JPH03213519A - Conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber, composed of a low moisture absorbing polyamide layer and high moisture absorbing polyamide layer in a specific proportion and capable of providing comfortable feeling of wear even in exercise due to advantages of nylon and excellent water and moisture absorbing properties equal to those of natural fiber. CONSTITUTION:The objective fiber, composed of (A) a low moisture absorbing polyamide layer and (B) a high moisture absorbing polyamide layer at 40-80wt.% ratio of the component (B) in the whole fiber and having >=4.5% moisture adsorption coefficient as conjugate fiber at 20 deg.CX65RH% and >=1.5%/5min moisture absorption rate. Furthermore, nylon 6 containing 1-20wt.% montmorillonite having <=2mu average particle diameter, etc., are preferably used as the component (A). A polyamide such as nylon-4 having >=6% moisture adsorption coefficient at 20 deg.CX65RH% is preferably used as the component (B). The objective fiber converted into a sheath-core structure using the component (B) as a core component and the component (A) as a sheath component is preferred with hardly any stickiness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to synthetic fibers with excellent hygroscopicity. More specifically, the present invention relates to a new nylon-based synthetic fiber that is water-absorbent and hygroscopic and can be used for clothing that requires moisture-absorbing properties, such as sportswear, bedding, towels, and dish towels.

[Conventional technology]

Conventionally, nylon fibers have the advantages of being strong, soft, and resistant to fading, and have been widely used in fields such as women's underwear, stockings, and carpets.

In addition, nylon is a hydrophilic polymer and is
It has an equilibrium moisture content of 3.5 to 4.0 h in RH%.

In other words, compared to polyester fibers and acrylic fibers, it has high water absorption and moisture absorption rate.

[Problem to be solved by the invention]

However, compared to natural fibers such as cotton, wool, and silk, its water absorption rate is quite low, and it cannot be used in fields that require moisture absorption, such as sportswear, bedding, towels, and dish towels. .

Therefore, we aimed to create a fiber that takes advantage of the advantages of nylon and gives it a water absorption and moisture absorption rate that is different from that of natural fibers, which is comfortable to wear during exercise, and which can also be used in fields that require particularly high water absorption. invention has been achieved.

[Means to solve the problem]

In order to achieve the above object, the inventors of the present invention have made intensive studies and found that composite fibers of highly hygroscopic polyamide and low hygroscopic polyamide, in particular, highly hygroscopic polyamide is used as the core and low hygroscopic polyamide is used as the sheath. The sheath composite fiber maintains excellent strength and elongation, flexibility, and resistance to set, and has high moisture absorption similar to cotton and moisture absorption and release speed similar to wood, and does not feel sticky even when absorbing moisture. It was discovered that the amount of fibers was reduced, and the present invention was achieved.

That is, the present invention provides a conjugate fiber consisting of a low hygroscopic polyamide layer and a highly hygroscopic polyamide IWI, in which the ratio of the hygroscopic polyamide layer is 40 to 80% by weight of the entire fiber, the conjugate fiber and ( The moisture absorption rate at 20℃ x 65RH is 4.5v or more, and the moisture absorption rate is 1.5φ15
It is a composite fiber characterized in that it has a thickness of at least 100%. Preferably, the fiber is a core-sheath composite fiber in which a highly hygroscopic polyamide is a core component and a low hygroscopic boronamide is a sheath component, and the highly hygroscopic polyamide is a nylon-4 composite fiber. Nylon containing 40 to 90% by weight of pyroic acid or piperazine, etc., is copolymerized with highly hygroscopic polyamide.
It is a composite fiber that is nylon-6 or nylon-12. It is a composite fiber in which the hygroscopic polyamide is a microporous polyamide containing inorganic fine particles with an average particle size of 0.5 μ or less, and the low hygroscopic polyamide contains silica with an average particle size of 0.1 μ or less from 0.3 It is a composite fiber that is a roughened polyamide containing 5 wt%.

As the highly hygroscopic polyamide of the present invention, the temperature is 20°C x 65RH.
% moisture absorption is preferably 6 or more, specifically nylon-6, nylon-66, nylon-12.
It can be obtained by copolymerizing or kneading polyether segments, polyamine segments, Na sulfonate segments, etc., singly or in combination, based on nylon 4.6 or the like alone or in copolymers. Especially good-11
In other words, copolymerization of beoic acid, piperazine, etc. results in high moisture absorption. In the case of copolymerization, it has been experimentally confirmed that it is not necessarily necessary to copolymerize with the main chain of polyamide, but grafting it onto the side chain gives higher hygroscopicity. Furthermore, there is no problem in adding a third component that imparts hygroscopicity, and there are no restrictions on the addition of antioxidants, ultraviolet absorbers, whitening agents, and the like.

Nylon is a highly hygroscopic polyamide.
There are 4. Nylon-4 is disclosed in, for example, U.S. Patent No. 4,2
81,105, in the polymerization of 2-beeridone with an alkaline polymerization catalyst in the presence of 802,
It is polymerized using quaternary ammonium ()sulfite as a polymerization accelerator, and even if it contains a matting agent, antioxidant, etc.

In addition, nylon 4 is a crystalline polymer that is insoluble in water.
The moisture absorption rate is 8.5 to 9 in an environment of 20°C x 65RH%, which is higher than that of cotton with 7 to 8 strips. No other polymer has these characteristics, making it a very unique polymer. However, when these highly hygroscopic polyamides are used alone, they become sticky when wet, and their strength and elongation and Young's modulus are quite low, making them difficult to use for underwear, towels, carpets, etc.
This results in a fabric that is less comfortable and less practical. For this purpose, it is effective to combine these highly hygroscopic polyamides with conventionally commonly used low hygroscopic polyamides to improve the drawbacks and take advantage of the advantages of both composite fibers and 5-carbon polyamides.

The low hygroscopic polyamide referred to in the present invention is 20°C
It is preferable that the moisture absorption rate at 5RH% is 4.2 inches or less,
Specifically, 2 such as nylon-6, nylon-6,6, nylon-12, nylon-6/10, nylon 6/12, etc.
This is a melt-spun polyamide composed of an organic acid and an organic amine having a functional group, in which the starting material constituting the polyamide can be weighed on an 85-weight plate.

Other substances added to polyamide include various additives that are added to modify and improve polyamide properties such as gloss reduction, additives, and antistatic properties, flame retardance, and high Young's modulus properties. .

The composite fiber in the present invention is not limited to the cross-sectional shape of the fiber, and refers to commonly used shapes composed of two or more components, such as side-by-side, multilayer lamination, multicore-sheath, core-sheath, etc. Moreover, the core-sheath means a single-core sheath, a multi-core sheath, and an eccentric core-sheath. Figure 1 shows the cross-sectional shape of a typical composite fiber.

6- Next, the ratio of highly hygroscopic polyamide to composite fiber is 4
Q wt ratio to F30 wt% is desirable. 40 wt%
Below that, the level of hygroscopicity reaches that of conventional nylon-6 and nylon-6,6, resulting in low hygroscopicity.

If it exceeds s o wt %, the hygroscopicity is high, but the advantages of low hygroscopic polyamide such as toughness, abrasion resistance, and flexibility are lost. More preferably, the ratio of hygroscopic polyamide is 50
wt%~70WteIbte.

It is necessary that the obtained composite fiber has a hygroscopicity of 4.5% or more at 20°C and 65RH'%. If it is less than 4.5%, it cannot be said that comfort when worn is good. Further, the moisture absorption rate W needs to be 1.5% for 15 minutes or more.

If W is less than 1.5 inches, it will not be able to sufficiently absorb sudden changes in the environment or increases in humidity within the clothing at the start of exercise. This moisture absorption rate W is calculated by determining the weight of the sample after drying the fiber in a dryer at a temperature of 105°C until it reaches a constant weight (absolutely dry weight), and then leaving the fiber in a constant temperature and humidity chamber at 20°C and a relative humidity of 65%. The weight increase is determined for each hour, and the value is calculated from the weight increase after 5 minutes using the following formula.

7- W = ((fiber weight after 5 minutes - bone dry fiber weight) / bone dry fiber weight) x 10 As a method to further reduce the sticky feeling, a highly hygroscopic polyamide is used as the core component and a low hygroscopic polyamide is used as the sheath component. The core-sheath composite fiber used is effective. In this case, humidity and moisture are absorbed by the core, and the low hygroscopic polyamide present on the fiber surface has low humidity and moisture and dries easily, making it less sticky and more comfortable.

Furthermore, the low hygroscopic polyamide is montmorillonite with an average particle size of 2μ or less. Nylon-6 containing 0 wt% to 20 wt% is preferable.

Nylon-6 and other polyamides generally have the advantage of being strong, flexible, and resistant to fading, but are said to be too soft and lack flexibility. Polyamide containing montmorillonite has a high elastic modulus, and when the fibers are made into fabric,
It has sufficient strength and elasticity, eliminating the drawbacks of conventional polyamide. Although it is not entirely clear why montmorillonite has a high elastic modulus, it is also thought to be due to the ion exchange properties of montmorillonite.

8- The content of montmorillonite is 0.5 wt% to 20 wt
Chi is preferred. If the amount is less than 0.5 wt%, the improvement effect will not be sufficient. Adding more than 20 wt% deteriorates processability and tends to make fiberization impossible. More preferably 1
．． Qwt%.

Further, as a low hygroscopic polyamide, a porous polyamide containing inorganic fine particles having an average particle diameter of 0.5 μm or less is effective. If the sheath is porous, the rate of moisture absorption and release of steam between the core and the outside air will be high, increasing comfort.

As a method for making the polyamide of the sheath part porous, for example, foamable inorganic fine particles such as calcium carbonate or magnesium carbonate are added to the polyamide of the sheath part in an amount of 6 to 5 wtq of Q, 3 wtq, and foamed by the melting heat during spinning, followed by alkali elution. Alternatively, this can be achieved by acid treatment. The particle size of the calcium carbonate, etc. to be added is preferably 0.5 μ or less considering the pore size and yarn production.
, 3 wt% to 5 wt% of the roughened polyamide is preferable. When the sheath is made of roughened polyamide, the vapor from the core and the outside air can move smoothly through the thin part of the sheath, increasing the rate of moisture absorption and desorption.The average particle diameter of silica added to the polyamide It is desirable that the diameter is 0.1μ or less, and if it is more than 0.1μ, it will cause poor silk-spinning properties.
The amount added is preferably 0.3 to 5wt.s0.
If it is less than 3 wt%, it will not be possible to obtain a clear roughened structure, and if it is more than 5 wt%, it will cause defects in processability such as thread-spinning properties.Composite fibers containing silica in the sheath part A roughened fiber can be obtained by treating with an alkali or an acid, and the surface has a roughened structure on the order of the wavelength of light, which reduces specularly reflected light on the fiber surface and gives the dyed product a deep color.

〔Effect of the invention〕

A new comfortable fiber has been obtained that exceeds conventional polyamide composite fibers, with a high rate of moisture absorption and desorption of steam, and an equilibrium moisture content of 4.5% or more at 20°C x 65RH%. A highly hygroscopic fiber with improved disadvantages such as sometimes stickiness can be obtained.

A polymer produced from chiron with [η]=6.2 measured at 30° C. of 1/1 of 10-tan was used. Various polyamides (nylon-6) were used as other components. Nylon-6 has [η] = 1.4.

Details are shown in Table 1.

The composite fibers were spun to have the cross-sectional shapes shown in Table 1, and then drawn to obtain drawn yarns of 75 d/24 f. A circular knit is formed from these, and the oil is removed and relaxed during diving, and some of them contain 4 wt% of sodium hydroxide.
The aqueous solution was subjected to elution treatment at 96°C, and various performances were investigated. In addition, the stickiness was evaluated by soaking the circular knit in water for 10 minutes, dehydrating it, and then holding the circular knit at 20°C until it reached a water adhesion state of 10 wt% based on the equilibrium moisture content of 20°C x 65RH. It was air-dried in ×65RH% and subjected to sensory evaluation by texture evaluation.

Examples 1 to 4 are composite fibers having nylon-4 as the core and nylon-6 as the sheath. .2 is different.

All of these fibers are superior to Comparative Examples 1 and 2 in terms of hygroscopicity, moisture absorption rate, sticky feel, etc., and are comfortable fibers.

Example 5 is a core-sheath yarn in which the core is nylon-4 and the sheath is made of nylon-6 containing 2.0 wt% montmorillonite, and the sheath is stiffer than that of nylon-6 and has improved flexibility. It had been.

In Example 6, the sheath was made of nylon-6 containing 3 wt% of CaCO5, and the cacOs was eluted with an alkali to develop a porous structure, and the rate of moisture absorption and desorption was improved.

Further, in Examples 7 and 8, fine irregularities of 0°2 μ to 0.7 μ were developed on the fiber surface after the alkali treatment. Examples 6 to 8 were made with comfortable fibers that were superior to Comparative Examples 1 to 2 in terms of moisture absorption rate, moisture absorption rate, and sticky feel.

Examples 9 and 10 are nylon-12 whose core is copolymerized with 50 wt% PEO acid (20°C x 65RH%) with a moisture absorption rate of 9%.
), the sheath is made of highly hygroscopic fibers made of nylon-6,
It was a comfortable fiber with excellent moisture absorption and moisture absorption speed, and less sticky feeling.

As described above, the present invention is a composite fiber in which a highly hygroscopic polyamide polymer represented by nylon-4 and a low hygroscopic polyamide are formed with a ratio of 40 to 80 wt% of the highly hygroscopic polyamide, compared to the conventional nylon-6. Or nylon
Compared to 66-only fibers, it has a higher moisture absorption level and moisture absorption rate, and provides a comfortable fiber material with less sticky feeling when wet.

Margin below 3- 4,

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a typical core-sheath composite fiber of the present invention.

Claims (1)

[Claims] It consists of a low hygroscopic polyamide layer and a highly hygroscopic polyamide layer, and the proportion of the highly hygroscopic polyamide layer is 40% of the total fiber.
~80% by weight of composite fibers, which have a moisture absorption rate of 4.5% or more at 20°C x 65RH% and a moisture absorption rate of 1.5%/5 minutes or more. Characteristic composite fiber.