JPH0670192B2 - Metal anticorrosion composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal rust preventive composition.

More specifically, it is stable at room temperature, forms an effective film by coating the metal surface with water present in the air or by slight heating, and shows good rust resistance, and the coating film has weather resistance. The present invention relates to a rust preventive composition which is excellent in properties, does not deteriorate such as discoloration even after long-term outdoor exposure, maintains good adhesion, and continues the rust preventive effect, and particularly copper, shinchiyuu, and silver. The present invention relates to a rust preventive composition suitable for copper or copper alloys, and zinc plated steels, steels and other metals coated with various chromate glossy coatings such as yellow, black and green.

Conventionally, as a rust preventive treatment for metals, various paints such as solvent-based, water-based or powder-like various forms of epoxy, alkyd, polyester, acrylic, urethane and other thermosetting paints are applied and baked. , A method of welding and coating thermoplastic resins such as polyamide and polyester, a method of applying various oils (mineral oil, animal oil, vegetable oil), electrolytic plating of zinc, nickel, chromium, cadmium, etc., melting of zinc, aluminum etc. Metuki,
A method of forming a coating film of a dissimilar metal such as a vapor-deposited metal such as aluminum on the surface, and a method of chemical conversion treatment such as a chromic acid-based aqueous solution or a phosphoric acid-based aqueous solution are used. Of these, coating with thermosetting or thermoplastic resin paints is possible even in systems containing anticorrosion pigments such as chromate and phosphate.
Unless a thick coating of 10 to 2,000 μm is applied, sufficient rust prevention cannot be exhibited, and high temperature heat is required for baking and welding the paint, which causes problems such as damage to the base material and loss of thermal energy. In addition, since harmful corrosive pigments are used, there are many restrictions on work hygiene and environmental hygiene.

Also, the method of applying oil to the metal base material is used only for the purpose of temporary rust prevention, and under the conditions where the base material is originally used, oil that is "dirt" is usually degreased. is there.

In addition, there are two methods of metal plating, for example, sacrificial rust prevention using zinc such as a zinc steel plate, and when plating chromium that is essentially excellent in corrosion resistance. However, even when chrome or the like is used, defects in the varnish coating often occur, and in many cases the original rust preventive property cannot be exhibited.

In addition, the method of chemical conversion treatment is much inferior in rust prevention compared to the case of coating with the above-mentioned paint, and it is usually used as a base of paint coating or as a surface treatment after metal plating. is there.

As a result of intensive studies to overcome the above problems, the inventors of the present invention previously disclosed in Japanese Patent Application No. 57-203758, an organosilicon compound containing an aminoalkyl group and an alkoxy group, and a compound having an oxirane ring. The present invention relates to a metal rust preventive composition comprising the following:
One or more resins selected from the group consisting of vinyl acetate copolymers, acrylic polymers and polyvinyl acetal resins (hereinafter referred to as component A), and an organosilicon compound having an aminoalkyl group and an alkoxy group (hereinafter referred to as component B) And a compound having an oxirane ring (hereinafter referred to as component C).

The base material to which the composition of the present invention can be applied is wide-ranging, but the effect is particularly remarkable for metals such as copper and copper alloys, iron with various chromate coatings, and zinc. The copper alloy mentioned here is, for example, Shinchu (alloy of copper 67, zinc 33), Western silver (alloy of copper 50, zinc 25, nickel 25), etc., and the chromate film is chromic acid or chromate salts. A surface coating formed by immersing a metal in a treatment liquid containing a mineral acid as a main component, such as XCr ₂ O ₃ · YCrO ₃ · ZH ₂
A film made of O.

The main advantages that occur when the composition of the present invention is applied to a metal substrate are as follows. (Hereinafter, the metal base material means the metal itself and a metal that has been subjected to surface treatment such as plating) 1) A metal base material is immersed in a composition, preferably a composition liquid diluted with a solvent, A coating film can be formed only by air-drying or by slightly heating, and excellent rust prevention can be imparted very easily.

2) Even if the coating film to be formed on the metal base material has an extremely thin thickness of 1 to 10 μm, it shows good rust-preventing properties, and the work is caused by the increase in the thickness of the base material due to the coating film. Various troubles in the process do not occur.

3) The coating film is transparent, does not hide or hide the base material, and retains the gloss and appearance peculiar to the metal base material.

4) It is advantageous in terms of environmental hygiene since it does not require the addition of a toxic anticorrosive pigment.

5) The coating film has excellent weather resistance, little deterioration such as discoloration even when used outdoors for a long period of time, maintains good adhesion, and continues the rust preventive effect.

A specific example of the ethylene-vinyl acetate copolymer in the component A used in the composition of the present invention is an ethylene vinyl acetate copolymer resin (EVA resin) obtained by radical copolymerizing ethylene and vinyl acetate. There are, those having various physical properties are obtained by the composition ratio and molecular weight of ethylene and vinyl acetate, in the present invention, these various ethylene-vinyl acetate copolymers can be used,
For example, those described in Encyclopedia of Polymer Science and Technology (published by Jyon Wheelie & Sons), Vol. 6, P409-416 can be used.

The acrylic polymer in the component A used in the composition of the present invention means an acrylic acid ester or a methacrylic acid ester (hereinafter collectively referred to as (meth) acrylic acid ester) as a polymerizable monomer component. A polymer obtained by using and polymerizing, for example, encyclopede of
Polymer Science and Technology (published by Jiwillie & Sons) Vol. 1.P246 The following can be used. Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl-hexyl (meth) acrylate, hexyl (meth). Examples thereof include acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate and dimethylmethylamino (meth) acrylate. The above-mentioned (meth) acrylate was used as a concept including both acrylate and methacrylate. As the polymerizable monomer used to obtain the acrylic polymer in the present invention, it is also possible to use a monomer component copolymerizable with these at the same time as the (meth) acrylic acid ester. As a typical example, styrene is mentioned, but in addition, ethylene, vinyl acetate, acrylonitrile, etc. are also mentioned.

In the present invention, a metal rust preventive composition comprising an organosilicon compound having an aminoalkyl group and an alkoxy group and a compound having an oxirane ring exhibits excellent rust preventive performance, and the above acrylic polymer is added to the composition. By further adding, it is possible to further improve the rust preventive performance and also improve the weather resistance. As this acrylic polymer, an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in its side chain is used. By using, the weather resistance can be further improved.

That is, conventionally, a metal color peculiar to metal, a metal material having a luster and a metal subjected to a surface treatment such as beetle are used in many fields such as automobiles, two-wheeled vehicles, industrial machines, electric devices, and building materials. In the outdoor environment, it is affected by various environmental factors such as sunlight, wind and rain, oxygen, ozone, oxygen disulfide, dust and salt damage. Therefore, such a metal surface treatment is required to have excellent weather resistance in addition to rust prevention. In this respect, by using an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in the side chain, the weather resistance of the obtained coating film is particularly excellent, and there is little deterioration such as discoloration even in a long-term outdoor environment. It was found that the good adhesion to the metal base material is maintained and the rust prevention effect is maintained.

The acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in its side chain is obtained by using a polymerizable (meth) acrylic acid ester represented by the following formula as a polymerizable monomer component. .

(In the formula, R ¹ and R ² are a hydrogen atom or a methyl group, R ³ is a methyl group, an ethyl group, a phenyl group, and R ⁴ is an alkyl group.
Further, l and m are integers satisfying l ≧ 0, m ≧ 3, l + m = 3 to 20. q is an integer of 1 to 3, p is 0 or 1, and n
Is an integer of 0 to 2 when p = 0 and 2 when p = 1. The compound (i) is a (meth) acrylic acid ester having a fluoroalkyl group in a side chain, and the (meth) acrylic acid ester having such a fluoroalkyl group (hereinafter referred to as fluoroalkyl (meth) acrylate) As an example of, the following is given.

However, R ¹ is the same as above.

Further, the compound (ii) is a (meth) acrylic acid ester having an alkoxysilyl group in its side chain, for example,
Examples thereof include acrylate-based silanes and / or methacrylate-based silanes (hereinafter collectively referred to as (meth) acrylate-based silanes).

Specific examples of the (meth) acrylate-based silane include γ-
(Meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyldimethoxysilane, 3- (2- (meth) acryloyloxyethoxy) propyltrimethoxysilane, 3- (2-
(Meth) acryloyloxyethoxy) propylmethyldimethoxysilane, 3- (2- (meth) acryloyloxyethoxy) propyldimethylmethoxysilane, 5-((meth) acryloyloxy) pentyltrimethoxysilane, 5-((meth) acryloyl (Oxy) pentylmethyldimethoxysilane, 5-((meth) acryloyloxy)
Examples include pentyldimethylmethoxysilane.

As a method of polymerizing (meth) acrylic acid esters,
It is the simplest to carry out by ordinary solution polymerization, and it is preferable to use a solvent free from the inclusion of water. The polymer concentration in the solution is preferably about 20 to 70%, 30 to 60%.
% Is more preferable.

The substitution ratio of these groups when using an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in the side chain varies depending on the type of the polymerizable monomer used in combination,
From the viewpoint of compatibility with other composition components, crosslinkability, and effective addition of a trace amount to improve rust-prevention property, 0.1 to 0.6 mol and 0.1 to 0.7 mol, respectively, relative to 1 mol of the main chain monomer Is preferred, and 0.2 to 0.5 mol and 0.4 to 0.7 mol are more preferred.

In the solution polymerization, the usable organic solvent varies depending on the polymer composition, but as an example, toluene, xylene, benzene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, diester. Acetone alcohol,
Cellosolve acetate, carbon tetrachloride, trichloroethylene, perchlorethylene, chloroform, tetrahydrofuran, ethyl ether, dimethylformamide, mineral spirits, solvent naphtha, hexane and the like, alone or as a mixed solvent thereof.

Next, the polyvinyl acetal resin in the component A used in the composition of the present invention is a general term for polyvinyl alcohol acetalized with an aldehyde, for example, polyvinyl alcohol obtained by saponifying polyvinyl acetate with formaldehyde. Examples of the polyvinyl acetal include an acetalized (formalized) polyvinyl formal and a polyvinyl alcohol obtained by acetalizing (butyralized) polyvinyl alcohol with butyraldehyde. Although various kinds of vinyl acetals having various physical properties can be obtained depending on the kind of vinyl acetal, its composition, the degree of polymerization, etc., these various polyvinyl acetals can be used in the present invention.

In addition, as the polyvinyl acetal resin used in the present invention, those described in Encyclopedia of Polymer Science and Technology (published by Jiyon Wheelie & Sons), Vol. 14, P208-239 are also available. It can be illustrated.

Specific examples of the organosilicon compound which is the component B of the composition of the present invention include, for example, aminomethyltriethoxysilane,
Aminoalkyltrialkoxysilanes having one aminoalkyl group and three alkoxy groups such as γ-aminopropyltriethoxysilane and γ-aminoisobutyltrimethoxysilane; N- (β-aminoethyl) aminomethyltrimethoxysilane , N- (β-aminoethyl) aminomethyltriethoxysilane, N- (β-aminoethyl)-
N- (aminoalkyl) aminoalkyltrialkoxysilanes having N- (aminoalkyl) aminoalkyl groups such as γ-aminopropyltrimethoxysilane and three alkoxy groups; aminomethylmethyldiethoxysilane, γ
-Aminoalkyldialkoxysilanes having aminoalkyl groups such as aminopropylmethyldiethoxysilane and two alkoxy groups; N- (β-aminoethyl) having N- (aminoalkyl) aminoalkyl groups and two alkoxy groups ) -Γ-Aminopropylmethyldimethoxysilane and the like, and those having two or more alkoxy groups are preferred for the present invention because they have improved rust prevention.

Specific examples of the compound having an oxirane ring, which is the C component of the composition of the present invention, include generally known epoxy resins,
That is, bisphenol A and F type epoxy resin X: Or Or H Y: alkyl group or H 2 glycidylamine type epoxy resin, for example X: R ¹ , R ² : alkylene group, araalkylene group, cycloalkylene group, etc. Novolac type epoxy resin, for example X: R: alkyl group, araalkyl group, etc. can be applied. Further, compounds having an oxirane ring other than the above epoxy resins can also be used.

As the compound having an oxirane ring other than the epoxy resin, there is an organosilicon compound having an oxirane ring and an alkoxy group. Examples of such a compound include glycidoxyalkyltrialkoxysilane such as γ-glycidoxypropyltrimethoxysilane and glycidoxyalkylalkyldialkoxysilane such as γ-glycidoxypropylmethyldimethoxysilane. Preferred for use in the present invention is an organosilicon compound having an oxirane ring and an alkoxy group, and especially an alkoxy group having an alkoxy group of 2
Those having one or more are preferable.

The mixing ratio of each component in the present invention is preferably 90/10 to 30/70 by weight ratio of A component / C component, and more preferably 85/1.
It is 5 to 50/50. When the amount of A component / C component is more than 90/10, the adhesion of the resin to the base material becomes poor, and when it is less than 30/70, the weather resistance, which is the object of the present invention, becomes poor. .

The blending ratio B / (A + C) of the B component is 5/95 to 70 by weight.
/ 30 is preferable, and more preferably 10/90 to 60/40. If the ratio is less than 5/95, the resulting coating may be insufficiently cured and may become brittle and weaken the coating strength.

However, when an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in the side chain is used as the acrylic polymer in the component A, the weight ratio of component B / component C is 5/95 to 70/30. It is preferably in the range, more preferably 20/80 to 60/40. When B / C is less than 5/95,
Although it is stable as a composition, effective coupling of the oxirane ring and the amino ring is not substantially performed, and the film forming ability is low, and when it exceeds 70/30, the composition is not stable and the viscosity increases. A tendency of gelation / precipitation is formed, and the obtained coating is inferior in rust preventive property due to lack of toughness.

The weight ratio of A component / (B component + C component) is 0.01 to 100.
〜20 / 100 is preferable and more preferably 0.05 / 10-10 / 100
Is.

If this weight ratio is less than 0.01 / 100, almost no improvement in rust prevention is seen, and if it exceeds 20/100, the adhesion of the coating is significantly reduced, floating, peeling, etc. occur, This causes a significant decrease in rust resistance.

It is not clear why the composition of the present invention exerts anticorrosion property against metal very effectively, but it not only prevents the infiltration of corrosive substances such as oxygen and water as a coating film, but also chemically reacts with the metal on the metal surface. It is considered that the binding to chromium prevents the elution of chromium ions and zinc and also prevents the corrosion due to the ionization of the metal.

Furthermore, in the present invention, when a composition prepared by blending an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in a side chain is applied onto a metal base material, a film is formed by binding the alkoxy group by dealcoholization reaction. , And an amino group and a glycidyl group are bonded to each other, but the acrylic polymer having a bondable alkoxysilyl group is strongly bonded to the film-forming component by moisture absorption at room temperature or slight heating, and has a side chain. It is considered that the fluoroalkyl group of 1 has a permanent water-repellent action, and the water resistance and moisture permeability of the coating are remarkably enhanced, whereby the rust preventive property is more effectively exhibited.

Although a method of imparting water repellency and exhibiting anticorrosive properties by blending a fluorine-based compound has been conventionally performed, the effect is not maintained due to lack of the fluorine-based compound when used outdoors for a long time.

In addition, the crosslinkable fluorine-based coating material did not exhibit any effect, according to the studies made by the present inventors.

For practical use, the composition of the present invention is preferably a composition dissolved in a solvent. As the solvent to be used, it is possible to use a single solvent or a mixed solvent of two or more kinds as long as each component of the composition of the present invention is uniformly dissolved and mixed. The solvent used can be a wide range of non-polar solvents and polar solvents, such as benzene, toluene, xylene, cyclohexane, acetone, methyl ethyl ketone, methanol, ethanol, isopropanol, ethyl ether, cellosolve, and methyl cellosolve. . When a solvent is used, the total concentration of the components A, B and C in the composition is preferably 40% by weight or less, more preferably 30% by weight or less. The dissolving operation can be easily carried out by stirring at room temperature or with slight heating.

Further, it is also possible to add other components to the composition of the present invention, for example, in combination with a rust preventive agent such as amine-based, phosphate-based, etc. within a range that does not cause gelation-thickening phenomenon, It is possible to appropriately add a known condensation catalyst for the purpose of promoting the formation of siloxane bond. Examples of such condensation catalysts include organic metal compounds such as dibutyltin dimaleate, titanic acid esters such as tetrabutyl titanate, organic acids such as paratoluene sulfonic acid, amine compounds such as triethylamine.

When the composition of the present invention is applied on a metal substrate, it is considered that the film formation is carried out by a bond by an oxirane ring and an amino group, a siloxane bond by dealcoholization of an alkoxy group-containing organosilicon compound, etc. Since a good coating film is formed by heating or the moisture absorption of the coating film, the step of heating the metal substrate to a particularly high temperature is unnecessary.

The method of applying the composition of the present invention to a metal substrate may be a method of liquefying by heating and then dipping, or a method of powdering the composition by a known powder coating method, etc., but as described above. Particularly, a known method such as spray coating, dip coating, brush coating, or roll coating method can be adopted after the composition is dissolved in a solvent. After coating, the solvent is removed at room temperature or under heating conditions to form a uniform coating film. The film thickness is 1 to 300 μ, preferably 1 to 200 μ.

As described above, the composition of the present invention can improve the drawbacks of the chromate film and exhibit excellent rust prevention performance. That is, the chromate film is usually widely used as a protective plating for metals such as zinc, cadmium, aluminum, and copper, and it shows effective corrosion resistance along with its aesthetic appearance. It is possible to confirm from many experiments that the corrosion resistance according to the salt spray test (JIS-Z-2371) is virtually the same as that without the chromate coating when heated at a temperature of 80 ° C or higher. . The cause of this is that cracking occurs due to dehydration of the chromate film due to heating, the soluble chromium content changes to insoluble, etc., and in the past, effective rust prevention treatment in such cases has not been developed. It was There are many demands for applying a chromated metal to a heated portion or for heat processing to obtain a new product, and many efforts have been made to overcome the above problems in such a case. When the composition of the present invention is applied, it is applied on a chromate film having no heat history, and even when it is heated, even when it is applied on a heated and destroyed chromate film, it is equivalent or more than before heating. It is surprising that the anti-corrosion property can be exhibited, which is a great feature of the present invention.
According to the present invention, copper and copper alloys, it is possible to easily perform anticorrosion treatment of various chromate metal substrates and the like,
The rust preventive property is greatly improved, and the metal substrate treated with the composition of the present invention can be applied to various parts without considering heat deterioration of corrosion resistance. Contributes greatly to the industrial world.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. The test method was as follows.

1) Film thickness of the film ... Calculated by a weight method for the film after drying.

2) Appearance of coating ... Observing coloring and transparency of coating.

3) Salt spray test: Carried out according to JIS-Z-2371.

The rusting state at a certain time is represented by the following symbols.

◎ No rusting ○ Slightly white rust or black corrosive substance was generated.

△ White rust was generated on about half of the test piece surface. × White rust was generated on the entire surface of the test piece. 4) Adhesiveness ...
00 pieces were made and the cellophane tape was completely adhered, and the tape was immediately peeled off in the direction perpendicular to the coated surface, and the number of left eyes was checked. For example, 100/100 means that all of them remain, and 50/100 means that 50 out of 100 rice balls have peeled off.

5) Accelerated weather resistance test: A Sunshine weatherometer was used in accordance with JIS-Z2371. After exposure for a certain period of time, changes in appearance such as yellowing and stall and damage such as blistering and peeling of the film were observed.

In addition, a synthesis example of an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in a side chain used in the following Examples and Comparative Examples will be shown.

Synthesis Example 1 Fluoroalkyl acrylate below (N = 8, 10, 12, 14) 50 parts, γ-methacryloxypropyltrimethoxysilane 50 parts, methyl ethyl ketone (MEK) 200 parts as a solvent, azobisisobutyronitrile as a polymerization initiator (hereinafter referred to as AIBN 2 parts (abbreviated) were placed in a flask equipped with a condenser, a stirrer, and a thermometer, and reacted in a nitrogen atmosphere at a temperature of 90 ° C. for 4 hours.

To this, 700 parts of toluene was added to obtain an acrylic polymer having a solid content of 10%.

Synthesis Example 2 Fluoroalkyl acrylate below (N = 8,10,12,14 mixture) 50 parts, γ-methacryloxypropyltrimethoxysilane 25 parts, stearyl methacrylate (hereinafter abbreviated as SMA) 25 parts, MEK20 as solvent
Using 0 part and 2 parts of AIBN as a polymerization initiator, the same operation as in Synthesis Example 1 was carried out to react.

To this, 700 parts of toluene was added to obtain an acrylic polymer having a solid content of 10%.

Synthesis Example 3 Fluoroalkyl acrylate below Using 40 parts, γ-acryloyloxypropylmethyldimethoxysilane 30 parts, styrene 30 parts, MEK 200 parts as a solvent, and AIBN 2 parts as a radical polymerization initiator, the same operation as in Synthesis Example 1 was carried out to react.

To this, 300 parts of toluene was added to obtain an acrylic polymer having a solid content of 20%.

Example 1 and Comparative Example 1 Ethylene vinyl acetate copolymer "Epaflex 40" (manufactured by Mitsui Polychemical Co., Ltd.) 30 g, γ-aminopropyltriethoxysilane 35 g, and γ-glycidoxypropyltrimethoxysilane 35 g were added to methyl ethyl ketone. : Toluene was mixed and dissolved in a 2: 8 (weight ratio) mixed solvent to obtain a colorless transparent solution having a component concentration of 10% by weight.

Using a steel plate (made by Nippon Test Panel Industry Co., Ltd.) treated with zinc plated colored chromate as a test piece, it was immersed in the above composition solution, taken out, and dried at room temperature. A transparent and glossy film was obtained, except that the iridescent color of the original colored chromate disappeared and became uniform yellow after drying. The coated plate and the uncoated plate (Comparative Example 1) were put into a salt spray tester. After the addition, white rust occurred on the unpainted board after 200 hours, but no rust was seen on the painted board even after 300 hours, and the rust resistance was remarkably improved.

Examples 2 to 5 and Comparative Examples 2 to 4 According to the same method as in Example 1, 25 m / m × 100 with a thickness of 3 m / m.
A zinc / chrome plated chromate steel sheet (manufactured by Japan Test Panel Industry Co., Ltd.) with a size of m / m is applied by dip coating to a composition solution having the composition shown in Table 1 to form a film, and then a salt spray test is conducted. Done. The results are shown in Table 1, and all the compositions of the present invention showed good rust preventive properties.

Example 6, Comparative Example 5 γ-aminopropyltriethoxysilane (molecular weight 221) 7
0 parts, Bisphenol A type epoxy resin Epicoat 828
30 parts (average molecular weight 335 manufactured by Yuka Shell Epoxy Co., Ltd.) was diluted with 900 parts of a 1: 1 (weight ratio) mixed solvent of toluene and MEK to obtain a composition having a component concentration of 10% by weight.

To this, 50 parts of the solution composition of the acrylic polymer having the fluoroalkyl group and the alkoxysilyl group synthesized in Synthesis Example 1 was added and stirred to obtain a uniform transparent solution composition. After dipping a zinc plated chromate treated steel plate prepared as follows as a test plate in this solution,
Air dried. Further, as Comparative Example 5, a solution composition prepared by dipping and coating a solution composition containing no acrylic polymer having a fluoroalkyl group and an alkoxysilyl group was prepared.

Preparation of zinc plated chromate-treated test piece As a test piece, an iron plate with a size of 70 x 150 m / m and a thickness of 0.5 m / m (SP
CC-SD) is coated with alkaline zinc plating (thickness 5 μm), washed with water, immersed in a 3% (vol) nitric acid aqueous solution for 15 seconds, washed again with water, and then chromic anhydride, sulfuric acid, sodium sulfate, nitric acid, and acetic acid, respectively. 150g, 2m in 1 aqueous solution
The zinc plated steel sheet was immersed in a chromate solution containing 1, 20 g, 20 g, and 10 ml at room temperature for 10 seconds, left in the air for 15 seconds, washed with water, and air-dried to prepare a chromate-treated zinc plated steel sheet.

These test pieces were subjected to accelerated weathering test and salt spray test (JI
SZ-2371). The results are shown in Table 2.

Examples 7 to 10 Solutions having the compositions shown in Table 2 were prepared in the same manner as in Example 6, and the same zinc plated chromate-treated steel sheet as that used in Example 6 was immersed and air-dried. After exposing this to a Sunshine Inn Weather Ometer for 500 hours, a salt spray test was conducted. The results are shown in Table 2.

As shown in Table 2, by using an acrylic polymer having an alkoxysilyl group and a fluoroalkyl group in the side chain, deterioration due to discoloration of the coating film is small even after outdoor exposure for 500 hours, and the coating film has weather resistance. It can be seen that it is excellent in properties, does not show rusting, maintains adhesion, and continues to have a rust preventive effect over a long period of time.

Examples 11 and 12 and Comparative Examples 6 to 10 Treated plates were prepared in the same manner as in Example 6 except that the solutions having the compositions shown in Table 3 were prepared, and a salt spray test was conducted. The results are shown in Table 3.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyoshi Hirose 1-1 Funami-cho, Minato-ku, Nagoya, Aichi Prefecture, Toagoai Chemical Industry Co., Ltd. (72) Inventor Kaneko St. Funami-cho, Minato-ku, Nagoya, Aichi Prefecture 1-1 Inside Toagosei Chemical Industry Co., Ltd. (72) Inventor, Hotaro Yasuda 1-1 Funamachi, Minato-ku, Nagoya, Aichi Prefecture Inside Toagosei Chemical Industry Co., Ltd. (56) Reference JP-A-53-37746 (JP, A) JP-A-54-43940 (JP, A) JP-B-35-16031 (JP, B1) Masao Kodama, "Paints and Coatings" Showa 48.30, issued by Power Co., Ltd. 95

Claims (1)

[Claims] 1. One or more resins selected from the group consisting of ethylene-vinyl acetate copolymers, acrylic polymers and polyvinyl acetal resins, an organosilicon compound having an aminoalkyl group and an alkoxy group, and an oxirane ring. A metal rust preventive composition comprising a compound having: