JPH09105081A - Dyeing of leathery sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly dye a lathery sheet from the surface to the inner layer in high reproducibility by conducting a pad dyeing of the sheet through a dyeing bath of specific composition. SOLUTION: First, an aqueous dyeing liquid is prepared by incorporating water with 2-30wt.% of a nonvolatile water-soluble organic polymeric material >=120 deg.C in thermal decomposition temperature such as a polyalkylene glycol, 1-20wt.% of a water-insoluble colorant such as an organic or inorganic pigment or sulfurized dye and 0.01-10wt.% of a water-soluble dye such as a metal complex dye. Next, a fibrous sheet such as a knitted fabric, nonwoven fabric or a raised fabric made by raising the surface thereof is impregnated with a polyurethane polymer to make a leathery sheet, which is, in turn, immersed in the above aqueous dyeing liquid and then squeezed within the range of squeezing rate 70-200% followed by drying under heating to obtain the objective dyed leathery sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dyeing method for uniformly dyeing a leather-like sheet obtained by impregnating a fibrous sheet such as a knitted or woven fabric or a nonwoven fabric with an elastic polymer such as polyurethane from the surface to the inner layer. .

[0002]

2. Description of the Related Art Various methods are known as a method for dyeing a leather-like sheet obtained by impregnating a fiber sheet such as a knitted woven fabric or a nonwoven fabric with an elastic polymer such as polyurethane. It was insufficient in terms of quality. For example, since polyurethane has an affinity for many dyes, the amount of dye adsorbed on the surface of the leather-like sheet is relatively large, the interior is likely to remain white, and the fastness after dyeing is low, and reproducibility is low. Was bad. Also, when a disperse dye which is relatively hard to be adsorbed by polyurethane is used, it is difficult to obtain a dark color, and when a 1: 2 type metal acetate dye is used when the fiber sheet is made of nylon, this dye has an affinity for nylon. The nylon fibers on the sheet surface are dyed in a dark color, and the dye is adsorbed by the polyurethane, and the dye does not reach the inside, so that the inside remains white and a great effort is required to remove the dye adsorbed by the polyurethane. Needed.

As a method for solving such a problem, a method of uniformly dyeing the inside evenly by using a large amount of a dye having a very low dyeing rate on fibers and elastic polymers (see JP-A-6-43667). ) Was proposed, but this method uses a large amount of a dye having a poor dyeing rate, dyes it with a large bath ratio using a jigger or wins as a dyeing machine, and flows undyed dye by soaping. Therefore, there is a problem that waste of the dye increases.

[0004]

According to the present invention, the leather-like sheet is subjected to pad dyeing with a low bath ratio to greatly reduce the waste of colorants such as dyes and pigments, and furthermore, to provide a deep color from the surface to the inside. To improve the reproducibility and improve the color fastness.

[0005]

The first means is a method of dyeing a leather-like sheet obtained by impregnating an elastic polymer into a fiber sheet such as a knitted or woven fabric or a nonwoven fabric.
A water-soluble organic polymer material and a water-insoluble colorant, which are non-volatile at 20 ° C. or higher, are added to water to form a dyeing solution. The leather-like sheet is immersed in the dyeing solution, followed by squeezing and heating and drying. A method characterized by the following.

The above-mentioned fiber sheet is a knitted or woven fabric made of synthetic fibers such as nylon, acrylic and polyester, and has a fineness of 0.01 to 0.6 d.
And the basis weight is preferably 60 to 180 g / m ² . The elastic polymer impregnated in the fiber sheet is preferably a urethane elastomer such as polyether urethane or polyester urethane, or a synthetic rubber elastomer such as styrene butadiene or acrylonitrile butadiene. 260 g / m
² is preferred. The leather-like sheet made of the above fiber sheet and elastic polymer may be formed in a suede-like shape by polishing the surface and fuzzing the leather.

The above-mentioned water-soluble organic polymer material has a decomposition temperature of 120 ° C. or higher and is nonvolatile, and examples thereof include polyalkylene glycols such as polyethylene glycol and polypropylene glycol having a relatively low molecular weight. Examples of the water-insoluble colorant include organic pigments, inorganic pigments, vat dyes, disperse dyes, and sulfur dyes. If necessary, a water-soluble dye, for example, a metal-containing acid dye such as a 1: 1 type metal acetate dye or a 1: 2 type metal acetate dye, an acid dye, a reactive dye and a dispersant may be used in combination with water. A disperse dye or the like which disperses and shows an affinity for the fiber sheet is added.

The above-mentioned heat drying may be any of hot air drying, cylinder drying or steam drying. Cylinder drying is preferred because dye transfer during drying is particularly large. Further, the temperature is preferably 100 to 120 ° C. In addition, soaping can be performed following the above-mentioned heating and drying. In addition, steaming can be performed prior to heat drying, and then the above-described heat drying and soaping can be performed. In addition, drying is performed by steam drying, and then 130 to 150 days.
C. and heat treatment and soaping may be performed. When the above heat treatment is performed, the concentration can be further increased. After the above-described soaping, drying, oiling, and softening treatment are performed, and depending on the application, a water-repellent treatment can be further performed using a silicone-based or fluorine-based treatment agent.

The water-insoluble colorant and the water-soluble dye are easily diffused into the leather-like sheet as the concentration of the colorant and the dye on the surface of the leather-like sheet increases.
In the present invention, the leather-like sheet is immersed in a dye solution in which a water-insoluble colorant alone or a water-soluble dye is dispersed in an aqueous solution of a water-soluble organic polymer material, and heated and dried after squeezing. Sometimes, as the water on the leather-like sheet surface evaporates, the concentration of the water-soluble dyes and water-insoluble colorants on the sheet surface increases.

Further, since the water-insoluble colorant has a low affinity for fibers and elastic polymers, it can easily reach the inside without being adsorbed on the surface, and is assisted by the compatibility of the water-soluble organic polymer material. The coarsening of the particles due to the association of the colorants is prevented. Therefore, the water-insoluble coloring agent, which originally has a very low dyeing rate, is efficiently adsorbed by the elastic polymer and the fiber sheet, and the leather-like sheet is dyed deep inside. And since this coloring agent is insoluble in water, it has excellent fastness after dyeing. When coloring the elastic polymer as a raw material, a pigment having high fastness can be used, and a dark color can be obtained more easily.

When a water-soluble dye is added, the concentration on the surface of the fiber sheet increases with the above-mentioned drying, so that the dye is easily diffused into the fiber and the inside of the fiber is dyed in a deep color. You. However, since the above-mentioned water-soluble dye is adsorbed on the fiber surface while moving on the fiber surface, the fiber surface is dyed with higher priority than inside the fiber. In addition, when the leather-like sheet has nap on the surface, since the water-soluble dye is protected by a water-soluble organic polymer material having good water retention,
The dye solution is efficiently moved to the nap portion, and the nap portion is uniformly and deeply dyed. In addition, since the water-soluble organic polymer material has a decomposition temperature of 120 ° C. or higher and is non-volatile, it does not disappear due to decomposition or the like at a normal drying temperature, and the water-insoluble colorant is also dried during drying. The dispersing function and the protecting function of the water-soluble dye are effectively maintained.

The second means is that the water-soluble organic polymer material of the first means is limited to polyalkylene glycol, and the decomposition temperature of the polyalkylene glycol is 3 or less.
Since the temperature is not lower than 00 ° C., even when the drying temperature or the heat treatment temperature is increased, the function of dispersing the water-insoluble colorant and the function of protecting the water-soluble dye are more effectively maintained.

The third means is a method of adding a water-soluble dye to the dyeing solution used in the second means. In this case, the difference in transparency between the water-insoluble colorant and the water-soluble dye causes the elastic polymer. When the leather-like sheet has naps, the naps are dyed dark.

The fourth means limits the composition of the liquor used in the third means, wherein 2 to 30% of the weight of the liquor is a polyalkylene glycol, 1 to 20% is a water-insoluble colorant, 0.1 to 1%. 0
Since the water-soluble dye is used for 1 to 10% and the remainder is water, the dyeing rate is further improved. However, if the content of the polyalkylene glycol is less than 2%, the stability of the water-soluble dye or the water-insoluble colorant is insufficient, and if it exceeds 30%, the stability becomes excessive and waste increases. On the other hand, if the content of the water-insoluble colorant is less than 1%, the inside and outside of the leather-like sheet become insufficiently dyed.
If it exceeds%, the concentration will increase more than necessary during heating and drying. Further, when the content of the water-soluble dye is less than 0.01%, the concentration becomes insufficient, and when it exceeds 10%, the concentration becomes excessive and waste increases.

The fifth means is to limit the squeezing rate of the squeezed liquid in the fourth means to 70 to 200%, whereby an appropriate amount of the dyeing liquid is held on the surface of the leather-like sheet during heating and drying. Uniform dyeing becomes easy. However, 7
If it is less than 0%, it becomes too squeezed and the dyeing liquid on the surface becomes insufficient, and a desired concentration cannot be obtained. Conversely, if it exceeds 200%, the dyeing liquid becomes excessive and dripping occurs during heating and drying. And, by limiting the above-described drawing rate to 100 to 150%,
Uniform dyeing becomes easier and the fastness after dyeing is further improved.

The sixth means uses a suede-like sheet having nap fibers on the surface as the leather-like sheet of the fifth means, so that the tips of the nap are dyed dark as described above. The fineness of the fibers constituting the above fiber sheet is 0.01
0.6 denier is preferred, whereby a good texture and color tone as a leather-like sheet can be obtained. However,
If it is less than 0.01 denier, it is difficult to obtain a deep color and the surface tends to be light, while if it exceeds 0.6 denier, a leather-like texture cannot be obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 The dyeing liquor is a low molecular weight water-soluble polypropylene glycol 5
%, A sulfur dye (water-insoluble coloring agent) 3%, a 1: 2 type metal salt dye (water-soluble dye) 3%, and the remaining water composition, and this dyeing solution was applied to a nylon fiber non-woven fabric ( A leather-like sheet obtained by impregnating a fiber sheet) with a polyester-based polyurethane (elastic polymer) is padded, and a drawing ratio of 150 is obtained.
%, Followed by a cylinder dryer (temperature 120 ° C)
Dry with. At this time, the polypropylene glycol is
Dispersion of insoluble sulfur dyes which prevent precipitation of sulfur dyes and 1: 2 type acetic acid dyes, prevent particles from increasing due to association of colorants, greatly contribute to stabilization of dyeing liquors, and diffused inside. Help.

Therefore, the concentration at the fiber interface increases simultaneously with the progress of drying, and the dyeing rate at the end of drying is improved. Inside, at the time of immersion in the dyeing liquor, the colorant diffuses inside simultaneously with the diffusion of water. That is, the undyed 1: 2 type acetic acid dye migrates to the surface of the leather-like sheet at the same time as the water migration of the 1: 2 type acetic acid dye, and the inside is dyed to the extent that there is no uncomfortable feeling. Selectively dyed in dark color with type 2 acetic acid dye, unlike conventional dyeing method with large bath ratio, it is dyed quickly with dye that has penetrated into the inside to obtain leather-like sheet with high color fastness Can be

Embodiment 2 The above-mentioned dried leather-like sheet is soaped with a winch or a jet dyeing machine, and subsequently dried with a pin drier. In the soaping, a reducing agent is added to warm water at a temperature of 40 to 80 ° C. to which a dispersing agent has been added in an amount of 1 to 2 g / liter and soda ash is added in an amount of 2 to 4 g.
By adding g / liter, the water-insoluble colorant and the water-soluble dye that are not diffused into the fiber sheet and the elastic polymer are reduced and removed, and the water-insoluble colorant and the water-soluble dye that are efficiently adsorbed to the leather-like sheet are removed. The sex dye is not decomposed. This reduction washing enables low cost dyeing of any color from an elegant light color to an elegant color, and a product having good reproducibility, high quality and high fastness can be obtained.

Embodiment 3 By rubbing the leather-like sheet of Embodiment 1 with sandpaper, naps are formed on the surface, and then padding and squeezing are performed in the same manner as in Embodiment 1, followed by a cylinder dryer. After drying, the reduction washing of the second embodiment is performed to dye the tip of the napped hair more deeply.

[0021]

[Example] Nonwoven fabric composed of nylon fiber (fineness 0.1 denier) and polyester fiber (fineness 0.2 denier) (mixing ratio of nylon fiber and polyester fiber 65/3)
5, with a basis weight of 120 g / m ² ) and a solvent-type polyester-based urethane having dimethylformamide as a solvent,
% Solution with a black pigment added to give a solid content of 160 g
/ M ² , applied, impregnated, baked, and fluffed with sandpaper to obtain a suede-like leather-like sheet.

On the other hand, a dyeing liquor was prepared according to the following formulation (% by weight). Polypropylene glycol 5% Sulfur dye (Asahi Dye Co., trade name "Asathiosol Black S-RC") 3% Sulfur dye (Asahi Dye Co., trade name "Asathiosol Navy S-RN") 2% 1: 2 type acetic acid salt Dye (Sand Co., trade name "Lanacyn Navy S-BL") 3% Water 87% Total 100%

The obtained dyeing liquor is put in a padder, the leather-like sheet is immersed, squeezed so that the squeezing rate becomes 150%, and 2 m / m 2 using a cylinder drier (temperature: 120 ° C.).
Dry slowly at a speed of minutes. At this time, the precipitation of the sulfur dye and the 1: 2 type acetic acid dye is prevented by the polypropylene glycol, the particles are prevented from increasing due to the association of the colorant, and the dispersion of the insoluble sulfur dye diffused into the interior is assisted. High-quality leather with the density at the fiber interface increasing at the same time as the drying progresses, the dyeing rate at the end of drying being improved, the inside being dyed darker, and the nap on the surface being dyed darker A similar sheet was obtained.

[0024]

According to the first aspect of the present invention, there is provided a method for dyeing a leather-like sheet obtained by impregnating an elastic polymer into a fiber sheet such as a knitted fabric or a nonwoven fabric, wherein the decomposition temperature is 1%.
A water-soluble organic polymer material and a water-insoluble colorant, which are non-volatile at 20 ° C. or higher, are added to water to form a dyeing solution. The leather-like sheet is immersed in the dyeing solution, followed by squeezing and heating and drying. Since the method for dyeing a leather-like sheet is characterized by the fact that the association of the colorant in the bath is prevented by the water-soluble organic polymer material, and the internal dyeing of the high-density leather-like sheet and the surface of the sheet are performed. The deep dyeing can be dyed continuously in one bath with padding plus a drying step.

In the conventional exhaustion method (no padding, bath ratio 1:20 to 1:60, dyeing method performed at room temperature to 130 ° C.), the dyeing rate is as low as 1% or less, but the padding rate is low. It becomes possible to immerse at an apparent bath ratio of 1: 2 or less, and even when the bath ratio is reduced in the drying step after squeezing, the water-insoluble colorant is incorporated into the water-soluble organic polymer material. Therefore, tar formation and particle increase due to mutual adsorption of the water-insoluble colorant are prevented, and the concentration of the liquor at the fiber interface can be increased up to 20 times that at the time of padding. The dyeing of the coating rate can be performed, and the cost can be reduced, and the quality, reproducibility and fastness are improved.

According to a second aspect of the present invention, the water-soluble organic polymer material of the first aspect is limited to a polyalkylene glycol, and the decomposition temperature of the polyalkylene glycol is 300 ° C. or higher. Therefore, even when the drying temperature or the heat treatment temperature increases, the water-insoluble colorant does not disappear due to decomposition or the like, and functions more effectively.

According to a third aspect of the present invention, in the method for dyeing a leather-like sheet according to the second aspect, a water-soluble dye is added to the dyeing solution. improves.

The invention described in claim 4 limits the composition of the dye liquor in the method for dyeing a leather-like sheet according to claim 3, wherein 2 to 30% by weight of the dye liquor is polyalkylene glycol and 1 to 20%. A water-insoluble colorant, 0.01-10%
Is a water-soluble dye, and the remainder is water, so that the exhaustion rate can be further increased by lowering the bath ratio, preventing the association of the dye or colorant with the decrease in the moisture content during drying, and It facilitates diffusion into the interior, and facilitates removal of the undyed dye and the unadsorbed colorant after drying in a subsequent step.

According to a fifth aspect of the present invention, in the method of dyeing a leather-like sheet according to the fourth aspect, the squeezing rate at the time of squeezing is limited to 70 to 200%. The concentration of the water-insoluble colorant or water-soluble dye is effectively increased by the polyalkylene glycol, and the internal dyeing and the deep dyeing of the surface of the leather-like sheet in the invention according to claim 4 can be more easily performed. .

According to a sixth aspect of the present invention, in the method for dyeing a leather-like sheet according to the fifth aspect, since the leather-like sheet has nap fibers on its surface, the suede-like leather-like sheet is dyed. In this case, the tip of the nap fiber can be dyed particularly darkly, and the quality as a leather-like sheet is further improved.

Claims (6)

[Claims] 1. A method for dyeing a leather-like sheet obtained by impregnating a fibrous sheet such as a knitted or woven fabric or a nonwoven fabric with an elastic polymer, comprising: a non-volatile water-soluble organic polymer material having a decomposition temperature of 120 ° C. or higher; A method for dyeing a leather-like sheet, comprising adding a water-soluble colorant to water to form a dye liquor, immersing the leather-like sheet in the dye liquor, followed by squeezing and heating and drying. 2. The method for dyeing a leather-like sheet according to claim 1, wherein the water-soluble organic polymer material is a polyalkylene glycol. 3. The method for dyeing a leather-like sheet according to claim 2, wherein a water-soluble dye is added to a dyeing solution. 4. The method for dyeing a leather-like sheet according to claim 3, wherein 2 to 30% of the weight of the liquor is a polyalkylene glycol, 1 to 20% is a water-insoluble colorant, and 0.01 to 10%.
A method for dyeing a leather-like sheet in which% is a water-soluble dye and the remainder is water. 5. The method for dyeing a leather-like sheet according to claim 4, wherein the squeezing solution is drawn to a squeezing rate of 70 to 200%. 6. The method for dyeing a leather-like sheet according to claim 5, wherein the leather-like sheet has nap fibers on its surface.