JPS6139989B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a metal surface treating agent composition. Specifically, the present invention relates to a metal surface treating agent composition that imparts corrosion resistance and coating base properties to metal surfaces, has excellent adhesion to metal surfaces, and is free from the risk of causing pollution. Conventionally, chromate treatment or phosphate treatment has been carried out for the purpose of imparting corrosion resistance to metal surfaces and providing a coating base for improving adhesion with paints. However, these methods have the problem of generating pollution. Therefore, several alternative methods have been proposed. For example, JP-A-51-
No. 82325 discloses a method using silicic acid or polysilicate. Also, special public service 1968-19686
The specification discloses a method of using a silicate and an anionic resin in combination. However, in all of the methods disclosed in these publications, the adhesion between the surface treatment agent and the coating material is poor, and the corrosion resistance after coating is also insufficient. In view of the current situation, the present inventors have conducted extensive research and have found that an excellent metal surface treatment agent composition can be created by using a hydrolyzate of alkyl silicate and a cationic resin and/or amphoteric ionic resin. The present inventors have discovered that the present invention can be obtained, and have completed the present invention. Therefore, the purpose of the present invention is to provide metal surfaces with corrosion resistance and coating base properties, and to provide excellent adhesion to metal surfaces.
Furthermore, the present invention provides a metal surface treating agent composition that is free from the risk of causing pollution. That is, the metal surface treatment agent composition of the present invention contains 0.5 to 250 g of alkyl silicate hydrolyzate (hereinafter referred to as hydrolyzate ()) in terms of SiO ₂ per metal surface treatment agent composition. 0.5 to 250 g of cationic resin and/or zwitterionic resin () (hereinafter referred to as resin ())
It is characterized by containing an amount in the range of . The alkyl silicate used in the present invention is
It is an orthosilicate or a partial condensate thereof represented by the following general formula. general formula (However, in the formula, R represents an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 0 to 11.) Examples of such alkyl silicates include methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, Examples include butyl orthosilicate, amyl orthosilicate, and partial condensates thereof. Among these, methyl orthosilicate, ethyl orthosilicate, and partial condensates thereof are particularly useful in the present invention because they are industrially inexpensive and easily available. In order to obtain a hydrolyzate () from these alkyl silicates, hydrolysis may be carried out in a mineral acid such as hydrochloric acid, phosphoric acid, or sulfuric acid by a conventional method. At this time, it is preferable to carry out the hydrolysis in the presence of the resin (2), since the dispersion stability of the hydrolyzate (2) in the resulting metal surface treating agent composition will be good. In such hydrolysis, it is desirable to hydrolyze at least 50% or more of the silicate used, preferably almost completely. Silicic acid and polysilicic acid are produced by the hydrolysis of such alkyl silicate, and alcohol is produced as a by-product. The alcohol by-produced may be contained in the metal surface treatment composition of the present invention, or it may be distilled under reduced pressure. Part or all of it may be removed by conventional methods such as removal. The amount of the hydrolyzate ( ) obtained in this way is in the range of 0.5 to 250 g, preferably 2 to 250 g in terms of SiO ₂ per 1 metal surface treatment agent composition of the present invention.
Contained in amounts ranging from 200g. If the amount is less than 0.5g, the resulting coating film will be too thin and the effect will be insufficient.
On the other hand, if it exceeds 250 g, the coating film will become too thick and workability will deteriorate, both of which are undesirable. The resin used in the present invention is one selected from the group consisting of cationic resins and amphoteric resins.
species or two or more species. Among these, cationic resins refer to cationic water-soluble resins or cationic water-dispersible resins, and are water-soluble or water-dispersible resins that have cationic nitrogen in their molecules, such as the following: Examples of the resins listed in each of the sections 1 to 2 can be mentioned. Polyalkylene polyamines such as polyethyleneimine, polypropyleneimine, etc. and derivatives thereof. Polyamide polyamines and their derivatives produced by condensation of polycarboxylic acids and polyamines. A cationic epoxy resin obtained by reacting a polyglycidyl compound such as an epoxy resin with an amine and/or a polyamine. A cationic urea resin obtained by reacting a polyisocyanate compound such as a urethane prepolymer with an amine and/or a polyamine. Derived from one or more types selected from vinyl compounds containing amino ester groups such as dialkylaminoalkyl (meth)acrylates, and cationic nitrogen-containing vinyl compounds such as vinylpyridine, vinylimidazole, or their salts. Polymers or multicomponent copolymers of these cationic nitrogen-containing vinyl compounds and other monomers that can be copolymerized. A polymer derived from one or more monomers selected from the group consisting of diallylamine and salts thereof, or a copolymer of these monomers and other monomers copolymerizable. An aminomethyl group-containing resin obtained by reacting a chloromethyl group- and/or hydroxymethyl group-containing polymer with an amine and/or polyamine. A polycondensate of polyhaloalkane and/or epihalohydrin and/or polyepihalohydrin and amine and/or polyamine. In addition, zwitterionic resin refers to zwitterionic water-soluble resin or zwitterionic water-dispersible resin, and is a water-soluble or water-dispersible resin that has cationic nitrogen and anionic carboxyl group in the molecule. Examples of such resins include the resins shown in the following items. A resin in which a carboxyl group is introduced as an anionic group into the cationic resin of item 1 to 2 by a known method (using chloroacetic acid or the like as an example). A carboxyl group-containing resin such as (meth)acrylic resin, alkyd resin or maleated polybutadiene, and a basic nitrogen-containing alkylating agent such as an aziridine compound such as ethyleneimine, propyleneimine or hydroxyethyleneimine, or glycidylamine or its salt. A resin containing amphoteric ionic groups obtained by the reaction of One or more basic nitrogen-containing vinyl compounds such as dialkylaminoalkyl (meth)acrylate, vinylpyridine, vinylimidazole, or their salts, and (meth)acrylic acid, crotonic acid, maleic acid, etc. A copolymer with one or more carboxyl group-containing vinyl compounds, or a multicomponent copolymer with other copolymerizable monomers. Both of these cationic resins and amphoteric ionic resins can be synthesized by common known methods. Among these cationic resins and amphoteric ionic resins, polyalkylene polyamine resins, cationic epoxy resins, homopolymers or copolymers of vinyl compounds containing amino ester groups, and cationic epoxy resins are used. Zwitterionic epoxy resin obtained by ionizing the resin, Zwitterionic resin obtained by reacting a carboxyl group-containing resin with an aziridine compound,
Alternatively, a copolymer of an aminoester group-containing vinyl compound and a carboxyl group-containing vinyl compound is particularly effective as the resin () in the present invention. In the present invention, various cationic resins and/or amphoteric ionic resins can be used as the resin (), for example, as shown in the above sections.
However, in the case of cationic resins, the amount of cationic nitrogen measured by commonly known methods such as colloid titration, conductivity titration, etc.
Amounts ranging from 0.1 to 24 mmol are preferred. In the case of amphoteric ionic resins, the amount of cationic nitrogen and the amount of carboxyl groups that can be anionized (these amounts can also be measured by colloid titration, conductivity titration, etc.) are each 0.01 per gram of the resin. Amounts in the range ˜20 mmol are desirable. If it is outside this range, the effect as a metal surface treating agent composition will be insufficient, which is not preferable. When using the resin () in the present invention, it may be used as is, or some or all of the cationic nitrogen contained in the resin () may be replaced with an organic or inorganic acid such as hydrochloric acid, nitric acid, phosphoric acid, formic acid, or acetic acid. It can also be used as a salt or a quaternary ammonium salt. Among these, if it is used as a phosphate, it is more advantageous in terms of corrosion resistance. The resin () is contained in an amount ranging from 0.5 to 250 g, preferably from 1 to 200 g per metal surface treating agent composition of the present invention. If the amount is less than 0.5 g, the adhesion between the resulting metal surface treating agent composition and the metal surface will be insufficient. On the other hand, if a large amount exceeding 250 g is used, the resulting coating film will be too thick, resulting in poor workability and poor water resistance. The metal surface treatment agent composition of the present invention is composed of a hydrolyzate () and a resin (), and by using a water-insoluble or water-dispersible inorganic substance in combination, the metal surface treatment composition of the present invention Improvements in condition and corrosion resistance can be obtained. Such water-insoluble or water-dispersible inorganic substances include finely powdered silica, talc, diatomaceous earth, calcium carbonate, clay, titanium dioxide, aluminum silicate, aluminum phosphate, colloidal silica, alumina sol, magnesia sol, titania sol, and zirconia. Sol etc. can be mentioned. The amount used is preferably 50 g or less per metal surface treating agent composition of the present invention. When obtaining the metal surface treating agent composition of the present invention from the hydrolyzate () and the resin (), these and water may be mixed in any order. A conventional mixing method can also be used. The scope of the present invention is not limited by these mixing order or method. In addition, tannic acid, gallic acid, which is generally known as a component of a rust preventive agent,
It can also be used by adding thioureaic acid or the like. The metal surface treatment agent composition of the present invention can be used in a wide pH range of 0.5 to 13.0, but preferably 0.5 to 13.0.
It is desirable to use it in the PH range of ~7.0. If the pH is less than 0.5, excessive erosion of the metal to be coated will occur, and if the pH exceeds 7.0, the reactivity with the metal surface will be too low, and in some cases, the stability of the resin will deteriorate, making it less effective. This may be undesirable as it may be insufficient. Examples of PH regulators to achieve such a preferable PH range include inorganic or organic acids such as hydrochloric acid, phosphoric acid, nitric acid, formic acid, and acetic acid; alkalis such as ammonia, sodium hydroxide, and potassium hydroxide; dimethylamine; diethylamine, ethanolamine,
Organic amines such as N.N-dimethylethanolamine are used, but among them, phosphoric acid is more preferable from the viewpoint of corrosion resistance. The metal surface treatment agent composition of the present invention obtained in this way has excellent adhesion to metal surfaces due to the combined action of the hydrolyzate () and the resin (). It provides water resistance, corrosion resistance, and coating base properties, and there is no risk of causing pollution. The metal surface treatment agent composition of the present invention can be used for metals such as iron, steel, alloy steel, zinc, zinc alloy, aluminum, and aluminum alloy, and is particularly effective for zinc and zinc alloy. It is effective. Moreover, these objects to be coated can have various shapes such as plate, pipe, and line. In order to use the metal surface treatment composition of the present invention, after coating the surface of the metal to be coated at room temperature to 150°C, preferably room temperature to 70°C, by brush coating, spray coating, roll coating, dipping, etc., It is only necessary to dry at a temperature of room temperature to 200°C, preferably room temperature to 100°C, for several tens of seconds to several minutes. The thickness of the coating film obtained at this time is 0.5
It is preferable that the thickness is about 5 μm. The coating film of the metal surface treatment agent composition of the present invention obtained in this way hardly peels off even in the process of removing adhering oil (degreasing), which is generally performed in the pre-painting process. The phosphating process that is done at home can be omitted. In this respect as well, the metal surface treating agent composition of the present invention has extremely excellent effects. In addition, the metal surface treatment composition of the present invention can be used not only as a direct surface treatment agent for metal surfaces, but also as a non-polluting post-treatment in place of chromate sealing on conventional phosphate-treated plates. Can be used. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. However, the invention is not limited only to these examples. In addition, % in an example shall represent weight % unless otherwise specified. Reference example 1 Molecular weight approximately 10,000, cationic nitrogen 5.2 mmol/
3.3 g of a 30% aqueous solution of polyethyleneimine/epichlorohydrin modified resin containing g in phosphoric acid.
After neutralizing the pH to 3.0, add 400 g of water, slowly add 87 g of ethyl orthosilicate while stirring, hydrolyze at room temperature for 3 hours, and then add water to make the total volume 500 ml. ) as _SiO2
A slightly cloudy metal surface treatment agent composition of the present invention with a pH of 2.9 was obtained, containing 50 g/and 2 g/of polyethyleneimine epichlorohydrin modified resin. This is referred to as composition A. Reference Example 2 Epoxidized polybutadiene with a molecular weight of about 1000 (trade name "BF-1000" manufactured by Adeka Argus) is reacted with polyethyleneimine with a molecular weight of 300, and by partially neutralizing it with acetic acid, the cationic nitrogen is reduced to 2.3
An aqueous dispersion (PH6.8, solid content 20%) of a cationic water-dispersible epoxy resin containing mmol/g was obtained. Take 10g of this as solid content and PH it with phosphoric acid.
After neutralization, add 300 g of water to 3.0, add 87 g of ethyl orthosilicate with stirring, hydrolyze at room temperature for 3 hours, add water to make a total volume of 500 ml, and add 50 g of the hydrolyzate () as SiO ₂ / and cations. A metal surface treating agent composition of the present invention was obtained in the form of a pale yellow emulsion with a pH of 3.0 containing 20 g of a water-dispersible epoxy resin. This is referred to as composition B. Reference example 3 Add 87 g of ethyl orthosilicate after hydrolysis to 5 g of 30% phosphoric acid, hydrolyze at a temperature of 30 to 40°C, and add water to make a total volume of 500 ml to obtain 50 g of the hydrolyzate () as SiO ₂ An aqueous solution of ethyl orthosilicate hydrolyzate containing: Maleated polybutadiene with an acid value of 80 and a molecular weight of about 2000 (trade name "Nisseki Polybutadiene M-2000" manufactured by Nippon Petrochemical Co., Ltd.) was added to 100 ml of this aqueous solution, partially aminoethylated with ethyleneimine, and then dissolved in acetic acid. Add 7.5 g of the amphoteric ionic water-dispersible resin (containing 2.5 mmol/g of cationic nitrogen and 0.3 mmol/g of carboxyl groups) as a solid content, and then add water to the total amount. By reducing the amount to 125 ml, the hydrolyzate () contains 40 g/SiO ₂ and the zwitterionic resin 60 g/
A metal surface treatment agent composition of the present invention containing PH3.5 was obtained. This is referred to as composition C. Reference Example 4 A cationic water-dispersible resin obtained by reacting a bisphenol type epoxy resin (trade name "Epiclon 850" manufactured by Dainippon Ink Co., Ltd.) with dimethylaminoethylenediamine and then neutralizing it with formic acid ( 7.4 mmol/g of cationic nitrogen was taken as a solid content, and added to 900 ml of the hydrolyzate of ethyl orthosilicate obtained in Reference Example 3.
Next, by adding water to bring the total amount to 1, the metal surface treatment agent composition of the present invention with a pH of 2.8 contains 45 g of the hydrolyzate (as SiO ₂ ) and 10 g of the cationic water-dispersible resin. I got it. This is composition D.
shall be. Reference Example 5 A carboxyl group was created using an acrylic terpolymer with a molecular weight of approximately 200,000, consisting of 40% methyl methacrylate, 50% butyl acrylate, and 10% acrylic acid.
Acrylic resin containing 1.39 mmol/g N-
Zwitterionic water-dispersible resin partially aminoalkylated with hydroxyethylethylenimine and then phosphated (cationic nitrogen 0.6 mmol/
g and contains 0.8 mmol/g of carboxyl groups)
Take 70g as a solid content, add it to 600ml of the aqueous solution of the hydrolyzate of ethyl orthosilicate obtained in Reference Example 3, and then add water to bring the total amount to ₁ . Contains 70g/zwitterionic water-dispersible resin, PH3.5
A metal surface treating agent composition of the present invention was obtained. This will be referred to as composition E. Reference Example 6 Zwitterionic water-dispersible resin obtained by reacting the acrylic terpolymer used in Reference Example 5 with propylene imine (cationic nitrogen content of 0.66
mmol/g and contains 0.8 mmol/g of carboxyl groups) as a solid content, add it to 100 ml of composition B obtained in Reference Example 2, and then add water to make the total volume 167 ml to obtain a hydrolyzate ( ) was obtained as SiO ₂ (30 g/containing), and a total of 80 g/containing a cationic water-dispersible resin and an amphoteric ionic water-dispersible resin, with a pH of 3.5, a metal surface treating agent composition of the present invention was obtained. . This is referred to as composition F. Reference Example 7 Zwitterionic water-dispersible resin (cationic 10.5 g of solid content (containing 1.2 mmol/g of nitrogen and 0.2 mmol/g of carboxyl groups) was taken as a solid content, and 100 ml of composition B obtained in Reference Example 2 was prepared.
In addition, water was then added to make the total volume 250 ml, so that the hydrolyzate () contained 20 g/ _SiO2 , and the cationic water-dispersible resin and the amphoteric water-dispersible resin were combined. 50g/containing PH
A metal surface treatment agent composition of the present invention having a concentration of 3.0 was obtained. This is referred to as composition G. Reference Example 8 In Reference Example 1, hydration was performed in the same manner as in Reference Example 1, except that a partial condensate of ethyl orthosilicate (trade name "Ethylsilicate 40" manufactured by Nippon Colcourt Chemical Co., Ltd.) was used instead of ethyl orthosilicate. PH2.0 containing 30g of decomposition product () as SiO ₂ and 0.5g of cationic water-soluble resin
A metal surface treating agent composition of the present invention was obtained. This is referred to as composition H. Reference Example 9 In Reference Example 1, hydration was performed in the same manner as in Reference Example 1, except that a partial condensate of ethyl orthosilicate (trade name "HAS-6" manufactured by Nippon Colcourt Chemical Co., Ltd.) was used instead of ethyl orthosilicate. Contains 20 g of decomposed product () as SiO ₂ and 15 g of cationic water-soluble resin. A metal surface treatment agent composition of the present invention having a pH of 3.1 was obtained. This is referred to as Composition I. Reference Example 10 In Reference Example 1, instead of the polyethyleneimine-epichlorohydrin-modified resin, a polyamide/polyamine-epichlorohydrin-modified resin obtained by reacting a condensate of adipic acid and diethylenetriamine with epichlorohydrin (containing 2.8 mmol/g of cationic nitrogen) was used. Hydrolyzate () was converted to SiO ₂ in the same manner as in Reference Example 1 except that SiO 2
50g/ and cationic water-soluble resin 2g/
A metal surface treating agent composition of the present invention containing PH4.0 was obtained. This is designated as composition J. Reference Example 11 In Reference Example 3, instead of the mylenated polybutadiene, a cationic water-dispersible product consisting of a hydrochloride of methyl methacrylate-ethyl acrylate-dimethylaminoethyl methacrylate containing 1.0 mmol/g of cationic nitrogen was used. The metal surface of the present invention with a pH of 3.8 containing 40 g of the hydrolyzate (SiO ₂ ) and 10 g of the cationic water-dispersible resin was prepared in the same manner as in Reference Example 3 except that the terpolymer was used. A processing agent composition was obtained. This is referred to as composition K. Examples 1 to 11 Electrolytic galvanized steel sheets with a thickness of 0.5 mm were degreased, washed with water, and dried in a conventional manner to prepare test plates. Each of the metal surface treating agent compositions of the present invention shown in Table 1 was applied to this steel plate using a roll, followed by drying at 100° C. for 30 seconds to obtain a surface treating solution. The film thickness of all these surface-treated plates was approximately 1 to 3 microns. In order to examine the primary corrosion resistance of these surface-treated plates, a salt spray test was conducted according to JIS Z-2371, and the area where white rust occurred after 24 hours was evaluated using a 10-point scale. In other words, a score of 10 indicates that there is no area where white rust has occurred, and a score of 9 indicates that the area where white rust has occurred is up to 10% (the same criteria apply hereinafter). In addition, in order to check the paint adhesion and corrosion resistance after painting, we baked alkyd melamine resin (weight ratio 7/3, PWC 50%) at 140℃ for 20 minutes to obtain a film thickness of about 30-35μ and a pencil hardness of 2H. A film was created. As a secondary corrosion resistance test
After 120 hours of the salt spray test according to JIS Z-2371, a cellophane tape was pressed onto the cross cut portion and then peeled off to determine the paint peeling width from the cross cut portion. Also, to check paint adhesion, the interval is 1mm.
The width was cut into 100 goblets, and after extruding Erichsen 5 mm, a cellophane tape was crimped and peeled off, and the number of remaining goblets was measured on a 10-point scale for evaluation. In other words, 10 points indicates 100 remaining Goban eyes. In addition, in order to examine water resistance, the paint coated board was immersed in boiling water at 100°C for 3 hours, and then the occurrence of blisters on the coated board was observed. Note that ○ indicates no blister, △ indicates slight blister occurrence, and × indicates blister occurrence. The results are summarized in Table 1. For comparison, Comparative Example 1 uses only the alkyl silicate hydrolyzate obtained in Reference Example 3, Comparative Example 2 uses the cationic resin used in Reference Example 2 alone, Comparative Example 3
was treated at a pH of 2.8 containing 70 g of the anionic acrylic terpolymer used in Reference Example 5 and 30 g of the hydrolyzate of ethyl orthosilicate () obtained in Reference Example 3 as SiO ₂ . Comparative Example 4 used a commercially available electrogalvanized steel sheet treated with zinc phosphate, and Comparative Example 5 used a test plate without surface treatment. Tests were conducted and evaluated.

【table】

[Table] From the results shown in Table 1, it is clear that the metal surface treating agent composition of the present invention has excellent performance. It is also clear that the cationic resin and/or the zwitterionic resin have significantly superior effects compared to conventional anionic resins. Examples 12-13 Titanium dioxide and colloidal silica (trade name "Snowtex O" manufactured by Nissan Chemical Co., Ltd.) were added as inorganic substances to the composition G obtained in Reference Example 7, and the mixture was diluted with water. Each metal surface treating agent composition of the present invention shown in Table 2 was obtained. Using this, electrogalvanized steel sheets were treated in the same manner as in Examples 1 to 11, and the performance of each was evaluated in the same manner as in Examples 1 to 11. The results are shown in Table 2. For comparison, the same evaluation was also conducted using only titanium dioxide or colloidal silica.

[Table] From the results in Table 2, it can be seen that the performance is further improved by using an inorganic substance in combination with the metal surface treating agent composition of the present invention. Example 14 A hot-dip galvanized steel sheet was used instead of the electrogalvanized steel sheet used in Examples 1 to 11, and composition F of the present invention obtained in Reference Example 6 was used so that the film thickness was about 2.5μ. When treated, extremely excellent corrosion resistance and paint adhesion were obtained. Example 15 Using a cold-rolled steel plate (JIS G-3141, thickness 0.5 mm) that had been alkali degreased, washed and dried by a conventional method, the composition E obtained in Reference Example 5 was adjusted to pH 1.5 with phosphoric acid. After treating the metal surface treatment agent composition to a film thickness of 1.8μ, the alkyd melamine resin used in Examples 1 to 11 was applied and baked at 130°C for 20 minutes to form a coated plate with a film thickness of 20μ. Created. A salt spray test was conducted using this product, and no abnormality was observed even after 72 hours had passed. For comparison, a steel plate coated with an alkyd melamine resin without any treatment after degreasing produced many blisters within 18 hours.

Claims (1)

[Claims] 1. Per 1 metal surface treatment agent composition, the hydrolyzate of alkyl silicate () converted to SiO ₂
A metal surface treating agent composition, characterized in that it contains an amount ranging from 0.5 to 250 g and a cationic resin and/or a zwitterionic resin () in an amount ranging from 0.5 to 250 g. 2. The metal surface treating agent composition according to claim 1, wherein the alkyl silicate is one or more selected from the group consisting of methyl orthosilicate, ethyl orthosilicate, and partial condensates thereof.