JPS6140372A - Aqueous coating composition - Google Patents

Abstract

PURPOSE:The titled composition, obtained by incorporating a specific reactive high polymer with an epoxy resin and organic acid in a specific proportion, and having improved drying property and curability at ordinary temperature or low temperatures and improved gloss and film properties. CONSTITUTION:An aqueous coating composition obtained by adding (B) 30- 300pts.wt. epoxy resin, e.g. glycidyl ether type epoxy resin having 80-1,000 epoxy equivalent, and (C) 0.25-1.0mol equivalent, based on amino groups, organic acid to (A) 100pts.wt. high polymer having 500-10,000 molecular weight, 50-500 iodine value, carbon-carbon double bonds and 30-200 millimol, based on 100g high polymer, tertiary amino groups. EFFECT:Films having improved water and corrosion resistance and adhesion are obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is the same as the method for producing a highly stable aqueous epoxy resin emulsion, which is water-based and has excellent corrosion resistance and adhesion. The present invention relates to a method for producing a one-component hardening emulsion eye.

[Conventional technology]

There are two types of water-based paints: a water-soluble type and an emulsion type, and since these use water as a diluent, they are less toxic and flammable than organic solvent-based paints, and are expected to develop in the future as non-polluting or non-polluting paints. It is expected.

However, in the water-soluble paints that have been developed in the past, increasing the molecular weight of the resin increases the viscosity of the aqueous solution, making it practically unusable, so only relatively low molecular weight resins can be used. Therefore, the hardness of the coating film is low and the physical properties are poor. Furthermore, chemical properties such as water resistance and chemical resistance are also inferior.

Therefore, the uses of water-soluble paints are limited, and no water-soluble paints have yet been developed that can be applied by conventional painting methods such as spraying and that cure at room temperature to provide a coating film with excellent physical properties.

On the other hand, emulsion-type water-based paints have the advantage of being able to use polymeric resins and can be used at high concentrations due to the low viscosity of the system, but as a result of the use of surfactants during emulsion production, water resistance is poor. Another drawback is that a glossy coating film cannot be obtained.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to provide a method for producing a new water-dispersible coating film-forming substance that has good drying and curing properties at room temperature or relatively low humidity, is glossy, and has excellent i-film physical properties.

[Means for solving problems]

In the present invention, a stable epoxy resin emulsion can be obtained by using the specific reactive polymer surfactant used in the present invention without using a low molecular weight surfactant that is used in ordinary emulsions. Furthermore, they discovered that the coating film obtained by drying at room temperature or by heating has excellent water resistance, corrosion resistance, adhesion, etc., and completed the present invention.

The greatest feature of the present invention lies in the use of a specific polymeric surfactant, which will be described in detail below, as the polymeric surfactant.

500 to io, which is the starting material r1 of the component (A) of the present invention,
A polymer compound having a carbon-carbon double bond with a molecular weight of 50 to 500 and an iodine value of 50 to 500 is produced by a conventionally known method.

That is, a conjugated diolefin having 4 to 10 carbon atoms alone, or a combination of these diolefins, or an aromatic vinyl monomer in an amount of 50 mol% or less based on the conjugated diolefin, using an alkali metal or an organic alkali metal compound as a catalyst. For example, a typical manufacturing method is anionic polymerization or copolymerization of styrene, α-methylstyrene, vinyltoluene, or divinylbenzene at a humidity of 0° C. to 100° C. In this case, in order to control the molecular weight and obtain a light-colored low polymer with a low gel content, an organic alkali metal compound such as sodium benzyl is used as a catalyst, and a compound having an alkylaryl group, such as toluene, is used as a chain transfer agent. chain transfer polymerization method (US Pat. No. 37890)
90) or a living polymerization method using a polycyclic aromatic compound such as naphthalene as an activator and an alkali metal such as sodium as a catalyst in a tetrahydrofuran solvent (Japanese Patent Publication No. 42-17485, 43-27432); Polymerization method using an aromatic hydrocarbon such as toluene or xylene as a solvent, a dispersion of an alkali metal such as sodium as a catalyst, and controlling the molecular weight by adding an ether such as dioxane. 744'6, same 3
No. 8-1245, No. 34L101sa) and the like are suitable I! This is the J method. It is also produced by coordination anionic polymerization using an acetylacetonate compound J3 of a Group 8 metal such as cobalt or nickel and an alkyl aluminum halide (Japanese Patent Publication No. 45-'-507,
No. 46-80300) Low polymers can also be used.

Also linseed oil, soybean oil, safflower oil, dehydrated castor oil,
Drying and semi-drying oils such as cottonseed oil, tall oil, and tung oil can also be used.

Component (A) of the present invention, that is, a polymer compound having a molecular weight of 500 to 10,000, an iodine number of 50 to 500, a carbon-carbon double bond, and an amino group of 30 to 200 mmol per 100 g [well known in the art] manufactured by the method.

- After adding maleic anhydride to a polymer compound having an anionic double bond, the general formula [Here, Ro is a hydrocarbon group having 1 to 20 carbon atoms, R and R are one of them] 1 to 20 carbon atoms, some of which may be substituted with hydroxyl groups
A method of introducing an amino group by reacting a diamine compound shown by
No. 147638, No. 53-8629, No. 53-634
No. 39) or a method in which a polymer compound having a carbon-carbon double bond is epoxidized using a peroxide such as hydrogen peroxide or peracid, and then a secondary amine is added (JP-A-53-1)
No. 6048 and No. 53-117030) are known.

Preferably (A>component is an epoxy compound containing oxirane oxygen of 0.5 to 12 weight by epoxidizing a high molecular weight compound having a carbon-carbon double bond with a molecular weight of 500 to 5,000 and an iodine number of 100 to 500. A epoxidized high molecular weight compound is prepared, and a part of the epoxy group of the epoxidized high molecular weight compound is added to the general formula [wherein R and R5 independently represent a hydrocarbon group having 1 to 10 carbon atoms, and each group is Even if a part of it is substituted with a hydroxyl group, an amine compound represented by J:<, R4 and R5 may form a ring structure] is heated at 50 to 200°C in the presence or absence of a solvent. Alternatively, the α,β unsaturated carboxylic acid or molecule mi represented by the general formula
oo ~ 350 with 10% by weight of carbon-carbon conjugated double bonds
Unsaturated fatty acids or mixtures thereof containing more than 100%
It is produced by reacting at temperatures of ~200°C.

Examples of amines used in the reaction are dimethylamine,
Examples include aliphatic amines such as diethylamine, and cyclic amines such as methylethanolamine and jetanolamine.

The amount of amine to be added is 30 per 100g of epoxy compound.
~200 mmol, preferably 50-150 mmol.

Examples of α,β unsaturated carboxylic acids include acrylic acid, methacrylic acid and crotonic acid.

Molecular weight 100-300 and 10 carbon-carbon conjugated double bonds
Examples of unsaturated fatty acids containing more than % by weight include sorbic acid, Chinese tung oil fatty acid, sunflower oil fatty acid, and dehydrated castor oil fatty acid. Chemical fatty acids can also be used, and purified eleostearic acid and conjugated linoleic acid can also be used. Alternatively, a mixture may be used in which an unsaturated fatty acid having a carbon-carbon conjugated double bond of 10% by weight or less is mixed with an unsaturated fatty acid having a large number of conjugated double bonds, so that the total amount of conjugated double bonds is 10% by weight or more. be able to. Among them, dehydrated castor oil fatty acids are advantageous and preferred because they are easily available industrially.

It is preferable that the total amount of the α,β unsaturated carboxylic acid and the unsaturated fatty acid to be added is 50 to 150 mmol in terms of carboxylic acid per 100 y' of the epoxidized polymer compound.

Component (B) of the present invention is a known commercially available epoxy resin containing at least two or more epoxy bases per molecule, such as that described in Kuniyuki Hashimoto, published by Nikkan Kogyo Shimbun, 1969. That is, any epoxy resin such as a glycidyl ether type epoxy resin, a glycidyl ether/ester type epoxy resin, a linear aliphatic epoxy resin, or an alicyclic epoxy resin can be used, especially one having an epoxy equivalent of 80 to 1,000. preferable. In particular, in order to obtain a coating film with good water resistance and corrosion resistance, it is preferable to use a glycidyl ether type epoxy resin.

The method for producing the epoxy resin emulsion of the present invention is (A> an aqueous solution neutralized with 0.25 to 1.0 molar equivalent of a water-soluble organic acid such as formic acid, acetic acid, propionic acid, or lactic acid to the amino group of the component). It can be produced by dropping a solution of a liquid epoxy resin or a solid epoxy resin dissolved in a solvent with component (B) while stirring.The temperature ranges from room temperature to 6 ℃.
Approximately 0°C is appropriate.

Examples of solvents for dissolving the epoxy resin component (B) include ethyl cellosolve, propyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diacetone, which can dissolve both resins (A) and (B). Organic solvents such as alcohol, 4-methoxy-4-methylpentanone-2, methyl ethyl ketone, isopropyl alcohol, and butanol can be used. By using such an organic solvent, the fluidity of the resin can be improved and the smoothness of the coating film can be improved. The organic solvent is preferably used in an amount of 10 to 100 parts by weight per 100 parts by weight of each component (A) and (B).

Alternatively, the epoxy resin emulsion of the present invention can be prepared by mixing the component (A) with the epoxy resin and, if necessary, a solvent, and then adding an organic acid and water to prepare the mixture.

In the present invention, (A) is used as a reactive polymer emulsifier.
It is important that the amine groups in the components are tertiary amino groups; only in this case a stable emulsion can be obtained.

The content of amino groups in the polymer compound (A) is in the range of 30 to 200 mmol, preferably 50 to 150 mmol, per 100 g of the polymer compound.

Component (B) has an amino group content of 30 mmol or less.
It is difficult to disperse and the dispersion lacks stability. When the amino group content is 200 mmol or more, the component (B) can be easily dispersed, but the water resistance of the resulting coating film is
Corrosion resistance such as salt spray resistance tends to be poor.

The content of component (B) is 3 parts per 100 parts by weight of component (△).
It ranges from 0 to 300 parts by weight, preferably from 50 to 250 parts by weight.

If the content of component (B) is less than this, the improvement in corrosion resistance will not be sufficient, and if it is more than this, water dispersibility will be deteriorated.

〔Effect of the invention〕

The epoxy resin emulsion of the present invention obtained as described above is very stable and, for example, even when left at room temperature for three months, the emulsion does not separate, thicken, or gel, and the supernatant does not change to some extent. Even if it separates, it can be returned to its original state by simple stirring.

The emulsion of the present invention can be dried and assimilated either at room temperature or by heating.

Furthermore, the component (A) used in the present invention can be cured at a lower temperature by adding a dryer. In this case, the usual dryer, cobalt, lead, manganese etc. formic acid, acetic acid, naphthenic acid, octyl I! Salt etc. can be used.

Appropriate pigments can be blended into the emulsion of the present invention. For example, one or more pigments such as lead oxide, iron oxide, strontium chromate, zinc phosphate, barium metaborate, carbon black, titanium dioxide, talc, aluminum silicate, and barium sulfate can be blended.

These pigments can be added to the composition of the present invention as they are, but first, a large amount of the pigments is added to a portion of the neutralized component (A) and dispersed in water or made into an aqueous solution, and then mixed to form a paste-like masterbatch. This paste-like pigment can be added to the composition.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

11 ■ Yunisseki Polybutadiene B-2000 (number average molecule Jft2
000, 1.2 bond 65%) was epoxidized using m vinegar R and epoxidized polybutadiene (El) with an oxirane oxygen content of 6.4% was epoxidized with l? I did it.

This epoxidized polybutadiene (El) 1.000
After charging 333 g of chlorine and ethylcerone into a 21 autoclave, 34 g of dimethylamine was added and heated to 150°C.
After reacting for 5 hours, unreacted amine was distilled off to produce a resin solution (A1) of component (A) of the present invention. The amine value of this product was 56 mmol/100 g solution, and the solid content concentration was 75.0% by weight.

11■l Epoxidized polybutadiene (E,') obtained in Production Example 1
i, ooog and butyl cellosolve 340g 21
After charging the autoclave, dimethylamine 739 was added and the mixture was reacted at 150° C. for 5 hours, and unreacted amine was distilled off to produce a resin solution (A2) of component (A) of the present invention.

The amine value of this product was 112 mmol/10 (in a liter solution, the solid content concentration was 75% by weight).

艷i亚ゆ Nippon Seki Polybutadiene B-i, goo (number average molecular weight 1.
800. 1.2 bond (64%) was epoxidized using peracetic acid to prepare epoxidized polybutadiene (E2) having an oxirane oxygen content of 6.5%.

This epoxidized polybutadiene (E2) 1,00
358 g of ethyl cellosolve and 75.1 g of methylethanolamine were placed in a 31J separable flask and reacted at 150° C. for 6 hours. Reaction reaction, 120℃
A mixture of 1179.2 g of acrylic, 2 g of hydroquinone and 27 g of ethyl cellosolve was added, and 1
A resin solution of component A of the present invention (
A3) was produced.

The amine value of this product is 67.5 mmol/100 g
The solution had an acid value of 9.9 mmol/100'J, and the solid content concentration was 75% by weight.

Production Example 4 Eight-stone polybutadiene B-i, a used in Production Example 3
oo was epoxidized using peracetic acid to produce epoxidized polybutadiene (E3) having an oxirane oxygen content of 8.3%.

This epoxidized polybutadiene (E3) 1,000
After charging 21J autoclave with 15g of dimethylamine and 15g of dimethylamine,
After reacting at 0° C. for 6 hours, unreacted amine and butyl cellosolve were distilled off to synthesize a solution (A4) having a solid content of 75% by weight and used in a comparative example of the present invention. The amine value of this solution was 1 mmol/100 g of solution.

Production Example 5 Epoxidized polybutadiene (El) obtained in Production Example 1
After charging i, ooog and butyl cellosolve 3339 into a 21 autoclave, 10.5 g of dimethylamine was added, and the reaction was carried out at 150°C for 5 hours. Unreacted amine was distilled off, and the resin solution used in the comparative example of the present invention ( A5)
was manufactured. The amine value of this product is 16 mmol/10
0g solution, and the solids concentration was 75% by weight.

100 g of each resin solution (A1) obtained in Direct Placement Production Example 1 was added with vinegar @ 1.79. 2.5 g and 3.3 g of each were added dropwise and water was added to obtain a translucent or transparent aqueous solution (A1-I) with a solid content concentration of 30% by weight.

(A-It>, (A1-n[)) were produced.

Separately, a solution (
B1) was produced.

While stirring 1'OOg each of aqueous solutions (A1-I), (A1-If), and (A1-■) at a humidity of 50-60°C
B1) Drop each 37.59 and add water to a colander to make a solid content concentration of 40% by weight.
Pl-If) and (Pl-1[[) were produced.

Lead naphthenate and cobalt naphthenate were added to each emulsion to give 0.1% lead and 0.05% cobalt, and the mixture was applied to a bright steel plate (JIS-G-3141) using a 3 mil applicator. After drying at ℃ for 30 minutes, cuts were made in the coating film, and a corrosion resistance test was conducted by spraying a 5% NaCIJ aqueous solution.Table 1 shows the results. For comparison, the results of similar tests on commercially available styrene-acrylic emulsions and epoxy ester emulsions are also shown.

Table 1 Note) Shows the maximum length of the chain from the cut part.

Example 2 6.7 g of acetic acid was added dropwise to 100 g of the resin solution obtained in Production Example 2 in the same manner as in Example 1, and water was further added to bring the solid content concentration to 30.
A % by weight aqueous solution (A2-I) was prepared.

Separately, Epicoat 1001 (manufactured by Yuka Shell Epoxy ■) 6
A solution (B2) was prepared by dissolving 0 part by weight in 40 parts by weight of butyl cellosolve.

Aqueous solution (A2-I)
1 solution 37.5 g, 75 g and B2 solution 50 g
9 and 100 g were added dropwise, and further water was added to form the emulsion of the present invention (P
-I), (P2-II).

(P m ) Oyo U (P 2 1 V) was prepared, IC0 Table 2. On the other hand, aqueous solution (A2-I) 10 (9 Cl of red iron in 1,
45 g of zinc phosphate and 45 g of charcoal were placed in a ball mill and kneaded until the size of pigment particles became 30 μm or less to obtain a mill base. While stirring, add 50 g of each of the emulsions shown in Table 2, 0.1 part of lead naphthenate and cobalt naphthenate, and 0.0 g of lead naphthenate to 250 g of mill base prepared in 1 q.
3 parts were added and mixed thoroughly to obtain an aqueous coating composition.

Each aqueous coating composition was applied to a bright steel plate using a 3 mil applicator, and after drying at 120°C for 30 minutes, JIS K-5 was applied.
400. The results are shown in Table 3.

Table 3 Example 3 1.5 g and 2.3 g of GiM were added to each 1009 of the resin solution 'a (A3) obtained in Production Example 3 with stirring to neutralize it, and then water was added to solidify it. Translucent or transparent aqueous solution (A3-I) with a concentration of 30% by weight and (A3
-II) was produced.

Separately, 80g of Epicote 828 and Petilse O Tsuru 110
A solution (B3) was prepared by mixing 10 g of g and n-butanol.

Aqueous solution ('A3-I) and (A3-.11) 10 each
0g of solution (B3) 4 while stirring while keeping it at 50-60℃.
The emulsion of the present invention (P3-
I) and (P3-II) were produced. 'This was applied to a bright steel plate using a 3 mil applicator, and after drying at 20°C for 7 days, a corrosion resistance test was conducted under the same conditions as in Example 1. Table 4 shows the results.

Comparative Example 1 Vinegar M5□oga5 and 1.57 were added to each 100 g of the resin solution obtained in Production Example 4 while stirring to neutralize it, and then water was added to make a transparent solution with a solid content concentration of 30% by weight. Aqueous solutions (A4-I) and (Δ4-■) were prepared.

The epoxy resin solution EP-1 prepared in Example 1 and the epoxy resin solution EP-2 prepared in Example 2 were prepared as aqueous solutions (A4-I) and (A4-II) in the same manner as in Example 1.
and further diluted with water to prepare four emulsions used in comparative examples of the present invention having a solid content of 40% by weight. These emulsions were applied to a bright steel plate using a 3 mil applicator and a corrosion resistance test was conducted under the same conditions as in Example 1. The results are shown in Table 4.

Table 4 It can be seen that the corrosion resistance is inferior compared to the test results of Example 1.

Comparative Example 2 0.6 (j) of acetic acid was added to 10 CI of the resin solution prepared in Production Example 5 while stirring to neutralize it, and then water was added to a colander to form a cloudy aqueous solution with a solid content of 111 degrees and 30% by weight. An emulsion was prepared by adding 37.5 g of a butyl cellosolve solution of 80% Epicote 828 to 100 g of this aqueous solution with stirring.This emulsion had poor stability, separating when left at room temperature for about a week.

Claims (1)

[Claims] (A) a carbon-carbon double bond with a molecular weight of 500 to 10,000 and an iodine value of 50 to 500 and 30 per 100 g;
100 parts by weight of a polymer compound having ~200 mmol of tertiary amino groups, (B) 30 to 300 parts by weight of an epoxy resin, and (C) an organic acid of 0.25 to 1 part by weight per amino group.
．． Aqueous coating composition with 0 molar equivalents added.