JP2005042250A - Leather-like sheet and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leather-like sheet having a high-class touch feeling with proper tack feeling while having moist feeling, further having peculiar feeling characterized by the surface touch giving soft feeling, and excellent fastness of color; and to provide a method for producing the leather-like sheet. <P>SOLUTION: The leather-like sheet contains an elastic polymer in the inside of a fiber-interlaced body, and has a low molecular weight polyurethane, a silicone resin, a water repellent, a softener and a silk protein-based material on a napped surface of the leather-like sheet having the nap composed of ultrafine fiber at least on one surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a unique texture characterized by a touch that makes the leather-like sheet feel both soft and soft without compromising the fullness of the leather-like sheet. Apparel that has a wet appearance and exhibits good dyeing fastness, and that can be touched by the user's skin such as upper and lining of shoes, gloves, clothing, bags, and belts. The present invention relates to a leather-like sheet suitable as an application material.

  In so-called suede-like, nubuck-like, and semi-silver-like leather-like sheets with napped surfaces, the touch of the surface has a great influence on the texture of the product, and as a result, the value of the product is significantly affected. As a result, techniques for applying various touches such as silk touch and silicone touch have been proposed. In particular, various textures such as sliminess, smoothness, and softness have been studied for the realization of the most luxurious touch in suede-like and nubuck-like leather-like sheets. For example, a method of treating the surface of a standing fur leather-like sheet with a mixture of a softening agent and a silk protein material has been proposed as a method for realizing a so-called silk touch texture (see, for example, Patent Document 1). The leather-like sheet obtained by this method is excellent in terms of texture, but particularly in the case of a leather-like sheet dyed, it has the disadvantage that the dyeing fastness, particularly the dyeing fastness when wet, is markedly reduced. . This is one of the important uses of suede or nubuck leather-like sheets, which is a very big problem in applications where it is inevitable to directly touch other textile products such as clothing and shoes. When this leather-like sheet is used for such applications, there is a restriction that applicable colors are limited to light colors.

JP 2002-161482 A

  The present invention solves all the problems as described above, and has a moist touch that can be expressed as a slimy feeling and a smooth touch, and also has a touch that makes you feel soft. It has a unique texture and has a wet appearance, that is, it has an appearance that gives a considerable amount of oil, and is also excellent in dyeing fastness and is suitable for clothing and shoes. The purpose is to obtain a leather-like sheet that does not cause problems such as significant contamination of other textile products with colorants such as dyes.

  As a result of intensive studies to solve such problems, the present inventors give not only softeners and silk protein substances to the surface of leather-like sheets but also low molecular weight polyurethanes, silicone resins, and water repellents. Thus, the present inventors have found that such drawbacks are greatly improved, and have achieved the present invention.

  That is, the present invention provides a low molecular weight polyurethane, a silicone resin, and a water repellent agent on the raised surface of a leather-like sheet in which an elastic polymer is contained in the fiber entangled body and at least one surface has raised fibers made of ultrafine fibers. A leather-like sheet characterized by the presence of a softener and a silk protein material. The present invention also provides a low molecular weight polyurethane, a silicone resin, and a water repellent agent on the raised surface of the leather-like sheet having raised fibers made of ultrafine fibers on at least one surface of the leather-like sheet containing the elastic polymer in the fiber entangled body. The method for producing a leather-like sheet is characterized in that at the time of applying the softening agent and the silk protein material, at least a low molecular weight polyurethane and a silk protein material are separately provided.

  According to the present invention, while having a unique texture characterized by a high-class hand feeling that is moist but moderately tacky, and a touch that also feels soft, migration, fastness to dyeing friction, etc. It is possible to obtain a leather-like sheet having excellent characteristics. The leather-like sheet obtained by the present invention requires both a differentiated texture and a high level of dyeing fastness, such as clothing and footwear, because of its excellent texture and non-contamination. It is particularly suitable for various applications.

The present invention is described in further detail below.
The leather-like sheet in the present invention contains an elastic polymer inside the fiber entangled body and has napped fibers made of ultrafine fibers on at least one surface, and appropriately determines the average napped length and the number of napped fibers per unit area. Not only various raised states obtained by selection, but also a raised state in which a part having raised parts and a part having substantially no raised parts are mixed, that is, the appearance is so-called suede, nubuck, or semi-silvery. In the present invention, the leather-like sheet includes any napped state. The ultrafine fibers of the present invention are made of conventional fiber-forming polymers such as polyamide, polyester, polyacrylonitrile, polyolefin and the like, and are produced by a conventionally known method such as a direct spinning method, a mixed spinning method, or a composite spinning method. . The fineness is preferably about 0.5 dtex or less, more preferably about 0.3 dtex or less, and even more preferably, napped fibers of leather-like sheets are formed with ultrafine fibers having an average single fineness of about 0.3 to 0.0001 dtex. By doing so, even if there is a mixture of smoothness and fineness of the napped formation part, and even parts where virtually no napping is formed, a high-class feeling and elegance that can be obtained comprehensively as a whole surface including them Such an excellent appearance can be obtained, and the tactile sensation is preferably used because the napping is soft and the smoothness of the napped portion can be realized.

  From the viewpoint of the texture as a leather-like sheet, the fiber-forming polymer is more preferably polyamide or polyester, and most preferably polyamide. When a fiber entangled body made of polyamide or polyester is used as the ultrafine fiber, at least a portion of the obtained leather-like sheet made of the fiber entangled body is made of a metal-containing complex dye, acid dye, disperse dye, sulfur dye, A method of coloring with a dye mainly composed of at least one dye selected from the group consisting of dyed dyes and sulfur vat dyes, or a method of incorporating a pigment into a fiber-forming polymer from the spinning stage alone or in combination In addition, not only is the background or the portion where there is virtually no napping present on the surface of the leather-like sheet surface colored, but also the back surface of the leather-like sheet or the end surface when cut is the desired color tone. A leather-like sheet colored on the surface is obtained. The dyeing method is not particularly limited, for example, a known dyeing method using a known dyeing machine, such as a dip dyeing method, a coating method, etc., but in the case of applications such as clothing, shoes, gloves, or sofa interiors. The dyeing method is preferred in terms of texture and fastness, and as the dyeing machine, a wine dyeing machine, a circular dyeing machine, a dash line dyeing machine, a jigger dyeing machine and the like are usually used as dyeing machines, In particular, when high-temperature and high-pressure dyeing is required, or in the case of dyeing that includes an oxidation-reduction reaction, a sealed circular dyeing machine is preferably used. Of these dyes, sulfur dyes, vat dyes and sulfur vat dyes are excellent in fastness to washing because the dyes themselves are insoluble in water, and are used for clothing, shoes, gloves, interiors such as sofas, etc. It is preferable to use it for applications that may come into contact with water in the assumed usage environment such as the daily life of the user. In addition, as a method for coloring ultrafine fibers, one of the methods in which a fiber-forming polymer can contain a pigment from the spinning stage can also be adopted, in consideration of physical properties such as strength required for the napped portion and color tone. Also, this method alone or a method based on a combination with the above-described dyeing method is preferably a coloring method. In particular, in the configuration of the present invention, it is preferable to perform a coloring treatment with a dye because various colors can be provided while suppressing a decrease in the fastness to friction of the leather-like sheet surface.

  The fiber entangled body is not particularly limited as long as the texture as a leather-like sheet, the mechanical properties and durability in the intended use can be realized, and the type of fiber used is the same type of fiber as the ultrafine fiber forming napped Even if the fineness of the fibers used is the same as that of the ultrafine fibers forming the napped fibers, the fineness is different, that is, the fineness is smaller than that of the ultrafine fibers, or greater. However, it is not necessary to be of a single type or a single fineness, but when an efficient production method is to be devised, it is preferable that the fineness is the same as that of the ultrafine fiber. For example, in a sea-island type composite fiber obtained by a mixed spinning method or a composite spinning method, a fiber-forming polymer is used as an island component, and the island component polymer is removed as a sea component by dissolving or decomposing it without damaging it. It is possible to remove the sea component at any stage from the formation of the fiber entanglement to the formation of napped hair by using a polymer that can be used, or the same as the island component as a component of the split type composite fiber. By using a method such as peeling at the interface between different types of polymers at a desired stage by using the other polymer as the other component with the polymer of which the adhesiveness with this polymer is appropriately selected. A fiber entangled body can be obtained. After producing a fiber entangled body from a sea-island type composite fiber or a split type composite fiber first, a fiber entangled body made of ultrafine fibers can be produced by modifying the fibers into ultrafine fibers at any stage. The step of modifying into ultrafine fibers may be before or after the elastic polymer as described later is contained in the fiber entanglement, but preferably after the elastic polymer is contained. By generating the fibers, it is possible to make the contained elastic polymer and the ultrafine fibers not substantially adhered to each other, thereby suppressing the curing of the texture of the leather-like sheet.

  As the elastic polymer to be contained in the fiber entangled body, any known polymer such as styrene elastomer, olefin elastomer, vinyl chloride elastomer, urethane elastomer, polyester elastomer, polyamide elastomer can be used. Although there are sensibility aspects such as texture when used as a leather-like sheet that is a composite with a fiber entanglement, strength aspects such as breaking strength, tearing strength, etc., characteristics in environments that are expected to be used as materials, In various factors such as adhesion to each material to be provided on the napped surface, which will be described later, and the price as a resin, urethane elastomers are most preferable, and a specific example is polyester having an average molecular weight of 500 to 3000. Diol, polyether diol, polyester ether Mainly at least one organic diisocyanate selected from at least one polymer diol selected from all, polylactone diol, polycarbonate diol, etc., aromatic diisocyanate, aliphatic diisocyanate or alicyclic diisocyanate, if necessary. Organic diisocyanates blended with organic diisocyanates or organic triisocyanates, and compounds having two or more active hydrogen atoms such as low molecular diols, low molecular diamines, hydrazines, hydroxyamines, etc. by solution polymerization, melt polymerization, bulk polymerization, etc. Polyester polyurethane obtained by polymerization, polyether polyurethane, polyester ether polyurethane, polylactone polyurethane, polycarbonate polyurethane and the like. These polyurethanes can be dissolved in a suitable solvent, or dispersed in a dispersion medium to form a polymer solution, then impregnated into a fiber entanglement, treated with a coagulation solution containing a non-solvent and wet coagulated, or dried, etc. By removing the solvent or the dispersion medium by dry solidification, a fibrous sheet can be obtained as a base portion of the leather-like sheet of the present invention having a structure in which an elastic polymer is contained inside the fiber entangled body. .

  The leather-like sheet of the present invention can be produced by forming napped fibers made of ultrafine fibers on at least one side of the fibrous sheet thus obtained. There are no particular limitations on the formation state of the nap consisting of ultrafine fibers, and the formation method thereof, and as described above, various nap states obtained by appropriately selecting the average nap length and the number of naps per unit area Not only a raised state in which a portion having raised hair and a portion having substantially no raised hair are mixed, that is, any raised state that is expressed as a so-called suede tone, nubuck tone, or semi-silver tone as its appearance. Are also included in the leather-like sheet in the present invention, and the formation method thereof includes raising the surface of a fiber sheet in which at least the fibers constituting the surface portion are made of ultrafine fibers, or fibers made of extrafine fibers prepared separately Examples of the method include raising the surface of the fibrous sheet to form ultrafine fiber napping, and then bonding it to at least one surface of the fibrous sheet. Examples of the raising method include slicing or buffing with sandpaper, and raising with a cloth. The thickness of the leather-like sheet is preferably about 0.3 to 2.0 mm when used as a material for the intended purpose, but is particularly limited in exhibiting the effects of the present invention. It is not a thing. In addition, in order to adjust the raised state, before the raising treatment, a treatment liquid containing a solvent of the contained elastic polymer is applied, and a part of the elastic polymer existing in the surface layer portion is dissolved and fixed. It is also preferable to apply or coagulate a solution or dispersion of any of the elastic polymers described above. Further, as the surface state of the leather-like sheet preferably used in the present invention, the nappings made of ultrafine fibers are only partially present, and the coating layer made of an elastic polymer is present in the part where the nappings are not present. One of them is the so-called semi-silvery one. As a method of making the leather-like sheet into a semi-silver-like surface state, an appropriate amount of an elastic polymer solution or dispersion is applied to the surface of the leather-like sheet in which ultrafine fiber napping is formed on the entire surface as described above. Can be obtained. However, in order to obtain a semi-silver tone, the amount of the solid content of the elastic polymer and its application state are important. When the elastic polymer is applied in a substantially discontinuous state, the elastic polymer film is not coated. In this case, when the essential treatment substances in the present invention are applied to the surface, most of the treatment substances may be fixed to the leather-like sheet surface. Therefore, it is difficult to obtain the texture and appearance intended by the present invention, and problems such as the processing substances being easily transferred to other materials occur.

Next, a low molecular weight polyurethane, a silicone resin, a water repellent, a softening agent, and a silk protein material are applied to the leather-like sheet colored with the dye or pigment of the present invention, or the uncolored leather-like sheet.
The low molecular weight polyurethane used in the present invention is a polyurethane having a number average molecular weight of 1000 to 10,000, and more preferably a polyurethane having a number average molecular weight of 2500 to 7500. If the number average molecular weight is less than 1000, the blend may have mobility, or the urethane itself may migrate during contact, and the dyeing friction fastness of the leather-like sheet may be greatly reduced. In addition, when the number average molecular weight exceeds 10,000, the texture of the leather-like sheet is cured, the balance is lost, or the naps of the ultrafine fibers are converged or hardened, and the nap feeling of the naps is lost. Etc., the commercial value of the leather-like sheet tends to be impaired. The low molecular weight polyurethane of the present invention is preferably a low molecular weight polyurethane obtained from a polyol mainly composed of polyalkylene glycol, a polyisocyanate mainly composed of aliphatic diisocyanate and a low molecular polyamine mainly composed of N-alkyldiethanolamine. . As a polyol component of the low molecular weight polyurethane, it is possible to use a polyol mainly composed of polyester glycol instead of using a polyol mainly composed of polyalkylene glycol. However, in terms of durability, the main component is polyalkylene glycol. Is preferred. Of course, a part of the above three components may be replaced with other components within a range not impairing the object and effect of the present invention. The polyalkylene glycol is at least one polyalkylene glycol selected from polyethylene glycol, polypropylene glycol, polyhexamethylene glycol, polyethylene propylene glycol, polytetramethylene glycol, polyalkylene ether glycols, etc., and the number average molecular weight is 200-3000 are preferred, more preferably those having a number average molecular weight of 350-2500, and the aliphatic diisocyanates include hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate). And at least one aliphatic diisocyanate selected from, for example, N-alkyldiethanolamine And at least one N-alkyldiethanolamine selected from N-methyldiethanolamine, N-ethyldiethanolamine, and the like. The mass ratio of polyalkylene glycol, aliphatic diisocyanate, and N-alkyldiethanolamine in the low molecular weight polyurethane is preferably 1: 1.5-3: 0.5-2. The average molecular weight of the low molecular weight polyurethane can be easily set to a predetermined value by appropriately selecting the mass ratio and the average molecular weight of the polyalkylene glycol.

  The silicone resin used in the present invention can be used as long as it is available as various processing agents such as a texture processing agent and a softening agent for textile products, or any processing agent comprising a compound similar to this. When it is used as a compound when it is applied to a sheet, it is compatible with other substances mixed in the compound, matching with viscosity, etc. Silicone is preferred. By using such a silicone resin in combination with a low molecular weight polyurethane, sticking of the napping by the polyurethane existing in the napping portion of the leather-like sheet is suppressed, and the nap feeling can be maintained. In addition, as the water repellent, a fatty acid amide compound, alkylmethylol amide, methylhydrogenpolysiloxane, or a fluorocarbon group such as perfluoroalkyl or perfluorohexacenyl in the side chain, polyacrylic acid A treatment agent comprising a water repellent, an oil repellent, an antifouling agent for a textile product such as a fluorine-containing polymer having an ester or methacrylic acid ester polymer in the main chain, or a similar compound. Any of them can be used, but fatty acid amide compounds are particularly preferred from the viewpoint of less texture hardening as leather-like sheets. Of these, fatty acid amide epichlorohydrin quaternary salts are the best. The presence of such a water repellent greatly contributes to improving the color fastness because it reduces the amount of moisture absorbed into the leather-like sheet.

  As the silk protein-based material used in the present invention, any of water-soluble or water-insoluble protein derived from silk or a partial hydrolyzate thereof can be used. Specific examples include water-solubilized silk fibroin, a water-soluble partial hydrolyzate of silk fibroin, and water-insoluble silk powder obtained by mechanically pulverizing silk fibers. However, in the case of silk powder, if the amount of application per unit area is increased, the white fine powder of silk becomes more conspicuous and the leather-like sheet tends to appear white. When such whitened appearance is disliked, water-solubilized silk fibroin and / or a water-soluble partial hydrolyzate of silk fibroin is preferably used as the silk protein-based material. More preferably used.

  Examples of the water-solubilized silk fibroin include those obtained by dissolving silk fibroin in an aqueous solution of calcium chloride, calcium nitrate, lithium bromide, dichloroacetic acid and the like. Examples of the water-soluble partial hydrolyzate of silk fibroin include, for example, those obtained by partially hydrolyzing the above silk fibroin with an enzyme (protease), or an acid such as an alkali such as sodium hydroxide or an acid such as sulfuric acid. And neutralized after mechanical hydrolysis. In particular, as the water-soluble partial hydrolyzate of silk fibroin, those having an average molecular weight of 100 to 10,000, preferably an average molecular weight in the range of 500 to 3,000 are suitably used from the viewpoint of touch and workability.

  As the softener used in the present invention, various softeners generally used in the fiber-related field are considered in consideration of the affinity with the ultrafine fibers and the elastic polymer constituting the leather-like sheet and the softening effect. Appropriate ones can be selected and used. Examples of the softener that can be used in the present invention include various silicone softeners such as alkyl silicone, amino-modified silicone, amide-modified silicone, and epoxy-modified silicone, and amide-based softener such as polyamide and fatty acid amide. Agents, polyhydric alcohol softeners, and the like, and one or more of these can be used. Among them, in the present invention, a silicone-based softener and / or a polyamide-based softener, particularly a polyamide-based softener, is preferably used from the viewpoint of the softening effect with respect to the applied amount and workability. Preferred examples of such softeners include alkyl silicone softeners such as “Dick Silicone Softener 120” manufactured by Dainippon Ink and Chemicals, and amino-modified silicones such as “Nikka Silicon AM-204” manufactured by Nikka Chemical. And polyamide-based softeners such as “Lacset K-150” manufactured by Shinto Kasei Co., Ltd.

The total amount of low molecular weight polyurethane, silicone resin, water repellent, softening agent, and silk protein-based material applied depends on the napped state of the surface of the leather-like sheet and the area occupied by the napped portion, but the leather-like sheet 1 m ² 1-50 g per unit, preferably 5-40 g, more preferably 10-30 g. If the amount is less than 1 g, a sufficient texture improving effect is not observed, and if it exceeds 50 g, migration of the treatment agent itself starts to be a problem. The ratio of the applied amount of low molecular weight polyurethane, silicone resin, water repellent, softener, and silk protein-based material is compatible with the moist feeling of adhesion as intended by the present invention and the feel of sliding, and In order to achieve a unique texture characterized by a touch that also feels soft, it is preferably in the range of 10-50 / 1 to 10/1 to 2/10 to 30/10 to 60. It is particularly preferably in the range of ˜30 / 2 to 5/1 to 2/15 to 25/20 to 50, but depending on the desired touch and texture, it may deviate somewhat from the above ratio, or other processing agents may be added. Although it can be used in combination, the ratio of the low molecular weight polyurethane is the most important as a ratio to the total applied amount. When the ratio of the low molecular weight polyurethane to the total applied amount decreases, the color fastness decreases, and the texture and appearance also lose the unique wet feeling and the product value decreases. Since it becomes stronger and sticks, the commercial value is lost. Therefore, it is preferable to determine the ratio while sufficiently checking these characteristics.

  As other substances, when the ratio of the silicone resin to the total applied amount, and thus the applied amount itself, decreases, the fixation of the fibers by the low molecular weight polyurethane becomes stronger, the feeling of napping becomes poorer, and the tackiness also becomes stronger, especially the lining, It is unsuitable as a material for clothing such as gloves and clothing from the viewpoint of detachability. On the other hand, if the amount of silicone resin applied is too large, problems such as oil stains and stains due to significant transfer of the silicone resin to other materials in contact with the leather-like sheet occur. Moreover, when there is little application amount of a water repellent with respect to the total application amount, hygroscopicity will become strong, and especially the dyeing fastness at the time of moisture will fall large. On the other hand, if the amount is too large, when the application treatment to the leather-like sheet of the present invention is performed, the state of adhesion of the treatment liquid becomes unstable, which may cause application amount unevenness. If the amount of softener applied is small relative to the total amount applied, the surface feel becomes hard and the soft texture that is the object of the present invention cannot be obtained. The object of the present invention cannot be achieved. If the amount of silk protein substance applied is small relative to the total amount applied, the stickiness will be emphasized, resulting in a texture with a low commercial value. On the other hand, if the amount is too large, the surface touch will become dry and the moist feeling will disappear. The value goes down.

  In the present invention, the method for imparting each of the above-mentioned substances to the leather-like sheet is not particularly limited, and a method for immersing the leather-like sheet in a blended solution containing two or more kinds of substances prepared in advance, a leather-like sheet A method of spray-coating the compounded liquid on the surface, a method of transferring and applying the compounded liquid to the leather-like sheet surface with a roll such as a gravure, a method of applying the compounded liquid to the leather-like sheet surface with a coater such as a knife or a bar, leather-like A method of applying the sheet surface by bringing it into contact with a slit (lip) to which the compounding liquid is supplied can be exemplified, but the compound can be concentrated on the leather-like sheet surface that is dominant to the touch, and more efficient. In particular, since the unique texture desired by the present invention can be imparted, only a small amount of low concentration and low viscosity compounding liquid such as spray coating, gravure coating, etc. A uniform possible coating method is also applied in the portion is preferably a local, inter alia be very uniformly mottled without imparting, moreover transfer coating by gravure roll or the like because it can accurately quantify the coating weight is most effective.

  In the present invention, the low molecular weight polyurethane is imparted at least between the layer formed by the silk protein-based material and the surface layer of the leather-like sheet, so that excellent touch that makes the dyeing fastness and flexibility feel as well. More preferable in terms of both feeling and texture. In other words, by being applied as an intermediate layer, while suppressing the migration of the dye from the leather-like sheet surface to other materials, the component that promotes the transfer of the dye will penetrate into the leather-like sheet. Can be prevented. In addition to being effective in improving the fastness to dyeing, the silk protein material can effectively relieve the tack feeling of low molecular weight polyurethane and give it a moist feeling of adhesion and a slippery touch. This has the effect of smoothly attaching and detaching shoes, clothes or gloves using the leather-like sheet of the invention. Even when both are mixed, a certain effect can be obtained, but a particularly high effect can be obtained by the state of being given separately as described above.

  In the present invention, the low molecular weight polyurethane is mainly present between the layer formed by the silk protein-based material and the surface portion of the fibrous sheet. The compounded treatment liquid containing at least the low molecular weight polyurethane is used as the fibrous sheet surface. A method of applying a blending treatment solution containing at least a silk protein-based substance after the application to can be exemplified. At this time, the silicone resin, the water repellent and the softening agent are not particularly affected at any point in the process of sequentially applying these blending treatment liquids. Of course, it can be applied independently of the compounding treatment solution containing low molecular weight polyurethane and the compounding treatment solution containing silk protein substances at any time, but it is easy to apply and control the application ratio. From the standpoint of ease of use, a method of applying by mixing in at least one of a blending treatment liquid containing at least a low molecular weight polyurethane, a blending treatment liquid containing at least a silk protein material, or both is preferably employed. . The low molecular weight polyurethane is particularly preferably a blended treatment liquid mixed with a silicone resin or a silicone-based softening agent for the reasons described above.

  Further, in the present invention, it is also preferable to apply low molecular weight polyurethane, silicone resin, water repellent, softener and silk protein-based material to the raised surface of the leather-like sheet, and then immerse in water and re-dry. This is one of the embodiments. By such treatment, the dispersant added in order to stably disperse the silk protein substance or the like in the compounding treatment liquid or the excess part of the softening agent is removed and optimized, and as a result It is possible to further improve the color fastness while maintaining the unique texture.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by this.

  Various numerical values in this embodiment are obtained by the following method. In addition, unless otherwise indicated, the part and% shown in an Example are a mass part and the mass%.

Average fineness The average fineness is appropriately observed at a magnification of several hundred to several thousand times using the density of the polymer used for fiber formation and a scanning electron microscope. It is calculated from the fiber constituting the sheet or the cross-sectional area of the ultrafine fiber.

Texture 5 subjects touched the surface of the leather-like sheet with their hands, and then gently grasped and evaluated according to the following evaluation criteria. If only 2 or less evaluations were collected for any item, 2 subjects The evaluation result of the leather-like sheet was determined based on the worse result among the evaluation items, and when the evaluation of three or more people was collected.
[Texture Evaluation Criteria]
○: A slimy and moist feeling is sufficiently felt and flexible.
Δ: Either a slimy feeling, moist feeling or flexibility is not sufficiently felt.
×: Nullness, moistness, and flexibility are not sufficiently felt, and it seems that no special treatment is performed.

Detachment feeling 30 cm wide and 40 cm long leather-like sheets are sewn into a cylindrical shape with the treated surface inside, creating a cylinder with a circumference of 30 cm and a length of 40 cm, and five subjects wearing a cotton long-sleeved shirt Evaluate the ease of threading when you pull out the sleeve and then pull out the sleeve according to the following criteria. If only two or less evaluations are collected for any item, the evaluation of the two people gathered The result of the worse one, and when three or more evaluations were collected, the item was regarded as the evaluation result of the leather-like sheet.
[Evaluation criteria for attachment / detachment feeling]
○: Can pass smoothly.
Δ: Although there is a slight feeling of catching, it can be passed without any particular problem.
X: A catch is felt strongly and it is hard to pass.

Appearance Wet feeling felt when five subjects visually observe the surface of a 15cm square leather-like sheet was evaluated according to the following criteria, and if only two or less evaluations were collected in any item, two people The evaluation result of the leather-like sheet was determined based on the worse result among the evaluation items, and when the evaluation of three or more people was collected.
○: It seems to have an apparent wet-like appearance.
Δ: Although there is a slight wet feeling, it is not a feeling that can be called a feature.
X: Little or no wet feeling is felt.

Transferability After touching a 15cm square leather-like sheet surface several times by hand, the feeling of stickiness and slipperiness remaining on the hand was evaluated according to the following criteria. If only the following evaluations were collected, the result of the worse of the two evaluation items was collected, and if more than three evaluations were collected, the item was evaluated as the evaluation result of the leather-like sheet. did.
○: It is not different from before touching, and there is no residual feeling in the hand.
Δ: Some treatment agent is slightly left but seems to remain in the hand, and a sense of incongruity is felt.
X: Adhesion of some treatment agent to the hand is clearly felt.

Dyeing fastness The dyeing fastness is the degree of color transfer to an attached white cloth evaluated by JIS L0849 (using a clock meter, wet test), and is grade 5 (good) to 1 according to the standard defined by the JIS standard. Judged by grade (bad).

[Manufacture of leather-like sheets]
(1) Nylon-6 chips (relative viscosity 3.2 when dried) and low-density polyethylene chips were mixed at a mass ratio of 50:50 and melt mixed spinning at 280 ° C. After the production of sea-island type mixed spun fiber using polyethylene and sea component as the sea component, the short fiber-like short fiber having an average single fiber fineness of about 4 decitex and an average fiber length of about 51 mm by wet heat drawing, mechanical crimping, oiling and cutting. A fiber was produced.

(2) The cotton-like short fibers obtained in the above (1) are opened with a card, made into a web with a cross wrap webber, and further subjected to a three-dimensional entanglement process of 1500 punch / cm ² using a needle punching machine with a felt needle. To produce a fiber entangled body.

(3) A polymer diol having a number average molecular weight of 2,000 comprising polyurethane [poly (3-methyl-1,5-pentaneadipate) and polyethylene glycol, Polyurethane formed using '-diphenylmethane diisocyanate and 1,4-butanediol] was impregnated with a dimethylformamide (hereinafter sometimes abbreviated as DMF) solution. Next, it was wet-solidified in a porous state in a DMF / water mixed bath, and the DMF in the sheet was replaced with water, and then the polyethylene in the sea-island type mixed spun fiber in a 90 ° C. toluene bath. Was extracted to form nylon-6 ultrafine fibers. Subsequently, the toluene in the sheet is replaced with water, dried in a pin tenter dryer, and a fiber sheet having a basis weight of 420 g / m ² , a thickness of 1.2 mm, and a fiber: polyurethane mass ratio of 65:35. Manufactured. In the fibrous sheet thus obtained, the adhesion between the nylon-6 ultrafine fiber bundle and the polyurethane was not substantially generated, and the freedom of movement of the ultrafine fiber bundle was high.

(4) After applying and drying a treatment liquid containing 15% DMF on both sides of the fibrous sheet obtained in (3) above with a 200 mesh gravure roll, both sides are buffed with No. 400 sandpaper, Further, lightly brush with No. 600 sandpaper, then divide into two in the thickness direction, and the surface generated by the division is lightly ground with No. 320 sandpaper to adjust the thickness to 0.5 mm. Nylon-6 A nap-like leather-like sheet in which nappings made of ultrafine fibers were uniformly formed was obtained. In addition, the single fiber fineness of the ultrafine fiber of the napped portion was 0.006 dtex.

(5) The leather-like sheet obtained in (4) above is subjected to a dyeing process with a wine dyeing machine under the dyeing conditions shown below, and then dried in a pin tenter dryer, and further scoured and hair-treated. As a result, a brown leather-like sheet having a mean nap length of 0.25 mm and an extremely good suede appearance (mesh weight = 182 g / m ² ) was obtained.
[Dyeing conditions]
"Ranil Brown GR" (dye) 4% owf manufactured by Sumitomo Chemical Co., Ltd.
"Leeberan NKD" manufactured by Maruhishi Oil Chemical Co., Ltd. (dyeing aid) 2g / liter Dyeing temperature 90 ° C
Bath ratio 1:20

[Granting of treatment agent]
Low molecular weight polyurethane aqueous dispersion (polyethylene glycol: hexamethylene diisocyanate: N-methyldiethanolamine = 1: 2: 1, number average molecular weight 5000, solid content concentration 20%) 50 parts, amino-modified silicone emulsion (Nikka Chemical Co., Ltd.) "Nikka Silicone AM-204" (solid content concentration 20%) 30 parts, water repellent (fatty acid amide epichlorohydrin quaternary salt, solid content concentration 20%) 10 parts, water-soluble partial hydrolyzate of silk fibroin (manufactured by Kanebo Co., Ltd.) 5 parts of “Silk Peptide” and 20 parts of a polyamide softener (“Lacset K-150” manufactured by Toto Kasei Co., Ltd.) were mixed to prepare a blended treatment solution. The leather-like sheet was obtained by carrying out this gravure coating process twice using a 150-mesh gravure roll on the leather-like sheet prepared by the production of the leather-like sheet. The solid content was 12 g / m ² . The evaluation results of this leather-like sheet are shown in Table 1.

Except that the number of gravure coating treatments in Example 1 was three, the same operation as in Example 1 was performed to obtain a leather-like sheet. The solid content was 17.5 g / m ² . The evaluation results of this leather-like sheet are shown in Table 1.

Low molecular weight polyurethane aqueous dispersion (polyethylene glycol: hexamethylene diisocyanate: N-methyldiethanolamine = 1: 2: 1, number average molecular weight 5000, solid content concentration 20%) 50 parts, amino-modified silicone emulsion (Nikka Chemical Co., Ltd.) 30 parts of “Nikka Silicone AM-204” (solid content concentration 20%) and 10 parts of a water repellent (fatty acid amide epichlorohydrin quaternary salt, solid content concentration 20%) were mixed to prepare a blended treatment solution A. Further, 5 parts of a water-soluble partial hydrolyzate of silk fibroin (“Silk Peptide” manufactured by Kanebo Co., Ltd.) and 20 parts of a polyamide-based softener (“Lacset K-150” manufactured by Nitto Kasei Co., Ltd.) are mixed and mixed. B. A 150 mesh gravure roll is used on the surface of the leather-like sheet after the dyeing process formed in Example 1 and 150 g gravure roll is used to apply the compounding treatment liquid A once and then a 150 mesh gravure roll is used. The compounding treatment liquid B was subjected to gravure coating treatment once. The solid content adhered to the leather-like sheet was 12 g / m ² . The evaluation results of this leather-like sheet are shown in Table 1.

  The leather-like sheet obtained in Example 3 was dipped in water and squeezed (water content after squeezing about 60%) twice and dried. The obtained leather-like sheet had a unique texture characterized by a high-quality hand with a moderately tacky feeling while being moist and a surface touch that makes it feel soft. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 1
The dyed leather-like sheet used in Example 1 was evaluated in the same manner as in Example 1. The texture of the obtained leather-like sheet did not exhibit a wet appearance with respect to the examples and had a feeling of roughness. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 2
A leather-like sheet was obtained in exactly the same manner as in Example 1 except that the low molecular weight polyurethane aqueous dispersion was not added to the compounding solution. The texture of the obtained leather-like sheet lacks a touch that makes it feel moist and soft with a silk touch. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 3
A leather-like sheet was obtained in exactly the same manner as in Example 1 except that a polyurethane having a number average molecular weight of 50000 was used instead of the low molecular weight polyurethane used in the blending treatment liquid. The evaluation results are shown in Table 1. The surface condition of the leather-like sheet evaluated was the surface of the leather-like sheet covered with a treatment agent, most particularly polyurethane, provided with most nappings, even though the dyed leather-like sheet was suede-like napping. As a result, the surface state was a so-called semi-silver-like surface, and the surface touch was also sticky to the examples. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 4
A leather-like sheet was obtained in the same manner as in Example 1 except that the amino-modified silicone emulsion was not added to the blending treatment solution. The obtained leather-like sheet had a surface-tacky adhesion to the examples. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 5
A leather-like sheet was obtained in the same manner as in Example 1 except that the water repellent was not added to the blending treatment solution. The obtained leather-like sheet had a surface touch and a feeling of tackiness and roughness with respect to the examples. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 6
A leather-like sheet was obtained in exactly the same manner as in Example 1 except that the softening agent was not added to the blending treatment solution. The obtained leather-like sheet had a surface-tacky adhesion to the examples. The evaluation results of this leather-like sheet are shown in Table 1.

Comparative Example 7
A compounded leather-like sheet was obtained in exactly the same manner as in Example 1 except that silk protein was not added to the compounding solution. The obtained leather-like sheet had a surface touch and a feeling of tackiness and roughness with respect to the examples. The evaluation results of this leather-like sheet are shown in Table 1.

The present invention provides a unique texture characterized by a touch that makes the leather-like sheet feel both soft and soft without compromising the fullness of the leather-like sheet. Apparel that has a wet appearance and exhibits good dyeing fastness, and that can be touched by the user's skin such as upper and lining of shoes, gloves, clothing, bags, and belts. Suitable as a material for applications.

Claims (10)

  A low molecular weight polyurethane, a silicone resin, a water repellent, a softener, and silk are formed on the raised surface of the leather-like sheet that contains an elastic polymer inside the fiber entangled body and at least one surface is made of ultrafine fibers. A leather-like sheet characterized by the presence of protein substances.   The leather-like sheet according to claim 1, wherein the fibers inside the leather-like sheet and the elastic polymer are not substantially bonded.   The leather-like sheet according to claim 1 or 2, wherein the silk protein-based substance is at least one selected from water-solubilized silk fibroin and a water-soluble partial hydrolyzate of silk fibroin.   The leather-like sheet according to any one of claims 1 to 3, wherein the low molecular weight polyurethane has a number average molecular weight of 1,000 to 10,000.   The leather-like sheet according to any one of claims 1 to 4, wherein the silicone resin is amino-modified silicone.   The leather-like sheet according to any one of claims 1 to 5, wherein the water repellent is a fatty acid amide compound.   The leather-like sheet according to any one of claims 1 to 6, which is colored with a dye.   Low molecular weight polyurethane, silicone resin, water repellent, softener and silk on the raised surface of the leather-like sheet having raised fibers made of ultrafine fibers on at least one side of the leather-like sheet containing the elastic polymer inside the fiber entangled body A method for producing a leather-like sheet, wherein at least a low-molecular-weight polyurethane and a silk protein-based material are added separately when applying a protein-based material.   The method for producing a leather-like sheet according to claim 8, wherein the silk protein material is applied after at least low molecular weight polyurethane is applied to the raised surface of the leather-like sheet. The leather-like sheet according to claim 8 or 9, wherein a low molecular weight polyurethane, a silicone resin, a water repellent, a softener and a silk protein-based material are applied to the raised surface of the leather-like sheet, followed by dipping in water and re-drying. Sheet manufacturing method.