JPS58153784A - Managenent of phosphate film chemical forming treatment liquid - Google Patents

Abstract

PURPOSE:To restore the chemical conversion film forming capacity of a chemical conversion liquid for forming a phosphate film, by passing said liquid through a specific adsorbing material when said liquid on the surface of a metal product is deteriorated by the mixing of an org. substance to remove said org. substance. CONSTITUTION:A phosphate film comprising zinc phosphate, iron phosphate or manganese phosphate is formed in order to enhance the paintability of the surface of a steel plate. In this case, an org. substances such as anti-rust sealer, an adhesive, an anti-rust additive or a surfactant adhered to the surface of the steel plate are introduced into a treating liquid when the phosphate film is formed and accumulated therein, the phosphate film forming capacity is decreased. This aged treating liquid is treated with an adsorbing material selected from activated carbon, clay mineral such as bentonite, diatomaceous earth or slag, and harmful org. substances contained therein are removed to restore or regenerate the phosphate film forming capacity thereof.

Description

[Detailed description of the invention] The present invention relates to a method for managing a phosphate film chemical conversion treatment solution.

Conventionally, when protecting minor products such as steel products with C-cladding, phosphate film conversion treatment is generally employed as a pre-treatment in order to improve the coating effect. In this chemical conversion treatment, many of the various constituent components in the treatment solution are consumed through chemical reactions with the treated material, chemical decomposition, precipitation, and removal by the treated material, so there is a constant constant In order to maintain the chemical conversion treatment, a treatment solution management method is adopted in which various agents are replenished as needed. Furthermore, the object to be subjected to the chemical conversion treatment is generally degreased prior to the chemical conversion treatment so that the surface thereof is maintained in a state suitable for the treatment.

By the way, in the actual line of such a chemical conversion treatment system (for example, chemical conversion treatment of automobile bodies).

If the treatment is carried out for a long period of time, even if a pre-degreasing treatment is carried out and treatment liquid management is carried out using conventional methods, a situation may occur that leads to defects in the chemical conversion treatment.

Specifically, the reduction in weight of the chemical conversion coating, coarsening of crystals and deformation of the chemical conversion coating, unevenness and sagging of the chemical conversion coating, and the occurrence of chemical conversion coating sagging and sagging occurring on the eII plate side of the zinc-cutting-steel plate joint. An example of this is increased rust.

The inventors of the present invention have repeatedly conducted persuasive research to solve the above-mentioned problems, and have found that despite the prior degreasing treatment, organic substances (--the above-mentioned Although the actual line (for example, anti-corrosion seek, adhesive "RI: 11") in the case of automobile bodies in the factory was taken into the chemical conversion treatment solution, it was found that it could be removed.
Other organic substances that are brought into the FS treatment solution include rust preventive oil, lubricating oil, and the like. Unfortunately, even though the degreasing agent is washed with clean water in the final stage of the degreasing process, its organic components (e.g. active agents) are also removed from the IL formation treatment solution. It was found that: The treatment was carried out for 6 months on the actual car body production line of Sult,
Chemicals 98 Science 711 COI) 50 to 200 ppm.

When such an organic component is subjected to chemical conversion treatment in a chemical conversion treatment solution, it is assumed that, although the details are unknown, the presence of something that affects the adsorption of the metal surface in the organic component causes defects in the acid treatment. It has been shown that defects in chemical conversion treatment can be avoided by treating the chemical conversion treatment solution containing such harmful organic components with an adsorbent such as activated carbon.

The present invention was developed based on the knowledge of Kita, and its gist is that when treating a metal surface with a phosphate coating solution, The present invention resides in a method for managing a processing liquid, characterized in that harmful organic components that are brought into the processing liquid by objects to be processed and have an adverse effect on the chemical conversion treatment are removed by an adsorbent.

The treatment liquids that correspond to A in the management method of the present invention include zinc phosphate, iron phosphate, manganese phosphate, and phosphoric acid 11! A well-known immersion type or sufu based on lead, calci, cum, etc.

The phosphate film chemical conversion treatment solution used in the complete treatment ζ may contain useful organic components such as citric acid and starch as additives, if necessary.

Among the organic components that are brought into the treatment solution by the objects to be treated, (IS formation treatment) These include spot welding sheep, hood back mastic, seed back rust prevention sealer, dash upper water leak sealer, rubber thread sealer, epoxy thread sealer, asphalt sealer, which has been used for a long time as sealer for hemmink, etc.
- Adhesives (for example, in the case of automobile bodies, epoxy adhesives and acrylic adhesives used as roof back member adhesives) - Rust preventive additives (e.g. petroleum sulfonates, sorbitan) ester, metal soap, amine derivative Nisdel, wax oxide), surfactant (e.g. alkylphenol alkylene oxide, higher alcohol alkylene oxide, polyether, alkylbenzene sulfonate, alkylbenzene sulfonate, phosphate ester), etc. for metal surfaces. Examples include those that exhibit adsorption properties.

The content of harmful organic components in the execution solution that adversely affects the chemical conversion treatment varies depending on various factors such as the type of metal surface, the type of treatment liquid, the treatment method, and the type of harmful organic components. - One example is the typical example of alkylphenol alkylene oxide and 1. When a nonylphenol ethylene oxide adduct is added to a commercially available zinc phosphate-based film chemical conversion treatment solution for immersion treatment and chemical conversion treatment is carried out, the additive IJn
Stirring 51) Although no abnormality is observed in the chemical conversion film with plTl, adding more than 8 ppm leads to severe formation of the chemical conversion film (-) and a decrease in film thickness1. The adsorbent used in the present invention is - 2. Harmful A) Any material that has the function of adsorbing organic components is good, specifically activated carbon, clay minerals (e.g. bentonate, acid clay, anthrazite), natural adsorbents (e.g. ：Keiso”−
), slag, and polyolefin adsorbents. The use of this adsorbent also depends on the type and content of harmful rf1 components,
It varies depending on various factors such as the adsorption process method and the type of adsorbent, and cannot be specified as a rule. In the actual treatment line for automobile bodies, which are chemically treated with an immersion type phosphoric acid JFF lead-based film chemical conversion treatment solution after washing with water, the treatment solution that was at C01) Oppm at the time of bath construction is used for 5 months. After normal treatment, COI) becomes 180 ppm, and as a result, abnormal phenomena such as crystal coarsening (coarseness and collapse) of the chemical conversion coating occur, or powdered activated carbon 3001) is added to the treatment solution.
By adding m to reduce the COI 3 Q ppm, a suitable conversion coating can be obtained.

Treatment using an adsorbent ■1)) The adsorption treatment of the liquid is performed using the adsorbent II.
``-type (corresponding to this) ii 'ij: It may be carried out, for example, by directly introducing the adsorbent into the treatment liquid, or by adding the absorbent to the 4 absorbent light 1'' + tower (this way, the treatment liquid is passed through the Yes, that sucks:r
The removal efficiency of harmful organic components from the treatment solution by t treatment is as follows:
It does not necessarily have to be 100%; for example, in the case of the actual line of "J", the objective can be achieved by reducing the value number from 180 PP1n to 130 ppm1. .

According to the present invention, which is configured as follows, the object to be treated can be satisfactorily degreased prior to chemical conversion treatment, and the treatment t1g can be carried out satisfactorily.
Even if the conventional method of managing the processing solution by focusing on inorganic components as the middle and lower constituents of the chemical treatment solution is carefully implemented, it is possible to solve the problem of defective chemical conversion treatment that occurs in the actual production line, so it is very useful for practical use. This is a great invention.

Furthermore, as mentioned above, the degreasing agent (carrying of machine components into the processing solution also causes poor performance during the chemical conversion process). In washing with water, the washing water can be adsorbed in accordance with the present invention. The object of the present invention can be more satisfactorily achieved by combining the adsorption treatment of the treatment liquid.

These points are also included within the scope of the present invention.

Furthermore, it is also possible to target chemical conversion treatment liquids that have completely aged due to the accumulation of harmful organic components and to treat them according to the method of the present invention described above.Of course, this point also applies to the present invention. It is included in

Next, the present invention will be specifically explained with reference to Examples.

Incidentally, this embodiment also includes an example for the first bite.

Example 1 A commercially available immersion type degreaser (manufactured by Nippon Paint Co., Ltd. [Ridrin S I] containing 21 parts of alkylphenol ethylene oxide and polyether) ) 200'') at 50°C for 2 minutes, and then a commercially available zinc phosphate-based film conversion treatment solution for immersion treatment (manufactured by Nippon Paint Co., Ltd.
Granodin 5D2000", COl at the time of new construction) Qpp
A system is adopted in which fL formation treatment is performed for 2 minutes at a total acidity/free acidity = 18/1 and a toner value of 1.5.50''C.

Table 1 shows the state of the chemical conversion film formed when a new bath is constructed.

Table 1 shows the state of the chemical conversion film formed when the above-mentioned system was implemented for 5 months and the contaminated bath reached a point where the GO+) value of the treatment solution reached iso ppm.

Activated carbon (Yatacol YG/YB manufactured by Shiromaru Co., Ltd.) was added to the contaminated bath above.
Table 1 shows the state of the chemical conversion film formed using this regeneration bath.

Table 1 (Note) ○: Good △: Slightly scratched × ×: Yellow rust ■Reference 5 All cases are scanned using a ν Ichiko microscope (JSM-T20 manufactured by Nippon Juko Co., Ltd.) at an angle of 55 degrees and a magnification of 1500 times. It was photographed in

It is clear from the above results that in the actual line in this example, it is necessary to maintain the 00D value of the liquid at or below 130 pl (thereby ensuring a uniform and good chemical conversion coating). You can get 7 in a row.

By providing an adsorption tower filled with activated carbon and passing the contaminated bath through it at a rate of LV=lQm/hr, an effluent with a COI of 120 PPm or less can be obtained. Therefore, by using such an adsorption tower,
Contamination of the treatment solution is prevented and normal chemical conversion coatings can be obtained continuously.

Example 2 11000p of bentonite (manufactured by Kukita Pharmaceutical Co., Ltd.) was added to the contaminated bath.
The amount of fluid is 140 pp.
The same as in Example 1 except that m is used (when carried out, a chemical conversion coating with good appearance and granular crystals with a size of 3 to 7 μm is obtained on the steel plate part, and the zinc steel plate-steel plate joint (v/lI plate) A chemical conversion film having a surface size of 2 to 15 μm is made of granular crystals and has a good appearance (11).

Patent applicant: Nippon Paint Co., Ltd. Representative Patent Attorney Tsutsuyama Tsutsuyama and 1 other person 1 (12)

Claims (1)

[Claims] ■ Treating the metal surface with a phosphate coating 1-conversion chemical treatment solution (
A method for managing a processing solution, which comprises using an adsorbent to remove harmful organic components that are brought into the processing solution by objects to be processed and swell during processing and have an adverse effect on the chemical conversion treatment. 2. The method of item 1 above, in which the object to be treated is washed with washing water treated with an adsorbent immediately before being treated with the treatment liquid.