JPH09315637A - Film roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce deforming force received by a film layer from a winding end so as to improve planeness of a film at a core part by setting an angle of an end face over the front and rear faces of the film to the core surface into a specific range, and setting the thickness of the film into a specific range. SOLUTION: An angle θ of a film end 5 to the core surface 1a in the winding end of an innermost layer film 2a brought into contact with a core 1 in a film roll is set to a range of about 5-85 deg., and the thickness of a film 2 is to be in a range of about 25-1000μm. The winding strength of the film roll is measured by a rubber hardness meter and set in a range of about 70-99 deg.. The core 1 is made of paper, paper impregnated with resin, plastic, glass epoxy or metal. As a result, the deformation of the film at a core part caused by the step difference of the film at the core part is hardly generated, and the planeness of the film after being pulled out is kept satisfactory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film roll which has a good flatness after being drawn out and is excellent in processing such as coating, printing and vapor deposition, and more particularly to a film roll suitable for a polyester film.

[0002]

2. Description of the Related Art Polyester films have been widely used in various applications such as magnetic tapes, adhesive tapes, printed products, electrical insulating products, photographic image receiving bases and floppy disks because of their flatness and dimensional stability. The polyester film has been wound around a core in a roll shape, and has been subjected to processing such as coating, printing and vapor deposition from the surface layer of the roll to the core portion.

However, the winding core of the film roll has a large winding tightness and often causes wrinkles and poor planarity, and sometimes the winding core cannot be processed. Especially when the polyester film is thick,
That is, a step is formed by the winding end of the innermost film, and the step deforms the film of the core portion wound on the film, which causes poor flatness when rewound.
The poor planarity may reach several tens of meters or several hundreds of meters from the winding core, causing problems in processing such as coating, printing and vapor deposition.

As an attempt to improve the transfer to the film, for example, Japanese Patent Laid-Open No. 61-98569 has been proposed.
Further, as an attempt to improve the wrinkles of the film of the winding core, for example, Japanese Patent Laid-Open No. 62-222976 has been proposed. However, the planarity failure due to the transfer of the step by the film thickness is
It has not been sufficiently improved.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a film roll which has improved flatness due to a thickness difference at the winding end of the film and is excellent in processing stability such as coating, printing and vapor deposition. To do.

[0006]

In order to solve the above-mentioned problems, the film roll of the present invention is a film roll in which a film is wound on a core, of the winding end of the film of the innermost layer which contacts the core, The angle between the front and back surfaces of the film with respect to the core surface is in the range of 5 to 85 °, and the thickness of the film is in the range of 25 to 1000 μm.

More precisely, the angle of the film end surface at the winding end of the film is the angle formed by the end surface and the surface (contact surface) extending in the tangential direction of the core surface at the position of the end surface. . In the case where the end surface extends in a direction orthogonal to the film longitudinal direction, that is, in the film width direction, a cross section formed by the tangent line between the end surface and the core surface when the film winding end is cut by the cut surface extending in the film longitudinal direction. It becomes an angle. However, this end surface may extend linearly in the film width direction, or may extend in a curved shape or a zigzag shape. Further, it may extend obliquely with respect to the film width direction. When it extends obliquely, it may extend linearly, or may extend curvedly or zigzag.

In such a film roll according to the present invention, the angle of the film end face at the film winding end is in the range of 5 to 85 ° with respect to the core surface.
As compared with the conventional case of substantially 90 °, the deformation force that the film layer wound on the film layer receives from the winding end becomes smaller, and the flatness of the film in the winding core portion when the film is pulled out from the film roll is reduced. improves.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. First, the material of the film of the film roll according to the present invention is not particularly limited, and the present invention can be applied to any film-shaped material typified by a plastic film. Among them, the present invention is suitable for a polyester film that requires a high level of flatness, as described above.

The polyester film in the present invention is
Although it may be an unstretched film or a uniaxially stretched film, the effect of the present invention is particularly large in the case of a biaxially stretched film which is stretched and oriented in the longitudinal direction and the width direction. As the polyester film, a polyester film represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or a polyester film of a copolymer thereof can be used. Alternatively, they may be a laminated film or a strengthened film. In addition, inside the film, internally precipitated particles made during polyester polymerization, calcium carbonate,
It may contain inert inorganic particles or organic particles typified by aluminum oxide, silicon oxide, titanium oxide and the like.

As shown in FIG. 1, the film roll of the present invention is formed as a film roll 3 in which a film 2 is wound around a core 1 in a roll shape. In this film roll 3, as shown in FIG. 2, the angle θ of the film end surface 5 at the winding end of the innermost layer film 2a in contact with the core 1 with respect to the core surface 1a may be in the range of 5 to 85 °. is necessary. If the angle of the end surface 5 is larger than 85 °, the flatness failure due to the transfer to the upper film 2b, 2c, ... May reach several tens of meters from the winding core, which is not preferable. If the angle of the end face 5 is smaller than 5 °,
It is not preferable because the workability of sticking to the core 1 becomes poor. A more preferable range of the angle of the end face 5 is 15 to 7.
5 °, and a more preferable range is 30 to 60 °.

Further, in the film roll of the present invention, the film thickness needs to be in the range of 25 to 1000 μm. If the film thickness is more than 1000 μm,
Since the rigidity of the film is strong, the transfer is small and the effect of the present invention is hardly obtained. If the thickness of the film is less than 25 μm, the workability of attaching the film to the core 1 is deteriorated, which is not preferable. The more preferable range of the film thickness is 38 to 5
00 μm, and a more preferable range is 50 to 350 μm.

Further, in the film roll of the present invention, particularly in the polyester film roll, the winding hardness of the film roll is preferably in the range of 70 to 99 degrees as measured by a rubber hardness meter. When the winding hardness of the film roll is less than 70 degrees, the transfer is small and the effect of the present invention is hardly obtained. If the winding hardness of the film roll is greater than 99 degrees, the core may be deformed, which is not preferable. The more preferable range of the winding hardness is 74 to 98.
The more preferable range is 77 to 97 degrees.

The core used in the film roll of the present invention is not particularly limited, but if the surface has elasticity, the effect of the present invention is small. Therefore, the effect of the present invention becomes remarkable in the case of paper, resin-impregnated paper, plastic, glass epoxy or metal core.

Next, an example of the method of manufacturing the film roll of the present invention will be described, but the invention is not limited to this. The raw material of polyethylene terephthalate is melt-extruded by an extruder and cooled, and this is stretched in the longitudinal direction and the width direction. The stretching ratio is 3 to 6 times in the longitudinal direction and 3 to 4 in the width direction.
The range is usually 5 times, and this may be further longitudinally stretched and laterally stretched. After that, heat treatment with a tenter to a thickness of 25
Make polyester film in the range of ~ 1000μm,
For example, roll it up as a jumbo roll. When slitting this into a predetermined width and length with a slitter, cut the film so that the end face angle of the winding end of the film of the most winding core that contacts the core is in the range of 5 to 85 ° with respect to the core surface. Cut with. Alternatively, the film may be cut obliquely so that the end face angle of the film is in the range of 5 to 85 ° with respect to the core surface. The tip of the film does not necessarily have to be sharp and may have a trapezoidal shape. The film is glued to a paper or resin impregnated paper, plastic, glass epoxy or metal core. For the attachment, an adhesive tape, water, or another liquid may be used. Use a slitter to put this on the film 3 to 50 kg / m
And a pressing pressure of 5 to 50 kg / m are applied to wind it into a predetermined length to make a polyester film roll having a winding hardness of 70 to 99 degrees.

In the film roll thus formed, the end face angle of the film of the most winding core which comes into contact with the core is set to 5 to 5.
Within the range of 85 °, the deformation of the film in the winding core portion is almost eliminated due to the step of the film of the most winding core, and the flatness of the film after being pulled out is kept good.

[Measurement Method of Physical Properties] (1) Film End Face Angle The film end face angle was measured by observing a cross section of the film cut in the longitudinal direction with a microscope.

(2) Rolling hardness of film roll The film was measured with a standard rubber hardness meter specified by JIS.

[0019]

【Example】

Example 1 A raw material of polyethylene terephthalate was heated at 280 ° C. in an extruder.
Melted, extruded and cooled to 25 ° C. to obtain an unstretched film having a thickness of 1.2 mm. This was stretched 3.3 times in the longitudinal direction and 3.5 times in the width direction, and heat-treated at 220 ° C. for 10 seconds with a tenter to wind a 100 μm-thick polyester film on a jumbo roll. 1m wide with a slitter,
A polyester film roll was prepared by slitting it to a length of 1000 m and winding it up on a resin-impregnated paper core.

When slitting, the film was cut obliquely with a cutter so that the end face angle of the winding end of the film of the most wound core which comes into contact with the core was 45 ° with respect to the surface of the core. For the attachment to the core, glue was applied to the core and the cut film was attached.

The slit tension was set to 10 kg / m and the pressing pressure was set to 10 kg / m, and the film was wound up to obtain a polyester film roll having a winding hardness of 89 degrees.

After this polyester film roll was allowed to stand at room temperature for one month, it was unwound to the core and the flatness was examined. As a result, there was no flatness defect due to transfer of the thickness difference at the winding end of the film.

Comparative Example 1 A width of 1 m and a length were obtained in the same manner as in Example 1 except that the end face angle of the film of the most wound core that comes into contact with the core during slitting was 90 ° with respect to the core surface. A polyester film roll having a length of 1000 m and a winding hardness of 89 degrees was obtained.
As a result of inspecting the flatness in the same manner as in Example 1, there was defective flatness in the portion from the winding core to 70 m due to the transfer of the thickness difference at the winding end of the film.

[0024]

As described above, according to the film roll of the present invention, a film having a thickness in a specific range is
By setting the angle of the end face of the winding end with respect to the core surface within a specific range, it is possible to obtain a film roll excellent in various processing stability without causing defective flatness due to transfer of the thickness step of the winding end of the film. In particular, in coating, printing, vapor deposition, and other processes, even the roll core can be used, and various effects such as yield improvement and quality improvement can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of a film roll according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of section II of FIG.

[Explanation of symbols]

 1 core 1a core surface 2 film 2a innermost film 2b, 2c film wound on it 3 film roll 4 winding end 5 end face θ angle of end face to core surface

Claims (4)

[Claims] 1. A film roll having a core wound with a film, wherein the winding end of the innermost layer of the film that contacts the core has an angle of 5 to 85 ° with respect to the core surface of the end surface extending between the front and back surfaces of the film. And a film roll having a thickness of 25 to 1000 μm. 2. The film roll according to claim 1, wherein the wound film roll has a winding hardness in the range of 70 to 99 degrees as measured by a rubber hardness meter. 3. The core is made of paper, resin impregnated paper, plastic, glass epoxy or metal core.
The film roll according to claim 1 or 2. 4. The film roll according to claim 1, wherein the film is a polyester film.