JP2002061751A - Water stopping structure for roll shaft portion ! butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water stopping structure for a roll shaft portion that adjusts to service environment conditions of a processing tank and suffers less wear. SOLUTION: An etching tank 10 has a shaft hole 26 via which a shaft portion 24 of a feed roll 12 projects outward, and has a fixed water stop member 44 of glass-containing polytetrafluoroethylene on a diaphragm 38 fixed to the shaft hole 26. The shaft portion 24 is mounted with a rotary water stop member 50 of silicon carbide slidingly rotatable relative to the fixed water stop member 44 to thereby prevent liquid leakage from the shaft hole 26. The combination of the water stop members different from each other reduces wear of the water stop members and prolongs the life of the water stopping structure even when the processing tank interior is in such a service environment state as a spray state and a dry state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stopping structure of a roll shaft for conveying a printing plate metal plate in a processing tank.

[0002]

2. Description of the Related Art A metal plate for a printing plate, for example, a thin plate of aluminum (hereinafter referred to as "web") is subjected to photosensitive lithographic printing after a surface roughening treatment, a coating step, a drying step and the like. Version.

In some processing steps, a processing liquid is sprayed on a web in a spraying state in a processing tank. A transport roll that transports the web is disposed in the processing tank, and the shaft of the transport roll projects outward from a shaft hole that penetrates the tank wall of the processing tank and is supported by the shaft.

As shown in FIG. 7, a diaphragm 38 is provided in a shaft hole 26 passing through a processing tank 80. A ring-shaped stationary water-stop member 60 made of silicon carbide (SIC) is attached to the inner periphery of the diaphragm 38.
Is penetrating.

[0005] A disk 48 is mounted on the outer peripheral surface of the shaft portion 24, and a ring-shaped rotating water-stop member 62 is mounted on the outer peripheral portion of the disk 48. Rotating water stop member 62
Is formed of silicon carbide (SIC), and slides and rotates with respect to the fixed-side water stopping member 60.

In such a water stopping structure, when the processing liquid is stored in the processing tank 80, there is no problem such as abrasion. However, in the case of a spray tank or a dry processing tank, the rotation side water stopping member 62 is not used. If the material of the fixed-side water-stopping member 60 is silicon carbide (SIC), the material will adhere (lick) due to friction, and the life of the water-stopping structure will be shortened.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a water-stopping structure for a roll having a small amount of wear, which is compatible with the environmental conditions of the processing tank.

[0008]

According to the first aspect of the present invention, there is provided a water stopping structure for a roll for transporting a metal plate for a printing plate in a processing tank. The processing tank is provided with a shaft hole from which the shaft of the roll projects outward, and the shaft hole is provided with a fixed-side water blocking member. A rotating water stopping member that slides and rotates with respect to the fixed water stopping member is attached to the shaft portion, thereby preventing liquid leakage from the shaft hole.

Here, the stationary water-stopping member is formed of glass-containing fluororesin, and the rotating water-stopping member is formed of cemented carbide, ceramics, or silicon carbide.

As described above, by combining different water-stopping members, even when the processing liquid is not stored in the processing tank, that is, in a use environment state such as a spray state or a dry state. In addition, wear of the water stopping member is small, and the life of the water stopping structure is extended.

The invention according to claim 2 is characterized in that the roll is not immersed in the processing solution in the processing tank.

According to the third aspect of the present invention, the seal water is sprinkled on the sliding portion between the fixed water stopping member and the rotating water stopping member. Thereby, the sliding portion is kept in a wet state, and lubricity and wear resistance are improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The water stopping structure of a roll according to the present embodiment will be described below by taking the chemical etching process shown in FIG. 1 as an example.

In the chemical etching process, the web W is transported in the etching bath 10 by the transport rolls 12 provided in the etching bath 10. The introduction pipe 1 is introduced into the etching tank 10 by a liquid feed pump 14.
Through 6, the etching liquid mainly containing sodium hydroxide stored in the liquid preparation tank 18 is sent to the spray 20, and the spray 20 sprays the etching liquid uniformly in the width direction of the web W. When the web W exits the etching bath 10, the surface of the web W is wiped by the nip roll 22 to prevent the etchant from being taken out.

The web W as a metal plate for a printing plate
Usually, an aluminum plate that is lightweight and has excellent surface treatment properties, workability, and corrosion resistance is used. As the aluminum plate, JIS1050 material, JIS1100 material, Al-Mn
System alloy, Al-Mn-Mg system alloy, etc. are used.

As shown in FIG. 2 and FIG.
The second shaft portion 24 protrudes outward from a shaft hole 26 penetrated through the tank wall 10 </ b> A of the etching bath 10. Tank wall 10
A gantry 28 is provided outside of the gantry A.
8, the drive shaft 32 of the motor 30 and the shaft 2
4 is coupled, and the connecting portion 24 of the shaft portion 24 is connected.
A is supported by the bearing 31. Thereby, a stable rotational force is applied to the transport roll 12.

A flange projects from the periphery of the shaft hole 26 to receive the etching solution.
4. A drain pipe 36 for draining the leaked etchant is connected to the bottom surface of the tray 34.

Further, an outer peripheral portion of a ring-shaped diaphragm 38 is fixed to a peripheral portion of the shaft hole 26 in a watertight state by a fixing member 39. When the diaphragm 38 is viewed in cross section, the diaphragm 38 is curved toward the outside of the tank wall 10A, and is configured to generate a surface pressure toward the outside.

At the inner periphery of the diaphragm 38, a metal core 40 is provided.
Is embedded, and the diaphragm 38 can be held in a predetermined circular shape. A support member 44 on which an O-ring 42 is mounted is attached to the cored bar 40.
Further, a ring-shaped stationary water stopping member 46 is fixed to the support member 44 via the O-ring 42. The fixed-side water blocking member 46 is formed of glass-filled Teflon.

On the other hand, the shaft 24 of the transport roll 12 has O
A metal disk 48 is fixed via a ring 43. A ring-shaped rotating water stop member 50 is fixed via an O-ring 42 to the outer peripheral portion of the disk 48. Abuts in a watertight state on the stationary side water stopping member 46 which has received the surface pressure. The rotation side water blocking member 50 is formed of silicon carbide (SIC).

When the water stopping structure as in the present embodiment is used in an environment in a spray state, the fixed water stopping member 46 and the rotating water stopping member 5 depend on the temperature and relative humidity in the processing tank.
The wear state of 0 changes.

Therefore, as shown in Examples 1 and 2 below, the degree of abrasion of the water-stopping member was tested by changing environmental conditions. In addition, whether or not it was worn was determined based on the abnormal current value of the motor 30 (vector inverter motor: rated 2 A). (Example 1) Annular condition: temperature 0 ° C, relative humidity 10%, motor rotation speed: 148 rpm (sliding speed of rotation-side water stopping member 50:
(1.8 m / min) and the operation period was 7 days.

As shown in the table of FIG. 4, five days after the start of operation, the current value of the motor increased, and the fixed-side water stopping member 46 (Teflon with glass) was abnormally worn.
In the conventional water-blocking structure (both the water-blocking members are silicon carbide), the table is not shown, but close contact (licking) occurs in about 3 to 5 minutes from the start of operation, and the sealing function is not achieved. In comparison with this, in Example 1, even under severe environmental conditions, it is possible to reduce the wear of the water stopping member. (Example 2) Annular condition: temperature 20 ° C, relative humidity 50%, motor rotation speed: 148 rpm (sliding speed of rotation-side water stopping member 50:
(1.8 m / min) and the operation period was 60 days.

As shown in the table of FIG. 5, the current value of the motor does not increase even after 60 days from the start of the operation, and no abnormal wear has occurred on the water stopping member.

Further, although a table is not shown, the results of the following environmental conditions are shown when the abrasion state of the fixed-side water blocking member (Teflon with glass) is 〇: good, △: normal, ×: bad. .

At a temperature of 5 ° C. and a relative humidity of 15%, the wear state is Δ, at a temperature of 10 ° C. and a relative humidity of 20%, the wear state is Δ, at a temperature of 50 ° C. and a relative humidity of 70%, the wear state is 〇, when the temperature was 80 ° C. and the relative humidity was 100%, the abrasion state was 〇.

As a result, when using the water blocking structure of this embodiment other than in a liquid, it is preferable that the temperature is in the range of 5 ° C. to 80 ° C. and the relative humidity is in the range of 15% to 100%. I understand.

Further, in the water stopping member of the present embodiment, a combination of glass-filled Teflon and silicon carbide is adopted, but the present invention is not limited to this. Glass-filled Teflon and ceramic, carbon-filled Teflon and silicon carbide, and carbon-filled A combination of Teflon and cemented carbide, or Teflon containing carbon and ceramic may be used.

As shown in FIG. 6, by using a nozzle 54 to spray sealing water 56 on the sliding portion A between the fixed-side water stopping member 46 and the rotating-side water stopping member 50, the operating environment conditions can be improved. Thus, lubricity and wear resistance can be improved.

The term “water” of “water stoppage” used in the description so far is a concept indicating a liquid, and does not literally refer to water itself.

Lastly, a general post-process of a roughened web is schematically described.

After the surface-treated web is washed with water,
It was immersed in a 10% by weight aqueous solution of sodium hydroxide at 35 ° C., etched so that the amount of aluminum dissolved was 1 g / m ² , and washed with water. Next, it is immersed in a 30% by weight aqueous sulfuric acid solution at 50 ° C., desmutted, and then washed with water.

Further, a porous anodic oxide film forming treatment was performed in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) at 35 ° C. using a direct current. That is, electrolysis was performed at a current density of 13 A / dm ² , and the anodic oxide film weight was adjusted to 2.7 g / m ² by adjusting the electrolysis time. To prepare a negative photosensitive lithographic printing plate using a diazo resin and a binder, the support was washed with water, immersed in a 3% by weight aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried.

[0034] The thus-obtained aluminum support, reflection density was measured with Macbeth RD920 reflection densitometer 0.30, the center line average roughness R _a as defined in JIS B00601 is 0.58μm met Was.

Next, methyl methacrylate /
A 1.0% by weight aqueous solution of ethyl acrylate / 2-acrylamide-2-methylpropane sodium sulfonate copolymer (average molecular weight: about 60,000) (molar ratio: 50/30/20) was dried by a roll coater to obtain a coating amount of 1.0%. 0.05g
/ M ² .

Further, the following photosensitive solution-1 was applied using a bar coater and dried at 110 ° C. for 45 seconds. The dry coating amount was 2.0 g / m ² . Photosensitive solution-1 Diazo resin-1 0.50 g Binder-1 5.00 g Stylite HS-2 (manufactured by Daido Kogyo Co., Ltd.) 0.10 g Victoria Pure Blue BOH 0.15 g Tricresyl phosphate 0.50 g Dipicolinic acid 0 .20 g FC-430 (surfactant manufactured by 3M) 0.05 g Solvent 1-methoxy-2-propanol 25.00 g Methyl lactate 12.00 g Methanol 30.00 g Methyl ethyl ketone 30.00 g Water 3.00 g The above diazo resin-1 Is obtained as follows. First, 29.4 g of 4-diazodiphenylamine sulfate (purity: 99.5%) was added at 25 ° C to 96% sulfuric acid 70%.
ml and stirred for 20 minutes. to this,
3.26 g of paraformaldehyde (purity 92%)
The mixture was gradually added over 0 minutes, and the mixture was stirred at 30 ° C. for 4 hours to allow the condensation reaction to proceed. The condensation molar ratio between the diazo compound and formaldehyde is 1: 1. The reaction product was poured into 2 liters of ice water with stirring, and treated with a cold concentrated aqueous solution in which 130 g of sodium chloride was dissolved. The precipitate is collected by suction filtration, the partially dried solid is dissolved in one liter of water, filtered, cooled on ice and washed with potassium hexafluorophosphate 23.
g was dissolved in an aqueous solution. Finally, the precipitate was collected by filtration and air-dried to obtain 1 g of diazo resin.

Binder-1 was 2-hydroxyethyl methacrylate / acrylonitrile / methyl methacrylate / methacrylic acid copolymer (weight ratio 50/20/26 /
4, average molecular weight 75,000, acid content 0.4 meq /
g) is a water-insoluble, alkaline water-soluble film-forming polymer.

Stylite HS-2 (manufactured by Daido Industry Co., Ltd.)
Is a polymer compound having a higher oil sensitivity than the binder,
It was a copolymer of styrene / mono-4-methyl-2-pentyl maleate = 50/50 (molar ratio), and the average molecular weight was about 100,000.

[0039]

According to the present invention having the above-described structure, by employing a combination of water-stopping members corresponding to the use environment conditions of the processing tank, wear of the water-stopping members is reduced, and the life is extended.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a chemical etching treatment apparatus to which a water blocking structure of a roll shaft according to the present embodiment is applied.

FIG. 2 is a cross-sectional view showing a main part of a water stopping structure of a roll shaft according to the embodiment.

FIG. 3 is an enlarged view of FIG. 2;

FIG. 4 is a table showing experimental results of Example 1.

FIG. 5 is a table showing experimental results of Example 2.

FIG. 6 is a cross-sectional view of a main part showing an example in which water spraying means is provided in the water stopping structure of the roll shaft according to the present embodiment.

FIG. 7 is a cross-sectional view showing a conventional water stopping structure of a roll shaft.

[Explanation of symbols]

 46 Fixed-side water-stopping member 50 Rotation-side water-stopping member 54 Nozzle

Claims (3)

[Claims] 1. A water stopping structure for a roll shaft for transporting a printing plate metal plate in a processing tank, wherein the shaft of the roll is provided in a shaft hole protruding outside the processing tank. A member, a rotation-side water stopping member that is attached to the shaft portion and slidably rotates with respect to the fixed-side water stopping member to prevent liquid leakage from the shaft hole, the fixed-side water stopping member includes: A water stopping structure for a roll shaft portion, wherein the water stopping member is formed of a glass-containing fluororesin, and the rotation-side water stopping member is formed of cemented carbide, ceramics, or silicon carbide. 2. The water stopping structure for a roll shaft according to claim 1, wherein the roll is not immersed in the processing liquid in the processing tank. 3. The water stopping structure for a roll shaft according to claim 2, wherein seal water is sprayed on a sliding portion between the fixed water stopping member and the rotating water stopping member.