JPH10325019A - Divided type composite fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject fiber consisting of a specific polymer segment in which one kind of polymer is divided by another kind of polymer to plural numbers, having a specific ratio of the length of a joined part and the thickness of the polymer, and excellent in softness, flexibility, etc. SOLUTION: This divided type composite fiber has 10-10 L/W1 and L/W2 ratios of a length L of a mutual joined part of polymers to thicknesses of 2 kinds of the polymers W1 and W2 , in which one kind of the polymer is composed of (A) an aromatic polyester segment consisting of dicarboxylic acid units and diol unit in which >=70 mol% dicarboxylic acid units is an aromatic and >=70 mol% diol units is a 2-4C aliphatic α,ω-diol units, etc., and (B) an aliphatic polyester segment composed of dicarboxylic acid units and diol units, in which >=60 mol% dicarboxylic acid is a 6-14C saturated aliphatic dicarboxylic acid units and >=70 mol% diol units is a 5-12C aliphatic diol units, in a weight ratio of the components A/B=(95/5)-(30/70).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a splittable conjugate fiber, a fiber obtained by splitting the splittable conjugate fiber into fibrils, and a fabric or a fiber product produced by using the splittable conjugate fiber obtained by splitting fibrillation. Divided fibrillated compounds. More specifically, when the splittable conjugate fiber of the present invention and the fabric comprising the conjugate fiber and the fiber product are subjected to split fibrillation treatment, the split fibrillated fiber and the split fibrillated product having high flexibility, stretchability and bulkiness can be obtained. Obtainable.

[0002]

2. Description of the Related Art A woven or knitted fabric, a nonwoven fabric or the like is manufactured by using a yarn composed of a splittable conjugate fiber in which two or more types of mutually incompatible fiber-forming polymers are joined in a side-by-side type, and the split is produced. It is known that, when fibrillated, the fibril is divided into individual joining units of the splittable conjugate fiber and turned into ultrafine fibers, and a split fibrillated material having excellent flexibility, bulkiness, etc., and excellent in feel and cleaning function is obtained. The split fibrillated product takes advantage of its excellent properties to make use of various clothing, sporting goods, sanitary goods (paper diapers, sanitary napkins, etc.), cleaning supplies (wipers, wiping cloths, etc.), filters, masks, Disposable surgical gown,
It is used in many applications, such as synthetic leather backings, and its demand is increasing due to the needs of consumers.

[0003] As the demand increases, more functions are required depending on the application. One of them is elastic. It stretches even under low stress, and has excellent elastic recovery. In order to provide such a function, it may be considered to provide a splittable conjugate fiber containing a polymer excellent in elastic recovery as one component. Generally, polyurethane or polyetherester block copolymer can be used as the polymer having excellent elastic recovery. However, these polymers having excellent elastic recovery properties have very poor light resistance, so that the use as a component of the splittable conjugate fiber is limited.

[0004] For the purpose of improving the light resistance, a polyester ester block copolymer having an aliphatic polyester as a soft segment has also been employed, but the block copolymer is produced in an extruder during spinning. , Randomization occurs in the polymer structure of the block copolymer, and the block copolymer structure is impaired. As a result, the obtained splittable conjugate fiber has inferior elasticity, and the split fibrillated product obtained by splitting and fibrillating a fiber product manufactured using such a splittable conjugate fiber is not only stretchable. It tends to be less flexible.

Further, in order to suppress the randomization of the polyester ester block copolymer due to the above-mentioned melt retention, a method of adding phosphoric acid, phosphorous acid, an ester thereof, an ammonium salt, a metal salt or the like to the polymer, A method of adding a phosphorus compound in the presence of a system catalyst has been proposed, but these compounds significantly reduce the durability of the obtained split fibrillated fiber or split fibrillated product.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a splittable conjugate fiber and a fiber product produced by using the splittable conjugate fiber by splitting and fibrillating the splittable conjugate fiber, thereby improving the stretchability, flexibility and bulkiness. An object of the present invention is to provide a high-quality split fibrillated product having excellent properties. Also, the splittable conjugate fibers may be split and fibrillated during spinning / drawing, crimping, weaving and knitting, cutting into short fibers, manufacturing nonwoven fabrics, and the like of the split conjugate fibers. Therefore, an object of the present invention is to provide a splittable conjugate fiber capable of smoothly performing those steps without causing troubles such as winding of fibrils, adhesion and breakage of the fibril around the device.

[0007]

Means for Solving the Problems The present inventors have conducted various studies to achieve the above object, and found that a composite comprising a specific polyester ester block copolymer as one component of a splittable conjugate fiber. The fiber can be compounded with a fiber-forming polymer having a high spinning temperature, the split fibrillation process is good, and the obtained split fibrillated product is excellent in stretchability, flexibility, bulkiness and high quality. I found something.

That is, the present invention comprises two types of incompatible fiber-forming polymers, wherein one type of polymer is divided into a plurality of types by another type of polymer, and the fiber-forming polymers are combined. And the thicknesses (W1, W2) of the two types of fiber-forming polymers located across the joint.
2) wherein the ratio (L / W1, L / W2) is in the range of 1 to 10, and one kind of fiber-forming polymer is a polyester ester block copolymer shown below. It is a composite fiber. (I) Consisting of an aromatic polyester segment (A) and an aliphatic polyester segment (B),
(A) The aromatic polyester segment (A) is mainly composed of a dicarboxylic acid unit and a diol unit, and at least 70 mol% of the dicarboxylic acid unit is an aromatic dicarboxylic acid unit and 70% of the diol unit. A mole% or more of an aliphatic α, ω-diol unit having 2 to 4 carbon atoms;
At least one diol unit selected from the group consisting of -cyclohexane dimethanol unit, and (b) the aliphatic polyester segment (B) is a dicarboxylic acid unit and a
At least one of an aliphatic polyester segment (B1) mainly composed of an aliphatic polyester segment (B1) and an aliphatic polyester segment (B2) mainly composed of a hydroxycarboxylic acid unit.
At least 60 mol% of the dicarboxylic acid units in 1) are saturated aliphatic dicarboxylic acid units having 6 to 14 carbon atoms, and at least 70 mol% of the diol units are aliphatic diol units having 5 to 12 carbon atoms. And 60 mol% or more of the hydroxycarboxylic acid units in the aliphatic polyester segment (B2) are saturated aliphatic hydroxycarboxylic acid units having 6 to 10 carbon atoms, and (ii) the aromatic polyester segment (A) / Aliphatic polyester segment (B) is 95/5 to 30/70 by weight, and (iii)
The hydroxyl group concentration is 10 μeq / g or less, and (i
v) A polyester ester block copolymer having a carboxyl group concentration of 20 μeq / g or less.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyester ester block copolymer described above will be described first. When the proportion of the aromatic dicarboxylic acid unit in the aromatic polyester segment (A) constituting the copolymer is less than 70 mol% based on the total dicarboxylic acid units constituting the aromatic polyester segment (A), The heat resistance of the polyester ester block copolymer is reduced, so that a polyester ester block copolymer having good physical properties cannot be obtained, and thus a conjugate fiber containing the polyester ester block copolymer as a component is melt-spun. Is difficult to do.
In order to improve the heat resistance of the polyester ester block copolymer and to satisfactorily melt-spin a splittable conjugate fiber containing the copolymer as one component (hereinafter sometimes simply referred to as a conjugate fiber). , 80 mol% of dicarboxylic acid units
The above is preferably an aromatic dicarboxylic acid unit,
It is more preferred that at least 90 mol% be aromatic dicarboxylic acid units.

The aromatic dicarboxylic acid unit includes
Any aromatic dicarboxylic acid unit derived from an aromatic dicarboxylic acid having a molecular weight of 400 or less may be used, and is not particularly limited. Specifically, derived from aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, biphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, and sodium sulfoisophthalate. Units to be used. These aromatic dicarboxylic acids may be used alone or in combination of two or more. The above-mentioned aromatic polyester segment (A) may contain, if necessary, other dicarboxylic acid units of less than 30 mol%, preferably 20 mol% or less, more preferably 10 mol% or less, for example, 1,4-cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acid units such as units,
One or more aliphatic dicarboxylic acid units composed of aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid may be used in combination.

Further, in the aromatic polyester segment (A), an aliphatic α, ω-di-
And at least one diol unit selected from 1,4-cyclohexanedimethanol units is 70 moles based on all diol units constituting the aromatic polyester segment (A). %, The elasticity of the obtained composite fiber at low stress is reduced. In this respect, aliphatic α, ω- having 2 to 4 carbon atoms
Diol unit and 1,4-cyclohexanedimethano-
The ratio of at least one diol unit selected from the diol units is preferably at least 80 mol% of all the diol units constituting the aromatic polyester segment (A), particularly preferably at least 90 mol%. Is preferred.

The aliphatic α, ω-diol unit having 2 to 4 carbon atoms is a unit composed of 1,4-butanediol, 1,3-propanediol, and 1,2-ethylene glycol. Can be mentioned. The aromatic polyester segment (A) may have only one of these diol units and 1,4-cyclohexanedimethanol unit, or may have two or more thereof.

Further, if necessary, the aromatic polyester segment (A) is less than 30 mol%, preferably 2 mol%.
0 mol% or less, more preferably 10 mol% or less of other diol units such as 1,5-pentanediole, 1,1
6-hexanediol, neopentyl glycol, 3-
Methyl-1,5-pentaneddiol, 2-methyl-1,
8-octanediol, 1,9-nonanediol, 1,1
Aliphatic diols such as cyclohexanediol; aromatic diols such as 1,4-bis (β-hydroxyethoxy) benzene and p-xylene glycol One or more diol units such as diols may be used in combination. If the amount of the aromatic polyester segment (A) is small (preferably 1 mol% or less of the total polyol), trimethylo-
Luethane, trimethylolpropane, glycerin, 1,
It may contain a unit composed of a polyvalent alcohol such as 2-hexanetriol and pentaerythritol.

In the polyester ester block copolymer according to the present invention, the aromatic polyester segment (A) has a poly (tetramethylene terephthalate) segment and a poly (tetramethylene-2,6-naphthalenedicarboxylate) segment. ) Segments and one or more of poly (1,4-cyclohexane dimethylene terephthalate) segments, because of the spinnability of the copolymer and the low stress of the composite fibers. This is preferred in terms of stretchability.

In the copolymer, the aliphatic polyester segment (B) is mainly composed of dicarboxylic acid units and diol units, and the aliphatic polyester segment (B1) is mainly composed of hydroxycarboxylic acid units. It is also characterized by comprising at least one of the segments (B2).

The aliphatic polyester segment (B1)
In the above, when the proportion of the saturated aliphatic dicarboxylic acid having 6 to 14 carbon atoms is less than 60 mol% based on all dicarboxylic acid units constituting the aliphatic polyester segment (B1), the resulting composite fiber has low stress. And the flexibility is also reduced. 250 ° C or higher, especially 27
In terms of the effect of suppressing the random structuring of the block copolymer structure at the time of melting and staying at a high temperature such as 0 ° C. or more, the properties of the obtained composite fiber such as elasticity under low stress and flexibility are improved. In order to do so, the ratio of the saturated aliphatic dicarboxylic acid unit having 6 to 14 carbon atoms is preferably 70 mol% or more, more preferably 80 mol% or more.

The aliphatic polyester segment (B
Examples of the saturated aliphatic dicarboxylic acid unit having 6 to 14 carbon atoms in 1) include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, monodecandioic acid,
Units composed of saturated aliphatic dicarboxylic acids such as dodecandioic acid, tridecandioic acid, and tetradecandioic acid can be mentioned, and the aliphatic polyester segment (B1) is one or more of these saturated aliphatic dicarboxylic acid units. Can be used in combination.

The aliphatic polyester segment (B
1) is, if necessary, less than 40 mol%, preferably 30 mol%.
Mol% or less, more preferably 20 mol% or less of other dicarboxylic acid units, for example, a saturated alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid; phthalic acid, terephthalic acid,
Aromatic dicarboxylic acids such as isophthalic acid; unsaturated aliphatic dicarboxylic acids such as maleic acid, phthalic acid and itaconic acid;
It may have one or more dicarboxylic acid units composed of halogen-containing dicarboxylic acids such as tetrabromophthalic acid. If the aliphatic polyester segment (B1) is in a small amount (preferably 1 mol% or less of the total acid units) together with the above-mentioned dicarboxylic acid unit, a polyvalent such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, etc. It may contain a unit composed of a carboxylic acid.

Further, in the aliphatic polyester segment (B1), the proportion of the aliphatic diol unit having 5 to 12 carbon atoms is 70 mol based on the total diol unit constituting the aliphatic polyester segment (B1). %, The effect of suppressing the random structuring of the block copolymer structure at the time of melting and staying at a high temperature of 250 ° C. or higher, particularly 270 ° C. or higher, is reduced, and the elasticity of the composite fiber under low stress is reduced. Flexibility decreases. From this point, the proportion of the aliphatic diol unit having 5 to 12 carbon atoms is preferably at least 80 mol%, more preferably at least 90 mol%.

The aliphatic diol unit having 5 to 12 carbon atoms includes, for example, 1,5-pentanediole and 1,6-pentanediol.
Hexanediol, 1,7-heptanediol, 1,8
-Octanediol, 1,9-nonanediol, 1,1
0-decanediol, 1,11-monodecanediol,
Linear aliphatic diol unit consisting of 1,12-dodecanediol; neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1 , 3-propanediol, 3-methyl-1,5-
Examples include branched aliphatic diol units such as pentanediol and 2-methyl-1,8-octanediol, and the aliphatic polyester segment (B1) has one of the aliphatic diol units described above. It may have only one species or two or more species. Among the aliphatic diol units having 5 to 12 carbon atoms, the aliphatic diols having 5 to 12 carbon atoms among the branched aliphatic diol units in order to improve the elasticity and flexibility under low stress of the conjugate fiber. It is preferable that the ratio of the hydroxyl unit is 30 mol% or more, preferably 40 mol% or more, particularly preferably 50 mol% or more.

The aliphatic polyester segment (B)
1) is optionally less than 30 mol%, preferably less than 20 mol%.
It may have one or more other diol units of up to mol%, especially up to 10 mol%. Other diol units include alicyclic diols such as cyclohexanediol and cyclohexanedimethanol; and aromatics such as 1,4-bis (β-hydroxyethoxy) benzene and p-xylene glycol. A diol unit composed of diol and the like can be mentioned. If the amount is small (preferably 1 mol% or less of the total polyol), polyhydric alcohols such as trimethylolethanetrimethyloluropan, glycerin, 1,2-hexanetriol and pentaerythritol may be used.
May be included.

In the aliphatic polyester segment (B2), the proportion of the saturated aliphatic hydroxycarboxylic acid unit having 6 to 10 carbon atoms is 60 moles based on all the hydroxycarboxylic acid units constituting the aliphatic polyester segment (B2). %, The elasticity and flexibility under low stress of the conjugate fiber are reduced. 250 ℃ or more, especially 2
In view of the effect of suppressing the random structuring of the block copolymer structure at the time of melting and staying at a high temperature of 70 ° C. or more, the saturated aliphatic hydroxy having 6 to 10 carbon atoms has been considered in terms of improving the various physical properties of the above-mentioned conjugate fiber. The proportion of carboxylic acid units is preferably at least 80 mol%, particularly preferably at least 90 mol%.

Examples of the saturated aliphatic hydroxycarboxylic acid unit having 6 to 10 carbon atoms in the aliphatic polyester segment (B2) include saturated aliphatic hydroxy groups such as ε-hydroxycaproic acid, 6-hydroxyenanthic acid and 7-hydroxycaprylic acid. And a unit derived from a carboxylic acid, and an aliphatic polyester segment (B2).
May have one or more of these saturated aliphatic hydroxycarboxylic acid units.

The aliphatic polyester segment (B) according to the present invention may be the above-mentioned aliphatic polyester segment (B1) alone, the aliphatic polyester segment (B2) alone, or the aliphatic polyester segment (B2). It may be composed of both the segment (B1) and the aliphatic polyester segment (B2), and it is preferable to have the aliphatic polyester segment (B1) because it is difficult to thermally decompose at a high temperature.

In the polyester ester block copolymer according to the present invention, the ratio of the aromatic polyester segment (A) / aliphatic polyester segment (B) is expressed in terms of weight ratio, and the former / latter = 95/5 to 30.
/ 70 is required. When the proportion of the aromatic polyester segment (A) exceeds 95% by weight, the stretchability and flexibility of the conjugate fiber become poor. On the other hand, when the proportion of the aromatic polyester segment (A) is less than 30% by weight, the heat resistance of the copolymer becomes poor, and a problem may occur in the adhesive property between the conjugate fibers during spinning.
From this point, the ratio of the aromatic polyester segment (A) / aliphatic polyester segment (B) is preferably the former / the latter = 90/10 to 40/60 (weight ratio), particularly 80/20 to 40 /. It is preferably 60 (weight ratio).

Further, in order to improve the strength and elongation, elastic recovery and the like of the conjugate fiber of the present invention, the number average molecular weight of the aromatic polyester segment (A) constituting the copolymer is preferably about 10%. 500 to 10,000, the number average molecular weight of the aliphatic polyester segment (B) is about 500 to 10,000
It is preferred that

The intrinsic viscosity of the copolymer is pheno-
Toluene / tetrachloroethane mixed solvent (equal weight ratio), 30
When measured at ° C, it is preferably at least 1.0 dl / g, more preferably at least 1.2 dl / g.
It is preferable that it is above.

It is a very important feature that the polyester ester block copolymer of the present invention has a hydroxyl group concentration of 10 μeq / g or less. When the hydroxyl group concentration of the copolymer exceeds 10 μequivalent / g, transesterification between the aromatic polyester segment (A) and the aliphatic polyester segment (B) when the polymer is melted and retained at a high temperature of 270 ° C. or higher. When a reaction occurs, the block copolymer structure is lost to form a random structure, the inherent properties of the polyester ester block copolymer are lost, and the elasticity of the composite fiber under low stress is reduced. In order to more effectively suppress the disappearance of the block copolymer structure when retained in a molten state at a high temperature, the hydroxyl group concentration of the copolymer is preferably 5 μeq / g or less, and particularly preferably 3 μeq / g. The following is preferred. The “hydroxyl concentration” in the present invention refers to the hydroxyl concentration measured by the method described in the following examples.

Further, it is an important feature that the above-mentioned copolymer has a carboxyl group concentration of 20 μeq / g or less. If the carboxyl group concentration of the copolymer exceeds 20 μeq / g, the ester exchange reaction between the aromatic polyester segment (A) and the aliphatic polyester segment (B) will occur when the copolymer is kept in a molten state at a high temperature. , The original properties of the copolymer are lost, and the elasticity of the composite fiber under low stress is reduced. In addition, when the carboxyl group concentration exceeds 20 μeq / g, the durability of the copolymer, such as hydrolysis resistance, also decreases. From such a point, the carboxyl group concentration of the copolymer is preferably 10 μeq / g or less, particularly preferably 5 μeq / g or less. The “carboxyl group concentration” in the present invention refers to a carboxyl group concentration measured by the method described in the following examples.

It is important that the polyester ester block copolymer according to the present invention satisfies the requirements (i) to (iv) as described above. Even when the composite fiber as one component, especially polyester and composite spinning at high temperature, the block copolymer structure is maintained and does not form a random structure, and therefore the composite fiber has good elasticity and flexibility, The composite fiber has elasticity and flexibility after the split fibrillation treatment.

The polyester ester block copolymer according to the present invention is obtained by subjecting an aromatic polyester and an aliphatic polyester to a transesterification reaction. At least one of the aromatic polyester and the aliphatic polyester is reacted with potassium titanium oxalate as a catalyst. When the polyester produced by using the polyester is used, a polyester ester block copolymer excellent in durability and color tone such as hydrolysis resistance can be obtained. As a result, a conjugate fiber having improved durability can be obtained. In particular, when polybutylene terephthalate is used as the aromatic polyester, a polyester ester block copolymer having a more excellent effect can be obtained by using a product produced using potassium titanium oxalate as a catalyst. Thus, a composite fiber can be obtained.

The term "potassium titanium oxalate" used herein means:
Oxalic acid in which the carboxyl group is in the form of a salt with titanium and potassium. Generally, about 0.5 mol of titanium atoms and about 1 mol of potassium atoms are bound per 1 mol of oxalic acid. Has the chemical formula: K
₂ Ti (C ₂ O ₄ ) · nH ₂ O. Such potassium titanium oxalate can be produced, for example, by reacting oxalic acid with potassium titanate that has been sufficiently hydrolyzed. However, the production method is not limited, and is, of course, not limited to the above-mentioned chemical formula. Any of the potassium titanium oxalate represented can be used.

The composite shape of the splittable conjugate fiber of the present invention, when viewed in cross section of the fiber, is composed of two types of incompatible fiber-forming polymers, and one type of polymer is composed of a plurality of types of other types of polymers. As a typical example, the fiber-forming polymers A and B, which are incompatible with each other, are joined in parallel or almost in parallel as shown in FIGS. , Those joined radially as shown in (c), those joined randomly as shown in (d), etc. It is not limited.

The composite fiber of the present invention has a cross section of
The length (L) of the junction of the two incompatible polymers and the thickness (W1, W1) of the two polymers located across the junction.
Each ratio (L / W1, L / W2) with W2) is in the range of 1 to 10;
Necessary in terms of wiping properties and the like, particularly 1.0 to 8.
It is preferably in the range of 0. A specific example will be described with reference to FIGS. Let L be the length of the joint 1 where the two incompatible polymers A and B are joined, and W be the thickness of the polymer A located across the joint.
1. The thickness of the polymer B located across the joint is W2
Then, L / W1 = 1 to 10 and L / W2 = 1 to 1
It means 0. If these values are less than 1, a divided fibrillated product having excellent flexibility, bulkiness, etc. cannot be obtained, while if these values exceed 10, the releasability between the polymers at the joint decreases, and satisfactory results are obtained. The split fibrillation cannot be performed.

Here, the thickness W1 of the polymer A and the thickness W2 of the polymer B are determined as shown in FIG.
When a large number of A and polymer B are joined in parallel or substantially parallel to each other, the distance can be simply obtained as the distance of a straight line that intersects the joining portion at right or almost right angles. When the joining of the polymer A and the polymer B is not parallel or almost parallel to each other as shown in FIG. 1 (c) or (d), the polymer A located across the joint 1 Thickness W
1. The thickness W2 of the polymer B is, as shown in FIG. 2 (b), the length of a perpendicular line dropped from the point b located on the outer periphery of the fiber of the joint 1 to another adjacent joint. And

In the present invention, as can be seen from the composite cross-sectional shape of FIG.
And the thicknesses W1, W2 are different, but L / W1, L / W2
Is within the range of 1 to 10, the divided fibrillation process is smoothly performed, and the divided fibrillated product also has excellent flexibility and bulkiness. In addition, in the present invention, the split type composite fibers in which the composite shape between the filaments is different at random are also included. It should just be in the range of.

In the examples described later, the values L / W1 and L / W2 are calculated by measuring the length of the joint portion of the composite fiber after the split fibrillation treatment and the thickness of each polymer. The reason is that it is easier to measure each value after performing the split fibrillation treatment. There are various types of split fibrillation means, and the above-mentioned L / W1 and L / W2 are slightly affected depending on the degree of weight loss by the aqueous alkali solution. Is almost the same as before alkali weight loss.

The division number of the incompatible polymer in the fiber cross section of the splittable conjugate fiber of the present invention, that is, the number of laminations is not particularly limited as long as it is 3 or more. It is preferable that the number of laminations is about 3 to 15 depending on the fineness of the ultrafine fibers formed by the split fibrillation treatment. The fineness of the single fiber of the splittable conjugate fiber is usually about 1 to 15 denier.
It is preferable in terms of stretching processability, weaving and knitting properties, nonwoven fabric productivity, ease of split fibrillation, and the like. The fineness of the ultrafine fibers formed after the split fibrillation treatment is 0.1%.
The split fibrillated product is excellent in stretchability, flexibility and bulkiness by setting the single fiber fineness and the number of laminations of the splittable conjugate fiber so as to be 9 denier or less, especially 0.6 denier or less. Can be obtained.

Fibers obtained by subjecting the above-mentioned splittable conjugate fibers to split fibrillation treatment have irregular cross-sectional shapes of the fibers among the filaments. For example, Figure 1 (a)
(B) In the group of ultrafine fibers obtained by subjecting the yarn composed of two or more splittable conjugate fibers of the composite shape shown in (c) to split fibrillation processing, there are also ultrafine fibers having the same cross-sectional shape,
There are also microfibers with different cross-sectional shapes. Further, as described above, the ultrafine fibers obtained by splitting and fibrillating a yarn composed of two or more splittable conjugate fibers having different random conjugate shapes between filaments are different from each other. It has a cross-sectional shape. What is necessary is just to set the composite shape of a composite fiber according to the objective.

The fiber cross-sectional shape of the splittable conjugate fiber of the present invention is not particularly limited, and may be circular; elliptical; triangular, square, polygonal, multi-leaf, array, T-shaped, V-shaped, etc. be able to. Further, it may be a solid fiber or a hollow fiber.

One of the two incompatible polymers constituting the composite fiber of the present invention is the above-mentioned polyester ester block copolymer, but the other types of polymers include:
The polyester ester block copolymer is not particularly limited as long as it is an incompatible polymer,
It is preferable to use general-purpose fiber-forming polymers such as polyester and polyamide.

When a polyester is used, a terephthalic acid unit and at least one glycol unit, preferably one or more alkylene glycols selected from ethylene glycol, trimethylene glycol and tetramethylene glycol. Preferred is a polyester mainly composed of units consisting of The polyester may have a small amount of other dicarboxylic acid units or oxycarboxylic acid units together with terephthalic acid units, if necessary. Other dicarboxylic acid units, oxycarboxylic acid units as isophthalic acid,
Aromatic dicarboxylic acids and aromatic oxycarboxylic acids such as sodium sulfoisophthalate, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid and p-oxybenzoic acid; adipic acid, sebacic acid, Examples of the unit include aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and alicyclic dicarboxylic acids.

Further, the polyester may have a small amount of other glycol units in addition to the above-mentioned glycol units. Other glycol units include cyclohexane-1,4-dimethanol, neopentyl glycol,
Diol units such as bisphenol A and bisphenol S; and polyoxyalkylene glycol units. Examples of the polyester include polycarboxylic acids such as trimellitic acid and pyromellitic acid; and polyols such as glycerin, trimethylolpropane and pentaerythritol as long as the linear structure is not substantially impaired. Can be. In the present invention, among the polyesters described above, it is preferable to use a polyester in which 80 mol% or more of the repeating unit is composed of an ethylene terephthalate unit, and a polyester having an intrinsic viscosity of 0.50 to 0.75 is used. It is preferred to use.

When polyamide is used, for example, nylon 6, nylon 66, nylon 610, nylon 11
And other fiber-forming polyamides. Among them, nylon 6 is preferable in terms of quality, handleability, and price.
Further, a polyamide having an intrinsic viscosity of 1.0 to 1.4 is preferable.

The compounding ratio of each polymer in the splittable conjugate fiber of the present invention can be adjusted according to the type and use of the polyester ester block copolymer and other polymers. : Other polymer = 15:85 to 85:15, especially 25:75 to
It is preferably 75:25 (weight ratio). When polyester is used as another polymer, polyester ester block copolymer: polyester = 25: 7
The ratio is preferably from 5 to 75:25, particularly preferably from 30:70 to 60:40 (weight ratio). When the other polymer uses polyamide, the polyester ester block copolymer: polyester = 25: 75 to 75. : 25, particularly preferably 25:75 to 70:30 (weight ratio).

It is preferable that the splittable conjugate fiber of the present invention is completely split when split fibrillation is performed, but it is sufficient in the present invention even if only a part of the splittable conjugate fiber is split. The object of the present invention can be achieved.

The splittable conjugate fiber of the present invention can be produced by a known conjugate spinning method. For example, splittable composite fibers having different composite shapes between filaments can be obtained by spinning using a spinning machine equipped with a static mixer having a suitably selected number of mixing elements. The spun undrawn yarn is once wound or continuously drawn as it is. In this case, a high-speed spinning method in which composite spinning is performed at a spinning speed of 3000 m / min or more can also be employed. Further, the spun yarn is once cooled to 50 ° C. or lower immediately below the spinneret, and then passed through a heating zone to reduce the yarn temperature to 50 ° C.
A direct spin drawing method in which the film is thermally drawn at a temperature of at least 2000C and wound up at a speed of at least 2,000 m / min can also be employed.

Spun and drawn yarn (split type composite fiber)
Manufactures a knitted fabric or a woven fabric through a weaving knitting process, or manufactures a nonwoven fabric in the form of long fibers or short fibers, or a spun yarn after a spinning process, and then uses the yarn to knit or knit the fabric. Etc. can be manufactured. Then, the woven or knitted fabric obtained as described above is formed into a nonwoven fabric and then subjected to a division fibrillation treatment. In the present invention, in the process until the split fibrillation treatment is performed, the polyester ester block copolymer and other polymers constituting the splittable conjugate fiber, such as polyester and polyamide, are not separated and exfoliated. Since the processability can be carried out smoothly, and split fibrils which can be split almost completely to individual minimum units at the time of split fibrillation after forming into fibrous products such as woven and knitted fabrics and nonwoven fabrics are obtained. is there. In the case of a nonwoven fabric, a split fibrillation treatment may be performed after the nonwoven fabric is manufactured, or a split fibrillation process may be performed before the nonwoven fabric is manufactured.

The split fibrillation treatment can be performed by a chemical treatment method, a high pressure fluid injection method, or the like according to various situations such as a combination of a polyester ester block copolymer with another polymer.
The method can be appropriately selected from a false twisting method, a needle punching method, a heat treatment method and the like. For example, when polyester is used as another polymer, a chemical treatment method, specifically, an alkali weight loss method using an aqueous alkali solution can be used. When the other polymer is a polyamide, a method such as a chemical treatment method, a false twisting method, and a high-pressure fluid injection method can be used.

The fibrous product subjected to the split fibrillation treatment as described above can be subjected to a dyeing treatment as needed or after sewing. When the other polymer is a polyester, it can be dyed with a disperse dye, and when the other polymer is a polyamide, it can be dyed using a combination of a disperse dye and a metal-containing dye.

[0051]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In the examples, each physical property value is a value measured and calculated by the following method. (1) Intrinsic Viscosity of Polyester Ester Block Copolymer The copolymer was dissolved in a mixed solvent of phenol / tetrachloroethane in an equal weight and measured at 30 ° C. (2) Intrinsic Viscosity of Polyester The polyester was dissolved in an equal weight mixture of phenol and tetrachloroethane and measured at 30 ° C. (3) Intrinsic Viscosity of Polyamide A polyamide was dissolved in an equal weight mixed solvent of phenol / tetrachloroethane and measured at 30 ° C. (4) Hydroxyl Group Concentration of Polyester Ester Block Copolymer The hydroxyl group concentration of the copolymer was determined by proton NMR [JEOLX-500NMR, manufactured by JEOL Ltd.]. (5) Carboxyl group concentration of polyester ester block copolymer The pellet of the copolymer was dried, dissolved in benzyl alcohol at a temperature of 215 ° C over 3 minutes, and after dissolution, chloroform was added to the solution. Using a methanol solution of potassium hydroxide and phenol red as an indicator, the neutralization point was determined, and the carboxyl group concentration was calculated.

(6) Spinning / Drawing Process Evaluated by the number of broken yarns / ton. Thread breaking / ton of 1 or less was determined to be good, and thread breaking / ton of 10 or more was determined to be poor. (7) Measurement of L / W of composite fiber The fiber after the splitting treatment was performed by SEM observation. The average value of 50 samples was shown. (8) Elasticity of conjugate fiber The drawn yarn is cut to a length of 10 cm, and a take-up speed of 200 mm
/ 50% elongation at / min, and after holding for 3 seconds after elongation, the stress is unwound, and the yarn length L2 (cm) at the moment when the stress is unwound
Was measured, and the elastic recovery rate was calculated by the following equation. Elastic recovery rate (%) = [{5- (L2-10)} / 5] ×
100 (9) Divided fibrillability A sample is taken from the woven fabric and tubular knitted fabric after the fibril splitting treatment, and the sample is stretched and aligned to be consolidated into one piece with paraffin, and perpendicular to the length direction of the yarn. Microto
A thin section is prepared by observing the section with an electron microscope, and the total number of each fiber unit on the cut surface (total of completely divided fiber units, undivided or incompletely divided fiber units) The total number of fiber units divided into one layer of the minimum unit with respect to (number) was calculated as a percentage and evaluated. ：: The split ratio is 80% or more Δ: The split ratio is 50% or more and less than 80% ×: The split ratio is less than 50%

Reference Example 1 Sebacic acid having 10 carbon atoms (Sb
A) 20.2 kg and 3-methyl- having 6 carbon atoms
A reactor was charged with 14.2 kg of 1,5 pentaneddiol (MPD), and an esterification reaction was carried out under atmospheric pressure at a temperature of 200 ° C. while distilling off water generated outside the system. When the acid value of the reaction product became 10 or less, 11 g of titanium potassium oxalate catalyst was added, and at a temperature of 250 ° C., 200 mmHg
The reaction was continued while gradually reducing the pressure from to 100 mmHg. When the acid value of the reaction product reached 1.0, the degree of vacuum was gradually increased with a vacuum pump to complete the reaction (abbreviated as polyester B). 6000 g of polybutylene terephthalate having an intrinsic viscosity of 0.80 and the above polyester B4000
240 ° C. using g and 20 g of sebacic acid (SbA)
At 150 ° C. for 150 minutes under a reduced pressure of 0.3 mmHg, followed by solid phase polymerization. As a result, as shown in Table 1, a polyester ester block copolymer having an intrinsic viscosity of 1.7 dl / g, a hydroxyl group concentration of 3 μeq / g, and a carboxyl group concentration of 5 μeq / g was obtained.

Reference Examples 2 to 4 Polyester ester block copolymers were obtained in the same manner as in Reference Example 1 except that the acid component, diol component and catalyst shown in Table 1 were used. Table 1 shows the intrinsic viscosity, hydroxyl group concentration, and carboxyl group concentration of the obtained copolymer. However, in Reference Example 2, since polyethylene terephthalate was used as the polyester B, the temperature for polymerizing the copolymer was set at 265 ° C. A coalescence was obtained.

Example 1 TPEE-1 shown in Table 1 was used as a polyester ester block copolymer, and nylon 6 [intrinsic viscosity 1.23, 1013B manufactured by Ube Industries, Ltd.) was used as the other polymer.
K-1] was used. Each is extruded by a separate extruder, and the weight ratio of TPEE-1 to nylon 6 is 50/50.
After metering each with a gear pump, the above two types of polymers are supplied into a spinning pack equipped with a Kenix 4-element static mixer to form a layered divided polymer stream, which is then distributed. After passing through a distribution plate having 12 paths, the mixture was discharged from a 24-hole round nozzle at a die temperature of 270 ° C. and wound up at a speed of 1000 m / min.

The obtained spun yarn is stretched at a hot roller of 65 ° C., a hot plate of 120 ° C. and a magnification of 3.1 times by a usual roller plate type stretching machine, and is subjected to 75 denier.
/ 24 filament drawn yarn was obtained. Both spinnability and stretchability were good. The drawn yarn was used as a warp and a weft to prepare a plain woven fabric having a warp density of 85 yarns / inch and a weft yarn density of 81 yarns / inch. Then, after drying and pre-setting, the fibrillated fiber is subjected to a fibrillation treatment (weight loss rate: 8%) with an aqueous sodium hydroxide solution (NaOH concentration: 40 g / liter, temperature: 98 ° C.), washed with water, dried, and then subjected to the fibrillation. The ratio between the length and the width of the portion corresponding to the joint in was calculated. Table 2 shows the results.

Example 2 In Example 1, the intrinsic viscosity was changed to 0.6 instead of nylon 6.
Example 1 except that the polyethylene terephthalate of No. 5 was used and the spinneret temperature was 290 ° C., the hot roller temperature was 80 ° C., the hot plate temperature was 130 ° C., and the draw ratio was 3.3 times.
A conjugate fiber was obtained in the same manner as described above to obtain a drawn yarn. Using the obtained drawn yarn, a plain woven fabric similar to that of Example 1 was produced and subjected to a split fibrillation treatment. The treatment conditions were a NaOH concentration of 40 g / liter, a temperature of 98 ° C., and a weight loss rate of 10%. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results.

Example 3 A plain fabric was woven by spinning and stretching in the same manner as in Example 1 except that TPEE-2 shown in Table 1 was used as the polyester ester block copolymer. Then, a split fibril treatment was performed under the same conditions, followed by washing with water and drying. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results
Shown in

Example 4 Spinning and stretching were performed in the same manner as in Example 2 except that TPEE-2 shown in Table 1 was used as the polyester ester block copolymer, and a plain fabric was woven. Then, a split fibril treatment was performed under the same conditions, followed by washing with water and drying. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results
Shown in

Comparative Example 1 Spinning and stretching were performed in the same manner as in Example 1 except that TPEE-4 shown in Table 1 was used as the polyester ester block copolymer, and a plain fabric was woven. Then, a split fibril treatment was performed under the same conditions, followed by washing with water and drying. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results
Shown in Although the hydroxyl group concentration and the carboxyl group concentration of TPEE-4 were high and spinning and drawing were possible, single yarn breakage occurred and it was difficult to say that it was good. Further, when the structural analysis of the obtained drawn yarn by TPEE-4 by NMR showed that the blockiness was not maintained, and it was found that the structure was close to that of a random copolymer. The fiberization processability and split fibrillation processability were poor, and the obtained plain woven fabric did not have sufficient elasticity and did not have flexibility.

Example 5 Using TPEE-3 shown in Table 1, the other polymer was used.
As nylon 6 [intrinsic viscosity 1.23, 1 made by Ube Industries, Ltd.]
013BK-1] and melt-extruded with separate extruders, respectively, so that the weight ratio of TPEE-1 to nylon 6 is 5
After each was measured by a gear pump so that it became 0/50, it was supplied into the spinning pack, and the die temperature was 270 ° C.
The film was wound at a speed of 0 m / min. The cross section of the yarn was a vertically split cross-section (11-layer alternating lamination type) structure. The obtained spun yarn was drawn under the same conditions as in Example 1 to obtain a drawn yarn of 75 denier / 24 filaments. Subsequently, the drawn yarn was false-twisted at a number of false twists of 3390 T / M at 150 ° C. to perform a split fibrillation treatment. The knitted knitted fabric of the knitted fabric was prepared using the yarn after the treatment, and relaxation and scouring were performed. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fibers in the tubular knitted fabric was calculated. Table 2 shows the results.

Example 6 In Example 5, the intrinsic viscosity was changed to 0.6 instead of nylon 6.
Example 5 except that the polyethylene terephthalate of No. 5 was used and the spinneret temperature was 290 ° C., the hot roller temperature was 80 ° C., the hot plate temperature was 130 ° C., and the draw ratio was 3.3 times.
A conjugate fiber was obtained in the same manner as described above to obtain a drawn yarn. Using the obtained drawn yarn, a tubular knitted fabric of a knitted fabric was produced and subjected to a split fibrillation treatment. The processing conditions are NaOH concentration 4
At 0 g / liter and a temperature of 98 ° C., the weight loss rate was 11%. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results.

Comparative Example 2 In Example 5, TPEE-4 was used instead of TPEE-3.
In the same manner as above, spinning and stretching were performed, and a split fibrillation treatment was performed to knit a tubular knitted fabric. The ratio of the length to the width of the portion corresponding to the joint in the ultrafine fiber after split fibrillation was calculated. Table 2 shows the results. TPEE-
Although the hydroxyl group concentration and the carboxyl group concentration of No. 4 were high and spinning and drawing were possible, single yarn breakage occurred and it was difficult to say that it was good. Further, when the structural analysis of the obtained drawn yarn by TPEE-4 by NMR showed that the blockiness was not maintained, and it was found that the structure was close to that of a random copolymer. The fiberization processability and split fibrillation processability are poor, and the obtained plain woven fabric does not have sufficient elasticity,
He didn't have the flexibility.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

According to the present invention, it is possible to provide a splittable conjugate fiber capable of obtaining a fabric or a fiber product having excellent stretchability, flexibility and bulkiness.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a cross-sectional structure of a splittable conjugate fiber of the present invention.

FIG. 2 shows the length (L) of the joint between two types of incompatible polymers in the splittable conjugate fiber and the thickness (W1, W2) of the two types of polymers located across the junction. FIG. 7 is a diagram showing a measurement method of FIG.

[Explanation of symbols]

 A: Polyester ester block copolymer B: Fiber-forming polymer

Claims (3)

[Claims] 1. A fiber-forming polymer comprising two types of incompatible fiber-forming polymers, wherein one type of polymer is divided into a plurality of types by another type of polymer, and The ratio of the length (L) to the thickness (W1, W2) of the two types of fiber-forming polymers located across the joint (L / W1,
(L / W2) is in the range of 1 to 10, and one kind of fiber-forming polymer is a polyester ester block copolymer shown below. (I) the aromatic polyester segment (A) and the aliphatic polyester segment (B), and (a) the aromatic polyester segment (A) mainly comprises a dicarboxylic acid unit and a diol unit, and the dicarboxylic acid unit Is an aromatic dicarboxylic acid unit, and 70% by mole or more of the diol unit is an aliphatic α, ω-diol unit having 2 to 4 carbon atoms and 1,4.
And (b) an aliphatic polyester segment (B1) in which the aliphatic polyester segment (B) is mainly composed of a dicarboxylic acid unit and a diol unit. And at least one of aliphatic polyester segments (B2) mainly comprising hydroxycarboxylic acid units, wherein at least 60 mol% of the dicarboxylic acid units in the aliphatic polyester segment (B1) are saturated aliphatic dicarboxylic acids having 6 to 14 carbon atoms. At least 70 mol% of the diol units are aliphatic diol units having 5 to 12 carbon atoms, and at least 60 mol% of the hydroxycarboxylic acid units in the aliphatic polyester segment (B2). 6-10 carbon atoms
(Ii) a saturated aliphatic hydroxycarboxylic acid unit of
The aromatic polyester segment (A) / aliphatic polyester segment (B) has a weight ratio of 95/5 to 30 /
70, (iii) a hydroxyl group concentration of 10 μeq / g or less, and (iv) a carboxyl group concentration of 20 μeq / g or less. 2. A fiber obtained by subjecting the splittable conjugate fiber according to claim 1 to split fibrillation treatment, wherein the outer shape in the cross section is irregularly different between filaments, and the average fineness of the filaments is 0. A split fibrillated fiber having a denier of 9 or less and a part of the filament is constituted by a polyester ester block copolymer shown below. (I) the aromatic polyester segment (A) and the aliphatic polyester segment (B), and (a) the aromatic polyester segment (A) mainly comprises a dicarboxylic acid unit and a diol unit, and the dicarboxylic acid unit Is an aromatic dicarboxylic acid unit, and 70% by mole or more of the diol unit is an aliphatic α, ω-diol unit having 2 to 4 carbon atoms and 1,4.
And (b) an aliphatic polyester segment (B1) in which the aliphatic polyester segment (B) is mainly composed of a dicarboxylic acid unit and a diol unit. And at least one of aliphatic polyester segments (B2) mainly comprising hydroxycarboxylic acid units, wherein at least 60 mol% of the dicarboxylic acid units in the aliphatic polyester segment (B1) are saturated aliphatic dicarboxylic acids having 6 to 14 carbon atoms. At least 70 mol% of the diol units are aliphatic diol units having 5 to 12 carbon atoms, and at least 60 mol% of the hydroxycarboxylic acid units in the aliphatic polyester segment (B2). 6-10 carbon atoms
(Ii) a saturated aliphatic hydroxycarboxylic acid unit of
The aromatic polyester segment (A) / aliphatic polyester segment (B) has a weight ratio of 95/5 to 30 /
70, (iii) a hydroxyl group concentration of 10 μeq / g or less, and (iv) a carboxyl group concentration of 20 μeq / g or less. 3. A fibrillated split product obtained by subjecting a fabric or a fiber product produced using the splittable conjugate fiber according to claim 1 to fibrillation splitting.