JPH0663000B2 - A method for producing tanned leather with a fine grained surface with a fine silver surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a method for producing a finely grained, finely grained tanning with a silver surface. More specifically, after immersing the pelt in an alkaline solution and reaching the parallel state, the pelt is taken out from the alkaline solution, or while still immersed in the alkaline solution, formaldehyde, glutaraldehyde, a synthetic tannin agent that are organic tanning agents. , A plant tannin agent or a mixture thereof, and a method for producing a tanned skin with a finely grained and fine grained surface which has not been obtained by a conventional method using the same tanning agent.
Furthermore, the pelt that has reached the equilibrium state is slightly acidic,
Preferably, the pelt is soaked in a solution having a pH of 3.5 or more or a neutral solution for a short time, and then the pelt is used with the above tanning agent or a mixture thereof to produce a tanned leather with a fine grained surface and a fine grain. It also relates to the method. In this case, the immersion time in the slightly acidic or neutral solution depends on the buffering capacity of the alkaline buffer solution and the buffering capacity of the weakly acidic or neutral solution to be used later. No, but in most cases less than about 20 minutes is appropriate.

Traditionally, plant tannin agents, synthetic tannin agents [Tanigan (Ta
nigan) P2, PAK, OS, and various other Retingan agents, and agents that have similar effects.], when pelt is tanned with an organic tanning agent such as formaldehyde or glutardialdehyde, until pickling The prepared pelt is in a neutral or acidic state, and when this is tanned using the above tanning agent, the texture and grain of the silver surface are
It was not always satisfactory. There was a demand for a tanned leather with a finer grain and a fine grain.

When using pelt in an alkaline state and chrome tanning it, it is cut from almost the same part of the same half-cut of the same raw leather, and it has a silver surface compared to the neutral or acidic belt that has been prepared for pickling The fact that gagame is mellow is as described in Japanese Patent Application No. 63-56284.

According to the present invention, plant tanning agents, synthetic tannin agents, organic tanning agents (eg formaldehyde, glutardialdehyde), or a mixture thereof are used to pelt pelts while tanning while maintaining a smooth texture on the silver surface. Thus, it was confirmed that a leather with a finer silver surface was obtained than a tanning leather produced by a normal tanning method.

That is, the present invention, after immersing the pelt in an alkaline liquid, a plant tannin agent, a synthetic tannin agent, an organic tanning agent, or a mixture thereof is allowed to act on the pelt, and the silver surface has a fine texture and fine grain. A method for producing a tanned skin; and, after immersing the pelt in an alkaline solution, immersing the pelt in a weakly acidic to neutral solution, and in the pelt, a plant tannin agent, a synthetic tannin agent, an organic tanning agent, or a mixture thereof. Is used to produce a tanned leather with a fine grained surface and a fine grain.

As the alkaline solution, it is preferable to use a buffer solution which does not react with the organic tanning agent, such as a phosphate buffer solution or a carbonate buffer solution. Further, its pH is preferably 8.5 or more. When the pelt is further dipped in the above alkaline solution, and the pelt is dipped in a weakly acidic to neutral solution, the pH of the solution is preferably 3.5 or more, and the dipping time is as short as possible, for example, within 20 minutes. Is desirable.
For example, when the immersion time was 45 minutes, it was not possible to obtain a tanned leather with a fine grained surface and a fine grained surface, which had the characteristics of the present invention.

Example 1 280 kg of pelt (23 half-cuts) prepared by preliminarily performing deliming and baking on steered hide were put in a drum in an amount almost equal to that of Briton Robinson (B) of pH 9.8.
ritton-Robinson) Soak in buffer for 2 hours and spin occasionally to mix well with the solution, then while rotating, add 30Kg of 40% formaldehyde solution to 3 parts every hour and add 5
It was rotated for 6 hours.

After standing overnight, water was discharged, 300 l of a 5% sodium sulfate solution was added, and the mixture was rotated for 30 minutes, then discharged, and washed 4 times with the same amount of water as the skin. Then, the emulsion was fattened with a glyceride fatliquor.

The leather obtained in this manner had a considerably finer silver surface texture than the leather obtained by tanning pelt under a lower pH condition than the method of the present invention.

Example 2 Stairpelt 110 kg after the preparatory work described in Example 1
(8 half-cuts), soaked in the same amount of Britton-Robinson buffer of pH 10.2 in a drum, spin for 2 hours to allow the liquid to soak into the skin (cut the skin with a knife Then, the pH of each part of the cut is checked to check the liquid permeation state.) 3.9 kg of glutardialdehyde was added twice over 60 minutes at intervals. At the end of this operation, 7% hydrochloric acid was added to bring the final pH of the solution to about 8.5. After standing overnight, water was discharged, a solution of 5.5 kg ammonium sulfate dissolved in 150 l of water was added, and the mixture was rotated for about 2 hours and then discharged, and washed twice with the same amount of water as the pelt. After that, the emulsion was greased with a greasing liquid.
It was confirmed that the obtained tanning skin and the belt made of the same raw material had a finer silver surface than those produced by a conventional method (under weakly acidic conditions).

Example 3 74 kg (5 pieces of half-cut) of Stairpelt which had undergone the preparatory work described in Example 1 was dipped in a drum in the same amount of Menzel buffer solution (sodium hydrogen carbonate / sodium carbonate system) having a pH of 10.6 as the skin. It was rotated for 3 hours so that the buffer solution was sufficiently permeated into the skin. After draining the liquid from the drum, pH 4.6
Walpole buffer solution: acetic acid /
Sodium acetate type) is injected and rotated, and from the beginning of injection
Immediately after 10 minutes, 2.6 kg glutardialdehyde was added and spun. After leaving it overnight, the liquid was discharged, and a solution of 4.0 kg of ammonium sulfate dissolved in 100 l of water was added,
After rotating for a while, the liquid was drained and then washed twice with the same amount of water as the skin. The emulsion was then fattened with a fatliquor. It was confirmed that the obtained leather had a finer silver surface texture than that produced by using the same raw material, pelt, and an ordinary formulation. However, in this example, it is necessary to immerse the alkaline pelt in Walpol's weakly acidic buffer solution before the addition of glutardialdehyde as short as possible. For example, when the soaking time was 45 minutes, the silver surface texture was no longer different from that produced with the usual recipe using the same raw material pelt.

Specific examples of the present invention have been shown above, but it is clear that the present invention is not limited by these, and various improvements can be made without departing from the scope and spirit of the present invention. Since they are obvious, they are all considered to be within the scope of the invention.

Claims (3)

[Claims] 1. After immersing the pelt in an alkaline solution having a pH of 8.5 to 11, a tannin agent, a synthetic tannin agent, an organic tanning agent, or a mixture thereof is allowed to act on the pelt so that the silver surface has a fine texture. A method of producing tanned leather with a fine, fine grain. 2. After immersing the pelt in an alkaline solution having a pH of 8.5 to 11, the pelt is dipped in a weakly acidic to neutral solution, and the pellent is treated with a plant tannin agent, a synthetic tannin agent, an organic tanning agent, Alternatively, a method of producing a tanned leather with a fine grained surface by using a mixture of these materials and having a fine silver surface. 3. A method for producing a tanned leather having a fine silver surface and fine grain by re-tanning the tanned leather obtained by the method of claim 1.