JP2010043142A - Black-colored natural leather - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a black-colored natural leather whose temperature hardly rises even under an irradiation of an infrared ray for a long period. <P>SOLUTION: This natural leather is a natural leather produced by staining a natural leather with a specific black azo-based acidic dye in which the black dye is any one selected from (1) SELLA_SET_BLACK_BR, (2) SELLA_SET_BLACK_BR, LURAZOL_SN and ENIVEL_NT, SELLA_COOL_BLACK, (3) (3-[ethyl[4-[4-[3-(sodiosulfophenyl)azo]-1-naphthalenylazo]phenyl]aminomethyl]benzenesulfonic acid sodium salt) and (4) SELLA_FAST_BLACK_FN, and which has a coating layer containing a mixed-color pigment playing a role as a black color and formed from a perylene-based pigment or pigments of at least three or more colors as the pigment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a black natural leather (a black natural leather dyed in black, which is a black natural leather whose temperature does not easily rise even when exposed to direct sunlight).

Natural leather is porous, has a lot of voids, has a large specific heat, has a low thermal conductivity, is easy to be heated from the viewpoint of handling heat, etc. It is the most excellent material for preventing the temperature rise used in the environment (Non-patent Document 1: New edition leather chemistry, published by the Japan Leather Association on November 25, 1992, page 227 "2.4 Thermal Properties". Section). With regard to heat resistance, it is 77 to 120 ° C. for chrome-tanned cowhide, 75 to 97 ° C. for leather tanned with zirconium, 70 to 89 ° C. for vegetable tanning, and 65 to 85 ° C. for glutaraldehyde tanning. In the case of natural leather, the heat denaturation temperature changes with changes in water content. It is already known that the denaturation temperature exceeds 120 ° C. when the water content is low (Non-patent Document 2 Leather Handbook, January 30, 2005, edited by Japan Leather Technology Association, published by Jike Shobo, pages 98 to 101). . In addition, it has been pointed out that the synthetic resin constituting the synthetic leather is softened, melted, and that combustion continues to burn out even if the fire source is removed.
On the other hand, natural leather is not softened and shrinks at about 120 ° C., and is not flammable and has no softening point or melting point (the above-mentioned same page).
Considering the above, it can be said that natural leather is the best material to be used in the interior of automobiles that pursue safety and comfort.

  Even when natural leather is exposed to sunlight in an automobile or the like, the temperature of the natural leather rises and white smoke may be generated. It is considered that the result is that the dye or pigment existing on the surface of natural leather, for example, enters the surface or inside of natural leather without being blocked by sunlight and absorbs heat. In order to prevent light from entering the inside of natural leather, a cover is installed on the surface of natural leather or on the surface, and a material that blocks the passage of direct sunlight is placed on these surfaces, and the material reflects heat. It is generally considered to do so. However, I feel that such measures cannot be expected to be effective enough.

Conventionally, dyes are used when coloring natural leather. The dye is trapped in the natural leather, and as a result, the natural leather is uniformly dyed with the dye to produce the desired color. For the coloring of leather, dyeing is performed in the dyeing and greasing process, and dyes and pigments are used in the finishing process later (Non-patent Document 3 Handbook of dyeing, July 20, 1970, edited by the Organic Chemistry Association, Inc.) Issued by Maruzen Co., Ltd., page 248).
When natural leather is dyed with a dye, the dye can enter not only the surface but also the inside of the tissue. Even when the cross-sectional portion is visible from the outside, the inner tissue is stained, so that the whole appears to be stained and looks good. As a result, the natural leather covering the seat, the instrument panel, the steering wheel, and the knob can give a good impression even when the cross section is visible from the outside.
Natural leather is also colored with leather pigments. The pigment is used in the form of a paint. In the finishing process, the leather silver surface is colored like paint. The pigment has a particle size larger than that of the dye and does not enter the inner surface of the leather. Therefore, by using the pigment, the pigment is an important process for coloring the silver surface and increasing the value of gloss, smoothness, water resistance, abrasion resistance, and the like (Non-patent Document 3, supra 251). page). Depending on the sunlight, the durability is lowered and the color of the dye is likely to change. In this case, when a pigment is used in combination, fading can be remarkably reduced as compared with that.
Optical properties due to light reflection have been regarded as important in expressing the character and beauty of leather due to its gloss, luster, color depth, and pattern. When a coat layer is formed on the leather surface, it is common to form a layer by adding a pigment to the base coat layer or the intermediate coat layer (Non-patent Document 2, pages 86 to 87).

Natural leather dyed in black is popular due to its high-class feeling. However, the black leather produced as described above, when exposed to high temperature conditions for a long time, becomes even hotter than other colors. For this reason, there is an extremely high demand for leather that has been subjected to black processing, in which the temperature of the leather is difficult to increase.
Carbon black has been used to make the leather black.
However, the present inventors have considered that the use of carbon black makes it easier to absorb infrared rays, resulting in an inevitable increase in temperature. We thought that it was necessary to stop the use of carbon black and to determine a black dye that would not increase in temperature in order to dye leather black, and at the same time to determine a pigment that would not lead to an increase in temperature.

  The problem to be solved by the present invention is that when natural leather is dyed black, it is effective to select and dye a black dye that does not lead to an increase in temperature, and simultaneously use a pigment that does not cause an increase in temperature. Based on the idea, a new black natural leather dyed natural leather with a black dye that has not been used before, a new coating layer with a pigment that has not been used as a conventional coating layer, and a coating layer formed on the surface of the natural leather The present invention is to provide a novel natural black leather that is capable of preventing temperature rise.

  In order to avoid the temperature increase of black natural leather, there is an invention that can prevent the temperature increase without using a dye, or by stopping the use of carbon black and using a pigment (Patent Document 1). No. 2001-187574, Japanese Patent Application Laid-Open No. 2001-113975, Japanese Patent Application Laid-Open No. 2001-122044). In Patent Document 1, 0051 describes the use of a perylene pigment when natural leather is used. In Patent Documents 2 and 3, a perylene pigment is used as an infrared reflecting pigment, and PALIOGEN BLACK (registered trademark) L0084 of BASF is described. However, when natural leather is dyed black, it is basically impossible to dye black using only a pigment without using a dye. It is necessary to overcome this point.

Using beads containing phase changing materials (from PCM's, English initials) with the aim of achieving proper temperature control of the leather (US Pat. No. 6,179,796). 879), the leather still exhibits a fairly high temperature and does not exhibit the required comfort when the parts in the car are heated.
In US Pat. No. 6,194,484 (Patent Document 5), the absorption near the infrared range of 0.7 to 2.5 μm is increased by 10% at 0.07 and 50% at 0.5 μm. , Pigments or particles having the ability to reflect up to 80% of visible light in the range of 0.35-0.7 μm. Radiation in the 8-14 μm range is generally reduced by 90%. However, because the maximum energy of solar irradiation is around 1 μm, energy absorption in this range is undesirable on the surface of a thermally comfortable substratum.
In Japanese Patent Application Laid-Open No. 2005-526878 (Patent Document 6), an aniline derivative having an azo group which does not contain any compound having a high infrared adsorptivity such as an organometallic compound or a naphthalene derivative is used as an organic colorant (from 0028). 0030).
The substance having high reflectivity with respect to infrared rays is selected from colorants or pigments having high infrared reflectivity, and preferably has a reflectance of 40% or more at a wavelength interval of 750 to 2500 nm, more preferably organic or inorganic. Selected from colorants or pigments.
The substance having a low heat adsorption capacity as referred to in the present invention reaches 80 ° C. as the maximum temperature in one hour after being irradiated by a 250 watt infrared lamp vertically installed 20 cm from the surface of the laminate. On the other hand, it is stated that the prior art laminate reaches 130 ° C., which affects the molecular structure, appearance and mechanical properties of the laminate. As an organic colorant, an aniline derivative having an azo group that does not contain any compound having high infrared absorption ability such as an organometallic compound or a naphthalene derivative, preferably does not contain any squalium, pentamethine cyanine naphthoquinone and naphthalocyanine, and has a specific structure Although the substance of the formula is described, the upper limit of the reflectance of 40% or more is not clarified, and it is not specified as a specific dye substance. From the above, there is no clarified acid dye that can be used as a leather dye when the infrared reflectance is specifically about 40% or more under the condition of being irradiated with infrared rays for a long time. .
Natural leather that has undergone black processing that does not easily raise the temperature of the natural leather under infrared irradiation conditions is still unresolved, and a solution is urgently required.

In the production of colored suede-like synthetic leather by impregnating colored polyurethane with a raised fiber base material composed of synthetic fiber ultrafine yarn, wet coagulation treatment and fluff exposure treatment, There is an invention in which a black pigment having a near-infrared reflectance in the wavelength range of 900 nm to 1500 nm is 60% or more, and the obtained synthetic leather has a near-infrared reflectance of 60% or more. Perylene pigments and azomethine pigments are preferred (Japanese Patent Application Laid-Open No. 5-321159). In addition, black pigments of organic pigments such as quinone, perylene, and azomethine azo that satisfy the above are preferable (Japanese Patent Laid-Open No. 7-42084).
In a dyed suede-like artificial leather made of polyurethane, the polyurethane contains at least one of a yellow pigment, a red pigment, and a blue pigment, (1) an infrared reflectance at 850 nm is 60% or more, and (2) light irradiation. (3) Artificial leather having a light fastness of 3rd grade or higher (Patent Document 9, Japanese Patent Application Laid-Open No. 2004-52120, Japanese Patent Application Laid-Open No. 2003-253572, Japanese Patent Application Laid-Open No. 2004-2005) No. 52120, Japanese Patent Laid-Open No. 2002-327377).
At least one surface of the sheet has a lightness expressed by Munsell value of 0 to 8.0, a saturation of 0 to 1.0, and an infrared reflectance of 20 to 80 in a wavelength region in the range of 800 to 1300 nm. %, And the portion where the infrared reflectance is in the range of 20 to 80% is 50% or more in area ratio (Patent Document 12 Patent No. No. 4032715) is known.
A colored sheet material having a colored resin layer having a through-hole on a sheet substrate (Patent Document 13 Japanese Patent Application Laid-Open No. 2008-87167) describes that a pigment is used for the colored resin layer.
Each of these uses a pigment as an infrared reflective material. It is not sufficient to dye natural leather black with pigments. In order to dye natural leather black, it is necessary to use a black dye. Therefore, by showing the infrared reflectance by a pigment, it is not a specific example showing dyeing natural leather black.

In the field of synthetic resin fabrics, there are inventions that utilize infrared absorbing substances that use dyes (Patent Document 14, JP-A-5-222682, and Patent 3094130). In the present invention, acid dyes, metal complex dyes, and reactive dyes are used. CI acid black 132, 194, 112, 58, 170, 222, etc. are exemplified as the black dye, but CI acid black 112 is 10% (shown in FIG. 1 and FIG. 13 in this specification). Even in the case of acid black 132, it does not reach 60% (shown in FIG. 2 and FIG. 14 in this specification), and in the case of CI acid Black 58, it does not reach 20% (see FIG. 3 and FIG. 15 in this specification). ). It has been shown that black dyes generally have a low infrared reflectance for black dyes.
Polyamide fiber not containing sulfide and reducing agent, and solid-dyed using a sulfur dye having no sulfur double bond, polyester fiber in which at least one of cellulose fibers is uniformly distributed in a woven or knitted fabric In the invention of the light-absorbing and heat-storing woven or knitted fabric (Patent Document 15, Japanese Patent Application Laid-Open No. 2007-046175), which exhibits an infrared reflectance of 70% or less over an infrared wavelength region of 600 to 1300 nm. 70% or less of those using dyes, and sulfur dyes are not originally used in natural leather, and it is not possible to expect high infrared reflectance when used in natural leather (Patent Document 16 Japanese Patent Application Laid-Open No. 2007-046175). Issue gazette).
Further, dyeing with a vat dye on cotton knitted fabrics in the infrared wavelength region of 600 to 1200 nm is 5 to 18% at 600 to 660 nm, 18 to 45% at 700 to 720 nm, 30 to 65% at 740 to 760 nm, 1000 In a method for producing a camouflage cotton knitted fabric characterized by performing camouflage processing showing infrared reflectance of 54 to 66% at ˜1200 nm (Patent Document 17 Patent 3424134), as a vat dye, for example, CI Vat Yellow 2 CI Vat Yellow 48 CI Vat Red 10 CI Vat Orange 9 CI Vat Orange 2 CI Vat Blue 66 CI Vat Blue 14 CI Vat Blue 25 CI Vat Green 1 CI Vat Green 13 CI Vat Brown 1 CI Vat Black 19 etc. And Infrared reflectance is not particularly high, nor is it a dye used in natural leather.
Therefore, the fact that these are known does not indicate that they can be used as dyes for dyeing natural leather.
Near-infrared absorption that increases the temperature of the fabric faster than that of black-dyed products when dyed with other dyes and dyes that have higher absorption characteristics in the near-infrared region than black dyes. In the processing method (Patent Document 18 Japanese Patent Laid-Open No. 9-291463), the near-infrared absorption is such that the fabric has a spectral reflectance of 65% or less within a range of 750 to 1500 nm, particularly 750 to 900 nm. Suppose that the reflectance is 50% or less. A direct dye, reactive dye, naphthol dye, or vat dye can be selected, but a part of the vat dye is particularly effective. Infrared reflectance is not particularly high, nor is it a dye used in natural leather.
The fact that these are known does not indicate that they can be used as dyes for dyeing natural leather. In addition, although black dye means the reactive dye REMAZOL Black B (made by Hoechst) etc. which are conventionally used typically as a black dye for cellulose conventionally, this absorbs infrared rays. The case where the temperature rises will be described.
JP 2001-187574 A JP 2001-113975 A Japanese Patent Laid-Open No. 2001-1222044 US Pat. No. 6,179,879 US Pat. No. 6,194,484 JP 2005-526878 A JP-A-5-321159 JP 7-42084 A JP 2004-52120 A JP 2003-253572 A JP 2002-327377 A Japanese Patent No. 4032715 JP 2002-327377 A Japanese Patent Laid-Open No. 5-222682 and Japanese Patent No. 3094130 JP 2007-046175 A JP 2007-046175 A Japanese Patent No. 3424134 JP-A-9-291463 New edition leather chemistry, November 25, 1992, published by Japan Leather Association, page 227 "2.4 Thermal Properties" Leather Handbook January 30, 2005 Edited by Japan Leather Technology Association, published by Juki Shobo, pages 98-101 Handbook of dyes July 20, 1969 Edited by the Organic Chemistry Association, published by Maruzen Co., Ltd. page 248

  The problems to be solved by the present invention include a novel natural leather obtained by dyeing natural leather with a black dye that has not been conventionally used, a novel coating layer that is not conventionally used as a coating layer, and a coating on the surface of the natural leather. It is a novel natural leather that forms a layer, and is to provide a novel natural leather that can prevent an increase in temperature.

(1) The present inventors indicate that the black natural leather described in the above problem has high infrared reflectance, and that the natural leather does not easily rise in temperature even under long-term exposure to infrared irradiation. Found and completed the invention.
(I) Dyeing with black azo acid dye selected from (1) SELLASET BLACK BR (trade name) or (2) SELLASET BLACK BR (trade name), LURAZOL SN (trade name) and ENIAVEL NT (trade name) Natural infrared leather having an infrared reflectance of more than 0.3 at 700 nm, more than 0.5 at 800 nm, more than 0.6 at 1000 nm, and more than 0.8 at 1200 nm, and after that it reaches 0.1600 nm until 1600 nm. Natural leather that exceeds 7. As can be seen from these results, these are dyes having high infrared reflectance.
(B) Black leather that is natural leather dyed with SELLA FAST BLACK FN (trade name) (black azo acid dye), tanned with glutaraldehyde prior to dyeing, and retanned with a retanning agent Natural leather.
(C) dyed with a black azo acid dye which is 3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo) -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt The black natural leather has an infrared reflectance of more than 0.2 at 700 nm, more than 0.8 at 800 nm, more than 0.9 at 1000 nm, and more than 0.9 at 1200 nm, and thereafter reaches 0.1400 nm until 1400 nm. Natural leather that exceeds 9, exceeds 0.85 at 1500 nm, and exceeds 0.92 at 1600 nm. As can be seen from these results, these are dyes having high infrared reflectance.
(D) Black color formed by a mixed color pigment or a perylene pigment that plays the role of black formed by at least one of three or more colors of pigments in at least one of an undercoat layer, an intermediate coat layer and a topcoat layer containing a polyurethane resin. By using a coating layer provided on the surface of natural leather characterized by comprising a coating layer containing a pigment that plays a role as a coating layer, it is possible to obtain a coating layer capable of highly increasing infrared reflectance.
(E) Natural leather obtained by forming a coating layer provided on the surface of the natural leather described in (d) above on the surface of the natural leather described in (i) or (b) or (c) By using dyes and pigments with high infrared reflectance for all coating layers provided on the surface of natural leather, it is possible to obtain a new natural leather that does not easily rise in temperature even under conditions exposed to infrared irradiation. it can.
(F) Next, the natural leather obtained by the above (e) is turned on a 150 W incandescent lamp, and when the surface temperature of the natural leather is measured over time, it is 87 ° C. or 91 ° C. even after 180 minutes ((1) (When a mixed color pigment or perylene pigment is used for the coating layer) on the natural leather of A), and even after 180 minutes, 50 ° C. (when a mixed color pigment is used for the natural leather of (1) in the coating layer) Similarly, 91 ° C. and 87 ° C. (when a mixed color pigment or perylene pigment is used in the natural leather of (2) for the coating layer), and maintained at 74 ° C. or 65 ° C. after 180 minutes ((3) It has been found that when the mixed color pigment or perylene pigment is used for the natural leather, the heated temperature can be maintained at a constant temperature.
This is a natural leather produced using black dyes and black pigments that have not been used in the past, and is a new natural leather that does not easily rise in temperature even under conditions of prolonged exposure to infrared irradiation. Can do.
Regarding interior parts for automobiles, even when placed under heating conditions by radiant heat, it is possible to maintain the heated temperature at a constant temperature by preventing white smoke from becoming difficult to use, as has been seen in the past. It is the result. Even under the influence of radiant heat including infrared rays such as sunlight, a constant temperature condition can be maintained over time, and the temperature rise does not continue or continue. If the heat exchange in the vehicle can be sufficiently performed, it means that the temperature increase in the vehicle can be prevented.

According to the present invention, black natural leather obtained by dyeing natural leather with a specific dye has high infrared reflectance. In addition, a coating layer for natural leather having a high infrared reflectance can be obtained by making the coating layer formed on the surface of the black natural leather have a pigment capable of highly enhancing the infrared reflectance.
The natural leather obtained by installing the coating layer on the surface of the black natural leather turns on a 150 W incandescent lamp, and when the surface temperature of the natural leather is measured over time, it maintains a constant temperature after 180 minutes. As a result, even when used in an environment where infrared rays enter natural leather, the temperature rise is suppressed to a certain level. Natural leather that can withstand sufficient use even in an infrared irradiation environment can be obtained.

The black natural leather obtained by the present invention is the following natural leather.
[1] Dyeing with a black azo acid dye selected from (1) (I) SELLASET BLACK BR, or (2) a mixture of SELLASET BLACK BR (trade name), LURAZOL SN (trade name) and ENIAVEL NT (trade name) Black natural leather (both using chrome tanning as a tanning agent), and the infrared reflectivity exceeds 0.3 at 700 nm from the result of measuring the infrared reflectivity by means of infrared reflectivity measuring means described later. Black natural leather which exceeds 0.5 at 800 nm, exceeds 0.6 at 1000 nm, exceeds 0.8 at 1200 nm and then exceeds 0.7 until 1600 nm. The measurement results of the infrared reflectance of these natural leathers are as shown in FIG. 1 or FIG.
[2] Even in the case of black natural leather that has been tanned with glutaraldehyde prior to dyeing with SELLAFAST BLACK FN (trade name) and further tanned with a retanning agent, the infrared reflectance is high. Become.

[3] Black natural dyed with a black dye which is 3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo) -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt From the result of actually measuring infrared reflectance by means of measuring infrared reflectance described later, the infrared reflectance exceeds 0.2 at 700 nm, exceeds 0.8 at 800 nm, and 0.9 at 1000 nm. More than 0.9 at 1200 nm and then 0.9 until 1400 nm, 0.85 at 1500 nm and 0.92 at 1600 nm.
The measurement results of the infrared reflectance of these natural leathers are as shown in FIG.
As is apparent from the results of FIG. 9, it can be seen that the highest results are obtained compared to the infrared reflectances that have been conventionally observed.

Among the above dyes, SELLASET BLACK BR is a product name of TFL, LURAZOL SN is a product name of BASF, and ENIAVEL NT is a product name of Dynatech.
SELLAFAST BLACK FN
It is the product name of TFL Leddertechnik GmbH (according to the company's Material Safety Data Sheet (issued June 1, 2005 (revised May 31, 2005)).
Also, 3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo) -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt (CAS registration number: 70210-06-9, (Molecular weight: 673.670: Ceracool Black: trade name, company name: TFL Company, Material Safety Data Sheet, issued February 1, 2002, updated by 2006.10.30 by 2007.10.29 printing.)

  The dyeing step is for dyeing the leather obtained through the retanning step using the dye. It is dyed with an acidic aqueous dye. The acidic aqueous dye is composed of components such as an aqueous medium and a dye. The aqueous medium means water and a mixture of water and a water-soluble solvent such as alcohol.

The composition containing the dye has a relatively strong acid side (pH = 3 to 4), and based on the weight of the leather, the leveling agent comprising 250% water, 2.5 to 4% of the dye, and an anionic surfactant. It is supplied as a 5% water-soluble composition.
The processing temperature is about 50 ° C. Process in the drum for about an hour.
After completion of the dyeing process, the dye is fixed with 1% formic acid (% by weight based on leather).
The prescription at the time of dyeing is as follows for the dyeing of the chrome-tanned cowhide having a thickness of about 1.4 mm in the surface dyeing for upper leather.
After retanning, wash with 400% water (based on shaving leather weight, the same shall apply hereinafter), and when dyeing, 250% water (50 ° C), 0.5% leveling agent, 2.5% surface Treat in aqueous solution of dyeable dye (1:20). The 1/2 process is rotated for 20 minutes, and the remaining 1/2 process is processed for 30 rotations. The fixing operation is 1% formic acid (1:10), the 2/3 process is rotated for 10 minutes, and 1/3 is rotated for 10 minutes.
The azo acid dye is used in an amount of 2.5% to 3.5% by weight based on the wet weight of leather. If it is this range, it is enough as a dye for dyeing natural leather, and can also prevent the infrared rays that enter through the surface layer from entering.

In the natural leather thus obtained, it was confirmed by the following measurement method whether the infrared reflectance actually becomes a high result.
The infrared reflectance of leather samples is measured using the Fiberspec multichannel spectrometer S-2650 for the visible light range (400 to 900 nm), and the Fastvert multichannel spectrometer S-2700 for the near infrared light range (900 to 1600 nm). Using Soma Optics Co., Ltd.) to investigate the wavelength distribution of the incident light and reflected light.
The leather sample is irradiated with white light from the end of the optical fiber, and the reflected light is reflected in the same direction as the irradiation with the optical fiber and spectroscopically measured. The relative reflectance is calculated with the reflection of a white diffuse reflection standard plate (Edmond Optics) as 1.
The results of examining the state of infrared reflectance of natural leather dyed with the above dye are as shown in FIGS.

  The natural leather used for the above dyeing is the leather obtained from the tanning process in (1) pretreatment before tanning, (2) "tanning" process, and (3) "retanning" process. Is a natural leather obtained by retanning using a synthetic tanning agent and a retanning agent comprising a resin. The process up to that point will be described below.

(1) The pre-treatment and the tanning process before tanning are processes included in the process starting from the raw skin rinsing / dipping process and leading to the trimming process (FIG. 16).
In the raw skin washing and soaking process, the raw skin that has been stored at a low temperature and preserved for freshness and prevented from being spoiled is transferred to a lime drum, the salted raw skin is rehydrated and returned to the state of raw hide, salt and impurities are removed, For pH adjustment.
In the freshening / trimming process, it is transferred to a freshening machine or a trimming machine, where excess back nibs such as fat are mechanically removed, salt and impurities are also removed, and the periphery is shaped. In the lime picking process, it is transferred to a lime drum, which dissolves the hair on the skin surface and removes the dirt, and infiltrates the lime inside the skin to loosen the fibers.
In the raw band splitting process, it is transferred to a band machine, and the skin is spread to a thickness according to the application, and the skin is divided into a silver layer and a floor.
The decalcification / fermentation / pickling process is as follows: decalcification of the lime, enzymatic decomposition / enzymatic decomposition, and pickling.
In the tanning process, the obtained skin is tanned with a tanning agent to produce the skin.
In the dehydration process, the leather is transferred to a water squeezer and dehydrated. Next, sorting is performed to perform grading according to the surface conditions such as scratches, holes, and area.
In the shaving process, the leather is transferred to a shaving machine and cut to a thickness appropriate for the application. In the trimming process, unnecessary breaks and the like are cut on the trimming stand to prevent tearing in the subsequent process and improve work performance.

(2) The characteristics of the tanning process are as follows.
The tanning step is to treat the skin under acidic conditions and the tanning agent in the presence of water. The tanning agent is an operation of causing the collagen material of the skin to be cross-linked, giving the skin heat resistance, resistance to microorganisms and chemical substances, and imparting flexibility.
As the tanning agent, a trivalent chromium complex, for example, a chromium compound using hexaacocrystalline sulfuric acid expressed as Cr ₂ (SO ₄ ) ₃ , an aldehyde compound such as glutaraldehyde, or the like is used. All of these are conventionally known, and a commercially available product may be purchased and used.
The chromium complex is as follows.
Chromitan B, Chromitan MS, Chromitan FM, BaychromaCH, BaychromaCL, BrancorRN, BlancorRC, etc.
In the tanning process, Cr ₂ O ₃ is supplied with a chromium salt at a concentration corresponding to 2 to 2.5% of the naked skin, but 70 to 80% of this is not fixed in the skin. 20-30% is said to be released during overflow.
About glutaraldehyde, it is as follows.
When commercially available glutaraldehyde is purchased and used, Lergan GT-50, Lergan GT-24, Lergan GTW (manufactured by BASF), Delgan-2080, Delgan-3080, Delgan-Z (manufactured by Schill + Seilacher), Eucer Tanning agent GA-25, Euker tanning agent GA-50, and the like can be used.
The amount of glutaraldehyde used is about 1 to 10% by weight based on the weight of leather (Japanese Patent Laid-Open No. 08-232000).
In both cases, the tanning agent chemically binds to the leather component.
In addition, synthetic tanning agents (synthetic tanning agents will be described in the retanning step) and plant tannins (such as mimosa ME, mimosa FE, and quebratcho) can be used. All of them are conventionally known, and commercially available products may be purchased and used.

The retanning process, dyeing process and greasing process are performed in one drum.
After each process is completed, the washing operation is sufficiently performed so that the result of the previous process does not affect the subsequent process (FIG. 17).

In the retanning step, synthetic tanning agents, plant tanning agents, and the like are used as retanning agents. In some cases, the tanning agent such as chromium or glutaraldehyde may be added and used.
It is carried out by confirming beforehand whether or not neutralization is performed during retanning. A pH indicator is dropped on the cross section of the leather, and the discolored layer is observed. As a rough guide, the upper is the upper type, the surface layer is about pH 5 to 6, and the inner layer is about 3 to 4.

(1) As the synthetic tanning agent, the following tanning agents are used.
A formaldehyde condensate of aromatic sulfonic acid (mainly naphthalene and phenol sulfonic acid), a condensate of amino compound and formaldehyde, and the like are as follows.
(I) The following are known as formaldehyde condensates of phenol sulfonic acid.
(A) Phenolsulfonic acid and bishydroxyphenylsulfone are condensed at a molar ratio of 1: 3 with 2 mol of formaldehyde at 100-120 ° C. in an aqueous solution at a pH of 6-9, and the pH is adjusted to 3.5 with sulfuric acid. The acid value (AN) is adjusted to 120 with phthalic acid and dried.
(B) Phenolsulfonic acid (65% solution) sodium salt is mixed with bishydroxyphenylsulfone (55% suspension) in a molar ratio of 2.5: 1. 2.5 equivalents of formaldehyde (30% solution) are added to the hot mixture and condensed at 112-115 ° C. for 3 hours. The crude condensate is adjusted to an acid value of 100 with adipic acid and dried.
The molecular weight distribution of the formaldehyde condensate of phenolsulfonic acid is distributed between Mw 400 and 4000 as measured by gel chromatography developed with an organic solvent, and the center is around Mw 3000.
These can be used by purchasing the following commercial products.
Phenol sulfonate formaldehyde polycondensate: Basyntan DLX-N, MLB, SL, SW Liquid, Tamol NNOL (BASF), Tanigan WLF (LANXESS)
(B) Formaldehyde condensate of sulfonic acid of naphthalene (a) Naphthalene is sulfonated with 1.4 equivalent of H ₂ SO ₄ at 145 ° C. for 2 hours. 1000 g of the naphthalenesulfonic acid mixture thus obtained, 800 g of bishydroxyphenylsulfone and 250 ml of 37% formaldehyde solution are condensed at 100 to 120 ° C. for 3 hours. The resulting product is adjusted to pH 3.5, brought to AN 80 with sodium hydroxide solution and phthalic acid and spray dried.
It can also be manufactured by:
(B) Naphthalene is sulfonated with 1.4 mol of H ₂ SO ₄ at 145 ° C. for 3 hours, condensed with 0.66 mol of formaldehyde for 3 hours, cooled, pH adjusted to 3.5, sodium hydroxide Make AN 50 with solution and glutaric acid and spray dry.
These molecular weight distributions are about Mw 200 to 2000 when measured by gel chromatography developed with an organic solvent, and the center is Mw 1300.
Any of these can be purchased and used.
Polycondensate of naphthalene sulfonic acid and formaldehyde: Basyntan FC, Tamol NA (BASF), Ukatan GM (Schill + Seilacher), Tanigan BN (LANXESS), Irgatan LV (TLF), BELLCOTAN A, PT, PS (manufactured by Nippon Seika Co., Ltd.)
(C) Phenolsulfonic acid, urea and formaldehyde condensate obtained by treating 1 mol of phenol and 0.5 mol of sulfuric acid, 1 mol of urea and 0.9 mol of formaldehyde under a strongly acidic reaction at 100 to 110 ° C. The condensate is buffered with 0.2 molar sodium hydroxide solution. The intermediate product thus obtained is further condensed with 0.8 mol of phenol and 1.2 mol of formaldehyde, cooled, the pH adjusted to 3.5, with sodium hydroxide solution, formic acid and phthalic acid. AN is 80 and spray dried.
When purchased and used, there are the following compounds.
Basyntan (registered trademark) DLX) can be purchased and used.
(2) When using a resin tanning agent The main component is a condensate of an amino compound such as urea, dicyandiamide, and melamine with formaldehyde.
As a mixture of the melamine formaldehyde condensate and the urea formaldehyde condensate, Relugan D, DLF, S (manufactured by BASF) or the like can be used.
As the polyacrylic acid resin tanning agent, Relugan SE, RE, RV (manufactured by BASF), Luburitan GX (manufactured by Rohm and Haas), and the like can be used.

In the retanning step, the tanning agent such as the synthetic tanning agent used is used in the form of an aqueous solution which preferably contains 50 to 200% by weight with respect to the weight of the leather used.
Conditions are used within a pH range of 3.0 to 8.0, preferably 3.5 to 6.5. The retreatment process is preferably carried out in 1.5 to 24 hours, in particular 2 to 8 hours.
After retanning, wash with 400% water (based on shaving leather weight, hereinafter the same).

  The dyeing process after retanning is as described above, and has already been described, so this point is omitted.

The greasing process is as follows.
In the greasing step, treatment with a greasing agent is performed.
The greasing process is a process performed after the dyeing process after retanning, and is performed in order to impart flexibility required for leather products, and is processed with an oil agent called a greasing agent. Among these, many have surface activity. As a result, it is easy to penetrate inside the leather.
The leather treated in the greasing process after the dyeing process is in a wet state and retains the flexibility of the fibers due to the water present in the fiber bundles and between the fibers, but the fibers stick together when dried. The fibers and tissues harden. Before drying, it is effective to treat with an oil agent that becomes a substance that inhibits adhesion between fibers. It also provides functions such as leather fiber protection (water repellency, waterproofness), feel, and swelling. For this purpose, there is a greasing step and a greasing agent is used.

The greasing agents include the following.
These are selected and used.
(1) Anionic greasing agents are as follows.
(I) Sulfated oil Sulfated oil is a product obtained by adding sulfuric acid to natural unsaturated fats and oils to make a sulfate ester. A part of hydroxyl groups and double bonds are sulfated.
Sulfated fatty acid ester: Lipoderm Liquor PU (BASF),
Synthetic sulfonated lipid: SYNCUROL KV (MUNZING),
Mixture of sulfonated ester and hydrocarbon: SYNCUROL 79 (manufactured by MUNZING), sulfonated ester: SYNCUROL SE (manufactured by MUNZING),
Synthetic sulfonated esters: SYNCUROL PF, MAX (manufactured by MUNZING).
(B) Sulfonated oil The sulfonated oil is obtained by treating a synthetic oil natural oil having an unsaturated group with sulfuric anhydride, fuming sulfuric acid, chlorophonic acid or the like, and sulfonating and neutralizing double bonds in the molecule.
Examples of the sulfonated oil include SK oil HF (manufactured by Sampras), Perastol ES (manufactured by Zschimmer & Schwarzchemische Fabriken), and the like.
SK oil HF is a synthetic sulfonated oil having yellowing resistance, and is a mixture of 50% by weight of unreacted raw oil, 25% by weight of its sulfate ester and 25% by weight of the hydrolysis product.
In addition, Turcon FA-200 (manufactured by Taiko Yushi Chemical Co., Ltd.), Pergrasol SF (manufactured by Zschimmer & Schwarzchemische Fabriken) and the like can be mentioned. Turcon FA200 is a mixture of fatty acid monoglyceride, sulfonated natural oil, oxidation products thereof, and the like.
(C) Sulphite oil Sulphite oil is a sulfonate salt obtained by using a highly unsaturated natural oil or synthetic oil as a raw material and using a sulfite as a sulfonating agent.
Mixture of sulfitized fish oil, natural oil and emulsifier: Lipsol EB (manufactured by Schill + Seilacher), sulfitized fish oil: OPTIMALIN UPNC (manufactured by MUNZING), aqueous emulsion of vegetable oil and sulfitized animal oil: Lipoderm Liquor A1 (manufactured by BASF) ,
(D) fatty acid soap,
Fatty acid soap is a soap obtained by saponifying natural fats and oils with an alkaline aqueous solution. Ammonium salts and potassium salts are also used as greasing agents. Since fatty acids are liberated on the acidic side from neutral, there are effects of surfactant components and neutral oil.
Denatured fatty acid: Lipoderm Liquor LA (BASF)
(E) Phosphorylated oil Phospholipids such as egg yolk and soybean lecithin have been used. Recently, phosphorylated oils are often used in higher alcohols or phosphate esters of polyoxyethylene alkyl ethers.
Synthetic oil and lecithin oil mixture emulsion: Lipsol LQ (manufactured by Schill + Seilacher), phosphate ester oil: Lipoderm Liquor PU (manufactured by BASF)
Blend of sulfated vegetable oil, fatty alcohol phosphate ester and hydrocarbon: Ricker KIM (Nagi Shokai),
(F) Multipolar greasing agents are a mixture of anionic, nonionic and small amounts of cationic greasing agents. (G) Other anionic greasing agents Mono- or dialkyl succinic acid, alkylmalonic acid, both alkyl chains There are those having a complex active group such as a terminal carboxylate, and polyacrylic acid derivatives having a long-chain alkyl group.

(2) Cationic greasing agent As the cationic greasing agent, a quaternary ammonium salt, an aliphatic amine, or an aliphatic polyamine condensate is used.
(3) Amphoteric greasing agent For amphoteric greasing agents, lecithin has long been used as a greasing agent having both anionic and cationic properties in the same molecule.
(4) Nonionic greasing agent Nonionic greasing agents are rarely used alone and are used in combination with anionic and cationic greasing agents.
Water-soluble natural oil and nonionic surfactant: Lipoderm Liquor IC (BASF), mixed aqueous solution of wax, natural oil and surfactant: Lipoderm Liquor SC (BASF), nonionic surfactant, sulfite Oil, sodium salt aqueous solution: Lipoderm Liquor WF (manufactured by BASF), natural oil, synthetic oil, synthetic emulsifier mixture: Lipsol MSG (manufactured by Schill + Seilacher)
(5) Neutral oils, specifically (i) animal oils, (b) marine animal oils, (c) plant (d) mineral oils, (e) synthetic oils, and the like.

The composition containing a greasing agent is as follows.
Water is 110% to 130% of leather weight,
Synthetic greasing agent is 2-5% of leather weight,
Lanolin-based greasing agent is 0.6 to 0.8% of leather weight,
The pH of the liquid is 3.5
The water temperature is about 50 ° C.
The above composition is supplied to the leather in the drum, and after the treatment, it is sufficiently washed with water to complete the operation.

  In the setter process, the tanned and softened leather is transferred to a setting machine, and the moisture of the dyed leather is reduced to facilitate drying. Also stretch the wrinkles to make the leather bigger. In the pattern drying process, the leather is transferred to a pattern drying machine, the leather is dried to completely absorb chemicals and dyes, and the leather is dried once to create a texture. In the seasoning process, the leather is transferred to a seasoning shower machine and an aqueous solution of an antioxidant is applied. Seasoning is done by applying a small amount of water to dry leather. This is ultimately related to the even stretch and swelling of the leather.

  In the vibration process, the leather is transferred to a vibration machine, where the hardness of the toes and edges is removed, the wrinkles are removed, and the area is increased. In the blanking process, the leather is transferred to a blanking drum to loosen the leather fibers after drying. After that, in the drying, buffing and vibration process, the leather is transferred to a fin-back machine, the leather after emptying is toggled, the leather is stretched and dried (net tension drying), and the leather is flattened. Move the leather to a vibration machine, loosen the fibers, take the hardness around the toe edge, remove the wrinkle of the blank, and increase the area. Then, an intermediate inspection of the product is performed, and items such as grade, pattern, texture, color tone, thickness, etc. are inspected.

FIG. 18 shows a back paste spraying process and a resin coating process. In the back paste spraying process, a backing treatment is performed with an aqueous spray to prevent the adhesion of back fluff to the painted surface. At this time, resin coating is applied to the back of the leather. By applying a resin coating to the back of the leather, it is possible to physically block the release of the causative substance of glass fogging. In the painting process, the first pigment coating is applied to the leather surface with a reverse coater, and in the embossing process, the leather surface is patterned and concealed.
About the natural leather which passed through the greasing process, the process normally performed is performed. Stretching is performed over a setter, pattern drying is performed, and taste removal, vibration, empty, drying, buffing and vibration processing are performed.

In the finishing process of painting, a coating layer is formed on the surface of natural leather.
This coating layer is formed from the following three layers.
It is natural that any of the undercoat layer, the intermediate coat layer and the topcoat layer containing a polyurethane resin comprises a coating layer containing a mixed color pigment or a perylene pigment that serves as a black color formed by at least three or more pigments. It is a coating layer provided on the surface of leather.

  A mixed color pigment that plays the role of black formed by pigments of at least three colors or at least one of the undercoat layer, intermediate coat layer, and topcoat layer containing polyurethane resin, or the role of black formed by perylene pigment A coating layer containing a pigment that works is used.

A bottom coat layer obtained by coating the surface of the obtained natural leather base material with an aqueous paint containing a pigment, a base coat layer obtained by coating the aqueous coat on the coat layer, and further on the coat layer Then, a top coat layer is formed.
(1) Bottom coat coating Bottom coat coating is performed by roll coating or spray coating using an aqueous coating agent containing a pigment. The film thickness of this bottom coat is usually 3 to 10 μm. After the coating, it is subjected to a drying treatment, but usually a treatment of about 10 minutes with an 80 ° C. hot air dryer is sufficient.
After drying, a press treatment is performed to form a smooth surface of the bottom coat. When roll coating is performed in bottom coat coating, press treatment may be omitted.

(2) Base coat coating Base coat coating is performed after the bottom coat coating, and it is preferable to perform the base coat coating by a two-time coating operation in order to make the color tone or various physical properties of the final product sufficient. The water-based paint used in this base coat coating contains a UV absorber (especially zinc oxide is preferred), but the amount of the UV absorber is usually based on the binder solids used in the water-based paint. 10 to 40%. As the zinc oxide, a water dispersion type is used.

  As the above-mentioned binder, usually two to three kinds of binders are mixed and used, but acrylic ester, acryl-vinyl acetate, styrene-butadiene, acrylonitrile-butadiene, butadiene-methacrylate, vinylidene chloride are used. Synthetic resin binders are used as emulsion-type binders, and polyurethane-based synthetic resin binders are used as solution-type binders.

  When the base coat is applied by applying twice, the drying process is once performed after the first application. For this drying treatment, a treatment of about 10 minutes with an 80 ° C. hot air dryer is usually sufficient. The film thickness of the base coat is usually 7 to 30 μm as the total film thickness. After the base coat is finished, it is subjected to a drying process as described above.

(3) Topcoat painting After the basecoat painting, topcoat painting is performed. Spray with two-component urethane resin paint. The film thickness of the top coat is usually about 10 μm. After the coating, it is subjected to a drying process, and this drying process is also the same as the drying process in each of the aforementioned coating processes.

The bottom coat coating is formed of an aqueous coating agent containing a resin binder such as water-based polyurethane resin or water-based polyacrylic resin and a pigment, and the film thickness is usually 30 μm, and the black color is formed by three or more pigments. The ratio of the color mixing pigment that plays a role to the resin binder is (80: 400) (weight ratio).
The base coat (intercoat) is formed of an aqueous coating agent containing a mixed color pigment that plays the role of black formed by a resin binder such as an aqueous polyurethane resin or an aqueous polyacrylic resin and three or more pigments, and the thickness of the layer Is about 20 μm, and the ratio of the mixed color pigment to the resin binder is (100: 450) (weight ratio).
The top coat is formed of a resin binder such as water-based polyurethane / acrylic resin or water-based polyurethane resin, and the thickness of the layer is 10 μm, and the mixed color pigment and resin that play the role of black formed by three or more pigments The binder ratio is (8: 500).

  In this step, coating with a polyurethane resin or an acrylic resin is performed as a treatment agent. Moreover, a pigment is added to these and coloring is performed.

  The perylene pigment or mixed color pigment used in the present invention is as follows.

（式中、Rはアルキル基、芳香族炭化水素基、脂環式炭化水素基、アラールキル基、又は窒素含有複素環式芳香族基を示す。）
以下の公開公報などにも具体的に開示されている（特開2004-323534、特開平11-286489）。
以上の構造式で示されるペリレン系黒色顔料を用いる。
ペリレン顔料である、ペリレン−３，４，９，１０−テトラカルボン酸ビスイミドは、長い間高度耐光性の建染染料および顔料として、また最近では均一溶液中の蛍光染料として（たとえば、H. Zollinger, Color Chemistry, VCH Verlagsgesellschaft, Weinheim, １９８７参照）使われてきた。このほか、ペリレン−３，４−ジカルボキシイミドなどが知られている。
ビス（２−フェニルエチル）ペリレン−３，４，９，１０−テトラカルボン酸ジイミド、
ビス（メトキシベンジル）ペリレン−３，４，９，１０−テトラカルボン酸ジイミド、
ビス（ヒドロキシエチル）ペリレン−３，４，９，１０−テトラカルボン酸ジイミド、
ビス（ヒドロキシヘキシル）ペリレン−３，４，９，１０−テトラカルボン酸ジイミドなどがある。
一般的な合成経路は、工業的に製造されるペリレン−３，４，９，１０−テトラカルボン酸二無水物（３）と一級アミンとの縮合により可能である。
これらは、ＴＦＬ社製の皮革用ペリレン顔料及び東洋インキ製造株式会社製のペリレン顔料を購入して用いることができる。 Perylene pigments are known as pigments with high infrared reflectance.
The perylene pigment is represented by the following structural formula.

(In the formula, R represents an alkyl group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, an aralkyl group, or a nitrogen-containing heterocyclic aromatic group.)
It is also specifically disclosed in the following publications (JP 2004-323534, JP 11-286489).
A perylene-based black pigment represented by the above structural formula is used.
Perylene-pigment, perylene-3,4,9,10-tetracarboxylic acid bisimide has long been used as a highly light-resistant vat dye and pigment, and more recently as a fluorescent dye in homogeneous solution (eg H. Zollinger , Color Chemistry, VCH Verlagsgesellschaft, Weinheim, 1987). In addition, perylene-3,4-dicarboximide and the like are known.
Bis (2-phenylethyl) perylene-3,4,9,10-tetracarboxylic acid diimide,
Bis (methoxybenzyl) perylene-3,4,9,10-tetracarboxylic acid diimide,
Bis (hydroxyethyl) perylene-3,4,9,10-tetracarboxylic acid diimide,
Bis (hydroxyhexyl) perylene-3,4,9,10-tetracarboxylic acid diimide.
A general synthetic route is possible by condensation of industrially produced perylene-3,4,9,10-tetracarboxylic dianhydride (3) with a primary amine.
These can be purchased and used as a perylene pigment for leather manufactured by TFL and a perylene pigment manufactured by Toyo Ink Manufacturing Co., Ltd.

Formulation examples when using a perylene pigment are as follows.
A perylene-based black pigment, which is a dye having a quinone structure (generic name for a cyclic organic compound derived from a benzene ring) having higher fastness and infrared reflectance than conventional pigments, is used. Use pigments such as red, blue, and yellow, and adjust the color by mixing pigments such as red, blue, and yellow. An example is shown in the following table.
The red, blue, and yellow pigments are selected from CI and No. of pigments such as those manufactured by Dainippon Ink, Toyo Ink, BASF, and Stahl.

Mix many pigments to produce black. This is called subtractive color mixing. If the light is not reflected (absorbed) over the entire visible light area, it looks black, so even if a pigment that absorbs only part of the visible light wavelength range is combined with a different absorption wavelength range, the entire area is absorbed. Becomes a black pigment. This is mixed with each coating solution of undercoat, intermediate coat and top coat and applied to the leather surface.
An example is as follows.

The pigments used for preparing mixed color pigments used for the undercoat, intermediate coat, and top coat are as follows.
(1) For red pigments:
(A) CI: Pigment Red 161 Component: Pigment (Condensed polycyclic pigment)
(B) CI: Pigment Red 254 Component: Pigment (Condensed polycyclic pigment)
(2) The yellow pigment is as follows.
(I) CI: Pigment Yellow 42 Component: Pigment (yellow iron oxide)
(B) CI: Pigment Yellow 130 Component: Pigment (disazo yellow pigment)
(C) CI: Pigment Yellow 81 Ingredient: Pigment (Disazo Yellow Pigment)
(D) CI: Pigment Yellow 128 Component: Pigment (condensed azo pigment)
(E) CI: Pigment Yellow 110 Component: Pigment (Condensed polycyclic pigment)
(3) The blue pigment is as follows.
(I) CI PIGMENT BLUE 15-2 Ingredient: Pigment (copper phthalocyanine blue)
(B) PIGMENT BLUE 60 Component: Pigment (Anthraquinone)
(4) The green pigment is as follows.
(I) CI: Pigment Green 7 Component: Pigment (copper phthalocyanine green)
(5) Brown is as follows.
(I) Pigment Red 202 component: Pigment (iron oxide)
The pigments can be appropriately selected from the above CI number color pigments and used in combination.
The mixing of pigments is as follows.
When a black pigment is obtained by mixing colors, three color pigments are mixed. The amount of the three color pigments used is about 20% to 50% of the total. A considerable amount of other pigments (for example, red, yellow, blue, green, white, etc.) not used as three-color pigments are used. The reason for using other pigments in this way is used in order to match as much as possible the color sample by the automobile company that is the user. There are more than 10 types of color samples per automobile company even in the case of black alone, but it is an important item in quality control to match the color with this sample exactly to the intended color.
The type of pigment necessary to match the color sample is selected using a machine (color matching system). When all the pigments are designated when the pigment composition is given, the composition can be determined by selecting an appropriate pigment.

  When a mixed color pigment is made with a pigment other than black, the target black can be basically produced with three colors of red, yellow and blue. The reason why green and white are slightly added in the embodiment is to facilitate color matching. When correcting the deviation from the color swatch, adding a new pigment that is not included in the initial pigment composition makes it difficult to predict a change in color. By doing so, it is easy to predict a color change and color matching becomes easy.

The natural leather formed with the coating film obtained as described above is irradiated with an incandescent lamp, the temperature of the natural leather formed with the coating film is increased, and the surface of the natural leather dyed with the dye of the present invention is coated with the pigment. The natural leather provided with a membrane layer was irradiated with an incandescent lamp in the same manner as described above to examine the temperature rise of the natural leather.
SELLA COOL BLACK (3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo) -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt)), SELLA SET BLACK BR In this case, a perylene pigment, a mixed color pigment, or carbon is used as a pigment that is dyed with a mixture of BLACK LURAZOL SN and ENIVEL NT and used for a coating film formed on the surface of natural leather.
In the following specific examples, the tanning agent used when tanning natural leather is the case where chromium is used.

Natural leather tanned with glutaraldehyde in the usual way, tanned again, dyed black with SELLAFAST BLACK FN, and formed a coating film using mixed pigments on natural leather obtained by a greasing process Table 5 shows the state of temperature rise when the leather is irradiated with an incandescent lamp.
In this case, glutaraldehyde tanning agents include Lergan GT-50, Lergan GT-24, Lergan GTW (manufactured by BASF), Delgan-2080, Delgan-3080, Delgan-Z (manufactured by Schill + Seilacher), and Eucher tanning agent GA-25. Euker tanning agent GA-50, etc. can be used. Subsequent retanning agents and the like are the same as in the above case.

Measurement of the infrared reflectance of the dyed layer obtained by the present invention and the leather provided with a coating layer on the surface of the dyed layer is as follows.
Measurement of Infrared Reflectance The method for measuring the infrared reflectance shown in the drawing is as follows.
The infrared reflectance of leather samples is measured using the Fiberspec multichannel spectrometer S-2650 for the visible light region (400 to 900 nm), and the Fastvert multichannel spectrometer S-2700 for the near infrared light region (900 to 1600 nm). Using Soma Optics Co., Ltd.) to investigate the wavelength distribution of the incident light and reflected light.
The leather sample is irradiated with white light from the end of the optical fiber, and the reflected light is reflected in the same direction as the irradiation with the optical fiber and spectroscopically measured. The relative reflectance is calculated with the reflection of a white diffuse reflection standard plate (Edmond Optics) as 1.

The natural leather obtained by the above procedure was irradiated with light from an incandescent lamp and the temperature rise was analyzed. Check the characteristics of natural leather.
Install a 150W incandescent lamp (for power reflex indoor use, RS100 / 110V: 100W-E, Toshiba) at a height of 15 cm with respect to the test piece and comparison piece. Measure the temperature with a contact thermometer.

FIG. 1 shows the state of infrared reflectance of natural leather obtained by dyeing natural leather subjected to chrome tanning with 3% by weight of SELLA SET BLACK BR with respect to the wet weight of shaving leather.
It shows that the infrared reflectance is in a high state for each wavelength.
It is known that a dyed layer dyed with a black dye generally does not give a high result as described above (see FIGS. 13 to 15). This aspect is described in Japanese Patent Laid-Open No. 05-222682 (Patent No. 3094130). From these results, it is clear that the present invention is a good natural leather.

Infrared reflectivity of natural leather dyed SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT with a dye that is 3% by weight of the wet weight of shaving leather (Fig. 6) It was shown to.
It shows that the infrared reflectance is in a high state for each wavelength.
It is known that a dye layer containing a black dye generally does not produce high results as described above (see FIGS. 13 to 15). This aspect is described in Japanese Patent Laid-Open No. 05-222682 (Patent No. 3094130). From these results, it is clear that the present invention is a good natural leather.

A chrome-tanned natural leather was prepared from 3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt (Ceracool Black). (Product name, company name (manufactured by TFL)) shows the state of infrared reflectance of natural leather dyed by 3% by weight with respect to the wet weight of shaving leather (Fig. 9). It shows that it is moving in a high state.
It is known that a dye layer containing a black dye generally does not produce high results as described above (see FIGS. 13 to 15). This aspect is described in Japanese Patent Laid-Open No. 05-222682 (Patent No. 3094130). From these results, it is clear that the present invention is a good natural leather.

The result of measuring the infrared reflectance of natural leather formed with a coating film containing a perylene pigment on the surface of natural leather dyed by 3% by weight with respect to the wet weight of SELLA SET BLACK BR shaving leather formed in Example 1 is shown. It is shown in FIG.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective when compared with FIG. 4 showing the infrared reflection of natural leather formed with a coating film containing carbon black.

Infrared ray of natural leather formed with a coating film containing a perylene pigment on the surface of natural leather obtained by dyeing SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT formed in Example 2 with 3% by weight of wet weight of shaving leather The result of measuring the reflectance is shown in FIG.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective as compared with FIG. 8 showing the infrared reflection of natural leather formed with a coating film containing carbon black.

Infrared ray of natural leather formed with a coating film containing a perylene pigment on the surface of natural leather obtained by dyeing SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT formed in Example 2 with 3% by weight of wet weight of shaving leather The result of measuring the reflectance is shown in FIG.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective as compared with FIG. 8 showing the infrared reflection of natural leather formed with a coating film containing carbon black.

Infrared ray of natural leather formed with a coating film containing a perylene pigment on the surface of natural leather obtained by dyeing SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT formed in Example 2 with 3% by weight of wet weight of shaving leather The result of measuring the reflectance is shown in FIG.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective as compared with FIG. 8 showing the infrared reflection of natural leather formed with a coating film containing carbon black.

3- [Ethyl [4- [4-[(3- (sodiosulfo) phenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt (CAS Registry Number: 70210-06) formed in Example 3 -9, Molecular weight 673.670: Ceracool Black: Trade name, company name TFL manufactured by TFL Company material safety data sheet (issued February 1, 2002) 2007.10.29 printing 2006.3.10 update FIG. 10 shows the results of measuring the infrared reflectance of natural leather in which a coating film containing a perylene pigment was formed on the surface of natural leather dyed with 3% by weight of the shaving leather wet weight.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective when compared with FIG. 12 showing infrared reflection of natural leather formed with a coating film containing carbon black.

3- [Ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt formed in Example 3 (Ceracool Black (trade name) , Company name (manufactured by TFL)) Figure showing the result of measuring the infrared reflectance of natural leather with a coating containing mixed color pigment on the surface of natural leather dyed with 3% by weight of the shaving leather wet weight 11 shows.
It shows that the infrared reflectance is in a high state for each wavelength.
It can be seen that this result is sufficiently effective when compared with FIG. 12 showing infrared reflection of natural leather formed with a coating film containing carbon black.

As tanning agents, glutaraldehyde (Lergan GT-50, Lergan GT-24, Lergan GTW (manufactured by BASF), Delgan-2080, Delgan-3080, Delgan-Z (manufactured by Schill + Seilacher), Eucher tanning agent GA-25, Yuker tanning And the subsequent retanning agent is subjected to the same retanning as in Example 3 and dyed with SELFAST BLACK BLACK FN, which is an acidic black dye. After obtaining a fat process, natural leather was prepared using a mixed color pigment on the surface coating of this natural leather.

  The results of performing an irradiation test on the natural leather obtained in the example are as shown in the following table.

(1) 3- [Ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt (SELLA COOL BLACK: trade name, company name) In the case of leather obtained by dyeing leather (made by TFL) and including a perylene pigment in the coating layer, the temperature rose to 73 ° C. after 60 minutes, and thereafter at the same temperature.
Similarly, in the case of leather obtained by adding a mixed color pigment to the coating layer, the temperature increased to 64 ° C. after 60 minutes, and thereafter at the same temperature.
Similarly, in the case of leather obtained by including carbon in the coating layer, the temperature rose to 93 ° C. after 60 minutes, and white smoke was generated, resulting in a dangerous state, and subsequent infrared irradiation was stopped.
As a result, it was found that even if the dye was dyed with a dye having a high infrared reflectance, good results could not be obtained unless a pigment having a high infrared reflectance was used as the pigment. In this case, it was found that the temperature increase can be further suppressed when the mixed color pigment is used.
(2) In the case of leather obtained by dyeing leather with SELLA SET BLACK BR and including a perylene pigment in the coating layer, the temperature rose to 91 ° C. after 30 minutes, and then passed at the same temperature.
Similarly, in the case of leather obtained by adding a mixed color pigment to the coating layer, 30 minutes passed and the temperature rose to 86 ° C., and thereafter the same temperature passed.
Similarly, in the case of leather obtained by including carbon in the coating layer, the temperature rose to 93 ° C. after 60 minutes, and white smoke was generated, resulting in a dangerous state, and subsequent infrared irradiation was stopped.
As a result, it was found that when dye is dyed with SELLA SET BLACK BR having a high infrared reflectance, the pigment can be controlled in the range of 86 to 91 ° C. by using a pigment having a high infrared reflectance.
(3) In the case of leather obtained by dyeing leather with SELLA SET BLACK BR, LURAZOL SN and ENIVEL NT and including a perylene pigment in the coating layer, the temperature rises to 77 ° C after 60 minutes, and the same temperature thereafter Passed.
Similarly, in the case of leather obtained by adding a mixed color pigment to the coating layer, the temperature rose to 77 ° C. after 60 minutes, and thereafter the same temperature passed.
Similarly, in the case of leather obtained by including carbon in the coating layer, the temperature rose to 92 ° C. after 60 minutes, and white smoke became dangerous, and the subsequent infrared irradiation was stopped.
In the end, this shows that when leather is dyed with SELLA SET BLACK BR, LURAZOL SN, and ENIVEL NT, which have infrared reflectance, the dye can be controlled within a range of about 77 ° C by using a pigment with high infrared reflectance. It was.
Further, it was found that the temperature rise can be suppressed when dyed with a mixed dye of SELLA SET BLACK BR, LURAZOL SN and ENIVEL NT than when dyed with SELLA SET BLACK BR alone.
In any case, from these results, it can be seen that after the temperature rise, the temperature was kept constant in the range of 65 to 91 ° C., and the temperature rise was suppressed.

The result of irradiation with an incandescent lamp using the natural leather obtained in Example 10 was as follows. The temperature rise was suppressed to 50 ° C., and good results were obtained.

Diagram showing the infrared reflectance of natural leather dyed with SELLA SET BLACK BR The figure which shows the infrared reflectance of the natural leather which formed the coating film containing a perylene pigment on the surface of the natural leather dye | stained by SELLA SET BLACK BR. The figure which shows the infrared reflectance of the natural leather which formed the coating film containing the color mixing pigment on the surface of the natural leather dyed by forming the coating film containing the color mixing pigment on the surface of the natural leather dyed by SELLA SET BLACK BR Diagram showing the infrared reflectance of natural leather with a coating containing carbon black formed on the surface of natural leather dyed by SELLA SET BLACK BR Diagram showing infrared reflectance of natural leather dyed with SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT The figure which shows the infrared reflectance of the natural leather which formed the coating film containing a perylene pigment on the surface of the natural leather dye | stained by SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT. Infrared of natural leather that has formed a paint film containing mixed color pigment on the surface of natural leather dyed by forming a paint film containing mixed color pigment on the surface of natural leather dyed by SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT Diagram showing reflectivity Diagram showing the infrared reflectance of natural leather with carbon black coating formed on the surface of natural leather dyed with SELLA SET BLACK BR, LURAZOL SN, ENIVEL NT Infrared of natural leather dyed by SELLA COOL BLACK (3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt) Diagram showing reflectivity Surface of natural leather dyed with SELLA COOL BLACK (3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt) The figure which shows the infrared reflectance of the natural leather in which the coating film containing a perylene pigment was formed in. Surface of natural leather dyed with SELLA COOL BLACK (3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt) Figure showing the infrared reflectance of natural leather formed with a coating containing perylene pigment on the surface of natural leather dyed by forming a coating containing mixed color pigments Surface of natural leather dyed with SELLA COOL BLACK (3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo] -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt) Of infrared reflectivity of natural leather with a coating containing carbon black A diagram showing that the infrared reflectance is low when the conventional black dye is used. A diagram showing that the infrared reflectance is low when the conventional black dye is used. A diagram showing that the infrared reflectance is low when the conventional black dye is used. The processing steps from the treatment of the raw leather to the end of the tanning step are shown. The processing steps from retanning to formation of the surface layer are shown. The resin coating process is shown from the back glue spray process.

Claims (8)

  (1) SELLASET BLACK BR (trade name) or (2) SELLASET BLACK BR (trade name), LURAZOL SN (trade name) and natural azo dyes selected from a mixture of ENIAVEL NT (trade name) It is leather, and its infrared reflectance exceeds 0.3 at 700 nm, exceeds 0.5 at 800 nm, exceeds 0.6 at 1000 nm, exceeds 0.8 at 1200 nm, and then exceeds 0.7 until 1600 nm Black natural leather, characterized by   SELLA FAST BLACK FN (trade name) (natural leather dyed with black azo acid dye), characterized in that it is tanned with glutaraldehyde prior to dyeing and further tanned with a retanning agent. Black natural leather.   3- [ethyl [4- [4-[(3- (sodiosulfophenyl) azo) -1-naphthalenylazo] phenyl] aminomethyl] benzenesulfonic acid sodium salt, natural leather dyed with a black dye, Its infrared reflectance exceeds 0.2 at 700 nm, exceeds 0.8 at 800 nm, exceeds 0.9 at 1000 nm, exceeds 0.9 at 1200 nm, then exceeds 0.9 until 1400 nm, and is 0 at 1500 nm. Black natural leather characterized by exceeding .85 and exceeding 0.92 at 1600 nm.   A mixed color pigment that plays the role of black formed by pigments of at least three colors or at least one of the undercoat layer, intermediate coat layer, and topcoat layer containing polyurethane resin, or the role of black formed by perylene pigment A coating layer provided on the surface of natural leather, comprising a coating layer containing a pigment that holds   A black natural leather, wherein a coating layer provided on the surface of the black natural leather according to claim 4 is formed on the surface of the natural leather according to any one of claims 1 to 3.   A steering wheel, which is covered with the black natural leather according to claim 5.   A shift knob, which is covered with the black natural leather according to claim 5.   An automobile interior part, which is covered with the black natural leather according to claim 5.

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