JPH0364595A - Coating blade and its production - Google Patents

Abstract

PURPOSE:To obtain the title blade good in wear resistance, prevented from chipping with suppressed, hydrogen brittleness for application on e.g. printing coating paper by making an electroplating under specified conditions in the proximity of such a part of a coating blade made of flexible steel as to come into contact with base paper to be coated to effect chromium coating. CONSTITUTION:A coating layer 3 of a metal except chromium (e.g. nickel) capable of hindering hydrogen occlusion is formed in the proximity of such a part of a coating blade 1 made of flexible steel as to come into contact with base paper to be coated. The resulting blade is put to electroplating at 35-65 deg.C in an electroplating solution containing 100-400g/l of chromic anhydride and sulfuric acid at such an amount as to be 1/70-1/120 times that of the chromic anhydride under such a condition that the stress due to chromium deposition fall at + or -15kg/mm<2> or lower, effecting coating in the proximity of said part of the blade 1 with a chromium plated layer 2 with >=5mu thickness, thus obtaining the objective coating blade.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a coating blade, which is used to coat base paper in the manufacturing process of coated paper such as printing coated paper, pressure-sensitive copying paper, or heat-sensitive recording paper. It is used in the so-called coating process, in which water-based paints containing pigments and adhesives as main components are applied to surfaces.

[Prior Art] Conventionally, a coating blade (coater blade) used for coating base paper has a thickness of about 0.2 to 0.8 mm, a plate width of about 50 to 150 mm, and a length of about 150 mm. ~7000m
Steel materials having flexibility up to m, such as J I 5-G-
Carbon tool steel (SK material) and 5U specified in 4401
It is composed of S410 and the like.

Coating blades are roughly divided into two types, depending on the amount of paint to be applied: heher blades that use the tip of the blade, and bent blades that use the side of the blade. The reality is that the blade steel is damaged by wear in a relatively short period of time due to continuous rubbing.

For example, Japanese Patent Application Laid-Open No. 5988995 is an attempt to prevent damage caused by abrasion of coating blades as much as possible and increase durability. This is a blade steel material coated with a ceramic material, particularly alumina, alumina-titania, chromium oxide, etc., by a thermal spraying method.

However, although the blade according to the above-mentioned publication has improved wear resistance compared to conventional blades, the area near the contact surface with the base paper is not entirely coated with ceramic, so it may rust or cause problems peculiar to ceramic materials. This is not always satisfactory because of the brittleness and porosity of the material, which results in chipping and the formation of voids on the contact surface due to the porosity. Furthermore, in order to thermally spray ceramic materials, there is a restriction that the material must be melted and sprayed using a plasma flame or dregs flame at a temperature of at least several thousand to tens of thousands of degrees, since ceramic materials have a high melting point. As a result, there are problems such as deformation of the blade material (not to mention problems such as the need for polishing after thermal spraying in order to maintain the flatness and smoothness of the contact area of the blade).

[Problems to be Solved by the Invention] The present invention provides a coating blade that can prevent rusting due to breakage due to brittle coating and incomplete coating, and also provides an economical coating blade that does not deform. The purpose of this invention is to provide a method for manufacturing the same.

[Means for Solving the Problems] In the present invention, in order to solve the problem described in item 1, in the coating blade made of flexible steel, a coating blade is provided near the contact portion with the base paper for coating. It is characterized in that it is coated with a metal other than chromium that prevents hydrogen absorption, and that chromium is coated on the coating to a thickness of 5 μm or more and thinner than the thickness of the steel material.

Another method is to coat the entire surface of the blade with a metal other than chromium, which has anti-corrosion properties against steel and prevents hydrogen absorption, and injects 5μIn of chromium into the vicinity of the contact area of the coating with the base paper for coating.
The coating may be made thinner than the thickness of the steel material.

Further, instead of coating with a metal other than chromium, it may be coated with chromium and then annealed at 1.10°C to 145°C. Furthermore, the chromium coating is formed by electroplating, and the composition of the electroplating solution is chromic anhydride ranging from 100 to 10.
0g/N, sulfuric acid is 1/70 of the anhydrous 177n acid concentration
It is characterized in that the amount is 1/120 and the stress due to chromium precipitation is less than ±1.5 K g/mm2 at a liquid temperature of 35 to 65°C.

[Function] In order to solve the above problems, the present inventors conducted detailed studies on the selection of coating materials, wear tests, analysis of the causes of coating chipping, omission of the polishing process, provision of corrosion resistance, etc. .

Firstly, in order to determine the coating material for the blade steel, the present inventors investigated appropriate coatings by measuring the wear loss of various coatings using a Taber type abrasion tester. The results are shown in Table 1. In the table, the unit of wear loss is [mFi/1
000rev, ). Table 1 also lists the measured values of each coating hardness [11V].

Table 1 In Table 1, treatment A after coating formation is left as polishing, and treatment B is polishing f! Annealing was performed at t200°C for 1 hour.

The material to be rubbed against the coating is silicon carbide (H-
1,0). A load of Ikg is added to silicon carbide. The chemical composition of S K-5 is C: 0.8
0-0.90, Si:<0.35, Mn:<0.50.
P:<0.03, S:<0.03. The composition of alumina-titania was A12033%Ti○2. The thickness of each coating is 0.15 mm.

As is clear from Table 1, among the compared coatings, chrome plating has the best wear properties, about 10 times as resistant to 5K-5 and about 4 times as resistant to alumina ditania. It was found to be abrasive and suitable for coating blades.

1 draw 1 Next, the above coating was actually applied to a blade, and an abrasion test using a test coater was attempted. Width u+-55mm, length N=50 as shown in Figure 4 from S K-5#I material
A blade having a thickness of 0 mm and a thickness of d=0.5+nm was produced.

In the figure, d is −0, 1 man, and θ−30°.

This blade was coated with alumina-titania and chromium carbide by thermal spraying, and chromium and nickel-phosphorus alloy by plating. The coverage range was set as shown in FIG. 5, and the coverage width was 111-10+ nm. Although the target thickness of the coating was 100 μm (0.1 mm), deformation (bending) occurred in the blade steel in all cases except for the nickel-phosphorus alloy. The thermal spray coating, that is, alumina-titania, showed only slight deformation, so it was decided to use it as is, but the chromium carbide coating had significant deformation, so the test was discontinued.

In addition, as a result of various studies regarding chromium coating by plating, we have found that when the coating thickness exceeds 5 μm, whether the internal stress of the chromium plating caused by depositing the chromium plating is tensile stress or compressive stress, It was found that deformation occurs when the weight exceeds 1.5 kg and 7 mm2. In order to keep the stress within the above range, chromic anhydride, which is a component in the chromium plating solution, should be added to OO
~400g/l, preferably 250-350g# binding,
The composition contains sulfuric acid in an amount of 1/70 to 1/120 of chromic anhydride, preferably 1/770 to 1/90, and the liquid temperature is 35 to 6.
It has been discovered that by selecting the current density at 5°C, preferably 40 to 48°C, chromium can be coated with almost no deformation.

By the way, the paint used in the coating process for manufacturing coated paper consists of water, dispersant, adhesive, pigment, auxiliary agent, etc. in the case of coated paper for printing, and in the case of pressure-sensitive copying paper. , developer,
In the case of heat-sensitive recording paper, there are precautions against adhesives, microcapsules, etc., and in the case of thermal recording paper, there are precautions against color developers, dyes, adhesives, etc., but the wear of the blade is caused by continuous contact with the base paper and only by rubbing However, the components contained in the paint, especially the inorganic materials used in the pigments, accelerate the wear of the blade steel, making it necessary to replace it within a relatively short period of time. Typical inorganic components used as pigments include fluoride, calcined kaolin, calcium carbonate, talc, silica satin white, titanium white, aluminum hydroxide, activated clay, fine silica, zinc oxide, and organic pigments. To summarize these, calcium carbonate and sulfate, magnesium carbonate, titanium oxide, barium sulfate, aluminum hydrate, zinc white, calcium/magnesium carbonate, silicic acid and its silicic acid. Salt, etc., coated paper for printing,
These are selected as appropriate depending on the properties required for coated paper such as pressure-sensitive copying paper, thermal recording paper, inkjet recording paper, etc.
The reality is that they are used in combination.

In the test coater, the paint was formulated as follows, and the solid content concentration was adjusted to 60% with water and used in the test.

Kaolin 80 parts by weight Calcium carbonate 20 parts by weight Sodium pyrophosphate
0.1 parts by weight styrene/phthalene latex 12 parts by weight starch
Further, the operating conditions of the test coater were set as follows, and changes in the contact surface of the coated blade with the base paper were successively investigated.

Speed: 1. OOOm/min blade linear pressure + 0.8Kg/cn + base paper 60g
/m2 Coating amount], Og/m2 The surface roughness of the beveled surface of the blade after coating is as shown in Table 2, and although there are differences in degree, it is rougher than the original blade steel. Therefore, except for the 5K-5 material which was not provided with a coating, all the materials were polished to a surface roughness of 0.6 to 0.8 μRmax and subjected to the test. The driving time was 2.0 hours, but 0.5
The amount of wear was investigated every hour, and the results are shown in Table 2. In addition, the surface roughness of the beveled surface after 2 hours of operation is also shown. The unit of surface roughness is [μRmax].

Table 2 In Table 2, blade ■ is 5K-5 play 11 de, blade ■ is 5K with alumina-titania coating.
-5 blade, blade (2) is a 5K-5 blade coated with chrome plating, and blade (2) is a 5K-5 blade coated with nickel-phosphorous alloy. The amount of wear is 0.5
The wear amount (■) was measured after 1.0 hours, the wear amount (■) was measured after 1.5 hours, and the wear amount (■) was measured after 20 hours. Also, although not listed in the table, Blade ■ and Blade ■
After the test, the coating was found to be chipped in some places on the cutting edge of the blade.

From Table 2, the blade ■ with chrome plating coating is:
Although some chipping was observed on the cutting edge, the durability was approximately four times greater than that of SK-5 steel, confirming the results of the coating selection test.

(Original) As mentioned above, chrome-coated blades show chipping at the cutting edge, albeit locally, and from the perspective of uniform coating, the point at which chipping occurs is the end of the blade's lifespan. There may also be cases where the wear resistance of chromium cannot be demonstrated.Therefore, various studies were conducted to clarify the cause of coating chipping.

The inventors have a length of 100 mm, a width of 10 mm, and a thickness of 0.
Prepare 5mm 5K-5 material, add 5μm of chromium to it,
TOμm, 50μm, 100μm, 300μm whole surface coating and 3μIl+ of nickel in advance.

After coating the entire surface with 5 μm and 50 μm, 3 μm of chromium was applied.
．． One coated with 5μm and 100μm of nickel, one coated with 5μIn of nickel-phosphorous alloy by electroless nickel plating and coated with 100μm of chromium, and the other coated with 5μm of copper using a copper cyanide bath and then coated with 100μm of chromium.
We prepared coated materials and confirmed whether the coating made the materials more prone to chipping. The results are shown in Table 3. Specifically, a method was used to check the degree of embrittlement by bending the material 90 degrees.

(Margin below) In Table 3, ◯ indicates that the product will not be damaged even if it is bent, △ indicates that it may or may not be damaged when it is bent, and × indicates that it will be completely damaged when it is bent. According to Table 3, for 5K-5 material coated only with chromium, the thickness of the coating is 5μ.
It was found that when the thickness exceeds m, it becomes easy to break, and this is thought to be the cause of partial chipping of the blade edge in the test coater.

The present inventors discovered that by coating the intermediate layer between chromium and S K-5 material with nickel, nickel-phosphorus alloy, copper, etc.
It has been discovered that embrittlement of the material can be prevented when the thickness of the intermediate layer is only 5 μm. Also, the length 1 from the chrome coated part and uncoated part of the chrome coated blade used in the test coater.
When a 00 mm bending test piece was cut out and bent in the same manner, embrittlement was observed only in the chromium coated portion. Therefore, deoxidization was considered to be a phenomenon that occurs only in the chromium-coated area due to chromium coating, and this was presumed to be hydrogen embrittlement as a result of hydrogen gas absorption that occurs during chromium plating. If the embrittlement is hydrogen embrittlement, it should be possible to dehydrogenate and remove the embrittlement by annealing after coating with chromium.
It was possible to remove the embrittlement itself by annealing in the range of 250°C for 5 days. However, the above-mentioned general annealing temperature presents problems such as changes in the springiness required for the blade steel material. Therefore, we investigated in detail whether embrittlement could be removed without changing the springiness (flexibility), and found that
We found that annealing with 200°C can remove the brittleness without any change in visibility.

Figures 1 (,) to (d) are cross-sectional views of bent-type blades whose brittleness has been removed by annealing, and Figures (e) and (f).
is a cross-sectional view of a bevel type blade whose brittleness has been removed by annealing. In the figure, 1 is a blade steel material, and 2 is a chrome plating coating. Figures 2(,) and (b) are cross-sectional views of a bent type blade in which brittleness has been removed by the presence of the intermediate layer 3 without annealing, and Figure 2(c) is a cross-sectional view of a bent type blade in which brittleness has been removed by the presence of the intermediate layer 3 without annealing. FIG. 3 is a cross-sectional view of a bevel type blade from which brittleness has been removed. In this case, the intermediate layer 3 is made of nickel, nickel phosphorus alloy, nickel-boron alloy, or copper, and has a thickness of 3 to 50 μm.

4LE food! The present inventors found that when coating blade steel with chromium, by selecting the composition of the chromium plating solution, it was possible not only to obtain a chromium-coated blade without deformation, but also to omit the polishing process after coating with chromium. I thought it could be done. As a result of various studies on the composition of the chromium plating solution for this purpose, we found that the composition of the chromium plating solution was 100 to 400 g//! To a solution in which sulfuric acid was added in an amount of 1/70 to 1/1.20 of the concentration of chromic anhydride,
Addition of fluorosilicic acid, fluorosilicic acid salts (e.g. sodium fluorosilicic acid), boric acid, borates (e.g. borax), sulfamic acid, alkyl sulfonic acids, etc. at a rate of 1 to 25 g/l results in a smooth and virtually chromium-coated surface. We discovered that not only can we eliminate the need for subsequent final polishing, but we can also obtain blades that do not deform due to stress.

Table 4 shows the surface roughness [μRmax] of blades made of polished 5K-4 steel with various chromium coatings after the coating is completed.
The data measured by the stylus method and the coating hardness CHV (1
00/30)), and data of electrodeposition stress CKg/mm2:] measured by a spiral contractometer.

Table 4 In Table 4, the composition of the chromium solution No. 1 is chromic anhydride 300g/l and sulfuric acid 4g/L The composition of the chromium solution No. 2 is chromic anhydride 300g/l and sulfuric acid 4g/l
, boric acid 5 g/l, No. 3, the composition of the chromium solution is chromic anhydride 300 g/fl, sulfuric acid 2.5 g/R, and sodium silicofluoride 1.5 g/l. Moreover, one sign of stress indicates compression side stress. The surface roughness of the uncoated S K-4 material is 0.90~○95μRmax, and the hardness is 583.
fi V (100730).

As is clear from Table 4, when boric acid, sodium silicofluoride, etc. are added except for No. 1 chromium solution,
It can be seen that the roughness of the material is smoother than the original roughness, and the stress is low. Additionally, an increase in hardness was observed as an accompanying effect. In addition, these chromium-coated S
When the K-4 material was bent at 90 degrees, No. 4, 2.
It was found that the chrome coatings made with each of the chromium solutions in No. 3 were easily damaged from the material. In addition, it has been found that annealing or coating nickel, nickel-phosphorus alloy, copper, etc. with a thickness of 5 μm or more in front of the vehicle is effective in preventing deoxidization of chromium solutions No. 2 and No. 3. Admitted. As mentioned above, when appropriate amounts of fluorosilicic acid and its salts, boric acid and its salts, sulfamic acid, alkylsulfonic acids, etc. are added to a solution containing chromic anhydride and sulfuric acid, there is no deformation at all, and polishing after chromium coating is possible. I was able to create a blade that was no longer needed.

9 Red Plan 1 ■ EL The chromium-coated blade had a significant life extension effect compared to conventional blades that were not coated with chromium. Rust has come to pose a new problem with the extension of durability (life).

Therefore, as a solution to this problem, coating not only specific parts of the blade but also the entire blade with nickel or nickel-phosphorus alloy coating, which can be used to prevent the embrittlement (hydrogen embrittlement) of the steel material that occurs with chromium-coated blades, will remove the chromium-uncoated parts. Rust can be prevented, and the same coating can simultaneously prevent embrittlement and rust, which is extremely economical.

FIGS. 3(a) and 3(b) are cross-sectional views of bent type and bevel type blades in which the intermediate layer 3 is coated over the entire surface of the blade steel material to prevent rust and embrittlement. In this case, the intermediate layer 3 is made of nickel, nickel phosphorus alloy, nickel-
It is made of at least one metal of boron alloy.

Note that copper, which is effective in preventing hydrogen embrittlement of chromium-coated blades, does not meet the above objective due to the lack of corrosion resistance of copper as a metal. For coating nickel and nickel-phosphorus alloys, electroplating can be used for nickel, and both electroplating and electroless plating can be used for nickel-phosphorus alloys, but to prevent embrittlement, Electroless plating is slightly better. Further, the thickness required to provide corrosion resistance is 3 μIn or more, and this thickness almost corresponds to the thickness required to prevent embrittlement. Even if the thickness is increased, the corrosion resistance can be further improved without changing the embrittlement prevention function.
The power of doing the following is amazing. In addition, the chromium coating range is preferably 5 mm from the tip in the direction of contact with the coating base paper, as it is convenient in view of the springiness of the steel material for the blade.
It is preferable to set it to 0 mm or less.

As is clear from the above study results, in a coating blade made of visible steel, a metal other than chromium that prevents hydrogen absorption is coated near the contact area with the base paper for coating, and a metal other than chromium is coated on the coating. By coating the blade with a thickness of 5 μm or more thinner than the thickness of the steel material, the hydrogen embrittlement of chromium is prevented due to the presence of metals other than chromium that prevent hydrogen absorption, which would normally cause chromium to become embrittled. Can prevent chipping. Further, by coating the entire surface of the blade with a metal other than chromium, which has anti-corrosion properties against steel and prevents hydrogen storage, it is possible to prevent rusting of the blade at the same time.

On the other hand, even if the above-mentioned intermediate layer is not provided between the blade steel material and the chromium, if the coating blade made of visible steel has a coating thickness of 5 μm or more near the contact area with the coating base paper, and the steel material coated with chromium thinner than the thickness of
Hydrogen embrittlement can be removed by annealing at C to 145°C. At this time, by selecting the annealing temperature as described above, it is possible to prevent changes in the flexibility of the steel material.

In addition, at least the vicinity of the contact area with the coating base paper of the coating blade made of flexible steel is coated with chromium by electroplating, and the composition of the electroplating solution is chromic anhydride and chromium.
00-400g/f, sulfuric acid has chromic anhydride concentration]/7
0 to 1/120, the liquid temperature is 35 to 65℃, and the plating conditions are such that the stress due to chromium precipitation is ±15Kg/+nm2 or less, the electrodeposition stress of chrome plating is reduced and blade deformation is prevented. can.

Furthermore, at least one compound selected from fluorosilicic acid, fluorosilicic acid, boric acid, borate, sulfamic acid, and alkyl sulfonic acid is added to the electroplating solution, and the amount of addition is such that polishing is not required after chromium plating. If the range is such that a certain level of chromium smoothness can be obtained, the blade can be manufactured economically by omitting the polishing step.

[Example] The present inventors created a bent type blade made of 5K-51 material (width) -00 mm, length 2220 mm, thickness 0.
381 mm), the chrome coating range is 1 from the tip.
0 mm, four types of chromium-coated blades were prepared, and the operating conditions of the paint and blade coater were the same as those described above.

After coating the blade with 40μm of chromium, it was heated at 140℃ for 1
After annealing for 0 hours, the chromium-uncoated portions were coated with antirust paint. The composition of the electroplating solution used for chromium coating was 300g/l of chromic anhydride and 4g/l of sulfuric acid.
/l. The surface roughness of the blade is 0.93 to 1.0
(μRmax), 1.7 to 1.8 (μRmax) after chromium coating
Rmay), after polishing 0°81~0.85 (μRm
ax).

The entire blade was coated with nickel to a thickness of 5 μm, and then coated with chromium to a thickness of 40 μm. The composition of the electroplating solution used for nickel coating was 350g//-1 of nickel sulfamate.
The amount of nickel chloride was 10 g/f, and the amount of boric acid was 35 g/β. Furthermore, the composition of the electroplating solution used for chromium coating was the same as in Example 1. The surface roughness of the blade is 0.90~0
．． 95 (μRmax), 19-22 (after chromium coating)
μRmnx), 0.95 to 1. O(μRma
x).

4. After coating the entire surface of the blade with 5 μm of nickel, it was coated with 40 μm of chromium. The composition of the electroplating solution used for nickel coating was 240 g/l of nickel sulfate, 20 g/l of nickel chloride, and 45 g/l of boric acid. Also, the composition of the electroplating solution used for chromium coating was 300 g/l of chromic anhydride and 2.5 g/l of sulfuric acid! , silicofluoride l ~ zolium 1. '3g/l. The surface roughness of the blade was 094-0.98 (μRmax), and after chromium coating was 0.30-0.45 (μRmax). The polishing step after chromium coating was omitted.

Tenjo IPJ4 The entire blade was coated with nickel-phosphorus alloy to a thickness of 10μIn, and then coated with 40μII+ of chromium. The composition of the electroplating solution used for coating the nickel-phosphorus alloy was 30 g/l of nickel sulfate and 'J-Og/l of sodium hypophosphite.
, sodium citrate is 1. Og# closed. Further, the instant preparation of the electroplating solution used for chromium coating was the same as in Example 3. The surface roughness of the blade is 0.9C) to 0.92(
μRmax), 0.25 to 0.30 (after chromium coating)
μRmax). The polishing step after chromium coating was omitted.

Biao Hee Salmon Ri A blade made of uncoated 5K-5 steel was used.

Comparative Example 1 was used and compared under actual machine operating conditions, including a blade made of 5K-5 steel material for comparison.
The chromium-uncoated blades of 2000 were unusable after 7 hours of operation, whereas in Example 1, they were unusable after 28 hours, in Example 2, 36 hours, in Example 3, 48 hours, and in Example 4, 52 hours. I endured.

``Otama Kita'' - As a paint formulation, 65 parts of aluminum hydroxide, 20 parts of zinc oxide, a mixture (mixture) of zinc 3,5-di(α-methylbenzyl)salicylate and α-methylstyrene/styrene copolymer were used. 15 parts of melting ratio 80/20), 5 parts of polyvinyl alcohol aqueous solution (solid content) and 300 parts of water were mixed in a ball mill.
Using an aqueous coating liquid for pressure-sensitive copying paper prepared by adding 20 parts (solid content) of carboxy-modified styrene-butadiene copolymer latex to a dispersion obtained by grinding for 4 hours, the blade coater conditions were: speed 800+n; The blade blade was subjected to a wear test in the same manner as in Examples 1 to 4, except that the coating solids M5g/m2 (solid content) and the base paper/IOg/Io2 were used.As a result, the blade blade could be used for 30 hours.

Hitsukita-21 The test was carried out in the same manner as in Example 5 except that a blade made of uncoated 5K-5 steel was used. The usable time of the blade was 6 hours.

[Effect of the invention] As is clear from the above description, claim 1 or 2
According to the invention described in , hydrogen embrittlement can be prevented by providing a metal coating that prevents hydrogen absorption in the lower layer of the chromium plating in a coating blade equipped with a chrome plating coating with good wear resistance. This has the effect of preventing chipping due to brittleness of the coating. Further, according to the third or fourth aspect of the present invention, by spreading the metal coating under the chromium plating over the entire surface of the blade, rusting of the blade can also be prevented.

On the other hand, according to the invention as set forth in claim 5, hydrogen embrittlement can be prevented by annealing after forming the chromium plating, and chipping due to brittleness of the coating can be prevented even without providing a metal coating under the chromium plating. Moreover, the annealing temperature is 110-14
Setting the temperature to 5° C. has the effect of preventing the visibility of the blade steel from being impaired.

According to the invention as set forth in claim 6, the stress caused by chromium precipitation can be reduced, so there is an effect that deformation of the blade can be prevented.

According to the seventh aspect of the invention, the smoothness of chromium plating can be improved by adding additives to the electroplating solution, the polishing step after coating can be omitted, and a coating blade can be manufactured at low cost.

[Brief explanation of drawings]

FIGS. 1(a) to (f), FIGS. 2(a) to (c), and FIGS. 3(a) and (b) are sectional views showing different sectional structures of the coating blade of the present invention, respectively, FIG. 4 is a cross-sectional view of a blade steel material used in the wear test of a coating blade of the present invention, and FIG. 5 is a cross-sectional view of a main part of the same blade steel material with a coating applied thereto. 1 is a blade steel material, 2 is a chrome plating coating, and 3 is an intermediate layer.

Claims (7)

[Claims] (1) In a coating blade made of flexible steel, a metal other than chromium that prevents hydrogen absorption is coated near the contact part with the base paper for coating, and the coating is coated with chromium with a thickness of 5 μm or more and the steel material A coating blade characterized by being coated thinner than the thickness of the coating blade. (2) The coating according to claim 1, wherein the metal other than chromium that prevents hydrogen storage is nickel, nickel-phosphorus alloy, nickel-boron alloy, or copper, and is coated to a thickness of 3 to 50 μm. blade. (3) In a coating blade made of flexible steel, the entire surface of the blade is coated with a metal other than chromium that has anti-corrosion properties against steel and prevents hydrogen absorption, and the contact portion of the coating with the base paper for coating A coating blade characterized in that the vicinity thereof is coated with chromium to a thickness of 5 μm or more and thinner than the thickness of the steel material. (4) The coating according to claim 3, wherein the metal other than chromium, which has anti-corrosion properties against steel and prevents hydrogen absorption, is at least one of nickel, nickel-phosphorus alloy, or nickel-boron alloy. Industrial blade. (5) The coating blade made of flexible steel is coated with chromium in a thickness of 5 μm or more and thinner than the steel material near the contact area with the coating base paper, and then annealed at 110°C to 145°C. A method for manufacturing a coating blade, characterized by: (6) The coating blade made of flexible steel is coated with chromium by electroplating at least the vicinity of the contact area with the coating base paper, and the composition of the electroplating solution is 1 part chromic acid anhydride.
00-400g/l, sulfuric acid is 1/7 of chromic anhydride concentration
A method for manufacturing a coating blade, characterized in that the plating conditions are such that the plating amount is 0 to 1/120, the liquid temperature is 35 to 65°C, and the stress due to chromium precipitation is ±15 Kg/mm^2 or less. (7) At least one compound selected from fluorosilicic acid, fluorosilicic acid, boric acid, borate, sulfamic acid, and alkyl sulfonic acid is added to the electroplating solution, and the amount of addition is such that polishing is not required after chromium plating. 7. The method for manufacturing a coating blade according to claim 6, wherein the range is such that a certain degree of smoothness of chromium can be obtained.