JP6930051B2 - Coating tools and coating equipment - Google Patents

Description

The present invention relates to a coating tool mounted on a coating device called a roll coater, a coating die, a slot die, a coater die, or the like, and in particular, a coating tool tip portion that comes into contact with or approaches a material to be coated has corrosion resistance and wear resistance. The present invention relates to a coating tool made of cemented carbide and a coating device on which the coating tool is mounted.

Conventionally, a heat-sensitive film, a conductive film, a low-reflection conductive film, an ultraviolet ray blocking film, an electromagnetic wave blocking film, a protective film, a magnetic film, etc. have been applied to the surface of a material to be coated made of plastic, metal foil, paper, glass, etc. Coating is performed by a coating device, and in recent years, an electrode paste or the like of a secondary battery (for example, a lithium ion secondary battery) is coated by the coating device (Japanese Patent Laid-Open No. 2013-101838). Is also being done.
When applying the coating liquid to the surface of the material to be coated, a coating device equipped with a coating tool is used, and as a material constituting the coating tool, cemented carbide, stainless steel, or the like is mainly known. (For example, refer to JP-A-2004-261678, JP-A-2006-272204, JP-A-2014-200719, etc.).
When the coating tool is made of stainless steel, it can be manufactured at a relatively low cost (material cost, processing cost), is easy to process, and has excellent corrosion resistance. It has the disadvantages that it is inferior in wear resistance as compared with cemented carbide, it is difficult to produce sharp edges (burrs are likely to occur), and it is difficult to maintain its shape for a long period of time.
On the other hand, when cemented carbide is used as the constituent material of the coating tool, it has high hardness and excellent wear resistance, so that it is possible to obtain sharp edges, and it is possible to control the film thickness with high accuracy and liquid. Although it has the advantage of good cutting, it has the disadvantage of being inferior in corrosion resistance to stainless steel.
Therefore, some proposals have been made conventionally for the materials constituting the coating tools, particularly from the viewpoint of achieving both wear resistance and corrosion resistance.

For example, in Patent Document 1 and Patent Document 2, in a coating tool provided with a coating tip portion for coating a coating film, at least the coating tip portion of the coating tool is made of cemented carbide, and the cemented carbide is used. Contains 2 to 16% by weight of a bonding phase containing cobalt as a main component and a hard phase containing the remaining tungsten carbide as a main component, and the cemented carbide has a Rockwell hardness of 90.0 (HRA) on an A scale. ) Or more and 93.0 (HRA) or less, the hardness is expressed as X (unit: HRA), and the coercive force of the cemented carbide is expressed as Y (unit: Elstead). In addition, the coercive force Y and the hardness X of the cemented carbide maintain the relationship of 50X-4320> Y ≧ 35X-3035, or maintain the relationship of 60X-5100 ≧ Y ≧ 50X-4320. It has been proposed to improve the strength, hardness, toughness, abrasion resistance, and lubricity of cemented carbide by defining X and Y, and further, 75% by weight or more in the bonded phase is cobalt, and the balance is It has been proposed to improve corrosion resistance and abrasion resistance by using one or more of cemented carbide, chromium, vanadium, chromium carbide, vanadium carbide and the like as a bonding phase strengthening substance.

Patent Document 3 describes that in a coating tool in which the tip portion in contact with or close to the coated surface of the object to be coated is made of cemented carbide, the cemented carbide is used as a hard phase containing tungsten carbide as a main component, nickel and chromium carbide. By setting the nickel content to 10.0 to 20.0% by weight and the chromium carbide content to 1.0 to 7.0% by weight, the bonding phase containing A coating tool showing the above has been proposed. According to this coating tool, corrosion resistance can be improved, unevenness in the coating thickness of the magnetic paint can be prevented, and a stable and uniform thickness for a long period of time can be prevented. It is said that the magnetic paint can be applied.

Patent Document 4 describes, as a tungsten carbide-based sintered body used as an abrasion-resistant member of a coating tool head, a first phase containing tungsten carbide as a main component, and group 4 elements, group 5 elements, and group 6 elements. (Specifically, the "Group 4 element" means any of Ti, Zr and Hf, and the "Group 5 element" means any of V, Nb and Ta, and "Group 6 element". The "element" has a second phase containing a carbonitride of one or more elements selected from the group consisting of Cr, Mo, and W as a main component, and the second phase. A tungsten carbide-based sintered body in which the body integration ratio of the above is 0.5% by volume or more and 5% by volume or less and the balance is composed of the first phase is described, and in this sintered body, it is a second phase component. The carbonitride effectively suppresses the grain growth of tungsten carbide and forms a dense structure that does not contain coarsened particles, thereby improving chemical durability such as corrosion resistance in addition to mechanical strength. Has been proposed.
Further, in Patent Document 4, as a method for producing a tungsten carbide-based sintered body, tungsten carbide and a desired carbonitride powder are used as raw material powder, and the molded body is molded after mixing the mixture, and the molded body is, for example, 1500. It is described that sintering is performed at ~ 2000 ° C., and even if HIP (Hot Isostatic Pressing) treatment is performed in an inert atmosphere after sintering to remove pores in the sintered structure. It is said to be good.

Patent Document 5 describes that in a coating tool provided with a coating tip made of a super hard alloy, the super hard alloy at the coating tip is tungsten carbide or tungsten carbide, carbides of groups 4a, 5a, 6a in the periodic table, and charcoal. A hard phase of 82 to 98% by weight consisting of a nitride and at least one cubic structural compound selected from these mutual solid solutions, and a bonding phase of 2 to 18% by weight of a solid solution element dissolved in cobalt and / or nickel. The solid solution element contains Cr-V, Cr-C, VC, or Cr-VC as an essential element, and the total content of the essential element is the bond. Coating tools that are 1 to 15 wt% relative to the phase have been proposed.
More specifically, in the hard phase, 98% by weight or more of the hard phase is tungsten carbide, and the balance is carbides of Ti, Ta, Nb, carbonitride of Ti, and W-Ti, W-Ti-. It contains at least one cubic structure compound selected from the composite carbides of Ta, W-Ti-Nb, W-Ti-Ta-Nb, and composite carbonitrides, and the tungsten carbide and the cubic structure. A coating tool having a coating tip made of a cemented carbide in which a compound is uniformly dispersed has been proposed.
Then, by using the above coating tool, the optimum solid-dissolving element is solid-dissolved in the bonded phase, the particle size distribution of tungsten carbide is made uniform, and the tungsten carbide and the bonded phase are uniformly dispersed and uniformly mixed to bond. By eliminating the unevenness of the phase distribution, the strength, hardness, toughness, wear resistance, and lubricity are improved, and the impact resistance and microfracture resistance are improved. It is said that the corrosion resistance, wear resistance and lubricity against chemical corrosion and electrical corrosion caused by liquid can be significantly improved.

Japanese Patent No. 3029106 Japanese Unexamined Patent Publication No. 2000-233150 JP-A-2002-346456 Japanese Patent No. 5856752 Japanese Patent No. 3454423

As shown in Patent Documents 1 to 5, wear resistance and corrosion resistance are required as the characteristics of the coating tool, but in recent years, various coating liquids have been dealt with in response to diversifying coating liquids. However, there is an increasing demand for coating tools that are versatile and have both wear resistance and corrosion resistance.
Conventionally, when a coating tool made of cemented carbide is used for a coating liquid to which acid-based (hydrochloric acid, sulfuric acid, nitric acid, etc.) components are added, cobalt, which is the main component of the bonding phase, reacts with the coating liquid. , There is a phenomenon that it elutes in the coating liquid with redox. Then, as this phenomenon progresses, the holding force of the tungsten carbide, which is a hard phase component, weakens, and the tungsten carbide particles begin to fall off.
In order to deal with this, it is possible to obtain a certain degree of corrosion resistance by substituting nickel for the bonding phase component or adding chromium, which is expected to have a corrosion resistance, but corrosion progresses over time. After all, the life as a coating tool is short.

On the other hand, when stainless steel is used as a coating tool, chromium, which is a component of stainless steel, combines with oxygen in the air to form a passivation film, and this passivation film has a corrosion resistance effect at the initial stage. However, after the passivation film is destroyed, corrosion progresses at once. This phenomenon occurs not only in the case of an acidic coating liquid but also in a neutral to alkaline coating liquid, although the progress is gentle. Further, depending on the type of coating liquid, the required performance may be satisfied by the corrosion resistance effect of stainless steel, but as another problem, the big problem that the wear resistance of the coating tool is insufficient still remains. ing.

Further, when the coating liquid contains a hard component such as graphite or alumina, when the coating liquid continuously passes through the coating tool, the hard component contained in the coating liquid scrapes the coating tool. Graphite wear phenomenon (ablation wear) occurs. Then, as the ablation wear progresses, the original shape of the coating tool cannot be maintained, and as a result, the film thickness of the coated liquid varies, and there is a problem that a coating film having a desired thickness cannot be formed.
Since the occurrence of such a phenomenon can be suppressed by using a high-hardness material with excellent wear resistance, it is generally harder than stainless steel when the wear resistance of the coating tool is important. Cemented carbide is used.

An object of the present invention is to provide a versatile coating tool having excellent wear resistance and corrosion resistance against various coating liquids in order to solve the above-mentioned problems.

The present inventors have conducted diligent research to improve the corrosion resistance of the cemented carbide while maintaining the hardness (that is, wear resistance) of the cemented carbide constituting the tip of the coating tool. It has been found that it is effective to reduce the content of the bonded phase component (for example, Co, Ni, Fe) in the cemented carbide, which is the main factor, as much as possible.
Then, as a specific measure for reducing the bonded phase component in the cemented carbide, when producing the cemented carbide, a raw material powder for forming a bonded phase (for example, cobalt powder, nickel powder, iron powder) is particularly used. Without using, only tungsten carbide (hereinafter referred to as "WC") powder and titanium carbide (hereinafter referred to as "TiC") powder are used as the powder for forming the hard phase, and WC powder and TiC powder are used. It was stored in a stainless steel mixing container and mixed with an attritor using WC-Co cemented carbide or WC-Co-Ni cemented carbide as a medium to prepare a powder compact, and the compact was sintered. After that, when a cemented carbide was produced by subjecting a HIP treatment for densification of the sintered body, the contents of Co, Ni, and Fe, which are the bonding phase components of the cemented carbide, could be suppressed to an extremely low level (Co, A cemented carbide having WC and TiC as hard phases (hereinafter referred to as "WC-TiC cemented carbide") having a total content of Ni and Fe (less than 2.0% by mass) was prepared. Found to get.
Since this cemented carbide is subjected to HIP treatment after sintering, the densification of the sintered body progresses to a theoretical density of nearly 100%, so that the cemented carbide has a hardness not inferior to that of the conventional cemented carbide. It has been found to have excellent wear resistance.

Further, a solid solution of tungsten, titanium and carbon (hereinafter referred to as a solid solution of tungsten, titanium and carbon) can be used as a powder for forming a hard phase without using a raw material powder for forming a bonded phase (for example, cobalt powder, nickel powder, iron powder) for producing a cemented carbide. , "(W, Ti) C".) Using powder, this is mixed with the attritor to prepare a powder compact, which is sintered, and then subjected to HIP treatment to obtain a cemented carbide. As in the case of the WC-TiC cemented carbide, the content of Co, Ni, and Fe, which are the bonding phase components of the cemented carbide, can be suppressed to an extremely low value (the content of Co, Ni, Fe). A cemented carbide having (W, Ti) C as a hard phase (hereinafter referred to as "(W, Ti) C cemented carbide") is produced. I was able to.
The theoretical density of this (W, Ti) C cemented carbide can also be increased to nearly 100% as described above, and has hardness and wear resistance comparable to those of conventional cemented carbide. there were.

Further, when the corrosion resistance test was carried out on the WC-TiC cemented carbide and the (W, Ti) C cemented carbide prepared above, the content of Co, Ni and Fe which are the bonding phase components was determined by the conventional WC group. It was found that since the amount was suppressed to an extremely small amount as compared with the cemented carbide, it exhibited excellent corrosion resistance against a coating liquid (corrosive environment) of acidic to weak alkali (pH 1 to 9).

Further, it said WC-TiC cemented carbide and (W, Ti) for C cemented carbide as the raw material powder for the hard phase forming, further, carbide ceramic powder (e.g., VC, NbC, TaC, TaNbC , Cr 3 C 2 (E. When the alloy was prepared, it was possible to prepare a cemented carbide containing an additive component as a secondary hard phase.
Further, in the above cemented carbide containing the secondary hard phase, since the secondary hard phase improves the corrosion resistance and the oxidation resistance, the coating liquid (corrosive environment) of acidic to weak alkali (pH 1 to 9) is subjected to. It was found to show excellent corrosion resistance.

The present invention has been made based on the above findings.
"(1) In the coating tool mounted on the coating device,
At least the tip of the coating tool that comes into contact with or approaches the material to be coated is made of cemented carbide within 1 mm.
The cemented carbide has a bonded phase consisting of one or more selected from Co, Ni and Fe, and the balance is one or two selected from WC, TiC and W and Ti and C solid solutions. It is characterized in that the total content of Co, Ni, and Fe constituting the bonded phase, which is composed of the hard phase and unavoidable impurities as described above, accounts for less than 2.0% by mass in the entire cemented carbide. Coating tool.
(2) Described in (1), wherein the content ratio of W, which is a metal component in the hard phase, in the entire cemented carbide is 40% by mass or more and 80% by mass or less in the cemented carbide. Coating tool.
(3) For the cemented carbide, the diffraction peak intensity is measured by the X-ray diffraction method, and the count number corresponding to the top of the diffraction peak intensity in which the diffraction angle 2θ exists in the range of 40 ° to 43 ° is defined as Ia, and the diffraction angle 2θ is set. The number of counts corresponding to the top of the diffraction peak intensities existing in the range of 46 ° to 50 ° is determined as Ib, and the relationship of Ib / Ia ≦ 1 is satisfied, according to (1) or (2). Coating tool.
(4) The cemented carbide, VC, NbC, TaC, one or two or more carbide ceramic selected from among TaNbC and _Cr 3 _{C 2,} further characterized in that it contains as a hard phase (1) The coating tool according to any one of (3) to (3).
(5) The cemented carbide is any one of (1) to (4), further containing one or more kinds of nitrided ceramics selected from TiN, TaN and NbN as a hard phase. The coating tool described in.
(6) The coating tool according to any one of (1) to (5), wherein the portion other than the tip portion of the coating tool is made of stainless steel.
(7) The coating tool according to any one of (1) to (6), wherein the cemented carbide has a hardness of 89.0 HRA or more and 95.0 HRA or less on a Rockwell hardness A scale.
(8) A coating device equipped with the coating tool according to any one of (1) to (7) above. "
It is characterized by.

The coating tool of the present invention is composed of a cemented carbide at least within 1 mm at the tip of the coating tool that comes into contact with or approaches the material to be coated, and the cemented carbide is one or two selected from Co, Ni and Fe. The bond phase of more than one species and the balance consist of one or more hard phases selected from WC, TiC and (W, Ti) C and unavoidable impurities, and Co, Ni, Fe constituting the bonded phase. The total content of the cemented carbide is less than 2.0% by mass of the total cemented carbide, and the content ratio of the bonded phase in the cemented carbide is extremely small.
Therefore, the coating tool of the present invention exhibits excellent corrosion resistance against both acidic coating liquids and weakly alkaline coating liquids.
Further, the cemented carbide at the tip of the coating tool has a high hardness of 89.0 HRA or more and 95.0 HRA or less on the Rockwell hardness A scale, so that it has excellent wear resistance and is further contained in the coating liquid. It also has excellent ablation wear resistance against hard powder and the like.
Therefore, since the coating tool of the present invention has both corrosion resistance and wear resistance, it can be used as a versatile coating tool, and its life can be extended.

A schematic cross-sectional view seen from the side surface of the coating tool is shown. A schematic diagram of an attritor for mixing raw material powder is shown. The starting powder is W, TiO2, and graphite, and the treated powder is blended so that the mass ratio of WC: TiC is 70:30, and then the powder that has been subjected to solution heat treatment (2000 ° C) at the same time as carbonization is used as the raw material powder. The diffraction chart obtained by the X-ray diffraction method about the produced super hard alloy is shown. The starting powder is W, TiO2, and graphite, and the treated powder is blended so that the mass ratio of WC: TiC is 70:30, and then the powder that has been subjected to solution heat treatment (2200 ° C.) at the same time as carbonization is used as the raw material powder. The diffraction chart obtained by the X-ray diffraction method about the produced super hard alloy is shown. A diffraction chart obtained by an X-ray diffraction method is shown for a cemented carbide prepared as a raw material powder of a powder (powder not subjected to solution heat treatment) in which WC and TiC are mixed so as to have a mass ratio of 70:30. The transition of time (Hr) -weight change (wt /%) in the strong acid (hydrochloric acid of pH 1.8) immersion corrosion test is shown.

FIG. 1 shows a schematic cross-sectional view of the coating tool of the present invention. The coating tool of the present invention is mounted on the coating device with its tip in contact with or close to the material to be coated, and the tip of the coating tool is mounted on the coating device. The coating liquid is supplied and discharged from the portion to the surface of the material to be coated to form a coating film having a predetermined thickness on the surface of the material to be coated.
The tip of the coating tool within 1 mm is made of at least cemented carbide, but the other parts of the coating tool can be made of stainless steel.

The cemented carbide at the tip of the coating tool is selected from one or more bonded phases selected from Co, Ni and Fe, and the rest is selected from WC, TiC and (W, Ti) C. It consists of one or more hard phases and unavoidable impurities.
The unavoidable impurity is an impurity component at the ppm level that is unavoidably mixed from the raw material powder or the manufacturing process, and is, for example, O, S, P, Cu, or the like.
The total content of Co, Ni, and Fe constituting the bonded phase is less than 2.0% by mass of the total cemented carbide, while one selected from WC, TiC and (W, Ti) C or The hard phase composed of two or more kinds occupies approximately 98.0% by mass or more and 99.9% by mass or less of the entire cemented carbide.

In the conventional production of general cemented carbide, a hard phase forming powder (for example, WC powder) and a bonded phase forming powder (for example, Co powder) are mixed as a raw material powder, and this is sintered. Although a sintered body is produced, the cemented carbide of the present invention does not positively contain so-called bonded phase components Co, Ni, and Fe as raw material powders in the production thereof.
However, in the cemented carbide manufacturing process, when the raw material powder is mixed with an attritor as shown in FIG. 2, WC-Co cemented carbide or WC-Co-Ni cemented carbide is used as the mixing medium. Further, since the stirring part at the time of mixing is made of WC-Co cemented carbide and the mixing container is made of stainless steel, the produced cemented carbide has Co, Ni, which are bonding phase components. Fe is contained in a trace amount.
Since the content of Co, Ni, and Fe, which are the components of the bonded phase, deteriorates the corrosion resistance of the cemented carbide, it is desirable that the content thereof is as small as possible, but the total content is less than 2.0% by mass. If so, the corrosion resistance of the cemented carbide will not be significantly reduced.
Therefore, in the cemented carbide of the present invention, the total content of the bonded phase components Co, Ni, and Fe is set to less than 2.0% by mass.
As a specific means for limiting the content of the bonded phase component in the cemented carbide to less than 2.0% by mass with respect to the entire cemented carbide, a mixing medium or a mixing container for mixing the raw material powder is used. It can be controlled by selecting a material such as, etc., and by adjusting the number of revolutions and the operating time as mixing conditions.
For example, when the raw material powder is mixed by the attritor shown in FIG. 2, WC-Co cemented carbide or WC-Co-Ni cemented carbide is used as the ball-shaped medium, and the stirring part is WC-Co cemented carbide. The mixing container is made of stainless steel, and by adjusting the respective materials and further adjusting the mixing rate and mixing time, Co, Ni, and Fe mixed (contained) in the raw material powder can be used. The amount, in other words, the content of the bonded phase in the cemented carbide, can be controlled.

However, even if the contents of the coupling phase components Co, Ni, and Fe are reduced as much as possible, it is practically very difficult to reduce the total content to less than 0.1% by mass. Therefore, the cemented carbide of the present invention contains the total content of Co, Ni, and Fe as the bonding phase component in an amount of 0.1% by mass or more and less than 2.0% by mass with respect to the entire cemented carbide. become.
Even if the total content of Co, Ni, and Fe is reduced to less than 0.1% by mass by some means to further improve the corrosion resistance, conversely, the cemented carbide is densified. This makes it impossible to achieve the problem, and defects (burrows) remain, so that the mechanical strength of the cemented carbide is significantly reduced.
Therefore, considering the characteristics (corrosion resistance, hardness, strength) required for cemented carbide used as a coating tool, the total content of Co, Ni, and Fe is intentionally reduced to less than 0.1% by mass. There is no need to reduce to.

The cemented carbide of the present invention is substantially, except for Co, Ni, and Fe contained as the bonded phase component (the total content thereof is 0.1% by mass or more and less than 2.0% by mass). In addition, since it is a cemented carbide composed of one or more hard phases selected from WC, TiC and (W, Ti) C, the content of the hard phase is almost the same as that of the whole cemented carbide. It is 98.0% by mass or more and 99.9% by mass or less.
In the cemented carbide of the present invention, it is unavoidable to mix a small amount of raw material powder or unavoidable impurities such as O, S, P, and Cu that are inevitably mixed in from the manufacturing process, but these are at the ppm level. Since it is a very small amount, it does not significantly affect the properties of cemented carbide (for example, hardness, corrosion resistance, etc.).

In the cemented carbide of the present invention, the content ratio of W, which is a metal component in the hard phase, in the entire cemented carbide is preferably 40% by mass or more and 80% by mass or less.
This is because if the W content is less than 40% by mass, the wettability with the bonded phase component deteriorates, so that densification at the time of sintering becomes difficult to proceed, and conversely, the W content If the amount exceeds 80% by mass, the cemented carbide will be discolored when used as a coating tool for applying a negative electrode slurry for a lithium ion secondary battery, for example.

As shown in FIGS. 3 and 4, when the diffraction peak intensity of the cemented carbide of the present invention is determined by the X-ray diffraction method, it corresponds to the top of the diffraction peak intensity at which the diffraction angle 2θ is located at 40 ° to 43 °. When the count number is Ia and the count number corresponding to the top of the diffraction peak intensity where the diffraction angle 2θ is located at 46 ° to 50 ° is determined as Ib, it is preferable to satisfy the relationship of Ib / Ia ≦ 1.
This is because when Ib / Ia> 1, when the powder compact is sintered, it becomes difficult for the sintered body to be densified, and even if the HIP treatment is applied, the product has defects (cavities). This is because it remains and the hardness and wear resistance are lowered.
It is more preferable to satisfy the relationship of Ib / Ia ≦ 0.5.

For example, in FIG. 3, the start powder is W, TiO2, and graphite, and the treated powder is blended so that the mass ratio of WC: TiC is 70:30, and then solidification heat treatment (2000 ° C.) is performed at the same time as carbonization. A diffraction chart obtained by an X-ray diffraction method for a super hard alloy subjected to HIP treatment after producing a sintered body using the resulting powder as a raw material powder has a diffraction angle of 2θ = 40 ° to 43 °. A (W, Ti) C or TiC diffraction line (the number of counts at the top of the peak intensity is Ia) is observed at the position, and a WC diffraction line (peak) is observed at a diffraction angle of 2θ = 46 ° to 50 °. As for the count number corresponding to the top of the intensity, Ib) is observed, and moreover, Ib / Ia ≦ 1 (Ib / Ia ≦ 0.5) is satisfied.

Further, in FIG. 4, the start powder is W, TiO2, and graphite, and the treated powder is blended so that the mass ratio of WC: TiC is 70:30, and then solidification heat treatment (2200 ° C.) is performed at the same time as carbonization. A diffraction chart obtained by an X-ray diffraction method for a super hard alloy subjected to HIP treatment after producing a sintered body using the resulting powder as a raw material powder has a diffraction angle of 2θ = 40 ° to 43 °. A (W, Ti) C or TiC diffraction line (the count number corresponding to the top of the peak intensity is Ia) is observed at the position, but a WC diffraction line is observed at the position where the diffraction angle is 2θ = 46 ° to 50 °. Since it is not observed (the count number Ib ≈ 0 cps, which corresponds to the top of the peak intensity), Ib / Ia ≦ 1 (Ib / Ia ≦ 0.5) is satisfied.

On the other hand, in FIG. 5, a sintered body is prepared by using a powder (powder not subjected to solidification heat treatment) in which WC powder and TiC powder are simply mixed so as to have a mass ratio of 99: 1 as a raw material powder, and then a sintered body is prepared. It is a diffraction chart obtained by the X-ray diffraction method for the HIP-treated superhard alloy. At the position of the diffraction angle 2θ = 46 ° to 50 °, the WC diffraction line (the number of counts corresponding to the top of the peak intensity is While Ib) is observed, the diffraction line of (W, Ti) C or TiC at the position of the diffraction angle 2θ = 40 ° to 43 ° is not observed (count number Ia ≈ 0 cps corresponding to the top of the peak intensity), so Ib / Ia ≦ 1 and Ib / Ia ≦ 0.5 are not satisfied.

As is clear from the description of FIGS. 3 to 5, in order to satisfy the relationship of Ib / Ia ≦ 1, or preferably, in order to satisfy the relationship of Ib / Ia ≦ 0.5. It is desirable to use a solution heat-treated powder that has been subjected to a solution heat treatment as a raw material powder for cemented carbide.
Here, the "powder subjected to the solid solution heat treatment" is not only a powder composed of only the total solution of W, Ti and C, but also a mixture of the total solution of W, Ti and C and WC and TiC. (In particular, it is preferable to satisfy the relationship of peak intensity ratio Ib / Ia ≦ 1 in X-ray diffraction).

Cemented carbide of the present invention, in addition to the hard phase, VC, NbC, TaC, one or two or more carbide ceramic selected from among TaNbC and _Cr 3 _{C 2,} further comprising as a secondary hard phase By doing so, the corrosion resistance and oxidation resistance of the cemented carbide can be further improved, and one or more kinds of nitrided ceramics selected from TiN, TaN and NbN are further contained as the secondary hard phase. Thereby, the corrosion resistance and the oxidation resistance of the cemented carbide can be further improved.
The total content of the hard phase composed of WC, TiC, and (W, Ti) C and the secondary hard phase is approximately 98.0% by mass or more and 99.9% by mass or less of the entire cemented carbide.

In the coating tool of the present invention, the tip portion of the coating tool, which is required to have wear resistance as well as corrosion resistance, is made of the cemented carbide, and the portion other than the tip portion is not strongly required to have wear resistance. , It may be made of stainless steel having excellent corrosion resistance.

In order to ensure wear resistance, it is desirable that the cemented carbide constituting the tip of the coating tool has a hardness of 89.0 or more and 95.0 HRA or less on the Rockwell hardness A scale.
This is because if the hardness of the cemented carbide is less than 89.0 HRA on the Rockwell hardness A scale, sufficient wear resistance cannot be ensured, while if the hardness exceeds 95.0 HRA, the coating tool This is because minute damage and minute defects are likely to occur at the tip of the surface.

The super hard alloy of the present invention does not use a bonded phase forming powder such as Co, Ni, Fe as a raw material powder for sintering, and is a hard phase forming raw material powder such as WC powder, TiC powder or solution heat treatment. It can be produced by using a powder or a raw material powder for forming a secondary hard phase.
For example, when a solution heat-treated powder is used as the raw material powder for forming a hard phase, it can be produced by the following steps.
(1) First, W powder, TiO ₂ powder, and graphite powder are mixed at a predetermined mixing ratio (for example, WC powder after carbonization: TiC powder = 40: 60 to 80:20 (however, mass ratio)). The powder is mixed and subjected to solution heat treatment and carbonization at 2000 ° C. at the same time to prepare a solution heat treatment powder.
(2) The solution heat-treated powder prepared above is used as a raw material powder for forming a hard phase, and is mixed with alcohol without using a powder for forming a bonded phase consisting of Co, Ni, and Fe, and the attritor shown in FIG. Wet mixing is performed by.
At that time, for example, WC-30 mass% Co cemented carbide was used as a ball-shaped medium having a diameter of 1.0 mm, the stirring part was WC-10 mass% Co cemented carbide, and the mixing container was made of stainless steel. Mix for a predetermined time in a container at a predetermined number of revolutions with a lighter.
(3) After mixing for a predetermined time, the mixed slurry of the solution heat-treated powder and alcohol is taken out, vacuum-dried, and then the solution heat-treated powder is recovered.
(4) By press molding, a green compact of (W, Ti) C powder is formed, sintered under the condition of vacuum sintering maximum reaching temperature of 1500 ° C., and then hot or the like under the condition of 1400 ° C. × 100 MPa. The sintered body is densified by performing a pressure pressurization treatment (HIP treatment).
By producing the cemented carbide in the steps (1) to (4) above, the total content of the bonded phases composed of Co, Ni and Fe is less than 2.0% by mass with respect to the entire cemented carbide. A cemented carbide can be produced, but when the cemented carbide thus produced is subjected to X-ray diffraction, for example, a diffraction pattern having the form shown in FIG. 3 can be obtained.
In the above step, the solid-dissolved heat-treated powder was used as the raw material powder for forming the hard phase because the sintered body was easily densified in the vacuum sintering and the HIP treatment, and a sintered body with few defects was obtained. Although it is easy, even when WC powder and TiC powder are used as the raw material powder for forming the hard phase, or when the raw material powder for forming the secondary hard phase is further added, Co, Ni, which are the bonding phase forming components, A cemented carbide having a total Fe content of less than 2.0% by mass based on the entire cemented carbide can be produced.

Hereinafter, the present invention will be described with reference to Examples.

[Example 1]
The start powder is W, TiO2, and graphite, and the treated powder is blended so that the mass ratio of WC: TiC is 70:30, and then the solution heat-treated powder is subjected to solution heat treatment (2200 ° C.) at the same time as carbonization. The powder was prepared (average particle size 1.2 μm), and this solution heat-treated powder was used as a raw material powder for forming a hard phase. This was mixed with an alcohol containing ethanol as a main component, and wet-mixed with an attritor.
At that time, as the mixed media, a ball-shaped WC-30 mass% Co cemented carbide media having a diameter of 1.0 mm was used. Further, a material made of WC-10 mass% Co cemented carbide was used for the stirring part in contact with the mixed media and the raw material. Further, as a container for mixing, a container made of SUS304 was used, and the mixture was mixed at a rotation speed of 120 rpm for 10 hours.

After mixing for 10 hours as described above, the raw material powder and alcohol were taken out, dried in a vacuum dryer, and then the solution heat-treated powder was recovered.
Then, a powder compact was formed at a unit pressure of 1 MPa with a hydraulic press, and this was sintered under the condition of a maximum ultimate temperature of 1500 ° C. for vacuum sintering.
Further, the sintered body produced above is densified by a hot isostatic pressing method (HIP) under the condition of 1400 ° C. × 100 MPa, and the cemented carbide 1 of the present invention (“the present invention” Invention 1 ") was produced.

The product 1 of the present invention was polished with a diamond grindstone so that the surface roughness was Ra 0.025 μm.
Then, the polished surface was observed using an electron probe microanalyzer (EPMA), qualitative analysis of the elements was performed using wavelength dispersive X-ray analysis (WDS), and quantitative analysis of the detected elements was performed.
The results are shown in Table 1.

[Example 2]
The start powder was W, TiO2, and graphite, and the treated powder was blended so that the mass ratio of WC: TiC was 80:20. (Average particle size 1.1 μm) Prepared as a raw material powder for forming a hard phase, and as a raw material powder for forming a secondary hard phase, TaC powder having an average particle size of 1.5 μm is 2.40% by mass of the total raw material powder. This is mixed with an alcohol containing ethanol as a main component, wet-mixed with an attritor under the same conditions as in Example 1, and thereafter, according to the same method as in Example 1, the present invention is prepared. A super hard alloy 2 (referred to as "the product 2 of the present invention") was produced.
Further, in the same manner as in Example 1, quantitative analysis of elements was performed on the product 2 of the present invention.
The results are shown in Table 1.

[Example 3]
The start powder was W, TiO2, and graphite, and the treated powder was blended so that the mass ratio of WC: TiC was 50:50. (Average particle size 1.5 μm) Prepared as a raw material powder for forming a hard phase, and as a raw material powder for forming a secondary hard phase, TaC powder having an average particle size of 1.5 μm and NbC powder having an average particle size of 1.0 μm. Was blended so that the respective contents were 1.5% by mass and 11.5% by mass of the total raw material powder, respectively, and this was mixed with an alcohol containing ethanol as a main component, and wet-mixed with an attritor. Was done. At that time, as the mixed media, a ball-shaped WC-15 mass% Co-20 mass% Ni cemented carbide media having a diameter of 1.0 mm was used. Further, a material made of WC-20 mass% Co cemented carbide was used for the stirring part in contact with the mixed media and the raw material. Further, as a container for mixing, a container made of SUS304 was used, and the mixture was mixed at a rotation speed of 120 rpm for 20 hours.
Then, cemented carbide 3 (referred to as “Product 3 of the present invention”) was produced under the same sintering conditions and HIP conditions as in Example 1.
Further, in the same manner as in Example 1, quantitative analysis of elements was performed on the product 3 of the present invention.
The results are shown in Table 1.

[Example 4]
The start powder was W, TiO2, and graphite, and the treated powder was blended so that the mass ratio of WC: TiC was 70:30. (Average particle size 1.2 μm) Prepared as a raw material powder for forming a hard phase, and as a raw material powder for forming a secondary hard phase, TaN powder having an average particle size of 1.5 μm and NbN powder having an average particle size of 1.1 μm. Was blended so that the respective contents were 2.5% by mass and 2.5% by mass of the total raw material powder, respectively, and this was mixed with an alcohol containing ethanol as a main component, and wet-mixed with an attritor. Was done. At that time, as the mixed media, a ball-shaped WC-20 mass% Co-10 mass% Ni cemented carbide media having a diameter of 1.0 mm was used. Further, a material made of WC-20 mass% Co cemented carbide was used for the stirring part in contact with the mixed media and the raw material. Further, as a container for mixing, a container made of SUS304 was used, and the mixture was mixed at a rotation speed of 120 rpm for 20 hours.
Then, cemented carbide 4 (referred to as “Product 4 of the present invention”) was produced under the same sintering conditions and HIP conditions as in Example 1.
Further, in the same manner as in Example 1, quantitative analysis of elements was performed on the product 4 of the present invention.
The results are shown in Table 1.

In Examples 1 to 4, none of the raw material powders for forming a bonded phase such as Co, Ni, and Fe are used as the raw material powder for producing the cemented carbide.
However, in Comparative Examples 1 to 4 described below, a cemented carbide composed of a hard phase and a bonded phase was produced using raw material powders for forming a bonded phase such as Co, Ni, and Fe.
Further, in all of Examples 1 to 4, after sintering, the sintered body was densified by the hot isostatic pressing method (HIP), but the comparative products 1 to 4 were also hot. The sintered body was densified by the isotropic pressing method (HIP).

[Comparative Example 1]
First, WC powder having an average particle size of 1.0 μm is used as a raw material powder for forming a hard phase, Co powder having an average particle size of 0.9 μm is used as a raw material powder for forming a bonded phase, and average particles are further used as a compound carbide. _{Using Cr 3} C ₂ powder having a diameter of 1.0 μm, WC powder, Co powder and Cr ₃ C ₂ powder are mixed so that the mass ratio of WC: Co: Cr ₃ C _{2 is 90:10: 1.} , Ethanol was mixed with alcohol containing ethanol as a main component, and wet mixing was carried out by the attritor shown in FIG.
At that time, as the mixed media, a ball-shaped WC-8 mass% Co cemented carbide media having a diameter of 1.0 mm was used. Further, a material made of WC-8 mass% Co cemented carbide was used for the stirring part in contact with the mixed media and the raw material. Further, as a container for mixing, a container made of SUS304 was used, and the mixture was mixed at a rotation speed of 120 rpm for 10 hours.

After mixing for 10 hours as described above, the raw material powder and alcohol were taken out, dried in a vacuum dryer, and then the mixed powder of _{WC powder, Co powder and Cr 3} C _{2 powder was recovered.}
Then, a pressure powder is formed at a unit pressure of 1 MPa with a hydraulic press device, and this is sintered under the condition of a maximum vacuum sintering temperature of 1500 ° C., and then the sintered body is subjected to a condition of 1400 ° C. × 100 MPa. The sintered body was densified by the hot isostatic pressing method (HIP) of the above, and a cemented carbide 1 (referred to as "comparative product 1") of Comparative Example was produced.

The above comparative product 1 was polished using a diamond grindstone so as to have a surface roughness Ra of 0.025 μm.
Then, the polished surface was observed using an electron probe microanalyzer (EPMA), qualitative analysis of the elements was performed using wavelength dispersive X-ray analysis (WDS), and quantitative analysis of the detected elements was performed.
The results are shown in Table 2.

[Comparative Example 2]
In Comparative Example 1, the blending ratio of the WC powder, the Co powder, and the Cr ₃ C ₂ powder was changed so that the mass ratio of WC: Co: Cr ₃ C ₂ was 189: 10: 1, and other steps were performed. Made a cemented carbide 2 (referred to as "Comparative Product 2") of Comparative Example by the same method as in Comparative Example 1.
Table 2 shows the results of the quantitative analysis investigated for the comparative product 2.

[Comparative Example 3]
A WC powder having an average particle size of 1.0 μm is used as a raw material powder for forming a hard phase, and a Ni powder having an average particle size of 0.8 μm is used as a raw material powder for forming a bonded phase. Using 1.0 μm Cr ₃ C ₂ powder, WC powder, Ni powder and Cr ₃ C ₂ powder are mixed so that the mass ratio of WC powder: Ni powder: Cr ₃ C ₂ powder is 187: 12: 1. Then, it was mixed with an alcohol containing ethanol as a main component, and wet-mixed with an attritor under the same conditions as in Comparative Example 1.
In other steps, the cemented carbide 3 of Comparative Example (referred to as “Comparative Product 3”) was produced in the same manner as in Comparative Example 1.
Table 2 shows the results of the quantitative analysis investigated for the comparative product 3.

[Comparative Example 4]
WC powder having an average particle size of 1.0 μm and TiC powder having an average particle size of 1.0 μm are used as raw material powders for forming a hard phase, and Co powder having an average particle size of 0.9 μm and an average particle size of 0. Using 8 μm Ni powder as a raw material powder for forming a bonded phase, and using Cr ₃ C ₂ powder having an average particle diameter of 1.0 μm as a compound carbide, (WC powder + TiC powder) and (Co powder + Ni powder + Cr ₃ C ₂₎ (Powder) is blended so that the mass ratio of (WC + TiC): (Co + Ni + Cr ₃ C ₂ ) is 88:12, mixed with alcohol containing ethanol as a main component, and attritor under the same conditions as in Comparative Example 1. Wet mixing was performed with.
In other steps, the cemented carbide 4 of Comparative Example (referred to as “Comparative Product 4”) was produced in the same manner as in Comparative Example 1.
Table 2 shows the results of the quantitative analysis investigated for the comparative product 4.

The Rockwell hardness A scale (HRA) measurement was performed on the products 1 to 4 of the present invention and the comparative products 1 to 4 produced above based on the Rockwell hardness hardness test-test method in accordance with JIS Z 2245.
Table 3 shows the measurement results.
From the results shown in Table 3, it can be seen that the products 1 to 4 of the present invention exhibit rockwell hardness comparable to that of the comparative products 1 to 4, and thus have wear resistance equivalent to that of the conventional cemented carbide.

Next, in addition to the products 1 to 4 of the present invention and the products 1 to 4 of the comparative products, for reference, three types of stainless steels (SUS304, SUS316L, SUS630) were used to carry out a corrosion test in a strong acid corrosive environment. Corrosion resistance was evaluated.
Corrosion test:
By immersing the test piece in a corrosive solution prepared by mixing hydrochloric acid and pure and adjusting the pH to 1.8 and measuring the weight of the test piece for each elapsed time, the weight change rate (wt /%) for each elapsed time. The one with a small rate of change in weight was judged to have good corrosion resistance.
Table 3 shows the rate of change in weight (wt /%) after 140 hours of immersion and after 400 hours of immersion.
In addition, "◎ mark" in the column of corrosion resistance evaluation of Table 3 indicates that the weight change rate (wt /%) is very small and has extremely excellent corrosion resistance, and "○ mark" is sufficiently satisfactory in corrosion resistance. It indicates that it is not a thing, and "x" indicates that the corrosion resistance is extremely inferior.
Further, FIG. 3 shows the transition of the weight change rate (wt /%) until 140 hours have passed after immersion as a graph (horizontal axis: immersion time (h), vertical axis: (wt /%)). ..

From the results shown in Table 3 and FIG. 6, the products 1 to 4 of the present invention were compared with the comparative products 1 to 4 and the three types of stainless steels (SUS304, SUS630) with respect to a strong acid (hydrochloric acid having a pH of 1.8). It can be seen that it has extremely excellent corrosion resistance.

Further, the products 1 to 4 of the present invention and the products 1 to 4 of the comparative products were subjected to a corrosion test on a negative electrode slurry for a lithium ion secondary battery.
The negative electrode slurry of the lithium ion secondary battery (weakly acidic to weakly alkaline with a pH of 5 to 9) is used as a corrosive liquid, and the test piece is half-bathed in the corrosive liquid. The presence or absence of discoloration in the appearance of the unimmersed portion was observed, and the quality of corrosion resistance was evaluated according to the degree of discoloration.
Here, the negative electrode slurry for the lithium ion secondary battery has the following composition.
AB (acetylene black): 1%,
SBR (Styrene-butadiene rubber): 1%,
CMC (Carboxymethyl Cellulose): 1%,
Graphite: 97%,
Solvent: Water The SBR (styrene-butadiene rubber) is a type of synthetic rubber, which is a copolymer of a hydrocarbon in which one of the hydrogen atoms of benzene is replaced with a vinyl group and an unsaturated hydrocarbon, and is a CMC (carboxymethyl cellulose). ) Is a carboxymethyl group bonded to a part of the hydrocarbon group of the glucopyranose monomer constituting the skeleton of cellulose.
Table 3 shows the presence or absence of discoloration after 24 hours and the presence or absence of discoloration after 400 hours as the results of the corrosion resistance test.
In the corrosion resistance evaluation column of Table 3, "◎ mark" indicates that the discoloration resistance is very excellent, "○ mark" indicates that surface turbidity is generated, and "x mark" indicates that surface turbidity is generated. Indicates inferior discoloration.

From the results shown in Table 3, the products 1 to 4 of the present invention are superior to the negative electrode slurries for lithium ion secondary batteries (weakly acidic to weakly alkaline at pH 5 to 9) as compared with the comparative products 1 to 4. It can be seen that it has corrosion resistance.

As described above, the cemented carbide of the present invention has the same hardness and wear resistance as the conventional cemented carbide, and also has excellent corrosion resistance to various coating liquids ranging from strong acid to weak alkalinity. Have.

The coating tool of the present invention has both corrosion resistance and wear resistance, and is a versatile coating tool capable of coating various coating liquids without being limited to the type of coating liquid. Since it has a long life as a coating tool, it is expected to contribute to efficiency, labor saving, and cost reduction in the coating process.

Claims (8)

In the coating tool mounted on the coating device
At least the tip of the coating tool that comes into contact with or approaches the material to be coated is made of cemented carbide within 1 mm.
The cemented carbide has a bonded phase consisting of one or more selected from Co, Ni and Fe, and the balance is one or two selected from WC, TiC and W and Ti and C solid solutions. It is characterized in that the total content of Co, Ni, and Fe constituting the bonded phase, which is composed of the hard phase and unavoidable impurities as described above, accounts for less than 2.0% by mass in the entire cemented carbide. Coating tool. The coating tool according to claim 1, wherein in the cemented carbide, W, which is a metal component in the hard phase, accounts for 40% by mass or more and 80% by mass or less in the entire cemented carbide. .. The diffraction peak intensity of the cemented carbide is measured by an X-ray diffraction method, and the number of counts at which the diffraction peak intensity 2θ exists in the range of 40 ° to 43 ° is defined as Ia, and the diffraction angle 2θ is 46 °. The coating tool according to claim 1 or 2, wherein when the count number corresponding to the top of the diffraction peak intensity existing in the range of 50 ° is determined as Ib, the relationship of Ib / Ia ≦ 1 is satisfied. The cemented carbide, VC, NbC, TaC, one or two or more carbide ceramic selected from among TaNbC and _Cr 3 _{C 2,} of claims 1 to 3, characterized in that it further comprises a hard phase The coating tool according to any one item. The cemented carbide according to any one of claims 1 to 4, wherein the cemented carbide further contains one or more kinds of nitrided ceramics selected from TiN, TaN and NbN as a hard phase. Coating tool. The coating tool according to any one of claims 1 to 5, wherein the portion other than the tip portion of the coating tool is made of stainless steel. The coating tool according to any one of claims 1 to 6, wherein the cemented carbide has a hardness of 89.0 HRA or more and 95.0 HRA or less on a Rockwell hardness A scale. A coating device equipped with the coating tool according to any one of claims 1 to 7.

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