JPH0133509B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a rust-preventing coating composition. Conventional water-based anti-corrosion paints for metal materials include water-based acrylic resins, alkyd-melamine resins, water-based epoxy resin paints, etc. These are applied and dried at room temperature or at a relatively low temperature of about 80 to 150 degrees Celsius. There is. However, even metal materials coated with these water-based resin paints have insufficient corrosion resistance, and there are problems in that rust occurs, and blistering or peeling occurs due to decreased adhesion. Furthermore, it is well known that water-based polyurethane resins have superior chemical resistance, abrasion resistance, and bending resistance compared to other water-based alkyd resins, acrylic resins, alkyd-melamine resins, epoxy resins, etc. However, the actual situation is that it has not been used as a general anti-rust paint for metal materials due to its high price. The inventors of the present invention have conducted extensive research to solve the above-mentioned problems, and as a result, have provided the present invention. That is, (A) a water-based polyurethane resin with a crosslink density of 0.02 to 1.00 per 1000 atomic weight, (B) red lead, lead zinc oxide, lead cyanamide, basic lead chromate, calcium leadate, basic lead sulfate, Zinc chromate, strontium chromate, zinc phosphate, calcium phosphate, ammonium phosphate, titanium phosphate, silicon phosphate, condensed aluminum phosphate, zinc molybdate, calcium molybdate, zinc calcium molybdate, zinc potassium molybdate, aluminum molybdate at least one anticorrosion pigment and/or organic inhibitor selected from the group consisting of , calcium molybdate, barium metaborate, calcium borate, zinc oxide and micaceous iron oxide in an amount of 0.5 to 97% by weight in the total solid content. %, the water-based polyurethane resin has an average molecular weight of 50 to 50%.
10,000 and a polyhydroxy compound containing two or more active hydrogen atoms, or a combination of the above polyhydroxy compound and a polyvalent amine compound having an average molecular weight of 50 to 10,000 and containing two or more active hydrogen atoms, reactive with organic polyisocyanates, and NCO groups. An anionic water-based polyurethane resin prepared by mixing and emulsifying a polyurethane resin having a salt-forming group in water using a salt-forming agent, which is synthesized from a compound having an active hydrogen atom and a salt-forming group. This is a rust-preventing paint composition. As mentioned above, the water-based polyurethane resin used in the present invention is a polyhydroxy compound having an average molecular weight of 50 to 10,000 and containing two or more active hydrogen atoms, or a polyhydroxy compound containing the above polyhydroxy compound and an average molecular weight of 50 to 10,000.
10,000 in combination with a polyvalent amine compound containing two or more active hydrogen atoms, organic polyisocyanate, and
An anionic system in which a polyurethane resin having a salt-forming group synthesized from a compound having an active hydrogen atom reactive with an NCO group and a salt-forming group is mixed and emulsified in water by a known method using a salt-forming agent. Examples include water-based polyurethane resins. In the water-based polyurethane resin, examples of the polyhydroxy compound having an average molecular weight of 50 to 10,000 and containing two or more active hydrogen atoms include diethylene glycol, butanediol, hexanediol,
Polyhydric alcohols such as bisphenol A, trimethylolpropane, glycerin, and pentaerythritol, their alkylene derivatives, or their esterified products; poly(oxyethylene ether) polyols,
poly(oxypropylene ether) polyol,
Polyol compounds such as poly(oxyethylene propylene ether) polyol, polyester polyol, polythioether polyol, polyacetal polyol, polytetramethylene glycol, polybutadiene polyol, and castor oil polyol have an average molecular weight of 50 to 10,000 and two or more active hydrogen atoms. Examples of the contained polyvalent amine compounds include low molecular weight polyvalent amines such as ethylene diamine, propylene diamine, diethylene triamine, triethylene tetramine, and tetraethylene pentamine; high molecular weight polyvalent amine compounds such as epoxy amine adducts or polyamide resins, etc. It will be done. The polyhydroxy compound or polyvalent amine compound needs to have an average molecular weight of 50 to 10,000. If the average molecular weight of the polyhydroxy compound or polyvalent amine compound is outside the range of 50 to 10,000, the object of the present invention will not be achieved. Next, examples of organic polysocyanates include naphthylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, and all aromatic, aliphatic, and alicyclic polysocyanates. These isocyanates may be used alone or in mixtures. Next, examples of the compound having an active hydrogen atom and a salt-forming group reactive with the NCO group include compounds having a salt-forming carboxylic acid or sulfonic acid group and corresponding salt-forming agents. Examples of compounds having a salt-forming carboxylic acid or sulfonic acid group include hydroxy acids such as glycolic acid, malic acid, glycine, aminobenzoic acid, alanine, dimethylolpropionic acid, aminocarboxylic acids, polyhydric hydroxy acids, and taurine. ,2
- Aminosulfonic acids such as hydroxyethanesulfonic acid, hydroxysulfonic acids, etc.; corresponding salt forming agents include monovalent metal hydroxides such as sodium hydroxide, calcium hydroxide, ammonia, trimethylamine, triethylamine, etc. Examples include tertiary amine compounds. The water-based polyurethane resin used in the present invention must have a crosslink density of 0.02 to 1.00 pieces per 1000 atomic weight. If the crosslink density of the water-based polyurethane resin is outside the range of 0.02 to 1.00 crosslinks per 1000 atomic weight, the object of the present invention will not be achieved. Here, the crosslinking density referred to in the present invention is calculated as follows, for example. That is, an active hydrogen atom-containing compound with a molecular weight MW ₁ and a functional group number F ₁
W ₁ g, an active hydrogen atom-containing compound W ₂ g having a molecular weight MW ₂ and a functional group number F ₂ , an active hydrogen atom-containing compound W _{o-1 g} having a molecular weight MW o-1 and a functional group number F _{o- 1} , and a molecular weight MWn, number of functional groups
The crosslinking density per 1000 atomic weight of the water-based polyurethane resin obtained by reacting Fn with organic polyisocyanate Wng is as follows: CD = {W ₁ (F ₁ -2)/MW ₁ } + {W ₂ (F ₂ -2) /MW ₂ }+
...It is calculated as {Wn (Fn-2)/MWn}/W ₁ +W ₂ ...+Wn×1000. The antirust pigments used in the present invention include red lead, lead zinc oxide, lead cyanamide, basic lead chromate, calcium lead oxide, basic lead sulfate, zinc chromate,
Strontium chromate, zinc phosphate, calcium phosphate, ammonium phosphate, titanium phosphate, silicon phosphate, condensed aluminum phosphate, zinc molybdate, calcium molybdate, zinc calcium molybdate, zinc potassium molybdate, aluminum molybdate, molybdate At least one selected from the group consisting of calcium, barium metaborate, calcium borate, zinc oxide, and micaceous iron oxide is mentioned. Organic inhibitors used in the present invention include organic phosphate esters, phosphonates, amine phosphates, phosphonium compounds, sarcosines,
Benzoates, oxycarboxylic acids, amines,
1,2,3, benzotriazole, cinnamate,
Polyacrylamide, lignin sulfonate, lignins, sodium succinate, gluconate,
Examples include p-aminobenzaldehyde, higher fatty acid salts, sodium benzoyl acrylate, n-lauroylsarcosine, piperidine 3,5-dinitrobenzoate, and mixtures thereof. Metal materials to be subjected to rust prevention in the present invention include civil engineering materials, building materials, automobile materials, steel plates such as electrical and electronic industrial products, pipes, metal processed parts, various metal materials, etc., and the above-mentioned uses. iron, cast iron, ductile iron, aluminum, copper,
Examples include alloys such as zinc, beryllium, titanium, magnesium and stainless steel, various platings such as galvanized iron and tinplate, and surface-treated products thereof such as phosphates and chromates. The rust-preventing coating composition according to the present invention is a composition in which the above-mentioned water-based polyurethane resin is blended with the above-mentioned rust-preventing pigment and/or organic inhibitor. The anticorrosion pigment and/or organic inhibitor must be blended in an amount of 0.5 to 97% by weight based on the total solid content. If the content of the anti-rust pigment and/or organic inhibitor exceeds 97% by weight, the water permeability of the coating film itself will decrease as well as the density will decrease, and the concentration of the water-based polyurethane resin, which is the binder for the anti-rust pigment, will be insufficient.
Water resistance deteriorates significantly and impact resistance also decreases, which is not preferable. In addition, anti-rust pigments and/or organic inhibitors
If it is less than 0.5% by weight, corrosion resistance will be insufficient. In the present invention, various dispersants are used to stably disperse rust-preventing pigments and/or organic inhibitors, anti-skinning agents and leveling agents used when formulating paints,
Various additives such as antifoaming agents, film-forming aids, coloring pigments, thickeners, and extender pigments can be added within the range that does not impair performance in order to achieve desired properties. Examples of methods for applying the anticorrosive coating composition of the present invention to metal materials include various coating methods such as a spray method, a dipping treatment method, a brush coating method, and a roller coater method. When the anticorrosion coating composition obtained according to the present invention is applied to a metal material, it does not cause a decrease in adhesion or the occurrence of blistering, and it is a coated metal material that has excellent corrosion resistance such as water resistance and salt water resistance. It provides
It can be used in civil engineering, construction, automobile materials, or electrical equipment. EXAMPLES Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples. Synthesis example 1 Polybutylene adipate (MW2000, 2.0 functionality)
70 parts by weight, 1,6-hexanediol (MW118,
2.0 functional) 20 parts by weight, trimethylolpropane (MW134, 3.0 functional) 3 parts by weight, dimethylolpropionic acid (MW134, 2.0 functional) 6.5 parts by weight, isophorone diisocyanate (MW222, 2.0 functional)
After synthesizing an isocyanate prepolymer consisting of 70 parts by weight in acetone, this was mixed and emulsified in water containing triethylamine. The crosslinking density of this water-based polyurethane resin is 0.132. Synthesis example 2 Polybutylene adipate (MW2000, 2.0 functionality)
70 parts by weight, 1,6-hexanediol (MW118,
2.0 functional) 20 parts by weight, trimethylolpropane (MW134, 3.0 functional) 10 parts by weight, dimethylolpropionic acid (MW134, 2.0 functional) 6.5 parts by weight, isophorone diisocyanate (MW222, 2.0 functional)
After synthesizing 95 parts by weight of an isocyanate prepolymer in acetone, this was mixed and emulsified in water containing 4.6 parts by weight of triethylenetetramine (MW146, 4.0 functional) and triethylamine. The crosslinking density of this water-based polyurethane resin is 0.66. Synthesis example 3 Polybutylene adipate (MW2000, 2.0 functionality)
70 parts by weight, 1,6-hexanediol (MW118,
20 parts by weight of trimethylolpropane (MW134, 3.0 functionality), 6.5 parts by weight of dimethylolpropionic acid (MW134, 2.0 functionality), isophorone diisocyanate (MW222, 2.0 functionality)
After synthesizing 65 parts by weight of an isocyanate prepolymer in acetone, this was mixed and emulsified in water containing triethylamine. The crosslinking density of this water-based polyurethane resin is 0.009. Synthesis example 4 Polybutylene adipate (MW2000, 2.0 functionality)
70 parts by weight, 1,6-hexanediol (MW118,
20 parts by weight of trimethylolpropane (MW134, 3.0 functionality), 6.5 parts by weight of dimethylolpropionic acid (MW134, 2.0 functionality), isophorone diisocyanate (MW222, 2.0 functionality)
After synthesizing 140 parts by weight of an isocyanate prepolymer in acetone, this was mixed and emulsified in water containing 11.2 parts by weight of triethylenetetramine (MW146, 4.0 functional) and triethylamine, but gelation occurred during emulsification. The crosslinking density of this water-based polyurethane resin is 1.13. Synthesis example 5 Polytetramethylene glycol (MW1000,
2.0 functional) 70 parts by weight, 1,4-butanediol (MW90, 2.0 functional) 15 parts by weight, trimethylolpropane (MW134, 3.0 functional) 7 parts by weight, hexamethylene diisocyanate (MW168, 2.0 functional) 60
After synthesizing an isocyanate prepolymer consisting of parts by weight in acetone, a taurine-sodium hydroxide aqueous solution was mixed therein, and the mixture was mixed and emulsified in water. The crosslinking density of this water-based polyurethane resin is 0.344. Example 1 50 parts by weight of various water-based polyurethane resin paints (solid content) were mixed with 50 parts by weight of zinc oxide powder as a rust preventive paint, dispersed in a ball mill for 24 hours, and then sprayed onto a cold rolled steel plate to a thickness of 10 microns. Apply and 80
The sample was force-dried at ℃ and used as a test piece. In addition, as a comparative example, a test piece was prepared by spray coating a cold rolled steel plate to a thickness of 10 microns and forced drying at 80°C. The results are shown in Table 1. 40℃ hot water resistance...Immersed in 40℃ hot water for 48 hours, salt spray test...Sprayed with salt water for 120 hours, impact resistance test...Dupont 1/4inch, 1Kg, 50cm The following examples are the same.

[Table] Example 2 A water-based polyurethane resin and anti-corrosion pigment or organic inhibitor were dispersed in a ball mill for 24 hours, and then sprayed onto a cold rolled steel plate to a thickness of 10 microns, and force-dried at 80°C to obtain a test piece. did. In addition, as a comparative example, a test piece was prepared by spray coating a cold rolled steel plate to a thickness of 10 microns and forced drying at 80°C. The results are shown in Table 2.

【table】

Claims (1)

[Claims] 1 (A) Crosslink density is 0.02 to 1.00 per 1000 atomic weight
(B) Red lead, lead zinc oxide, lead cyanamide, basic lead chromate, calcium leadate, basic lead sulfate, zinc chromate, strontium chromate, zinc phosphate, calcium phosphate, phosphoric acid Ammonium, titanium phosphate, silicon phosphate, condensed aluminum phosphate, zinc molybdate, calcium molybdate, zinc calcium molybdate, zinc potassium molybdate, aluminum molybdate, calcium molybdate, barium metaborate, calcium borate, oxidized A rust-preventing paint composition containing at least one rust-preventing pigment and/or organic inhibitor selected from the group consisting of zinc and micaceous iron oxide in an amount of 0.5 to 97% by weight in the total solid content, The water-based polyurethane resin has an average molecular weight of 50 to
10,000 and a polyhydroxy compound containing two or more active hydrogen atoms, or a combination of the above polyhydroxy compound and a polyvalent amine compound having an average molecular weight of 50 to 10,000 and containing two or more active hydrogen atoms, reactive with organic polyisocyanates, and NCO groups. An anionic water-based polyurethane resin prepared by mixing and emulsifying a polyurethane resin having a salt-forming group in water using a salt-forming agent, which is synthesized from a compound having an active hydrogen atom and a salt-forming group. Rust-preventing paint composition.