JPS6157433B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a fibrous sheet material having elegant naps. BACKGROUND ART Conventionally, various types of fiber sheet-like materials having raised naps, including suede-like artificial leather, have been known. Among these, ultrafine thermoplastic synthetic fibers are fiber sheet-like products invented by the present inventors and already available on the market, which are made by adding an elastic polymer such as polyurethane to a three-dimensional aggregate of ultrafine fiber bundles. Products with raised hair consisting of these have been well-received by Ehu due to their excellent raised state, appearance that closely resembles natural leather, easy care properties, multicolor properties, lightness, etc. However, even with such excellent products, there is a strong demand for even higher quality products. One of these is the desire to further increase the nap density and improve the yoke mark properties. Conventionally, various methods have been used to improve the physical properties of naps, such as increasing the density of naps. Typical examples include increasing the fiber density of the sheet by heat shrinking, increasing the weaving or knitting density (needle punch density in the case of non-woven fabrics), or adding a large amount of elastic polymer. Are known. This method does increase the napping density and improve other physical properties, but on the other hand, major drawbacks have started to appear, such as difficulty in napping and curling of the naps. In order to eliminate such drawbacks, the present inventors have already proposed a method of applying a substance having the effect of imparting release properties, such as silicone, to the sheet before or during napping,
Patent applications have been filed (Japanese Patent Application No. 1983-122918 and No. 51-122918)
123880). Although this method was revolutionary in terms of improving the nap density, it still had the following accompanying drawbacks in the sheet manufacturing process. That is, since silicone does not easily fall off during the dyeing process after raising, uneven dyeing due to uneven silicone adhesion (uneven shedding) tends to occur, and the tackiness of the napped product becomes an oil tack. In addition, there were problems in the process, such as buffing would cause the sandpaper to become clogged, and raising with a napping machine would cause the napping needle to wear easily. It has also been found that this method has little effect on some fibers, such as those made from nylon-6. Furthermore, silicone and fluorine resins have a fatal drawback of being expensive. Furthermore, these fiber sheet-like materials are usually given an elastic polymer to give them a good leather-like texture and a sense of luxury, as well as to prevent the nap from slipping off and significantly strengthen their physical properties. If such an elastic polymer is applied, it is extremely difficult to raise the cloth with cloth raising, and even if buffing is performed, buffing must be performed under extremely strong conditions compared to when the elastic polymer is not applied. If the fibers are thermoplastic fibers and are ultra-fine fibers of 0.8 denier or less, the nap tends to become more curly, and silicone-based oils have not been able to solve this problem. . The present invention does not suffer from such drawbacks, and
The purpose is to satisfy the conventional demands as described above. In other words, the present invention relates to an improvement in the method of applying a substance having the effect of imparting mold release properties, such as silicone, during napping, and the drawbacks thereof are largely improved. In particular, the present invention provides an improved method for minimizing the occurrence of wrinkles in the raised fibers, which are thought to be caused by the raised fibers of ultra-fine thermoplastic synthetic fibers. The gist of the invention is as follows. When producing a sheet-like product with napped fibers by raising a sheet-like product in which an elastic polymer is added to a fiber sheet-like product in which the fibers to be raised are mainly made of ultrafine thermoplastic synthetic fibers of 0.8 denier or less, the napping process is carried out. A method for producing a sheet-like product having raised naps with little wrinkling, characterized in that the napping process is performed before dyeing, and mineral oil is applied to the sheet-like product before or during the napping process. . The present invention will be explained in detail below. There are various types of fiber sheet materials used in the present invention, and there are no particular limitations. non-woven fabric,
Typical examples include composite fiber sheets in which elastic polymers such as polyurethane, NBR, etc., or polymers such as polyvinyl alcohol are applied before, after, or simultaneously with the application of these elastic polymers to fabrics such as woven and knitted fabrics. In addition, it is necessary that thermoplastic ultrafine fibers of 0.8 denier or less are mainly used in the raised part. This is because the nap-raised nap exhibits good tie-yoke mark properties, has a soft texture, and is extremely effective in preventing naps from coming off, imparting a good leather-like texture, and greatly improving physical properties. More preferably 0.5 denier or less, especially 0.3
Less than denier. In addition, from the viewpoint of ease of napping, fiber sheets woven in twill, warp, pile, double weave, etc. are preferable, and from the viewpoint of uniformity of physical properties in the entire area direction, nonwoven fabrics are suitable. There is. Especially in the case of knitted fabrics, 0.8
It is preferable to use ultrafine fibers of denier or less, and to use normal denier fibers for other parts that are difficult to raise, from the viewpoint of the product's balance of physical properties and cost. There are various methods for obtaining ultrafine fibers of 0.8 denier or less, and any of these known methods can be used in the present invention, but those obtained by ultrafine treatment of multicomponent fibers are preferred. Examples of multicomponent fibers include sea-island fibers such as polymer arrays shown in Japanese Patent Publication No. 48-44849, multicore fibers, island fibers, multisegment fibers, nebular fibers, and multicore fibers. type fibers, multi-wedge type fibers, and core-sheath type fibers, such as concentric circular type fibers, kidney type fibers, sea-island type multi-branched fibril-retaining type polymer blend fibers, sea-island type - short fibril-retaining type mixed and kneaded fibers, etc. Examples include ultra-fine fibers made of multiple components. These multi-component fibers may be made ultrafine by a method of chemically dissolving or decomposing at least one of the multiple components, or by a method of separating the components by mechanical processing such as kneading, heat treatment, etc. It's okay if it's hot. Further, a combination of these methods may be used, and there is no particular limitation.
In order to make the fibers extremely fine, a method of chemically dissolving the components is suitable. The polymer composition of the multicomponent fiber is not particularly limited, but typical examples include polyester/polystyrene and copolymer (hereinafter referred to as Pst), polyamide/
Examples include combinations of Pst, polyolefin/Pst, polyester/polyamide, polyolefin/polyester, polyester/easily soluble polyester copolymer, polyacrylonitrile copolymer/cellulose acetate, and the like. In this example, the components are 2
It goes without saying that a combination of three or more species may be used. As an example of a combination of three components, Pst is the sea component and the island component is polyester/
Examples include mixed components of polyamide, polyester/polyolefin, polyamide/polyolefin, and the like. In this case as well, it is not a so-called sea-island type,
Several types of polymers can be arranged in a sandwich pattern or a rhinoceros pattern. In particular, when increasing the nap density, it is preferable to select a material that increases the shrinkage rate of the fibers. When multicomponent fibers are used, their fineness is carried out before or after forming them into a sheet. However, it is preferable to carry out the process after forming into a sheet. If this is done before, the process passability when used as a staple, such as card passability, deterioration of subsequent spinnability, occurrence of thread breakage when made into a knitted fabric, and frequent needle breakage when made into a needle-punched nonwoven fabric. This is because various troubles are likely to occur. Also, it is much cheaper to make ultra-fine sheets in sheet form.
From the viewpoint of manufacturing cost, it is preferable to carry out the process after forming the sheet into a sheet. When ultra-fine fibers are produced, problems such as thread breakage and fluffing tend to occur. Such ultra-fine reduction does not necessarily have to be carried out over the entire length of the multicomponent fiber. Only a part of it, for example, a part to be raised, may be ultra-fine. Furthermore, even if ultrafineness does not appear to occur in the ultrafine treatment, the present invention is also effective in cases where it becomes apparent during napping. Mineral oil is applied to the fiber sheet at an appropriate time before or during napping. When multicomponent fibers are used, it is desirable to carry out the process after or simultaneously with the ultrafine reduction. In the method of ultrafine fibers by dissolving and removing at least one component of multicomponent fibers, the solvent for the polymer is often the solvent for mineral oil, so the mineral oil that has been applied may be removed during the ultrafine treatment. It is desirable to apply mineral oil after the fibers have been ultra-thinned, since it can cause uneven adhesion. However, in ultrafine treatment of fibers by machining or the like that does not involve dissolution and removal, it is an effective method to apply mineral oil during the ultrafine treatment. Particularly in systems where a part of the multicomponent fiber contains polystyrene polymer, mineral oil embrittles Pst, so it is a very effective method to apply mineral oil during ultrafine treatment. For applying mineral oil, other conventional oil application methods such as impregnation, coating, spraying, etc. can be used. The amount of mineral oil applied varies widely depending on the mineral oil and the type of fiber sheet material, but it is desirable to apply at least 0.001% by weight, preferably 0.05% by weight. On the other hand, if the amount of mineral oil applied is too large, it may bleed out or adhere to the napping machine, causing trouble. Since problems such as stickiness and increased cost may occur, the maximum amount applied is preferably 10% by weight or less. Particularly preferably, the content is 8% by weight or less. The mineral oil to be applied is not particularly limited. It is desirable to use a high viscosity when the raising speed is fast, and a relatively low viscosity when the raising speed is slow. Further, the form of the applied mineral oil may be 100% mineral oil, a dispersion of this in water with ethers or esters, or a dispersion of this in water such as tricrene. However, from the viewpoint of uniformity of the applied amount, it is preferable to apply it as a dispersion system or a solution system. Furthermore, it is also effective to use an antistatic agent or other oil agent for the purpose of preventing troubles due to static electricity generation during napping. The elastomeric polymer coated fiber sheet thus coated with mineral oil is then raised. It goes without saying that mineral oil may be applied while brushing.
For fiber sheets to which a large amount of elastic polymer is applied, in order to form beautiful long naps, it is very important to apply mineral oil once before applying the polymer, and then apply mineral oil again after applying the polymer. This is the preferred method. The present invention is particularly effective in the production of so-called artificial suede-raised blankets in which a polymer is applied to fabrics such as woven fabrics, knitted fabrics, and non-woven fabrics using ultrafine fibers, and then buffed. It is particularly effective for fabrics that have a large amount of polymer attached and have the potential to increase nap density, that is, woven fabrics with a high knitting density, and nonwoven fabrics with a high apparent density. Also, as a polymer, the molecular weight is 1000 to 5000.
It is also one of the particularly preferred embodiments of the present invention to use a polyurethane produced by reacting a polyol selected from polycabrolactone glycol and polyhexane adipage glycol, diisocyanate, and a bifunctional active hydrogen compound as main components. . Although such polyurethanes have high physical properties, they have the disadvantage of being difficult to raise, but according to the present invention, dense raised naps can be formed. However, the effectiveness of the present invention is not limited to these. There are two methods for raising the cloth: raising using a raising machine (needle cloth raising) and raising using a buffing method.
In the present invention, it is necessary to perform buffing. If a fiber sheet to which an elastic polymer has been applied is raised with needle cloth raising, it will be extremely difficult to raise the fiber sheet, and even in the case of buff raising, if an elastic polymer is applied, the raising will occur more than when it is not applied. It is difficult to attack, so a fairly strong buff is required. The stronger the buffing conditions, the more severe the nap becomes curled, but the present invention does not have this drawback. Also, buffing must be done before dyeing. If buffing is performed after dyeing, the naps tend to become long and short, resulting in unsightly surface quality, and other unexpected drawbacks.Furthermore, if the applied mineral oil needs to be further removed after dyeing, Furthermore, a removal process is required, and furthermore, when buffing is performed after dyeing, the dyed portion is removed and color unevenness is likely to occur, which is another problem. Buffing is performed using sandpaper, sand cloth, sand net, sand brush, whetstone, etc. In the case of peelable fibers, ultra-fine multicomponent fibers may also be caused by the raising operation itself. Although the details are unknown, the mechanism of action of the present invention is thought to be roughly as follows. That is, it is presumed that the effect of buffing etc. on the fibers that are to become the nap is softened by the presence of mineral oil between them, and the fibers are raised without the action of a very strong force. However, the invention is based on relatively low melting point polymers,
Considering that it can be applied to nylon-6 and the like, and silicone and the like cannot be applied to such polymers, it is presumed that other factors are at play. In the present invention, mineral oil refers to one that has been refined and has a viscosity of about 40 to 500 seconds. The sheet-like product thus obtained has the surprising characteristics of having beautiful and elegant raised hair, being glossy, having no raised hair or curling, and having high physical properties. Next, the remarkable effects of the present invention will be listed in itemized form. (1) Conventionally, in the case of fiber sheets that have a high nap density and the naps are made of ultra-fine fibers, the naps may not be developed properly due to the fibers being cut during the napping operation, or even if they are produced, the naps may be curly. However, the present invention eliminates these drawbacks and makes it possible for the first time to produce a fiber sheet with an elegant nap. (2) Even if the sheet is coated with a large amount of polymer such as polyurethane, it is possible to form elegant naps. (3) Mineral oil can be removed by simple post-treatment.
It can prevent uneven dyeing of sheets to which mineral oil is attached. In addition, it becomes possible to dye the product into a variety of textures through post-dyeing, thereby expanding the range of product development. (4) When the fibers constituting the fiber sheet have a relatively low melting point (as in the case of nylon-6, for example), in the conventional method, the naps would wrinkle during the dyeing process, but in the present invention, Even in such cases, it is effective because it can produce beautiful piloerection. (5) Beautiful raised hair can be formed with a small amount of raised hair. (6) Mineral oil is very cheap, so it is advantageous in manufacturing. The fiber sheet-like material having raised naps obtained by the present invention can be effectively used not only for various clothing purposes, but also for furniture such as upholstery, wall coverings, gloves, and various other industrial materials. It will be done. Next, examples according to the present invention will be shown together with comparative examples, but the effectiveness of the present invention is not limited or limited by these in any way, but rather the following applications,
It brings about expansion and development. Example 1 A sea-island type fiber in which the sea component is polystyrene and the island component is polyethylene terephthalate, the island component is dispersed in the sea component, and the island component is continuous in the fiber axis direction, and the sea-island ratio is 50/50. Cut cotton with 16 islands, sea-island fiber denier 3.8d, crimp count 15/inch, cut length 51mm is formed into a web using the cross wrapper method, and needle punched at 3000 pieces/cm ² to produce a fabric weight of 520g/m. ² , an entangled nonwoven fabric having an apparent density of 0.18 g/cm ³ was obtained. Further, when this nonwoven fabric was subjected to hot water shrinkage at 97 to 100°C, the basis weight and apparent density in the dry state were 823 g/m ² and 0.325 g/m ³ , respectively. Next, this nonwoven fabric is impregnated with a polyvinyl alcohol (PVA) solution with a degree of saponification of about 88% to the sea-island fibers so that the solid content is 40 parts, and after drying, the sea component is removed using trichlorethylene.
99.5% removed. In this sea-free nonwoven fabric, the polyol component is polycaprolactone (molecular weight approximately 2000), the isocyanate is 4,4'-diphenylmethane diisocyanate,
The island component fibers were impregnated with a dimethylformamide (DMF) solution of polyurethane containing methylene bisaniline as a chain extender at a solid content of 62 parts, and subjected to water bath coagulation and PVA removal (DMF removal at the same time). The basis weight and apparent density of the intermediate product at this time are 590g/m ² and 0.295g/cm ³ respectively in the dry state.
It was hot. This cloth was wetly impregnated with about 150% of a 2% solution of mineral oil in which mineral oil having a viscosity of 60 seconds was dispersed in water using an ester, and dried at 110 to 120°C. The dried mineral oil treated cloth is then sliced and
The non-sliced surface was subjected to a buffing machine to obtain a sheet having a raised surface. Thereafter, it was scoured with a nonionic surfactant Sunretz G-2a (manufactured by Sanyo Kasei Co., Ltd.), removed from mineral oil, and dyed with a disperse dye. The product was further subjected to reduction cleaning. The obtained product was a suede-like product with a luxurious feel in both surface quality and feel. Table 1 shows the characteristics of the product according to the present invention and the comparative product.

【table】

[Table] Example 2 A nonwoven fabric obtained in the same manner as in Example 1 after sea removal was added to a polyol component of polycaprolactone (molecular weight approximately 2000), an isocyanate of 4,4'-diphenylmethane diisocyanate, and a chain extender. A dimethylformamide solution of polyurethane (25 °C, 30% viscosity 960 Poise) consisting of ethylene glycol,
The island component fibers were impregnated with a solid content of 58 parts, coagulated in a water bath, and processed to remove polyvinyl alcohol (and simultaneously remove dimethylformamide). The basis weight and apparent density of the intermediate product at this time were 584 g/m ² and 0.289 g/cm ³ respectively in a dry state. Next, this intermediate product is coated with a mineral oil-based oil Soft Oil Y (manufactured by Miyoshi Oil & Fats) that has a releasing or slipping effect.
It was impregnated approximately 150% with a 3% solution of 100% when wet, and dried at 110 to 120°C. The dried mineral oil-treated cloth was divided into two intermediate products using a slicing machine, and the non-sliced side was subjected to a buffing machine to form a sheet having a raised surface. Finally, it was pressure-dyed to a beige color at 125°C using a disperse dye, and then reduced and washed with a hydrosulfite base solution at 70-80°C to produce a product. The obtained product had the same surface quality as Example 1,
It was a suede product with a luxurious feel. Table 2 shows the characteristics of the product according to the present invention and the comparative product.

【table】

[Table] Example 3 Raw cotton having the same composition as that of Example 1 except that the island component was nylon-6 was mixed and opened, and a web was formed by the cross lapping method and needle punched to make felt. This felt was subjected to a process of shrinking with hot water, applying PVA, and removing 98.5% of the sea component by weight using trichlene. Next, 3% by weight of polyol LBY, a mineral oil-based oil, was dissolved in triclene, and the felt was impregnated with 150% by weight and dried at 90°C. Thereafter, 68 parts of the same polyurethane as in Example 1 was impregnated into the island component fibers, and the fibers were coagulated in a water bath and desorbed.
PVA, dried. Thereafter, it was further impregnated with 120% by weight of a 2% aqueous solution of polyol LBY and dried at 105 to 115°C. After slicing, sandpaper buffing was performed. The resulting polyester component, nylon-6
A fiber sheet with both ingredients and beautifully raised fibers was obtained. This suede fabric was refined in the same manner as in Example 1 to remove the mineral oil, and then subjected to dispersion and two-bath dyeing with an acid dye. the result,
The color tones became very rich, similar to those seen in textiles made by blending wool and various types of yarn-dyed cotton. Furthermore, the naps were very beautiful for both polyester and nylon naps, and good chiyoke marks were also generated. Comparative Example 1 65 parts of the polyurethane of Example 1 was impregnated into the island component fibers of the de-sea fabric of Example 3, and the fibers were coagulated in a water bath and desorbed.
PVA was performed, dried, sliced, and then sandpaper buffed. However, the nap could not be raised well, and the nap was very short and the number of naps was small. Furthermore, dispersion and two-bath dyeing with an acid dye were performed. The result was a very interesting color tone, but the nap was short and made of nylon.
The 6 ingredients curled up, resulting in a suede-like sheet that was ugly and didn't show any yellow marks. Comparative Example 2 A felt was made in the same manner as in Example 1 using the composite fiber of Example 3 whose island component was nylon-6. This felt was subjected to hot water shrinkage, addition of polyvinyl alcohol (PVA), and treatment with trichlene to remove 97.5% of the sea component. Next, Example 1
50% of the same polyurethane as the island component fiber.
Partial impregnation was applied, water bath coagulation, PVA removal, and drying were performed. After that, apply a 3% solution of dimethylpolysiloxane emulsion silicone oil (silicone viscosity 200 centisutes before emulsion) to approximately
Impregnated 150% and dried at 110-120°C. after that,
Furthermore, it was sliced and buffed with sandpaper to make a nap sheet. Thereafter, it was scoured in the same manner as in Example 1 and dyed with acid dyeing. The dyeing temperature was 100°C. However, the nap was ugly and wrinkled, and could not be called a very good artificial leather. It has been found that even if a silicone oil is used in this manner, the object of the present invention cannot be achieved. Comparative Example 3 Woolly yarn (commercially available false-twisted yarn) with polyethylene terephthalate of 150 denier and 48 filaments was used as the warp, and the following high fiber yarn (commercially available false-twisted yarn) was used as the warp, and the island component was polyethylene terephthalate and the sea component was a polymer mainly composed of polystyrene. Using the molecular array fiber as the 20th twin spun yarn, 5 pieces of satin were woven into it. Number of islands: 16, island component ratio: 50%, sea component ratio: 50%,
Denier 3.8d, fiber length 51mm, crimp 12 threads/in. When this was introduced into boiling water, it shrank by about 14.1% in width and by about 12.1% in length, resulting in an area shrinkage of 24.4%. This was thoroughly washed five times with trichlorethylene to remove sea components. Thereafter, the same polyurethane as in Example 1 was impregnated with 40 parts of the solid content into the fiber. Thereafter, it was wet-coagulated, and after drying, it was impregnated with about 150% by weight of a 2% solution of an ether-based water dispersion of mineral oil having a viscosity of 80 seconds, and dried at 100 to 110°C. This was passed through a German-style and a French-style napping machine a total of 10 times. However, when raising clothing, if an elastic polymer is applied, hardly any raising can be achieved even when the mineral oil of the present invention is applied, and the polyurethane remains attached to the nape over a wide area, resulting in an extremely unsightly appearance. Summer. Also, the clothing was damaged and it became necessary to replace the expensive clothing. When this sheet was refined and dyed with disperse dye using a circular pressure dyeing machine,
The polyurethane adhered to the naps, leaving a wide area of the sheet with an extremely ugly mottled pattern, and it could not be called a good suede-like high-quality brushed fabric. Therefore, it can be seen that the combination of buffing and mineral oil is important in sheets made of ultrafine fibers coated with elastic polymers.

Claims (1)

[Claims] 1. When producing a sheet-like product with napped fibers by raising a sheet-like product in which an elastic polymer is added to a fiber sheet-like product in which the fibers to be raised are mainly made of ultrafine thermoplastic synthetic fibers of 0.8 denier or less, the napping treatment is carried out. is buff-raised, the napping treatment is performed before dyeing, and mineral oil is applied to the sheet-like material before or during the napping, and the production of a sheet-like article having raised naps with little wrinkling. Method.