CN105835376A - Solution film forming method and apparatus - Google Patents

Abstract

The invention provides a solution film forming method and apparatus which can avoid periodic recessed portions in the length direction in the condition that a long film having the thickness of less than 50 [mu]m IS manufactured through stretch processing in the width direction. The solution film forming apparatus (10) includes a tape casting die (24), a pair of rollers (22, 23), a tape (21) and a stretching machine (16). The tape (21) is made of metal and is formed by welding in a circular shape. The temperature of a tap casting surface of the tape (21) of a tape casting mucilage (11) is regulated by the rollers (22, 23). The height of a welding portion of a back surface of the tape (21) is in the range of 3 [mu]m to 30 [mu]m. A film (12) is held by a clamp (31) of the stretching machine (10) to be conveyed, and is stretched in the width direction. In addition, the film (12) is dried in the stretching machine (16).

Description

Solution film-forming method and device

Technical field

The present invention relates to solution film-forming method and device.

Background technology

Solution film-forming method is had as one of method manufacturing thin polymer film (hereinafter referred to as thin film).Solution film-forming method It is by polymer being dissolved into the polymer solution obtained in solvent to the method manufacturing thin film.With solution film-forming method system In the case of making the thin film of strip, polymer solution is continuously flowed out to the supporter of movement from curtain coating mould and forms curtain coating Film, strips this casting films from supporter and is dried.The band used as supporter arrives multiple rollers with ring-type formation, erection On move along its length.Thus, band is carried out with the position that strips stripping casting films at the casting position of cast polymer solution Circulation.Additionally, as the raw material of band, use the rustless steel of such as austenite.

Thin film is required that flatness, i.e. pellicular front are smooth.Owing to the curtain coating face of the cast polymer solution of band can be right The flatness of thin film impacts, so making smooth as far as possible.Additionally, use the stainless of austenite in the raw material of band In the case of steel, damage the flatness of thin film sometimes because of martensitic phase transformation.It is thus possible, for instance at Japanese Unexamined Patent Publication 2007- No. 083451 publication has been recorded solution film-forming method and the device of the band of the concavo-convex degree in the specific above-mentioned curtain coating face of use, by This inhibits martensitic phase transformation.

But, in the solution film-forming method when manufacturing the thin film of strip, in order to make thin film show such as optical function Etc. specific function, sometimes the thin film of film-forming process is implemented the stretch processing on width.Additionally, along with liquid crystal display The display devices such as device lightening, also requires that the most lightening to the thin film used in display device.

But, even if by method described in Japanese Unexamined Patent Publication 2007-083451 publication, the most also can be Periodic in the longitudinal direction depressed part seen from thin film.This depressed part is in the situation of the thin film of the thickness manufacturing below 50 μm Under, because of visible via the stretch processing on the width in film-forming process.Even manufacturing the thin of the thickness of below 50 μm In the case of film, the thin film before the stretch processing on width in the fabrication process and not via drawing on width Stretch and the most do not see on the thin film processed and manufacture.Additionally, the most do not see in the case of manufacturing the thin film than 50 μ m-thick.Should Depressed part is about a length of more than 40mm and below 50mm, width is more than 10mm and below 20mm left and right is the least Elongated groove is along arrangements multiple with the direction that the length direction of thin film intersects, the length direction of each groove and the length of thin film Degree direction is the most consistent.

Summary of the invention

It is an object of the invention to provide the stretch processing implementing on width and manufacture the length that below 50 μm are the thinnest Solution film-forming method that in the case of the thin film of bar, on length direction, periodic above-mentioned depressed part is suppressed and device.

The solution film-forming method of the present invention has curtain coating operation, stripping process and stretching process.Curtain coating operation is to pass through One end of the band of metal strip and welding of the other end and with ring-type formation, be wrapping with in pair of rolls and to length direction On the band of movement, polymer is dissolved into the polymer solution obtained in solvent and continuously flows out from curtain coating mould.Stripping process It is to form thin film by casting films being peeled from band.Stretching process is by thin film edge when keeping each sidepiece of thin film Length direction is carried, and is dried by heating by the thin film in carrying, stretches in the width direction on one side.The formation of band The temperature in the curtain coating face of casting films is adjusted by the regulation of all surface temperatures of at least one in pair of rolls, in the back side of band Weld part is made into the height in the scope of below more than 3 μm and 30 μm.

Weld part in curtain coating face is preferably made in the scope of more than 0.1 DEG C and less than 1.0 DEG C relative to non-solder portion Temperature difference.

The solution film-forming device of the present invention possesses curtain coating mould, metal band, pair of rolls and stenter.Curtain coating mould will polymerization Thing is dissolved into the polymer solution obtained in solvent and continuously flows out.Band with ring-type formation, by moving along its length and Being formed casting films by the polymer solution flowed out from curtain coating mould, the weld part in the back side is made to below more than 3 μm and 30 μm In the range of height.Pair of rolls is by being wrapping with band and at least one circumferentially carries out rotating and makes Tape movement, by least one The regulation of individual all surface temperatures adjusts the temperature in curtain coating face.Stenter is at the thin film keeping peeling casting films from band and formed Each sidepiece state under thin film is carried to length direction, will carrying in thin film by heat and be dried, one Edge width direction stretches.

At stretching process, thin film is carried out with the stretching ratio in the scope of more than 5% and less than 40% situation about stretching Under, above-mentioned solution film-forming method and solution film-forming device are the most effective.Situation at the thickness that thin film is below 50 μm manufactured Under, the effect of above-mentioned solution film-forming method and solution film-forming device is notable.The degree of depth in the back side of band is more than 3 μm and 300 μm In the scope that maximum inclination is 0.1 μm/more than mm and 1.5 μm/below mm of the depression preferred surface in following scope.

According to the present invention, on length direction, the generation of periodic above-mentioned depressed part is suppressed, and can manufacture and implement The thin film of the thinnest strip below 50 μm of the stretch processing on width.

Accompanying drawing explanation

Above-mentioned purpose, advantage are by referring to appended accompanying drawing, and read the detailed description of preferred embodiment, this area Technical staff can easily understand that.

Fig. 1 is the skeleton diagram of solution film-forming device.

Fig. 2 is the top view of band.

Fig. 3 is along the sectional view of the band of Fig. 2 (III)-(III) line.

Fig. 4 is the explanatory diagram seeking method of the temperature difference in the curtain coating face of band.

Fig. 5 is the explanatory diagram of the depression at the back side of band.

Fig. 6 is the explanatory diagram of the depression at the back side of band.

Fig. 7 is the skeleton diagram of stenter.

The explanation of symbol

10 solution film-forming devices

11 rubber cements

12 thin film

15 casting units

16 stenters

17 roller drying machines

18 coiling machines

21 bands

21a is cast face

The 21b back side

21n non-solder portion

21w weld part

22,23 roller

22a, 23a temperature controller

24 curtain coating moulds

24a flow export

25 angle strippers

26 casting films

27 air supplying part

28 air supplying part

31 fixtures

32 air supply units

33 air supplying part

34 rollers

38 temperature sensing liquid wafers

41,42 track

43 chambers

45 preheating intervals

46 stretching intervals

47 lax intervals

48 cooling intervals

51 runners

52 sprocket wheels

61 depressions

61a surface

62 depressions

62a surface

CL tangent line

H weld part height

The length of L1 vertical line

The length of the straight line on the 21b of the L2 back side

PC casting position

PP strips position

The thickness of T21 band

Z1 length direction

Z2 width

Z3 thickness direction

Detailed description of the invention

Solution film-forming device 10 shown in Fig. 1 is the device for being continuously manufactured by thin film 12 by rubber cement 11.Thin film 12 Be thickness be the thin film of below 50 μm, in present embodiment, thickness makes the scope of below more than 10 μm and 50 μm.Rubber cement 11 It is that polymer is dissolved into the polymer solution obtained in solvent.In present embodiment, use triacetyl cellulose as polymer Element (TAC, triacetylcellulose), uses the mixture of dichloromethane and methanol as solvent, but polymer and solvent It is not limited to these.Details about the polymer that can use in the present invention and solvent is described below.Rubber cement 11 In can also comprise the various additives such as plasticizer, UV absorbent, delay controlling agent, for preventing thin film adhesion each other Delustering agent.

Solution film-forming device 10 possesses casting unit 15, stenter 16, roller drying machine 17 from upstream side successively and batches Machine 18.Casting unit 15 possesses the band 21 with ring-type formation, supports with 21 and the pair of rolls that moves to length direction Z1 with side face 22,23, curtain coating mould 24 and angle stripper 25.It addition, the length direction also appending symbols Z1 to thin film 12.In pair of rolls 22,23 At least one circumferentially rotates, and by this rotation, the band 21 being wrapping with is to length direction Z1 continuous moving.Present embodiment In, make both roller 22 and roller 23 circumferentially drive rotation.About with 21 details, use other accompanying drawings to chat later State.Curtain coating mould 24 is configured at the top of roller 22 in this example embodiment but it also may the band 21 being configured between roller 22 and roller 23 upper Side.

The rubber cement 11 that supply is come by curtain coating mould 24 continuously flows out from with 21 flow export 24a in opposite directions.By moving In band 21 on continuously flow out rubber cement 11, rubber cement 11 band 21 on be cast, band 21 on formed casting films 26.In Fig. 1, to glue Slurry 11 initially forms position (hereinafter referred to as casting position) the appending symbols PC of casting films 26 with contacting with 21.

Roller 22,23 possesses temperature controller 22a, 23a (with reference to Fig. 4) of regulation week surface temperature.Utilization have adjusted side face temperature The roller 22,23 of degree, via the temperature adjusting casting films 26 with 21.

Present embodiment makes casting films 26 solidify by desiccant gel mode.Desiccant gel mode is by curtain coating Film 26 carries out heating and promotes to be dried makes it solidify the mode of (gelation).Set opposite to each other with from roller 22 towards the band 21 of roller 23 Putting air supplying part 27, arrange air supplying part 28 opposite to each other with from roller 23 towards the band 21 of roller 22, this is promoting casting films 26 further The aspect being dried is preferred, in present embodiment the most so.Air supplying part 27,28 is having respectively with on 21 forward surfaces in opposite directions Having multiple nozzle (not shown), air temperature being adjusted is sent from these nozzles.

About from curtain coating mould 24 arrive with 21 on rubber cement 11, so-called welding bead, it is also possible to 21 length direction Z1 On upstream decompression chamber (not shown) is set.The atmosphere in the upstream side region of this decompression chamber rubber cement 11 to flowing out is inhaled Receive and is reduced pressure in this region.By this decompression, from flow export 24a, the shape towards the rubber cement 11 with 21 is stabilized.

Make casting films 26 solidify on 21 to can to stenter 16 carrying degree after, wrap solvent-laden shape Peel from band 21 under state.Angle stripper 25 is the roller for casting films 26 being stripped continuously from 21.Angle stripper 25 will be logical Crossing the thin film 12 stripped from 21 and formed to support the most from below, casting films 26 peeled from 21 strips position PP Keep constant.The method stripped can be by the method for thin film 12 downstream side stretching or to make angle stripper 25 circumferentially rotatable Method etc. in any one.

Strip in the case of desiccant gel mode from 21, such as at the solvent containing ratio of casting films 26 3 The period in scope more than quality % and below 100 mass % is carried out.It addition, in this specification, solvent containing ratio is (single Position: %) be the value of dry measure standard, specifically, the quality of the thin film 12 measuring object that will obtain solvent containing ratio is set to X, when the quality after being completely dried by this thin film 12 is set to Y, is with { the percentage rate that (X-Y)/Y} × 100 are obtained.It addition, it is so-called " it is completely dried " and need not the residual quantity of solvent strictly for " 0 ", the most in the present embodiment, relative to the thin film measuring object 12, the quality after carrying out the dried of more than 3 hours more than 120 DEG C, in the temperature chamber of relative humidity less than 10% sets For Y.

As described above, casting unit 15 is formed thin film 12 by rubber cement 11.Band 21 passes through at casting position PC and strips position Put PP loopy moving, thus the curtain coating of rubber cement 11 and the stripping of casting films 26 are repeated.

In the transport road of the thin film 12 between casting unit 15 and stenter 16, it is also possible to be configured to promote thin film 12 Be dried pressure fan (not shown).The thin film 12 stripped and formed is directed to stenter 16.Stenter 16 has as inciting somebody to action Thin film 12 carries out the function of stretching-machine that stretches and as carrying out thin film 12 along the width Z2 orthogonal with length direction Z1 The function of the 1st drying machine heated and be dried.Details uses other accompanying drawings described below, in stenter 16, by thin Each sidepiece of film 12 holds with fixture 31 respectively, by being moved along the length direction Z1 of thin film 12 by fixture 31, while increasing The interval (grip separation the most in opposite directions) of big fixture in opposite directions, thus thin film 12 Z1 along its length is carried Z2 stretches the most in the width direction.

Stenter 16 possesses air supply unit 32 and air supplying part 33.Air supply unit 32 will be adjusted to being dried of various temperature Air supply in air supplying part 33, from this air supplying part 33, the thin film 12 in stenter 16 is blown attached air and makes it be dried.This Outward, being heated or cooled, by this by the thin film 12 blown in the attached described later each interval carrying out stenter 16 of this air It is heated or cooled to regulate the temperature of thin film 12.

Roller drying machine 17 is the 2nd drying machine, possesses multiple roller 34 and air conditioner (not shown).Each roller 34 supports thin with side face Film 12.Thin film 12 is wrapping with to be carried on roller 34.The temperature of the inside of air conditioner regulation roller drying machine 17 or humidity etc..Batch Machine 18 is the device for being batched with web-like by thin film 12.

With reference to Fig. 2, band 21 is illustrated.Band 21 is metal system, by the rustless steel shape of austenite in present embodiment Become.Make in the following manner with 21: make utilization calendering make one end of the length direction of the metallic plate of the band of strip Dock with the other end and weld, and this weld part is ground.Weld part 21w is along the direction intersected with length direction Z1 Extend.Weld part 21w can extend along the width Z2 with 21, it is also possible to edge and width Z2 as in the present embodiment The direction intersected extends.It addition, casting films 26 with the width of thin film 12 due to consistent with the width with 21, so right Casting films 26 and the width also appending symbols Z2 of thin film 12.The zone face forming casting films 26 is referred to as curtain coating face 21a, will be with The zone face of 21a opposition side, curtain coating face is referred to as back side 21b.Weld part 21w except curtain coating face 21a in addition to, the back side as will be described later 21b has been also carried out milled processed.

Weld part 21w is to be melted by heating in the case of docking with the other end in the one end making band and welding Region, can be by visually determining.It addition, following, the region in addition to weld part 21w with 21 is referred to as non-solder portion 21n.The thickness T21 (with reference to Fig. 3) of the band 21 of present embodiment is made to 1.5mm.But, the thickness T21 with 21 does not limit In this, for time in the scope of more than 0.5mm and below 2.5mm, effect of the present invention is the biggest.Band 21 is to become as far as possible uniform thick The mode of degree T21 makes.But, the thin film 12 of the thickness below by 50 μm is such as entered in the direction of the width by stenter 16 In the case of row stretching manufactures, for the band when seeing above-mentioned depressed part on thin film, middle weld part protuberance overleaf And becoming convex, the thickness of the band of this part becomes thicker than the thickness in non-solder portion.Therefore, for 21 back side 21b, will welding The height H of portion 21w is made in the scope of below more than 3 μm and 30 μm.Below by the weld part 21w in the 21b of the back side with symbol H The height represented is referred to as weld part height.In the case of weld part height H is below 30 μm, with the situation phase more than 30 μm Ratio, as roller 22,23 becomes to the heat transfer that curtain coating face 21a is overall, as will be described later, non-solder portion 21n in curtain coating face 21a Diminish with the temperature difference of weld part 21w.Additionally, be set to weld part height H less than 3 μm, this is in the processing of milled processed etc It is difficult in precision.Weld part height H is more preferably in the scope of below more than 3 μm and 20 μm, more preferably 3 μm with In scope above and below 10 μm.

In order to make weld part height H become in above-mentioned scope, the back side 21b of weld part 21w is ground.This reality Execute in mode, grinding uses grinding stone.Weld part height H is the overhang from non-solder portion 21n in the 21b of the back side, such as Can be obtained by laser displacement gauge, present embodiment uses the LJ-V7080 of Co., Ltd. KEYENCE.Swash using In the case of weld part height H obtained by light displacement meter, can be with the width (water in Fig. 3 of the weld part 21w of back side 21b Square to) on central authorities centered by, the scope of 200mm is measured the most continuously in the 21b of the back side from non-solder portion 21n Overhang, using the maximum in measured value as weld part height H.

Weld part 21w in the 21a of curtain coating face is preferably more than 0.1 DEG C and the model of less than 1.0 DEG C relative to non-solder portion 21n Enclose interior temperature difference.That is, in curtain coating face 21a, the temperature of weld part 21w is set to Tw, the temperature of non-solder portion 21n is set to During Tn, the temperature difference obtained with | Tw-Tn | is preferably in the scope of more than 0.1 DEG C and less than 1.0 DEG C.This temperature difference | Tw-Tn | In more preferably more than 0.1 DEG C and the scope of less than 0.5, more preferably in the scope of more than 0.1 DEG C and less than 0.3 DEG C. The details seeking method of temperature difference | Tw-Tn | uses other accompanying drawings described below.

The method of asking of | Tw-Tn | poor to said temperature illustrates with reference to Fig. 4.Temperature difference | Tw-Tn | can use such as city The temperature sensing liquid wafer sold and obtain.Temperature sensing liquid wafer is as it is well known, by micro-for the liquid crystal that changes color because of temperature Encapsulated, and make, by printing etc., the sheet that this microcapsule carrier obtains to the thin film formed by paper or polymer etc..This reality Execute in mode, as temperature sensing liquid wafer, use the RW-25 of Microcapsule company of Japan.Temperature difference | Tw-Tn | can make Obtained by following method with temperature sensing liquid wafer.

First, the curtain coating face 21a of the band 21 started before moving attaches temperature sensing liquid wafer 38.In present embodiment, patch Attached 3 temperature sensing liquid wafers 38, but it is not limited to this sheet number.Each temperature sensing liquid wafer 38 with weld part 21w through temperature-sensitive liquid crystal The mode of the general central authorities on the sheet surface of sheet 38 attaches.Additionally, configure photographing unit opposite to each other with the side face of roller 23.This embodiment party In formula, on the position in the downstream of 1/8 of the girth from the roller 23 roller 23 with the upstream extremity with 21 regions contacted, with band 21 configure photographing unit opposite to each other.The all surface temperatures being made roller 22 by temperature controller 22a are 19 DEG C, by temperature controller 23a The all surface temperatures making roller 23 are 32 DEG C, make band 21 with movement in 35m/ minute.By with 21 movement, make temperature sensing liquid wafer 38 at roller Through 5 times on 23.In the 5th through out-of-date, with photographing unit, temperature sensing liquid wafer 38 is shot.In present embodiment, to 3 Temperature sensing liquid wafer 38 shoots respectively but it also may shoot 1 or 2 selected from them.For example, it is possible to only 1 of side, most upstream on length direction Z1 in temperature sensing liquid wafer 38 is shot.By the temperature sensing liquid wafer 38 shot Color, obtains temperature Tw and temperature Tn of non-solder portion 21n of weld part 21w in the 21a of curtain coating face, calculates it poor.Calculate The absolute value of value is temperature difference | Tw-Tn |.

As shown in Figure 5 with seeing on the back side 21b of 21 in the scope with below more than 3 μm and 300 μm Degree of depth D depression 61 in the case of, preferably by the maximum gradient in the gradient of the surface 61a of depression 61 (hereinafter referred to as For maximum inclination) it is set in the scope of 0.1 μm/more than mm and 1.5 μm/below mm, present embodiment is set to such as 1.0 μ m/mm.Gradient as shown in Figure 5, describe depression 61 surface 61a in tangent line LC time, be oblique with tangent line LC Limit, by the straight line on this hypotenuse, back side 21b and down to the vertical line from tangent line LC of the straight line on the 21b of this back side (along thickness The straight line that direction Z3 extends) in the right angled triangle that constitutes, it is straight divided by the 21b of the back side of length L1 (unit is μm) of vertical line The value that length L2 (unit is mm) of line obtains, the value i.e. calculated with L1/L2 (unit as μm/mm).Therefore, there is depression The angle (wherein, when this angle is set to θ, being 0 °≤θ≤90 °) relative to back side 21b in tangent line in the surface of 61 is Big tangent line is maximum inclination as the gradient obtained in the right angled triangle of hypotenuse.Maximum inclination is more preferably made In the scope of 0.2 μm/more than mm and 1.2 μm/below mm, further preferably make 0.3 μm/more than mm and 1.0 μm/below mm In the range of.It addition, for gradient, in each interval distinguished along back side 21b, it is also possible to obtain as meansigma methods, The most concrete asks method described below.

Hereinafter example when making the maximum inclination of depression 61 within the above range is illustrated.On band 21, sometimes It is deformed or produces on curtain coating face 21a the defect of recess because utilizing the part heat treatment of welding etc..In order to make this Kind of deformation or the defect of recess flatten, and have a following situation: back side 21b with 21 is punched out, grinding, grinding, afterwards general The part of the protuberance of 21a side, curtain coating face reams and makes it smooth.Punching is to carry out tapping with the parts that tap being referred to as drift Process, owing to being to tap the process that carries out with the back side 21b of 21, so referred to as back side punching.By making curtain coating face 21a become Smooth such process, remains such depression 62 shown in Fig. 6 the most overleaf on 21b.This depression 62 such as has drift The surface of the most precipitous inclination of the vestige of front end and the surface of inclination that slows down because of grinding of its periphery.In this depression 62 Big-inclination, more than in the case of 1.5 μm/mm, carries out grinding further to the surface 62a of depression 62, or, use and constitute Depression 62 is filled by the metal that metal with 21 is identical by welding, and the built-up welding part forming landfill carries out grinding etc., Make the depression 61 shown in Fig. 5 that maximum inclination is 0.1 μm/more than mm and 1.5 μm/below mm.Furthermore it is possible to grind Mill replaces grinding, it is also possible to be also ground in addition to grinding.In present embodiment, grinding uses grinding stone.In Fig. 5 If below the degree of depth 300 μm of shown depression 61, then can also be deeper than the degree of depth of the depression 62 shown in Fig. 6.It addition, Fig. 5 Shown in depression 61 be general cone shape, i.e. there is the cross sectional shape of general triangle.In the back side 21b of this depression 61 The diameter of opening can be bigger than the diameter of the opening in the back side 21b of the depression 62 shown in Fig. 6, preferably more than 50mm and In the scope of below 600mm.

The shape of depression 61 can be obtained by such as laser displacement gauge, uses Co., Ltd. in present embodiment The LJ-V7080 of KEYENCE.As the method obtaining maximum inclination, such as, there is following such method.First, utilization swashs Light displacement meter measures the cross section shape of depression 61 in the way of the deep through depression 61 along the such as width Z2 with 21 Shape.For the cross sectional shape of this mensuration, with the distance on the such as width Z2 measured as transverse axis, enter with degree of depth D for the longitudinal axis Row pictorialization.With the deep of depression 61 as starting point, the constant width of about every more than 5mm and below 20mm on width Z2 The interval of degree, obtains multiple slope as gradient, obtains the G-bar of the meansigma methods as them.Obtain each district successively Between G-bar until depression 61 back side 21b in opening i.e. end till.Make with the maximum of these G-bars For maximum inclination.It addition, seek method as G-bar, have above-mentioned by use the measured value that above-mentioned each interval is obtained The methods such as the slope of a curve (differential value) in interval averages.When obtaining maximum inclination, in order to remove each measurement Error, it is also possible to application removes the methods such as the maximum in the value of multiple G-bars and minima.

As shown in Figure 7, stenter 16 has above-mentioned fixture 31, air supply unit 32, air supplying part 33, track 41,42 and chamber 43.In chamber 43, the preheating that transport road is divided into for preheating procedure from upstream side successively is interval 45, lax interval 47, for the cooling of refrigerating work procedure interval for relax operation interval 46 for the stretching of stretching process 48.Preheating is interval 45, stretching is interval 46, lax interval 47, cooling interval 48 is according to sending from air supplying part 33 (with reference to Fig. 1) The interval that the temperature of air and the set-up mode of track 41,42 are spatially distinguished and are formed, not by utilizing partition etc. Differentiation and the interval that formed.Additionally, be set with holding starting position in the upstream of preheating interval 45, interval 48 times of cooling Trip side is set with holding and releases position.

Track 41,42 is configured at the both sides of the transport road of thin film 12.Track 41,42 is set with multiple fixture respectively 31.Each fixture 31 moves freely along corresponding track 41,42, and its moving direction is specified by track 41,42.Each track 41,42 be arranged to ring-type, above-mentioned ring-type have by fixture 31 from hold starting position move to hold release position outlet portion With the loop portion that the fixture 31 that will be moved to holding releasing position returns to hold starting position.Fixture 31 is located at certain intervals All-round in each track 41,42, but Fig. 7 only depicts a part of fixture 31.It addition, as keeping thin film in present embodiment The holding member of the sidepiece of 12 uses fixture 31, but holding member is not limited to this.For example, it is also possible to use by thin film Sidepiece thrust multiple pin keep thin film 12 needle plate to replace fixture 31.

On track 41,42, ring-type chain (not shown) edge of multiple fixture 31 is installed the most at a prescribed interval Track movably to arrange.Chain frame is located to compare and is held starting position and be configured at the runner 51 of more upstream side and compare handle Hold releasing position to be configured on the sprocket wheel 52 of further downstream.Sprocket wheel 52 is rotated by drive division (not shown), thus chain Along track 41,42 loopy moving.Carried out with certain speed along track 41,42 by the mobile and each fixture 31 of this chain Mobile.It addition, below, in the case of expressing outlet portion, loop portion the most especially, carry out as 41,42 pairs of outlet portions of track Explanation.

Start parts in the holding holding starting position and being provided with the holding making side that fixture 31 starts thin film 12 (not scheme Show).Additionally, release position and be provided with the holding of the holding making sidepiece that fixture 31 releases thin film 12 holding and release parts (not Diagram).For thin film 12, each sidepiece is held by fixture 31, by the mobile edge of fixture 31 in holding starting position Length direction Z1 is handled upside down, and sequentially passes through and preheats interval 45, stretching interval 46, lax interval 47, cools down interval 48.Through pre- Between hot-zone 45, stretching interval 47, the period of cooling interval 48 interval 46, lax, thin film 12 is implemented the process in each interval, is being held The holding releasing place holder 31 is released from.

From holding starting position to stretching interval 46, track 41,42 is parallel with length direction Z1, and between making each other Constant every (hereinafter referred to as orbital spacing).Thus, the fixture 31 on the track 41 made in opposite directions and the fixture 31 on track 42 Under the state that grip separation is constant in opposite directions, fixture 31 Z1 along its length is moved.

In preheating interval 45, the thin film 12 before being stretched is heated (hereinafter referred to as preheating).Therefore, in preheating In interval 45, thin film 12 is not to have the state of stretching to be preheated.Preheat and come by the heated air from air supply unit 32 Carry out.The temperature of this air is preferably more than 25 DEG C and the scope of less than 120 DEG C.

In stretching interval 46, track 41,42 is configured to straight line, but to form draw angle between length direction Z1 The mode of θ configures to tyre angle, and downstream towards, orbital spacing gradually broadens.Thus, the moving direction making fixture 31 is relative In length direction Z1 with draw angle θ towards outside, it is gradually increased presss from both sides in opposite directions along with the moving of length direction Z1 of fixture 31 Tool interval, thus thin film 12 Z2 in the width direction is stretched.In this stretching interval 46, the width W1's before stretching is thin Till film 12 extends to width W2.Further, since parallel relative to length direction Z1 preheating interval 45 middle orbits 41,42, institute It is the stretching interval 46 angle relative to the increment of the moving direction of the fixture 31 in preheating interval 45 with draw angle θ.Stretching Multiplying power α (unit is %) is obtained by α=(W2/W1) × 100, such as, set based on target optical characteristic.Stretching ratio α In the case of the biggest, depressed part the most easily occurs, in the scope that stretching ratio α is more than 5% and less than 40% in the case of, Available especially significant effect.

In stretching interval 46, by the heated air from air supply unit 32, thin film 12 is heated.Draw The temperature stretching the thin film 12 in interval 46 such as sets based on target optical characteristic.

In the present embodiment, lax interval 47, cooling interval 48 as preheating interval 45, track 41,42 and length Direction Z1 is parallel, makes orbital spacing constant.Therefore, in these lax intervals 47, cooling interval 48, grip separation in opposite directions is made Constant state lower clamp 31 moves, and thin film 12 maintains width W2 to be handled upside down.In lax interval 47, thin film 12 is added Heat, in cooling interval 48, cools down thin film 12.Alternatively, it is also possible to be not provided with lax interval 47.Lax interval 47 and cooling zone Between the temperature of thin film 12 in 48 adjusted from the temperature of the air of air supply unit 32 by regulation.

Effect to above-mentioned composition illustrates.Rubber cement 11 outflows, at casting position PC continuously from curtain coating mould 24 Casting films 26 (curtain coating operation) is formed on the band 21 of movement with stripping position PP iterative cycles.Due to 21 curtain coating face 21a Adjust temperature by roller 22,23, thus casting films 26 via band 21 and adjust temperature, adjusted by this temperature and utilize from The dry promotion of the air of air supplying part 27,28 and solidify.It addition, as in this example of desiccant gel mode, casting films 26 By via with 21 heating and utilize the heating of air from air supplying part 27,28, be dried and accelerate, by the evaporation of solvent Solidification.

Wherein, the weld part height H in the 21b of the back side is the biggest, the connecing relative to roller 22,23 of the weld part 21w of back side 21b Pressing and become the biggest, therefore the above-mentioned contact pressure in the weld part 21w of back side 21b contacts pressure with above-mentioned in non-solder portion 21n Difference i.e. contact pressure reduction and become big.In the case of this contact pressure reduction is the biggest, from roller 22,23, the heat transfer to curtain coating face 21a becomes uneven Deng, therefore temperature difference | the Tw-Tn | in curtain coating face 21a is the biggest.The thin film 12 manufactured is the thinnest, and casting films 26 the most more thinly forms, In the case of the thickness of thin film 12 manufactured is below 50 μm, the difference of above-mentioned solidification is notable.Excessive in the difference solidified like this In the case of, in the stretching utilizing stenter 16 carried out later, produce and result from the inequality of stress of difference of solidification.Should The inequality of power becomes the uneven reason with the contraction being dried of thin film 12, on the film portion that the degree of this contraction is little becomes State depressed part.Further, due to the film portion corresponding with the region on weld part 21w and with the region pair on non-solder portion 21n The film portion answered is compared, and the stress produced by stretching is less, so diminishing with the degree of the contraction being dried.That is, examine Observing this depressed part is to produce in the thin membrane regions corresponding with the region on the weld part 21w of casting films.It addition, as this reality Execute mode like that in the case of desiccant gel mode, being dried from the unequal and casting films 26 of the heat transfer of roller 22,23 The difference of degree is relevant, the solidification in the region on weld part 21w in casting films 26 and coagulating in the region on non-solder portion 21n Solid difference and degree of drying poor corresponding.The difference of such degree of drying, compared with the situation utilizing cooling gel mode, makes The stress of the stretching utilizing stenter 16 of resulting from is more uneven.Cooling gel mode is to make it solidify casting films cooling Mode.It addition, with 21 with roller 22,23 contact pressure such as can pass through Prescale (Fuji Photo Film Co., Ltd.'s system, LLLW) and Prescale parsing system (Fuji Photo Film Co., Ltd.'s system, FPD-9270) and obtain, in present embodiment also this Sample.

About this point, for the back side 21b of the band 21 of present embodiment, due to weld part height H little to 3 μm with Scope above and below 30 μm, so temperature difference | Tw-Tn | is little in curtain coating face 21a.Owing to temperature difference | Tw-Tn | is little, curtain coating Film 26 is dried in Zone Full equably, even in the case of manufacturing the thin film 12 of below 50 μm, for casting films For 26, the region on weld part 21w is also suppressed less with the difference of the degree of drying in the region on non-solder portion 21n.Cause This, in the stenter 16 carried out later, the region of the thin film 12 corresponding with the region on weld part 21w in casting films 26 and The region of the thin film 12 corresponding with the region on non-solder portion 21n is stretched the most comparably.

Owing to temperature difference | the Tw-Tn | in curtain coating face 21a is made in the scope of more than 0.1 DEG C and less than 1.0 DEG C, so For casting films 26, the region on weld part 21w is suppressed with the difference of the degree of drying in the region on non-solder portion 21n Minimum.

For the depression 61 of degree of depth D in the scope with below more than 3 μm and 300 μm in the 21b of the back side, maximum Gradient is by the scope being suppressed to 0.1 μm/more than mm and 1.5 μm/below mm smaller.Therefore, by 21 impartings High tension force, utilize band 21 elongation and from the pressure of the side face of pair of rolls 22,23 at least any one, carry 21 and roller 22,23 contact more reliably.Thus, from roller 22,23 to the heat transfer with 2 throughout carrying 21 Zone Fulls more homogenization, with 21 Temperature is controlled evenly.As a result of which it is, the resulting from generation of depression of thin film 12 of depression 62 shown in Fig. 6 is pressed down System.It is it addition, result from the depression of inequality this thin film 12 homogenized of heat transfer caused because of depression 62 and moves along its length The depression that the rotation of dynamic ring-type band 21 occurs cycle turnover accordingly, e.g. uses stenter 16 to carry out stretching, in 50 μm The depression seen in the thin film 12 of following thickness.Further, this depression on pellicular front with circular opening.

Casting films 26 is stripped from band 21 by angle stripper 25, is consequently formed thin film 12 (stripping process).Thin film 12 is drawn Being directed in stenter 16, each sidepiece is held by fixture 31.Thin film 12 is when being held sidepiece by fixture 31, to sequentially pass through Preheating is interval 45, stretching is interval 46, lax interval 47, the mode Z1 along its length of cooling interval 48 is handled upside down, by from The air of air supplying part 33 promotes to be dried.From holding starting position period to stretching interval 46, thin film 12 is not drawn It is handled upside down with stretching.In preheating interval 45, thin film 12 is preheated (preheating procedure) when not stretching.Pre-by this Heat, the stretching in stretching interval 46 promptly starts, and gives on width Z2 relative to thin film 12 when this stretching simultaneously Tension force evenly.In stretching interval 46, thin film 12 is dried by heating, and Z2 is stretched the most in the width direction, Till the thin film 12 of the width W1 before stretching is extended to width W2 (stretching process).This is stretching in the state heated by thin film 12 Under carry out.In lax interval 47, cooling interval 48, thin film 12 maintains width W2 to be handled upside down.In lax interval 47, pass through Thin film 12 is heated when making its width W2 constant, by should fluffing of producing because of stretching in interval for stretching 46 Relax (lax operation).In cooling interval 48, thin film 12 is cooled down and the molecule of thin film 12 is shaped (refrigerating work procedure).

Promote further to be dried by roller drying machine 17 holding the thin film 12 releasing the holding that position relieves fixture 31. So, the drying process of thin film 12 comprises the preheating interval 45 utilized in stenter 16, stretching interval 46 and lax interval 47 1st drying process, and utilize the 2nd drying process of roller drying machine 17.The thin film 12 utilizing roller drying machine 17 and be dried passes through Coiling machine 18 is wound in core make web-like.

Thin film 12 such as can utilize as optical thin film.As optical thin film, the protection of such as polaroid can be listed Thin film, phase-contrast film.Above-mentioned embodiment be use a kind of rubber cement 11 to manufacture the example of the thin film 12 of single layer structure, but system The thin film made can also be multiple structure.In the case of the thin film manufacturing multiple structure, as long as by well-known stream altogether Prolong and multiple rubber cement is cast.

Above-mentioned embodiment is to use TAC as the example of polymer, but replaces TAC, it is also possible to be its different from TAC His cellulose acylate, cyclic polyolefin etc..For cellulose acylate, below it is described in detail.

<cellulose acylate>

Cellulose acylate is particularly preferred: the replacement of the ratio that carries out the hydroxyl carboxylic acid of cellulose being esterified, i.e. acyl group Degree (hereinafter referred to as acyl substitution) meets following formula (1)～the full terms of (3).It addition, in (1)～(3), A and B is acyl Base substitution value, the acyl group in A is acetyl group, the acyl group in B be carbon number be the acyl group of 3～22.

2.4≤A+B≤3.0 (1)

0≤A≤3.0 (2)

0≤B≤2.9 (3)

The glucose unit constituting cellulose and β-1,4 bonding has free hydroxyl 2,3 and 6.Cellulose Acylate be part or all of hydrogen esterified, hydroxyl of the hydroxyl of such cellulose be the acyl of more than 2 by carbon number The polymer that base replaces and obtains.If further, since the esterification of a hydroxyl in glucose unit is 100%, then substitution value Being 1, therefore in the case of cellulose acylate, if the hydroxyl of 2,3 and 6 is respectively by 100% esterification, then substitution value becomes It is 3.

Wherein, the acyl substitution of in glucose unit 2 is set to DS2, the acyl substitution of 3 is set to DS3, will The acyl substitution of 6 is set to DS6, and the total acyl substitution utilizing " DS2+DS3+DS6 " to obtain is preferably 2.00～3.00, more It is preferably 2.22～2.90, more preferably 2.40～2.88.And then, " DS6/ (DS2+DS3+DS6) " be preferably 0.32 with On, more preferably more than 0.322, more preferably 0.324～0.340.

Acyl group can simply be a kind, it is also possible to for two or more.When acyl group is two or more, one of preferably wherein for acetyl Base.The summation of the substitution value utilizing acetyl group of the hydrogen of the hydroxyl of 2,3 and 6 is set to DSA, by 2,3 and 6 In the summation of the substitution value utilizing acyl group in addition to acetyl group when being set to DSB, the value of " DSA+DSB " be preferably 2.2～ 2.86, particularly preferably 2.40～2.80.DSB is preferably more than 1.50, and particularly preferably more than 1.7.Further, DSB preferably its More than 28% is the replacement of 6 hydroxyls, and more preferably more than 30%, further preferred more than 31%, particularly preferred more than 32% is 6 The replacement of position hydroxyl.Additionally, the value of " DSA+DSB " of the 6 of cellulose acylate is preferably more than 0.75, more preferably 0.80 Above, particularly preferably more than 0.85.By using above such cellulose acylate, available in order to make for solution The polymer solution of masking and preferred dissolubility.

Be the acyl group of more than 2 as carbon number, can be fatty group can also be aryl, be not particularly limited.Example If any alkyl-carbonyl ester, alkenyl carbonyl ester or the aromatic carbonyl ester of cellulose, aromatic alkyl carbonyl ester etc., they also may be used To have the group being replaced the most further.Propiono, bytyry, valeryl, caproyl, caprylyl, caprinoyl can be listed Base, lauroyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, isobutyryl, tertiary bytyry, Cyclohexane carbo, oleoyl, benzoyl, naphthyl carbonyl, cinnamoyl etc..In them, more preferably propiono, bytyry, ten Dialkanoyl, octadecanoyl, tertiary bytyry, oleoyl, benzoyl, naphthyl carbonyl, cinnamoyl etc., particularly preferred propionyl Base, bytyry.

In the case of using cellulose acylate as polymer, as the solvent of rubber cement 11, it is possible to use known molten Agent is as the solvent of rubber cement when utilizing solution film-forming to manufacture cellulose acylate film.For example, dichloromethane, various alcohol, Various ketone etc..The multiple mixing that can also will select from them, and this mixture is used as solvent.

Hereinafter, embodiments of the invention and the comparative example relative to the present invention are listed.

[embodiment]

[embodiment 1]～[embodiment 8]

In embodiment 1～8, manufacture thin film 12 by solution film-forming device 10.The condition of each embodiment is shown in table 1 In.In table 1, the weld part height H of the band 21 used is shown in " weld part height H " hurdle, the temperature difference in curtain coating face 21a | Tw-Tn | being shown in " temperature difference | Tw-Tn | " hurdle, the thickness of the thin film 12 of manufacture is shown in " thickness of thin film " hurdle.Additionally, roller 22, each all surface temperatures of 23 are shown in " all surface temperatures of roller 22 " hurdle and " all surface temperatures of roller 23 " hurdle.

For each thin film 12, evaluate the degree that has that it's too late of depressed part.Evaluation is with glimmering to the sample sampled from each thin film 12 Light light irradiation light, by visually observing.It addition, sampling is for the overall with region of each thin film 12, according to being included in this sample The mode at the position formed on inherent weld part 21w is carried out.For utilizing visual observation, the first distance at sample is thin The position of face 1m is carried out, and in the case of not observing depressed part, carries out in the position of distance pellicular front 50cm.According to Under standard evaluation observed result.A is qualified level, and B, C are defective level.Evaluation result is shown in Table 1.It addition, in order to The following thin film being evaluated as C is used for anti-glare sheet or polarizer protection film and be coated liquid coating or with other In the case of film adhered, sometimes produce the crawling of coating fluid or deform.

A: carry out observing in the position of distance pellicular front 50cm and do not see depressed part

B: carry out observing in the position of distance pellicular front 50cm and see depressed part

C: carry out observing in the position of distance pellicular front 1m and see depressed part

Table 1

[comparative example 1]

Thin film is manufactured, as comparative example 1 by possessing the solution film-forming device of the band of the weld part height H shown in table 1. The condition of this comparative example is shown in Table 1.Additionally, for obtained thin film, enter according to the method identical with embodiment and standard Row is evaluated.Evaluation result is shown in Table 1.

It addition, the thin film obtained in comparative example 1 exists depressed part, confirm that this depressed part is that Z1 extends along its length Thin groove along arrangements multiple with the direction that length direction Z1 intersects.Groove is a length of more than 40mm and below 50mm In the range of, width be the elongated groove in the scope of more than 10mm and below 15mm.

[embodiment 9]～[embodiment 16]

Thin film 12 is manufactured by solution film-forming device 10.The condition of each embodiment is shown in Table 2.In table 2, the band 21 of use Back side 21b in degree of depth D of depression 61 be shown in " degree of depth D " hurdle, maximum inclination is shown in " maximum inclination " hurdle, curtain coating Temperature difference | Tw-Tn | in the 21a of face is shown in " temperature difference | Tw-Tn | " hurdle, and the thickness of the thin film 12 of manufacture is shown in the " thickness of thin film Degree " in hurdle, each week surface temperature of roller 22,23 is shown in " all surface temperatures of roller 22 " hurdle and " all surface temperatures of roller 23 " hurdle, manufactures The thickness of thin film 12 be shown in " thickness of thin film " hurdle.It addition, the weld part height H with 21 is 5.0 μm.

For each thin film 12, evaluate the inhibition of the depression of the opening with circular.There is opening of circular The depression of mouth in the case of using xenon lamp to irradiate light and pass through visually to observe relative to pellicular front, it was observed that the degree of depth is more Deeply, blackout more increases.That is, blackout is the lightest, and the degree of depth of depression is the most shallow.Further, in the situation of the part do not seen with blackout Under, it is meant that the depression not having the above-mentioned opening with circular or the degree of depth caved in are the most shallow.Therefore, evaluation is to utilize Following method is carried out: utilize xenon lamp that each thin film 12 irradiates light, and by visually observing.Embodiment 9～16 is seen With blackout part be the thin film 12 of embodiment 16, even if be the thin film 12 of this embodiment 16 be also not have in practicality The level of problem, for the category of qualified level.With this embodiment 16 as standard (described in table 2 it is " standard "), according to following Standard evaluation embodiment 9～15.

A: by visually not seeing the part with blackout.

B: have the part with blackout, but turn black compared with the thin film of embodiment 16 and be observed thinly.

Table 2

Claims (10)

1. a solution film-forming method, it has a following operation:

Curtain coating operation, its by with ring-type formation, be wound around in pair of rolls and on the metal band that length direction moves, Polymer is dissolved into the polymer solution obtained in solvent continuously flow out from curtain coating mould, thus forms casting films；

Stripping process, it forms thin film by described casting films being peeled from described band；And

Stretching process, its when keep described thin film each sidepiece described thin film is carried along its length, one While the described thin film in carrying is dried by heating, stretch in the width direction,

Wherein, the temperature in the curtain coating face forming described casting films of described band is by the side face of at least one in the pair of roller The regulation of temperature and adjust,

Weld part in the back side of described band is made into the height in the scope of below more than 3 μm and 30 μm.

Solution film-forming method the most according to claim 1, wherein, the described weld part in described curtain coating face is relative to non-weldering The portion of connecing is made into the temperature difference in the scope of more than 0.1 DEG C and less than 1.0 DEG C.

Solution film-forming method the most according to claim 1 and 2, wherein, described stretching process by described thin film with more than 5% And less than 40% scope in stretching ratio stretch.

Solution film-forming method the most according to claim 1 and 2, wherein, the thin film of manufacture is the thickness of below 50 μm.

Solution film-forming method the most according to claim 1 and 2, wherein, the degree of depth in the described back side of described band be 3 μm with The maximum inclination on the surface of the depression in scope above and below 300 μm is 0.1 μm/more than mm and the model of 1.5 μm/below mm In enclosing.

6. a solution film-forming device, it possesses:

Curtain coating mould, polymer is dissolved into the polymer solution obtained in solvent and continuously flows out by it；

Metal band, it is with ring-type formation, by move along its length and described in flowing out from described curtain coating mould Polymer solution forms casting films, and the weld part in the back side is made into the height in the scope of below more than 3 μm and 30 μm；

Pair of rolls, described band is wrapping with and is circumferentially carried out by least one rotating and making described Tape movement, by least by it The regulation of all surface temperatures of adjusts the temperature in described curtain coating face；And

Stenter, its when keep peeling described casting films from described band and by described when each sidepiece of the thin film that formed Thin film is carried to length direction, is dried by heating by the described thin film in carrying, enters in the width direction on one side Row stretching.

Solution film-forming device the most according to claim 6, wherein, the described weld part phase in the described curtain coating face of described band Temperature difference in the scope of more than 0.1 DEG C and less than 1.0 DEG C is made into for non-solder portion.

8. according to the solution film-forming device described in claim 6 or 7, wherein, described stenter by described thin film with more than 5% and Stretching ratio in the scope of less than 40% stretches.

9. according to the solution film-forming device described in claim 6 or 7, wherein, the thin film of manufacture is the thickness of below 50 μm.

10. according to the solution film-forming device described in claim 6 or 7, wherein, the degree of depth in the described back side of described band is 3 μm The maximum inclination on the surface of the depression in scope above and below 300 μm is 0.1 μm/more than mm and 1.5 μm/below mm In the range of.