Aerosol products and unmanned aerial vehicles

Abstract

To provide an aerosol composition that has high pigment dispersion stability to offer good visibility, and can be sprayed to a target site with high accuracy and from a long distance.SOLUTION: An aerosol composition contains a pigment, clay mineral A, a polymer thickener and water. In the aerosol composition, the content of the clay mineral A is 0.8 mass%-12.0 mass% and the content of the polymer thickener is 0.03 mass%-0.9 mass%. The water dispersion of the clay mineral A has thixotropy.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an aerosol composition used as a marking agent or the like, and an aerosol product and an unmanned aerial vehicle using the aerosol composition. [Background technology]

[0002] In recent years, against the backdrop of a declining birthrate, aging population, and aging infrastructure, the civil engineering and construction fields have been actively utilizing remotely controlled unmanned aerial vehicles such as drones and multicopters. For example, at infrastructure inspection sites, it is necessary to mark areas that require repair during inspection, but by loading an aerosol onto an unmanned aerial vehicle such as a drone, marking can be done easily, efficiently, and safely, even on bridges and structures that require scaffolding. For example, Patent Document 1 considers performing marking by spraying liquid from an aerosol container provided on an unmanned aerial vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-175683 Summary of the Invention [Problem to be solved by the invention]

[0004] When considering marking using aerosol spray from unmanned aerial vehicles such as drones, it has become clear that the functionality of the aerosol is important, such as the ability to spray over long distances of 3 m or more and to spray stably from various angles. However, there are currently no aerosol compositions that can meet these needs. In view of these problems, the present disclosure provides an aerosol composition that has high pigment dispersion stability, good visibility, high elasticity, and can be sprayed over long distances, as well as an aerosol product and an unmanned aerial vehicle that use the aerosol composition. [Means for solving the problem]

[0005] The present disclosure provides an aerosol composition comprising: The aerosol composition contains a pigment, a clay mineral A, a polymeric thickener, and water; the content of the clay mineral A in the aerosol composition is 0.8% by mass to 12.0% by mass; the content of the polymer thickener in the aerosol composition is 0.03% by mass to 0.9% by mass, The clay mineral A relates to an aerosol composition in which the aqueous dispersion thereof has thixotropy. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide an aerosol composition that has high pigment dispersion stability, good visibility, high elasticity collection, and can be sprayed over long distances, as well as an aerosol product and an unmanned aerial vehicle that use the aerosol composition. DETAILED DESCRIPTION OF THE INVENTION

[0007] The expressions "XX or more and YY or less" or "XX to YY" that represent a numerical range mean a numerical range including the endpoints, that is, the lower limit and the upper limit, unless otherwise specified. When numerical ranges are stated in stages, the upper and lower limits of each numerical range can be combined in any way.

[0008] Each component used in the aerosol composition will now be described. The aerosol composition contains a pigment. The pigment is not particularly limited, and known pigments such as inorganic pigments and organic pigments can be used. The use of a pigment can impart the visibility required as a marking agent to the aerosol composition. The pigment preferably contains an inorganic pigment.

[0009] Examples of inorganic pigments include white pigments such as titanium oxide, zinc oxide, white lead, calcium carbonate, magnesium carbonate, and silica; black pigments such as carbon black, titanium black, and iron black; red pigments such as red iron oxide and cadmium red; yellow pigments such as yellow lead, yellow ochre, and cadmium yellow; and blue pigments such as iron blue, sea blue, and cobalt blue. Examples of organic pigments include alkali blue, lysol red, carmine 6B, disazo yellow, phthalocyanine blue, quinacridone red, and isoindolinone yellow.

[0010] Among these, from the viewpoint of visibility, the pigment preferably contains at least one selected from the group consisting of white pigments, and more preferably contains titanium oxide. If necessary, in addition to the white pigment, at least one selected from the group consisting of a red pigment, a yellow pigment, and a blue pigment may be mixed from the viewpoint of visibility.Furthermore, in addition to the pigment, at least one selected from the group consisting of a red dye, a yellow dye, and a blue dye may be used in combination from the viewpoint of visibility.

[0011] The content of the pigment in the aerosol composition can be changed appropriately depending on the required visibility and is not particularly limited, but is preferably 1.0% by mass to 10.0% by mass, more preferably 1.00% by mass to 10.00% by mass, even more preferably 2.0% by mass to 5.0% by mass, and even more preferably 2.00% by mass to 5.00% by mass. When the inorganic pigment is in the form of fine particles such as titanium oxide, the number average particle size of the primary particles is preferably 10 nm to 30 μm, more preferably 50 nm to 1000 nm, and even more preferably 100 nm to 500 nm.

[0012] The aerosol composition contains clay mineral A. It is necessary that the aqueous dispersion of clay mineral A has thixotropy. The phrase "an aqueous dispersion having thixotropy" means that the viscosity of the aqueous dispersion decreases when shear stress is applied, and gradually returns to normal when the stress is removed. For example, if a 1% by mass aqueous dispersion of a clay mineral has thixotropy, the clay mineral can be determined to be clay mineral A. The thixotropy of the aqueous dispersion of clay mineral A reduces the viscosity of the aqueous dispersion when pressure is applied to the aqueous dispersion, such as during aerosol spraying. As a result, the flight distance of the aerosol composition is significantly improved, enabling long-distance spraying. Furthermore, the inclusion of a clay mineral such as clay mineral A in the aerosol composition improves the viscosity of the aerosol composition, making it less likely to diffuse during spraying, thereby improving the flight distance of the aerosol composition.

[0013] The clay mineral A is not particularly limited as long as it can impart thixotropy to the aerosol composition, and any known clay mineral can be used. The clay mineral A also contributes to the dispersion stability of the pigment. Clay mineral A is preferably at least one selected from the group consisting of smectite clay minerals, mica clay minerals, kaolinite clay minerals, and holmite clay minerals, and more preferably at least one selected from the group consisting of smectite clay minerals. The clay mineral A is preferably a clay mineral that forms a house-of-cards structure in its aqueous dispersion (for example, in a 1% by mass aqueous dispersion of the clay mineral). It has a complex, unoriented, layered structure. For example, negatively charged layer faces and positively charged edge faces attract each other, forming a three-dimensional association structure of layer face-edge bonds. When shear force is applied, the house-of-card structure is destroyed, reducing the viscosity of the dispersion.

[0014] Examples of smectite clay minerals include saponite, montmorillonite, bentonite, beidellite, hectorite, nontronite, sauconite, stevensite, etc. More preferably, the aerosol composition contains saponite.

[0015] The content of clay mineral A in the aerosol composition is 0.8% by mass to 12.0% by mass. If the content is less than the lower limit, the pigment dispersion stability decreases and a good flight distance cannot be obtained. On the other hand, if the content is more than the upper limit, a sufficient flight distance cannot be obtained. The content of clay mineral A in the aerosol composition is preferably 0.80% by mass to 12.00% by mass, more preferably 1.0% by mass to 10.0% by mass, even more preferably 1.00% by mass to 10.00% by mass, still more preferably 1.8% by mass to 7.0% by mass, and particularly preferably 1.80% by mass to 7.00% by mass.

[0016] The average thickness of the primary particles of clay mineral A is preferably 0.2 nm to 10.0 nm, and more preferably 0.5 nm to 3.0 nm. The average length of the primary particles of clay mineral A is preferably 10 nm to 1000 nm, more preferably 20 nm to 600 nm, and even more preferably 50 nm to 150 nm.

[0017] For example, the viscosity of a 4% by mass aqueous dispersion of clay mineral A is preferably 100 mPa·s to 10,000 mPa·s, more preferably 200 mPa·s to 7,000 mPa·s, and even more preferably 2,000 mPa·s to 6,000 mPa·s. The viscosity here is a value measured immediately after preparing a 4% by mass aqueous dispersion of the clay mineral using a BM-type viscometer with a No. 4 rotor at 60 rpm, 60 seconds, and 25°C.

[0018] The aerosol composition contains a polymeric thickener. The polymeric thickener improves the aerosol composition's collection properties. Furthermore, the improved collection properties make the aerosol composition less likely to diffuse, thereby improving the aerosol composition's flight distance. Furthermore, the polymeric thickener makes it easier to control the amount of aerosol composition sprayed at a constant level. The polymer thickener is not particularly limited, and known polymer thickeners can be used. For example, the following can be mentioned.

[0019] Cellulose-based thickeners such as cellulose gum, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydrophobized hydroxypropylmethylcellulose, sodium cellulose sulfate, and cellulose powder; Plant-based thickeners such as gum arabic, locust bean gum, tara gum, guar gum, glucomannan, xanthan gum, pectin, and agar. starches such as starch, carboxymethyl starch, and methylhydroxypropyl starch; Alginate-based polymers such as sodium alginate and propylene glycol alginate; Also, vinyl thickeners such as carboxyvinyl polymers, acrylic acid-alkyl methacrylate copolymers, acrylates / alkyl acrylate crosspolymers, and sodium polyacrylate; Highly polymerized polyethylene glycol (highly polymerized PEG, preferably with an average degree of polymerization of 2,000 to 150,000), (PEG-240 / decyltetradeceth-20 / HDI) copolymer, poly Polymerization-based polymers such as urethane.

[0020] Among the above, at least one selected from the group consisting of cellulose-based thickeners, plant-based thickeners, and vinyl-based thickeners is preferred, and at least one selected from the group consisting of cellulose-based thickeners and plant-based thickeners is more preferred. Further, at least one selected from the group consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydrophobized hydroxypropyl methylcellulose, xanthan gum, and sodium polyacrylate is more preferred, at least one selected from the group consisting of xanthan gum, hydroxyethyl cellulose, and sodium polyacrylate is even more preferred, and at least one selected from the group consisting of xanthan gum and hydroxyethyl cellulose is particularly preferred.

[0021] The content of the polymer thickener in the aerosol composition is 0.03% by mass to 0.9% by mass. If the content is less than the lower limit, sufficient elasticity cannot be obtained. On the other hand, if the content is more than the upper limit, sufficient flight distance cannot be obtained and nozzle clogging may occur. The content of the polymer thickener is preferably 0.03% by mass to 0.90% by mass, more preferably 0.05% by mass to 0.8% by mass, even more preferably 0.05% by mass to 0.80% by mass, still more preferably 0.18% by mass to 0.6% by mass, and particularly preferably 0.18% by mass to 0.60% by mass.

[0022] The aerosol composition contains water. The combination of water and clay mineral A can impart suitable thixotropy to the aerosol composition, thereby improving the flight distance of the aerosol composition. Furthermore, when considering loading the aerosol onto unmanned aerial vehicles such as drones and multicopters, hazardous materials such as organic solvents cannot be used, and therefore water must be used as the base. The water content in the aerosol composition is preferably 50.0% by mass to 90.0% by mass, more preferably 50.00% by mass to 90.00% by mass, even more preferably 60.0% by mass to 85.0% by mass, still more preferably 60.00% by mass to 85.00% by mass, especially preferably 65.0% by mass to 80.0% by mass, and particularly preferably 65.00% by mass to 80.00% by mass.

[0023] The aerosol composition preferably contains an alcohol. When the aerosol composition is used as a marking agent, it is preferable that the aerosol composition has high washability so that the pigment can be quickly washed away by water or rain after the marking function is completed. The aerosol composition contains an alcohol, which improves the washability. The inventors believe that the reason why alcohols improve the cleaning properties of pigments is that alcohols act as wetting agents, for example by forming a film on the surface of the pigment, improving its compatibility with water.

[0024] In order to improve the throw distance of the aerosol composition, it is preferable that the nozzle attached to the aerosol container is relatively long. In this case, alcohols, which have improved cleanability, are effective in preventing nozzle clogging. In particular, when it is assumed that an aerosol is to be loaded onto an unmanned aerial vehicle, the aerosol container is heavy and is therefore placed as close to the center as possible. Furthermore, in order to reduce the influence of wind from a propeller or the like on the ejected aerosol composition, it is necessary to make the nozzle somewhat long. In such cases, in order to prevent nozzle clogging, it is preferable that the aerosol composition contains an alcohol, which improves cleaning properties.

[0025] The alcohols may be aliphatic alcohols or aromatic alcohols, such as ethanol, propanol, isopropanol, butylene glycol, propane glycol, and the like. Examples of suitable oleic acid dispersants include pyrene glycol, dipropylene glycol, 1,3-butylene glycol, isopentyl diol, 1,3-pentanediol, pentylene glycol, 1,3-propanediol, glycerin, and phenoxyethanol.

[0026] Among these, from the viewpoints of wettability and compatibility with water, at least one selected from the group consisting of aliphatic diols (preferably having 1 to 6 carbon atoms, more preferably having 2 to 4 carbon atoms) is preferred. For example, at least one selected from the group consisting of butylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, isopentyl diol, 1,3-pentanediol, pentylene glycol, and 1,3-propanediol is preferred. From the viewpoints of cleanability and prevention of nozzle clogging, the aerosol composition more preferably contains propylene glycol.

[0027] The content of alcohols in the aerosol composition is preferably about 3.0% to 40.0% by mass, more preferably about 3.00% to 40.00% by mass, even more preferably about 10.0% to 30.0% by mass, still more preferably about 10.00% to 30.00% by mass, especially preferably about 15.0% to 25.0% by mass, and particularly preferably about 15.00% to 25.00% by mass.

[0028] The aerosol composition may contain other known additives to the extent that the effect of the aerosol composition is not impaired. For example, other thickeners, surfactants, colorants, fluorescent materials, etc. may also be added. The aerosol composition is preferably for marking purposes.

[0029] Next, aerosol products will be described. Aerosol products are An inner container filled with an aerosol composition is housed in an outer container equipped with a discharge mechanism, and a propellant is filled in the space formed between the inside of the outer container and the inner container. The discharge mechanism and the container are not particularly limited, and known ones can be used. The container may be any one that can withstand the pressure of the propellant, and known resin or metal containers can be used.

[0030] In an aerosol product, for example, an inner container, which is a foldable flexible bag, is sealed to an opening inside an outer container in a discharge mechanism. A space is formed between the outer container and the inner container, and this space is filled with a propellant for discharging the aerosol composition from the discharge mechanism. The discharge mechanism has a discharge port for discharging the aerosol composition filled in the inner container, and when a valve is operated, a flow path to the outside of the inner container is created. Pressure from the propellant placed between the inner container and the outer container applies pressure to the inner container, and the filled aerosol composition is discharged out of the outer container. Such aerosol products are generally called bag-on-valve or bag-in-can aerosol products. Aerosol products using a bag-on-valve can expel the contents of the bag equally from any angle, and can expel 95% of the contents.

[0031] The propellant is not particularly limited, and liquefied gas or compressed gas may be used. Since it is assumed that the aerosol will be loaded onto an unmanned aerial vehicle, hazardous materials cannot be used, so the aerosol product preferably contains compressed gas. It is preferable that the aerosol product does not contain a flammable propellant. The compressed gas is not particularly limited, and any known gas that can be used in aerosol products can be used. The compressed gas is preferably at least one selected from the group consisting of carbon dioxide gas, nitrogen gas, nitrous oxide gas, argon, helium, and compressed air, and more preferably at least one selected from the group consisting of carbon dioxide gas and nitrogen gas.

[0032] The compressed gas is preferably filled so that the pressure inside the aerosol container (gauge pressure) at 25°C is 0.4 MPa to 1.0 MPa, and more preferably 0.6 MPa to 0.8 MPa.

[0033] The method for producing the aerosol composition is not particularly limited, and examples thereof include the following methods. The aerosol composition can be obtained by mixing water, pigment, clay mineral A, a polymeric thickener, and, if necessary, alcohols and other ingredients in any desired ratio.

[0034] The aerosol product is preferably used by being mounted on an unmanned aerial vehicle such as a drone or a multicopter. That is, an unmanned aerial vehicle on which the aerosol product is mounted is a preferred embodiment. The unmanned aerial vehicle is not particularly limited, and any known unmanned aerial vehicle may be used. For example, a multicopter having multiple rotors on its body can be used. Various known multicopters can be used, such as a tricopter with three rotors, a quadcopter with four rotors, and a hexacopter with six rotors.

[0035] The means for mounting the aerosol product on the multicopter is not particularly limited, and any known method may be used. For example, the aerosol product may be mounted horizontally on the aircraft, or with the discharge mechanism facing downward. The unmanned aerial vehicle preferably includes an opening / closing mechanism that can remotely open and close the discharge mechanism of the aerosol product. The shape of the nozzle of the aerosol product is not particularly limited and may be changed as appropriate depending on the purpose. When marking a wall surface, a horizontal nozzle may be used, and when marking the ground, a nozzle bent 90° downward from the horizontally mounted aerosol product may be used. [Example]

[0036] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the aspects of the following examples.

[0037] <Examples 1 to 11 and Comparative Examples 1 to 4> The raw materials were mixed according to the formulation (mass %) shown in Table 1 to prepare aerosol compositions of Examples 1 to 11 and aerosol compositions of Comparative Examples 1 to 4.

[0038] [Table 1]

[0039] In Table 1, the materials used are as follows: Sumecton SA: Saponite (Kunimine Industries Co., Ltd.) TITANIX JR-806: Titanium oxide (Teika Corporation) Echo Gum T: Xanthan gum (DSP Gokyo Food & Chemical Co., Ltd.) HEC SE600: Hydroxyethyl cellulose (Daicel Miraize Co., Ltd.) AH-105X: Sodium polyacrylate (Toagosei Co., Ltd.) Industrial propylene glycol: Propylene glycol (ADEKA Corporation) Snow fluorescent water, magenta: legally required dye (Shin-Roihi Co., Ltd.)

[0040] Each of the resulting aerosol compositions was filled into a bag-on-valve aerosol container to obtain an aerosol product. Nitrogen was used as the propellant, and the pressure (gauge pressure) inside the container was set to 0.7 MPa.

[0041] The resulting aerosol compositions were evaluated as follows, and the results are shown in Table 1. (1. Pigment dispersion stability) The stock solution was collected in a 50 ml vial and stored in a 45°C incubator for 3 months as an accelerated test. The sedimentation state of the pigment inside was checked. A: No pigment sedimentation B: A small amount of pigment sedimentation C: Pigment sedimentation

[0042] The resulting aerosol product was evaluated as follows, and the results are shown in Table 1. (Distance and accuracy) After immersing the aerosol product in a thermostatic water bath at 25°C for 30 minutes, a nozzle with an inner diameter of 1.0 mm, an outer diameter of 2.6 mm, and a length of 5 mm was attached to the tip of a nozzle with a length of 20 cm and an inner diameter of 3 mm. This nozzle was used to evaluate the flight distance and accuracy of the aerosol product. An A3 sheet of paper was placed 3m horizontally away from the aerosol product, the contents were sprayed for 0.5 seconds, and the flight distance and accuracy were evaluated according to the following criteria. (2. Flying distance) A: More than 90% of the discharged contents (by mass) reach the target. B: More than 50% but less than 80% of the discharged contents reach the target. C: Less than 50% of the discharged contents reach the target. (3.Elastic collection) A: Spray pattern diameter less than 11cm B: Spray pattern diameter is 11cm or more but less than 17cm C: Spray pattern diameter is 17cm or more

[0043] (cleanability) After immersing the aerosol product in a thermostatic water bath at 25°C for 30 minutes, the aerosol product equipped with a button with a nozzle diameter of φ0.5 mm was placed on a platform 1.5 m high and sprayed for 1 second toward a mortar wall 1.5 m away. After leaving it at room temperature (20°C to 30°C) for 1 week, the amount of dust adhering to the wall was measured. The cleanability of the contents was confirmed. A: Just run water over it for 30 seconds and the residue will come off. B: After running water for 30 seconds, scrubbing with a damp scrubbing brush (10 times) removes the residue. C: After running water for 30 seconds, the deposits did not come off even after scrubbing with a damp scrubbing brush (10 times).

[0044] (Clogging) The aerosol product was immersed in a thermostatic water bath at 25°C for 30 minutes, and then sprayed for 1 second using a button with a nozzle diameter of 0.5 mm. The product was then stored in a thermostatic chamber at 25°C for 1 week. After storage, the button was operated to check for clogging. A: It can be sprayed with one operation. B: There is initial clogging, but it can be sprayed after 2 to 5 operations C: Cannot be sprayed even after 6 to 10 operations

Claims

1. An aerosol product, comprising: An inner container filled with an aerosol composition is housed in an outer container equipped with a discharge mechanism, and a propellant is filled in a space formed between the inside of the outer container and the inner container; The aerosol composition contains a pigment, a clay mineral A, a polymeric thickener, and water; The content of the clay mineral A in the aerosol composition is 0.8% by mass to 12.0% by mass, the content of the polymer thickener in the aerosol composition is 0.03% by mass to 0.9% by mass; The clay mineral A is an aerosol product characterized in that its aqueous dispersion has thixotropy.

2. 2. The aerosol product according to claim 1, wherein the clay mineral A is at least one selected from the group consisting of smectite clay minerals, mica clay minerals, kaolinite clay minerals, and holmite clay minerals.

3. 3. The aerosol product according to claim 1, wherein the clay mineral A is a clay mineral that forms a house-of-cards structure in its aqueous dispersion.

4. 4. The aerosol product according to claim 1, wherein the content of the clay mineral A in the aerosol composition is 1.0% by mass to 10.0% by mass.

5. The aerosol product according to any one of claims 1 to 4, wherein the aerosol composition contains an alcohol.

6. 6. The aerosol product according to claim 5, wherein the alcohol is at least one selected from the group consisting of aliphatic diols having 1 to 6 carbon atoms.

7. 7. The aerosol product according to claim 5, wherein the content of the alcohol in the aerosol composition is 3.0% by mass to 40.0% by mass.

8. 8. The aerosol product according to claim 1, wherein the pigment comprises an inorganic pigment.

9. 9. The aerosol product according to claim 1, wherein the content of the polymer thickener in the aerosol composition is 0.05% by mass to 0.8% by mass.

10. The aerosol product according to any one of claims 1 to 9, wherein the polymer thickener is at least one selected from the group consisting of cellulose-based thickeners, plant-based thickeners, and vinyl-based thickeners.

11. An aerosol product described in any one of claims 1 to 10, wherein the aerosol composition is an aerosol composition for marking.

12. An unmanned aerial vehicle equipped with the aerosol product according to any one of claims 1 to 11.

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