JPS58141248A - Colored metallic pigment and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled pigment whose particle size is small and on the surface of which a color pigment is uniformly deposited, by polymerizing a monomer in a specified org. solvent to deposit a color pigment on the surface of a metallic pigment by means of the formed polymer. CONSTITUTION:A monomer having a polymerizable double bond is polymerized in the presence of a polymn. initiator in an org. solvent is which said monomer is soluble and the resulting polymer is insoluble, to deposit a color pigment on the surface of a metallic pigment by means of the polymer. Said metallic pigment and said color pigment may be dispersed in the polymn. medium prior to the polymn. reaction. Alternatively, only the metallic pigment is dispersed in the polymn. medium, prior to the polymn. reaction and the color pigment may be gradually added after the beginning of the polymn. reaction. The latter method is preferred, since the distribution density of the color pigment on the surface of the metallic pigment is high, the distribution is uniform, and a colored metallic pigment having clear color tone can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a colored metallic pigment and a method for producing the same.

Paints containing metallic pigments have traditionally been widely used for the purpose of imparting metallic luster to various types of paint, and in recent years, colored metallic pigments with various tones have been developed. Most of the
None of them were satisfactory in terms of weather resistance, solvent resistance, metallic feel, etc., and there was a problem that they could not be put to practical use.

Therefore, the present applicant has previously proposed the following colored metallic pigment (Japanese Patent Publication No. 36525/1983). This colored metallic pigment is produced by forming a resin film on the surface of the metallic pigment and containing the colored pigment in the resin film. A metallic pigment and a colored pigment are mixed and dispersed in a resin-like material containing a 1/9 to 1 overlapping portion, and this mixture is spray-dried to adhere the colored pigment to the surface of the metallic pigment. It is. The colored metallic pigment obtained in this way has each particle of the metallic pigment colored, so it cannot be used as a conventional colored metallic paint, that is, a mixture of colored pigment and metallic pigment in the paint. In comparison, metallic pigments provide an excellent coated surface with clear color tones, and a resin film is formed on the surface of the metallic pigments. For,
It also exhibits excellent effects on solvent resistance and weather resistance.

However, the above colored metallic pigments have the following problems. That is, in the manufacturing process, a resin-like material in which metallic pigments and colored pigments are dispersed must be sprayed from a nozzle. In this case, several metallic pigment particles are sprayed from the mouth of the nozzle when the nozzle is opened. This nozzle jets all! Since the resin begins to dry when
Adhesion and aggregation of metallic pigments is likely to occur during spraying.

Therefore, even if a metallic pigment with a fine particle size is used as a raw material, only a colored metallic pigment with a coarse particle size can be obtained. In addition, since the drying of the resin coating the surface of the metallic pigment occurs from the periphery of the metallic pigment particles, it is difficult for the colored pigment to adhere to the periphery of the metallic pigment powder. Since the metallic pigment aggregates in the center of the powder surface and the surface is not uniformly colored, there is also a problem in the sharpness of paints using this colored metallic pigment.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a colored metallic pigment having a fine particle size and having a colored pigment uniformly adhered to the surface of the metallic pigment, and a method for producing the same.

This invention involves reacting and polymerizing monomers in the presence of a polymerization initiator in an organic solvent in which monomers having polymerizable double bonds are soluble and the resulting polymer is insoluble. is uniformly adhered by the above polymer to obtain a colored metallic pigment.

In this invention, the metallic pigment and the colored pigment can be mixed and dispersed in the reaction system before the start of polymerization, or only the metallic pigment can be dispersed in the reaction system before the start of polymerization. Although the colored pigment may be added gradually after initiation, the latter method results in a higher distribution density of the colored pigment on the surface of the metallic pigment and a more uniform distribution, resulting in a colored metallic with a more vivid tone. pigments can be obtained.

Monomers having polymerizable double bonds used in this invention include styrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylnitrile, vinyl acetate, vinyl propionate, acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid. Acid esters, crotonic acid, itaconic acid, citraconic acid, oleic acid, maleic acid, maleic anhydride, l, 6-hesanodiol diacrylate, 1,4-butanediol diacrylate, divinylbenzene, epoxidized polybutadiene, cyclohexene There are vinyl monooxide, divinylbenzene monooxide, etc. It goes without saying that these 7-mers can be used alone, but good results can also be obtained when they are used in combination.

Above J [' As the metallic pigment, aluminum powder, copper powder, zinc powder, iron powder, nickel powder, etc. are used, and leafing type and non-leafing type flaky aluminum pastes are particularly suitable.

The particle size of this metallic pigment is not particularly limited, but is usually several microns to several hundred microns.

Further, as the above-mentioned coloring pigment, any organic pigment or inorganic pigment may be used as long as it does not dissolve in the organic solvent used in the polymerization system of this invention, but dyes may be used in terms of solvent resistance and heat resistance. is not desirable. These colored pigments can be freely selected from achromatic colors to chromatic colors, and two or more types of pigments can be mixed and used as necessary. Specific examples of the organic pigments include heptalocyanine, azo lake, triphenylmethane, anthraquinone, perylene, quinacridone, thioindigo, and condensed azo pigments. Specific examples of the above inorganic pigments include lead-based pigments (yellow, molybdate orange, etc.), iron oxide pigments (bengara, transparent iron oxide, etc.), and metal oxide-based pigments (cobalt blue, cobalt green, manganese black, etc.). ), there are other pigments such as navy blue, cadmium pigments, titanium oxide, carbon black, clay, and mica. For example, when aluminum is used as the metallic pigment, the amount of the colored pigment added is preferably 1 to 30 parts by weight per 100 parts by weight of aluminum. This is the color pigment that is added to the aluminum 1
If the amount is less than 1 part by weight per 00 parts by weight, the amount of coloring pigment will be too small and will not change the color tone of the metallic pigment.
This is because it has no meaning as a colored metallic pigment, and even if the amount of the colored pigment is 30 parts by weight or more based on 100 parts by weight of aluminum, there is a limit to the coloring effect, which is undesirable in terms of cost.

Examples of organic solvents include aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane, and mineral spirits, aromatic hydrocarbons such as benzene, toluene, and xylene, chlorobenzene, trichlorobenzene, perchloroethylene, and trichloro. Halogenated hydrocarbons such as ethylene, alcohols such as alcohol, ethanol, n-propyl alcohol, and n-butanol, ketones such as n-propanone and 2-butanone, and esters such as ethyl acetate and propyl acetate. , tetrahydro-7rane, diethyl ether, ethylglobyl ether, and other ethers.

As the polymerization initiator, [-butyl peroxide,
acetyl peroxide, benzoyl peroxide,
Examples include organic peroxides such as lauroyl peroxide and cumyl peroxide, and azo compounds such as α,α'-azobisisobutyronitrile.

Although it is necessary to select an appropriate reaction temperature in the reaction system of this invention depending on the type of polymerization initiator used, generally a temperature range of 60 to 200°C is suitable, and 60°C or less. At a temperature of 200° C. or higher, problems such as a decrease in the efficiency of the polymerization initiator and an increase in reaction time occur.

Further, the polymerization reaction of the present invention is preferably carried out in an inert gas such as nitrogen, helium, or argon.

Examples and comparative examples are listed below. In addition, in Examples and Comparative Examples, parts refer to parts by weight.

Example 1 Blend> Monomer methyl methacrylate 5.3 parts 1.6-
Hexanediol diacrylate 5.0 parts Acrylic acid 2.3 Fine organic solvent Mineral spirit 840 parts Metallic pigment aluminum paste 250 parts (Toyo Aluminum MG-1000"r Luminium content 70
．． 9%) Colored pigment Chromophthal Red BR 9 parts (equivalent to 5.0 parts per 100 parts of aluminum) Polymerization initiator α,α'-azobisin butyronitrile 1 part Reaction atmosphere> Nitrogen gas F monomer, organic solvent , after mixing the metallic pigment and the colored pigment, and then increasing the temperature in the reactor to 70 ° C.
A polymerization initiator was added and the mixture was reacted for 8 hours.

After completion of the reaction, the mixture in step 1 was concentrated by filtration to obtain a non-volatile content of 75.
A 5% colored aluminum paste was obtained.

Example 2 Formulation> Monomer epoxidized polybutadiene 4.9 parts (BF-1000 manufactured by Adeka Argus) 1.6-hexanethiol diacrylate 7.2 parts acrylic acid
2.3 parts Organic solvent Mineral spirit 840 parts Metallic pigment aluminum paste 250 parts
．． 9%) Colored pigment Chromo 7 Tarred BR 9 parts (equivalent to 5.0 parts per 100 parts of aluminum) Polymerization initiator α,α'-azobisinbutyronitrile 1 part Reaction atmosphere> Nitrogen gas monomer and organic solvent After mixing and raising the temperature inside the reactor to 80°C, a polymerization initiator was added, and after 30 minutes, the colored pigment dispersed in mineral spirit was added to L
It was gradually added dropwise to the above mixture and reacted at 80°C for 4 hours.

After the reaction, the above mixture was concentrated by mouth to reduce the non-volatile content to 60%.
．． A 3% colored AnoC minium paste was obtained.

Example 3 Blended monomer Epoxidized polybutadiene 4.9 parts (BF-1000 manufactured by Adeka Argus) 1.6-hexanediol diacrylate 7.2 parts Acrylic acid
23 parts Organic solvent mineral spirit 840 parts Metallic pigment aluminum paste 275 parts (713ON manufactured by Toyo Aluminum Co., Ltd. Aluminum content 65.3%) Colored pigment copper phthalocyanine blue 9 parts (equivalent to 5.0 parts per 100 parts of aluminum) Polymerization initiator 1 part α,α'-azobisisobutyronitrile Reaction atmosphere> Nitrogen gas A colored aluminum paste with a nonvolatile content of 60.7% was obtained in the same manner as in Example 2.

Example 4 Compounding monomer Epoxidized polybutadiene 10.4 parts (BF-1000 manufactured by Adeka Argus) 1.6-hexanediol diacrylate 15.3 parts Acrylic acid
4.9 parts Organic solvent Mineral spirit 750 parts Metallic pigment aluminum paste 250 parts (Toyo Aluminum H5-2 - Aluminum content 71.3%) Color pigment Chromophthal Yellow 8G 27 parts (
(equivalent to 15.1 parts per 100 parts of aluminum) Polymerization initiator α,α-azobisisobutyronitrile 1 part Reaction atmosphere> Nitrogen gas A colored aluminum paste with a non-volatile content of 605% was obtained in the same manner as in Example 2. Ta.

Example 5 Seven months Methyl methacrylate 3.6 parts 1.
6-Hexanediol diacrylate 2.4 parts Organic solvent Mineral spirit 920 parts Metallic pigment aluminum paste 250 parts (
MG-1000 manufactured by Toyo Aluminum Co., Ltd. Aluminum content 70.9%) Color pigment Chromophthal Red BR 3.6 parts (equivalent to 2.0 parts per 100 parts aluminum) Polymerization initiator α, α'-azobisin butyronitrile 1 part reaction atmosphere> Nitrogen gas A colored aluminum paste with a nonvolatile content of 75.8% was obtained in the same manner as in Example 2.

Example 6 Monomer epoxidized polybutadiene 2.5 parts (
rManufactured by Deca Argus B F-1000) 1,6-hexanediol diacrylate 3.5 parts Acrylic acid 1.2 parts Organic solvent Mineral spirit 920 parts Metallic pigment aluminum paste 250 parts (
MG-1000 (manufactured by Toyo Aluminum Co., Ltd. Aluminum content 70.9%) Color pigment chromophthal red BRl, 5 parts (equivalent to 0.76 parts per 100 parts of aluminum) Polymerization initiator α,α'-azobisisobutyro Nitrile 1 part reaction atmosphere> Nitrogen gas A colored aluminum paste with a non-volatile content of 64.9% was obtained in the same manner as in Example 2, but since the amount of colored pigment added to the metallic pigment was small, the effect as a colored metallic pigment was There weren't many.

Example 7 In Example 4, only the color pigment was changed to titanium oxide,
A colored aluminum paste with a nonvolatile content of 586% was obtained.

Comparative Examples 1 to 7 Aluminum paste and color pigments are simply mixed in the paint, and the aluminum paste and color pigments used are the same as Examples 1 to 7, respectively, and the pigment combination was made to prevent the paint from being made. The ratios are also the same.

Comparative Example 8 1) 60 parts of triincyanate (resin solid content), 40 parts of polyol (resin solid content), and 100 parts of lacquer thinner are mixed to prepare liquid (A).

2) Prepare solution (B) by mixing and dispersing 100 parts of chromophthal red BR in 1000 parts of lacquer thinner.

3) Aluminum paste (Toyo Aluminum Co., Ltd. IG-1000, aluminum content 70.9%) 141
Prepare solution (C) by mixing 0 parts and 2000 parts of lacquer thinner.

4) Mix liquids (A), (B), and (C), add 2000 parts of solvent to adjust the viscosity, and spray with air F 61'l/cd from a nozzle with a nozzle diameter of 1 m to form a resin film. The powder was collected by drying and drying at the same time. Thereafter, it was left to stand at room temperature for 10 days to harden the resin coating and obtain colored aluminum powder.

Next, the colored metallic pigment obtained in Example 2 and that of Comparative Example 8 were photographed using an electron microscope at a magnification of 3.000 times (7
I observed it. FIG. 1 shows the former case, and it can be seen that the colored pigment is uniformly dispersed and adhered to the entire surface of the flaky aluminum powder. On the other hand, in the conventional colored metallic pigment shown in FIG. 3, the colored pigment is not attached to the periphery of the flaky aluminum powder, and the colored pigment is concentrated in the center of the aluminum powder.

Further, the colored metallic pigment obtained in Example 2 and that of Comparative Example 8 were photographed and observed using an electron microscope at a magnification of 30-0. Figure 2 shows the former case, where the aluminum powder in the form of 7 flakes is dispersed without agglomerating, but in the conventional colored metallic pigment shown in Figure 4, the aluminum powder in the form of flakes forms several layers above and below. The colored metallic pigment itself has a coarse particle size.

Furthermore, the colored metallic pigment obtained in Example 2 and that of Comparative Example 8 were compared by measuring the sieve residue using a 400 mesh (37μ) screen.

As a result, as shown in Table 1, it was found that the sample of Example 2 had a significantly smaller amount of sieve residue than that of Comparative Example 8, and had less agglomeration of aluminum powder.

Table 1 Furthermore, 2 g of the aluminum content of the pigments obtained in Examples 1 to 7 and Comparative Examples 1 to 8 was added to NC-based varnish (manufactured by Nippon Paint Co., Ltd., Pylac & 3200, non-volatile 35%).
A paint was prepared by dispersing it in 50g using a homomixer, and each of these paints was applied using a doctor blade (thickness: 250μ), and the coated plates were measured and compared using a color difference meter (Table 2).
.

Table 2 (1) From the results in Table 2 above, the paints using the colored metallic pigments of Examples 1 to 5 have a JV value of Σ compared to paints made with the same formulation (aluminum paste, colored pigments). It is recognized that the coloring strength is very high. This characteristic is particularly remarkable in Examples 2-4. Also, when comparing Example 2 and Comparative Example 8, Comparative Example 8 has the following:
It can be seen that even though the amount of color pigment added was twice that of Example 2, the value of \/a2+b2 was low, and the coloring power ° was considerably inferior to that of the present invention.

In Table 2, the amount of resin coating is determined by producing a resin coated aluminum paste without adding any colored pigment under the same production conditions as the colored aluminum pigment produced in each example, and applying this resin coated aluminum paste to n-
This is the amount of resin measured by washing through the mouth with hexane, dissolving the aluminum content with a mixed acid (hydrochloric acid/nitric acid/water = 1/1/2) after death with parathater, and drying the remaining resin content.

As mentioned above, in the colored metallic pigment of the present invention, the colored pigment adheres uniformly to the surface of the metallic pigment, and the metallic pigment itself is not aggregated, so that it has poor coloring power, dispersibility, hiding power, etc. This makes it possible to obtain painted surfaces with vivid colors.

In addition, the colored metallic pigment of the present invention has the following excellent effects.

(a) The coloring pigment used as a raw material only needs to be able to be dispersed in an organic solvent;
Since it is not particularly limited, any color tone can be obtained.

(b) The raw material metallic pigment is not particularly limited in particle size as long as it has a particle size that can be dispersed in an organic solvent.
Any particle size can be obtained.

(c) The surface of the metallic pigment is coated with a resin, and since a pigment with excellent weather resistance can be selected as a raw material, it has good weather resistance.

) As in Comparative Example 8, the production cost is relatively low because the special process of spray drying is not required.

(e) Since the surface of the metallic pigment is coated with a resin, the cohesive force and electrical insulation of the coating film are improved, and electrostatic painting is possible.

[Brief explanation of the drawing]

FIGS. 1 and 2 are electron micrographs of a colored metallic pigment according to the present invention, and FIGS. 3 and 4 are electron micrographs of a conventional colored metallic pigment, respectively. Same agent sickle 1) Text 2 Figure 1 Figure 2

Claims (2)

[Claims] (1) A colored metallic pigment in which a colored pigment is uniformly adhered to the surface of the metallic pigment using a polymer made of a monomer having a polymerizable double bond. (2) In the presence of a polymerization initiator in an organic solvent in which the monomer having a polymerizable double bond is soluble and the resulting polymer is insoluble, 7-mer is reacted and polymerized, and other colored pigments are added to the surface of the metallic pigment. A method for producing a colored metallic pigment, which comprises uniformly adhering the pigment to the above polymer.