EP1647335A2

EP1647335A2 - Method for coating a substrate with a coating containing metallic powder and coated member

Info

Publication number: EP1647335A2
Application number: EP05255771A
Authority: EP
Inventors: Toru Taniguchi
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-10-12
Filing date: 2005-09-16
Publication date: 2006-04-19
Also published as: JP2006110398A; JP4974451B2; EP1647335A3

Abstract

A metallic powder coating method in which a base material is covered by coating with a mixture of metallic powder of particle diameters between 3 mm and 0.01 mm. In said coating process, a synthetic resin member is mixed with at least one type of said metallic powder. Said synthetic resin member attaches itself around said metallic powder particles of diameters between 3 mm and 0.01 mm, thereby adhering the metallic powder particles to each other and to the base material. In a subsequent drying process, said synthetic resin member is dried, thereby adhering said metallic powder and synthetic resin member more securely to said base material.

Description

[Technical field]

The present invention concerns a metallic powder coating method and metallic powder coating member that permit the sheen distinctive to metallic powder to be brought out at low cost. More particularly, the present invention concerns a metallic powder coating method and metallic powder coating member that permit distinctive surface shapes, colour tones, sheens, and other effects to be brought out based on the combination of said metallic powders and the ratios in which they are combined. The present invention further concerns a metallic powder coating method and metallic powder coating member that permit the creation of a great variety of surfaces by means of the reflections from the metallic powder itself, actively induced unevenness, actively polished surfaces, and other such means.

[Background art]

Conventionally, in the case of the powder coatings used to paint car bodywork, a desired surface finish and colour have been achieved by using particle diameters of several tens of microns and spraying from a spray nozzle. For example, the powder coating described in unexamined Japanese patent application publication 1996-231892 (Reference 1) contains between 0.1 and 10% by weight of conductive pigment and, by adding and combining with bright pigment, is used on metal, timber, glass, ceramic, plastic, and inorganic construction materials.
The wall-painting technique described in unexamined Japanese patent application publication 2003-172009 (Reference 2) provides a priming process in which a cement-based primer is applied to a base wall material and patterned undulations are formed on the surface by the time the primer hardens, a middle-coat process in which a first ceramic paint formed by mixing coloured aggregate with synthetic resin emulsion is applied to the entire surface of said primer, and a final-coat process in which a second ceramic paint of a different shade or a coloured paint based on silicon resin, urethane resin, acrylic resin, or fluorocarbon resin is applied partially to the surface of the first ceramic paint.

[Disclosure of the invention]

[Problems to be solved by the invention]

The conventional powder paints described above required metallic powders with particle diameters of several tens of microns, and, as well as the fact that metallic powder-based paints are themselves expensive, various adaptations were made to the paint applicator - to prevent the nozzle tip from becoming blocked, for example - making this a high cost coating method. The previous example, in which synthetic resin is applied to the base wall material, permits the forming of patterned undulations by means of the colour member and the synthetic resin, but factors such as colour tone, brilliance, and sheen are inferior when compared to metallic powder.
To solve problems of this kind, the present invention aims to provide a metallic powder coating method and metallic powder application member whereby metallic powder of different particle diameters can be produced cheaply and new levels of colour tone, brilliance, sheen, and other such effects achieved without the use of special coating equipment.
Accordingly the present invention provides a metallic powder coating method in which a base material is covered in metallic powder of particle diameters between 3 mm and 0.01 mm, characterized by comprising the steps of a coating process in which a synthetic resin member is combined with at least one type of said metallic powder and applied to said base material, and a drying process in which the composite member constituted by said metallic powder and said synthetic resin member is subsequently dried.
Preferably, an embossing process is also carried out after the coating process and before the drying process, and a final polishing process may also be included after the drying process, followed by an optional protective coating.
The coating is preferably applied using a spray nozzle whereby the pattern of application of the powder may be changed by altering the speed of movement of the spray nozzle.
The base material may, for example, comprise at least one of a concrete member, concrete block, cement board, synthetic resin member, timber, plywood, or unglazed ceramic, and the synthetic resin member may comprise at least one type of acrylic resin, epoxy resin, or cation resin.

[Benefits of the invention]

Using the present invention, when metallic powder consisting of particles of varying diameters is applied to a base material, the strength of the base material is increased and the aesthetic feel improved by the formation of patterns. The metallic powder coating method in the present invention produces a completely different finish from conventional methods such as electrodissolution and plating, exhibiting the distinctive colour tones and sheen of the metallic powder itself or the metallic powder mixture.
Utilising the present invention, the metallic powder and the metallic powder coating device are cheaper because there is no need to use metallic powder with particles of a fixed diameter, and the finish also provides a completely different aesthetic feel from conventional methods. When applied to the base material, the metallic powder of particle diameters between 3 mm and 0.01 mm in the present invention forms fine undulations on the surface, and the different reflections produced by these undulations provide, in combination with the colour tones of the metallic powder, a beautiful surface sheen.
It is also easy to produce any desired pattern using an embossed or polished finish when the metallic powder is applied, thereby providing the member to which the metallic powder is applied with an aesthetic feel that fits the purpose for which it will be used at low cost.
Distinctive colour tones, glossy sheens and other such effects can be achieved by changing the type or combination ratio of the metals in the mixture, and flat surfaces of the requisite smoothness can be produced by polishing.
The thickness and pattern of the metallic powder on the metallic powder coating member can be varied by moving either the base material or an applicator nozzle back, forth, left, and right, at the desired speed.
It is also possible to achieve various distinctive colours of the metallic powder by using for the metal powder, single metals such as iron, copper, aluminium, nickel, chrome, magnesium, and precious metals such as gold or platinum, or at least one alloy of these metals, or by oxidizing these metals, as well as which different colours can also be produced depending on the combination ratios of the above, allowing an infinite variety of colours to be produced, even including some unique colours not available in the natural world.
By using a concrete member, concrete block, cement member, synthetic resin member, timber, plywood, unglazed ceramic, and so forth for the base material, and at least one type of acrylic resin, epoxy resin, or cation resin for the synthetic resin member serving as the adhesive, the synthetic resin member acts as the joining agent or adhesive between the base material and the metallic powder and, when worked into the metallic powder, adheres securely and evenly to the surface being coated.
Since the present invention utilizes large particle diameters at between 3 mm and 0.01 mm, an off-the-shelf mortar spray gun can be used, as well as which a variety of different sheens and colour effects can be achieved using different sized particles.
The present invention also allows the application of metallic powder consistent with base materials of complex shapes, which means that, as well as being used for the decoration of the internal and external walls and floors of buildings, the invention can be also used for objects of various different shapes, including elements of interior décor such as ceilings, walls, floors, and doors, as well as furniture, consumer appliance and other packages, light fittings, the bodywork of vehicles, ships, sailing vessels and so forth, large structures, sculptures, and art objects.
The metallic powder coating member obtained by coating a synthetic resin member combined with at least one type of metallic powder of particle diameters between 3 mm and 0.01 mm onto a base material can also be applied to anything from flat board to objects of complex shape, and the relatively large particle diameter of the metallic powder permits factors such as colour tone, sheen, and brilliance to be improved.

[Brief description of drawings]

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a schematic block diagram summarizing the metallic powder coating device in Embodiment 1 of the invention.
Figure 2 is a schematic diagram summarizing the metallic powder coating member in the embodiments of the invention.
Figure 3 is a schematic block diagram summarizing the metallic powder coating device in Embodiment 2 of the invention.

[Explanation of symbols]

11	Metallic powder coating system
12	Metallic powder coating device
121	Spray gun
122	Hopper
123	Nozzle
124	Rail
125	Stand
13	Conveyor
14	Base material
15	Embossing machine
16	Dryer
21	Metallic powder coating member
211	Base material
212	Metallic powder
213	Synthetic resin member
31	Spray gun
32	Hopper
33	Movable rack
34	Castors
35	Hose
36	Nozzle

In the metallic powder coating method of the preferred embodiment, a base material is covered by coating with a mixture of metallic powder of particle diameters between 3 mm and 0.01 mm. In said coating process, a synthetic resin member is combined with at least one type of said metallic powder. The synthetic resin member attaches itself around the metallic particles of diameters between 3 mm and 0.01 mm, thereby adhering the metallic particles to each other and to the base material. If required, the coating process can also be carried out by spraying.
The subsequent drying process then serves to adhere the metallic powder and synthetic resin member more securely to the base material by drying the synthetic resin member. When the metallic powder of varying particle diameters is applied to the base material, the strength of the base material is increased and the aesthetic feel improved by the formation of patterns. The metallic powder coating method in the present invention produces a completely different finish from conventional methods such as electrodissolution and plating, exhibiting the distinctive colour tones and sheen of the metallic powder (whether alone or in combination).
Conventional powder coatings using metallic powders with particle diameters of between several microns and several tens of microns required expensive equipment to perform the coating. The metallic powder coating method in the present invention, by contrast, allows the cost to be reduced to anywhere between 1/3 and 1 /10 of the previous cost because there is no need to use special equipment, and is therefore a low-cost coating method, as well as which the finish has an aesthetic feel completely different from conventional approaches.
In the embossing process, patterns of any desired shape can be formed on the mixture of metallic powder and synthetic resin member prior to drying. These patterns require only that the die used in the embossing machine be produced with the desired form, thereby providing the member coated with the metallic powder with a pattern suited to the purpose for which it will be used at low cost.
The polishing process allows distinctive colour tones, glosses and sheens to be produced on the surface of the mixture of the metallic powder and synthetic resin member after drying based on the type or combination ratio of the metals in the mixture, thereby achieving the required surface finish.
The metallic powder would typically be made up, for example, of single metals such as iron, copper, aluminium, nickel, chrome, magnesium, or a precious metal such as gold or platinum, or alternatively of at least one alloy of these metals. However, the metallic powder in the present invention may also include metals other than those mentioned above. Not only can the distinctive colours of the metallic powders be produced on the base material onto which the metallic powder is sprayed, but different colour tones can also be achieved depending on the ratio in which the metals are combined or the degree of rust that they contain.
In the case of iron, for example, the colour of the metallic powder coating can be changed to almost red as the degree of rust increases, and black as it decreases. In other words, the metallic powder coating method in the present invention is not only capable of producing an infinite variety of colours, but can also yield unique colours not available in the natural world. Precious metals such as gold and platinum are well suited for coating sculptures and other art objects.
The pattern of the metallic powder can be changed by spraying from a nozzle and altering the speed of movement of either the base material or the nozzle as desired in at least one direction, back, forth, left, or right. The pattern can thus be adapted to the purpose or place of use of the base material and other such conditions.
The composite member may also be coated with a protective member composed, for example, of lacquer or urethane, thereby protecting its surface.
The base material preferably comprises at least one of a concrete member, concrete block, cement member, synthetic resin member, timber, plywood, unglazed ceramic, or the like. In other words, the metallic powder coating method can be used to apply metallic powder unless the member is composed of glass, porcelain, glazed ceramic, gas, or fluid.
The synthetic resin member preferably comprises at least one type of acrylic resin, epoxy resin, or cation resin, and serves as a joining agent or adhesive for the metallic powder. When worked into the metallic powder, the synthetic resin member adheres securely and evenly to the surface being coated.
In a preferred form of the metallic powder coating method of the invention, the particle diameters of the metallic powder in Inventions are large, at between 3 mm and 0.01 mm, so that an off-the-shelf mortar spray gun can be used for the spraying. More particularly, particles of between 3 mm and 0.01 mm are mixed together because the metallic powder is passed through meshes of 3 mm and 0.01 mm once the metal has been pulverized, and the metallic powder of particles varying between these sizes is thus able to produce a variety of colour tones, sheens, and moods.
Preferably the coating process is carried out by placing the nozzle of the spray gun in a robot, and the coating can be applied by moving the robot automatically along a complex shape of the base material. As well as the decoration of the internal and external walls and floors of buildings, the invention can be also used for objects of various different shapes, including elements of interior decor such as ceilings, walls, floors, and doors, as well as furniture, consumer appliance and other packages, light fittings, the bodywork of vehicles, ships, sailing vessels and so forth, large structures, sculptures, and art objects.
The metallic powder coating member of the Invention can be applied to anything from flat board to objects of complex shape, and the relatively large particle diameter of the metallic powder enables colour tone, sheen, brilliance, and other effects to be improved.
Since the metallic powder is formed in patterns on the surface of the base material and is composed of particles far larger than those of a standard metallic coating, and comprises a mixture of different sized particles, this means that the reflections from the light irradiated onto each particle are different, and appear as attractive patterns.
Preferably the base material comprises at least one type of metallic member face, concrete member face, synthetic resin member face, timber face, plywood face, or unglazed ceramic face. The present invention can thus be used with any member without particular restriction, except those such as glass or glazed ceramic, provided the synthetic resin member can adhere to it.
Figure 1 is a schematic block diagram summarizing the metallic powder coating device in Embodiment 1 of the invention. In Figure 1, a metallic powder coating system 11 is composed of a metallic powder coating device 12, a conveyor 13, a base material 14, an embossing machine 15, and a dryer 16. The embossing machine 15 can be installed if required. It is also possible to add a polishing machine to the equipment shown in Figure 1. The metallic powder coating device 12 also features a controller, not shown.
The metallic powder coating device 12 is composed, at minimum, of a spray gun 121 fitted with a compressor or other device, a hopper 122 into which the metallic powder and synthetic resin member are placed (not shown), a nozzle 123 for spraying the mixture of the metallic powder and synthetic resin member, a rail 124 for moving the spray gun 121 left and right on Figure 1, and a stand 125 to support the rail 124, spray gun 121, and other equipment in a moving state.
The shape of the nozzle 123 may be of approximately the same width as the base material, or narrower than the base material. The nozzle 123 is structured so as to be capable of spraying metallic powder of particle diameters between 3 mm and 0.01 mm, as described later. For the metallic powder coating device 12, it is possible to use, for example, a machine for applying mortar. The conveyor 13 moves in sequence from the right to the left on Figure 1 with the base material 14 placed in the required location.
As well as being moved to the left by means of the conveyor belt, as described above, the base material 14 can also be made to move in the opposite direction, to the right. In addition, the spray gun 121 is set up so that it can be moved along the rail 124 width-ways across the base material. By controlling it with the controller (not shown), the nozzle 123 can therefore be located at any selected position on the base material 14, and the mixture of the metallic powder and synthetic resin member sprayed in the intended volume.
The mixture of the metallic powder and synthetic resin member sprayed from the nozzle 123 is controlled by the controller such that patterns of any desired thickness can be formed. Further different shapes can, if required, be created from the metallic powder and synthetic resin member sprayed onto the base material 14 using the embossing machine 15. The mixture of the metallic powder and synthetic resin member formed on the base material 14 to which said pattern has been applied can subsequently be dried using the dryer 16 and thereby adhered securely to the base material 14. In addition, the surface of the metallic powder and synthetic resin member adhered to the base material 14 can, if required, be polished using the polishing machine.
Figure 2 is a schematic diagram summarizing the metallic powder coating member in an embodiment of the present invention. In Figure 2, metallic powder coating member 21 is composed of a base material 211, a metallic powder 212 applied to the top of the base material 211, and a synthetic resin member 213 mingling around the particles of metallic powder 212. When mixed with the metallic powder 212 in the hopper 122, the synthetic resin member 213 is, if required, made to mingle more easily around the metallic powder 212 by introducing a thickening agent.
As a result of various experiments, it was decided to make the diameter of the particles in the metallic powder 212 between 3 mm and 0.01 mm in order to provide ease of application and the aesthetic effect of reflecting light. These particle sizes mean that the powder can be used, for example, with a mortar spray gun, as well as which the mixture contains different-sized powder particles that do not reflect the light consistently, thereby producing distinctive colour tones and shades. By using for the metallic powder single metals such as iron, copper, aluminium, nickel, chrome, magnesium, gold, or platinum, an alloy of these metals, or at least one variety or mixture of them, it is possible to produce shades not available in the natural world.
In addition, the metallic powder can be given varied colour tones based on the degree of rust. Iron, for example, can be varied from red to black depending on the degree to which it has rusted, allowing an infinite variety of colours to be achieved. Once the iron rust described above is of the desired colour and has been mixed with the synthetic resin member 213 and sprayed onto the base material 211, it will, when dried, reach the condition shown in Figure 2, at which point change will cease and the colour will remain constant. The same rust effect can be achieved with copper and aluminium.
Once the metal material has been pulverized, and the metallic powder 212 passed through a sieve of 3 mm mesh followed by a sieve of 0.01 mm mesh, particles that are exclusively between 3 mm and 0.01 mm can be selected.
The base material 211 to which the mixture is applied can be anything except glass, porcelain, glazed ceramic, gas, or fluid, such as, for example, a concrete member, cement member, plastic, timber, plywood, or unglazed ceramic. By working in the synthetic resin member 213 of acrylic resin, epoxy resin, cation resin or other such material, the mixture can be securely and evenly adhered to the surface being coated. Subsequent polishing of the coated surface gives a further sheen from the metallic powder.
Figure 3 is a schematic block diagram summarizing the metallic powder coating device in Embodiment 2 of the invention. In Figure 3, a metallic powder coating device is composed of a spray gun 31, a hopper 32, a movable rack 33, castors 34, a hose 35, a nozzle 36, and a compressor, controller and other equipment, not shown. The metallic powder coating device in Embodiment 2 is movable and can therefore be used on complex shapes or walls and other vertically installed structures, and is essentially the same as that in Embodiment 1.
This completes the detailed exposition of the embodiments of the invention, but the invention is not limited to the embodiments described above, and a number of design changes could be made within the scope of the appended claims. The spray gun included in the embodiments has not been described in any detail, but a device for the application of mortar could be used without modification. Items commonly or publicly known could be used for the conveyor, stand, embossing machine, dryer and other equipment described in the embodiments.
As well as using the spray gun described above, it would also be possible to combine the use of conventional approaches based on rollers, trowels and other such means with the metallic powder coating method in the present invention, allowing it to be carried out in places such as general light-equipment factories, construction sites, and interior decoration sites.

Claims

A metallic powder coating method in which a base material is covered in metallic powder of particle diameters between 3 mm and 0.01 mm,
characterized by comprising the steps of
a coating process in which a synthetic resin member is combined with at least one type of said metallic powder and applied to said base material, and
a drying process in which the composite member constituted by said metallic powder and said synthetic resin member is subsequently dried.
A metallic powder coating method according to claim 1, further
characterized by
an embossing process in which the composite member constituted by said metallic powder and said synthetic resin member is embossed after said coating process and before said drying process.
A metallic powder coating method according to claim 1 or claim 2 further comprising a polishing process in which the composite member is polished after said drying process.
A metallic powder coating method according to any one of claims 1 to 3
characterised in that, during said coating process, the pattern of the metallic powder is changed by altering the speed of movement of the base material, or an applicator nozzle, in at least one direction, back, forth, left, or right.
A metallic powder coating method according to any one of claims 1 to 4 further comprising a final step of coating the composite member with a protective coating.
A metallic powder coating method according to any one of the preceding claims, characterised in that said base material comprises at least one of a concrete member, concrete block, cement member, synthetic resin member, timber, plywood or unglazed ceramic.
A metallic powder coating method according to any one of the preceding claims, characterised in that said synthetic resin member comprises at least one type of acrylic resin, epoxy resin, or cation resin.
A metallic powder coating method according to any one of the preceding claims, characterised in that said coating process uses a mortar spray gun including a spray nozzle.
A metallic powder coating method according to claim 8, characterised in that, in said coating process, base materials of complex shape are coated by moving the nozzle of the spray gun automatically using a robot.
A metallic powder coated member produced by the method of any preceding claim.
A metallic powder coated comprising a base material sprayed with at least one type of metallic powder of particle diameters between 3 mm and 0.01 mm combined with a synthetic resin member.
A metallic powder coated member according to claim 11, characterised in that patterns are formed on the surface coated with said metallic powder.
A metallic powder coated member according to claim 11 or claim 12,
characterised in that said base material comprises at least one type of metallic member face, concrete member face, synthetic resin member face, timber face, plywood face or unglazed ceramic face.
A metallic powder coated member as according to any one of claims 11 to 13, characterised in that said base material is comprised of complex shapes.