JP2799354B2 - Dyeing method for foamed polyurethane - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for dyeing polyurethane foam. The present invention relates to footwear such as shoes and boots (hereinafter simply referred to as shoes).
It is particularly useful for dyeing a foamed polyurethane molded article used as a part of the product.

2. Related Art and its Problems In recent years, demand for high added value of shoes has rapidly increased, and fashionability and functionality have also been required for shoe soles. As a result, many new materials have come to be used and colored.
In particular, shoes manufactured by bonding polyurethane unit shoe soles or polyurethane direct soap are highly evaluated in terms of fashionability and functionality. At present, coloring of polyurethane is mainly performed by the following methods, but in each case, not only clear coloring is not obtained, but also there are other disadvantages.

(1) There is a method of manufacturing a unit sole by mixing and kneading a coloring material with a polyurethane raw material.

However, in this method, when the color is changed, the raw material tank needs to be washed, and the remaining colored raw material is wasted, so that it is unavoidable that the cost is increased. Further, the types of colors are limited to about two or three colors due to the mixing property with the raw material.

(2) There is a method of manufacturing a multicolor combination integral type polyurethane sole shoe by an injection molding method.

However, this method is expensive because the injection molding machine used is expensive, and the type of color is limited.

(3) There is a shadow processing method in which a polyurethane-based paint containing a coloring material is spray-painted on a unit sole or an injection-molded shoe sole and colored.

In this method, since only the surface layer of the sole is colored, the colored layer is easily worn. In addition, since the paint does not spread to the fine air pool, uniform coloring cannot be obtained, and buffing is necessary when bonding the shoe sole.

(4) In producing a unit sole or direct-shoe injection shoes, there is a method in which a colored polyurethane-based paint is sprayed on a mold in advance, and after drying, polyurethane is immediately injection-molded.

In this method, the spray unevenness of the sole, coloring other than the sole,
It is easy to cause contamination of the equipment. Also, since only the surface layer is colored, the colored layer is immediately worn.

Means for Solving the Problems As a result of repeated studies in view of the state of the art as described above, the present inventor has found that (a) foamed polyurethane can be dyed with a disperse dye, (b) surprisingly, This staining operation
It has been found that it is completed at a lower temperature and in a shorter time than a general dyeing operation, and that (c) the thick colored layer formed is clear and extremely excellent in fastness to sunlight and washing. .

That is, the present invention provides the following method: A method for dyeing a foamed polyurethane, which comprises dyeing the foamed polyurethane with a disperse dye.

The dyeing method as described above, wherein the foamed polyurethane is a part of shoes or boots.

The present invention has been completed based on the coloring of foamed polyurethane originally used as shoe soles, but is applicable to coloring of all foamed polyurethane products. Therefore, in the following, the present invention will be described by taking coloring of soles as a typical example, but the present invention is not limited to such an example.

The foamed polyurethane to be the object of the present invention is a material known as a material for manufacturing shoe soles, and is not particularly limited.Specifically, polyol-based, polyester polyol-based, and polyether-based prepolymers and isocyanates Are exemplified. Among these, foamed polyurethane obtained from polyester polyol and methylene diisocyanate, which are most commonly used for producing shoe soles, are preferred.

The disperse dye used in the present invention is not particularly limited, and specifically, Disperse Fast Yellow, Disperse F
ast Brown, Disperse Fast Orange, Disperse Fast Rub
ine, Disperse Red, Disperse Blue, Disperse Green,
Disperse Diazo Black, Disperse Direct Black, Diper
Known disperse dyes such as se Luminas are exemplified.

The method of the present invention is usually carried out as follows. First, after preparing a dyeing bath having a concentration appropriately determined according to the type of the dye, the use of the shoe sole, and the like, the foamed polyurethane product is immersed in the bath to dye. As a dyeing bath, either a hot water bath or a hot water bath containing a penetrant can be used,
In order to dye deep inside the foamed polyurethane product,
It is preferable to use a hot water bath containing a penetrant. Known penetrants such as anionic surfactants such as sodium dioctyl sulfosuccinate used in ordinary fiber dyeing baths, alkylnaphthalene sulfonates, and fatty acid condensates can be used. Dyeing conditions vary greatly depending on the type of disperse dye used, desired color density, product dimensions, product form, desired washing fastness, etc., but usually at a temperature of about 70 to 90 ° C. for 10 to 30 minutes. It is enough to hold the degree. In ordinary dyeing, a low temperature of less than 80 ° C requires a long operation, but in the method of the present invention,
Even at a low temperature of about 70 to 80 ° C., the required time may be 30 minutes or less. After dyeing, the product is washed with water, soaped, washed again with water and dried as in the case of dyeing the fibers.

Effects of the Invention According to the present invention, the following remarkable effects are achieved.

(1) The foamed polyurethane product can be easily dyed under mild conditions.

(2) The foamed polyurethane product according to the present invention has a thickness of 1 to
It shows vivid colors up to about 2 mm and fine pinholes with uneven patterns.

(3) The foamed polyurethane product dyed has excellent fastness to sunlight and washing, and does not transfer color.

(4) There are many types of colors that can be dyed.

(5) In the case where the shoe unit sole is dyed by the method of the present invention, it is possible to dye in units of several pairs or one pair, so that individual shoes can be produced at a low price according to the customer's favorite color. It became possible to provide.

(6) Since the use of expensive injection molding machines is not required, and there is no loss of raw materials or loss of waiting time, the production cost of shoes is greatly reduced from this point as well.

(7) It is not necessary to perform a pretreatment such as buffing on the adhesive surface of the shoe unit sole, and a strong adhesive force can be obtained even if the primer treatment is omitted.

Examples Hereinafter, examples will be shown to further clarify features of the present invention.

Example 1 Using a composition composed of a polyester polyol and methylene diisocyanate, specific gravity 0.60, size
A 23.0 cm foamed polyurethane unit sole was manufactured.

Using the disperse dye shown below, a dye bath having a dye concentration of 1 g / l and a penetrant concentration of 1 g / l was prepared, and the foamed polyurethane unit sole was immersed therein at a temperature of 80 ° C. for 10 minutes, and then washed with water. And an anionic activator (trademark "Monogen",
It was immersed in a 2 cc / l solution of Daiichi Kogyo Seiyaku Co., Ltd. at 50 ° C. for 1 minute, washed again with water, and dried at 50 ° C. for 10 minutes.

Table 1 shows the color and sunlight fastness of each dyed product (JIS L-0841
Grade) and washing fastness (JIS L-0844 grade)
Is shown.

In addition, only the disperse dye No. B used was manufactured by BASF Corporation.
The details of all other products manufactured by Sumitomo Chemical Co., Ltd. are as follows.

A; Sumikaron Brilliant Flarine S-10 B; Paranil Luminas Red GC; Sumikaron Red S-RPD D; Sumikaron Yellow SE-RPD E; Sumikaron Yellow S-RPD F; Sumikaron Red SE-RPD G; Sumikaron Blue S-RPD H; Sumikaron Black S-BL From the results shown in Table 1, it is clear that the process according to the invention makes it possible to dye foamed polyurethane products in virtually all colors.

In addition, when each product was cut and its dyeing depth was observed, it was dyed at least 1 mm or more from the surface.

Reference Example 1 A synthetic leather upper and a midsole were suspended, a polyurethane-based adhesive was applied and dried, and shoes in which each unit sole obtained in Example 1 was pressure-molded and assembled were manufactured.

When these shoes were tested and tested, after one month, the color was not changed at all and the appearance was good. After February, the bottom was slightly worn (about 0.5 mm), but no color change was observed.

The adhesive strength between the dyeing unit sole and the shoe shell was 3.0 kg / cm for normal adhesive strength and 3.0 kg / cm for water-resistant adhesive strength. No peeling occurred even after two months of test wear.

Furthermore, sublimation which was a concern when a disperse dye was used did not occur at all, and as a result, no dye transfer (color transfer) from the dyeing unit sole to the shoe upper and the insole was observed. This indicates that the disperse dye and the polyurethane foam were completely reacted according to the method of the present invention.

Comparative Example 1 A foamed polyurethane sole was dyed in the same manner as in Example 1 except that a metal-containing acid dye or an acid dye was used as the dye.

Table 2 shows the color of each dyed product, the permeability to the polyurethane foam, and the dyeability.

The details of the dyes used (all manufactured by Sumitomo Chemical Co., Ltd.) are as shown below. I to V are metal-containing acid dyes, and VI to X are acid dyes.

I; Lanyl Brilliant Yellow 3G II; Lanyl Orange R III; Lanyl Red GG IV; Lanyl Brilliant Blue G extra conc V; Lanyl Black BG extra conc VI; Suminol Milling Red RS 120% VII; Suminol Milling Bordeaux B VIII; Suminol Milling Black VLG IX; Suminol Milling Brown 3G X; Suminol Milling Yellow O The criteria for determination shown in Table 2 are as follows.

×: Only adheres to the surface and does not penetrate.

B ... Contaminated but not stained.

(B) Only the surface is stained.

C ... not dyed.

As is clear from the results shown in Table 2, when a metal-containing acid dye or an acid dye is used, it is not possible to dye a foamed polyurethane product.

Reference Example 2 An outsole unit (1) made of urethane foam shown in FIG. 1 was produced by injection molding using the following raw materials.

Liquid I: methylene diisocyanate component (trademark "U-950P", manufactured by Toyo Tire & Rubber Co., Ltd.) 18.900 kg II liquid: polyol component (trademark "U-950RCN", manufactured by Toyo Tire & Rubber Co., Ltd.) 18.000 kg Catalyst 0.240 kg Pigment / foam stabilizer 0.720 kg The molding conditions were cream time 7 seconds, tack-free time 35 seconds, rise time 60 seconds, and temperature 45 ° C. The specific gravity of the obtained product was 0.48.

Next, the outsole unit (1) is dyed using the disperse dyes A to H in the same manner as in Example 1, and then inserted and fixed in the outsole portion of the bottom mold (3), and the final mold (5) is formed. The mounted shoe shell (7) and side mold (9) are set in place, and the polyurethane material is injected into the space corresponding to the midsole (11) under the above conditions, and the two-color bottom is injected. Molded polyurethane shoes were manufactured.

The obtained shoes showed the same excellent performance as the shoes obtained in Reference Example 1.

[Brief description of the drawings]

FIG. 1 is a drawing showing an outline of a method for producing an injection-molded polyurethane shoe using an outsole unit made of a polyurethane foam obtained by the method of the present invention. (1) Outsole unit (3) Bottom mold (5) Last (7) Shoe cover (9) Side mold (11) Midsole

Claims (2)

(57) [Claims] 1. A method for dyeing a foamed polyurethane, comprising immersing the foamed polyurethane in a dyeing bath containing a disperse dye and a penetrant at a temperature of 70 to 90 ° C. 2. The method according to claim 1, wherein the foamed polyurethane is a part of shoes or boots.