JPS58197369A - Fibrilation of sheet constituting fiber - 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 The present invention relates to a method for thinning constituent fibers of a fibrous sheet material.

It is well known that in recent years, suede-like artificial leather, which is based on ultrafine fiber bundles and is made by fibrillating and raising such fiber bundles, has been invented and is still gaining popularity to this day. Many proposals have been made as methods for obtaining such ultrafine fiber bundle sheets.

The most useful method is to form sea-island fibers using two or more types of polymer substances with different solubility, such as polymer array fibers, form a sheet, and then dissolve and remove sea components using a solvent. A method for obtaining ultrafine fiber bundles is mentioned.

There are also attempts to make ultra-fine fibers by physically peeling multi-component fibers made of two or more components into single-component fibers, and physically peeling bundles of self-adhesive fibers to make them ultra-fine. .

The ultrafine fiber bundles obtained by this method are puffed.

The conventional method was to form fibrils by processing with a needle punch, water punch, etc.

However, in such conventional methods, the sea component dissolution method requires a solvent treatment step and a solvent recovery step.

It has the disadvantage that the process is complicated, and since the peeling method can only be used in combinations of usable raw material polymers, there is a disadvantage that there is little flexibility and it cannot be used as a general-purpose technique. Even when it comes to peeling off self-adhesive fiber bundles, it can only be applied to extremely limited raw material polymers and cannot become a general-purpose technique. Furthermore, it was necessary to perform the thinning and fibrillation of the fibers as separate steps.

The present inventors have intensively studied a method for efficiently forming ultrafine fibrils from such ultrafine fiber bundle-forming multicomponent yarn fibers, and have arrived at the present invention.

That is, an object of the present invention is to provide a method for easily and efficiently converting fibers constituting a fibrous sheet into ultrafine fibrils. Another object of the present invention is to provide a method for producing a novel fibrous sheet having a structure in which ultrafine fibers are fibrillated and entangled.

This is the gist of the present invention.

(1) 2 which is capable of forming ultrafine fiber bundles and contains polyalkylene glycols in at least one component;
Fibrils of sheet-constituting fibers, characterized in that a fibrous sheet-like material formed by aggregating multicomponent fibers made of at least one type of polymeric substance is treated by spraying a high-speed fluid stream on at least one surface thereof. There is a method of conversion.

In the method of the present invention, by mixing polyalkylene glycols with at least one component of the ultrafine bundle-forming multicomponent fiber, the mixed component is split by the jetting of a high-speed fluid stream, and as a result, the multicomponent fiber is split. The ultrafine fiber bundles inside the system fibers are easily exposed, causing the fibers to become thinner and fibrillated by the fluid flow. Furthermore, it is also possible to form a structure in which fibrils are intertwined with each other.

If polyalkylene glycol is not mixed, and if at least one component of the multi-component fiber is to be split by fluid jetting, it is necessary to use an extremely high-pressure fluid stream or to extremely increase the number of jettings. , it cannot be an industrial method. For the purpose of the present invention, which is to achieve fibrillation easily and efficiently, it is essential to mix polyalkylene glycol.

The ultrafine rut-forming multicomponent fibers that can be used in the present invention include fibers with a chrysanthemum-shaped cross section in which one component is radially interposed between other components, multilayer bimetal fibers, and multilayer bimetal fibers with a donut-shaped cross section. Composite fibers, such as composite fibers, mixed spun fibers made by melt-mixing two or more components and spinning them, and polymer mutual array fibers, which are a large number of ultra-fine fibers that are continuous in the fiber axis direction and are assembled and wrapped with other components. Examples include sea-island type fibers and high-order sea-island type fibers in which a plurality of sea-island structures exist in one sea. Among them, sea-island fibers such as mixed spun fibers, polymer array fibers, and high-order sea-island fibers are preferably used.

The polymer substances forming the ultrafine fiber bundle components of these multicomponent fibers include nylon 6, nylon 66°, nylon 1
2. Examples include polyamides such as copolymerized nylon, polyesters such as polyethylene terephthalate, polybutylene terephthalate, copolymerized polyethylene terephthalate, and copolymerized polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyurethane, polyacrylonitrile, and vinyl polymers. Among these, polyesters and polyamides are preferred.

Furthermore, in the multicomponent fiber of the present invention, the component to which polyalkylene glycol is mixed is the intervening component in composite fibers or the sea component in seabird type fibers, and the polymeric substances forming these include polystyrene, styrene- Particularly preferred are acrylonitrile copolymers, copolymers of styrene and higher alcohol esters of acrylic acid and/or higher alcohol esters of methacrylic acid, and polyamides, polyesters, polyolefins, polyacrylonitrile, and vinyl polymers. etc. can also be used.

The polyalkylene glycols to be mixed with the above components include polyalkylene glycol or its derivatives, including polyethylene glycol (polyethylene oxide).
and those whose molecules are blocked with an alkyl group at one or both ends, polypropylene glycol, polyethylene-polypropylene glycol block polymers, mixtures, polyalkylene glycol derivatives made from various glycols or acids, block polyether polyamides, etc. It is not limited to these.

Furthermore, these polyalkylene glycols having a molecular weight of 5,000 to 600,000 can be used;
0 to 100,000 is preferred. 100000
The following two substances are difficult to polymerize using an inexpensive method.

The amount of these polyalkylene glycols to be added is preferably selected in relation to the properties of the components to be mixed, but is usually preferably 05 to 30% by weight.

If it is less than 0.05% by weight, the effect of the present invention cannot be fully exhibited,
Moreover, if it exceeds 30% by weight, the spinnability of the fibers will be low and the workability during sheet formation will be poor. When the mixture is polystyrene-based, the appropriate amount to be added is about 0.5 to 10% by weight.

Methods for mixing polyalkylene glycols with components to be mixed include: (1) adding the polyalkylene glycols during polymerization of the components to be mixed; (1) mixing and melting both and discharging them to form chips; (6) mixing both chips; (b) melting them separately; There are several methods of mixing.

The thickness of the multicomponent fiber and the single fiber thickness of the ultrafine fiber bundle used in the present invention are not particularly limited, but are usually selected within the range of 05 to 20 denier for the former and finer than 05 denier for the latter. It's good.

The method of assembling the multicomponent fibers into a fibrous sheet is known as a conventional nonwoven fabric forming method. Methods of forming sheets from cards, cross wrappers, random units, and filaments can be used. Also to improve shape retention.

Needle punching is also useful. More textiles.

It is also possible to take the form of a knitted fabric, a laminate of these and a nonwoven fabric, or a laminated nonwoven fabric.

When a high-speed fluid stream is sprayed onto the fiber sheet thus obtained, the mixed component of polyalkylene glycols is easily split, the ultrafine fiber bundles are exposed, and the exposed fiber bundles are further fibrillated.

The fibrillated fibers can be further subjected to a blowing treatment to form an entangled structure.

In the high-speed fluid flow treatment of the present invention, water is most preferable as the fluid used for the high-speed fluid flow, but organic solvents, aqueous solutions of alkalis, acids, etc. may also be used depending on the purpose.

The fluid is pressurized by a high-pressure pump and injected through a small-diameter nozzle or narrowly spaced slits.
It is sprayed onto the surface of the fibrous sheet as a high-speed columnar flow or curtain flow.

As for the pressure conditions, a range of about 5 to 300 q/♂ can be used.

If the pressure is lower than 5 kg/an'', the fibrillation effect will be small (at a pressure higher than 1 in 300 kg/an'', impact defects or deformation will occur and the object of the present invention cannot be achieved.The preferred range is 20~
200kg/-', more preferably 60-150kg
/(2)゛. In order to avoid the impact locus caused by the jet K, it is effective to move the jet nozzle and the fibrous sheet relatively or to repeat the number of passes.

Further, the spraying treatment may be performed from one side or from both sides. It is possible to select according to the purpose. In the case of single-sided processing, when combined with the processing pressure conditions,
It is possible to obtain sheet-like materials with different degrees of fibrillation and entanglement in the thickness direction, and by combining with known artificial leather techniques such as impregnation, temporary fixation, and removal of one fiber component, it is possible to obtain sheets with a density gradient. You can also get seats. In the case of double-sided processing, a dense sheet can be obtained as a single sheet, or by combining slices, the same sheet can be obtained as 2 sheets with single-sided processing.
You can also get them together.

As described above, the method of the present invention can easily expose the ultrafine fiber leather, easily fibrillate the ultrafine fiber bundle, and form a dense fibrillated entangled layer, thereby forming a multicomponent fiber. In addition to its application in the component removal process, in the field of silver-finished artificial leather, which has conventionally been made by laminating polyurethane films to create a silver surface, we have developed a new sheet with a surface made of fibrillated and entangled ultrafine fiber bundles similar to natural leather. It is possible to obtain. Therefore, the treated sheet obtained by the present invention can be widely used as a base material for artificial leather, such as silver-finished artificial leather and spuck-like artificial leather.

This enables the use of natural leather in all kinds of applications, including suede-like artificial leather.

The present invention will be described in detail below with reference to Examples, but the present invention is of course not limited thereto. In the Examples, all parts 0 and 0 refer to weight.

Example 1 Polyethylene terephthalate 5 as ultrafine fiber bundle island component
0 parts, polyethylene glycol (molecular weight 2
0000) 50 parts of polystyrene containing 5%;
Polymer array fiber type multi-component fiber with 16 islands is spun into a 68 denier, 51 m long stable, opened and carded.

Through each process of cross wrapper and needle punch.

Fabric weight: 190 g/m', thickness: 1. It was made into an ON fibrous sheet-like material.

On the other hand, for comparison purposes, a fibrous sheet material with a basis weight of 190 g/m' and a thickness of 1.0 mm was obtained in the same manner except that polystyrene containing no polyethylene glycol was used as the sea component.

Both fibrous sheet materials were dried by repeating the process of spraying a columnar water stream at a pressure of 80 kg/an'' five times from a spray nozzle in which holes with a diameter of 0.1 rnrn were arranged in a row at a pitch of 0.6 mm. .

When both sheets were observed under a microscope, it was found that the polystyrene portion of the fiber sheet of the present invention had been almost completely removed, and that the single fibers were fibrillated and entangled bundles of ultrafine fibers each having a diameter of about 0.1 denier. I'm here.

The texture became very supple, whereas the comparative fiber sheet material remained much of the polymer array fiber.
The texture was as stiff as before treatment. In the comparative example, the spraying treatment was repeated 15 times to remove the polystyrene portion to the same extent as in the present invention.

Example 2 Nylon 6 and a styrene copolymer (higher alcohol ester copolymer of styrene and acrylic acid) containing 7 units of polyethylene glycol with a molecular weight of 100,000 were mixed at a nylon 6/styrene copolymer ratio of 50,750. A mixed spinning type multi-component fiber is spun into a 4 denier x
A fibrous sheet-like product with a thickness of 50 fields and a basis weight of 540 g/m' was obtained by forming staples with a length of 51 plates and passing through the steps of opening, carding, cross-lattice, and needle punching.

On the other hand, for comparison, a styrene copolymer containing no polyethylene glycol was used, but the thickness
A fibrous sheet material with a filter size of 0 mm and a basis weight of 540 g/m' was obtained.

Both fibrous sheets were prepared with holes of 0.5 mm in diameter.
Pressure 60 kg from injection nozzles lined up in a row with mm pitch
The process of spraying a columnar water stream on the fibers was repeated three times from both sides, and when both dried sheets were observed under a microscope, it was found that most of the styrene copolymer portion was removed in the fiber sheet of the present invention and the fiber sheet of Ming. The single fibers are fibrillated and entangled bundles of ultrafine fibers with a diameter of about 0,009 denier, whereas the comparative fibrous sheet material is composed of a polymer array surrounded by a styrene copolymer. Most of the body fibers remained, and the condition was almost unchanged compared to before treatment.

After both treatments, the fibrous sheet was impregnated with a polyurethane emulsion, all of the styrene copolymer was removed with perchlorethylene, and the fibrous sheet was embossed with a leather-like embossing roll, then dyed. It wasn't good.

Example 6 The same polymer array fibers of the present invention and comparison as used in Example 1 were used as spun yarns of number 2-0 twin yarns, respectively, to make 5-ply sateen woven fabrics.

After shrinking with boiling water, the same high-pressure water jet treatment as in Example 1 was performed once. When both fabrics were observed under a microscope, it was found that the polystyrene portion of the fabric of the present invention had been removed, the ultrafine fiber bundles had become fibrillated, and the texture was extremely supple, whereas the comparative fabric had a polymer-like structure. Since the shape of the arrayed fibers remained considerably and the texture was hard, the water treatment was repeated 9 times until the texture was the same as in the present invention example, but it took 7 times.

Claims (1)

[Claims] (1) It is possible to form ultrafine fiber bundles, and at least 1
A fibrous sheet-like material formed by aggregation of multi-component fibers made of two or more types of polymeric substances mixed with polyalkylene glycols is treated by spraying a high-speed fluid stream onto at least one surface of the fibrous sheet-like material. A method for fibrillating sheet-constituting fibers.