WO2020195819A1 - 光学フィルムの製造方法及び光学フィルム - Google Patents

光学フィルムの製造方法及び光学フィルム Download PDF

Info

Publication number
WO2020195819A1
WO2020195819A1 PCT/JP2020/010488 JP2020010488W WO2020195819A1 WO 2020195819 A1 WO2020195819 A1 WO 2020195819A1 JP 2020010488 W JP2020010488 W JP 2020010488W WO 2020195819 A1 WO2020195819 A1 WO 2020195819A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
optical film
polyimide
bis
ring
Prior art date
Application number
PCT/JP2020/010488
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
奈々恵 藤枝
Original Assignee
コニカミノルタ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by コニカミノルタ株式会社 filed Critical コニカミノルタ株式会社
Priority to JP2021508995A priority Critical patent/JPWO2020195819A1/ja
Publication of WO2020195819A1 publication Critical patent/WO2020195819A1/ja

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements

Definitions

  • the present invention relates to an optical film manufacturing method and an optical film. More specifically, the present invention relates to a method for producing an optical film having excellent transparency and peelability during film formation, and an optical film.
  • glass has been used as a base material constituting various display members such as solar cells and displays.
  • glass has drawbacks such as being fragile and heavy, and does not have sufficient characteristics in response to recent demands for thinner, lighter, and more flexible displays. Therefore, in recent years, a method of applying a polyimide film using a polyimide resin as a transparent member of a flexible device instead of glass has been disclosed in, for example, US Pat. No. 8,207,256 and Japanese Patent Application Laid-Open No. 2008-163309. ..
  • a polyimide precursor solution is applied onto a support, for example, a metal support, the solvent in the polyimide precursor solution is removed, and then the film is peeled off from the support as an autonomous film. Then, the obtained autonomous film is heated to imidize and produced, or a polyimide precursor solution is applied to a support and then heated to remove the solvent in the solution, and the polyimide precursor is imide.
  • a method of obtaining the film as an autonomous film by peeling it from the support a method of applying a polyimide solution to the support, removing the solvent in the solution, and then peeling it from the support as an autonomous film. ing.
  • the polyimide film obtained from the polyimide composition having the constitution disclosed in Patent Document 1 has a problem that the compatibility between the polyimide resin and the heterocyclic compound is poor and the formed film becomes cloudy. ..
  • Patent Document 2 a method for producing a polyimide film using a polyimide-based varnish containing a polyimide-based polymer, an organic solvent, and water is disclosed (see, for example, Patent Document 2).
  • a film having a good appearance and flexibility can be obtained by containing water in the range of 0.60 to 4.5% by mass in a polyimide varnish. ing.
  • Patent Document 2 has a high water content in the polyimide varnish and causes cloudiness.
  • the present invention has been made in view of the above problems and situations, and a solution thereof is to provide a method for producing an optical film and an optical film having excellent transparency and peelability during film formation.
  • the present inventor has prepared a dope containing at least a polyimide resin, an organic solvent, water and an anionic water orientation accelerator as a method for producing an optical film.
  • a dope containing at least a polyimide resin, an organic solvent, water and an anionic water orientation accelerator as a method for producing an optical film.
  • a method for producing an optical film containing at least a polyimide resin It is a method of producing by controlling the distribution state of the anionic water orientation accelerator by using a dope containing at least a polyimide resin, an organic solvent, water and an anionic water orientation accelerator.
  • a secondary ionic strength distribution curve derived from the anionic water orientation accelerator detected using a time-of-flight secondary ion mass spectrometer (TOF-SIMS) is created in the thickness direction of the optical film.
  • the region S (%) in the film thickness direction in which the secondary ion intensity is 50% or more of the maximum value M with respect to the maximum value M of the secondary ion intensity distribution curve is in the range of 50 to 90% of the total film thickness.
  • a method for producing an optical film which comprises producing under the conditions inside.
  • it contains an anionic water orientation accelerator
  • a secondary ionic strength distribution curve derived from the anionic water orientation accelerator detected using a time-of-flight secondary ion mass spectrometer (TOF-SIMS) is created in the thickness direction of the optical film
  • the region S (%) in the film thickness direction in which the secondary ion intensity is 50% or more of the maximum value M with respect to the maximum value M of the secondary ion intensity distribution curve is in the range of 50 to 90% of the total film thickness.
  • the polyimide resin has an acyclic group having an electron-withdrawing property in the side chain, or a cyclo ring, -CO-, -SO 2- , or -CR- (R represents a fluorene skeleton) in the main chain.
  • the water is oriented to the surface of the polyimide film during peeling to promote the peeling, but the water remaining on the surface of the polyimide film is dried. Since it volatilizes, it does not contribute to the white turbidity of the finally produced polyimide film, and it is considered that the formation of the uneven structure on the surface of the polyimide film due to the volatilization of water also contributes to the improvement of transportability.
  • the present inventor paid attention to the interaction between the polyimide resins and the interaction between the support used during film formation, for example, the metal support and the polyimide resin.
  • the anionic group which is a hydrophilic group of the anionic water alignment accelerator, forms a network with highly polar water. Therefore, it is considered that the dissolution energy is supplemented.
  • the formed network can weaken the interaction between the polyimide resins and, as a result, increase the probability of water presence in the entire polyimide film.
  • At least a dope containing a polyimide resin, an organic solvent, water and an anionic water orientation accelerator is used to control the distribution state of the anionic water orientation accelerator.
  • TOF-SIMS time-of-flight secondary ion mass spectrometer
  • the use of an aqueous solution of an anionic water orientation accelerator having a concentration in the range of 5 to 50% by mass can control the water content in the dope within a desired range.
  • the concentration is in the range of 10 to 40% by mass, and even more preferably, the concentration is in the range of 10 to 30% by mass.
  • the water content in the dope is in the range of 0.05 to 0.5% by mass with respect to 100% by mass of the polyimide resin. It is preferable in that a secondary ionic strength distribution curve can be obtained. It is more preferably in the range of 0.1 to 0.5% by mass, and even more preferably in the range of 0.3 to 0.5% by mass.
  • the optical film containing the polyimide resin of the present invention further contains an anionic water orientation accelerator, and a time-of-flight secondary ion mass spectrometer (TOF-SIMS) is used in the thickness direction of the optical film.
  • TOF-SIMS time-of-flight secondary ion mass spectrometer
  • the polyimide resin has an acyclic group having an electron-withdrawing property in the side chain, or a cyclo ring, -CO-, -SO 2- , or -CR- (R) in the main chain. Represents a fluorene skeleton.) It is preferable to have at least one of them in terms of excellent colorless transparency.
  • Optical film In the method for producing an optical film of the present invention, at least a dope containing a polyimide resin, an organic solvent, water and an anionic water alignment accelerator is used, and the distribution state of the anionic water alignment accelerator is controlled to produce an optical film. It is characterized by being manufactured.
  • an anionic water orientation accelerator detected using a time-of-flight secondary ion mass spectrometer (TOF-SIMS) as a composition profile in the layer of the optical film to be produced.
  • TOF-SIMS time-of-flight secondary ion mass spectrometer
  • the region S in the film thickness direction in which the secondary ionic strength is 50% or more of the maximum value M with respect to the maximum value M of the secondary ionic strength distribution curve is characterized in that it is produced under the condition that (%) is in the range of 50 to 90% of the total film thickness.
  • a dope containing at least a polyimide resin, an organic solvent, water and an anionic water orientation accelerator (hereinafter, also referred to as "resin-based varnish") is used in the film forming step.
  • a polyimide film (also referred to as a web) is formed by casting on a body, for example, an endless metal belt, and in a drying step, an organic solvent or an organic solvent is used so as to have a predetermined residual solvent amount in the polyimide film. After removing water, it is peeled off from a metal belt to prepare a polyimide film which is an optical film.
  • the present invention by adding an anionic water orientation accelerator to the dope containing the polyimide resin, more water is oriented to the surface using the anionic water orientation accelerator as a medium.
  • the amount of the anionic water alignment accelerator oriented to the film surface by the anionic water alignment accelerator and the water associated therewith increases, and the peelability between the metal belt and the polyimide film is improved.
  • the present invention as a method for confirming the above characteristics, it is derived from an anionic water orientation accelerator in the thickness direction of an optical film detected by using a time-of-flight secondary ion mass spectrometer (TOF-SIMS).
  • TOF-SIMS time-of-flight secondary ion mass spectrometer
  • the region S defined in the present invention is in the film thickness direction in which the secondary ionic strength is 50% or more of the maximum value M with respect to the maximum value M of the secondary ionic strength distribution curve measured by the following method for the polyimide film. In the area (film thickness) of, it is displayed as a ratio when the total thickness is 100%.
  • FIG. 1A and 1B are graphs showing an example of the range of the region S (%) with respect to the maximum value M in the secondary ion concentration distribution curve
  • FIG. 1A is the polyimide film of the present invention in which water is present at the time of film formation. It is a distribution curve of the secondary ion intensity of the resin component (broken line) and the water orientation accelerator (solid line) in the film thickness direction
  • FIG. 1B shows the distribution curve in the film thickness direction of the polyimide film in the comparative example in which water does not exist at the time of film formation. It is a distribution curve of the secondary ion strength of the resin component and the water orientation accelerator.
  • the region S (%) is the secondary ionic strength that is 50% of the maximum value M (secondary ionic strength: 0.26) in the distribution curve of the secondary ionic strength of the water orientation accelerator shown by the solid line in FIG. 1A.
  • the value of the ratio of the film thickness when the total layer thickness is 100% is defined as the region S (%).
  • the region S shown in FIG. 1A is a water orientation in which the secondary ionic strength is 50% or more of the maximum value M up to the vicinity of the film surface with respect to FIG. 1B of the comparative example in which the film is formed under the condition of not containing water, which is a comparative example. It can be seen that the region where the accelerator and water are present is formed.
  • the surface composition is measured while etching in the depth direction from the surface.
  • examples thereof include a method of cutting out a cross section of a polyimide film and measuring the secondary ion intensity distribution while scanning the thickness direction of the cross section. In the present invention, the latter method is preferably used.
  • the produced polyimide film is cut to a predetermined size, then embedded in an epoxy-embedded resin for pretreatment, the resin is cured, and then the thickness for measurement is measured by an ultramicrotome equipped with a diamond knife. An ultrathin section of about 100 nm is made.
  • the secondary ion intensity of each component was measured with respect to the film cross section of the prepared ultrathin section using a time-of-flight secondary ion mass spectrometer (TOF-SIMS), and the horizontal axis is the depth direction of the polyimide film.
  • the measurement position ( ⁇ m) in the (thickness direction) is plotted on the vertical axis by plotting the secondary ion intensity derived from the polyimide resin and the anionic water orientation accelerator to create a secondary ion intensity distribution curve.
  • region S (%) when the total film thickness of the polyimide film is 100%, a region (film thickness) of 50% or more of the maximum value M of the secondary ionic strength derived from the anionic water orientation accelerator. Range) is obtained, and this is defined as region S (%).
  • ionic strength in the film thickness direction from the viewpoint of ensuring smoothing of the measurement data, eliminating noise of the data that appears specifically, and improving the accuracy of the measurement data, it is 1 ⁇ m in the thickness direction.
  • the secondary ionic strength was measured at 5 points within the range, the average value was obtained, and this was taken as the ionic strength at the thickness position (center film thickness position).
  • TFS-2100 TRIFT2 manufactured by Physical Electricals, USA Measurement condition; Primary ion species: Ga (+) ion Primary ion energy: 25 kV Primary ion current (DC): 1 nA Pulse width: ⁇ 10ns Hunting: Uncharged neutralization: Time resolution: 0.138ns / ch Secondary ion polarity: Negative mass range (M / z): 0.5 to 2000 Raster size: 100 ⁇ m Measurement time: 20 minutes Energy filter: No contrast diaphragm: # 0 Position detector: Raster Post-stage acceleration: 5kV Sample cooling temperature: -100 ° C
  • a method for controlling a region S (%) in the film thickness direction in which the secondary ionic strength defined in the present invention is 50% or more of the maximum value M within a range of 50 to 90% of the total film thickness Specifically, a method of applying a water-soluble anionic water orientation accelerator, and adjusting the concentration of the applied anionic water orientation accelerator aqueous solution, that is, the content of water in the dope to a predetermined condition. It can be achieved by such means.
  • the more preferable range of the region S (%) defined in the present invention is in the range of 55 to 80%, and more preferably in the range of 60 to 75%.
  • the method for producing a polyimide film which is an optical film of the present invention, is characterized by using a dope containing at least a polyimide resin, an organic solvent, water, and an anionic water orientation accelerator.
  • polyimide resin The polyimide used in the optical film of the present invention (hereinafter, also referred to as "polyimide film of the present invention") is a transparent heat-resistant resin having an imide structure (hereinafter, also referred to as a polyimide resin), and has an imide bond in a repeating unit. It is a transparent heat-resistant resin containing.
  • the polyimide film of the present invention contains polyamic acid or polyimide.
  • the polyamic acid or polyimide is preferably formed from a diamine or a derivative thereof and an acid anhydride or a derivative thereof.
  • the polyimide resin according to the present invention includes an acyclic group having an electron-withdrawing property in the side chain, or a cyclo ring in the main chain, -CO-, -SO 2- , or -CR- (R is fluorene). It is characterized by having at least one of (representing a skeleton).
  • the "main chain” means the longest linearly bonded molecular chain portion.
  • the “side chain” is a molecular chain branched from the main chain and refers to a portion other than the main chain.
  • Examples of the electron-withdrawing acyclic group include a cyano group, a trifluoromethyl group, a halogen atom, a carbonyl group which may be substituted, a sulfonyl group which may be substituted, and a boryl which may be substituted.
  • Examples thereof include a whole oxide ring and a carbolin ring.
  • cyclo ring examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, decalin, adamantyl, cyclohexenyl and the like.
  • polyimide having an electron-withdrawing property in the side chain, or at least one of a cyclo ring, -CO-, -SO 2- , or -CR- (R represents a fluorene skeleton) in the main chain.
  • polyimide according to the present invention include the following polyimides A to K.
  • a polyimide having a repeating unit represented by the following general formula (1.1) is particularly preferable.
  • R is an aromatic hydrocarbon ring or an aromatic heterocycle, or a tetravalent aliphatic hydrocarbon group having 4 to 39 carbon atoms or an alicyclic hydrocarbon group (cyclo ring).
  • ⁇ is a divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms, an alicyclic hydrocarbon group (cyclo ring), an aromatic hydrocarbon group, or a group consisting of a combination thereof, and as a bonding group, Group consisting of -O-, -SO 2- , -CO-, -CH 2- , -C (CH 3 ) 2- , -OSi (CH 3 ) 2- , -C 2 H 4 O- and -S- It may contain at least one group selected from.
  • Examples of the aromatic hydrocarbon ring represented by R include a fluorene ring, a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, a naphthalene ring, a triphenylene ring, o-.
  • Terphenyl ring m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronen ring, fluorantrene ring, naphthalene ring, pentacene ring, perylene ring, pentaphene ring, picene ring, pyrene ring, pyranthrene ring, anthra entre Benzene ring and the like.
  • examples of the aromatic heterocycle represented by R include a silol ring, a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and an oxadi ring.
  • Azol ring triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzthiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, thienothiophene ring, carbazole ring, azacarbazole ring (carbazole ring, azacarbazole ring) Any one or more of the carbon atoms constituting the carbazole ring are replaced with nitrogen atoms.), Dibenzosilol ring, dibenzofuran ring, dibenzothiophene ring, benzothiophene ring or any carbon atom constituting the dibenzofuran ring.
  • Examples of the tetravalent aliphatic hydrocarbon group having 4 to 39 carbon atoms represented by R include butane-1,1,4,4-triyl group and octane-1,1,8,8-triyl group. Examples include groups such as decan-1,1,10,10-triyl groups.
  • Examples of the tetravalent alicyclic hydrocarbon group having 4 to 39 carbon atoms represented by R include cyclobutane-1,2,3,4-tetrayl group and cyclopentane-1,2,4,5. -Tetrayl group, cyclohexane-1,2,4,5-tetrayl group, bicyclo [2.2.2] octo-7-en-2,3,5,6-tetrayl group, bicyclo [2.2.2] Octane-2,3,5,6-tetrayl group, 3,3', 4,4'-dicyclohexyltetrayl group, 3,6-dimethylcyclohexane-1,2,4,5-tetrayl group, 3,6- Examples thereof include groups such as diphenylcyclohexane-1,2,4,5-tetrayl groups.
  • Examples of the divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms having or not having the above-mentioned bonding group represented by ⁇ include a group represented by the following structural formula.
  • n represents the number of repeating units, preferably 1 to 5, and more preferably 1 to 3.
  • X is an alkanediyl group having 1 to 3 carbon atoms, that is, a methylene group, an ethylene group, a trimethylene group and a propane-1,2-diyl group, and among them, a methylene group is preferable.
  • Examples of the divalent alicyclic hydrocarbon group having 2 to 39 carbon atoms having or not having the above-mentioned bonding group represented by ⁇ include a group represented by the following structural formula.
  • Examples of the divalent aromatic hydrocarbon group having 2 to 39 carbon atoms having or not having the above-mentioned bonding group represented by ⁇ include a group represented by the following structural formula.
  • Examples of the group composed of a combination of an aliphatic hydrocarbon group represented by ⁇ , an alicyclic hydrocarbon group and an aromatic hydrocarbon group include a group represented by the following structural formula.
  • the group represented by ⁇ is preferably a divalent aromatic hydrocarbon group having 2 to 39 carbon atoms having a bonding group, or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group, particularly.
  • a group represented by the following structural formula is preferable.
  • the acid anhydride used in the present invention is a carboxylic acid anhydride, preferably a derivative of an aliphatic or alicyclic tetracarboxylic acid, for example, an aliphatic or alicyclic tetracarboxylic acid ester, an aliphatic or an alicyclic tetracarboxylic acid ester.
  • Aliphatic tetracarboxylic dianhydride and the like can be mentioned.
  • an alicyclic tetracarboxylic dianhydride is preferable.
  • the derivative is a compound that can be changed to an aliphatic or alicyclic tetracarboxylic acid.
  • an aliphatic tetracarboxylic acid dianhydride a compound having two carboxy groups instead of the anhydride.
  • a compound in which one or both of these two carboxy groups are esterified, or an acid chloride in which one or both of these two carboxy groups are chlorinated is preferably used.
  • Examples of the aliphatic tetracarboxylic acid include 1,2,3,4-butanetetracarboxylic acid.
  • Examples of the alicyclic tetracarboxylic acid include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, and 1,2,4,5-cyclohexanetetracarboxylic acid.
  • Bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic acid Bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, etc. Can be mentioned.
  • Examples of the aliphatic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above aliphatic tetracarboxylic acids.
  • Examples of the alicyclic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the alicyclic tetracarboxylic acids.
  • the alkyl group moiety is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.
  • Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride.
  • Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 1,2. , 4,5-Cyclohexanetetracarboxylic dianhydride, Bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, Bicyclo [2.2.2] Examples thereof include octane-2,3,5,6-tetracarboxylic dianhydride.
  • 1,2,4,5-cyclohexanetetracarboxylic dianhydride is particularly preferred.
  • polyimide containing an aliphatic diamine as a constituent component polyamic acid and diamine, which are intermediate products, form a strong salt. Therefore, in order to increase the molecular weight, a solvent having a relatively high salt solubility, for example, It is preferable to use cresol, N, N-dimethylacetamide, ⁇ -butyrolactone, N-methyl-2-pyrrolidone and the like.
  • 4,4'-biphthalic anhydride 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic hydride, 4- (2,2) 5-Dioxo tetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic hydride, 3,3', 4,4'-diphenylsulfonetetracarboxylic hydride, 3,4'-oxydiphthal
  • an acid anhydride having a fluorene skeleton or a derivative thereof may be used. It has the effect of improving the coloring peculiar to polyimide.
  • the acid anhydride having a fluorene skeleton include 9,9-bis (3,4-dicarboxyphenyl) fluorenic dianhydride and 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl. ] Fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-phenylphenyl] fluorenic dianhydride and the like can be used.
  • Aromatic, aliphatic or alicyclic tetracarboxylic acid or a derivative thereof may be used alone or in combination of two or more. Further, another tetracarboxylic acid or a derivative thereof (particularly, dianhydride) may be used in combination as long as the solvent solubility of the polyimide, the flexibility of the film, the thermocompression bonding property, and the transparency are not impaired.
  • tetracarboxylic acids or derivatives thereof include pyromellitic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4'-biphenyltetracarboxylic acid, 2, 2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1 , 3,3,3-hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, bis (3,4-dicarboxyphenyl) Phenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, bis (2,3-dicarboxyphenyl) ether, 3,3', 4,4'-benzophenone tetracarboxylic acid, 2,2'
  • the repeating unit represented by the general formula (1.1) is preferably in the range of 10 to 100 mol%, more preferably in the range of 50 to 100 mol%, with respect to all the repeating units. It is more preferably in the range of 80 to 100 mol%, and particularly preferably in the range of 90 to 100 mol%.
  • the number of repeating units of the general formula (1.1) in one molecule of polyimide is in the range of 10 to 2000, preferably in the range of 20 to 200, and in this range, the glass transition temperature is further increased.
  • the temperature is preferably in the range of 230 to 350 ° C, more preferably in the range of 250 to 330 ° C.
  • ⁇ 1.1.2 Structure on the diamine side>
  • aromatic diamine or isocyanic acid ester is preferable, and aromatic diamine is preferable.
  • the diamine or a derivative thereof used in the present invention may be any of aromatic diamines, aliphatic diamines or mixtures thereof, and aromatic diamines are preferable from the viewpoint of suppressing whitening of the film.
  • the "aromatic diamine” represents a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or the like is part of the structure thereof. It may contain a substituent (for example, a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.).
  • the "aliphatic diamine” represents a diamine in which an amino group is directly bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group or other substituent (a part of the structure thereof) is used. For example, it may contain a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.).
  • aromatic diamines include, for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, benzidine, o-trizine, m-trizine, bis (trifluoromethyl).
  • aliphatic diamine examples include ethylenediamine, hexamethylenediamine, polyethylene glycol bis (3-aminopropyl) ether, polypropylene glycol bis (3-aminopropyl) ether, 1,3-bis (aminomethyl) cyclohexane, and 1,4.
  • a diamine having a fluorene skeleton or a derivative thereof may be used for the purpose of improving the coloring peculiar to polyimide.
  • a diamine compound having a triazine mother nucleus represented by the following structural formula can be preferably used.
  • R 1 represents a hydrogen atom and an alkyl group or an aryl group having 1 to 12 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms).
  • R 2 represents an alkyl group or an aryl group having 1 to 12 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), and R 1 and R 2 may be different and are the same. There may be.
  • alkyl or aryl group having 1 to 12 carbon atoms of R 1 and R 2 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, phenyl, benzyl, naphthyl, methylphenyl, and biphenyl. And so on.
  • the aminoanilino group connected to the two NH groups of triazine is 4-aminoanilino or 3-aminoanilino, which may be the same or different, but 4-aminoanilino is preferable.
  • diamine compound having a triazine matrix and represented by the above formula examples include 2,4-bis (4-aminoanilino) -6-anilino-1,3,5-triazine and 2,4-bis (3).
  • -Aminoanilino) -6-anilino-1,3,5-triazine 2,4-bis (4-aminoanilino) -6-benzylamino-1,3,5-triazine
  • 2,4-bis (4-aminoanilino) -6 -Biphenylamino-1,3,5-triazine 2,4-bis (4-aminoanilino) -6-diphenylamino-1,3,5-triazine
  • Examples of the isocyanic acid ester which is a diamine derivative include diisocyanate obtained by reacting the above aromatic or aliphatic diamine with phosgene.
  • Examples of other diamine derivatives include diaminodisilanes, and examples thereof include trimethylsilylated aromatic or aliphatic diamines obtained by reacting the above aromatic or aliphatic diamines with chlorotrimethylsilane.
  • the above diamines and their derivatives may be arbitrarily mixed and used, but the amount of diamines in them is preferably 50 to 100 mol%, more preferably 80 to 100 mol%.
  • the polyimide contained in the polymer blend composition has an acyclic group having an electron-withdrawing property in the side chain, or a cyclo ring, -CO-, -SO 2- , or a main chain in the main chain.
  • -CR- R represents a fluorene skeleton
  • the difference between the maximum weight average molecular weight and the minimum weight average molecular weight of the two or more types of polyimides is 20000 to 200,000. It is preferably within the range, and is appropriately selected from the above-mentioned diamine or a derivative thereof and an acid anhydride or a derivative thereof so as to form the polyimide according to the present invention.
  • anionic water orientation accelerator examples include the following compounds, for example, higher alcohol (8 to 22 carbon atoms) sulfate ester salts (for example, sodium salt of lauryl alcohol sulfate, etc.).
  • Alkylamide sulfonates eg, C 17 H 33 CON (CH 3 ) CH 2 SO 3 Na, etc.
  • dibasic fatty acid ester sulfonates eg, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate) Acid dihexyl ester, etc.
  • sulfates and sulfonates are particularly preferably used.
  • a phosphate ester-based water orientation promoter a carboxylic acid or carboxylic acid salt-based water orientation promoter, a sulfonic acid or sulfonate-based water orientation promoter, and a sulfate ester-based water.
  • Orientation promoters are effective.
  • a fluorine-based water orientation accelerator in which a part of hydrogen atoms bonded to the hydrocarbon chain of the anionic water orientation accelerator is replaced with a fluorine atom is also effective. Specific compounds RZ-1 to RZ-18 of the anionic water orientation accelerator are shown below.
  • the optical film of the present invention is a polymer film containing the polymer blend composition, and preferably has a yellow index value of 5.0 or less.
  • the yellow index (YI) value of the polymer film of the present invention is preferably in the range of 0.2 to 2.0. The smaller the yellow index value, the less the coloring, which is preferable.
  • the yellow index value can be adjusted by selecting the composition of polyimide, and in order to reduce the yellow index value to 5.0 or less, it is preferable to use a monomer having an electron-withdrawing group.
  • the yellow index value can be obtained according to the YI (yellow index: yellowish index) of the film defined in JIS K7103.
  • a sample of a polymer film is prepared, and it is defined in JIS Z8701 using a spectrophotometer U-3300 of Hitachi High-Technologies Corporation and an attached saturation calculation program.
  • the tristimulus values X, Y, and Z of the light source color are obtained, and the yellow index value is obtained according to the definition of the following equation.
  • the polymer film of the present invention preferably has a haze of 1% or less, more preferably 0.5% or less.
  • Haze (all haze) can be measured using a haze meter, for example, NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K-7136.
  • the polymer film of the present invention is preferably long, specifically, preferably in the range of about 100 to 10000 m, and is in the form of a roll. It is taken up by.
  • the width of the polymer film of the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably in the range of 1.4 to 4 m.
  • the film thickness is preferably in the range of 1 to 200 ⁇ m from the viewpoint of strength and transparency as a flexible printed circuit board.
  • the film thickness is 1 ⁇ m or more, the film strength required for an optical film can be exhibited.
  • the film substrate can be provided with flexibility. In particular, it is preferably in the range of 1 to 100 ⁇ m.
  • Total light transmittance For the polymer film of the present invention, a sample having a thickness of 55 ⁇ m is prepared, and the total light transmittance is preferably 80% or more, more preferably 85% or more, 90. It is more preferably% or more. By setting the total light transmittance to 80% or more, there is an advantage that the range of application to various electronic devices as a film for optical applications is widened.
  • the total light transmittance of the film sample can be measured according to JIS K-7375 for the sample whose humidity has been adjusted for 24 hours in an air-conditioned room at 23 ° C. and 55 RH.
  • the polymer film of the present invention preferably contains the following additives in addition to the polymer blend composition.
  • the polyimide film of the present invention has, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, and hydration. It is preferable to contain inorganic fine particles such as calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate, and a matting agent such as a crosslinked polymer. Above all, silicon dioxide is preferable in that the haze of the film can be reduced.
  • the primary average particle size of the fine particles is preferably 20 nm or less, more preferably in the range of 5 to 16 nm, and particularly preferably in the range of 5 to 12 nm.
  • These fine particles preferably form secondary particles having a particle size in the range of 0.1 to 5 ⁇ m and are contained in the polyimide, and the average particle size is preferably in the range of 0.1 to 2 ⁇ m, more preferably. Is in the range of 0.2 to 0.6 ⁇ m. As a result, unevenness having a height of about 0.1 to 1.0 ⁇ m is formed on the film surface, whereby appropriate slipperiness can be imparted to the film surface.
  • the primary average particle size of the fine particles used in the present invention is measured by observing the particles with a transmission electron microscope (magnification: 500,000 to 2,000,000 times), observing 100 particles, measuring the particle size, and averaging the particles. The value is taken as the primary average particle size.
  • the polyimide film of the present invention contains an ultraviolet absorber from the viewpoint of improving light resistance.
  • the ultraviolet absorber is intended to improve the light resistance by absorbing ultraviolet rays of 400 nm or less, and in particular, the transmittance at a wavelength of 370 nm is preferably in the range of 0.1 to 30%. It is more preferably in the range of 1 to 20%, still more preferably in the range of 2 to 10%.
  • the UV absorbers preferably used in the present invention are benzotriazole-based UV absorbers, benzophenone-based UV absorbers, and triazine-based UV absorbers, and particularly preferably benzotriazole-based UV absorbers and benzophenone-based UV absorbers.
  • chinubins such as chinubin 928, all of which are commercially available products manufactured by BASF Japan Co., Ltd. and can be preferably used. Of these, halogen-free ones are preferable.
  • a disk-shaped compound such as a compound having a 1,3,5-triazine ring is also preferably used as an ultraviolet absorber.
  • the polyimide film of the present invention preferably contains two or more types of ultraviolet absorbers.
  • a polymer ultraviolet absorber can also be preferably used, and in particular, the polymer type ultraviolet absorber described in JP-A-6-148430 is preferably used. Moreover, it is preferable that the ultraviolet absorber does not have a halogen group.
  • the method of adding the ultraviolet absorber is to dissolve the ultraviolet absorber in an alcohol such as methanol, ethanol or butanol, an organic solvent such as dichloromethane, methyl acetate, acetone or dioxolane, or a mixed solvent thereof, and then add the ultraviolet absorber to the dope. It may be added directly into the dope composition.
  • an alcohol such as methanol, ethanol or butanol
  • an organic solvent such as dichloromethane, methyl acetate, acetone or dioxolane, or a mixed solvent thereof
  • inorganic powders that do not dissolve in organic solvents use a dissolver or sandmill in the organic solvent and polyimide film to disperse them before adding them to the dope.
  • the amount of the UV absorber used is not uniform depending on the type of UV absorber, usage conditions, etc., but when the dry film thickness of the polyimide film is 15 to 50 ⁇ m, it is 0.5 to 10% by mass with respect to the polyimide film. Is preferable, and the range of 0.6 to 4% by mass is more preferable.
  • Antioxidants are also called antioxidants. When an electronic device or the like is placed in a high humidity and high temperature state, the polyimide film may deteriorate, and an antioxidant is used to prevent these.
  • the function of the antioxidant is, for example, to delay or prevent the decomposition of the polyimide film due to the residual solvent amount of halogen in the polyimide film, phosphoric acid of the phosphoric acid-based plasticizer, or the like.
  • a hindered phenol-based compound is preferably used, and for example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3, 3,).
  • 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-T-Butyl-5-methyl-4-hydroxyphenyl) propionate] is preferable.
  • a hydrazine-based metal inactivating agent such as N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine or tris (2,4-di-).
  • a phosphorus-based processing stabilizer such as t-butylphenyl) phosphite may be used in combination.
  • the amount of these compounds added is preferably in the range of 1 ppm to 1.0% by mass with respect to the polyimide film, and more preferably in the range of 10 to 1000 ppm.
  • Phase difference control agent In order to improve the display quality of an image display device such as a liquid crystal display device, a retardation control agent is added to the polyimide film or an alignment film is formed to provide a liquid crystal layer for polarization. By combining the phase difference derived from the plate protective film and the liquid crystal layer, it is possible to impart optical compensation ability to the polyimide film.
  • phase difference control agent examples include aromatic compounds having two or more aromatic rings as described in European Patent No. 911656A2, rod-shaped compounds described in JP-A-2006-2025, and the like. Further, two or more kinds of aromatic compounds may be used in combination.
  • the aromatic ring of this aromatic compound is preferably an aromatic heterocycle containing an aromatic heterocycle in addition to the aromatic hydrocarbon ring.
  • Aromatic heterocycles are generally unsaturated heterocycles. Of these, the 1,3,5-triazine ring described in JP-A-2006-2026 is preferable.
  • the amount of these retardation control agents added is preferably in the range of 0.5 to 20% by mass and preferably in the range of 1 to 10% by mass with respect to 100% by mass of the polyimide film-based resin. More preferred.
  • the additive contained in the polyimide film of the present invention is not limited to the compounds described above.
  • Step of preparing an aqueous solution of anionic water orientation accelerator 2) A step of dissolving the above-mentioned polyamic acid or polyimide in a solvent to prepare a dope (dope preparation step). 3) A step of casting the dope onto a support to form a casting film (casting step).
  • the water content in the dope is preferably in the range of 0.05 to 0.5% by mass with respect to 100% by mass of the polyimide resin, and the water supply.
  • One of the sources is water contained in an aqueous solution of an anionic water orientation accelerator, but if necessary, if the water content in the above-mentioned dope is insufficient by itself, water is separately subjected to a dope preparation step. Is also preferably added to obtain the water content specified above.
  • the preferable range of the addition amount of the anionic water orientation accelerator aqueous solution is in the range of 0.1 to 1.0% by mass, and more preferably in the range of 0.3 to 0.7% by mass with respect to the polyimide resin. Is inside.
  • the low boiling point solvent it is preferable to use a low boiling point solvent having a boiling point of 80 ° C. or lower as the main solvent.
  • “used as the main solvent” means that 55% by mass or more is used with respect to the total amount of the solvent in the case of a mixed solvent, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably. Is to be used in an amount of 90% by mass or more. Of course, if used alone, it will be 100% by mass.
  • the low boiling point solvent may be any one that simultaneously dissolves polyimide, an anionic water orientation accelerator and other additives.
  • the chlorine-based solvent is dichloromethane
  • the non-chlorine-based solvent is methyl acetate or ethyl acetate.
  • examples of low boiling point solvents having a boiling point of 80 ° C. or lower include dichloromethane (40 ° C.), ethyl acetate (77 ° C.), methyl ethyl ketone (79 ° C.), tetrahydrofuran (66 ° C.), and acetone (56.5 ° C.).
  • at least one selected from 1,3-dioxolane (75 ° C.) is preferably contained as the main solvent.
  • the numerical values in parentheses represent the boiling points.
  • the solvent contained in the case of the mixed solvent as long as it can dissolve the polyimide according to the present invention, it can be used as long as the effect of the present invention is not impaired, and as a solvent other than those described above,
  • a solvent other than those described above For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylcaprolactam, hexamethylphosphoramide, tetra.
  • an alcohol solvent can be used. It is preferable that the alcohol solvent is selected from methanol, ethanol and butanol from the viewpoint of improving the peelability and enabling high-speed casting. Of these, it is preferable to use methanol or ethanol. Higher proportions of alcohol in the dope gels the web, facilitating delamination from the metal support.
  • a method performed at normal pressure a method performed below the boiling point of the main solvent, a method performed by pressurizing above the boiling point of the main solvent, JP-A-9-955544, JP-A-9-
  • Various melting methods can be used, such as the method performed by the cooling dissolution method described in JP-A-95557 or JP-A-9-95538, the method performed at high pressure described in JP-A-11-21379, and the like.
  • the prepared dope is guided to a filter by a liquid feed pump or the like and filtered.
  • the main solvent of the dope is dichloromethane
  • the gel-like foreign matter in the dope can be removed by filtering the dope at a temperature of + 5 ° C. or higher at a boiling point of the dichloromethane at 1 atm.
  • the preferred temperature range is 45 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably within the range of 45 to 55 ° C.
  • the main dope may contain a return material in the range of 10 to 50% by mass.
  • the return material is a part that is reused as a raw material for some reason. For example, it is a finely crushed polyimide film, and both side parts of the film are cut off, which is generated when the polyimide film is formed. Or, a polyimide film raw fabric that exceeds the specified value of the film due to scratches or the like is used.
  • the raw material of the resin used for the dope preparation those in which polyimide and other compounds are pelletized in advance can also be preferably used.
  • Casting film forming step The prepared dope is pumped onto a die through a liquid feed pump (eg, a pressurized metering gear pump) and transferred indefinitely on an endless support, such as a stainless steel belt or a metal support such as a rotating metal drum. Spread the dope from the die to the position.
  • a liquid feed pump eg, a pressurized metering gear pump
  • an endless support such as a stainless steel belt or a metal support such as a rotating metal drum.
  • the metal support in casting is preferably a mirror-finished surface, and the support is a stainless steel belt or a drum whose surface is plated with a casting, or a metal support such as a stainless steel belt or a stainless steel belt. Is preferably used.
  • the width of the cast can be in the range of 1 to 4 m, preferably in the range of 1.5 to 3 m, and more preferably in the range of 2 to 2.8 m.
  • the support does not have to be made of metal, for example, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film.
  • a belt such as polytetrafluoroethylene can be used.
  • the polyimide may be wound together with the metal support in which the polyimide is cast.
  • the transport speed of the metal support is not particularly limited, but is usually 5 m / min or more, preferably in the range of 10 to 180 m / min, and particularly preferably in the range of 80 to 150 m / min.
  • the higher the transport speed of the metal support the easier it is for companion gas to be generated, and the more remarkable the occurrence of film thickness unevenness due to disturbance.
  • the transport speed of the metal support is the moving speed of the outer surface of the metal support.
  • the surface temperature of the metal support is preferably higher because the drying rate of the casting film can be increased, but if it is too high, the casting film may foam or the flatness may deteriorate. , It is preferable to carry out at a temperature within the range of ⁇ 50 to ⁇ 10 ° C. with respect to the boiling point of the solvent used.
  • the die has a shape that gradually becomes thinner toward the discharge port in a cross section perpendicular to the width direction.
  • the die usually has tapered surfaces on the downstream side and the upstream side in the traveling direction of the lower portion, and a discharge port is formed in a slit shape between the tapered surfaces.
  • a metal die is preferably used, and specific examples thereof include stainless steel and titanium. In the present invention, when producing films having different thicknesses, it is not necessary to change to dies having different slit gaps.
  • the pressure die includes a coat hanger die, a T die, and the like, and any of them is preferably used. Even when films of different thicknesses are continuously produced, the discharge rate of the die is maintained at a substantially constant value. Therefore, when a pressure die is used, conditions such as extrusion pressure and shear rate are also omitted. It is maintained at a constant value. Further, in order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the doping amount may be divided and laminated.
  • the solvent evaporation step is a pre-drying step performed on a metal support, heating the cast film on the metal support, and evaporating the solvent.
  • a method of blowing heating air from the casting film side and the back side of the metal support with a dryer for example, a method of blowing heating air from the casting film side and the back side of the metal support with a dryer, a method of transferring heat from the back surface of the metal support with a heating liquid, and a method of transferring heat from the front and back by radiant heat. And so on. A method of appropriately selecting and combining them is also preferable.
  • the surface temperature of the metal support may be the same as a whole or may differ depending on the position.
  • the temperature of the heating air is preferably in the range of 10 to 220 ° C.
  • the solvent evaporation step it is preferable to dry the casting film until the residual solvent amount is in the range of 10 to 150% by mass from the viewpoint of the peelability of the casting film and the transportability after peeling.
  • the amount of residual solvent can be expressed by the following formula.
  • Residual solvent amount (mass%) ⁇ (MN) / N ⁇ x 100
  • M is the mass of the casting film (film) at a predetermined time point
  • N is the mass of M when it is dried at 200 ° C. for 3 hours.
  • M when calculating the residual solvent amount achieved in the solvent evaporation step is the mass of the cast film immediately before the peeling step.
  • the peeling tension when peeling the metal support and the casting film is usually in the range of 60 to 400 N / m, but if wrinkles are likely to occur during peeling, the metal support is peeled at a tension of 190 N / m or less. Is preferable.
  • the temperature at the peeling position on the metal support is preferably in the range of ⁇ 50 to 60 ° C., more preferably in the range of 10 to 40 ° C., and in the range of 15 to 40 ° C. Is the most preferable.
  • the peeled film may be sent directly to the stretching step, or may be sent to the stretching step after being sent to the first drying step so as to achieve a desired residual solvent amount.
  • the film is sequentially fed to the first drying step and the stretching step after the peeling step.
  • the first drying step is a drying step of heating the film and further evaporating the solvent.
  • the drying means is not particularly limited, and for example, hot air, infrared rays, a heating roller, microwaves, or the like can be used. From the viewpoint of convenience, it is preferable to dry the film with hot air or the like while transporting the film with rollers arranged in a staggered pattern.
  • the drying temperature is preferably in the range of 30 to 200 ° C. in consideration of the amount of residual solvent, the expansion / contraction rate during transportation, and the like.
  • the casting step is a step of stretching a film peeled from a metal support, and the film thickness, flatness, orientation, etc. of the film can be controlled.
  • the stretching operation in the casting process may be carried out in multiple stages. Further, when biaxial stretching is performed, simultaneous biaxial stretching may be performed, or biaxial stretching may be performed step by step.
  • stepwise means, for example, that stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any of the steps. Is also possible.
  • stretching steps are also possible: ⁇ Stretching in the longitudinal direction ⁇ Stretching in the width direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the width direction ⁇ Stretching in the width direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction ⁇ Stretching in the longitudinal direction
  • Stretching in the longitudinal direction also, for simultaneous biaxial stretching Also includes the case of stretching in one direction and contracting the other with relaxation of tension.
  • the amount of residual solvent at the start of stretching is preferably in the range of 0.1 to 200% by mass.
  • the amount of residual solvent at the start of stretching is 0.1% by mass or more, the effect of improving flatness by stretching can be obtained, and if it is 200% by mass or less, the film strength becomes high and stretching becomes easy.
  • the film may be stretched at least in the longitudinal direction or the width direction, preferably in the width direction so that the film thickness after stretching is within a desired range. It is preferable to stretch the film in a temperature range of (Tg-200) to (Tg + 100) ° C. with respect to the glass transition temperature (Tg) of the film. When stretched in the above temperature range, the stretching stress can be reduced, so that the haze of the obtained film is lowered. In addition, a polyimide film that suppresses the occurrence of breakage and is excellent in flatness and colorability of the film itself can be obtained.
  • the stretching temperature is more preferably in the range of (TgL-150) to (TgH + 50) ° C.
  • a self-supporting film peeled from a support can be stretched in the longitudinal direction by regulating the transport speed with a stretching roller.
  • the entire width of the film or a part of the drying treatment as shown in JP-A-62-46625 is performed in the width direction, and both ends of the width of the film are held by clips or pins.
  • a method of drying while doing so (called a tenter method), in particular, a tenter method using a clip is preferable.
  • the film stretched in the longitudinal direction or the unstretched film is introduced into the tenter with both ends in the width direction gripped by the clip, and is stretched in the width direction while traveling together with the tenter clip.
  • the film When stretching in the width direction, it is preferable to stretch the film at a stretching speed in the range of 50 to 1000% / min in the width direction from the viewpoint of improving the flatness of the film.
  • the stretching speed is 50% / min or more, the flatness is improved and the film can be processed at high speed, which is preferable from the viewpoint of production suitability.
  • the stretching speed is 1000% / min or less, the film breaks. It can be processed without any problem, which is preferable.
  • a more preferred stretching rate is in the range of 100-500% / min.
  • d 1 is the width dimension in the stretching direction of the resin film after stretching
  • d 2 is the width dimension in the stretching direction of the resin film before stretching
  • t is the time (min) required for stretching.
  • holding and relaxation are usually performed after stretching. That is, in the stretching step, it is preferable to perform a stretching step of stretching the film, a holding step of holding the film in a stretched state, and a relaxing step of relaxing the film in the stretching direction in these orders.
  • the stretching at the stretching ratio achieved in the stretching step is held at the stretching temperature in the stretching step.
  • the relaxation step the stretching in the stretching step is held in the holding step, and then the tension for stretching is released to relax the stretching.
  • the relaxation step may be performed under the conditions below the stretching temperature in the stretching step.
  • the stretched film is heated and dried.
  • a means for preventing the mixing of used hot air by installing a nozzle capable of exhausting used hot air is also preferably used.
  • the hot air temperature is preferably in the range of 40 to 220 ° C.
  • the drying time is preferably in the range of 5 seconds to 30 minutes, more preferably in the range of 10 seconds to 15 minutes.
  • the heating and drying means in the second drying step is not limited to hot air, and for example, infrared rays, heating rollers, microwaves, and the like can be used. From the viewpoint of convenience, it is preferable to dry the film with hot air or the like while transporting the film with rollers arranged in a staggered pattern.
  • the drying temperature is preferably in the range of 40 to 220 ° C. in consideration of the amount of residual solvent, the expansion / contraction rate during transportation, and the like.
  • the second drying step it is preferable to dry the film until the residual solvent amount becomes 0.5% by mass or less.
  • the winding process is a step of winding a film-formed film into a roll and cooling it to room temperature.
  • the winder may be one that is generally used, and can be wound by a winding method such as a constant tension method, a constant torque method, a taper tension method, or a program tension control method with a constant internal stress.
  • the thickness of the film is not limited to, for example, preferably in the range of 1 to 200 ⁇ m, and particularly preferably in the range of 1 to 100 ⁇ m.
  • both ends of the film sandwiched between the tenter clips and the like when stretched and conveyed may be slit and removed. It is preferable that the slit end of the film is finely cut within a width of 1 to 30 mm, then dissolved in a solvent and reused as a return material.
  • the ratio of the portion of the molded film that is reused as the return material is preferably in the range of 10 to 90% by mass, more preferably 20 to 80% by mass, and further preferably 30 to 70% by mass.
  • the input amount varies slightly depending on the amount of the return material generated during or finally in the film forming process, but usually, the mixing ratio of the return material with respect to the total solid content in the dope is about 10 to 50% by mass, preferably about 10 to 50% by mass. , It is in the range of about 15 to 40% by mass. It is preferable that the mixing ratio of the return material is as constant as possible in terms of production stability.
  • Each step from the solvent evaporation step to the winding step described above may be carried out in an air atmosphere or an inert gas atmosphere such as nitrogen gas. Further, each step, particularly the drying step and the stretching step, is carried out in consideration of the explosive limit concentration of the solvent in the atmosphere.
  • a step of slitting the widthwise end portion of the polyimide film, a step of removing static electricity from the polyimide film when it is charged, and the like may be further provided.
  • the polyimide film of the present invention can suppress warpage due to temperature and humidity environment fluctuations when laminated with an electronic device.
  • the applicable electronic device is not particularly limited, and examples thereof include an organic EL device, a liquid crystal display device (LCD), an organic photoelectric conversion device, a printed circuit board, a thin film transistor, a touch panel, a polarizing plate, and a retardation film. From the viewpoint that the effects of the present invention can be obtained more efficiently, it is preferably used for flexible printed circuit boards, LED lighting devices, and front members for flexible displays.
  • the flexible printed circuit board according to the present invention can be obtained by using the polyimide film of the present invention as a base film and pressure-bonding a metal foil to the base film with an adhesive.
  • the adhesive used here include acrylic adhesives, polyimide adhesives and epoxy adhesives.
  • the metal foil that is thermocompression-bonded to the polyimide film via an adhesive is preferably a copper foil from the viewpoint of cost reduction, but other metal foils such as aluminum, gold, silver, nickel, and tin may also be used.
  • the LED lighting device according to the present invention is not particularly limited as long as the LED substrate using the polyimide film of the present invention is used, and examples thereof include a double-sided substrate and a composite substrate with an aluminum plate. When higher heat dissipation is required due to the increase in brightness of the LED, it is possible to improve the heat dissipation by combining it with an aluminum plate. It can also be applied to an organic electroluminescence illuminator using an organic material.
  • the front member for a flexible display according to the present invention is not particularly limited as long as it is made of the polyimide film of the present invention.
  • the flexible display on which the front member for a flexible display according to the present invention is mounted includes, for example, an organic EL device in which an organic functional layer such as a light emitting layer is laminated on a substrate, a gas barrier film, a film color filter, one side or both sides.
  • a polarizing plate provided with a polarizing plate protective film, a film-type touch sensor, and the like are laminated in this order.
  • the front member for a flexible display of the present invention is laminated on, for example, a film-type touch sensor of a flexible display configured as described above.
  • the polyimide film of the present invention may be used as a substrate for an organic EL device constituting the flexible display, or may be used as a polarizing plate protective film for a polarizing plate constituting the flexible display.
  • Dope 1 having the following composition was prepared. First, dichloromethane (boiling point 40 ° C.) was added as solvent 2 to the pressure dissolution tank. Next, the polyimide AI1 and the remaining components prepared above were charged into the pressure dissolution tank containing the solvent 2 with stirring. This is heated and completely dissolved while stirring, and this is Azumi Filter Paper No. 1 manufactured by Azumi Filter Paper Co., Ltd. Filtration was performed using 244 to prepare Dope 1.
  • the amount of the anionic water orientation accelerator A1 aqueous solution (concentration: 10% by mass, anionic A1) added to the polyimide PI1 was 0.55% by mass, and the solvent was added to 100 parts by mass of the polyimide PI1.
  • the water content ratio of 1 is 0.495% by mass.
  • the peeled polyimide film was stretched 1.50 times in the width direction using a clip-type tenter while applying heat at 200 ° C.
  • the amount of residual solvent at the start of stretching was 20% by mass.
  • polyimide film 4 In the preparation of the polyimide film 2, the polyimide film 4 was prepared in the same manner except that the water orientation accelerator used in the preparation of the dope was changed to the nonionic water orientation accelerator N1 aqueous solution.
  • polyimide film 6 In the preparation of the polyimide film 2, the polyimide film 6 was prepared in the same manner except that the anionic water alignment accelerator A1 used in the preparation of the dope was used and the anionic water orientation accelerator A2 (anionic A2) was used. did.
  • polyimide film 7 In the preparation of the polyimide film 2, the polyimide film 7 was prepared in the same manner except that the polyimide PI2 prepared by the following method was used instead of the polyimide PI1 used in the preparation of the dope.
  • the content ratio of water as solvent 1 to 100 parts by mass of polyimide PI1 in the dope used for producing the polyimide film 8 is 0.08% by mass, and 100% by mass of polyimide PI1 in the dope used for producing the polyimide film 9.
  • the content ratio of water as solvent 1 to the portion is 0.24% by mass.
  • the secondary ion strength of each component was measured with respect to the film cross section of the prepared ultrathin section using a time-of-flight secondary ion mass spectrometer (TOF-SIMS), and the horizontal axis is the depth direction of the polyimide film.
  • TOF-SIMS time-of-flight secondary ion mass spectrometer
  • a secondary ionic strength distribution curve was created by plotting the secondary ionic strength derived from the polyimide resin and the anionic water orientation accelerator on the measurement position ( ⁇ m) and the vertical axis.
  • the range of 1 ⁇ m in the thickness direction is used from the viewpoint of ensuring smoothing of the measurement data, eliminating noise of the data that appears specifically, and improving the accuracy of the measurement data.
  • the secondary ionic strength was measured at 5 points in the room, the average value was obtained, and this was taken as the ionic strength at the thickness position (center film thickness position).
  • the specific measurement conditions are as follows.
  • ⁇ measuring device TFS-2100 TRIFT2 manufactured by Physical Electricals, USA ⁇ Measurement condition; Primary ion species: Ga (+) ion Primary ion energy: 25 kV Primary ion current (DC): 1 nA Pulse width: ⁇ 10ns Hunting: Uncharged neutralization: Time resolution: 0.138ns / ch Secondary ion polarity: Negative mass range (M / z): 0.5 to 2000 Raster size: 100 ⁇ m Measurement time: 20 minutes Energy filter: No contrast diaphragm: # 0 Position detector: Raster Post-stage acceleration: 5kV Sample cooling temperature: -100 ° C
  • peelability In the manufacturing process of each polyimide film by the solution casting method, the peelability in the peeling step and the presence or absence of horizontal steps on the surface of the polyimide film immediately before the winding step are visually observed, and the peelability is evaluated according to the following criteria. It was. ⁇ : Peeling is good and no horizontal steps are observed. ⁇ : Peeling is good, but slight horizontal steps are observed, but the quality is good. ⁇ : Catch is generated during peeling. Although some horizontal rows are generated, the quality is practically acceptable. ⁇ : There is a strong catch at the time of peeling, and many strong horizontal rows are generated, which is a quality that poses a problem in practical use.
  • the haze of each polyimide film was measured using a haze meter NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K-7136, and evaluated according to the following criteria.
  • the light source of the haze meter was a 5V9W halogen bulb, and the light receiving part was a silicon photocell (with a luminosity filter).
  • the haze was measured under the conditions of 23 ° C. and 55% RH.
  • Haze Haze is 0.3% or more and less than 0.5%
  • Results obtained by haze of 0.5% or more are shown in Table I.
  • the polyimide films of the present invention in which the region S (%) with respect to the maximum value M of the moving average graph in the thickness direction of the polyimide film is in the range of 50 to 90% are compared.
  • the peelability from the support during film formation is excellent, the haze is low, and the transparency is excellent.
  • an optical film having excellent transparency and peelability during film formation can be obtained, and an organic EL device, a liquid crystal display device (LCD), and an organic photoelectric conversion device can be obtained.
  • Organic EL device a liquid crystal display device (LCD)
  • LCD liquid crystal display
  • organic photoelectric conversion device a photoelectric conversion device

Landscapes

  • Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
PCT/JP2020/010488 2019-03-26 2020-03-11 光学フィルムの製造方法及び光学フィルム WO2020195819A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2021508995A JPWO2020195819A1 (enrdf_load_stackoverflow) 2019-03-26 2020-03-11

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019-057686 2019-03-26
JP2019057686 2019-03-26

Publications (1)

Publication Number Publication Date
WO2020195819A1 true WO2020195819A1 (ja) 2020-10-01

Family

ID=72608701

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/010488 WO2020195819A1 (ja) 2019-03-26 2020-03-11 光学フィルムの製造方法及び光学フィルム

Country Status (3)

Country Link
JP (1) JPWO2020195819A1 (enrdf_load_stackoverflow)
TW (1) TWI794598B (enrdf_load_stackoverflow)
WO (1) WO2020195819A1 (enrdf_load_stackoverflow)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015165491A (ja) * 2014-02-06 2015-09-17 三菱化学株式会社 有機電界発光素子及びその製造方法
JP2015178541A (ja) * 2014-03-18 2015-10-08 富士ゼロックス株式会社 ポリイミド前駆体組成物、ポリイミド成形体の製造方法、及びポリイミド成形体
WO2016027825A1 (ja) * 2014-08-20 2016-02-25 東京応化工業株式会社 多孔質ポリイミド膜製造用ワニス及びそれを用いた多孔質ポリイミド膜の製造方法
JP2016075894A (ja) * 2014-10-02 2016-05-12 コニカミノルタ株式会社 光学フィルム、その製造方法、フレキシブルプリント基板及びｌｅｄ照明
WO2017051827A1 (ja) * 2015-09-24 2017-03-30 旭化成株式会社 ポリイミド前駆体、樹脂組成物および樹脂フィルムの製造方法
JP2019023249A (ja) * 2015-12-11 2019-02-14 コニカミノルタ株式会社 ポリイミドフィルム、フレキシブルプリント基板、ｌｅｄ照明装置及びフレキシブルディスプレイ用前面部材

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9650543B2 (en) * 2014-03-18 2017-05-16 Fuji Xerox Co., Ltd. Polyimide precursor composition, method for manufacturing polyimide molded body, and polyimide molded body

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015165491A (ja) * 2014-02-06 2015-09-17 三菱化学株式会社 有機電界発光素子及びその製造方法
JP2015178541A (ja) * 2014-03-18 2015-10-08 富士ゼロックス株式会社 ポリイミド前駆体組成物、ポリイミド成形体の製造方法、及びポリイミド成形体
WO2016027825A1 (ja) * 2014-08-20 2016-02-25 東京応化工業株式会社 多孔質ポリイミド膜製造用ワニス及びそれを用いた多孔質ポリイミド膜の製造方法
JP2016075894A (ja) * 2014-10-02 2016-05-12 コニカミノルタ株式会社 光学フィルム、その製造方法、フレキシブルプリント基板及びｌｅｄ照明
WO2017051827A1 (ja) * 2015-09-24 2017-03-30 旭化成株式会社 ポリイミド前駆体、樹脂組成物および樹脂フィルムの製造方法
JP2019023249A (ja) * 2015-12-11 2019-02-14 コニカミノルタ株式会社 ポリイミドフィルム、フレキシブルプリント基板、ｌｅｄ照明装置及びフレキシブルディスプレイ用前面部材

Also Published As

Publication number Publication date
TWI794598B (zh) 2023-03-01
JPWO2020195819A1 (enrdf_load_stackoverflow) 2020-10-01
TW202102582A (zh) 2021-01-16

Similar Documents

Publication Publication Date Title
JP6638654B2 (ja) ポリイミドフィルムとその製造方法、フレキシブルプリント基板、フレキシブルディスプレイ用基材、フレキシブルディスプレイ用前面板、ｌｅｄ照明装置及び有機エレクトロルミネッセンス表示装置
JP6806141B2 (ja) ポリイミドフィルムの製造方法
JP6874759B2 (ja) ポリイミドフィルム及びその製造方法
JP6834440B2 (ja) ポリイミドフィルムおよび当該フィルムを用いる表示装置
KR102662946B1 (ko) 폴리이미드 필름, 폴리이미드 필름의 제조 방법, 및 폴리이미드 전구체 수지 조성물
JP7036021B2 (ja) 透明ポリイミド樹脂、透明ポリイミド樹脂組成物、透明ポリイミド樹脂フィルム、赤外線吸収組成物、赤外線カットフィルター及び透明ポリイミド樹脂フィルムの製造方法
WO2017169306A1 (ja) 光学フィルムの製造方法
WO2017169651A1 (ja) 表示装置表面部材及びその製造方法
WO2017099041A1 (ja) ポリイミドフィルム、フレキシブルプリント基板、ｌｅｄ照明装置等
JP2016075894A (ja) 光学フィルム、その製造方法、フレキシブルプリント基板及びｌｅｄ照明
JPWO2017010178A1 (ja) 偏光板、その製造方法、液晶表示装置及び有機エレクトロルミネッセンス表示装置
JP2017187617A (ja) 光学フィルムの製造方法及び製造装置
JP2016064642A (ja) ポリイミドフィルムの製造方法、フレキシブルプリント基板の製造方法及びｌｅｄ照明用基板の製造方法
JPWO2019203037A1 (ja) ポリマーブレンド組成物及びポリマーフィルム
JP2018103392A (ja) 透明ポリイミドフィルム積層体
WO2020195819A1 (ja) 光学フィルムの製造方法及び光学フィルム
JP2017185743A (ja) ポリイミドフィルムの製造方法、及び製造装置
WO2017057247A1 (ja) ポリイミドフィルム、フレキシブルプリント基板、ｌｅｄ照明用基板及びフレキシブルディスプレイ用前面板
JP6772519B2 (ja) ポリイミドフィルム、その製造方法、透明導電フィルム及びタッチパネル
KR20200000365A (ko) 수지 필름 롤의 제조 방법
KR20200000362A (ko) 투명 수지 필름의 제조 방법
JP6862956B2 (ja) フレキシブルディスプレイ前面板用の透明ポリイミドフィルム及びその製造方法、並びに有機エレクトロルミネッセンスディスプレイ
JP2017187562A (ja) 光学フィルムの製造方法及び製造装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20778066

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021508995

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20778066

Country of ref document: EP

Kind code of ref document: A1