KR20130109034A - Web roll and method for manufacturing the same, and method for manufacturing optical sheet - Google Patents

Abstract

PURPOSE: A web roll, a manufacturing method thereof, and a manufacturing method of an optical sheet are provided to use a bonding member as a shock absorbing material when a web is wound around the front end of a previous web. CONSTITUTION: A web roll comprises a core (23), a web, a bonding member, a support, a core side adhesion layer (31b), and a web side adhesion layer (31c). The web is wound around the core. The front end of the web is fixed to the outer surface of the bonding member. The support is formed in the bonding member. The core side adhesion layer is formed in the bonding member and is stuck to the core. The web side adhesion layer is formed in the bonding member and fixes the front end of the web to the core.

Description

WEB ROLL AND METHOD FOR MANUFACTURING THE SAME, AND METHOD FOR MANUFACTURING OPTICAL SHEET

This invention relates to a web roll, its manufacturing method, and the manufacturing method of an optical sheet.

Polymer films are used in various fields as optical films and the like from the advantages of having excellent light transmittance and flexibility and being capable of lightweight thin films. Especially, the cellulose-ester type film using cellulose acylate etc. is used for the optical film. As an optical film, there exist a protective film, retardation film, etc. of the polarizing plate which is a structural member of the liquid crystal display device which the market expanded recently, including the film for photosensitive.

The polymer film is continuously produced in a band shape by a melt film forming method, a solution film forming method, or the like. This polymer film is wound in a roll shape, for example, in a cylindrical core, stored as a film roll, and transported.

As shown in FIG. 8, when the polymer film 3 is wound around the core 2, the film is joined by the bonding tape 4 or the like so that the tip 3a of the film 3 does not fall off from the core 2. The tip 3a of (3) is fixed to the core 2. As for the bonding tape 4, the adhesion layers 4b and 4c are formed in both surfaces of the support body 4a. And the outer peripheral surface 2a of the core 2 and the joining tape 4 are joined through the adhesion layer 4b. Moreover, the film tip part is fixed to the core 2 through the adhesion layer 4c.

When the long polymer film 3 is wound in the form of a roll in the core 2 in this manner, a step 5 called a cut surface projection 2 is formed at a position overlapping the tip (cut surface) 3a of the film 3. It appears on the film surface after the winding. Although the step 5 is influenced by the kind of the web such as the long polymer film 3 and the winding condition, it may occur from the start point of winding to the place of the 100th winding or more. The cut surface projection which consists of this step 5 becomes a failure with respect to the web, for example, an optical film which requires smooth flatness, and produces big loss.

For this reason, various methods for reducing the cut surface projection have been proposed. For example, in Japanese Patent Laid-Open No. 8-244035, the thickness of a knurling that is reduced in thickness at both side edges in the width direction of the web is gradually reduced from the core side to the outer circumferential side to be wound up. In Japanese Patent Laid-Open No. 9-58935, a convex end portion having a height of 1 to 10 times the thickness of the film to be wound is formed on both outer peripheral portions of the cylindrical core. In addition, in Japanese Patent Laid-Open No. 2001-63876, a joining tape is bonded to the outer peripheral portions of both ends of the cylindrical core instead of the convex end portion. In this way, in order to reduce the surface pressure applied radially with respect to the web at the center, convex steps or joining tapes are provided at the outer peripheral portions of both ends of the core, or knurling is formed at both edges of the web to thereby generate the cut surface projection. I try to suppress it.

However, as in Japanese Unexamined Patent Publication No. Hei 8-244035, it is difficult to diminish the amount of protrusion of the knurling, and there are problems such as complicated knurling device. Further, as in Japanese Patent Laid-Open No. Hei 9-58935, by forming the stepped portions on the outer peripheral surface of both ends, it is necessary to align the web both side edges with the stepped portions. In Japanese Laid-Open Patent Publication No. 2001-63876, in addition to attaching a joining tape to both ends of the core, it is necessary to align both edges of the web, and there is a problem such as requiring skill for winding.

An object of this invention is to provide the web roll, its manufacturing method, and the manufacturing method of an optical sheet which suppressed generation | occurrence | production of a cut surface projection.

In the web roll of the present invention, a strip-shaped web is wound around a core, and includes a core, a web, a joining member, a support, a core side adhesive layer, and a web side adhesive layer. In the core, the web is wound. The web is wound around the outer peripheral surface of the core. The joining member fixes the distal end of the web to the outer circumferential surface of the core. The support is provided in the joining member. The core side adhesion layer is provided in the bonding member and adhered to the core. The core-side adhesive layer is formed on one surface of the support. The web side adhesion layer is provided in the bonding member, and fixes the tip end of the web to the core by sticking with the tip end of the web. The web side adhesion layer is formed in the other surface of a support body. With the margin part exposed to the web side adhesion layer formed, the front-end | tip part of a web is covered with a web side adhesion layer.

It is preferable that a buffer material is arrange | positioned at a margin part.

The shock absorbing material is formed thicker than the thickness of a web, and is comprised by the elastic member deformed below the thickness of a web by winding up to the core of a web.

The tip of the web is cut so that the inclination angle θ1 with respect to the web width direction is within a range of −30 ° <θ1 <30 °, and the joining member is preferably bonded to the core in parallel with the tip of the web.

It is preferable that the web is an optical film.

It is preferable that an optical film turns into an optical sheet by cutting into sheet form.

The web roll manufacturing method of the present invention comprises a bonding step (step A), a set step (step B), a fixing step (step C), and a winding step (step D), and a belt-shaped web is placed on the core. Wind up to produce web rolls. Step A adheres the joining member to the core. The bonding member includes a support, a first adhesive layer, and a second adhesive layer. The support is band-shaped. The first adhesive layer is formed on one surface of the support and adheres to the core. The second adhesive layer is formed on the other side of the support. In step B, the winding core to which the joining member is bonded is set at the web winding position. Step C fixes the tip of the web to the core through the joining member. Covering a portion of the second adhesive layer with the tip of the web forms a margin portion exposed to the second adhesive layer. Step D winds the web around the core by rotating the core.

It is preferable that a cushioning material elastically deformed is provided in the margin.

The shock absorbing material is formed thicker than the thickness of a web, and is comprised by the elastic member deformed below the thickness of a web by winding up to the core of a web.

The tip of the web is cut so that the inclination angle θ1 with respect to the web width direction is within a range of -30 ° <θ1 <30 °, and in step A, it is preferable to bond the joining member to the outer peripheral surface of the core in parallel with the tip of the web. Do.

The manufacturing method of the optical sheet of the present invention includes the bonding step (step E), the set step (step F), the fixing step (step G), the winding step (step H), the drawing step (step I), A cutting step (J step) is provided. Step E adheres the joining member to the core. The bonding member includes a support, a first adhesive layer, and a second adhesive layer. The support is band-shaped. The first adhesive layer is formed on one surface of the support and adheres to the core. The second adhesive layer is formed on the other side of the support. In step F, the winding core to which the joining member is bonded is set at the winding position. Step G fixes the tip of the optical film to the core through the bonding member. The margin part exposed to the 2nd adhesion layer is formed by covering a part of 2nd adhesion layer by the front-end | tip part. In step H, the optical film is wound around the core by rotating the core. In step I, the wound optical film is taken out from the core. In step J, the optical film drawn out from the core is cut into a sheet to form an optical sheet.

According to this invention, each adhesion layer of a joining member acts as an elastic member. For this reason, when the next web is wound around a web end, a joining member acts as a shock absorbing material, and it can avoid that the next web touches a web end and becomes cut surface projection.

The above objects and advantages will be readily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the film roll manufacturing equipment which implements this invention.
It is a top view which shows the attachment state of the film front end to the core.
3 is a cross-sectional view taken along the line III-III in FIG. 2.
4 is a cross-sectional view taken along the line III-III of FIG. 2 in a state where the film is wound twice on the film tip.
FIG. 5 is a cross-sectional view taken along the line III-III of FIG. 2 using the bonded tape of the second embodiment of the present invention.
FIG. 6 is a cross-sectional view taken along the line III-III of FIG. 2 in a state where a film is wound twice on a film tip portion. FIG.
It is a top view of 3rd Embodiment of this invention which shows the attachment state of the film front end to the core.
Fig. 8 is a cross-sectional view showing a mounting state of the tip of a film with a core by a conventional bonding tape.

As shown in FIG. 1, the film roll (web roll) manufacturing facility 10 for implementing this invention has the film manufacturing line 11, the knurling apparatus 12, and the winding apparatus 13. As shown in FIG. Although not shown, the film production line 11 has a casting apparatus, a tenter, and a drying apparatus in order from an upstream side. The film production line 11 manufactures a strip | belt-shaped polymer film 15, for example, a TAC (triacetyl cellulose) film, for example by the solution film forming method.

The knurling device 12 is disposed between the film production line 11 and the winding device 13. The knurling apparatus 12 has the support roller 16, the knurling roller 17, and the shift parts 18 and 19. FIG. At the time of knurling, the support roller 16 and the knurling roller 17 are moved to the nip position by the shift portions 18 and 19, and the embossing is applied to both edges (edge portions) of the polymer film 15. Thereby forming a knurling (not shown).

The winding device 13 has a turret arm 21 and winds up the polymer film 15 on the winding core 23 set on the winding shaft 22. The turret arm 21 is intermittently rotated by 180 degrees by an arm driving unit (not shown), and selectively switches the winding core 23 to the winding position PS1 and the winding core replacement position PS2. In addition, the guide arm 25 is provided in the intermediate position of the turret arm 21 in the rotational direction, and the guide roller 26 is attached to the tip end of the guide arm 25. The guide roller 26 supports the polymer film 15 so that the polymer film 15 does not come into contact with the turret arm 21 or the arm mounting shaft 27 when the turret arm 21 is rotating. do.

The winding shaft 22 is provided at the distal end portion of the turret arm 21, and the winding core 23 is set on the winding shaft 22. At the winding position PS1, the polymer film 15 sent from the guide roller 28 is wound around the winding core 23. Moreover, at the core exchange position PS2, the polymer film 15 of a predetermined length is wound up, and the film roll 29 wound up by a predetermined amount, for example, together with the core 23 is separated from the winding shaft 22. . And in the core exchange position PS2, the new empty core 23 is set to this winding shaft 22, and exchange of the core 23 is performed.

In the winding position PS1, when the polymer film 15 of a predetermined length is wound on the winding core 23, and the film roll 29 is almost close to the winding, the turret arm 21 rotates 180 degrees, The film roll 29 near the whole winding is located in the core exchange position PS2. In addition, an empty new winding 23 is positioned at the winding position PS1. When the film roll 29 has a predetermined length, a film cutting device (not shown) is operated to cut the polymer film 15. As the film cutting device, for example, a web winding replacement device described in JP 2005-89177 A, JP 2008-230723 A, etc. are used. The rear end of the cut preceding film is wound on the film roll 29 at the core exchange position PS2. Moreover, the front-end | tip part of the trailing film cut | disconnected is wound by the empty core 23 at the winding position PS1.

Hereinafter, similarly, the polymer film 15 is wound around the core 23 so that the polymer film 15 that is continuously sent is used as the film roll 29 to form a product. As the polymer film 15, there are optical films such as a polarizing plate protective film and a retardation film. Moreover, the film roll 29 obtained in this way is taken out from the core 23 by the polymer film 15, and cut | disconnected to a required size, and is a sheet-shaped polarizing plate protective film (polarizing plate protective sheet) and retardation film (retardation sheet). It is used as. Moreover, an optically anisotropic layer, an antireflection layer, an anti-glare layer, etc. are provided to the polymer film 15, and it is used as a high functional film.

As shown in FIG. 2, the strip | belt-shaped bonding tape (bonding member) 31 is adhere | attached to the empty core 23. As shown in FIG. The bonding tape 31 is for fixing the distal end portion (hereinafter referred to as the film distal end) 15b of the polymer film 15 to the core 23. The bonding tape 31 is adhered to the outer circumferential surface 23a of the core 23 by a core side adhesive layer (first adhesive layer) 31b (see FIG. 3).

As shown in FIG. 3, the bonding tape 31 is equipped with the strip | belt-shaped support body 31a, the core side adhesion layer 31b, and the film side adhesion layer (2nd adhesion layer) 31c. The support 31a is made of PET (polyethylene terephthalate). The core side adhesion layer 31b is formed on one surface (rear surface) of the support body 31a, and the film side adhesion layer 31c is formed on the other surface (surface) of the support body 31a. The thickness of the support body 31a exists in the range of 10 micrometers or more and 40 micrometers or less, Preferably it exists in the range of 10 micrometers or more and 35 micrometers or less, More preferably, it exists in the range of 10 micrometers or more and 30 micrometers or less. The core side adhesive layer 31b should just adhere to the core 23 and the polymer film 15, and is formed in the whole surface of the back surface of the support body 31a. The thickness of the core side adhesive layer 31b is in the range of 10 µm or more and 50 µm or less, preferably in the range of 10 µm or more and 40 µm or less, and more preferably in the range of 20 µm or more and 40 µm or less.

As shown to FIG. 2 and FIG. 3, the film side adhesion layer 31c is formed in the whole surface of the support body 31a, and is formed in the same thickness with the composition similar to the core side adhesion layer 31b, You may make it different thickness. Although illustration is abbreviate | omitted to the formation surface (surface used as the object of adhesion | attachment of the polymer film 15) of the film side adhesion layer 31c, the peeling tape is adhere | attached. The peeling tape is peeled off before winding up the polymer film 15, after bonding the bonding tape 31 to the core 23 by the core side adhesive layer 31b. As the joining tape 31, a Nitto Denko product (model: 5601, 5603, 5605, 5608, 5610, 5612) is used, for example.

As shown in FIG. 4, when the polymer film 15 is wound and the next polymer film 15 overlaps with the film tip 15a, the winding side adhesive layer 31b of the bonding tape 31 and the film side adhesion are shown. Layer 31c acts as a cushioning material. The polymer film 15 is positioned in such a manner that the film tip 15a forms a margin in the film side adhesive layer 31c, and the tip portion covers a part of the film side adhesive layer 31c and the film side adhesive layer 31c. ) Is adhered to. Thus, by exposing a part of the film side adhesion layer 31c, the margin part 32b was formed in the film side adhesion layer 31c, and the film front-end part 15b adheres to the film side adhesion layer 31c, and is wound up It is fixed to 23. Therefore, compared with the conventional joining method by the bonding tape shown in FIG. 8, the following polymer film superimposed on the film tip 15a becomes loosely curved shape. For this reason, since there is no extreme deformation like conventionally, surface projection is suppressed.

Adhesion of the bonding tape 31 and adhesion by the bonding tape 31 of the film tip portion 15b may be performed by a user or automatically by using a film bonding apparatus having a film cutter. In the case of a user, a film reservoir (not shown) is provided just in front of the winding device 13 (near the upstream side). The film reservoir temporarily stores a film for a time necessary for cutting the polymer film 15 and fixing to the core 23, and cuts and wound the polymer film 15 during the storage. Winding up is done. Film for hours means the film of the length sent in the time. Moreover, when performing automatically, it cut | disconnects the polymer film 15 and fixes to the core 23 using the film adhesive apparatus. In this case, the bonding tape 31 on the core 23 is detected, and the polymer film 15 is cut based on the detection timing so that the margin 32 is formed on the cut film tip 15a. The film tip 15b is bonded to the film side pressure-sensitive adhesive layer 31c.

In the present embodiment, the film tip 15a is formed along the width direction of the polymer film 15. That is, the film tip 15a and the film width direction are parallel. However, you may form so that the film front-end 15a may be inclined (intersected) with respect to the film width direction like 3rd Embodiment mentioned later (refer FIG. 7).

Moreover, in this embodiment, the bonding tape 31 is arrange | positioned so that the longitudinal direction of the bonding tape 31 may follow the cylinder core direction of the winding core 23. The barrel direction of the winding core 23 coincides with the width direction of the polymer film 15.

As for the thickness t1 of the bonding tape 31, when the thickness of the polymer film 15 is set to t0, (0.5 * t0) <= t1 <= (1.5 * t0) is preferable. Since the thickness t1 of the joining tape 31 is more than (0.5xt0), the buffer effect becomes more evident compared with the case below (0.5xt0). Moreover, since the thickness t1 of the joining tape 31 is less than (1.5xt0), cutting surface projection is less likely to occur than when it exceeds (1.5xt0). Moreover, when setting the thickness of each adhesion layer 31b, 31c to t2, it is preferable that it is (0.4xt1) <= t2 <= (0.5xt1). When the thickness t2 of each adhesion layer 31b, 31c is more than (0.4xt1), the buffer effect is more reliably obtained compared with the case below (0.4xt1). When the thickness t2 of each adhesion layer 31b, 31c is larger than (0.5xt1), the closer it is to (0.5xt1), the larger the buffer effect becomes, and the suppression effect of cut surface projection becomes high.

In addition, the width of the polymer film 15 is not particularly limited, but is preferably 600 mm or more, and more preferably in the range of 1400 mm or more and 2500 mm or less. Moreover, even if the width | variety of the polymer film 15 is larger than 2500 mm, this invention is effective. It is preferable that the thickness of the polymer film 15 exists in the range of 30 micrometers or more and 200 micrometers or less, It is more preferable to exist in the range which is 40 micrometers or more and 150 micrometers or less, It is further more preferable to exist in the range which is 40 micrometers or more and 100 micrometers or less. It is preferable that it is 2000 m or more, and, as for the length of the polymer film 15, it is more preferable to exist in the range of 4000 m or more and 8000 m or less. Moreover, it is preferable that the winding radius of the film roll 29 is 450 mm or more, and it is more preferable to exist in the range of 650 mm or more and 920 mm or less.

Although the length L2 of the bonding tape 31 in the core direction of the core 23 is not specifically limited, L2 = (W1-0) mm-based on the width W1 of the polymer film 15. (W1-10) mm is preferable. By setting it as such length L2, cutting surface projection is suppressed substantially over the film whole surface.

The polymer used as the raw material of the polymer film 15 is not particularly limited. In the solution film forming method, for example, cellulose acylate, cyclic polyolefin, or the like is used. In the melt film forming method, for example, a cellulose acylate, a lactone ring-containing polymer, a cyclic polyolefin, a polycarbonate, or the like is used. The details of the cellulose acylate are described in paragraphs [0140] to [0195] of Japanese Patent Laid-Open No. 2005-104148. These descriptions can also be applied to the present invention. In addition, additives such as solvents, plasticizers, antidegradants, ultraviolet absorbers (UV agents), optically anisotropic control agents, retardation control agents, dyes, matting agents, release agents, and release promoters are similarly described in Japanese Patent Application Laid-Open No. 2005-104148. Paragraphs [0196] to [0516] are described in detail.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. In addition, the same code | symbol is attached | subjected to the same structural member as 1st Embodiment, and the overlapping description is abbreviate | omitted. In addition, illustration of the polymer film 15 is abbreviate | omitted in FIG. In 2nd Embodiment, the joining tape 41 which arrange | positioned the buffer material 40 on the margin part 32 of the front side (downstream side) of the winding direction 23 in 1st Embodiment is used. As for the buffer material 40, it is higher than the thickness of the polymer film 15, and what becomes below the thickness of the polymer film 15 by elastic deformation is used preferably. As the shock absorbing material 40, elastic deformation is possible, and the material or the like is not particularly limited as long as it does not adversely affect the polymer film 15 by contact. For example, Nitto Denko (models: 5606, 5608), the Teraka company (NO. 7075), the Tessa company (NO. 4980), etc. are used preferably.

In the second embodiment, the cushioning material 40 is mounted on the margin part 32 in a shape projecting upward from the margin part 32. For this reason, the alignment at the time of joining becomes easy by pressing the film tip 15a to the upstream edge 40a of the shock absorbing material 40 in the rotation direction of the winding core 23. Moreover, even if the next polymer film 15 is polymerized to the film front end 15a by winding up the polymer film 15, the next polymer film 15 is pushed back by the elasticity of the buffer material 40. For this reason, the extreme bending deformation | transformation to the polymer film 15 as before is eliminated, and generation | occurrence | production of the cut surface projection resulting from the press of the next polymer film 15 at the film front-end 15a is suppressed. Although the shock absorbing material 40 is formed in strip shape, cross-sectional shape is not limited to a rectangle, You may make it semi-circle shape, trapezoid shape, and other arbitrary shapes.

As shown in FIG. 7, in the third embodiment, the inclination angle θ1 is set to 16 ° with respect to the film width direction reference line BL1 in the film tip 15a. In this case, the bonding tape 31 is also adhered to the core 23 at the same inclination angle θ1 in accordance with the inclination angle θ1 of the film tip 15a. In addition, the film width direction reference line BL1 is a line along the film width direction, ie, a coincidence line.

In this way, the inclination angle θ1 is an angle formed by the film tip 15a and the film width direction reference line BL1. The inclination angle θ1 may be 0 ° as in the first embodiment, or may be an angle different from 0 ° as in the third embodiment. The angle of inclination θ1 of the film tip 15a with respect to the film width direction reference line BL1 is preferably in the range of -30 ° <θ1 <30 °, more preferably in the range of -20 ° <θ1 <20 °. More preferably, it is the range of -10 degrees <(theta) 1 <10 degrees. This is because the closer the angle of inclination θ1 is to 0 °, the smaller the stress caused by the influence of the film surface pressure superimposed thereon on the film tip 15a, thereby further suppressing the cut surface projection.

Moreover, also when using the bonding tape 41 which arrange | positioned the buffer material 40 like 2nd Embodiment, you may incline the film front-end 15a with respect to the film width direction reference line BL1 similarly to 3rd Embodiment. Also in this case, similarly to 3rd Embodiment, the bonding tape 41 is inclined and used with the same inclination angle (theta) 1 as the film front-end 15a with respect to the film width direction reference line BL1.

In each said embodiment, although the manufacturing method of the film roll 29 which wound the polymer film 15 in roll shape was demonstrated, it is not limited to the polymer film 15, The other various web in which surface projection becomes a problem The present invention can be practiced with respect to. In each of the above embodiments, the polymer film 15 is adhered to the core 23 using the bonding tapes 31 and 41. However, instead of the bonding tapes 31 and 41, the polymer film 15 may be bonded to the core by an adhesive.

Next, in order to confirm the presence or absence of the effect of this invention, the following experiment was done. The experiment as the present invention is an "example", and the experiment conducted as a control is a "comparative example". In the film roll manufacturing equipment 10 shown in FIG. 1, the film roll 29 by TAC whose length is 5000 m, width is 1500 mm, and thickness is 80 micrometers was manufactured. In Example 1, the film tip 15a is adhere | attached as shown in FIG. 4 using the bonding tape 31 shown in FIG. 2 and FIG. Example 2 was set as the same conditions as Example 1 except using the bonded tape 41 shown in FIG. Example 3 made the inclination-angle (theta) 1 of the film tip 15a shown in FIG. 7 into 16 degrees, and adhere | attached the bonding tape 31 to the core 23 in parallel with the film tip 15a accordingly. Other conditions were the same as in Example 1. Example 4 was the same as Example 3 except having set the inclination angle (theta) 1 of the film front-end 15a of Example 3 to 20 degrees. Example 5 was the same as Example 3 except having set the inclination angle (theta) 1 of the film front-end 15a of Example 3 to 25 degrees. Similarly, Example 5 was the same as Example 3 except having set the inclination angle (theta) 1 of the film front-end 15a of Example 3 to 30 degrees. Comparative Example 1 was set to the same conditions as in Example 1 except that the film tip 15a was attached to the core 23 using the bonding tape 4 in the conventional method shown in FIG. 8. Comparative Example 2 was set to the same conditions as in Example 1 except that the inclination angle of the film tip 15a was set to 30 ° with respect to that of Comparative Example 1.

Other control conditions and the like at the time of winding are as follows. The film roll 29 was made into the film production line 11 shown in FIG. 1, with the tension applied to the polymer film 15 being 100 N / film width, the film running speed being 60 m / min, and the diameter of the core 23 being 169 mm. Prepared.

By the above method, the film roll 29 wound up and formed was stored for 30 days in 25 degreeC and the environment of 65% RH. Next, the film roll 29 which passed 30 days was set to the winding machine which is not shown in figure, and it wound up again. By rewinding by this rewinding, the film tip part wound around the core of the film roll 29 was made observable. Next, the evaluation test which calculates | requires the length which a cutting | disconnection surface projection lose | disappears about this film tip part was done. In the evaluation test, the film tip portion was left standing on a table covered with black cloth. Next, the light of fluorescent lamp was irradiated to the film surface from the top. Visually evaluate whether or not there is a cut-off projection by the reflected light. And the length to which the cut-off projection near the core is lost was calculated | required.

Eight film rolls 29 were manufactured by each Example and Comparative Example, but in Examples 1 to 6 with respect to those of Comparative Examples 1 and 2, cut surface projection was confirmed, as is apparent from Table 1 below. It can be seen that the length L3 from the core part having a practical problem with respect to the cut surface projection is reduced to 1/10 to 1/2 or less, and the cut surface projection is improved. In addition, the level which has a practical problem about cut | projection surface cutting was based on the limit sample (the sample which showed the limit of the quality used as a good or defective product). In Example 3 in which the cut line at the tip of the film was inclined at an inclination angle θ1 of 16 ° with respect to the film width direction reference line BL1, the evaluation result of Example 1 in which the other conditions were the same was 40 m for 10 m. It is long. Further, in Examples 4 to 6 in which the inclination angle θ1 was raised to 20 °, 25 °, and 30 °, it can be seen that the length L3 becomes longer as the inclination angle θ1 increases, and the inclination angle θ1 is achieved. It is understood that the closer to 0 °, the more preferable.

Bonding Tape Buffer material Angle of inclination
(θ1) (°) Embodiment Length
(L3) (m) evaluation Example 1 3 radish 0 4 8 A Example 2 5 U 0 6 20 B Example 3 3 radish 16 4, 7 30 B Example 4 3 radish 20 4, 7 35 B Example 5 3 radish 25 4, 7 40 C Example 6 3 radish 30 4, 7 50 C Comparative Example 1 8 (Prior Example) radish 0 8 100 D Comparative Example 2 8 (Prior Example) radish 30 8 120 D

Moreover, the film length L3 by which the cut surface projection from the "A" core part of evaluation in Table 1 is confirmed is less than 10 m, and means that it is favorable as an evaluation result of cut surface projection. Similarly, "B" means that the length L3 is 10 m or more and less than 40 m, and the projection of the cut surface occurs slightly weakly, but is approximately a good result as an evaluation result. Similarly, "C" means that the length L3 is 40 m or more but less than 60 m, and the projection of the cut surface occurs, but is at a level practically without problems. A, B, and C are pass levels. Similarly, "D" means that the length (L3) is more than 60m, the product loss is large, fail level.

Claims (13)

In the web roll wound the strip-shaped web,
Winding core to which the web is wound;
A web wound on the outer circumferential surface of the core;
A joining member for fixing the distal end of the web to the outer circumferential surface;
A support body provided in the joining member;
A core-side adhesive layer provided on the bonding member and adhering to the core;
A web-side adhesive layer provided on the bonding member to fix the tip portion to the core by sticking with the tip portion;
And,
The winding side adhesive layer is formed on one surface of the support,
And the web side adhesive layer is formed on the other side of the support, and the tip end portion is covered with the web side adhesive layer in a state where a margin part exposed to the web side adhesive layer is formed. The method of claim 1,
A web roll, characterized in that a buffer is disposed in the margin. 3. The method of claim 2,
The said cushioning material is formed thicker than the thickness of the said web, The web roll characterized by being comprised by the elastic member deformed below the thickness of the said web by the winding of the said web to the said core. The method according to any one of claims 1 to 3,
The tip of the web is cut so that the inclination angle θ1 with respect to the web width direction is within a range of −30 ° <θ1 <30 °, and the joining member is bonded to the winding core in parallel with the tip of the web. Characterized by a web roll. The method according to any one of claims 1 to 3,
The web roll is characterized in that the optical film. 5. The method of claim 4,
The web roll is characterized in that the optical film. The method of claim 5, wherein
The optical film is cut into a sheet shape to be an optical sheet. The method according to claim 6,
The optical film is cut into a sheet shape to be an optical sheet. As a web roll manufacturing method which winds a strip | belt-shaped web in the core and manufactures a web roll,
(A) adhering the joining member to the core,
(B) setting the winding core to which the joining member is bonded to a winding position;
(C) fixing the leading end of the web to the core through the joining member; and
(D) winding the web around the core by rotating the core;
And,
The bonding member includes a support, a first adhesive layer and a second adhesive layer, the support is in a band shape, and the first adhesive layer is formed on one surface of the support to adhere to the core, and the second The adhesive layer is formed on the other side of the support,
Covering a portion of the second pressure-sensitive adhesive layer with the tip portion to form a margin portion exposed to the second pressure-sensitive adhesive layer. The method of claim 9,
A method for producing a web roll, characterized in that a buffer material elastically deformed is provided in the margin. 11. The method of claim 10,
The said buffer material is formed thicker than the thickness of the said web, The web roll manufacturing method characterized by including the elastic member deformed below the thickness of the said web by the winding to the said core. 12. The method according to any one of claims 9 to 11,
The tip end of the web is cut so that the inclination angle θ1 with respect to the web width direction is within a range of -30 ° <θ1 <30 °, and the step A of the winding member is performed in parallel with the tip end of the web. A web roll manufacturing method characterized by bonding to an outer circumferential surface. As a manufacturing method of an optical sheet,
(E) adhering the joining member to the core,
(F) setting the winding core to which the joining member is bonded to a winding position;
(G) fixing the leading end of the optical film to the core through the bonding member,
(H) winding the optical film around the core by rotating the core;
(I) taking out the wound optical film from the core; and
(J) cutting the optical film taken out from the winding core into a sheet to form an optical sheet;
And,
The bonding member includes a support, a first adhesive layer and a second adhesive layer, the support is in a band shape, and the first adhesive layer is formed on one surface of the support to adhere to the core, and the second The adhesive layer is formed on the other side of the support,
The margin part exposed to the said 2nd adhesion layer is formed by covering a part of said 2nd adhesion layer by the front-end | tip part, The manufacturing method of the optical sheet characterized by the above-mentioned.

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