Non-metal tanning process for leather using specific compounds
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Solution Overview
Problem
Chrome-based tanning methods are environmentally unfriendly and require additional steps and precise enzyme control, while existing alternatives do not offer satisfactory non-metal tanning solutions for achieving high-quality leather production.
Innovation Solution
A non-metal tanning process using tanning agents of specific compounds, such as those defined by formula (I), which do not include cationic metal compounds, and are applied in a tanning bath with a pH of 6 to 10, allowing for the omission of pickling steps unless necessary, and enabling the production of high-quality leather without the need for metal-based tanning agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chrome-based tanning agents are used, then high shrinkage temperature and suppleness are achieved, but environmental friendliness deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of tanning agents from chrome-based to non-metal alternatives (vegetable, synthetic, or enzyme-based agents), maintaining effective tanning while eliminating environmental harm. The tanning bath pH is optimized to 6-10 to enhance the performance of these alternative agents.
Solution Approach 2:
The invention extracts and removes harmful chrome-based metal compounds from the tanning process, replacing them with environmentally benign substances. This extraction eliminates the harmful factors while preserving the essential tanning function through alternative chemical mechanisms.
2Object-affected harmful factors
If laccase enzymes and oxidizing agents are added to tanning bath, then non-metal tanning is achieved, but process complexity and enzyme activity control requirements increase
Solution Approach 1:
The patent extracts and removes enzymes and oxidizing agents from the tanning process, simplifying it to use straightforward non-metal tanning agents alone. This eliminates the need for complex enzyme activity control and additional processing steps while maintaining environmental friendliness.
Solution Approach 2:
The invention uses simple, readily available non-metal tanning agents that do not require complex activation or control mechanisms. These agents can be applied directly in a simplified process without needing expensive or delicate biological catalysts.
3Strength
If pre-treatment with crosslinking compounds is performed before metal tanning, then resistance to deterioration is improved, but process complexity and number of steps increase
Solution Approach 1:
The patent merges the pre-treatment and main tanning steps into a single unified process. The non-metal tanning agents perform both the initial treatment and the primary tanning function simultaneously, eliminating the need for separate pre-treatment steps and reducing overall process complexity.
Solution Approach 2:
The non-metal tanning agents used in this invention serve multiple functions: they provide the primary tanning effect, improve resistance to deterioration, and work effectively across a broad pH range. This multi-functionality eliminates the need for specialized pre-treatment compounds and steps.
4Reliability
If pickling step is performed before tanning, then substrate preparation is improved, but process complexity and time consumption increase
Solution Approach 1:
The patent performs preliminary preparation of the substrate through bating and pH adjustment to the optimal range of 6-10 before applying the non-metal tanning agents. This preliminary action prepares the substrate effectively without requiring an additional pickling step, saving time while ensuring good tanning results.
Solution Approach 2:
The non-metal tanning agents are designed to work effectively across a broad pH range (6-10), making them universally applicable to various substrate types and conditions. This universality eliminates the need for specialized pickling steps that would be required for more pH-sensitive tanning processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in high-quality leather with improved shrinkage temperature, softness, and consistency, while being environmentally friendly by eliminating the use of metal-based tanning agents and simplifying the tanning process by potentially omitting pickling, thus reducing environmental impact and operational complexity.
Implementation Method 1
J. H. Bowes and C. W. Cater in the article 'Crosslinking of Collagen' in J. Appl. Chem., 15, July, 1965, describe some crosslinking tests carried out on collagen of denatured animal tendon
Implementation Method 2
in a tanning bath, the tanning bath having a pH of from 6 to 10 at the beginning of tanning step
Data Source
AI summary
Tanned leather, skin or pelt is produced by non-metal tanning, comprising the step of tanning a bated hide, skin or pelt with a tanning agent (A), the tanning agent (A) being at least one compound of formula (I), wherein Hal signifies chlorine or fluorine, X signifies N or CR, Y signifies hydrogen, C1-8-alkyl, C1-4-alkyl-carbonyl, C1-4-alkyl-sulphonyl or a radical of formula (la), or (lb) R signifies hydrogen or chlorine, q is 1 to 10 and M signifies hydrogen or an alkali metal cation or an ammonium cation, the ammonium cation being a protonated tertiary amine or a quaternary ammonium cation, in a tanning bath, the tanning bath having a pH of from 6 to 10 at the beginning of the tanning step.