JPH06294081A - Method for coloring leather - Google Patents

Abstract

PURPOSE:To obtain a soft colored material of leather excellent in abrasion resistance and washability, etc., and colorable even in the interior by subjecting a leather to immersion treatment with a bath containing an aqueous pigment dispersing body, a bath containing a synthetic resin emulsion and then a bath containing a crosslinking agent. CONSTITUTION:Tanned leather is subjected to immersion treatment with a bath containing an aqueous pigment dispersing body obtained by dispersing a pigment consisting of an inorganic or organic pigment and having 50-300nm particle diameter using preferably an anionic and a nonionic surfactant and then subjected to immersion treatment with a bath containing a copolymer emulsion obtained by subjecting (meth)acrylic acid ester, etc., as a synthetic resin emulsion and successively, a bath containing a crosslinking agent (e.g. ethylene glycol diglycidyl ether) to emulsion polymerization to provide a colored material of leather excellent in abrasion resistance and washability as well as tearing strength and colorable even in the interior of leather. In this leather, strong film binding to a part of dispersing agent of pigment and binding to a part of the synthetic resin emulsion is formed on the surface of leather and in the interior of the leather and the pigment is retained in the film.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is excellent in light resistance, abrasion resistance, washing resistance, tear strength, has a soft texture, has a beautiful appearance in which the leather surface is uniformly colored, and even the inside of the leather is colored. The present invention relates to a coloring method for obtaining a leather colored product.

[0002]

2. Description of the Related Art Leather is used for shoes, bags, clothes, furniture, etc.
It is a material closely related to everyday life. Leather is rarely used in tanned leather itself, and is generally dyed with a dye,
Alternatively, it is further coated with a dye or pigment to protect and beautify the surface and at the same time hide the scratches on the leather surface to enhance the commercial value. Acid dyes, direct dyes,
Although basic dyes are used, it has the advantage of being able to dye the inside of the leather tissue, but it also has the disadvantages of light resistance, abrasion resistance, poor washing resistance, etc. Therefore, leather dyed with a dye is rarely used as it is, and is coated with a pigment-containing paint in order to make up for the disadvantages or obtain an arbitrary color. On the other hand, some leather finishes the surface of the leather only with pigment-containing paint, but in many cases the color of the cut surface and the back surface is unified, and after dyeing with a dye of the same color to increase the commercial value, it is necessary to paint with pigment-containing paint. It was the current situation that I didn't get a mark.
Studies have been conducted on methods for dyeing leather with pigments that can solve the disadvantages of these dyes all at once, but it is not always possible to find satisfactory ones, such as a reduction in leather tear strength, a reduction in friction fastness, and a loss in leather texture. The current situation is that they have not been obtained.

[0003]

DISCLOSURE OF THE INVENTION In the present invention, in coloring leather, the synthetic resin emulsion, which is part of the cause of the deterioration in the fastness, is wrapped with the crosslinker at the same time as the synthetic resin emulsion is wrapped. By promoting cross-linking between the two and smoothing out the formation of a strong resin film, the original strength of the leather that could not be solved by the conventional dyeing method for leather is maintained, and light resistance, abrasion resistance, washing resistance, It is intended to provide a leather colored product which has excellent tear strength, a soft texture, a uniformly colored appearance, and even the inside of leather.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a pigment which has not been completely wrapped in a synthetic resin emulsion, which is a cause of a decrease in fastness, is wrapped with a crosslinking agent, and at the same time, crosslinking between the synthetic resin emulsions is promoted. It is a coloring method for obtaining colored leather having high fastness which cannot be solved by the conventional dyeing method of leather by smoothing the formation of a strong resin film.

That is, the present invention relates to a method for coloring leather, which comprises successively immersing the leather in a bath containing an aqueous pigment dispersion, a synthetic resin emulsion and then a bath containing a cross-linking agent. The present invention relates to a method for coloring leather, which comprises immersing in a bath containing an aqueous pigment dispersion and synthetic resin emulsion, and then immersing in a bath containing a crosslinking agent.

The leather used in the present invention is not particularly selected in the wet or dry state as long as it is leather of cattle, pigs, sheep, goats or the like which has been tanned with chrome or vegetable tannins. Examples of the pigment used in the present invention include inorganic pigments such as titanium oxide, yellow iron oxide, red iron oxide, carbon black, and organic pigments such as insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, slene pigments, and quinacridone pigments. , Dioxazine pigments, isoindolinone pigments, etc. with excellent light resistance and wash resistance are selected.

The aqueous pigment dispersion used in the present invention is
The pigment is dispersed in water with a surfactant, and the average particle diameter of the pigment is 50 nm to 300 nm. The pigment content in the aqueous pigment dispersion is from 5 parts by weight (hereinafter, simply referred to as “parts”) to 80 parts, preferably from 10 parts to 60 parts. Sufficient coloring power cannot be obtained at 5 parts or less, and at 80 parts or more. A good aqueous pigment dispersion cannot be obtained.

The surfactant component for dispersing the pigment is preferably an anionic surfactant, a water-soluble nonionic surfactant, or a combination of an anionic surfactant and a water-soluble nonionic surfactant. Examples of the ionic surfactant include alkyl sulfates, alkylbenzene sulfonates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and polyoxyethylene alkyl sulfates. Examples of the water-soluble nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, and polyoxyethylene fatty acid ester.

The amount of the surfactant used to disperse the pigment is
5 to 70 parts per 100 parts of pigment in the aqueous pigment dispersion
Parts, the minimum controlled amount that allows dispersion of the pigment. The amount of the pigment dispersion used is 1 to 30 parts, preferably 1 to 15 parts, relative to 100 parts of chromium tanned leather (hereinafter referred to as tanned leather) containing 50% by weight (hereinafter, simply referred to as “%”) of water. If it is less than 1 part, sufficient coloring power cannot be obtained,
When the amount is 30 parts or more, the improvement in coloring is not observed despite the large amount used.

The synthetic resin emulsion used in the present invention means monomers of acrylic acid, acrylic acid ester, methacrylic acid ester, vinyl chloride, vinyl acetate, ethylene, styrene, butadiene, alone or as a constituent in the resin. An emulsion of a copolymer obtained by emulsion polymerization. As a monomer component, for example, acrylic acid /
Acrylic acid ester, acrylic acid / methacrylic acid ester, acrylic acid / acrylonitrile, acrylic acid / styrene, acrylic acid / butadiene, acrylonitrile,
Acrylic acid / acrylic acid ester / methacrylic acid ester, acrylic acid / acrylic acid ester / methacrylic acid ester / acrylonitrile, acrylic acid / acrylic acid ester / methacrylic acid ester / acrylonitrile / styrene, acrylic acid / acrylic acid ester / Methacrylic acid ester / acrylonitrile / styrene / butadiene, acrylic acid ester / methacrylic acid ester, acrylic acid ester / acrylonitrile, acrylic acid ester / styrene, acrylic acid ester / butadiene, acrylic acid ester / methacrylic acid ester / Acrylonitrile, acrylic ester / methacrylic ester / acrylonitrile / styrene, acrylic ester / methacrylic ester / acrylonitrile /
Styrene / butadiene, methacrylic ester / acrylonitrile, methacrylic ester / styrene, methacrylic ester / butadiene, methacrylic ester / acrylonitrile / styrene, acrylonitrile / styrene, acrylonitrile / styrene / butadiene, styrene / Butadiene, acrylic acid / methacrylic acid ester / acrylonitrile, acrylic acid / methacrylic acid ester / acrylonitrile / styrene, acrylic acid / methacrylic acid ester / acrylonitrile / styrene / butadiene, acrylic acid / acrylonitrile /
Styrene, acrylic acid / acrylonitrile / styrene /
Butadiene, acrylic acid / styrene / butadiene, acrylic ester / acrylonitrile / styrene, acrylic ester / acrylonitrile / styrene / butadiene, acrylic ester / styrene / butadiene, methacrylic ester / styrene / butadiene, acrylic acid / chlorinated Vinyl, acrylic ester / vinyl chloride, methacrylic ester / vinyl chloride, acrylonitrile / vinyl chloride, styrene / vinyl chloride, butadiene / vinyl chloride, vinyl acetate / vinyl chloride, acrylic acid / ethylene, acrylic ester / ethylene, Methacrylic acid / ethylene, acrylonitrile / ethylene, styrene /
Examples include ethylene, butadiene / ethylene, vinyl acetate / ethylene, vinyl chloride / ethylene, vinyl acetate / vinyl chloride / ethylene, and the like.

The resin solid content in the emulsion is 20% to 60%, and the resin particle diameter is 0.1 μm to 0.5 μm.
It is a liquid substance emulsified in water having an average diameter of 0.2 μm.
Furthermore, a urethane emulsion containing a urethane group inside the molecule can also be used. These products are generally widely marketed and used properly depending on the desired texture. Further, use of a crosslinkable emulsion resin having a carboxyl group, an amide group, an epoxy group, a methylol group, etc. inside the molecule is preferable for obtaining a colored leather with a pigment having high fastness. These synthetic resin emulsions are made from 100 leathers.
0.5 to 15 parts per part, preferably 1 to 1 part
0 parts are used.

The cross-linking agent used in the present invention is a compound having two or more ring-opening reactive groups in the molecule, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglyceride. Glycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol polyglycidyl ether,
Glycerol polyethylene oxide polyglycidyl ether, trimethylolethane polyglycidyl ether, trimethylolpropane polyglycidyl ether,
3-methylpentanetriol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, diglycidyl dimethylhydantoin, triglycidyl isocyanurate, succinic acid diglycidyl ether, adipic acid diglycidyl ether and the like can be mentioned. In addition to these, diphenylmethane-bis-4,4-N, N'-ethyleneurea may be mentioned.

These cross-linking agents combine with a part of the pigment dispersant and also with a part of the synthetic resin emulsion to form a strong film on or inside the leather fiber.
By holding the pigment in these films, abrasion resistance,
It is possible to obtain a leather coloring material having excellent wash resistance. These crosslinking agents are supplied as the compound itself or as an aqueous solution or as an aqueous dispersion, and 0.1 part to 10 parts, preferably 0.2 part to 5 parts, in terms of solid content with respect to tanned leather, is a preferable range of use. .

The general method of the coloring step according to the coloring method of the present invention is as follows. Most of the steps of the present invention are carried out in an aqueous medium. A drum is used as the coloring device, but the coloring device is not particularly limited, and any device having a similar function can be used. The rotation speed of the drum is 5 to 50 rotations per minute, and the optimum rotation speed is determined by the drum capacity and diameter. Put leather inside the drum,
300 to 1000 parts of water is added to 100 parts of leather, and the product is rotated for 20 minutes and washed with water. Care must be taken as rotation will damage the tanned leather tissue over a long period of time. The rotation time varies depending on the size of the drum, the number of rotations, the amount of tanned leather to be added, and the amount of water added, but it is generally about 20 to 60 minutes. Replace the bath with 200 parts of water,
Add 1.5 parts of sodium formate and 1.0 part of sodium bicarbonate and rotate for 40 minutes to neutralize. This step is to uniformize the pH change and partial deviation of the tanned leather over time, and to maintain the optimum pH for coloring with the pigment in the next step.

Next, the bath is replaced with 50 parts of warm water at 50 ° C., 2.0 parts of auxiliary synthetic tanning agent, 3.0 parts of alternative synthetic tanning agent, 3.0 parts of vegetable tanning agent, and 5. 0 part of the aqueous pigment dispersion is added sequentially or all at once, and the mixture is rotated for 60 minutes to perform pigmentation. Auxiliary synthetic tanning agents, alternative synthetic tanning agents,
At the same time when the leather is re-tanned, it also has a function of helping the pigment to penetrate into the surface or inside of the leather fiber. Continuously 150 parts of warm water at 50 ° C. and 12.0 parts of anionic greasing agent, 3.0
Part of the synthetic resin emulsion is sequentially or all at once, and is rotated for 60 minutes. This step is to impart flexibility to the leather and prevent migration of the pigment to the surface, and at the same time, to bond with the crosslinking agent in the next step. Then add formic acid and rotate. This operation is repeated and the pH of the bath is changed between 3.0 and 4.0. Next, a crosslinking agent is added and the mixture is rotated for 30 minutes. Further, a cation resin tanning agent is added, the bath is rotatively drained for 10 minutes, the final step of washing with water is carried out with water at 30 ° C., the water is drained off, and the coloring step with a filler is completed. After that, the leather is dried according to the usual method.

[0016]

【Example】

(1) Preparation of Pigment Dispersion 1 Carbon Black (CI Pigment Black 7) 25
Parts, 1 part of sodium lauryl sulfate, 6 parts of polyoxyethylene oleyl ether (HLB13.6), and 68 parts of water were dispersed in a sand mill to obtain a tube gauge (JISK-540).
Coarse particles of the dispersion were measured by a method according to 0) 10 μ
A black pigment aqueous dispersion having an average particle size of 0.10 μm or less (measured with a centrifugal sedimentation type particle size distribution measuring device) was prepared.

(2) Preparation of Pigment Dispersion 2 Insoluble Azo Yellow (CI Pigment Yellow 83) 20
Parts, polyoxyethylene nonyl phenyl ether (HL
B14.5) 10 parts and water 70 parts were dispersed by a sand mill. Wedge gauge 10μm or less, average particle size 0.08μ
m yellow pigment aqueous dispersion was prepared.

(3) Preparation of Pigment Dispersion 3 3 parts of carbon black, 10 parts of insoluble azo yellow (CI Pigment Yellow 83), 7 parts of quinacridone violet (CI Pigment Violet 19), sodium salt of phosphoric ester of polyoxyethylene lauryl ether 7 And 73 parts of water were dispersed by a sand mill. A brown pigment aqueous dispersion having a tub gauge of 10 μm or less and an average particle diameter of 0.15 μm was prepared.

Example 1 Chrome tanned cowhide thickness 1.4 mm, paired tanned leather 100 parts Bath pH Washing with water 300 parts Water (30 ° C.) 20 minutes rotation, drainage neutralization 200 parts Water (30 ° C.) 1.5 parts Sodium formate 1.0 part Sodium bicarbonate 40 minutes rotation, bathing 5.5 Retanning 50 parts Water (50 ° C) 2.0 parts Collagen V (Hoechst brand name) 3.0 parts Orotan T (Rohm & Haas company) Trade name) 3.0 parts Mimosa powder 5.0 parts Pigment dispersion 1 60 minutes rotation Greasing 150 parts Water (50 ° C) 12 parts Turcon ON200 (Taiko Yushi Co., Ltd. trade name) 3.0 parts Tokuryl N220 60 minutes rotation (Product name of Toyo Ink Mfg. Co., Ltd .; carboxyl group-containing acrylic resin emulsion) 0.5 parts Formic acid 10 minutes rotation 0.5 parts Formic acid 10 minutes rotation 0.5 parts Formic acid 10 minutes rotation 3 5 Fixing 2.0 parts Ethylene glycol 10 minutes rotation Diglycidyl ether 2.0 parts Bustamol B 10 minutes rotation Bath (BASF brand name) Washing water (30 ° C) 4 minutes rotation Draining According to the procedure described above to obtain a black leather.

Example 2 Plant Tannin Tanned Cowhide Thickness 1.6 mm, 100 parts by weight of tanned leather Bath pH Hot water reconstitution 1000 parts Water (40 ° C.) 60 minutes rotation, bath neutralization 500 parts Water (40 ° C.) 1.0 Part Ammonium bicarbonate 40 minutes rotation, bathing 6.0 retanning 100 parts water (50 ° C) dyeing 5.0 parts Orotan PC (trade name of Rohm & Haas Co.) 5.0 parts pigment dispersion 2 rotation 60 minutes Fat 300 parts Water (50 ° C) 20 parts Leatherlicker OS-1 (Hoechst brand name) 8.0 parts Implanil DLP 60 minutes rotation (Bayer brand name; urethane resin emulsion) 1.0 parts Formic acid 10 minutes rotation 2.0 parts Formic acid 20 minutes rotation, drainage 4.0 Fixing 300 parts Water (50 ° C) 3.0 parts Glycerol 20 minutes rotation, diglycidyl ether 4.0 parts Lutan B 10 minutes Rolling, rotary exhaust bath (BASF Corporation, trade name) washing 500 parts water (30 ° C.) 10 min, exhaust bath after the drying according to a conventional method of the leather, to give a yellow leather.

Example 3 Chrome-tanned pig leather (suede) Thickness 0.6 mm, 100 parts by weight of tanned leather Bath pH Washing 200 parts Water 0.5 parts Hostapua CX Rotate for 60 minutes (Hoechst brand name) Washing water (40 Rotation for 20 minutes, draining neutralization 200 parts Water (40 ° C) 2.0 parts Sodium bicarbonate 2.0 parts Ammonium bicarbonate 60 minutes rotation, bath 5.5 Retanning 200 parts Water (50 ° C) dyeing 3 0.0 parts Berkotan PS (Yoshikawa Oil Co., Ltd. trade name) 4.0 parts Pigment Dispersion 3 60 minutes rotation Greasing 15 parts # 232 40 minutes rotation (Taiko Yushi Co. trade name) 0.5 parts Formic acid 10 minutes rotation 0 .5 parts Formic acid 10 minutes rotation 2.0 parts Pigment Dispersion 3 10 minutes rotation 3.5 Fixing 3.0 parts Polyamine dispersion 0.5 parts Formic acid 20 minutes rotation Drainage bath flush water (50 ° C) 5 minutes rotation, Off Fixing 200 parts Water (50 ° C) 2.0 parts Drazil TX 20 minutes rotation, bath (Henkel's trade name) 2.0 parts Tokuryl N121-2 (Toyo Ink's trade name; carboxyl group and N-methylol Group-containing acrylic resin emulsion) 2.0 parts Diphenyl methane 20 minutes rotation-Bis-4,4-N, N'-ethylene urea 0.5 parts Formic acid 20 minutes rotation Drain bath 3.5 Rinsing 300 parts Water (30 ° C ) After rotating for 10 minutes and taking a bath, the leather was dried according to a conventional method to obtain yellow leather.

Comparative Example 1 Chromium-tanned cowhide thickness 1.4 mm, anti-tanned leather 100 parts Bath pH Washing with water 300 parts Water (30 ° C) 20 minutes rotation, drainage neutralization 200 parts Water (30 ° C) 1.5 parts Sodium formate 1.0 part Sodium bicarbonate 40 minutes rotation, bathing 5.5 Retanning 50 parts Water (50 ° C) 2.0 parts Collagen V (Hoechst brand name) 3.0 parts Orotan T (Rohm & Haas company) Product name: 3.0 parts Mimosa powder 5.0 parts CORANIL BLACK HEV 60 minutes rotation (Product name by Hoechst) Greasing 150 parts Water (50 ° C) 12 parts Turcon ON200 (Product name by Taiko Yushi Co., Ltd.) 3. 0 copy Tokuryl N220 60 minutes rotation (trade name of Toyo Ink Mfg. Co., Ltd.) 0.5 copy Formic acid 10 minutes rotation 0.5 copy Formic acid 10 minutes rotation 0.5 copy Formic acid 10 minutes rotation 3.5 Fixing 0.0 parts Ethylene glycol 10 minutes rotation Diglycidyl ether 2.0 parts Bustamol B 10 minutes rotation Bath (BASF brand name) Washing water (30 ° C) 4 minutes rotation Draining After that, dry the leather according to the usual method. , Black leather was obtained.

Comparative Example 2 Plant Tannin Tanned Cowhide Thickness 1.6 mm, 100 parts by weight of tanned leather Bath pH Hot water reconstitution 1000 parts Water (40 ° C.) 60 minutes rotation, bath neutralization 500 parts Water (40 ° C.) 1.0 Part Ammonium bicarbonate 40 minutes rotation, bathing 6.0 retanning 100 parts water (50 ° C) dyeing 5.0 parts Orotan PC (trade name by Rohm & Haas Co.) 5.0 parts Luganir Yellow NGG 60 minutes rotation (BASF) Product name) Greasing 300 parts Water (50 ° C) 20 parts Leatherlicker OS-1 (Hoechst product name) 8.0 parts Implanil DLP 60 minutes rotation (Bayer product name) 1.0 part Formic acid 10 minutes Rotation 2.0 parts Formic acid 20 minutes rotation, drain bath 4.0 Fixing 300 parts Water (50 ° C) 3.0 parts Glycerol 20 minutes rotation, diglycidyl ether 4.0 parts Lutan B 1 Rotation for 0 minutes, bathing (BASF Co., Ltd.) Washing with water 500 parts Water (30 ° C) Rotation for 10 minutes, bathing After that, the leather was dried according to a conventional method to obtain yellow leather.

Comparative Example 3 Chrome-tanned pig leather (suede) Thickness 0.6 mm, 100 parts by weight of tanned leather Bath pH Washing 200 parts Water 0.5 parts Hostapua CX Rotate for 60 minutes (Hoechst brand name) Washing water (40 Rotation for 20 minutes, draining neutralization 200 parts Water (40 ° C) 2.0 parts Sodium bicarbonate 2.0 parts Ammonium bicarbonate 60 minutes rotation, bath 5.5 Retanning 200 parts Water (50 ° C) dyeing 3 0.0 parts Berkotan PS (Yoshikawa Oil Co., Ltd. product name) 4.0 parts Remadan Brown HR 60 minutes rotation (Hoechst product name) Greasing 15 parts # 232 40 minutes rotation (Taiko Yushi Co., Ltd. product) 5 parts Formic acid 10 minutes rotation 0.5 parts Formic acid 10 minutes rotation 2.0 parts Pigment dispersion 3 10 minutes rotation 3.5 Fixing 3.0 parts Polyamine dispersion 0.5 parts Formic acid 20 minutes rotation Drainage bath Washing water (50 ° C) 5 minutes rotation, draining fixing 200 parts Water (50 ° C) 2.0 parts Drazil TX 20 minutes rotation, bathing (Henkel's trade name) 2.0 parts Tokuriru N121-2 (Toyo Ink Company) Product name) 2.0 parts Diphenyl methane 20 minutes rotation-bis-4,4-N, N'-ethylene urea 0.5 parts Formic acid 20 minutes rotation Drain bath 3.5 Rinsing 300 parts Water (30 ° C) 10 After rotating for a minute and after bathing, the leather was dried according to the usual method to obtain yellow leather.

The evaluation results are shown in the table.

[Table 1]

The evaluation method is as follows. (1) Texture: Evaluation was made by touch. (2) Level dyeing property: visually evaluated. (3) Light resistance: Discoloration and fading after 50 hours of exposure were examined by JISL-0842-1971 (testing method for dyeing fastness against carbon arc light). (4) Friction resistance: evaluated according to JIS K-6547. (5) Washing resistance: evaluated according to JIS K-6552.

[0027]

By the coloring method of the present invention, it is excellent in light resistance, abrasion resistance, washing resistance and tear strength, has a soft texture and a beautiful appearance in which the leather surface is uniformly colored, and even the inside of the leather is colored. A colored leather product was obtained.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koichi Maruyama 4-5-6 Kuramae Taito-ku, Tokyo Morimoto Sangyo Co., Ltd. (72) Inventor Masaaki Fukuda 4-5-6 Kuramae Taito-ku, Tokyo Morimoto Sangyo Within the corporation

Claims (2)

[Claims] 1. A method for coloring leather, which comprises successively immersing the leather in a bath containing an aqueous pigment dispersion, a bath of synthetic resin emulsion and then a bath containing a crosslinking agent. 2. A method for coloring leather, which comprises immersing the leather in a bath containing an aqueous pigment dispersion and a synthetic resin emulsion, and then immersing it in a bath containing a crosslinking agent.