JPH01177380A - Additive and aqueous solution for metal surface treatment - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance on a metal surface and coating adhesion by applying an aq. soln. contg. the title metal surface treating additive consisting of a specified hydroxystyrene-based water-soluble or self-water- dispersible org. polymer as the essential component on the surface of a metal such as Al, Cu, and Zn. CONSTITUTION:A 0.01-5% aq. soln. contg. the metal surface treating additive consisting of an anionic, cationic, or amphoteric hydroxystyrene-based water-soluble or self-water-dispersible org. polymer shown by formula I and having 2,000-100,000 weight average mol.wt. as the essential component and further contg. >=1 kind of ion of the metal among Ti, Zr, Hf, Zn, Ni, Co, Cr, Mn, Al, Ca, and Mg is applied on the surface of Cu, Zn, Al, and an Al alloy, and baked to impart the corrosion resistance and coating adhesion equivalent to or superior to those obtained by conventional chromating to the surface. The waste soln. from such a soln. does not cause environmental pollution unlike the chromating soln.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an additive for metal surface treatment and an aqueous solution for metal surface treatment. More specifically, the present invention relates to an additive for metal surface treatment and an aqueous solution for metal surface treatment that can thicken (improve) the corrosion resistance and paint adhesion of metal surfaces.

[Conventional technology]

For chemical treatment of metal surfaces, e.g. as a pre-treatment for the application of paints, adhesives and plastics, the metal surface is first cleaned, then rinsed with water and finally applied with an aqueous solution forming a conversion film followed by a liquid film. Methods for complete drying are known. This results in the formation of thin non-metallic coatings on the metal, the surface quality of which can be decisively improved by appropriate selection of the treatment liquid composition and reaction conditions. For example, when paints, adhesives and plastics are applied to such pretreated metals, this results in strongly adhering coatings and significantly increases corrosion resistance.

As this type of method, various chromate coatings using Cr are well known. However, when using Cr, it is necessary to install pollution prevention equipment to remove Cr from the waste liquid of the processing solution and prevent environmental pollution, but constructing this equipment requires a large amount of money. .

For this reason, treatment solutions that do not contain Cr have been studied in recent years, and in particular, a composition containing specific amounts of zirconium and/or titanium as well as phosphate and activated fluoride (U.S. Pat. 41486
No. 70), compositions containing polyacrylic acid and/or polyacrylic esters and fluorozirconic acid, fluorotitanic acid or fluorosilicic acid (U.S. Pat. No. 41
91596) and a composition containing tannins, titanium and fluoride ions (US Pat. No. 4,054,466).

However, the chemical conversion coatings obtained by these methods are inferior to chromate-treated coatings in performance such as corrosion resistance and paint adhesion.

Furthermore, JP-A-59-207971 proposes a method using a water-soluble or water-dispersible organic polymer having a specific substituent, but it still has insufficient performance in terms of corrosion resistance, paint adhesion, etc. I haven't reached the point where I can get it.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a chemical conversion coating having high corrosion resistance and paint adhesion to metal surfaces.

That is, the present invention provides an additive for metal surface treatment and an aqueous solution for metal surface treatment that can impart corrosion resistance and paint adhesion equivalent to or better than chromate treatment to the surfaces of metals such as aluminum (including aluminum alloys), copper, and zinc. It provides:

Further, for example, chromate treatment applied to galvanized steel sheets has the disadvantage that it not only has problems with wastewater treatment, but also that although it has excellent corrosion resistance, it does not provide satisfactory performance in terms of paint adhesion. Therefore, by applying the product of the present invention to chromate treatment, it is possible to improve the paint adhesion of the chromate film.

[Means for solving problems]

As a result of repeated studies to solve the above-mentioned problems, we found that high corrosion resistance and paint adhesion can be obtained by using water-soluble or self-water-dispersible organic polymers with a specific structure for metal surface treatment. Heading, the invention was completed.

That is, the present invention provides the following: (1) The following general formula (A) [where n is an arbitrary number up to n≧3 and the weight average molecular weight of general formula (A) is 1 million; Q<k ≦2゜; 0≦p≦2゜; R'-1? " is H or an alkyl group having 1 to 5 carbon atoms; Y is -303M or -C5OJ.

;Z is J　R6 Y', 0CR3ICN R'.

S or an alkyl or aryl group having 1 to 18 carbon atoms, (in the formula; H1 is an alkali metal, alkaline earth metal, or an organic cation such as amines; Y' is Halogen, y2ey3 (9 is a halogen ion, an organic acid anion,
A counter ion such as an inorganic acid anion; formerly S or 0; R4 to R11 are the same or different, and are straight-chain or branched alkyl groups or alkyl group derivatives such as hydroxyalkyl groups, or aromatic groups; R6 and R7 may form a ring with the N group.

, R9 to RIS are the same or different, and are linear or branched alkyl groups, alkyl group derivative groups such as hydroxyalkyl groups, aromatic groups, or H; (1, 3, t, u is O or 1 ; r indicates 0.1 or 2)] An additive for metal surface treatment consisting of an anionic, cationic or amphoteric hydroxystyrene water-soluble or self-water dispersible organic polymer, and the additive. Ti, Zr, Hf, Z
n, Ni+Co, Cr, Mn, A
1. The present invention provides an aqueous solution for metal surface treatment characterized by containing one or more metal ions selected from Ca and Mg.

By using the additive of the present invention, it is possible to obtain a film particularly excellent in corrosion resistance and paint adhesion.

In the present invention, water-soluble means that 0.1 g or more of an organic polymer is completely contained in a standard surface treatment aqueous solution (solutions A to D listed in Table 2 in Examples described later) at 25°C. means that it is dissolved in Furthermore, self-water dispersibility refers to the amount of 0.01 g in the aqueous solution 11 at 25°C.
It means a state in which the above organic polymers are self-dispersed.

In the above general formula (A), n, and p are not defined as integers, but are arbitrary numbers (real numbers) within a certain range. If we consider the monomers that make up the polymer, k
, p are naturally integers, and when considering each molecule, n is an integer.

However, a polymer is essentially a mixture, and it is more accurate to consider the properties of a polymer as a property of the mixture than to consider its individual constituent units. Therefore, in the present invention, the formula (A ) are expressed as average compositions.

The hydroxystyrene organic polymer represented by the above general formula (A) is Y in the general formula (1), i.e. -303M or -C-S(hM (;
M has a substituent represented by HlS (alkali metal, alkaline earth metal, or organic cation such as amines) as an essential substituent, and even if it has a substituent represented by Z, it does not have It doesn't have to be.

The alkali metals or alkaline earth metals for H in the substituent Y include Li, Na, K+ Mg, Ca,
Sr+Ba etc. are suitable.

Hydroxystyrene or isopropenylphenol, which is a polymerized unit of a hydroxystyrene polymer, may be an ortho form, a meta form, a para form, or a mixture thereof, but preferably a para form or a meta form.

Introduction of a sulfone group can be achieved by a conventional sulfonation method using fuming sulfuric acid or sulfuric anhydride as a sulfonation agent. Also, the substituent of the hydroxystyrene RAR & I ren unit -C-N-R' or S I R5R? are different types, and are straight-chain or branched alkyl groups having 1 to 36 carbon atoms, or alkyl derivative groups such as hydroxyalkyl groups, aminoalkyl groups, phosphoalkyl groups, and mercaptoalkyl groups, or straight-chained alkyl groups having 1 to 16 carbon atoms. A group selected from aromatic groups such as a benzyl group substituted with a chain or a branched alkyl group, and having a carbon chain such that the compound (A) is no longer water-soluble or self-water dispersible. be. Also R6 and R? may form a ring. Therefore, preferably straight-chain or branched alkyl groups,
Examples include aromatic groups substituted with hydroxyalkyl groups or linear or branched alkyl groups having 1 to 5 carbon atoms. The above-mentioned tertiary amino group can be easily introduced by, for example, Mannilla reaction using dialkylamine and formaldehyde to easily obtain (-C-N-R').

Furthermore, in order to improve water solubility or self-water dispersibility, an organic or inorganic acid that neutralizes the amine moiety is used. Acids useful for this purpose are acetic acid, citric acid, oxalic acid, ascorbic acid, phenylphosphonic acid, chloromethylphosphonic acid, mono.

Di- and trichloroacetic acid, trifluoroacetic acid, sulfuric acid,
Examples include phosphoric acid, hydrochloric acid, boric acid, nitric acid, hydrofluoric acid, hexafluorosilicic acid, hexafluorotitanic acid, and hexafluorozirconic acid. These may be used alone or in combination.

The introduction of the quaternary ammonium base can be easily carried out by, for example, the Menschudkin reaction of the above-mentioned tertiary aminated compound with an alkyl halide. Furthermore, the substituent R' (O
R9).

-(C)70-P (= oath) q(B)! I R’　　　(R”)z−“ R’ (OR”).

R9 to RI5 in -(C)τP (=W)9(C) R'(R")z-1 are the same or different, and are H or a straight or branched alkyl group having 1 to 36 carbon atoms, or From among alkyl derivative groups such as hydroxyalkyl groups, aminoalkyl groups, mercaptoalkyl groups, and phosphoalkyl groups, or aromatic groups such as phenyl groups substituted with linear or branched alkyl groups having 1 to 16 carbon atoms. The carbon chain length is such that the compound (A) is not water-soluble or self-dispersible in water.Therefore, it is preferably a straight chain or branched chain having 1 to 8 carbon atoms. The hydroxystyrene polymer represented by the formula (C), which includes an alkyl group, a hydroxyalkyl group, or an aromatic group substituted with a linear or branched alkyl group having 1 to 5 carbon atoms, is, for example, As shown in Publication No. 53-47489, it is obtained by first halogenating or halomethylating a hydroxystyrene polymer, reacting it with a trivalent phosphorus compound (Arbuzov reaction), and then subjecting it to thermal rearrangement. The compound represented by formula (B) is obtained by methylolizing a hydroxystyrene polymer and then reacting it with a phosphoric acid or phosphate ester group-introduced product, as disclosed in, for example, JP-A-53-71190. obtained by letting

As shown in JP-A No. 61-34444, hydroxystyrene polymers containing phosphonium groups can be produced by halogen methylation (e.g. -CH2Cl conversion) by reacting hydrogen halide with formaldehyde.
It can be easily obtained by carrying out the following steps and then reacting with a trivalent phosphite. Furthermore, the hydroxystyrene polymer used in the present invention may be produced by any method, and its origin does not matter.

The water-soluble or self-water-dispersible organic polymer that can be used in the present invention preferably has a weight average molecular weight of 1,000 or more, and must be 1,000,000 or less. Preferably in the range of 1000 to 500,000, most preferably 2
Limited to a range of 000 to 100,000. The reason for this is that the molecular weight of the organic polymer affects the effect of the present invention;
If the molecular weight is less than 1,000,000, it is difficult to obtain a large coating adhesion effect, while if the molecular weight exceeds 1,000,000, organic polymers have poor solubility or dispersibility in aqueous solutions, and there is a limit to the concentration of addition to aqueous solutions for surface treatment. This is because it becomes a problem and at the same time makes it difficult to obtain the effects of the present invention. that's all,
Considering the ease of exhibiting functions such as solubility or dispersibility in an aqueous solution for surface treatment and paint adhesion, the weight average molecular weight is most preferably in the range of 2,000 to 100,000.

The preferred range of polar group density of polar groups such as sulfone groups and phosphoric acid groups (not including hydroxyl groups and aromatic rings) is 9,500 mol.
On average between 0.1 and 5, more preferably 1 per unit
~3 pieces. If the polar group density is less than 0.1, the solubility or dispersibility in an aqueous solution will be poor, which will cause a problem, and if it exceeds 5, the corrosion resistance of the resulting film will be reduced, which will be a problem. As the polar group, a sulfone group is essential, and other phosphorus-containing groups or amine groups are preferable. This is because those having these polar groups exhibit excellent paint adhesion.

As a result of extensive and deep studies on the behavior of polyhydroxystyrene derivatives in liquids containing metal ions such as surface treatment liquids, we have found that anionic polar groups (especially sulfone groups) act effectively. I found out.

In other words, it was discovered that the sulfone group has a strong electrostatic interaction with the metal cations in the treatment solution and is incorporated into the chemical conversion film in a stable chemical state, resulting in extremely strong paint adhesion and corrosion resistance. It is something that The reason for the improvement in corrosion resistance is thought to be that polyhydroxystyrene having a sulfone group as a substituent exists stably in the chemical conversion coating and is therefore less likely to be redissolved in the solution. Such effects cannot be expected with polyhydroxystyrene having only amino groups as substituents.

The water-soluble or self-water-dispersible organic polymers of the present invention are about o
, oos to about 20% by weight, more preferably 0.01 to 5%.

In addition, the water-soluble or self-water dispersible organic polymer of the present invention can be applied to the treatment of metal surfaces such as aluminum (including aluminum alloys), steel, zinc, etc., but it is particularly effective when applied to the surface treatment of aluminum. can be obtained. As the surface treatment method, generally known methods such as dipping method and spray method are used.

The metal surface treated using the product of the present invention can be coated with a paint by a conventional coating method such as brush coating, spray coating, electrostatic coating, dip coating, or roller coating.

As a result of the treatment according to the present invention, metal surfaces can have unprecedentedly high corrosion resistance and high paint adhesion.

〔Example〕

The present invention will be explained in more detail below using Examples, but the present invention is not limited to these Examples.

The water-soluble and self-water dispersible polymers used in the following examples are shown in Table 1, the surface treatment liquids and treatment methods are shown in Table 2, and the paints and coating methods are shown in Table 3.

In addition, evaluation of corrosion resistance and paint adhesion was performed by the following method.

Evaluation of Corrosion Resistance> I: Indicates the time from spraying salt water until blistering occurs at the cross-cut portion of the coating film based on JIS Z-2371.

■：JIS237 adjustment piece with painted cross-cut
After continuously spraying a 5% aqueous sodium chloride solution based on 1, a tape peeling test was conducted at the cross-cut portion, and the peeling width of the coating film from the cut line (single width) is shown.

Evaluation Criteria A: After 3 weeks of continuous spraying, peeling width within 1lIIIl1, no blistering of the coating around the crosscut.

B: After 2 weeks of continuous spraying, peeling width within 11, no blisters around the periphery.

C: After continuous spraying for 1 week, peeling width within 11, no blisters around the periphery.

D: Peeling of more than 1 mm is observed after one week of continuous spraying.

E: After one week of continuous spraying, peeling of more than 1 mm was observed, and bulges were also observed in the peripheral areas.

<Paint adhesion evaluation> I: Gobun test Draw 100 goblets reaching the base surface at 1 mm intervals,
It is expressed as the number of remaining coatings when removed with cellophane tape.

(2): Erichsen extrusion test After drawing 100 goblets at 1 mm intervals reaching the base surface, Erichsen extrusion processing was performed, followed by a cellophane tape peeling test.

Evaluation Criteria A: No peeling due to tape peeling after 8 mm extrusion processing is observed.

B: No peeling due to tape peeling after extrusion processing of 7 mm was observed.

C: No peeling due to tape peeling after extrusion processing of 6 mm was observed.

D: Peeling by tape peeling after extrusion of 5 mm is less than 100/100.

Table 1 Table-1 continued Table-1 Continued Surface treatment liquid and treatment method table 2 Paint and coating method table -3 Example 1 After degreasing the aluminum plate A-3004 plate with an acidic cleaning agent,
The treatment was carried out using a solution obtained by adding the water-soluble and self-water dispersible polymers shown in Table 1 to the treatment solution A or B shown in Table 2. Furthermore, coating was performed using method a or b shown in Table 3. The results are shown in Table 4.

Comparative Example 1 The outside of the point plate was treated with or without adding polymers other than the present invention to the treatment solution A or B shown in Table 2. Display the results -
4.

Table 4 (Continued from Table 4) Table 4 shows the corrosion resistance and paint adhesion of a film surface-treated on an aluminum plate using the water-soluble or self-water-dispersible organic polymer according to the present invention, along with comparative products. It is something.

First, looking at the corrosion resistance, when treated with either treatment solution A or B, except for a slight decrease in fish 3 (11 ml to 2
．． 4 to 21) all exhibit the highest corrosion resistance.

On the other hand, the comparative products (Nos. 22 to 26) treated with either treatment solution A or B show significantly inferior performance to the invention products.

Next, regarding paint adhesion, the products of the present invention (Kan 1 to 21)
All have the highest paint adhesion, except Fish 3 and Ik19, which are ranked B in the Erichsen extrusion test. On the other hand, the comparative product without polymer addition (Na22.23
) is significantly inferior to the invention product in both the cross-cut test and the Erichsen extrusion test. When polymers other than the present invention were added (numbers 24 to 26), they were significantly inferior to the invented product in the Erichsen test.

Example 2 After degreasing a hot-dip galvanized plate with acetone, C shown in Table-2
Alternatively, the treatment was performed using a solution obtained by adding the water-soluble and self-water-dispersible polymers shown in Table 1 to the treatment solution of D. Further table-
Painting was performed by method C or d shown in 3. The results are shown in Table-5.

Comparative Example 2 Table 5 shows the results of a sample treated in the same manner as in Example 2 except for the point plate, which was treated without adding the product of the present invention to the treatment solution C or D shown in Table 2.

Table 5 Table 5 shows the corrosion resistance and paint adhesion of a film surface-treated on a galvanized steel sheet using the water-soluble or self-water dispersible organic polymer according to the present invention, along with comparative products. .

First, looking at the corrosion resistance, the products of the present invention all showed the highest rank A corrosion resistance, except for the cases where the amount of polymer added was slightly lower (3) and the amount added was slightly higher (9), which resulted in B rank. On the other hand, comparative products [14, 15] show only low corrosion resistance.

Next, regarding paint adhesion, the results of the cross-over test show that there is no difference between the products of the present invention and the comparative products. However, in the more severe Erichsen extrusion test, all products of the present invention obtained the highest rank A, whereas the comparative product 1'h14
．． 15 is a low rank.

Applicant's agent Kaoru Furutani

Claims (1)

[Claims] 1 The following general formula (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (A) [In the formula; n is n≧3 and the weight average molecular weight of the general formula (A) is 1 million. Any number up to; 0<k≦2;0≦p≦2; R^1 to R^3 are H or an alkyl group having 1 to 5 carbon atoms; Y is -SO_3M or ▲ formula; There are chemical formulas, tables, etc.▼
, ;Z is -Y^1, -OCH_3, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, CR^4R^5O
R^4, -CH^2OH or an alkyl or aryl group having 1 to 18 carbon atoms, (wherein M is H, an alkali metal, an alkaline earth metal, or an organic cation such as amines) , ;Y^1, Y^4 are halogens: Y^2^■Y^3^■ are counter ions such as halogen ions, organic acid anions, inorganic acid anions; W is S or O; R^4~R^ 5 is the same or different, and is an alkyl group derivative such as a linear or branched alkyl group or a hydroxyalkyl group, or an aromatic group, or H, and R
^6 and R^7 may form a ring with the N group. ;
R^9 to R^1^5 are the same or different, and are a linear or branched alkyl group, an alkyl group derivative group such as a hydroxyalkyl group, an aromatic group, or H ; q, s, t, u is 0 or 1; r is 0, 1 or 2)] An additive for metal surface treatment consisting of an anionic, cationic or amphoteric hydroxystyrene water-soluble or self-water dispersible organic polymer. . 2. The additive for metal surface treatment according to claim 1, wherein the organic polymer has a substituent (-OH) of general formula (A) at the para position. 3. The additive for metal surface treatment according to claim 1 or 2, wherein the structure of the organic polymer is ▲a mathematical formula, a chemical formula, a table, etc.▼, (0<p≦2). 4. The additive for metal surface treatment according to claim 1 or 2, wherein the structure of the organic polymer is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, (0<p≦2). 5. The additive for metal surface treatment according to claim 1 or 2, wherein the organic polymer has the following structure: (0<p≦2). 6. The additive for metal surface treatment according to claim 1 or 2, wherein the organic polymer has a structure of p=0. 7 The following general formula (A) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (A) [In the formula; n is any number where n≧3 and the weight average molecular weight of general formula (A) is 1 million. ,;0<k≦2, ;0≦p≦2, ;R^1~R^3 is H or an alkyl group having 1 to 5 carbon atoms, ;Y is -SO_3M or ▲Mathematical formula, chemical formula, table, etc. ▼
, ;Z is -Y^1, -OCH_3, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, CR^4R^5O
selected from R^6-, -CH_2OH or an alkyl or aryl group having 1 to 18 carbon atoms, (
In the formula; Y^1 is H, an alkali metal, an alkaline earth metal, or an organic cation such as amines; Y^1 and Y^4 are halogens; Y^2^■Y^3^■ is a halogen ion; Counter ions such as organic acid anions and inorganic acid anions; W is S or O; R^4 to R^5 are the same or different, and are straight-chain or branched alkyl groups or alkyl group derivatives such as hydroxyalkyl groups, or aromatic group, or H, and further R
^6 and R^7 may form a ring with the N group. ;R^9 to R^1^5 are the same or different, and are linear or branched alkyl groups, alkyl group derivative groups such as hydroxyalkyl groups, aromatic groups, or H ;q, s, t, u is 0 or 1; r is 0, 1 or 2); Ti, Zr, Hf, Zn, N
An aqueous solution for metal surface treatment, characterized by containing one or more metal ions selected from i, Co, Cr, Mn, Al, Ca, and Mg. 8. The aqueous solution for metal surface treatment according to claim 7, wherein the organic polymer has a substituent (-OH) of general formula (A) at the para position. 9. The aqueous solution for metal surface treatment according to claim 7 or 8, wherein the structure of the organic polymer is ▲Mathematical formula, chemical formula, table, etc.▼, (0<p≦2). 10. The aqueous solution for metal surface treatment according to claim 7 or 8, wherein the organic polymer has the following structure: (0<p≦2). 11. The aqueous solution for metal surface treatment according to claim 7 or 8, wherein the structure of the organic polymer is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, (0<p≦2). 12. The aqueous solution for metal surface treatment according to claim 7 or 8, wherein the organic polymer has a structure of p=0.