JPH0450272A - Surface-treating solution for tinplate di can - Google Patents

Abstract

PURPOSE:To obtain the subject treating solution having a specific pH, imparting excellent corrosion resistance and adhesion with paint to the surface of tinned tinplate DI can and also imparting slipperiness in conveyer transferring containing phosphoric acid ion, condensed ion and a specific water-soluble resin. CONSTITUTION:The aimed ink having pH 2.0-6.5 contains (A) 1-30g/l phosphoric acid ion, (B) 0.1-5g/l condensed phosphoric acid ion (e.g., one, two or more species of pyrophosphoric acid ion, tripolyphosphoric acid ion and tetrapolyphosphoric acid ion) and (C) 0.1-20g/l (calculated as solid) water-soluble resin expressed by formula I (n is 10-80; X and Y are H or Z expressed by formula II; R1 and R2 are 1-10C alkyl or hydroxyl alkyl; introducing fraction of Z per an aromatic ring is 30-200 mol%).

Description

[Detailed description of the invention] [Industrial application field]

The present invention is a method for drawing and ironing tin-plated steel sheets.
Before painting and printing tinplate DI cans, which are formed by ironing and ironing), we apply a coating of excellent corrosion resistance and paint adhesion to the surface of the can, which is necessary for smooth conveyance of the cans. The present invention relates to a novel surface treatment liquid for tinted DI cans that also imparts slipperiness (hereinafter simply referred to as slipperiness).

[Prior art]

Regarding this type of surface treatment liquid for tinplate DI cans, for example, the invention disclosed in Japanese Patent Application Laid-open No. 1-100281 filed by the same applicant can be mentioned as a conventional example. This invention is
Phosphate ion 1~50g/l, oxygen M ion 0.2~
20.0g/I! 1 tin ion 0.01-5.0g/l
, having condensed phosphate ions 0.01-5.0 g/l, p
A coating chemical solution for metal surface treatment consisting of H2-6,
By treating with this chemical conversion treatment liquid, a phosphate film with excellent corrosion resistance can be formed on the surface of tin DI cans. As a treatment method for the purpose of imparting corrosion resistance and adhesion using a water-soluble resin, for example,
The invention disclosed in the above publication is mentioned. This invention is a method of treating a metal surface with a solution containing a derivative of a useful polyhydric phenol compound. On the other hand, in the manufacturing process of metal cans, the high coefficient of friction on the outer surface of the can makes the surface of the can less slippery when the can is transferred on a conveyor, causing the can to overturn and causing transportation problems. In particular, the transportability of cans becomes a problem when trying to transport them to a printer. Therefore, there has been a need in the can manufacturing industry to reduce the coefficient of static friction of the outer surface of a can without adversely affecting the adhesion of paint or lacquer applied to the can. As a method to improve this slipperiness, for example, ■
The invention disclosed in Japanese Patent Application Laid-Open No. 64-85292 is mentioned. The present invention relates to a surface treatment agent for metal cans containing a water-soluble organic substance selected from phosphoric acid esters, alcohols, -valent or polyvalent fatty acids, fatty acid derivatives, and mixtures thereof.

[Problem to be solved by the invention]

In the invention (2) above, a phosphate film with excellent corrosion resistance is formed on a tinplate DI can, but in recent years, tinplate DI cans have been manufactured using tin in consideration of economic efficiency. Cans with less plating began to be produced. For this reason, there has been a demand for surface treatments with significantly better corrosion resistance than in the past, but this is still not sufficient to meet these demands. Also, in the invention (2) above, sufficiently stable performance (corrosion resistance) has not been obtained for the tinplate DI cans manufactured in recent years. Furthermore, the invention (2) also has various problems, such as a certain improvement in slipperiness, but no improvement in corrosion resistance or paint adhesion. Therefore, in the conventional example, even cans with a small amount of tin plating have problems that must be solved in forming a film with excellent corrosion resistance, improving slipperiness, and improving paint adhesion.

[Means to solve the problem]

As a specific means for solving the above-mentioned conventional problems, the present invention includes the following:
Phosphate ion 1-30g/l, condensed phosphate ion 0
．． Contains 1 to 5 g/l and 0.1 to 20 g/l of a water-soluble resin represented by the following formula as a solid content, and has a pH of 2.0 to 2.0 g/l.
6.5. A surface treatment liquid for tinplate DI cans. - Numerical formula (in the formula, n is 10 to 80, X and Y are hydrogen or Z shown by the following formula, R1 and R2 are C1
-It is an alkyl group or a hydroxylalkyl group of CIO, and the introduction rate of Z per aromatic ring is 30 to 200 mol%
It is. ), and by applying the surface treatment liquid of the present invention, before painting and printing tinplate DI cans, excellent corrosion resistance and paint adhesion can be imparted to the surface of tin cans, and
In addition, it is possible to provide excellent slipperiness necessary for smooth conveyor transport of cans.

[Composition and process description]

The surface treatment liquid of the present invention relates to an acidic treatment liquid containing phosphate ions, condensed phosphate ions, and a water-soluble resin as essential components. In order to contain phosphate ions in the treatment solution, phosphoric acid () 1
3PO4), sodium phosphate (Na3pO4), etc. can be used. A good content range is 1 to 30 g/l, especially 5 to 15 g/l! A range of is preferred. 1
If it is less than g/l, the reactivity will be poor and a film will not be formed sufficiently. Although a good film is formed even if the amount exceeds 30 g/no,
This poses an economical problem because the cost of the treatment liquid increases. The condensed phosphate ion is one or more selected from pyrophosphoric acid, tripolyphosphate ion, and tetrapolyphosphate ion. To contain condensed phosphate ions,
Its acids or salts can be used. For example, to contain pyrophosphate ions, pyrophosphate (H4P2
0□), sodium pyrophosphate (Na4P207), etc. can be used. The content is preferably in the range of 0.1 to 5 g/n, particularly preferably in the range of 0.4 to 1 g/n. If it is less than 0.1 g/1, the etching effect will be weak and a sufficient film will not be formed. Moreover, if it exceeds 5 g/l, the etching effect will be too strong and will inhibit the film forming reaction. The water-soluble resin of the present invention is a polymer represented by the following general formula. In the general formula, n is 10 to 80, and if it is less than 10, the molecular weight is too low and no improvement in corrosion resistance is observed. Moreover, if it is 81 or more, the stability of the aqueous solution becomes low and there is a problem in actual use. X and Y are hydrogen or Z,
Z is expressed by the following formula. Here, Rh and R2 are an alkyl group or a hydroxylalkyl group of 01 to Cto. When C is 11 or more, the functional group becomes too bulky and the stability of the aqueous solution decreases. Z
is -CH2N (CH3)2 or -CH2N
(CH3'')CH2CH20H is preferable. Also, the introduction rate per aromatic ring of the polymer resin is 30 to 20
It is 0 mol%. For example, if 5 pieces of 2 are introduced into a polymer in which n is 10, the introduction rate is 50 mol%. When the introduction rate is less than 30% by mole, the resin is difficult to become water-soluble and there is a problem in stability. The resin content is 0.1 to 20 g/l as solid content, but 0.1 g/J! If it is less than this, the concentration is too low and it becomes difficult to form a stable film on the can surface. Also, 2
If it exceeds 0 g/l, the cost of the treatment solution increases and there is an economical problem. The pH of the treatment solution is adjusted to 2.0 to 6.5, but 2.0
If it is less than 6.5, etching will increase and it will be difficult to form a film, and if it exceeds 6.5, the resin will tend to precipitate and the life of the solution will be shortened. Therefore, the pH is 2.
It must be controlled within the range of 0 to 6.5. The pH is adjusted by using acids such as phosphoric acid, nitric acid, hydrochloric acid, and hydrofluoric acid and alkalis such as sodium hydroxide, sodium carbonate, and ammonium hydroxide. Furthermore, if metal (tin, iron) ions are mixed into the treatment liquid, the resin and metal may form a complex and cause precipitation. In such cases, it is advisable to add a chelating agent to the treatment liquid. Useful chelating agents include tartaric acid, ethanolamine, gluconic acid, and oxalic acid, and are not particularly limited. Next, the method for producing the surface treatment liquid of the present invention will be outlined. According to the method described above, a predetermined amount of phosphate ions and condensed phosphate ions are dissolved in water and thoroughly stirred. If the pH of this solution is not 7 or less, adjust the pH to 7 or less with the above-mentioned appropriate acid. Next, while stirring, the water-soluble resin defined in the present invention is added and completely dissolved, and the pH is adjusted by the method described above. Next, the film to be formed will be outlined. The film formed by the surface treatment solution of the present invention is a tin phosphate composite film. The substrate is etched by the phosphate ions and condensed phosphate ions, and at this time a local pH increase occurs at the interface, causing phosphate to precipitate on the surface. Furthermore, the amine groups of the resin have a chelating effect and form a type of coordination compound with the newly formed surface of the substrate formed by etching. Basically these 2
An organic-inorganic composite film is formed by these two actions, but when condensed phosphate ions coexist, resin-metal coordination compounds are more easily formed, and as a result, organic-inorganic composite films are formed stably over a wide pH range. This makes it possible to form an inorganic composite film on the surface. Next, a process for treating tinplate 01 cans to which the surface treatment liquid of the present invention is applied will be outlined. The treatment solution of the present invention is applied in the following preferred exemplary process. ■Surface cleaning of tinplate 01 can: Degreasing (use a weakly alkaline cleaning agent for shooting) ■Water washing ■Film formation treatment (application of the treatment solution of the present invention) Treatment temperature: Room temperature to 80''C Treatment method Nispray treatment time = 2 to 60 seconds ■ Water washing ■ Deionized water washing ■ Drying The treatment temperature of the surface treatment solution of the present invention can be from room temperature to 80°C, but it is usually preferable to use it heated to 40 to 60°C. Spray time However, if the groove is left in the groove for 2 seconds, the reaction will not be sufficient and a film with excellent corrosion resistance will not be formed.If the treatment time exceeds 60 seconds, no improvement in performance will be observed, so the treatment time is 2 seconds. A range of 60 seconds is appropriate.

【Example】

Some examples of the surface treatment liquid of the present invention are listed below, and their superiority is shown in comparison with comparative examples. The corrosion resistance of the cans was evaluated by iron exposure degree (IEV). The IEV was measured in accordance with the invention of US Pat. No. 4,332,646. IE
The lower the value of V, the better the corrosion resistance, and usually 150 or less is good. Paint adhesion was determined by applying epoxy urea-based can paint to the surface of the treated can to a film thickness of 5 to 7 μm.
C for 4 minutes, cut the can into strips of 5 x 150 mm, heat-pressed them with a polyamide film to make test pieces, peeled them off using the 180 degree beer test method, and evaluated the beer strength at that time. did. Therefore, the higher the beer strength, the better the paint adhesion. Generally 1,5k
A width of gf15111 or more is good. Furthermore, the slipperiness was evaluated by measuring the coefficient of static friction on the outer surface of the can. Therefore, the lower the coefficient of static friction, the better the slipperiness. Generally 1.
It is good if it is 0 or less. Example Tinplate 01 can made by DI processing of S-plated steel plate was treated with a weak alkaline degreaser (registered trademark Fine Cleaner 436).
After cleaning with a 1% heated aqueous solution of 1A1 (manufactured by Nippon Parkerizing Co., Ltd.), the surface treatment liquid 1 was heated to 60°C and sprayed for 30 seconds, and then washed with tap water.
Furthermore, 10% with deionized water of 3ooo, oooΩcm or more.
After spraying for seconds, it was dried for 3 minutes in a hot air drying oven at 180°C. Surface treatment liquid 1 75% phosphoric acid (F13PO,) 10.0g/I (PO4”: 7.2g/
Sodium pyrophosphate (Na4P207・1OH
20) 1.0g/f (P2O74-: 0.4g
/f) Resin solid content 2.0 g/l pH 4.0 (adjusted with sodium hydroxide) Water-soluble resin 1 Here, n was 40 on average and the introduction rate was 100 mol%. Water-soluble resin 1 was synthesized by the method shown below. Cellsolve solvent 10 was added to a 1 000 m f reaction flask equipped with a condenser, nitrogen sparge, overhead stirrer, thermometer, etc.
Then, 60 g of poly-4-vinylphenol having a molecular weight of 5000 was added and dissolved. Add 40 g of 2-methylamine ethanol and 100 g of deionized water.
The mixture was heated to 0°C to react. 40 g of 37% formaldehyde solution was added over 1 hour and stirred at 50°C for 2 hours, then warmed and stirred at 80°C for 3 hours. After cooling the reaction, 15 g of 85% orthophosphoric acid was added followed by 700 g of deionized water. Next, the pH of this reaction solution was 8.
A 10% sodium hydroxide solution was added to precipitate the resin until the concentration reached ~9. Thereafter, the precipitated resin was filtered, washed with water, and dried. Example 2 After cleaning a tin DI can under the same conditions as in Example 1, surface treatment liquid 2 was heated to 60° C. and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 2 75% phosphoric acid (H3PO4) 10.0g / 1. (PO43-: 7.2 g
/f) Sodium pyrophosphate (Na4P207.1
OH20) 1.0g/1 (P207'-: 0.
4 g/1) Resin solid content 0.4 g/l pH 5.0 (adjusted with sodium carbonate) Water-soluble resin was the same as in Example 1 Example 3 After cleaning a tin DI can under the same conditions as Example 1, the surface Treatment liquid 3 was heated to 60°C and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 3 75% phosphoric acid (H3PO4) 20.0g/l (PO4": 14.4g/l) Sodium pyrophosphate (Na4P20.-10H20) 1
．． 0g / 1 (P207'-: 0.4 g /
i) Resin solid content 8.0 g/l pH 4.0 (adjusted with hydroxide) Water-soluble resin is the same as in Example 1 Example 4 After cleaning the tin DI can under the same conditions as Example 1, Surface treatment liquid 4 was heated to 60°C and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 4 75% phosphoric acid (H3PO4) 15.0g/j (PO43-: 10.9g/l) Sodium pyrophosphate (Na, P2O7-10H20)2
．． 5g/ノ (P20?'-: 1.0 g/f!
) Resin solid content 4.0 g/pH 3.0 (adjusted with sodium carbonate) Water-soluble resin was the same as in Example 1 Example 5 After cleaning a tin DI can under the same conditions as Example 1, surface treatment liquid 5 was applied. It was heated to eo'c and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 5 75Vo phosphoric acid (t13P04) 30.0g/7 (PO43-: 21.Eig/l)
Sodium tripolyphosphate (Na6P30..) 0.6
g/I (P:zO engineering.5-:0.4 g/)) Resin solid content 2.0 g/l pH 3.5 (adjusted with sodium hydroxide) Water-soluble resin is the same as Example 1 Example 6 Implementation After cleaning tin can 01 under the same conditions as in Example 1, surface treatment liquid 6 was heated to 60° C. and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 6 75% phosphoric acid (Il [3P04) 10.0g/no (PO43-: 7.2 g/l sodium pyrophosphate (Na4P207-10H20)
1.0 g/l (P207'-: 0.4 g/l) Resin solid content 2.0 g/7 pH 4,0 (adjusted with hydroxide) Water-soluble resin 2 Here, n is 40 on average, The introduction rate used was 50 mol%. Water-soluble resin 2 is the same as 1, with 60 g of poly-4-vinylphenol, 20 g of 2-methylaminoethanol, and 37%
It was synthesized from 40 g of formaldehyde solution. Example 7 After cleaning a tin DI can under the same conditions as in Example 1, surface treatment liquid 7 was heated to 60°C and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 7 75% phosphoric acid (H3PO4) 10.0g/no (PO43-: 7.2 g/)) Sodium pyrophosphate (Na4P20□・IoH2o) 1
．． 0g / 1 (P207'-: 0.4 g /
)) Resin solid content 2.0g/1 pH 6.0 (adjusted with sodium hydroxide) Water-soluble resin 3 Water-soluble resin 3 is the same as 1, with 60 g of poly-4-vinylphenol, 20 g of 2-methylamine ethanol, and 37 %
It was synthesized from 40 g of formaldehyde solution. Table 1 shows the results. It can be seen that excellent corrosion resistance, adhesion, and slipperiness can be obtained under the conditions of the present invention. Here, n was 40 on average and the introduction rate was 100 mol%. Table 1 Test Results Comparative Example 1 After cleaning tin DI cans under the same conditions as in Example 1, surface treatment liquid 8 was heated to 60° C. and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 8 75% phosphoric acid (H3PO4) 10.0 g/no (PO43-: 7.2 g/1
)Resin solid content 2.0g/no pH 4.0 (adjusted with sodium carbonate) Water-soluble resin was the same as in Example 1 Comparative Example 2 After cleaning a tin DI can under the same conditions as Example 1, surface treatment liquid 9 was applied. It was heated to 60°C and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in the example. Surface treatment solution 9 75% phosphoric acid (H3PO4) 1.0 g/l (PO43-: 0.72 g/l) Resin solid content 2.0 g/no pH 7.0 (hydroxide) Adjusted with IJum) Water soluble Comparative Example 3 The resin was the same as in Example 1 After cleaning a tin DI can under the same conditions as in Example 1, the surface treatment liquid 10 was heated to 60° C. and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in Example 1. Surface treatment liquid 10 75% phosphoric acid (H3PO4) 10.0g/7 (PO43-: 7.2.g/
1) Sodium pyrophosphate (Na4P-〇, -108
20) 1.0g/j (P20t'-: 0.4g
/ 1) Resin solid content 0.05 g/1 pH 4.0 (adjusted with sodium carbonate) Water-soluble resin is the same as Example 1 Comparative Example 4 After cleaning a tin DI can under the same conditions as Example 1, surface treatment Liquid 11 was heated to 60°C and sprayed for 30 seconds. After the treatment, it was washed with water and dried under the same conditions as in the example. Surface treatment liquid 11 75% phosphoric acid (H3PO4) 1.0 g/l (PO43-: 0.72 g/sodium pyrophosphate (Na4P2O7.10H20) 1.
0g/1 (P2(h'-:0.4g/1)
Resin solid content 2.0 g/l pH 4.0 (adjusted with sodium hydroxide) Water-soluble resin 4 Here, n was 40 on average and the introduction rate was 100 mol %. Water-soluble resin 4 was synthesized by the method shown below. Poly-4 with a molecular weight of 5000 was placed in a 1000 m reaction flask equipped with a condenser, nitrogen blowing tube, overhead stirrer, thermometer, etc.
- 50 g of vinylphenol was added and 500 g of 1,4-dioxane was added and dissolved. The solution was kept at around 10° C. and 380 g of liquid was added over 1 hour. Thereafter, the mixture was heated to 80° C. and reacted with stirring for 4 hours. then 1
The solution was neutralized with a solution of IJ (0% hydroxide) and the solvent was distilled off.

【Effect of the invention】

As explained above, the tinplate DI can surface treatment liquid according to the present invention contains 1 to 30 g/! of phosphate ions. , 0.1 to 5 g/! of condensed phosphate ions! Contains 0.1 to 20 g/l of a water-soluble resin represented by the following formula as a solid content, and p
H2, 0 to 6.5, general formula (in the formula, n is 10 to 80, X and Y are hydrogen or Z shown by the following formula, R and -R2 are 02
-It is an alkyl group or a hydroxylalkyl group of CIO, and the introduction rate of Z per aromatic ring is 30 to 200 mol%
It is. ) By treating tin-plated tin DI cans with a surface treatment liquid having the following composition, excellent corrosion resistance and paint adhesion can be imparted to the surface of tin DI cans before painting or printing, and This has the excellent effect of forming a film that also provides the excellent slipperiness necessary for smooth conveyor transport. In addition, one or more types of condensed phosphate ions selected from pyrophosphate ions, tripolyphosphate ions, and tetrapolyphosphate ions can be used, and - Z in the formula is represented by the following formula. , H3 / Z = -CH2N \ H3 or CH2cH2o) ( / Z = -CH2N \ H3, which has the excellent effect of forming a film with further improved corrosion resistance, paint adhesion and slipperiness. .

Claims (4)

[Claims] (1) Contains 1 to 30 g/l of phosphate ions, 0.1 to 5 g/l of condensed phosphate ions, and 0.1 to 20 g/l of a water-soluble resin represented by the following general formula as a solid content, and has a pH of
A surface treatment liquid for tinplate DI cans, characterized in that the temperature is 2.0 to 6.5. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, n is 10 to 80, X and Y are hydrogen or Z shown by the following formula,
There are tables, etc. ▼; R_1 and R_2 are C_1 to C_1_0 alkyl groups or hydroxylalkyl groups, and the introduction rate of Z per aromatic ring is 30 to 200 mol%. ) (2) The surface treatment liquid for tinplate DI cans according to claim (1), wherein the condensed phosphate ions are one or more selected from pyrophosphate ions, tripolyphosphate ions, and tetrapolyphosphate ions. (3) The surface treatment liquid for tinplate DI cans according to claim (1), wherein Z in the general formula is represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (4) The surface treatment liquid for tinplate DI cans according to claim (1), wherein Z in the general formula is represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼