What is a phosphorus-free film?

On the basis of the successful development and production of non-phosphorus degreasing agent, the non-phosphorus coating agent that replaces the phosphating solution was produced in China by drawing on and introducing the technology of foreign non-phosphorus coating solution, which successfully achieved the full line of non-phosphorus coating pretreatment process in China and fundamentally eliminated the problem of phosphorus pollution in the pretreatment process. The non-phosphorus degreasing agent and non-phosphorus skin film fluid developed and produced by the Institute of Surface Technology have fundamentally eliminated phosphorus pollution, adjusted the urgent need for environmental protection, and their treatment effect is also very prominent. The treatment effect of the non-phosphorus degreasing agent at room temperature and the non-phosphorus degreasing agent at low temperature has exceeded the traditional phosphorus degreasing agent, and has been widely used throughout the country. The non-phosphorus skin film fluid has also begun to be applied in the mainland, showing a very good prospect.

With the increasingly strengthening of environmental protection work, the pollution of phosphorus has been highly valued by relevant departments and enterprises at home and abroad. There are many regions and cities in China that prohibit the use of phosphorus-containing detergent and phosphorus-containing detergent. The environmental protection department has increasingly strict requirements for the treatment of phosphorus-containing wastewater after pretreatment before coating, resulting in a significant increase in the comprehensive cost of pretreatment before coating.

In the face of this grim situation of environmental protection,

2. The role of phosphorus in coating pretreatment agent

2.1 Phosphorus plays a very special role in traditional coating treatment agents, and its main role is shown in the following two aspects:

① In degreaser

It is mainly added to degreasing agent in the form of phosphate. The commonly used phosphate is sodium tripolyphosphate (Na5P3O10); Disodium hydrogen phosphate (Na2HPO4); Trisodium phosphate (Na3PO4), etc., whose functions in degreasing agents are emulsification, buffering and complexing, and have good water washability and low use cost, are the main components of phosphorus-containing degreasing agents, which is the main reason why phosphorus-containing degreasing agents still have a certain market.

The prerequisite for manufacturing phosphate-free degreasing agent is to synthesize new compounds that can replace phosphate. The Institute of Surface Technology of Chengdu Langtuo Technology Co., Ltd. has successfully synthesized a compound with good emulsification, dispersion, softening of hard water and complex metal calcium, magnesium and iron ions, and the degreasing ability is significantly better than single phosphate and composite phosphate, which is an ideal substitute for phosphate. The phosphating company of Chengdu Langtuo Technology Co., Ltd. has applied this major technological innovation to develop a new type of non-phosphorus low temperature degreasing agent and non-phosphorus normal temperature degreasing agent with degreasing effect reaching and exceeding that of phosphorus-containing degreasing agent.

② In phosphating solution

Phosphorus is the most basic component and the most important component in the phosphating coating solution. It is the main film-forming substance of the phosphating solution. Commonly used include zinc dihydrogen phosphate and alkali metal phosphate, among which the commonly used alkali metal phosphate includes alkali metal first generation phosphate, alkali metal second generation pyrophosphate, alkali metal polyphosphate, etc. Phosphate coating agent can significantly improve adhesion and corrosion resistance, and is a good substrate for coating film. However, due to the large amount of pollution source-phosphorus element, there are many sediment in the process of use, and the environmental pollution is serious, which is strictly restricted by the relevant departments. In this case, if the performance of phosphating solution is maintained and phosphorus pollution is eliminated, it becomes an important research topic in the field of surface pretreatment at home and abroad. Chengdu Langtuo Technology Co., Ltd. has successfully developed a phosphorus-free neutral coating solution based on the foreign phosphorus-free coating agent technology and the actual situation in China to meet the actual needs of the coating pretreatment industry.