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Chromium-free passivation solution, preparation method and application method thereof

A chrome-free passivation and solution technology, applied in the coating process of metal materials, etc., can solve the problems of high porosity, poor water solubility, and suspension of the passivation layer, and achieve fast passivation treatment speed, firm adhesion, The effect of low porosity

Active Publication Date: 2017-07-11
HUNAN JINYU CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Hexavalent chromium will not only cause serious pollution to the environment, but also has high toxicity to the human body. Half a tablespoon (about 2 ml) of a high-concentration hexavalent chromium solution can cause human death
The chemical materials such as phytic acid and titanyl sulfate added in this formula have extremely poor water solubility, which may cause suspension, and the passivation layer formed usually has a large porosity, which is not conducive to production and use.

Method used

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  • Chromium-free passivation solution, preparation method and application method thereof

Examples

Experimental program
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Effect test

Embodiment 1-12

[0041] Examples 1-12 respectively provide the composition of the chromium-free passivation solution of the present invention, as shown in Table 1 and Table 2, wherein, the unit of the numerical value of each ingredient is g / L, and the volume of the solution is 1L.

[0042] Table 1 embodiment 1-6 passivation solution formula composition

[0043] Example 1 2 3 4 5 6 Sodium molybdate 60 60 65 65 70 70 Sodium Tungstate 5 7 9 10 5 6 ethanol 7 5 6 3 5 4 Acetic acid 15 35 25 50 30 20 hydrogen peroxide 30 20 35 40 25 30 Disodium edetate 5 9 8 10 7 5 water margin margin margin margin margin margin

Embodiment 7-12

[0044] Table 2 embodiment 7-12 passivation solution formula composition

[0045] Example 7 8 9 10 11 12 Sodium molybdate 75 75 80 80 80 80 Sodium Tungstate 8 10 5 6 8 10 ethanol 2 7 4 2 7 5 Acetic acid 40 50 50 25 40 15 hydrogen peroxide 40 35 40 25 20 35 Disodium edetate 6 9 5 8 10 7 water margin margin margin margin margin margin

[0046] The preparation method of above embodiment 1-12 passivation solution is as follows:

[0047] (1) Dissolve disodium edetate in half the volume of required water, add sodium molybdate and sodium tungstate, dissolve completely and stir evenly to obtain a salt solution;

[0048] (2) Mix ethanol and acetic acid, stir well, then slowly add hydrogen peroxide to obtain a mixed solution;

[0049] (3) Mix the salt solution in step (1) with the mixed solution in step (2), add the remaining water to the required volume, stir well, and stir for 2 hours t...

Embodiment 13

[0068] Take 100ml of the chromium-free passivation solution of Example 10, add water to dilute to 700ml and mix well to make a passivation working solution (bath solution), heat it to 60°C and maintain the temperature during the application process, and then process 100 pieces of purification After the carbon steel workpiece, the passivation time is 3 minutes, after the treatment, it is successively baked in a 55°C hot air furnace for 15 minutes to dry, and the passivated workpiece is obtained; the passivation condition of each workpiece is better, and the color is consistent, respectively. 10, 30, 50, 70, and 100 pieces of workpieces were subjected to neutral salt spray corrosion test, natural rust test, and measured passivation film porosity, passivation film and spray coating adhesion, all of which can reach the values ​​listed in Table 5 passivation effect.

[0069] It can be seen from the above examples and comparative examples that the passivation layer of the chromium-f...

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Abstract

The invention provides a chromium-free passivation solution as well as preparation and using methods thereof. The passivation solution is prepared by dissolving a solute composed of multiple substances into deionized water, wherein the solute in the solution comprises the following raw materials according to the ratio: 60-80g / L of sodium molybdate, 5-10g / L of sodium tungstate, 2-7g / L of ethanol, 15-50g / L of acetic acid, 20-40g / L of hydrogen peroxide, 5-10g / L of ethylenediaminetetraacetic acid disodium and the balance of water. The chromium-free passivation solution is firm in adhesive force, low in porosity and corrosion-resistant.

Description

technical field [0001] The invention relates to the field of metal surface treatment agents, in particular to a chromium-free passivation solution, a preparation method and a use method thereof. Background technique [0002] For a long time, the passivation treatment of metal surfaces has generally used chromate passivation solution containing hexavalent chromium. The passivation film has good isolation performance and self-healing ability, and has good corrosion resistance. However, hexavalent chromium is highly toxic and carcinogenic, and its environmental pollution and harm to humans have received widespread attention. Many countries have begun to restrict or prohibit the use of chromate passivation treatment, such as the European Union in 2003. Decree No. 2002 / 95 / EC was promulgated on March 13, referred to as the ROHS Directive, the "Clean Production Promotion Law" implemented in my country on January 1, 2003 and the Chinese version of the "Clean Production Promotion Law"...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23C22/40
CPCC23C22/40
Inventor 桂成方
Owner HUNAN JINYU CHEM
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