A leather tanning method using chrome-free and formaldehyde-free adhesive pertains to the technical field of leather tanning, in which the quaternary ammonium salt cationic resin adhesive is used for leather pretanning and retanning. After drying, the leather has excellent performance, which is comparable to traditional chrome and formaldehyde tanned leather. The method solves the drawbacks of using chromium and formaldehyde tanning agents in the leather tanning industry, which pollutes the environment and raises health concerns. The present disclosure has obvious advantages in environmental protection, huge industrial application value, and has broad application prospects.

A leather tanning method using chrome-free and formaldehyde-free adhesive pertains to the technical field of leather tanning, in which the quaternary ammonium salt cationic resin adhesive is used for leather pretanning and retanning. After drying, the leather has excellent performance, which is comparable to traditional chrome and formaldehyde tanned leather. The method solves the drawbacks of using chromium and formaldehyde tanning agents in the leather tanning industry, which pollutes the environment and raises health concerns. The present disclosure has obvious advantages in environmental protection, huge industrial application value, and has broad application prospects.

Provided is a composition for manufacturing leather comprising: hydroxide and borax (Na.sub.2B.sub.4O.sub.7•10H.sub.2O).

Provided is a composition for manufacturing leather comprising: hydroxide and borax (Na.sub.2B.sub.4O.sub.7•10H.sub.2O).

Provided is a method of manufacturing leather, comprising: preparing fabric including soaking, fleshing, liming, reliming, band knifing, deliming, and bating of natural leather; shaving the prepared fabric to a uniform thickness; neutralizing the shaved fabric to a pH of 5 to 7; flame retardant processing of performing a flame retardant treatment on the neutralized fabric with a composition for manufacturing leather; and drying the flame retardant treated fabric.

A method is provided for producing sustainable leather using by-products from parts of all varieties and species of the plant genus Persea including among them both the American species and the Hass variety. A hide or leather may be produced by the method, and a method is provided for producing the natural tanning agents used in the method to produce sustainable leather and the natural tanning agents produced by the method.

A process for tanning leathers including a pre-tanning step and a tanning step is provided. In the pre-tanning step leathers are treated with a cationic active agent including a quatemized ester of a fatty acid and triethanolamine, or mixtures thereof and, subsequently, with an anionic active agent including tannins vegetable extracts and a natural or synthetic dispersant selected from the group consisting of lignosulfonates, distillation stillages, sulfonated disulfonic polymers, sulfonated naphthalene polymers or mixtures thereof, to obtain leathers with a shrinkage temperature of at least 65° C. The pre-tanning and tanning steps do not include treatment with aldehydes or aldehyde donor compounds and/or with metal salts.

A process for tanning leathers including a pre-tanning step and a tanning step is provided. In the pre-tanning step leathers are treated with a cationic active agent including a quatemized ester of a fatty acid and triethanolamine, or mixtures thereof and, subsequently, with an anionic active agent including tannins vegetable extracts and a natural or synthetic dispersant selected from the group consisting of lignosulfonates, distillation stillages, sulfonated disulfonic polymers, sulfonated naphthalene polymers or mixtures thereof, to obtain leathers with a shrinkage temperature of at least 65° C. The pre-tanning and tanning steps do not include treatment with aldehydes or aldehyde donor compounds and/or with metal salts.

A method for dyeing and/or retanning of leather objects includes providing a leather object. The leather object has been processed by at least a tanning process. The leather object is introduced into a process chamber. The leather object is subjected in the process chamber to a pressurized fluid. The pressure of the pressurized fluid is controlled to reach a supercritical state. The leather object is subjected to a dyeing agent and/or a retanning agent, which dyeing or retanning agent is dissolved and/or transported in the pressurized fluid for at least a predefined period of time while the pressurized fluid is in the supercritical state. The pressure is reduced in the process chamber. The leather object is removed from the process chamber. The pressure reduction is controlled over time.

A cationic cyanuric chloride derivative tanning agent and a preparation method thereof are disclosed. The method includes: mixing 9.22-36.88 parts of cyanuric chloride, 21.35-100.31 parts of a solvent, and 7.12-33.44 parts of deionized water, all by mass, in an ice-water bath to obtain a mixture A; at a temperature of 0-5° C., adding 2.98-20.44 parts of a tertiary ammonia compound to the mixture A, and subjecting the resulting mixture to a reaction for 4-6 hours, during which its pH value is adjusted with an acid-binding agent solution to 6.0-7.0, to obtain a mixture B; filtering the mixture B, washing the filter cake, and vacuum drying for 4-6 h to obtain a solid C, and grinding to obtain the cationic cyanuric chloride derivative tanning agent.