JP2019183088A - Aluminum pigment composition - Google Patents

Abstract

To provide, while reducing volatile organic solvent, an aluminum pigment composition that can realize an excellent designability and a coating film property (in particular, when made into a coating film, the residual odor, curability, and water resistance of coating film).SOLUTION: The present invention relates to a novel metal pigment, and more particularly to a metal pigment which, when used as a paint pigment, reduces the residual odor and provides a metallic coating film having an excellent physical property while maintaining the excellent designability.SELECTED DRAWING: None

Description

  The present invention relates to an aluminum pigment composition and a paint containing the same.

Conventionally, aluminum pigments have been used for metallic paints, printing inks, plastics kneading, and the like for the purpose of obtaining a cosmetic effect that emphasizes a metallic feeling.
Such an aluminum pigment contains a volatile organic solvent such as mineral spirit in order to make it difficult to become dust, and is in a paste form (see, for example, Patent Document 1).
In recent years, however, there has been an increasing demand for reducing the amount of volatile organic solvents in paints from the environmental viewpoint. For this reason, it is necessary to reduce the amount of the volatile organic solvent in the aluminum pigment.
In order to satisfy this requirement, when kneaded into a resin, the solvent is changed to a high boiling point solvent (see, for example, Patent Document 2). In this case, the high boiling point solvent remains in the coating film. Therefore, depending on the blending amount, the physical properties of the coating film are affected.

JP-A-3-294360 JP-A-2015-74711

  Therefore, in the present invention, in view of the above-mentioned problems of the prior art, while reducing the volatile organic solvent, excellent design properties and coating film properties (especially when used as paint pigments, residual odor, curing It is an object to provide an aluminum pigment composition capable of realizing properties and physical properties excellent in coating film water resistance.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have completed the present invention.
That is, the present invention is as follows.

[1]
(A) scaly aluminum powder;
(B) a polyol compound having a number average molecular weight of 300 to 7000 and having two or more hydroxyl groups;
Including
The (B) polyol compound is at least one selected from polytetramethylene ether glycol, polyester polyol, acrylic polyol, and polycarbonate diol, and the mass ratio of the (A) flaky aluminum powder to the (B) polyol compound An aluminum pigment composition in which (A) / (B) is 95/5 or more and 40/60 or less.
[2]
The aluminum pigment composition according to [1], which contains a volatile organic solvent having a boiling point of 260 ° C. or less, and the content of the organic solvent is 2% by mass or less.
[3]
A paint containing the aluminum pigment composition according to [1] or [2].

  The present invention relates to a novel aluminum pigment, and more particularly, when used as a paint pigment, while reducing the volatile organic solvent, excellent design properties and coating film properties (particularly when used as a paint pigment). , Residual odor, curability, and coating water resistance) can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. However, the present invention is not limited to the following embodiment. The present invention can be variously modified without departing from the gist thereof.

≪Aluminum powder≫
The scaly aluminum powder used in the aluminum pigment composition of the present invention (also referred to as “(A) scaly aluminum powder” in the present application) is required for metallic pigments such as surface glossiness, whiteness, and glitter. Those having surface properties, particle sizes and shapes are suitable. For example, a material having a thickness in the range of 0.001 to 1 μm and a length or width in the range of 1 to 100 μm is preferable. The aspect ratio is preferably in the range of 10 to 200. Here, the aspect ratio is a value obtained by dividing the average major axis of the scaly aluminum powder by the average thickness of the aluminum powder. Further, the purity of the aluminum powder is not particularly limited, but the purity used for coating is 99.5% or more. The aluminum powder can be obtained by a known method, for example, a production method described in International Publication No. 99/54074, but is usually commercially available in a paste state and can be used.

≪Polyol compound≫
The aluminum pigment composition of the present invention is a polyol compound having two or more hydroxyl groups having a number average molecular weight of 300 or more and 7,000 or less (in the present application, “(B) a number average molecular weight of 300 or more and 7,000 or less and having two or more hydroxyl groups. The polyol compound "or" (B) polyol compound "), and the polyol compound is at least one selected from polytetramethylene ether glycol, polyester polyol, acrylic polyol, and polycarbonate diol. This polyol compound can react with a curing agent having two or more isocyanate groups to form a urethane bond.
In this case, since the polyol compound (B) forms a part of the coating film, it does not substantially remain in the coating film and does not affect the physical properties of the coating film, which is preferable.
(B) The polyol compound can be appropriately selected according to the required physical properties, but is preferably at least one selected from polyester polyol, acrylic polyol, and polycarbonate diol from the viewpoint of handleability. . More preferred is polycarbonate diol. Further, from the viewpoint of coating film physical properties (particularly, residual odor property, curability, and coating film water resistance when used as a paint pigment), polytetramethylene ether glycol and polycarbonate diol are preferable.

  In the aluminum pigment composition of the present invention, (B) the content of the polyol compound having two or more hydroxyl groups having an average molecular weight of 300 or more and 7000 or less and the content of (A) the flaky aluminum powder is the value relative to the (B) polyol compound. (A) The mass ratio of the scaly aluminum powder (also referred to as “(A) / (B)” in the present application) is 95/5 to 40/60. When the mass ratio is 95/5 or more, aluminum dust is likely to be generated, and when it is 40/60 or less, the amount of the aluminum pigment composition used is more than necessary.

≪Resin≫
The surface of the (A) flaky aluminum powder in the present invention can be optionally covered with a resin obtained by reacting a radical polymerizable monomer and / or oligomer having one or more double bonds in the molecule. It is.
The radically polymerizable monomer and / or oligomer is not particularly limited, and conventionally known monomers can be used. For example, in addition to acrylic acid esters, methacrylic 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, Mention may be made of vinyl monomers having a silyl group.

≪Manufacturing≫
The aluminum pigment composition of the present invention can be obtained by adding (B) a polyol compound to (A) scaly aluminum powder.
Usually, since it is commercially available in a paste state containing (A) flaky aluminum powder and a volatile organic solvent having a boiling point of 260 ° C. or lower, the solvent is removed from this and (B) a polyol compound is added. But you can get it.
A known method can be used as a method for removing the volatile organic solvent.
For example, the method of heat-processing under reduced pressure and evaporating a volatile organic solvent is mentioned. In this case, the heat treatment temperature is preferably 50 ° C. or higher and 200 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower. If the temperature is low, homogenization of the product may be difficult when the viscosity of the (B) polyol compound is high, and conversely, modification of the (B) polyol compound may occur when the temperature is high.
After removing the volatile organic solvent, the (B) polyol compound may be added, but the (B) polyol compound is added and heated under reduced pressure while containing the volatile organic solvent. A method of removing the volatile organic solvent is preferred.

≪Volatile organic solvent≫
The volatile organic solvent contained in the present invention is preferably 2% by mass or less based on the aluminum pigment composition of the present invention in order to reduce the influence on the environment. More preferably, it is 1.5 mass% or less.
On the other hand, in order to obtain the aluminum pigment composition of the present invention, when the solvent is removed from a paste state containing (A) flaky aluminum powder and a volatile organic solvent having a boiling point of 260 ° C. or lower, the aluminum pigment composition It is economically preferable that the volatile organic solvent is 0.01% by mass or more.
As the volatile organic solvent having a boiling point of 260 ° C. or lower, (A) it may be inert to the flaky aluminum powder. For example, aliphatic hydrocarbons such as hexane, heptane, octane, mineral spirit, benzene, Aromatic hydrocarbons such as toluene, xylene and solvent naphtha, ethers such as tetrahydrofuran and diethyl ether, alcohols such as ethanol, 2-propanol and butanol, esters such as ethyl acetate and butyl acetate, ethylene glycol monoethyl ether, etc. Of cellosolves.

≪Curing agent≫
The aluminum pigment composition of the present invention can form a urethane bond by reacting with a curing agent having two or more isocyanate groups.
Examples of these curing agents include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and mixtures thereof (TDI), crude TDI, diphenylmethane-4,4′-diisocyanate (MDI), crude MDI, and naphthalene. -1,5-diisocyanate (NDI), 3,3′-dimethyl-4,4′-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate (XDI), phenylene diisocyanate and other known aromatic diisocyanates; Known aliphatic diisocyanates such as 4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI) Anocyanates, and isocyanurate-modified products, carbodiimidization-modified products, biuret-modified products and the like of these isocyanates. These organic polyisocyanates may be used alone or in combination of two or more. These organic polyisocyanates may be used by masking isocyanate groups with a blocking agent.

≪Use of aluminum pigment composition≫
The aluminum pigment composition of the present invention can be used as a paint or ink. At that time, if it is necessary to adjust the viscosity, a minimal diluent can be used. Diluents that can be used in solvent-based paints and inks include aromatic compounds such as toluene and xylene, aliphatic compounds such as hexane, heptane and octane, alcohols such as ethanol and ptanol, ethyl acetate and butyl acetate. Examples include esters, ketones such as methyl ethyl ketone, chlorine compounds such as trichloroethylene, and cellosolves such as ethylene glycol monoethyl ether. These diluents can be used alone or in combination. The composition may be appropriately determined in consideration of solubility in paint and ink resins, coating film formation characteristics, coating workability, and the like.
As the coating resin, any of the coating resins used in conventional metallic coatings and metallic inks can be used. Examples of the resin include acrylic resin, alkyd resin, oil-free alkyd resin, vinyl chloride resin, urethane resin, melamine resin, unsaturated polyester resin, urea resin, cellulosic resin, epoxy resin, fluorine resin, etc. They may be used alone or in combination.
The amount of the aluminum pigment composition of the present invention to be used as a paint and ink is preferably 0.1 to 300 parts by weight, more preferably 0.2 parts by weight with respect to 100 parts by weight of the coating resin. It is preferable to use ~ 200 parts by mass. 0.1 mass part or more is preferable from the surface of a metallic luster, and 300 mass parts or less is preferable from the surface of a coating-film physical property.
In addition, for paints and inks, pigments, dyes, wetting agents, dispersants, anti-splitting agents, leveling agents, slip agents, anti-skinning agents, anti-gelling agents, antifoaming agents commonly used in the paint industry Additives such as agents can be added.
The metallic paint and the metallic ink can also be used as an aqueous paint by using an aqueous paint resin. However, aluminum pigments can react with water in aqueous paints and inks. In such a case, it is necessary to add a reaction inhibitor. Here, the resin for water-based paint and ink is a water-soluble resin or a water-dispersible resin, and these may be used alone or as a mixture thereof. There are various types depending on the purpose and application, and it is not particularly limited. However, for paints, water-based paint resins such as acrylic, acrylic-melamine, polyester, and polyurethane are generally listed. Among them, acrylic-melamine is most commonly used.
The amount of the aluminum pigment composition of the present invention when used as a water-based paint and ink is preferably 0.1 to 300 parts by weight, more preferably 0.2 parts by weight with respect to 100 parts by weight of the paint resin. It is preferable to use parts to 200 parts by mass. 0.1 mass part or more is preferable from the surface of metallic luster, and 300 mass parts or less is preferable from the surface of coating film physical properties.
Examples of various additives include dispersants, thickeners, sagging inhibitors, antifungal agents, ultraviolet absorbers, film forming aids, surfactants, other organic solvents, water, and the like in this field. It can be used as long as it is an amount that does not impair the effects of the present invention and that does not impair the effects of the present invention.
The aluminum pigment composition of the present invention can be used by being kneaded into a thermoplastic resin.

≪Painting method≫
Various known methods can be used as the coating method of the paint or ink containing the aluminum pigment composition of the present invention. Examples thereof include a spray spraying method, a flow coating method, a roll coating method, a brush coating method, a dip coating method, a spin coating method, a screen printing method, a casting method, a gravure printing method, and a flexographic printing method.
Further, after coating, it is possible to carry out heat treatment, ultraviolet irradiation, or the like preferably at 20 ° C. to 500 ° C., more preferably at 40 ° C. to 250 ° C., if desired. Moreover, it is also possible to apply | coat a coating material with respect to the base material heated at 40-250 degreeC.

≪Usage≫
The aluminum pigment composition of the present invention is for automobiles, general household appliances, information household appliances typified by mobile phones, and printing, for coating a metal such as iron or magnesium alloy, or a substrate such as plastic, for printing applications. Can be suitably used, and can exhibit high design properties. When kneaded into a thermoplastic resin, the molded product can be applied to a molded product or a laminated product having a glittering property, for example, a casing of an electronic device such as a notebook personal computer or a mobile phone.

The present invention will be specifically described by the following examples and comparative examples, but these do not limit the scope of the present invention.
In Examples and Comparative Examples, physical properties of the coating film (residual odor, curability, and water resistance of the coating film) and design properties were measured by the following methods.

[Measurement method of physical properties]
1. Residual odor The residual odor of the coating film was evaluated by a sensory test. ○: No collection of organic solvent Δ: Some odor is felt ×: Strong odor is felt Curability The curability of the coating film was evaluated by touch.
○: Even if it is touched with a finger strongly, it does not change. Δ: If it is only lightly touched with a finger, the paint does not touch the finger. Water resistance of coating film Half of the coating film was allowed to stand in water at 23 ° C. for 24 hours, and the change in the coating film state was visually judged. ○: No change at all Δ: Some change was observed ×: Significant change was observed 4 . Design property The design property of the coating film was visually determined.
○: Metallic feeling was high and the appearance was excellent △: Metallic feeling was low ×: There was no metallic feeling

[Production Example 1]
To an 8 L vertical mixer, 2,000 g of commercially available aluminum paste (manufactured by Asahi Kasei Corporation, MH-8801 (average particle size 15 μm, non-volatile content 65%)), polyethylene glycol 2,000 (manufactured by Tokyo Chemical Industry, average molecular weight 2, 000, OH number = about 28 mgKOH / g) was charged in an amount of 700 g. Thereafter, the mixture was kept at a temperature of 80 ° C. and a pressure of 2 kPa for 12 hours with stirring to remove the volatile organic solvent. It collect | recovered after cooling, when the content rate (%) of the volatile organic solvent was measured by measuring a heating residue and deducting from 100, it was 0.8%. In addition, (A) scale-like aluminum powder / (B) polyol compound at this time was 65/35.

[Production Example 2]
Instead of polyethylene glycol 2,000 of Production Example 1, 700 g of polytetramethylene oxide 2,000 (manufactured by Wako Pure Chemical Industries, average molecular weight 2000, OH number = about 56 mgKOH / g) was added as polytetramethylene ether glycol. When other experiments were conducted in the same manner, the content (%) of the volatile organic solvent was 0.7%. In addition, (A) scale-like aluminum powder / (B) polyol compound at this time was 65/35.

[Production Example 3]
Instead of polyethylene glycol 2,000 in Production Example 1, 700 g of Duranol T5650J (registered trademark, manufactured by Asahi Kasei Corporation, average molecular weight 800, OH value = about 140 mgKOH / g) was added as a polycarbonate diol. In other cases, the experiment was performed in the same manner. As a result, the content (%) of the volatile organic solvent was 0.8%. In addition, (A) scale-like aluminum powder / (B) polyol compound at this time was 65/35.

[Production Example 4]
Instead of polyethylene glycol 2,000 in Production Example 1, 700 g of liquid paraffin (manufactured by Wako Pure Chemical Industries) was added. When other experiments were conducted in the same manner, the content (%) of the volatile organic solvent was 1.3%. In addition, (A) scale-like aluminum powder / (B) polyol compound at this time was 65/35.

[Example 1]
For 10 g of polyol resin Duranol T5650E (registered trademark, manufactured by Asahi Kasei Corporation, average molecular weight 500, OH value = 225 mgKOH / g), 2.3 g of metal pigment composition of Production Example 2 (based on 100 parts by mass of polyol resin) 15 parts by weight of aluminum), TPA-100 (trade name, manufactured by Asahi Kasei Co., Ltd., NCO% = 23.1%) as a curing agent, 7.4 g (OH / NCO = 1) are added, and Awatori Netaro (trade name) , Manufactured by Shinky Co., Ltd.) to obtain a metallic paint.
The obtained metallic paint was applied to a glass plate with a thickness of 100 μm using a bar coater and allowed to stand at 23 ° C. for 7 days. When the obtained coating film was evaluated, there was no residual odor at all, and it was favorable evaluation ((circle)), and both curability and water resistance were favorable evaluation ((circle)). Furthermore, the design property was also good (◯). The results are shown in Table 1.

[Example 2, Comparative Examples 1-3]
The composition of Example 1 was changed and the others were similarly tested. In particular, as an aluminum pigment composition, the one obtained in Production Example 3 in Example 2, the one obtained in Production Example 1 in Comparative Example 1, the one obtained in Production Example 4 in Comparative Example 2, and the comparison In Example 3, MH-8801 (trade name, aluminum paste manufactured by Asahi Kasei Corporation) was used. The results are summarized in Table 1.

  From the results of Table 1, the aluminum pigment composition of the present invention can provide a good coating film having no coating odor, no residual odor, and excellent coating properties with excellent curability and water resistance. I understood that I could do it.

  The aluminum pigment composition of the present invention is for automobiles, general household appliances, information household appliances represented by mobile phones, and printing, respectively, for coating of metals such as iron and magnesium alloys, or substrates such as plastics, and printing applications. Therefore, when it is kneaded into a thermoplastic resin, the molded product is a glossy molded product or laminated product, for example, a casing of an electronic device such as a notebook computer or a mobile phone. There is a possibility of use as.

Claims (3)

(A) scaly aluminum powder;
(B) a polyol compound having a number average molecular weight of 300 to 7000 and having two or more hydroxyl groups;
Including
The (B) polyol compound is at least one selected from polytetramethylene ether glycol, polyester polyol, acrylic polyol, and polycarbonate diol, and the mass ratio of the (A) flaky aluminum powder to the (B) polyol compound (A) / (B) is 95/5 or more and 40/60 or less,
Aluminum pigment composition.   The aluminum pigment composition according to claim 1, which contains a volatile organic solvent having a boiling point of 260 ° C. or less, and the content of the organic solvent is 2% by mass or less.   The coating material containing the aluminum pigment composition of Claim 1 or 2.