JPS5936165A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition of high corrosion-proof performance, free from any toxic metal, by incorporating a specific amount of particular chelate reagent in a cocondensate prepared from a specific proportion of epoxy resin, mono or dihydric phenol resin, and 2-imidazolyl group-contg. compound. CONSTITUTION:The objective coating composition can be obtained by incorporating (A) a cocondensate prepared from (i) 100pts.wt. of an epoxy resin with an epoxy equivalent of 900-3,000, (ii) 5-40pts.wt. of a mono- or dihydric phenol resin (e.g., an alkyl catechol), and (iii) 0.5-6pts.wt. of a 2-imidazolyl group- contg. compound (pref. 2-methyl imidazole) with (B) 0.3-5pts.wt. of a chelate reagent having, in the same molecule, both hydroxyl and amino groups capable of forming chelate compound by coupling with metallic ion (pref. aminophenol). EFFECT:Capable of coating even on a thin film of 5-10mu thick, providing extremely high corrosion-proof performance.

Description

[Detailed description of the invention] Kijiri 1 relates to a rust-preventing paint composition.

Rust-preventing paints currently in use, including wash primers, contain heavy metals such as lead oxide, lead sulfate, and chromate as rust-preventing pigments, and their exhaust and wastewater are considered to be one of the causes of pollution. ing.

Self-polishing ship bottom paints, which have recently attracted particular attention, also contain heavy metals as anti-corrosion pigments and cause marine pollution.

In addition to the above paints, there are also paints that contain less toxic metals as rust preventive pigments, such as non-heavy metals such as zinc, aluminum, stainless steel powder, or ζd scale iron oxide, but in these cases, large amounts of the metals are used. 6, it is difficult to coat, or it cannot be coated in a thin film, resulting in a large amount of use.

An object of the present invention is to provide a coating material that has extremely excellent antirust properties without using not only highly toxic heavy metals but also lowly toxic metals.

Another object of the present invention is to provide a paint that can be applied to a thin film of about 5 to 10 microns and has excellent antirust properties when applied.

The present invention has an epoxy equivalent of 900 to 300 (100 parts by weight of + epoxy resin, 5 to 40 parts by weight of monovalent or I''i divalent phenol resin, and 05 to 6 parts by weight of 2-imigzolyl group-containing compound) 4 parts A chelating reagent in which a hydroxyl amino group is added to a cocondensate consisting of a metal ion to form a chelate compound in the same molecule.
A rust-preventing coating that is characterized by containing 5 tons of hanging parts? 'Relates to 1 set of IE items.

The unexploded IJ and lK will be explained below. Epoxy resin is white and has good adhesion to metal surfaces, good chemical resistance to acids and alkalis, and excellent rust prevention. unexploded[
Among the epoxy resins used in ``-1'', 4 (1) and 900-3000 are preferably used.Specifically, Epicoat 1004.10 fJ 7.
1009 (Shell Chemistry gl[) etc. Example 1': Can be done.

Misfire + (tfJ as phenolic resin in IJ, 1
(111i or dihydric phenols, such as phenol, talesol, glycylenol, carbonate,
Resins obtained from resorcinol, etc., altehydes such as formaldehyde, acetaltehyde, furfural, etc., and their modified resins are used. In particular, dihydric phenols are used to sharpen natural lacquer, and are made by bonding side chains to dihydric phenols. An example is alkylcatechol A4. R, in particular, does it have the ability to combine with metals to form chelate compounds to protect metal surfaces?1, such phenolic resins can be used as epoxies in 100 parts (weight is parts, hereinafter (and similar)). It is preferable to use 5 to 40 parts.

Next, as the 2-imidazolyl group (i) compound, a compound having hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group as a substituent at the 2-position of imidazole can be used. Good (J, imidazole on the body side, 2-
medyl imidazole, 2-
Examples include combitecylimidazole and 2-phenylimidazole.

Such a 2-imidazolyl group-containing compound forms a metal chelate by itself and acts as a curing agent for the epoxy resin, and is usually used in an amount of 0.5 to 6 times per 100 parts of epoxy Jftl.

In the case of misfire 1s1, the original excellent properties of epoxy resin are utilized (in addition, phenol resin is used as a hardening agent, and it also forms a metal chelate by itself to protect the metal 1n'i).
- Compounds containing imidazolyl groups are used as epoxy curing agents to improve the 111 performance of epoxy resins. As a curing agent for epoxy resin, amines, polyamide 4:
M fats, acids, silicic acid anhydrides, and amines such as diethylenetriamine easily form metal chelates, but they react violently with epoxy resins and are difficult to maintain.
Middle school 97. As the hardness progresses, gelation occurs, making it impossible to maintain the stability of the paint. Sweet polyamide 4 layers (1
First, if an acid or acid anhydride is used as an epoxy hardener, the rust prevention effect will be poor, probably due to the acid component in the hardener.

The epoxy resin, phenol resin, and 2-imidazolyl group-containing compound are co-condensed to produce a special IJ1. By obtaining a co-M compound with enhanced
A rust-preventing paint with high anti-crystalline properties can be obtained without using any heavy metals or the like.

Among various reagents, it is necessary to use a chelating reagent having a hydroxyl group and an amine group in the same molecule, such as aminophenol and 8-oxyquinoline, as the chelating reagent described in -1- used in the present invention. . By using such a chelating reagent, the stability and antirust effect of the paint can be significantly improved. Other chelating reagents include those containing acid groups such as salicylic acid and maleic acid, but these have low antirust effects. A chelating reagent that has two or more amine groups has the disadvantage of acting as a curing agent for epoxy and impairing the stability of the paint. Furthermore, when dihydric and 3611i phenols are used as chelating reagents, such phenols have not been converted into resins, so the coloring phenomenon is slow, and they are easily dissolved in solvents, especially when applied with two-coat paints. If the coating is applied, a bleed phenomenon may occur and the coating may change color.

Misfire 1 In 1, add 1-2 chelating reagent to epoxy resin 1
It is preferable to mix 0.3 to 5 parts to 0.00 parts.

To show an example of the production of @Iwagumi acid products of the present invention, first, the epoxy resin and phenol resin described above are added to an organic solvent and dissolved by heating and stirring, and then the 2-imidazolyl compound is added. The mixture is reacted by heating and stirring to obtain a co-condensate.

The solution of this co-condensate did not explode! I-] When the chelating reagent to be used is added and dissolved, it is possible to use one type of organic solvent, such as methyl seronulp, ethyl cellosol, butyl cellosol, etc. Preferred are cellosolve solvents, ketone solvents such as acetone and methyl ethyl ketone, and aromatic hydrocarbon solvents such as toluene and xylene. It is also possible to add one ton of a known paint additive.

The present invention will be explained below with reference to Examples.

Example 1 Epicote 1007 (x poxy hl', 1750-
21tlO, Shell Chemical) 500g, phenolic resin (
Regitop PS-27801. Light yellow lumpy, Gunei Chemical)
50g, Doolol 775g, Ethyl Cellosolp 775
Put 3/3 g into a 30 flask and heat it on a hot water bath for 70~80T.
Hold and stir gently to dissolve.

When Epicote 1007 and the phenol resin are completely dissolved, 4 g of imidazole is added, heated to 95-98°C, and reacted at that temperature with stirring for about 3 hours. At this point, the imidazole and epoxy resin almost reacted, and the compatibility of the phenol resin and Epicol 1-1 (107) was poor, resulting in some turbidity and increased transparency.
After 2 to 3 hours of reaction, it becomes completely transparent. When 5 g of aminophenol was added and dissolved, and the mixture was cooled, 2100 g of a coating composition was obtained by 11 J.

When 100 g of this composition was added with 25 g of dolol and 25 g of ethylceronlube and applied to a mild steel plate that had been degreased with a solvent, the dry coating film was 5 to 10 microns. Further, the test piece was dried for 4 days at room temperature, 60°C x 30 minutes, and 120°C x 20 minutes. Salt spray test (5% saline, 35°C) for 144 hours. at (,lJ[
Peeling the cellophane tape 1j from the part where the ``'' was applied was 1.
Within mm, it was equivalent to the two-component Kuotsushi J-Primer, which uses heavy metals as antirust pigments.

Using a mild steel plate, an aluminum plate, a copper plate, a stainless steel plate, a galvanized steel plate, etc. as a metal substrate, the entire coating composition was coated, and after drying at room temperature for 20 minutes, a melamine alkyd paint was further applied.
After baking and drying the test piece at 20°C for 20 minutes, it was immersed in boiling water for 1 hour, and there was no abnormality in appearance such as foaming, and no abnormality in tightness was observed.

Example 2 The main component of Chinese lacquer is curdiol, which is a typical natural algylated dihydric phenol with a side chain attached to a dihydric phenol. When doruol is added to this Chinese-produced lacquer and left to stand while stirring, it is divided into 1-1 parts of brown doluor lacquer and an aqueous phase containing water at the bottom.

''The two parts of the doruol phase are raw lacquer -1:, I component urushiol-containing doruol lever solution 1'& is reduced - Distillation produces a viscous liquid of kurushiol - urushiol 2
0 (Add 10g of Urotropis to 1g and heat. Approx.
Foaming and reaction start at 0"C. 3 at 120-125°C.
After stirring for 0 minutes, foaming completely disappears and the mixture becomes viscous at high temperatures.
A Kurdiol resin liquid which is solid at room temperature is obtained. This resin liquid is made by reacting tuldiol with formalin or ammonia as a catalyst, and due to the heating and ammonia, the lacquer flaking that is characteristic of raw lacquer is reduced, making subsequent operations easier.

Epicoat 1009, (epoxy equivalent - total 2400-30
00) 500 g, 800 g of tuldiol, and 80 Fl g of ethyl cellosolve were placed in a 31-30 flask, kept at 70 to 80°C on a water bath, and stirred and dissolved. When Epicor) 1009 and Curdiol 4f1 fat liquid are completely dissolved, add 4 g of 2-methylimidazole and heat to 95 to 98°C.
Allow the reaction to occur with occasional stirring. After the reaction, 5 g of 8-oxyquinoline was added and dissolved, and 2150 g of the coating R1 composition was applied.

As a result of applying this coating composition to a mild steel plate and conducting a salt spray test, the same coating as in Example 1 was obtained.

(hereinafter) -) Agent: Patent attorney 1) Question: Written amendment to Iwao procedure (voluntary) September 191-1, 1972 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of the case 1982 Patent application No. 12423 (3) No. 2, Name of the invention Paint composition 3, Relationship with the person making the amendment Patent applicant number 1) Showa 24, Agent 2-8 Maru Building, Sonezaki l-2, Kita-ku, Osaka 530 Phone: 06 (365) 0170 Section 8 of No. 8, the contents of the amendment are corrected.

Claims (1)

[Claims] (1) 100 parts by weight of epoxy resin with an epoxy equivalent of 900 to 3000, 5 parts of monovalent or divalent phenol resin
40 A cocondensate consisting of 0.5 to 6 parts by weight of a compound is added with 03 to 5 parts by weight of a chelating reagent having a hydroxyl-supporting amino group in the same molecule that binds with a metal ion to form a chelate compound. 4? A rust-preventing paint composition with a characteristic of