JP3315760B2 - Metal material surface treatment agent, water-based cleaning and rust inhibitor, and surface treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly belongs to the field of cleaning metal materials such as steel, aluminum, copper, galvanized steel and the like, and in particular, water-based cleaning agents replacing solvent-based cleaning such as fluorine-based and chlorine-based cleaning agents. The present invention relates to a post-treatment agent mainly used for rust prevention after cleaning a metal material by the method. Further, the present invention relates to a water-based cleaning and rust preventive for cleaning a metal material also for rust prevention and a surface treatment method using a water-based cleaning agent.

[0002]

2. Description of the Related Art Cleaning of metal materials with a fluorine-based organic solvent such as chlorofluorocarbon or a chlorine-based organic solvent such as trichloroethane is easy because the cleaning process can be easily controlled and the cleaning properties are good. It has been widely used for pre-cleaning such as heat treatment, plating, and chemical conversion of materials.

However, in recent years, from the viewpoint of global environmental protection,
Restrictions on the use of CFCs and trichloroethane have been realized. In order to cope with such strict regulations, an aqueous cleaning agent is currently being developed as an alternative to the organic solvent cleaning. Aqueous detergents are broadly classified into inorganic and organic, and each is further divided into acid, neutral and alkaline depending on the pH. Ingredients of the inorganic detergent include caustic soda, caustic potash, sodium phosphate, sodium pyrophosphate and the like.

[0004] Since water-based cleaning cannot be performed by steam cleaning as in organic solvent-based cleaning, the metal surface is more likely to rust than solvent cleaning. The entire surface of the metal surface washed with the water-based cleaning agent after the washing or water-washing step is covered with a water film or a liquid film, and usually has a hydrophilic (water-wettable) surface. For this reason, the metal surface becomes extremely easily rusted particularly between drains after washing with water and during drying. For example, in the case of iron, yellow rust occurs, and in a galvanized plate, white rust occurs. As a countermeasure against this, a chemical called a draining dry rust inhibitor is commercially available. This chemical is said to have the effect of reducing the drainage time by lowering the surface tension of water, but the effect of reducing the attached water is not remarkable since the surface of the metal material is entirely wet.

[0005]

Since the water and the cleaning liquid adhere to the entire surface of the metal material treated with the conventional aqueous processing agent, the amount of the cleaning liquid taken out to the next step and the amount of water used are large. , The burden of wastewater treatment was increasing. Further, in the conventional aqueous post-cleaning treatment method, it is necessary to evaporate the residual water by performing drying after spraying with a rust preventive or alcohol or the like for draining.

The use of a large amount of washing water increases the length of the washing process, so that the size of the washing apparatus is increased, and a large amount of wastewater is generated. Had occurred. In recent years, there is a serious problem in these situations from the standpoint of responding to environmental problems and resource saving, which are particularly problematic.

Accordingly, the present invention provides a novel cleaning agent which achieves a drastic reduction in the amount of chemicals used in comparison with conventionally used chemicals and improves drying properties for preventing rust after aqueous cleaning of the surface of a metal material. The primary purpose is to provide Further, the present invention has a second object to provide a novel water-based cleaning and rust preventive agent, thereby greatly reducing the amount of water to be washed and reducing the burden on wastewater treatment equipment. The third purpose is to provide

[0008]

SUMMARY OF THE INVENTION The present invention provides an aqueous cleaning method using a metal as a main object to form an adsorption layer of an organic compound having water repellency and rust prevention on the surface of the metal. As a result of studying the effects of various organic compounds based on the idea that the water consumption of the washing method is greatly reduced and the drying property is improved, it was found that sorbitan and fatty acids having 8 to 26 carbon atoms such as sorbitan monooleate were used. (Hereinafter referred to as "sorbitan fatty acid ester") and a solution containing an anionic surfactant (hereinafter referred to as "water-repellent treatment liquid").

Therefore, the surface treatment agent having excellent water repellency to be used after the aqueous cleaning of the metal surface according to the first aspect of the present invention comprises an ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan in an amount of 0.01 to 5%. % By weight and 0.01 to 5% by weight of an anionic surfactant, and the balance substantially consists of water.

The ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan (sorbitan fatty acid ester) used in the present invention includes polyesters such as dilaurate and trioleate in addition to monoesters such as sorbitan monooleate and monolaurate. Esters can also be used. As the fatty acid ester of the present invention, a saturated fatty acid, an unsaturated fatty acid and an ester of sorbitan can be used together. Particularly, those having both good water repellency and rust prevention properties include saturated fatty acids having 8 to 16 carbon atoms. Or 11 carbon atoms
And sorbitan esters of up to 26 unsaturated fatty acids. If the concentration of the sorbitan fatty acid ester is less than 0.01% by weight, good water repellency cannot be obtained, and if it exceeds 5% by weight, the amount adsorbed on the metal surface becomes excessive, which may cause a problem in a subsequent step. Therefore, 0.01 to 5% by weight
Must be in the range of A preferable range for obtaining a more stable effect is 0.02 to 1% by weight.

An anionic surfactant is a dispersant for uniformly dispersing or solubilizing a sorbitan fatty acid ester in a liquid. Suitable types of anionic surfactants include alkali salts of fatty acids such as sodium oleate, alkali salts of alkyl benzene sulfonic acid, higher alcohol sulfates, alkyl ether carboxylic acids and alkali salts thereof. When the concentration of these anionic surfactants is less than 0.01% by weight, the sorbitan fatty acid ester does not dissolve in the treatment liquid and is easily separated from the liquid layer, so that a uniform water-repellent surface cannot be obtained. On the other hand, if it exceeds 5% by weight, the undispersed sorbitan fatty acid ester adheres to the surface of the treated material, making it difficult to obtain a clean surface. The preferred concentration of anionic surfactant is 0.1.
02 to 1% by weight.

Further, as a result of further studies, the dissolution of sorbitan fatty acid esters was promoted by adding polyhydric alcohols such as ethylene glycol, polyhydric alcohol ethers such as ethylene glycol dimethyl ether, and cyclic ethers such as dioxane. It has been found that a good water repellent surface can be obtained.

When a polyhydric alcohol or a polyhydric alcohol ether is added to the treatment liquid, various polyhydric alcohols such as ethylene glycol, hexylene glycol, ethylene glycol methyl ether, and dioxane, alcohol ethers, and cyclic ethers can be used. The addition amount of these must be 0.05% by weight or more, and if less than this, the solubility becomes unsatisfactory. The metals that can be treated with the water-repellent surface treatment liquid of the present invention are various materials such as iron and stainless steel, galvanized steel, aluminum, magnesium, and copper alloy.

In the present invention, water is repelled from the surface to be treated by cleaning the metal surface with an ordinary aqueous cleaning agent and then treated with the above-mentioned water-repellent surface treatment solution, and the drying conditions to be performed thereafter are extremely short and / or. Alternatively, the temperature can be lowered. In this case, the washing with water or hot water (hereinafter simply referred to as “washing”) after the treatment with the water-repellent surface treatment liquid can be reduced or the washing can be omitted. As a method of treating a metal with the water-repellent surface treatment liquid, a method of bringing the metal into contact with the treatment liquid by dipping or spraying is used as a standard, but a contact time of about 20 seconds to about 10 minutes is generally suitable. The processing temperature can be normal temperature, but a preferable range is 40 to 80 ° C. The subsequent drying conditions are 40 to 15
About 20 seconds to 30 minutes at 0 ° C. is suitable. The removal of water can be promoted by vibrating the treatment material during drying or by performing air blowing on the treatment material, and drying can be performed in a short time.

Further, the present inventors added the above-mentioned ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan and an anionic surfactant to various conventional aqueous detergents,
When water repellency was imparted to the metal surface at the same time as washing, the amount of water adhered after water washing was 1/5 of that of the hydrophilic surface.
Since it was reduced to 1/10, it was confirmed that there was a great effect on improving the washing efficiency and drying property. Therefore, the third aspect of the present invention
The aqueous cleaning agent for metal surfaces according to the above, the ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan is 0.01 to 5
% By weight, 0.01 to 5% by weight of an anionic surfactant and 0.01 to 5% of a nonionic surfactant having an HLB of 9 to 16.
A metal having one or two types selected from the group consisting of 0.05% by weight and 0.05-10% by weight of an inorganic builder, and the balance substantially consisting of water. It relates to a surface treatment agent for a material. As this inorganic builder, alkali hydroxide, phosphoric acid, polyphosphoric acid,
Alkali salts such as carbonic acid, boric acid and silicic acid can be preferably used. The amount of these alkali builders is from 0.05 to 10% by weight. Nonionic surfactants are agents that enhance detergency. If the HLB is less than 9, the ability to disperse the oil becomes small and the oil cannot be removed from the surface of the treated material. On the other hand, if the HLB exceeds 16, the foam tends to foam and is not suitable for cleaning metals. As a nonionic surfactant, polyoxyethylene alkyl ether,
Polyoxyethylene alkylphenol ether, polyoxyethylene sorbitan oleate, polyoxyethylene glycol carboxylate, and the like can be preferably used. The amount of these nonionic surfactants is from 0.01 to 5% by weight.

The reasons for limiting the composition of the sorbitan fatty acid ester and the anionic surfactant in the aqueous cleaning and rust preventive agent according to the present invention are the same as those described for the water-repellent surface treating solution. Further, the detergency can be enhanced by adding a polyhydric alcohol, a polyhydric alcohol ether and a cyclic ether (claim 3).

According to the fourth aspect of the present invention, when the metal material is washed with a water-based cleaning and rust preventive agent and then subjected to ordinary water washing, the water-based treating agent is repelled from the treated surface together with the washing water, so that the metal material is used in the washing step. The amount of drug that gets in
Correspondingly, the amount of washing water used is significantly reduced. After washing with water, drying can be performed under the same conditions as the water-repellent surface treatment liquid. According to the aqueous cleaning method of the present invention, it is not necessary to perform a treatment with a special rust preventive or a draining agent after cleaning with the aqueous clean and rust preventive, and the amount of chemicals can be greatly reduced.

[0018]

The water repellency as referred to in the present invention is a property measured by the area from which water has been repelled by the method described in Examples below. Also,
On the water-repellent metal surface, the sorbitan fatty acid ester in the surface treatment liquid is adsorbed on the metal surface to form a monomolecular layer, and this layer exhibits water repellency.

Since the sorbitan fatty acid ester molecules adsorbed on the metal surface are not removed even by short-time washing with water,
Sufficient water repellency can be obtained even after washing with water. Since this adsorption layer is extremely thin and has a small adsorption amount, there is an advantage that the treatment such as dry plating and chemical conversion treatment after the water washing step is hardly adversely affected.

The sorbitan fatty acid ester molecule-adsorbed layer formed on the metal surface after the cleaning treatment with the aqueous cleaning agent of the present invention stabilizes the metal surface. It has the feature of preventing rusting very well.

The sorbitan fatty acid ester is extremely hardly soluble in water, and requires an anionic surfactant as a dispersant and a solubilizing agent. Since the anionic surfactant has an effect of adsorbing and surrounding the sorbitan fatty acid ester and imparting a negative charge, it is considered that the anionic surfactant is dissolved in a stable colloidal state by Coulomb repulsion. Similarly, polyhydric alcohols, polyhydric alcohol ethers, and cyclic ethers added to the bath also promote dissolution of the sorbitan fatty acid ester in the processing solution, increase the solubility of the surfactant, and make the adsorption more complete. It is thought to have an effect. Hereinafter, the present invention will be described with reference to examples.

[0022]

EXAMPLES Examples of the present invention will be specifically described below with reference to comparative examples. Example (I) (Example of water-repellent treatment liquid / treatment method) Test plate of steel, cast iron, aluminum, copper, magnesium, and galvanized steel as a test plate (total surface area of each material: 21)
0 cm 2), and alkali degreasing with a conventional aqueous degreasing agent (Fine Cleaner 4360, product name of Nippon Parkerizing Co., Ltd.) to remove dirt, oil, etc. on the surface and clean it. What was used was used. The pretreated test plate was dipped in a water-repellent surface treatment solution shown in Table 1 below at a bath temperature of 60 ° C. for 3 minutes, spray-washed for 15 seconds, held vertically, and repelled after 10 seconds. The area (%) in which water is present was visually measured to determine water repellency, and the amount of water adhered was determined by measuring the weight of water. The water repellency is represented by a five-point evaluation based on the following criteria based on the water repelling area. The rust prevention was evaluated by immersing in a surface treatment solution maintained at 60 ° C. for 5 minutes, followed by drying with hot air, and the degree of rust generated was evaluated in four steps. The names of the sorbitan fatty acid ester, surfactant, and water-soluble additive as components of the water-repellent treatment liquid are shown in (3). Table 2 shows the evaluation test results of the examples and the comparative examples. As is clear from this table, Examples 1 to 1 were used.
4 was excellent in water repellency and rust prevention, but Comparative Examples 1 to 7 were inferior in water repellency and rust prevention.

[0023] (1) water repellency evaluation criteria Review points water- soluble washing water adhesion amount 5: Water repellency area 99% 5 mL / m @ 2 or less 4: 〃 99~80% 6~9 mL / m2 3: 〃 79 to 20% 10 to 19 mL / m2 2: １９ 19 to 1% 20 to 39 mL / m2 1:未 満Less than 1% 40 mL / m2 or more

[0024] (2) corrosion resistance criterion Review point rust resistance 4: No rust 3: rust number 1-5 pieces 2: 〃 6-10 1: 〃 11 or more

(3) Components in treatment liquid Sorbitan fatty acid ester sorbitan monooleate sorbitan sesquioleate sorbitan trioleate sorbitan monolaurate sorbitan monopalmitate sorbitan monocaprylate sorbitan monomyristate sorbitan monolinoleate sorbitan monolinolenate

[0026] 2. Surfactants Symbol boundary surface active agent species A polyoxyethylene nonyl phenylalanine ether (nonionic: HLB = 12) B sodium oleate (anionic) C Sodium stearate (anion) D Potassium palmitate (anion) E n-dodecyl Sodium benzenesulfonate (anion) F Polyoxyethylene ether carboxylic acid (anion: EO = 7 mol) G Potassium lauryl sulfate (anion) H Sodium hexadecyl sulfate ester (anion) I Polyoxyethylene nonylphenyl ether (nonion: HLB = 7.0) J Polyoxyethylene alkyl phenyl ether (nonionic: HLB = 14.8) K Polyoxyethylene glycol (1000) monoester stearate (nonionic: HLB = 15.8)

3. Water-soluble additives a. Ethylene glycol b. Diethylene glycol dimethyl ether c. Ethylene glycol monomethyl ether d. Polyethylene glycol monomethyl ether e. Ethylene glycol monomethyl ether acetate f. Diethylene dioxide (1,4 dioxane)

[0028]

[Table 1] Liquid component Sorbitan fatty acid surfactant Additive No. Ester (*) 1 Sorbitan monooleate D: 0.2 wt% None (18): 0.2 wt% 2 Sorbitan sesquioleate C: 0.03 wt% None (18): 0.02 wt% 3 Sorbitan trioleate B: 0.1 wt% None (18 ): 0.2 wt% 4 Sorbitan monolaurate F: 0.1 wt% None (12): 0.05 wt% 5 Sorbitan monopalmitate E: 0.5 wt% None (16): 2.0 wt% 6 Sorbitan monocaprylate G: 2.0 wt % None (8): 4.5 wt% 7 Sorbitan monomisulylate H: 4.8 wt% None (14): 4.2 wt% 8 Sorbitan monolinoleate C: 0.2 wt% None (18): 1.0 wt% 9 Sorbitan monolinolenate B : 0.2 wt% None (18): 0.15 wt% F: 0.3 wt% 10 Sorbitan monooleate B: 0.05 wt% b: 2.5 wt% (18): 0.1 wt% 11 Sorbitan trioleate C: 0.2 wt% c: 10wt% (18): 0.5wt% 12 sorbita Monolaurate F: 1.5wt% d: 0.05wt% (12): 3.5wt%

Liquid component Sorbitan fatty acid surfactant Additive No. Ester (*) 13 Sorbitan trioleate B: 0.6 wt% f: 55 wt% (18): 0.3 wt% 14 Sorbitan monooleate A: 0.5 wt% a: 1.5 wt% (18): 0.05 wt% B: 1.5 wt% e: 2.5 wt% 15 None B: 0.2wt% None 16 None C: 0.2wt% None 17 None D: 0.2wt% None 18 Sorbitan monooleate A: 0.2wt% None (18): 0.2wt% 19 None B: 0.2wt % B: 0.5wt% 20 None A: 0.2wt% None 21 Sorbitan monoethylate B: 0.2wt% None (3): 0.5wt% (*) The number in the parenthesis is the carbon number of the fatty acid.

[0030]

[Table 2] Item No. Metal material liquid component No. Water repellency and rust prevention 1 Steel 1442 Cast iron 24 43 Aluminum 34444 Copper 44 44 Real 5 Galvanized steel 54 44 Magnesium 64 44 7 Steel 74 44 88 Steel 84 49 Steel 9 44 4 Application 10 Steel 10 5 4 11 Cast iron 1 15 4 12 Aluminum 12 5 4 13 Copper 13 5 4 Example 14 Steel 14 5 4 1 Steel 15 2 2 Ratio 2 Cast iron 16 2 23 Aluminum 17 2 22 Comparison 4 Copper 18 2 25 Magnesium 19 2 1 Example 6 Steel 20 2 17 Galvanized steel 21 2 1

Example (II) (Aqueous cleaning solution and cleaning method)
Example) Rust-proof oil (NoxRust 88) was applied to the steel sheet of Example (I) as a test plate.
1: Parker Kosan Co., Ltd.)
Each of the cleaning solutions shown in Table 3 was immersed in degreasing cleaning at 60 ° C. for 3 minutes. The degreased test plate was spray-washed for 30 seconds, held vertically for 15 seconds, and evaluated for water repellency in the same manner as in Example (I). Analysis was performed with an analyzer (manufactured by LECO CORPORATION), and the degreasing and cleaning properties were evaluated according to the following criteria. The water repellency and rust resistance after washing were evaluated according to the same criteria as in Example 1. (1) Degreasing and Detergency Evaluation Criteria Degreasing and Detergency Residual Carbon Deposition Amount 5 mg / m 2 or less Δ 6 to 15 mg / m 2 × 16 mg / m 2 or more The results are shown in Table 4.

[0032]

[Table 3] Liquid component Sorbitan fatty acid Surfactant Alkaline No. Ester (*) Builder, etc. 22 Sorbitan monooleate D: 0.1 wt% Na4P2O7, (18): 0.2 wt% J: 0.2 wt% NaOH 1 wt% each 23 Sorbitan sesquioleate C: 0.03 wt% KOH: 1 wt% (18): 0.03 wt % A: 0.5 wt% 24 Sorbitan trioleate B: 0.1 wt% d: 5 wt% (18): 0.2 wt% KOH: 1.5 wt% 25 Sorbitan monolaurate K: 0.1 wt% f: 1 wt% (12): 0.5 wt% Na2CO3: 1 wt% 26-J: 0.1 wt% 1 wt% each of Na4P2O7 and NaOH 27-C: 0.03 wt% KOH: 1 wt% 28-A: 0.5 wt% K: 0.2 wt% 29-B: 0.1 wt% d : 5 wt% KOH: 1.5 wt% 30-F: 0.1 wt% f: 1 wt% I: 0.1 wt% Na2CO3: 1 wt% The surfactants are as shown in Table 1, and the additives d and f are "3. As described above.

[0033]

[Table 4] Metal material liquid component No. Water-repellent rust-preventive cleaning property Remarks steel 22 5 4 ○ Example 15 Aluminum 2 25 4 ○ Example 16 Steel 23 5 4 ○ Example 17 Steel 24 5 4 ○ Example 18 Copper 24 5 4 ○ Example 19 Steel 25 5 4 ○ Example 20 Aluminum 25 5 4 ○ Example 21 Steel 26 1 2 ○ Comparative Example 8 Steel 27 2 2 ○ Comparative Example 9 Aluminum 28 1 1 ○ Comparative Example 10 Copper 29 2 2 △ Comparative Example 11 Steel 30 1 2 × Comparative Example 12

Table 4 shows the evaluation test results of the examples and the comparative examples. As is clear from this table, Examples 15 to 21 were excellent in both water repellency, rust prevention and washing properties, but Comparative Example 8
No. 12 were inferior in both water repellency and rust prevention.

[0035]

As described above, by treating a metal surface with the metal material surface treating agent of the present invention, a surface having both excellent water repellency and rust prevention can be formed.
If this treatment liquid is used as a post-treatment liquid in a solvent replacement water-based cleaning system, it can be dried in a shorter time without rusting, and the amount of water required for water washing can be reduced, and wastewater can be saved. An effect can also be obtained in reducing the amount and the consumption of the medicine. Further, when a cleaning component is added to the treatment liquid of the present invention and used in a solvent-based water-based cleaning system, the same effects as above can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-9764 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23G 1/06 C23F 11/12 C23F 11 / 12 102

Claims (4)

(57) [Claims] 1. An ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan in an amount of 0.01 to 5% by weight, an anionic surfactant in an amount of 0.01 to 5% by weight, and the balance being substantially the same. A surface treatment agent for a metal material having excellent water repellency, which is used after washing with an aqueous detergent, characterized by being made of water. 2. An ester compound of a fatty acid having 8 to 26 carbon atoms and sorbitan in an amount of 0.01 to 5% by weight, an anionic surfactant in an amount of 0.01 to 5% by weight, and an HLB of 9 to 1%.
Water-based metallic material, characterized by containing at least one of 0.01 to 5% by weight of a nonionic surfactant and 0.05 to 10% by weight of an inorganic builder, and substantially consisting of water. Cleaning and rust inhibitor. 3. The aqueous cleaning prevention of a metal material according to claim 2, further comprising 0.1 to 30% by weight of one or more compounds selected from polyhydric alcohols, polyhydric alcohol ethers and cyclic ethers. Rust agent. 4. A surface treatment method for a metal material, comprising washing the metal material with the water-based cleaning and rust preventive agent according to claim 2, washing with water, and then drying.