JPS6241375A - Production of extremely fine fiber sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] [Prior Art] Conventionally, many proposals have been made for producing fibrous structures using bonded multicomponent fibers.

For example, Japanese Patent Publication No. 39-933 discloses a method in which two types of polymers that have poor affinity for each other are composite-spun into m-fibers with a bonded structure, and each component is separated and separated at the bonding surface by applying bending. Peel it off. Special Publication No. 45-28728, Special Publication No. 48-23% 8 or Special Publication No. 48-2
No. 6804 discloses false twisting to form fibrils. In Japanese Patent Publication No. 49-38929 and Japanese Patent Publication No. 50-22615, a low-moisture oil or non-aqueous oil is applied during composite spinning to form a fibrous structure, which is then treated with hot water and peeled off. Japanese Patent Publication No. 52-30628 discloses peeling using the difference in thermal shrinkage. JP-A-52-85575 proposes peeling by treatment with a swelling agent.

[Problem that the invention seeks to solve]

Conventionally, in the production method of ultrafine fiber sheets using bonded multicomponent fibers, sufficient m, ii is required for easy peeling and splitting.
There are problems such as not being able to obtain strength, not being able to provide sufficient mechanical crimp, or not being able to obtain a good fiber structure.

On the other hand, in the case of non-peelable and splittable properties, there are problems such as a complicated process for producing ultra-fine fibers and complicated processing conditions. The object of the present invention is to solve the above-mentioned problems and to produce a good ultrafine fiber sheet.

[Means for solving problems]

The present invention consists of at least two types of polymers, and the bonding strength of the bonding interface of the mutually bonded polymers is such that the surface tension is 40 dynA or more, and the polymers that do not substantially split in an aqueous solution are combined and melt-spun. At least a part of the bonded interface of the polymer is a bonded multicomponent fiber that communicates with the fiber surface, and the bonded multicomponent fiber is used to make a fiber sheet, and then the fiber sheet is prepared using an aqueous solution having a surface tension of less than 40 dyn/n. The ultrafine fiber sheet is manufactured by peeling and dividing the bonded multicomponent fiber into each component to produce ultrafine fibers.

The bonded multicomponent fiber made of at least two types of polymers of the present invention has a bond strength of 4.
Select polymers with low affinity for each other that do not substantially split in an aqueous solution of 0 dynA 11 or more, and at the spinning head or spinneret, mutual polymer flows are formed at least at the bonding interface of each constituent polymer, such as a multilayer structure or a radial structure. A part of the fiber passes through the fiber surface and is spun into a splittable fiber structure.

The spun yarn is coated with a conventional oil agent, and is hot-stretched by 92 to 7 times by hot-stretching using a shear binder or/and plate, dry heat or/and moist heat, or hot water stretching as necessary. Fix it. It is then mechanically crimped and cut into staples. Alternatively, a fiber sheet is obtained by performing a process such as false twisting. The polymer that makes up the fiber is
For example, nylon-6, nylon-66, nylon-6
10. Polyamides such as nylon-11, nylon-12, condensed Togane polyamide of aromatic diamine and aromatic carboxylic acid or/and aliphatic dicarboxylic acid, or copolyamide containing these as main components. Polyesters such as polyethylene terephthalate, polybutylene terephthalate, or copolyesters containing these as main components. Polyolefins such as polyethylene, poly-10-pyrene, polybutylene, or copolymerized polyolefins containing these as main components. At least two types of polymers selected from polyurethane, polyester efstomer containing an aromatic ring, polyamide efstomer obtained by reacting aromatic or/and aliphatic diamine, dicarboxylic acid, and polymer glycol, polycarbonate, etc. Combine and melt-spun.

Furthermore, if the bonding strength of the at least two selected polymers does not fall within the range desired by the present invention, a third component may be added to either of the polymers within a range that does not impair fiber performance.

Next, the bonded multicomponent fibers are made into fiber sheets such as knitted fabrics, woven fabrics, woven fabrics, webs, entangled nonwoven fabrics, etc. using the usual method, and then the fibers are peeled and divided into each component to make ultra-fine fibers. do.

The method of peeling and dividing bonded multicomponent fibers of the present invention is characterized in that it is treated with an aqueous solution having a surface tension of less than 40 dyn/ff, preferably less than 35 dyn/m. That is, the aqueous solution having a surface tension of less than 40 dyn/2-1I is, for example, a carboxylic acid salt such as sodium thurate, sodium stearate, or sodium oleate. high class ay co-y
, is alkyl ether, sulfate ester salts such as fatty acid esters. Anionic surfactant selected from sulfated oils, alkylbenzene sulfonates, olefin sulfonates, phosphate ester salts, etc. A nonionic surfactant selected from polyethylene oxide or its adducts, fatty acid esters or alkyl ethers of polyhydric alcohols, etc. Furthermore, a cationic surfactant or an amphoteric surfactant having a low surface tension and the ability to peel and divide fibers can be used. In this case, a surfactant having functionality such as a fiber softening agent, a bactericidal agent, an antistatic agent, a water generating agent, etc. may be used, and these functionalities may be imparted at the same time as the fiber is peeled and divided.

In addition, alcohols that lower the surface tension to less than 40 dyn/c's, glycerin, aliphatic carboxylic acids,
A water-soluble compound selected from amines and ethers may be used. Select one or two types of these surfactants,
Use by dissolving in water. The concentration of surfactant is 0.05~
It is in the range of 5%. If it is less than 0.05%, the peeling and dividing effect cannot be obtained. Moreover, if it is more than 5%, there is no difference in the effect and it is not a waste, but sometimes foaming becomes noticeable. Further, the water temperature during treatment may be at room temperature, but it is also preferable to heat the water to 40° to 95° C. in order to accelerate the peeling and dividing speed. Furthermore, it is also preferable to apply mechanical stress such as jet water flow, kneading, beating, and rubbing of the fiber sheet.

Specific examples of cross-sectional structures of bonded multicomponent fibers in which at least a portion of the bonding interface of each component polymer of the present invention communicates with the fiber surface are shown in FIGS. 1 to 6. as bs in the diagram
Each C is a true polymer of chemical structure or composition.

〔Example〕

Next, the present invention will be specifically explained using examples. It should be noted that the figures in the middle part of the examples or percentages refer to weight.

Example 1 Polyethylene terephthalate and 6-nylon were melt-spun in a weight ratio of so:so using a bonded composite spinneret, and the cross-sectional shape was as shown in FIG. 1, with a being polyethylene terephthalate and b being An undrawn yarn of a bonded multicomponent fiber of 6-nylon was obtained. This undrawn yarn was stretched 3.5 times using a heating roller at 90°C, and heat-set by contacting with a plate at 150°C to obtain a composite fiber of 72 dr -24r.

This composite fiber was mechanically crimped and cut into staples with a fiber length of 51 mm to obtain raw cotton for web production.

This raw cotton is 3[i! I<! D Even when the card is turned over and passed through, there is no problem such as wrapping around the wire of the card, and there is virtually no separation between the polymers. Next, this raw cotton was intertwined with a web using a random uniper and a needle punch to obtain a fabric weight of 300 y7yl.

A three-dimensional laminated nonwoven fabric with an apparent density of 0.15 y7cJ was obtained.

Next, this nonwoven fabric was coated with 70% of sodium balmitate.
After immersing in warm water at 95°C (surface tension 32 dyn/ff) for 2 minutes, washing with hot water at 95°C and drying in hot air, the area shrinks by 20.0% and the apparent density is 0.1817c.
A nonwoven fabric was obtained.

The resulting nonwoven fabric has the components of the composite fibers sufficiently exfoliated to become ultrafine, and the fiber entanglement is less uneven, so it has excellent drape properties and has the glossy appearance and feel unique to ultrafine fibers. there were.

Example 2 Polypropylene and polyester polyurethane were melt-spun at a weight ratio of 60:40, and the cross-sectional shape was as shown in FIG. An undrawn yarn of type multicomponent fiber was obtained. This undrawn yarn was stretched three times in hot water at 70°C, mechanically crimped to form a fiber with a number of crimps of 2 degrees/1 inch, and then cut into fibers with a length of 51. It was made into raw cotton.

As in Example 1, it was confirmed that the component polymers were not substantially peeled off even when the card was repeatedly passed through the card three times.

Next, this raw cotton was made into a web using a random unipper, and subjected to hydroentanglement treatment under the conditions of a nozzle diameter of 0.151111 s pitch 1.0 mm and a pressure cuff of 0 kg/cj.
It was made into a three-dimensional bonded nonwoven fabric with an apparent density of 0 y, 4 and an apparent density of 0.11 y/14.

This non-woven fabric contains 0.5% sodium stearate.
When it was immersed in warm water at 95°C (surface tension z s ayn/cyx ) for 3 minutes and then washed with hot water at 95°C, there was a 50% area shrinkage and the apparent density was 0.31. In this nonwoven fabric, the composite fibers are separated into their constituent components, and the polyurethane fine fibers are loosened and contracted to about two-thirds of the actual fiber length, while the polypropylene fine fibers are more entangled. The nonwoven fabric as a whole was a fibrous sheet-like material with a leather-like firm texture and drapability, and a smooth surface texture.

In addition, when this bonded composite AM was stretched in hot water and mechanically crimped, fibers with high fiber strength were obtained without peeling and splitting into constituent components.

Comparative Example 1 The nonwoven fabric obtained in Example 1 was immersed in an aqueous solution of sorbitan monostearate with the concentration shown in Table 1 for 5 minutes, and then washed with hot water at 95°C. Peeling was also insufficient, and the obtained nonwoven fabric did not have excellent appearance, drapeability, and feel.

surface tension of aqueous solution) (Future) The degree of division will be determined by electron microscope observation.

Comparative Example 2 Polypropylene and polyethylene terephthalate were melt-spun at a weight ratio of 50:50 to obtain an undrawn bonded composite fiber yarn having the cross-sectional shape shown in FIG.

This undrawn yarn was drawn in hot water at 90°C, mechanically crimped to obtain fibers with a number of crimps of 30/1 nch, and a fiber length of 51
Raw cotton was made by cutting it into lengths of m. However, most of the composite fibers were already separated and split into constituent components during drawing and mechanical crimping, and could not be wound around card wires in web production to form a web.

Comparative Example 3 A bonded conjugate fiber having the cross-sectional shape shown in FIG. 15 by melt-spinning polyethylene terephthalate and 6-nylon at a weight ratio of 50:50, where a is polyethylene terephthalate and b is 6-nylon. An undrawn yarn was obtained. This undrawn yarn was stretched 3.5 times using a heating roller at 90°C and brought into contact with a plate at 150°C to obtain a filament of 75 dr24F.

This filament was used as the weft, and ordinary polyester yarn was used as the warp to form a four-ply satin weave. After immersing this woven fabric in 70°C warm water containing 1% sodium stearate for 5 minutes,
When washed with hot water at 95°C, no peeling occurred, and no product with the appearance and feel unique to ultrafine fibers was obtained.

〔Effect of the invention〕

The m-fine fiber sheet obtained by the method of the present invention has high fiber strength because it is hardly peeled and split into component ultrafine fibers during the fiber manufacturing process, and has good card passability, so it has less unevenness. A good entangled nonwoven fabric can be produced. Furthermore, since it has good peeling and splitting properties, it can be easily made into fine fibers, so that a fiber entangled body with good flexibility and stretchability can be produced.

Furthermore, the peeling and dividing treatment of fibers also has the advantage that the treatment liquid is easy to handle and does not cause deterioration of the working environment.

[Brief explanation of drawings]

FIG. 1 is an example of the cross-sectional structure of the bonded multicomponent fiber of the present invention.

Claims (1)

[Claims] 1. Consisting of at least two types of polymers, the bonding strength of the bonding interface of the mutually bonded polymers is such that the surface tension is 4.
Polymers that do not substantially split in an aqueous solution of 0 dyn/cm or more are combined and melt-spun to obtain a bonded multicomponent fiber in which at least a portion of the bonding interface of each component polymer communicates with the fiber surface, and the bonded multicomponent fiber An ultrafine method characterized by making a fiber sheet using fibers, then treating the fiber sheet with an aqueous solution having a surface tension of less than 40 dyn/cm, and peeling and dividing the bonded multicomponent fiber into each constituent component to obtain ultrafine fibers. Method for manufacturing fiber sheets. 2. The aqueous solution for treating the fiber sheet has a surfactant concentration of 0.
The method for producing a microfiber sheet according to claim 1, wherein the ultrafine fiber sheet is a 0.05 to 5% aqueous solution. 3. The method for producing an ultrafine fiber sheet according to claims 1 and 2, in which mechanical stress is used in conjunction with the treatment of the fiber sheet. 4. The method for producing an ultrafine fiber sheet according to claim 1, wherein the fiber sheet is a fiber-entangled nonwoven fabric.