JPH0643667B2 - Method for dyeing leather-like sheets - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dyeing method with less uneven dyeing when dyeing a leather-like sheet composed of two or more materials having different dyeing behavior.

[Prior Art] Conventionally, for dyeing a leather-like sheet made of a fiber entangled body and a resin, a dyeing method and condition setting have been made mainly with a focus on dyeability of constituent fibers. Then, in order to make a leather-like sheet with less uneven dyeing, dyeing at high temperature for a long time, or dyeing under high temperature pressure with a dye composition in which dyes that are dyed on each of the fiber and resin are mixed, 1% by weight or more (Japanese Patent Publication No. 57-21588) or dyeing with a carrier has been used. Further, the applicant of the present invention has less uneven dyeing, and in order to obtain a leather-like sheet excellent in dyeing fastness, the leather-like sheet is dyed with a dye that becomes water-soluble by being reduced in the presence of an alkali such as a sulfur dye, Then, the dyeing method that combines under dyeing that fixes the dye by oxidation treatment
It was proposed in Japanese Patent No. 61-25834 and Japanese Patent Publication No. 61-46592.
Furthermore, a dyeing method in which a dye is dissolved in a solvent such as alcohol and dyed, for example, Japanese Patent Publication No. 25521/1975 is proposed.

[Problems to be Solved by the Invention] In the conventional dyeing method, since the dyeing properties of the fiber are mainly set, the resin mainly made of the elastic polymer is not dyed sufficiently or the dyeing state is different. The hue of the surface layer is different from that of the inside. The dyeing process becomes complicated. Dye fastness is poor. Deterioration of resin, eg molecular weight (viscosity)
However, there was a problem such as deterioration and deterioration. Furthermore, the dyeing method using a solvent has problems in terms of equipment, work and quality.

[Means for Solving Problems] The present invention relates to a method for dyeing a leather-like sheet which has less dyeing unevenness, is dyed even inside the leather-like sheet, and has excellent dyeing fastness.

That is, the present invention, when dyeing a leather-like sheet composed of a resin mainly composed of a fiber entangled body and an elastic polymer, the dyeing amount for the fiber and the resin is 10 mg / g or less and contains at least 20% by weight. The method for dyeing a leather-like sheet is characterized by dyeing with a dye composition.

Furthermore, the present invention, when dyeing a leather-like sheet composed of a resin mainly composed of a fiber entangled body and an elastic polymer, (1) a dyeing amount of 10 mg / g or less for the fiber and the resin is at least 20. A method for dyeing a leather-like sheet, which comprises successively performing a step of underdying with a dye composition contained in a weight percentage and a step (2) of overdying with a dye composition having a dyeing amount of at least 30 mg / g.

The leather-like sheet composed of a resin mainly composed of a fiber entangled body and an elastic polymer dyed in the present invention is a synthetic fiber,
Fiber entanglement or fiber entanglement such as woven fabric, knitted fabric or cloth having a fiber raised surface thereof, or a woven fabric produced by mixing two or more kinds of fibers selected from natural fibers or regenerated fibers Is a napped leather-like sheet with a fiber entangled body containing a resin mainly composed of an elastic polymer and a fiber raised surface on the surface of the substrate or a porous resin mainly composed of the elastic polymer on the surface of the substrate. A so-called silvered leather-like sheet finished by applying a coating layer composed of a porous layer and / or a non-porous layer. In particular, in order to obtain a sheet having a leather-like texture and appearance, the fibers constituting the fiber entangled body are ultrafine fibers having a single fineness of 0.3 denier or less and / or bundled fibers thereof. Further, the elastic polymer is a polymer selected from polyurethane elastomer, polyester elastomer, polyamide elastomer, polyacrylate, synthetic rubber and the like, and preferably polyurethane elastomer. In particular, as a leather-like sheet to which the dyeing method of the present invention can be effectively used, a polyurethane entanglement is mainly used in a fiber entangled body mainly composed of ultrafine fibers having a single fineness of 0.3 denier or less and / or bundled fibers thereof. A napped leather-like sheet finished with a resin-containing substrate, or a substrate containing the polyurethane entangled resin containing a resin mainly containing a polyurethane elastomer, or a resin-free substrate having one surface coated with a resin mainly containing a polyurethane elastomer It is a leather-like sheet with silver finished by adding layers. It is also effective for dyeing a hydrophobic or dense leather-like sheet, which is a sheet having a water absorption of 200% or less. When the water absorption rate is high, the dye solution is likely to permeate or come in and out relatively easily, and the filtering effect on the sheet surface is small, so that the uneven dyeing state is reduced.

Next, the dye used in the under-dyeing process of the leather-like sheet of the present invention needs to have a dyeing amount of 10 mg / g or less with respect to the fiber and the resin. The use of a dye having a dyeing amount of 10 mg / g or less is a special treatment agent such as a penetrating agent, a carrier,
It is possible to reduce the amount of solvent used and to allow the dye to penetrate into the inside of the sheet to be dyed without using it, resulting in good leveling properties and small reductions in dyeing fastness. To be And the dyeing amount to the fiber and resin is 10 mg / g or less means that the dyeing amount to the dyeing object is not so large that the dye affinity to the dyeing object is essentially large, or the dyeing condition is changed. It is a small dye. The dyeing amount of the subdying dye is selected to be 10 mg / g or less, preferably 10 to 1 mg / g, or a dyeing condition. Further, the compounding amount of the dye having a dyeing amount of 10 mg / g or less is a dye composition containing at least 20% by weight. The amount used is determined by the color tone or shade of the material to be dyed. The dyeing amount of the under-dyed dye being 10 mg / g or less means not the apparent dyeing amount but the dyeing amount after soaping and washing after dyeing. The same applies to the dyeing amount of the top dye of 30 mg / g or more.

The dye having a dyeing amount of 10 mg / g or less of the underdyeing dye of the present invention is a dye showing a different dyeing behavior depending on the dyeing condition, when dyeing by selecting a dye whose dye affinity to the object to be dyed is not essentially large. May be selected and dyed. For example, when dyeing a leather-like sheet composed of a fiber entangled body of 6-nylon fibers and polyester-based polyurethane, disperse dyes, acid dyes, reactive dyes, Dyes and the like belong to the dye department. On the other hand, acid dyes, metal complex dyes, and the like belong to the dye group as dyes that exhibit different dyeing behavior depending on the dyeing conditions. The dye concentration of the underdye is 0.1 to 15% by weight with respect to the weight of the material to be dyed, and the dyeing temperature is 2
The range of 5 to 60 ° C is preferred. In particular, when the dyeing temperature is high, the penetration of the dye is suppressed, the colorant between the inside and the surface becomes large, the color tone between the fiber and the resin is different, and color unevenness occurs, which is not preferable. Therefore, it is preferable to carry out the subdyeing at a low temperature.

Next, the object to be dyed after under-dying of the present invention is further dyed to obtain a desired color tone. Top dyeing is performed using a dye having a high affinity for the material to be dyed or a dye having a large dyeing amount on the material to be dyed by changing the dyeing conditions. Select at least 30 mg / g of dye or dyeing conditions for the dyeing amount of top dye. The type and amount of the dye used are selected according to the affinity of the dye for the material to be dyed and the desired color tone, shade, and the like. Also, the dyeing temperature is selected so that the dyeing fastness is obtained. Since the dyeing time can be shortened as compared with the dyeing method in which the under-dying is not performed, a product which is less likely to cause deterioration of the resin or which does not cause a quality change can be obtained.

The conventional dyeing method is applied as the dyeing method for under-dying and over-dying of the present invention. As the dyeing machine, for example, a normal dyeing equipment such as a Jigger dyeing machine, a Wins dyeing machine, a jet dyeing machine is applied as it is. Then, the under-dyeing and the over-dyeing may be performed as continuous steps or as separate steps. After subdying, soaping, washing, drying, etc. may or may not be performed, but after overdying, soaping,
Washing with water and, if necessary, dye fixing treatment, softening treatment, water repellent treatment, flame retardant treatment and the like are performed. The obtained leather-like sheet is in a good dyeing state even inside, and a product with no change in resin quality can be obtained. In particular, a good product with little or no reduction in flex resistance of the resin coating layer is obtained.

[Examples] Next, embodiments of the present invention will be specifically described with reference to Examples.
The parts and% in the examples relate to weight unless otherwise specified.

Examples 1 to 5 Porous polyurethane elastomer consisting of 90 parts of polyester-based polyurethane elastomer and 10 parts of polyether-based polyurethane elastomer in an entangled nonwoven fabric of an ultrafine fiber bundle in which about 450 ultrafine 6-nylon fibers having an average single fineness of 0.006dr are bundled. Made into a fibrous sheet [A] with an apparent density of 0.37 g / cm ₃ and a thickness of 1.5 mm. Suede leather-like sheet [B] and fibrous sheet
[A] One side is coated with a resin liquid mainly composed of polyurethane elastomer to give a non-porous coating layer with an average thickness of about 30 μm, embossed to give a pattern to the surface, and the silvered leather finished Sheet [C] was used as the article to be dyed.

As a sub-dying condition, milling dye [acid blue (dyeing amount 8.5 mg / g)] as dye having a dyeing amount of 10 mg / g or less with respect to 6-nylon fiber and polyurethane elastomer.
(The following (hereinafter referred to as dye M) and the dyeing amount are at least
As a dye of 30 mg / g, a 1: 2 type metal complex salt dye [Acid blue (dyeing amount 148 mg / g)] (hereinafter referred to as dye N) was mixed and dyed by the dip dyeing method under the following conditions, then dyed, sung and washed with water. The dyed state of the dyed product obtained by drying is shown in Table 1.

Total dye concentration 1.5% owf bath ratio 1: 100 temperature-hour 90 ℃ -60 minutes That is, it is considered that the dye having a small dyeing amount does not tend to be adsorbed on the surface and penetrates to the inside.

Next, the underdyed leather-like sheets [B] and [C] were dyed under the following conditions.

Dye and concentration 1: 2 type metal complex dye 1.0% owf Bath ratio 1: 100 Temperature-hour 90 ° C-30 minutes After dyeing, the dyed products obtained by soaping, washing with water, and drying were compared, and as a result, the product of the present invention was in a good dyeing condition to the inside.
In particular, the products of Examples 1 and 2 were products having a soft texture and a smooth surface feel. On the other hand, in the products of Comparative Examples, the dye was dyed only on the surface, and not only the color difference between the surface and the inside was further emphasized, but also the texture was hardened and the surface was rough. Further, in the flex resistance test using a flexometer, the products of the examples showed no abnormality after bending 1,000,000 times, while the products of the comparative examples showed cracks after bending 820,000 times.

Examples 6 to 8 When dyeing the leather-like sheets [B] and [C] of Example 1, as a dye having a dyeing amount of 10 mg / g or less at a dyeing temperature of 40 ° C., a disperse dye [brown (dying amount of 4 mg / g)] (hereinafter referred to as Dye O) and 1: 2 type metal complex salt dye [Acid Brown (dyeing amount 9 mg / g)] (hereinafter referred to as Dye P) are subdyed by the dip dyeing method under the following conditions, and then The dyeing conditions obtained by dyeing with different dyeing conditions, soaping, washing with water, and drying are shown in Table 2.
It was shown to.

(1) Under-dyeing Dye concentration Dye O 1.0% owf (40) Dye P 1.5% owf (60) Bath ratio 1: 100 hours 15 minutes (2) Over-dyeing temperature-time 90 ℃ -60 minutes That is, the leather-like sheet product of the present invention is in a good dyeing state up to the inside, whereas the product of the comparative example has almost no dyeing inside, and only the surface is dark, and the feel is bad. It was

Example 9 When dyeing a leather-like sheet [C] under the conditions of Example 4 and Comparative Example 1, a penetrant of 2 g / amount was used in the subdying process, and in Example 4, the inside was almost satisfactory. Although it was dyed, in Comparative Example 1, the inside was dyed to a degree of contamination. Therefore, only in Comparative Example 1, when the penetrant was increased to 6 g / and under dyeing under the same conditions, the inside was dyed in a slightly light color, but the color difference was large.

Next, when these under-dyed sheets [C] were further dyed under the same conditions as in Example 4, the finished product of Example had a high dyeing fastness in the dyed state up to the inside. However, the finished product of the comparative example had an insufficient dyeing condition inside, and the dyeing fastness was lower than that of the example by about grade 2.

[Effects of the Invention] The present invention is a leather-like sheet composed of two or more materials having different dyeing behaviors, which has less uneven dyeing, can be dyed even in the interior, and has excellent fastness to dyeing, and hardens the texture and feels the surface. It is possible to obtain a product that does not deteriorate in bending resistance and does not deteriorate.

Claims (9)

[Claims] 1. When dyeing a leather-like sheet composed of a resin mainly composed of a fiber entangled body and an elastic polymer, at least 20% by weight of a dye having a dyeing amount of 10 mg / g or less is contained in the fiber and the resin. A method for dyeing a leather-like sheet, which comprises dyeing with a dye composition. 2. The method for dyeing a leather-like sheet according to claim 1, wherein the fiber entangled body is ultrafine fibers having a fineness of 0.3 denier or less and / or bundled fibers thereof. 3. The method for dyeing a leather-like sheet according to claim 1 or 2, wherein the leather-like sheet has fiber naps on its surface. 4. The leather-like sheet according to claim 1 or 2, wherein the surface of the leather-like sheet is provided with a porous or / and non-porous coating layer of a resin mainly containing an elastic polymer. Sheet dyeing method. 5. When dyeing a leather-like sheet composed of a fiber entangled body and a resin mainly composed of an elastic polymer, (1) at least 20 dyes having a dyeing amount of 10 mg / g or less with respect to the fiber and resin are dyed. A step of subdying with a dye composition containing wt%,
(2) A method for dyeing a leather-like sheet, which comprises sequentially performing a step of dyeing with a dye composition having a dyeing amount of at least 30 mg / g. 6. The method for dyeing a leather-like sheet according to claim 5, wherein the fiber entangled body is an ultrafine fiber having a single fineness of 0.3 denier or less and / or a bundle fiber thereof. 7. The method for dyeing a leather-like sheet according to claim 5 or 6, wherein the leather-like sheet has a water absorption rate of 200% or less. 8. The method for dyeing a leather-like sheet according to any one of claims 5 to 7, wherein the leather-like sheet has fiber naps on its surface. 9. The leather-like sheet according to claim 5, wherein a surface of the leather-like sheet is provided with a porous and / or non-porous coating layer of a resin mainly containing an elastic polymer. A method for dyeing a leather-like sheet as described above.