JP2016216778A - Coating and method of forming same coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating that is small in number of cracks and pores and includes an inorganic oxide having a less risk of decreasing in corrosion resistivity and mechanical characteristics, and a method of forming same coating.SOLUTION: A method of forming a coating according to the present invention is designed to form a coating including inorganic oxide particles on a base material, the method comprising: a heating process of heating the inorganic oxide particles held in a non-fusion state; a spraying process of spraying the inorganic oxide particles, having been heated in the heating process, on a processed surface of the base material; and a coating forming process of forming a coating of the inorganic oxide particles on the base material by sintering the inorganic oxide particles, sprayed on the processed surface of the base material in the spraying process, on the base material. The heating process includes sintering resin using a resin composition having the inorganic oxide particles dispersed in the resin as a raw material for the inorganic oxide particles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film and a method for forming the film, and more particularly to a film containing inorganic oxide particles and a method for forming the film.

Conventionally, it is known to form a film containing inorganic oxide particles on a base material and to modify the characteristics of the base material. Among the methods for forming the film, there is a thermal spraying method. As the thermal spraying method, for example, a thermal spray flame is formed by electric discharge, and inorganic oxide particles are supplied into the thermal spray flame so that the inorganic oxide particles are in a molten state (in other words, a liquid state). Plasma spraying that forms a film containing inorganic oxide particles on the substrate by impinging the object particles against the surface to be treated of the substrate and cooling and solidifying the molten inorganic oxide particles on the substrate Law.
The thermal spraying method has the advantages that (i) the film forming speed is high, (ii) it is a dry process, the environmental load is small, and (iii) it can be applied to film forming over a large area. On the other hand, since the crystal phase of the inorganic oxide particles may undergo phase transition before and after the film formation, the film formed on the substrate may be inferior in corrosion resistance and mechanical properties. II) In order to prevent cracks and pores in the film due to rapid cooling of the liquid inorganic oxide particles, that is, generation of cracks and pores due to rapid cooling, and (III) deterioration of fluidity due to aggregation of the inorganic oxide particles. In addition, since it is necessary to make the particle size of the inorganic oxide particles in the micro order, voids between the grains become large, and cracks and pores are generated in the film, that is, generation of cracks and pores depending on the gaps between the grains. There are also drawbacks.

As a method for forming the film on the substrate, a suspension plasma spraying method (SPS method or SPPS method) has been proposed.
In the SPS method, a suspension in which nano-order inorganic oxide particles, which are thermal spray materials, are suspended in a liquid medium such as alcohol, and the inorganic oxide particles suspended in the suspension are sprayed. Using an SPS device.
The SPS apparatus includes a nozzle that is arranged so that a central axis is orthogonal to a surface to be processed of the base material, and is formed by discharge from a front end portion of the nozzle toward the surface to be processed of the base material. The plasma generator for discharging the spray flame along the direction of the central axis, the tank for storing the suspension, and the suspension stored in the tank from the direction perpendicular to the central axis of the nozzle And a suspension supply section arranged to supply the liquid into the thermal spray flame (see Patent Document 1).
In the SPS method, when the suspension is supplied into the spray flame, the liquid medium is combusted and the inorganic oxide particles are brought into a molten state. The inorganic oxide particles in the molten state are accelerated by the spray flame, collide with the surface to be treated of the base material, and are cooled and solidified on the base material. Thereby, the membrane | film | coat containing the said inorganic oxide particle is formed on the said base material.

Special table 2014-502670 gazette

  According to the above SPS method, since nano-order inorganic oxide particles can be supplied into the spray flame emitted from the plasma generating portion, inorganic oxide particles having a smaller diameter than conventional ones are deposited on the substrate. be able to. Therefore, the generation of cracks and pores depending on the gaps between the grains is reduced. That is, according to said SPS method, said (III) can be solved.

However, even in the above SPS method, the inorganic oxide particles collide with the surface to be treated of the base material in a molten state, and are cooled and solidified on the base material, so that generation of cracks and pores due to rapid cooling occurs. The drawback (above (II)) has not been solved.
In addition, the crystal phase of the inorganic oxide particles may undergo a phase transition during the cooling and solidification (for example, when the inorganic oxide particles are aluminum oxide having an α phase, the crystal phase is changed from an α phase to a γ phase. Therefore, the drawback (above (I)) that the film formed on the substrate may be inferior in corrosion resistance and mechanical properties has not been solved.
Furthermore, in order to maintain the state in which the inorganic oxide particles are dispersed in the suspension, the ratio of the inorganic oxide particles in the liquid medium, that is, the inorganic oxide particles in the liquid medium. The concentration needs to be lowered. Therefore, the concentration of the inorganic oxide particles in the liquid medium is usually about several mass% to 10 mass%.
For the above-described reason, when the coating is formed on the substrate by the SPS method, there arises a problem that the film forming speed is lowered as compared with the case of the plasma spraying method, that is, the advantage (i) described above is lost. There is an aspect.

  In view of the above problems, an object of the present invention is to provide a film containing inorganic oxide particles with few cracks and pores, and less likely to deteriorate corrosion resistance and mechanical properties, and a method for forming the film.

The method for forming a film according to the present invention includes:
A method of forming a film that forms a film containing inorganic oxide particles on a substrate,
A heating step of heating the inorganic oxide particles while maintaining the non-molten state;
A spraying step of spraying the inorganic oxide particles heated in the heating step onto the surface to be treated of the substrate in a non-molten state;
A film forming step of sintering the inorganic oxide particles sprayed on the treated surface of the base material in the spraying step on the base material to form a film of the inorganic oxide particles on the base material; Have
In the heating step, a resin composition in which the inorganic oxide particles are dispersed in a resin is used as a raw material for the inorganic oxide particles, and the inorganic oxide particles are heated by burning the resin.

According to such a configuration, since the film is formed on the base material using the inorganic oxide particles in a non-molten state, the influence of cracks and pores caused by the rapid cooling of the liquid inorganic oxide particles can be reduced.
Moreover, since the aggregation of the inorganic oxide particles can be suppressed by dispersing the inorganic oxide particles in the resin, the influence of cracks and pores depending on the voids between the grains can be reduced.
In addition, since non-molten inorganic oxide particles are used, there is little risk of phase transition of the crystalline phase of the inorganic oxide particles before and after film formation. For this reason, the film formed by the above forming method is less likely to deteriorate the corrosion resistance and mechanical properties.

In the method for forming the film,
In the heating step, the inorganic oxide particles are heated in contact with a flame, and the surface temperature of the inorganic oxide particles may be in the range of a melting point of −150 ° C. to a melting point of + 150 ° C. .

  According to this structure, it can be set as the temperature which can sinter, maintaining an inorganic oxide particle in a non-molten state. Therefore, the influence of cracks and pores resulting from the rapid cooling of the liquid inorganic oxide particles can be suitably reduced. Moreover, in the film formed by the above-described forming method, it is possible to suitably suppress the possibility that the corrosion resistance and the mechanical characteristics are lowered.

In the method for forming the film,
The particle diameter of the inorganic oxide particles before heating can be 10 to 1000 nm.

  When the particle diameter is 1000 nm or less, the voids between the grains depending on the particle diameter can be reduced. Therefore, it is possible to reduce the influence of cracks and pores generated in the film due to the voids between the grains. When the particle diameter is 10 nm or more, aggregation of the inorganic oxide particles can be suppressed.

In the method for forming the film,
The resin composition may contain 10 to 60% by volume of the inorganic oxide particles.

If it is 10 volume% or more, since the inorganic oxide particles can be contained at a high concentration in the resin composition, the film forming rate on the substrate can be improved.
If it is 60 volume% or less, the possibility that the dispersibility of the inorganic oxide particles in the resin composition may be suppressed can be suppressed.

In the method for forming the film,
The inorganic oxide particles may be aluminum oxide particles.

  According to such a configuration, the phase transition of the crystal phase of the inorganic oxide particles can be more preferably suppressed before and after film formation. Therefore, in the film formed by the above method, it is possible to more suitably suppress the possibility that the corrosion resistance and the mechanical properties are lowered.

The film according to the present invention is
Using the resin composition in which the inorganic oxide particles are dispersed in the resin, the inorganic oxide particles are heated while maintaining the non-molten state by burning the resin, and the inorganic oxide particles are in the non-molten state And spraying onto the surface to be treated of the base material, and sintering the inorganic oxide particles on the base material.

According to such a configuration, since it is possible to form a film in which inorganic oxide particles in a non-molten state are deposited on a substrate, there are few cracks and pores generated due to rapid cooling of the liquid inorganic oxide particles. Become.
Moreover, since the aggregation of the inorganic oxide particles can be suppressed by dispersing the inorganic oxide particles in the resin, the influence of cracks and pores depending on the voids between the particles is reduced.
In addition, since non-molten inorganic oxide particles are used, there is little risk of phase transition of the crystalline phase of the inorganic oxide particles before and after film formation. Therefore, the film can be excellent in corrosion resistance and mechanical properties.

  As described above, according to the present invention, there are provided a film for forming a film containing inorganic oxide particles with few cracks and pores and less risk of deterioration in corrosion resistance and mechanical properties, and a method for forming the film.

The flowchart of the formation method of the membrane | film | coat which concerns on one Embodiment of this invention. Sectional drawing which shows the spraying apparatus used for the heating process and spraying process of this embodiment. The graph which shows the relationship between the shear rate for every stirring time, and the shear stress of the resin composition which added the aluminum oxide particle so that it might become 40 volume% to the thermosetting acrylic resin. (A) is a graph when the resin composition is stirred for 5 minutes. (B) is a graph when the resin composition is stirred for 10 minutes. (C) is a graph when the resin composition is stirred for 15 minutes. The graph which shows the relationship between the shear rate and the shear stress of each resin composition which added the aluminum oxide particle to the thermosetting acrylic resin so that it might become 20-40 volume%. The figure which shows the measurement result of the temperature of the surface of an aluminum oxide particle, and the spraying speed of an aluminum oxide particle. The figure which imaged the surface of the aluminum oxide particle collected on the water board. The figure which imaged the membrane | film | coat formed on the base material. (A) is the figure which imaged the membrane | film | coat formed by the method of this invention. (B) is the figure which imaged the membrane | film | coat formed by plasma spraying. The figure which shows the measurement result by a powder X ray diffraction method about the membrane | film | coat formed on the base material. (A) is a figure which shows the measurement result of the membrane | film | coat formed by the formation method of the membrane | film | coat of this invention. (B) is a figure which shows the measurement result of the membrane | film | coat formed by plasma spraying.

  First, the film | membrane which concerns on one Embodiment of this invention is demonstrated. The coating according to this embodiment uses a resin composition in which inorganic oxide particles are dispersed in a resin, and burns the resin to heat the inorganic oxide particles while maintaining a non-molten state. The inorganic oxide particles are sprayed onto the surface to be treated of the base material in a non-molten state, and the inorganic oxide particles are sintered on the base material. In other words, the film according to the present embodiment is formed having a layer formed by sintering the inorganic oxide particles on the base material. As used herein, “non-molten state” means that the inorganic oxide particles maintain a solid state, or only the surface portion of the inorganic oxide particles is melted to such an extent that the particle state can be maintained. Means state. Since the coating according to the present embodiment is a coating in which inorganic oxide particles in a non-molten state are deposited on a substrate, the effect of cracks and pores caused by rapid cooling of the liquid inorganic oxide particles is small It is. Moreover, since the aggregation of the inorganic oxide particles can be suppressed by dispersing the inorganic oxide particles in the resin, the influence of cracks and pores depending on the voids between the grains is small. Furthermore, since there is little possibility that the crystal phase of the inorganic oxide particles undergo phase transition before and after film formation, the corrosion resistance and mechanical properties can be excellent.

Examples of the inorganic oxide particles include aluminum oxide particles (alumina, Al ₂ O ₃ ), zirconium dioxide particles (zirconia, ZrO ₂ ), titanium oxide (titania, TiO ₂ ), and a mixed material of alumina and zirconia. And alumina zirconia particles (Al ₂ O ₃ / ZrO ₂ ) obtained by melting and solidifying alumina and zirconia raw materials, alumina titania (Al ₂ O ₃ / TiO ₂ ), and the like. Among these, it is preferable to use aluminum oxide particles. If it is an aluminum oxide particle, the phase transition of the said crystal phase can be suppressed more appropriately before and after film formation, and the corrosion resistance and mechanical properties of the film can be excellent. The aluminum oxide particles preferably have an α phase. This is because it is superior in corrosion resistance and mechanical properties than the γ phase.

  The particle diameter of the inorganic oxide particles is preferably in the range of 10 to 1000 nm. If it is 1000 nm or less, the influence of cracks and pores generated in the film due to the intergranular voids can be reduced, and if it is 10 nm or more, aggregation of the inorganic oxide particles can be suppressed. The particle diameter of the inorganic oxide particles is more preferably in the range of 150 to 190 nm. The particle diameter of the inorganic oxide particles is measured with a scanning electron microscope (SEM) before heating. Specifically, using an image taken with a scanning electron microscope, the particle diameter of 100 arbitrary particles in the image is measured, and the average value is calculated.

  The material of the substrate is not particularly limited. Various conventionally known materials made of SUS, ceramics, plastics and the like can be used.

  Next, a film forming method according to this embodiment will be described with reference to FIGS. 1 and 2.

  The film forming method according to the present embodiment is a film forming method for forming a film containing inorganic oxide particles on a substrate, and heating the inorganic oxide particles while maintaining the non-molten state. And the step of spraying the inorganic oxide particles heated in the heating step onto the surface to be treated of the base material in a non-molten state, and the inorganic oxidation sprayed on the surface to be treated of the base material in the spraying step And forming a film of the inorganic oxide particles on the base material by sintering product particles on the base material, and in the heating step, as a raw material of the inorganic oxide particles Using the resin composition in which the inorganic oxide particles are dispersed in a resin, the inorganic oxide particles are heated by burning the resin.

(Heating process)
In this step, the inorganic oxide particles are heated at a temperature at which a non-molten state can be maintained. The heating of the inorganic oxide particles is performed by bringing the inorganic oxide particles into contact with a combustion flame generated when a mixed gas (for example, oxygen-acetylene gas) of a combustible gas and an auxiliary combustion gas is burned. To do. Preferably, the heating of the inorganic oxide particles is performed at a temperature in a range where the temperature of the surface of the inorganic oxide particles becomes a melting point −150 ° C. to a melting point + 150 ° C. When the heating of the inorganic oxide particles is performed at a temperature in the above range, the inorganic oxide particles can be set to a temperature at which sintering is possible while maintaining the non-molten state. Thereby, the influence of the cracks and pores resulting from the rapid cooling of the liquid inorganic oxide particles can be suitably reduced, and the possibility that the corrosion resistance and mechanical properties are lowered can be suitably suppressed.
The temperature of the surface of the inorganic oxide particles can be obtained by measuring the infrared intensity emitted from the inorganic oxide particles when contacting the combustion flame and converting the measured infrared intensity into temperature. it can.

In this step, a resin composition in which the inorganic oxide particles are dispersed in a resin is used as a raw material for the inorganic oxide particles, and the inorganic oxide particles are heated by burning the resin. Thereby, since aggregation of the said inorganic oxide particle can be suppressed, the influence of the crack depending on the space | gap between grains and a pore can be decreased.
The resin is not particularly limited as long as it has a viscosity capable of maintaining the dispersed state of the inorganic oxide particles. The resin composition may be in the form of a cured product obtained by curing the inorganic oxide particles in a dispersed state. In this case, the resin is preferably a thermosetting resin. For example, it is preferable to use various resins such as a thermosetting acrylic resin, an epoxy resin, a phenol resin, a urea resin, and a melamine resin. By using a cured material having no fluidity as the resin composition, it is possible to prevent the raw material from flowing down before spraying as in the case of the SPS method, and the film formation efficiency is improved.

  As for the heating conditions (heating temperature and heating time) when the resin composition is made into the cured body, refer to the type of the resin and select a condition that does not cause large shrinkage or cracking in the resin composition during curing. Can be set as appropriate. The hardened body may be molded into a rod shape or the like. In addition, in the said hardening body, the said inorganic oxide particle is maintaining the dispersed state.

  The resin composition preferably contains 10 to 60% by volume of the inorganic oxide particles. If it is 10 volume% or more, since the said inorganic oxide particle can be contained in the said resin composition by high concentration, the film-forming speed | rate on a base material can be improved. If it is 60 volume% or less, the possibility that the dispersibility of the inorganic oxide particles in the resin composition may be suppressed can be suppressed. More preferably, the resin composition contains 20 to 40% by volume of the inorganic oxide particles. The inorganic oxide particles are blended in the resin composition at a predetermined ratio. The volume of the inorganic oxide particles is obtained by measuring the mass of the inorganic oxide particles blended in the resin composition and dividing the measured mass of the inorganic oxide particles by the density of the inorganic oxide particles. Ask.

  The resin composition is prepared, for example, using a rotation / revolution stirrer. The rotation and revolution stirrer includes a container that accommodates the inorganic oxide particles and the resin, and a stirring unit that can be fitted with the container and rotates and revolves the loaded container. The rotation / revolution stirrer is configured to defoam air in the resin by centrifugal force generated by revolving motion (planetary motion) of the container, and rotate the container to rotate the inorganic oxide in the container. Mix the particles and the resin. That is, the rotation and revolution stirring device can perform both the defoaming of the air in the resin and the mixing of the inorganic oxide particles and the resin at the same time by performing both the rotation motion and the revolution motion. The operating conditions such as rotation speed, rotation speed, and operation time of the rotation / revolution stirrer are appropriately determined according to the kind of the inorganic oxide particles and the resin, the concentration of the inorganic oxide particles in the resin composition, and the like. Can be set.

(Blowing process)
In this step, for example, the inorganic oxide particles are accelerated toward the surface to be processed of the substrate by the pressure generated when the combustion flame is ejected, and sprayed on the surface to be processed of the substrate. That is, while the inorganic oxide particles are heated by the combustion flame and maintained in a non-molten state, the inorganic oxide particles are sprayed onto the surface to be treated of the substrate by the pressure generated when the combustion flame is ejected.

  The said heating process and the said spraying process can be performed using the spraying apparatus 10 as shown in FIG. Below, the direction which approaches the base material 20 is made into the front, and the direction which leaves | separates from the base material 20 is made into back, and the structure of the spraying apparatus 10 is demonstrated. In the present embodiment, an example in which inorganic oxide particles dispersed in a resin rod 30 formed by molding is used as a spraying raw material used in the spraying apparatus 10 will be described.

  As shown in FIG. 2, the spraying device 10 includes a housing portion 11 that houses the resin rod 30 therein, and the resin rod 30 is supplied from the housing portion 11 to the inside, and the supplied resin rod 30 is heated by a combustion flame. And a heating / spouting part 12 for bringing the inorganic oxide particles into contact with the combustion flame and ejecting the inorganic oxide particles. The inside of the accommodating part 11 and the inside of the heating / spouting part 12 are arranged linearly and communicate with each other. In detail, the accommodating part 11 is comprised so that the resin rod 30 may be accommodated in the inside, and the resin rod 30 may be sequentially sent out toward the heating / spouting part 12. The heating / spouting unit 12 is configured to heat the inorganic oxide particles while burning the resin of the resin rod 30 sequentially delivered from the housing unit 11 and to eject the heated inorganic oxide particles. The accommodating part 11 and the heating / spouting part 12 are formed in a hollow cylindrical shape, and are arranged so that the respective central axes coincide with each other. The front end side of the accommodating portion 11 is connected to the rear end side of the heating / spouting portion 12. An opening 12 ′ for ejecting inorganic oxide particles as a raw material is formed at the front end of the heating / ejection section 12. The spraying device 10 is arranged such that the opening 12 ′ faces the surface to be processed of the base material 20 and the opening 12 ′ is spaced from the surface to be processed of the base material 20 by a predetermined distance.

  The accommodating portion 11 includes a rod delivery portion 11 a for sequentially delivering the resin rods 30 accommodated therein toward the heating / spouting portion 12. The heating / spouting unit 12 heats the inorganic oxide particles by burning the resin of the resin rod 30 and generates a mixed gas (combustible gas and combustible gas) that generates a combustion flame for ejecting the heated inorganic oxide particles. Mixing gas with gas (for example, oxygen-acetylene gas) 12A for supplying gas, and compression for accelerating the inorganic oxide particles heated by the combustion flame and cooling the heating / jetting part 12 And a compressed air supply unit 12b for supplying air.

  The rod delivery part 11a includes a pair of roller parts 11aa and 11ab arranged at a predetermined interval at a position symmetrical with respect to the central axis. Between the roller portion 11aa and the roller portion 11ab, a resin rod 30 is loaded so as to come into contact with both the rollers 11aa and 11ab, and by rotating the roller portions 11aa and 11ab, the resin is applied to the heating / spouting portion 12. The rods 30 are sent out sequentially. The feeding speed of the resin rod 30 can be appropriately set according to the target film forming speed and the like.

The mixed gas supply unit 12a is arranged to supply a mixed gas toward the front end side. For example, it is formed in a cylindrical shape and is arranged along the central axis direction at the center of the heating / spouting portion 12. The mixed gas supplied to the front end side is burned to generate a combustion flame. At the center of the mixed gas supply unit 12a, a path for receiving the resin rod 30 and sending the resin rod 30 to the front end side of the mixed gas supply unit 12a is formed. This path communicates with the inside of the accommodating portion 11 in a straight line.
The compressed air supply unit 12b is provided outside the mixed gas supply unit 12a, and supplies compressed air toward the front end side. The supply speed of the compressed air can be appropriately set according to the target film formation speed or the like.

  In the spraying device 10, the resin rods 30 loaded in the storage chamber 11 are sequentially sent out toward the heating / spouting unit 12 by the rod feed-out unit 11 a and are sequentially fed out to the front end side of the heating / spouting unit 12. The resin rod 30 delivered to the front end side of the heating / spouting unit 12 comes into contact with the combustion flame blown out from the front end edge of the mixed gas supply unit 12a. As a result, the resin is burned out, and the inorganic oxide particles are heated in contact with the combustion flame. The inorganic oxide particles are accelerated by the combustion flame and compressed air, and sprayed toward the surface to be treated of the substrate 20 through the opening 13 ′.

(Film formation process)
In the film forming step, the inorganic oxide particles are made to collide with the surface to be treated of the substrate 20 and sintered on the substrate 20. As a result, a film of the inorganic oxide particles is formed on the substrate 20.
In addition, in the spraying apparatus 10, the heating / spouting part 12 heated by the combustion flame is cooled by the compressed air.

  As described above, according to the method for forming a film according to the present embodiment, the film is formed on the base material using the inorganic oxide particles in a non-molten state, which is caused by the rapid cooling of the liquid inorganic oxide particles. Can reduce the effects of cracks and pores. Moreover, since the inorganic oxide particles can be prevented from aggregating by dispersing the inorganic oxide particles in the resin, the influence of cracks and pores depending on the intergranular voids can be reduced. In addition, since non-molten inorganic oxide particles are used, there is little risk of phase transition of the crystalline phase of the inorganic oxide particles before and after film formation. Therefore, the film formed by the film forming method is less likely to be deteriorated in corrosion resistance and mechanical properties.

  Hereinafter, the present invention will be described in more detail with reference to examples. The following examples are intended to illustrate the invention in more detail and are not intended to limit the scope of the invention.

(Evaluation of fluid properties of resin composition)
Thermosetting acrylic resin (manufactured by JSR, product name: KC1278) and aluminum oxide particles having an α-phase average particle diameter of 170 nm (manufactured by Daimei Chemical Co., Ltd., product name: TM-DAR) are 40% by volume. Added as follows. Using a rotation and revolution stirring device (product name: SK-350T, manufactured by Photochemical Co., Ltd.), the resin composition containing the aluminum oxide particles and the thermosetting acrylic resin is stirred while defoaming, and stirring time is obtained. Every time (5 minutes, 10 minutes, 15 minutes), the fluid properties of the resin composition were evaluated. The evaluation of fluid characteristics was performed by examining changes in the value of the shear stress when the value of the shear rate was changed using a viscosity-viscoelasticity measuring device (manufactured by BROOKFIELD, product name: MRVT115). Specifically, after increasing the value of the shear rate continuously for the resin composition, the change in the value of the shear stress when the value was continuously decreased was examined.
The operating conditions of the rotation / revolution stirring apparatus were set so that the rotation speed was 700 rpm, the rotation speed was 300 rpm, and the stirring time was 15 minutes.
The average particle diameter of the aluminum oxide particles was measured with a scanning electron microscope (SEM). Specifically, using an image taken with a scanning electron microscope, the particle diameter of 100 arbitrary particles in the image was measured, and the average value was calculated. The aluminum oxide particles were blended in the resin composition at a predetermined ratio. The volume of the aluminum oxide particles is determined by measuring the mass of the aluminum oxide particles blended in the resin composition, and the measured mass of the aluminum oxide particles is the density of the aluminum oxide particles (3.9 g / cm ^3). ) The results of evaluating the fluid properties of the resin composition for each stirring time are shown in FIG.

When the stirring time was 5 minutes, it was found that a linear curve close to the Newtonian fluid was drawn as shown in FIG. When such a curve is drawn, the aluminum oxide particles are hardly dispersed in the thermosetting acrylic resin. When the stirring time was 10 minutes, it was found that the drawn curve showed a hysteresis loop as shown in FIG. When such a curve is drawn, the aluminum oxide particles are in a slightly dispersed state in the thermosetting acrylic resin. When the stirring time is 15 minutes, as shown in FIG. 3 (c), when the shear rate value is continuously increased, the shearing is performed at a certain shear rate value (A in FIG. 3 (c)). When the stress value is decreased and the shear rate value is continuously decreased, the shear stress when the shear rate is continuously increased at a certain shear rate value (B in FIG. 3C). It was found that the value of and the value of the shear stress when the shear rate was continuously decreased were almost the same. This is because when the resin composition after stirring for 15 minutes is a soft plastic material such as mayonnaise and the value of the shear rate is continuously increased, the presence state of the resin composition is solid. Since the solid and liquid are mixed into a liquid state, and the liquid state is changed to a liquid state, the shear stress value decreases when the resin composition is in a liquid state, and the shear rate value is reduced. When the value is continuously decreased, the behavior is opposite to that described above, and therefore the resin composition is in a solid state at a certain shear rate (B in FIG. 3C). It is thought that it was because of it. The curve as shown in FIG. 3C is a curve drawn in the case of a soft plastic body exhibiting good thixotropy. In the soft plastic body, a solid medium is highly dispersed in a liquid medium. Yes.
From the above results, in the resin composition containing the aluminum oxide particles and the thermosetting acrylic resin, if the stirring time of the rotation and revolution stirring device is set to 15 minutes, the thermosetting acrylic resin It was found that the aluminum oxide particles were highly dispersed therein.

Next, the fluid characteristic was investigated about the several resin composition which changed the content rate (concentration) of the said aluminum oxide particle. The plurality of resin compositions are thermosetting acrylic resin (manufactured by JSR, product name: KC-1278), aluminum oxide particles having an α phase and an average particle diameter of 170 nm (manufactured by Daimei Chemical Co., Ltd., product name: TM-DAR) was added so as to be 20 and 30% by volume, respectively, and was prepared using the above-described rotation and revolution stirring apparatus. The operating conditions of the rotation and revolution stirrer were the same as described above, and the fluid characteristics were evaluated for each resin composition after 15 minutes of stirring time. The fluid property was determined by examining the change in the value of the shear stress when the value of the shear rate was changed using the above-described viscosity-viscoelasticity measuring device. The aluminum oxide particles were blended in the resin composition at a predetermined ratio. The volume of the aluminum oxide particles is determined by measuring the mass of the aluminum oxide particles blended in the resin composition, and the measured mass of the aluminum oxide particles is the density of the aluminum oxide particles (3.9 g / cm ^3). ) The results of evaluating the fluid characteristics of each resin composition are shown in FIG.

  As shown in FIG. 4, any resin composition has the same tendency as the curve drawn in the case of the resin composition obtained by adding 40% by volume of the aluminum oxide particles to the thermosetting acrylic resin. It turns out that the curve which shows is drawn. Therefore, it is found that the aluminum oxide particles are highly dispersed in the thermosetting acrylic resin even in a resin composition obtained by adding 20 and 30% by volume of the aluminum oxide particles to the thermosetting acrylic resin. It was.

(Formation of film)
As described above, a resin composition is produced by adding 40% by volume of the aluminum oxide particles to the thermosetting acrylic resin, and a brass mold (product name: mold, manufactured by Seiwa Machine Co., Ltd.) having an inner diameter of 4 mm and a height of 200 mm. ) Is filled with the resin composition, and the brass mold is heated at 120 ° C. for 60 minutes using an electric furnace (manufactured by Yamada Denki, product name: NF type muffle electric furnace MF-215-P). The composition was cured to produce a resin rod. Then, the resin rod is loaded along the central axis direction in the accommodating portion of the spraying apparatus (product name: rod gun manufactured by Toko Seiko Co., Ltd.) shown in FIG. 2, and the resin extends from the accommodating portion to the front end side of the heating / spouting portion. The rods are sequentially sent out, and the thermosetting acrylic resin is burned by bringing the resin rod into contact with a combustion flame generated by burning oxygen-acetylene gas at the front end side of the heating / spouting portion, and the aluminum oxide particles are burned. Heated. Then, the aluminum oxide particles are sprayed from the opening of the spraying device toward the surface to be treated of a 50 × 50 × 1 mm SUS304 stainless steel substrate (hereinafter referred to as SUS304 substrate) by a combustion flame and compressed air. Thus, a film of the aluminum oxide particles was formed on the surface to be treated of the SUS304 base material. The SUS304 base material was disposed at a position where the distance between the surface to be processed and the opening was 100 mm. The operating conditions of the spraying device were set as follows.

Operating conditions / Rod feed speed: 2.5 to 6.0 mm / s
・ Compressed air pressure: 3.0 to 6.0 kg / cm ²
・ Oxygen pressure: 6.0-8.0 kg / cm ²
Acetylene pressure: 1.0 to 2.6 kg / cm ²

Further, a thermal spray monitoring device is also used for the temperature of the surface of the aluminum oxide particles and the spraying speed of the aluminum oxide particles sprayed toward the SUS304 base material when the oxygen-acetylene gas comes into contact with the combustion flame generated by combustion. (Measured by Sulzer Metco, product name: Aculus spray-G3C). The surface temperature of the aluminum oxide particles was determined by measuring the intensity of infrared rays emitted from the aluminum oxide particles when contacted with the combustion flame and converting the measured infrared intensity into temperature.
Furthermore, in order to investigate the existence state of the aluminum oxide particles sprayed from the opening, a water plate formed in a cylindrical shape having a diameter of 500 mm × depth of 400 mm and containing water up to a depth of 200 mm is shown in FIG. Aluminum oxide particles sprayed from the spraying device were collected. Specifically, the water plate is arranged so that the water surface is located at a position spaced 550 mm from the opening of the spraying device, and the aluminum oxide particles are sprayed from the opening of the spraying device toward the water plate, The aluminum oxide particles were collected in the basin. The operating conditions of the spraying device were set to the same conditions as described above.

  FIG. 5 shows the result of measuring the temperature of the surface of the aluminum oxide particles and the spraying speed of the aluminum oxide when the thermal spray monitoring device is in contact with the combustion flame generated by burning the oxygen-acetylene gas. . In FIG. 5, a white portion extending in the horizontal direction in the drawing indicates a combustion flame generated by burning the oxy-acetylene gas, and among the four meters displayed at the bottom of the drawing, FIG. The second meter from the left inside shows the result of measuring the spraying speed of the aluminum oxide particles, and the third meter from the left in the figure shows the surface temperature of the aluminum oxide particles when contacting the combustion flame. The measurement results are shown. The thermal spray monitoring device measures the various parameters described above at the positions circled in the figure. From FIG. 5, it was found that the aluminum oxide particles were sprayed toward the SUS304 substrate at a spraying speed of 375 m / s, and the surface temperature of the aluminum oxide particles was 2080 ° C. Here, since the melting point of the aluminum oxide particles was 2055 ° C., it was found that the surface temperature of the aluminum oxide particles was almost the same as the melting point of the aluminum oxide particles. From this result, it was found that when the resin rod was burned by the combustion flame, the aluminum oxide particles were kept in a non-molten state.

FIG. 6 shows the result of imaging the aluminum oxide particles after burning the resin rod by the combustion flame. The aluminum oxide particles were imaged using a scanning electron microscope (manufactured by JEOL Ltd., product name 6010LA). Imaging conditions were as follows.

Imaging conditions / Acceleration voltage: 20 kV
・ Shooting magnification: 20,000 times

In the enlarged view of FIG. 6, lines defining the crystal surface indicate crystal grain boundaries, and granular portions (portions surrounded by white circles) indicate primary particles. As shown in FIG. 6, it was observed that crystal grain boundaries could be observed in the form of microbulks on the surface of the collected aluminum oxide particles, and primary particles remained on the surface of the aluminum oxide particles. . From this result, it was found that after burning the resin rod by the combustion flame, the aluminum oxide particles were bonded in a microbulk shape by sintering without being melted. That is, FIG. 6 confirmed that the aluminum oxide particles maintained in the non-molten state even after the resin rod was burned by the combustion flame. It was also found that the aluminum oxide particles collide with the treated surface of the base material in a sintered state.

FIG. 7A shows a result of imaging the film of the aluminum oxide particles formed on the surface of the SUS304 substrate by the method of the present invention. For comparison, FIG. 7B shows the plasma. The result of having imaged the film of the said aluminum oxide particle formed in the to-be-processed surface of the said SUS304 base material by thermal spraying was shown. Each aluminum oxide particle film shown in FIGS. 7A and 7B was imaged using a digital microscope (manufactured by Keyence Corporation, product name: VHX-1000). Imaging conditions were as follows.

Imaging conditions / magnification: 400 times / image mode: sharp mode / shutter speed: auto

For forming the film of the aluminum oxide particles in FIG. 7B, aluminum oxide particles having an α phase and an average particle diameter of 21.3 μm (manufactured by Kowa Abrasives Co., Ltd., product name: KCP-WA) were used. The average particle diameter of the aluminum oxide particles was measured by an electric resistance method.
Moreover, plasma spraying was performed under the following conditions using a thermal spraying apparatus (manufactured by Sulzer Metco, product name: 9 MB).

Conditions for plasma spraying ・ Primary gas: Argon, pressure 100 psi, flow rate 80 scfh
Secondary gas: hydrogen, pressure 80 psi, flow rate 15 scfh
・ Current: 500A
・ Voltage: 70V
・ Spraying distance: 120mm

7A and 7B, the portion shown in white on the lower side in the drawing is the SUS304 base material, and the portion laminated on the upper side in the drawing in the portion shown in white is the oxidation. The film of aluminum particles is shown. Moreover, the black portions in the aluminum oxide particle film indicate pores and cracks. From FIG. 7 (a), the film of the aluminum oxide particles formed on the treated surface of the SUS304 base material by the method of the present invention has almost no pores or cracks, and is formed densely. I understood. On the other hand, from FIG. 7B, it was found that pores and cracks were clearly confirmed in the film of the aluminum oxide particles formed on the treated surface of the SUS304 base material by plasma spraying.

FIG. 8 (a) shows the result of evaluating the film formed on the surface of the SUS304 base material by the method for forming a film of the present invention by the powder X-ray diffraction method.
The powder X-ray diffraction method was performed under the following conditions using a powder X-ray diffractometer (manufactured by Rigaku Corporation, product name: Ultimate IV).

Measurement conditions of powder X-ray diffraction method / X-ray: 40 kV / 40 mA
・ Divergent slit: 2/3 °
・ Divergent length restriction slit: 10mm
・ Scatter slit: 2/3 °
・ Reception slit: 0.3mm

FIG. 8B shows a general measurement result obtained by measuring a film formed by plasma spraying using aluminum oxide particles having an α phase by a powder X-ray diffraction method.
As shown in FIG. 8 (a), a peak derived from the α phase is prominently observed in the film formed by the film forming method of the present invention. As shown in FIG. 8 (b), the film is formed by plasma spraying. It was found that a peak derived from the γ phase was noticeable in the coated film. From this result, the film formed by plasma spraying undergoes a phase transition from the α phase to the γ phase before and after the film formation, but the film formed by the film forming method of the present invention has the α phase before and after the film formation. It was found that the phase was maintained.

  The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments and examples are for explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments and the examples but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

Claims (6)

A method of forming a film that forms a film containing inorganic oxide particles on a substrate,
A heating step of heating the inorganic oxide particles while maintaining the non-molten state;
A spraying step of spraying the inorganic oxide particles heated in the heating step onto the surface to be treated of the substrate in a non-molten state;
A film forming step of sintering the inorganic oxide particles sprayed on the treated surface of the base material in the spraying step on the base material to form a film of the inorganic oxide particles on the base material; Have
In the heating step, using the resin composition in which the inorganic oxide particles are dispersed in a resin as a raw material for the inorganic oxide particles, the inorganic oxide particles are heated by burning the resin.
Method for forming a film. In the heating step, the inorganic oxide particles are heated in contact with a flame, and the temperature of the surface of the inorganic oxide particles is a temperature ranging from a melting point of −150 ° C. to a melting point of + 150 ° C.,
The method for forming a film according to claim 1. The particle diameter of the inorganic oxide particles before heating is 10 to 1000 nm.
The method for forming a film according to claim 1 or 2. The resin composition contains 10 to 60% by volume of the inorganic oxide particles.
The method for forming a film according to any one of claims 1 to 3. The inorganic oxide particles are aluminum oxide particles.
The method for forming a film according to any one of claims 1 to 4.   Using the resin composition in which the inorganic oxide particles are dispersed in the resin, the inorganic oxide particles are heated while maintaining the non-molten state by burning the resin, and the inorganic oxide particles are in the non-molten state A film formed by spraying the surface to be treated of the substrate and sintering the inorganic oxide particles on the substrate.