JP2009227432A - Web support roller and web conveying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To convey a web while preventing a slip and face transfer. <P>SOLUTION: This web support roller includes a roller body 18a and a rotary shaft. The web support roller supports a web by the circumferential surface of the roller body 18a for travelling. The circumferential surface of the roller body 18a has an edge contact region 18e and a product contact region 18c. The edge contact region 18e is brought in contact with edges formed at both ends in the cross direction of the web. The edge contact region 18e is formed with valleys 30 and crests 31 each having a nearly circular arc cross section along the circumferential direction of the roller body 18a. The valleys 30 and the crests 31 are arranged alternately relative to the axial direction AX. A pitch Pm of the crests 31 is set to 0.01-2 mm. A height Hv_m from a bottom 30a to a peak 31a is set to 0.01-1 mm. Curvature radii Rm of the crests 31 are set to 0.1-0.5 mm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a web support roller for supporting and running a web, and a web conveying method using the web support roller.

  In manufacturing equipment such as magnetic tape, photographic film, and optical functional film, functional materials such as magnetic materials, photosensitive materials, optical functional materials, etc. are continuously fed out from the rolls wound in a coil. After being applied to one surface of the material and dried, it is wound up in a coil shape again. In such a manufacturing facility, a plurality of rollers are provided along a predetermined conveyance path in order to support and run the web on the peripheral surface.

  In recent years, with the miniaturization of apparatuses using magnetic tapes, photographic films, optical functional films, etc., web thinning and smoothing have been promoted. For this reason, the roller slips with respect to the web during conveyance by the roller, and the web may be scratched or creased. In addition, when the web immediately after the functional material is applied is conveyed, so-called surface printing in which a roller mark is left on the coating film may occur, resulting in a problem that the product yield deteriorates.

In order to solve this problem, in order to convey a thin web having a thickness of 25 μm or less, there has been proposed a roller in which a spiral groove and a raised portion are formed on the peripheral surface (see Patent Documents 1 and 2). ). In addition, a web support roller is proposed in which fine recesses are provided on the peripheral surface of the roller body, the depth of the recesses is 5 μm to 50 μm on average, and the area occupied by flat portions other than the recesses is 50% to 70%. (See Patent Document 3).
JP-A-8-175727 JP-A-10-77146 JP 2003-146505 A

  The rollers described in Patent Documents 1 and 2 are intended for webs having a thickness of 25 μm or less, and convey the web before the functional material is applied, so the web immediately after the functional material is applied The problem of surface projection that occurs when transporting the sheet is not taken into consideration.

  The web support roller described in Patent Document 3 forms a recess by performing a blasting process in which fine powder such as alumina sol or glass beads is sprayed on the peripheral surface of the roller. For this reason, the recesses are randomly distributed, and the size and the size of the recesses are not constant due to variations in the size of the fine powder. In addition, when the web conveyance speed is increased, the frictional force cannot be maintained and the web slips.

  Also, in the so-called film formation for producing a film made of a polymer, as in the case of coating, a long film may slip during conveyance by a roller, and the film may be scratched or wrinkled. there were. When a film containing a solvent such as solution casting, a film heated to a high temperature, or a film at a high temperature such as a substantially melting point such as melt casting is transported to the film itself. Roller marks may occur. In the following description, the roller marks generated on the film itself during film formation are also referred to as surface projection.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a web support roller and a web transport method using the web support roller, which can prevent web scratches, dragging and wrinkles. And

  In order to achieve the above object, the present invention provides a web support roller for running the web while supporting the web on the circumferential surface, the cylindrical roller body, and the width of the web on the circumferential surface of the roller body. A plurality of ridges provided in the ear portion contact region where the ear portions at both ends in the direction come into contact with each other, formed along the circumferential direction of the roller body and spaced apart in the rotation axis direction of the roller body, Has a substantially arcuate apex having a radius of curvature of 0.1 mm or more and 0.5 mm or less in a cross section including the rotation axis of the roller body, and the pitch of the plurality of protrusions in the rotation axis direction is 0. The height is 01 mm or more and 2 mm or less, and a valley is formed between the protrusions, and the height between the bottom of the valley and the top is 0.01 mm or more and 1 mm or less.

  Further, the present invention provides a web support roller for running the web while supporting the web on the circumferential surface, and a cylindrical roller body, and a circumferential surface of the roller body, the ears at both ends in the width direction of the web. A plurality of protrusions that are provided in a contact area of the ear portion and that are formed along the circumferential direction of the roller body and spaced apart in the direction of the rotation axis of the roller body; In the cross section including the rotating shaft, the rotating shaft has a flat top portion that is parallel to the rotating shaft direction and has a length in the rotating shaft direction of 0.05 mm to 0.5 mm, and a plurality of protrusions in the rotating shaft direction. The pitch is 0.01 mm or more and 2 mm or less, and a valley is formed between the protrusions, and the height between the bottom of the valley and the top is 0.01 mm or more and 1 mm or less.

  In the peripheral surface of the roller main body, it is preferable that a top portion of the protrusion protrudes with respect to a product portion contact area where a product portion made of the web excluding the ear portion contacts. The protrusions formed in the first ear contact area formed at one end of the roller main body and the second ear contact area formed at the other end of the roller main body are wound in a mutually winding direction. Preferably, the roller bodies are formed in different spiral shapes, and the direction of the roller body is defined so that the pair of spiral protrusions gradually separates as the web travels in the web traveling direction.

  Furthermore, the web transport method of the present invention is characterized in that the web is transported by supporting the web having a thickness of 20 μm or more and 200 μm or less using the web support roller described above.

  According to the web support roller of the present invention, the minute protrusions having a predetermined shape are spaced apart in the rotation axis direction of the roller body so as to be along the circumferential direction in the ear contact area on the circumferential surface of the roller body. Provided, so that the height of the bottom of the valley and the top of the ridge provided between the ridges is within a predetermined range, the occurrence of slipping and chamfering of the web during conveyance is suppressed, and consequently The web can be supported and run while preventing the web from being scratched or pulled. In addition, the dimensions and shape of the protrusions and valleys are appropriately determined so that the contact area where the web and the peripheral surface of the roller body are in contact with each other, and the cross-sectional area of the valley in the cross section including the axis of the roller body is a certain level or more. Adjust it. Thereby, holding | maintenance force with respect to a web can be hold | maintained more than fixed, and it can implement | achieve simultaneously that the air which flowed in between the web and the surrounding surface of a roller main body escapes to a trough, and suppresses generation | occurrence | production of a slip.

  In addition, according to the web conveying method of the present invention, the web is prevented from being scratched, dragged, and exposed, and the product yield is improved. Therefore, the manufacturing cost can be suppressed.

  In FIG. 1, a web transport device 20 according to the present invention has a feeding unit 12 that continuously feeds a web 11 from an original roll 10 wound in a coil shape, and a functional material is applied to the surface of the web 11 to form a magnetic material. A coating unit 13 for forming a functional coating film such as a coating film, a photosensitive coating film, an optical functional coating film, a drying unit 14 for drying the coating film, and a web 11 (hereinafter referred to as film 15) on which the coating film is formed. And a take-up portion 16 that takes up again in a coil shape. Here, the functional material includes magnetic materials and photosensitive materials used for magnetic tapes and photographic films, optical functional materials for liquid crystal display devices, and the like.

  The web 11 is a flexible support, for example, having a width of 100 mm to 3000 mm, a length of 100 m to 5000 m, a thickness of 20 μm to 200 μm, and a surface roughness Ra = 1 nm to 100 nm. Moreover, it is more preferable that the width | variety of the web 11 is 1000 mm or more and 2500 mm or less. As the material of the web 11, plastic films such as polyethylene terephthalate, polyethylene-2,6-naphthalate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide; paper; Examples thereof include papers coated or laminated with α-polyolefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, and ethylene butene polymers; metal foils such as aluminum, copper, and tin;

  A web support roller 18 is provided between the coating unit 13 and the drying unit 14 for transporting the web 11 (hereinafter referred to as a wet film 17) immediately after the coating film is applied by the coating unit 13. ing. The web support roller 18 is rotationally driven by a motor 19 so as to have the same rotational speed as the conveyance speed of the wet film 17.

  In FIG. 2, the web support roller 18 includes a roller body 18a and shaft portions 18b fitted to both ends of the roller body 18a. The roller body 18a formed in a substantially columnar shape conveys the wet film 17 in the direction MD while supporting the wet film 17 on its peripheral surface. As materials for the roller body 18a and the shaft portion 18b, materials having excellent corrosion resistance, such as aluminum, iron, stainless steel, carbon fiber reinforced plastic (CFRP), and the like are used. The roller body 18a is not limited to a substantially cylindrical shape, and may be a substantially cylindrical shape.

  An ear contact area 18e and a product contact area 18c are provided on the peripheral surface of the roller body 18a. The ear part contact region 18 e is a part of the peripheral surface that supports both side end parts (hereinafter referred to as ear parts) 17 e in the direction AX of the wet film 17. The product part contact region 18c is a part of the peripheral surface that supports the product part 17c sandwiched between the pair of ear parts 17e.

  As shown in FIGS. 3 and 4, in the ear contact region 18e, a trough 30 and a peak 31 having a substantially arc-shaped cross section are formed along the circumferential direction of the roller body 18a. The troughs 30 and the crests 31 are alternately arranged with respect to the axial direction AX. The valley portion 30 and the mountain portion 31 are processed and formed with high accuracy by, for example, a precision lathe using a cutting tool.

  The distance between the adjacent top portions 31a of the mountain portions 31, that is, the pitch Pm of the mountain portions 31 is 0.01 mm or more and 2 mm or less. When the pitch Pm is less than 0.01 mm, lathe processing becomes difficult. When this lathe processing is performed, the manufacturing cost is increased and the cost becomes very expensive. On the other hand, if the pitch Pm is larger than 2 mm, slipping or surface projection occurs. The pitch Pv is preferably 0.01 mm or more and 2 mm or less. Furthermore, it is more preferable that the pitches Pv and Pm of the valley part 30 and the peak part 31 are 0.3 mm or more and 0.5 mm or less.

  The height Hv-m from the bottom 30a to the top 31a is 0.01 mm or more and 1 mm or less. When the height Hv-m is less than 0.01 mm, the effect of releasing air between the wet film 17 and the wet film 17 is lost, and slipping easily occurs. When the height Hv-m is larger than 1 mm, lathe processing becomes difficult, and when this lathe processing is performed, the manufacturing cost is increased and the cost becomes very expensive. This air refers to the air that enters between the peripheral surface of the roller body 18a and the wet film 17 when the wet film 17 runs or the roller body 18a rotates. The height Hv-m is more preferably 0.02 mm or more and 0.1 mm or less.

  The distance from the center Om of the circle forming the cross section of the peak 31 to the apex 31a, that is, the radius of curvature Rm of the peak 31 is 0.1 mm or more and 0.5 mm or less. When the curvature radius Rm is less than 0.1 mm, the contact area with the wet film 17 becomes small and slip occurs. The distance from the center Ov of the circle forming the cross section of the valley 30 to the bottom 30a, that is, the radius of curvature Rv of the peak 31 is preferably 0.1 mm or more and 0.5 mm or less. Furthermore, it is more preferable that the curvature radii Rv and Rm of the valley part 30 and the peak part 31 are 0.2 mm or more and 0.4 mm or less.

  Next, the operation of the web conveyance device 20 having the above configuration will be described. First, as shown in FIG. 1, the web 11 is unwound from the unwinding roll 10 from the unwinding unit 12 and is conveyed to the coating unit 13. In the application unit 13, a functional material is applied to the surface of the conveyed web 11, and the wet film 17 is conveyed toward the web support roller 18.

  The wet film 17 is conveyed to the drying unit 14 by the web support roller 18. The wet film 17 conveyed to the drying unit 14 is dried by the drying unit 14 to become a film 15 and is wound up again in a coil shape by the winding unit 16. The coil-shaped, that is, roll-shaped film 15 is transferred to the next processing step and processed into a product.

  As shown in FIGS. 3 and 4, when the web support roller 18 supports the wet film 17 by the peripheral surface of the roller body 18a and travels, air is generated between the peripheral surface of the roller body 18a and the wet film 17. Enter. Since the wet film 17 is a soft film, it enters a part of the valley 30 along the surface of the peak 31. Since the peak portion 31 is provided in a predetermined shape and size, a large frictional force is generated on the wet film 17 while suppressing occurrence of surface projection. On the other hand, since the trough 30 is provided so as to be recessed from the peak 31 by a predetermined height Hv-m, air that has entered between the web support roller 18 and the wet film 17 can be released. Therefore, according to the web support roller 18 of the present invention, it is possible to suppress the occurrence of slipping and surface blurring due to the ingress of air. As a result, the wet film 17 is prevented while preventing the generation of scratches and wrinkles. Can be supported and run.

  By providing such peak portions 31 over the entire region of the ear contact region 18e and the product portion contact region 18c, that is, the entire peripheral surface of the roller body 18a, it is possible to exert an effect of preventing the occurrence of slipping or surface projection. However, since the required processing accuracy is high when forming the peak portion 31, the manufacturing cost is increased. According to the present invention, since the peak portion 31 is provided only in the ear contact region 18e, it is possible to manufacture a web support roller that can exhibit the effect of preventing the occurrence of slipping and surface projection at low cost.

  When the conveyance speed of the web support roller, that is, the peripheral speed of the roller body 18a is 50 m / min or more, slip due to the ingress of air is likely to occur. However, according to the web support roller of the present invention, the high speed Even when transported at the transport speed, the wet film 17 can be supported and traveled while preventing the occurrence of slipping or surface projection.

  Further, depending on the material and properties of the web 17, a tension in the direction MD is applied to the web 17 by contact with the peripheral surface of the web support roller 18, or a film finally obtained by elongation due to this tension. The 15 characteristics and quality may not be as desired. Since the web support roller 18 of the present invention has the predetermined peak portion 31 in the ear contact area 18e, the ear 17e of the wet film 17 is strongly supported by the ear contact area 18e, while the product portion 17c. Does not come into contact with the product portion contact area 18c due to the ingress of air, or remains in a weak contact. Therefore, even if the characteristics and quality of the web 17 are deteriorated due to contact with the peripheral surface of the web support roller 18, the adverse effect remains in the ear portion 17e, and the characteristics and quality of the product portion 17c are deteriorated. Can be suppressed. For example, when the film 15 is an optical film such as a polarizing plate protective film or an optical compensation film, it is required that the retardation of the final film 15 is isotropically excellent or within a desired range. However, this retardation varies depending on the tension applied to the wet film 17 in the manufacturing process. By using the web support roller of the present invention as the means for transporting the wet film 17, the tension applied to the wet film 17 or the like during the transport and the elongation generated there may occur in the ear part even if it occurs in the ear part. As a result, the film 15 having a desired retardation can be produced.

  In the above embodiment, as shown in FIGS. 3 and 4, the heights in the radial direction of the product part contact area 18c and the bottom part 30a are substantially equal, and the peak part 31a protrudes from the product part contact area 18c. However, the present invention is not limited to this, and web support rollers 40 and 45 shown in FIGS. 5 and 6 may be used. Hereinafter, although the detail of the web support rollers 40 and 45 is demonstrated, the same code | symbol is attached | subjected about the component and member same as the said embodiment, and the detailed description is abbreviate | omitted.

  As shown in FIG. 5, the web support roller 40 has a roller body 40a similar to the roller body 18a. The roller body 40a has an ear part contact area 40e and a product part contact area 40c, and the ear part contact area 40e is provided with a valley part 30 and a peak part 31. Further, the valley portion 30 is provided such that the bottom portion 30a protrudes from the product portion contact region 40c. According to this web support roller 40, since the top part 31a protrudes from the product part contact area 40c, a larger frictional force can be generated on the web. As such a processing method of the roller main body 40a, the ear contact area 40e of the roller main body 40a is processed to provide a predetermined valley portion 30 or peak portion 31, and then lower than the radial height of the bottom portion 30a. As described above, the product part contact region 40c may be shaved by polishing or the like. In the radial direction, the height difference H between the middle abdomen 41 and the product part contact region 40c, which is higher by about half of the height Hv-m than the bottom part 30a, is 0.01% or more of the radius of the roller body 40a. It is preferable to make it 2% or less.

  As shown in FIG. 6, the web support roller 45 has a roller body 45a similar to the roller body 18a. The roller main body 45a has an ear part contact region 45e and a product part contact region 45c, and the ear part contact region 45e is provided with a valley part 30 and a peak part 31. Further, the peak portion 31 is provided such that the height of the top portion 31a in the radial direction is substantially the same as that of the product portion contact region 40c.

  In the web support roller described above, the valley portion 30 and the peak portion 31 are provided so that the bottom portion 30a and the top portion 31a are located at the boundary between the ear portion contact region and the product portion contact region. However, the present invention is not limited to this, and the valley portion 30 and the peak portion 31 may be provided so that a portion in the middle between the bottom portion and the top portion is located at the boundary between the ear portion contact region and the product portion contact region.

  In the said embodiment, although the trough part 30 and the peak part 31 were provided in the whole region of the ear | edge part contact area 18e, this invention is not limited to this, The trough part 30 and the peak part 31 are a part of the ear | edge part contact area 18e. May be provided. In addition, when no adverse effect such as surface projection occurs, the valley 30 or the peak 31 may be provided in the whole or part of the product portion contact area 18c. In addition, you may provide the edge cutting apparatus which cuts and removes the ear | edge part of the wet film 17 or the film 15 between the drying part 14 and the web support roller 18, or between the drying part 14 and the winding-up part 16. As a result, even if surface projection occurs on the ears of the wet film 17 or the film 15 by the web support roller of the present invention, the ears where the surface projection has occurred may be cut and removed by this ear-cutting device.

  In the above embodiment, the valley portion 30 having a substantially arc-shaped cross section is provided. However, the present invention is not limited to this, and when the wet film 17 is supported by the mountain portion 31, a shape and size that can ensure a gap through which air can pass. If so, it may be a rectangle, a triangle, or other cross-sectional shape. For example, as shown in FIG. 7, a flat surface 31 f substantially parallel to the axial direction AX may be formed on the top portion 31 a of the peak portion 31. The flat surface 31f is formed by, for example, subjecting the top portion 31a of the peak portion 31 to a polishing process or the like with a polishing machine after the valley portion 30 and the peak portion 31 are formed. Thereby, generation | occurrence | production of a stripe-like surface projection can be suppressed. The width Wf in the axial direction of the flat surface 31f is 0.05 mm or more and 0.5 mm or less. As a result, it is possible to further suppress streaky surface projection while exhibiting a frictional force against the wet film 17. When the width Wf is less than 0.05 mm, a portion that cannot be polished depending on the processing accuracy of the peak portion 31 is generated. If the width Wf is larger than 0.5 mm, the valleys 30 and the peaks 31 cannot be formed at the pitch defined above. The width Wf is more preferably 0.1 mm or greater and 0.3 mm or less.

  In the said embodiment, although the peak part 31 and the trough part 30 were divided and provided for every 1 round, you may provide so that it may become a spiral shape. As shown in FIG. 8, the web support roller 47 has a pair of spiral portions 48 in the ear contact region 47 e that contacts the ear 17 e on the peripheral surface of the web support roller 47. The spiral part 48 includes a peak part extending in a spiral shape and a valley part provided between the peak parts. The troughs and the crests provided in the spiral portion 48 have the same structure as the troughs 30 and the crests 31. Furthermore, the peak portions provided in the pair of spiral portions 48 are provided so that their winding directions are different from each other. And the web support roller 47 is provided so that a pair of peak parts leave | separate as it goes to the running direction MD of the wet film 17. As shown in FIG. Thereby, generation | occurrence | production of the wrinkle of the wet film 17 can be prevented, preventing generation | occurrence | production of a slip and surface projection. The spiral portion 48 may be provided with a plurality of spiral peaks.

  In the above embodiment, the web support roller 18 is described as an example of a drive roller that is rotationally driven by the motor 19, but the present invention is not limited to this and is applied to a free roller to which a drive source is not connected. May be. Further, as shown in FIG. 1, the web support roller 18 is provided so as to wind the wet film 17 at a predetermined wrap angle. However, the present invention is not limited to this, and the wrap angle may be 0 °.

  In the above embodiment, one web support roller 18 is used, but the present invention is not limited to this, and a plurality of web support rollers 18 may be used. For example, one or a plurality of web support rollers may be provided on one or both of the upstream side and the downstream side in the conveyance direction of the wet film 17 with respect to the web support roller 18. The web support roller in this case may be a free roller provided rotatably, in addition to a drive roller driven to rotate by a motor.

  The web support roller 18 can be used in solution casting equipment and melt casting equipment. In the solution casting apparatus, the web guided by the web support roller 18 is after being peeled from the casting support, and a so-called wet film containing a solvent, and a film obtained by drying the wet film, It is. In solution casting equipment, a dope containing a polymer and a solvent is cast on a casting support to form a casting film on the casting support, and the casting film is used as a wet film from the casting support. Strip off. The wet film thus peeled off is conveyed to the drying chamber by the web support roller 18. In the drying chamber, the contained solvent is evaporated by drying the wet film containing the solvent. The film obtained by this drying is wound up by a winding device so as to be in a roll form. The roll-shaped film wound up by the winding device can be used as the original fabric roll 10 in the web conveyance device 20 shown in FIG. Further, in the melt film-forming equipment, the web guided by the web support roller 18 is a film obtained by melting a raw material polymer by a melt extruder and extruding it into a thin film shape.

  The film produced from the solution casting apparatus is preferably at least 100 m in the longitudinal direction (casting direction). Moreover, it is preferable that the width | variety of a film is 600 mm or more, and it is more preferable that they are 1400 mm or more and 2500 mm or less. The present invention is also effective when it is larger than 2500 mm. The present invention is also applied when manufacturing a thin film having a thickness of 40 μm or more and 60 μm or less.

  The wet film in solution casting contains a solvent and is heated to accelerate drying. In addition, the film in the melt film formation has a high temperature of approximately the melting point when extruded from the melt extruder. As described above, when the web support roller 18 of the present invention is used to guide a web containing a solvent or a high-temperature web, the web can be guided without slipping. Does not occur. Below, the aspect in a solution film-forming equipment is demonstrated as an example of the aspect which uses the web support roller 18 in a film-forming equipment.

[material]
As a dope raw material, a known polymer and solvent capable of producing a film by solution casting can be used. Among the polymers, cellulose acylate and cyclic polyolefin can be preferably used. Since any of these polymers is basically the same in the construction of the production equipment and the flow of the production method, the case where a cellulose acylate film is used as a polymer component will be described below as an example.

Among cellulose acylates, the ratio of esterifying the hydroxyl group of cellulose with carboxylic acid, that is, the degree of acyl group substitution (hereinafter referred to as acyl group substitution degree) satisfies all the conditions of the following formulas (I) to (III). What is satisfied is more preferable. In (I) to (III), A and B are both acyl group substitution degrees, the acyl group in A is an acetyl group, and the acyl group in B has 3 to 22 carbon atoms.
2.5 ≦ A + B ≦ 3.0 (I)
0 ≦ A ≦ 3.0 (II)
0 ≦ B ≦ 2.9 (III)

  Glucose units constituting cellulose and having β-1,4 bonds have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer in which some or all of these hydroxyl groups are esterified, and hydrogen of the hydroxyl groups is substituted with acyl groups having 2 or more carbon atoms. Since the degree of substitution is 1 when esterification of one hydroxyl group in the glucose unit is 100%, in the case of cellulose acylate, the hydroxyl groups at the 2nd, 3rd and 6th positions are each 100% ester. The degree of substitution is 3.

  Here, the substitution degree of the acyl group at the 2-position of the glucose unit is DS2, the substitution degree of the acyl group at the 3-position is DS3, and the substitution degree of the acyl group at the 6-position is DS6. The total acyl group substitution degree determined by DS2 + DS3 + DS6 is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and even more preferably 2.40 to 2.88. . Further, DS6 / (DS2 + DS3 + DS6) is preferably 0.28 or more, more preferably 0.30 or more, and further preferably 0.31 to 0.34.

  There may be only one kind of acyl group, or two or more kinds. When there are two or more acyl groups, it is preferable that one of them is an acetyl group. DSA + DSB, where DSA is the sum of the substitution degrees of the hydrogens of the hydroxyl groups at the 2nd, 3rd and 6th positions with the acetyl group, and DSB is the sum of the substitution degrees other than the acetyl groups at the 2nd, 3rd and 6th positions The value of is preferably 2.22 to 2.90, particularly preferably 2.40 to 2.88. DSB is preferably 0.30 or more, and particularly preferably 0.70 or more. Further, 20% or more of the DSB is preferably a substituent at the 6-position hydroxyl group, more preferably at least 25%, even more preferably 30% or more, and particularly preferably 33% or more is a substituent at the 6-position hydroxyl group. Preferably there is. The 6-position DSA + DSB value of cellulose acylate is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. By using the cellulose acylate as described above, a dope having a preferable solubility and a dope having a low viscosity and a good filterability can be produced. In particular, when a non-chlorine organic solvent is used, the above cellulose acylate is preferable.

  The acyl group having 2 or more carbon atoms may be an aliphatic group or an aryl group, and is not particularly limited. For example, there are cellulose alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc., and these may each further have a substituted group. Propionyl group, butanoyl group, pentanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, iso-butanoyl group, t-butanoyl group, cyclohexane Examples thereof include a carbonyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, and a cinnamoyl group. Among these, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a t-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and a propionyl group and a butanoyl group are particularly preferable.

  The details of cellulose acylate are described in paragraphs [0140] to [0195] of JP-A-2005-104148, and these descriptions can also be applied to the present invention.

  Solvents for producing the dope include aromatic hydrocarbons (eg, benzene, toluene, etc.), halogenated hydrocarbons (eg, dichloromethane, chloroform, chlorobenzene, etc.), alcohols (eg, methanol, ethanol, n-propanol, Examples thereof include n-butanol, diethylene glycol, etc., ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (eg, tetrahydrofuran, methyl cellosolve, etc.). Here, the dope is a polymer solution or dispersion obtained by dissolving a polymer in a solvent or dispersing in a dispersion medium.

  As the solvent, among the above compounds, a halogenated hydrocarbon having 1 to 7 carbon atoms is preferable, and dichloromethane is most preferable. And from the viewpoint of properties such as solubility of cellulose acylate, peelability from a cast film support, mechanical strength of the film, and optical properties of the film, one or several kinds of alcohols having 1 to 5 carbon atoms are used. Is preferably mixed with dichloromethane. At this time, the content of the alcohol is preferably 2% by weight to 25% by weight and more preferably 5% by weight to 20% by weight with respect to the whole solvent. Preferable specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, etc. Among them, methanol, ethanol, n-butanol, or a mixture thereof is preferably used.

  For the purpose of minimizing the influence on the environment, the dope may be manufactured without using dichloromethane. As the solvent in this case, an ether having 4 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, and an ester having 3 to 12 carbon atoms are preferable, and these may be appropriately mixed and used. These ethers, ketones and esters may have a cyclic structure. A compound having two or more functional groups of ether, ketone and ester (that is, —O—, —CO— and —COO—) can also be used as the solvent. The solvent may have another functional group such as an alcoholic hydroxyl group in the chemical structure.

  Depending on the purpose, the dope may be added with various known additives such as a plasticizer, an ultraviolet absorber (UV agent), a deterioration preventing agent, a slipping agent, and a peeling accelerator. For example, as the plasticizer, phosphate plasticizers such as triphenyl phosphate and biphenyldiphenyl phosphate, phthalate plasticizers such as diethyl phthalate, and various known plasticizers such as polyester polyurethane elastomers are used. be able to.

  The same applies to additives such as solvents and plasticizers, deterioration inhibitors, ultraviolet absorbers, optical anisotropy control agents, dyes, matting agents, release agents, etc., paragraph [0196] of JP-A-2005-104148. To [0516] paragraphs, and these descriptions can also be applied to the present invention.

  The dope whose cellulose acylate density | concentration is 5 to 40 weight% is manufactured using the above raw material. The cellulose acylate concentration is more preferably in the range of 15% by weight to 30% by weight, and further preferably in the range of 17% by weight to 25% by weight. The concentration of the additive is preferably in the range of 1% by weight to 20% by weight with respect to the entire solid content.

  Regarding the production of the dope, the raw material dissolution method, filtration method, defoaming, and addition method are described in detail in paragraphs [0517] to [0616] of JP-A-2005-104148. The contents of can also be applied to the present invention.

[Film production method]
FIG. 9 is a schematic view showing the solution casting apparatus 50. However, the present invention is not limited to the solution casting apparatus 50. In the solution casting apparatus 50, a dope 51 in which cellulose acylate is dissolved in a solvent is cast to form a wet film 52 which is a cellulose acylate film containing the solvent, and a wet film 52 is conveyed. A first drying chamber 56 that dries while drying, a tenter 57 that dries while transporting the wet film 52 while holding both side ends of the wet film 52 that has left the first drying chamber 56, and ears of the wet film 52 In order to cool the film 59, a second drying chamber 61 for separating the ear-cutting device 58, a cellulose acylate film 59 (hereinafter simply referred to as a film) 59 which is dried while transporting the wet film 52 and contains almost no solvent. Cooling chamber 62, a static elimination device 63 for reducing the charge amount of the film 59, and a knurling roller pair 66 for embossing the side ends. , And the winding portion 67 for winding up the film 59 is provided.

  The casting chamber 53 includes a casting die 71 that flows out of the dope 51 and a drum 72 as a casting support. The casting die 71 is preferably a coat hanger type die. A temperature controller (not shown) for controlling the temperature of the casting die 71 is attached to the casting die 71 so that the temperature of the dope 51 is maintained at a predetermined temperature.

  The width of the casting die 71 is not particularly limited, and in the present embodiment, it is about 1.1 to 2.0 times the width of the film 59 that is the final product. Further, the casting die 71 is provided with a plurality of thickness adjusting bolts (heat bolts) for adjusting the gaps of the slits of the casting die 71 at predetermined intervals in the width direction in order to adjust the thickness of the beads when flowing out. It is preferred that

  A drum 72 as a casting support is attached to a shaft (not shown). The drum 72 rotates around an axis under the control of a control unit (not shown). The peripheral surface of the drum 72 that travels by this rotation supports the dope 51. The width of the peripheral surface of the drum 72 is not particularly limited. In the present embodiment, the width is 1.1 to 2.0 times the casting width of the dope 51. The peripheral surface of the drum 72 has an average roughness of 0.01 μm or less and is subjected to chrome plating or the like. A heat transfer medium circulation device (not shown) is connected to the drum 72, and the heat transfer medium circulation device controls the temperature of the heat transfer medium, and passes through the heat transfer medium provided in the drum 72. Circulating supply. As a result, the temperature of the peripheral surface of the drum 72 is kept substantially constant within a predetermined range. The temperature of the peripheral surface of the drum 72 may be appropriately set according to the type of solvent, the type of solid component, the concentration of the dope 51, and the like, but is preferably −15 ° C. or higher and 0 ° C. or lower, for example.

  A casting bead is formed from the casting die 71 to the peripheral surface of the drum 72, and a casting film 78 is formed on the drum 72. The cast film 78 is cooled by contact with the peripheral surface of the drum 72, and self-supporting property is expressed by gelation. A decompression chamber 76 is provided on the upstream side of the casting bead. The upstream bead is depressurized with respect to the casting beat to stabilize the casting bead.

  The pressure in the upstream area with respect to the bead is preferably 2000 Pa to 10 Pa lower than the downstream area. In order to keep the casting bead in a desired shape, it is preferable to attach a suction device (not shown) to the edge portion of the casting die 71 and suck both sides of the bead. The suction air volume is preferably in the range of 1 L / min to 100 L / min.

  The casting chamber 53 has a temperature control device 77 for keeping the internal temperature at a predetermined value, and a condenser (not shown) for condensing and recovering the solvent evaporated from the dope 51 and the casting film 78. And are provided. A recovery device (not shown) for recovering the condensed and liquefied solvent is provided outside the casting chamber 53. The solvent recovered by the recovery device is regenerated and reused as a solvent for dope production.

  The casting chamber 53 is provided with a peeling roller 85 that supports the wet film 52 in order to peel the casting film 78 from the drum 72. The stripping roller 85 strips the casting film 78 having self-supporting properties from the drum 72. The weight of the residual solvent of the casting film 78 at the time of peeling is preferably 10 to 200 when the weight of the solid content is 100.

  Instead of the drum 72, a pair of backup rollers and a band that spans the backup rollers can be used. In this case, self-supporting property can be provided by drying the casting film 78 and evaporating the solvent contained in the casting film 78.

  The first drying chamber 56 is provided with a blower (not shown). The temperature of the drying air from the blower is preferably in the range of 20 ° C to 250 ° C. The first drying chamber 56 is provided with a web support roller 18 for guiding the wet film 52 to the tenter 57. Thereby, even if it is the wet film 52 containing a solvent, and even if the temperature of the wet film 52 is 100 degreeC or more with a fan, it can be stably conveyed without slipping, and it is wet It is possible to prevent the film 52 from being scratched or wrinkled. Further, the web support roller 18 does not press the foreign matter against the wet film 52, and the wet film 52 is not uneven. When the web support roller 18 is used, there is an effect that there is no surface projection. The tension applied to the wet film 52 by the web support roller 18 is preferably 50 N / m or less. Thereby, a wet film having a residual solvent amount of 100% by weight or more and 250% by weight or less can be transported while suppressing elongation in the transport direction. The amount of residual solvent in the present specification is the amount of residual solvent based on the dry amount. When the film weight at the time of sampling is “x” and the weight after the sampling film is dried is “y” {(xy ) / Y} × 100.

  A plurality of web support rollers 18 may be provided in the first drying chamber 56. Note that all of the plurality of rollers provided in the conveyance path of the first drying chamber 56 may be the web support roller 18, or only a part thereof may be the web support roller 18. Of the plurality of rollers, the driving roller is more preferably the web support roller 18, but the free rotation roller is more preferably the web support roller 18.

  In the first drying chamber 56, with respect to the plurality of rollers arranged in the conveyance path, draw tension is applied to the wet film 52, that is, the conveyance direction, by making the rotation speed of the downstream roller faster than the rotation speed of the upstream roller. The tension in can be applied. Thereby, sagging and deformation of the wet film 52 can be prevented.

  Both ends of the wet film 52 sent to the tenter 57 are held by holding means (not shown), and are conveyed by the movement of the holding means. And it dries during this conveyance. Examples of the holding means include a clip that holds the side portion of the wet film 52, and a plurality of pins that pierce and hold the side portion. When the drum 72 is used as a casting support and the casting film 78 cooled with almost no solvent evaporated is peeled off, a pin is preferably used as the holding means in the tenter 57. On the other hand, when a band is used as the casting support and the casting film is peeled off after part of the solvent is evaporated, the holding means in the tenter 57 is preferably a clip. In the tenter 57, the wet film 52 is dried by being set to a temperature of 120 ° C. or higher and 180 ° C. or lower.

  After the wet film 52 is dried by the tenter 57, the ear portion thereof is cut and removed by the ear clip device 58. The separated ear is sent to the crusher 89 by a cutter blower (not shown). The crusher 89 pulverizes the ears into chips. This chip is reused for dope production.

  On the other hand, the wet film 52 from which both ends have been removed is sent to the second drying chamber 61 and further dried while being conveyed. Although the internal temperature of the 2nd drying chamber 61 is not specifically limited, It is preferable to set it as 60-140 degreeC. Similarly to the first drying chamber 56, the web support roller 18 is also provided in the conveyance path of the second drying chamber 61. Thereby, even if the temperature of the wet film 52 is a high temperature of, for example, 100 ° C. or higher, the wet film 52 can be stably conveyed without slipping, and the wet film 52 can be prevented from being scratched, wrinkled, or the like. it can. Further, the web support roller 18 does not press the foreign matter against the wet film 52, and the wet film 52 is not uneven. When the web support roller 18 is used, there is an effect that there is no surface projection.

  Note that all of the plurality of rollers provided in the conveyance path of the second drying chamber 61 may be the web support roller 18, or only a part may be the web support roller 18. Of the plurality of rollers, the driving roller is more preferably the web support roller 18, but the free rotation roller is more preferably the web support roller 18.

  The dried film 59 is preferably cooled to approximately room temperature in the cooling chamber 62. The static eliminator 63 is a so-called forced static eliminator such as a static eliminator, and makes the voltage of the film 59 within a predetermined range. It is preferable to neutralize the film 59 so that the charged voltage is −3 kV to +3 kV. The position of the static eliminating device 63 is not limited to the downstream side of the cooling chamber 62.

  The knurling roller pair 66 applies knurling to both side ends of the film 59 by embossing. The embossing is preferably performed so that the height of the unevenness at the knurled portion is 1 μm to 200 μm.

  Inside the winding unit 67, a winding device 92 for winding the film 59 and a press roller 93 for controlling the tension at the time of winding are provided.

  In addition, the conveyance path of the solution casting apparatus 50 includes a roller (not shown), and the web support roller of the present invention can be used for any of these rollers. As a result, the wet film 52 and the film 59 can be transported more stably than in the prior art, and scratches and wrinkles of the film 59 can be prevented and surface exposure does not occur. Both the free roller and the driving roller are conventionally used as the rollers provided in the conveying path. However, the web conveying roller according to the present invention can be used as a driving roller instead of the conventional driving roller. Is big.

[Experiment 1]
In order to clarify the effect of the web support roller of the present invention, Experiment 1 was performed under the following conditions. First, as the web support roller 18, a roller body 18 a made of stainless steel (no plating) having a diameter of 300 mm and a surface length of 1000 mm was fitted with a shaft portion 18 b. Valley portions 30 and peak portions 31 were formed on the roller body 18a so that the pitches Pv and Pm were 1 mm, the height Hv-m was 0.5 mm, and the curvature radii Rv and Rm were 0.3 mm.

  And the film 59 was manufactured from the dope 51 with the solution casting apparatus 50 shown in FIG. Using the casting die 71, the dope 51 was cast on the casting support to form a casting film 78. As the casting support, the peripheral surface of the drum 72 that rotates the shaft was used. The temperature of the peripheral surface of the drum 72 was adjusted to be substantially constant within a range of −15 ° C. to 0 ° C. The cast film 78 was cooled by the contact with the peripheral surface of the drum 72, and self-supporting property was expressed by gelation. The casting film 78 having self-supporting property was peeled off from the peripheral surface of the drum 72 to obtain a wet film 52. The residual solvent amount of the wet film 52 immediately after peeling off was 100% by weight or more and 250% by weight or less. The wet film 52 was conveyed to the pin tenter using the web support roller 18. The conveying conditions of the wet film 52 were a tension of 50 N / m and a peripheral speed of the web support roller 18 of 20 to 60 m / min. In the pin tenter, the wet film 52 was dried. Then, after the ear | edge part of the wet film 52 was cut | disconnected with the ear cutting device 58, it was made to dry in the drying chamber 61, and it was set as the film 59. FIG. The dried film 59 was sent to the winding chamber 67 through the cooling chamber 62 and the like. The film 59 had a width of 2000 mm and a thickness of 80 μm. The obtained film 59 had an in-plane retardation Re of 4 mm and a thickness direction retardation Rth of 45 nm.

The method for measuring the in-plane retardation Re of the film 59 is as follows. The film 59 was cut into 70 mm × 100 mm, conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and measured with a vertical birefringence meter (KOBRA21DH Oji Scientific Co., Ltd.) from the vertical direction at 632.8 nm. It calculated according to the following formula from the extrapolation value of the foundation value.
Re = | nMD−nTD | × d
nMD is the refractive index in the transport direction, nTD is the refractive index in the width direction, and d is the thickness (film thickness) of the film.

The measuring method of the thickness direction retardation Rth of the film 59 is as follows. The film 59 was cut into 30 mm × 40 mm, conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, measured with an ellipsometer (M150 manufactured by JASCO Corporation) at 632.8 nm from the vertical direction, and the film surface It calculated according to the following formula from the extrapolated value of the retardation value measured in the same manner while tilting.
Rth = {(nMD + nTD) / 2−nTH} × d
nTD represents the refractive index in the thickness direction.

  The formulation for preparing the polymer solution (dope) used in the production of the polymer film is shown below.

[Preparation of dope]
The prescription of the compound used for preparation of the dope 51 is shown below.
Cellulose triacetate (degree of substitution 2.85) 100 parts by weight plasticizer A (triphenyl phosphate) 7.1 parts by weight plasticizer B (biphenyl diphenyl phosphate) Solid content (solute) having a composition ratio of 3.6 parts by weight Was appropriately added to a mixed solvent consisting of 80 parts by weight of dichloromethane, 13.5 parts by weight of methanol, and 6.5 parts by weight of n-butanol, and dissolved by stirring to prepare a dope 51. The TAC concentration of the dope 51 was adjusted to be approximately 23% by weight. The dope 51 is filtered with a filter paper (Toyo Filter Paper Co., Ltd., # 63LB), further filtered with a sintered metal filter (Nihon Seisen Co., Ltd. 06N, nominal pore size 10 μm), and further filtered with a mesh filter. I put it in the tank.

[Cellulose triacetate]
The cellulose triacetate used here has a residual acetic acid content of 0.1% by weight or less, a Ca content of 5 ppm, a Mg content of 42 ppm, a Fe content of 0.5 ppm, free acetic acid of 40 ppm, It contained 15 ppm of sulfate ion. The degree of substitution of the acetyl group with respect to the hydrogen at the 6-position hydroxyl group was 0.91. Further, 32.5% of all acetyl groups were acetyl groups in which the hydrogen of the hydroxyl group at the 6-position was substituted. Moreover, the acetone extraction part which extracted this TAC with acetone was 8 weight%, and the weight average molecular weight / number average molecular weight ratio was 2.5. The obtained TAC had a yellow index of 1.7, a haze of 0.08, and a transparency of 93.5%. This TAC is synthesized using cellulose collected from pulp as a raw material. In the following description, this is called a pulp raw material TAC.

[Experiment 2] to [Experiment 10]
Experiments 2 to 10 are the same as Experiment 1 except that the web support roller 18 used in Experiment 1 is different from Pm and Hv-m, and the web support roller does not have a peak. I went. Each condition (presence / absence of peak portion, Pm, Hv-m) of the web support roller used in Experiments 2 to 10 is shown in Table 1, respectively.

  The above Experiment 1 to Experiment 10 were evaluated as follows, and the results are shown in Table 1. In addition, the number of the evaluation result shown in Table 1 shows the number attached | subjected to each evaluation item hereafter.

1. Evaluation of presence or absence of slip The presence or absence of slip of the wet film 17 by the web support roller 18 was evaluated according to the following criteria.
(Double-circle): There was no generation | occurrence | production of the slip of the wet film 17, and there was no generation | occurrence | production of an abrasion and a wrinkle.
○: Slip of the wet film 17 occurred slightly, but almost no scratches or wrinkles were observed.
X: Slip of the wet film 17 was generated, and scratches and wrinkles were generated.

2. Presence / absence of surface exposure failure The presence / absence of surface exposure of the wet film 17 by the web support roller 18 was evaluated according to the following criteria.
(Double-circle): The surface film did not generate | occur | produce in the wet film 17.
◯: Some surface exposure occurred in the wet film 17, but there was no practical problem.
X: Surface exposure occurred remarkably in the wet film 17.

  In Experiments 1-3, 6, and 7, the wet film did not slip or appear in the first drying chamber 56. In Experiment 10, since no peak portion was provided, slip of the wet film and surface projection occurred in the first drying chamber 56. Further, as in Experiments 4, 8, and 9, when Hv-m is smaller than the predetermined range or Pm is out of the predetermined range, the cross-sectional area of the trough is reduced, so that the air removal effect is sufficiently exerted. Instead, slips and cut-outs occurred. Further, as in Experiment 5, when Hv-m is larger than the predetermined range, as in Experiments 1-3, 6, and 7, the occurrence of slipping and chamfering is suppressed, but the processing of the roller body is not performed. Cost and effort increased.

  From the above results, it has been found that the web support roller of the present invention can convey the web while preventing the web from slipping or seeing off because the peak portion of the predetermined condition is provided in the ear contact region.

It is a figure which shows the outline of the web conveyance apparatus of this invention. It is a top view when the web support roller which supports the single side | surface of a wet film is seen from the said single side | surface side of a wet film. It is an expanded partial sectional view of the 1st web support roller in the section containing an axis. FIG. 6 is an enlarged partial cross-sectional view of a first web support roller that supports a wet film in a cross-section including an axis. It is an expanded partial sectional view of the 2nd web support roller in the section containing an axis. It is an expanded partial sectional view of the 3rd web support roller in the section containing an axis. It is an expanded partial sectional view of the 4th web support roller in the section including an axis. It is a top view when the 5th web support roller which supports the single side | surface of a wet film is seen from the surface side on the opposite side to the said single side | surface of a wet film. 1 is a schematic view of a solution casting apparatus including a web support roller.

Explanation of symbols

11 Web 17 Wet film 17c Product part 17e Ear part 18, 40, 45, 47 Web support roller 18a Roller body 18b Shaft part 18c Product part contact area 18e Ear part contact area 20 Web conveying device 30 Valley part 30a Bottom part 31 Mountain part 31a Top part 31f Flat surface 48 Spiral part

Claims (5)

In the web support roller for running the web while supporting the web on the circumferential surface,
A cylindrical roller body;
Provided on the peripheral surface of the roller main body at the ear contact region where the ears at both ends of the web in the width direction come into contact with each other, and are formed along the circumferential direction of the roller main body and spaced apart in the rotation axis direction of the roller main body. A plurality of protrusions,
The protrusion has a substantially arcuate apex having a radius of curvature of 0.1 mm or more and 0.5 mm or less in a cross section including the rotation axis of the roller body.
The pitch in the rotation axis direction of the plurality of protrusions is 0.01 mm or more and 2 mm or less,
A web support roller characterized in that a valley is formed between the protrusions, and a height between the bottom of the valley and the top is 0.01 mm or more and 1 mm or less. In the web support roller for running the web while supporting the web on the circumferential surface,
A cylindrical roller body;
Provided on the peripheral surface of the roller main body at the ear contact region where the ears at both ends of the web in the width direction come into contact with each other, and are formed along the circumferential direction of the roller main body and spaced apart in the rotation axis direction of the roller main body. A plurality of protrusions,
The protrusion has a flat top portion in a cross section including the rotation axis of the roller body, parallel to the rotation axis direction and having a length in the rotation axis direction of 0.05 mm or more and 0.5 mm or less,
The pitch in the rotation axis direction of the plurality of protrusions is 0.01 mm or more and 2 mm or less,
A web support roller characterized in that a valley is formed between the protrusions, and a height between the bottom of the valley and the top is 0.01 mm or more and 1 mm or less.   The top part of the said protrusion protrudes with respect to the product part contact area | region where the product part which consists of the said web except the said ear | edge part contacts in the surrounding surface of the said roller main body. Web support roller.   Spirals in which the ridges formed in the first ear contact area formed at one end of the roller body and the second ear contact area formed at the other end of the roller body have different winding directions. The roller body is formed in a shape, and the direction of the roller body is defined so that the pair of spiral protrusions gradually separates as the web travels in the traveling direction of the web. 3. The web support roller according to any one of 3 above.   A web transport method comprising transporting the web by using the web support roller according to claim 1 to support a web having a thickness in a range of 20 μm to 200 μm.

Images