CN102344577A

CN102344577A - Drying device and film producing method from solution

Info

Publication number: CN102344577A
Application number: CN2011102170179A
Authority: CN
Inventors: 吉田俊一; 加藤仁
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2010-07-30
Filing date: 2011-07-29
Publication date: 2012-02-08
Anticipated expiration: 2031-07-29
Also published as: CN102344577B; KR101810523B1; JP5591010B2; JP2012030481A; KR20120065220A

Abstract

Provided are a drying device and a film producing method from solution. A second drying unit for drying a curtain coating film (30) comprises a case-like feeding pipe, vertical nozzles (32b) venting drying wind (402), and suction pipes (32c) sucking drying wind (402). A feeding pipe is arranged at the upside of the curtain coating film (30). The vertical nozzles (32b), from the bottom of the feeding pipe, protrude toward the curtain coating film (30). The suction pipes (32c) are arranged at both sides of the B direction of the vertical nozzles (32) which are arranged along the direction toward the A direction. The suction pipes (32c) are provided with suction ports (32cx) for sucking the drying wind (402). The suction ports (32cx) are arranged at the position farther away from the curtain coating film (30) than the blowing-in slots (32bx) arranged upon the vertical nozzles (32b). A suction path is formed among the vertical nozzles (32b).

Description

Drying installation and solution film-forming method

Technical field

The present invention relates to a kind of drying installation and solution film-forming method.

Background technology

Polymeric film (below, be called film) with light transmission is because in light weight and easy moulding, so extensively utilize as blooming.Wherein, use the cellulose ester mesentery of cellulose acylate etc. to be used for picture photosensitive with the blooming (for example, phase retardation film or polarization board protective film etc.) headed by the film as the component parts of the liquid crystal indicator of the market expansion in recent years.

Such film is through the solution film-forming method manufacturing.The summary of solution film-forming method is as follows.1st, the polymers soln that comprises polymkeric substance and solvent (below, be called dope) is flowed, and on supporter, form casting films.2nd, make solvent become the state that can transmit independently up to casting films from the casting films evaporation.3rd, peel casting films as moistening film from supporter.Afterwards, evaporate from moistening film through making solvent, thereby can obtain film by moistening film.

As the drying means of casting films, known for example have as the open 2007-290375 communique of Japanese Patent from the method for the top winding-up dry wind of casting films.As shown in figure 15, in the drying means of putting down in writing in the open 2007-290375 communique of Japanese Patent, above the casting films 201 that transmits through casting belt 200, drying installation 202 is set as supporter.In the drying installation 202, be arranged alternately air-supply slit 202a and attract a mouthful 202b towards the delivery direction of casting films 201.Air-supply slit 202a sees dry wind 203 off towards casting films 201.Attract mouthful 202b to attract dry wind 203.Through using such drying installation 202 to blow dry wind 203, thereby make the solvent evaporation that is contained in the casting films 201 to casting films 201.

In recent years, along with the increase in demand of liquid crystal indicator and LCD maximization, the new problem that creates blooming supplier of wide cut blooming with display panel etc.

During the method in utilizing the open 2007-290375 communique of Japanese Patent, put down in writing, need prolong air-supply slit 202a more longways and attract a mouth 202b to the width of casting films according to the wide cutization of casting films.But, attract a mouthful 202b because of prolonging, be difficult to make the traffic attraction of dry wind even on width.Therefore, cause drying conditions unstable on the width of casting films.Blooming through the drying process of this condition causes optical characteristics (for example Re, Rth) unstable on width.

Summary of the invention

The present invention accomplishes for solving such problem, and its purpose is to provide a kind of and casting films is carried out the drying installation of drying process and have the solution film-forming method of this drying process with condition impartial on width.

In order to solve above-mentioned problem, drying installation of the present invention possesses conduit, a plurality of nozzle, air-supply slit and attracts mouth.It is relative with the zonal casting films that transmits to long side direction that said conduit is adapted to.Said casting films comprises polymkeric substance and solvent.Said a plurality of nozzle is arranged on the delivery direction of said casting films.Said nozzle is to be provided with towards the outstanding mode of said casting films from conduit.Said air-supply slit will be seen off to said casting films as dry wind from the dry gas of said conduit.Said air-supply slit extends and forms to the width of said casting films at the front end of said nozzle.The said mouthful said dry wind that suction is seen off from said air-supply slit that attracts.Said attraction mouthful on the said delivery direction between said nozzle and said nozzle.The said mouth that attracts is positioned at the both sides than the more close said width of said casting films.Said attraction mouthful and the distance of said casting films distance greater than said air-supply slit and said casting films.

In this drying installation, preferred said air-supply slit and said attraction mouth are alternately arranged towards the downstream side from said delivery direction upstream side.

Preferably from more forming said attraction mouth to downstream side than the more close said delivery direction of a said nozzle near the upstream side of said delivery direction than a said nozzle.

Preferred said attraction mouth is relative with said casting belt.

Preferred said attraction actinal surface is to said width center side.

The amount of residual solvent of the said casting films that preferred said dry wind touched is below the above 350 quality % of 150 quality %.

Preferred said conduit is arranged at the top of said casting films.

The width of preferred said casting films is below the above 2400mm of 1500mm.

Solution film-forming method of the present invention is to make said solvent obtain the solution film-forming method of film from the casting films evaporation that comprises polymkeric substance and solvent.Solution film-forming method of the present invention possesses the step (supplying step) of seeing dry wind off and the step (attraction step) that attracts said dry wind.Supplying step is seen dry wind off to the zonal said casting films that transmits along long side direction.Said dry wind is utilized in the air-supply slit of arranging on the delivery direction of said casting films and sees off.Said air-supply slit is relative with said casting films.Said air-supply slit extends to the width of said casting films.Attract in the step, said dry wind is from attracting than the position of said air-supply slit further from said casting films.Attract in the step, said dry wind is from more attracting near the position of width both sides than said casting films.

In solution film-forming method, the amount of residual solvent of the said casting films that preferred said dry wind touched is below the above 350 quality % of 150 quality %.

The width of preferred said casting films is below the above 2400mm of 1500mm.

The invention effect

According to the present invention, owing to will attract the attraction mouth of dry wind to be arranged at both end sides, so even under the situation that the width of casting films broadens, also can attract dry wind equably than the more close width of casting films.In addition, owing to attract mouthful distance with casting films, so can suppress the drawback that the attraction because of dry wind brings greater than the distance of slit and casting films of blowing.Therefore, can produce the blooming that the deviation of optical characteristics is inhibited according to the present invention.

Description of drawings

Those skilled in the art can understand above-mentioned purpose and advantage easily through with reference to the accompanying drawings and read DETAILED DESCRIPTION OF THE PREFERRED.

Fig. 1 is the explanatory view of the summary of expression solution film-forming equipment.

Fig. 2 is the side-view of the summary of expression the 1st drying unit and the 2nd drying unit.

Fig. 3 is the stereographic map of the summary of expression the 2nd drying unit.

Fig. 4 is the stereographic map of the summary of expression the 2nd air-supply conduit and perpendicular nozzle.

Fig. 5 is the V-V line sectional view of the summary of expression the 2nd drying unit.

Fig. 6 is the sectional view of summary of the front end of expression perpendicular nozzle.

Fig. 7 is the sectional view of summary of the front end of expression perpendicular nozzle.

Fig. 8 is that the expression perpendicular nozzle is seen the stereographic map that the 2nd dry wind, negative pressure catheter attract the summary of the 2nd dry wind off.

Fig. 9 is the sectional view that expression is arranged at the summary of the attraction sectional area between the perpendicular nozzle.

Figure 10 is that expression has the 1st sectional view of summary of the 2nd drying unit of becalming plate.

Figure 11 is that expression has the 2nd sectional view of summary of the 2nd drying unit of becalming plate.

Figure 12 is the sectional view of the summary of expression the 2nd negative pressure catheter.

Figure 13 is the sectional view of the summary of expression the 3rd negative pressure catheter.

Figure 14 is the sectional view of the summary of expression the 4th negative pressure catheter.

Figure 15 representes the stereographic map of the summary of drying installation in the past.

Embodiment

(solution film-forming method)

As shown in Figure 1, solution film-forming equipment 10 has curtain coating chamber 12, clip tenter machine 13, kiln 15, cooling room 16 and batches chamber 17.Curtain coating mould 21, casting belt 22, rotation roller 23a, 23b and stripper roll 24 are set in the curtain coating chamber 12.

Casting belt 22 forms through binding between the two ends of long side direction of zonal belt body and forms, and in the form of a ring.With the axle is that center rotation rotation roller 23a, 23b freely arranges with the mode of axial one-tenth level.At rotation roller 23a, the last coiling cyclic of 23b casting belt 22.Through the driving of not shown motor, if at least one side rotation among the rotation roller 23a, 23b, it is mobile to pre-determined direction (below, be called the A direction) circulation then to be wound in the last casting belt 22 of rotation roller 23a, 23b.

Curtain coating mould 21 flows out the dope 28 that comprises polymkeric substance and solvent continuously, and has the slit outlet of flowing out dope 28 at front end.Curtain coating mould 21 is positioned at the top of rotation roller 23a, and sets with casting belt 22 opposed modes with the slit outlet.

Preferred curtain coating mould 21, casting belt 22 and rotation roller 23a, 23b are stainless steel, from having the viewpoint of sufficient erosion resistance and intensity, and SUS316 system more preferably.

Export continuous effusive dope 28 after casting belt 22 extends from the slit of curtain coating mould 21, form the banded casting films 30 of extending more longways to the A direction.The casting belt 22 that casting films 30 moves through circulation transmits to the A direction.

The 1st drying unit 31～the 3rd drying unit 33 sets to the downstream side than the more close A direction of curtain coating mould 21 in the vicinity of casting belt 22 successively.The 1st drying unit 31～the 2nd drying unit 32 is arranged at specific rotation transfer roller 23a, 23b more near the position of top, and the 3rd drying unit 33 is arranged at the position of the more close below of specific rotation transfer roller 23a, 23b.

The 1st drying unit 31～the 3rd drying unit 33 is seen predetermined dry wind off towards casting films 30.Through the dry wind from the 1st drying unit 31～the 3rd drying unit 33, solvent becomes the state that can transmit independently after casting films 30 evaporations.

Stripper roll 24 be equipped on casting belt 22 neighbouring, promptly between the 3rd drying unit 33 and the curtain coating mould 21.The casting films 30 that becomes the state that can transmit is independently peeled off as moistening film 37 through stripper roll 24, and guides to the downstream side of curtain coating chamber 12.

Rotation roller 23a, the last connection of 23b register 39.Be built-in with the temperature regulation section of the temperature of regulating heat-transfer medium in the register 39.Register 39 makes the heat-transfer medium that is adjusted to temperature desired in temperature regulation section and be arranged between the stream in rotation roller 23a, the 23b and circulate.Through the circulation of this heat-transfer medium, the temperature of casting belt 22 can be remained on temperature desired.

The temperature of preferred rotation roller 23a is lower than the temperature of rotation roller 23b.The temperature of preferred rotation roller 23a for example is more than 3 ℃ below 30 ℃.And the temperature of preferably rotating roller 23b for example is more than 20 ℃ below 50 ℃.

And, though having omitted diagram, through condensing works that solvent contained in the atmosphere in the condensation curtain coating chamber 12 is set and the retrieving arrangement that reclaims the solvent of condensation, the concentration of solvent contained in the atmosphere in the curtain coating chamber 12 can be remained in the constant scope.

In addition, attraction is formed at the travel direction upstream side of the curtain coating liquid pearl between curtain coating mould 21 and the casting belt 22 through dope 28 the underpressure chamber of gas also can be set.Preferred underpressure chamber more is being configured to adjacent with curtain coating mould 21 near the upstream side of A direction than curtain coating mould 21.Through the attraction based on the gas in underpressure chamber, the pressure that can make the upstream side of curtain coating liquid pearl is lower than the pressure status in the downstream side of curtain coating liquid pearl.The upstream side of preferred curtain coating liquid pearl and the pressure difference in downstream side are below the above 2000Pa of 10Pa.

The downstream of curtain coating chamber 12 are disposed with clip tenter machine 13, kiln 15, cooling room 16 and batch chamber 17.Transfering department 51 between curtain coating chamber 12 and clip tenter machine 13 is provided with the fan 51a and the supporting roll 51b that supports moistening film 37 that blows dry wind to moistening film 37.A plurality of supporting roll 51b arrange to the delivery direction of moistening film 37.Supporting roll 51b is the center rotation with the axle through not shown motor.Supporting roll 51b supports the moistening film of seeing off from curtain coating chamber 12 37, and guides to clip tenter machine 13.In addition, among the figure, be illustrated in the situation that transfering department 51 is arranged 2 supporting roll 51b, but the invention is not restricted to this, also can be at the transfering department 51 supporting roll 51b of arrangement more than 3.

13 pairs of moistening films 37 of clip tenter machine are implemented predetermined processing, obtain film 55 by moistening film 37.See off to kiln 15 from the film 55 that clip tenter machine 13 is seen off.

Be provided with a plurality of rollers 57 in the kiln 15, film 55 is wound on these rollers and is transmitted.The temperature of atmosphere or humidity etc. are regulated through not shown air conditioning machinery in the kiln 15.In kiln 15, carry out the drying treatment of film 55.Connect absorbing recovery device 58 on the kiln 15.Absorbing recovery device 58 reclaims through the solvent of absorption from film 55 evaporations.

The temperature that 16 pairs of films 55 of cooling room cool off up to film 55 becomes roughly room temperature.Cooling room 16 and batching between the chamber 17 sets gradually except that torch 59, annular knurl from upstream side and to give roller 60 and trimming device 61.Removing torch 59 carries out the electrical treating of seeing off from cooling room 16 and charged film 55 removes electricity that removes.Annular knurl is given roller 60 and is given batching to the width two ends of film 55 and use annular knurl.The width two ends of trimming device 61 cutting films 55 are so that annular knurl is left at the width two ends of the film after cutting 55.

Batch and be provided with pressure roller 64 and reeling machine 66 in the chamber 17, be sent to the film 55 that batches chamber 17 when pushing, batch at volume core 65 and be the roller shape through pressure roller 64 with volume core 65.

As shown in Figure 2, the 1st drying unit 31 possesses the 1st supplying duct 31a and angled nozzle 31b.The 1st supplying duct 31a supplies with dry gas through not shown feed unit.Angled nozzle 31b will be supplied to the dry gas of the 1st supplying duct 31a and see off as the 1st dry wind 401.Angled nozzle 31b be arranged at the 1st supplying duct 31a below, a plurality of angled nozzle 31b arrange on the A direction.See 1st dry wind 401 of preset temperature, predetermined wind speed from angled nozzle 31b towards casting films 30 through not shown controller, solvent is from casting films 30 evaporations.

Injection direction and direction A that preferred angled nozzle 31b is adapted to dry wind 401 are acute angle.Thus, can prevent to flow to curtain coating mould 21 sides and be formed at the curtain coating liquid pearl vibration between curtain coating mould 21 and the casting belt 22 from the dry wind 401 that angled nozzle 31b sees off.

Like Fig. 2 and shown in Figure 3, the 2nd drying unit 32 possesses the 2nd supplying duct 32a, perpendicular nozzle 32b and negative pressure catheter 32c.The 2nd supplying duct 32a supplies with dry gas through feed unit 32p.Perpendicular nozzle 32b will be supplied to the dry gas of the 2nd supplying duct 32a and see off as the 2nd dry wind 402.Negative pressure catheter 32c attracts the 2nd dry wind 402.

Like Fig. 4 and shown in Figure 5, the 2nd supplying duct 32a forms box-shaped, and is arranged to cover casting belt 22.Perpendicular nozzle 32b is arranged at the following 32au of the 2nd supplying duct 32a, and 32au arranges to the A direction below, and to be provided with towards casting films 30 outstanding modes from following 32au.

See the air-supply slit 32bx of the 2nd dry wind 402 off in the front end setting of perpendicular nozzle 32b.Air-supply slit 32bx extends to the width of casting films 30 (below, be called the B direction) more longways.Perpendicular nozzle 32b is provided with the injection direction and the roughly rectangular mode of direction A of dry wind 402.Thus, compare during with inclination, can improve Heat transfer coefficient, material transport coefficient, its result can improve exsiccant efficient.

The length L 1 of air-supply slit 32bx on the B direction can be seen off to the degree in the whole zone of B direction of casting films 30 for dry wind 402 and get final product.For example, the length L 1 of slit 32bx on the B direction of preferably blowing equals the width of casting films 30 or is longer than the width of casting films 30.And the length of preferred the 2nd supplying duct 32a on the B direction also equals the width of casting films 30 or is longer than the width of casting films 30.

Like Fig. 6 and shown in Figure 7,, then be involved in the air of air-supply slit 32bx vicinity if see the 2nd dry wind 402 off from air-supply slit 32bx.Its result, this air and the 2nd dry wind 402 together touch casting films 30 (with reference to figure 6).Its result is difficult to regulate the drying conditions of casting films 30 through the condition of regulating the 2nd dry wind 402.Therefore, in perpendicular nozzle 32b, preferably the periphery at air-supply slit 32bx is provided with reflex part 32by (with reference to figure 7).Through reflex part 32by, the air and the 2nd dry wind 402 of the slit 32bx vicinity that can prevent to blow together touch casting films 30.

Like Fig. 5 and shown in Figure 8, preferred negative pressure catheter 32c is arranged between the perpendicular nozzle 32b on the A direction, promptly than perpendicular nozzle 32b more near the both sides of B direction.On negative pressure catheter 32c, be provided with and attract the 2nd of the 2nd dry wind 402 to attract a mouthful 32cx.The 2nd attracts mouthful 32cx to be positioned at the position than the more close top of air-supply slit 32bx.The opening direction of preferred the 2nd attraction mouthful 32cx is a B direction center side.

Get back to Fig. 1, the dry gas that the 3rd drying unit 33 is incited somebody to action never illustrated feed unit supply is as the 3rd dry wind 403.The 3rd drying unit 33 possesses parallel nozzle 33a that sees off towards casting films 30 and the attraction nozzle 33b that attracts the 3rd dry wind 403.Parallel nozzle 33a and attraction nozzle 33b set gradually towards the downstream side from A direction upstream side.Parallel nozzle 33a has the 3rd supplying opening 33ax that sees the 3rd dry wind 403 off.The 3rd supplying opening 33ax is opening towards A direction downstream side.Attract nozzle 33b to have and attract the 3rd of the 3rd dry wind 403 to attract a mouthful 33bx.The 3rd attracts mouthful 33bx towards A direction upstream side opening.Through parallel nozzle 33a and attraction nozzle 33b, can make the 3rd dry wind 403 and casting films 30 almost parallel flows.

Then, effect of the present invention is described.In solution film-forming equipment 10, in curtain coating chamber 12, carry out film successively and form operation, film drying process and stripping process.And, in clip tenter machine 13 or kiln 15, carry out the film drying process, in batching chamber 17, carry out coiling process.Below, the detailed content of each operation is described.

(film formation operation)

In the curtain coating chamber 12, curtain coating mould 21 flows out dope 28 continuously towards the casting belt 22 that moves to the circulation of A direction.Form the casting films 30 that constitutes by dope 28 on the casting belt 22.

(film drying process)

Casting films 30 transmits to the A direction through casting belt 22.Transfer rate for example is more than 10m/ minute below 60m/ minute.The the 1st～the 3rd drying unit 31～33 is seen predetermined dry wind 401～403 off towards the casting films 30 that transmits through casting belt 22.Through with the contacting of each dry wind 401～403, solvent is from casting films 30 evaporations.In addition, the detailed content of film drying process is stated after carrying out.

(stripping process)

Stripper roll 24 is after the film drying process, and the casting films 30 that will become the state that can transmit is independently peeled off as moistening film 37, and guides to clip tenter machine 13 through transfering department 51.

The amount of residual solvent of casting films 30 is below the above 50 weight % of 25 weight % when preferably peeling off.In addition, among the present invention, will represent that the quantity of solvent of quantity of solvent residual in casting films 30 or each film is made as amount of residual solvent with dry basis.And its measuring method does, from object film collected specimens, the weight of this sample is made as weight after x, the dry sample when being made as y, in case (x-y)/and calculate y} * 100.

(film drying process and coiling process)

Clip tenter machine 13 keeps the two ends of moistening film 37 and transmits moistening film 37.In addition, clip tenter machine 13 blows dry wind to moistening film 37, makes solvent from moistening film 37 evaporations.Its result can obtain film 55 from moistening film 37.The two ends of the film 55 that trimming device 47 cutting is seen off from clip tenter machine 13.The film 55 that is cut open two ends is implemented predetermined processing successively through kiln 15 and cooling room 16 in each chamber.The film of seeing off from cooling room 16 55 implemented to give based on the annular knurl that removes electrical treating, gives roller 60 based on annular knurl that removes torch 59 successively handle and handle based on the side cut of trimming device 61.When delivering to the film 55 that batches chamber 17 and push, be wound in core 65 and be the roller shape through pressure roller 64.

Then, the detailed content to the film drying process describes.In the film drying process, carry out successively based on the 1st dry wind 401 the 1st film drying process, based on the 2nd film drying process of the 2nd dry wind 402 and based on the 3rd film drying process of the 3rd dry wind 403.

(the 1st film drying process)

Like Fig. 1 and shown in Figure 2, the 1st drying unit 31 is delivered to casting films 30 with the 1st dry wind 401.Through with the contacting of the 1st dry wind 401, solvent is from casting films 30 evaporations.Preferred the 1st film drying process is that the casting films below the 400 quality % 30 is carried out more than the 250 quality % to amount of residual solvent, is that the casting films below the 350 quality % 30 is carried out more than the 300 quality % to amount of residual solvent more preferably.The temperature of preferred the 1st dry wind 401 is more than 30 ℃ below 80 ℃.And the wind speed of preferred the 1st dry wind 401 is the 5m/ second of above 25m/ below second.

(the 2nd film drying process)

Perpendicular nozzle 32b sees the 2nd dry wind 402 off towards casting films 30.Through with the contacting of the 2nd dry wind 402, solvent is from casting films 30 evaporations.Preferred the 2nd film drying process is that the casting films below the 300 quality % 30 is carried out more than the 150 quality % to amount of residual solvent.The temperature of preferred the 2nd dry wind 402 is more than 30 ℃ below 80 ℃.And the wind speed of preferred the 2nd dry wind 402 is the 5m/ second of above 25m/ below second.

(the 3rd film drying process)

The 3rd drying unit 33 is delivered to casting films 30 with the 3rd dry wind 403.Through with the contacting of the 3rd dry wind 403, solvent is from casting films 30 evaporations.Preferred the 3rd film drying process is that the casting films below the 150 quality % 30 is carried out more than the 20 quality % to amount of residual solvent.The temperature of preferred the 3rd dry wind 403 is more than 40 ℃ below 80 ℃.And the wind speed of preferred the 3rd dry wind 403 is the 5m/ second of above 20m/ below second.

As shown in Figure 8; Attract the 2nd of the 2nd dry wind 402 to attract mouthful 32cx to be arranged between the perpendicular nozzle 32b on the A direction and than casting films 30 more near the both sides of B direction; And be positioned at than air-supply slit 32bx more near the position of top; So between casting films 30 and the 2nd drying unit 32, be clipped in the attraction path 70 (with reference to figure 9) that space between the perpendicular nozzle 32b that the A direction is arranged becomes the 2nd dry wind 402.

So, owing between the perpendicular nozzle 32b on the A direction and than casting films 30, more the 2nd an attraction mouthful 32cx is set, need not to carry out the 2nd the growing up that attracts mouthful 32cx according to the growing up of air-supply slit 32bx near the both sides of B direction.Therefore, according to the present invention, can on the B direction, attract the 2nd dry wind 402 equably.

In addition; Along with the growing up of air-supply slit 32bx, need to increase the 2nd traffic attraction that attracts among mouthful 32cx, but the 2nd when attracting mouthful 32cx and casting films 30 close; On the flow direction of the dry wind 402 that is attracted, form striped etc., the face shape of the film 55 that causes finally obtaining is worsened.According to the present invention, the 2nd attracts mouthful 32cx to compare further from casting films 30 with air-supply slit 32bx, so even increase traffic attraction, also can avoid the face shape of the film 55 that the attraction by dry wind 402 causes to worsen.

As shown in Figure 9; Preferably the sectional area in the attraction path 70 of clamping through adjacent perpendicular nozzle 23b between the 2nd supplying duct 32a and the casting belt 22 (below; Be called the exhaust sectional area) ratio of S1 and the port area S2 of air-supply slit 32bx (=S1/S2) be more than 15, more preferably more than 25.

And, the ratio of the preferred distance C L1 that attracts mouthful 32cx and casting films 30 and air-supply slit 32bx and the distance C L2 of casting films 30 (=CL1/CL2) be more than 2, more preferably more than 3.

In addition, like Figure 10 and shown in Figure 11, also the plate 80 of becalming can be set in the B of perpendicular nozzle 32b direction both sides.The plate 80 of becalming can be in attracting the path be provided with (with reference to Figure 10) with the mode of blocking whole part from B direction exposed at both sides, also can block a part and from the mode of the part of B direction exposed at both sides (with reference to Figure 11) is set.Through the setting like this plate 80 of becalming, dry wind is difficult for flowing out to the outside.Therefore, can keep the state that the pressure that attracts the path is higher than the external pressure of the 2nd drying unit.And, be maintained higher state through the pressure that will attract the path, can prevent that the air outside that is in the 2nd drying unit from flowing into the attraction path.Its result is maintained in equalization with drying conditions easily.In addition, also can use the parts of becalming of bulk etc. the plate 80 that replaces becalming.

In the above-mentioned embodiment, be provided with an attraction mouthful 32cx in B direction inboard, but the invention is not restricted to this, also can make to attract mouthful 32cx towards the below, promptly (with reference to Figure 12) to be set with casting belt 22 opposed modes.

In the above-mentioned embodiment, between perpendicular nozzle 32b, be provided with a plurality of negative pressure catheter 32c, but the invention is not restricted to this.A plurality of negative pressure catheter 32c (with reference to Figure 13 and Figure 14) also can be set integratedly.In addition, in order to make the mobile stabilization of the 2nd dry wind 402, the balance of the supply of the 2nd dry wind 402 among the needs adjusting perpendicular nozzle 32b and the attraction of the 2nd dry wind 402 among the negative pressure catheter 32c.Regulate the consideration of easness viewpoint from the supply of the 2nd dry wind 402 and the equilibrated of attraction, preferably on each perpendicular nozzle 32b, negative pressure catheter 32c is set.

In the above-mentioned embodiment, more be provided with negative pressure catheter 32c than perpendicular nozzle 32b, but the invention is not restricted to this, also can more negative pressure catheter 32c be set than casting films 30 near the both sides of B direction near the both sides of B direction.

In the above-mentioned embodiment, the top casting films 30 of utilizing 32 pairs of the 2nd drying units to be in casting belt 22 has been carried out drying, but the invention is not restricted to this, also can carry out drying to the following casting films 30 that is in casting belt 22.When being solution film-forming equipment 10 shown in Figure 1, also can use the unit with the 2nd drying unit 32 same structures to replace the 3rd drying unit 33.That is, an attraction mouthful 32cx also can be between perpendicular nozzle 32b.

The film 55 that obtains according to the present invention especially can use in phase retardation film or polarization board protective film.

The width of preferred film 55 is more than the 600mm, more preferably below the above 2500mm of 1400mm.And the present invention is also effective during greater than 2500mm at the width of film 55.And the thickness of preferred film 55 is below the above 120 μ m of 30 μ m.

And postponing Re in the face of preferred film 55 is below the above 300nm of 20nm, the thickness direction retardation Rth of preferred film 55 is-and below the above 300nm of 100nm.

The measuring method that postpones Re in the face is as follows.Delay Re has used under 25 ℃ of temperature, humidity 60%RH sample film has been carried out 2 hours damping in the face, and with the length of delay of automatic double refraction appearance (prince's KOBRA21DH metering outfit Co., Ltd.) from the vertical direction mensuration of 632.8nm.In addition, Re representes with following formula.

Re＝|n1-n2|×d

N1 representes the specific refractory power of slow axis, and n2 representes the specific refractory power of leading phase shaft 2, and d representes the thickness (thickness) of film.

The measuring method of thickness direction retardation Rth is as follows.From under 25 ℃ of temperature, humidity 60%RH, sample film being carried out 2 hours damping; And the extrapolated value of the length of delay measured with the inclination face time of the value of measuring from vertical direction according to 632.8nm with ellipsometer (M150 Japan beam split Co., Ltd. system), according to following formula calculating. identically

Rth＝{(n1+n2)/2-n3}×d

N3 representes the specific refractory power of thickness direction.

(polymkeric substance)

In the above-mentioned embodiment, become not special qualification of polymkeric substance of the raw material of polymeric film, cellulose acylate or cyclic polyolefin etc. are for example arranged.

(cellulose acylate)

The acyl group that is used for cellulose acylate of the present invention can only be a kind, perhaps also can use the acyl group more than 2 kinds.When using the acyl group more than 2 kinds, preferably its 1 is ethanoyl.Preferably with carboxylic acid to cellulosic hydroxyl carry out esterification ratio, be that the substitution value of acyl group satisfies all following formulas (I)～(III).In addition, in following formula (I)～(III), A and B represent the substitution value of acyl group, and A is the substitution value of ethanoyl, and B is the substitution value of the acyl group of carbonatoms 3～22 in addition.In addition, 90 weight % of preferred cellulosetri-acetate (TAC) are above is the particle of 0.1mm～4mm.

(I)2.0≤A+B≤3.0

(II)1.0≤A≤3.0

(III)0≤B≤2.0

More preferably the full substitution value A+B of acyl group is more than 2.20 below 2.90, especially is preferably more than 2.40 below 2.88.And more preferably the acyl substituted degree B of carbonatoms 3～22 more than 0.30, especially is preferably more than 0.5.

As the Mierocrystalline cellulose of the raw material of cellulose acylate also can be the Mierocrystalline cellulose that from any of linters, paper pulp, obtains.

As the acyl group of carbonatoms more than 2 of cellulose acylate of the present invention, both can be that fatty group also can be an aryl, not special the qualification.These for example are cellulosic alkyl carbonyl ester, alkene carbonyl ester or aromatic series carbonyl ester, aromatic series alkyl carbonyl ester etc., can have further substituted group respectively.As their preferred example, can enumerate propionyl, butyryl radicals, pentanoyl, caproyl, capryloyl, decanoyl, lauroyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutyryl, uncle's butyryl radicals, cyclohexyl carbonyl, oleoyl, benzoyl, naphthalene carbonyl, cinnamoyl etc.Wherein more preferably propionyl, butyryl radicals, lauroyl, octadecanoyl, uncle's butyryl radicals, oleoyl, benzoyl, naphthalene carbonyl, cinnamoyl etc., especially preferred propionyl, butyryl radicals.

(solvent)

Solvent as the preparation dope; (for example can enumerate aromatic hydrocarbons; Benzene, toluene etc.), halohydrocarbon (for example; Methylene dichloride, chlorobenzene etc.), alcohol (for example; Methyl alcohol, ethanol, n-propyl alcohol, propyl carbinol, glycol ether etc.), ketone (for example; Acetone, methylethylketone etc.), ester (for example, methyl acetate, ethyl acetate, propyl acetate etc.) and ether (for example, tetrahydrofuran (THF), methylcyclohexane etc.) etc.In addition, in the present invention, dope is meant polymer dissolution or is scattered in the solvent and the polymers soln that obtains, dispersion liquid.

Wherein, preferably use the halohydrocarbon of carbonatoms 1～7, most preferably use methylene dichloride.The viewpoint of the rerum naturas such as optical characteristics of the separability on from the solvability of polymkeric substance, casting films from supporter, the mechanicalness intensity of film etc. and film is considered, preferably except that methylene dichloride, also mixes a kind of alcohol to several carbonatomss 1～5.The content of alcohol all solvents relatively is preferably 2 weight %～25 weight %, more preferably 5 weight %～20 weight %.Object lesson as alcohol can be enumerated methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol etc., but preferred methyl alcohol, ethanol, propyl carbinol or their mixture of using.

But; Recently; Will the influence of environment be suppressed to bottom line is purpose; Solvent composition when not using methylene dichloride is also studied; For this purpose, preferably using carbonatoms is that 4～12 ether, carbonatoms are that 3～12 ketone, carbonatoms are that 3～12 ester, carbonatoms are 1～12 alcohol.Sometimes suitably mix these uses.For example, can enumerate the mixed solvent of methyl acetate, acetone, ethanol, propyl carbinol.These ethers, ketone, ester and alcohol also can have ring texture.And, have 2 above ethers, ketone, ester and alcohol functional group (that is ,-O-,-CO-,-COO-and-any compound in OH-) also can be used as solvent and uses.

In addition, [0140] section that the detailed content of cellulose acylate is recorded in open 2005-104148 number of Japanese Patent is to [0195] section.These records can also be applied among the present invention.And; Relevant solvent and softening agent, deterioration preventing agent, UV light absorber (UV agent), optical anisotropy control agent, postpone suppressor factor, dyestuff, delustering agent, stripper, peel off additive such as promotor, too write up in [0196] section of open 2005-104148 number of Japanese Patent in [0516] section.

[embodiment]

(experiment 1)

In solution film-forming equipment 10 shown in Figure 1, made film 55.In the curtain coating chamber 12, utilize curtain coating mould 21 curtain coating dope on casting belt 22, on casting belt 22, formed casting films 30.The curtain coating width of this moment is 1800mm.Afterwards, utilize the 1st～the 3rd drying unit 31～33 to carry out the drying of casting films 30.Air-supply slit 32bx on the A direction is spaced apart 5mm, and the length L 1 (with reference to figure 5) of the air-supply slit 32bx on the B direction is 1800mm, and CL1 (with reference to figure 9) is 150mm, and CL2 (with reference to figure 9) is 150mm.And, sprayed the 2nd dry wind 402 of 50 ℃ of temperature with the wind speed of 20m/ second from nozzle 32b.

(experiment 2)

Except CL1 is made as the 250mm, make film 55 with experiment 1 identically.

(experiment 3)

Except CL1 is made as the 350mm, make film 55 with experiment 1 identically.

(experiment 4)

Use conduit shown in Figure 14 as negative pressure catheter 32c, CL1 is made as 250mm, in addition make film 55 identically with experiment 1.

(experiment 5)

Except using drying installation shown in Figure 15 202, make film 55 with experiment 1 as the 2nd drying unit 32 identically.

(experiment 6)

Except the time that the 2nd film drying process is required increases by 40 seconds, make film 55 with experiment 5 identically.

(evaluation)

About the film 55 that in experiment 1～6, obtains, following project is estimated.

1. face shape is estimated

Utilize the schlieren method investigation in the film of gained, to observe striped.Estimate according to following benchmark.

A: do not observe striped.

B: observe striped.

2. drying efficiency

Measured the amount of residual solvent ZY1 on the casting films when peeling off.

3.Rth measure

On width, measure the delay Rth of the thickness direction of film, calculate the deviation delta Rth value that postpones Rth.With the mean value that postpones the measured value of Rth be made as Xav, the maximum value that postpones the measured value of Rth is made as Xmax, when the minimum value that postpones the measured value of Rth is made as Xmin, with (Xmax-Xmin)/Xav} * 100 expression Δ Rth.

In experiment 1～6, time and evaluation result that the film drying process is required are shown in table 1.

[table 1]

In experiment 5, because the amount of residual solvent ZY1 of casting films is 41 quality % when peeling off, so in the film of gained, found to result from the deviation of peeling off the tensile slow axis.On the other hand, in experiment 1～4, because that the casting films when peeling off continues is dry, so in the film that finally obtains, find to result from the deviation of peeling off the tensile slow axis.Under the condition of experiment 5, make the amount of residual solvent ZY1 of casting films when peeling off and experiment 1～4 become same degree, must increase the required time of the 2nd film drying process.Result according to experiment 5 and 6 we can say, according to the present invention, compares and the 2nd film drying process can be shortened 40 seconds with drying means in the past.Therefore, we can say,, and compared in the past, can more effectively carry out the drying of casting films according to the present invention.

Claims

1. a drying installation is characterized in that, possesses as follows:

Conduit is adapted to relative to the banded casting films of long side direction transmission, and said casting films comprises polymkeric substance and solvent;

A plurality of nozzles are arranged on the delivery direction of said casting films, and said nozzle is to be provided with towards the outstanding mode of said casting films from conduit;

The air-supply slit is that dry wind is seen off to said casting films with the dry gas from said conduit, and said air-supply slit extends and forms to the width of said casting films at the front end of said nozzle; And

Attract mouth; The said dry wind that attraction is seen off from said air-supply slit; Said attraction mouthful on the said delivery direction between said nozzle and said nozzle; The said mouth that attracts is positioned at the both sides than the more close said width of said casting films, and the distance of said attraction mouth and said casting films is greater than the distance of said air-supply slit and said casting films.

2. drying installation as claimed in claim 1 is characterized in that,

Said air-supply slit and said attraction mouth are from said delivery direction upstream side towards the downstream side alternately side by side.

3. drying installation as claimed in claim 1 is characterized in that,

From than a said nozzle more near said delivery direction upstream side to more forming said attractions mouth near said delivery direction downstream side than a said nozzle.

4. drying installation as claimed in claim 1 is characterized in that,

Said attraction mouth is relative with said casting belt.

5. drying installation as claimed in claim 1 is characterized in that,

Said attraction actinal surface is to said width center side.

6. drying installation as claimed in claim 1 is characterized in that,

The amount of residual solvent of the said casting films that said dry wind touched is below the above 350 quality % of 150 quality %.

7. drying installation as claimed in claim 1 is characterized in that,

Said conduit is arranged at the top of said casting films.

8. drying installation as claimed in claim 1 is characterized in that,

The width of said casting films is below the above 2400mm of 1500mm.

9. solution film-forming method makes said solvent from the casting films evaporation that comprises polymkeric substance and solvent and obtain film, it is characterized in that possessing following steps:

Zonal said casting films to transmitting along long side direction is seen dry wind off; Said dry wind is utilized in the air-supply slit of arranging on the delivery direction of said casting films and sees off; Said air-supply slit is relative with said casting films, and said air-supply slit extends to the width of said casting films; And

Attract said dry wind, said dry wind is from attracting further from the position of said casting films than said air-supply slit, and said dry wind is from more attracting near the position of width both sides than said casting films.

10. solution film-forming method as claimed in claim 9 is characterized in that,

11. solution film-forming method as claimed in claim 9 is characterized in that,

The width of said casting films is below the above 2400mm of 1500mm.