JPH03277667A - Water-base quick-drying primer composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an aqueous quick-drying primer composition, and more specifically, it is used for rust prevention of lightweight steel sections, deck plates, etc. used as construction materials. The present invention relates to a water-soluble and quick-drying primer composition.

[Conventional technology]

In the past, steel materials used as building materials were transported to the site unpainted, assembled there, and sometimes coated with a rust-preventing primer. However, in recent years, due to issues such as construction period and quality, it has become common for products to be coated with a primer in advance at the factory before being transported to the site and assembled. In particular, lightweight sections and deck plates are often painted at the factory, then bundled into several sets and transported to the site where they are assembled. In order to apply a primer in a factory like this, a primer that dries quickly and quickly develops coating hardness is required, and for this purpose, for example, A lacquer primer is often used. This paint is
This paint is suitable for painting on metal surfaces. It uses nitrocellulose as the main film-forming element and is designed to form a film in a short time by air drying. In addition to nitrocellulose, it contains resins, plasticizers, etc. It is prepared by dispersing pigments in a vehicle made by dissolving them in a solvent. Although this primer has good performance in terms of quick drying, as its quality is specified as having a drying time (h) of 2 or less, it has poor performance in terms of heating residue (X). Although the JIS standard stipulates it to be 35 or more, in actual paint design, the maximum limit is about 40. Furthermore, when using paint, use a spray gun, and in this case JIS
K 54003.4 (3) allows flow time from 15 to
It is necessary to dilute with thinner and use it so that it is within the range of 20 seconds, and the solid content of the paint during spraying is substantially 20 or less. In other words, it is necessary to use a large amount of organic solvent.

Additionally, in May 1988, a law was promulgated to partially revise the Fire Service Act, which came into effect from May 1990. Regarding paint in particular, previously it was sufficient to judge the dangerous substance rank based on Attached Table 1 of the Ministry of Home Affairs Ordinance, but this system was abolished and after May 1990, the flash point etc. of the paint was measured. The classification of dangerous goods has been revised based on the results of the hazard confirmation tests obtained by conducting the tests.

Therefore, with the strengthening of the above-mentioned judgment means, the storage amount of paints containing a large amount of solvents with low flash points will be more limited than before, which will hinder the smooth implementation of construction work. There is an increasing demand for highly safe paints that can be stored in large quantities without causing problems.

On the other hand, regarding anti-rust paint, JIS K 5621
~5629 Act, and among them, there are also 1 major
It is divided into two types: Type 1 is specified as using boiled oil as a vehicle, and type 2 is specified as using festival as a vehicle. It is specified that θ is within 16.

By the way, it is generally believed that the rust-preventing effect and drying time are contradictory properties, and it often depends on the condition and treatment of the metal base, but one type has better rust-preventing performance than the other two. is large.

Furthermore, these anti-rust paints include red lead PbJ<, zinc pbto, basic lead chromate mPbo-nPbc.
rot, cyanamide lead PbCN2, zinc dust Zn, zinc chromate Kt・4Zn0・4CrOs・3H20 or ZnCr0.・4Zn(OH)2, calcium leadate C
Metal pigments containing lead or chromium with atPbO< are included as antirust pigments, and many of these substances are regulated by the Poisonous and Deleterious Substances Control Law.

Therefore, various non-polluting anti-rust pigments were developed as an alternative to these pigments, and published in Japanese Patent Application Laid-open No. 64-38.482 and Japanese Patent Application Laid-Open No. 64-64
No. 40.563 and other publications propose rust-preventive paint compositions containing aluminum orthophosphate and aluminum metaphosphate as rust-preventive pigments. However, although all of them have antirust effects, they are by no means sufficient when compared to pigments containing lead and chromium.

Furthermore, in recent years, efforts have been focused on the development of water-based paints due to social demands such as pollution-free, resource-saving, and the above-mentioned safety. One way to achieve this is through emulsion-type paints.In particular, in the case of acrylic resin emulsions, the glass transition point (Tg) can be freely designed based on the monomer composition, and because the molecular weight is large, the coating film is hard and relatively dry. Although they are excellent, they have the drawbacks of poor film-forming properties and generally poor water resistance and corrosion resistance.

In addition, as another means, carboxyl groups (
-COOH) and neutralize it with ammonia or amine to make it water-soluble.

Examples of the polymer include acrylic resin, polyester resin, and alkyd resin. The water solubility of the resin obtained in this way can be increased by designing it to increase the number of carboxyl groups and the amount of neutralizing ammonia or amines, but conversely, the initial water resistance However, in order to improve water resistance, reducing the number of carboxyl groups and reducing the amount of neutralizing ammonia or amines increases water resistance but reduces water solubility. , have contradictory properties. In particular, in the case of room temperature drying type paints, it usually takes a long time to dry after application and the initial water resistance is poor.

[Problem to be solved by the invention]

As mentioned above, various attempts have been made to develop primers that use non-polluting pigments, have excellent adhesion stability and anti-corrosion ability, are quick-drying, and are also water-soluble.
No satisfactory composition has yet been proposed.

Therefore, the present inventors have conducted intensive research to solve these problems, and have found that these problems can be solved by using a specific water-dispersed alkyd resin and a rust-preventing pigment containing molybdenum oxide. They discovered this and completed the present invention.

Therefore, an object of the present invention is to provide a water-soluble, non-polluting plummer composition that dries quickly, has excellent adhesion stability and antirust performance, and is water-soluble.

[Means to solve the problem]

That is, the present invention is modified with the following components (a) and (b): fa) fatty acid or its triglyceride, the amount of modification is 20 to 50% by weight, and tris(2- 10 to 50% by weight of hydroxyethyl)isocyanurate and/or tris(hydroxymethyl)isocyanurate, with a number average molecular weight of 5
00 to 5°000 and whose acid value is 30 or less, a water-dispersed resin obtained by neutralizing at least a portion of the carboxyl groups in an alkyd resin; (b) an anticorrosive pigment containing molybdenum oxide; The main component is Component (a) in an amount of 100 parts by weight (solid content).
A water-soluble quick-drying primer composition containing 5 to 40 parts by weight of component (b), preferably in which the anticorrosive pigment has the general formula xAB0.yMo03-zH,O or xA,B,Os
yMoO+・zPzOs (However, A and B are Ca,
represents AI or Zn, and x, y and 2 are 1.2 or 3).

The present invention will be explained in detail below.

The main feature of the aqueous quick-drying primer composition of the present invention is that its constituent components are a water-dispersible alkyd resin modified with a specific substance.

First, the water-dispersed alkyd resin used as component (a) in the present invention is a type of polyester resin obtained by condensing a polybasic acid and a polyhydric alcohol, and furthermore, a part of the polybasic acid is mixed with vegetable oil etc. It is a resin obtained by modifying a part of a fatty acid obtained from a fatty acid or a polyhydric alcohol thereof with a polyhydric alcohol obtained from a transesterification reaction between an oil, which is a triglyceride of a fatty acid, and another alcohol. And the ratio of the number of hydroxyl groups to the number of carboxyl groups is 1.0/1 to 1.
．． It is obtained by dispersing in water a neutralized resin obtained by neutralizing at least a part of the carboxyl groups in a resin with an acid value of 30 or less obtained by blending the resin so that the ratio is 6/1 and carrying out a condensation reaction. It is something.

In this invention, the water-dispersible alkyd resin used is one modified with an unsaturated group, that is, an air-drying fat or oil or a fatty acid separated therefrom, and the amount of modification thereof is 20 to 50% by weight. Preferably 30-40% by weight
belongs to. As the oil or fatty acid used for this purpose, various conventionally known oils or fatty acids having unsaturated groups can be used, but soybean oil, linseed oil, safflower oil, dehydrated castor oil, or oils and fats derived from these oils are preferably used. Separated fatty acids are mentioned. The fatty acid used in this alkyd may also be its triglyceride. The reason for this is that when synthesizing alkyd resins using oil as a raw material, first the oil, that is, fatty acid triglyceride and polyhydric alcohol, are transesterified using a catalyst such as Lissage, and then other polyhydric alcohols are transesterified. This is because it is also possible to synthesize by adding a basic acid or a polyhydric alcohol thereto. Furthermore, regarding the amount of modification mentioned above, if it is less than 20% by weight, drying to the touch will be fast, but the final hardness after air drying will be insufficient; on the other hand, if it is more than 50% by weight, drying to the touch will be slow and the stacking resistance will be poor. Sexuality becomes insufficient.

Other polybasic acids in the alkyd resin include phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-nindomethylenetetrahydrophthalic anhydride, maleic acid, fumaric acid, adipic acid, and cepatine. Acid, dimer acid, trimellitic anhydride, etc. can be selected and used from the viewpoint of coating film performance.

Next, in the present invention, the polyhydric alcohol component used in producing the alkyd resin includes trihydric alcohol tris(2-hydroxyethyl)isocyanurate and/or trihydric alcohol.
or tris(hydroxymethyl)isocyanurate 1
It is essential to use 0 to 50% by weight, and 10% by weight
If it is less than 50% by weight, the rise in hardness and drying properties will be insufficient, and if it exceeds 50% by weight, gelation will occur and unreacted substances will be produced.

Other polyhydric alcohol components in the alkyd resin include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, diethylene glycol, neopentyl glycol, 1.4-butanediol, 1.6-hexanediol, cyclohexane dimetatool, Trimethylbentanediol, lycerine, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, etc. can be selected from the viewpoint of coating performance.

In addition, in this alkyd production method, the ratio of the number of hydroxyl groups/the number of carboxyl groups is 1.0/1 to 1.6/1, more preferably 1.0/1 to 1.4/1. The mixture is mixed and reacted at 200 to 250°C in a nitrogen stream until the acid value reaches 30 or less. If the acid value is 30 or more, water resistance and alkali resistance will be insufficient.

Then, some or all of the carboxyl groups in the alkyd resin are neutralized. The degree is preferably 1) 16 or more. Examples of neutralizing agents include amines such as ammonia, triethylamine, dimethylaminoethanol, morpholine, and 2-amino-2-methylpropanol; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide;
There are bicarbonates such as bicarbonate of soda. Further, it is more preferable to add a water-soluble solvent before neutralizing the alkyd resin and dispersing it in water, in order to improve the dispersibility. Such solvents include alcohols such as ethanol, isopropanol, lowobanol, 3-methyl-3-methoxybutanol, n-butanol, isobutanol, 5ee-butanol, tert-butanol,
Ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether,
Examples include diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether.

Next, as the component (b) as a pigment used in the present invention, a rust preventive pigment containing molybdenum oxide is used, preferably having the general formula xABO・yMo03・zt(20 or x
A, B, O7・yMoOJ-zP20s (However, A
and B represents Ca, M or 2n, and x, y and Z are 1
, 2 or 3) is used. These anti-corrosion pigments are non-polluting, and ions are carried to the metal surface by moisture that permeates in an alkaline environment, forming a passivation film containing various molybdic acid complex compounds and condensed ions on the surface. It is thought that this prevents the formation of rust. An even bigger advantage is that
Paint films containing such anti-rust pigments are highly effective in preventing rust from forming in damaged areas, minimize the formation of blisters in the surrounding areas, and also have water resistance, chemical resistance, etc. and lead-based ones.

In addition, the blending ratio of the aqueous quick-drying primer composition of the present invention is as follows: (100 parts by weight (solid content) of the water-dispersed alkyd resin as the component (a), and 5 to 5 parts of the antirust pigment as the BL component)
The amount is 40 parts by weight, preferably 15 to 25 parts by weight. If the proportion of this rust-preventive pigment is less than 5 parts by weight, the rust-preventive property will be poor;
Moreover, if it exceeds 40 parts by weight, the water resistance will be poor.

The aqueous quick-drying primer composition of the present invention may optionally contain colored pigments such as titanium dioxide, carbon black, iron oxide, and other pigments such as barium sulfate and hydrated silica for the purpose of reinforcing the coating film. Magnesium acid, aluminum silicate, calcium carbonate, etc. alone or in combination
More than one species may be used in combination. In addition, for the purpose of curing the unsaturated components of the alkyd resin component, metal salts as desiccants, such as manganese naphthenate, cobalt naphthenate, lead ofthenate, etc., may be used alone or in combination of two or more. good. Furthermore, other additives such as a pigment dispersant, a suspending agent, a leveling agent, and an antifoaming agent can also be blended.

In addition, the aqueous quick-drying primer composition of the present invention may be prepared by using one or more water-soluble solvents, such as alcohol, ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, etc., and water, taking into account its evaporation rate.
Using above seeds together, add the rust preventive pigment (b) component and other additives such as pigments as necessary to the water-dispersed alkyd resin (fa) component, and knead with a sand grinder mill, attritor, etc. Therefore, it can be easily manufactured.

The composition obtained as described above dries quickly, has excellent stacking resistance, adhesion, and rust prevention properties, and also has good coating properties such as spray workability.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Examples and Comparative Examples.

Preparation of water-soluble resin Production example-1 In a reactor equipped with a stirrer, thermometer, cooler and nitrogen gas introduction device, 305 parts by weight of soybean oil fatty acid (manufactured by Nisshin Oil Co., Ltd.) and tris(2-hydroxyethyl) isocyanurate (Shikoku Kasei Kogyo Co., Ltd. 278 parts by weight, trimethylolethane 8
0 parts by weight, 12 parts by weight of neopentyl glycol, 277 parts by weight of isophthalic acid, and 45 parts by weight of polyethylene glycol (molecular weight 5,000) were charged, and the reaction was carried out in a nitrogen stream while removing reaction water from the system. A resin with an acid value of 5 was obtained.

To 100 parts by weight of the resin thus obtained, 30 parts by weight of ethylene glycol monoisopropyl ether and 1.4 parts by weight of triethylamine were added to give 50 to 6 parts by weight of the resin.
1) 9 parts by weight of water was added at 0° C. to obtain a water-dispersed alkyd resin with a heating residue of 40% and a viscosity of 55 beads/25° C.

This resin is modified with fatty acids, and the amount of modification is 32
．． 1% by weight, and 27.8% by weight of tris(2-hydroxyethyl)isocyanurate was used, and the number average molecular weight was 2,550. The obtained resin was designated as water-dispersed alkyd resin A.

Production Example-2 In a reactor equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas introduction device, 281 parts by weight of dehydrated castor oil (manufactured by Ito Oil Co., Ltd.), 8 parts by weight of trimethylolethane 1), and hydroxide as a catalyst for the transesterification reaction were added. After adding 1.02 parts by weight of lithium-hydrate and carrying out transesterification at 240°C in a nitrogen stream for 2 hours, 136 parts by weight of tris(2-hydroxyethyl)isocyanurate (manufactured by Shikoku Kasei Kogyo (II)) was added. parts, cyclohexane dimetatool 81 parts by weight, isophthalic acid 321 parts
Part by weight, polyethylene glycol (molecular weight 2.000)
63 parts by weight was charged, and while removing the reaction water from the system, 2
As a result of the reaction at 30°C, a resin with an acid value of 13 was obtained.

To 100 parts by weight of the resin thus obtained, 30 parts by weight of ethylene glycol monoisopropyl ether and 1.4 parts by weight of triethylamine were added to give 50 to 6 parts by weight of the resin.
1) 9 parts by weight of water was added at 0°C to obtain a water-dispersed alkyd resin having a heating residue of 40% and a viscosity of 100 J7/25°C.

This resin has been modified with triglyceride, a fatty acid, and the amount of modification is 29.1% by weight.
-hydroxyethyl) isocyanurate was used in an amount of 13.6% by weight, and the number average molecular weight was 2.880. The obtained resin was designated as water-dispersed alkyd resin B.

Production Example-3 Linseed oil fatty acids (Nissin Oil Co., Ltd.) were placed in the same equipment as Production Example-1.
manufactured by f@: L-75) 282 parts by weight, tris(2-hydroxyethyl) isocyanurate (Shikoku Kasei Kogyo Co., Ltd.)
414 parts by weight of neopentyl glycol, 9 parts by weight of neopentyl glycol, 3 parts by weight of phthalic anhydride (1), 126 parts by weight of isophthalic acid, and 56 parts by weight of polyethylene glycol (molecular weight 2.000), and 230 parts by weight while removing reaction water from the system. As a result of the reaction at ℃, a resin having an acid value of 17 was obtained.

To 100 parts by weight of the resin thus obtained, 30 parts by weight of ethylene glycol monoisopropyl ether and further 1.4 parts by weight of triethylamine were added.
Add 1) 9 parts by weight of water at 60℃, heating residue 40% viscosity 9
5. A water-dispersed alkyd resin at 25° C. was obtained.

This resin is modified with fatty acids, and the amount of modification is 30
．． 0% by weight, and 44.0% by weight of tris(2-hydroxyethyl)isocyanurate is used.
The number average molecular weight was 301 O. The resulting resin was designated as water-dispersed alkyd resin C.

Production Example 4 (Water-dispersed alkyd resin different from the present invention) Soybean oil fatty acid (Nissin Oil Co., Ltd.) 336 parts by weight, trimethylolethane 167 parts by weight, and pentaerythritol 82 parts by weight were placed in the same apparatus as Production Example 1. Parts by weight, phthalic anhydride 35
8 parts by weight, polyethylene glycol (molecular weight 2,000
2) while removing reaction water from the system.
As a result of the reaction at 30°C, a resin with an acid value of 15 was obtained.

To 100 parts by weight of the resin thus obtained, 30 parts by weight of ethylene glycol monoisopropyl ether and further 1.4 parts by weight of triethylamine were added.
At 60°C, 1) 9 parts by weight of water was added to obtain a water-dispersed alkyd resin having a heating residue of 40% and a viscosity of 80 poise at 725°C.

The obtained resin was made into a water-dispersible alkyd resin.

Production Example-5 (Water-soluble alkyd resin different from the present invention) In the same apparatus as Production Example-1, 282 parts by weight of soybean oil fatty acid (manufactured by Nisshin Oil Co., Ltd.), 283 parts by weight of trimethylolpropane, and 253 parts by weight of isophthalic acid were added. 123 parts by weight of benzoic acid were charged, and the reaction was carried out while removing the reaction water from the system until the acid value reached 6. Further, 5 parts by weight of trimellitic anhydride was charged.
As a result of adding 9 parts by weight and carrying out the reaction at 190°C, the acid value was 40.
of resin was obtained. To 100 parts by weight of the resin thus obtained, 30 parts by weight of ethylene glycol monoisopropyl ether was added, and after cooling to room temperature, 5.2 parts by weight of aqueous ammonia (35%) was added to the mixture. After Wa,
1) 4 parts by weight of water was added to obtain a water-soluble alkyd resin having a heating residue of 40% and a viscosity of 60 poise/25°C. The obtained resin was designated as water-soluble alkyd resin E.

Production Example-6 (Water-soluble acrylic resin different from the present invention) 343 parts by weight of isopropyl alcohol was charged into a reactor equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas introducing device, and 90 parts by weight of ethyl acrylate was added in a nitrogen stream. A mixture of 50 parts by weight of methyl methacrylate, 20 parts by weight of acrylic acid, 10 parts by weight of 2-hydroxyethyl methacrylate, and 0.5 parts by weight of azobisisobutyronitrile was added dropwise at a constant rate over 1 hour while maintaining the temperature at 80°C. . After completion, 185 parts by weight of ethyl acrylate, 9 parts by weight of methyl methacrylate
A mixture of 0 parts by weight, 35 parts by weight of acrylic acid, 20 parts by weight of 2-hydroxyethyl methacrylate, and 0.5 parts by weight of azobisisobutyronitrile was added dropwise in fixed amounts over 2 hours while maintaining the temperature at 80°C.

After the dropwise addition was completed, the temperature was maintained at 80°C for 2 hours, then cooled to room temperature, and 50 parts by weight of ammonia water (35X) was added to neutralize it. 230 parts by weight of water was added, and the heating residue was 40% and the viscosity was A water-soluble acrylic resin having a temperature of 150 poise/25°C was obtained. The obtained resin was designated as water-soluble acrylic resin F.

PM-303W manufactured by Kikuchi Shikoku Kogyo ■ as aluminum phosphomolybdate for expanded rattan stars (composition: AlzO+・MQO+・
hOi water soluble content: 0.2X, oil absorption 35, pH: 6.8,
SG:3. O), and as calcium molybdate, MC-400WR (composition: Ca
0-M2O3・H2O, water soluble: 0.4X, oil absorption 30
, pH: 8.7, SG: 3.2). In addition, other anti-rust pigments include strontium chromate (manufactured by Kikuchi Shikoku Kogyo, composition: 5rCrOt) and basic lead silicochromate (manufactured by Kikuchi Shikoku Kogyo, Ltd., 5100, composition: mPb0.
nPbCr sail 5i02) were used, respectively.

Examples 1 to 6 and Comparative Examples 1 to 6 (Preparation of paints) 50 parts by weight of resin and 5 parts by weight of antirust pigment were mixed in the combinations shown in Table 1. However, in Comparative Example 6, no antirust pigment was added. ), as well as other ingredients, 10 parts by weight of water, 5 parts by weight of Red Garla (Toda Kogyo Part name: Todakara-12OR), calcium carbonate (Takehara Chemical Industry Co., Ltd. product name: Sunrai)
SL-1000) 25 parts by weight, 5 parts by weight of talc (Hayashi Kasei (shared product name: Talcan Powder PKS)), anti-settling agent (manufactured by NL CHEMICALS, product name: BENTO)
NE LT) 0. 2 parts by weight, and 0.6 parts by weight of I:1 mixture of 5 cobalt naphthenate-W and 20X-lead naphthenate-W (Inu Nippon Ink Chemical Industry Co. Ltd. trade name, Metal Dryer). Water-soluble acrylic resin F
(Do not add a metal dryer), stir thoroughly with a known stirrer, then use tabletop Santo Mill (Kampe household paint).
Dispersion treatment was carried out using The degree of dispersion is JIS K
54004. ．． Using the crush gauge specified in 4, the test was carried out until the reading became 20 or less.

The paints prepared in the above Examples and Comparative Examples in Table 1 were spray-painted onto a steel plate having a thickness of 1 sieve to a film thickness of 25 ± 3IiIR to prepare test pieces.

Coating film test method (a) Drying time: A test was conducted based on the JIS K 54005.8 method, and dryness to the touch, semi-hardened drying and hardened drying were examined.

(b) Topcoat compatibility: A test was conducted based on the JIS K 54006.1 method, and those that passed were evaluated as ○, and those that failed were evaluated as ×.

(c) Adhesion stability: A test was conducted based on the JIS K 56215.9 method, and those that passed were evaluated as ○, and those that failed were evaluated as ×.

(d) Salt water resistance: A test was conducted based on the JIS K 54007.6 method, and those that passed were evaluated as ○, and those that failed were evaluated as ×.

(e) Non-adhesiveness: A test was conducted based on the JIS K 54006.8 method, and those that passed were evaluated as ○, and those that failed were evaluated as ×. However, the drying time was 1 hour. The results of these tests are shown in Table 2.

〔Effect of the invention〕

According to the present invention, a water-based, quick-drying, and non-polluting primer composition can be provided, and its practical effects are extremely remarkable.

Claims (2)

[Claims] (1) The following components (a) and (b): (a) Modified with a fatty acid or its triglyceride, the amount of modification is 20 to 50% by weight, and the trihydric alcohol is tris(2-hydroxyethyl ) isocyanurate and/or tris(hydroxymethyl)isocyanurate is used in an amount of 10 to 50% by weight, the number average molecular weight @Mn@ is 500 to 5,000, and the acid value is 3.
A water-dispersed resin obtained by neutralizing at least a part of the carboxyl groups in an alkyd resin having a carbon content of 0 or less; (b) a rust-preventing pigment containing molybdenum oxide; A water-soluble quick-drying primer composition comprising 5 to 40 parts by weight of component (b) per 100 parts by weight (solid content). (2) The antirust pigment has the general formula xAB0・yMoO_3・ZH
_2O or xA_x, B_y, O_z・yMoO_3・
zP_2O_5 (A and B are Ca) Al or Zn
2. The water-soluble quick-drying primer composition according to claim 1, wherein x, y, and z are 1, 2, or 3.