JPS62259B2 - - Google Patents

Description

Detailed Description of the Invention The present invention has a suede-like surface covered with napped ultra-fine fibers on one side, and a dense silver-like surface formed by fibrillation and entanglement of ultra-fine fibers on the other side. The present invention relates to a sheet-like product that can be used on both the front and back sides, and a method for producing the same. Conventionally, with the aim of being a substitute for natural leather, artificial leather with a silver surface made of a polymer material such as polyurethane as a surface layer, and napped artificial leather with a suede-like appearance based on a nonwoven fabric made of microfine fiber bundles have been created. That is well known. However, conventional artificial leather has been developed depending on the use and purpose, such as silver-like or suede-like, so even if it is suitable for each use, it is possible to combine the two or make it reversible to create new designs and fashions. When trying to use it as a material for development, basic problems such as different textures and quality, incompatibility in color tone, and differences in color fastness became problems.
It was not possible to meet such a purpose. In recent years, new fashion materials have been introduced, especially in the clothing field, and there is an increasing demand for materials that can freely combine the silver-finish and suede-like styles described above. While suede-like materials have appeared that can meet these demands, silver-covered artificial leather has until now had a polyurethane film on its surface, resulting in a vinyl-like luster and color tone, making it difficult to use for combination wear. There were only inappropriate materials. Moreover, there was no way I could have hoped for a reversible material. The present inventors improved such drawbacks, and
We are actively researching ways to obtain a sheet-like material with high quality, texture, and good dyeing properties that can be used in a combination of suede and silver-tone finishes, and can also be used as a reversible material on both the front and back sides. A sheet-like product was obtained. That is, the object of the present invention is to obtain a sheet-like product that can be used on both the front and back surfaces, with one side having a suede-like raised surface and the other side having a silver-like dense surface, and a method for producing the same. be. The present invention provides a sheet-like material in which one surface has a silver-like surface and the other surface has a raised-like surface. A fibrous sheet consisting mainly of ultra-fine fiber bundles (referred to as primary fiber bundles) and fiber bundles in which a large number of the primary fiber bundles are gathered (referred to as secondary fiber bundles), and in the thickness direction of the sheet. On the other hand, the vicinity of the grain-like surface is mainly composed of a structure in which ultrafine fibers branched from a primary fiber bundle are fibrillated and entangled, and then a structure in which the primary fiber bundles are mainly entangled, and then further It is characterized by having a surface and cross-sectional structure in which the secondary fiber bundles reach a structure in which they are mainly entangled, and finally become a raised-like surface mainly covered with raised fibers opened from the secondary fiber bundles. The present invention relates to a sheet-like material that can be used on both sides, and a method for producing the same. The sheet-like material of the present invention has a silver surface formed by fibrillating and intertwining ultrafine fibers, and as the ultrafine fibers move away from the surface in the thickness direction, a large number of the ultrafine fibers converge into one. It has a special fiber structure in which a secondary fiber bundle is formed, and then multiple primary fiber bundles are brought together to form a secondary fiber bundle, and finally the secondary fiber bundle reaches the napped surface of the opened ultra-fine fiber. As a result, the structural balance is extremely well-balanced, good bending wrinkles are generated, and good kneading texture can be easily imparted through post-processing. It has a silver-like surface all over, which cannot be achieved with silver-surfaced artificial leather.
The other side is a sheet-like material with an elegant suede-like raised surface. Therefore, the sheet-like material of the present invention can be used as a suede-like material or as a silver-like material, and can be used in combination or reversibly. Moreover, unlike the silver surface of conventional polyurethane films, the silver surface created by the entanglement of ultra-fine fibrils is mainly fibrous, so the dyeing and finishing can be exactly the same as the raised surface, resulting in an extremely natural gloss and color tone. , vinyl-like drawbacks are eliminated. The fibers constituting the sheet material of the present invention include:
It is a sea-island type fiber made of at least two kinds of polymeric substances, and a plurality of sea-island structures made of many island components and sea components are further surrounded by one sea, and after removing all the sea components, the sea-island structure is 0.2 A multicomponent fiber having a structure in which a plurality of ultrafine fiber bundles (primary fiber bundles) consisting of a large number of ultrafine fibers of denier or less are further assembled to form a secondary fiber bundle is preferably used. The preferred concept for such multicomponent fibers is the first one.
2 and 3. That is,
It is as if a sea-island structure consisting of a large number of island components 1 and a sea component 2 is surrounded by one larger sea component 3. When the whole sea component is removed from such a multicomponent fiber, a primary fiber bundle consisting of a large number of ultra-fine fibers and a secondary fiber bundle consisting of a plurality of primary fiber bundles are obtained. As for the means for producing such multicomponent fibers, for example, a method using an island-in-the-sea type spinneret for multicomponent fibers disclosed in JP-A No. 125718/1986 is preferred. In this method, the arrangement of the island component 1, sea component 2, and sea component 3 can be completely controlled, and the number and thickness of the island component can be arbitrarily changed by the design of the cap. As a modification of this method, it is also preferable to use a static mixer as a mechanism for dividing the island component flow into a plurality of parts or more and merging them with other island component flows. That is, in this method, the flow of the island component 1 and the sea component 2 of the present invention is introduced into a static mixer to form a sea-island structure, and then the sea component 3 is coated. As a static mixer, if a fluid mixer such as that described in Japanese Patent Publication No. 53-36182 is used, the number and thickness of the islands can be changed by changing the number of mixing elements, and the obtained island component can be obtained using the above-mentioned special mouth method. Similarly, the fibers are substantially continuous in the axial direction. The multicomponent fibers produced by each of the above means are the most suitable fibers for the purpose of the present invention in that each ultrafine fiber is continuous from the fibril state through the primary fiber bundle to the secondary fiber bundle. However, for the purpose of the present invention, the island components do not necessarily have to be continuous, and any fiber that produces a fibrillar state, a primary fiber bundle, a secondary fiber bundle, or a nap structure can be used. In this sense, for example, multicomponent fibers such as those described in Japanese Patent Publication No. 47-37648, in which island components of a polymer mutual array are blended with a polymer and the island components form a sea-island structure, can be used. . However, polymer blends made by simple chip mixing, extruder mixing, or static mixer mixing of the type that breaks the flow have poor spinnability, and the fibers are essentially discontinuous. It is necessary to devise the conditions, and the critical island ratio resulting in a sea-island structure is lower than the above-mentioned preferred manufacturing method.
The decline is unavoidable. Examples of island components constituting the above multicomponent fibers include nylon 6, nylon 66, nylon
12, Other polyamides such as copolymerized nylon, polyesters such as polyethylene terephthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, copolymerized polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyacrylonitrile, polyurethane, and vinyl polymers. Combination etc. are used. Examples of sea components include polystyrene, polypropylene, alkali-soluble copolymerized polyethylene terephthalate, polyamide, polyurethane, styrene-acrylonitrile copolymer,
Copolymers of styrene and higher alcohol esters of acrylic acid and/or higher alcohol esters of methacrylic acid, polyvinyl alcohol, copolymerized polyvinyl alcohol, etc. are used. As the sea component, polystyrene, styrene-acrylonitrile copolymer, copolymer of styrene and higher alcohol ester of acrylic acid and/or higher alcohol ester of methacrylic acid are preferable from the viewpoint of ease of spinning and ease of dissolution and removal. . Further, it is preferable to mix a small amount of a different type of polymer such as polyethylene glycol with the sea component in order to make it easier to split the sea component by a high-speed fluid flow. The selection of the island component and the sea component requires combinations with different solubility in the solvent, and the selection of the sea component 2 and sea component 3 may be the same or different polymers, but the solubility in the solvent is Combinations having the same gender are preferred. Island component 1 - Sea component 2 - Sea component 3
Preferred combinations include nylon 6 - polystyrene (including copolymers) - polystyrene (including copolymers), polyethylene terephthalate (including copolymers) - polystyrene (including copolymers) - polystyrene (copolymers). Examples include, but are not limited to, polybutylene terephthalate-polystyrene (including copolymers)-polystyrene (including copolymers). The number of island components that form the primary fiber bundle depends on which multicomponent fiber manufacturing method is selected, and variable conditions such as the design of the die, the number of elements in the fluid mixer, and the island ratio in the blend. control is possible. A large number of fibers (at least 5 or more) is required, but the larger the number, the thinner the thickness, the more dense the grain structure formed by fibrillation, and the more dense the naps are, so it is preferable. From this point of view, the method using the special fluid mixer described above is particularly preferable because it is easy to use a very large number of Shimamotos. The number of primary fiber bundles forming the secondary fiber bundle can be controlled by how many channels are provided for the confluence of the island component and the sea component 2, and is preferably 5.
More than one book is used. There is no particular limit on the upper limit, but there is a limit depending on the manufacturing precision of the cap. The thickness of the island component needs to be ultra-fine, 0.2 denier or less, preferably 0.15 denier or less, in order to achieve the object of the present invention. As a result, if thick fibers are used, even if a silver surface can be formed by fibrillation and entanglement, the smoothness and density will be poor, and the raised quality of the suede-like surface will be poor. It is not possible to obtain a sheet with FIG. 4 shows a preferred concept of the sheet-like article of the present invention, which is formed by intertwining fibrils of ultrafine fibers, primary fiber bundles, and secondary fiber bundles as described above.
That is, the primary fiber bundle 5 made up of a large number of ultra-fine fibers is fibrillated into ultra-fine fibers near the surface, and is tightly intertwined to form a dense grain layer 4.
A plurality of primary fiber bundles 5 are further bundled toward the back surface to form a secondary fiber bundle 6, and the entire fiber bundle has an entangled structure. Further, the secondary fiber bundle is opened to form a raised nap 7, which becomes a raised nap surface. It is also preferable to have a structure in which a resin is attached to such a basic structure, particularly a structure in which the resin is present at least on the surface, in a portion near the surface, or in a void inside the sheet. In particular, it is preferable that it exists in a form surrounding ultra-fine fibers or fiber bundles. Of course, FIG. 4 is just one conceptual diagram, and even though the relative relationship between the fibrillated entangled structure 4, the primary fiber bundle 5, and the secondary fiber bundle 6 is as shown, the ratio relationship in the thickness direction may change. There is no problem at all.
Since this structure relationship is caused by the jetting process of high-speed fluid flow, the structures 4, 5, and 6 may be locally mixed and entangled, but within the range where the effects of the present invention can be obtained. There is nothing wrong with that. There are roughly two methods for obtaining the silvered leather-like sheet material of the present invention having such a structure. The first method is to cut the multi-component fibers mentioned above to an appropriate length and use them as staple fibers, such as open cotton, carded fibers, etc.
A sheet-like web is formed through the process of web formation, and then entangled with a needle punch to obtain a nonwoven fabric sheet.A high-speed fluid stream is sprayed from one side of the nonwoven fabric to split the sea component and expose the exposed ultrafine fiber bundles. After that, the sea component of the multicomponent fiber is dissolved and removed using a solvent for the sea component and a non-solvent liquid for the island component.
Next, the surface treated with the high-speed fluid flow is pressed or pressed, and the surface not treated with the high-speed fluid flow is buffed to form the sheet-like product of the present invention. Alternatively, the sea component dissolving step and the embossing or pressing step may be reversed. Conventional artificial leather manufacturing techniques may be freely combined between these main steps depending on the desired quality design of the leather sheet. That is, shrinkage of the nonwoven fabric is performed before or after high-speed fluid flow treatment, and a resin liquid such as a polyurethane elastomer is applied after high-speed fluid flow treatment, and the resin is applied around the fibers or fiber bundles by wet coagulation or dry coagulation. It is possible to combine techniques such as subjecting both sides of a thick non-woven fabric to a high-speed fluid flow treatment followed by slicing in an appropriate step, or applying an appropriate resin before embossing or pressing. Part 2 is the same as in Part 1, after making an entangled nonwoven fabric by needle punching, one side is attached to a sheet in which the sea component has been dissolved and removed using a liquid that is a solvent for the sea component of the multicomponent fiber and a non-solvent for the island component. A high-speed fluid stream is ejected from the surface to fibrillate and entangle the ultrafine fiber bundles on the surface to form a sheet with a dense surface.The surface treated with the high-speed fluid stream is then embossed or pressed, and the surface treated with the high-speed fluid stream is then treated with a high-speed fluid stream. In this method, the untreated surface is buffed to form the sheet-like product of the present invention. Similar to Part 1, this method can also be freely combined with existing artificial leather techniques. In other words, shrinking the nonwoven fabric, applying a temporary fixing polymer such as polyvinyl alcohol before removing the sea component and removing it by extraction in a subsequent appropriate process, and applying the temporary fixing polymer and/or after high-speed fluid flow treatment. Applying a resin such as polyurethane elastomer, wet coagulation or dry coagulation, then extracting and removing the temporary fixing polymer, applying an appropriate resin before embossing or pressing,
Techniques such as high velocity fluid flow treatment on both sides followed by slicing in a suitable step can be used. In addition, in this method, it is also possible to perform high-speed fluid flow treatment both before and after removing the sea component in order to improve the dimensional stability during the removal of the sea component. That is, in order to obtain the sheet-like product of the present invention that can be used on both the front and back sides, a high-speed fluid flow jetting treatment and a high-speed fluid flow jetting treatment are performed to form the structure of the ultrafine fiber fibrillated entangled structure, the primary fiber bundle, and the secondary fiber bundle. Dissolving and removing sea components is important, especially the method of spraying high-speed fluid flow. Although water is most preferable as the fluid used for high-speed fluid flow, 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 is injected from a nozzle with a small diameter or narrowly spaced slits, and is applied to the surface of the nonwoven fabric sheet as a high-speed columnar flow or curtain flow. In method 1, where a sea component is present, relatively high pressure conditions are required because both the splitting of the sea component and the fibrillation of the ultra-fine fibers are required, and the pressure is in the range of about 70 to 300 ^kgcm2 . is preferred. On the other hand, in the second method in which no sea component is present, splitting of the sea component is not necessary, so a relatively low pressure condition is sufficient and a favorable range is about 5 to 100 kg/cm ² . In order to avoid the impact locus caused by the spray abutment, it is effective to move the jet nozzle and the sheet relatively, to increase the number of passes, or to use a pulsed flow. By spraying such a high-speed fluid flow, the fiber structure, which was initially composed of only secondary fiber bundles, is divided into primary fiber bundles in the areas near the surface that is easily affected by the spray, and the surface that is directly exposed to the liquid pressure is divided into primary fiber bundles. In the vicinity of the surface, the primary fiber bundle is further divided to form ultrafine fibers into fibrils, and the fibrils are intertwined to form an extremely dense surface, which can be made into a grain surface by subsequent embossing or pressing. On the other hand, the surface of the secondary fiber bundle is opened and raised by buffing, resulting in a suede-like surface. The conditions for embossing or pressing may be determined based on the characteristics of the fiber material and resin material, and are not particularly limited.
It is usually carried out at a temperature of 100 to 250°C and under pressure. When applying a suitable resin before embossing or pressing, polyurethane resins, vinyl chloride resins, polyvinyl butyral resins, polyacrylic acid resins, polyamino acid resins, silicone resins, and mixtures or copolymers thereof are used. The sheet-like product of the present invention, which can be used on both the front and back sides, obtained as described above is subjected to high-order processing such as coating with finishing resin, dyeing, water repellent treatment, and rubbing to improve its quality and increase its commercial value. It can be applied to various applications where natural leather is used, such as clothing, shoes, and materials. In this case, it goes without saying that an unprecedented design can be created by freely using the silver-like surface and the raised-like surface. The present invention will be explained in detail below with reference to Examples. All parts and percentages are by weight. Example 1 Using a sea-island type multi-component fiber spinneret disclosed in JP-A-54-125718, the island component was polyethylene terephthalate and the sea component was polystyrene (island/sea ratio 60/4).
0), a multicomponent fiber with a cross section in which 16 islands exist in the sea component, and 16 islands are gathered together to form a single polystyrene sea (island/total sea ratio). = 48/52), and a staple fiber of 3.8 denier x 51 mm was obtained through the steps of stretching 2.5 times, crimping, and cutting. One island component was an ultra-fine fiber of 0.007 denier. Open this staple fiber, card,
It was made into a non-woven fabric through the steps of cross wrapping and needle punching. From an injection nozzle in which holes with a diameter of 0.1 mm are lined up in a row at intervals of 0.6 mm on one side of the nonwoven fabric,
3. Spraying a columnar water stream at a pressure of 100Kg/ ^cm2
It was repeated several times and then dried. Next, a 15% dimethylformamide solution of polyester-based polyurethane was impregnated from the side not sprayed with water, and after wet coagulating with water, the dried sheet was coated with 2-component polyurethane at 4 g/m ² using a gravure coater, and the leather was coated at 160°C. It was embossed with an emboss roll with a pattern carved into it to give it a silver surface, and then treated with trichlorethylene to remove the sea component of the multicomponent fiber. Furthermore, the back side was buffed with 150 mesh sandpaper to create a raised surface, and then a polyurethane finish containing pigment was applied to the silver surface at 2 g/m ² using a gravure coater.
The material was rubbed and dyed in a high-temperature dyeing machine at 120° C. for 1 hour to obtain a sheet product of the present invention with a silver-like appearance on one side and a raised-like appearance on the other side. When we observed the nonwoven fabric after the columnar water treatment using a scanning electron microscope, we could clearly see that the ultra-fine fibers were fibrillated and entangled on the surface, and then a primary fiber bundle of 16 ultra-fine fibers was visible, and below that was a The primary fiber bundles were further bundled into an entangled layer consisting mainly of secondary fiber bundles. Furthermore, one surface of the finished sheet is a silver surface where the fibers fibrillated by embossing and the resin surrounding them are integrated, and below that is a primary fiber bundle and a porous polyurethane part, and then a secondary fiber bundle and a porous polyurethane part. It was observed that the fiber bundles and polyurethane porous layer continued to the back side. The other side had a suede-like surface with dense, elegant naps, and the naps were continuous with the secondary fiber bundles. The silver surface of the obtained sheet material according to the present invention is
The embossed texture and the random texture caused by rubbing during dyeing are appropriately mixed to create a high-quality surface appearance similar to the silver surface of natural leather, while the raised surface has a natural deerskin-like suede appearance. It has an elegant appearance, making it suitable as a reversible material. Example 2 In the apparatus of JP-A No. 54-125718, the fluid mixer described in JP-B No. 53-36182 is used as a part of the mechanism in which one island component flow is divided into a plurality of parts or more and merges with other island component flows. A spinning device using 10 stacked elements (inner diameter 10 mm) was fabricated, and the spinning device was used to combine the flow of nylon 6 and the flow of polystyrene so that the nylon 6/polystyrene ratio was 50/50. The polymer flow introduced into the fluid mixer, merged and split, is divided into 16 streams, and these 16 streams are further divided into 1 stream.
The multicomponent fiber of the present invention was obtained by a method of coating with a sea of polystyrene so that the ratio of nylon 6/total polystyrene was 40/60. The cross-section of the multicomponent fiber had a sea-island structure in which about 400 fine islands of nylon 6 were surrounded by a sea of polystyrene, and then 16 islands were gathered together to form a sea-island structure surrounded by a sea of polystyrene. . One of the island components of the 6 denier x 51 mm staple was an ultra-fine fiber with an average size of 0.0004 denier. This staple fiber was made into a nonwoven fabric through carding, cross wrapping, and needle punching processes. 5 on the nonwoven fabric
% polyvinyl alcohol aqueous solution was applied, dried and shrunk, and then treated with perchlorethylene to dissolve and remove the sea component of the multicomponent fiber. Next, after removing polyvinyl alcohol by showering hot water, a columnar water stream was sprayed on both sides three times at a pressure of 60 kg/cm ² from an injection nozzle with holes 0.1 mm in diameter arranged in a row at 0.6 mm intervals. Dry. followed by 10%
After impregnating the sheet with a polyurethane emulsion solution and drying it, the sheet was divided into two sheets by slicing, and the water-treated surface of each sheet was coated with 5 g/ ^m2 of polyurethane using a gravure coater, and a leather-like grain was carved at 150℃. Emboss with an embossing roll, buff the side that has not been treated with water jets to create a raised surface, then dye with a metal-containing dye at 100℃ for 1 hour, then rub with a tumbler. A sheet-like product of the present invention was thus obtained. When the nonwoven fabric after columnar water treatment was observed with a scanning electron microscope, it was found that Example 1
Similar to the present invention example, the surface has ultra-fine fibers fibrillated and entangled, and then a single layer of ultra-fine fibers bundled together.
The structure was a secondary fiber bundle in which 16 primary fiber bundles were bundled together. The entangled state of the ultrafine fibers on the surface was even more dense than that observed in Example 1. For finished sheet-like products, polyurethane is attached to such a fiber structure, and one surface has a structure in which the ultra-fine fibers and the surrounding polyurethane resin are integrated by embossing to form a silver surface. I was getting used to it. Other surfaces are 2
It had a suede-like surface with dense raised fibers made of opened fiber bundles. The silver surface of the resulting sheet of the present invention has a moderate mix of embossed grains and random textured grains created by tumbler rolling, giving it a high-quality sheepskin-like surface appearance. It had an elegant appearance similar to high-quality calf suede, and was suitable for reversible materials. Example 3 Using the spinning method used in the invention examples of Example 1 and Example 2 and the spinning method described in Japanese Patent Publication No. 47-37648, the multicomponent of the present invention was prepared using the raw materials and component ratios shown in Table 1. A fiber was obtained. These fibers are used to create a non-woven fabric through the carding, cross-wrapping, and needle-punching processes, and then one side of the non-woven fabric has a diameter
It was dried by spraying a high-speed columnar water stream at a pressure of 100 Kg/cm ² from a spray nozzle with 0.1 mm holes arranged at 0.6 mm intervals, and the sea components were dissolved and removed using trichlorethylene. Furthermore, the same spraying process is carried out at a pressure of 70
Kg/cm ² , apply on the same surface as previously sprayed, and after drying, apply polyurethane solution with a gravure coater, embossing with a 170℃ embossing roll, and buff the surface with sandpaper. After that, Examples 4 and 5 were subjected to jet dyeing at 120° C. for 1 hour, and Example 6 was jet dyed at 100° C. for 1 hour.
The obtained sheet-like product of the present invention consists of a grain layer formed by integrating a fibrillated entanglement of ultra-fine fibers and a polyurethane resin surrounding it, as in Examples 1 and 2, and then a layer of ultra-fine fibers. A primary fiber bundle that is bundled together, a secondary fiber bundle that is further bundled by the primary fiber bundle,
The fibers had a structure of dense naps that were opened from secondary fiber bundles. These sheet-like products of the present invention have a silver surface with a natural surface appearance similar to natural leather, with a moderate mix of embossed grains created by embossing rolls and grains created by the rubbing action of jet dyeing. ,
It had a deerskin-like raised surface on the front and back, and achieved the object of the present invention. 【table】

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are cross-sectional views of one multicomponent fiber that can be used in the present invention. FIG. 4 is a conceptual cross-sectional view of the sheet-like product of the present invention.

Claims (1)

[Claims] 1. A sheet-like material in which one surface has a silver-like surface and the other surface has a raised-like surface, ultrafine fibers of 0.2 denier or less, and a large number of the ultrafine fibers. A fibrous sheet mainly consisting of an assembled ultra-fine fiber bundle (referred to as a primary fiber bundle) and a fiber bundle in which a larger number of the primary fiber bundles are assembled (referred to as a secondary fiber bundle), In the thickness direction of the sheet, from the silvery surface, which is mainly composed of a structure in which ultrafine fibers branched from a primary fiber bundle are fibrillated and entangled, the primary fiber bundle passes through a structure in which the primary fiber bundles are mainly entangled, and then further It is characterized by having a surface and cross-sectional structure in which the secondary fiber bundles reach a structure in which they are mainly entangled, and finally become a raised-like surface mainly covered with raised fibers opened from the secondary fiber bundles. A sheet material that can be used on both sides. 2. A sheet-like material that can be used on both the front and back sides according to claim 1, characterized in that a resin is present at least on the grain-like surface and/or in the voids inside the sheet. 3. A method for producing a sheet-like material that can be used on both sides, characterized by combining at least the following steps ○I to ○E. ○B A sea-island type fiber made of at least two types of polymeric substances, in which a plurality of sea-island structures made of a large number of island components and a sea component are further surrounded by one sea, and after all sea components are removed, is a tertiary multi-component fiber with a structure in which a large number of ultra-fine fibers of 0.2 denier or less are gathered together (primary fiber bundle), which are further gathered together to form a secondary fiber bundle. A process of obtaining a fibrous sheet with a pre-entangled structure. ○B A process of spraying a high-speed fluid stream onto at least one surface of the fibrous sheet. ○C Process of dissolving or decomposing and removing the sea components of multi-component fibers. ○D A process of embossing or pressing one side onto which a fluid stream has been applied. ○E Process of buffing the opposite side of the embossed or pressed side to create a raised surface of ultra-fine fibers.