JP7315312B2 - Resin compound-adhered aluminum pigment and method for producing the same - Google Patents

Description

The present invention relates to a resin compound-attached aluminum pigment, a paint or ink composition containing the resin compound-attached aluminum pigment, a coating film containing the paint composition, and a printed material containing the ink composition, which enables the formation of a metallic matte coating film with excellent design and alkali resistance without using any conventional matting agents (specifically, conventional matting agents such as silica particles and urethane resin particles). The present invention also relates to a method for producing the resin compound-attached aluminum pigment.

Automobile bodies, automobile parts, automobile interior parts, home electric appliances, and the like are sometimes given a metallic matte paint finish. Usually, such a metallic matte coating finish method is achieved by adding a matte agent for gloss adjustment, such as silica or urethane resin particles, as an additive to the paint in addition to the aluminum-based bright pigment (see, for example, Patent Documents 1 and 2).
However, in the conventional technology, when an external impact is applied to the finished coating film, the matting agent particles (for example, silica or urethane resin particles) unevenly distributed on the coating film surface are scraped off.
In addition, not only in the field of paints as described above, but also in the field of inks used in high-end printing such as gravure printing, offset printing, screen printing, etc., there is a current situation that realization of metallic matte with superior design properties, especially realization by a simple method is desired.

JP 2005-290314 A JP 2018-76438 A

Therefore, in order to solve the above-mentioned problems of the prior art, it is an object of the present invention to provide a resin compound-attached aluminum pigment that can form a coating film having a good finished metallic matte design and excellent alkali resistance without using any matting agent that may be scraped off from the coating film by an external impact or the like, and can exhibit high water resistance even when used in an aqueous coating composition (so-called "paint"). Further, it is an object of the present invention to provide a coating composition capable of forming a finished coating film having a good metallic matte design property without using any matting agent, in other words, capable of forming a coating film free from the problem of an increase in glossiness of the scraped-off matting agent portion caused by the impact caused by the coating composition using a conventional matting agent, even against an external impact on the finished coating film.
Another object of the present invention is to provide a resin compound-adhered aluminum pigment which enables the production of printed matter having a good finished metallic matte design and excellent alkali resistance without using any matting agent, and which can exhibit high water resistance even when used in a water-based ink composition (so-called "ink"). Another object of the present invention is to provide an ink that allows printed matter having the above effects to be produced easily because no matting agent is used.

As a result, the present inventors were carefully examined to solve the above issues, and found that "flake -like aluminum powder, resin compound attached to the surface of flakes aluminum powder, and aluminum pigments attached to resin compounds, with a duplicate compound in the molecule. The polymerization of the leophypertonic body and/or oligomer, the ratio of the resin compound substance per unit mass of the aluminum pigment of the resin compound (hereinafter, "A (G/G)" or "A = resin compound material amount (G)/resin compound adhesive aluminum pigment (G)". According to the aluminum pigment, which is at least 0.375, which is at least 0.375, it is possible to provide paint and ink compositions that can demonstrate good finished metallic glossy design without using any glossy agents, and also create paintings with excellent alkaline and printing. It was found that it was possible, and it was possible to show high water resistance even when used as a water -based paint or ink component, and the present invention was completed.
That is, the present invention is as follows.

[1]
flaky aluminum powder;
a resin compound adhering to the surface of the flaky aluminum powder;
A resin compound-attached aluminum pigment containing
The resin compound is a radical polymerizable monomer and/or oligomer polymer having one or more double bonds in the molecule,
The ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment is at least 0.375,
The resin compound-adhered aluminum pigment.
[2]
The resin compound-attached aluminum pigment according to [1] above, wherein the resin compound attached to the outermost surface of the resin compound-attached aluminum pigment and having a portion protruding from a circle with a radius of 0.2 μm is present at least 9 points per 48 μm ² of the outermost surface area of the resin compound-attached aluminum pigment.
[3]
A coating composition containing no matting agent, comprising the resin compound-deposited aluminum pigment according to [1] or [2] above.
[4]
The coating composition according to [3] above, wherein the solid content mass ratio of the resin compound-attached aluminum pigment to 100 parts of the solid content of the coating composition is 5% or more and 20% or less.
[5]
The coating composition according to [4] above, wherein the gloss of the coating film obtained by coating on art paper exhibits a 60-degree specular reflectance of less than 30 when the incident angle and the light-receiving angle are both 60 degrees.
[6]
The coating composition according to any one of [3] to [5], further comprising a black pigment.
[7]
The alkali resistance of the coated plate obtained by applying it to an acrylic resin plate is represented by the color difference ΔE between the immersed portion and the unimmersed portion when immersed in a 5N sodium hydroxide solution at 55 ° C. for 4 hours.
[8]
An aqueous coating composition containing no matting agent, wherein the amount of gas generated when kept at 40° C. for 72 hours is 3 ml or less, comprising the resin compound-adhered aluminum pigment according to [1] or [2] above.
[9]
A coating film containing the coating composition according to any one of [3] to [8].
[10]
An ink composition containing no matting agent, comprising the resin compound-deposited aluminum pigment according to [1] or [2] above.
[11]
A printed matter containing the ink composition according to [10] above.
[12]
A dispersion obtained by adding flaky aluminum powder and a resin composition of a polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule to an organic solvent, wherein the concentration of the aluminum powder is 0.1% by weight or more and 40% by weight or less, and the concentration of the resin composition is 0.06% by weight or more and 27% by weight or less;
adding an external vibrational effect to the dispersion liquid during the process of attaching the resin composition to the aluminum powder;
A method for producing the resin compound-deposited aluminum pigment according to the above [1] or [2].

According to the present invention, it is possible to obtain a resin compound-adhered aluminum pigment that enables the formation of a coating film having a good finished metallic matte design and excellent alkali resistance without using any matting agent that may be scraped off from the coating film by an external impact or the like, and that can exhibit high water resistance even when used in a water-based paint. Therefore, if the resin compound-attached aluminum pigment is used as a component of the paint composition, it is possible to provide a paint that can exhibit a good finished metallic matte design without adding any conventional matting agent such as silica or urethane resin particles as an additive. As a result, even when the finished coating film is subjected to an external impact, etc., the problem of an increase in the glossiness of the scraped-off matting agent portion due to the impact caused by the conventional coating composition using a matting agent does not inherently occur.
In addition, according to the present invention, it is possible to obtain a resin compound-attached aluminum pigment that can produce printed matter having a good finished metallic matte design and excellent alkali resistance without using any matting agent, and can exhibit high water resistance even when used in water-based inks.
Therefore, if the resin compound-attached aluminum pigment is used as an ink composition component, it is possible to produce a printed material having a good finished metallic matte design and excellent alkali resistance without adding any conventional matting agent represented by silica or urethane resin particles as an additive, and furthermore, it is possible to provide a water-based ink exhibiting high water resistance. Since no matting agent is used, a printed matter having the above effect can be produced easily.

1 is a photograph showing an SEM image of the outermost surface of a primary particle of a resin compound-deposited aluminum pigment that is one embodiment of the present invention, obtained using a scanning electron microscope (manufactured by HITACHI, S-2600H).

EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth "this embodiment") for implementing this invention is demonstrated in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be modified appropriately within the scope of its gist.

[Resin compound-adhered aluminum pigment]
The resin compound-attached aluminum pigment of the present embodiment is a resin compound-attached aluminum pigment containing flaky aluminum powder and a resin compound attached to the surface of the flaky aluminum powder, wherein the resin compound is a polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule, and the ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment (A (g/g)) is at least 0.375.
In the resin compound-attached aluminum pigment of the present embodiment, the resin compound having a portion protruding from a circle size with a radius of 0.2 μm, which is attached to the outermost surface of the resin compound-attached aluminum pigment, preferably exists at least 9 points per 48 μm ² of the outermost surface area of the resin compound-attached aluminum pigment.

As described above, the resin compound-attached aluminum pigment of the present embodiment contains flaky aluminum powder and a resin compound attached to the surface of the flaky aluminum powder. The resin compound is a polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule (this "polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule" will be described in detail later in the item "(Resin compound that is a polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule)").
Here, the resin compound adhering to the flaky aluminum powder does not simply mean that the flaky aluminum powder and the resin compound are mixed, but means that there is an interaction between the "flaky aluminum powder" and the "resin compound".
Interactions include, for example, chemical bonds, hydrogen bonds, ionic bonds, van der Waals forces, and the like.
The "flake-shaped aluminum powder" will be described in detail in the item "(flake-shaped aluminum powder)" below.
With respect to the resin compound-deposited aluminum pigment, the presence or absence and amount of adhesion of the resin compound to the aluminum pigment can be confirmed, for example, by the following method.
The resin compound-attached aluminum pigment is dispersed in an organic solvent and filtered to remove the resin compound not attached to the aluminum pigment, and then the solvent is volatilized to obtain particles in which the resin compound is attached to the aluminum pigment (that is, the resin compound-attached aluminum pigment of the present embodiment) (B1).
Next, (B1) is treated in an electric furnace to remove the resin compound adhering to the aluminum pigment, leaving only the aluminum pigment (B2).
By calculating the difference in mass between (B1) and (B2), the presence or absence and amount of resin adhesion can be confirmed.
The conditions for removing the resin compound adhering to the aluminum pigment in an electric furnace or the like are appropriately selected depending on the molecular weight and crosslink density of the resin.

In the resin compound-attached aluminum pigment of the present embodiment, the resin compound mass ratio (A (g/g)) per unit mass of the resin compound-attached aluminum pigment is at least 0.375 (that is, 0.375 or more). In addition, the ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment (A (g/g)) is preferably 0.545 or less, more preferably 0.412 or more and 0.545 or less from the viewpoint of metallic matte design.

As described above, the resin compound-attached aluminum pigment of the present embodiment preferably has at least 9 points of the resin compound attached to the outermost surface of the resin compound-attached aluminum pigment and having a portion protruding from a circle with a radius of 0.2 μm per 48 μm ² of the outermost surface area (that is, the outermost surface area) of the resin compound-attached aluminum pigment.
Here, the attached resin compound in the resin compound-attached aluminum pigment is usually amorphous, and it is difficult to specify its size. Therefore, from the SEM image of the outermost surface of the primary particles of the resin compound-attached aluminum pigment, the attached resin compounds scattered around the outermost surface area of ⁴⁸ μm are specified, and a circle with a radius of 0.2 μm is placed in the center of each specified attached resin compound. As such, not all portions of the adherent resin compound (ie, the entire adherent resin compound) must exceed the size of a circle with a radius of 0.2 μm. This point will be described below using the SEM image of FIG. Among the adhering resin compounds shown in the SEM image of FIG. 1, those with a circle with a radius of 0.2 μm filled with a black line around the circle correspond to adhering resin compounds having a portion protruding from the size of the circle with a radius of 0.2 μm. As can be seen from this SEM image, some of the adhered resin compounds in which a circle with a radius of 0.2 μm with a black line around the circumference is filled have a portion within the size of the circle with a radius of 0.2 μm, and not all portions exceed the size of the circle with a radius of 0.2 μm. However, all of the adhered resin compounds in which a circle with a black line and a radius of 0.2 μm are filled have at least one portion that protrudes from the size of a circle with a radius of 0.2 μm. On the other hand, if there is no such protruding portion, i.e., if a circle size with a radius of 0.2 μm is applied to the center of the adhered resin compound and the entire portion fits within that circle size, it does not correspond to the adhered resin compound having a portion that protrudes from the circle size with a radius of 0.2 μm.
In the resin compound-attached aluminum pigment of the present embodiment, the resin compound having a portion protruding from a circle size of 0.2 μm in radius attached to the outermost surface of the resin compound-attached aluminum pigment per maximum surface area of 48 μm ² of the resin compound-attached aluminum pigment preferably exists (interspersed) at least 9 points (interspersed), and more preferably at 15 points or more. On the other hand, per the maximum surface area of 48 μm ² of the resin compound-attached aluminum pigment, the resin compound attached to the outermost surface of the resin compound-attached aluminum pigment and having a portion protruding from a circle with a radius of 0.2 μm preferably has a score of 87 or less, more preferably 66 or less, from the viewpoint of metallic matte design.

The resin compound-attached aluminum pigment of the present embodiment has a solid content mass ratio (PWC: Pigment Weight Concentration) of 10% with respect to 100 parts of the solid content of the coating composition that does not contain any matting agent. When measured, it preferably exhibits a metallic matte design with a 60-degree specular reflectance of less than 30.
In other words, the coating composition containing the resin compound-attached aluminum pigment of the present embodiment and not containing a matting agent preferably exhibits a gloss of a coating film obtained by coating on art paper with a 60-degree specular reflectance of less than 30 when the incident angle and the light-receiving angle are each 60 degrees.

The resin compound-attached aluminum pigment of the present embodiment preferably exhibits alkali resistance such that ΔE is less than 1.0 (ΔE=1.0) when a coating film formed by applying a coating composition containing the resin compound-attached aluminum pigment and a black pigment onto an acrylic resin plate is immersed in a 5N sodium hydroxide solution at 55° C. for 4 hours and according to a test method for evaluating alkali resistance based on the color difference ΔE between an immersed portion and an unimmersed portion. If the alkali resistance ΔE is less than 1.0, it is preferable in that it is possible to provide a one-coat specification coating film with excellent workability for fields that require very high alkali resistance.
The coating composition can be prepared by mixing the resin compound-deposited aluminum pigment of the present embodiment and a black pigment. Further, the color difference ΔE can be measured with a colorimeter. Specifically, it can be measured by the method described later (that is, see the item <4. Alkali resistance> in Examples).

The resin compound-deposited aluminum pigment of the present embodiment is greatly improved in the amount of gas generated when dispersed in a water-based paint as compared with the conventional product, which exhibits a gas generation amount of 27 ml or more under the same evaluation conditions. The gas generation amount measured by the method described later (that is, see the item <5. Gas generation amount in a specific water-based paint> in Examples) is preferably 3 ml or less, more preferably 1 ml or less.

(flaky aluminum powder)
As the "flaky aluminum powder" used for the resin compound-attached aluminum pigment of the present embodiment, those having surface properties, particle size, and shape required for metallic pigments such as surface glossiness, whiteness, and luster are suitable.
As for the shape, various shapes such as granular, plate-like, lumpy, and scaly can be used, but the scaly is preferred in order to give the coating film an excellent metallic effect and brightness.
The flaky aluminum powder preferably has a thickness in the range of 0.001 μm to 1 μm and a length and width in the range of 1 μm to 100 μm.
The aspect ratio of the flaky aluminum powder is preferably in the range of 10 or more and 20000 or less.
Here, the aspect ratio is a value obtained by dividing the average length of the flake-shaped aluminum powder by the average thickness of the flake-shaped aluminum powder.
Although the purity of the flake-shaped aluminum powder is not particularly limited, it is preferable that the purity of the aluminum powder used for paint is 99.5% or higher.
The flaky aluminum powder can be obtained by a known method such as the manufacturing method described in International Publication No. 99/54074, but it is usually commercially available in a paste state, and this can also be used.

(Resin compound that is a polymer of radically polymerizable monomers and/or oligomers having one or more double bonds in the molecule)
The "radical polymerizable monomer and/or oligomer" is not particularly limited, and conventionally known ones can be used.
Examples of the radically polymerizable monomer and/or oligomer include, but are not limited to, (meth)acrylic acid, (meth)acrylic acid esters, aromatic vinyl compounds, vinyl cyanides, amide group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, epoxy group-containing vinyl monomers, carbonyl group-containing vinyl monomers, anionic vinyl monomers, mono- or diesters of phosphoric acid or phosphonic acid, and vinyl monomers having a silyl group.

In the present specification, (meth)acryl simply means methacryl or acryl.

Examples of the (meth)acrylic acid ester include, but are not limited to, (meth)acrylic acid alkyl esters having 1 to 50 carbon atoms in the alkyl portion, and (poly)oxyethylene di(meth)acrylates having 1 to 100 ethylene oxide groups.
Examples of (meth)acrylic acid esters include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate, lauryl (meth)acrylate, and dodecyl (meth)acrylate.
Examples of the (poly)oxyethylene di(meth)acrylate include, but are not limited to, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, diethylene glycol methoxy(meth)acrylate, tetraethylene glycol di(meth)acrylate, and the like.
In addition, trimethylolpropane tri(meth)acrylate, tetramethylolpropane tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, di-pentaerythritol hexa(meth)acrylate, di-pentaerythritol penta(meth)acrylate, di-pentaerythritol penta(meth)acrylate monopropionate, and the like.
Furthermore, cyclic unsaturated compounds (e.g., cyclohexene) and aromatic unsaturated compounds (e.g., styrene, α-methylstyrene, vinyltoluene, divinylbenzene, cyclohexenevinylvinyl monoxide, divinylbenzene monoxide, vinyl acetate, vinyl propionate, allylbenzene or diallylbenzene) can also be suitably used.

Examples of the hydroxyl group-containing vinyl monomer include, but are not limited to, hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl monobutyl fumarate, allyl alcohol, and ethylene oxide groups. (poly)oxyethylene mono(meth)acrylate having 1 to 100 propylene oxide groups, (poly)oxypropylene mono(meth)acrylate having 1 to 100 propylene oxide groups, and “PLAXEL FM, FA Monomer” (trade name of caprolactone addition monomer manufactured by Daicel Chemical Industries, Ltd.) and other hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids.

Examples of the (poly)oxyethylene mono(meth)acrylate include, but are not limited to, ethylene glycol (meth)acrylate, ethylene glycol methoxy(meth)acrylate, diethylene glycol (meth)acrylate, diethylene glycol methoxy(meth)acrylate, tetraethylene glycol (meth)acrylate, tetraethylene glycol methoxy(meth)acrylate, and the like.

Examples of the (poly)oxypropylene mono(meth)acrylate include, but are not limited to, propylene glycol (meth)acrylate, propylene glycol methoxy(meth)acrylate, dipropylene glycol (meth)acrylate, dipropylene glycol methoxy(meth)acrylate, tetrapropylene glycol (meth)acrylate, tetrapropylene glycol methoxy(meth)acrylate, and the like.

Examples of the epoxy group-containing vinyl monomer include, but are not limited to, glycidyl (meth)acrylate, allyl glycidyl ether, allyl dimethyl glycidyl ether, and the like.

Further, the mono- or diesters of phosphoric acid or phosphonic acid are not limited to the following, but examples include 2-methacryloyloxyethyl phosphate, di-2-methacryloyloxyethyl phosphate, tri-2-methacryloyloxyethyl phosphate, 2-acryloyloxyethyl phosphate, di-2-acryloyloxyethyl phosphate, tri-2-acryloyloxyethyl phosphate, and diphenyl-2-acryloyloxyethyl phosphate. , dibutyl-2-methacryloyloxyethyl phosphate, dioctyl-2-acryloyloxyethyl phosphate, 2-methacryloyloxypropyl phosphate, bis(2-chloroethyl) vinyl phosphonate, diallyl dibutyl phosphonosuccinate, 2-methacryloyloxyethyl phosphate, 2-acryloyloxyethyl phosphate and the like.

Examples of vinyl monomers having a silyl group include, but are not limited to, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltri-n-propoxysilane, 3-(meth)acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and allyl. trimethoxysilane, 2-trimethoxysilylethylvinylether and the like.

Other resin compounds include, but are not limited to, olefins such as (meth)acrylamide, ethylene, propylene, and isobutylene; dienes such as butadiene; haloolefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, tetrafluoroethylene, and chlorotrifluoroethylene; Carboxylic acid vinyl esters such as vinyl laurate; Carboxylic acid isopropenyl esters such as isopropenyl acetate and isopropenyl propionate; Vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether and cyclohexyl vinyl ether; Aromatic vinyl compounds such as styrene and vinyl toluene; Allyl esters such as allyl acetate and allyl benzoate; Tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6,-pentamethylpiperidine, perfluoromethyl (meth)acrylate, perfluoropropyl (meth)acrylate, perfluoropropylomethyl (meth)acrylate, vinylpyrrolidone, allyl (meth)acrylate and the like. Only one resin compound may be used alone, or two or more resin compounds may be used in combination.

(Polymerization initiator)
When producing the resin compound-attached aluminum pigment of the present embodiment, it is preferable to use a polymerization initiator.
The method for producing the resin compound-deposited aluminum pigment of the present embodiment will be described later (that is, see the item "[Method for producing resin compound-deposited aluminum pigment]").
The polymerization initiator is generally known as a radical generator, and its type is not particularly limited.
Examples of polymerization initiators include, but are not limited to, peroxides such as benzoyl peroxide, lauroyl peroxide, and bis-(4-t-butylcyclohexyl)peroxydicarbonate; and azo compounds such as 2,2'-azobis-isobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile. mentioned.
The amount of the polymerization initiator used is not particularly limited because it is adjusted depending on the reaction rate of the radically polymerizable monomer and/or oligomer, but the range is preferably 0.1 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the flaky aluminum powder.

(other ingredients)
As will be described later, the resin compound-deposited aluminum pigment of the present embodiment may be added with a chain transfer agent for the purpose of controlling the molecular weight of the reaction product together with the radically polymerizable monomer and/or oligomer after dispersing the flaky aluminum powder in a predetermined organic solvent.
Examples of the chain transfer agent include, but are not limited to, alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan; aromatic mercaptans such as benzyl mercaptan and dodecyl benzyl mercaptan; thiocarboxylic acids such as thiomalic acid or salts thereof or alkyl esters thereof; Allyl compounds such as togen disulfide and thioglycol, and dimers of α-methylstyrene are included.
The amount of these chain transfer agents used is preferably 0.001% by mass or more and 30% by mass or less, more preferably 0.05% by mass or more and 10% by mass or less, relative to the resin.

[Method for producing resin compound-deposited aluminum pigment]
The resin compound-deposited aluminum metal pigment of the present embodiment can be produced by dispersing flaky aluminum powder in an organic solvent, heating, stirring, adding a radically polymerizable monomer and/or oligomer, and optionally a polymerization initiator, and reacting the dispersion while applying an external vibrational effect (for example, irradiating ultrasonic waves with an ultrasonic generator).
Examples of the organic solvent include aliphatic hydrocarbons such as hexane, heptane, octane, and mineral spirits; aromatic hydrocarbons such as benzene, toluene, xylene, and solvent naphtha; naphthenic hydrocarbons; isoparaffinic hydrocarbons; ethers such as tetrahydrofuran and diethyl ether; cellosolves such as monoethyl ether;

The mass concentration of the flaky aluminum powder in the organic solvent is preferably 0.1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 35% by mass or less.
From the viewpoint of efficiently adhering the resin compound to the flaky aluminum powder, the mass concentration of the flaky aluminum powder in the organic solvent is preferably 0.1% by mass or more, more preferably 1% by mass or more. Moreover, from the viewpoint of keeping the flaky aluminum powder uniformly dispersed, the mass concentration of the flaky aluminum powder in the organic solvent is preferably 40% by mass or less, more preferably 35% by mass or less.

The mass concentration of the radically polymerizable monomer and/or oligomer in the organic solvent is preferably 0.06% by mass or more and 27% by mass or less, more preferably 0.6% by mass or more and 23% by mass or less. From the viewpoint of efficiently adhering the resin compound to the flaky aluminum powder, the content is preferably 0.06% by weight or more, more preferably 0.6% by weight or more. From the viewpoint of maintaining a uniform adhesion state of the resin compound to the flaky aluminum powder, the content is preferably 27% by mass or less, more preferably 23% by mass or less.

When producing the resin compound-deposited aluminum pigment of the present embodiment, it is preferable to use both a shearing external effect and a vibrating external effect as external effects.
Shearing external action refers to the action of adding a high shearing force to promote physical dispersion when dispersing an aluminum pigment in an organic solvent and adding a monomer to the dispersion. Examples of methods for this include a method of dispersing an aluminum pigment or a monomer using a disper.
The term “external vibrational action” refers to the action of using a vibration-generating device, an ultrasonic generator, or the like to mechanically and strongly vibrate the dispersion or the mixed solution during the polymerization reaction, thereby promoting physical dispersion.
Examples of the mode of addition of the vibrational external action include various modes such as a mode of intermittent addition during the polymerization reaction, a mode of continuous addition during the polymerization reaction, and a mode of combining intermittent addition and continuous addition during the polymerization reaction.
In addition, the method of applying the external vibrational action includes a method of indirectly applying the external action from the vibration generator and the ultrasonic oscillator by applying vibration and irradiation of ultrasonic waves to the reactor, a method of directly applying the external action to the treated dispersion in the reactor, and a method of circulating the treated dispersion in an external circulation type container and indirectly or directly applying the external action of vibration to the external circulation type container.
It is preferable that the vibration caused by an external action by a vibration generator or the like has a frequency of 10 Hz or more and 24 kHz or less.
Ultrasonic waves of external action by an ultrasonic generator or the like are a kind of elastic vibration that propagates through an elastic body, and are usually longitudinal waves that propagate compression and expansion in the direction of wave propagation. As a technical definition, ultrasonic waves include sound waves that are not intended to be heard directly, and all sound waves that propagate through the surface or inside of liquids or solids are also included in ultrasonic waves. As the ultrasonic wave, a frequency of 15 kHz or more and 10000 kHz or less and an output of 5 W or more can be preferably used.

When a polymerization initiator is used during the polymerization reaction of the radically polymerizable monomer and/or oligomer, the timing of adding the polymerization initiator is not particularly limited, but it is preferably added simultaneously with and/or after the radically polymerizable monomer and/or oligomer.
The temperature at which the polymerization initiator is added is not particularly limited as long as the polymerization reaction of the radically polymerizable monomer and/or oligomer occurs, but is preferably 40° C. or higher and 150° C. or lower. In addition, it is preferable to add or react in an atmosphere of an inert gas such as nitrogen or helium in order to increase the reaction efficiency.

In addition, a solvent may be added or substituted as necessary during the reaction of the radically polymerizable monomer and/or oligomer.
As the organic solvent, an ester-based solvent is preferable from the viewpoint of environmental load and drying property.
In particular, when propyl acetate is used, the amount of residual solvent is small even when the drying temperature is low, which is preferable from the viewpoint of adhesion and odor.

[Usage Mode of Resin Compound-Deposited Aluminum Pigment]
The resin compound-attached aluminum pigment of the present embodiment can be used as a pigment for a paint composition or an ink composition (that is, a paint composition component pigment or an ink composition component pigment).
Here, in the coating composition or ink composition containing the resin compound-attached aluminum pigment of the present embodiment, since the matting effect can be provided without using any matting agent, the matting agent is not required. Here, the matting agent means a solid particle additive used for the purpose of imparting a matting effect, and is usually distinguished from pigments. Specific examples include inorganic particles such as silica particles, ceramic particles, and lime particles, urethane resin particles (urethane beads), acrylic resin particles (acrylic beads), polyethylene resin particles (polyethylene beads), polyolefin wax and its derivative particles, montan wax and its derivative particles, and organic particles such as paraffin wax and its derivative particles. However, it is possible to optionally add such a matting agent to the coating composition or ink composition.

Both solvent-based and aqueous-based coating compositions and ink compositions can be used.
When the resin compound-attached aluminum pigment of the present embodiment is used in a solvent-based paint or ink composition, the paint or ink resin used in conventional metallic paints and metallic inks can be used as the resin for the paint composition or ink composition.
Examples of the resin for the coating composition or the ink composition include, but are not limited to, acrylic resins, alkyd resins, oil-free alkyd resins, vinyl chloride resins, urethane resins, melamine resins, unsaturated polyester resins, urea resins, cellulose resins, epoxy resins, fluorine resins, and the like.
These may be used singly or in combination of two or more.

When used as a pigment for a solvent-based paint or ink composition, the amount of the resin compound-attached aluminum pigment used in the present embodiment is such that the solid content mass ratio (PWC) of the resin compound-attached aluminum pigment is preferably 5% or more and 20% or less with respect to 100 parts of the solid content of the coating composition. It is more preferably 8% or more and 14% or less from the viewpoint of metallic mattness. 10% is particularly preferred.

Diluents for solvent-based paints and inks include, but are not limited to, 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; ketones such as methyl ethyl ketone; These diluents may be used singly or in combination of two or more.
The composition of the diluent may be appropriately determined in consideration of the solubility in paint and ink resins, coating film-forming properties, coating workability, and the like.

Furthermore, paints and inks may further contain additives such as pigments, dyes, wetting agents, dispersing agents, anti-color separation agents, leveling agents, slip agents, anti-skinning agents, anti-gelling agents, anti-foaming agents, etc., which are commonly used in the paint industry.

Moreover, paints and inks can also be used as water-based paints by using resins for water-based paints.
However, when aluminum pigments are used, they may react with water in water-based paints and inks. In such cases, it is necessary to add reaction inhibitors.
Here, the water-based coating resin is a water-soluble resin or a water-dispersible resin, and may be used singly or as a mixture of two or more. The type thereof may be appropriately selected depending on the purpose and application, and is not particularly limited, but for coatings, generally water-based coating resins such as acrylic, acrylic-melamine, polyester, and polyurethane resins are mentioned, among which acrylic-melamine-based resins are most commonly used.

When used as a water-based paint or ink, the amount of the resin compound-attached aluminum pigment used in the present embodiment is such that the solid content mass ratio (PWC) of the resin compound-attached aluminum pigment to 100 parts of the solid content of the coating composition is preferably 5% or more and 20% or less. It is more preferably 8% or more and 14% or less from the viewpoint of metallic mattness. 10% is particularly preferred.

In addition, as various additives, for example, dispersants, thickeners, anti-sagging agents, anti-mold agents, ultraviolet absorbers, film-forming aids, surfactants, other organic solvents, water, and the like, those that can be commonly used in the art and do not impair the effects of the present invention can be used, and it is preferable to add them in an amount that does not impair the effects of the present invention.

[Painting method]
A known method can be applied as a coating method using the paint or ink containing the resin compound-attached aluminum group pigment of the present embodiment.
For example, spraying method, flow coating method, roll coating method, brush coating method, dip coating method, spin coating method, screen printing method, casting method, gravure printing method, flexographic printing method and the like can be mentioned.
After coating, heat treatment at preferably 20° C. or higher and 500° C. or lower, more preferably 40° C. or higher and 250° C. or lower, ultraviolet irradiation, or the like can be performed as desired. It is also possible to apply the coating material to a substrate heated to 40° C. or higher and 250° C. or lower.

[Use]
The resin compound-attached aluminum pigment of the present embodiment can be used for coating of automobiles, general household appliances, and information appliances typified by mobile phones, or for predetermined printing applications.
A substrate made of a predetermined material such as a metal such as iron or a magnesium alloy or a plastic can be coated and printed, and a metallic matte design can be exhibited.

EXAMPLES The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

In Examples and Comparative Examples, various physical properties were measured by the following methods.
[Measurement method of physical properties]

<1. Resin compound mass per unit mass of resin compound-adhered aluminum pigment (A (g/g))>
1 g of the resin compound-attached aluminum pigment (aluminum paste) obtained in Examples 1 to 4 and Comparative Examples 2 to 3 was weighed in a 100 ml beaker, and 50 ml of petroleum benzene was added and sufficiently dispersed, and then heated in a constant temperature water bath at 40 ° C. for 1 hour.
The warmed dispersion was filtered and thoroughly washed with acetone before collection. The solid sample obtained after filtration was dried in a desiccator for 24 hours or more.
A portion of the dried sample was analyzed by thermogravimetric/differential thermal TG-DTA, and the ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment in the resin compound-attached aluminum pigment (A (g/g)) was obtained.
Specifically, the ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment (A (g/g)) in the resin compound-attached aluminum pigment of each example and each comparative example is as shown in Table 1.

<2. Number of resin compounds having a portion protruding from a circle size of 0.2 μm in radius per maximum surface area of 48 μm ² attached to the outermost surface of the resin compound-attached aluminum pigment>
5 g of ethyl acetate and 5 g of methyl ethyl ketone were added to 1 g of the resin compound-deposited aluminum pigments obtained in Examples 1-4 and Comparative Examples 2-3, and the mixture was stirred with a magnetic stirrer for 5 minutes to obtain a dispersion. One drop of the dispersion liquid was dropped on a sample table dedicated to observation with a scanning electron microscope (S-2600H manufactured by HITACHI), and then placed in a dryer at 50° C. and dried for 3 hours.
The state of the outermost surface of the primary particles of the resin compound-attached aluminum pigment was observed over the entire surface at a magnification of 15,000 using the scanning electron microscope. 150 fields of view were observed, with one field of view having a maximum surface area of 48 μm ² . Excluding the resin compound scattered on the edge portion of the primary particles of the resin compound-attached aluminum pigment, the number of resin compounds having a size larger than a circle with a radius of 0.2 μm adhering to the outermost surface of the flat portion of the primary particles of the resin compound-attached aluminum pigment was counted and evaluated as follows in association with the metallic matte property. ○ indicates the best metallic matte property, which is at a level equal to or higher than that in the case of using a conventional matting agent, and △ indicates a level that is inferior to ○ but has no problem in terms of practicality. However, x is a level at which there is a problem in terms of practicality. Therefore, ○ and △ were regarded as acceptable, and × was regarded as unacceptable.
FIG. 1 shows an SEM image of one field of view of the outermost surface of the primary particles of the resin compound-deposited aluminum pigment obtained in Example 1. As shown in FIG.
evaluation
◯: 9 or more points are present in all visual fields out of 150 visual fields.
Δ: 90 or more but less than 120 visual fields in 150 visual fields.
x: Less than 90 visual fields in which 9 or more points exist in 150 visual fields.

<3. Metallic matte design>
Using resin compound-deposited aluminum pigments obtained in Examples and Comparative Examples described later, metallic base paint compositions having the following compositions were prepared.
Metallic base paint composition
· Resin-adhered aluminum pigment (Examples 1 to 4 and Comparative Examples 2 to 3): (C1) = 3.23 g (mass of solid content)
0.92 g of flaky aluminum powder paste and 2.31 g of acrylic resin particles (Comparative Example 1): (C2) = 3.23 g (mass of solid content)
・Thinner (Kansai Paint Co., Ltd., product name “Aclic 2000GL”: (D) g
Here, the mass of (D) was adjusted so that the total amount of (C1) of each resin-deposited aluminum pigment or (C2) and (D) of the flaky aluminum powder paste was 13 g.
・Clear (clear containing acrylic resin and mixed solvent, acrylic resin content 30%): 97 g

The resulting metallic base was applied to art paper with an applicator so that the dry film thickness was 30 μm to obtain a coating film.
The obtained coating film was dried at 20° C. for 24 hours and used as an evaluation sample.
60 degree gloss (60 degrees for both incident angle and reflection angle) was measured using a gloss meter (manufactured by Suga Test Instruments Co., Ltd., digital variable angle gloss meter UGV-5D), and the gloss of the reference surface of the specular gloss was expressed as a percentage when the gloss was 100. The evaluation criteria are as follows, and in consideration of practicality, ◯ was accepted, and Δ and × were rejected.
evaluation
○: The value of the 60-degree specular reflectance is less than 30 △: The value of the 60-degree specular reflectance is 30 or more and less than 40 ×: The value of the 60-degree specular reflectance is 40 or more

<4. Alkali resistance>
Using the resin compound-deposited aluminum pigments obtained in Examples and Comparative Examples, a metallic base coating composition was prepared with the following composition.
Metallic base paint composition
· Resin compound-attached aluminum pigment (Examples 1 to 4 and Comparative Examples 2 to 3): (E1) = 2 g
0.57 g of flaky aluminum powder paste and 1.43 g of acrylic resin particles (Comparative Example 1): (E2) = 2 g
Here, each resin-deposited aluminum pigment (E1) or flaky aluminum powder paste (E2) was mixed with the following materials to form a paint.

・ Ethyl acetate: 2 g
・ Black pigment-containing acrylic resin (manufactured by Origin Electric Co., Ltd., SV-9): 21 g
・Thinner (manufactured by Origin Electric Co., Ltd., #174): 30 g

The above paint was applied to an ABS resin plate using an air spray device so that the dry film thickness was 20 μm, and dried in an oven at 60° C. for 30 minutes to obtain a coated plate for evaluation.
The lower half of the coated plate prepared above was immersed in a beaker containing a 5.0 N NaOH aqueous solution and left at 55° C. for 4 hours. After the coated plate was washed with water and dried after the test, the color of the immersed portion and the non-immersed portion was measured according to JIS-Z-8722 (method 8-d), and the color difference ΔE was obtained according to JIS-Z-8730. Evaluation was made as follows according to the value of the color difference ΔE. It was judged that the smaller the value, the more excellent the alkali resistance of the coating film formed on the coated plate. In consideration of practicality, ○ was set as a pass, and x was set as a fail.
evaluation
○: Less than ΔE1.0 ×: ΔE1.0 or more

<5. Amount of gas generated in a specific water-based paint>
Using the resin compound-deposited aluminum pigments obtained in each example and comparative example, a specific water-based paint was prepared with the following composition.
Aqueous paint composition
· Resin compound-attached aluminum pigment (Examples 1 to 4 and Comparative Examples 2 to 3): (F1) = 5 g
1.43 g of flaky aluminum powder paste and 3.57 g of acrylic resin particles (Comparative Example 1): (F2) = 5 g
Here, each resin compound-attached aluminum pigment (F1) or flaky aluminum powder paste (F2) was mixed with the following materials to prepare a water-based paint.
・Methoxypropanol: 40g
・Water: 50g
・Acrylic emulsion (manufactured by DSM, trade name “NeoCryl A-2091”): 110g

Each water-based paint thus prepared was placed in a 200 ml Erlenmeyer flask, a graduated pipette with a rubber stopper was attached, and the amount of gas generated after standing at 40° C. for 72 hours was measured. The evaluation criteria were as follows, and it was judged that the smaller the amount of gas generated, the better. In consideration of practicality, ○ was set as a pass, and x was set as a fail.
evaluation
○: Less than 3 ml ×: 3 ml or more

[Example 1]
81 g of flaky aluminum powder paste 0-2100 (manufactured by Asahi Kasei Corporation, average particle size 10 μm, non-volatile content 74%) was placed in a 2 L four-necked flask, 567 g of mineral spirit was added, and the mixture was stirred while introducing nitrogen gas.
Then, 1.80 g of acrylic acid was added and stirring was continued at 50° C. for 60 minutes.
Next, a solution consisting of 10.70 g of divinylbenzene, 17.98 g of trimethylolpropane trimethacrylate, 7.19 g of di-trimethylolpropane tetraacrylate, 0.30 g of 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile and 100 g of mineral spirits was prepared and added all at once.
The polymerization process was carried out for a total of 12 hours while maintaining the temperature in the system at 50°C.
During the polymerization process, an ultrasonic cleaner (B5510J-DTH, manufactured by Emerson Japan, Ltd.) was used to indirectly irradiate the mixture in the 2 L four-necked flask with ultrasonic waves having a frequency of 42 kHz and an output of 180 W. The method of applying the external vibrational action by ultrasonic waves during polymerization was as follows.
Continuous ultrasonic irradiation was performed from the start of polymerization to the first hour of polymerization. Intermittent ultrasonic irradiation (ultrasonic irradiation for 5 minutes every 15 minutes during polymerization) was performed from the 1st hour to the 12th hour of polymerization.
Then, when the polymerization process for 12 hours was completed, a solution consisting of 0.30 g of bis-(4-t-butylcyclohexyl)peroxydicarbonate and 10 g of mineral spirit was prepared and added all at once.
The polymerization process was continued for 1 hour while maintaining the temperature in the system at 50°C.
When the unreacted amount of trimethylolpropane trimethacrylate in the filtrate sampled after the polymerization was analyzed by gas chromatography, 99% or more of the added amount was found to have reacted.
After completion of the polymerization, the mixture was naturally cooled, and the slurry was filtered to obtain a paste-like resin compound-adhered aluminum pigment.
The non-volatile content of this paste (according to JIS-K-5910) was 35.2% by mass.

[Example 2]
A resin compound-adhered aluminum pigment was obtained in the same manner as in Example 1 except that an ultrasonic cleaner (B8510J-DTH, manufactured by Emerson Japan Co., Ltd.) was used in the same manner as in Example 1 except that the frequency was changed to 44 kHz and the output was 320 W. The non-volatile content of this paste according to JIS-K-5910 was 35.6% by mass.
[Example 3]
A resin compound-attached aluminum pigment was obtained in the same manner as in Example 1, except that 17.98 g of divinylbenzene, 29.97 g of trimethylolpropane trimethacrylate, and 11.99 g of di-trimethylolpropane tetraacrylate were used. The non-volatile content of this paste according to JIS-K-5910 was 33.3% by mass.
[Example 4]
A resin compound-attached aluminum pigment was obtained in the same manner as in Example 1, except that 21.58 g of divinylbenzene, 35.96 g of trimethylolpropane trimethacrylate, and 14.39 g of di-trimethylolpropane tetraacrylate were used. The non-volatile content of this paste according to JIS-K-5910 was 30.1% by mass.

[Comparative Example 1]
Physical properties were measured by combining the flaky aluminum powder paste 0-2100 of Example 1 and acrylic resin particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 20 μm) used for the purpose of imparting a matting effect.
[Comparative Example 2]
A resin compound-attached aluminum pigment was obtained in the same manner as in Example 1, except that 5.40 g of divinylbenzene, 8.99 g of trimethylolpropane trimethacrylate, and 3.60 g of di-trimethylolpropane tetraacrylate were used. The non-volatile content of this paste according to JIS-K-5910 was 42.1% by mass.
[Comparative Example 3]
A resin compound-attached aluminum pigment was obtained in the same manner as in Example 1, except that 10.61 g of divinylbenzene, 17.68 g of trimethylolpropane trimethacrylate, and 7.07 g of di-trimethylolpropane tetraacrylate were used. The non-volatile content of this paste according to JIS-K-5910 was 30.4% by mass.

Table 1 shows the evaluation results of Examples 1 to 4 and Comparative Examples 1 to 3.

From the above results, it was confirmed that the coating composition containing the resin compound-attached aluminum pigment of the present invention does not use any matting agent that may be scraped off from the coating film by an external impact or the like, and has an excellent metallic matte design, alkali resistance, and high water resistance even when used as a component of a water-based coating composition. Therefore, it was found that the resin compound-attached aluminum pigment of the present invention can form a coating film having a good finished metallic matte design and excellent alkali resistance without using any matting agent that may be scraped off from the coating film by an external impact or the like, and can exhibit high water resistance even when used in a water-based paint.
Further, from the results of Examples 1 to 4 and Comparative Example 1, according to the coating composition of the present invention, without using a matting agent, it is possible to obtain a metallic matte design equivalent to or higher than that of a conventional aluminum-containing coating composition using a matting agent. Also, from the results of Examples 3 and 4, it is possible to obtain excellent metallic matting when the resin compound mass (A (g / g)) per unit mass of the resin compound-adhered aluminum pigment is in the range of 0.412 or more and 0.545 or less. It was also found that it is possible to stably provide designability.

Although not shown in the table, it was confirmed that the ink composition containing the resin compound-attached aluminum pigment of the present invention also enables the production of printed matter having a good finished metallic matte design and excellent alkali resistance without using any matting agent, and exhibits high water resistance even when used in an aqueous ink. Therefore, it was found that the resin compound-attached aluminum pigment of the present invention enables the production of printed matter having a good finished metallic matte design and excellent alkali resistance without using any matting agent, and can exhibit high water resistance even when used in aqueous ink.

The resin compound-attached aluminum pigment of the present invention has industrial applicability as a paint for the automobile industry (including motorcycles), the aircraft industry, and the home appliance industry, such as various parts for automobiles and aircraft, general home appliances, and information home appliances such as mobile phones.

Claims (11)

flaky aluminum powder;
a resin compound adhering to the surface of the flaky aluminum powder;
A resin compound-attached aluminum pigment containing
The resin compound is a radically polymerizable monomer and/or oligomer polymer having one or more double bonds in the molecule,
The ratio of the resin compound mass per unit mass of the resin compound-attached aluminum pigment is 0.375 to 0.545 ,
The resin compound attached to the outermost surface of the resin compound-attached aluminum pigment and having a portion protruding from a circle size with a radius of 0.2 μm is present at least 9 points per 48 μm 2 of the outermost surface area of the resin compound-attached aluminum pigment ^.
The resin compound-adhered aluminum pigment. A matting agent-free coating composition comprising the resin compound-deposited aluminum pigment of claim 1 . 3. The coating composition according to claim 2 , wherein the solid content mass ratio of said resin compound-attached aluminum pigment to 100 parts of the solid content of the coating composition is 5% or more and 20% or less. 4. The coating composition according to claim 3 , wherein the gloss of the coating film obtained by coating on art paper exhibits a 60-degree specular reflectance of less than 30 when both the incident angle and the light-receiving angle are 60 degrees. 5. A coating composition according to any one of claims 2 to 4 , further comprising a black pigment. The coating composition according to claim 5, wherein the alkali resistance of the coated plate obtained by applying it to an acrylic resin plate is represented by the color difference ΔE between the immersed portion and the unimmersed portion when immersed in a 5N sodium hydroxide solution at 55 ° C. for 4 hours. A water-based coating composition containing no matting agent, wherein the amount of gas generated when kept at 40° C. for 72 hours is 3 ml or less, and containing the resin compound-deposited aluminum pigment according to claim 1 . A coating film containing the coating composition according to any one of claims 2 to 7 . A matting agent-free ink composition comprising the resin compound-deposited aluminum pigment of claim 1 . A printed matter containing the ink composition according to claim 9 . A dispersion obtained by adding flake-like aluminum powder and a resin composition of a polymer of a radical polymerizable monomer and/or oligomer having one or more double bonds in the molecule to an organic solvent, wherein the concentration of the aluminum powder is 0.1% by weight or more and 40% by weight or less, and the concentration of the resin composition is 0.06% by weight or more and 27% by weight or less;
adding an external vibrational effect to the dispersion liquid during the process of attaching the resin composition to the aluminum powder;
A method for producing the resin compound-deposited aluminum pigment according to claim 1 .