JPS5930872A - Aqueous coating composition - Google Patents

Abstract

PURPOSE:To provide titled composition of air-drying type, capable of affording coating film of high storage stability, outstanding water and alkali resistance, etc., comprising an aqueous solution or dispersion of an addition copolymer resin prepared by the reaction between a carboxyl group-contg. copolymer and an unsaturated aliphatic primary amine. CONSTITUTION:The objective composition comprising an aqueous solution or dispersion of an addition copolymer resin prepared by the reaction between (A) a carboxyl group-contg. copolymer (pref. synthesized by a solution polymerization usig a solvent such as toluene) consisting of (i) a carboxyl group-contg. monomer such as acrylic acid, maleic acid, and (ii) another copolymerizable monomer such as methyl methacrylate, styrene, and (B) an unsaturated aliphatic primary amine, in a weight ratio (A)/(B) of pref. 3/7-9/1. This proportion is such that the acid value of said addition copolymer resin will fall in the range 30-120(mgkOH/g) through the excessive amount of the carboxyl group of the component (A) relative to the amount of the amino group of the component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to air-drying aqueous coating compositions.

Air-drying aqueous coating compositions have been known for some time, and a typical water-soluble resin used in the aqueous coating composition is a water-soluble alkyd resin.

However, since this water-soluble alkyd resin contains many ester bonds in its main chain, it easily hydrolyzes when left in an aqueous solution, especially a neutralized aqueous solution. T:l for aqueous coating made of polyester alkyd resin
The product had the drawback of poor storage stability, and the resulting coating film was poor in water resistance, alkali resistance, weather resistance, etc.

In view of the above-mentioned current situation, the present inventors have made efforts to develop a water-soluble or water-dispersible resin that does not contain an easily hydrolyzed ester bond in its main chain and has air drying properties. This led to the present invention.

That is, the present invention provides Cal7!, which is composed of a carboxyl group-containing single group and other copolymerizable +1 acid bodies. This is a book about air-drying water-based coatings made of an aqueous solution or a water-in-water solution of an addition copolymer resin obtained by reacting an unsaturated aliphatic primary amine with an unsaturated aliphatic primary amine-containing copolymer. .

The carboxyl group-containing JIL material used in the present invention includes, for example, ethylenic annual salary monocar +l/
acid (such as acrylic acid, methacrylic acid, crotonic acid, sorbic acid, cinnamic acid, etc.), ethylenically unsaturated polycarboxylic acid (such as fumaric acid, maleic acid, itaconic acid, etc.), ethylenically unsaturated polycarboxylic acid (such as fumaric acid, maleic acid, itaconic acid, etc.); Examples include alkyl half esters, partial esters, and partial amino acids of Japanese polycarboxylic acids, and they can be used singly or as a mixture of two or more, but acrylic acid and methacrylic acid are preferred.

Other copolymerizable monophenols used in the present invention include, for example, acrylic acid 1 or methacrylic acid C,
-Alkyl esters of CI8 (e.g. methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, 'hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isopdyl methacrylate, hekynyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, etc.), glycidyl acrylate, methacrylic acid Glycidyl, alkoxyalkyl esters of acrylic acid or methacrylic acid (e.g. methoxyethyl acrylate, methoxybutyl acrylate, methoxyethyl methacrylate, methoxybutyl methacrylate, etc.), alkenyl esters of acrylic acid or methacrylic acid (e.g. allyl acrylate, methacrylate) hydroxyalkyl esters of acrylic or methacrylic acid (such as hydroxyethyl acrylate, hydroxyglobil acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, etc.), mono- or dialkylamino esters of acrylic or methacrylic acid (e.g. methylaminoethyl acrylate, diethylaminoethyl acrylate, methylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.), amides of acrylic acid or methacrylic acid (acrylic acid amide, methacrylic acid amide, N-methylol acrylamide, N-methylol methacrylamide, etc.), vinyl aromatic compounds (e.g. styrene, α-methylstyrene, vinyltoluene, p-chloromethylphnato),
Examples include polyolefin compounds (for example, butadiene, isoprene, chlorobrene, etc.), acrylonitrile, allyl methacrylate, etc., and a mixture of two or more of them may be used.

The carboxyl group-containing copolymer can be synthesized by a one-block polymerization method, a solution polymerization method, etc. in the same manner as in the synthesis of ordinary vinyl polymers, but a solution polymerization method is preferable.

Examples of solvents used in the solution polymerization method include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as mineral spirits, ethers such as dioxane,
Examples include estenoν such as butyl acetate, ketones such as methyl ethyl ketone, alcohols such as butanol, and glycols such as butyl cellosolp.
It is used as a mixture of fir1 or more.

Examples of radical initiators in the copolymerization reaction include organic peroxides such as benzyl peroxide, lauroyl peroxide, cumene hydroperoxide, di-L-butyl peroxide, and t-butyl peroxybenzoate; Examples include azo compounds such as butyronitrile.

The unsaturated aliphatic primary amine used in the present invention is an aliphatic amine whose main component is a primary amine that is made from an unsaturated fatty acid and retains the original unsaturated group,
For example, as described on page 98 of ``Fatty Acid Chemistry'' (published by Saiwai Shobo), a nitrile is usually obtained from a fatty acid, and then the nitrile is reduced.

Examples of unsaturated fatty acids include single fatty acids such as oleic acid, linoleic acid, lilunic acid, eleostearic acid, and ricinoleic acid; linseed oil fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids, soybean oil fatty acids, and tung oil fatty acids. Examples include dry or semi-dry fatty acids such as fatty acids, safflower oil fatty acids, tall oil fatty acids, and fish oil fatty acids, which may be used singly or as a mixture of two or more.

The addition of the unsaturated aliphatic primary amine to the carboxyl group-containing copolymer is carried out by forming an amide bond between the carboxyl group of the carboxyl group-containing copolymer and the amine group of the unsaturated aliphatic primary amine. , the amide bond forming reaction is carried out without catalyst, at 140-2o.

Proceeds rapidly at ℃ with dehydration.

The mixing ratio of the carboxyl group-containing copolymer and the unsaturated aliphatic primary amine is such that the carboxyl group-containing copolymer is stoichiometrically larger than the carboxyl group f of the polymer and the amine group of the unsaturated aliphatic primary amine. - IK ((Thus, the acid value of the resulting addition copolymer resin is 20 to 150
(ηKoyI/y), preferably set to 30-120ξ
Note: If the acid value is less than 20, it will be difficult to make it water-soluble or water-dispersible by itself, and if it exceeds 150, the resulting coating film will have poor water resistance.

Oda, carboxyl group-containing copolymer and unsaturated aliphatic first
The mixing ratio with amine is preferably 3/7 to 9/1 in terms of weight ratio; if it is less than 3/7, the hardness of the resulting coating film will be low, and if it exceeds 9/l. Due to the lack of unsaturated groups, drying properties are poor, and water resistance, chemical resistance, etc. are poor.

It is preferable to remove part or all of the water-immiscible solvent from the obtained addition copolymer resin by heating, reducing pressure, or the like.

The addition copolymer resin is then conventionally neutralized with ammonia or a volatile amine (e.g., methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, dimethylethanolamine, etc.) to neutralize the carboxyl groups of the addition copolymer resin. It becomes water-solubilized or water-dispersed by mixing.

The amount of ammonia or volatile amine used is usually 01 to 20, based on the carboxyl group in the addition copolymer resin.
The number of employees is preferably 0.3 to 1.2.

The water-solubilized or water-dispersed addition copolymer resin obtained as described above is used as a coating film-forming component in the aqueous coating composition of the present invention.

Note that the addition copolymer resin can be used by mixing with conventional water-soluble resins, water-dispersible resins, and the like.

To the aqueous coating composition of the present invention, extender pigments, coloring pigments, dryers, additives (for example, rust preventives, ultraviolet absorbers, surfactants, preservatives, etc.), etc. can be added as necessary.

Dryers are commonly used linoleates, naphthenates, resinates, etc. of calcyrano, zinc, cerium, lead, zirconium, chromium, manganese, iron, cobalt, nickel, etc., and these dryers By adding , the drying properties of the coating film can be significantly accelerated.

As described above, the 4i Radar water-based coating composition is applied to the object to be coated (for example, metal, wood, plastic, glass fiber reinforced plastic, concrete, etc.) by brush coating, roller coating, flow coating, spray coating, etc. , slate, etc.) and apply it directly (no need to use a primer).
By natural drying (or heat drying), a cured coating that dries quickly and has excellent lead hardness, adhesion, flexibility, water resistance, corrosion resistance, alkali resistance, storage stability, weather resistance, etc. A membrane is obtained.

Next, the present invention will be explained in further detail with reference to Examples and Comparative Examples. In the examples, parts are parts by weight, and chi is the weight ton.

Example 1 In a reaction vessel, butyl cellosolve 17011) Chef 60
The mixture was heated with stirring until it reached a reflux state at about 135°C.

After reaching the reflux state, while maintaining a gentle reflux state,
A mixture of a carboxyl group-containing monomer and other copolymerizable monomers (hereinafter referred to as monocell mixture) having the following composition was dropped into the reaction vessel from a dropping funnel over a period of about 2 hours.

Methyl methacrylate 371 parts Acrylic acid 88 t-Butylperoxybenzo 4 Etotoluene 25 Then 1
After continuing to reflux for a period of time, a polymerization initiator solution having the following composition was added.

2 parts of t-butyl peroxybenzo 20 parts of ethobutyl cellosolve Then, after refluxing the mixture, an unsaturated aliphatic primary amine solution having the following composition was added.

Unsaturated aliphatic primary amine (NOF 94 parts (produced by Nippon Oil Co., Ltd., soybean fatty amine, Nitsu → J-amine amine sn) Butyl cellosolve 70, then 1
Raise the temperature to 50℃ and remove the water produced by the reaction for 11 tlf.
After reacting for 2 hours while removing it from the system through a tube,
Toluene was removed by distillation.

Then, after cooling to 60°C, approximately 180 parts of isopropyl alcohol was added to reduce the heating residue to aO% and the resin acid value to be 83.
, a resin solution having a Gardner viscosity of z2 to zs was obtained.

The obtained resin solution was neutralized with 28% ammonia water in an amount of 1.0 equivalent to the carboxyl group of the resin solution to obtain an aqueous resin solution.

After adding 300 parts of rutile titanium dioxide, 2 parts of cobalt naphthenate (metal content 5%), and 5 parts of lead naphthenate (metal content 15%) to the resulting resin aqueous solution, it was milled in a sand mill using glass beads as the media. The mixture was dispersed in water, the viscosity was adjusted with water, and the mixture was coated on a degreased mild steel plate to a film thickness of 60 μm using a bar coater. Then, it was dried at 20° C. and 75% temperature for 7 days to obtain a test piece.

Regarding the obtained test pieces, drying properties, lead hardness, adhesion,
Tests were conducted for removability, water resistance, corrosion resistance, alkali resistance, storage stability, weather resistance, etc.

Table 1 shows the test results.

Example 2 In a reaction vessel, 170 parts of butyl cellosolve and 60 parts of toluene were added.
The mixture was heated with stirring until it reached a reflux state at about 135°C.

After reaching the reflux state, while maintaining a gentle reflux state,
A monomer mixture having the following composition was added dropwise into the reaction vessel from the dropping funnel over a period of 2 hours.

Butyl methacrylate 163 parts Styrene 1311 Acrylic acid 2-
Ethylhexyl 32I acrylic acid
96rt-butylperoxybenzo
4 parts Etotoluene 25 Then, 1
After continuing the reflux state, a polymerization initiator solution having the following composition was added.

t-Butyl peroxybenzo 2 parts ethbutyl cellosolve 20 Then,
After refluxing for 2 hours, an unsaturated aliphatic primary amine solution having the following composition was added.

Unsaturated aliphatic primary amine (previously - 131 parts Example 1) Butyl cellosolve 70 then 1
The temperature was raised to 50° C., and the reaction was carried out for 2 hours while water produced by the reaction was removed from the system through a separation tube, and then toluene was removed by distillation.

Then, after cooling to 60°C, about 181 parts of isopropyl alcohol was added to give a heating residue of 60% and a resin acid value of 81.
, a resin solution with a Gardner viscosity of z8 to z4 was obtained.

Thereafter, using the obtained resin solution, the same operation as in Example 1 was carried out to obtain a test piece.

The obtained test piece was subjected to the same test as in Example 1.

Table 1 shows the test results.

Example 3 170 parts of 1-butyl cellosolve and 60 parts of toluene in a reaction vessel
The mixture was heated with stirring until it reached a reflux state at about 135°C.

After reaching the reflux state, while maintaining a gentle reflux state,
A monomer mixture having the following composition was added dropwise to the reaction vessel using a dropping funnel over a period of 2 hours.

Butyl methacrylate 155 parts Styrene
E02 2-ethylhexyl acrylate 31y methacrylic acid
1371t-butylperoxybenzo 4
I ethtoluene 25I then 1
After continuing to maintain the reflux condition, a polymerization initiator solution having the composition shown below was added.

2 parts ethbutyl cellosolve 20 t-butyl peroxy 20 t-butyl cellosolve After refluxing for 2 hours, an unsaturated aliphatic primary amine solution having the following composition was added.

Unsaturated aliphatic primary amine (previously described - 196 parts Example 1) Butyl cellosolve 7 Q tr The temperature was then raised to 150°C, and the reaction was allowed to proceed for 2 hours while removing the water produced by the reaction from the system through a separation tube. ,
Toluene was removed by distillation.

After cooling to 60°C in a dry oven, about 200 parts of isopropyl alcohol was added to reduce the heating residue to 60% and the resin acid value to 86.
, a resin solution having a Gardner viscosity of Z1 to Z2 was obtained.

Thereafter, using the obtained resin solution, the same operation as in Example 1 was carried out to obtain a test piece.

The obtained test piece was subjected to the same test as in Example 1.

Table 1 shows the test results.

Comparative Example 1 A reaction vessel was charged with 456 parts of soybean oil fatty acid, 277 parts of trimethylolpropane, and 264 parts of inphthalic acid.
The esterification reaction was initiated by heating to 0°C.

Next, the temperature was raised to 240°C over 3 hours, and the resin acid value reached 1.
When the temperature reached 0, the mixture was cooled to 180°C, 87 parts of trimellitic anhydride was added, and the temperature was maintained at 170 to 175°C.

When the resin acid value reaches 50 to 6oK, cool it to 120℃,
The mixture was diluted with a mixed solvent of equal weights of butyl cellosolve and isopropyl alcohol to give a heating residue of 65% to obtain a water-soluble alkyd resin solution having a Gardner viscosity of U1 and a Gardner color number of 7.

Thereafter, using the obtained water-soluble alkyd resin solution, the same operation as in Example 1 was carried out to obtain a test piece.

The obtained test piece was subjected to the same test as in Example 1.

Table 1 shows the test results.

Table 1 Note (1) 3 test pieces with crosscuts reaching the substrate
The coating film was left standing in a 5°C saline spray room to examine the rusting state of the coating film.

(2) In a 300m can, a paint diluted with water to adjust the viscosity to 75KU was poured at 260mA, sealed, and stored in a constant temperature bath at 50°C for one month, and the condition of the paint was examined.

(3) Weather meter (JIS K-5400
) after SOO time accelerated weather resistance trial (6
0 degree specular gloss), () is the gloss before the test.

Special r “Applicant: Nippon Oil & Fats Co., Ltd.

Claims (1)

[Claims] An aqueous solution or dispersion of an addition copolymer resin obtained by reacting a carboxyl group-containing copolymer consisting of a carboxyl group-containing monomer and another copolymerizable monomer with an unsaturated aliphatic primary amine. An air-drying aqueous coating composition comprising: