Preparation method of dicyandiamide resin tanning agent

Abstract

The invention discloses a preparation method of a dicyandiamide resin tanning agent. The dicyandiamide resin tanning agent is prepared through steps of preparation of a sodium hydrogen sulfite solution, a condensation reaction and drying. The dicyandiamide resin tanning agent has the advantages as follows: the preparation technology of the resin tanning agent is improved, so that the prepared resin tanning agent has high filling performance, has an extremely high filling effect on soft parts of leather and has a good napping effect; excessive ammonium sulfite is added during condensation to react with free formaldehyde in materials, thus, the content of free formaldehyde in the product is reduced, and the product is more environmentally friendly.

Description

technical field

[0001] The invention belongs to the technical field of leather chemical synthesis, and in particular relates to a preparation method of a dicyandiamide resin tanning agent. Background technique

[0002] In recent years, retanning has shown its important role in the whole process of tanning, and is known as the "golden touch" in modern tanning industry technology. Retanning is the tanning of crust leather that has been main tanned. There are many kinds of retanning agents. Common organic retanning agents include natural retanning agents, resin tanning agents, synthetic tanning agents and aldehyde tanning agents. Playing a role in tanning, there are more and more types of retanning agents on the market, with rapid development and more diversified performance.

[0003] Dicyandiamide resin tanning agent, also known as resin tanning agent R6, can effectively solve the problem of loose surface of crust leather, improve the grain surface of finished leather, make ...

Examples

Embodiment 1

[0017] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0018] (1) Prepare ammonium bisulfite solution: add 80Kg of water to the dissolution kettle, start stirring, then add 50Kg of sodium bisulfite, and stir until completely dissolved;

[0019] (2) Condensation reaction: Transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 80Kg of formaldehyde, then add 80Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 75°C, and Insulate the reaction at high temperature for 2 hours. After the reaction, add 40Kg of urea from the manhole, and keep the reaction at 75°C for 1h. After the reaction, the temperature in the lower kettle is lowered to 60°C, and add 170Kg of water and 130-Kg of sulfurous acid from the manhole. ...

Embodiment 2

[0022] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0023] (1) Prepare ammonium bisulfite solution: add 100Kg of water to the dissolution kettle, start stirring, then add 60Kg of sodium bisulfite, and stir until completely dissolved;

[0024] (2) Condensation reaction: transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 90Kg of formaldehyde, then add 100Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 80°C, and Keep the reaction at high temperature for 4 hours. After the reaction, add 45Kg of urea from the manhole, and keep the temperature at 80°C for 3h. After the reaction, the temperature in the lowering kettle is lowered to 60°C, and add 190Kg of water and 150Kg of sodium bisulfite from the manho...

Embodiment 3

[0027] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0028] (1) Prepare ammonium bisulfite solution: add 90Kg of water to the dissolution kettle, start stirring, then add 56Kg of sodium bisulfite, and stir until completely dissolved;

[0029] (2) Condensation reaction: Transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 86Kg of formaldehyde, then add 90Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 77°C, and Insulate the reaction at high temperature for 3 hours. After the reaction, add 43Kg urea from the manhole, and keep the temperature at 77°C for 2h. After the reaction, the temperature in the lowering kettle drops to 60°C, and add 180Kg water and 140Kg sodium bisulfite from the manhole. , react...

technical field

[0001] The invention belongs to the technical field of leather chemical synthesis, and in particular relates to a preparation method of a dicyandiamide resin tanning agent. Background technique

[0002] In recent years, retanning has shown its important role in the whole process of tanning, and is known as the "golden touch" in modern tanning industry technology. Retanning is the tanning of crust leather that has been main tanned. There are many kinds of retanning agents. Common organic retanning agents include natural retanning agents, resin tanning agents, synthetic tanning agents and aldehyde tanning agents. Playing a role in tanning, there are more and more types of retanning agents on the market, with rapid development and more diversified performance.

[0003] Dicyandiamide resin tanning agent, also known as resin tanning agent R6, can effectively solve the problem of loose surface of crust leather, improve the grain surface of finished leather, make ...

Examples

Embodiment 1

[0017] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0018] (1) Prepare ammonium bisulfite solution: add 80Kg of water to the dissolution kettle, start stirring, then add 50Kg of sodium bisulfite, and stir until completely dissolved;

[0019] (2) Condensation reaction: Transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 80Kg of formaldehyde, then add 80Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 75°C, and Insulate the reaction at high temperature for 2 hours. After the reaction, add 40Kg of urea from the manhole, and keep the reaction at 75°C for 1h. After the reaction, the temperature in the lower kettle is lowered to 60°C, and add 170Kg of water and 130-Kg of sulfurous acid from the manhole. ...

Embodiment 2

[0022] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0023] (1) Prepare ammonium bisulfite solution: add 100Kg of water to the dissolution kettle, start stirring, then add 60Kg of sodium bisulfite, and stir until completely dissolved;

[0024] (2) Condensation reaction: transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 90Kg of formaldehyde, then add 100Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 80°C, and Keep the reaction at high temperature for 4 hours. After the reaction, add 45Kg of urea from the manhole, and keep the temperature at 80°C for 3h. After the reaction, the temperature in the lowering kettle is lowered to 60°C, and add 190Kg of water and 150Kg of sodium bisulfite from the manho...

Embodiment 3

[0027] A kind of preparation method of dicyandiamide resin tanning agent, completes the preparation of dicyandiamide resin tanning agent through preparation sodium bisulfite solution, condensation reaction and drying step; Concrete steps are as follows:

[0028] (1) Prepare ammonium bisulfite solution: add 90Kg of water to the dissolution kettle, start stirring, then add 56Kg of sodium bisulfite, and stir until completely dissolved;

[0029] (2) Condensation reaction: Transfer the above-prepared sodium bisulfite solution into the condensation kettle, start stirring, add 86Kg of formaldehyde, then add 90Kg of dicyandiamide from the manhole, raise the temperature in the kettle to 77°C, and Insulate the reaction at high temperature for 3 hours. After the reaction, add 43Kg urea from the manhole, and keep the temperature at 77°C for 2h. After the reaction, the temperature in the lowering kettle drops to 60°C, and add 180Kg water and 140Kg sodium bisulfite from the manhole. , react...

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