JPH10183306A - Convertic line (treatment process for manufacturing polarizing plate) - Google Patents

Abstract

PROBLEM TO BE SOLVED: To especially hold film running precision at the time of dyeing and drawing a polarizing plate and to prevent the generation of defective dyeing nonuniformity by using a specified composition range of stainless steel bearing in a berating part. SOLUTION: The stainless steel containing, by wt., 4.0-10.5% Ni, 20.1-35.0% Cr and 0.5-2.9% Mo is used in the bearing used in a treatment process for manufacturing the polarizing plate. The corrosion resistant effect is displayed in the case of especially using in iodine compound mixing aqueous solution and iodine vapor in the process. Further, Vickers hardness of the bearing is specified to be 450-900 and the withstand load is specified to be 100-500kg. When deviating from this range, forming workability into the bearing and dimensional precision are reduced, flaking and insufficient fitting precision with the shaft or the like rare generated, and dyeing nouniformity of products is inclined to generate. Also, although the structure and type of the bearing are not especially defined, the shaft diameter of the bearing installing part is preferably specified to be 15-50mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a convertible line for manufacturing a polarizing plate, and more particularly to a convertible line useful for a dyeing line, a stretching line, a drying line, etc. in a polarizing plate manufacturing process. It is.

[0002]

2. Description of the Related Art In recent years, the progress of liquid crystal display devices using a polarizing plate has been intense. In the past, only TN type liquid crystal display devices such as small watches were used. STN type liquid crystal display devices and TFT type liquid crystal display devices have been invented and actually used. In particular, the progress of TFT type liquid crystal display devices has been remarkable, and large-sized display and display quality comparable to CRT display devices have become possible.

Accordingly, it is required that various performances of various parts such as a glass cell, a liquid crystal material, a polarizing plate, and a retardation plate in a liquid crystal display device be improved, and that defects in the components are further reduced and the number thereof is reduced. It has become. The polarizing plate, which used to be only an 8-segment monochrome display, has been implemented in notebook PCs and car navigation systems, leading to more detailed and precise color moving image display, optical performance, durability, visibility, appearance quality, and large area. Various improvements in performance such as reduction in optical performance and unevenness in optical performance have been required. Even at a polarizing plate manufacturing site, when a TN type polarizing plate such as a small watch used to be manufactured in the past, in the case of a slight uneven dyeing defect in the longitudinal direction of the product, the transmittance is 1.
Even if there is 5% uneven dyeing, the current TF
At the time of manufacturing a T-type polarizing plate, it is required that there be no uneven dyeing (that is, 0%), and in reality, it is required to be 0.1% or less.

[0004] On the other hand, conventionally, a polarizing plate has been prepared by dyeing and stretching a polyvinyl alcohol (hereinafter sometimes referred to as PVA) film in an aqueous solution of an iodine compound or a mixed aqueous solution of a boron compound and an iodine compound. After drying, lamination processing is manufactured,
In performing such a dyeing treatment and a stretching treatment, it is necessary to immerse such a film in these solutions, and as for a convertible line for manufacturing a polarizing plate in such a process, a bathtub for storing these solutions is provided. Guide rolls or nip rolls are usually arranged in the bath, and the bearings of such rolls are either placed in these liquids or placed in contact with these liquids. In any case, no matter what kind of shaft seal is applied to protect the bearing, the bearing used must be in contact with the liquid due to the exudation of these solutions, gas sublimated from these solutions, solid iodine after solidification, Exposure to a solution containing dissolved iodine that has sublimed due to condensation of moisture is unavoidable, that is, such bearings are subject to short-term corrosion. Is not, by such corrosion, operational (particularly uneven dyeing occurs) stop and occurrence of foreign matters or uneven dyeing occurs a great deal of damage has occurred. Further, the boron compound used in the stretching in the production of the polarizing plate has a low solubility in water, and the bearing is exposed to the solution of the boron compound / iodine compound mixed aqueous solution used in the production of the polarizing plate and dried as it is. When cooled below the precipitation temperature, precipitated crystals of boron compounds (iodine also coexists) are generated near the bearing portion and enter the bearing, so wear due to the precipitated crystals of the bearing (iodine also coexists) is unavoidable and corrosion of iodine is inevitable. Further accelerating it, causing the same damage as above. When performing the next drying treatment, the equipment is dried using a blower and equipment with guide rolls. However, the iodine vapor and water vapor evaporate from the film, and the mixed vapor of the iodine vapor and water vapor accelerates bearing corrosion. And the same damage as above.

[0005]

Normally, the bearing of the bearing portion of the apparatus is protected by a shaft seal such as a labyrinth seal, a mechanical seal, an oil seal, a gland packing, a Wilson packing, an O-ring, and a flinger. However, in the case of a polarizing plate manufacturing apparatus, these seals are used so as not to allow the solution or vapor of iodine to enter the bearing portion. However, any of these seals is broken by iodine. that is,
These shaft seals (constituting metal and plastic materials) were broken by iodine corrosion and corroded by iodine invading bearings, and iodine sublimated from these liquids and diffused into the air. Later, again
Condensed (coagulated) into walls, floors, details of machine parts, air ducts, lubricating oil, etc., and moved. Further, the movement of sublimation → condensation (coagulation) → sublimation → condensation (coagulation) was repeated, thereby sealing the shaft. Even if the seal is not breached, it will be corroded by the iodine vapor or iodine solids that get in. (Because machines are inevitably unsealed and lubricated for these bearings for regular maintenance. That's because).

On the other hand, corrosion resistance has been sufficiently improved in hydrochloric acid, chlorine gas, aqueous hypochlorite solution, iodine compound aqueous solution, iodine vapor, sulfuric acid, and aqueous solution of organic acid such as lemon water. There are few stainless steel materials that can be exhibited, and there is no stainless steel material that can sufficiently exhibit corrosion resistance especially in an aqueous solution of an iodine compound or in an iodine vapor. Furthermore, the stainless steel material for bearings that can be used even when such substances are exposed to water or exposed to steam in an aqueous solution of iodine compound or iodine vapor is not only corrosion-resistant to these iodine, but also the cutting process when molding into a bearing. It must satisfy the properties and toughness when used as a bearing, and there is no good material.

For example, SUS304, SUS304L, S
US309, SUS309S, SUS310S, SUS
311, SUS314, SUS321, SUS347,
SUS348, SUS403, SUS410, SUS4
05, SUS406, SUS410, SUS414, S
US430, SUS430F, SUS431, SUS4
40A-C, SUS442, SUS443, SUS44
6, SUS447JI, SUS630, SUS JIS
35, SUS XM 27, SHOMAC 30-2,
SEA-CURE and HR-8N are unsuitable because they have no durability because the raw material itself corrodes in an aqueous solution of an iodine compound or in the vapor of iodine without needing to be a bearing. SUS316L, S
US317, SUS317L, SUS316J1, SU
S316J2, CARPENTER 20, MONT
Has relatively good iodine corrosion resistance, but does not satisfy the cutting workability at the time of molding into a bearing, the surface treatment workability after molding, the gin property at the time of use as a bearing, etc. It is inappropriate and cannot be satisfactorily processed at the time of finishing processing as a bearing. Further, a bearing capable of satisfying wear resistance and load resistance cannot be obtained. As a result, in the dyeing process, stretching process, and drying process of the polarizing plate manufacturing process, the running accuracy of the film, that is, the rotational accuracy of the bearing. For a long time,
At present, there is no bearing that can withstand iodine corrosion.

That is, in view of the above background, the present invention relates to a polarizing plate manufacturing apparatus and ancillary equipment in the vicinity thereof, and particularly to a corrosion-resistant apparatus which can be used in an aqueous solution of an iodine compound, an aqueous solution of a boron compound / iodine compound mixture, or in an iodine vapor. Properties, wear resistance,
Obtain good load-bearing bearings and maintain the running accuracy of the film during dyeing / stretching, especially during dyeing / stretching of polarizing plates for TFT-type liquid crystal display devices, and do not generate uneven dyeing defects. With the goal.

[0009]

In order to solve the above-mentioned problems, the present inventor has proposed that a bearing of a convert-tech line for producing a polarizing plate has a nickel content of 4.0 to 10.5% by weight and a chromium content of 20%. A convertible line using a bearing made of stainless steel containing 0.1 to 35.0% by weight and molybdenum: 0.5 to 2.9% by weight meets the above purpose, and furthermore, X = Cr + Mo + 1.5. Si
+ 0.5 · Nb, Y = Ni + 30 · C + Mn,
It has been found that when using stainless steel satisfying the following formula, the effect of the present invention can be remarkably obtained, and the present invention has been completed. 0.357.X-4.29 ≦ Y ≦ 0.821.X-7.86 (1) 20.6 ≦ X ≦ 37.9 (2) 4.0 ≦ Y ≦ 10. 5 (3) where Cr: weight% of chromium in stainless steel, Mo:
Molybdenum weight percent in stainless steel, Si: weight percent of silicon in stainless steel, Nb: weight percent of niobium in stainless steel, Ni: weight percent of nickel in stainless steel, C: carbon percent in stainless steel % By weight, Mn: indicates the weight% of manganese in the stainless steel.

In the present invention, a film in which a PVA film is provided with a polarizing property by the adsorption orientation of an iodine compound is called a “dyeing film”, and a cellulose-based protective film is provided on both sides (or one side) of the “dyeing film”. When a film is provided, it is referred to as a "polarizing plate" and is distinguished.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The bearing used in the present invention is nickel:
4.0 to 10.5% by weight, chromium: 20.1 to 35.0
Stainless steel containing 0.5% to 2.9% by weight of molybdenum, and nickel of 4.5 to 2.9% by weight.
It is preferable to use stainless steel containing 7.5% by weight, chromium: 24.5 to 30.5% by weight, and molybdenum: 1.9 to 2.9% by weight. Nickel: less than 4.0% by weight, chromium: less than 20.1% by weight, molybdenum: 0.5% by weight
When the content is less than 7.5%, the corrosion resistance of the above-mentioned iodine is disadvantageously lost or the wear resistance is deteriorated. When the content of nickel exceeds 7.5% by weight, the content of chromium is 35.0% by weight.
When molybdenum exceeds 2.9% by weight,
Lost toughness, weakened to impact, poor in machinability,
It is inconvenient.

Further, in the above-mentioned constitutional range of stainless steel, X = Cr + Mo + 1.5.Si + 0.5.Nb, Y
= Ni + 30.C + Mn When the stainless steel satisfies the following equation, the effect of the present invention can be maximized. 0.357 · X-4.29 ≦ Y ≦ 0.821 · X-7.86 (1) 20.6 ≦ X ≦ 37.9 (2) 4 ≦ Y ≦ 10.5・ ・ (3) Here, Cr: weight% of chromium in stainless steel, Mo:
Molybdenum weight percent in stainless steel, Si: weight percent of silicon in stainless steel, Nb: weight percent of niobium in stainless steel, Ni: weight percent of nickel in stainless steel, C: carbon percent in stainless steel % By weight, Mn: indicates the weight% of manganese in the stainless steel. Usually, the contents of silicon, niobium, carbon and manganese are appropriately selected at 1% by weight or less, and the remaining weight% is constituted by iron.
Y <0.357.X-4.29 or 0.821.X-
When 7.86 <Y, the corrosion resistance to iodine is inferior, and when 20.6> X or 4> Y, the corrosion resistance to iodine corrosion tends to be weak, and X> 37.9. Alternatively, when Y> 10.5, the toughness tends to decrease, which is inconvenient. Preferably, the range of 27 ≦ X ≦ 33 and 5 ≦ Y ≦ 8 is optimal. X corresponds to the chromium equivalent of Schaeffler, and Y corresponds to the nickel equivalent of Schaeffler.

[0013] The method of manufacturing a bearing using such stainless steel can be manufactured by a known manufacturing method, and is not particularly limited. Usually, a stainless steel material having the above-described composition is manufactured by using a special furnace such as a high-frequency furnace or an Eru electric furnace. After hot melting into a predetermined shape by a casting method such as dry mold casting, shell mold, precision casting, centrifugal casting, etc., the temperature is 850 to 1150 ° C.
Temperature for 15 minutes to 8 hours.
/ H at a cooling rate of not more than 730 to 510 ° C, and after the cooling is stopped, the temperature is reduced to 0.5 to 730 to 490 ° C.
By reheating and holding for 10 hours and then cooling to a normal temperature range, a block for forming the above steel composition is obtained, and components such as bearing inner ring, outer ring, rolling elements, cage, cap and the like are obtained from the block. Through cutting or forging, shot blasting, acid cleaning, etc.
Assembled and manufactured.

Thus, the bearing used in the present invention is obtained and incorporated into a bearing of a convertible line for producing a polarizing plate and put into practical use. Examples of the convertible line include a polyvinyl alcohol-based film, a dyed film, and a cellulose-based film. There is no particular limitation as long as it is a line for running the film and the polarizing plate after lamination, and an auxiliary device therefor. However, a dyeing / stretching device and an auxiliary device in the vicinity thereof (specifically, a local scrubber device, a local clean device) , A local liquid circulation device, a paper passing device, a meandering correction device, a cooling device for a drive motor, etc.), a drying device and ancillary devices in the vicinity thereof (specifically, a humidity control device, a paper passing device device, a meandering correction device, Drive motor cooling device, nozzle opening / closing device, etc.)
When used in an iodine compound mixed aqueous solution, iodine vapor in the vicinity thereof, and iodine vapor, the effect can be exhibited and the object of the present application can be achieved.

Next, a convert-tech line for manufacturing a polarizing plate will be specifically described. With a convertible line for manufacturing a polarizing plate, usually, a polyvinyl alcohol-based film described below as a raw material, it is treated with an iodine compound or a boron compound, that is, specifically, usually, in an aqueous solution of an iodine compound, After dyeing while stretching at 1.1 to 3.0 times, in a boron compound / iodine compound mixed aqueous solution, while stretching at 1.5 to 5.0 times, fix the boron compound cross-linking and adjust the color. Performing a drying treatment after the production of a dyed film, a convertible line for laminating a cellulose-based film as a protective film on at least one side of the dyed film, and such a line is common, but is not limited thereto. If it is a converttech line that manufactures a polarizing plate by processing using an iodine compound or a boron compound, for example, After stretching above polyvinyl alcohol-based film, including convergence Tech line deposited with these compounds.

In the following, a description will be given of a film and a chemical used in such a convertec line. The raw material (polyvinyl alcohol-based resin) for the polyvinyl alcohol-based film is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. However, the present invention is not limited to this. Unsaturated carboxylic acids (salts,
(Including esters, amides, nitriles, etc.), olefins, vinyl ethers, unsaturated sulfonates, and the like, and may contain components copolymerizable with vinyl acetate. The thickness of the polyvinyl alcohol-based film is not particularly limited, but is preferably 20 to 150 μm, and more preferably 45 to 85 μm.
μm is preferred.

The iodine compound aqueous solution is not particularly limited, but is usually 0.001 to 100 g of iodine.
/ L, iodide compounds such as potassium iodide, sodium iodide, iodic acid, sodium iodate and the like 0.5 to 200 g / l
And used at 0-30 ° C. Also,
0.5 g / l or less of a boron compound or sodium thiosulfate described below is added depending on the purpose.
0.1% water-soluble organic solvent such as isopropyl alcohol
g / l or less.

The aqueous solution of a boron compound / iodine compound mixture is not particularly limited, but 30 to 70 g / l of a boron compound such as boric acid or borax, and 0.000001 to 5 g of iodine.
/ L, a mixed aqueous solution of 10 to 100 g / l of an iodide compound such as potassium iodide, sodium iodide, iodic acid, etc.
Used at 5-65 ° C. Depending on the purpose, zinc chloride, cobalt chloride, zinc iodide, cobalt iodide, sodium thiosulfate and potassium hydroxide are added at 0.5 g / l or less, and a water-soluble organic solvent such as methanol, isopropyl alcohol or the like is added. 0.1 g / l or less.

The cellulose-based film is made of cellulose ester as a raw material. The cellulose ester is not particularly limited as long as it is an ester of cellulose and acid, but is preferably an ester of cellulose and fatty acid, and is preferably cellulose triacetate. , Cellulose diacetate, cellulose tripropionate, cellulose dipropionate and the like are used. As a raw material for such a cellulose-based film, which is used as a polarizing plate, cellulose triacetate (cellulose triacetate) is preferable because of its low birefringence and high transmittance. The thickness of the cellulose-based film is not particularly limited.
0 to 150 μm is preferred. Usually, such a cellulose-based film becomes a laminate material for a polarizing plate after being saponified with an acid or an alkali, but the saponification-converted line is also exposed to iodine gas in circulating air and various moving iodine. Part occurs.

Next, the convertible line for manufacturing such a polarizing plate will be described more specifically. As mentioned above, the Convertech line for the production of polarizing plates is the Convertech line for dyeing, the Convertech line for stretching, the Convertech line for drying, the Convertech line for laminating with cellulose-based films, and the saponification described above. Convertec line to be processed, consisting of these auxiliary devices. These converttech lines and their associated devices will be described, but are not limited to these descriptions.

A convertible line for dyeing and a convertible line for stretching are generally made of a material which is resistant to corrosion against iodine, for example, titanium, Hastelloy C,
SUS316, rigid PVC resin, polyester resin, polyethylene resin, epoxy resin, wood, cement, glass,
A tub made of a material such as ceramic, enamel, or FRP, and a roll made of the same material (preferably titanium,
Hastelloy C, SUS316, hard PVC resin), rubber rolls whose surfaces are covered with rubber such as EPDM, silicon, etc., and drive parts for these rolls. These rolls are formed by guide rolls and drive nip rolls. At both ends of these rolls, a shaft and a bearing are provided extending to the ends of the rolls, and bearings are arranged in the bearings together with a shaft seal.

Here, usually, some of these rolls are arranged in the above-mentioned chemical solution, and such bearings are protected by a seal and are immersed in such a solution. In some cases, the bearing is arranged near the outside of the bathtub by holding the roll shaft out of the bathtub. Some of these rolls also include drive shafts, chains, sprockets, gears, belts,
Driving is performed by an electric motor device such as a vector motor via pulleys and the like, and bearings and bearings are used everywhere in these portions. These rolls are arranged in the same way, not only in such a bathtub but also before and after the bathtub, and similarly use bearings and bearings.

Next, the polarizing film subjected to the dyeing treatment and the stretching treatment is dried, and then completed as a polarizing plate by laminating a cellulose film on at least one surface. Such drying treatment is usually carried out by a dryer. This dryer is treated by a heater that generates hot air and a blower that circulates it, an exhaust fan that exhausts air containing volatile matter after drying, a nozzle that can adjust the air volume,
It is composed of a guide roll, a meandering correction roll, a spreading roll, and the like, and bearings are also used at bearings of the rotating part. The laminating process is composed of an adhesive coating device and a laminator device, and such devices are provided with various coating rolls, guide rolls, laminating rolls, meandering correction rolls, spreading rolls, and the like. Bearings are also used at various locations in the bearings of the rotating part of the accessory device.

In the present invention, as the bearing used in the above-mentioned processing step (converter line), nickel as described above: 4.0 to 10.5% by weight,
Chromium: 20.1-35.0% by weight, molybdenum: 0.1%.
The greatest feature is that a bearing made of stainless steel containing 5 to 2.9% by weight is used. Such a bearing is not particularly limited as long as it contains the metal component as described above. The bearing preferably has a Vickers hardness of 450 to 900 and a hardness of 45
When the value is less than 0, flaking is liable to occur. When the value exceeds 900, the moldability of the bearing and the dimensional accuracy of the bearing are reduced, and the dyeing unevenness tends to occur. The bearing load of the bearing is also not particularly limited, but is preferably 100 to 500 kg, and 10 to 500 kg.
If the weight is less than 0 kg, stretching cannot be performed, and vertical color streaks will occur. If the weight exceeds 500 kg, unevenness in dyeing tends to occur due to insufficient fitting accuracy between the bearing and the shaft and between the bearing and the housing.

The structure of the bearing is not particularly limited, but the diameter of the shaft on which the bearing is mounted is 15 to 5 mm.
0 mm (for example, for deep groove ball bearing, 6
002 to 6210 are preferred), and when it is less than 15 mm, the roll cannot withstand its own weight or the tension at the time of stretching.
When the thickness exceeds mm, stretching line unevenness tends to occur during stretching, which is not preferable. Also, the type of the bearing is not particularly limited, and may be a radial type, a thrust type, or a composite type thereof, and the specific type is not particularly limited. Any type of swing ball bearing, cylindrical roller bearing, conical roller bearing, and needle bearing (that is, the transmission body may be a sphere, a roller, or a needle) may be used.
These may be used singly, in a back row, or in any combination.

If the inner and outer rings of the bearing are made of stainless steel having the above-mentioned steel composition, the cap, the cage and the rolling elements are made of materials that can withstand corrosion and load during use. The material of the cap and the retainer is not particularly limited, and it is preferable to use a silicon-based resin, a fluorine-based resin, or the like other than the above stainless steel, and it is also possible to use the above stainless steel as the material of the transmission body. However, ceramics are preferred in terms of flaking and life. Although not particularly limited, such ceramics are mainly silicon nitride such as Si ₃ N ₄ , rare earth metal oxides such as Y ₂ O ₃ , aluminum oxides such as Al ₂ O ₃ , aluminum nitride, silicon carbide, magnesia ( A transmission body which is a sintered body to which MgO) and spinel (MgAl ₂ O ₄ ) are added is preferable.

Thus, in the polarizing plate manufacturing line using the present invention, uneven dyeing defects are not generated at the time of dyeing / stretching, and not only a polarizing plate for a general-purpose TN type or STN type liquid crystal display device, but also a TFT type liquid crystal display device. A polarizing plate for the device can be obtained.

In the above, the rotation axis of the conversion line of the polarizing plate manufacturing apparatus and the auxiliary equipment in the vicinity thereof have been described. In addition to these, exposure to iodine vapor or an aqueous solution of an iodine compound or an aqueous solution of a boron compound / iodine compound mixture was carried out. Equipment, for example, a circulation fan of a clean air conditioner of a clean room incorporating a convert line of a polarizing plate manufacturing apparatus, a bearing of a rotating part of an exhaust fan, an aqueous solution of an iodine compound or a mixed aqueous solution of a boron compound / iodine compound in the above-mentioned tank. The temperature control of the tank for storing the iodine compound aqueous solution and the boron compound / iodine compound mixed aqueous solution used in the bearing of the rotating part such as the circulating pump, the stirring device, the titrator, etc. Circulating pon for concentration control , Agitating equipment, a bearing of a rotating part of a titrator, a bearing of a rotating part of a fan of a scrubber device for neutralizing harmful iodine vapor generated from the above-mentioned tank, and an entrance and exit of a clean room. Bearings for rotating parts such as automatic showers, fans, and brushes for air showers and shoe cleaners, and bearings for rotating parts for adjusting the angle of cameras that monitor the inside of a clean room or a film surface.
It is also very useful for bearings in bearings in rotating parts of automatic transfer devices in clean rooms.

As described above, the use of the above-mentioned bearing in an aqueous solution of an iodine-related substance or in an iodine vapor has been mainly described. However, in a solution of the iodine-related substance in a solvent or in a strongly corrosive substance other than the iodine-related substance. In an acid and an oxidizing agent that are substances, that is, in a strong acid having a pH of 3 or less or in an oxidizing agent having a redox potential of 0.2 or more, for example, in hydrochloric acid, in chlorine gas,
Hypochlorite aqueous solution, sulfuric acid, even in organic acid aqueous solution such as lemon water, it is useful to retain a high degree of corrosion resistance and abrasion resistance, and, as described above, the present invention, Although the board production line has been described, other production lines that use these other groups of highly corrosive substances, such as the converttech line for bleaching and under-bleaching before dyeing the fabric, and the stretching of aramid film in sulfuric acid. It is also useful for the Convertech line. In the present invention, as described above, a bearing as a bearing in an aqueous solution of an iodine-related substance or in an iodine vapor, that is, a rolling bearing has been described, but other types using a component having the above steel composition have been described. It is very effective in improving the corrosion resistance and wear resistance of bearings (for example, journal bearings, floating bush bearings, thrust bearings, pivot bearings, etc.) in use of an iodine-related substance in an aqueous solution or iodine vapor.

[0030]

Next, the present invention will be described in more detail with reference to examples. Example 1 2,000 mm width, 20,000 mm length, 1000 m depth
m of titanium bathtubs arranged in the vertical direction, each having a diameter of 150 mm and a surface length of 1700 mm
20 roll guide rollers in the form of a rubber roll coated with EPDM rubber (thickness: 20 mm) and a nip roll (2
This set of four) was installed, and eight drive guide rolls and one nip roll (a set of two) were arranged at the front and rear of the two tanks and at the connection between the two tanks. Both ends of these rolls have an outer diameter of 1 to hold the rolls.
A 7 mm shaft is attached to the shaft, and a deep groove ball type bearing, type 6003 is arranged in a row on the shaft. The bearing type ball is sintered ceramics (Si ₃ N _4).
With MgAl ₂ O ₄ as a sintering aid)
The inner ring, outer ring, retainer, and cap of such a bearing are nickel: 7.1% by weight and chromium: 28.2.
% By weight, molybdenum: 2.0% by weight (X = 31.
3, Y = 8.5) stainless steel. The Vickers hardness of the bearing was 500, and the withstand load was 300 kg. The injection oil of the bearing and the shaft seal device were not used, and the one in which the roll was arranged in the tank was used in a form in which the bearing was also arranged in the tank and immersed in the used chemical solution.

A dyeing tank and a stretching tank as described above were prepared, and an aqueous iodine compound solution, that is, 0.1 g of iodine /
and a mixed aqueous solution (20 ° C.) of potassium iodide 18 g / l
0 m ³ , and a boron compound / iodine compound mixed aqueous solution, namely, boric acid 50 g / l and iodine 0.000
003 g / l, potassium iodide 60 g / l mixed aqueous solution (5
(0 ° C.) 30 m ³ , thickness 80 μm, width 1300
mm, degree of polymerization 4700, degree of saponification 99.6 mol% Polyvinyl alcohol-based film is dyed while stretching 1.5 times in a dyeing tank, and then stretched 4.5 times in a stretching tank to fix boric acid and adjust color. After performing a drying treatment at 50 ° C. for 5 minutes to obtain a polarizing film having a thickness of 20 μm and a width of 650 mm, a cellulose triacetate film having a thickness of 80 μm and a width of 670 mm is laminated on both sides of the polarizing film to transmit light. A polarizing plate having a ratio of 44.5% and a degree of polarization of 99.95% (measured by Otsuka Electronics MCPD Lets 2000) was obtained.

The length of the polarizing plate in the width direction and the length in the longitudinal direction are 4
A sample for cutting evaluation was obtained at 00 mm, and the following evaluation was performed.・ (Dyeing unevenness defect) The transmittance at the center of the diagonal line of the sample,
The degree of polarization was measured. Next, the transmittance and the degree of polarization of the same position of the polarizing plate were measured under the same dyeing and stretching conditions after 2000 hours of actual use of the bearing. Regarding the dyeing unevenness defect, a sample having a transmittance unevenness of 0.1% or less and a polarization degree unevenness of 0.1% or less was evaluated as ○, and the others were evaluated as x.

Example 2 A polarizing plate was manufactured in the same manner as in Example 1 except that the ceramic rolling element of the bearing used in Example 1 was changed to the same stainless steel as the inner ring, outer ring, retainer and cap.
Evaluation was performed in the same manner as in Example 1. The Vickers hardness of the bearing was 500, and the withstand load was 300 kg.

Comparative Example 1 The inner ring, outer ring, cage, and bearing of the bearing used in Example 1
Nickel: 0.5% by weight, chromium: 16.5
% By weight, molybdenum: 0.5% by weight (X = 1
7. . 5, Y = 31.0) stainless steel (SUS44)
A polarizing plate was manufactured in the same manner as in Example 1 except that the temperature was changed to 0C), and evaluated in the same manner as in Example 1. The Vickers hardness of such a bearing is 650, and the withstand load is 50 kg.
Met.

Comparative Example 2 The inner ring, outer ring, cage, and bearing of the bearing used in Example 1
Nickel: 3.5% by weight, chromium: 16.5
% By weight, molybdenum: composition of 0.1% by weight or less (X = 1
A polarizing plate was manufactured and evaluated in the same manner as in Example 1 except that the stainless steel (SUS630) of 7.5, Y = 6) was used. The Vickers hardness of the bearing was 500 and the load capacity was 50 kg.

Comparative Example 3 Inner ring, outer ring, cage, and bearing of the bearing used in Example 1
Nickel: 9.5% by weight, chromium: 18.5
% By weight, molybdenum: composition of 0.1% by weight or less (X = 2
0.3, Y = 10.3) stainless steel (SUS30
A polarizing plate was manufactured in the same manner as in Example 1 except for changing to 4), and evaluated in the same manner as in Example 1. The Vickers hardness of the bearing was 200 and the load resistance was 10 kg.

Comparative Example 4 The inner ring, outer ring, cage, and bearing of the bearing used in Example 1
Nickel: 12.3% by weight, chromium: 17.
2 wt%, molybdenum: 2.5 wt% composition (X = 2
0.2, Y = 14.2) stainless steel (SUS31)
A polarizing plate was manufactured in the same manner as in Example 1 except for changing to 6), and evaluated in the same manner as in Example 1. The Vickers hardness of the bearing was 200 and the load resistance was 10 kg.

Table 1 shows the evaluation results of the uneven dyeing defects of the examples and the comparative examples.

[Table 1]

[0039]

According to the present invention, nickel: 4.0 to 10.5 is added to a bearing of a convertible line for producing a polarizing plate.
Since a bearing made of stainless steel containing 2% to 35.0% by weight of chromium, 20.1 to 35.0% by weight of molybdenum and 0.5 to 2.9% by weight of molybdenum is used, a polarizing plate free from uneven dyeing defects can be obtained. Can be

Claims (7)

[Claims] 1. A bearing portion of a convertible line for producing a polarizing plate is provided with nickel: 4.0 to 10.5% by weight, chromium: 20.1 to 35.0% by weight, molybdenum: 0.5.
A converttech line characterized by using a bearing made of stainless steel containing up to 2.9% by weight. 2. X = Cr + Mo + 1.5.Si + 0.5
The stainless steel which satisfies the following formula when Nb and Y = Ni + 30.C + Mn.
Convertech line described. 0.357 · X-4.29 ≦ Y ≦ 0.821 · X-7.86 (1) 20.6 ≦ X ≦ 37.9 (2) 4 ≦ Y ≦ 10.5・ ・ (3) (where Cr: weight% of chromium in stainless steel, M
o: weight% of molybdenum in stainless steel, Si: weight% of silicon in stainless steel, Nb: weight% of niobium in stainless steel, Ni: weight% of nickel in stainless steel, C: weight% of stainless steel % By weight of carbon, Mn: indicates the% by weight of manganese in stainless steel. ) 3. The method of claim 1, wherein the bearing is placed in an iodine compound aqueous solution.
The converttech line according to claim 1 or 2, wherein the convertine line is used in one of a boron compound / iodine compound mixed aqueous solution and iodine vapor. 4. A bearing having a Vickers hardness of 450 to 450.
The convert line according to any one of claims 1 to 3, wherein the number is 900. 5. The bearing has a withstand load of 100 to 500 k.
The converttech line according to any one of claims 1 to 4, wherein g is g. 6. The convert-tech line according to claim 1, wherein the shaft diameter of the bearing is 15 to 50 mm. 7. The convert-tech line according to claim 1, wherein the rolling elements of the bearing are ceramic.