KR20100002463A

KR20100002463A - Composition of coating for protecting corrosion

Info

Publication number: KR20100002463A
Application number: KR1020080062368A
Authority: KR
Inventors: 권오숙
Original assignee: 정주식
Priority date: 2008-06-30
Filing date: 2008-06-30
Publication date: 2010-01-07

Abstract

The present invention relates to a coating composition for preventing corrosion, and more particularly, to prepare a coating composition by mixing a urethane epoxy resin, a curing agent, a dispersing agent and a pigment with a filler to improve the rust resistance and adhesion, it does not contain chromium or the like. It is a coating composition for corrosion prevention, characterized by excellent environmental resistance, chemical resistance, corrosion resistance, heat resistance, adhesion, etc. by coating the surface of various structures, etc. The composition is composed of an average molecular weight of 800 ~ 8000 urethane epoxy resin In the coating composition for corrosion prevention using a known topic, consisting of 20 to 45% by weight, 15 to 20% by weight of an amine curing agent, 20 to 25% by weight of zinc powder as a pigment, and 12 to 17 alkali metal salts or ammonium salts as a dispersant. It provides what consists of weight percent and 13 to 18 weight percent of the filler.

Description

Composition of coating for protecting corrosion

The present invention relates to a coating composition for preventing corrosion, and more particularly, to prepare a coating composition by mixing a urethane epoxy resin, a curing agent, a dispersing agent and a pigment with a filler to improve the rust resistance and adhesion, it does not contain chromium or the like. The present invention relates to a coating composition for preventing corrosion, which is excellent in chemical resistance, corrosion resistance, heat resistance, adhesion, and environment-friendly by coating a surface of various structures and the like.

In general, steel structures installed in industrial sites are generally protected by painting with paint on the surface of the structure as an effective way to prevent durability reduction and deterioration due to corrosion. Therefore, when corrosion progresses, the rusted part must be painted by carrying out a kering process, and thus, as it takes a lot of economic cost and time, it is covering the outer surface of the structure with a coating with excellent anti-corrosion to prevent corrosion as a solution for this.

Common methods for producing a corrosion resistant layer on a metal surface thus include chromating, phosphating, coating and anodizing.

Due to the toxicity issues and the corresponding reclassification of chromates, the industrial significance of chromate treatments today is decreasing (EU Directive 2000/53 / EG). Thus, despite the excellent anti-corrosion properties of chromate treatments, chromium-free systems are generally of great interest.

Methods of phosphating iron, steel, zinc and aluminum have long maintained the state of the art. Combination of phosphate treatment with cladding is sufficient to provide fully acceptable corrosion protection, but the two systems alone do not produce the desired results.

Protective oxide films made by electrolysis over metals, such as aluminum or titanium, provide brittle protection, but are brittle as the oxide film increases in thickness and require large amounts of energy to produce them. do.

Recently, attempts have been made to adhere complete monolayer films on metal surfaces and have also been developed with conversion coatings of cerium (Galvanotechnik 92 (12), 2001, 3243).

Another method for avoiding chromate (VI) is a formulation containing chromium (III), so it cannot be considered that the formulation does not contain heavy metals.

Eco-friendly corrosion resistant layers can be obtained using silanes and hydrolyzed silanes (WO 98/19798, WO 00/46310) or silane-based sol-gel condensates (US Pat. No. 5,200,275). Can be.

To coat the surface, the metal substrate is first degassed and cleaned. Cleaning steps may include treatment with organic solvents and also alkaline and acid pickling operations (Metalloberflache, 29 (10), 1975, 517). The silane is hydrolyzed in an aqueous solution or at least water containing solution and then contacted with the metal surface by dipping, spraying and / or spin coating.

Curing or condensation takes place in air at room temperature or at elevated temperatures.

WO 98/30735 describes a method of double coating a metal with an organosilane solution. The film thickness achieved in this case is usually 10 to 100 nm.

Sol-gel systems (also called sols) are prepared from hydrolyzable silicon compounds, often by acidic or basic catalysts, with the corresponding Al, Ti and / or Zr precursors. To this end, the components are hydrolyzed together and converted into a sol or gel. The solvent / diluent used may also be an alcohol formed during the hydrolysis of the compound. The coating composition is prepared according to the coating method already mentioned above.

It can then be applied to a metal substrate again. The coating composition is preferably applied at a dry film thickness of 1 to 50 μm without considering the final coating with the topcoat material (Germany Patent Publication No. 198 13 709).

EP 1 130 066 A1 describes a corrosion resistant metal surface which is pretreated with a silane composition and then extrusion coated with a polyamide compound. The water and alcohol containing silane compositions used, in particular, start from alkoxysilanes Q having functional groups, for example aminoalkylalkoxysilanes and alkoxysilanes M such as alkylalkoxysilanes, alkenylalkoxysilanes and tetraalkoxysilanes. Based on hydrolyzates, condensates and / or co-condensates, where the molar ratio of component (M) and component (Q) is 0 ≦ M / Q <20.

Therefore, the present invention for solving the above problems is a coating composition for preventing corrosion prepared by mixing various additives and fillers such as a curing agent, a dispersing agent to improve the antirust and adhesion to the urethane epoxy resin, It is an object to provide a coating composition for preventing corrosion, characterized in that it does not contain lead and chromium, which can prevent environmental pollution and thus have an excellent working environment.

According to a feature of the present invention for achieving the above object, in the coating composition for corrosion prevention using a known theme consisting of an average molecular weight of 800 ~ 8000 urethane epoxy resin, the main 20 to 45% by weight, amine curing agent 15 ~ A coating composition for corrosion prevention comprising 20 wt%, 20-25 wt% of zinc powder as a pigment, 12-17 wt% of an alkali metal salt or ammonium salt as a dispersant, and 13-18 wt% of a filler is a problem solving means. .

The present invention having the above structure is a coating composition for preventing corrosion prepared by mixing various additives and fillers such as a curing agent and a dispersing agent in a urethane epoxy resin, and does not contain lead and chromium that are regulated to prevent environmental pollution. It is excellent in working environment, and it can maximize the property of wear resistance, heat resistance and chemical resistance by suppressing yellowing phenomenon when exposed to ultraviolet rays. Even if a coating layer is formed without a kering process for removing corrosion of the surface, the coating agent may react with the metal material to form the surface layer as an inert coating.

Hereinafter, the configuration of the present invention in more detail as follows.

The present invention is a coating composition for corrosion prevention using a known theme consisting of an average molecular weight of 800 ~ 8000 urethane epoxy resin, the main 20 to 45% by weight, amine curing agent 15 to 20% by weight, zinc powder 20 to 25 as a pigment It is characterized by consisting of 12 to 17% by weight of the alkali metal salt or ammonium salt and 13 to 18% by weight of the filler as a dispersant.

The urethane epoxy resin, which is a known subject, is selected from polypropylene glycol having a hydroxy group equivalent of 200 to 3000, selected polyols of polyethylene glycol and hexamethylene diisocyanate, isophorone diisocyanate and diphenylmethane diisocyanate having an isocyanate equivalent of 70 to 140. , Obtained by reacting a urethane polyol obtained by reacting a selected diisocyanate compound of any one of 4,4-dicycloheximethane diisocyanate with an epoxy compound having an epoxy group equivalent of 150 to 300, and having a number average molecular weight of 800 to 8000 A known urethane epoxy resin was used, wherein the epoxy compound was glycidyl obtained from at least one selected from the group consisting of ethylene glycol, propylene glycol, butanediol, 2-methyl propanediol, 1,6-hexanediol and trimethylol propane Ethe From the group consisting of glycidyl ester epoxy compounds, bisphenol A type epoxy compounds and bisphenol F type epoxy compounds obtained from at least one selected from the group consisting of le epoxy compounds, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid and hexahydrophthalic acid It may include at least one selected.

The main subject of the present invention is a urethane epoxy resin having a coating stability of epoxy and corrosion and corrosion resistance of urethane, and serves to protect the surface of the coating member, and the amount of the compound is preferably 20 to 45% by weight. .

The amine curing agent used in the present invention shortens the reaction time to improve coating properties of the coating agent and improves adhesion and bondability. The mixing amount is preferably 15 to 20% by weight. If the mixing amount is less than 15% by weight, the curing time may be long due to insufficient content of the curing agent, and the physical properties may decrease due to moisture in the air. If the mixing amount is more than 20% by weight, the surface of the coating member may be applied. The film hardens rapidly and can absorb moisture in the air, thereby improving the film properties, but there is a concern that the film stability is lowered.

The amine curing agent is a group consisting of amidoamine, amidoamide amine, mannichbase, polyether amine, metaxylene diamine, isophorone diamine, ethylene diamine, diethylene triamine, triethylene tetraamine and tetraethylene pentaamine It may include at least one selected from.

As said pigment, it is preferable that all the average particle diameters are 20 micrometers or less, More preferably, it is 15 micrometers or less, Especially preferably, it is about 10 micrometers. When the average particle diameter of the said pigment exceeds 20 micrometers, the dispersibility of these components in the coating composition obtained will worsen, coating nonuniformity will generate | occur | produce, the density of a coating film will fall, and it exists in the tendency for corrosion and rust prevention property to fall. As zinc alloys which are pigments other than zinc powder, conventionally well-known alloys, such as zinc-aluminum and zinc-magnesium, are mentioned. As other pigments, specifically, a zinc phosphate type (aluminum) compound is a brand name "LF Bowsei CP-Z" (made by Kikuchi Color Co., Ltd.), a zinc phosphite type (calcium) compound is a brand name "Protex, for example." YM-60 "(made by Daihei Chemical Industry Co., Ltd.), a zinc phosphite (strontium) compound, a brand name" Protex YM-92NS "(made by Daihei Chemical Industry Co., Ltd.), a tripolyphosphate-type compound are brand names" K white # 84 "(made by Teika Co., Ltd.), a molybdate-type compound are brand names" LF Bowsei M-PSN "(product made by Kikuchi color company), cyanamide zinc-based compound is a brand name" LF Bousei ZK- 32 "(Kikuchi Color Co., Ltd. product) etc. are mentioned.

These pigments are generally contained in an amount of 15 to 70% by weight, preferably 20 to 60% by weight, particularly preferably 20 to 40% by weight, based on 100% by weight of the total solids in the paint. Preferred at

Moreover, it is preferable for the reason mentioned above that it is contained in the amount of 15-70 weight% normally, Preferably it is 20-60 weight% in the coating film (dry coating film) which dries this coating material.

And as the dispersant, alkyl or aryl sulfonic acid, alkyl or aryl sulfonic acid, alkyl or aryl ether sulfonic acid, dodecyl sulfuric acid, or alkyl represented by dioctyl sulfosuccinic acid or dodecylbenzene sulfonic acid or the like, alkyl or aryl ether sulfate, alkyl or aryl substitution N-alkyl or arylsarcosic acid represented by phosphoric acid, alkyl or arylether substituted phosphoric acid, dodecyl sarcosinic acid, alkyl or arylcarboxylic acid represented by oleic acid or stearic acid, etc. And nonionic emulsifiers or dispersants such as alkali metal salts or ammonium salts of alkyl acids, alkyl or aryl substituted polyethylene glycols, polyvinyl alcohols, alkyl substituted celluloses, polyvinylpyrrolidone, and polyacrylic acid derivatives. These can be used combining one type or two types or more.

Examples of the filler include crystalline silica, barium sulphate, magnesium silicate, calcium silicate, mica, mica sea iron oxide, calcium carbonate, zinc powder, aluminum, aluminum silicate, and the like, preferably aluminum silicate, crystalline silica Barium sulfate, calcium carbonate and the like can be used.

Hereinafter, the configuration of the present invention will be described in detail with reference to the following Examples, the configuration of the present invention is not necessarily limited to the following examples.

1. Preparation of coatings to prevent corrosion

Table 1

(weight%)

Composition Example One 2 3 4 subject Urethane Epoxy Resin 34 42 36 40 Hardener Ethylene diamine 16 10 13 10 Pigment Zinc powder 23 20 - - YM 60 (zinc phosphate (calcium) compound) - - 22 21 Dispersant Alkali metal salt 12 14 - - Polyvinyl alcohol - - 13 15 Filler Calcium carbonate 15 14 16 14

The change in formulation according to the examples was based on the comparison of the inorganic and organic matter of the pigment and the comparison of the ionic and nonionic materials of the dispersant.

2. Test piece production

The coating agent prepared according to the composition ratio of [Table 1] was coated on a cold rolled steel sheet specimen of standard L 150 × B 70 m / m using a barcode so as to have a coating thickness of 10 to 12 μm, and then dried at 300 ± 5 ° C. for 1 hour. And after hardening, the coating film test piece was produced.

3. Measuring method

1) The thickness is measured according to the measurement of the dry film thickness of KS M ISO 19840.

2) Chemical resistance is measured by immersing the test specimen in room temperature, 10% HCl, 10% H2SO4 and 10% NaOH for 24 hours, respectively, in accordance with KS M 5000 paint and related raw material test methods.

3) Corrosion resistance is tested by KS D 9502's salt spray tester when no fading and fading occurs after 200 hours (○), and when fading and fading within 5% (△), 5% or more. When discoloration and fading occur (x), it is evaluated separately.

4) Heat resistance when bubbles and cracks do not occur after 1 hour at 300 ± 5 ° C (○), when bubbles and cracks occur within 5% (△), when bubbles and cracks occur by 5% or more (×) Evaluate by classifying

4. Measurement result

TABLE 2

Measurement item Example One 2 3 4 Thickness (㎛) 10 13 12 11 Chemical resistance Room temperature clear clear clear clear HCl 10% clear clear clear clear H2SO4 10% clear clear clear clear NaOH 10% clear clear clear clear Corrosion resistance ○ ○ ○ ○ Heat resistance ○ ○ ○ ○

As shown in Table 2, in Examples 1 to 4, the corrosion resistance test did not cause discoloration and discoloration, ie, yellowing, on the surface of the sample after 200 hours, and at 300 ± 5 ° C. in the heat resistance test. After 1 hour, bubbles and cracks did not occur, which was evaluated as being excellent.

The excellent adhesion, corrosion resistance, and heat resistance performance is due to the role of the substrate that reduces the moisture penetration due to the uniform coating of the effective dispersant and filler as urethane epoxy resin is used as the subject. It was evaluated that the adhesion and corrosion resistance were strongly improved.

Claims

In the coating composition for corrosion prevention using a known motif consisting of an average molecular weight of 800 ~ 8000 urethane epoxy resin, 20 to 45% by weight of the main ingredient, 15 to 20% by weight amine curing agent, 20 to 25% by weight of zinc powder as a pigment, 12 to 17% by weight of the alkali metal salt or ammonium salt and 13 to 18% by weight of the filler as a dispersant coating composition for preventing corrosion.

The method of claim 1,

The curing agent in the group consisting of amidoamine, amidoamideamine, mannichbase, polyether amine, metaxylene diamine, isophorone diamine, ethylene diamine, diethylene triamine, triethylene tetraamine and tetraethylene pentaamine Coating composition for preventing corrosion, characterized in that it comprises at least one selected.

The method of claim 1,

The pigment is zinc powder, zinc alloy powder, zinc phosphate compound, calcium phosphate compound, aluminum phosphate compound, magnesium phosphate compound, zinc phosphate compound, calcium phosphate compound, aluminum phosphite compound, strontium phosphite compound, Coating agent for corrosion prevention, characterized in that it contains one or two or more pigments selected from the group consisting of tripolyphosphate-based compound, molybdate-based compound, cyanamide zinc-based compound, borate compound, nitro compound, complex oxide Composition.