JPH0357231B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coloring a napped fabric, particularly a suede-like artificial leather having napped surfaces.

In recent years, the development of suede-like artificial leathers with raised naps on the surface has progressed, and some types of artificial suede have even surpassed natural suede leather.

Such artificial suede usually has a structure in which ultrafine fibers of 0.5 denier or less or entangled bodies of ultrafine fiber bundles are filled with porous polyurethane elastomer, and the nap on the surface is formed from the ultrafine fibers. The main reason for using ultra-fine fibers is to obtain artificial suede with excellent appearance (pile length, lighting effect, texture, feel, etc.), but the disadvantage is that if the fibers are less than 0.5 denier, they will not be as good as regular fibers of the same weight. The surface area is extremely increased compared to the fiber surface, and light is diffusely reflected on the fiber surface, resulting in poor light absorption efficiency of the dye of the dyed object and poor color development. Therefore, in order to obtain sufficient coloring properties for ultrafine fibers, several tens of times the amount of dye used for normal fibers is required, resulting in high dye costs. Furthermore, during the dyeing process, the napped fibers become tangled and pilling occurs.

In addition, as a dyeing method for the raised fabric made of ultrafine fibers and porous polyurethane elastomer, methods such as ○A dip dyeing or ○B printing are used. Batch dyeing is carried out using a dyeing machine, which has poor production efficiency and requires a large amount of dye as it dyes the inside and back of the napped fabric, which is disadvantageous in terms of cost and also causes tangles in the napped fabric during the dyeing process. There is also the downside of waking up. The printing method (○) is lower in cost than the dip dyeing method in that it dyes only the surface of the nap, but it has the disadvantage that the process is complicated and workability is poor due to the preparation of the size agent and the removal of the size agent. Furthermore, this method has the disadvantage that it is difficult to control the distribution of dye into the ultrafine fibers and the porous polyurethane elastomer, resulting in a lack of level dyeing.

Furthermore, it is absolutely necessary for the suede-like material to have water repellency as a product performance. Water repellency can be achieved by treating with a water repellent before or after the dyeing process, but if water repellent treatment is applied before the dyeing process, the fabric will be dyed with water repellency, resulting in difficulty in dyeing or uneven dyeing. Dyeing work becomes difficult due to the fact that staining is likely to occur.
On the other hand, if water repellent treatment is applied after the dyeing process, problems such as discoloration and fading of the dyed product will occur.

The inventors of the present invention took into account these shortcomings and, as a result of intensive studies, decided to use a fabric with napped microfibers that has a water repellency of 70 points or higher, and to dye the surface mainly. Therefore, it has been found that it is possible to obtain a raised fabric that uses less dye, has excellent appearance, feel, and texture, and has fewer dyed spots.

The object of the present invention is to provide a dyeing method for a fabric having napped microfibers that does not impair the appearance and feel or harden the texture, has few dye spots, and has good dyeing abrasion fastness.

That is, the present invention consists of polyamide ultrafine fibers with a surface of 0.5 denyl or less and a porous polyurethane elastomer, and also comprises a fluorine-based water repellent, a silicone-based water repellent, a fatty acid amide-based water repellent, and an epihalohydrin polycondensate of a polyamine derivative. Water repellency (JIS L-1096-
1979 Acid dyes, metal acetate dyes, acid mordant dyes, basic dyes, and oil-soluble dyes that can dye both polyamide and polyurethane elastomers are applied to the surface of raised fabrics with a score of 70 points or higher (6.32.1A). At least one dye selected from the group consisting of an organic solvent and water that has a boiling point of 100°C or more and has an affinity with the material constituting the napped fabric and water but does not attack the material constituting the napped fabric. The solution was applied by gravure printing, dried, and then soaked in hot water of 80℃ or higher.
This is a method for coloring raised fabric, which is characterized by moist heat treatment for ~10 minutes and then drying.

In the raised fabric of the present invention made of polyamide microfibers with a surface of 0.5 denier or less and porous wet polyurethane elastomer, polyamide microfibers obtained by a known manufacturing method are used. By using generation type fibers, such as sea-island type fibers in which polyamide is an island component (or core component), and exfoliation type fibers in which other polymers of polyamide are bonded to multiple components, woven fabrics, knitted fabrics,
Alternatively, a fabric such as a fiber-entangled nonwoven fabric is used, and the fibers are treated to become ultrafine fibers before or after applying the polyurethane elastomer. Then, if necessary, the surface is subjected to a napping treatment to obtain a napped fabric, such as a napped woven or knitted fabric in a velvet style, a kohl texture, a bedding style, etc., or a raised nonwoven sheet-like material in a suede style, a nubuck style, etc. Alternatively, it is an ultrafine fiber flocked fabric obtained by electro-flocking ultrafine fibers or ultrafine fiber-generating fibers using a fabric made using ordinary fibers as a base material.

The polyurethane elastomer to be contained in the fabric is a polyurethane obtained by reacting at least one polyol selected from the group of polyols such as polyester polyols, polyether polyols, and polylactone polyols, an organic diisocyanate, and a chain extender. using elastomers or mixtures thereof. The polyurethane elastomer is impregnated into a fabric as a solution or dispersion, and the polyurethane elastomer is fixed to the fabric by a wet coagulation method or a dry coagulation method. In particular, in order to obtain a raised fabric with excellent flexibility, it is preferable to use a porous wet polyurethane elastomer produced by a wet coagulation method.

Next, the raised fabric having ultrafine polyamide fiber naps containing a porous wet polyurethane elastomer is subjected to a water repellent treatment on at least the surface to which the dye is to be attached prior to the dyeing treatment. The purpose of water repellent treatment is to prevent products from getting wet when used as outerwear, for example, and to prevent dye solutions applied to the surface from penetrating into the fabric unnecessarily, so that more dye stays on the surface of the raised fabric. It is to make it. In order to suppress the permeation of the dye solution and give the raised fabric water repellency during use, the raised fabric should be measured using the JIS L-196-1979 6.32.1A method before applying the dye solution. The water repellency must be 70 points or higher. If the water repellency does not reach 70 points, the desired effect cannot be obtained because the water repellency of the fabric is insufficient. Also,
Since the water repellent used greatly contributes to the napping properties of the fabric, it is preferable and rational to perform a water repellent treatment before the napping process. Although known water repellents can be used, in the fabric of the present invention composed of polyamide fibers and polyurethane elastomer, in particular, fluorine-based water repellents, silicone-based water repellents, fatty acid amide-based water repellents, At least one water repellent selected from the group of epihalohydrin polycondensates of polyamine derivatives and cationic surfactants is effective. The fabric is treated with a water repellent in a dispersion or solution system, dried, and further cured if necessary to obtain a fabric with a water repellency of 70 points or more.

The dyeing method for the water-repellent raised fabric is one that has the ability to dye polyamide fibers and polyurethane elastomers, and the subsequent hot water and moist heat treatment removes the adhering dye with little difference depending on the constituent material. . Such dyes include, for example, acid dyes,
It is preferable to use at least one dye selected from the group of metal salt dyes, acidic mordant dyes, basic dyes, and oil-soluble dyes. However, dye affinity changes depending on the type of polyurethane elastomer, so in addition to the dye selected from the above group, for example, at least one dye selected from the group of direct dyes and reactive dyes may be mixed. It is also possible to use

In addition, the solvent composition for dissolving the dye is a mixture of water and an organic solvent that has an affinity for the fiber and polyurethane elastomer and an affinity for water in order to quickly dye the dye on the fiber and polyurethane elastomer. A mixed composition liquid is used. The purpose of mixing water is to reduce changes in the concentration of the dye composition solution over time and to suppress penetration of the dye solution into the fabric. In order to reduce changes in the solvent composition of the dye solution over time, the boiling point of the solvent used is preferably high. Preferably, the temperature is higher than the boiling point of water (100°C) in order to obtain a uniform dyed product. Suitable examples of such organic solvents include 1,4-dioxane, ethylene glycol monomethyl ether, tethylene glycol monoethyl ether, diacetone alcohol, dimethyl sulfoxide, n-butyl alcohol, and dimethyl formamide. Among these, 1,4-dioxane and diacetone alcohol are preferred because they have no effect on polyamides and polyurethane elastomers. When using an organic solvent that swells or dissolves polyamide or polyurethane elastomer, it is necessary to reduce the mixing ratio and use it after confirming that substantially no change in the raised fabric occurs. The dye concentration in the dye solution is usually less than 20% by weight. The mixing ratio of organic solvent and water is usually 10-60:90-40 by weight.
is within the range of

Next, methods for applying the dye solution to the raised fabric include a surface layer dipping method in which the surface layer is brought into contact with the liquid surface, a spray method, a roll coating method, etc.
A gravure printing method using the eye roll is used, and the gravure printing method using the eye roll is preferred from the viewpoint of uniformity of application of the dye solution, ease of controlling the amount of application, workability, etc. The amount of dye solution to be applied is determined based on the desired color tone, density, dyeing area, etc. However, if too much liquid is applied at one time, uneven penetration into the fabric may occur, and the fibers and polyurethane elastomer may be damaged. This causes a difference in the amount of liquid attached,
Since this may cause color unevenness, the preferred amount of liquid applied at one time is in the range of 3 to 50 g/m ² . The raised fabric coated with the dye solution is then dried to remove the solvent and fix the dye to the fibers and polyurethane elastomer.

The dye-attached raised fabric is treated with moist heat to fix the temporarily attached dye to the polyamide and polyurethane elastomer, while at the same time removing auxiliary agents such as activators and dispersants in the dye, and the treatment time is 1. ~10 minutes. The processing time is very important; if it is less than 1 minute, the fixation will be insufficient, and if it is longer than 20 minutes, the dye will migrate into the raised fabric layer, causing the surface color to become pale.
This results in color spots and the object of the present invention cannot be achieved. The moist heat treatment temperature is preferably 80° C. or higher, although dyeing will occur if the temperature is higher than the glass transition point of the polyamide. The higher the temperature, the better the color development will be, but since water is used industrially, its boiling point is usually the upper limit.

In the present invention, the raised fabric subjected to the moist heat treatment is finally dried, and this drying is also closely related to the moist heat treatment. That is, the lowest drying temperature is the above-mentioned moist heat temperature, and it is preferable for color development to be carried out at a high temperature, for example, 100 to 150° C. under hot air.

In the raised fabric dyed according to the present invention, the raised surface is dyed to a desired color tone, and the inside of the fabric is hardly dyed or the dye concentration is low, so the texture is not hardened. In addition, the dye on the raised surface is sufficiently fixed to the object to be dyed through moist heat treatment and subsequent high-temperature drying treatment, so it has high dyeing friction fastness, and has good raised condition and water repellency. A fabric is obtained.

Next, embodiments of the present invention will be specifically described with reference to Examples. Note that parts and percentages in the examples are by weight unless otherwise specified.

Example 1 A mixed spun fiber consisting of 50 parts of polyamide (ultrafine fiber component) and 50 parts of polyethylene was drawn, crimped, and cut into a stable material with a fineness of 6 dr and a fiber length of 51 mm. A wep was created with a cross wrapper, and then needle punched. A three-dimensionally entangled nonwoven fabric was obtained. Next, the nonwoven fabric was impregnated with a 15% dimethylformamide solution of polyester-based polyurethane elastomer, placed in water for wet coagulation, washed, and dried to obtain a sheet-like product. This sheet-like material was immersed in percrene to extract and remove the polyethylene in the fibers to obtain a base sheet-like material containing a porous polyurethane elastomer in an entangled nonwoven fabric of polyamide ultrafine fiber bundles. Next, both sides of the base sheet were buffed with sandpaper to form a raised surface of ultrafine fibers, giving it a suede-like appearance. This suede-like sheet material is coated with a commercially available fluorine-based water repellent, "Asahi Guard" (product of Asahi Glass Co., Ltd.).
% water dispersion, and after removing excess liquid,
Dry in a hot air dryer at 135°C. This suede-like sheet material had a thickness of 1.1 mm, an apparent density of 0.29, and a surface water repellency of 80 points as measured by JIS L-1096-1979, 6.32.1A method.

Next, dye {(Nippon Kayaku) Kayanol Milling Blue GW50g/} and dioxane/water =
A dye solution consisting of 1/1 was applied to the surface of the raised fabric in two stages using a gravure printing method using a gravure cut 150 mesh roll, dried, and then immersed in hot water at 95°C for 3 minutes. ,130℃
When dried under hot air, the surface layer of the raised fabric was approximately
A thick artificial suede-like sheet of blue color with a flexible texture was obtained in which 100μ was dyed without any dyeing spots.

Comparative Example 1 The above-mentioned thick nap fabric with a water repellency of 80 points was dyed using a small wince dyeing machine, and in order to obtain a hue similar to the blue obtained in Example 1, the dye concentration for the sheet material was 3.7. % dye was required. This is because the entire genus of the raised fabric is dyed, and the dye cost is naturally high since it is 4 parts of the dye used in the method of the present invention. In addition, the appearance of dyed spots and tangles of raised piloeres were also observed on the surface. Furthermore, the texture became a little harder.

Comparative Example 2 An aqueous solution of Kayanol Milling Blue GW 50 g/W was applied to the surface of the above-mentioned thick nap fabric with a water repellency of 80 points.
When applied using a gravure printing method using a 150 mesh roll and dyed in the same manner as in Example 1, the obtained artificial suede was a little lighter in color than that in Example 1 and had some dyeing spots. It was something I had. The reason for this appearance is that the solvent of the dye solution is only water, which has poor transferability from the roll and poor penetration into the surface of the raised fabric.

Example 2 A nonwoven fabric made using a mixed spun fiber obtained by adding 3% carbon black to 50 parts of the polyamide component of the mixed spun fiber of Example 1, and further adding 1% carbon plack to the polyurethane elastomer solution. A sheet-like material was obtained in the same manner as in the example, and treated with a 0.7% toluene solution of the commercially available water repellent "Softlon" (product of Yoshimura Yukagaku Co., Ltd., fatty acid amide water repellent) to obtain a mixed spun fiber. The polyethylene component was extracted and removed to obtain a sheet material containing a porous polyurethane elastomer in an entangled nonwoven fabric of polyamide ultrafine fibers. This sheet-like material is subjected to a water repellent treatment at the same time as polyethylene is extracted and removed. Both sides of this sheet-like material were subjected to buffing treatment with sandpaper to obtain a suede-like sheet material with a raised surface of dark polyamide ultrafine fibers. The resulting raised fabric had a water repellency of 80 points, had well-aligned naps, and had a dark color due to the carbon black effect.

Next, metal salt dye (manufactured by Civer Geigy)
Irgaran Black GBL 5%, dioxane 20%,
A dye solution consisting of 75% water was applied twice using a gravure printing method using a roll of 140 mesh, dried, and then treated with moist heat for 5 minutes in hot water at 75°C, 85°C, and 95°C. When dried under hot air at 75°C, a thick black artificial suede was obtained which is excellent as an interior material and has no tangles or pilling. 2
The color development was significantly inferior to that of seeds.

Comparative Example 3 A dye solution consisting of 5% Irgaran Black and 95% water was applied to the raised fabric of Example 2 with a water repellency of 80 points.
After applying it twice using a roll coating method using a 140 mesh roll and drying, it was immersed in hot water at 95℃ for 5 minutes, and then dried under hot air at 100℃ to obtain a raised fabric with a black surface layer. However, this product had some drawbacks because the root part of the raised hairs was not dyed sufficiently black and there was uneven dyeing with a shimmering effect.

Comparative Example 4 In the method of Example 2 above, the water repellency of the sheet material that was not treated with a water repellent agent was 50 points, and this sheet material was subjected to the same coloring treatment as in Example 2 without being treated with a water repellent agent. As a result, the obtained sheet-like material had a very shallow blackness and poor color development compared to that obtained in Example 2. The reason for this is thought to be that the dye solution did not stay on the sheet surface but penetrated into the inner layer.

Claims (1)

[Claims] 1 The surface is made of polyamide ultrafine fibers with a denier or less of 0.5 denier and porous polyurethane elastomer, and contains a fluorine-based water repellent, a silicone-based water repellent, a fatty acid amide-based water repellent, an epihalohydrin polycondensate of a polyamine derivative, and a cationic activator. Water repellency treated with at least one water repellent selected from the group (JIS L-1096-1979 6.32.
A dye selected from the group of acid dyes, metal salt dyes, acid mordant dyes, basic dyes, and oil-soluble dyes that can dye both polyamide and polyurethane elastomer is applied to the surface of the raised fabric with 1A) of 70 points or more. at least one dye having a boiling point of 100°C or higher,
Applying a dye solution consisting of water and an organic solvent that has an affinity with the raised fabric constituent material and water but does not attack the raised fabric constituent material using a gravure printing method,
A method for coloring a raised fabric, which is characterized in that after drying, it is subjected to a moist heat treatment with hot water of 80°C or higher for 1 to 10 minutes, and then dried.