JP6955353B2 - Aqueous paint composition - Google Patents

Description

The present invention relates to a water-based coating composition, and more particularly to a water-based coating composition suitable for coating a wood base material and using a naturally derived component.

Conventionally, paints using naturally derived components such as vegetable oils (so-called natural paints) have been used as paints for wood interiors and exteriors such as floors and walls. In particular, in recent years, such natural paints have tended to be preferred due to the growing awareness of safety for the human body and the environment. Natural paints are "impregnated type" that impregnates the base material, "film-forming type" that forms a protective film on the surface of the base material, and "coating" that is used to form an auxiliary film on the upper layer after painting these paints. It is roughly classified into "membrane protection type". Of these, the impregnated natural paint is excellent in design because it leaves a wood texture, gives an unpainted feeling, and emphasizes the wet color when the wood base material is painted.

Impregnated natural paints are further classified into oil-based paints that use an organic solvent as a diluent and water-based paints that use water as a diluent, and the latter is superior in terms of safety to the human body and the environment. ..
As such an impregnated water-based paint, for example, Patent Document 1 discloses a water-based paint for wood composed of an aqueous dispersion made from vegetable oil and fat and an additive, and the vegetable oil includes flaxseed oil and the like. Drying oil is mentioned, and insect repellents and the like are mentioned as additives. Further, Patent Document 2 discloses a silicone-based water-based water repellent composition for wood containing a pyrethroid-based insecticide.

Japanese Unexamined Patent Publication No. 2008-297413 Japanese Unexamined Patent Publication No. 2004-066461

However, the conventional impregnated water-based paint has room for further improvement in the effect of knocking down mosquitoes (hereinafter, also referred to as "mosquito knockdown effect") even when an insect repellent is contained. I understood.

Further, the conventional impregnated water-based paint has a problem in terms of water repellency in the base material after painting, and even when a water repellent is added to the paint to solve this problem, the water repellency is maintained. There is a problem that it is insufficient or it takes several days until sufficient water repellency is exhibited.

In view of such problems in the prior art, it is an object of the present invention to provide a water-based coating material capable of exhibiting an excellent mosquito knockdown effect on an object to be coated and exhibiting water repellency at an early stage after coating. And.

As a result of diligent research, the present inventor has found that the above problems can be solved when the water-based coating composition containing a drying oil and an insect repellent further contains a water repellent agent, and has completed the present invention.
The present invention relates to the following [1] to [7].

[1]
An aqueous coating composition which is an emulsion of a drying oil (A) and water and contains an insect repellent (B) and a water repellent (C).

[2]
The aqueous coating composition according to the above [1], wherein the insect repellent (B) is a pyrethroid compound.

[3]
The water-based coating composition according to the above [1] or [2], wherein the water repellent (C) is a reactive silicone resin.

[4]
Further, the aqueous coating composition according to any one of [1] to [3] above, which contains functional microcapsules.

[5]
The water-based coating composition according to any one of [1] to [4] above, which is used for coating a wood substrate.

[6]
A wood base material coated with the water-based coating composition according to any one of [1] to [5].

[7]
A method for producing a painted wood base material, which comprises a step of painting at least a part of the surface of the wood base material with the aqueous coating composition according to any one of [1] to [5].

When the water-based coating composition of the present invention is used for coating, an excellent mosquito knockdown effect can be exhibited on the object to be coated, and water repellency can be exhibited early after coating.

Hereinafter, the water-based coating composition of the present invention will be described in more detail.
<Aqueous paint composition>
The aqueous coating composition of the present invention is an aqueous emulsion of drying oils (A) and contains an insect repellent (B) and a water repellent (C).

(A) Drying oils The drying oils (A) solidify by oxidation inside a base material (for example, a wood base material) coated with the coating composition of the present invention and function as a binder. Furthermore, antibacterial properties can be imparted to the base material.

Examples of the drying oils (A) include flaxseed oil, mustard oil, Benibana oil, sesame oil, sunflower oil, walnut oil, tung oil, shiso oil and other drying oils, polymerized oils made from the drying oils, and the drying properties. Examples thereof include boiled oil made from oil and an ester of a fatty acid and a polyalcohol constituting the drying oil.

Among these, a drying oil is preferable from the viewpoint of excellent antibacterial properties, and flaxseed oil is more preferable as the drying oil. The drying oils (A) may be used alone or in combination of two or more.

The content of the drying oils (A) in the aqueous coating composition of the present invention is preferably 50 to 95% by mass, more preferably 60 to 85% by mass. The content of the drying oils (A) is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, based on the solid content (components excluding water) of the aqueous coating composition.

The water-based coating composition of the present invention is an emulsion in which the drying oils (A) are dispersed in water. The aqueous coating composition of the present invention preferably contains an emulsifier for stably dispersing the drying oils (A). As the emulsifier, a conventionally known emulsifier used for producing an emulsion of water and drying oils, for example, a surfactant can be used. The ratio of the emulsifier in the aqueous coating composition of the present invention is preferably 5 to 40 parts by mass, and more preferably 15 to 30 parts by mass with respect to 100 parts by mass of the drying oil (A).

(B) Insect repellent The insect repellent (B) is a substance having a knockdown effect and / or a repellent effect on pests, and a known insect repellent can be appropriately selected and used. In the water-based coating composition according to the present invention, by using the insect repellent (B) and the water-repellent agent (C) described later in combination, the water-repellent agent (C) is more repellent than when the water-repellent agent (C) is used alone. Aqueousness can be improved.

As the insect repellent (B), a pyrethroid compound is preferable from the viewpoint of mosquito knockdown effect and water repellency improvement. As the pyrethroid compound, conventionally known natural pyrethroids and synthetic pyrethroids can be used. The insect repellent (B) may be used alone or in combination of two or more.

The content of the insect repellent (B) in the water-based coating composition of the present invention is preferably 0.05 to 2.0 parts by mass, more preferably 0. 1 to 0.4 parts by mass.

Further, since the pyrethroid compound is insoluble or sparingly soluble in water, the water-based coating composition of the present invention preferably contains the insect repellent (B), especially when the insect repellent (B) is a pyrethroid compound. Contains an emulsifier for stable dispersion. As the emulsifier, a conventionally known emulsifier used for dispersing an insect repellent such as a pyrethroid compound in water can be used. When the emulsifier is used, the ratio is preferably 300 to 500 parts by mass with respect to 100 parts by mass of the insect repellent (B).

(C) Water- repellent agent The water-repellent agent (C) is a substance that imparts water repellency to an object to be coated, and a known water-repellent agent can be appropriately selected and used. In the water-based coating composition according to the present invention, the combined use of the insect repellent (B) and the water repellent (C) improves the mosquito knockdown effect as compared with the case where the insect repellent (B) is used alone. be able to.

Examples of the water repellent (C) include silicone-based water repellents, zirconium acetate-based water repellents, fluorine-based water repellents, wax-based water repellents, and the like. Of these, silicone-based water repellents and zirconium acetate-based water repellents are preferable, and silicone-based water repellents are more preferable. Examples of the silicone-based water repellent include a silicone resin having a reactive group. Examples of the reactive group include a group capable of reacting with a hydroxyl group existing on the surface of a wood substrate, for example, an alkoxy group such as a methoxy group and an ethoxy group. As the water repellent (C), a silicone resin having a reactive group is particularly preferable from the viewpoint of repelling mites of the object to be coated.

Examples of the commercially available product of the water repellent (C) include SILRES WH (Asahi Kasei Wacker Silicone Co., Ltd.) as the silicone resin-based water repellent. Examples of the zirconium acetate-based water repellent include Manalox WB10 (Fedchem). Examples of the fluorine-based water repellent include Surflon S-241 (AGC Seimi Chemical Co., Ltd.). Examples of the wax-based water repellent include HYDROPEL GP (Shamrock). The water repellent (C) may be used alone or in combination of two or more.

The content of the water repellent (C) in the water-based coating composition of the present invention is preferably 300 to 1,000 parts by mass, more preferably 500 to 800 parts by mass with respect to 100 parts by mass of the insect repellent (B). It is a mass part. When the content of the water repellent (C) is in this range, the base material coated with the water-based coating composition of the present invention is excellent in water repellency and mosquito knockdown effect.

The aqueous coating composition of the present invention preferably contains an emulsifier or a surfactant for stably dispersing the water repellent (C). As the emulsifier or surfactant, a conventionally known emulsifier or surfactant used for dispersing the water repellent in water can be used. When this emulsifier or surfactant is used, the ratio is preferably 300 to 1,000 parts by mass with respect to 100 parts by mass of the water repellent (C).

(D) Additive The aqueous coating composition of the present invention contains an optional additive in addition to the drying oil (A), the insect repellent (B), the water repellent (C) and water as a solvent. It may be included.

Examples of this additive include emulsifiers or surfactants, functional microcapsules, metal dryers, formalin catchers, ultraviolet absorbers, light stabilizers, colorants and the like.

Emulsifier or surfactant;
As described above, the aqueous coating composition of the present invention is an emulsifier or a surfactant for dispersing the drying oil (A), the insect repellent (B) and the water repellent (C) in water as a solvent. May include.

Functional microcapsules;
The water-based coating composition of the present invention may contain microcapsules containing a functional substance in order to impart desired functions such as insect repellent, antibacterial and aromatic properties to the object to be coated. In the present invention, the microcapsules containing the drying oil (A), the insect repellent substance or the water repellent substance are the drying oil (A), the insect repellent (B) or the water repellent (C). Instead, it shall be classified as functional microcapsules.

Examples of the functional substance include natural essential oils such as hiba oil (eg, Aomori hiba oil), shiso oil, hinoki oil, and eucalyptus oil; photocatalytic substances such as titanium dioxide; and vegetable extracts such as catechin.

Examples of the material for the shell of the microcapsules include urethane and melamine, and urethane is preferable from the viewpoint of not containing formaldehyde and being excellent in safety to the human body and the environment.
The content of the functional microcapsules in the aqueous coating composition of the present invention is appropriately set, and is, for example, 10 to 20 parts by mass with respect to 100 parts by mass of the drying oil (A).

Metal dryer;
The water-based coating composition of the present invention may contain a metal dryer (metal soap) in order to accelerate the polymerization reaction (drying) of the drying oils (A) after coating. Examples of the metal dryer include resin salts of metals such as cobalt, zinc or manganese, octanates, linoleates, and naphthenates.
The content of the metal dryer in the aqueous coating composition of the present invention is appropriately set, and is, for example, 0.5 to 2.5 parts by mass with respect to 100 parts by mass of the drying oil (A).

<Manufacturing method of water-based paint composition>
The water-based coating composition of the present invention is prepared by mixing the drying oil (A), the insect repellent (B), the water repellent (C) and water as a solvent, and any additive by a conventional method. Can be manufactured.

As the drying oil (A), the insect repellent (B) and the water repellent (C), those dispersed in water may be mixed, and the dispersion liquid contains an emulsifier or a surfactant. It may be blended. For example, as the dry oil (A), the dry oil containing an emulsifier of preferably 5 to 40 parts by mass (more preferably 15 to 30 parts by mass) with respect to 100 parts by mass of the dry oil (A) (more preferably 15 to 30 parts by mass). An emulsion of A) and water may be mixed, and the insect repellent (B) contains an emulsifier of preferably 300 to 500 parts by mass with respect to 100 parts by mass of the insect repellent (B). An emulsion of B) and water may be mixed, and the water repellent (C) is preferably an emulsifier or an interface of 300 to 1,000 parts by mass with respect to 100 parts by mass of the water repellent (C). An emulsion (or dispersion) of the water repellent (C) containing an activator and water may be used for mixing.

In the water-based coating composition of the present invention, for example, the drying oil (A) and an emulsifier are mixed, then a metal dryer is added and further mixed, and then an emulsion of the insect repellent (B) and water, the repellent. An emulsion of the liquid agent (C) and water and optionally the functional microcapsules may be added and further mixed, and then water may be added and further mixed to produce.

<Use of water-based paint composition>
The water-based coating composition of the present invention can be suitably used for coating a wood base material. The wood base material preferably includes a wood base material used for the walls or floors of buildings. The coating method is not particularly limited, and the base material (preferably a wood base material) can be coated with the water-based coating composition of the present invention by a conventional method.

The wood substrate coated with the water-based coating composition of the present invention is excellent in mosquito knockdown effect, water repellency (particularly, expression of water repellency in the early stage after coating), and antibacterial property. The reason why the mosquito knockdown effect is excellent is not necessarily clear, but it is considered that the water repellent (C) pushes up the insect repellent (B) onto the surface of the wood substrate and uniformly distributes it. Specifically, hydroxyl groups or carboxyl groups are present on the surface of the wood substrate, and these react with the water repellent (C) (reactive group of reactive silicone or zirconium acetate), so that the water repellent agent It is considered that the hydrophobic portion of (C) is located on the surface side, and as a result, the hydrophobic insect repellent (B) is pushed up. Further, it is considered that the drying oils (A) enhance the adhesion of the insect repellent (B) to the surface of the wood substrate.

Hereinafter, the present invention will be described in more detail based on Examples, but the embodiments of the present invention are not limited to these Examples.
[Example 1]
(Manufacturing of paint)
80 parts by mass of water-soluble fat and oil containing 85% by mass of flaxseed oil and 15% by mass of an emulsifier was charged into a container, and 1.2 parts by mass of a metal dryer as a curing accelerator was added thereto while stirring with a disper. Stirring was performed for 2 hours.

Next, 0.8 parts by mass of a pyrethroid insect repellent (pyrethroid content: 20% by mass), 2 parts by mass of a reactive silicone resin water repellent (reactive silicone resin content: 55% by mass), antibacterial and repellent. 10 parts by mass of microcapsules (shell: urethane) containing an aqueous natural essential oil was added, and the mixture was stirred for 0.2 hours.

Then, 6 parts by mass of tap water was added, and the mixture was stirred for 0.5 hours.
The obtained emulsion was filtered through a 100-mesh filter to obtain Paint 1. Table 1 shows the details of the raw material composition of the coating material 1 and the evaluation results by the following methods.

(Mosquito contact repellent test)
As a base material, a wood base material (pine material, length 50 mm × width 50 mm) is prepared, and the paint 1 prepared above is applied to the main surface of the base material at a coating amount of 30 g / m ² , according to the present invention. A wood base material impregnated and cured with the water-based coating composition was obtained. Subsequently, a cube consisting of the above-mentioned base material on three sides and an unprocessed mesh (length 50 mm x width 50 mm) on the remaining three sides was prepared, and 10 adult female human staghorn insects anesthetized with _{CO 2 were prepared in the cube.} Was left for 5 hours in an environment of room temperature of 25 ° C. and humidity of about 65%, and the number of knockdowns of the test insects was observed. The evaluation results of the paint 1 are shown in Table 1.

(Tick repellent test)
JIS L 1920: 2007 "Invasion Prevention Method" of "Tick-proof Performance Test Method for Textile Products"
The tick repellent test was conducted as follows with reference to.

Prepare a mite medium containing about 3,000 live mites (Dermatophagoides farinae) evenly spread on a glass petri dish with an outer diameter of about 90 mm and a height of about 20 mm and place it on an adhesive trap for insects with a diameter of 100 mm or more. A plastic plate cut into a length of about 50 mm and a width of about 50 mm was installed in the center.

On top of this, a wood substrate prepared in the same manner as in the mosquito contact repellent test was placed as a test sample, and 0.05 g of a mite-uninoculated medium was placed in the center of the test sample. This was placed in a plastic container for food preservation containing saturated saline together with the adhesive trap and sealed. Next, this plastic container for food storage was allowed to stand in an incubator in a dark state, and the container was bred for 24 ± 1 hours while maintaining a temperature of 25 ± 2 ° C. and a humidity of 75 ± 5%. After that, the test sample and the unincubated medium of the invited mites were washed with water to collect the mites and then counted, and the repellent rate (%) was calculated by the following formula. The test was repeated 3 times in consideration of variability.
Repellent rate (%) = (number of mites in 1-treatment group / number of mites in control group) x 100

(Water repellency test)
The paint 1 prepared above was brush-coated on a wood base material (pine material) with a coating amount of 50-60 g / m ² , left for 2-3 minutes, and then the coated surface was sufficiently wiped with a waste cloth to prepare a test plate. The test plate was stored in a constant temperature and humidity device having a temperature of 23 ° C. and a humidity of 50%, and the water contact angle of the painted surface was measured one day after painting.

In the measurement of the water contact angle, DM500 manufactured by Kyowa Interface Science Co., Ltd. was used, 1.0 μL of ion-exchanged water was dropped and dropped on the coated surface of the test plate, and 10 seconds later, the water contact angle (θ). Was measured. This measurement was performed three times, and the average value of the water contact angle (θ) was obtained.

(Antibacterial test)
An antibacterial test was conducted in accordance with JIS Z 2801: 2010 "Antibacterial processed product-Antibacterial test method / antibacterial effect".
As the antibacterial processed product, a wood base material prepared in the same manner as in the mosquito contact repellent test was used. A stomacher film (length 50 mm x width 50 mm, thickness about 0.09 mm) was prepared as a blank (unprocessed product) test piece, and a stomacher film (length 50 mm x width 50 mm, thickness about 0) was prepared as a coating film. .04 mm) was used. The test bacteria were Staphylococcus aureus and Escherichia coli, and the antibacterial activity value after being left for 24 hours was determined. Those having an antibacterial activity value of 2.0 or more for the antibacterial processed product against the blank were evaluated as having an antibacterial effect.

[Examples 2 and 3, Comparative Examples 1 and 2]
Paints 2 to 5 were obtained in the same manner as in Example 1 except that the raw materials and the blending amounts thereof were changed as shown in Table 1, and each of them was subjected to a mosquito contact repellent test or the like. Table 1 shows the details of the raw material compositions of the coating materials 2 to 5 and the evaluation results.

Claims (6)

An emulsion of drying oils (A) and water, containing an insect repellent (B) and a water repellent (C) .
The insect repellent (B) is a pyrethroid compound, and the insect repellent (B) is a pyrethroid compound.
A water-based coating composition in which the water repellent (C) is a silicone-based water repellent or a zirconium acetate-based water repellent, and the silicone-based water repellent is a silicone resin having a reactive group. The water-based coating composition according to claim 1, wherein the content of the water repellent (C) is 300 to 1,000 parts by mass with respect to 100 parts by mass of the insect repellent (B). The aqueous coating composition according to claim 1 or 2 , further comprising functional microcapsules. The water-based coating composition according to any one of claims 1 to 3 , which is used for coating a wood base material. A wood base material coated with the water-based coating composition according to any one of claims 1 to 4. A method for producing a painted wood base material, which comprises a step of painting at least a part of the surface of the wood base material with the water-based coating composition according to any one of claims 1 to 4.