JP5901929B2 - Oil and fat-containing rayon fiber, method for producing the same, and fiber structure - Google Patents

Description

  The present invention relates to a rayon fiber containing a specific fat and oil, a method for producing the same, and a fiber structure.

  It is known that rayon fibers using regenerated cellulose are produced by various methods such as viscose method, copper ammonia method, solvent spinning method and the like. Since rayon fiber is made of cellulose as a substrate, it itself has a gentle nature to the skin. Conventionally, various proposals have been made to further exhibit the properties of the rayon fiber. For example, as proposals regarding regenerated cellulose fibers kneaded with fatty acids (oils and fats), proposals for kneading oleic acid or metal salts of oleic acid (Patent Document 1), proposals for kneading γ-linolenic acid emulsion (Patent Document 2) -3), proposal to knead docosahexaenoic acid (DHA) emulsion (Patent Document 4), proposal to knead emulsion of γ-linolenic acid (Patent Document 5), knead oleic acid or salt thereof, cellular region Proposal of Rayon Fiber (Patent Document 6) Formed with Cation, Proposal of Rayon Fiber Formed with Cellulose Region by Kneading Fatty Acid or its Salt and Fat-soluble Antioxidant (Patent Document 7), Rice Oil, γ-Oryzanol There are proposals for kneading an emulsion containing ferulic acid (Patent Document 8), proposals for cellulosic fibers in which a phase change material is encapsulated and added (Patent Document 9), and the like. Patent Document 10 proposes a non-woven fabric for cosmetics and beauty using oil-containing fibers such as rayon fibers containing oil such as squalane as raw material fibers. Patent Document 11 proposes a fiber structure including a viscose rayon fiber containing a natural protein.

  Since the fatty acid used in Patent Documents 1 to 7 has a melting point of 14 ° C. or lower, it is liquid at room temperature and can be easily emulsified. Moreover, the rice oil used in Patent Document 8 also contains a lot of unsaturated fatty acids, so has a low melting point and can be easily emulsified. In Patent Document 9, fats and oils or fatty acids are added in microcapsules. Squalane used as an oil component in Patent Document 10 is liquid at room temperature and can be easily emulsified.

JP-A-53-143722 JP 2002-161428 A JP 09-296322 A JP 09-296321 A JP 08-337918 A JP 2007-138324 A JP 2008-28579 A JP 2007-314914 A Special table 2009-544866 gazette JP 2010-195735 A JP 2010-216053 A

  However, it is not easy to add fats and oils having a melting point of 20 ° C. or more directly to the rayon fiber. When oil and fat are melted and liquefied and added at a temperature of 20 ° C. or higher, there is a possibility that viscose will gel. In addition, fats and oils are saponified by contact with the alkali in the viscose, making spinning difficult. In addition, the technology for microencapsulation has a problem that the cost is high, and the capsule material must be able to withstand the alkali in the viscose and the strong acid of the spinning bath, and the selection of the material is difficult. Moreover, the viscose rayon fiber of patent document 11 has only the property derived from a natural protein, and the further function is calculated | required.

  In order to solve the above-mentioned conventional problems, the present invention can stably and directly mix viscose even if it is an oil having a melting point of 20 ° C. or higher, and can be finely dispersed in the cellulose constituting the rayon fiber. And a rayon fiber containing oil and fat that is gentle to the skin, a method for producing the same, and a fiber structure.

Fat-containing rayon fiber of the present invention is a fat-containing rayon fibers fat is mixed into viscose in rayon fibers, the oil comprises at least one fatty acid component selected from fatty acids and glycerol esters, and 20 ° C. In which the cellulose and the fats and oils in the viscose rayon fiber are incompatible with each other, and the fats and oils are finely dispersed in the cellulose.

  The method for producing fat-and-oil-containing rayon fibers of the present invention includes at least one fatty acid component selected from fatty acids and glycerin esters thereof, and oils and fats that are solid at 20 ° C. with an HLB (Hydrophile-Lipophile Balance) of 16-19. 5 and an HLB of 6 to 12 are added to prepare an emulsion having an average particle size of 0.02 to 2 μm, and the emulsion is mixed with a viscose stock solution containing cellulose and spun. A viscose solution for spinning is prepared, the spinning viscose solution is extruded from a nozzle, spun, and coagulated and regenerated.

  The fiber structure of the present invention includes the oil-containing rayon fiber.

  The fat and oil-containing rayon fiber of the present invention can be made into a rayon fiber that is gentle to the skin by kneading fat and oil that contains a fatty acid component and is solid at room temperature into the rayon fiber. Further, when a large number of oils and fats are finely dispersed in the fibers, the functions of the oils and fats themselves are exhibited, and the fibers have a soft feeling and a soft texture.

  In the production method of the present invention, an emulsion having an average particle size of 0.02 to 2 μm is prepared by combining oils and fats with emulsifiers having different HLB, and the emulsion is mixed with a viscose stock solution containing cellulose. By using the viscose liquid for use, even if the oil has a melting point of 20 ° C. or higher, it can be directly and stably mixed without altering the viscose.

  The fiber structure of the present invention is gentle to the skin, has a slimy feeling, and can have a soft texture.

FIG. 1A is an optical micrograph (magnification: 320 times) showing the side surface of the oil-and-fat-containing rayon fiber (fiber A) in Example 1 of the present invention, and FIG. 1B is a transmitted light with a microscope (magnification: 3000 times). It is the photograph of the same cross section observed. FIG. 2A is an optical micrograph (magnification: 320 times) showing a side surface of the oil-and-fat-containing rayon fiber (fiber B) in Example 2 of the present invention, and FIG. 2B is a transmitted light with a microscope (magnification: 3000 times). It is the photograph of the same cross section observed. FIG. 3 is a chart showing differential scanning calorimetry (DSC) measurement data of the shea butter used in Examples 1 and 2 of the present invention. FIG. 4 is an infrared absorption spectrum chart of a conventional regular rayon fiber. FIG. 5 is an infrared absorption spectrum chart of the shea butter used in Examples 1 and 2 of the present invention. FIG. 6 is an infrared absorption spectrum chart of the oil-and-fat-containing rayon fiber (fiber B) in Example 2 of the present invention. FIG. 7 is a photograph of the cross section of the oil-and-fat-containing rayon fiber (fiber F) in Example 5 of the present invention observed with transmitted light using a microscope (magnification: 3000 times). FIG. 8A is an optical micrograph (magnification: 640 times) showing a side surface of the oil-and-fat-containing rayon fiber (fiber G) in Example 6 of the present invention, and FIG. 8B is a transmission light with a microscope (magnification: 3000 times). It is the photograph of the same cross section observed. FIG. 9 is a chart showing differential scanning calorimetry (DSC) measurement data of beef tallow used in Example 5 of the present invention. FIG. 10 is a chart showing differential scanning calorimetry (DSC) measurement data of the shortening used in Example 6 of the present invention. FIG. 11 is a graph showing the relationship between the number of oils and fats extracted and the oil and fat extraction rate in the raw cotton (fiber E) of Example 4 washed once. FIG. 12 is a graph showing the fat and oil extraction rate of the raw cotton (fiber E) of Example 4 that was washed 0 times, washed once, washed 5 times, washed 10 times, and washed 30 times.

The inventors of the present invention are able to produce fibers containing fats and oils in a large number of microscopic regions by adding and spinning fats and oils that contain a fatty acid component and are solid at room temperature to viscose under predetermined conditions. It was found that this was possible and resulted in the present invention. In the present invention, fats and oils that are solid at 20 ° C. can be finely present in the fibers by emulsifying them.

(1) Fats and oils The fats and oils used in the present invention contain at least one fatty acid component selected from fatty acids and glycerin esters thereof and are solid at 20 ° C. Examples of the fatty acids include saturated fatty acids and unsaturated fatty acids. Examples of the glycerin esters of the fatty acids include saturated fatty acid glycerin esters, saturated fatty acid mixed glycerin esters, unsaturated fatty acid glycerin esters, and unsaturated fatty acid mixed glycerin esters. And mixed glycerin esters of saturated and unsaturated fatty acids. In general, the melting point of a fatty acid increases as the number of carbon atoms increases. When the number of carbon atoms is the same, the melting point of a saturated fatty acid tends to be higher than that of an unsaturated fatty acid. By containing solid fats and oils at 20 ° C., naturally derived fats and oils have many melting points of 20 ° C. or more, and can give a better effect to the skin than liquid oils and fats at room temperature. Moreover, by containing solid fats and oils at 20 degreeC, it is preferable at the point which can provide the function which liquid oils and fats do not have at normal temperature. In this invention, the fats and oils which are solid at 20 degreeC mean that melting | fusing point of fats and oils is 20 degreeC or more.

  The fatty acid component contained in the fats and oils used in the present invention may be any of saturated fatty acids, unsaturated fatty acids, and glycerin esters thereof. Although it does not specifically limit as carbon number of a fatty acid, For example, it is preferable that it is C16-22. The saturated fatty acid preferably contains at least one selected from palmitic acid, stearic acid, arachidic acid, pehenic acid and the like. The unsaturated fatty acid preferably contains at least one selected from palmitoleic acid, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, erucic acid and the like.

    The fats and oils preferably contain saturated fatty acids and unsaturated fatty acids, more preferably 30 to 55% by mass of saturated fatty acids and 45 to 70% by mass of unsaturated fatty acids. When saturated fatty acid and unsaturated fatty acid are included, it is preferable at the point which can receive the various effects which each fatty acid has. For example, saturated fatty acids are preferred because they are resistant to spoilage, have very good stability, and have a high moisture effect, and therefore have a moisturizing effect due to the property of retaining moisture in the subcutaneous tissue.

  Usually, the melting point of fats and oils depends on the melting point of fatty acids contained in the fats and oils. For example, in the case of fats and oils containing a plurality of fatty acids, the melting point when measured as fats and oils is used. When the melting peak is a single peak, if the melting point is 20 ° C or higher, it is included in the fats and oils that are solid at 20 ° C. In the case where a plurality of melting peaks appear, if at least one melting peak is 20 ° C. or higher, it is contained in the oil that is solid at 20 ° C.

  When the fats and oils are naturally derived fats and oils, they may exist as glycerin esters of saturated fatty acids and / or unsaturated fatty acids. By being present as a glycerin ester, the functions of each fatty acid can be exhibited widely. Moreover, even if it contains a fatty acid with a high melting point, the melting point shows a broad melting peak and shifts to the low melting point side. Specifically, the melting point of naturally derived fats and oils is preferably 20 to 82 ° C. More preferably, it is 25-60 degreeC.

  Examples of the naturally-derived oils and fats include, for example, Babas oil having a melting point of 22 to 26 ° C. obtained from Babas seed (usually caprylic acid 4.1 to 4.8%, capric acid 6.6 to 7.6%, laurin Acid 44.1-45.1%, myristic acid 15.4-16.5%, palmitic acid 5.8-8.5%, stearic acid 2.7-5.5%, oleic acid 11.9-16 1%, including linoleic acid 1.4-2.8%); Borneo fat (usually 18% palmitic acid, 43.3% stearic acid, oleic acid 37) obtained from the seeds of shoreastenoptera 4%, 0.2% linoleic acid, 1.1% arachidic acid); cocoa butter with a melting point of 32-35 ° C. obtained from cocoa seeds (usually 24.4% palmitic acid, 35.4 stearic acid) %, Oleic acid 38 1%, including linoleic acid 2.1%); palm oil with a melting point of 27-50 ° C. obtained from oil palm seeds (usually 0-1% lauric acid, 1-2% myristic acid, 39-46 palmitic acid) %, Stearic acid 3-5%, oleic acid 38-44%, linoleic acid 8-11%); butter obtained from dairy cow's milk with a melting point of 25-35 ° C. (usually 3.7% butyric acid, hexanoic acid 2.3%, Octanoic acid 1.4%, Decanoic acid 2.9%, Lauric acid 3.6%, Myristic acid, 11.9%, Pentadecanoic acid 1.7%, Palmitic acid 33.1%, Heptadecanoic acid 1%, stearic acid 10.0%, arachidic acid 0.2%, behenic acid 0.1%, lignoceric acid 0.1%, decenoic acid 0.3%, myristoleic acid 1.1%, palmitoleic acid 7%, heptadecenoic acid 0.3%, olein 21.8%, eicosenoic acid 0.2%, linoleic acid 2.1%, linolenic acid 0.5%, icosatrienoic acid 0.1%, arachidonic acid 0.1%); Shea butter obtained from embryos with a melting point of 25-45 ° C. (usually oleic acid 38-50%, stearic acid 34-45%, palmitic acid 3-9%, linoleic acid 5-8%, arachidic acid 1-2% Beef tallow; shortening (edible oil made from vegetable oil, margarine made by removing water and additives to obtain high-purity fat); lard; horse oil; sha fat; coconut oil and the like.

  In particular, when used in contact with human or animal skin, the oil / fat preferably has a melting peak near the body temperature. Specifically, it is preferable that melting | fusing point of fats and oils is 30-45 degreeC. When the melting point is in the above range, the oil or fat is softened or melted when it comes into contact with the skin, so that the familiarity with the skin is good and the texture becomes soft.

  It is preferable that the melting point of the fats and oils has a broad melting peak because it is stable against changes in the atmospheric temperature of the fat and oil-containing rayon fibers and fiber structures, has a good familiarity with the skin, and has a soft texture. For example, when the melting peak measured by the DSC method described later is a single peak, it can be said that the peak is broader as the half-value width in the melting peak is larger. The half width at the melting peak of the oil is preferably 3 to 20 ° C. More preferably, it is 5-15 degreeC. Moreover, when the melting peak measured by DSC method mentioned later has a some peak, it is preferable that the number of melting peaks is 2-8. Moreover, it is preferable that the difference of the minimum temperature and the maximum temperature is 10-60 degreeC among each melting peak. Oils and fats having such a plurality of melting peaks are preferred because they are stable against changes in the atmospheric temperature of the oil-and-fat rayon fibers and fiber structures, are well-familiar with the skin, and are soft to the touch. In the present invention, the “half-value width at the melting peak” is the intersection of the perpendicular line drawn from the vertex X of the melting peak (endothermic peak) measured by the DSC method to the temperature axis and the baseline of the endothermic peak as Y. When the point of bisecting the line segment XY is M, and the intersection points of the straight line passing through M and parallel to the temperature axis and the endothermic curve are N1 and N2, respectively, the line segment N1-N2 Length (temperature range).

  Among them, preferred fat is shea butter. Shea butter is a vegetable fat obtained from the seeds of the seeds of Shea butter of the Acetaceae family, and is a waxy solid at room temperature (20 ° C.). Mainly produced in Nigeria, Mali, Burkina Faso and Ghana in Africa. Although it is edible, it is widely known in recent years that it is mixed with hand creams, soaps, cosmetics and the like. The component of shea butter is mainly composed of glycerin esters of fatty acids including stearic acid and oleic acid, and also contains trace amounts of tocopherol, carotenoids, and triterpenes. By using shea butter, there may be a protective effect of sebum possessed by stearic acid, an antioxidant effect, an oil replenishment effect of sebum, a stratum corneum protection possessed by oleic acid, and a dry skin improving effect.

  The raw material quality of shea butter varies depending on the production area, harvest time, climatic conditions, etc., but the fatty acid composition of shea butter is preferably 30 to 55% by mass of saturated fatty acid and 45 to 70% by mass of unsaturated fatty acid. Within the above range, the function of each fatty acid component can be effectively exhibited.

  The melting point of shea butter has a broad melting peak and is preferably 35 to 40 ° C. The half width at the melting peak of shea butter is preferably 5 to 15 ° C. Thus, shea butter which is solid at 20 ° C. can be emulsified by the method described later.

  Of the oils and fats, it is preferable to use fats and oils close to the fatty acid composition of human sebum because they are familiar to the skin. Such fats and oils preferably contain palmitic acid as a saturated fatty acid in an amount of 10% by mass or more of the fatty acid composition of the fats and oils. More preferably, it contains 15 to 35% by mass. Palmitic acid has a function of preventing the growth of sebaceous glands, and has a function of stabilizing vitamin A that activates cells such as skin, hair, and mucous membranes. Moreover, it is preferable to contain oleic acid as an unsaturated fatty acid 10 mass% or more of the fatty acid composition of fats and oils. More preferably, the content is 15 to 55% by mass. Examples of fats and oils that satisfy the above fatty acid composition range include beef tallow, shortening, cocoa butter, butter, horse oil, and borneo fat.

(2) Emulsification of fats and oils The fats and oils are added to a viscose stock solution containing cellulose to give a viscose liquid for spinning. However, it is preferable to use the fats and oils as an emulsion liquid emulsified with emulsifiers having different HLB. . As an emulsification method, a known emulsification method such as a phase inversion emulsification method or a forced emulsification method can be used. As the emulsifier, a first emulsifier having a relatively high HLB and a second emulsifier having a relatively low HLB are used in combination.

  As the first emulsifier, an emulsifier having an HLB of 16 to 19.5, preferably 17 to 19 can be used. Examples of emulsifiers that satisfy the HLB range include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, polyoxyalkylene alkenyl ethers such as polyoxyethylene alkenyl ethers, polyoxyalkylene alkyl phenyl ethers, and polyoxyalkylene styrenated esters. Examples include phenyl ether, polyoxyalkylene alkyl styrenated ruphenyl ether, polyoxyalkylene cumyl phenyl ether, polyoxyalkylene β-naphthyl ether, polyoxyalkylene castor oil ether, polyoxyalkylene hardened castor oil ether, and the like. In particular, polyoxyethylene alkyl ether and / or polyoxyethylene alkenyl ether are preferable. The polyoxyethylene alkyl and polyoxyethylene alkenyl ether satisfying the HLB range preferably have a degree of polymerization as polyoxyethylene of 30 to 200, more preferably 40 to 150, and preferably the number of carbon atoms in the alkyl and alkenyl chains. It is 12-22, More preferably, it is 16-18. The amount of the first emulsifier added is preferably 5 to 35% by mass with respect to fats and oils, considering the low-temperature storage stability of the emulsion. In addition, when using it in the environment which does not require low-temperature storage stability, it is preferable that it is 5-15 mass%.

  As the second emulsifier, an emulsifier having an HLB of 6 to 12, preferably 8 to 11 can be used. Examples of the emulsifier satisfying the HLB range include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ether, polyoxyalkylene alkenyl ether, polyoxyalkylene cumyl phenyl ether, polyoxyalkylene β-naphthyl ether, and polyoxyalkylene phenyl ether. Polyoxyalkylene benzyl ether and the like can be used. The polyoxyethylene alkyl ether satisfying the HLB range preferably has a degree of polymerization of 1 to 8, more preferably 2 to 4, and preferably 4 to 12, more preferably 6 carbon atoms of the alkyl chain as polyoxyethylene. ~ 8. The amount of the second emulsifier added is preferably 2 to 25% by mass with respect to fats and oils, considering the low-temperature storage stability of the emulsion. In addition, when using it in the environment which does not require low-temperature storage stability, it is preferable that it is 2-10 mass%.

  By using the emulsifiers having different HLBs together, an emulsion liquid having good emulsification and good stability can be obtained. The mixing ratio of the first emulsifier and the second emulsifier is preferably 1: 1 to 20: 1 by mass ratio. More preferably, it is 1.5: 1 to 10: 1, and still more preferably 2: 1 to 5: 1. Secondary emulsifier with relatively low HLB (HLB6-12) affects the polarity of fats and oils, stable and small particle size when used in combination with primary emulsifier with relatively high HLB (HLB16-19.5) An emulsion is obtained. It should be noted that other emulsifiers may be added in addition to the first emulsifier and the second emulsifier as long as the predetermined emulsion in the present invention is obtained.

  In the present invention, the method of emulsifying the fats and oils is preferably a method of phase inversion emulsification of different HLB emulsifiers. By using an emulsifier having a high HLB, it is presumed that the high temperature stability, acid resistance, alkali resistance and the like of the emulsion are improved.

  The total addition amount of the first emulsifier and the second emulsifier is preferably 7 to 60% by mass with respect to fats and oils in consideration of low temperature storage stability of the emulsion. More preferably, it is 15-50 mass%. In addition, when using it in the environment which does not require low-temperature storage stability, it is preferable that it is 7-30 mass%. More preferably, it is 10-20 mass%. On the other hand, since the low-temperature storage stability is increased by increasing the emulsifier, the total amount of the first emulsifier and the second emulsifier is particularly preferably 30% by mass or more particularly in use in a cold region. Below this range, an emulsion with good stability cannot be obtained. If it exceeds the above range, a lot of bubbles are generated in the scouring process, which tends to cause scouring abnormalities.

  In addition to the emulsifier described above, a polyoxyethylene / polyoxyalkylene glycol block polymer (PAG) may be added to the emulsion. The addition amount of the polyoxyethylene / polyoxyalkylene glycol block polymer is preferably 0.5 to 3.0% by mass with respect to the fats and oils. When it is within the above range, the low-temperature storage stability of the emulsion at 5 ° C. or lower can be further improved.

  The average particle diameter of the emulsion in the emulsion liquid is preferably 0.02 to 2 μm. A more preferable average particle diameter is 0.05 to 1.5 μm, more preferably 0.08 to 1.2 μm, and particularly preferably 0.1 to 0.8 μm. When the average particle diameter is within the above range, oil and fat are finely dispersed, and rayon fibers including a large number of fine regions are obtained, which is preferable. The average particle size can be controlled by the composition of the emulsifier, the amount of the emulsifier added, and the emulsification conditions. The emulsion liquid preferably contains 3% or less of particles having an emulsion particle size of 3 μm or more. More preferably, it is 1% or less, More preferably, it is 0.1% or less. When the particle diameter of the emulsion is within the above range, oil and fat are finely dispersed, and rayon fibers containing a large number of fine regions are obtained, which is preferable. In the present invention, the particle diameter and average particle diameter of the emulsion are those measured and calculated by a light scattering method.

  It is preferable that the oil or fat has a melting point of 60 ° C. or lower because an emulsion liquid can be stably produced.

  In the present invention, an antioxidant may be added to the emulsion solution. By mixing an antioxidant with an emulsion liquid containing fats and oils, it is possible to prevent a decrease in fiber strength due to the oxidation of the fats and oils. As the antioxidant, for example, any of a fat-soluble antioxidant and a water-soluble antioxidant may be used. Examples of the fat-soluble antioxidant include natural antioxidants such as tocopherol, β-carotene, and ubiquinol (CoQ10), and synthetic antioxidants such as BHT (dibutylhydroxyl toluene) and BHA (butylhydroxyanisole). Is mentioned. Of these, natural antioxidants are preferred. As the tocopherols, either natural or synthetic tocopherols may be used. The natural tocopherol is generally extracted, concentrated and purified from vegetable oils and the like, and does not contain optical isomers (D form only). On the other hand, the synthetic tocopherol is generally industrially synthesized, and the optical isomer is a mixture of D-form and L-form. Examples of the synthetic tocopherol include tocopherol acetate. In particular, from the viewpoint of antioxidant properties, natural tocopherol is preferable. In addition, tocopherols include α-type, β-type, γ-type, and δ-type, and it is preferable that δ-type tocopherol is included from the viewpoint of antioxidant property. β-carotene, ubiquinol (CoQ10), BHT, and BHA have the same effects as tocopherols. Examples of the water-soluble antioxidant include ascorbic acid, isoascorbic acid; catechin, anthocyanin, tannin, quercetin (various glycosides such as rutin and quercitrin, and enzyme treatment and chemical treatment such as enzyme-treated isoquercitrin) Selected from flavonoids such as myricitrin, myricetin, and isoflavone; phenolic acids such as chlorogenic acid, ellagic acid, and curcumin; polyphenols such as apple polyphenol and cacao mass polyphenol; and carotenoids that are soluble in water such as astaxanthin and lutein At least one is preferred. The plant extract containing the water-soluble antioxidant may be, for example, an extract such as tea, rosemary, strawberry, camellia or bayberry. The plant extract is not particularly limited, and examples thereof include a plant solvent extract obtained by powdering the plant and then using a solvent such as water or hydrous alcohol, or a concentrated or dried product thereof. . Moreover, you may use the commercially available strawberry fruit juice containing anthocyanin, a grape skin pigment | dye, etc.

(3) Spinning conditions As the spinning solution (viscose solution), a viscose stock solution containing 7 to 10% by mass of cellulose, 5 to 8% by mass of sodium hydroxide, and 2 to 3.5% by mass of carbon disulfide is prepared. It is good to use it. At this time, additives such as ethylenediaminetetraacetic acid (EDTA) and titanium dioxide can be used as necessary. The temperature of the spinning solution (viscose solution) is preferably maintained at 19 to 23 ° C. The viscose solution for spinning is prepared by mixing the prepared viscose stock solution containing cellulose with an emulsion obtained by emulsifying fats and oils together with emulsifiers different in HLB as described above.

  The addition amount of the fat is preferably in the range of 0.5 to 15% by mass with respect to cellulose. More preferably, it is 0.8-14 mass%, More preferably, it is the range of 1-10 mass%. If it is the said range, effects, such as skin dryness, aging prevention, stratum corneum protection by oleic acid, dry skin improvement, metabolism promotion by linoleic acid, and normalization of skin cell function by linolenic acid, can be expected.

  The spinning bath (Mueller bath) preferably contains 95 to 130 g / liter of sulfuric acid, 10 to 17 g / liter of zinc sulfate, 290 to 370 g / liter of sodium sulfate, and a temperature of 45 to 60 ° C. A more preferable sulfuric acid concentration is 100 to 120 g / liter. As spinning conditions, the rayon fiber of this invention can be manufactured using a normal circular nozzle. The selection of the spinning nozzle depends on the target production amount, but preferably has a circular nozzle having a diameter of 0.05 to 0.12 mm and 1000 to 20000 holes.

  Using the spinning nozzle, the spinning viscose liquid obtained above is extruded into a spinning bath, spun, and coagulated and regenerated. The spinning speed is preferably in the range of 35 to 70 m / min. Further, the stretching ratio is preferably 39 to 50%. Here, the stretch ratio indicates how many percent the stretched length is increased when the stretched length is 100%. In terms of magnification, the ratio is 1 before stretching and 1.39 to 1.50 after stretching.

  The rayon fiber yarn obtained as described above is cut into a predetermined length and subjected to a scouring treatment. The scouring step is preferably performed in the order of hot water treatment, hydrosulfurization treatment, bleaching, pickling, and oil application.

  Then, after removing excess oil agent and water | moisture content from a fiber by methods, such as a compression roller and a vacuum suction, as needed, it can dry-process and can obtain the fat-containing rayon fiber of this invention.

  The oil-containing rayon fiber of the present invention preferably has a fineness of 0.3 to 6.0 dtex. More preferably, it is 0.6-4.0 dtex, More preferably, it is 0.9-3.3 dtex. If the fineness is less than 0.3 dtex, single fiber breakage tends to occur during stretching. If the fineness exceeds 6.0 dtex, it may be difficult to use for clothing.

  The fat and oil-containing rayon fiber of the present invention is provided in the form of long fibers (for example, tow, filament, nonwoven fabric, etc.), short fibers (for example, raw paper for wet papermaking, raw cotton for airlaid nonwoven fabric, raw cotton for cards, etc.) It is preferable to form a fiber structure. The fiber structure is preferably, for example, tow, filament, spun yarn, batting (padded cotton), paper, non-woven fabric, woven fabric, or knitted fabric, and is a kind selected from the group consisting of spun yarn, knitted fabric, woven fabric, and non-woven fabric. Is more preferable.

  The fiber structure of the present invention has a good texture because the rayon fiber contains fats and oils. This texture will be described in detail. When the oil-containing rayon fiber of the present invention is used, the surface has a slimy feeling and a soft texture is expressed when it is made into a fiber structure as compared with the conventional rayon fiber. The product has a gentle texture and can produce a very high-class effect on the product (hereinafter also referred to as the texture effect). In addition, since the fat and oil-containing rayon fiber of the present invention is kneaded with fats and oils in the fiber, the texture effect of the present invention is a so-called post-processing finish that imparts a softener at the final finishing stage of a conventional fiber structure. Compared with outstanding washing durability.

  As the fiber structure of the present invention, for example, in the case of a spun yarn, the oil-containing rayon fiber alone or other regenerated cellulose fibers, cotton, hemp, wool, acrylic, polyester, polyamide, polyolefin, polyurethane and other fibers It is preferable to be blended with and mixed with. Such spun yarn can be processed into a woven fabric or a knitted fabric and used for clothing or the like.

  When the fiber structure of the present invention is a woven fabric or a knitted fabric, the structure of the woven fabric or the knitted fabric is not particularly limited. For example, circular knitting, weft knitting, and warp knitting (tricot) are preferable for knitting, and plain weaving, twill weaving, and satin weaving are preferable forms of the fiber structure because the texture effect of the present invention can be exhibited well.

  As the fiber structure of the present invention, for example, in the case of a nonwoven fabric, the oil-containing rayon fiber alone or other regenerated cellulose fibers, cotton, hemp, wool, acrylic, polyester, polyamide, polyolefin, polyurethane and other fibers Can be used after blending. Examples of the form of the nonwoven fabric include a wet nonwoven fabric (wet papermaking), an airlaid nonwoven fabric, a hydroentangled nonwoven fabric, and a needle punched nonwoven fabric. Such a nonwoven fabric can be used, for example, for wet tissues, wet sheets such as interpersonal / objective wipers, hydrolytic sheets, and the like. Moreover, it can be used for sanitary sheets such as cosmetic puffs and absorbent bodies.

  In the fiber structure of the present invention, when mixed with other fibers, the oil-containing rayon fiber is preferably contained in an amount of 10% by mass or more. More preferably, it is 15 mass% or more, More preferably, it is 20 mass% or more, More preferably, it is 30 mass% or more. The upper limit of the content of the oil-and-fat-containing rayon fiber when mixed is preferably 90% by mass. When the oil and fat-containing rayon fiber is less than 10% by mass, the above-mentioned soft texture tends to be hardly obtained. In addition, when it exceeds 90% by mass, the ratio of rayon fibers increases, so in addition to the above-mentioned hand effect, the moisture absorption, moisture release, moisture absorption heat generation, and drape properties are high, but the inherent low strength of rayon fibers. It tends to be low dryness (hard to dry), low heat retention, and low stretchability. To supplement such performance, it is preferably combined with other fibers.

  Other fibers combined with the oil-and-fat-containing rayon fibers can be appropriately selected according to the purpose, and are not particularly limited. For example, in order to improve the strength, it is preferable to combine polyester fiber, the method of blending the fat-containing rayon short fiber and the polyester fiber, or the oil-containing rayon fiber and the polyester fiber are twisted and knitted together with the long fibers. It is preferable to make a composite by interweaving. In addition, it is preferable to compound a modified cross-section polyester (long) fiber to improve the low drying property of sweat or laundry. Cationic dyeable polyester fibers are preferred because they can increase dyeing fastness when dyed simultaneously with polyurethane-based elastic fibers. For improving heat retention, polyacrylic fibers are preferred. For improving the low stretchability, polyurethane elastic fibers are preferred. Polyamide fibers are preferred for improving color development and improving flexural strength. Further, since the hard texture of cotton can be improved and the warmth of wool can be taken into account, it is preferable to combine such fibers in accordance with the application and requirements.

  For example, in the fiber structure of the present invention, the oil-containing rayon fiber is 10 to 30% by mass, the polyacrylic fiber is 30 to 47% by mass, the cationic dyeable polyester fiber is 30 to 45% by mass, and the polyurethane elastic fiber is When 3 to 15% by mass is contained, there is a slimy feeling, soft texture, moisture absorption exothermic property, heat retention, strength, water absorption, drying property, stretchability, dyeing fastness, and excellent washing durability of the texture. It will be. And when this fiber structure (for example, knitted fabric) is used for winter thin fabric knit inner, etc., it is thin and light, has a slimy surface, has a soft texture, hygroscopic heat generation, heat retention, strength, water absorption, A product excellent in drying property, stretch property, dyeing fastness and washing durability of the texture can be obtained.

  Hereinafter, it demonstrates using drawing. FIG. 1A is an optical micrograph (magnification: 320 times) showing the side surface of the oil-and-fat-containing rayon fiber (fiber A) in Example 1 of the present invention, and FIG. 1B is a transmitted light with a microscope (magnification: 3000 times). It is the photograph of the same cross section observed. The black dots in FIG. 1A are finely dispersed fats and oils. The island part in the fiber cross section of FIG. 1B is a micro area part, and the finely dispersed fats and oils exist in this micro area. 1A-B show that the cellulose and the fats and oils in the rayon fiber are in an incompatible state, and the fats and oils are finely dispersed in the cellulose. FIG. 2A is an optical micrograph (magnification: 320 times) showing a side surface of the oil-and-fat-containing rayon fiber (fiber B) in Example 2 of the present invention, and FIG. 2B is a transmitted light with a microscope (magnification: 3000 times). As with the fiber A, the fats and oils are finely dispersed in the fiber. 2A-B also show that the cellulose and the fats and oils in the rayon fiber are in an incompatible state, and the fats and oils are finely dispersed in the cellulose.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples. In addition, when the addition amount is simply expressed as% in the following examples, it means mass%.

(Measuring method)
(1) Half width at melting point and melting peak Using a differential scanning calorimeter (DSC), nitrogen gas was flowed as a flow gas at a rate of 30 ml / min, and a temperature increase rate from 0 ° C. to 90 ° C. was 5 ° C./min. The minimum point of the endothermic peak was measured as the melting point (° C.). The half width at the melting peak is the line connecting the intersection of the peak of the melting peak (endothermic peak), the perpendicular line from the peak of the melting peak (endothermic peak) to the temperature axis, and the baseline of the endothermic peak. It was obtained from the length of the line segment (temperature width) connecting two intersections where a straight line parallel to the temperature axis passes through the point that bisects the line segment and intersects the endothermic curve.
(2) Infrared absorption (IR) measurement It measured by ATR method using FT-IR4100 made from JASCO.
(3) Average particle diameter It measured using the laser diffraction / scattering type particle | grain distribution measuring apparatus LA-950V2 by Horiba, Ltd.

(Production Examples 1-4)
[Preparation of emulsion]
Purified shea butter (produced by Ghana, manufactured by AMAX Co., Ltd.) having a fatty acid composition shown in Table 1 below as a fat and oil, a melting point of 38.4 ° C., and a half-value width at a melting peak of 7.75 ° C. Using the emulsifier shown in the following Table 2 as an emulsifier, the fats and oils and the emulsifier were mixed at the blending ratio shown in the following Table 2 to prepare emulsion liquids of Production Examples 1 to 4. The fatty acid composition of the fats and oils was 45.9% saturated fatty acids and 53% unsaturated fatty acids. Moreover, the emulsion liquid of the manufacture examples 1-4 contained 20 mass% fats and oils, and the total addition amount with respect to the fats and oils of an emulsifier was 15 mass%.

  As shown in Table 2, in Production Examples 1 to 4, it was possible to prepare emulsion liquids by emulsifying fats and oils by using polyoxyethylene alkyl ethers having different HLBs as emulsifiers. In particular, the emulsion liquids of Production Examples 1, 2, and 4 had a small average particle size of the emulsion and were finely dispersed. The emulsion liquid of Production Example 3 has a large average particle diameter of the emulsion, and thus agglomerates when allowed to stand for 2 to 3 weeks.

(Example 1)
[Preparation of viscose liquid for spinning]
The emulsion solution prepared in Production Example 4 was added to the raw material viscose so that the fat content was 3% by mass with respect to cellulose, and stirred and mixed with a mixer to prepare a spinning viscose solution. . The temperature was kept at 20 ° C. As the raw material viscose, a viscose stock solution containing 8.5% by mass of cellulose, 5.7% by mass of sodium hydroxide, and 2.7% by mass of carbon disulfide was used.

[Spinning conditions]
The obtained viscose solution for spinning was spun at a spinning speed of 60 m / min and a draw ratio of 50% by a two-bath tension spinning method to obtain a shea butter-containing rayon fiber having a fineness of 1.4 dtex. As the first bath (spinning bath), a Mueller bath (50 ° C.) containing 100 g / L of sulfuric acid, 15 g / L of zinc sulfate and 350 g / L of sodium sulfate was used. In addition, a circular nozzle having 4000 holes having a hole diameter of 0.06 mm was used as a spinneret for discharging viscose. During spinning, there was no inconvenience such as single yarn breakage, and the spinnability of the mixed viscose was good.

[Scouring conditions]
The viscose rayon yarn obtained above was cut into a fiber length of 38 mm and scoured. In the scouring step, after washing with hot water, washing with water, adding an oil agent, dropping excess moisture and oil agent from the fiber with a compression roller, and then performing a drying treatment (60 ° C., 7 hours) to obtain fiber A. .

(Example 2)
A fiber B was obtained in the same manner as in Example 1 except that the emulsion liquid obtained in Production Example 1 was added to the raw material viscose so that the fat content was 1% by mass with respect to cellulose.

The microscopic observation results of the obtained fiber A and fiber B are shown in FIGS. 1A and 2A are fats and oils in which black spots are finely dispersed in the micrographs of the fiber side surfaces. In the micrographs of the fiber cross-sections in FIGS. 1B and 2B, the island portion in the fiber cross-section is a micro-region portion, and it is considered that finely dispersed oil and fat exists inside the micro-region. Moreover, it was confirmed in FIGS. 4 to 6 that shea butter was present in the rayon fibers of the examples. 4 shows infrared absorption curve data of regular rayon fiber, FIG. 5 shows infrared absorption curve data of shea butter, and FIG. 6 shows infrared absorption curve data of fiber B obtained in Example 2. When these are compared, the absorption waveform of the portion of 2856.06 cm ⁻¹ (− (CH ₂ ) _n −) and the absorption waveform of the portion of 1749.12 cm ⁻¹ (—COOH) in FIG. Since it was seen in the infrared absorption curve data of the shea butter in FIG. 5, it was confirmed that shea butter was present in the fiber B. Furthermore, when the texture of the fiber A and the fiber B was evaluated by a sensory (tactile feeling) test, it was confirmed that the softness caused by the oil and fat and the good feeling of slime were obtained.

(Comparative Example 1)
Except not adding oil and fat, it implemented like Example 1 and obtained fiber C. The obtained fiber C was observed with a microscope in the same manner as the fiber A, but the oil and fat portion was not observed (not shown).

  The results of Examples 1 and 2 and Comparative Example 1 are summarized and shown in Table 3 below.

(Example 3)
Shea butter varies in raw material quality depending on the production area, harvest time, climatic conditions, etc. In this example, the action and effect were confirmed using shea butter having a fatty acid composition different from that of Examples 1-2. Specifically, the refined shea butter (produced by Uganda, manufactured by AMAX Co., Ltd.) having the fatty acid composition shown in Table 4 below, in which the fatty acid composition of the fat is 35.2% saturated fatty acid and 63.5% unsaturated fatty acid. Using. The emulsion liquid of Production Example 5 was prepared by adding the emulsifier to 30% by mass of the fats and oils at a blending ratio shown in Table 2 so that the total content of the oils and fats was 15% by mass. As shown in Table 2, in Production Example 5, by using together polyoxyethylene alkyl ethers having different HLBs as emulsifiers, it was possible to prepare an emulsion liquid by emulsifying fats and oils. In addition, the emulsion liquid of Production Example 5 had a small average particle diameter of the emulsion and was finely dispersed. And fiber D was obtained like fiber A except having added the emulsion liquid of manufacture example 5 to raw material viscose so that oil and fat content might be 3 mass% to cellulose.

  When the texture of the obtained fiber D was evaluated by a sensory (tactile sensation) test, the softness due to the oil and fat and the good feeling of slime could be confirmed.

(Production Example 6)
An emulsifier and the like were mixed with the purified shea butter having the fatty acid composition shown in Table 1 at a blending ratio shown in Table 5 below to prepare an emulsion liquid of Production Example 6. The emulsion liquid of Production Example 6 contains 20% by mass of fats and oils, and the total addition amount of the emulsifier to the fats and oils is 45% by mass of the total addition amount of the first emulsifier and the second emulsifier, and other emulsifier (PAG). Including it, it was 47% by mass. Further, 2 mass% of PAG (trade name “Newcol 3280” manufactured by Nippon Emulsifier Co., Ltd.) was added to the fats and oils.

(Production Example 7)
An edible beef tallow (edible beef tallow manufactured by Miyoshi Oil & Fats Co., Ltd.) was used as an oil and fat, and an oil and an emulsifier were mixed at a blending ratio shown in Table 5 to prepare an emulsion liquid of Production Example 7. Table 6 below shows the general fatty acid composition of edible beef tallow.

  The visual melting point of the edible beef tallow in a test tube was 46 ° C. Using a differential scanning calorimeter DSC3100SA (manufactured by Bruker AXS Co., Ltd.), the melting peak in the DSC method measured by heating from 10 ° C. to 80 ° C. at a heating rate of 1 ° C./min is 19.9 ° C. 32.1 ° C, 35.4 ° C, 38.9 ° C, 42.7 ° C, and 44.4 ° C. The difference between the highest peak temperature and the lowest peak temperature is 24.5 ° C. ° C.

(Production Example 8)
Using a shortening (shortening emblem manufactured by Miyoshi Oil & Fat Co., Ltd.) as the fat and oil, the fat and emulsifier and the like were mixed at the blending ratio shown in Table 5 to prepare the emulsion liquid of Production Example 8.

  The visual melting point of the shortening test tube was 40.5 ° C. Using a differential scanning calorimeter DSC3100SA (manufactured by Bruker AXS Co., Ltd.), the melting peak in the DSC method measured by raising the temperature from 10 ° C. to 80 ° C. at a heating rate of 1 ° C./min is 12.1 ° C. It had a plurality of peaks at 40.2 ° C. and 43.6 ° C., and the difference between the highest peak temperature and the lowest peak temperature was 31.5 ° C.

  As shown in Table 5 above, in Production Examples 6 to 8, by using together polyoxyethylene alkyl ethers having different HLBs as emulsifiers, the oils and fats were emulsified to prepare emulsion liquids. Further, by increasing the content of the emulsifier, the average particle size of the emulsion was as small as 0.2 μm or less and finely dispersed, and the low-temperature storage stability at 5 ° C. was also good.

Example 4
A fiber E was obtained in the same manner as in Example 1 except that the emulsion liquid obtained in Production Example 6 was added to the raw material viscose so that the fat content was 3% by mass with respect to cellulose.

(Example 5)
A fiber F was obtained in the same manner as in Example 1 except that the emulsion liquid obtained in Production Example 7 was added to the raw material viscose so that the fat content was 0.5 mass% with respect to cellulose.

(Example 6)
A fiber G was obtained in the same manner as in Example 1 except that the emulsion liquid obtained in Production Example 8 was added to the raw material viscose so that the fat content was 10% by mass with respect to cellulose.

  The microscopic observation results of the obtained fibers F and G are shown in FIGS. In the fibers F and G as well as the fibers A, B and D, the island portion in the fiber cross section is a minute region portion, and it is considered that finely dispersed oils and fats exist in the minute region.

In fibers A, F, and G, the presence of fats and oils in the rayon fibers and in the emulsions of Production Examples 4, 7, and 8 was confirmed by measuring the iodine value, and the results are shown in Table 7 below. It was.
(1) In the case of raw cotton, the moisture content of raw cotton is measured.
(2) The raw cotton or emulsion is precisely weighed so that the amount of oil and fat is about 0.1 g, and placed in an Erlenmeyer flask.
(3) Add 20 ml of cyclohexane and stir, and further add 10 ml of Wis reagent (acetic acid solution of iodine monochloride) and 20 ml of ion-exchanged water.
(4) Allow to stand at room temperature in a dark place for 30 minutes with occasional stirring.
(5) 20 ml of 10% by mass potassium iodide solution and 20 ml of ion-exchanged water are added and titrated with 0.1N sodium thiosulfate.
(6) When the color of the liquid becomes lighter, add a starch indicator and mark the end point where the color disappears.
(7) Do the same test without putting a sample, and make it a blank test.
(8) The iodine value is calculated using the following formula.
Iodine value of fiber [g / 100g] = (Blank test titration-titration) x 1.269 / Cotton dry mass Iodine number of fat and oil [g / 100g] = (Blank test titration-titration) x 1.269 / Amount of oil lipid In the above formula, 1.269 is a concentration conversion factor (amount [mg] of iodine corresponding to 1 ml of 0.1N sodium thiosulfate).

  Moreover, when the textures of the fibers E, F, and G were evaluated by a sensory (tactile feeling) test, softness due to the fats and oils and good sliminess were confirmed. In particular, the fibers E and G having a high cellulose content were excellent in slimy feeling.

  About Example 4 (fiber E), the washing durability in 30 washings was evaluated by the following method.

[Washing durability]
(1) Laundry Test sample: Raw cotton (Fiber E)
Washing method: Measured according to JIS L 0217 (103).
Detergent used: Neutral detergent (JAFET standard detergent)
Number of washings: 0, 1, 5, 10, 30 times (2) Oil and fat extraction (I) About 2.3 g of sample is precisely weighed and packed in a sample tube with a small hole in the bottom.
(II) The bottom hole is closed, and 10 ml of methanol as an extraction solvent is poured into the sample tube, allowed to stand for a certain period of time and allowed to permeate, and then the methanol treatment liquid is extracted by a press device.
(III) The extracted methanol is received in an aluminum cup set on a heater. The liquid on the cup is evaporated and the dried extract is weighed.
The above operations (II) to (III) were taken as one cycle, and extraction was repeated 7 times using the same sample. Measurement was performed at n = 2, and the average value was taken as the measurement result.
(3) Evaluation The results of the number of extractions and the extraction rate during one wash are shown in FIG. As can be seen from FIG. 11, it was found that the fats and oils in the fibers are not extracted all but extracted gradually. Since it was found that the fats and oils were almost extracted by 7 times of extraction, the oil and fat extraction rates were compared by the number of washings using the data obtained by repeating the extraction 7 times, and the washing durability was evaluated.

  FIG. 12 shows the oil and fat extraction rate when the extraction operation is repeated 7 times for every washing of the fiber E of Example 4. From FIG. 12, since the process oil applied in the refining process is attached to 0.2% of the raw cotton after washing 0 times (blank), the amount of oil extracted is increased, but it is extracted before and after washing. It was confirmed that the fat and oil (shea butter) was present in the fiber without falling off even after washing 30 times.

(Example 7)
In the same manner as in Example 3, an oil-containing rayon fiber (fineness 1.1 dtex, fiber length 38 mm) containing 3% by mass of shea butter with respect to cellulose was produced. The obtained fat and oil-containing rayon short fiber (fineness 1.1 dtex, fiber length 38 mm) 35% by mass and polyacrylic short fiber (fineness 1.0 dtex, fiber length 38 mm) 65% by mass are blended to spin the hair count of 80. I got a thread. The obtained spun yarn, a cation-dyeable polyester long fiber 84 dtex (48 filaments) having a cross-sectional mix (a mixed cross-section of a round cross section and a hexagonal cross section), and polyurethane elastic fiber 28 dtex, having a hook diameter of 34 mm and a gauge number We knit with 28 gauge, 40 wells / 吋, 62 courses / 吋, and knit into a bear knitted circular knitted fabric. Next, this living machine was set with a pin tenter at 180 ° C. for 40 seconds. Next, after refining and drying, the polyester long fiber and the polyacrylic short fiber side are dyed with a black cationic dye (Kayaacryl Black R-ED, 8% owf manufactured by Nippon Kayaku Co., Ltd.) at 110 ° C. for 40 minutes, The rayon fiber side was dyed with a black reactive dye (Sumitix Black B, 4% owf manufactured by Sumitomo Chemical Co., Ltd.) at 60 ° C. for 40 minutes to finish. The finished fabric has a width of 155 cm, a basis weight of 145 g / m ² , 48 wells / 吋, 61 courses / 吋, the fiber mixing ratio in the entire knitted fabric is 18% by mass of oil-containing rayon fiber of the present invention, 34% by mass of polyacrylic fiber, They were 39% by mass of cationic dyeable polyester long fibers and 10% by mass of polyurethane elastic fibers.

(Comparative Example 2)
A knitted fabric was obtained in the same manner as in Example 7 except that ordinary rayon fiber was used instead of the oil-and-fat-containing rayon fiber.

  The texture of the knitted fabric of Example 7 and Comparative Example 2, moisture absorption exothermic property, time (quick drying) when the residual moisture content is 30% or less, and the heat retention rate were evaluated as follows.

(1) Texture About the texture, sensory evaluation was performed in the following five stages. Specifically, sensory evaluation was performed by 10 subjects using a five-point point accumulation method.
5 points: very soft and soft texture 4 points: smooth and soft texture 3 points: normal and soft texture 2 points: little soft and soft texture 1 point ： No slime, hard texture, inferior

(2) Moisture absorption exothermic property A sample having a length of about 10 cm and a width of about 10 cm is attached to a sealed container, and a surface thermometer sensor is attached and read with a recorder so that the temperature of the sample can be measured. After starting the sample temperature measurement, dry air (humidity of 10% RH or less) passed through a silica gel container was fed into an indoor atmosphere at 20 ° C. in the measurement chamber to dry the sample. The sample surface temperature is the highest while air of about 90% RH passed through ion-exchanged water is fed for about 30 minutes against the surface temperature A when the sample is dried for 30 minutes or more and the sample temperature is stabilized. The reached temperature B was read, and the difference B−A was defined as the hygroscopic heat generation performance (° C.).

(3) Time for residual moisture content to be 30% or less (quick drying)
A sample having a length of about 10 cm and a width of about 10 cm was left in an atmosphere at 20 ° C. and 65% RH for 24 hours, and then the mass G (g) was read. Water is dropped, the mass Go (g) immediately after dropping is read, and the mass Gx (g) for each elapsed time after dropping is read. The time (minutes) when the residual moisture content (%) determined by the following formula was 30% with respect to the mass immediately after the dropping was determined.
Residual moisture content (%) = {(Gx−G) / (Go−G)} × 100

(4) Insulation rate Using a precise and rapid thermophysical property measuring instrument “Thermo Lab II” (KES-F7) from Kato Iron Works, put the sample in contact with the hot plate surface at a hot plate temperature of 40 ° C. Warmed up for 5 minutes to stabilize. After confirmation of the stable state, measurement was started and the power consumption W for 60 seconds was read. Separately, warming was performed at a hot plate temperature of 40 ° C. for 5 minutes without attaching a test piece to the hot plate, and after confirming the stable state, the measurement was started and the power consumption Wo for 60 seconds was read. Using the power consumption values Wo and W obtained in these manners, the heat retention rate (%) was obtained by the following formula.
Thermal insulation rate (%) = {(Wo-W) / Wo} × 100

  As a result of the above-mentioned sensory evaluation, Example 7 was a black bare tentacle knitting with a very soft texture and full of luxury. The point accumulation of the texture was 5 points for 8 out of 10 and 4 points for 2 and a total score of 48 points. Further, the texture after 30 washings was evaluated in the same manner, but there was almost no change in the texture, and the fabric had extremely high washing durability. The knitted fabric of Example 7 had a hygroscopic exothermic property of 2.3 ° C., a heat retention rate of 18.4%, and a quick drying property of 32 minutes. Further, the bursting strength, water absorption, stretchability, and dyeing fastness were at a level with no problem. When the knitted fabric of Example 7 was used, a wonderful winter innerwear was obtained which was light and warm and had such a texture and high functionality.

  On the other hand, the knit of Comparative Example 2 was hard, poor in sliminess, and inferior in texture. As for the details of the evaluation of the texture, 1 out of 10 people was 3 points, 7 people were 2 points, 2 people were 1 point, and the total score was 19 points. The texture was not good and was unsatisfactory as a winter innerwear fabric.

(Example 8)
In the same manner as in Example 3, an oil-containing rayon fiber (fineness 1.1 dtex, fiber length 38 mm) containing 3% by mass of shea butter with respect to cellulose was produced. The obtained fat and oil-containing rayon short fibers (fineness: 1.1 dtex, fiber length: 38 mm) 60% by mass and cotton (cotton) short fibers (fineness: about 2.5 dtex, fiber length: about 38 mm) were blended, and the cotton count 30 I got the spun yarn. This spun yarn, polyamide long fiber (nylon 6) 44 dtex (17 filaments), and polyurethane elastic fiber 22 dtex were knitted and knitted into socks to obtain a living machine. Next, in the obtained raw machine, the polyamide fiber side was dyed with a red metal-containing acid dye (Nylosan Red F-4BL manufactured by Huntsman, 3% owf) at 98 ° C. for 20 minutes, and then the rayon short fiber and the cotton short fiber were dyed. The blended yarn side of the fiber was dyed with a red reactive dye (Sumitix Supra Red E-XL, 3% owf, manufactured by Sumitomo Chemical Co., Ltd.) at 60 ° C. for 40 minutes, set at 120 ° C., and finished. The fiber mixing ratio in the finished socks was 47.4% by mass of oil and fat-containing rayon fibers, 31.6% by mass of cotton fibers, 17.9% by mass of polyamide fibers, and 3.1% by mass of polyurethane elastic fibers.

(Comparative Example 3)
Socks were obtained in the same manner as in Example 8 except that ordinary rayon fibers were used instead of the oil-and-fat-containing rayon fibers.

  The socks of Example 8 and Comparative Example 3 were evaluated for texture, hygroscopic heat generation and heat retention by the above-described evaluation methods.

  As a result of sensory evaluation, Example 8 was a red sock with a very soft texture and a high-class feeling. As for the details of the texture, 9 out of 10 people scored 5 points, and 1 person scored 4 points, giving a high score of 49 points in total. Further, the texture after 30 washings was evaluated in the same manner, but there was almost no change in the texture, and the fabric had extremely high washing durability. The sock of Example 8 had a hygroscopic exothermic property of 2.7 ° C. and a heat retention rate of 24.6%. Moreover, there were no problems with respect to bursting strength, water absorption, stretchability, dyeing fastness, and the like. It was a great sock that was perfect for fall and winter, with a light, warm, soft texture and excellent heat retention.

  On the other hand, the sock of Comparative Example 3 was hard, poor in sliminess, and inferior in texture. As for the details of the texture, 8 out of 10 were 2 points, 2 were 1 point, and the total score was 18 points. It was an ordinary sock with a soft touch.

  The oil and fat-containing rayon fiber of the present invention can be used for fiber structures such as spun yarn, knitted fabric, woven fabric, non-woven fabric, tow, filament, batting (padded cotton), paper and the like. In addition, the fiber structure of the present invention can be used for clothes, cosmetic puffs, hygiene materials such as absorbent bodies, wet tissues, wet sheets such as interpersonal / objective wipers, water-degradable sheets, dry wipers, filters, and the like.

Claims (9)

A fat-containing rayon fibers fat is mixed into viscose in rayon fibers,
The fat / oil contains at least one fatty acid component selected from fatty acids and glycerin esters thereof, and is solid at 20 ° C.,
The fat and oil-containing rayon fiber, wherein the cellulose and the fat and oil in the viscose rayon fiber are in an incompatible state, and the fat and oil are finely dispersed in the cellulose.   The fat-and-oil-containing rayon fiber according to claim 1, wherein the fat is a naturally-derived fat and oil having a melting point of 20 to 82 ° C.   The fat-and-oil-containing rayon fiber according to claim 1, wherein the fat is shea butter.   The fat and oil-containing rayon fiber according to any one of claims 1 to 3, wherein a blending amount of the fat is in a range of 0.5 to 15% by mass with respect to cellulose. It is a manufacturing method of oil and fat content rayon fiber given in any 1 paragraph of Claims 1-4,
An oil and fat containing at least one fatty acid component selected from fatty acids and glycerin esters thereof and solid at 20 ° C. is added with an emulsifier having an HLB of 16 to 19.5 and an emulsifier having an HLB of 6 to 12, Prepare an emulsion with a particle size of 0.02 to 2 μm,
A viscose solution for spinning is prepared by mixing the emulsion solution with a viscose stock solution containing cellulose,
A method for producing an oil-containing rayon fiber, wherein the spinning viscose liquid is extruded from a nozzle, spun, and coagulated.   The fiber structure containing the oil-fat containing rayon fiber of any one of Claims 1-4. Containing 10 to 90% by mass of the oil-containing rayon fiber,
The fiber according to claim 6, wherein at least one fiber selected from the group consisting of polyester fiber, cationic dyeable polyester fiber, polyacrylic fiber, polyamide fiber, polyurethane-based elastic fiber, cotton and wool is combined as the other fiber. Structure. The fat is shea butter,
The oil-and-fat-containing rayon fiber contains 10 to 30% by mass, polyacrylic fiber 30 to 47% by mass, cationic dyeable polyester fiber 30 to 45% by mass, and polyurethane elastic fiber 3 to 15% by mass. Or the fiber structure of 7.   The fiber structure according to any one of claims 6 to 8, wherein the fiber structure has a form selected from the group consisting of spun yarn, knitted fabric, woven fabric, and nonwoven fabric.