JPH05179300A - Production of reptile leather - Google Patents

Abstract

PURPOSE:To obtain a reptile leather excellent in flexibility, washability and slip-proofness, useful for sporting goods, etc., by treating a raw hide of e.g. a lizard belonging to monitor species using each specific hydrophobic polymer and stuffing agent during its tanning process. CONSTITUTION:The objective leather can be obtained by the following consecutive processes: a raw hide of e.g. a lizard belonging to monitor species is put to (1) water immersion, lime immersion, deashing, enzyme treatment, and sodium chlorite treatment, successively in this order, (2) bleaching made up of both potassium permanganate and sodium bisulfite treatments, (3) acid immersion, (4) combined tanning treatment with chromium and glutaraldehyde, (5) such dyeing as to make a dyeing with a vinylsulfone-based reactive dye followed by treatment with a phosphorylated dye, and (6) stuffing treatment with (a) a hydrophobic polymer prepared from a long chain monoalkyl phosphate and maleic anhydride-olefin copolymer and (b) a stuffing agent prepared by emulsifying the polar group of a long chain dialkylsulfosuccinate as the chief agent with diethylene glycol monobutyl ether in a high-boiling solvent at its boiling point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing leather which is excellent in flexibility, washable resistance, and slip resistance, using lizard leather of monitor species of reptile leather and leather of Karon Snake. The present invention provides a manufacturing method characterized by being used as leather for a wide variety of sports, working, clothing, and gloves at sea.

[0002]

2. Description of the Related Art Generally, small cow leather, deer leather, sheep leather, goat leather and other small animal leather have been widely used for clothing, gloves, bags, shoes and the like, and reptile leather is mainly used for decorative items such as bags, belts and bill holders. It is well known that it is widely used in articles. The reason for this is that reptile leather tends to be harder in comparison with cows, horses, deer leather, etc., although the entanglement of collagen fibers is essentially coarse, and attention is paid to leather for gloves. The reality is that there was no such thing.

However, regarding the karon skin (a kind of river snake which belongs to the subfamily "Acrochodina" belonging to the filed filed, known in the industry as the general name Karon and often inhabiting Java in Southeast Asia), it is DASLEDER 197.
4.1 Volume 25 No1 pages 12, 13 and Ch
emissary and technology of
novelty leader 1974. 7 part 2
On page 6, it is said that caron leather is a special kind and is important as leather for clothing or leather for gloves. Also, the monitor-type lizard is well known in the leather industry as a raw material leather that can be obtained from Southeast Asia. However, the Karon leather produced by those conventional methods lacks flexibility and resistance to water wetting when used in gloves, so-called washable resistance, and slip resistance, and is intended to improve the above-mentioned drawbacks of the present invention. There is no detailed teaching regarding the technology of.

[0004]

In the conventional leathermaking technique, that is, the method of using potassium permanganate and sodium bisulfite in the bleaching process, the strength is lowered in relation to the subsequent processing step. Lacks flexibility, and the removal of streaks and mottled patterns that these skins have is not enough,
It gave unfavorable results for gloves. Targeting gloves for all fields such as golf, marine, tennis, batting, mountain biking and other sports, drivers, working, clothing, etc., the required conditions must be strength (tensile strength, tear strength, It is necessary to have high frictional strength (silver surface), slip resistance, flexibility, and washing resistance. In this respect, the caron skin and the reserve (monitor type) skin have a Wart-like appearance peculiar to the silver surface. It has protrusions and satisfies the above conditions, and is intended as a luxury product.

As for the tanning agent, plant tannin tanning agents, chromium tanning agents, and tanning agents for common cowhide and deer hide,
Aldehyde tanning agents, zirconium, aluminum, oils and other tanning agents are used, but when the monitor type lizard and Karon snake skin are processed by the conventional method, the product becomes hard and lacks a fit feeling when gripping something. It is weak against sweat, has poor tensile strength, tear strength, flexibility, and water resistance as a whole and is significantly deteriorated by washing, and is not particularly suitable for sports-related products. As for the dyeing agent, direct dyes, acid dyes, basic dyes, mordant dyes and the like which have been conventionally used are not sufficiently fast in various types and have a problem in washability.

Next, the most important issues are permanent flexibility as gloves leather, resistance to perspiration resistance, that is, not to be slimy due to water wetting, not to be hard even after drying, and to have permanent slip resistance. Properties such as are most required as products. Conventionally, for fattening finish, emulsify beef tallow, beef leg oil, sheep's fat, matcha whale oil, shark oil, castor oil of vegetable origin, coconut oil, olive oil, etc. with anion, cation, nonionic activator. The inside of the leather is permeated and filled to give it flexibility. These are not preferable because the hydrophilic active ingredient remains in the leather and causes a parallel shift phenomenon with time, or the softness and mechanical strength of the leather is significantly impaired due to loss or deterioration due to repeated wet and dry cleaning. Recently, a method has been proposed in which an amino acid having a long-chain alkyl group or a betaine derivative substituted with an alkyl group having 12 to 14 carbon atoms is used as the greasing agent. However, they do not have the same suppleness as wet or dry-cleaning, and they do not have sufficient resistance under the severe conditions as slimy and non-slip gloves, and in addition, they are used for cow, deer, sheep leather, etc. It is intended for general leather and does not give any teaching as to the use of special things such as monitor-type lizards or Karon snake leather.

[0007]

The most important point of the present invention is to replace the animal or vegetable fats and oils conventionally used as a fatliquoring agent in the fatliquoring process.
It is a combination of a specific hydrophobic polymer softener and a high boiling point polar solvent. Of course, as an application method, some water is added to four types and it is applied to leather in the form of oil-in-water emulsion so that it penetrates evenly inside the leather tissue and becomes a water-in-oil type during drying, and it is more hydrophobic and flexible. Filled in leather as an agent. In addition, some of them are coordinated with the chrome of leather to lose their hydrophilic groups and exhibit permanent hydrophobicity, and they are also sufficiently deposited and fixed between the internal collagen tissues that form protrusions on the surface of the leather, and the protrusions on the surface of the glove for a long time. There is no sagging, and when you grasp something, you do not slip tightly.

The micron-order fine particles deposited between the leather collagen fiber bundles play a role as a lubricating buffer.
As a glove, it retains its flexibility for a long time and has good drainage against re-wetting with water or sweat. For example, when it is used as a golf glove, it has good fashionability and no slimy feel, and it does not come in close contact with the club grip and slip. The hydrophobic polymer softener used in the present invention is mainly composed of a long-chain dialkylsulfosuccinate, and is a copolymer of a long-chain monoalkyl phosphate ester and a maleic anhydride-unsaturated olefin monomer at a high boiling point with a polar group. After using as a solvent diethylene glycol monobutyl ether having, the hydrophilic group does not remain in the leather and exhibits a suitable action.

Regarding the bleaching agent, the sodium chlorite used in the present invention is used as a bleaching agent for general fibers and papers, but it is not widely used for rawhide. However, in the present invention, after the first stage treatment with soda chlorite, the latter stage treatment with potassium permanganate and sodium bisulfite is performed to obtain a product in correlation with other steps. On the other hand, the unexpected effect was brought about in the improvement of the said problem. The bleaching of small cowhide and other small animal skin is generally 5%.
Drumming with potassium permanganate solution for about 30 minutes and then with 12% sodium bisulfite solution for about 45 minutes, or using a synthetic tanning agent (generally a mixture of aromatic naphthalene, anthracene, etc. However, the lizard and Karon snake skin that have mottled or striped patterns on the raw hide itself cannot be completely removed by the conventional method, and it is not possible to remove it as in the present invention. These defects are improved by carrying out a step treatment, and the strength of leather (tensile strength, tensile strength,
It was possible to complete the bleaching operation while preventing a decrease in tear strength).

In the present invention, complex tanning (combination
The reason for doing so is to improve the quality of the leather at any time. Usually, the surface is re-tanned with vegetable tannin (or a synthetic tanning agent) after chrome tanning, or a composite of chrome tanning and basic aluminum tanning is used. Tanning, formalin and oil tanning, etc. are known, but no one has hitherto been particularly noted for finishing lizard Karon snake leather on a soft and well-balanced surface, and those should be done with the intention of wearing gloves. It was a very rare thing in itself. As a result of numerous experiments, the following complex tanning was found to have an effect of contributing to unexpected physical strength, flexibility, washable resistance, and slip resistance. That is, the above properties were dramatically improved by chrome tanning and then glutaraldehyde tanning. However, among aldehydes, formaldehyde and acetaldehyde are not preferable because they have poor sweat resistance. In addition, if it is desired to obtain white leather, a method of performing complex tanning with formalin and zirconium is also recommended.

The vinyl sulfone-based reactive dye used first in the dyeing process of the present invention has a commercial name: Re
mazol Brill Yellow 7GL, Ye
low GNL, Yellow RTN, Brill
Orange 3R, Brill Red 2B, Br
ill Violet 5R, Brill Blue
B, Black B (Heochst), etc. are used, but these do not damage the texture by dyeing by covalent bonding with the functional groups of the cortex and protecting the leather tissue, and the phosphorylated dye used in the latter stage is the hydroxyl group of the dye. Is modified with phosphoric acid ester, and dyes by coordinatively bonding to chromium of chrome-tanned leather, but controlling the amount used to prevent other bonds at that time suppresses factors that induce discoloration. Important in meaning.

[0012] It is difficult to dye the silver surface of leather in a dark color only with the vinyl sulfone-based reactive dye, and the dyeing means for increasing the density not only hardens the leather but also reduces the physical strength. It is not only that the silver surface of the leather is dyed in an extremely dark color even if a large amount of the reactive dye is not used by changing the binding mode and using an appropriate amount of the phosphorescent dye.
They found that it could be a product with excellent flexibility and strength. Commercially available dye: RCR
Yellow # 1, Red # 19, Blue # 1, Or
engine # 1, Brown # 21, Black P-2
Is a typical one.

[0013]

As mentioned above, it should be noted that the bleaching was carried out in two steps and the tanning treatment was performed in combination, and the dyeing was carried out in two steps of the vinyl sulfone-based reactive dye and the phosphorylated dye. By using a special hydrophobic softener consisting of three compositions as a fatliquoring agent, the flexibility, washable resistance and anti-slip properties of glove leather far surpasses the prediction range. An improved product was obtained. With regard to these actions, excellent results were obtained by repeating experiments by combining each step.

It is conceivable that contaminants and water-soluble proteins that could not be removed by lime picking by pretreatment with sodium chlorite in the bleaching step are removed, and collagen fibers are loosened to eliminate streaks and mottled patterns. In addition to being able to make a smooth leather, the dyeing process was performed in two steps, and the vinyl sulfone-based reactive dye was covalently bonded to the functional group of the leather in the first step, and the leather dye was made with a phosphorylated dye in the second step. It can be said that the complex reaction with the chromium ions bound in the tanned leather can be completed by coordinating to chrome, and the flexibility and strength are maintained, and the prevention of fading during washing is completed. In addition, since the softener composed of the above three components is embedded and fixed in the bundle of leather constituent fibers, resistance to sweat and water is obtained, and it is possible to maintain invariable softness. ..

[0015]

Examples 1 and 2 (1 is Karon snake skin, 2 is lizard skin of monitor species, and the following steps are exactly the same.) Soaked-The first step of leather production is to wash the raw leather with water. It is first treated with a water tank, paddle or drum, but it removes dirt such as mud and blood adhering to the raw material skin, sufficiently removes salt from the salted skin and softens water absorption, and soluble components in the skin, especially albumin. , Proteins such as globulin are eluted, but since they are easily affected by bacteria, careful adjustment of pH and temperature is required depending on the region and season. First, add salted skin to the drum and rotate it for about 20 minutes while running approximately 5 times the amount of water, and then add new water to dry skin 4 times.
Replace with 00% and let it soak for 24 hours. Lining-to promote uniform lime penetration during subsequent lime picking and to smooth the skin while rubbing and loosening while removing the tightening tissue on the back side.

Lime pickling-5 slaked lime in a water pickling drum
% And 2% sodium hydrosulfide with a concentration of 35%, rotate for about 30 minutes, stop for 30 minutes, repeat twice, then rotate 4 times every 5 hours for 5 minutes 4 times to swell the skin and leave it overnight ..
(The amount used is% by weight based on the weight of the absolutely dried skin.) After decalcification, beating, and lime pickling, the skin in a highly alkaline state is washed with water in a drum to remove alkali in the middle, and then washed with 300% water. Rotate for about 1 hour in a solution of 3% ammonium sulphate and 0.5% acidic sodium bisulfite dissolved at 30 ° C, and add 0.7% ammonium sulphate 0.7% enzyme preparation to 37-38 ° C water. Rotate with a paddle containing the dissolved liquid for about 3 hours. As the enzyme agent to be used, any of general pancreatin, pepsin, trypsin, protease, amylase and the like can be used.

Acid treatment-a treatment that can be said to be preliminary tanning, also referred to as ichimei pickling, is made weakly acidic in order to bring the skin exhibiting weak alkalinity closer to the pH of the chrome tanning solution, in which case neutral salt is added. To prevent the destruction of the skin due to acid swelling. As the acid to be used, both an inorganic acid and an organic acid are used, but both have advantages and disadvantages. In the present invention, formic acid and sulfuric acid were used in combination.

The skin that has been bleached and pickled is washed with water to remove acid and contaminants, and the following treatment is performed. First stage bleaching 200% Water (25 ° C) 20% Salt 30% Sodium chlorite (24 hours drumming) 15% Sodium thiosulfate (1 hour drumming) Second stage bleaching 200% Water (25 ° C) 20% Salt 3% Permanganate Potassium (Drumming for 30 minutes) 10% Sodium bisulfite (Drumming for 45 minutes) By this operation, the keratin substance is decomposed and a pseudo-tanning action occurs due to chlorine adsorption, and the cortex is not damaged even by bleaching in the subsequent stage.

The tanning chrome pre-tanned 25% chrome tanning solution (basicity _{33% C r2 O 3 5%} )
Was about 2 hours drumming added, followed by 25% chrome tanning solution (basicity _{41% C r2 O 3 5%} ) to be about 3 hours drumming added to soaked overnight, about 2% after Na HC
The pH is adjusted to 3.5 with O ₃ solution. Glutaraldehyde post-tanning Drumming a 30% glutaraldehyde solution with 1% sodium formate to 3% on the skin. The skin after the treatment had a smooth surface with a color close to white.

Dyeing In one step, Na ₂ CO ₃ and Na ₂ Al ₂ O ₃ are used as alkaline agents.
Is used at a ratio of 2: 1.5. Brilli Blue B (reactive dye) 5% Na ₂ SO ₄ 20% Na ₂ CO ₃ Na ₂ Al ₂ O ₃ } 5% Dye for 90 minutes in a drum, then add 2% formic acid to neutralize and wash with water. .. The phosphorylated dye used in the two steps is dyed with chrome-tanned leather by coordination bonding, and the dyeing was carried out by adjusting the amount used so that dyeing other than coordination bonding does not occur. Blue # 1 (phosphorylated dye) 0.5 to 1.5% Dyeing for 30 minutes in a drum. Then, formic acid 1% is added for neutralization, followed by washing with water.

Greasing finish 30% of a fattening softener having the following mixing ratio is added to dyed leather washed with water.
Add the agent and drum it for about 1 hour to sufficiently permeate and stabilize the agent in the leather, and then air-dry it slightly, plate it, and taste-dry it. Long-chain sodium dialkylsulfosuccinate 6 parts (R: C _{12 to} C ₁₈ ) Long-chain monoalkyl phosphate ester 6 parts Diethylene glycol monobutyl ether 10 parts Maleic anhydride-olefin copolymer 6 parts (Olefin: C _{2 to} C ₅ ) 2 parts of water

[0022]

[Comparative Example] Note-Comparative Examples 1 to 3 used snake leather caron. Comparative Example 1 is an acid dye having a soda base of sulfonic acid, which is often used for dyeing chrome-tanned leather in the dyeing process, except that 5% of acid blue was used instead of the reactive dye. Same as 2. The results are shown in Table 1 below, in which the leather faded and the leather gradually hardened with repeated washing. In Comparative Example 2, the hydrophobic polymer softener used in Examples 1 and 2 was replaced by C ₁₂
~ ₁₄ alkyl-substituted betaine derivatives and sulfated fish oil were emulsified and applied at 10% to leather. This moved parallel with the inside of the leather over time to increase hardness, and was low in water resistance, giving a strong slimy sensation due to water wetting and giving an unpleasant feeling. Comparative Example 3 was carried out according to the same conventional method as Comparative Examples 1 and 2 for dyeing and fatliquoring, and as a result, it was not comparable to the product of the present invention.

[0023]

[Table 1]

The bleaching process shown in the table was based on the method of the present invention in the comparative example, but it goes without saying that bleaching by the conventional method is inferior to the whole. Rating ──── 5: Excellent 4: Good 3: Normal
2: Inferior 1: Extremely inferior Tensile strength ─ JIS K 6550 Tear strength ─ JIS K 6550 Dyeing fastness ─ JIS 6086 (The degree of contamination of white cloth of vertical yarn wool and weft polyester attached to leather by washing method is graded. Shown with, grade 5 is the strongest, grade 1 is the weakest) Water resistance ─── JIS K 655
0 (time until 80 cm of water pressure is applied to the leather surface and water droplets appear on the opposite surface) Flexibility: This was measured by the JIS L 1005 bending resistance measurement method. The value is the value after repeating washing five times. (25 mm x 150 mm test piece was gently extruded in the longitudinal direction from a table having a slope of 45 ° at the tip, and the extruded length of the test piece when the tip was in contact with the slope, provided that the test piece was taken in the vertical direction. The comparative example is 100 when cured.
mm or more)

[0025]

[Effects of the Invention] First of all, attention has been paid to lizard and snake skin for gloves, and improvements have been made to achieve excellent flexibility and strength (tensile, tearing, surface friction resistance) and discoloration. It is very valuable as a luxury item because it has great significance in that it does not lose its luster upon repeated washing and that it does not lose its softness. Of particular interest is the application of a greasing agent to the skin, which consists of three types of polymeric substances,
It was discovered that a composition that is both a fatliquor and a softener, and that it is firmly fixed because it is deposited on the skin with a solvent-based dispersion, and has the characteristics that it does not deteriorate even after long-term use.

Since the conventional fatliquoring agent uses a surfactant as an emulsifier, it remains inside the leather after drying, which causes problems such as migration and deterioration, and it is weak against water in any case. If the water flies away, only the active substance remains, so it has an excellent effect. Next, as an effect to be seen, if the amount of reactive dye is increased in the dyeing process, it will be dyed in a dark color, but the polypeptide bond of the leather will be cut and the strength will be significantly impaired. Phosphorus brings about a kind of tanning effect even when used in a small amount, and since it does not hinder the leatheriness, the shrinkage temperature of the leather is high and the dyeing fastness and physical strength can be increased. In bleaching, it has a synergistic effect with the above items, and because it has a beautiful leather surface without leaving stripes or mottled patterns on lizards and snakeskin, it is one of the important factors as a commercial value.

Claims (4)

[Claims] 1. A tanned leather that is made from the skins of lizard and / or Karon snake of the monitor species as a raw hide, and is successively soaked in water, lime picked, decalcified, enzyme treated, bleached, soaked, tanned, dyed and greased. In the method for producing, a long-chain dialkylsulfosuccinate is used as a main component in a fatliquoring step, and a hydrophobic high-molecular polymer consisting of a long-chain monoalkyl phosphate ester and maleic anhydride-olefin copolymer is used as a solvent. As a softening agent, a liquid emulsified with diethylene glycol monobutyl ether having a high boiling point and a polar group as a fatliquoring agent, and being applied to leather by a specific method,
A method for producing reptile leather for various sports goods and various gloves and garments, which has excellent washability and slip resistance. 2. The method for producing reptile leather according to claim 1, wherein the dyeing step is carried out in two steps, first dyeing with a vinyl sulfone reactive dye and then treating with a phosphorylated dye. 3. The method for producing reptile leather according to claim 1, wherein the bleaching step is first treated with sodium chlorite and then treated with potassium permanganate and sodium bisulfite. 4. The method for producing reptile leather according to claim 1, wherein the tanning treatment is a composite tanning of chromium and glutaraldehyde or a composite tanning of formalin and zirconium.