JP4389066B2 - Water-dispersed rust-proof coating composition - Google Patents

Description

  The present invention relates to a water-dispersed rust preventive coating composition that is excellent in rust prevention and tape peel resistance after alkali treatment.

  The ionomer resin, which is a partially neutralized product consisting of a polymer chain mainly composed of hydrocarbons and in which part of the carboxyl groups in the side chain is neutralized with a metal cation, It is well known that it has good adhesion. For example, Journal of the Adhesion Society of Japan, Vol. 19, no. 3, p95-101 (1983), it has been reported that the coating properties and the degree of adhesion of ionomer resins differ depending on the type of cross-linking ions such as alkali metals and divalent metals.

  It is also known that an ionomer resin can be used as a rust preventive material for a metal substrate because the rust preventive layer made of this ionomer resin has excellent water resistance. Moreover, since ionomer resins neutralized with monovalent metal ions such as Na and K and amines can be dispersed in water, various rust preventive treatment materials using aqueous dispersions of ionomer resins have been developed. Currently, it is widely used in various industrial fields.

  However, this single ionomer resin treatment does not meet the performance required by customers, such as rust resistance and adhesion, and is mainly used for the production of organic coated composite steel sheets with chromate treatment on the base. It has been. However, in recent years, there has been an interest in environmental issues on a global scale, and there is an increasing demand for surface-treated metal products that do not use hexavalent chromium. For this reason, there has been a demand for a rust-preventing paint having the same rust-proofness and adhesion as in the prior art by only one-step treatment with an organic resin without performing chromate ground treatment.

Various studies have already been made to meet these requirements. For example, JP-A-11-012411 discloses an aqueous solution comprising an ionomer resin neutralized with a divalent metal to improve rust prevention performance, an epoxy group-containing compound, and a reaction product of an ionomer resin and an epoxy group-containing compound. Dispersion compositions are disclosed. However, as evaluated by the present inventors, in the above disclosed technique, the antirust property after alkali resistance treatment (hereinafter abbreviated as alkali resistance) and durability against adhesive tape peeling (hereinafter referred to as adhesive tape peeling). (Abbreviated to sex) could not be satisfied at the same time.
Japanese Patent Laid-Open No. 11-012411 Journal of the Adhesion Society of Japan, Vol. 19, no. 3, p95-101 (1983)

  An object of the present invention is to provide a conventional rust preventive coating composition having excellent alkali resistance and adhesive tape peelability.

  As a result of intensive studies, the present inventors have conducted a water-soluble zirconium compound and / or a water-soluble titanium compound having reactivity with a carboxyl group and an ionomer resin (A) neutralized with a monovalent metal ion and / or amine ( B) and a composition containing a water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) and a silane coupling agent (D) having two or more carbodiimide groups in one molecule are alkali resistant and pressure resistant tapes. The inventors have found that the releasability is improved and completed the present invention.

That is, the present invention is specified by the following [1] to [10].
[1] An ionomer resin (A) neutralized with a monovalent metal ion and / or an amine, a water-soluble zirconium compound having reactivity with a carboxyl group and / or a water-soluble titanium compound (B), in one molecule It is a composition containing two or more carbodiimide groups, water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) and silane coupling agent (D) as essential components, and the average particle size of the composition is 0.01 to 5 μm, and the composition is dispersed in water, and the water-soluble zirconium compound contains zirconium carbonate ammonium, zirconium carbonate potassium, zirconium nitrate, zirconium acetate, basic zirconium carbonate, zirconium tetraacetylacetate. , Zirconium monoacetylacetonate, zirconium bisacetylacetonate Is at least one selected from the bets, the water-soluble titanium compound, dihydroxy titanium lactate, diisopropoxy titanium bis aqueous dispersion-type rust, characterized in that at least one is selected from (triethanolaminate) Composition for paint.
[2] The water-dispersed rustproof paint composition according to [1], wherein the water-dispersed rustproof paint composition is for a non-chromate steel sheet .
[3] 0.5 to 20 parts by weight of water-soluble zirconium compound and / or water-soluble titanium compound (B) with respect to 100 parts by weight of ionomer resin (A), water-soluble having two or more carbodiimide groups in one molecule And / or water-dispersible polyfunctional carbodiimide resin (C) in an amount of 5 to 40 parts by weight and silane coupling agent (D) in a proportion of 0.1 to 5 parts by weight. Composition for rust paint.
[4] The ionomer resin (A) is a copolymer of ethylene and acrylic acid and / or methacrylic acid, containing 5 to 40% by weight of acrylic acid and / or methacrylic acid, and acrylic acid and / or methacrylic acid. The water-dispersed antirust paint composition according to [1], wherein the acid is neutralized with a monovalent metal ion by 20 to 90%.
[5] The ionomer resin (A) is a copolymer of ethylene and acrylic acid and / or methacrylic acid, containing 5 to 40 parts by weight of acrylic acid and / or methacrylic acid, and the ionomer resin (A). The water-dispersed rust preventive coating composition according to [1], wherein acrylic acid and / or methacrylic acid is neutralized with an amine at least 50%.
[6] The water-dispersed antirust paint composition according to [1], wherein the amine used for neutralization of acrylic acid and / or methacrylic acid is ammonia, trimethylamine, or monoethanolamine. [7] The composition for water-dispersed rust preventive paint according to [1], wherein the water-soluble zirconium compound and / or the water-soluble titanium compound (B) is ammonium zirconium carbonate and / or diisopropoxy titanium bis (triethanolaminate). object.
[8] The composition for water-dispersed rust preventive paint according to [1], wherein the polyfunctional carbodiimide resin (C) is water-dispersible and the carbodiimide group equivalent is 250 to 800 g / equivalent.
[9] The water-dispersed antirust paint composition according to [1], wherein the silane coupling agent (D) is a compound having a glycidyl group, an amino group or an amide group.
[10] A water-dispersed antirust paint composition obtained by prereacting the composition according to [1] at 40 to 120 ° C. for 5 to 100 minutes.

  According to the composition for rust preventive paints of the present invention, alkali resistance and adhesive tape peelability can be improved, and in particular, it can be suitably used as a rust preventive paint for non-chromate steel sheets.

  Hereinafter, the present invention will be described in detail.

  The ionomer resin (A), which is the main component of the composition for water-dispersible anticorrosive coating of the present invention (hereinafter abbreviated as “composition”), is composed of a polymer main chain mainly composed of hydrocarbons, and has a carboxyl group in the side chain. And at least one part of the carboxyl group is a polymer neutralized with a monovalent metal ion and / or amine. As a specific example of this ionomer resin, it is an ethylene-unsaturated carboxylic acid copolymer comprising a partially neutralized product in which at least one part of the carboxyl group contained is neutralized with a monovalent metal ion and / or amine. An ionomer resin (A-1) can be mentioned.

  The ethylene-unsaturated carboxylic acid copolymer constituting the main chain of the ionomer resin (A-1) may be a random copolymer or a graft copolymer of unsaturated carboxylic acid to polyethylene. In particular, an ethylene-unsaturated carboxylic acid random copolymer is preferable in terms of transparency. Further, the ethylene-unsaturated carboxylic acid copolymer may be only one type of unsaturated carboxylic acid, or may contain two or more types of unsaturated carboxylic acid.

  Examples of the unsaturated carboxylic acid that is a component of the ethylene-unsaturated carboxylic acid copolymer include unsaturated carboxylic acids having 3 to 8 carbon atoms. Specific examples of the unsaturated carboxylic acid having 3 to 8 carbon atoms include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, isocrotonic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, Examples thereof include nadic acid, methyl nadic acid, tetrahydrophthalic acid, and hexahydrophthalic acid. Among these, acrylic acid and methacrylic acid are particularly preferable.

  The ethylene-unsaturated carboxylic acid copolymer constituting the main chain of the ionomer resin (A-1) may contain a third component in addition to ethylene and the unsaturated carboxylic acid. Examples of the third component include unsaturated carboxylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and isobutyl (meth) acrylate, and vinyl acetate.

  The content ratio of ethylene and unsaturated carboxylic acid in this ethylene-unsaturated carboxylic acid copolymer is usually a ratio of 5 to 40 parts by weight of unsaturated carboxylic acid with respect to 95 to 60 parts by weight of ethylene, preferably The ratio of unsaturated carboxylic acid is 10 to 25 parts by weight with respect to 90 to 75 parts by weight of ethylene, and particularly the ratio of 15 to 22 parts by weight of unsaturated carboxylic acid with respect to 85 to 78 parts by weight of ethylene. It is preferable. When the ethylene-unsaturated carboxylic acid copolymer contains a third component, the third component is preferably present in an amount of 40% by weight or less.

  When the ethylene content is outside the above range and is too high, the particle size of the dispersion becomes large and it is difficult to obtain a stable dispersion, and the tape peel resistance deteriorates due to low adhesion to the steel sheet. It is difficult to achieve the original purpose. On the other hand, if it is too low, the alkali resistance deteriorates and it is difficult to achieve the original purpose.

  In this ionomer resin (A-1), the carboxyl group which is the side chain of the ethylene-unsaturated carboxylic acid copolymer is partially neutralized with a monovalent metal ion and / or amine. An ionomer resin neutralized with a divalent or trivalent metal ion has a large average particle size, so that a stable aqueous dispersion cannot be obtained, and the adhesive tape peelability is low and the object of the present invention cannot be achieved. .

In the present invention, as the monovalent metal ion for neutralizing the ionomer resin,
Li ⁺ , Na ⁺ , K ⁺ , Rb ^{+ and the} like can be mentioned. Examples of amines that neutralize ionomer resins include ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, trimethylamine, monopropylamine, dipropylamine, monobutylamine, dibutylamine, morpholine, piperidine, and monoethanol. , Diethanolamine, triethanolamine and the like. Among these, Na, K, ammonia, trimethylamine, and monoethanolamine are preferable. A monovalent metal ion and an amine can also be used in combination.

  In the ionomer resin (A-1), the proportion of carboxyl groups neutralized with monovalent metal ions with respect to the total amount of carboxyl groups that are side chains of the ethylene-unsaturated carboxylic acid copolymer, that is, neutralization The degree is preferably 20 to 90%, particularly preferably 30 to 80%, in order to impart alkali resistance and adhesive tape peelability. On the other hand, when neutralizing with an amine, the degree of neutralization is preferably 50% or more, particularly preferably 60% or more.

  If the ratio of the carboxyl group neutralized with a monovalent metal exceeds 90%, the adhesiveness is lowered, so that the alkali resistance and the adhesive tape resistance are lowered, and it is difficult to achieve the object. On the other hand, when the proportion of carboxyl groups neutralized with a monovalent metal is less than 20%, the particle size of the aqueous dispersion becomes large, and it is difficult to obtain a stable aqueous dispersion.

  Further, when neutralizing with an amine alone, when the degree of neutralization is less than 50%, the particle size of the aqueous dispersion becomes large, and it is difficult to obtain a stable aqueous dispersion.

  Further, the MFR of the ionomer resin (A-1) is preferably 0.05 to 500 g / 10 minutes, and particularly preferably 0.1 to 400 g / 10 minutes. The MFR is measured according to ASTM D 1238.

  If the MFR is 0.05 or more, the particle size of the aqueous dispersion can be reduced, and a stable aqueous dispersion can be obtained. Moreover, if MFR is 500 or less, the coating-film intensity | strength will improve and an adhesive tape peelability will also be favorable.

  This ionomer resin (A-1) can be produced, for example, by copolymerizing ethylene, an unsaturated carboxylic acid, and, if necessary, a third component by a high-pressure radical polymerization method, and obtaining an ethylene-unsaturated carboxylic acid copolymer. It can carry out according to methods, such as the method of neutralizing the carboxyl group of coalescence with the compound or amine which has the said monovalent metal ion. In addition, this production may be carried out by supplying predetermined components to the extruder and melt-kneading to react, or may be carried out in water or a suitable organic solvent.

  Examples of the compound having a monovalent metal ion include LiOH, NaOH, KOH, RbOH and the like. Of these, NaOH and KOH are preferred.

  Of the water-soluble zirconium compound and / or water-soluble titanium compound (B) used in the present invention, examples of the water-soluble zirconium compound that can react with a carboxyl group include ammonium zirconium carbonate, potassium zirconium carbonate, zirconium nitrate, zirconium acetate, Examples include basic zirconium carbonate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium bisacetylacetonate. Of these, ammonium zirconium carbonate and potassium zirconium carbonate are preferred, and ammonium zirconium carbonate is particularly preferred.

Further, the water-soluble zirconium compound and / or water-soluble titanium compound used in the present invention (
Among B), water-soluble titanium compounds that can react with a carboxyl group include dihydroxy titanium lactate and diisopropoxy titanium bis (triethanolaminate) [(C ₆ H ₁₄ O ₃ N) ₂ Ti (C ₃ H ₇ And titanate amine adducts such as O) ₂ ] . Of these, dihydroxytitanium lactate and diisopropoxytitanium bis (triethanolaminate) are preferable, and diisopropoxytitanium bis (triethanolaminate) is particularly preferable.

  In the composition of the present invention, the ratio of the water-soluble zirconium compound and / or water-soluble titanium compound (B) that can react with the carboxyl group is usually 0.5 to 100 parts by weight of the ionomer resin (A). 20 parts by weight. More preferably, 1 to 17 parts by weight, particularly 1 to 15 parts by weight is preferable.

  The water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) having two or more carbodiimide groups in one molecule used in the present invention usually has a carbodiimide group equivalent of 250 to 800 g / equivalent. More preferably, it is 300 to 750 g / equivalent, particularly 350 to 700 g / equivalent. Examples of such carbodiimide resins include Carbodilite V-02 (carbodiimide equivalent = 590 g / equivalent), Carbodilite V-02-L2 (carbodiimide equivalent = 385 g / equivalent), Carbodilite V-04 (carbodiimide), which are products manufactured by Nisshinbo Co., Ltd. Equivalent = 334 g / equivalent), carbodilite V-06 (carbodiimide equivalent = 269 g / equivalent), carbodilite E-01 (carbodiimide equivalent = 425 g / equivalent), carbodilite E-02 (carbodiimide equivalent = 445 g / equivalent), and the like. However, it is not limited to these.

  When the carbodiimide resin has a carbodiimide group equivalent of less than 250 g / equivalent, the coating film becomes hard and the adhesive tape peel resistance is lowered. On the other hand, if it exceeds 800 g / equivalent, the alkali resistance decreases.

  In the composition of the present invention, the water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) having two or more carbodiimide groups in one molecule is usually used with respect to 100 parts by weight of the ionomer resin (A). 5 to 40 parts by weight. More preferably, 10 to 35 parts by weight, particularly 10 to 30 parts by weight is preferable.

  When the water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) having two or more carbodiimide groups in one molecule is less than 5 parts by weight with respect to 100 parts by weight of the ionomer resin (A), alkali resistance is obtained. When the content is reduced and exceeds 40 parts by weight, the peel resistance of the adhesive tape is deteriorated.

  Examples of the silane coupling agent (D) that is an essential component of the present invention include ordinary silane coupling agents. More preferably, a silane coupling agent having a glycidyl group, amino group or amide group, particularly a silane coupling agent having a glycidyl group is preferred.

  In the composition of the present invention, the ratio of the silane coupling agent (D) is usually 0.1 to 5 parts by weight with respect to 100 parts by weight of the ionomer resin (A). More preferably, 0.2 to 4 parts by weight, particularly 0.3 to 3 parts by weight is preferable.

  When the proportion of the silane coupling agent (D) is less than 0.1 parts by weight, the alkali resistance is lowered, and when it exceeds 5 parts by weight, the tape peel resistance is deteriorated.

  In the composition of the present invention, the concentrations of ionomer resin (A), zirconium compound and / or titanium compound (B), polyfunctional carbodiimide resin (C) and silane coupling agent (D) are not particularly limited. It is adjusted as appropriate according to the coating method and the apparatus used for coating. Usually, it is used at a ratio of 100 to 2000 parts by weight of water with respect to 100 parts by weight of the total amount of (A), (B), (C) and (D).

  In addition, the composition of the present invention can be applied to a steel sheet by blending each component at room temperature, but can also be applied after pre-reacting the composition of the present invention. Pre-reaction conditions are 40 to 120 ° C. for 5 to 100 minutes, preferably 50 to 100 ° C. for 10 to 60 minutes, and particularly preferably 50 to 80 ° C. for 10 to 60 minutes.

  In addition to the water-soluble zirconium compound and / or water-soluble titanium compound (B) having the reactivity between the ionomer resin (A) and the carboxyl group, the composition of the present invention may contain various resins and compounding agents as necessary. You may contain other components, etc. in the range which does not impair the objective of this invention.

  Examples of other components include water-soluble or water-dispersed resins such as water-soluble amino resins and water-dispersed epoxy resins, organic thickeners, inorganic thickeners, rust inhibitors, and fillers such as silica.

  The water-soluble amino resin is used to improve the coating film strength, and examples thereof include water-soluble melamine resin, hexamethoxymelamine, methylolated benzoguanamine resin, methylol urea resin, and the like, and the addition amount thereof is an ionomer resin (A Water-soluble and / or water-dispersible polyfunctional carbodiimide resins having a water-soluble zirconium compound and / or water-soluble titanium compound (B) having reactivity with a carboxyl group and two or more carbodiimide groups in one molecule. 1 to 20 parts by weight is preferable with respect to a total of 100 parts by weight of (C) and the silane coupling agent (D), and 2 to 15 parts by weight is particularly preferable.

  As the water-dispersed epoxy resin, bisphenol B type epoxy resin produced using bisphenol A and epichlorohydrin as raw materials, or other epoxy resin dispersed in water using a surfactant, or one terminal group is a primary amine Examples include aqueous dispersions such as self-emulsifying epoxy resins synthesized by reacting a certain polyalkylene glycol with an epoxy resin, and the blending amount thereof is a water-soluble zirconium having reactivity between an ionomer resin (A) and a carboxyl group. Sum of water-soluble and / or water-dispersible polyfunctional carbodiimide resin (C) and silane coupling agent (D) having a compound and / or water-soluble titanium compound (B) and two or more carbodiimide groups in one molecule 1 to 50 parts by weight is preferable with respect to 100 parts by weight, and 5 to 35 parts by weight is particularly preferable.

  In the present invention, the composition is applied onto a steel plate, dried and cured to form a coating film. The composition can be applied by any of spraying, curtaining, flow coating, roll coating, brushing, and dipping methods. After applying the composition, it may be naturally dried, but is preferably baked. Usually, the baking temperature is 60 ° C. to 500 ° C., and by heating for 1 to 120 seconds, a coating film having good alkali resistance, tape peeling resistance and corrosion resistance can be formed.

[Example]
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention more concretely, this invention is not limited to these Examples.
[Evaluation methods]
An electrogalvanized steel sheet (plating adhesion amount: 20 g / m ² ) was used as the steel sheet, and the alkali resistance and adhesive tape peel resistance of the coating film baked on this steel sheet were evaluated by the methods described below.
Alkali resistance:
A treatment liquid (pH: about 13) is prepared by diluting 32 g of a degreasing agent (Nippon Parkerizing, Fine Cleaner L4460A: 20 g, L4460B: 12 g) with water to 1 L. A rust-proof steel sheet sample obtained by applying the rust-proofing agent shown in the following examples to a steel sheet and then baking it is immersed in the above-mentioned treatment liquid at 60 ° C. for 2 minutes. And after washing with water and drying at 60 ° C. for 1 hour, the state of the coating film is observed to give a score. Subsequently, the SST test (5% NaCl aqueous solution spray, 35 ° C.) is performed for 120 hours, and then the rusting area is measured.

In addition, a score is shown in five steps, and it is set as 5: good (no change of a coating film), 1: bad (whole surface dissolution or whole surface lifting).
Adhesive tape peel resistance:
Adhesive tape (product name: SLIONE TAPE) is attached to a rust-proof steel sheet baked with a rust-proofing agent, and after curing for 48 hours in a constant temperature and humidity chamber (temperature: 40 ° C., humidity: 90%), it is taken out. After a day, peel off the adhesive tape at once and observe the marks to give a score.

  In addition, a score displays the state of the trace which peeled in five steps, and is set as 5: favorable (no peeling) and 1: bad (full surface peeling).

  260 g of ethylene-methacrylic acid copolymer neutralized with Na ions in an autoclave with an internal volume of 1.5 L (MFR (190 ° C.) = 1.1 g / 10 min, methacrylic acid content 20% by weight, neutralization degree 50%) Then, 740 g of water was added and the temperature was raised to 150 ° C., followed by stirring for 2 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content concentration of 26.5%, a viscosity of 125 mPa · s, a pH of 10.0, and an average particle size of 0.02 μm. 5 parts by weight of ammonium zirconium carbonate (trade name: Baycoat 20) manufactured by Daiichi Elemental Chemical Co., Ltd., 100 parts by weight of this aqueous dispersion, carbodiimide (trade name: Carbodilite V-04, manufactured by Nisshinbo), carbodiimide equivalent: 334 g / equivalent ), 15 parts by weight of colloidal silica (manufactured by Nissan Chemical, product name: Snowtex), and 1 part by weight of a silane coupling agent (manufactured by Shin-Etsu Silicone, product name: KBE-403). A treating agent was prepared.

  Using a bar coater, this rust preventive agent is applied to a film thickness of 1.0 μm after drying, placed in an air oven at 250 ° C. and baked until the steel sheet reaches a temperature of 150 ° C. A sample was prepared. The rust-proof steel sheet samples were evaluated for alkali resistance and adhesive tape peelability, and the results are shown in Table 2.

  260 g of ethylene-methacrylic acid copolymer neutralized with Na ions in an autoclave with an internal volume of 1.5 L (MFR (190 ° C.) = 1.1 g / 10 min, methacrylic acid content 20% by weight, neutralization degree 50%) Then, 740 g of water was added and the temperature was raised to 150 ° C., followed by stirring for 2 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content concentration of 26.5%, a viscosity of 125 mPa · s, a pH of 10.0, and an average particle size of 0.02 μm. To 100 parts by weight of this aqueous dispersion, 3 parts by weight of ammonium zirconium carbonate (product name: Baycoat 20), carbodiimide (product name: Carbodilite V-02, carbodiimide equivalent: 590 g / equivalent) ), 35 parts by weight, 30 parts by weight of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name: Snowtex), and 1 part by weight of a silane coupling agent (manufactured by Shin-Etsu Silicone, trade name: KBE-403). A treating agent was prepared.

  Using a bar coater, this rust preventive agent is applied to a film thickness of 1.0 μm after drying, placed in an air oven at 250 ° C. and baked until the steel sheet reaches a temperature of 150 ° C. A sample was prepared. The rust-proof steel sheet samples were evaluated for alkali resistance and adhesive tape peelability, and the results are shown in Table 2.

  260 g of ethylene-methacrylic acid copolymer neutralized with Na ions in an autoclave with an internal volume of 1.5 L (MFR (190 ° C.) = 1.1 g / 10 min, methacrylic acid content 20% by weight, neutralization degree 50%) Then, 740 g of water was added and the temperature was raised to 150 ° C., followed by stirring for 2 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content concentration of 26.5%, a viscosity of 125 mPa · s, a pH of 10.0, and an average particle size of 0.02 μm. To 100 parts by weight of this aqueous dispersion, 3 parts by weight of ammonium zirconium carbonate (manufactured by Daiichi rare element chemical industry, trade name: Baycoat 20), carbodiimide (manufactured by Nisshinbo, trade name: carbodilite V-02-L2, carbodiimide equivalent: 385 g) / Equivalent) 20 parts by weight, colloidal silica (Nissan Chemical, trade name: Snowtex) 30 parts by weight, silane coupling agent (Shin-Etsu Silicone, trade name: KBE-403) 1 part by weight. A rust preventive was prepared.

  Using a bar coater, this rust preventive agent is applied to a film thickness of 1.0 μm after drying, placed in an air oven at 250 ° C. and baked until the steel sheet reaches a temperature of 150 ° C. A sample was prepared. The rust-proof steel sheet samples were evaluated for alkali resistance and adhesive tape peelability, and the results are shown in Table 2.

260 g of ethylene-methacrylic acid copolymer neutralized with Na ions in an autoclave with an internal volume of 1.5 L (MFR (190 ° C.) = 50.0 g / 10 min, methacrylic acid content 12% by weight, neutralization degree 60%) Then, 740 g of water was added and the temperature was raised to 150 ° C., followed by stirring for 2 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content concentration of 26.5%, a viscosity of 250 mPa · s, a pH of 10.0, and an average particle size of 0.25 μm. 3 parts by weight of ammonium zirconium carbonate (product name: Baycoat 20), 100 parts by weight of this aqueous dispersion, carbodiimide (manufactured by Nisshinbo, trade name: carbodilite E-01 , carbodiimide equivalent: 425 g / equivalent) 25 parts by weight, 30 parts by weight of colloidal silica (manufactured by Nissan Chemical, product name: Snowtex), and 1 part by weight of a silane coupling agent (manufactured by Shin-Etsu Silicone, product name: KBE-403) A treatment agent was prepared, and this treatment agent was heated and stirred at 80 ° C. for 40 minutes.

  Using a bar coater, this rust preventive agent is applied to a film thickness of 1.0 μm after drying, placed in an air oven at 250 ° C. and baked until the steel sheet reaches a temperature of 150 ° C. A sample was prepared. The rust-proof steel sheet samples were evaluated for alkali resistance and adhesive tape peelability, and the results are shown in Table 2.

An ethylene-methacrylic acid copolymer neutralized with Na ions in an autoclave with an internal volume of 1.5 L (MFR (190 ° C.) = 0.9 g / 10 min, methacrylic acid content 20% by weight, neutralization degree 20%) 260 g and 740 g of water were added and the temperature was raised to 150 ° C., followed by stirring for 2 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content concentration of 26.5%, a viscosity of 125 mPa · s, a pH of 10.0, and an average particle size of 0.02 μm. 10 parts by weight of diisopropoxytitanium bis (triethanolaminate) (manufactured by Matsumoto Pharmaceutical Co., Ltd., trade name: ORGATICS TC-400), 100 parts by weight of this aqueous dispersion, carbodiimide (manufactured by Nisshinbo, trade name: Carbodilite V-04) , Carbodiimide equivalent: 334 g / equivalent) 20 parts by weight, colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name: Snowtex), 30 parts by weight, silane coupling agent (manufactured by Shin-Etsu Silicone, trade name: KBE-403) 1 weight The antirust treatment agent was prepared by blending the parts.

  Using a bar coater, this rust preventive agent is applied to a film thickness of 1.0 μm after drying, placed in an air oven at 250 ° C. and baked until the steel sheet reaches a temperature of 150 ° C. A sample was prepared. The rust-proof steel sheet samples were evaluated for alkali resistance and adhesive tape peelability, and the results are shown in Table 2.

[Comparative Example 1]
A rust-proof steel plate sample was prepared in the same manner as in Example 1 except that Zirconium ammonium carbonate was not added and E-01 was added instead of V-04, and the alkali resistance and adhesive tape peel resistance were evaluated.

[Comparative Example 2]
A rust-proof steel plate sample was prepared in the same manner as in Example 1 except that carbodiimide was not added, and the alkali resistance and adhesive tape peelability were evaluated.

Claims (10)

Ionomer resin (A) neutralized with monovalent metal ions and / or amine, water-soluble zirconium compound having reactivity with carboxyl group and / or water-soluble titanium compound (B), carbodiimide group in one molecule It is a composition containing two or more water-soluble and / or water-dispersible polyfunctional carbodiimide resins (C) and silane coupling agents (D) as essential components,
The average particle size of the composition is 0.01 to 5 μm, and the composition is water-dispersed;
The water-soluble zirconium compound is at least one selected from ammonium zirconium carbonate, potassium zirconium carbonate, zirconium nitrate, zirconium acetate, basic zirconium carbonate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium bisacetylacetonate. And
A water-dispersed antirust paint composition, wherein the water-soluble titanium compound is at least one selected from dihydroxytitanium lactate and diisopropoxytitanium bis (triethanolaminate ) .   The water-dispersed rust-proof paint composition according to claim 1, wherein the water-dispersed rust-proof paint composition is for a non-chromate steel sheet.   0.5 to 20 parts by weight of water-soluble zirconium compound and / or water-soluble titanium compound (B) with respect to 100 parts by weight of ionomer resin (A) and / or water-soluble and / or having two or more carbodiimide groups in one molecule Or 5 to 40 parts by weight of a water-dispersible polyfunctional carbodiimide resin (C) and 0.1 to 5 parts by weight of a silane coupling agent (D). Composition.   The ionomer resin (A) is a copolymer of ethylene and acrylic acid and / or methacrylic acid, contains 5 to 40% by weight of acrylic acid and / or methacrylic acid, and 1 acrylic acid and / or methacrylic acid. The water-dispersed antirust paint composition according to claim 1, wherein the composition is neutralized with a valent metal ion by 20 to 90%. The ionomer resin (A) is a copolymer of ethylene and acrylic acid and / or methacrylic acid, contains 5 to 40 parts by weight of acrylic acid and / or methacrylic acid, and acrylic acid of the ionomer resin (A) and The water-dispersed rust preventive coating composition according to claim 1, wherein methacrylic acid is neutralized with an amine at least 50%.   The water-dispersed rust-proof coating composition according to claim 1, wherein the amine used for neutralizing acrylic acid and / or methacrylic acid is ammonia, trimethylamine, or monoethanolamine.   The water-dispersed rust preventive coating composition according to claim 1, wherein the water-soluble zirconium compound and / or the water-soluble titanium compound (B) is ammonium zirconium carbonate and / or diisopropoxy titanium bis (triethanolaminate).   The water-dispersed rust-proof coating composition according to claim 1, wherein the polyfunctional carbodiimide resin (C) is water-dispersible and has a carbodiimide group equivalent of 250 to 800 g / equivalent.   The water-dispersed antirust paint composition according to claim 1, wherein the silane coupling agent (D) is a compound having a glycidyl group, an amino group or an amide group.   A water-dispersed antirust paint composition obtained by pre-reacting the composition according to claim 1 at 40 to 120 ° C for 5 to 100 minutes.