A kind of chrome-free passivation solution based on dendrimers

Abstract

The invention discloses a chromate-free passivation solution based on dendrimers. The chromate-free passivation solution comprises, by weight, 0.2-15% of at least one type of silane having and only having epoxy functional groups, 0.1-5% of transition metal compounds, 0.1-5% of at least one type of dendrimers, 0.1-20% of phosphoric acid and / or phosphate and the balance being water. The chromate-free passivation solution based on dendrimers refers to the energy-saving environmental-friendly passivation solution with high storage stability, high solid content and low-temperature film forming property without chromate, and overcomes relative defects and application limits of the conventional passivation solution, especially solves the problem about the stability during long-distance transportation with high humidity high salinity at high temperature.

Description

technical field [0001] The invention relates to a chrome-free passivation solution based on dendrimers. Background technique [0002] Today's metal surface passivation technology includes two types of chromate passivation technology and chromium-free passivation technology. Chromium-free technology is the development trend and is gradually replacing chromate passivation technology. At present, the mainstream chromium-free passivation technology on the market, based on silane technology, usually contains a certain amount of metal salts, polymer resins, film-forming aids, etc. The shortcomings of the product mainly include two aspects: [0003] The first aspect is that the storage time is short, usually no more than 3 to 6 months, and even no more than one month under high temperature in summer. The reasons are as follows: 1. Silane has self-condensation and cross-condensation properties, and will gradually form precipitation or gel over time, especially in the case of compou...

AI Technical Summary

Problems solved by technology

This results in the product containing more than 70% water, which will not only greatly increase the transportation cost, but also have high requirements for the drying temperature of the passivation solution. Usually, it needs to be baked at a high temperature of 80-100°C to be effectively dried.

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