MXPA96003996A - Flat filaments provided with ribs and fibers not processed for fabrics of p - Google Patents

Abstract

The flat filaments have a planarity (A / B) of 7 to 25, where A is a length of two longer sides of a substantially rectangular cross section of each filament, and B is a length of two shorter sides of the section substantially rectangular cross section of each filament. The flat filaments also have a fineness of 0.5 to 40 denier, and are provided on each of the two longest sides, one or more ribs that extend continuously in a direction of a filament axis, and that have a width W and a height H. The number of ribs on each longer side is from 1 to A / 2W, the width W is from B / 2 to 3B, and the height H is from B / 2 to 2B.The filaments have a excellent no pegostiosidad and plush, and allow an easy elimination of the ripples by polishing, and can be used properly as unprocessed fibers that, when formed in a hair product, provide the hair product not only a soft feeling, but also an elastic sensation and substance

Description

FLAT FILAMENTS PROVIDED WITH RIBS AND FIBERS NOT PROCESSED FOR HAIR FABRICS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to filaments useful as a raw material for a hair product, and also to unprocessed fibers for hair fabrics. More specifically, the present invention relates to flat filaments, which are provided with ribs, are excellent in the brushing effect, that is, a property of the filaments in which they remain free of mutual cohesion or entanglement, and in fluff , which can provide both soft surface sensation and elastic and substantial feeling, and are optimal for hair products such as stuffed toy animals, interior fittings and clothing, and also to unprocessed fibers for hair fabrics, containing these unprocessed fibers at flat filaments, and being able to obtain hair products that are equipped with both a smooth surface feel and excellent elastic and substantial feel. 2. Prior Art Since a natural skin generally consists of hairs that are reduced in diameter at their free end portions, compared to their basal end portions, the feel of their surface gives a soft and flexible feeling characteristic despite its elastic and substantial appearance. In recent years, there is a tendency to avoid the use of natural skins from the point of view of protecting the natural environment. This has led to a strong desire to develop hair products that are made of synthetic fibers, which have soft feel surfaces comparable to those of the natural skins available, and when pressed, exhibit good elasticity and give a substantial feel. Among the synthetic fibers, the acrylic fibers can provide a particularly soft feel rather easily. Many hair products that are made of acrylic fibers and look like furs, have therefore been placed on the market. However, the inevitable use of fibers having a constant thickness, results in a thick and hard feeling when the fibers are formed with the same thickness as that of their basal portions, or leads to a non-elastic feeling when the fibers are formed with the same thickness as its free end portions. The following are examples of the prior art that are known to provide hair products due to the use of synthetic fibers that come closest in their feel to natural skins: (1) a technique that makes use of the tendency of fibers that have a flattened cross-section or an elongated circular cross-section, to be easily bent in at least one direction, and to give a softer touch feeling by comparing with fibers having the same fineness but a circular cross-section (e.g., Japanese Patent Open Number 59524/1975); (2) a technique in which the free end portions of the hairs of a hair product made of polyester fibers, are made pointed by dipping and hydrolyzing the free end portions in an aqueous alkaline solution (Japanese Patent Number 16909/1980 ), or the free end portions of the bound polyester fibers are made pointed by immersing the free end portions in an aqueous alkaline solution (Japanese Patent Laid-open No. 134272/1981); (3) a technique in which fibers with a characteristic soft touch feel are obtained despite the thickness of their basal portions, by spinning fibers having a Y-shaped cross section, and applying force to the fibers , such that the free end portions of the fibers are divided (Japanese Patent Publication Number 51564/1989); and (4) a technique in which the fibers, which have a fineness on the scale of 1.5 to 4 denier, and a rectangular cross section flattened, can be folded in the direction of their shorter sides, and have 1 to 6 asperities on an outer periphery of each fiber, and are used to provide a hair product with a better smooth surface feel and a brushing effect (Patent Japanese Open Number 200808/1990). The approaches (1) to (4) are all to achieve both a smooth superficial sensation and an elastic and substantial sensation without using soft hairs. Specifically described, according to the technique (1), indentations are formed as seen in an elongated circular cross-section, so that the inherent sticky feel of the polyester fibers can be improved- However, the resulting feeling it is more or less the available of the elongated cross section, failing in this way to obtain a smooth superficial sensation, and, when manually depressed, an elastic and substantial sensation, which are all comparable with those of the natural skins and are the intended ones by the present invention. According to the technique (2), it is difficult to control the sharpness of the fibers, and even more, the hydrolysis in the aqueous alkaline solution has to be practiced in batches, in such a way that the production efficiency is poor.

Furthermore, according to the technique (3), the drying load is substantially high due to a high water retention, of which the cross-sectional shape is responsible. For industrial use, special consideration is needed. Therefore, it is difficult for this technique to reach mass production at a low cost. Finally, according to the technique (4), the fibers tend to bend in the direction of their short sides as seen in their cross section, and due to the provision of asperities, the fibers receive an unduly high stiffness. In accordance with the description of the examples of this specification, it is stated that the fibers provide hair fabrics with a greater bulk due to the avoidance of close contact between the adjacent fibers, compared to the fibers having a "cross-sectional shape" simple flat ". However, these hair fabrics lack a smooth surface sensation. From the above, it is possible to realize the difficulty in satisfying the numerous requirements required for hair products. In addition to the techniques (1) to (4), an additional method is still known. In accordance with this method, a hair product is formed using unprocessed fibers composed of the combination of non-shrinkable fibers and shrinkable fibers. under hot dry or hot humid conditions, shrinkable fibers are only shrinked, so that non-shrinkable fibers and shrunken fibers are allowed to remain as guard hairs and soft hairs, respectively. It is preferred that a hair product has a surface that has a smooth feel, but when pressed, gives an elastic and substantial feel. In order to provide the surface of the hair product with a soft feel, it is important to note the manner of eliminating the twists of the guard hairs, which are buried in the soft hairs, or the way of converting them into fibers that can be easily straightened by a so-called polishing step, wherein the surface of the hair product is lightly rubbed with a hot roller subsequent to the shrinking of the soft hairs. For this purpose, the proportion of acrylonitrile in an acrylonitrile copolymer to be used for the production of the fibers is known to be reduced, so that the acrylonitrile copolymer can be provided with a reduced thermal distortion temperature. If the copolymerized amount of acrylonitrile in an acrylonitrile copolymer is reduced, the clarity of the dye and the colorability of the fibers are deteriorated, and furthermore, the sensation of the hair product is susceptible to changes through a light thermal history, for example. example, with drying or similar. The hair product thus obtained is therefore difficult to handle. According to this technique, the elastic and substantial sensation when the hair is pressed, develops by soft hairs. Here, the shrinkage factor of the fibers and their bulk and substantial feel, which are associated with the cross-sectional shape of the shrinkable fibers, become important factors. As a method to overcome these problems, Japanese Patent Nos. 21979/1985 and 209048/1985, for example, describe a technique in which shrinkable fibers are used, which have a shrinkage factor of at least 15 percent, a coefficient static friction between fibers of 0.23 or smaller, and are susceptible to shrinkage, such as soft hairs in hair products. To control the coefficient of static friction below 0.23, an essential requirement is the use of an aminosiloxane softener. However, an aminosiloxane softener tends to be deposited in a rubberized form on the drying rollers during a drying step of a fiber spinning process, and therefore has a tendency to cause process problems. Therefore, a technique that does not use said softener is desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide flat filaments provided with ribs, which are excellent in the brushing and tufting effect, which allow an easy elimination of twists by polishing, and when they are formed into hair products, which have a smooth feel and can show an elastic and substantial feel, and which are suitable as unprocessed fibers for hair fabrics and which are optimal for stuffed toy animals, interior fittings, clothing, and the like. Another object of the present invention is to provide unprocessed fibers for pile fabrics, containing the above described flat filaments provided with the ribs (hereinafter referred to as "ribbed flat filaments" for brevity), and when Form in hair fabrics, show a softer feeling. A further object of the present invention is to provide unprocessed fibers, comprising the flat filaments with ribs described above, and specific shrinkable fibers, which do not require mixing of the unprocessed fibers subjected to a special treatment such as the application of a fabric softener. Aminosiloxane, and that can obtain hair products equipped not only with a smooth surface sensation, but also with an excellent elastic and substantial feeling similar to that available in natural skins.

In a first aspect of the present invention, there is thus provided a flat filament having a planarity (A / B) of 7 to 25, where A is a length of two longer sides of a substantially rectangular cross section of the filament, and B being a length of two shorter sides of the substantially rectangular cross section of said filament, and a fineness of 0.5 to 40 denier; and provided on each of the two long sides with one or more ribs extending continuously in a direction of a filament axis, and having a width and a height H, the number of these ribs being on each longer side of 1 to A / 2, the width being from B / 2 to 3B, and the height H being from B / 2 to 2B. In a second aspect of the present invention, unprocessed fibers are also provided for a pile fabric, comprising at least 10 weight percent of ribbed flat filaments as defined above; and at most 90 percent by weight of flat filaments having a planarity (A '/ B1) of 5 to 25, where A' is a length of two longer sides of a substantially rectangular cross section of each of the filaments, and B 'being a length of two shorter sides of the substantially rectangular cross section of said filament, and a fineness of 1 to 40 denier. In a third aspect of the present invention, unprocessed fibers are also provided for a pile fabric, comprising from 20 to 60 weight percent of ribbed flat filaments, as defined above; 20 to 50 weight percent shrinkable fibers having a shrinkage factor of at least 15 percent, and a fineness of 1 to 5 denier; and 60 weight percent or less of non-shrinkable fibers.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention will be described hereinafter in more detail. Incidentally, the term "fineness" as used herein, means by itself "the fineness of a single filament". The flat filament with ribs according to the present invention is required to have a flatness of 7 to 25, as defined by a ratio of A / B, where A is a length of two longer sides of a substantially rectangular cross section of the filament, this cross section being perpendicular to a filament axis, and B is a length of two shorter sides of the substantially rectangular cross section of the filament. A planarity of 7 to 15 is more preferred. A planarity of less than 7 is not preferred because the filaments tend to become entangled with each other, and, when formed in a hair product, result in a surface having a sensation rough On the other hand; a flatness greater than 25 makes it difficult to produce a hair product, because these filaments have a lower mechanical strength due to a reduction in the possibility of stretching on the yarn. The term "substantially rectangular", as used herein to define the shape of a cross section of a base portion (i.e., a portion that still remains after the ribs are removed) of the flat filament with ribs in accordance with present invention, should be interpreted to encompass not only the rectangular shapes, but also the oval shapes, provided they can achieve the objects described above. present invention. It is required that the filament be provided, on each of the two longer sides, at least one rib, as seen in the cross section of the filament. The rib is required to extend continuously in one direction of the filament axis, and to have a width and a height H, this width W being from B / 2 to 3B, and the height H being from B / 2 to 2B. Due to the provision of these ribs extending continuously in the direction of the filament axis, the adjacent filaments remain loose without cohesion, thus having an excellent brushing and bulking effect, and, when formed in a hair product, They exhibit a soft sensation and even an elastic and substantial sensation. If the width of the ribs is less than B / 2 or greater than 3B, the effects of the ribs can not be observed, so that these filaments merely show a feeling and a brushing effect that are not different from those available with the simple flat filaments used. If the height H of the ribs is smaller - from B / 2, the effects of the ribs can not be observed, so that these filaments merely show a brushing sensation and effect that are not different from those available with the filaments simple drawings used. If the height H of the ribs exceeds 2B, these filaments can not be produced with good productivity. In addition, the number of ribs per longest side of the filament must be an integer on the scale of 1 to A / 2. If the number n of these ribs exceeds A / 2, there is not much space between the adjacent filaments, in such a way that the brushing effect is reduced, and the sensation is not different from that available when filaments of a cross section are used simple flat The fineness of the flat filament with ribs according to the present invention should be 0.5 to 40 denier, with 2 to 25 denier being preferred, and 3 to 20 denier being particularly preferred. A fineness less than 0.5 denier is not preferred, because these filaments tend to become entangled with each other, and, when formed in a hair product, result in a surface having a rough feel. On the other hand, a fineness greater than 40 denier can not show a soft feeling when formed into a hair product. No particular limitation is imposed on the position of each rib in the flat filament with ribs, provided it is located on the longer side of the basal portion of the filament. From the point of view of the sensation, it is particularly preferred that a midpoint of a rib width is located within a distance of A / 4 from a midpoint of the longer side. Although no particular limitation is imposed on the cross-sectional shape of each rib, the rib preferably has a cross-sectional shape that does not form any pocket between the rib and the basal portion of the filament, since its water retention can be control at a low level in a spinning step. Illustrative examples of the cross-sectional shape include triangular, square, rectangular, other polygonal and semicircular shapes. In particular, a cross-sectional shape defined by curved lines only without borders is preferred., because these unprocessed filaments also show a good cohesion in a spinning step, and moreover, when they are formed in a hair product, the mutual hooking of the filaments is reduced, and the hair product is still provided a better smooth superficial sensation. The term "cohesion" as used herein, indicates the operation on whether or not any inconvenience such as wick breaking occurs when filaments are formed into wicks as an intermediate material for the hair product. If the cohesion is bad, it is necessary to make longer the length of the cut of the unprocessed fibers that are to be spun. When the cross-sectional shape of each rib of curved lines is configured only, the length of the cut of the unprocessed fibers can be selected from a wider range, such that that cross-sectional shape is convenient to adjust the sensation. The preferred ranges of width and height H, where the characteristic features of the filament according to the present invention can be further improved, are a range of B / 2 to 2B, notably a range of B to 2B for the width, and a range of B / 2 to B for height H. The establishment of and H within these ranges makes it possible, in addition to the availability of excellent characteristic features of the unprocessed fibers, to produce filaments with a good productivity in the passage of spinning, and also achieve better cohesion in the spinning step. It is also important, for the development of a smooth surface sensation, to establish the ratio of a total length of the flat portions to the length of the longest side in the basal portion of the flat filament with ribs, (W / W), in a value higher. This value is preferably of 0.6 or greater, with a preference of 0.7 or greater. Ribbed flat filaments are preferably acrylic filaments made of an acrylonitrile polymer, because, among the synthetic fibers, the acrylic filaments obtain in a particularly easier way, the feeling, and are excellent in the clarity of the dye and in the colorability. The flat acrylic filaments with ribs can be produced as will be described hereinafter. The acrylonitrile polymer suitable for the production of the flat acrylic filaments with ribs is an acrylonitrile copolymer composed of 50 weight percent or more of acrylonitrile, and an unsaturated monomer copolymerizable with acrylonitrile. Especially when ribbed flat filaments are used in combination with shrinkable acrylic fibers and / or other acrylic fibers, an acrylonitrile polymer containing acrylonitrile in an amount of 90 weight percent or more is preferred. An acrylonitrile content of less than 50 percent by weight leads to filaments that are poorer in thermal properties, in clarity of colorant, and in colorability. No particular limitation is imposed on the unsaturated monomer that is used as a copolymerizable component. Useful examples include acrylic acid, methacrylic acid and derivatives thereof; vinyl acetate; acrylic amide, methacrylic amide, vinyl chloride, and vinylidene chloride; and, depending on the application, ionic unsaturated monomers such as benzenesulfonate. sodium vinyl, sodium metal sulfonate, and sodium acrylamidomethyl propansulfonate. No particular limitation is imposed on the polymerization process for the acrylonitrile polymer. For example, a conventional suspension polymerization or solution polymerization process may be employed. Furthermore, no particular limitation is imposed on the molecular weight of the acrylonitrile polymer, since the molecular weight falls within a molecular weight scale generally used for the production of acrylic filaments. However, it is preferred to have a reduced viscosity at 25 ° C within a scale of 1.5 to 3.0 when measured in the form of a 0.5 weight percent dimethyl formamide solution. A spinning solution is prepared by dissolving the acrylonitrile polymer in a solvent, such that the concentration of the acrylonitrile polymer falls within a range of 15 to 28 weight percent. Then the spinning solution is spun through a spindle having an orifice configuration substantially similar to the cross-sectional shape of the desired filaments. If the concentration of the acrylonitrile polymer in the spinning solution is less than 15 weight percent, the configuration of the fine spinning holes and the cross-sectional shape of the filaments differ substantially one of. the other at the time of coagulation. This makes it difficult to obtain the desired cross-sectional shape. This low concentration is not preferred. If the concentration exceeds 28 weight percent, on the other hand, the spinning solution has a stability based on the lowest time, in such a way that its spinnable properties are lowered. Nor is this high concentration preferred. Useful examples of the solvent include organic solvents such as dimethyl formamide, dimethyl acetamide, and dimethyl sulfoxide; and other solvents such as nitric acid; aqueous thiocyanate solutions; and an aqueous solution of zinc chloride. When attempting to control the cross-sectional shape of the filaments by the configuration of the fine spinning orifices, an organic solvent is convenient. By performing the spinning and gathering in such a way that a spinning stretch defined in terms of a rate of collection rate of the coagulated filaments at a linear delivery rate of a spinning solution falls within a range of 0.7 to 2.0, flat acrylic filaments having a cross-sectional shape substantially similar to the configuration of fine spinning holes can be obtained. A spinning stretch greater than 2.0 results in a more frequent end break in the solution of the coagulation bath, thus making it difficult to obtain the filaments themselves. The coagulated filaments thus obtained are then stretched, washed, and dried under known conditions by known methods, whereby the flat acrylic filaments according to the present invention can be obtained. Depending on the application, the filaments thus obtained are subjected to a thermal relaxation treatment or the like to impart well-balanced mechanical properties, and then cut into unprocessed fibers. Next, a description will be made about the unprocessed fibers for a pile fabric, which comprise flat filaments having a planarity (A '/ B?) Of 5 to 25, where A' is a length of two longer sides of a substantially rectangular cross section of the filaments, and B1 being a length of two shorter sides of the substantially rectangular cross section of the filament, and a fineness of 1 to 40 denier, and flat filaments with ribs in accordance with the present invention. If the unprocessed fibers for a pile fabric are formed of mere flat filaments only, the filaments have a close cohesion as described above, in such a way that their brushing effect is reduced, and, when they are formed into a hair product , the hair product has a rough feeling. If the unprocessed fibers are formed of super-flat filaments having a great flatness to impart a smooth feel, the resulting hair product has the aforementioned drawback, and also a low elasticity. However, the mixture of flat filaments with ribs according to the present invention with flat fibers results in the insertion of the ribbed filaments between the flat filaments, which themselves tend to have a close cohesion with one another. Accordingly, the filaments are prevented from having cohesion, resulting in an improvement in the brushing effect. In addition, since the individual filaments are independent of one another, they can be brought into direct contact with a hot roller when heated in a polishing step. This facilitates the transfer of heat from the hot roll to the individual filaments, in such a way that the elimination of twisting of the filaments is easier than that of the twists of the unprocessed fibers composed only of flat filaments with ribs in accordance with the present invention. Therefore, the resulting hair product is of a structure in which the flat filaments are reinforced by the flat filaments with ribs, in such a way that the hair product has an elastic and substantial feeling, while its surface has a smooth feel . Here, it is required that the flat filaments that are mixed with the ribbed flat filaments have a planarity (A '/ B1) of 5 to 25, where A' is a length of two longer sides of a substantially rectangular cross section of the filament. flat, and B 'being a length of two shorter sides of the substantially rectangular cross section of the flat filament, and a fineness of 1 to 40 denier, preferably 2 to 30 denier, more preferably 5 to 15 denier. If the flatness of the mixed flat filaments is less than 5, it is difficult to exhibit the specific softness for those flat filaments, thereby making it difficult to obtain a hair product that resembles a natural skin. If the planar exceeds 25, on the other hand, the mixed flat filaments have a strong tendency to have cohesion with each other, in such a way that, even when the flat filaments are mixed with ribs, the improvement of the degree can not be fully exhibited. of the effect of brushing the flat filaments with ribs. If the fineness of the mixed flat filaments is less than 1 denier, the filaments tend to become entangled with each other, such that, when formed in a hair product, the hair product has a surface having a rough feel. If the fineness exceeds 40 denier, the filaments can not exhibit the soft feeling, despite their flat configurations, when they are formed into a hair product. Therefore, it is difficult to obtain a hair product that resembles a natural skin. With respect to the mixing ratios of the flat filaments with ribs and the mixed flat filaments, the former should be 10 weight percent or more, more preferably 30 weight percent or more. If this ratio is smaller than 10 percent by weight, the proportion of the flat filaments with ribs that are located between the mixed flat filaments is so small that the flat filaments with ribs can not effectively avoid a pegostiosity or mutual cohesion of the filaments. flat filaments mixed. When they are formed into a hair product, the hair product tends to have a rough feel surface. It goes without saying that the unprocessed fibers for the pile fabric can be composed exclusively of flat filaments with ribs in accordance with the present invention. The flat filaments which are used to form the unprocessed fibers according to the present invention for the pile fabric, are preferably flat acrylic filaments because, between the synthetic fibers, it is easier for the acrylic filaments to obtain a particular feeling soft and they are excellent in the clarity of the coloring and in the colorabilidad. The flat acrylic filaments may be produced in a manner similar to the above-described production process of the flat acrylic ribs with ribs, except that the configuration of the fine spin holes has to be changed to a configuration substantially similar to the cross-sectional shape of flat acrylic filaments. The unprocessed fibers for a pile fabric can be obtained by mixing the flat filaments with ribs and the flat filaments in the proportions described above, or by using only flat filaments with ribs. The unprocessed fibers can then be formed into a pile fabric such as a boa, a high pile fabric, or a carpet. Next, a description will be made of unprocessed fibers according to the present invention for a pile fabric, which is composed of shrinkable fibers, having a shrinkage factor of at least 15 percent, and a fineness of single fibers from 1 to 5 denier, and flat acrylic filaments with ribs. These unprocessed fibers will be referred to hereinafter as "unprocessed fibers mixed with shrinkable fiber for a pile fabric". A natural skin exhibits a characteristic elastic and substantial sensation not only when it is strongly pressed, but also when it is lightly pressed. The feeling of the aforementioned unprocessed fibers for the pile fabric is very close to the feeling of the natural skin when pressed lightly, but when pressed strongly, the elastic and substantial sensation such as that available is not obtainable. in natural skin, from the unprocessed fibers to the pile fabric. In order to improve the feeling further, therefore, shrinkable filaments which become soft hairs when formed in a hair product are used in combination. The unprocessed fibers mixed with shrinkable fiber for the pile fabric are obtained by mixing the flat filaments with ribs, the shrinkable fibers having a shrinkage factor of at least 15 percent, and a fineness of single fibers from 1 to 5 denier, and non-shrinkable fibers. It is necessary to establish the proportions of the respective fibers in 20 to 60 weight percent for the flat filaments with ribs, 20 to 50 weight percent for the shrinkable fibers, and 60 weight percent or less for the fibers not shrinkable In this case, the flat filaments with ribs have a high rigidity, in such a way that they tend to remain straight in the pile fabric. When a hot roller is contacted with the ribbed flat filaments, in the so-called polishing step of the hair fabric production process, the flat ribbed filaments can make contact with the hot roll without flexing. This makes it possible to improve the efficiency of heat transfer from the hot roll to the flat filaments with ribs, whereby the twists can be straightened easily. If the proportion of the flat filaments with ribs in the unprocessed fibers mixed with shrinkable fiber for the pile fabric is less than 20 weight percent, it is impossible to provide the resulting pile fabric with a smooth feel surface. On the other hand, a proportion greater than 60 weight percent, makes it difficult to completely remove the effect of the shrinkable fibers thus mixed, i.e., to achieve improvements in the elastic and substantial feel of the resulting pile fabric when the hair cloth is strongly pressed . The shrinkage factor of the shrinkable fibers that become soft hairs when formed in the pile fabric is 15 percent or greater, preferably 20 percent or greater. A shrinkage factor of less than 15 percent leads to wicks sunk to the basal portions of the flat ribs with ribs, so that, when tightly pressed, the soft hairs can not have a paper to impair the elastic and substantial sensation of the hair fabric. Incidentally, the term "shrinkage factor of at least 15 percent (20 percent)", as used herein, indicates that the thermal shrink factor in wet (measured after treatment for 3 minutes in boiling water), or the dry thermal shrink factor (measured after treatment at 130 ° C for 10 minutes), is at least 15 percent (20 percent). If the proportion of the shrinkable fibers in the unprocessed fibers mixed with shrinkable fiber for the pile fabric is less than 20 weight percent, the resulting pile fabric can not exhibit a strong elastic and substantial feel when pressed tightly. On the other hand, a proportion greater than 50 weight percent leads to a hair cloth whose surface has a low filament density, whereby, the surface smoothness hair fabric is not provided. Shrinkable fibers are required to have a fineness of 1 to 5 denier. A fineness less than 1 denier results in the entanglement of the shrinkable fibers themselves, or the entanglement of the shrinkable fibers with the flat filaments with ribs as guard hairs, thus making it difficult to allow the shrinkable fibers to suffer even shrinkage. . A fineness greater than 5 denier, on the other hand, results in a fabric of hair that feels. rough in the basal portions of its filaments, and therefore, of lower quality. Further, if the proportion of the non-shrinkable fibers that can be used in addition to the flat filaments with ribs and the shrinkable fibers that are needed exceeds 60 weight percent, the proportions of the flat filaments with ribs as guard hairs and Shrinkable fibers such as soft hairs are reduced in accordance with the same, thus resulting in a pile fabric whose surface whose soft feel, elastic and substantial feel, are all reduced.

Moreover, the use of shrinkable and / or non-shrinkable fibers having a specific cross-sectional shape, such as shrinkable fibers and / or non-shrinkable fibers, leads to a still better quality pile fabric. With respect to the cross sections of the fibers of that specific cross-sectional shape, it is necessary to comply concurrently with the following three requirements: (1) the contour of each cross-section must be defined only by the edge-free curves. (2) Each cross section must satisfy the following formula: 2 < a / b < 5 where, when the cross section is sandwiched between two parallel straight lines, a is a maximum distance between the two parallel straight lines, and b is a minimum distance between the two parallel straight lines. (3) Each cross section defines at least two indentations in different places.

When the requirements (1) to (3) are satisfied, the opportunity of the mutual engagement of the single fibers is reduced by causing the shrinkable fibers to shrink into soft hairs. Shrinkable fibers, therefore, are allowed to undergo even shrinkage, leading to a pile fabric with an excellent elastic and substantial feeling still improved. It is a role of the non-shrinkable fibers to prevent the flat filaments with ribs from having cohesion with one another in the pile fabric, in such a way as to provide the pile fabric with an improved quality. The effect preventing the cohesion of these non-shrinkable fibers can also be further improved if the contours of their cross sections are each defined only by curves. Any fibers available by a known process, and having the characteristics described above, are useful as the shrinkable fibers in the unprocessed fibers mixed with shrinkable fiber for the pile fabric. No particular limitation is imposed on its production process. Shrinkable acrylic fibers are particularly preferred for their superior dye clarity and colorability. The shrinkable acrylic fibers can be produced by a known process, and to provide them with a cross-sectional shape that can meet the requirements described above (1) to (3), the configuration of the fine spinning holes and the spinning conditions are they select and combine suitably to have shrinkable acrylic fibers of the desired cross-sectional shape. With respect to the individual types of fibers that form the unprocessed fibers mixed with shrinkable fiber for the pile fabric, no particular limitations are imposed on their spinning steps or on the finishing oils that are used in the subsequent treatments after dyeing or similar. When colored unprocessed fibers are desired, it is only necessary to conduct the dyeing by a method known per se in the art, such as dyeing after the formation of the unprocessed fibers, or using fibers dyed from the producer or pigmented fibers. The flat filaments with ribs, the shrinkable fibers, and if necessary, the non-shrinkable fibers, are mixed in the proportions described above, and as unprocessed fibers for a pile fabric, they are formed into a hair product such as a boa , a high pile fabric, or a carpet, through a known hair formation process. The present invention will be further described hereinafter in the following by means of the following examples, wherein the individual measurement data were measured by the following methods.

(Reduced Viscosity of Acrylonitrile Polymer) The reduced viscosity of each acrylonitrile polymer was determined by dissolving it with dimethyl formamide in a 0.5 weight percent solution, and then measuring its viscosity at 25 ° C with a Cannon-Fenske viscometer.

(Measurement of the shrinkage factor) The measurement of the shrinkage factor of each filament was conducted by the following procedures. The length of the filament (Lw) before shrinkage was measured under a load of 10 milligrams / denier, and subsequent to the shrinkage processing, the temperature of the filament was allowed to fall to room temperature, and the length of the filament (L'w) was measured in the same way under a load of 10 milligrams / denier. Then its shrinkage factor was determined according to the following formula: Shrinkage factor (%) = (Lw - L'w) x 100 (Classification of the hair product) Based on the superficial softness of each hair product, determined by the human hand in an organoleptic test, the elastic and substantial sensation of the hair product when the hair product was pressed by hand, and the hair product, were classified according to the following standards. surface smoothness: A: excellent B: good C: average D: poor E: poor Elastic and substantial sensation: A: Excellent (a good elastic and substantial sensation was obtained not only when the hair product was strongly squeezed, but also when the hair product was slightly squeezed). B: Good (a good elastic and substantial feeling was obtained when the hair product was slightly depressed). C: Average D: Poor E: Bad (Water retention) After the filaments were washed, a sample was collected in a wet state before being processed with drying rollers. The sample was dried at 105 ° C for 2 hours. From the weights of the sample before and after drying, its water retention was calculated according to the following formula: Water retention (%) =. { (1 - W0) / W0) x 100 where 0 is the weight (grams) of the filaments after drying, and Vl1 is the weight (grams) of the filaments before drying.

(Position of the ribs) In each example, the position of each rib was indicated by expressing a midpoint of the underside of the rib in terms of (x, y) in a coordinate system composed in such a way that a point of intersection between the diagonal lines of a substantial rectangular cross section obtained by cutting the rib along a plane, which extends vertically in relation to a filament axis of the associated flat filament, is located at the origin of the coordinate axes x, y, the axis of the x coordinate extending in parallel with both long sides of the substantially rectangular cross section, while the y axis of the coordinate extended in parallel with both shorter sides of the substantially rectangular cross section.

Examples 1-15 and Comparative Examples l-ll In each of the examples and comparative examples, an acrylonitrile copolymer composed of 93 weight percent acrylonitrile and 7 weight percent vinyl acetate was obtained and had a reduced viscosity of 2.0, by a process of polymerization in aqueous suspension. The acrylonitrile copolymer was then dissolved in dimethyl acetamide, so that a spin solution containing the acrylonitrile copolymer at a concentration of 24 weight percent was obtained. However, in Comparative Example 1, the concentration of the acrylonitrile copolymer was set at 20 percent by weight. Through the thin spinning holes of a corresponding one of the orifice configurations, which are similar to the cross-sectional shapes of the desired types of filaments, respectively, the spinning solution was spun into a 40 percent aqueous solution. dimethyl acetamide, this aqueous solution having been controlled at 40 ° C, in such a way that the corresponding spinning stretch shown in Table 1 was obtained. The resulting filaments were drawn five times in hot water (6.5 times in Comparative Example 1 only) , they were washed and then dried with drying rollers. After they underwent the thermal relaxation treatment under a pressurized steam atmosphere of 2.5 kg / cm2, ripples were applied in a population of 9.5 curls / 2.54 centimeters, and at a degree of curling of 10.3 percent, whereby, They obtained flat acrylic filaments with ribs. These flat acrylic filaments with ribs were cut into 51-millimeter stretches to form unprocessed fibers. From the unprocessed fibers, wicks of 10 grams / meter thickness were produced. Using a wick weaving machine, they were formed into a wick fabric. Then the wick fabric was subjected to the polishing step, by which, a high pile fabric of a measure (basis weight) of 700 grams / square meter, and a hair length of 18 millimeters was obtained. The results of the evaluation of this high pile fabric are shown in Table 1.

Comparative Examples 12 and 13. In each Comparative Example, the yarn was conducted in a manner similar to that of Example 2, except that the configuration of each fine-spun hole in its rib-forming portions was modified. The water retention of the filaments was measured before their drying step, and is shown in comparison with that of the filaments of Example 2 of Table 2. Water retention before drying varies substantially, depending on the shape of the filament. rib, and the rib shapes of Comparative Examples 10 and 11 are expected to result in significant drying loads.

Examples 16-18 and Comparative Examples 14-18. In each of the examples and comparative examples, an acrylonitrile copolymer composed of 93 weight percent acrylonitrile and 7 weight percent vinyl acetate, and having a reduced viscosity of 2.0, was obtained by a process of polymerization in aqueous suspension. The acrylonitrile copolymer was then dissolved in dimethyl acetamide, so that a spinning solution containing the acrylonitrile copolymer at a concentration of 24 weight percent was obtained. Through the thin spinning holes of a corresponding planar configuration, the spinning solution was spun in a 40 weight percent aqueous solution of dimethyl acetamide, the aqueous solution being controlled at 40 ° C, while being collected at a Spinning stretch from 1.01 to 1.91. The resulting filaments were drawn five times in hot water, washed and then dried by drying rollers. After they underwent the thermal relaxation treatment under a pressurized vapor atmosphere of 2.5 kg / cm2, ripples were applied in a population of 9.5 curls / 2.54 centimeters and a degree of curling of 10.3 percent. The flat acrylic filaments with ribs were then cut into sections of 51 millimeters. In this way, six types of flat acrylic fibers shown in Table 3 were obtained. Each of the six types was mixed with the ribs with ribs 51 millimeters long, which had been obtained in the corresponding example of Examples 1 to 3 and Comparative Examples 2 and 4, in the proportions shown in Table 3, and wicks of 10 grams / meter thickness were produced. Using a wick weaving machine, they were formed into a wick fabric. Then the wick fabric was subjected to polishing processing, by which a high pile fabric of a measure of 700 grams / square meter and a hair length of 8 millimeters was obtained. The results of the evaluation of this high pile fabric are also shown in Table 3.

Examples 19-23 and Comparative Examples 19-22. In each of the examples and comparative examples, a spinning solution of the same composition as that used in Example 16 was spun in a 40 weight percent aqueous solution of dimethyl acetamide, this aqueous solution having been controlled at 40 °. C, through fine spin holes of a configuration similar to the cross-sectional shape of the desired filaments. Then the resulting filaments were stretched five times in boiling water, while the solvent was washed out, followed by drying through hot rolls controlled at 150 ° C. After they underwent the thermal relaxation treatment in pressurized steam at 2.5 kg / cm2, ripples were applied in a population of 9.5 curls / 2.54 inches and a degree of curl of 10.3 percent. In this way, different types of flat acrylic filaments with ribs were obtained, which were of different fineness and flatness, as shown in Table 4. Each type of flat acrylic filament with rib was then cut into 51-millimeter sections to provide fibers not processed. In addition, spinning was also done in the same way through fine circular holes. After the resulting filaments were subjected to the thermal relaxation treatment in pressurized steam, they were stretched 1.5 times in steam at a normal pressure, thus obtaining shrinkable acrylic fibers having a cross section in the shape of broad beans [fineness: 2 denier, a / b = 2.6, number of indentations: 1]. The shrinkage factor of these fibers was 26 percent, measured by treatment for 3 minutes in boiling water, and 17 percent when measured by treatment for 10 minutes at 130 ° C dry heat. These fibers were cut into 38 millimeter lengths to provide conventional unprocessed fibers of shrinkable acrylic fibers. The additional yarn was also made in the same way through the same fine circular holes. The resulting fibers were only subjected to a pressurized steam treatment, thereby obtaining shrinkable acrylic fibers having a wide bean-shaped cross section [fineness: 5 denier, a / b = 2.6, number of indentations: 1]. These fibers were cut into 38 millimeter lengths to provide conventional unprocessed fibers of shrinkable acrylic fibers. The three previously obtained types of unprocessed fibers were mixed together in proportions such that flat acrylic filaments with ribs, shrinkable fibers, and conventional acrylic fibers, accounted for 40 weight percent, 40 weight percent, and 20 percent by weight, respectively, and then wicks of 20 grams / meter thickness were produced. Using a wick weaving machine, they were formed into a wick fabric. Subsequent to the shrinkage treatment, the wick fabric was subjected to polishing processing, by which a high pile fabric measuring 700 grams / square meter and a hair length of 18 millimeters was obtained. His sensation was classified and is also shown in Table 4.

Examples 24-31 and Comparative Examples 23-25. In each of the examples and comparative examples, the same acrylonitrile copolymer of Example 1 was dissolved in dimethyl acetamide, such that a spinning solution containing the acrylonitrile copolymer at a concentration of 25 weight percent was obtained. The spinning solution was spun into a 40 weight percent aqueous solution of dimethyl acetamide, this aqueous solution having been controlled at 40 ° C, through fine spin holes of a configuration similar to the cross-sectional shape of the fibers desired. Then the resulting fibers were stretched five times in boiling water, while the solvent was washed out, followed by drying through hot rolls controlled at 150 ° C. They were then subjected to the thermal relaxation treatment in pressurized steam at 2.5 kg / cm2. In this way, four types of fibers were obtained that had cross-sectional shapes without edges, and were of a different shape [a / b, number of indentations]. Each type of fiber was then stretched 1.5 times in steam at a normal pressure, whereby shrinkable acrylic fibers having a fineness of 2 denier were obtained. The shrinkage factor of these filaments was 27 percent when measured by treatment for 3 minutes in boiling water, and 18 percent when measured by treatment for 10 minutes at 130 ° C dry heat. These fibers were cut into 38-millimeter sections to provide unprocessed fibers of shrinkable acrylic fibers. In a manner similar to that described above, spinning was performed through the fine circular holes, and the resulting fibers were subjected to treatment or processing until pressurized steam treatment, whereby conventional acrylic fibers were obtained with a fineness of 5 denier. These fibers were cut into 38-millimeter lengths to provide conventional unprocessed fibers of acrylic fibers. The two previously obtained types of unprocessed fibers were mixed with the flat acrylic filaments with ribs (fineness: 10 denier, flat: 13), which had been obtained in Example 1, in the proportions shown in Table 5, whereby , wicks of 10 grams / meter thick were produced. Using a wick weaving machine, they were formed into a wick fabric. Subsequent to the shrinkage treatment, the wick fabric was subjected to polishing processing, by which a high pile fabric measuring 700 grams / square meter and a hair length of 18 millimeters was obtained. Your results of the evaluation are also shown in Table 5.

EXAMPLE 32 The filaments obtained in Example 27, which had a cross-sectional shape without edges (a / b = 3.4, number of indentations: 2), were stretched 1.5 times in steam at a normal pressure subsequent to their treatment in pressurized steam , whereby shrinkable acrylic fibers having a fineness of 2 denier were obtained. The shrinkage factor of these fibers was 27 percent when measured by treating them for 3 minutes in boiling water, and 18 percent when measured by treating them for 10 minutes at 130ºC of dry heat. These fibers were cut into 38-millimeter sections to provide unprocessed fibers. In a manner similar to that described above, the spinning was performed, and the resulting fibers were subjected to a post-treatment or processing until the pressurized steam treatment, whereby non-shrinkable acrylic fibers having a cross-sectional shape were obtained without similar borders (a / b = 3.7, number of indentations: 2), and a fineness of 5 denier. These fibers were cut into 38-millimeter sections to provide unprocessed fibers. The two previously obtained types of unprocessed fibers were mixed with the filaments with ribs of the flat cross section (fineness: 10 denier, flat: 13), which had been obtained in Example 1, in proportions such that flat acrylic filaments with ribs, shrinkable acrylic fibers, and non-shrinkable acrylic fibers accounted for 30 percent by weight, 40 percent by weight, and 30 percent by weight, respectively, and then wicks of 10 grams / meter thickness were produced. Using a wick weaving machine, they were formed into a wick fabric. The wick fabric was subjected to shrinkage treatment for 5 minutes at 130 ° C dry heat, and then to shrinkage treatment, by which a high pile fabric of a measure of 700 grams / square meter and a length was obtained of 18 mm hair. A surface of this high pile fabric had a soft feel, and also had an excellent elastic and substantial feel. Therefore, it was a very high quality hair fabric. The flat filaments with ribs according to the present invention have an excellent brushing and bulking effect, allow easy removal of ripples by polishing, and, when formed in a hair product, provide not only a soft feel, but also a elastic and substantial feeling. Accordingly, they are suitable as unprocessed fibers for a pile fabric. The unprocessed fibers according to the present invention for the pile fabric still exhibit a softer feel when they are formed in the pile fabric. In addition, the unprocessed fibers mixed with shrinkable filaments for a pile fabric according to the present invention, obviate the mixture of unprocessed fibers "subjected to a special treatment such as the application of an aminosiloxane softener, and can be formed in a hair product equipped not only with a smooth surface sensation, but also with an excellent elastic and substantial sensation, all of which are highly comparable with those of natural skins.

Table 1 Table 1 (Continued) Table l (Continued) Table 2 Table 3 Table 4 Table 5

Claims (13)

1. A flat filament having a planarity (A / B) of 7 to 25, A being a length of two longer sides of a substantially rectangular cross section of the filament, and B being a length of two shorter sides of that cross section substantially rectangular filament, and a fineness of 0.5 to 40 denier; and provided on each of the two longer sides with one or more ribs extending continuously in a direction of a filament axis, and having a width and a height H, the number of these ribs on each side being longer from 1 to A / 2W, the width W being from B / 2 to 3B, and the height H being from B / 2 to 2B. The flat filament according to claim 1, wherein a midpoint of the width of each rib is located within a distance of A / 4 from a midpoint of the associated longest side. 3. The flat filament according to claim 1 or 2, wherein the planarity (A / B) is from 7 to 15, the fineness is from 3 to 20 denier, and the number of ribs on each longer side is The flat filament according to claim 1, 2, or 3, wherein each rib has a shape defined only by curves without edges, as seen in the cross section of said filament. 5. The flat filament according to claim 1, 2, 3, or 4, wherein the flat filament is an acrylic filament. 6. Unprocessed fibers for a pile fabric, which comprise: at least 10 weight percent of flat filaments with ribs as defined in claim 1; and at most 90 percent by weight flat filaments having a planarity (A '/ -.') from 5 to 25, with A1 being a length of two longer sides of a substantially rectangular cross section of each of the filaments, and B 'being a length of two shorter sides of the substantially rectangular cross section of the filament, and a fineness of 1 to 40 denier. 7. The unprocessed fibers according to claim 6, wherein the last flat filaments have a fineness of 2 to 30 denier. 8. The unprocessed fibers according to claim 6, wherein the last flat filaments have a fineness of 5 to 15 denier. 9. Unprocessed fibers for a pile fabric, including these fibers, shrinkable fibers, comprising: 20 to 60 weight percent of flat filaments with ribs as defined in claim 1; 20 to 50 weight percent shrinkable fibers having a shrinkage factor of at least 15 percent, and a fineness of 1 to 5 years; and 60 weight percent or less of non-shrinkable fibers. The unprocessed fibers according to claim 9, wherein each of the shrinkable fibers has a cross section defined only by curves without edges, defines at least two indentations' in different places as seen in the cross section, and satisfies the following formula: 2 < a / b < 5 where, when the cross section is sandwiched between two parallel straight lines, a is a maximum distance between those two parallel straight lines, and b is a minimum distance between those two parallel straight lines. The unprocessed fibers according to claim 9 or 10, wherein each of the non-shrinkable fibers has a cross section defined only by curves without edges, defines at least two indentations in different places as seen in the cross section , and satisfies the following formula: 2 < a / b < 5 where, when the cross section is sandwiched between two parallel straight lines, a is a maximum distance between the two parallel straight lines, and b is a minimum distance between the two parallel straight lines. 1

2. The unprocessed fibers according to claim 9, 10, or 11, wherein the shrinkable fibers are acrylic fibers. 1

3. The unprocessed fibers according to claim 9, 10, 11, or 12, wherein the non-shrinkable fibers are acrylic fibers.