JP3395425B2 - Artificial leather with improved anti-inner color unevenness - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial leather having naps of polyester ultrafine fibers which are excellent in color developability and are stable in quality without inversion color.

[0002]

2. Description of the Related Art The quality of artificial leather is dramatically improved by using an entangled body of ultrafine fibers as a base material, and today, as an authentic artificial leather, an entangled body of ultrafine fibers is used. It has reached the point of being solidified with a polyurethane binder. The role of the ultrafine fibers in this artificial leather is the appearance, texture, flexibility of natural leather,
Although it is extremely large in terms of touch and the like, on the other hand, the drawback is that the color development is poor. Various attempts have been made to improve this, and practically advanced technology has been developed.

For example, in JP-B-58-46593, there is a method in which a polyester obtained by copolymerizing sodium isophthalate sulfonate is used as a polyester ultrafine fiber, and this is dyed simultaneously or separately by using a cationic dye and a disperse dye in combination. It has been proposed, and this method is very effective in improving the color development of the polyester ultrafine fibers. However, when dyeing a wide and long artificial leather, or depending on the color or dye to be dyed, uneven dyeing within the fabric, for example, the color difference between the ear and the center of the fabric, or the color difference between the length direction and the lot In some cases, the dyeing fastness was insufficient or the dyeing fastness was insufficient.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an artificial leather which is more excellent in color developability and has good quality with no inversion color unevenness.

[0005]

The artificial leather with improved anti-inner color unevenness according to the present invention for solving the above problems has the following constitution.

That is, an artificial leather having a nap of polyester ultrafine fibers having a monofilament fineness of 0.3 denier or less on at least one side and dyed with a disperse dye, wherein the polyester ultrafine fibers mainly contain an aromatic dicarboxylic acid. It is composed of a polyester having a dicarboxylic acid component, an alkylene diol as a main diol component, and a sulfonate group-containing isophthalic acid and a polyalkylene glycol as a copolymerization component, and comprises a polyalkylene glycol component.
Polyurethane containing 0.1% by weight or more and 2% by weight or less
It is an artificial leather that is used as a binder and is joined, and has ΔE of 1.5 or less in the Lab color system, in which anti-internal color unevenness is improved.

The present invention will be described in detail below.

The polyester used for the polyester ultrafine fibers constituting the artificial leather of the present invention is a polyester having terephthalic acid as a main dicarboxylic acid component and alkylene diol as a main diol component. A polyester having alkylene glycol as a copolymerization component. Dyeing a fine fiber made of this polyester with a disperse dye or a disperse dye and a cationic dye increases the leveling property at the time of dyeing, and causes CIS-1976
ΔE in the Lab color system based on the year standard (hereinafter simply referred to as “Δ
"E". ) Is 1.5 or less, and an artificial leather with improved anti-inner color unevenness can be obtained. When ΔE exceeds 1.5, the unevenness of the inner color is conspicuous and the appearance is poor.

When polyurethane is used as a binder in the artificial leather of the present invention and is joined, the polyurethane is obtained by copolymerizing 0.1% by weight or more and 2% by weight or less of a glycol component with a normal polyurethane. It is possible to exert the effect even more by using synergistic effect with the polyester ultrafine fiber.

Examples of the sulfonate group-containing isophthalic acid component used in the polyester constituting the ultrafine fibers of the present invention include metal sulfonic acid groups and phosphonium sulfonate groups.

More specifically, examples of the metal as a metal sulfonic acid group include alkali metals such as Na, Li and K. Preferred examples thereof include dimethyl (5-sodium sulfo) isophthalate, bis-2-hydroxyethyl (5-sodium sulfoisophthalate, bis-4hydroxybutyl (5-sodium sulfo) isophthalate. , Na may be replaced with Li or K.

Specific examples of the phosphonium sulfonate group include 3,5-dicarbomethoxybenzenesulfonate tetramethylphosphonium group, 3,5-dimethoxybenzenesulfonate tetrabutylphosphonium group and 3,5-dicarbomethoxybenzenesulfone group. Acid tributylmethylphosphonium group, 2,6-dicarbomethoxynaphthalene-
4-sulfonic acid tetrabutylphosphonium group, 2,6-
Examples thereof include a tetramethylphosphonium group of dicarbomethoxybenzene sulfonate.

The isophthalic acid component containing such a sulfonate group may have only one kind in the polyester, or may have plural kinds.

In the present invention, a polyalkylene glycol component is further used in combination with the isophthalic acid component containing a sulfonate group as a copolymerization component of the polyester constituting the polyester ultrafine fiber.

The main feature of the present invention resides in that an isophthalic acid component containing a sulfonate group and a polyalkylene glycol component are used in combination as a copolymerization component of polyester, whereby coloring and leveling properties are obtained when dyed as artificial leather. Is greatly improved.

The polyalkylene glycol component used in the present invention is preferably an ethylene-based, propylene-based or butylene-based glycol having a molecular weight of 450 to 2000, particularly polyethylene glycol. The molecular weight of glycol is preferably 2000 or less from the viewpoint that the fiber is easily fibrillated.

The polyester used in the present invention has, as its molecular structure, an aromatic dicarboxylic acid as a main dicarboxylic acid component and an alkylene diol as a main diol component. Specifically, ethylene terephthalate units, butylene terephthalate units, A polyester having an ethylene naphthalate unit as a main component and further a copolymer of an isophthalic acid component having a sulfonate group as described above and a polyalkylene glycol component.

From the viewpoint of obtaining a level dyeing effect, the copolymerization ratio of these components is appropriately in the range of 0.6 mol% or more for the isophthalic acid component containing a sulfonate group and 0.2 wt% or more for the polyalkylene glycol component. It is preferable to use them in combination. On the other hand, from the viewpoint of preventing deterioration of strength of the fiber, deterioration of weather resistance after dyeing and deterioration of fastness to wet rubbing, the sulfonate group-containing isophthalic acid component is 3 mol% or less and the polyalkylene glycol component It is preferable to use them in an appropriate combination within the range of 3% by weight or less. These polyesters used in the present invention are disclosed in JP-A-59-265.
It can be obtained by ordinary copolymerization of polyester as disclosed in JP-A No. 21 and JP-A No. 62-299526.

Next, the method for producing the artificial leather of the present invention with improved anti-inner color unevenness will be described.

Ultrafine fibers are formed using the above polyester, and artificial leather is produced using the polyester ultrafine fibers. The ultrafine fibers and artificial leather made of the same are formed by forming ultrafine fibers in advance, and then using the same to form artificial leather, and further using ultrafine fibers or dividable composite fibers, and forming ultrafine fibers in the intermediate step. Conventionally known methods for producing artificial leather, such as the method for forming artificial leather by applying the above method, can be applied as they are. In this,
The effect of the present invention is particularly exhibited when the single fiber fineness of the fiber is 0.3 denier or less, preferably 0.1 denier or less. Generally, in such an ultrafine fiber region, the color developability of the fiber is significantly reduced.

Furthermore, as a more complicated artificial leather,
There is an artificial leather in which a non-woven fabric composed of ultrafine fibers and a woven or knitted fabric having different heat history or fineness of single fiber and having slightly different dyeing characteristics are integrated. As a concrete example of this, a normal woven or knitted material made of polyester, polyamide, polyphenylene sulfide, polyolefin, cotton, rayon, wool or the like, or a woven or knitted material made of ultrafine fibers having a single fiber fineness of 1 denier or less, and an artificial There is a piece of leather glued and bonded together. In addition, a woven or knitted material made of these materials and a polyester microfiber non-woven fabric are overlaid, and then a base material that is entangled and integrated with each other is formed by a needle punch or a water jet punch, and using this base material, an artificial leather is prepared by an ordinary method. Eggplant can be given. Artificial leather with such a structure has dimensional stability that cannot be obtained with conventional artificial leather,
It is possible to obtain improvement effects such as compatibility of strength, thinness and flexibility.

In the artificial leather, polyurethane may be used as a binder in addition to the combination of various fiber materials.

It is more difficult to uniformly dye such a complex artificial leather having many kinds of materials. That is, for example, even if fibers made of the same material and polymer have different monofilament fineness, when dyed, the distribution ratio (exhaust rate) of the dye to each fiber having different monofilament fineness is Depends on Therefore, it is considered that uneven dyeing occurs due to complicated distribution of dyes during the temperature rising process at the start of dyeing and the temperature decreasing process at the completion of dyeing. Furthermore, this dyeing unevenness is a very subtle thing that appears as a noticeable difference if the heat history is different even if the fibers are the same material and polymer and have the same single fiber fineness. Further, as described above, when polyurethane is added as a binder, the dyeing behavior becomes more complicated, and dyeing management becomes extremely difficult. Therefore, it can be understood that this improvement involves great difficulty.

The present invention can be applied to the case where the fibers constituting the woven or knitted fabric have the same dyeability as the ultrafine fibers of the non-woven fabric, but when both have different dyeability, especially ΔE is 1.5.
The effect is exhibited in the case different from the above.

As the polyurethane which can be used in the present invention, known ones generally used in artificial leather can be used. Specifically, for example, as the isocyanate, there are those selected from the group of isocyanates mainly having bifunctionality such as diphenylmethane diisocyanate, tolylene diisocyanate, dicyclohexylmethane diisocyanate, and the soft segment is polyether glycol, polyester glycol, Polycarbonate-based glycols, more specifically those having polytetramethylene glycol, polypropylene glycol, polybutylene adipate glycol, polyethylene adipate glycol, polycarbonate glycol and the like. Further, a chain extender having a usual glycol or diamine may be used.

The polyurethanes can be used in the artificial leather of the present invention, from the viewpoint of dyeing improvement, the polyalkylene glycol component of 0.1 wt% or more based on polyurethane contains
In addition, from the viewpoint of maintaining durability and preventing deterioration of dyeing resistance at high temperatures, the content of 2% by weight or less is used.
is there. As the polyalkylene glycol, specifically, polyethylene-based, polypropylene-based, polybutylene-based and modified glycols thereof are preferable. The molecular weight is preferably 400 to 2000.

In order to obtain such a polyurethane, polyalkylene glycol and another glycol may be simultaneously added as a diol component and polymerized in a normal polyurethane polymerization, or a prepolymer of polyalkylene glycol and an isocyanate may be formed in advance. Aside
This may be added to an ordinary prepolymer and polymerized. By incorporating such a polyalkylene glycol into the polyurethane, the affinity between the polyurethane and the dye in the dyeing process can be adjusted, and the dyeing behavior with the polyester ultrafine fibers can be well matched to improve the dyeing unevenness.

Further, such a polyurethane is relatively easy to remove a dye and is excellent in dyeing fastness (color fading). That is, generally, the dye exhausted to the polyurethane is easily discharged from the polyurethane after dyeing, and this tendency is particularly strong when dyeing with a disperse dye, which leads to a decrease in dyeing fastness as "color fading". Is. It can be said that it is preferable to forcibly remove the dye from the polyurethane in order to prevent the "color fading" and the deterioration of the dyeing fastness. The polyurethane containing the polyalkylene glycol component applied to the present invention in an amount of 0.1% by weight or more and 2% by weight or less is relatively easy to remove the dye,
It is also excellent in dyeing fastness (color fading).

Dyeing of the artificial leather in the present invention can be appropriately performed by using a disperse dye alone or a combination of a disperse dye and a cationic dye in one bath, or a two-bath dyeing of the disperse dye and the cationic dye. The dyes that can be used are both disperse dyes and cationic dyes, and commercially available dyes can be used, but in the case of a special combination, problems such as dye precipitation and staining may occur. PH
It is effective to properly select and add a regulator and a dye-proofing agent. Further, it is possible to appropriately incorporate reduction washing and washing with a surfactant after dyeing.

[0030]

EXAMPLES The present invention will be described more specifically below with reference to examples.

[Examples 1 to 3 and Comparative Examples 1 to 3] As a polyester, ethylene terephthalate was used as a main repeating unit, and as shown in Table 1, an isophthalic acid component (component A) containing a sulfonate group and a polyalkylene. A polyester containing a glycol component (B component) was produced by an ordinary method.

Using each of these polyesters as an island component and polystyrene as a sea component, a polymer array fiber defined in JP-B-46-3816 is disclosed in JP-B-47-26723.
It was manufactured using the apparatus described in Japanese Patent Publication No. At this time, the island component ratio was 50%, and the number of islands was 16 / filament.

The obtained fiber was applied to a card and a cross wrapper to prepare a web, and then needle punched to make a felt. The felt was contracted, dipped in a 12% aqueous solution of polyvinyl alcohol and dried, and then dipping with trichloroethylene and squeezing were repeated.

After drying, 12% of polyurethane consisting of dimethyldiisocyanate as the isocyanate with polytetramethylene ether glycol as the soft segment
It was impregnated with a dimethylformamide (DMF) solution and coagulated in water. After drying, it was sliced into two pieces, buffed on both sides, and each level had a thickness of 0.7 mm and a length of 30 m. This was dyed under the following dyeing conditions, and the fabric after dyeing was subjected to usual reduction washing.

<Dyeing conditions> Dye Disperse dye Resoline blue 0.3 wt% Kayaron polyester rubin 3.5 wt% Terra seal orange 1.6 wt% Cationic dye Kayacryl yellow 0.7 wt% Catillon red 6.0 wt% Catillon blue 0.5% by weight Dyeing temperature 120 ° C. × 1 hour ΔE in the width direction for each dyed fabric thus obtained
And L value were measured by a colorimeter (multi-source spectrophotometer manufactured by Suga Test Instruments Co., Ltd .: model MSC-2).

Table 1 shows the maximum value of ΔE at each level of anti-inner color unevenness and the minimum value of L value as the color developability.

[0037]

[Table 1] As is clear from Table 1, the artificial leathers of the present invention (Examples 1 to 3) are excellent in color development without unevenness in inner color, while in Comparative Examples, both or one of The characteristics were inferior.

[Examples 4 to 7 and Comparative Example 4] As a polyester, ethylene terephthalate was used as a main repeating unit, and a dimethyl (5-sodium sulfo) isophthalate component was added at 2 mol% to polyethylene glycol (component B). Polyesters were prepared in which the copolymerization ratio (% by weight) was changed as shown in Table 2.

Using each of the polyesters as an island component and polystyrene as a sea component, the number of islands was 70 islands / filament and the island ratio was 60%, and the yarn was spun in the same manner as in Example 1 to obtain 3.5 denier polymer array fibers. .

The obtained fiber is applied to a card or a cross-wrapper to prepare a web, and a woven fabric composed of the web and polyethylene terephthalate fiber (50 denier-92 filament, twist number 2000 times / m) is layered and needled. Punching was performed to obtain a needle punch felt.

Using the felt thus obtained, leather production and dyeing were carried out in the same manner as in Example 1. The length of this dyed fabric is 10 each
It was m. Then, ΔE, L value,
The weather fastness and wet rub fastness were measured. In this measurement, the weather fastness is JIS L 0804 (gray scale for discoloration and fading), and the wet friction fastness is JIS L 0849.
Was carried out according to.

The results are shown in Table 2.

[0043]

[Table 2] The sample of Example 5 was immersed in dimethylformamide to remove the polyurethane, and then the ultrafine fiber non-woven fabric portion was removed to expose the woven fabric, and the ΔE between the woven fabric and the ultrafine fiber was measured. As a result, this value was 3.7.

[Example 8] As a polyester, ethylene terephthalate was used as a main repeating unit.
Intrinsic viscosity 0.63 obtained by copolymerizing 5-dicarbomethoxybenzenesulfonic acid tetramethylphosphonium group in a proportion of 1 mol% and polyethylene glycol in a proportion of 0.8% by weight.
(Measured with an orthochlorophenol solution at 25 ° C.) was used.

Using this polyester, yarn production, leather production and dyeing were carried out in the same manner as in Example 4. The ΔE of this sample was 1.1, and the L value was 19.5.

[Examples 9 to 11 and Comparative Examples 5 to 6] As the polyester, butylene terephthalate was used as the main repeating unit, 1.5 mol% of dimethyl (5-sodiumsulfo) isophthalate and 1% by weight of polyethylene glycol were used. Polymerized polyester was used. Using this polyester, a polymer array fiber was produced in the same manner as in Example 1.

Then, using the obtained fiber, the woven fabric to be laminated on the web is composed of 75 denier-94 filament made of a polyester obtained by copolymerizing ethylene terephthalate as a main repeating unit with 3 mol% of dimethyl (5-sodiumsulfo) isophthalic acid. An artificial leather was obtained in the same manner as in Example 4 except that a woven fabric was used.

As the polyurethane to be used, the polyurethane used in Example 1 is mainly used, and the proportion of copolymerization of polyethylene glycol (component C) (% by weight) is used.
The leather was changed to the one shown in Table 3 to produce leather.

The dye thus obtained was dyed with 10% by weight of resorin blue, 5% by weight of terra-seal orange, and 10% by weight of catillon blue.

ΔE, L value and wet-rubbing fastness were measured for each level of dyed fabric, and the results are shown in Table 3.

[0051]

[Table 3] Color unevenness is seen in Comparative Example 5 as compared with Examples 9 to 11,
The fastness to wet rubbing was also slightly poor. In Comparative Example 6, some tears occurred during dyeing.

[0052]

EFFECTS OF THE INVENTION According to the present invention, an artificial leather using an ultrafine fiber, which has been a problem in the past, can be obtained, which has sufficient coloring property and is free from uneven inner color and has good dyeing fastness. To be

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-63-152403 (JP, A) JP-A-51-136922 (JP, A) JP-A-59-26521 (JP, A) JP-B-58- 46593 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) D06P 3/00 D01F 6/86

Claims (3)

(57) [Claims] 1. An artificial leather having a nap of polyester ultrafine fibers having a single fiber fineness of 0.3 denier or less on at least one side and dyed with a disperse dye, wherein the polyester ultrafine fibers are mainly aromatic dicarboxylic acid. It is composed of a polyester having a dicarboxylic acid component, an alkylene diol as a main diol component, and a sulfonate group-containing isophthalic acid and a polyalkylene glycol as a copolymerization component , and a polyalkylene glycol component of 0.1% or less.
Polyurethane containing from 2% to 2% by weight as binder
The artificial leather with improved anti-inner color unevenness, characterized in that the ΔE of the Lab color system is 1.5 or less. 2. A polyester ultrafine fiber comprising a polyester having a sulfonate group-containing isophthalic acid as a copolymerization component in an amount of 0.6 to 3 mol% and a polyalkylene glycol in an amount of 0.2 to 3% by weight. The artificial leather with improved anti-inner color unevenness according to claim 1. 3. The artificial leather with improved anti-inner color unevenness according to claim 1, wherein the polyester ultrafine fibers are integrated with a woven or knitted fabric having a different dyeability from the polyester ultrafine fibers. .