JP2001018192A - Synthetic resin cylindrical film cutting method and cylindrical molding die for cutting synthetic resin cylindrical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly cut a synthetic resin cylindrical film in the circumferential direction with accuracy without a slip. SOLUTION: A synthetic resin cylindrical film 2 is inserted around the outer periphery of a cylindrical molding die 1 provided with circumferential grooves 1a at the outer surface, and heated to the glass transition temperature of the synthetic resin cylindrical film 2 or to the softening point temperature or higher to form recessed deformed parts at the synthetic resin cylindrical film 2 parts on the grooves 1a, and then the synthetic resin cylindrical film 2 is cut along the recessed deformed parts with a cutting means. The groove 1a is formed near one end or both ends of the cylindrical molding die 1, and its structure has a U-shaped or V-shaped cross section. The synthetic resin cylindrical film 2 inserted around the outer periphery of the cylindrical molding die 1 can be cut along the recessed deformed parts with the cutting means while being circumferentially rotated together with the cylindrical molding die 1. The synthetic resin cylindrical film 2 is formed of a polyimide cylindrical film or the like formed by centrifugal coating, for instance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a flexible synthetic resin cylindrical film and a cylindrical mold for cutting the synthetic resin cylindrical film, and more particularly, to a static electricity such as a copying machine, a printer, a facsimile machine and the like. The present invention relates to a method for cutting a cylindrical film used as an endless belt for an intermediate toner carrier in a copying apparatus.

[0002]

2. Description of the Related Art Since a belt-like intermediate transfer member in an electrostatic copying machine is used for full-color image formation, a belt-like intermediate transfer member is required to be capable of color overlay with high precision. This intermediate transfer body is attached as a unit to the image forming apparatus,
When used as a belt, it is used as an endless belt.

The endless belt is obtained by (a) a method of laminating a sheet-like film at an end, (b) a method of dipping a synthetic resin liquid inside and outside a cylindrical mold, and (c) spraying an inner surface of the cylindrical mold. It is manufactured by a method of coating or stringing, or (d) an inflation method.

An endless belt used in an electrostatic copying machine is required to have properties such as heat resistance, flame retardancy, tensile strength, bending strength, and electrical stability. It is composed of a polyimide that can be filled. Polyimide is a resin that can be used as an adhesive because of its good adhesiveness, and therefore cannot be used to directly form a cylindrical film. Therefore, conventionally, for example, a solution of polyamic acid (also called polyamic acid), which is a precursor of polyimide, is centrifugally applied to a cylindrical coating mold of stainless steel or the like to form a cylindrical film,
This is heated and dried, and then heat-cured and imidized to form a polyimide cylindrical film. The polyamic acid solution is, for example, pyromellitic anhydride and 4,4 ′.
-Diaminodiphenyl ether is obtained by solution polymerization of two kinds of monomers in a polar solvent such as dimethylformamide.

In the centrifugal coating molding method, a resin solution is poured into the inner surface of a cylindrical coating die made of rotating aluminum, brass, stainless steel or the like by means of spray coating or the like.
This is a forming method in which the coating liquid is spread in the axial direction by the centrifugal force to form a uniform cylindrical film. The resin cylindrical film formed by the centrifugal coating method of the resin solution is dried and cured if necessary, and then removed from the cylindrical coating die to form an endless belt. According to the centrifugal coating molding method, (1) the film thickness can be arbitrarily adjusted by the amount of the coating solution, (2) the coating solution can be applied only in a required amount, and the efficiency is high. ) Since the inside of the cylindrical coating type is a closed space, there is an advantage that the solvent can be efficiently recovered outside by providing a solvent trap in the exhaust path when removing the solvent. .

[0006]

However, when the polyamic acid is centrifugally applied to the cylindrical coating type, if the cylindrical coating type has a rotational deflection, the thickness of the formed cylindrical film will vary, and moreover, Since the axial end of the cylindrical film to be formed does not become a straight line in the circumferential direction, there has been a problem that the dimensions cannot be adjusted to an appropriate size when the polyamic acid is centrifugally applied to the cylindrical coating mold.

Therefore, a polyamic acid film is formed in a long length on a cylindrical mold, and the polyamic acid cylindrical film is cured by heating, and then the polyimide film having a large variation in thickness at both ends of the polyimide cylindrical film obtained by demolding is cut. Then, we tried to make a polyimide cylindrical film of the size necessary to make an endless belt to be attached as a unit to the image forming apparatus.However, since the polyimide cylindrical film is a flexible material, it was cut in a straight line with high dimensional accuracy. There was a problem that you can not.

In addition, it is possible to extrapolate the polyimide cylindrical film obtained by releasing the mold from a cylindrical molding die, support the polyimide cylindrical film with the cylindrical molding die, and cut the polyimide cylindrical film from the outside with a blade. It is conceivable that when the polyimide cylinder film supported by such a cylindrical mold is cut from the outside with a blade, the polyimide cylinder film slips and twists, so that the polyimide cylinder film has a single line in the circumferential direction with high dimensional accuracy. There was a problem that cutting could not be performed as a clean straight line.

The object of the present invention is to solve such a problem. That is, an object of the present invention is to cut a synthetic resin cylindrical film smoothly in the circumferential direction with high precision and without slippage.

[0010]

Means for Solving the Problems In order to achieve the above object, the present inventor extrapolates a synthetic resin cylindrical film into a cylindrical mold having a circumferential groove formed on an outer surface thereof, and replaces the synthetic resin cylindrical film with the synthetic resin cylindrical film. After forming a concave deformed portion in the synthetic resin cylindrical film portion on the groove by heating to a temperature equal to or higher than the glass transition temperature or softening point, when cutting the synthetic resin cylindrical film along the concave deformed portion by cutting means, Due to the concave deformed portion formed on the groove due to the contraction of the synthetic resin cylindrical film, the cutting boundary line at the time of cutting the synthetic resin cylindrical film becomes clear, and therefore, the synthetic resin cylindrical film can be cut accurately in the circumferential direction. To complete the present invention.

That is, according to the first aspect of the present invention, a synthetic resin cylindrical film is extrapolated to a cylindrical mold having a circumferential groove formed on an outer surface thereof, and the cylindrical film is used for the glass transition temperature or softening point of the synthetic resin. Forming a concave deformed portion in the synthetic resin cylindrical film portion on the groove by heating to the above temperature, and then cutting the synthetic resin cylindrical film along the concave deformed portion by cutting means; Cutting method.

According to a second aspect of the present invention, in the first aspect of the present invention, the groove is formed near one end or near both ends of the cylindrical mold.

According to a third aspect of the present invention, in the first or second aspect, the groove has a U-shaped cross section or a V-shaped cross section.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the synthetic resin cylindrical film extrapolated to the cylindrical mold is circumferentially moved together with the cylindrical mold. The synthetic resin cylindrical film is cut by cutting means along the concave deformed portion while rotating.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the synthetic resin cylindrical film is a synthetic resin cylindrical film formed by centrifugal coating. It is.

The invention described in claim 6 is the invention described in any one of claims 1 to 5, wherein the synthetic resin cylindrical film is a polyimide cylindrical film.

According to a seventh aspect of the present invention, there is provided a cylindrical molding die for cutting a synthetic resin cylindrical film, wherein a circumferential groove is provided on an outer surface of the cylindrical molding die.

[0018] The invention described in claim 8 provides the invention described in claim 7
The groove is formed near one end or near both ends of the cylindrical mold.

The invention described in claim 9 is the invention according to claim 7
Alternatively, in the invention described in Item 8, the groove has a U-shaped cross section or a V-shaped cross section.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory sectional view of a method for cutting a synthetic resin cylindrical film according to an embodiment of the present invention. FIG. 2 is a cross-sectional explanatory view showing a cutting process of a method for cutting a synthetic resin cylindrical film according to an embodiment of the present invention, and FIG.
Shows a state in which the cutting blade is brought close to the concavely deformed portion of the synthetic resin cylindrical film, (b) shows a state in which the synthetic resin cylindrical film is cut, and (c) shows a state in which the synthetic resin cylindrical film is This shows a state in which, after removing the end cuts, it is removed by air blow. FIG. 3 is an explanatory cross-sectional view illustrating a method of forming a polyimide cylindrical film.

In the present invention, the synthetic resin cylindrical film to be cut (see 2 in FIG. 1) is formed on the inner surface of a slowly rotating cylindrical coating mold 4 by centrifugal coating molding, that is, as shown in FIG. A synthetic resin coating film 5 is formed by applying a resin solution, and then the cylindrical coating mold 4 is rotated at a high speed to make the synthetic resin coating film 5 uniform, and then sufficiently dried and, if necessary, heat-cured. And formed. Such a synthetic resin cylindrical membrane 2
May be molded by a molding method other than the centrifugal coating molding method, as long as the object of the present invention is not violated.

Such a synthetic resin cylindrical film 2 is shown in FIGS.
As shown in FIG. 1, the outer surface is extrapolated to a cylindrical mold 1 provided with a circumferential groove 1a, and this is heated to a temperature equal to or higher than the glass transition temperature or softening point of the synthetic resin cylindrical film 2 to thereby form the groove 1a. After forming the concave deformed portion 2a in the upper synthetic resin cylindrical film portion,
The synthetic resin cylindrical film 2 is cut along the concave deformed portion 2a with a cutting blade 3
And the like. 2b is a cutting part.

As described above, when the synthetic resin cylindrical film 2 is heated to a temperature higher than its glass transition temperature or softening point, the synthetic resin cylindrical film 2 contracts and comes into close contact with the cylindrical mold 1, and the grooves 1
Since the concave deformed portion 2a is formed at the portion of the synthetic resin cylindrical film 2 on a, the cutting boundary line at the time of cutting the synthetic resin cylindrical film 2 becomes clear, and therefore, the synthetic resin cylindrical film 2 is moved in the circumferential direction. It is possible to cut straight lines with high accuracy.

If the groove 1a is formed in the vicinity of one end or both ends of the cylindrical mold 1, a portion having a large variation in film thickness which tends to be formed in the end portion of the synthetic resin cylindrical film 2 can be cut off. . As shown in FIG.
When the grooves 1a, 1a are formed near both ends of the groove, the width of the synthetic resin cylindrical film 2 having a predetermined width is formed between the grooves 1a, 1a. The groove 1a has a U-shaped cross section or a V-shaped cross section.
The groove may be in the shape of a letter, but may be a groove having any other shape as long as the object of the present invention is not adversely affected.

The synthetic resin cylindrical film 2 extrapolated to the cylindrical mold 1 is positioned with a cutting means such as a cutting blade 3 on the concavely deformed portion 2a, and the cutting means is, for example, shown in FIG.
When pressed in the direction of the arrow shown in FIG. 1 and then rotated in the circumferential direction together with the cylindrical mold 1, the synthetic resin cylindrical film 2 can be cut along the concave deformed portion 2a by cutting means such as a cutting blade 3. . Synthetic resin cylindrical membrane 2 extrapolated to cylindrical mold 1
Is in close contact with the cylindrical mold, and when the synthetic resin cylindrical film 2 is cut along the concave deformed portion 2a by a cutting means such as a cutting blade 3 while rotating in the circumferential direction together with the cylindrical mold 1,
There is no displacement, and cutting can be performed accurately and precisely in the circumferential direction. The cut synthetic resin cylindrical film 2 is
After removing the end portion, for example, if it is pulled while air blowing in the direction of the arrow shown in FIG. 2C, it can be taken out smoothly.

The synthetic resin cylindrical film 2 is preferably a polyimide cylindrical film formed by a centrifugal coating method. However, when heated to a temperature higher than the glass transition temperature or the softening point, the film shrinks and adheres to the cylindrical mold 1. As long as it is a synthetic resin cylindrical film, a synthetic resin cylindrical film formed by a molding method such as a centrifugal coating method or a dipping method other than the polyimide cylindrical film may be used.

The cylindrical mold 1 used in the present invention
May be heat-resistant at a heat treatment temperature, that is, a temperature equal to or higher than the glass transition temperature or softening point of the synthetic resin. As the special cylindrical mold used in the present invention, there are a fluororesin-coated cylindrical mold, a heat-resistant glass cylindrical mold, and an amorphous silicon-coated cylindrical mold. However, the cylindrical mold 1 used in the present invention can sufficiently function even if it is an aluminum cylindrical mold, a brass cylindrical mold, or an iron cylindrical mold having a smooth upper surface, which is well known in the art.

[0028]

EXAMPLES (Example 1) Inner diameter 182 mm, length 700 m
Then, a polytetrafluoroethylene sheet was adhered to the inner surface near both ends of the cylindrical coating type of m, and was blocked. While slowly rotating the damped cylindrical coating mold, a polyamic acid solution (Trenice # 3000, manufactured by Toray Industries, Inc.) and a carbon black as a conductor were reduced to 30% with a solvent DMAC on the inner surface portion thereof. The diluted solution was applied by injection coating, and then the cylindrical coating mold was rotated at a high speed to make the coating film uniform. After drying the coating film thus uniformized,
It was cured by heating to 300 ° C. to form a polyimide cylindrical film having a width of 500 mm in the axial direction. Molded polyimide cylindrical membrane,
A lactam-treated aluminum cylindrical mold having an outer diameter of 180 mm and a length of 600 mm is inserted into an aluminum cylindrical mold having a V-shape having a depth of 0.5 mm formed in a circumferential direction at 60 mm from both ends thereof. Was put into a high-temperature bath and heated at 300 ° C. for 30 minutes. When the polyimide cylindrical film covered with the cylindrical mold was cooled and taken out, two concave deformed portions were formed on the polyimide cylindrical film along the grooves of the cylindrical mold. This cylindrical mold is attached to a chuck of a lathe, and after aligning the cutting means on the concave deformed portions of the two lines, the cutting means is pressed against the concave deformed portion and slowly rotated once in the circumferential direction. Meanwhile, the polyimide cylindrical film was cut along the concave deformed portion with a cutting blade. The cut ends at both ends of the polyimide cylindrical film were removed by hand, and the remaining end of the polyimide cylindrical film was pulled out while air blowing. Heating in the high-temperature bath does not involve solvent removal or heat-curing reaction, and thus can be easily removed from the cylindrical mold by floating with air blow. A non-stop tape was attached to the polyimide cylindrical film obtained in this way, and this was used as a transfer belt and attached to a transfer belt unit of a full-color copying machine (Pretail, manufactured by Ricoh Co., Ltd.). There was no problem such as displacement, and a good image was obtained.

(Comparative Example 1) A polyimide cylindrical film was formed in the same manner as in Example 1, and this was extrapolated to a cylindrical mold having no groove without reheating. Then, in the same manner as in Example 1, a cylindrical mold having the polyimide cylindrical film extrapolated was attached to a chuck, and the polyimide cylindrical film was cut by pressing a cutting blade against the polyimide cylindrical film. However, at the time of cutting, a slight gap was formed in the polyimide cylindrical film, and twist was generated from the position, and the cutting position was shifted and shifted.

Comparative Example 2 A polyimide cylindrical film was formed in the same manner as in Example 1, and this was extrapolated to a cylindrical mold having a groove with a predetermined width without reheating. And Example 1
In the same manner as described above, a cylindrical mold having the polyimide cylindrical film extrapolated was attached to a chuck, and a cutting blade was pressed against the polyimide cylindrical film to cut the polyimide cylindrical film. However, since there is a gap between the polyimide cylindrical film and the groove of the cylindrical mold, the cut portion of the polyimide cylindrical film is bent, and therefore, at the time of cutting,
Some parts cannot be cut in the circumferential direction. When the uncut portion was strongly pressed by the cutting blade, cutting could be performed, but the cylindrical mold was damaged by the cutting blade.

The advantages of the present invention are as follows. According to the first and seventh aspects of the present invention, a synthetic resin cylindrical film extrapolated to a cylindrical mold having a circumferential groove formed on the outer surface is heated to a temperature higher than the glass transition temperature or softening point of the synthetic resin. To form a concave deformed portion in the synthetic resin cylindrical film portion on the groove, so that the cutting boundary line at the time of cutting the synthetic resin cylindrical film becomes clear, and therefore, the synthetic resin cylindrical film is formed along the concave deformed portion. When the film is cut by the cutting means, the synthetic resin cylindrical film can be cut accurately in the circumferential direction. Also,
When the synthetic resin cylindrical film is heated to a temperature equal to or higher than the glass transition temperature or softening point of the synthetic resin, the synthetic resin cylindrical film contracts and adheres to the cylindrical mold, so that it does not slip when cutting,
Can be cut smoothly.

According to the invention described in claims 2 and 8,
Since the groove is formed near one end or both ends of the cylindrical mold, it is possible to cut off a portion of the synthetic resin cylindrical film having a large variation in film thickness which is likely to be formed at the end portion.

According to the third and ninth aspects of the present invention,
Since the groove has a U-shaped cross section or a V-shaped cross section, the cutting means such as a cutting blade does not shift in position, and the synthetic resin cylindrical film can be cut accurately in the circumferential direction.

According to the fourth aspect of the present invention, the synthetic resin cylindrical film extrapolated to the cylindrical mold is rotated along with the cylindrical mold in the circumferential direction along the concavely deformed portion. Is cut by the cutting means, so that the cutting means such as a cutting blade does not shift, and the synthetic resin cylindrical film can be cut accurately in the circumferential direction.

According to the invention described in claims 5 and 6,
A synthetic resin cylindrical film in which a synthetic resin cylindrical film is formed by centrifugal coating,
For example, in the case of a polyimide cylindrical film, the polyimide cylindrical film has a variation in film thickness at the end portion, but when the cutting method of the present invention is applied, the end portion can be cut with high accuracy, so that the It can be effectively used as an endless belt in a copying machine.

[0036]

According to the present invention, the synthetic resin cylindrical film can be cut smoothly in the circumferential direction with high precision and without slippage.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a method for cutting a synthetic resin cylindrical film according to an embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view showing a cutting process of a method for cutting a synthetic resin cylindrical film according to an embodiment of the present invention, and (a).
Shows a state in which the cutting blade is brought close to the concavely deformed portion of the synthetic resin cylindrical film, (b) shows a state in which the synthetic resin cylindrical film is cut, and (c) shows a state in which the synthetic resin cylindrical film is This shows a state in which, after removing the end cuts, it is removed by air blow.

FIG. 3 is a cross-sectional explanatory view illustrating a method of forming a polyimide cylindrical film.

[Explanation of symbols]

 Reference Signs List 1 cylindrical molding die 1a groove 2 synthetic resin cylindrical film 2a concave deformation part 2b cutting part 3 cutting blade 4 cylindrical coating die 5 synthetic resin coating film

Continued on front page F-term (reference) 2H032 AA15 BA09 BA18 3C021 AA02 EA08 4F205 AA40 AD12 AG08 AG16 AG23 AG28 AJ02 GA02 GA15 GB01 GC01 GE01 GN01 GN13 GN28 GN29 GW06 GW23

Claims (9)

[Claims] 1. A synthetic resin cylindrical film is extrapolated into a cylindrical mold having a circumferential groove formed on an outer surface thereof, and heated to a temperature higher than a glass transition temperature or a softening point of the synthetic resin. A method for cutting a synthetic resin cylindrical film, comprising: forming a concave deformed portion in the synthetic resin cylindrical film portion; and cutting the synthetic resin cylindrical film along the concave deformed portion by cutting means. 2. The method for cutting a synthetic resin cylindrical film according to claim 1, wherein the groove is formed near one end or near both ends of the cylindrical mold. 3. The method for cutting a synthetic resin cylindrical film according to claim 1, wherein the groove has a U-shaped cross section or a V-shaped cross section. 4. A synthetic resin cylindrical film cut along cutting concave portions while rotating a synthetic resin cylindrical film extrapolated in a cylindrical mold together with the cylindrical mold in a circumferential direction. The method for cutting a synthetic resin cylindrical film according to any one of claims 1 to 3. 5. The synthetic resin cylindrical film is a synthetic resin cylindrical film formed by centrifugal coating.
The method for cutting a synthetic resin cylindrical film according to any one of the above. 6. The method for cutting a synthetic resin cylindrical film according to claim 1, wherein the synthetic resin cylindrical film is a polyimide cylindrical film. 7. A cylindrical mold for cutting a synthetic resin cylindrical film, wherein a circumferential groove is provided on an outer surface of the cylindrical mold. 8. The cylindrical mold for cutting a synthetic resin cylindrical film according to claim 7, wherein the groove is formed near one end or near both ends of the cylindrical mold. 9. The cylindrical mold for cutting a synthetic resin cylindrical film according to claim 7, wherein the groove has a U-shaped cross section or a V-shaped cross section.