JPS6038426B2 - Aqueous coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous coating composition, and more particularly to an aqueous coating composition useful as a cold-curing anticorrosive coating composition and a glossy topcoat coating composition. .

In recent years, there has been a strong demand for pollution-free, safe, and sanitary paints from the standpoint of environmental protection and health and safety, and water-based paints have been attracting attention. There are two main types of water-based paints: those using water-soluble resins as vehicles and those using emulsions. However, although water-soluble resins can provide a high level of gloss, they have a large amount of hydrophilic components to make them water-soluble and have a small molecular weight, resulting in poor water resistance and film resistance of the dried paint film. . On the other hand, products using emulsions have poor pigment dispersibility, are difficult to obtain a glossy coating film, have poor adhesion to metal materials, and moreover, the coating film tends to be porous, which is characteristic of emulsions. The power is not enough either. The present inventors have made earnest efforts to develop an aqueous coating composition that overcomes these conventional deficiencies and has excellent water resistance, weather resistance, and corrosion resistance, and as a result, they have arrived at the present invention.

That is, the present invention relates to an emulsion (1) obtained by emulsion polymerization of a polymerized vinyl monomer using a neutralized and water-solubilized product of a maleated alkyd resin as an emulsifier, and maleation of a drying oil, a semi-drying oil, a synthetic oil, or a processed oil. neutralized product,
'21 Neutralized product of maleated addition polymer having a drying oil fatty acid base group and/or a semi-drying oil fatty acid group as a side chain, Q. Fatty acid-modified monomers obtained by reacting glycidyl esters of unsaturated acids, neutralized products of Q.8-ethylenically unsaturated acids and other addition-polymerizable unsaturated monomers, and [41 maleated polybutadiene] The present invention relates to an aqueous coating composition comprising, as a main vehicle component, an oxidatively crosslinked water-soluble or water-acidic resin (0) selected from neutralized products of such polymers. Emulsion (1) used in the present invention is obtained as follows.

The maleated alkyd resin, which is a precursor of the emulsifier of emulsion (1), is obtained by maleating a condensate of a polyhydric alcohol, a polybasic acid, and an unsaturated fatty acid.

Polyhydric alcohol components include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, trimethylolethane, glycerin, 2.
2-dimethylpro/fone diol, 1,2,6-hexanetriol, sorbitol, bentaerythritol,
Examples include diventaerythritol and diglycerol. Polybasic acid components include phthalic anhydride, isophthalic acid, trimellitic anhydride, maleic anhydride, fumaric acid, tetrachloromaleic anhydride, tetrahydrophthalic anhydride, adipic acid, chlorendic acid, succinic acid,
Examples include sebacic acid, hexahydrophthalic anhydride, azelaic acid, pyromellitic anhydride, and terephthalic acid.

Unsaturated fat-brewing ingredients include linseed oil, tung oil, oticica oil, eno oil, safflower oil, soybean oil, sesame oil, poppy oil, hempseed oil, grape kernel oil, corn oil, tall oil,
Mention may be made of fatty acids such as sunflower oil, cottonseed oil, walnut oil, rubber seed oil, fish oil, dehydrated castor oil, and/or other fatty acids. The maleation reaction for imparting oxidation is carried out by the same conventional method as for maleation of drying oils.
That is, the alkyd resin is placed in a reaction vessel together with maleic acid or maleic anhydride and, if necessary, a solvent, and the mixture is thoroughly purged with nitrogen.
All you have to do is heat it up. Maleated alkyd resin is made of drying oil fatty acid and/or semi-drying oil fatty acid with a fatty acid oil length of 20
~ Iso-ishi must now contain 40-8.

The degree of maleation is oxidized from 20 to 200, preferably from 60 to 150. If the molecular weight of the alkyd resin is too small, drying properties will be poor, and if it is too large, the maleation reaction will be hindered, so the number average molecular weight should be about 300 to
8000, preferably in the range of about 800 to 5000. The maleated alkyd resin thus obtained is neutralized using alcohol, amine, ammonia, etc.
Emulsion (1) is created by emulsion polymerization of a polymerizable vinyl monomer using the water-soluble material as an emulsifier.
is obtained.

A wide variety of polymerizable pinyl monomers can be used, but those that are too hydrophilic are not preferred to be used frequently, as in the case of general emulsion polymerization.

Examples of such polymerizable pinyl monomers include those of the general formula CH
2=C(R,)COOR2 (where R is hydrogen or a methyl group; when R is hydrogen, R2 is an alkyl group having 2 to 26 carbon atoms; when R is a methyl group, R2 is an alkyl group having 1 to 26 carbon atoms; (representing an alkyl group), glycidyl methacrylate, glycidyl acrylate, an adduct of glycidyl methacrylate or glycidyl acrylate with a carboxylic acid having 2 to 26 carbon atoms, ethylene glycol monoalkyl ether, Esterified products of propylene glycol monoalkyl ether or diethylene glycol monoalkyl ether (alkyl group has 1 to 8 carbon atoms) and acrylic acid or methacrylic acid, allyl acrylate, allyl methacrylate, hydroxypropyl methacrylate, hydroxyp. Pyracrylate, hydroxyethyl methacrylate, acrylic acid or methacrylic acid and Cardular E (
Shell Chemical Co., Ltd., product name), jetylaminoethyl methacrylate, allyloxyethyl acrylate, allyloxyethyl methacrylate, styrene, vinyltoluene, Q-methylstyrene, butadiene,
Examples include pentadiene, isoprene, chloroprene, and methacrylonitrile. These polymerizable vinyl monomers may be used alone or in combination of two or more, and furthermore, the vinyl monomers may contain water-soluble or hydrophilic compounds such as acrylic acid, methacrylic acid, acrylamide, and methacrylamide in an amount of about 10% by weight or less. A vinyl monomer or the like may be used in combination. The ratio of the emulsifier and these polymerizable pinyl monomers used in the present invention is such that the acid value in the total solid content of the produced emulsion before neutralization is about 3 to 150, particularly about 15 to 50.
It is desirable to make it so that Also, emulsion (1
) is preferably about 15 to 65%. Generally known methods can be used as the emulsion polymerization method to obtain the emulsion (1) used in the present invention.

Any polymerization initiator may be used as long as it generates radicals, and peroxide and azo initiators are generally used.

In the aqueous coating composition of the present invention, the oxidatively crosslinked water-soluble or water-dispersible resin (like substance) used in combination with the emulsion (1) as a main component includes {1-drying oil; Neutralization of maleated products of semi-drying oils, synthetic oils or processed oils, neutralization of maleated products of addition polymers having 2-drying fat and fat acid residues and/or semi-drying fat and fat acid residues as side chains. fatty acid modified monomers obtained by reacting glue-drying oil fatty acids and/or semi-drying oil fatty acids with glycidyl esters of Q.3-ethylenically unsaturated acids, Q.8-ethylenically unsaturated acids and other Examples include neutralized addition-polymerizable unsaturated monomers, maleated polybutadiene-based polymers, and the like.

The method for producing these oxidatively crosslinked water-soluble or water-dispersible resins {1} to {4} will be described below. '1
' To obtain a neutralized product of maleated saddle oil, semi-drying oil, synthetic oil or processed oil, the drying or semi-drying oil and boiled oil used to prepare the emulsifier of emulsion (1);
If synthetic or processed oils such as stand oils, esterified oils, styrenated oils, urethane oils, and cyclobentagenated oils are subjected to an addition reaction with maleic acid or maleic anhydride and have an acid value of 20 to 200, they can be neutralized. good.

t21 A neutralized product of a maleated addition polymer having a drying fat acid residue and/or a semi-drying oil fatty acid residue as a side chain is a homopolymer of a hydrous acid group- or glycidyl group-containing pinyl monomer, or a monopolymer of this monomer and others. A method of esterifying a polymer with a vinyl monomer that does not contain hydroxyl groups and glycidyl groups with a drying fatty acid and/or a semi-drying fatty acid; A homopolymer of a monomer obtained by adding a fatty acid or a copolymer of this monomer and the above vinyl monomer (■) is an addition polymer with an acid value of 20.
It is obtained by maleating to a concentration of ~350 and then neutralizing. In these reactions, it is preferable that the monomer composition of the resulting addition polymerized polymer contains 5% by weight or more of a hydrous acid group- or glycidyl group-containing vinyl monomer component. {3' In order to obtain a water-soluble or water-dispersible neutralized fatty acid-modified acrylic polymer, Q.8-ethylenically unsaturated acid is added to the dry or semi-dry fat and fat acid used to create the emulsifier in the emulsion (1). fatty acid-modified monomers obtained by reacting the glycidyl esters of What is necessary is just to combine so that an acid value may become 20-350.

'4} In order to obtain a neutralized product of a maleated polyptadiene-based polymer, a polybutadiene homopolymer or a polybutadiene unit having a number average molecular weight of about 200 to about 4,000 u, preferably about 500 to about 10,000, or 1% by weight or more as a putadiene unit is used. A butadiene copolymer having the above-mentioned number average molecular weight, preferably containing 4% by weight or more, or a modified product obtained by modifying a homopolymer or copolymer thereof by hydrogenation or cyclization reaction, etc., is mixed with maleic acid or anhydride. Acid value 20-35, preferably 40-2 depending on maleic acid
What is necessary is to neutralize the maleate so that it becomes 00.

In the oxidatively crosslinked water-droppable or water-dispersible resin (like material) of the present invention obtained as described above, the acid value is 2.
If the acid value is less than 0, the water solubility and water dispersibility will be poor, and if the acid value exceeds the respective upper limit, the water resistance of the produced film will be insufficient.

The blending ratio in the composition of the present invention can be determined within a wide range, but preferably the solid content/heavy soil ratio is (1) component/(B) component = 95/5 to 5/9, particularly 90/10 to 10/90. A range is preferred.

When the blending ratio of component (1) and component (0) is within the above range, it is preferable because the drying properties, weather resistance, and corrosion resistance of the coating are excellent. To create this composition, all the components need to be mixed together, and there is no problem in adding ordinary coloring pigments, anti-corrosion pigments, dryers, thickeners, foam control agents, and other additives. . The composition of the present invention is sufficiently cured at room temperature, but may also be cured by heating. The coating composition of the present invention is characterized not only by its excellent weather resistance, corrosion resistance, and drying properties, but also by the ability to obtain a high-gloss coating film, as well as by its excellent painting workability, especially its brush painting workability. , it has performance that is highly useful as an industrial material. below,
The present invention will be explained with reference to production examples and examples.

Note that "parts" and "%" refer to "parts by weight" and "% by weight" unless otherwise specified. Production Example 1 5 404 parts of phthalic anhydride, 523 parts of bentaerythritol, 2573 parts of linseed oil fatty acid, 175 parts of xylene, and 7 parts of dibutylthion oxide were placed in the reaction vessel, and the mixture was heated to 7.5 parts at 230 qo in the presence of nitrogen. Allowed time to react.

An alkyd resin having an acid value of 3.0 was obtained. 2 Into the reaction vessel, add 1 part of the above alkyd resin and 1 part of maleic anhydride.
5 parts were added thereto and reacted at 190° C. for 9 hours in the presence of nitrogen.

The reaction mixture was cooled to 100 qo, 55 parts of water was added, and 100 qo
oo for 3 hours. Resin acid value 100 Resin solid content 9
A 2.4% maleated alkyd resin solution was obtained. For 100 parts of this resin solution, 2 parts of butyl cellosolve,
It was neutralized by adding 10.6 parts of 28% ammonia water and dissolved in water to obtain a resin solution with a solid content of 50%. Production Example 2 320 g of the resin solution obtained in Production Example 1 was dissolved in 670 g of water.

Furthermore, add 16 tbsp of ethylene glycol monobutyl ether, mix well to dissolve thoroughly, add 414 tbs of n-butyl methacrylate, stir well, and thoroughly emulsify the mixture. Add 1 tbsp of ammonium persulfate to 20 tbs of water. Add the above ingredients, heat while heating, and react at 80 oo for 2 hours to obtain an emulsion. Production Example 3 320ml of the resin solution obtained in Production Example 1 was dissolved in 670ml of water.

Furthermore, 14 pieces of butyl cellosolve were added and dissolved well, followed by 207 pieces of styrene and 2-ethylhexyl methacrylate.
After adding 0.7 liters of water and stirring well to form an emulsion, heat 1 liter of ammonium persulfate and 20 parts of clean water while stirring thoroughly. Generates heat at 65°C.

Keep the temperature at 8-0 for 2 hours to obtain an emulsion.

Production Example 4 Using a Gardner Foam Viscometer, put 1367 kg of stand linseed oil of M to N (20 qC), 132 ml of maleic anhydride, and a small amount of toluene into 2 4-necked flasks, and
The mixture was reacted for 4 hours to obtain maleated stand linseed oil with an acid value of 96.

Furthermore, after neutralizing this with ammonia, it was added to water to reduce the solid content to 5.
Dilute to 0% to obtain resin varnish. Production Example 5 RJ-101 (number average molecular weight 1150, OH content 7.
7% styrene-allylic alcohol copolymer, manufactured by Monsanto Chemical ■) 1641 Tadiz oil and fat folic acid 2080
200 g of xylene and dibutyltin oxide 3.
Put 3 pieces of water into a 4-necked flask and add 2 pieces of water while dehydrating.
A resin having an acid value of 5.47 was obtained by reacting at 30°C for one hour.

Add 454 ml of maleic anhydride to this to make it 190-200
Carry out the maleation reaction in the afternoon for 7 hours. After removing xylene and unreacted maleic anhydride by distillation under reduced pressure, it was mixed with water and ethylene glycol monobutyl ether was added to give a total acid value of 104, a half acid value of 96, and a solid content of 80%. Obtain a solution. After neutralizing this solution by adding 9 parts of 28% ammonia water, 51 parts of water was added to make the solid content 50%.
of resin varnish. Production example 6 236 parts of linseed oil fatty acid, 1 part of glycidyl methacrylate
1 part of hydroquinone, 0.4 part of hydroquinone, and 0.2 part of tetraethylammonium bromide were placed in a reaction vessel, and reacted with stirring at a temperature of 140 to 150 q○ for about 4 hours to obtain an addition reaction product.

Next, put 10 pieces of n-butyl cellosolve into the reaction container,
Heating to 120 pm, 7 parts of azobisdimethylvaleronitrile was added to a mixture of 4 parts of the above addition reaction product, 47 parts of n-butyl methacrylate, and 13 parts of acrylic acid, and the mixture was heated to 120 pm in a nitrogen stream with candlelight. The reaction was carried out at ℃ for 8 hours.

After the reaction was completed, 75 parts of butyl cellosolve was distilled to obtain a polymer with a polymerization rate of 99.5%, an acid value of 91, and a solid content of 80%. 8 parts of 28% aqueous ammonia are added to 100 parts of this reaction product to make it water-solubilized, and 52 parts of water is added thereto to obtain a resin varnish with a solid content of 50%. Production example 7 Polybutadiene A (molecular weight 1900, 1.4cis type 7
2%, 1,4-trans type 27% and 1,2-pinyl type 1%) 150 ml, maleic anhydride 20 cc and xylene 75 cc were sealed in an autoclave, thoroughly replaced with nitrogen gas, and then heated at high speed to 190 ml. Heat and react at ~200°C for 5 hours.

After the reaction, wash thoroughly with water and add 60 cc of butyl cellosolve.
is added and water is removed using an evaporator to obtain a maleated polybutadiene solution.

The acid value of maleated polybutadiene is 93, and the concentration is 85.6.
%. Next, take 100 minutes and add 8.6 cc of 28% ammonia water to neutralize it while stirring and dissolve it in water to obtain a resin varnish with a solid content of 50%. Example 1 After adding 27 parts of water to 4 parts of the resin varnish obtained in Production Example 6, 80 parts of titanium dioxide, 1 part of Antifoam B (manufactured by Toray Silicon ■, trade name) as an antifoaming agent, and a dryer. Cobalt naphthenate and lead naphthenate were added as metal amounts of 0.1 part and 0.3 part, respectively, and the mixture was sufficiently kneaded using a rope mill, and then the pigment particle size was adjusted to 10 using a sand mill dispersion machine.
A pigment paste was obtained by dispersing the pigment to a concentration of 1C or less.

Then, 20 pieces of the emulsion obtained in Production Example 2 were added to this paste and stirred well. Thereafter, 8 parts of a 10% aqueous polyvinylpyrrolidone solution was added to increase the viscosity, and the mixture was thoroughly mixed again to obtain an aqueous coating composition with a viscosity of 90 KU. Examples 2 to 13 Aqueous coating compositions having a viscosity of 90 KU were prepared in the same manner as in Example 1.

However, in Examples 8 to 13, the pigment was dispersed so that the average particle size of the pigment in the pigment paste was 40 particles. The composition is shown in the table.
As shown in 1. Table 1 *1 Xylene solution with metal content of 5 *2 Comparative example of xylene solution with metal content of 15 or more 8 foundations, 1 part of Antifoam B (manufactured by Toray Silicone ■, trade name) as an antifoaming agent, and 0.1 part and 0.3 part of cobalt naphthenate and lead naphthenate as a dryer, respectively, were added. After sufficiently kneading with a machine, the mixture was dispersed with a sand mill dispersion machine so that the pigment particle size was 10 mounds or less to obtain a pigment paste.

Next, 174 parts of 3 balls of latex (solid content concentration 46%, manufactured by Dow Chemical Company, trade name), which is an acrylic polymer emulsion, and 8 parts of a 10% polyvinylpyrrolidone aqueous solution were added, stirred well, and added to tap water. An aqueous coating composition whose viscosity was adjusted to 9 mm was obtained. Comparative Example 2 A pigment paste was prepared in the same manner as in Comparative Example 1, and a pigment paste was prepared using Ucar Mottling 0, a copolymer emulsion of acrylic acid ester and styrene, solid content concentration 48%, manufactured by U.C.C.
167 parts of the product under the trade name and 8 parts of a 10% polyvinylpyrroldone aqueous solution were added thereto and mixed well to obtain an aqueous coating composition whose viscosity was adjusted to 6 ml with tap water.

Comparative Example 3 To 1 anchor part of the resin varnish obtained in Production Example 5, 1 base part of water was added, and then 10 parts of iron oxide pigment and 1 part of calcium molybdate were added.
Add anchorage and 15 parts of calcium carbonate, 1 part of Antiform B "manufactured by Toray Silicone ■, trade name" as an antifoaming agent, 0.025 parts of cobalt naphthenate and lead naphthenate each as a metal amount as a dryer, 0.075
The pigment was dispersed using a sand mill dispersing machine so that the average particle size of the pigment was 40 or less to obtain a pigment paste.

Next, 4 bags of acrylic acid ester emulsion Roplex AC-34 (solid content concentration 45%, manufactured by Rohm and Haas, trade name) and 2 parts of a 10% polyvinylpyrrolidone aqueous solution were added and thoroughly mixed. Then, tap water was added to adjust the viscosity to 90 KU to obtain an aqueous coating composition. Test method and test result The aqueous coating compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 3 were
70xo. It was applied to an 8-wall mild steel plate so that the dry film thickness was 45 to 50 mm, dried for 7 days at a temperature of 2 to 0, and a relative humidity of 75%, and then subjected to a test.

Test method Water resistance: The presence or absence of an abnormality in which a coating film was formed by immersion in 20 qo of clean water was observed.

Salt water resistance: The coating film was immersed in 3% saline solution at a temperature of 2.0 mm, and the presence or absence of abnormalities occurring in the coating film was observed.

Salt water misting resistance: A test plate with a cross cut that reached the substrate was placed in a salt water misting device covered with 35 qo, 5% salt water, and the presence or absence of any abnormality occurring in the coating film was observed.

Workability: Using a horsehair flat brush, 900 x 600 x 0.8
It was applied to the steel plate of the ribs, and the quality of the brushing was observed.

Outdoor peelability: A test plate with a cross cut that reached the substrate was placed outdoors and the presence or absence of any abnormalities in the coating film was observed.

Gloss: It was applied uniformly to a glass plate using an 8hil doctor blade, and after drying at 2000°C for 5 days, the 60° specular reflectance was measured.

The test results are shown in Table 2, and it can be seen that the aqueous coating composition of the present invention has excellent performance.

Table-2

Claims (1)

[Claims] 1 Emulsion (I) obtained by emulsion polymerization of a polymerizable vinyl monomer using a neutralized and water-solubilized maleated alkyd resin as an emulsifier and (1) a maleated product of drying oil, semi-drying oil, synthetic oil or processed oil. Neutralized product, (2
) a neutralized product of a maleated addition-polymerized polymer having drying oil fatty acid residues and/or semi-drying oil fatty acid residues as side chains; (3) α/β- Fatty acid modified monomers obtained by reacting glycidyl esters of ethylenically unsaturated acids, α and β-
Oxidatively crosslinked water-soluble or water-dispersible resin selected from neutralized products of ethylenically unsaturated acids and other addition-polymerizable unsaturated monomers, and (4) neutralized products of maleated polybutadiene polymers. An aqueous coating composition comprising (II) as a main vehicle component.