CN105835376B - Solution film-forming method and device - Google Patents

Abstract

The present invention provides the solution film-forming method and device that recessed portion periodic in the longitudinal direction will not be generated in the case where implementing the stretch processing in width direction to manufacture with a thickness of the film of 50 μm of strips below.Solution film-forming device (10) has curtain coating mould (24), a pair of rolls (22), (23), band (21) and stenter (16).Band (21) is made of metal, is to be formed by welding with ring-type.The curtain coating face for being cast the band (21) of rubber cement (11) adjusts temperature by roller (22), (23).The weld part height at the back side of band (21) is made into 3 μm or more and 30 μm of ranges below.Film (12) is held by the fixture (31) of stenter (16) on one side and is handled upside down, and is stretched in the width direction on one side.In addition, film (12) is promoted drying in stenter (16).

Description

Solution film-forming method and device

Technical field

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

Background technique

One of method as manufacture thin polymer film (hereinafter referred to as film) has solution film-forming method.Solution film-forming method The method for being the polymer solution obtained from polymer is dissolved into solvent to manufacture film.With solution film-forming method system In the case where the film for making strip, polymer solution is continuously flowed out from curtain coating mould to mobile supporter and forms curtain coating The casting films are stripped and are dried from supporter by film.The band used as supporter is formed with ring-type, is set up and is arrived multiple rollers On move along its length.Band is carried out in the casting position of cast polymer solution with the position that strips for stripping casting films as a result, Circulation.In addition, the raw material as band, use the stainless steel of such as austenite.

It is smooth for requiring flatness, i.e. pellicular front for film.Since the curtain coating face of the cast polymer solution of band can be right The flatness of film impacts, so being made as far as possible smooth.In addition, using the stainless of austenite in the raw material of band In the case where steel, the flatness of film is damaged because of martensitic traoformation sometimes.Thus, for example in Japanese Unexamined Patent Publication 2007- The solution film-forming method and device that the band for the concave-convex degree for having used above-mentioned curtain coating face specific is described in No. 083451 bulletin, by This inhibits martensitic traoformation.

However, manufacture strip film when solution film-forming method in, in order to make film show such as optical function Etc. specific function, implement the stretch processing in width direction to the film of film-forming process sometimes.In addition, along with liquid crystal display The display devices such as device it is lightening, film used in display device is also required further lightening.

It, according to circumstances sometimes also can be however, even if method by recording in Japanese Unexamined Patent Publication 2007-083451 bulletin Visible recessed portion periodic in the longitudinal direction on film.The recessed portion is the case where manufacturing the film of 50 μm of thickness below Under, it is visible due to via stretch processing in the width direction in film-forming process.Even 50 μm of thickness below of manufacture is thin In the case where film, film before the stretch processing in width direction in the fabrication process and not via the drawing in width direction It stretches processing and is not also seen on the film of manufacture.In addition, also not seen in the case where film of the manufacture than 50 μ m-thicks.It should Recessed portion is that length is 40mm or more and the left and right 50mm or less, width are 10mm or more and the left and right 20mm or less is very small in this way Elongated slot is made of the multiple arrangements in direction that the length direction with film intersects, the length direction of each slot and the length of film It is probably consistent to spend direction.

Summary of the invention

The object of the present invention is to provide the stretch processings in implementation width direction to manufacture 50 μm or less length thin in this way Periodic above-mentioned recessed portion is able to the solution film-forming method inhibited and device in the case where the film of item, on length direction.

Solution film-forming method of the invention has curtain coating process, stripping process and stretching process.Being cast process is to pass through One end of the band of metal strip and the welding of the other end and formed, be wrapping in a pair of rolls with ring-type and to length direction Mobile takes, and polymer solution obtained from polymer is dissolved into solvent is continuously flowed out from curtain coating mould.Stripping process It is to form film and peeling casting films from band.Stretching process is in the state of keeping each side of film by film edge Length direction is carried, and is on one side dried the film in carrying by heating, is stretched 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 adjusting of the circumferential surface temperature of at least one of a pair of rolls, in the back side of band Weld part is made into the height in 3 μm or more and 30 μm or less of range.

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

Solution film-forming device of the invention has curtain coating mould, metal band, a pair of rolls and stenter.Being cast mould will polymerize Polymer solution obtained from object is dissolved into solvent continuously flows out.Band is formed with ring-type, and moving along its length By from curtain coating mould flow out polymer solution form casting films, the weld part in the back side be made to 3 μm or more and 30 μm it is below Height in range.A pair of rolls passes through at least one by being wrapping with band and at least one circumferentially carries out rotating keeps band mobile A circumferential surface temperature is adjusted to adjust the temperature in curtain coating face.Stenter is in the film that holding peels casting films from band and is formed Each side in the state of film is carried to length direction, on one side by the film in carrying by heating dry, one Edge width direction is stretched.

The case where stretching process is stretched film with the stretching ratio in 5% or more and 40% or less range Under, above-mentioned solution film-forming method and solution film-forming device are especially effective.The case where the film of manufacture is 50 μm of thickness below Under, the significant effect of above-mentioned solution film-forming method and solution film-forming device.Depth in the back side of band is 3 μm or more and 300 μm The maximum inclination on the preferred surface of recess in following range is in the range of 0.1 μm/mm or more and 1.5 μm/mm or less.

According to the present invention, the generation of periodic above-mentioned recessed portion is inhibited on length direction, can be manufactured and be implemented The film of the strip thin in this way of 50 μm or less of stretch processing in width direction.

Detailed description of the invention

Above-mentioned purpose, advantage read the detailed description of preferred embodiment, this field by referring to appended attached drawing 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 the sectional view along Fig. 2 (III)-(III) line band.

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

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

Fig. 6 is the explanatory diagram of the recess 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 films

15 casting units

16 stenters

17 roller drying machines

18 coiling machines

21 bands

21a is cast face

The back side 21b

21n non-solder portion

21w weld part

22,23 roller

22a, 23a temperature controller

24 curtain coating moulds

24a outflux

25 angle strippers

26 casting films

27 air supplying parts

28 air supplying parts

31 fixtures

32 air supply units

33 air supplying parts

34 rollers

38 temperature-sensitive liquid crystal films

41,42 track

43 chambers

45 preheating sections

46 stretch section

47 relaxation sections

48 cooling sections

51 runners

52 sprocket wheels

61 recess

The surface 61a

62 recess

The surface 62a

CL tangent line

H weld part height

The length of L1 vertical line

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

PC casting position

PP strips position

The thickness of T21 band

Z1 length direction

Z2 width direction

Z3 thickness direction

Specific embodiment

Solution film-forming device 10 shown in Fig. 1 is the device for being continuously manufactured by film 12 by rubber cement 11.Film 12 It is with a thickness of 50 μm of films below, thickness is made in 10 μm or more and 50 μm or less of range in present embodiment.Rubber cement 11 It is polymer solution obtained from polymer is dissolved into solvent.In present embodiment, triacetyl cellulose is used as polymer Plain (TAC, triacetylcellulose), the mixture of methylene chloride and methanol, but polymer and solvent are used as solvent It is not limited to these.Details about the polymer and solvent that can be used in the present invention is described below.Rubber cement 11 In also may include plasticizer, ultraviolet absorbing agent, delay controlling agent etc. various additives, for preventing the mutual adherency of film Delustering agent.

Solution film-forming device 10 successively has casting unit 15, stenter 16, roller drying machine 17 and is batched from upstream side Machine 18.Casting unit 15 has the band 21 formed with ring-type, with circumferential surface supporting part 21 and a pair of rolls mobile to length direction Z1 22,23, curtain coating mould 24 and angle stripper 25.In addition, to the length direction of film 12 also appending symbols Z1.In a pair of rolls 22,23 At least one is circumferentially rotated, and by the rotation, the band 21 that is wrapping with is to length direction Z1 continuous moving.Present embodiment In, make the circumferentially driving rotation of both roller 22 and roller 23.About the details of band 21, chatted later using other accompanying drawings It states.It is cast the upper of the band 21 that mould 24 is configured at the top of roller 22 in this example embodiment, but can also be configured between roller 22 and roller 23 Side.

Curtain coating mould 24 continuously flows out the rubber cement 11 that supply comes from the outflux 24a opposite with band 21.By in movement In band 21 on continuously flow out rubber cement 11, rubber cement 11 is cast on band 21, on band 21 formed casting films 26.In Fig. 1, to glue Slurry 11 contacts and initially forms position (hereinafter referred to as casting position) the appending symbols PC of casting films 26 with band 21.

Roller 22,23 has temperature controller 22a, the 23a for adjusting circumferential surface temperature (referring to Fig. 4).Using having adjusted circumferential surface temperature The roller 22,23 of degree adjusts the temperature of casting films 26 via band 21.

Present embodiment solidifies casting films 26 by desiccant gel mode.Desiccant gel mode is by curtain coating Film 26 is heated and promotes the dry mode to make its solidification (gelation).It is set opposite to each other with the band 21 from roller 22 towards roller 23 Air supplying part 27 is set, air supplying part 28 is set opposite to each other with the band 21 from roller 23 towards roller 22, this is further promoting casting films 26 Dry aspect is preferably, in present embodiment also in this way.Air supplying part 27,28 has respectively on the forward surface opposite with band 21 There is multiple nozzles (not shown), the air by temperature through adjusting is sent out from these nozzles.

Rubber cement 11, so-called welding bead on band 21 are reached about from curtain coating mould 24, it can also be in the length direction Z1 of band 21 On upstream be arranged decompression chamber (not shown).The atmosphere of the upstream side region of the rubber cement 11 of outflow is inhaled by the decompression chamber It receives and depressurizes the region.It is stabilized towards the shape of the rubber cement 11 of band 21 from outflux 24a by the decompression.

After solidifying casting films 26 on band 21 until the degree that can be carried to stenter 16, solvent-laden shape is being wrapped It is peeled from band 21 under state.Angle stripper 25 is the roller for continuously stripping casting films 26 from band 21.Angle stripper 25 will lead to It crosses the film 12 for stripping and being formed from band 21 for example to support from below, strips position PP for what casting films 26 were peeled from band 21 It keeps constant.The method stripped can be method that film 12 downstream stretches or keep angle stripper 25 circumferentially rotatable Any one of method etc..

From stripping in the case where desiccant gel mode on band 21, for example, casting films 26 solvent containing ratio 3 It is carried out during in the range of quality % or more and 100 mass % or less.In addition, solvent containing ratio is (single in this specification : it is %) value of dry measure standard, specifically, the quality that will find out the film 12 of the measure object of solvent containing ratio is set as X is with { (X-Y)/Y } × 100 percentage found out when the quality after being completely dried the film 12 is set as Y.In addition, so-called The residual quantity that " being completely dried " does not need solvent is strictly " 0 ", such as in the present embodiment, the film relative to measure object 12, the quality after drying process in 3 hours or more will be carried out in 120 DEG C or more, the thermostat below of relative humidity 10% to be set For Y.

As described above, casting unit 15 forms film 12 by rubber cement 11.Band 21 is by casting position PC and stripping position PP loopy moving is set, so that the curtain coating of rubber cement 11 and stripping for casting films 26 be repeated.

In the transport road of film 12 between casting unit 15 and stenter 16, it also may be configured to promote film 12 Drying pressure fan (not shown).The film 12 for stripping and being formed is directed to stenter 16.Stenter 16 has conduct will Film 12 is carried out along the function of the width direction Z2 orthogonal with the length direction Z1 stretching-machine stretched and as to film 12 The function of 1st drying machine of heating and drying.Details is described below using other accompanying drawings, will be thin in stenter 16 Respectively with the holding of fixture 31, the length direction Z1 by one side by fixture 31 along film 12 is moved, is increased on one side for each side of film 12 The interval (hereinafter referred to as opposite grip separation) of big opposite fixture, so that Z1 is carried along its length by film 12 on one side Z2 is stretched in the width direction on one side.

Stenter 16 has air supply unit 32 and air supplying part 33.Air supply unit 32 will be adjusted to the drying of various temperature Air supply into air supplying part 33, attached air is blown to the film 12 in stenter 16 from the air supplying part 33 and is made it dry.This Outside, by the air blow it is attached carry out being heated or cooled for the film 12 in aftermentioned each section of stenter 16, by this It is heated or cooled to adjust the temperature of film 12.

Roller drying machine 17 is the 2nd drying machine, has multiple rollers 34 and air conditioner (not shown).Each roller 34 is supported thin with circumferential surface Film 12.Film 12 is wrapping with to carrying on roller 34.The temperature or humidity etc. of the inside of air conditioner regulating roller drying machine 17.It batches Machine 18 is the device for batching film 12 with web-like.

Band 21 is illustrated referring to Fig. 2.Band 21 is made of metal, by the stainless steel shape of austenite in present embodiment At.Band 21 makes in the following manner: making one end that the length direction of the metal plate of the band of strip is made using calendering It docks and is welded with the other end, and the 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 direction Z2 of band 21, can also edge as in the present embodiment and width direction Z2 The direction of intersection extends.In addition, casting films 26 with the width direction of film 12 due to consistent with the width direction of band 21, so right The width direction of casting films 26 and film 12 also appending symbols Z2.The zone face for forming casting films 26 is known as curtain coating face 21a, it will be with The zone face of curtain coating face 21a opposite side is known as back side 21b.Weld part 21w is other than being cast face 21a, the back side as will be described later 21b has been also carried out milled processed.

Weld part 21w in the case where making one end of band dock and be welded with the other end is melted by heating Region, can determine by visual observation.In addition, the region in addition to weld part 21w of band 21 is known as non-solder portion below 21n.The thickness T21 (referring to Fig. 3) of the band 21 of present embodiment is made to 1.5mm.But the thickness T21 of band 21 is not limited In this, when being in 0.5mm or more and the range of 2.5mm or less, effect of the present invention is especially big.Band 21 is to become uniform thick as far as possible The mode of degree T21 makes.But by the film 12 of 50 μm of thickness below for example by stenter 16 in the direction of the width into Row stretches come in the case where manufacturing, for band when seeing above-mentioned recessed portion on film, overleaf in weld part protuberance And becoming convex, the thickness of the band of the part becomes thicker than the thickness in non-solder portion.Therefore, it for the back side 21b of band 21, will weld The height H of portion 21w is made in 3 μm or more and 30 μm or less of range.Below by the weld part 21w in the 21b of the back side with symbol H The height of expression is known as weld part height.In the case where weld part height H is 30 μm of situations below, with phase the case where being greater than 30 μm Than becoming the same from roller 22,23 to the heat transfer of curtain coating face 21a entirety, as will be described later, being cast non-solder portion 21n in the 21a of face Become smaller with the temperature difference of weld part 21w.In addition, being set as weld part height H less than 3 μm, this processing in milled processed etc It is difficult in precision.Weld part height H is more preferably in 3 μm or more and 20 μm or less of range, further preferably 3 μm with In upper and 10 μm or less of range.

In order to become weld part height H in above range, the back side 21b of weld part 21w is ground.This reality It applies in mode, grinding stone is used in grinding.Weld part height H is the overhang from non-solder portion 21n in the 21b of the back side, such as It can be found out by laser displacement gauge, the LJ-V7080 of Co., Ltd. KEYENCE is used in present embodiment.Using sharp It, can be with the width direction (water in Fig. 3 of the weld part 21w of back side 21b in the case that light displacement meter finds out weld part height H Square to) on center centered on, the range of 200mm is for example continuously measured in the 21b of the back side from non-solder portion 21n Overhang, using the maximum value in measured value as weld part height H.

Weld part 21w in the 21a of curtain coating face is preferably 0.1 DEG C or more and 1.0 DEG C of models below relative to non-solder portion 21n Enclose interior temperature difference.That is, the temperature of weld part 21w is set as Tw, the temperature of non-solder portion 21n is set as in curtain coating face 21a When Tn, with | Tw-Tn | the temperature difference found out is preferably in 0.1 DEG C or more and 1.0 DEG C or less of range.The temperature difference | Tw-Tn | In more preferably 0.1 DEG C or more and 0.5 or less range, in further preferably 0.1 DEG C or more and 0.3 DEG C or less of range. Temperature difference | Tw-Tn | the details for seeking method be described below using other accompanying drawings.

To above-mentioned temperature difference | Tw-Tn | ask method to be illustrated referring to Fig. 4.Temperature difference | Tw-Tn | such as city can be used The temperature-sensitive liquid crystal film sold and find out.Temperature-sensitive liquid crystal film is as it is well known, the liquid crystal for changing color because of temperature is micro- It is encapsulated, and piece obtained from the microcapsule carrier to the film as formation such as paper or polymer is made as printing etc..This reality It applies in mode, as temperature-sensitive liquid crystal film, uses the RW-25 of Japanese Microcapsule corporation.Temperature difference | Tw-Tn | it can make It is found out with temperature-sensitive liquid crystal film by the following method.

Firstly, attaching temperature-sensitive liquid crystal film 38 on the curtain coating face 21a for starting the band 21 before movement.In present embodiment, patch Attached 3 temperature-sensitive liquid crystal films 38, but it is not limited to the piece number.Each temperature-sensitive liquid crystal film 38 passes through temperature-sensitive liquid crystal with weld part 21w The mode in the general center on the piece surface of piece 38 attaches.In addition, configuring camera opposite to each other with the circumferential surface of roller 23.This embodiment party In formula, on the position in 1/8 downstream side of the perimeter of the roller 23 the upstream end in the region contacted from roller 23 with band 21, with band 21 configure camera opposite to each other.Make 19 DEG C of circumferential surface temperature of roller 22 by temperature controller 22a, passes through temperature controller 23a Make 32 DEG C of circumferential surface temperature of roller 23, keeps band 21 mobile with 35m/ minutes.By the movement of band 21, make temperature-sensitive liquid crystal film 38 in roller Pass through 5 times on 23.In the 5th when passing through, temperature-sensitive liquid crystal film 38 is shot with camera.In present embodiment, to 3 Temperature-sensitive liquid crystal film 38 is shot respectively, but can also be shot to 1 selected from them or 2.For example, can be only 1 of most upstream side on length direction Z1 in temperature-sensitive liquid crystal film 38 is shot.By the temperature-sensitive liquid crystal film 38 that shoots Color finds out the temperature Tn of the temperature Tw and non-solder portion 21n of the weld part 21w in the 21a of curtain coating face, it is poor to calculate it.It calculates The absolute value of value is temperature difference | Tw-Tn |.

It is seen on the back side 21b of band 21 in the range with 3 μm or more and 300 μm or less as shown in Figure 5 Depth D recess 61 in the case where, preferably by be recessed 61 surface 61a gradient in maximum gradient (hereinafter referred to as For maximum inclination) it is set as in the range of 0.1 μm/mm or more and 1.5 μm/mm or less, such as 1.0 μ are set as in present embodiment m/mm.Gradient is as shown in Figure 5, is oblique with tangent line LC when describing the tangent line LC in the surface 61a for being recessed 61 Side, by the vertical line from tangent line LC of the straight line on the bevel edge, back side 21b and the straight line on the 21b of the back side (along thickness The extended straight line of direction Z3) it is the length L1 (unit be μm) of vertical line divided by straight on the 21b of the back side in the right angled triangle that constitutes It is worth obtained from the length L2 (unit mm) of line, i.e., the value (unit be μm/mm) calculated with L1/L2.Therefore, there is recess The angle (being 0 °≤θ≤90 ° when which wherein, being set as θ) relative to back side 21b in tangent line in 61 surface is most Big tangent line is maximum inclination as the gradient found out in the right angled triangle of bevel edge.Maximum inclination is more preferably made In the range of 0.2 μm/mm or more and 1.2 μm/mm or less, it is below that 0.3 μm/mm or more and 1.0 μm/mm is further preferably made In range.In addition, in each section distinguished along back side 21b, can also be used as average value for gradient and find out, Further specifically method is asked to be described below.

Below to make recess 61 maximum inclination within the above range when example be illustrated.On band 21, sometimes The defect of recess is deformed or generated on curtain coating face 21a because being heat-treated using the part of welding etc..In order to make this The defect of kind deformation or recess flattens, and has following situations: being punched out, is ground, grinds to the back side 21b of band 21, later will The part of the protuberance of the curtain coating face side 21a reams and keeps its flat.Punching is tapped with the percussion component for being referred to as formed punch Processing, due to being the back side 21b for tapping band 21 and the processing that carries out, so referred to as back side punching.By becoming curtain coating face 21a Flat such processing overleaf remains such recess 62 shown in Fig. 6 sometimes on 21b.The recess 62 is for example with formed punch Front end trace, that is, precipitous inclined surface and the inclined surface that slows down by grinding of its periphery.The recess 62 most Big-inclination be greater than 1.5 μm/mm in the case where, to recess 62 surface 62a further progress be ground, alternatively, using with composition The identical metal of metal with 21 will be recessed 62 by welding landfill, and the built-up welding part formed to landfill is ground etc., It is to be recessed 61 shown in 0.1 μm/mm or more and 1.5 μm/mm Fig. 5 below that maximum inclination, which is made,.Furthermore it is possible to be ground Mill can also also be ground to replace being ground other than grinding.In present embodiment, grinding stone is used in grinding.In Fig. 5 Shown in recess 61 depth if 300 μm hereinafter, then can also be deeper than the depth of recess 62 shown in Fig. 6.In addition, Fig. 5 Shown in recess 61 be general cone shape, i.e., with general triangle cross sectional shape.In the back side 21b of the recess 61 The diameter of opening can than shown in Fig. 6 recess 62 back side 21b in opening diameter it is big, preferably 50mm or more and In the range of 600mm or less.

The shape of recess 61 can be found out for example, by laser displacement gauge, and Co., Ltd. is used in present embodiment The LJ-V7080 of KEYENCE.As the method for finding out maximum inclination, such as there is following such method.Firstly, using swashing Light displacement meter is in a manner of the most deep by recess 61 along the section shape of such as width direction Z2 measurement recess 61 of band 21 Shape.For the cross sectional shape of the measurement, using the distance on such as width direction Z2 of measurement as horizontal axis, by the longitudinal axis of depth D into Row pictorialization.Using the most deep of recess 61 as starting point, every 5mm or more and the constant width of the left and right 20mm or less on width direction Z2 The section of degree finds out multiple slopes as gradient, finds out the G-bar of the average value as them.Successively find out each area Between G-bar until recess 61 back side 21b in open end, that is, end until.Made with the maximum value of these G-bars For maximum inclination.In addition, seeking method as G-bar, the above-mentioned of the measured value found out to above-mentioned each section will be used by having Slope of a curve (differential value) in section the methods of averages.When finding out maximum inclination, in order to remove each measurement Error can also apply the methods of maximum value and minimum value in the value for removing multiple G-bars.

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, transport road is successively divided into the preheating section for preheating procedure from upstream side 45, for stretching section 46, the relaxation section 47 for the process that relaxes, the cooling section for cooling process of stretching process 48.Preheating section 45, stretching section 46, relaxation section 47, cooling section 48 are sent out according to from air supplying part 33 (referring to Fig.1) The temperature of air and the set-up mode of track 41,42 are spatially distinguished and the section that is formed, not by utilizing partition etc. Differentiation and the section that is formed.Starting position is held in addition, being set in the upstream in preheating section 45, under cooling section 48 Trip side is set with holding and releases position.

Track 41,42 is configured at the two sides of the transport road of film 12.Multiple fixtures have been set separately on track 41,42 31.Each fixture 31 is moved freely along corresponding track 41,42, and moving direction is provided by track 41,42.Each track 41, circlewise, above-mentioned ring-type, which has, is moved to the outlet portion that holding releases position from starting position is held for fixture 31 for 42 settings The circuit portion for holding starting position is returned to the fixture 31 that will be moved to holding releasing position.Fixture 31 is located at certain intervals In the complete cycle of each track 41,42, but a part of fixture 31 is only depicted in Fig. 7.In addition, as holding film in present embodiment The holding member of 12 side uses fixture 31, but it's not limited to that for holding member.For example, it is also possible to using by film Side be pierced into multiple needles the needle plate of films 12 kept to replace fixture 31.

On track 41,42, cricoid chain (not shown) edge of multiple fixtures 31 is installed at a prescribed interval respectively Track be movably arranged.Chain frame be set to compared to hold starting position be configured at the runner 51 of more upstream side with compare handle Releasing position is held to be configured on the sprocket wheel 52 of further downstream.Sprocket wheel 52 is rotated by driving portion (not shown), thus chain Along track 41,42 loopy movings.It is carried out by mobile each fixture 31 of the chain along track 41,42 with certain speed It is mobile.In addition, hereinafter, being carried out in the case where not expressing outlet portion, circuit portion especially as 41,42 pairs of outlet portions of track Explanation.

Start component in the holding for holding the holding that starting position is provided with the side for making fixture 31 start film 12 (not scheme Show).In addition, releasing component (not holding the holding for releasing the holding that position is provided with the side for making fixture 31 release film 12 Diagram).For film 12, each side is held in holding starting position by fixture 31, passes through the mobile edge of fixture 31 Length direction Z1 is handled upside down, successively by preheating section 45, stretching section 46, relaxation section 47, cooling section 48.By pre- 45 between hot-zone, during stretching section 46, relaxation section 47, cooling section 48, film 12 implements the processing in each section, is holding The holding for releasing place holder 31 is released from.

From holding starting position until stretching section 46, track 41,42 is parallel with length direction Z1, and makes mutual It is constant every (hereinafter referred to as orbital spacing).Make the fixture 31 on opposite track 41 and the fixture 31 on track 42 as a result, In the state that opposite grip separation is constant, by fixture 31, Z1 is moved along its length.

In preheating section 45, the film 12 before being stretched is heated and (hereinafter referred to as preheated).Therefore, it is preheating Film 12 is preheated in section 45 with the state not stretched.Preheating by the heated air from air supply unit 32 come It carries out.The temperature of the air is preferably 25 DEG C or more and 120 DEG C of ranges below.

In stretching section 46, the configuration of track 41,42 is in line, but to form draw angle between length direction Z1 The mode of θ is configured to tyre angle, and downstream towards, orbital spacing gradually broadens.Make the moving direction of fixture 31 opposite as a result, In length direction Z1 with draw angle θ towards outside, as the length direction Z1 of fixture 31 is moved and is gradually increased opposite folder Tool interval, so that Z2 is stretched in the width direction by film 12.In the stretching section 46, by the thin of the width W1 before stretching Until film 12 extends to width W2.In addition, due to, the institute parallel relative to length direction Z1 in preheating 45 middle orbit 41,42 of section It is the angle for stretching section 46 relative to the increment of the moving direction of the fixture 31 in preheating section 45 with draw angle θ.It stretches Multiplying power α (unit %) is found out by α=(W2/W1) × 100, such as is set based on target optical characteristic.Stretching ratio α In the case where bigger, recessed portion is more easy to appear, in the case where in the range that stretching ratio α is 5% or more and 40% or less, Especially significant effect can be obtained.

In stretching section 46, film 12 is heated by the heated air from air supply unit 32.It draws The temperature for stretching the film 12 in section 46 is for example set based on target optical characteristic.

In the present embodiment, relaxation section 47, cooling section 48 and preheating section 45 are same, track 41,42 and length Direction Z1 is parallel, keeps orbital spacing constant.Therefore, in these relaxation sections 47, cooling section 48, make opposite grip separation Fixture 31 is mobile in the state of constant, and film 12 maintains width W2 to be handled upside down.In relaxation section 47, film 12 is added Heat, it is in cooling section 48, film 12 is cooling.Alternatively, it is also possible to be not provided with the section 47 that relaxes.Relaxation section 47 and cooling zone Between the temperature of film 12 in 48 adjusted by adjusting the temperature of the air from air supply unit 32.

The effect of above-mentioned composition is illustrated.Rubber cement 11 is continuously outflowed from curtain coating mould 24, in casting position PC Casting films 26 (curtain coating process) is formed on the band 21 of movement with position PP iterative cycles are stripped.Due to the curtain coating face 21a of band 21 Temperature is adjusted by roller 22,23, so casting films 26 adjust temperature via band 21, is adjusted by the temperature and using coming from The drying of the air of air supplying part 27,28 promotes and solidifies.In addition, in the example as desiccant gel mode, casting films 26 By the heating via band 21 and using the heating of the air from air supplying part 27,28, dry quickening passes through the evaporation of solvent Solidification.

Wherein, the weld part height H in the 21b of the back side is bigger, the connecing relative to roller 22,23 of the weld part 21w of back side 21b Pressing becomes bigger, therefore the above-mentioned contact pressure in the weld part 21w of back side 21b and the above-mentioned contact pressure in non-solder portion 21n Difference i.e. contact pressure difference become larger.In the case that the contact pressure difference is bigger, become uneven from roller 22,23 to the heat transfer of curtain coating face 21a Deng, therefore the temperature difference being cast in the 21a of face | Tw-Tn | it is bigger.The film 12 of manufacture is thinner, and casting films 26 also more thinly form, Manufacture film 12 with a thickness of in 50 μm of situations below, the difference of above-mentioned solidification is significant.It is excessive in the difference solidified like this In the case where, in the stretching using stenter 16 that carries out below, generate the unevenness of the stress of the difference due to solidification.This is answered The unevenness of power becomes the uneven reason with dry contraction of film 12, on the small film portion of the degree of the contraction becomes State recessed portion.Also, due to 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 generated by stretching is smaller, so becoming smaller with the degree of dry contraction.That is, examining Observing the recessed portion is generated in the corresponding thin membrane regions in region on the weld part 21w with casting films.In addition, as this reality The drying that mode is applied like that in the case where desiccant gel mode, from the unequal and casting films 26 of the heat transfer of roller 22,23 The difference of degree is related, solidifying in the solidification in the region on weld part 21w in casting films 26 and the region on non-solder portion 21n Solid difference and degree of drying it is poor corresponding.Compared with the difference of such degree of drying is in the way of cooling gel the case where, make Stress due to the stretching using stenter 16 is more uneven.Cooling gel mode is that casting films cooling is made its solidification Mode.In addition, band 21 with the contact pressure of roller 22,23 for example can by Prescale (Fuji Photo Film Co., Ltd.'s system, LLLW) with Prescale parsing found out with system (Fuji Photo Film Co., Ltd.'s system, FPD-9270), in present embodiment also this Sample.

About this point, for the back side 21b of the band 21 of present embodiment, due to as low as 3 μm of weld part height H with Upper and 30 μm of ranges below, so the temperature difference in curtain coating face 21a | Tw-Tn | it is small.Due to temperature difference | Tw-Tn | small, curtain coating Film 26 is equably dried in whole region, even in the case where 50 μm of films 12 below of manufacture, for casting films For 26, the difference in region and the degree of drying in the region on non-solder portion 21n on weld part 21w is also suppressed smaller.Cause This, in the stenter 16 carried out below, the region of the film 12 corresponding with the region on weld part 21w in casting films 26 and The region of film 12 corresponding with the region on non-solder portion 21n is probably comparably stretched.

Due to the temperature difference in curtain coating face 21a | Tw-Tn | it is made in 0.1 DEG C or more and 1.0 DEG C or less of range, so For casting films 26, the difference in region and the degree of drying in the region on non-solder portion 21n on weld part 21w is suppressed It is minimum.

It is maximum for the recess 61 of the depth D in the range with 3 μm or more and 300 μm or less in the 21b of the back side Gradient is suppressed to smaller in the range of 0.1 μm/mm or more and 1.5 μm/mm or less.Therefore, by assigning to band 21 High tension, using at least either in the elongation of band 21 and the pressure of the circumferential surface from a pair of rolls 22,23, band 21 and roller 22, it 23 more reliably contacts.21 whole region more uniformization of band is spread from roller 22,23 to the heat transfer of band 2 as a result, band 21 Temperature is controlled more evenly.As a result, the generation shown in Fig. 6 due to the recess of the film 12 of recess 62 is pressed down System.In addition, being due to the recess because of the homogenized film 12 of unevenness to conduct heat caused by recess 62 and moving along its length The recess that the rotation of dynamic cricoid band 21 accordingly occurs cycle turnover, is e.g. stretched using stenter 16, at 50 μm The recess seen in the film 12 of thickness below.Also, the recess is on pellicular front with roughly circular opening.

Casting films 26 are stripped from band 21 by angle stripper 25, and film 12 (stripping process) is consequently formed.Film 12 is drawn It is directed in stenter 16, each side is held by fixture 31.Film 12 is in the state of holding side by fixture 31, successively to pass through Preheat section 45, stretch section 46, relaxation section 47, cooling section 48 mode Z1 is handled upside down along its length, by coming from The air of air supplying part 33 promotes drying.During holding starting position until stretching section 46, film 12 is not drawn It is handled upside down with stretching.In preheating section 45, film 12 is preheated (preheating procedure) in the state of no stretching.It is pre- by this Heat, the stretching stretched in section 46 promptly start, while assigning on width direction Z2 in the stretching relative to film 12 Tension more evenly.In stretching section 46, film 12 is dried by heating on one side, and Z2 is stretched in the width direction on one side, Until the film 12 of width W1 before stretching is extended to width W2 (stretching process).This is stretching in the state for heating film 12 Lower progress.In relaxation section 47, cooling section 48, film 12 maintains width W2 and is handled upside down.In relaxation section 47, pass through Film 12 is heated in the state of keeping its width W2 constant, by stretch section 46 in generated by stretching should fluff It relaxes (relaxation process).In cooling section 48, the molecule of film 12 is formed (cooling process) by the cooling of film 12.

Drying is further promoted by roller drying machine 17 holding the film 12 for releasing the holding that position relieves fixture 31. In this way, the drying process of film 12 includes to utilize preheating section 45, stretching section 46 and the relaxation section 47 in stenter 16 1st drying process, and the 2nd drying process using roller drying machine 17.Using roller drying machine 17, dry film 12 passes through Coiling machine 18 is wound in core and web-like is made.

Film 12 for example can be used as optical thin film utilization.As optical thin film, the protection of such as polarizing film can be enumerated Film, phase-contrast film.Above embodiment is the example that the film 12 of single layer structure is manufactured using a kind of rubber cement 11, but is made The film made is also possible to multilayered structure.In the case where manufacturing the film of multilayered structure, as long as passing through well-known total stream Prolong and is cast a variety of rubber cements.

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

<cellulose acylate>

Cellulose acylate is particularly preferred: the substitution of ratio, i.e. acyl group that the hydroxyl of cellulose is esterified with carboxylic acid Degree (hereinafter referred to as acyl substitution) meets following formula (1)~(3) full terms.In addition, A and B are acyl in (1)~(3) Base degree of substitution, the acyl group in A are acetyl group, and the acyl group in B is the acyl group that carbon atom number is 3~22.

2.4≤A+B≤3.0 (1)

0≤A≤3.0 (2)

0≤B≤2.9 (3)

Constituting the glucose unit that cellulose and β -1,4 are bonded has free hydroxyl at 2,3 and 6.Cellulose Acylate be the hydroxyl of such cellulose part or all be esterified, the hydrogen of hydroxyl by carbon atom number be 2 or more acyl Polymer obtained from base replaces.If in addition, due to a hydroxyl in glucose unit esterification be 100%, degree of substitution Be 1, therefore in the case where cellulose acylate, if 2,3 and 6 hydroxyls respectively by 100% esterification, degree of substitution at It is 3.

Wherein, 2 in glucose unit acyl substitutions are set as DS2,3 acyl substitutions is set as DS3, it will 6 acyl substitutions are set as DS6, and the total acyl substitution for utilizing " DS2+DS3+DS6 " to find out is preferably 2.00~3.00, more Preferably 2.22~2.90, further preferably 2.40~2.88.In turn, " DS6/ (DS2+DS3+DS6) " be preferably 0.32 with On, more preferably 0.322 or more, further preferably 0.324~0.340.

Acyl group can be only a kind, or two or more.It one of is preferably wherein acetyl when acyl group is two or more Base.The summation of the degree of substitution using acetyl group of the hydrogen of 2,3 and 6 hydroxyls is set as DSA, by 2,3 and 6 In the summation of degree of substitution of acyl group of the utilization in addition to acetyl group when being set as DSB, the value of " DSA+DSB " is preferably 2.2~ 2.86, particularly preferably 2.40~2.80.DSB is preferably 1.50 or more, and particularly preferably 1.7 or more.Also, DSB preferably its 28% the above are the substitution of 6 hydroxyls, more preferable 30% or more, further preferred 31% or more, particularly preferred 32%, the above are 6 The substitution of position hydroxyl.In addition, the value of 6 " DSA+DSB " of cellulose acylate is preferably 0.75 or more, more preferably 0.80 More than, particularly preferably 0.85 or more.It is available to be used for solution to make by using above such cellulose acylate The polymer solution of film and preferred dissolubility.

The acyl group for being 2 or more as carbon atom number, can be fatty group and is also possible to aryl, be not particularly limited.Example If any the alkyl oxycarbonyl base ester of cellulose, alkenyl carbonyl ester or aromatic carbonyl ester, aromatic alkyl carbonyl ester etc., they can also Further to have substituted group respectively.Propiono, bytyry, valeryl, caproyl, caprylyl, caprinoyl can be enumerated Base, dodecane acyl group, tridecane acyl group, tetradecane acyl group, hexadecanoyl, octadecanoyl, isobutyryl, tertiary bytyry, Cyclohexane carbo, oleoyl, benzoyl, naphthyl carbonyl, cinnamoyl etc..In them, more preferable propiono, bytyry, ten Dialkanoyl, octadecanoyl, tertiary bytyry, oleoyl, benzoyl, naphthyl carbonyl, cinnamoyl etc., particularly preferred propionyl Base, bytyry.

In the case where using cellulose acylate as polymer, as the solvent of rubber cement 11, it can be used well known molten Solvent of the agent as rubber cement when manufacturing cellulose acylate film using solution film-forming.For example, methylene chloride, various alcohol, Various ketone etc..The a variety of mixing that can also will be selected from them, and used using the mixture as solvent.

Hereinafter, enumerating the embodiment of the present invention and relative to comparative example of the invention.

[embodiment]

[embodiment 1]~[embodiment 8]

In Examples 1 to 8, film 12 is manufactured 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 used band 21 is shown in the column " weld part height H ", the temperature difference being cast in the 21a of face | Tw-Tn | it is shown in " temperature difference | Tw-Tn | " column, the thickness of the film 12 of manufacture is shown in " thickness of film " column.In addition, roller 22,23 each circumferential surface temperature is shown in " the circumferential surface temperature of roller 22 " column and " the circumferential surface temperature of roller 23 " column.

For each film 12, the presence or absence of recessed portion and degree are evaluated.Evaluation is to the sample sampled from each film 12 with glimmering Light light irradiation light, is observed by visual observation.In addition, overall with region of the sampling for each film 12, according to included in the sample The mode at the position formed on inherent weld part 21w carries out.It is thin in the distance of sample first for observation visually The position of film surface 1m carries out, and in the case where recessed portion is not observed, carries out in the position apart from pellicular front 50cm.According to Under standard evaluation observation result.A is qualified level, and B, C are unqualified level.Evaluation result is shown in table in 1.In addition, in order to Following films for being evaluated as C is used for anti-glare piece or polarizer protection film and be coated liquid coating or with others In the case where film adhered, the crawling of coating fluid is generated sometimes or is deformed.

A: it is observed in the position apart from pellicular front 50cm without seeing recessed portion

B: it is observed in the position apart from pellicular front 50cm and sees recessed portion

C: it is observed in the position apart from pellicular front 1m and sees recessed portion

Table 1

[comparative example 1]

By having the solution film-forming device manufacturing film of the band of weld part height H shown in table 1, as comparative example 1. The condition of the comparative example is shown in Table 1.In addition, for obtained film, in accordance with the method identical with that in the embodiment and standard into Row evaluation.Evaluation result is shown in table in 1.

In addition, confirming that the recessed portion is Z1 extension along its length there are recessed portion in the film obtained in comparative example 1 Thin slot made of the multiple arrangements in direction intersected with length direction Z1.Slot is that length is 40mm or more and 50mm is below Range is interior, width is the elongated slot in 10mm or more and the range of 15mm or less.

[embodiment 9]~[embodiment 16]

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 that uses Back side 21b in the depth D of recess 61 be shown in the column " depth D ", maximum inclination is shown in " maximum inclination " column, curtain coating Temperature difference in the 21a of face | Tw-Tn | it is shown in " temperature difference | Tw-Tn | " column, the thickness of the film 12 of manufacture is shown in the " thickness of film In degree " column, each circumferential surface temperature of roller 22,23 is shown in " the circumferential surface temperature of roller 22 " column and " the circumferential surface temperature of roller 23 " column, manufacture The thickness of film 12 be shown in " thickness of film " column.In addition, the weld part height H of band 21 is 5.0 μm.

For each film 12, the inhibitory effect with the recess of generally circular opening is evaluated.It is opened with generally circular Mouthful recess, using xenon lamp irradiation light and in the case where observed by visual observation, observing that depth is got over relative to pellicular front Deep, nigrescence more increases.That is, it is lighter to black, the depth of recess is more shallow.Also, the case where not seeing with the part to black Under, it is meant that it is extremely shallow without the depth of the above-mentioned recess with generally circular opening or recess.Therefore, evaluation is to utilize What following methods carried out: using xenon lamp to each 12 irradiation light of film, and being observed by visual observation.It is seen in embodiment 9~16 Most it is the film 12 of embodiment 16 with the part to black, even if being the film 12 of the embodiment 16 is also not have on practical The level of problem, for qualified horizontal scope.It (is recorded as in table 2 " standard ") with the embodiment 16 for standard, according to below Standard evaluates embodiment 9~15.

A: it is not seen by visual observation with the part to black.

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

Table 2

Claims (6)

1. a kind of solution film-forming method, with the following process:

It is cast process, by being formed, being wound around in a pair of rolls and being taken to mobile metal of length direction with cyclic annular, Polymer solution obtained from polymer is dissolved into solvent is continuously flowed out from curtain coating mould, to form casting films；

Stripping process forms film and peeling the casting films from the band；And

Stretching process is carried the film in the state of keeping each side of the film, one along its length While the film in carrying is dried by heating, stretched in the width direction on one side,

Wherein, the film of manufacture is 50 μm of thickness below,

The circumferential surface temperature that the temperature in the curtain coating face of the formation casting films of the band passes through at least one of the pair of roller Adjusting and adjust,

Weld part in the back side of the band is made into the height in 3 μm or more and 30 μm or less of range,

Depth in the back side of the band is institute in the presence of the recess in 3 μm or more and 300 μm or less of range The maximum inclination for stating the surface of recess is in the range of 0.1 μm/mm or more and 1.5 μm/mm or less.

2. solution film-forming method according to claim 1, wherein the weld part in the curtain coating face is relative to non-weldering Socket part is made into the temperature difference in 0.1 DEG C or more and 1.0 DEG C or less of range.

3. solution film-forming method according to claim 1 or 2, wherein the stretching process is by the film with 5% or more And the stretching ratio in 40% or less range is stretched.

4. a kind of solution film-forming device, has:

It is cast mould, polymer solution obtained from polymer is dissolved into solvent continuously flows out；

Metal band is formed with ring-type, as from described in the curtain coating mould outflow and carrying out moving along its length Polymer solution forms casting films, and the weld part in the back side is made into the height in 3 μm or more and 30 μm or less of range；

A pair of rolls, the band, which is wrapping with, and circumferentially carries out rotating by least one keeps the band mobile, by least One circumferential surface temperature is adjusted to adjust the temperature in the curtain coating face of the formation casting films of the band；And

Stenter, will be described in the state of each side for the film that holding peels the casting films from the band and is formed Film is carried to length direction, on one side by the film in carrying by heating dry, on one side in the width direction into Row stretches,

Wherein, the film of manufacture is 50 μm of thickness below,

Depth in the back side of the band is institute in the presence of the recess in 3 μm or more and 300 μm or less of range The maximum inclination for stating the surface of recess is in the range of 0.1 μm/mm or more and 1.5 μm/mm or less.

5. solution film-forming device according to claim 4, wherein the weld part phase in the curtain coating face of the band The temperature difference being made into 0.1 DEG C or more and 1.0 DEG C or less of range for non-solder portion.

6. solution film-forming device according to claim 4, wherein the stenter by the film with 5% or more and Stretching ratio in 40% or less range is stretched.