JPH0249076A - Metallic paint - Google Patents

Abstract

PURPOSE:To provide the subject novel paint having excellent storage stability, chemical resistance, cosmetic resistance, finger-print resistance, etc., and composed of a resin for paint, a specific resin-coated metallic pigment and a thinner for dilution. CONSTITUTION:The objective paint is composed of (A) 100 pts.wt. of a resin for paint, (B) 0.1-100 pts.wt. of a resin-coated metallic pigment having an alkali resistance of <=1.0 and surface-coated with a resin derived from a radically polymerizable unsaturated carboxylic acid [e.g., (meth)acrylic acid] and/or a phosphoric acid monoester or diester having radically polymerizable double bond (e.g., 2-methacryloyloxyethyl phosphate) and a monomer having >=3 radically polymerizable double bonds [e.g., trimethylolpropane tri(meth)acrylate] and (C) a thinner for dilution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel metallic paint comprising a novel resin-coated metallic pigment, a paint resin, and a thinner.

This paint has excellent storage stability and provides a metallic coating film with excellent chemical resistance, cosmetic resistance, fingerprint resistance, etc.

[Conventional technology and its problems]

Conventionally, metal pigments have been used in metallic paints, printing inks, plastic kneading, etc., for the purpose of obtaining cosmetic effects that emphasize metallic appearance.

However, when used as a metallic paint, the metal pigment and resin components of the paint react with each other during storage, causing the paint to gel and become unusable.

In addition, there is a drawback that the water contained in the paint and the metal pigment react with each other to generate gas, which deforms the container. This gas generation is significantly accelerated in the presence of acid or alkaline components, leaving problems with storage stability.

Furthermore, the paint film obtained by painting with metallic paint does not have sufficient chemical resistance such as acid resistance and alkali resistance, and water resistance, and the painted surface changes color and loses gloss over time.
The uses of metallic paint are limited.

In recent years, metallic coatings have been used in a wide range of applications, and not only higher chemical resistance and water resistance than before are required, but also metallic coatings with excellent cosmetic resistance and fingerprint resistance. Cosmetic resistance refers to the performance against the phenomenon that cosmetics adhering to a metallic coating film leaves stains on the coating film, and fingerprint resistance refers to the performance against the phenomenon that cosmetics adhering to a metallic coating film leaves stains on the coating film.Fingerprint resistance refers to the performance against the phenomenon that the marks of fingerprints attached to the coated object cause black spots on the coating film. This is the performance against the phenomenon of floating. Both of these significantly reduce the commercial value of metallic coatings. Furthermore, when conventional metal pigments are used for kneading into plastics, for example into resins such as polyethylene and polyvinyl chloride, the metal pigments are not uniformly dispersed due to poor compatibility between the metal pigment and the resin. First, the desired uniform sheet or film cannot be obtained. Furthermore, when blended with polyvinyl chloride, the surface of the metal pigment changes color due to hydrogen chloride generated from the polyvinyl chloride, causing loss of metallic luster.

As a solution to these problems, a method has been proposed in which the metal pigment component is coated with a resin.

One known method for resin coating is a method (Japanese Patent Publication No. 56-43069) in which a suspension of a pigment is mixed with a solution of a pre-produced resin dissolved in a solvent, and the resin is deposited on the pigment. There is.

However, with this method, the pigment particles can be coated uniformly on the surface of the pigment particles.
Moreover, it is difficult to firmly adhere the resin. In the resin coating made by this method, the resin layer is merely physically attached to the metal surface, and its adhesion is weak. Therefore, the resin coating layer peels off or melts due to external mechanical force applied during the pigment dispersion process during paint manufacturing, or due to dissolution or softening by the solvent contained in paints manufactured using resin-coated pigments, resulting in the desired effect being lost. Significantly impaired.

In addition, it is easily melted or softened by applying heat, and the effect of resin coating cannot be obtained sufficiently when used for kneading plastics.

Furthermore, attempts have been made to proceed with the polymerization of monomers in a system in which metal pigments are dispersed, and simultaneously manufacture the resin and coat the pigment surface. Attempts have been made to create a chemical bond between the resin and the surface of the metal pigment (Japanese Patent Application Laid-Open No. 1983-2
Publication No. 6837). However, in addition to manufacturing problems such as the complicated and long manufacturing process, the formation of a resin layer on the pigment surface is not controlled, and as a result, sufficient water and chemical resistance effects cannot be achieved, and it has not yet been implemented industrially. This has not yet been achieved.

Furthermore, a method has been proposed in which a metal pigment is dispersed in water and polymerization is carried out under conditions that produce a positively charged polymer during polymerization (Japanese Patent Publication No. 4029/1983). However, even with this method, effects such as sufficient water resistance, alkali resistance, acid resistance, etc. cannot be obtained, and it has not been put into practical use industrially.

Furthermore, a method is known in which the surface of metal particles is coated with a resin obtained by proceeding a polymerization reaction in an organic solvent in which the monomer is soluble and the resulting polymer is insoluble (Japanese Patent Application Laid-Open No.
6-161470, Japanese Patent Application Laid-open No. 11818/1983)
However, the resin-coated metal pigments produced by these methods have not yet reached a practically sufficient level in terms of chemical resistance, water resistance, especially cosmetic resistance, fingerprint resistance, etc., and improvement is necessary. It is.

In addition, this resin-coated metal pigment also does not have sufficient heat resistance stability, so when it is used for kneading and placed under high temperature (150°C or higher), the resin coated with the metal pigment tends to soften. , bonding between pigments occurs, making it difficult to obtain the desired uniformly dispersed film or sheet.

[Means for solving problems]

The present inventors have solved the problems of conventional metal pigments (as a result of intensive research, we have developed a monomer having a radically polymerizable double bond and a carboxyl group in one molecule or a radically polymerizable We have discovered that the object can be achieved by firmly adhering a highly three-dimensional resin layer to the surface of a metal pigment by taking advantage of the characteristics of phosphoric acid mono- or diester having double bonds, and have thus arrived at the present invention.

That is, the present invention provides (a) a paint resin, and ('b) a radically polymerizable unsaturated carboxylic acid and/or a radically polymerizable double bond in an amount of 0.1 to 100 parts by weight per 100 parts by weight of the paint resin. A resin-coated metal pigment whose surface is coated with a resin produced from a phosphoric acid mono- or diester having the formula and a monomer having three or more radically polymerizable double bonds, and whose alkali resistance is 1.0 or less, and ( c) It relates to a metallic paint characterized in that it consists of a diluted thinner.

The resin-coated metal pigment used in the present invention exhibits unprecedented heat resistance stability, and when stored as a pigment for a long period of time, pigment aggregation is not observed, and other properties imparted by the resin coating (alkali resistance, It has excellent storage stability with no change in water resistance, etc.). The metallic paint of the present invention using this pigment provides a coating film that has excellent storage stability and exhibits excellent chemical resistance, water resistance, cosmetic resistance, and fingerprint resistance.

The radically polymerizable unsaturated carboxylic acid in the present invention is
These include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, etc., and they are used alone or in combination of two or more. The amount used varies depending on the type and properties of the metal pigment, especially its surface area, but is generally 0.00 parts per 100 parts by weight of metal pigment.
The amount is between 0.01 and 10 parts by weight. If it is less than 0.01 part by weight, the effects of the present invention, that is, chemical resistance such as water resistance and acid resistance, fingerprint resistance, etc., will not be exhibited well, and the polymerizable double When polymerizing monomers having 3 (Ili! or more) bonds, the polymerization system gels and cannot be stirred (
It may happen. Moreover, if it exceeds 10 parts by weight, water resistance will decrease. This is presumed to be because the amount of carboxyl groups contained in the radically polymerizable unsaturated carboxylic acid is too large.

The phosphoric acid ester monomer having a radically polymerizable double bond in the present invention includes 2-methacryloyloxyethyl phosphate, di-2-methacryloyloxyethyl phosphate, tri-2-methacryloyloxyethyl phosphate,
2-acryloyloxyethyl phosphate, di-2-acryloyloxyethyl phosphate, tri-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, diphenyl-2-
Acryloyloxyethyl phosphate-1, dibutyl-2
-methacryloyloxyethyl phosphate, dibutyl-
2-acryloyloxyethyl phosphate, dioctyl-2-methacryloyloxyethyl phosphate-1-, dioctyl-2-acryloyloxyethyl phosphate, 2
-methacryloyloxybrobyl phosphate-1, bis(2
-chloroethyl) vinyl phosphonate, diallyl dibutyl phosphonosuccinate, etc., and one type or a mixture of two or more types thereof are used.

Phosphoric acid monoester can be mentioned as a preferable phosphoric ester having a radically polymerizable double bond. This is presumed to be due to the presence of two 0-H groups in the phosphoric acid group, which causes the phosphoric acid group to be more firmly fixed to the surface of the aluminum particles. As a more preferable phosphoric acid monoester,
Examples include monoesters having a methacroyloxy group and an acroyloxy group, such as 2-methacryloyloxyethyl phosphate and 2-acryloyloxyethyl phosphate. These monoesters are often insoluble in common polymerization solvents.

The amount used varies depending on the type and properties of the metal pigment, especially its surface area, but is generally 0 to 100 parts by weight of the metal pigment.
．． 01 parts by weight to 30 parts by weight.

If the amount is less than 30 parts by weight, the effects of the present invention, i.e., chemical resistance such as water resistance and acid resistance, fingerprint resistance, etc., will not be exhibited well, and even if it is used in excess of 30 parts by weight. , there is almost no increase in effect.

Examples of monomers having three or more polymerizable double bonds in one molecule used in the present invention include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, and tetramethylolmethane tetraacrylate. One or more of these may be used.

The amount used is 2 parts by weight per 100 parts by weight of the metal content of the metal pigment.
Between 50 parts by weight and less than 2 parts by weight,
The effect of the present invention, that is, the chemical resistance decreases, and if it exceeds 100 parts by weight, no increase in the effect is expected, and the brightness, gloss,
The basic properties of a metallic paint, such as a metallic feel, deteriorate, making it difficult to put it into practical use.

A monomer having 1 to 2 polymerizable double bonds in one molecule within a range that does not impair the effects of the present invention, that is, 0 to 10 parts by weight based on 100 parts by weight of the metal content of the metal pigment. If the amount used exceeds 10ml/1 part, the effect of the present invention, that is, when a metallic coating film is created using the resulting resin-coated metallic pigment, the properties will deteriorate, or the metallic pigment will deteriorate. The heat resistance stability also decreases, making it difficult to put it into practical use.

Examples of monomers having one or two polymerizable double bonds in one molecule used in the present invention include styrene, α-methylstyrene, acrylic esters such as methyl acrylate, and methyl methacrylate. Methacrylic acid esters, acrylonitrile, meccrylonitrile, vinyl acetate, vinyl propionate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate 1-11.3-butylene glycol dimethacrylate, neopentyl glycol diacrylate, Examples include divinylbenzene, and one or more of these may be used.

The polymerization initiator used in the present invention is generally known as a radical host agent, and includes peroxides such as benzoyl peroxide, lauroyl peroxide, isobutyl peroxide, methyl ethyl ketone peroxide, and azobis Isobutyronitrile, etc.

The polymerization initiator is used in an amount of 0.1 to 50 parts by weight per 100 parts by weight of a monomer having three or more orthotropic double bonds in one molecule.
Use parts by weight. Preferably, 1 to 20 parts by weight is used. If it is less than 0.1 part by weight per 100 parts by weight of a monomer having three or more polymerizable double bonds in one molecule, it will take a long time to polymerize and is not practical.

If it exceeds 50!1 parts, the polymerization rate is too fast to be controlled and is not practical.

The alkali resistance of the present invention refers to the coating film obtained by blending and painting a predetermined paint. 55℃ with 1L of 1N-Na aqueous solution
The condition of the coating film before and after dipping was evaluated according to JISZ-8.
722 (1982), condition d (9-d method), and refers to the color difference (ΔEH) determined according to JIS-Z-87306, 3, 2.

The specified paint is a paint that uses a baking-type acrylic/melamine resin, and the pigment concentration is 15 parts by weight per 100 parts by weight of the acrylic/melamine resin (non-volatile content), and the required amount is with the addition of thinner. The acrylic resin used here is a commonly available acrylic resin for baking, and the melamine resin is a commonly available butylated melamine resin. The mixing ratio is 30 to 10 parts by weight of melamine resin to 70 to 90 parts by weight of acrylic resin.

The resin-coated metal pigment used in the present invention has an alkali resistance of 1
．． It is 0 or less, preferably 0.8 or less. 1.0
If it exceeds this value, discoloration of the coating film will be visually observed, it will not have sufficient alkali resistance, and it will not be included in the present invention.

In the present invention, a resin-coated metal pigment that does not substantially agglomerate in a heat stability test is one that shows almost no change in particle size when a predetermined temperature is applied to the resin-coated metal pigment for a predetermined period of time. That is, a heat resistance stability test was conducted in the same manner except that the temperature of JIS-54008, 2, 1 was changed to 150°C, the time was changed to 1 hour, and the amount of sample obtained was changed to 10 g.
The agglomeration is measured by the ratio of the particle size a, l before the test and the particle size al after the test.

The resin-coated metal pigment of the present invention has a dQ/d,' of 1.5 or less, more preferably 1.3 or less. If it exceeds 1.5, it is not preferable because uniform dispersion of the metal pigment cannot be obtained during high-temperature molding such as kneading.

A radically polymerizable unsaturated carboxylic acid and/or a V4 acid mono- or diester having a radically polymerizable double bond and a monomer having three or more radically polymerizable double bonds are reacted, and the surface is coated with the resulting resin. The preferred method for producing the metal pigment of the present invention is the first step of dispersing the metal pigment in an organic solvent and adding a radically polymerizable unsaturated carboxylic acid and/or a phosphoric acid mono- or diester having a radically polymerizable double bond. , 3 radically polymerizable double bonds
([This is a method of manufacturing through a second step of adding a monomer having 1a or more and an initiator and polymerizing it.

The first step is to disperse metal pigment particles in an organic solvent, then add a radically polymerizable unsaturated carboxylic acid or a phosphoric acid mono- or diester having a radically polymerizable double bond while continuing to stir. It will be done.

The treatment temperature in the second step may be room temperature, but it is preferably heated to 30 to 80°C.

The treatment time is generally 5 minutes or more, preferably 10 minutes or more, although the first step ends when the concentration of the unsaturated carboxylic acid or phosphoric acid ester remaining in the solvent becomes constant.

In performing the first step, there is also a method in which a part or all of the monomer having three or more radically polymerizable double bonds to be added in the second step has already been added.

However, in order to quickly and reliably complete the first step, monomers having three or more radically polymerizable double bonds are added in the second step before the first step is completed. In order to completely stop the initiation of polymerization, the first step preferably does not contain the monomer having three or more radically polymerizable double bonds, which is added in the second step. If the initiator used in the second step of thermal theory is added in the first step, the performance of the resulting resin-coated metal pigment will be significantly reduced, making it difficult to put it to practical use.

As a result, the carboxyl group of the radically polymerizable unsaturated carboxylic acid or the phosphoric acid group of the phosphoric acid ester having a radically polymerizable double bond is fixed on the surface of the metal pigment, and pigment particles having a radically polymerizable double bond on the surface are obtained. It is estimated that

This estimation is based on the fact that after the first step, the metal pigment is filtered out and the amount of radically polymerizable unsaturated carboxylic acid or phosphoric acid mono- or diester having a radically polymerizable double bond remaining in the solvent is quantified. This is supported by the fact that there is a significant decrease compared to the amount.

The second step proceeds after the first step is completed by adding a monomer having three or more polymerizable double bonds in one molecule and an initiator, followed by heating and stirring.

Through this operation, the double bond based on the unsaturated carboxylic acid previously fixed on the surface of the metal pigment and the monomer having three or more polymerizable double bonds in one molecule copolymerize, resulting in a highly cross-linked structure on the surface of the metal pigment. However, it is presumed that the excellent effects of the present invention are only manifested when a resin layer with a high network density is formed in a form that has chemical bonds with the surface of the metal pigment. This assumption is believed to be supported by the fact that the heat resistance stability of the resin-coated metal pigment of the present invention is significantly improved and there is almost no aggregation after the test.

It is preferable to replace the reaction system with an inert gas such as nitrogen or argon, and the temperature varies depending on the type of initiator, but is generally between 30°C and 150°C. The reaction time is between 30 minutes and 10 hours.

The reaction may be carried out by adding the monomer and/or initiator all at once or by adding them in portions.

In carrying out the second step, a radically polymerizable unsaturated carboxylic acid or a phosphoric acid ester having a radically polymerizable double bond, a monomer having three or more polymerizable double bonds in one molecule, and an initiator are used. If they are added all at once and the polymerization reaction is started immediately, the effects of the present invention will not be exhibited.

In addition, a radically polymerizable unsaturated carboxylic acid or a phosphoric acid ester having a radically polymerizable double bond is not used, and only a monomer having three or more polymerizable double bonds in one molecule is dispersed in an organic solvent. When polymerizing in the presence of metal pigment particles,
That is, if the first step is omitted and the second step is started, the polymerization system not only becomes thicker and cannot be stirred, but also the performance of the resulting resin-coated metal pigment is extremely poor.

This fact indicates that the metal surface is not sufficiently covered with the resin layer. These findings highlight the necessity of a first step prior to a second step.

Metal pigments used in the present invention include aluminum, copper,
Zinc, iron, nickel, and/or alloys thereof are used, with aluminum being a preferred example. Its shape is granular, such as flakes, spheres, and needles. The particle size of metal pigments varies depending on the application. For paints and printing, the average diameter is preferably about 1 to 100 μm, and for kneading into plastics, it is preferably about 1 to 200 μm, but the diameter is not particularly limited and can be applied to the present invention.

In detail about the aluminum pigment used in the present invention, aluminum flakes or granular powder are prepared by mechanical method 1a,
For example, it is produced by grinding together with several percent of a grinding aid using a stamp mill method, dry ball mill method, wet ball mill method, attritor method, vibrating ball mill method, or the like. This grinding aid functions as a grinding aid and at the same time influences the physical properties of the aluminum pigment. Higher saturated or unsaturated fatty acids such as stearic acid and oleic acid have been used as grinding aids.
Although higher aliphatic amines such as stearylamine are often used, the effects of the present invention can be obtained regardless of these grinding aids. Aluminum pigments obtained using stearic acid are generally well known as leafing type aluminum pastes, and are used as silver paints for tanks and other metal rust prevention applications. In addition, aluminum pigments obtained using oleic acid, stearylamine, etc. are generally known as non-leafing type aluminum pastes, and are used for cosmetic purposes as metallic paints for automobiles, furniture, etc.

Organic solvents used in the polymerization of the present invention include aliphatic hydrocarbons (e.g. hexane, heptane, octane, mineral spirits, etc.), aromatic hydrocarbons (e.g. benzene, toluene, solvent naphtha, xylene, etc.), esters (acetic acid ethyl, butyl acetate, etc.), ethers (tetrahydrofuran, diethyl ether, etc.), and metal pigments 10
50 to 3000 parts by weight is used relative to 0 parts by weight.

Preferably it is between 250 and 1000 parts by weight. If it is less than 50 parts by weight based on 100 parts by weight of the metal pigment, it will become paste-like and a radically polymerizable unsaturated carboxylic acid and 1
Monomers having three or more polymerizable double bonds in the molecule and polymerization initiators require a long time to uniformly diffuse, which is undesirable.
If it exceeds 3000 parts by weight, the polymerization time will become longer, which is not preferable.

After forming a resin coating layer on the surface of the metal pigment in the organic solvent as described above, the organic solvent was filtered off and the non-volatile content was removed by 3.
A paste containing the resin-coated metal pigment of the present invention is obtained, adjusted to 0 to 80% and added with other solvents, additives, etc. as necessary.

The metallic paint of the present invention includes fa) resin for paint, 0))
0.1 parts by weight to 1O per 100 parts of paint resin
0 parts by weight of resin-coated metal pigment, and fcl dilution thinner.

As the paint resin, any of the paint resins conventionally used in metallic paints can be used.
Furthermore, it can also be used for resins that have a large amount of functional groups that react with metals and easily cause gelation, which have not been used in conventional metallic paints. These resins include acrylic resins, alkyd resins, oil-free alkyd resins, vinyl chloride resins, urethane resins, melamine resins, unsaturated polyester resins, urea resins, cellulose resins, epoxy resins, etc. They may be used or mixed.

The resin-coated metal pigment of the present invention is used in an amount of 0.1 parts by weight to 100 parts by weight per 100 M parts of the paint resin.

In particular, it is preferable to use 1 part by weight to 50]i parts by weight.

If the amount of this resin-coated metal pigment is less than 0.1 part by weight, the metallic luster necessary for a metallic paint will be insufficient, and if it is used in excess of 100 M parts, the amount of metal pigment in the paint will increase. If too much is used, not only the painting workability deteriorates but also the physical properties become inferior, making it impractical.

Examples of diluent thinners include aromatic compounds such as toluene and xylene, aliphatic compounds such as hexane, heptane, and octane, alcohols such as ethanol and butanol, esters such as ethyl acetate and butyl acetate, and ketones such as methyl ethyl ketone. , chlorine compounds such as trichlorethylene, cellosolves such as ethylene glycol monoethyl ether, etc. It is preferable to use a mixture of two or more of these solvents, and this composition is determined by the solubility in the paint resin, Determined by taking into consideration paint film formation characteristics, painting workability, etc.

In addition, additives such as pigments, dyes, wetting agents, dispersants, color separation inhibitors, leveling agents, slip agents, anti-skinning agents, anti-gelling agents, anti-foaming agents, etc. commonly used in the paint industry. It is possible to add

〔Example〕

Next, examples of the present invention will be shown. First, the test methods and measurement methods used in Examples will be explained in detail.

[Weight of coated wood relative to 100 parts by weight of aluminum metal] Paste 10 containing the resin-coated aluminum pigment of the present invention
Disperse g well in 100ml of chloroform (reagent),
Next, the resin-coated aluminum pigment as the extraction residue was vacuum dried at 80°C for 1 hour and powdered.
．． Take 0g and add 200ml of 6N-HCl (reagent)
Melt the metal aluminum part little by little. The remaining insoluble resin content is filtered, and after vacuum drying at 80° C. for 14 hours, the weight is measured, and the resin content relative to 100 parts by weight of aluminum metal content is calculated.

[Alkali resistance]

A metallic paint for alkali resistance evaluation is prepared by using the resin-coated aluminum pigment and formulating the paint as shown below.

[Paint formulation]

(Parts by weight) Resin-coated aluminum pigment (non-volatile content) 7.5 Acrylic/melamine resin *1100 Shin - *2180 *1: Acrydifuku 47-712 (Non-volatile content: 50
%), 20 parts of Super Beckamine J-820 (non-volatile content: 50%) (manufactured by Nippon Reichhold) *2: Toluene (70 parts), ethyl acetate (20 parts), butyl cellosolve (10 parts) Next, the paint was air-sprayed onto an aluminum plate (70x1
50 x 1 mm (manufactured by Nippon Test Panel ■) to a film thickness of 20 μm, this coated plate was dried at 140° C. for 30 minutes, and used as a test coating for determining alkali resistance. A vinyl chloride cylinder with an inner diameter of 34 mm and a height of 15 mm was fixed to this coating using metal fittings. 1N-NaOH5m
1 and leave it at 55°C for 4 hours. After standing for 4 hours, the vinyl chloride cylinder is removed, the test coating is thoroughly washed with water, and the coating is dried.

The coating film before and after the test was evaluated according to JIS-Z-8722 (1
982) under condition d (method 9-d), JI
Calculate color difference △E)l according to 6.3.2 of S-Z-8730 (1980) (Measuring device: Suga Test Instruments S) I-4
-HCl type).

[Acid resistance]

0, lN-NaOH to 0. It is carried out in the same manner as for alkali resistance except that it is changed to 1N-H and SO4.

[Agglomeration by heat stability test]

Base containing resin-coated aluminum pigment) Weigh out 10g, put it in a bottle, put it in a dryer kept at a temperature of 150°C, and heat it for 1 hour. The particle size characteristic number of this resin-coated aluminum pigment was wet-sieved using mineral spirit as a dispersion medium, and the analysis results were determined according to German industrial standard DIN-411.
RR3 particle size diagram of Rosin-Rammler-3
pering grain size diagram). This value is d
Let it be i. Next, the particle size characteristic number is similarly determined for the resin-coated aluminum pigment before heating.

Let these values be d and I. The value of aW/d,l is obtained by calculation.

The sieve used here is a JIS standard sieve for 44g or more, and a micromensieve (Buck) for less than 44μ.
bee-raears Company product).

[Cosmetic resistance]

A resin-coated aluminum pigment is used to prepare a paint for plastic coating by formulating the paint as shown below.

[Paint formulation]

[Parts by weight] Paste containing resin-coated aluminum pigment (non-volatile content equivalent) 9 Thinner *1 40 Acrylic resin
*2100 *3 50 *1: Butyl acetate (30 parts), toluene (45 parts),
A mixture of isopropyl alcohol (20 parts) and ethyl cellosolve (5 parts) *2 Niacridic A-166 (non-volatile content: 45%)
) Air-drying acrylic resin made by Nippon Reichhold *3: LIG 1/2 (non-volatile content 70%) (manufactured by Asahi Kasei Kogyo ■, industrial nitrified cotton) with thinner *1 so that the non-volatile content becomes 16% The viscosity of the melted paint was adjusted to 13 seconds (Fe12.20℃) with thinner (*l), and the film thickness was 10μ) when sprayed on an ABS board at room temperature.
Dry in the sun and use for cosmetic resistance test.

Cosmetics (Al-Lifx Hand Cream: manufactured by Kao Soap Co., Ltd.) are applied to half of the test coating to a thickness of approximately 1 m+n.

Next, this coating film is left in a constant temperature and humidity bath adjusted to a temperature of 60° C. and a humidity of 90% for 5 days.

After the test, the paint film is washed with water, the moisture is wiped off, and after drying at room temperature for 1 hour, the appearance of the paint film on the areas with and without cosmetics applied is visually compared.

[Fingerprint resistance]

A coating film is prepared in the same manner as for cosmetic resistance, except that a fingertip is placed on an ABS board in advance to leave a fingerprint mark.

Immerse the entire test coating in a beaker containing warm water at 60°C.
Leave it for 3 hours.

After the test, the coating film is washed with water, the moisture is wiped off, and after drying at room temperature for 1 hour, the appearance of fingerprint marks is visually judged.

Example 1 Aluminum paste (manufactured by Asahi Kasei Corporation ?1601, metal content 65.2
%, average particle size 11 μm, flaky shape) and 400 g of mineral spirit were added, and the mixture was stirred while introducing nitrogen gas, and the temperature in the system was raised to 80° C. Next, 0.375 g of acrylic acid (reagent) was added to 80 g.
Stirring was continued for 30 minutes at °C. Next, 7.5 g of trimethylolpropane trimethacrylate (reagent) and 0.75 g of azobisisobutyronitrile (reagent) were added.
Polymerization was carried out at 0°C for 5 hours. After polymerization is complete, let it cool to room temperature,
This slurry was filtered to obtain a paste containing resin-coated aluminum pigment. Non-volatile content of this paste (JIS-
-5910) was 51.0% by weight. The amount of coating resin per 100 parts by weight of aluminum metal is 11
．． It was 4 parts by weight. It is estimated that 99% or more of acrylic acid, trimethylolpropane trimethacrylate, and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEX
) was 0.3, acid resistance (ΔEH) was also 0.3, and a good coating film was obtained with almost no discoloration.

Further, when the coating film was immersed in warm water at 60° C. for 7 days, there was almost no discoloration and the coating film was good. The paint was stored at 50°C for one month, but it was in good condition with no gelation.

The aggregation (a;/d+') after the heat resistance stability test was 1.05, and the powder had a uniform appearance, with virtually no aggregation observed.

Example 2 Aluminum paste (MB-21 manufactured by Asahi Kasei Corporation, metal content 72.0
%, average particle diameter 24 μm, flaky shape) and 325 g of mineral spirit were added, and the mixture was stirred while introducing nitrogen gas, and the temperature in the system was raised to 80° C.

Next, 0.255 g of acrylic acid (reagent) was added and stirring was continued at 80°C for 30 minutes. Next, 4.25 g of trimethylolpropane trimethacrylate (reagent) and 0.43 g of azobisisobutyronitrile (reagent) were added and polymerized at 80°C for 5 hours. After completion of the polymerization, the slurry was allowed to cool to room temperature. was filtered to obtain a paste containing resin-coated aluminum pigment. Non-volatile content of this paste (J
IS-5910> was 60.2% by weight. The amount of Fi resin was 5.7 parts by weight per 100 parts by weight of aluminum metal. It is estimated that 98% or more of acrylic acid, trimethylolpropane trimethacrylate, and abbisisobutyronitrile were deposited on the aluminum metal surface.

The alkali resistance (ΔE,
4) was 0.2, the acid resistance (ΔEH) was 0.1, and the aggregation <d'z/d: ) after the heat resistance stability test was 1.05, and the resin-coated aluminum pigment of the present invention was obtained. .

Example 3 Aluminum paste (manufactured by Asahi Kasei Corporation 4762, metal content 67.3%) was placed in a 1000 ml three-necked flask.
, average particle size: 9 μm, flaky shape) and 400 g of mineral spirit were added, and the mixture was stirred while introducing nitrogen gas, and the temperature in the system was raised to 80°C.

Next, 0.525 g of acrylic acid (reagent) was added and stirring was continued at 80°C for 30 minutes. Next, 10.5 g of trimethylolpropane trimethacrylate (reagent) and 0.525 g of azobisisobutyronitrile (reagent) were added and polymerized at 80°C for 6 hours. After completion of the polymerization, the slurry was allowed to cool to room temperature. A paste containing resin-coated aluminum pigment was obtained by filtration. Non-volatile content of this paste (J
IS-5910) was 53.0% by weight. The amount of coating resin was 16.4 parts by weight based on 100 parts by weight of aluminum metal. It is estimated that 99% or more of acrylic acid, trimethylolpropane trimethacrylate, and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEH) of this resin-coated aluminum pigment
) was 0.6, acid resistance (62M) was 0.1, and agglomeration (dλ/d;) after heat resistance stability test was 1.10, and the resin-coated aluminum pigment of the present invention was obtained.

Example 4 115 g of the aluminum paste M-601 used in Example 1 and 400 g of Mineral Subiliff were added to a 1000 ml three-necked flask, stirred while introducing nitrogen gas, and the temperature in the system was raised to 65 ° C. Next, 0.375 g of methacrylic acid (reagent) was added, and stirring was continued at 65°C for 60 minutes. Next, 7.5 g of trimethylolpropane triacrylate (reagent) and 0.75 g of azobisisobutyronitrile (reagent) were added and polymerized at 65° C. for 7 hours. After the polymerization was completed, the slurry was allowed to cool to room temperature and filtered to obtain a paste containing a resin-coated aluminum pigment. The nonvolatile content (according to JIS-5910) of this paste was 47.5% by weight.

The amount of coating resin was 11.2 parts by weight based on 100 parts by weight of aluminum metal. It is estimated that 97.4% of methacrylic acid, trimethylolpropane triacrylate, and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEH) of this resin-coated aluminum pigment
) is 0.4, acid resistance (ΔEH) is 0.5, aggregation after heat stability test (d,; /d,'> is 1.08,
A resin-coated aluminum pigment of the present invention was obtained.

Examples 5-7, Comparative Examples 1-2 Aluminum paste I'1G-2 used in Example 2
Polymerization shown in Table 1 was carried out in the same manner as in the preparation of the resin-coated aluminum pigment in Example 2 using 1, to obtain a paste containing the resin-coated aluminum pigment.

In Comparative Example 1, only trimethylolpropane trimethacrylate was polymerized, but the viscosity of the slurry in the system increased 1 hour after the start of polymerization, making stirring difficult. It is presumed that this is because the acrylic acid treatment was not performed, so the aluminum particles did not adhere to the surface and polymerization proceeded in the organic solvent (Mineral Subilift).

As shown in Table 1, Examples 5 to 7 showed extremely good performance, but Comparative Example 1 had poor alkali resistance, presumably because it was not coated with resin. Comparative Example 2 also showed inferior performance compared to Examples 5-7. This is presumed to be because the amount of carboxyl groups contained in acrylic acid was too large.

(Leaving space below) Examples 8 to 9, Comparative Example 3 Using the aluminum paste M-601 used in Example 1, the polymerization shown in Table 2 was carried out in the same manner as in the 8-circle production of the resin-coated aluminum pigment in Example 1. , a paste containing resin-coated aluminum pigment was obtained.

In Comparative Example 3, trimethylolpropane trimethacrylate, acrylic acid, and an initiator were simultaneously added and polymerized. One hour after the start of polymerization, the viscosity of the slurry in the system increased. This does not adhere well to the surface of the aluminum particles, and organic solvents (
It is presumed that polymerization progressed within the mineral spirit).

As the results are shown in Table 2, Examples 8 and 9 showed extremely good performance, but Comparative Example 3 showed poor alkali resistance, presumably because the resin was not coated.

(The following is a blank space) Example 10 A paste containing a resin-coated aluminum pigment was obtained in the same manner as in Example 1 except that acrylic acid was changed to 2-methacryloyloxyethyl phosphate.

The nonvolatile content (according to JIS-5910) of this paste is S4. It was 0% by weight. Aluminum metal content 10
The amount of coating resin was 11.4 parts by weight relative to 0 parts by weight.

This is 2-methacryloyloxyethyl phosphate,
It is estimated that 99% or more of trimethylolpropane trimethacrylate and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEM) of this resin-coated aluminum pigment
) was 0.2, acid resistance (ΔEH) was 0.1, and a good coating film was obtained with almost no discoloration. Also, soak the paint film in warm water at 60℃ for 7 days.
When immersed for one day, the coating film was good with almost no discoloration. The paint was stored at 50°C for one month, but it was in good condition with no gelation.

The aggregation (dQ/d,') after the heat resistance stability test was 1.03, and the powder had a uniform appearance, with virtually no aggregation observed.

Example 11 A paste containing the resin-coated aluminum pigment of the present invention was obtained in the same manner as in Example 2, except that 2-methacryloyloxyethyl phosphate was used instead of acrylic acid. The nonvolatile content (according to JIS-5910) of this paste is 59.
It was 0% by weight. The amount of coating resin was 5.8 parts by weight based on 100 parts by weight of aluminum metal. This is 2
- It is estimated that more than 99% of methacryloyloxyethyl phosphate, trimethylolpropane trimethacrylate, and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEH) of this resin-coated aluminum pigment
) was 0.3, acid resistance (ΔE1.I) was 0.2, and agglomeration (dQ/d,') after heat resistance stability test was 1.10, and the resin-coated aluminum pigment of the present invention was obtained. Ta.

Example 12 A paste containing the resin-coated aluminum pigment of the present invention was obtained in the same manner as in Example 1 except that acrylic acid was replaced with 2-acryloyloxyethyl phosphate. The nonvolatile content of this paste (according to JIS-5910) is 51.0
The i was 31%. The amount of coating resin was s, sffli parts with respect to 100 parts by weight of aluminum metal. It is estimated that 99% or more of 2-acryloyloxyethyl phosphate, trimethylolpropane trimethacrylate, and azobisisobutyronitrile were deposited on the aluminum metal surface.

Alkali resistance (ΔEs
) is 0.5, acid resistance (ΔE, ) is 0.3, and aggregation after heat stability test (d; / d, +) is 1.05.
The resin-coated aluminum pigment of the present invention was obtained.

Example 13 The resin-coated aluminum of the present invention was prepared in the same manner as in Example 2 except that 0.255 g of acrylic acid was changed to 2.55 g of 2-methacryloyloxyphosphate and 4.25 g of trimethylolpropane trimethacrylate was changed to 8.5 g. A paste containing pigment was obtained. Non-volatile content of this paste (JIS
-5910) was 57.9% by weight.

The amount of coating resin was 13.4 parts by weight based on 100 parts by weight of aluminum metal. This is 99% of 2-methacryloyloxyethyl phosphate, trimethylolpropane trimethacrylate, and azobisisobutyronitrile.
It is presumed that the above substances adhered to the aluminum metal surface.

The alkali resistance (AE,
) was 0.1, acid resistance (ΔEH) was o, 1, and aggregation (ai/d; ) after heat resistance stability test was 1.15, and the resin-coated aluminum pigment of the present invention was obtained.

Example 14 (1) Preparation of resin-coated aluminum pigment of Comparative Example 4 A paste containing a resin-coated aluminum pigment was obtained in the same manner as in Example 1 except that trimethylolpropane trimethacrylate was replaced with ethylene glycol dimethacrylate (reagent). . Non-volatile content of this paste (JIS4-591
0) was 51.5% by weight.

(2) Preparation of resin-coated aluminum pigment of Comparative Example 5 A paste containing a resin-coated aluminum pigment was obtained in the same manner as in Example 10, except that ethylene glycol dimethacrylate (reagent) was used instead of trimethylolpropane trimethacrylate. Non-volatile content of this paste (JIS-ni-5
910) was 49.5% by weight.

Resin-coated aluminum pigments of Comparative Examples 4 and 5 and Example 1
and 10 resin-coated aluminum pigments (alkali resistance, acid resistance, fingerprint resistance, cosmetic resistance, aggregation after heat stability test (dQ/a,')) were compared.

As shown in Table 3, Examples 1 and 10 exhibited extremely superior performance compared to Comparative Examples 4 and 5.

(margin below c)

Claims (1)

[Claims] (1) 0.1 to 100 parts by weight of (a) paint resin, (b) phosphoric acid monocontaining radically polymerizable unsaturated carboxylic acid and/or radically polymerizable double bond per 100 parts by weight of paint resin or a resin-coated metal pigment whose surface is coated with a resin produced from a diester and a monomer having three or more radically polymerizable double bonds, and whose alkali resistance is 1.0 or less, and (c) dilution thinner. A metallic paint characterized by consisting of.