymerized with a sodium sulfonate-based compound, the physical properties of the yarn are often insufficient, and it has been more difficult to impart a feeling improvement.

(Problems to be Solved by the Invention) The present inventors have found that polyester synthetic fibers have a soft feeling similar to natural silk fibers, a cross-sectional shape, and random natural spots such as single fiber denier. The present invention has been achieved as a result of extensive studies for the purpose of imparting a cationic dye easy dyeing performance together with the imparting.

That is, the present invention has clarified what kind of material should be used and what kind of configuration and conditions should be used to obtain the above-mentioned fiber.

(Means for Solving the Problems) The present invention is to form a fiber containing polyester having polyethylene terephthalate as a main component and a water-soluble polyester soluble or dispersible in water while maintaining a non-uniform mixture state,
After that, the water-soluble polyester in the fiber is reduced at a rate faster than that of polyethylene terephthalate by alkali reduction under predetermined conditions to form ultrafine fibril-like fibers randomly from the surface layer of the single fiber, and the fiber cross section. Random surface irregularities and irregular shapes with different shapes between single fibers, and large cracks randomly from the fiber surface to the inside of the fiber, and some cracks divide the single fiber randomly and partially in the fiber length direction. It is characterized by forming a denier-mixed state at the same time, and a water-soluble polyester having a specific polymer composition is selected in order to retain the easy dyeing property with respect to the cationic dye. By leaving a certain amount of water-soluble polyester in the It is polyester fiber characterized.

Polyethylene terephthalate used in the present invention, for example, terephthalic acid, isophthalic acid, naphthalene 2,6
Aromatic dicarboxylic acids such as dicarboxylic acid, phthalic acid, α, β- (4-carboxyphenoxy) ethane, 4,4′-dicarboxydiphenyl, 5-sodium sulfoisophthalic acid or adipic acid, sepacic acid, etc. Aliphatic dicarboxylic acids or their esters with ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexane-1,4
A fiber-forming polyester synthesized from a diol compound such as dimethanol, polyethylene glycol or polytetramethylene glycol, wherein 80 mol% or more of the constituent units, particularly 90 mol% or more, is a polyethylene terephthalate unit. preferable. Further, the polyester may contain a small amount of additives, for example, a matting agent such as titanium oxide, an antioxidant, a brightening agent, a stabilizer or an ultraviolet absorber.

As a method for expressing the desired polyester fiber structure, in particular, a polyester resin containing polyethylene terephthalate as a main component (hereinafter abbreviated as PET) and a water-soluble polyester resin dissolved or dispersed in water (hereinafter abbreviated as AQ-PES) are used. The most important point is to form fibers while maintaining the form in which the components are mixed in a non-uniform state to the extent that the aggregated state of the two-component polymers remains.

Although various compositions are conceivable as the water-soluble polyester resin which is dissolved or dispersed in water, in order to express the fiber structure of the present object, at least one dicarboxylic acid and at least one diol, namely, A diol containing at least 20 mol% of poly (ethylene glycol) having the formula HOCH ₂ CH _{2 n} OH (where n is an integer from 2 to 10) and a —SO ₃ M group bonded to the aromatic nucleus (where M is Hydrogen or metal ion-containing bifunctional monomer is 5 mol% of all dicarboxylic acid or all glycol components
It is necessary that the thermoplastic polyester has the above-mentioned constitution and has a glass transition point of 25 ° C. or higher and an intrinsic viscosity of at least 0.25 or higher. The term "water" as used herein naturally includes hot aqueous solutions. Intrinsic viscosity ([η]) used in this specification means 50% phenol and tetrachloroethane.
Viscosity measured at 30 ° C. with 50% solvent.

20 mol% or more of the diol component for producing the desired AQ-PES is poly (ethylene glycol) of the formula HOCH ₂ CH _{2 n} OH [n is an integer of 2 to 10], and a suitable polyethylene glycol Examples are diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol,
Heptaethylene glycol, octaethylene glycol, nonaethylene glycol and decaethylene glycol and mixtures thereof. Diethylene glycol, triethylene glycol or a mixture thereof is preferable. The remaining portion of the diol component is at least one aliphatic, cycloaliphatic, or aromatic diol. Examples of these diols are ethylene glycol, propylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2 -Ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,2
-Cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,
2,4,4-tetramethyl-1,3-cyclobutanediol, 4,
4'-thiodiphenol, 4,4'-methylenediphenol, 4,4 '-(2-norbornylidene) diphenol,
4,4'-dihydroxybiphenol, O-, m-, and p
-Dihydroxybenzene, 4,4'-isopropylidene diphenol, 4,4'-isopropylidene bis (2,6-dichlorophenol), 2,5-naphthalene diol and p-
Contains xylene diol. The copolymer is the above-mentioned diol 2
It may consist of seeds or more.

Another essential component is a bifunctional monomer containing a —SO ₃ M group attached to the aromatic nucleus, where M is hydrogen or a metal ion. The difunctional monomer component may be filed in any diol containing dicarboxylic acid (or derivatives thereof), or -SO ₃ M group containing -SO ₃ M groups. Further, it may be a mixture thereof. The —SO ₃ M group is attached to an aromatic nucleus, examples of which include benzene, naphthalene, anthracene, diphenyl, oxydiphenyl, sulfonyldiphenyl and methylenediphenyl. The metal ion of sulfonate base is Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , Cu ²⁺ , Fe ²⁺ or Fe ³⁺
Is. When a monovalent alkali metal ion is used, the resulting polyester is slightly dissolved or dispersed in cold water,
It completely dissolves or disperses in hot water. When a divalent or trivalent metal ion is used, it does not dissolve in cold water but easily dissolves or disperses in hot water. When the bifunctional monomer is a sodium salt of sulfoisophthalic acid, sulfoterephthalic acid, sulfophthalic acid, or 4-sulfonaphthalene-2,7-dicarboxylic acid (or a derivative thereof), the target AQ -Preferred as PES. A very suitable monomer is 5-
Sodiosulfoisophthalic acid or its derivatives, such as sodiosulfodimethylisophthalate.

When the bifunctional monomer having the —SO ₃ M group is an acid or a derivative thereof (eg ester), the AQ-PES must contain at least 5 mol% of the monomer based on the total acid component. However, it is necessary that the amount be 10 mol% or more. When the bifunctional monomer is a diol, the AQ-PES must contain at least 5 mol% monomer, and more preferably 10 mol% or more, based on the total diol component. is there. When the bifunctional monomer is a mixture of an acid and a diol, it must be 10 mol% or more of the total content of the acid or diol component of AQ-PES.

The upper limit of the content of the bifunctional monomer in the A polymer is not particularly limited, but as described later, it is desirable that the content is such that the intrinsic viscosity of the A polymer becomes 0.25 or more.

The other dicarboxylic acid component may be an aliphatic, alicyclic or aromatic acid. Examples of the dicarboxylic acid, oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, Maleic acid, itaconic acid, 1,3-
Cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-
Cyclohexanedicarboxylic acid, phthalic acid, terephthalic acid, isophthalic acid, 2,5-norbornanedicarboxylic acid, 1,4-naphthalic acid, diphenic acid, 4,4'-oxybenzoic acid, diglycolic acid, thiodipropion, 4, Four'
-Sulfonyldibenzoic acid, 2,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid. When terephthalic acid is used as the dicarboxylic acid component of AQ-PES, it is preferable to use at least 5 mol% of the above-mentioned one or other acid. However, "dicarboxylic acid" naturally includes acid anhydrides, esters and acid chlorides corresponding to the above-mentioned acids.

The properties of the polymer can be altered by varying the components of the various acids that form the dicarboxylic acid component of AQ-PES. For example, the polymer increases in flexibility as the proportion of terephthalic acid decreases. That is, the softening point and the flexibility can be widely changed by changing the ratio of various acids used as the dicarboxylic acid component. Furthermore, varying the mol% of the difunctional monomer containing sulfonate groups changes the water sensitivity of the polyester. What is important here is that the glass transition point of AQ-PES is 25 ° C or higher,
More preferably, it is necessary to select the polymer composition so that the temperature becomes 30 ° C. or higher. When the glass transition point is lower than 25 ° C., polymer pellets stick to each other when handling the polymer, and the extrusion property becomes poor during melt spinning, which often causes troubles, which is not preferable because the operability is significantly lowered. Further, after spinning, sticking occurs between the single yarns, unwinding failure occurs during drawing, inter-single yarn dislocation failure occurs, fluffs and yarn breakage occur frequently, and the obtained fibers themselves have poor physical properties. It is not preferable because it causes a bad shape.

Furthermore, the intrinsic viscosity of AQ-PES must be 0.25 or more,
It is more preferably 0.3 or more. When the polymer polymerization degree is too low, the melt viscosity at the time of spinning becomes low, and particularly when the mixed spinning of PET and AQ-PES as in the present invention is performed, the spinning temperature needs to be a high temperature of 280 ° C. or higher, and AQ-PES. Melt viscosity will be extremely reduced. If there is too much difference between the PET and AQ-PES melting, the spinnability will become unstable, and in particular, the nozzle hole discharge may be skewed or screws may drop.
I understand that there are many single yarn breaks and yarn breaks. Although the method for fiberizing of the present invention will be described in detail later, as a result of examining variously changing the intrinsic viscosity of AQ-PES, if the intrinsic viscosity is 0.25 or more, there is sufficient operability and there is no problem. I got caught. It has been found that when the ratio is preferably 0.30 or more, the A rating during spinning shows a good spinning process property of 95% or more.

Next, the characteristics of the fiber of the present invention will be described with reference to actual photographs. FIG. 1 shows an enlarged photograph of the fabric surface of a twill fabric having a 2/2 twill structure of the fiber of the present invention. Figure 1
After creating a twill fabric, after alkali weight reduction treatment under specific conditions,
Further, it is a surface photograph of a product which is further dyed with a cationic dye. FIG. 2 is a surface photograph of a part of the twill fabric enlarged to a higher magnification. It can be seen that innumerable ultrafine yarns are three-dimensionally formed on the surface of the woven fabric, and it can be understood that the polyester fabric has a fiber structure that cannot be seen in the conventional polyester woven fabric. That is, it can be seen from the surface layer of the single fibers that the ultrafine fibers are branched in a random state. It is considered that the ultrafine fibers generated from the surface layer of the fibers are one of the points having a good feeling effect when forming the cloth. Large cracks are randomly observed from the surface of the fiber to the inside of the fiber, but this structure is one of the elements that eliminates the unpleasant waxy feeling peculiar to synthetic fibers by melt spinning and develops a natural natural fiber-like feel. It is estimated that they are connected.

FIG. 3 shows an example of a cross-sectional photograph of the fiber of the present invention. Random surface irregularity irregular shape with different fiber cross-sectional shape between each single yarn and partially large cracks randomly from the fiber surface to the inside of the fiber, and a part of the crack divides the single fiber, It can be seen that a denier mix state is formed. Also, this denier mix state is
As a result of detailed observation, it has been confirmed that the fibers are not generated in the same state in the length direction of the fiber but are randomly generated. The fiber assembly having such a structure has never been noticed by the conventional synthetic fibers produced by melt spinning, and was achieved for the first time by the present invention. As a result, natural fibers, which have been insufficient with synthetic fibers produced by melt spinning,
In particular, it is possible to obtain a texture similar to that of natural silk fiber. In particular, since it was possible for the first time to give the appearance of a natural fiber surface appearance and the retention of random natural inhomogeneity not found in conventional polyesters, the natural silk fiber texture has a wonderful soft feeling. It can be said that a polyester fiber very similar to was made. Moreover, it can be said that the polyester fiber, which has been kept dyeable with a cationic dye, has been made by the present invention for the first time.

In the above description, a woven fabric of long fibers is shown as an example, but it goes without saying that similar effects can be expected with short fibers.

Further, the present invention has a shape similar to pentagonal and hexagonal by high-order processing such as false twist crimping, and a trilobal shape, a T-shape, a 4-lobed shape, and a 5-lobed shape by a modified cross-section nozzle during spinning. Leaf-shaped, 6
Even if it has a leaf shape, a 7-leaf shape, a 8-leaf shape, or other multi-leaf shape, and various cross-sectional shapes, the point is that if the fiber structure described so far is manifested, the polyester fiber having the good texture of the present invention is maintained. Can be obtained.

Next, a production example of the polyester fiber of the present invention will be described. In order to develop the polyester fiber structure of the present invention and to produce a polyester fiber which is easily dyed with a cationic dye, the first important thing is to use PET and AQ during spinning.
-The two-component polymer of PES left some aggregate state of each polymer. In other words, it is important to form fibers while maintaining a non-uniform mixed state, and an example of the spinning method is shown in FIG. Spinning may be carried out using a mixing spinneret device as shown in FIG. The PET and AQ-PES polymer melt streams respectively extruded from different melt extruders are separately metered by a predetermined amount by a meter, and then introduced from the introduction holes 2 and 3 of the introduction plate 1, respectively, and the mixing plate 4, 5 is mixed under a predetermined condition in the static mixer 11 provided in the No. 5 and is passed through the intermediate plate 6 and the filtering unit 12 of the sandbox 7.
After being filtered by, it is passed through the filter 8 and the rectifying plate 9
Spinned from 10.

Here, it is very important to properly select the number of mixing elements of the static mixer 11. There are several types of static mixers that are currently in practical use, for example, the Kenics 18
When using a static mixer of a type in which 2 ⁿ layers are divided when n elements arranged by shifting 90 ° left and right blades by shifting 90 ° are passed, the number of elements must be within the range of 3 to 15. The range of 4 to 8 is more preferable. When the number of elements is 16 or more, the mixing property of PET and AQ-PES becomes too good, and the mixing becomes close to uniform mixing, and it becomes difficult to develop the target fiber structure in the post-processing process due to fiberization.
That is, under alkaline weight loss conditions as described below, AQ-PES that is present in a non-uniform state is treated with an alkaline weight loss rate difference at a faster rate than polyethylene terephthalate to treat AQ-PES more than polyethylene terephthalate. Part of it is removed relatively selectively. As a result, the ultrafine fibril-like fibers were randomly formed from the surface layer of the single fiber in a branch shape, and the cross-sectional shape of the fiber was randomly varied from the fiber surface to the inside of the fiber with a random surface irregularity irregular shape and different shapes between the single fibers. It can be said that the cracks include the monofilaments, and the cracks partially divide the monofilaments to randomly form a denier-mixed state partially in the fiber length direction. However, what is important here is that the bifunctional monomer having a —SO ₃ M group bound to the aromatic nucleus is copolymerized in the molecule, and AQ-PES is completely removed from the fiber. It is important to be present in the fiber to some extent without This is because, when the amount of AQ-PES present is extremely small, the dyeability of the intended cationic dye becomes weak and it becomes difficult to obtain a dark-colored dyeing product. It is necessary to carry out alkali reduction treatment so that the AQ-PES content in the fiber is kept at 3% by weight or more. Regarding the alkali weight reduction treatment conditions, it is important to carry out the treatment at a lower alkali concentration condition, for example, 15 g / concentration of NaOH and a shorter treatment time than the usual alkali weight reduction treatment conditions for polyester fibers. It is preferable to keep the alkali weight loss rate at 20% or less. If the alkali weight loss ratio becomes too large, the texture maintains the desired fiber structure, but the ease of dyeing with the cationic dye, which is the other purpose, decreases. It is considered that this is because the AQ-PES content is extremely reduced, and thus the number of —SO ₃ M groups exerting cationic dyeability is reduced.

Most of the conventional cationic dyeable polyester fibers use a bifunctional monomer having a —SO ₃ M group in the PET molecule, for example, a copolymer of 5-sulfoisophthalic acid. As described above, as a polyester fiber in which PET and AQ-PES are made into a fiber in a state of being non-uniformly mixed in a polymer state, apparently having a cationic dyeability as a fiber and also expressing a natural silk fiber texture, It has not been found in the past, and it can be said that the present invention made it possible for the first time.

It is not certain at this point why the use of AQ-PES causes unprecedented natural silk texture, but AQ-PE which is easily dissolved or dispersed in water
Compared with PET, S has a much faster alkali weight loss rate, and PET
It is presumed that, due to the large rate of weight loss with, the conventional polyester-based polymer combination has come to exhibit a feeling that could not be sufficiently exhibited.

When kneading AQ-PES and PET during spinning, when the number of elements increases, PET and AQ-PES are close to the molecular mixing, and conversely, it is difficult to elute and remove AQ-PES as an aggregate. It is estimated that the fiber structure cannot be obtained. On the other hand, if the number of elements is too small, the mixing will be insufficient and the desired fiber having a good texture cannot be obtained, and the spinning processability will be unstable, which is not preferable.

Even when using static mixers from other companies, 2 ⁿ
It goes without saying that it is necessary to use a mixer having a number of elements corresponding to the number of layers or more. The Toray high-mixer (Hi-Mixer) and the loss ISG mixer made by Cherless & Ross are
Since the number of layer divisions when passing through n elements is ⁴ⁿ layer divisions, the number of elements is preferably 2 elements or more and 8 elements or less.

The mixing ratio of PET and AQ-PES during spinning is 95: 5 to 65:35.
It is desirable to set it in the range of wt%. When the mixing ratio of AQ-PES is 5% by weight or less, a sufficient natural silky feel cannot be obtained, which is not preferable. Further, the cationic dyeability is also lowered, which is not preferable. The ratio of PET and AQ-PES after developing the fiber morphology through the final treatment step should be in the range of 97: 3 to 70:30 wt% for PET: AQ-PES. Is desirable.

When the AQ-PES ratio is 35% by weight or more, the spinning processability,
Not only is the drawability deteriorated, but also the cost is considerably increased, which is not preferable. It is desirable to select the optimum mixing ratio in the range of 5 to 35% by weight by comprehensively judging the desired feeling, processability and cost up. The present invention uses a water-soluble polyester that dissolves or disperses in specific water, and is made into a fiber with polyethylene terephthalate in a heterogeneous mixed state under predetermined conditions to some extent, and then the water-soluble polyester in the fiber is mixed with polyethylene terephthalate under predetermined conditions. It was possible for the first time by carrying out the operation of reducing the alkali with a different alkali reduction rate.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1 A polycondensation reactor was used to carry out a polycondensation reaction at 260 ° C. using titanium isopropoxide as a catalyst in a conventional manner to obtain 82 mol of isophthalic acid, 18 mol of 5-sodiosulfoisophthalic acid, and 55 mol of diethylene glycol. , To produce a copolymerized polyester consisting of 45 moles of 1,4-cyclohexanedimethanol, extruded on the cooling drum in a strand form from the bottom of the polymerization vessel, cut using a strand cutter,
Pelletized. The obtained polymer had an intrinsic viscosity of 0.40 and was easily soluble in hot water. The glass transition point was 54 ° C. The glass transition point was measured by a differential scanning calorimeter (DSC) at a temperature rising rate of 10 ° C./min in a nitrogen stream and the temperature at which an endothermic peak was generated in the glass transition point region. .

The obtained water-soluble polyester pellets (A) and polyethylene terephthalate pellets (B) were melt-extruded by separate extruders, and weighed so that the ratio of A to B was 12 to 88% by weight. It is supplied to the spinning pack, and thereafter, in the spinning pack by the method shown in FIG.
The polymer and the B polymer were non-uniformly kneaded to such an extent that the existing state of the polymer and the polymer B were discharged, and then discharged from a round hole nozzle and spun. The spun raw yarn was drawn by a roller plate system under ordinary conditions to obtain a 75-dr-36f multifilament. Spinnability,
The stretchability was good and there were no problems. A 2/2 twill fabric was woven using the obtained multifilament as a warp and a weft. The weaving process could be carried out without any problems. The raw twill fabric was treated by a usual method, and then 15 g of caustic soda /
Alkali weight loss treatment was carried out at 90 ° C at a concentration of 10% to obtain a plain weave of 20% weight loss.

The obtained plain woven fabric had a very good feeling, and a woven fabric similar to natural silk fiber having a soft feeling which was not found in conventional polyester woven fabrics was obtained. When the fibers constituting the woven fabric were observed with a microscope and a scanning electron microscope, ultrafine fibril-like fibers were randomly formed from the surface layer of the single fiber in a branch shape, and the fiber cross-sectional shape was as shown in FIG. Random surface irregularities and irregular shapes that differ from each other between the fibers, and monofilaments that have large cracks randomly from the fiber surface to the inside of the fiber are included, and a part of the cracks divides the monofilament to randomly and partially in the fiber length direction. It was discovered that a denier mixed state was formed.

The woven fabric was dyed with a cationic dye by the following method, and the dyeing ratio was measured by a spectrophotometer by the residual bath colorimetric method by a conventional method.

The residual amount of the water-soluble polyester polymer (A) in the fiber was measured with a 500 MHz nuclear magnetic resonance spectrometer (NMR spectrum), and was about 8.0 wt%.
The result was obtained.

Examples 2 to 10 A water-soluble polyester pellet (A) having the same polymer composition as that of Example 1 was prepared, and Example 1 was prepared under the conditions shown in Table 1.
Fiberization was carried out by the same method as in Example 1, a twill fabric was prepared in the same manner as in Example 1, and then alkali reduction treatment was carried out under the conditions shown in Table 1, followed by dyeing with a cationic dye.

Examples 2 and 3 are examples in which the number of static mixer elements was changed to 4 elements and 12 elements, respectively, but all of them have good processability and a good texture with a characteristic fabric. Was given. The dyeability with the cationic dye was sufficient and the color development was good.

Examples 4 and 5 are examples in which the mixing ratio of the A polymer and the B polymer was changed to A / B 6/94 and A / B 25/75, respectively, but no particular problems occurred, and As in No. 1, a good fiber structure was developed, and a woven fabric with a good texture was obtained. Further, the dyeability with the cationic dye was sufficient and the color development was good.

In Examples 6 and 7, fiberizing was performed under the same method and conditions as in Example 1 to prepare a woven fabric, and then the treatment was performed by changing the alkaline conditions. Example 6 has a caustic soda concentration of 15 g /
The weight reduction rate was 15.0%, and in Example 7, the weight reduction treatment was performed on the fabric at a caustic soda concentration of 10 g / weight and a weight reduction rate of 19.0%. In each case, a good natural silk fiber texture having a soft texture was obtained, and the dyeability with a cationic dye was also good.

In Examples 8 and 9, tests were carried out by changing the intrinsic viscosity of the A polymer, but no particular problems occurred and the target fibers could be obtained. In each of Examples 2 to 9, the spinning nozzle uses a round hole nozzle and the spinning yarn cross section has a round cross-section shape. In Example 10, a Y-shaped irregular cross-section nozzle is used and a trilobal cross section is used. A spun raw yarn is obtained.
The processability such as spinnability, stretchability and weaving was good and there was no problem. When a woven fabric was produced by the same method as in Example 1, a slightly shredded feeling was added. A good natural silk fiber texture having a soft texture was obtained. The dyeability with a cationic dye was also good.

Comparative Examples 1 to 3 Fiberizing was carried out under the same method and conditions as in Example 1,
After making the woven fabric, the treatment was carried out by changing the alkaline conditions. Comparative Example 1 has a caustic soda concentration of 15 g / and a weight loss rate of 35%.
Processed. The resulting fabric texture was good,
The dyeability with a cationic dye was 10% or less and the color development was poor. Comparative Example 2 is a treatment in which the caustic soda concentration is 40 g / weight and the reduction rate is 22%. The dyeability with the cationic dye was good, but the texture of the fabric was slightly poorer than that of Example 1. Comparative Example 3 has a caustic soda concentration of 40 g /
Although the weight loss rate was 37%, the color development by the cationic dye was insufficient, and the fabric texture was not satisfactory.

Comparative Examples 4 and 5 The same water-soluble polyester (A) as in Example 1 was used, the mixing ratios with polyethylene terephthalate (B) were 4/96 and 35/65, respectively, and other conditions were exactly the same, and fiberization was performed. Was carried out. In Comparative Example 4, the processability was good and there was no problem, but the texture of the obtained woven fabric was not very characteristic, and a preferable one was not obtained. In Comparative Example 5, the spinnability was unstable, and the single yarn breakage due to the dropping of the screws was large, and a good spinning base yarn could not be obtained. Therefore, there are many troubles in stretchability and weavability, and it is impossible to obtain a woven fabric whose texture can be evaluated.

Comparative Examples 6 and 7 The same water-soluble polyester (A) as in Example 1 was used, the A / B polymer ratio was set to the same condition, and the number of elements of the static mixer was set to 25 and 2 elements, respectively. The fiber formation was carried out in exactly the same manner. In Comparative Example 6, the A polymer and the B polymer were excessively mixed, the viscosity during spinning was lowered, and the yarn dropping speed during spinning was too fast, resulting in a slight breakage of the single yarn. The obtained woven fabric texture was less characteristic than that of Example 1 because the A polymer was difficult to be selectively removed when the amount of alkali was reduced. Contrary to Comparative Example 6, Comparative Example 7 had an insufficient mixing property, and thus the difference in melt viscosity between the A polymer and the B polymer was too large, the spinning property was unstable, and a single yarn breakage occurred. Therefore, stretchability and weavability were also slightly poor. The texture of the obtained woven fabric is slightly inferior to that of Example 1,
When the surface of the fiber was observed with a scanning electron microscope, the state of formation of branch-shaped ultrafine fibril fibers generated from the surface layer of the single fiber was very small, and it could not reach a satisfactory level.

Comparative Example 8 Using the water-soluble polyester (A) having the same polymer composition as in Example 1 and an intrinsic viscosity of 0.21, the fiberization was performed under the same conditions as in Example 1 under other conditions. Since the viscosity of the A polymer was too low, the spinnability fell off and the number of yarn breakages was high, resulting in a poor result. It was not possible to obtain a sample that could be evaluated for feeling.

Example 11 Using a polycondensation reactor, using titanium isopropoxide as a catalyst, a polycondensation reaction was carried out at 260 ° C. by a conventional method. Isophthalic acid 25 mol, terephthalic acid 65 mol, 5-sodiosulfoisophthalic acid 10 Mol, ethylene glycol
Producing a copolyester consisting of 60 mol, 25 mol of diethylene glycol, 15 mol of triethylene glycol,
It was extruded in the form of a strand from the bottom of the polymerizer onto a cooling drum, cut with a strand cutter, and pelletized. The obtained polymer had an intrinsic viscosity of 0.50 and was easily soluble in hot water. The glass transition point was 45 ° C. The resulting water-soluble polyester pellet (A) and polyethylene terephthalate (B) were made into fibers by the same method as in Example 1. The processability such as spinnability, stretchability, and weavability was good and there was no problem. The obtained woven fabric also had a good texture similar to that of natural silk fiber having a soft feeling.
When the fiber structure was also observed by a scanning electron microscope, it was found that the same structure as in Example 1 was developed. Further, the dyeability by cation dyeing was also good.

Example 12 Using a polycondensation reactor, using titanium isopropoxide as a catalyst, a polycondensation reaction was carried out at 260 ° C. by a conventional method, isophthalic acid 91 mol, 5-sodiosulfoisophthalic acid 9 mol, diethylene glycol 75 mol, A copolymerized polyester consisting of 25 mol of 1,4-cyclohexanedimethanol was produced, extruded in strands from the bottom of the polymerization section onto a cooling drum, and cut into strands using a strand cutter. The obtained polymer had an intrinsic viscosity of 0.45 and was easily soluble in hot water. The glass transition point was 37 ° C. The resulting water-soluble polyester pellet (A) and polyethylene terephthalate (B) were made into fibers by the same method as in Example 1. The processability such as spinnability, stretchability, and weavability was good and there was no problem. The obtained woven fabric also had a good texture similar to that of natural silk fiber having a soft feeling. When the fiber structure was observed with a scanning electron microscope, it was found that a structure similar to that in Example 1 was developed. Further, the dyeability by cationic dyeing was also good.

Comparative Example 9 In the same manner as in Example 1, 93 mol of isophthalic acid, 5
-A copolymerized polyester of 7 mol of sodiosulfoisophthalic acid, 75 mol of diethylene glycol, and 25 mol of triethylene glycol and having a viscosity of 0.40 was polymerized. The polymer was extruded in strands from the bottom of the polymerization kettle onto a cooling drum and cut with a cutter, but there was severe sticking between the polymers and poor pelletization. The obtained polymer was readily soluble in water and had a glass transition point of about 22 ° C.

Although the fibers were made into fibers under the same conditions as in Example 1, pressure fluctuations frequently occurred due to defective Kami-Comi during spinning, and decent fibers could not be obtained.

Comparative Example 10 Using a polycondensation reactor, using titanium isopropoxide as a catalyst, polycondensation reaction was carried out at 260 ° C. by a conventional method. Isophthalic acid 50 mol, terephthalic acid 50 mol, 5-sodiosulfoisophthalic acid 3 mol , 100 mol of diethylene glycol, a copolyester consisting of 100 mol, and extruded on the cooling drum in a strand form from the bottom of the polymerization vessel,
It was cut into pellets using a strand cutter. The obtained polymer had an intrinsic viscosity of 0.55, but its solubility in hot water was poor. The glass transition point was about 40 ° C, although some measurement errors were considered. The obtained polyester pellet (A) and polyethylene terephthalate (B) were made into fibers by the same method as in Example 1. The processability such as spinnability, stretchability, and weavability was good and there was no problem.
However, the texture of the resulting fabric was not at a satisfactory level. Further, the dyeability with a cationic dye was also insufficient.

Comparative Example 11 Using a polycondensation reactor, using titanium isopropoxide as a catalyst, polycondensation reaction was carried out at 260 ° C. by a conventional method, isophthalic acid 90 mol, 5-sodiosulfoisophthalic acid 10 mol, ethylene glycol 85 mol. Copolyester consisting of 15 mol of diethylene glycol was extruded in a strand form from the bottom of the polymerization vessel onto a cooling drum, and cut into pellets using a strand cutter. The obtained polymer had a poor solubility in hot water with an intrinsic viscosity of 0.50. In addition, the glass transition point was about 45 ° C, although there was a slight measurement error. The resulting water-soluble polyester pellet (A) and polyethylene terephthalate (B) were made into fibers by the same method as in Example 1. The processability such as spinnability, stretchability, and weavability was good and there was no problem.
However, although the dyeability with the cationic dye was good, the texture of the resulting fabric was at a satisfactory level. I never happened.

(Effects of the Invention) As described above, in the present invention, a water-soluble polyester that is dissolved or dispersed in a specific water is combined in a predetermined condition in polyethylene terephthalate, and a predetermined post-treatment method is added. As a result, the conventional polyester fiber was able to invent a natural fiber-like structure and a texture having an easily dyeable performance in a cationic dye which was not achievable.

[Brief description of drawings]

FIG. 1 is an example of a surface photograph of a twill fabric made of the fiber of the present invention. FIG. 2 is an example of an enlarged photograph of a fabric surface photograph. FIG. 3 is an example of a cross-sectional photograph of the fiber of the present invention. FIG. 4 is a cross-sectional view showing an example of the fiber spinneret device of the present invention, in which 1 is an introduction plate, 2 and 3 are polymer introduction holes, 4 and 5 are mixing plates, 6 is an intermediate plate, and 7 is a sand box.
8 is a filter, 9 is a rectifying plate, 10 is a base plate, 11 is a static mixer, and 12 is a filtering part.

Continuation of front page (56) Reference JP-A-59-36775 (JP, A) JP-A-62-78213 (JP, A) JP-A-61-119771 (JP, A) JP-A-56-31014 (JP , A) JP 62-184185 (JP, A) JP 47-14051 (JP, B1)

Claims (2)

(57) [Claims] 1. The formula HOCH ₂ CH _{2 n} OH in all diol components.
A bifunctional compound containing 20 mol% or more of polyethylene glycol having [wherein n is an integer of 2 to 10] and having a —SO ₃ M group (M is hydrogen or a metal ion) bonded to an aromatic nucleus. A water-soluble polyester resin (A) soluble or dispersible in water, wherein the dicarboxylic acid or diol or any ester-forming derivative constitutes 5% by mole or more of the total dicarboxylic acid or total glycol component as a water-soluble monomer. A fiber obtained by mixing at least 3% by weight of the component A polymer with a thermoplastic polyester resin (B) containing polyethylene terephthalate as a main component, the fiber comprising:
The fiber cross-sectional shape has random surface irregularities that are different between single fibers, and includes single fibers that randomly have large cracks reaching the inside of the fibers from the fiber surface, and the cracks split the single fibers in the fiber length direction. A cation-dyeable polyester fiber, wherein the ultrafine fibers are randomly branched from the surface of the single fiber and partially form a denier mixed state. _{2. The} formula HOCH ₂ CH _{2 n} OH in all diol components.
A bifunctional compound containing 20 mol% or more of polyethylene glycol having [wherein n is an integer of 2 to 10] and having a —SO ₃ M group (M is hydrogen or a metal ion) bonded to an aromatic nucleus. Of a dicarboxylic acid or diol, or an ester-forming derivative of either of them as a water-soluble monomer, constitutes 5 mol% or more of all dicarboxylic acid or all glycol components, dissolves or disperses in water, has a glass transition point of 25 ° C. or more, A water-soluble polyester resin (A) having an intrinsic viscosity of 0.25 or more and a thermoplastic polyester resin (B) containing polyethylene terephthalate as a main component are separately melt-extruded, and the ratio of A: B is 5.95 to In the range of 30: 70% by weight, the mixture is mixed nonuniformly with a static mixer to the extent that the two-component layer state remains, and then extruded from a spinning nozzle to form fibers,
In the subsequent thread-like step or cloth step of the obtained fiber, the water-soluble polyester resin (A) and the thermoplastic polyester resin (B) containing polyethylene terephthalate as a main component are mixed in a weight ratio of the A-component polymer of at least 3 A process for producing a cation-dyeable polyester fiber, which comprises subjecting the alkali-reduction treatment so that the content of the dye becomes 10%.