JPH09111539A - Production of polyester filament yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject yarn, capable of readily separating a core part from a fin part by weight reduction with an alkali and useful for woven or knitted fabrics by adding and mixing a compound capable of microscopically separating a phase from a polyester with the polyester, discharging the core part and fin parts from separate discharging holes and then joining both the parts. SOLUTION: A compound having 0.1-2.0 compatibility parameter χ of the formula χ=Va /RT(δa -δb )<2> [Va is the molar volume of a polyester (cm<3> /mol); R is a gas constant (J/mol.K); T is the absolute temperature (K); δa and δb are each the solubility parameter of the polyester and added compound (J<1/2> /cm<3/2> )] in an amount of 0.5-5.0wt.% based on the total weight of the polyester is added and mixed with the polyester according to a masterbatch method. The core and fin parts are melt discharged from the separate discharging holes and then joined. Thereby, the filament yarn capable of assuming a bulky and soft touch feeling and producing a woven or a knitted fabric having a uniform appearance can be obtained by weight reduction with an alkali.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a special polyester filament, and more specifically, a core portion and a fin portion are easily separated by alkali reduction to form a large void in the filament,
The present invention relates to a method for producing a polyester filament capable of exhibiting a bulky and soft texture.

[0002]

2. Description of the Related Art Polyester fibers, especially polyethylene terephthalate multifilaments, are widely used as a material for clothing, but they have the disadvantages of hard texture and poor bulge due to their dense fiber structure. doing.

In order to improve such drawbacks, Japanese Patent Publication No.
No. 12487 and Japanese Examined Patent Publication No. 16922/1992, a bulky filament having a wing part separated from a body part and characterized by a free protruding end in which a part of the wing part is broken, and the filament can be manufactured. Cleavable filaments are disclosed.

However, since the cleavable filament is formed by discharging the polymer from a single discharge hole, the body portion and the wing portion are integrated, and it is extremely difficult to separate them at the boundary between them. Is.

For this reason, as a means for separating and breaking the wing portion, there has been no choice but to employ a physical means such as a fluid nozzle treatment using a high-pressure compressed air flow, which causes a great amount of energy transfer.

Moreover, since the separated wing portions are broken at least half to form free protruding ends, the appearance is as if they were spun yarns characterized by fluff, and they are well-balanced when made into a woven or knitted fabric. It had the drawback of lacking in sex.

Further, Japanese Patent Publication No. 2-38699 discloses that
A substantially continuous body portion and split from the body portion,
10 to 15 per 1 cm of yarn length, consisting of synthetic fiber elements, part of which comprises wing portions forming free protruding ends
A yarn having zero free end is disclosed.

This yarn, like the above filament, is a spun yarn characterized by fluff, and when it is made into a woven or knitted fabric, it also has the drawback of lacking uniformity.

On the other hand, a method in which a woven or knitted fabric made of polyester fibers is alkali-reduced and the contact pressure between the single fibers is reduced to give a soft silky feel is widely known from British Patent No. 652,948. There is.

However, this method has a limit in improving the bulkiness because the diameter of each single fiber is uniformly reduced and only a few voids are provided between the constituent single fibers.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to easily separate the core part and the fin part, to provide a bulky and soft texture, and to provide a uniform appearance. Another object of the present invention is to provide a method for producing a polyester filament capable of producing a woven or knitted fabric.

[0012]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a core portion having a circular cross section and a radial shape extending from the core portion along the length direction of the core portion. In producing a polyester filament having a protruding fin portion, the polyester is mixed with a compound capable of phase separation into a polyester and a micro phase by a masterbatch method, and after the core portion and the fin portion are discharged from separate discharge holes. It has been clarified that the fin portion can be easily separated by the alkali weight loss when the joining is carried out, and as a result, a desired filament can be obtained, and the present invention has been accomplished.

Thus, according to the present invention, a compound having a compatibility parameter χ represented by the following formula of 0.1 to 2.0 is added to the polyester in an amount of 0.5 to 5.0% by weight.
Polyester filament obtained by melt-spinning contained polyester, comprising a core portion having a circular cross section, and a plurality of fin portions radially protruding from the core portion and extending along the length direction of the core portion. , By reducing the alkali, when separating the fin portion from the core portion, a masterbatch containing a high concentration of the compound is added to and mixed with the polyester at a stage after the polymerization step of the polyester, Provided is a method for producing a polyester filament yarn, which comprises melt spinning.

[0014]

(Equation 3)

In the above formula, Va is the molar volume of the polyester (cm ³ / mol), and R is the gas constant (J / mol).
K) and T are absolute temperatures (K), and δa and δb are solubility parameters (J ^1/2
/ Cm ^3/2 ).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester polymer used in the present invention is a polyester polymer in which 85 mol% or more, preferably 90 mol% or more of repeating units are composed of ethylene terephthalate units.

Other polymer components may be copolymerized with the above polyester within a range not impairing the object of the present invention, and a small amount of a matting agent or an inorganic substance may be added.

The filament of the present invention is composed of a single polyester polymer, which means that it does not include a composite fiber composed of two or more polyester polymers, and the polymer composition itself. May be composed of two or more polyester polymers.

The viscosity of the above polyester is not particularly limited, and the intrinsic viscosity usually used for melt spinning is 0.5 to 1.1.
Any of the above can be used.

In the present invention, in addition to the above polyester,
The compatibility parameter χ represented by the following formula is 0.1 to 2.
The compound which is 0 is 0.5
˜5.0 wt%, preferably 0.5 to 4.0 wt%, must be added and mixed.

[0021]

(Equation 4)

In the above formula, Va is the molar volume of the polyester (cm ³ / mol), and R is the gas constant (J / mol).
K) and T are absolute temperatures (K), and δa and δb are solubility parameters (J ^1/2
/ Cm ^3/2 ).

Here, when χ is less than 0.1, the polyester and the above compounds are compatibilized with each other, and it becomes difficult to separate the fin portion due to the alkali reduction. On the other hand, when χ exceeds 2.0, the polyester and the above compound are completely phase-separated and the polymer is thickened, so that the spinning tone is deteriorated.

When the content of the above compound in the polyester is less than 0.5% by weight, the effect of the present invention is not sufficiently exhibited, while when the content exceeds 5.0% by weight. , The above compound causes aggregation, and the spinning condition deteriorates,
After all, the effect of the present invention is not sufficiently expressed.

Specific examples of the above compounds include polyethylene, polypropylene, polyisobutylene, polystyrene, polytetrafluoroethylene, polychlorotetraethylene, polychlorotrifluoroethylene, polyvinyl propionate, polyheptafluorobutyl acrylate, polybutadiene and poly. Isoprene, polychloroprene, polyethylene glycol, polytetramethylene glycol, polytriethylene glycol, polymethyl acrylate, polypropyl acrylate, polybutyl acrylate, polyisobutyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polybenzyl methacrylate, polyethoxyethyl methacrylate , Polyformaldehyde, polyethylene sulfide, polystyrene sulf Id like polymer, silicone, or the like modified products thereof. Two or more of the above compounds may be used in combination.

If the average molecular weight of the above compound is too small, thermal decomposition will occur when it stays in the ruder or spinning pack, while if it is too large, the melt miscibility with polyester will decrease, so it will be 3,000 to 3,000. It is preferably set to 25,000.

Further, when adding and mixing the above compound to the polyester, it is necessary to add and mix a masterbatch containing the compound at a high concentration to the polyester at a stage after the polymerization step.

A method other than the masterbatch method, for example,
After melt-kneading the above compound into polyester, pelletizing, a method of melt spinning the pellet, a method of injection blending the compound in the melt spinning step, or a static mixer, by blending the compound with the polyester When a method such as melt spinning is adopted, the polyester filament comprising the obtained core part and fin part is alkali-reduced, and when the fin part is separated from the core part, the fin part is sufficiently separated. In order to do so, it is necessary to add a large amount of the above-mentioned compound and to adopt a severe alkali weight loss condition, which causes a problem of high cost.

The base polymer of the masterbatch used in the present invention is preferably polyester, and particularly preferably the same polyester as the polyester to be added and mixed with the above compound.

The compounding amount of the above compound in the masterbatch is preferably 1 to 40% by weight, and when less than 1% by weight,
The mixing ratio of the masterbatch to the polyester must be increased, the localization of the compound becomes insufficient, and the effect of separating the fin portion becomes insufficient. On the other hand, if it exceeds 40% by weight, aggregation of the above compounds is likely to occur.

In the present invention, first of all, the above polyester polymer is formed into a circular discharge hole A and slit discharge holes radially arranged around the circular discharge hole A at intervals as shown in FIG. 1 (A). It is melted and discharged through B, joined in a molten state, then cooled and solidified, and a core portion having a circular cross-section, radially protruding from the core portion, and extending along the length direction of the core portion. A polyester filament including a plurality of fin portions is obtained.

In this case, the diameter of the circular discharge hole A is DA
, And LB and WB are the maximum length and the maximum width of the slit-shaped discharge hole B, it is preferable that DA, LB, and WB simultaneously satisfy the following formulas (1) and (2).

[0033]

(Equation 5)

When DA, LB, and WB are out of the above ranges, the spinning tone may be lowered, or sufficient bulkiness may not be exhibited when the material is woven or knitted.

The slit-shaped discharge hole does not necessarily have to be a uniform rectangle, and as shown in FIG. 1 (B), it has an arc-shaped bulge part or has a continuous width. It does not matter even if it changes.

When the above polyester polymer is discharged from a single discharge hole to obtain a polyester filament composed of a core portion and a fin portion, micro defects are not formed at the interface between the core portion and the fin portion. As described later, it becomes difficult to separate the fin portion due to alkali reduction.

The filaments may be subjected to stretching, heat treatment, etc., if necessary.

The number of fin portions in the filament is not particularly limited, but particularly preferable results are obtained when the number of fin portions is 3 to 6. More preferable number of fins is four.

Further, the cross-sectional area, length and width of each fin portion do not necessarily have to be the same, and may be different from each other. Furthermore, it is preferable that the fin portions radially protrude from the core portion at equal intervals, but the present invention is not limited to this.

Then, the filament is subjected to alkali reduction treatment to separate the fin portion from the core portion, but it is preferable to carry out under the condition that the free protruding end due to the cutting of the fin portion or the core portion is not formed as much as possible.

However, if the free protruding end is not formed as much as possible, it is intentionally formed in order to impart fluff to the yarn by using the physical means as disclosed in the above-mentioned Japanese Patent Publication No. 12487/1990. It means a state in which there is no free protruding end, and there may be a free protruding end that is accidentally formed during the yarn making process or the woven knitting process.

When the free end is formed, for example, when it is made into a woven or knitted product, it may have a spun yarn-like appearance and the uniformity of the woven or knitted product may be impaired.

The above alkali treatment may be carried out in the state of filaments, yarns or woven and knitted fabrics, and the usual alkali treatment conditions for polyester fibers can be employed as they are.

Specifically, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or the like is used, the concentration is 10 to 100 g / l, and the temperature is 40 to 180.
The temperature and the treatment time may be set appropriately within the range of 2 minutes to 2 hours. Moreover, the range of the preferable alkali weight loss rate is 5 to 25%.
It is.

By such alkali reduction, as shown in FIG. 2, a filament in which the fin portion is separated from the core portion can be obtained.

FIG. 2 is an enlarged side view showing an example of filaments produced by the method of the present invention, where 1 is a core portion,
2 and 3 are fin portions radially protruding from the core portion (see FIG. 2).
Shows only two of the four fins).

The fin portion 2 is easily separated from the core portion at the joint surface with the core portion 1 by the weight loss of alkali, and when it is made into a woven or knitted material, for example, a sufficient void can be provided between the adjacent core portions. Therefore, bulkiness is improved.

It is preferable that the above-mentioned separation of the fin portion occurs continuously in the longitudinal direction of the filament as in the fin portion 2 of FIG. 2 and the fin portion 2 can behave like an independent filament, but not always. It is not necessary to separate the filaments over the entire length thereof, and a portion joined to the core portion 1 like the fin portion 3 may be present. In order to obtain a woven or knitted fabric having good bulkiness, it is preferable that the separation rate S of the fin portion described below is 60% or more.

Further, the orientation of the separated fin portions 2 and 3,
When there is a difference in the orientation from the core part 1, the shrinkage difference between the fin parts 2 and 3 and the core part 1 becomes apparent when heated in the alkali reduction, dyeing of the woven or knitted fabric, or the finishing process, and Differences and loops are formed, and the bulkiness is further improved.

[0050]

In the bulky filament and the cleavable filament disclosed in Japanese Patent Publication Nos. 1-12487 and 1-16922, the joint surfaces of the body portion and the wing portion are firmly joined, As a means for separating and breaking the wings, it is necessary to employ a physical treatment using a fluid nozzle or the like using a high-pressure compressed air flow, and as a result, a broken free protruding end is formed.

Even if such a filament is treated with alkali, the entire filament is only uniformly reduced in weight.

On the other hand, in the present invention, the filament constituting the filament contains a compound that is microscopically phase-separated from the polyester, and the alkali weight loss property at the interface between the core portion and the fin portion is selectively reduced. Then, by subjecting this to alkali reduction, the fin portion can be separated from the core portion without forming a free protruding end.

That is, when the above compound is mixed in the polyester, it causes migration in the spinning process to which elongation stress is applied and forms micro defects on the surface of the spun yarn. And the fin portion is easily separated.

In particular, when the above compound is added as a masterbatch at a stage after the polymerization step and mixed, the dispersion of the above compound in the polyester becomes non-uniform, and as a result, the localization of the defective portion preferentially receiving alkali reduction is localized. Becomes more remarkable, and the fin portion becomes easier to separate. Therefore,
The texture of the woven or knitted fabric is improved, while the addition amount of the above compound can be reduced, the alkali weight loss condition can be made gentle, and the cost can be reduced.

Further, in the present invention, the polyester is melted and discharged through the circular discharge holes and the slit-shaped discharge holes radially arranged at intervals around the circular discharge holes, joined in the molten state, and then cooled and solidified. Therefore, micro defects are formed along the joint surface between the core portion and the fin portion (corresponding to the surface of the core portion and the fin portion before joining),
Separation of the fin portion occurs extremely easily.

When the filament having the fin portion separated from the core portion is made of, for example, a woven or knitted fabric, a sufficient space can be provided between the adjacent core portions, and filaments of different shapes and different denier are mixed. Like time
It can have a bulky and soft texture.

Further, since the polyester is melted and discharged through the circular discharge holes and slit-shaped discharge holes radially arranged around the circular discharge holes, the filaments which are melted and joined and then cooled and solidified are used. The core part and the fin part have a shrinkage difference due to a draft difference, and when heated in the alkali weight loss, dyeing of the woven or knitted fabric, or the finishing step, the shrinkage difference becomes apparent and the bulkiness is further improved. To do.

[0058]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each physical property in an Example was measured by the following method.

(1) Compatibility Parameter χ Solubility parameters δa and δb of the polyester and the compound that microphase-separates from the polyester were determined from the solubilities in various solvents and calculated by the following formula.

[0060]

(Equation 6)

In the above formula, Va is the molar volume of the polyester (cm ³ / mol), and R is the gas constant (J / mol).
K) and T are absolute temperatures (K), and δa and δb are solubility parameters (J ^1/2
/ Cm ^3/2 ).

(2) Spinning tone The number of yarn breakages generated during spinning was counted and expressed by the number of yarn breakages per 10 ⁶ m winding length of the spun yarn.

(3) Strength and Elongation Using an Instron type tensile tester, the sample length was 25 cm and the tensile speed was 30 cm / min.

(4) Separation rate S of fin section The number of separated fin sections was determined by observing photographs of 20 filaments after alkali reduction at a magnification of 1000, and the separation rate of fin section S ( %) Was calculated. When the separation rate S of the fin portion is 85% or more, favorable results are obtained.

[0065]

(Equation 7)

(5) Texture of Woven and Knitted The bulkiness and softness of the woven and knitted fabric were sensory-judged in four grades of extremely good (⊚), good (∘), normal (Δ) and poor (x).

[Examples 1 to 7, Comparative Examples 1 to 10] 20% by weight of the compounds shown in Table 1 were added to polyethylene terephthalate having an intrinsic viscosity of 0.64 and mixed to prepare masterbatches.

These masterbatches had an intrinsic viscosity of 0.
64 polyethylene terephthalate was mixed in a pellet state so that the amount of the compound added would be the value shown in Table 1,
1400 m when melted and discharged at 285 ° C. from a spinneret having 24 sets of discharge holes having the shape shown in FIG. 1B and cooled in a side blowing spinning cylinder while joining a core part and a fin part.
It was wound up at a speed of / minute.

At this time, LB / DA = 2, WB / DA = 1
/ 3.

Then, the wound filament group was drawn and heat-treated at a draw ratio of 2.4 times by using a drawing machine equipped with a heating roller at a temperature of 95 ° C. and a slit heater at a temperature of 150 ° C., to obtain 75 denier / 24 filaments. A multifilament yarn was obtained.

The obtained multifilament yarn was formed into a 20-gauge tubular knitted fabric, and the tubular knitted fabric was boiled in an aqueous sodium hydroxide solution having a concentration of 35 g / l to obtain a weight loss rate of 15% by weight.
Weight reduction processing was performed until it became.

Table 1 shows the value of χ and the amount of the compound added and mixed, and the spinning tone of each filament, and the strength and elongation of each filament obtained, the separation rate of the fin portion after the weight reduction, and the tubular knitted fabric. The texture is shown in Table 2.

On the other hand, for comparison, in Examples 1 to 4, instead of adding and mixing the compound that microphase-separates with the polyester in the masterbatch, the compound was directly added to and mixed with the polyester in the polymerization step. Conditions are Example 1
The filament yarns were manufactured and evaluated in the same manner as described above. The results are also shown in Tables 1 and 2.

[0074]

[Table 1]

[0075]

[Table 2]

As is clear from Table 1 and Table 2, addition,
The value of χ of the mixed compound is 0.1 to 2.0, the addition amount is 0.5 to 5.0 weight, and when added and mixed in the master batch (Examples 1 to 7), The separation ratio of the parts was high, and sufficient voids were provided between the filaments, so that a good feeling was obtained.

On the other hand, in the case of not adding the compound that microphase-separates from the polyester (Comparative Example 1),
When the value of χ and the addition amount of the mixed compound are out of the above ranges (Comparative Examples 2 to 6), or when the compound is added and mixed without depending on the masterbatch (Comparative Examples 7 to 10),
The spinning tone became poor, and sufficient voids were not provided between the filaments, and the bulkiness of the tubular knitted fabric was insufficient.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a discharge hole of a spinneret used in a method of the present invention.

FIG. 2 is a side view showing an example of filaments obtained by the method of the present invention.

[Explanation of symbols]

 1 Core part 2, 3 Fin part A Circular discharge hole B Slit discharge hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location D06M 11/38 D06M 5/02 F

Claims (3)

[Claims] 1. A compatibility parameter χ represented by the following formula:
A core part having a circular cross section, obtained by melt spinning a polyester containing 0.5 to 5.0% by weight of the compound of 0.1 to 2.0 with respect to the total weight of the polyester, and the core part. When the polyester filaments radially protruding from the core portion and comprising a plurality of fin portions extending along the lengthwise direction of the core portion are alkali-reduced to separate the fin portions from the core portion, the compound A method for producing a polyester filament yarn, wherein a masterbatch containing a high concentration of is added to and mixed with the polyester in a stage after the polymerization step of the polyester and melt spinning is performed. (Equation 1) (In the above formula, Va is the molar volume of the polyester (c
m ³ / mol), R is gas constant (J / mol · K), T
Is absolute temperature (K), and δa and δb are solubility parameters (J ^1/2 / c of polyester and compound, respectively).
m ^3/2 ). ) 2. When melt-spinning polyester, the polyester melted and discharged through the circular discharge holes is melted and discharged through the slit-shaped discharge holes radially arranged at intervals around the circular discharge holes. 2. A filament comprising a core portion having a circular cross section and fin portions radially protruding from the core portion along the length direction of the core portion, which are joined together in a state of being cooled and solidified. A method for producing the polyester filament yarn described above. 3. The polyester filament yarn according to claim 2, wherein the diameter DA of the circular ejection hole and the maximum length LB and maximum width WB of the slit-shaped ejection hole simultaneously satisfy the following formulas (1) and (2). Production method. (Equation 2)