WO2024262545A1 - 転写基材用または薄膜製造工程用二軸配向ポリプロピレンフィルム、離型層積層ポリプロピレンフィルム、転写用積層フィルム、転写方法、および薄膜の製造方法 - Google Patents

転写基材用または薄膜製造工程用二軸配向ポリプロピレンフィルム、離型層積層ポリプロピレンフィルム、転写用積層フィルム、転写方法、および薄膜の製造方法 Download PDF

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WO2024262545A1
WO2024262545A1 PCT/JP2024/022259 JP2024022259W WO2024262545A1 WO 2024262545 A1 WO2024262545 A1 WO 2024262545A1 JP 2024022259 W JP2024022259 W JP 2024022259W WO 2024262545 A1 WO2024262545 A1 WO 2024262545A1
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Prior art keywords
film
biaxially oriented
transfer
layer
oriented polypropylene
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English (en)
French (fr)
Japanese (ja)
Inventor
一仁 堀之内
浩司 山田
健介 種木
徹 今井
理 木下
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Toyobo Co Ltd
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Toyobo Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • 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
    • 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
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating

Definitions

  • This disclosure relates to a biaxially oriented polypropylene film for transfer substrates or thin film manufacturing processes, a release layer-laminated polypropylene film, a laminated film for transfer, a transfer method, and a method for manufacturing a thin film.
  • Biaxially oriented polypropylene films are used for industrial purposes such as packaging, release agents, and adhesive tapes, and have also been proposed as base films for transfer printing (e.g., Patent Documents 1 and 2).
  • base films for transfer printing e.g., Patent Documents 1 and 2.
  • PET polyethylene terephthalate
  • OPP biaxially oriented polypropylene
  • Biaxially oriented polypropylene films are used for industrial purposes such as packaging, release agents, and adhesive tapes, and have also been proposed as base films for thin film manufacturing processes (e.g., Patent Document 3).
  • PET polyethylene terephthalate
  • OPP biaxially oriented polypropylene
  • the second object is to provide a biaxially oriented polypropylene film for thin film manufacturing processes having excellent rigidity and heat resistance.
  • the biaxially oriented polypropylene film for transfer substrate, the release layer laminated polypropylene film for transfer, the laminated film for transfer, or the transfer method according to the first disclosure is preferably any one of the following [1] to [13]. This makes it possible to solve the first problem.
  • a biaxially oriented polypropylene film for transfer substrates which satisfies the following (1), (2), and (3): (1)
  • the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate has a mesopentad fraction of 97.5% or more.
  • the relationship between the loop stiffness stress S [mN] in the width direction and the thickness t ( ⁇ m) satisfies the following formula (A).
  • a release layer-laminated polypropylene film for transfer comprising the biaxially oriented polypropylene film for transfer substrate according to any one of [1] to [8] and a release layer laminated on at least one surface of the biaxially oriented polypropylene film for transfer substrate.
  • a transfer laminate film comprising the biaxially oriented polypropylene film for transfer substrate according to any one of [1] to [8] and a transfer layer.
  • the transfer layer includes at least one layer selected from the group consisting of a printing layer, a decorative metal thin film, a thermal transfer ink layer, a photosensitive resin layer, an optically functional layer, a conductive layer, a circuit, an adhesive layer, a pressure-sensitive adhesive layer, and a rubber sheet layer.
  • a transfer method comprising the steps of: bonding the transfer laminate film described in [10] to an object to be transferred; and peeling the biaxially oriented polypropylene film for transfer substrate of the transfer laminate film from the object to which the transfer laminate film is bonded.
  • the biaxially oriented polypropylene film for thin film manufacturing process and the method for manufacturing a thin film according to the second disclosure are preferably any one of the following [14] to [26]. This makes it possible to solve the second problem.
  • a biaxially oriented polypropylene film for thin film manufacturing processes which satisfies the following (1), (2), and (3): (1)
  • the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process has a mesopentad fraction of 97.5% or more.
  • the relationship between the loop stiffness stress S [mN] in the width direction and the thickness t ( ⁇ m) satisfies the following formula (A).
  • a method for producing a thin film comprising: step 1A of preparing a biaxially oriented polypropylene film for a thin film production process according to any one of [14] to [21]; step 1B of providing a thin film layer on at least one surface of the biaxially oriented polypropylene film for a thin film production process; and step 1C of peeling the thin film layer from the biaxially oriented polypropylene film for a thin film production process.
  • a method for producing a thin film comprising step 2A of preparing a release layer-laminated biaxially oriented polypropylene film for a thin film production process according to [22], step 2B of providing a thin film layer on the release layer surface of the release layer-laminated biaxially oriented polypropylene film for a thin film production process, and step 2C of peeling the thin film layer from the release layer.
  • step 2A of preparing a release layer-laminated biaxially oriented polypropylene film for a thin film production process according to [22]
  • step 2B of providing a thin film layer on the release layer surface of the release layer-laminated biaxially oriented polypropylene film for a thin film production process and step 2C of peeling the thin film layer from the release layer.
  • the method for producing a thin film according to [25] wherein the thin film layer includes any one of a resin film, a polymer electrolyte membrane, and a porous membrane.
  • first disclosure and the second disclosure may be combined.
  • the first disclosure makes it possible to provide a biaxially oriented polypropylene film for transfer substrates that has excellent rigidity and heat resistance. This allows for no wrinkles, good flatness, and high dimensional accuracy for precise transfer. This also makes it possible to make the film thinner than before, which results in less film waste after use and reduces the environmental impact.
  • the second disclosure makes it possible to provide a biaxially oriented polypropylene film for thin film manufacturing processes that has excellent rigidity and heat resistance. This makes it possible to form thin films with good flatness, quality, and appearance. This also makes it possible to make the film thinner than before, which results in less film waste after use and reduces the environmental impact.
  • FIG. 1 shows a schematic diagram of component separation of the decay curve of spin-spin relaxation time observed by 1 H-pulse NMR.
  • the biaxially oriented polypropylene film for transfer substrate according to the embodiment of the first disclosure will be described below.
  • the biaxially oriented polypropylene film for transfer substrate according to the embodiment satisfies the following (1), (2), and (3).
  • the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate has a mesopentad fraction of 97.5% or more.
  • the relationship between the loop stiffness stress S [mN] in the width direction and the thickness t ( ⁇ m) satisfies the following formula (A).
  • the biaxially oriented polypropylene film transfer substrate of the embodiment is preferably made of a polypropylene resin composition containing polypropylene resin as the main component.
  • the term "main component" means that the proportion of polypropylene resin in the polypropylene resin composition is 90% by mass or more, more preferably 93% by mass or more, even more preferably 95% by mass or more, and particularly preferably 97% by mass or more. The proportion may be 100% by mass or less, or 99% by mass or less.
  • the polypropylene resin composition may contain additives.
  • the additives may include a crystal nucleating agent, an antioxidant, a heat stabilizer, a slipping agent, an antistatic agent, an antiblocking agent, a filler, a viscosity modifier, a color inhibitor, or a combination thereof.
  • the polypropylene resin may contain a polypropylene homopolymer, a copolymer of propylene and ethylene and/or an ⁇ -olefin having 4 or more carbon atoms, or a mixture thereof. Of these, a propylene homopolymer that does not substantially contain ethylene and/or an ⁇ -olefin having 4 or more carbon atoms is preferred.
  • the amount of ethylene and/or an ⁇ -olefin having 4 or more carbon atoms is preferably 1 mol% or less, more preferably 0.5 mol% or less, even more preferably 0.3 mol% or less, and particularly preferably 0.1 mol% or less, based on 100 mol% of all constituent units of the copolymer.
  • the amount of the component may be 0.01 mol% or more.
  • Examples of the ⁇ -olefin component having 4 or more carbon atoms constituting such a copolymer include 1-butene, 1-pentene, 3-methylpentene-1, 3-methylbutene-1, 1-hexene, 4-methylpentene-1, 5-ethylhexene-1, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-eicosene, etc.
  • the polypropylene resin may contain two or more different polypropylene homopolymers, copolymers with ethylene and/or ⁇ -olefins having 4 or more carbon atoms, or mixtures thereof.
  • the mesopentad fraction of a polypropylene resin (hereinafter sometimes abbreviated as [mmmm]%) is quantified based on the peak assignment of the 13 C-NMR spectrum, and means the ratio of five consecutive propylene monomer units in the polypropylene resin having the same stereostructure, and is an index of stereoregularity.
  • the mesopentad fraction of a polypropylene resin is 97.5% or more, preferably in the range of 97.5 to 99.9%, more preferably in the range of 98.0 to 99.7%, even more preferably in the range of 98.3 to 99.5%, and particularly preferably in the range of 98.5 to 99.3%.
  • the crystallinity of the polypropylene resin is increased, and the melting point, crystallinity, and crystal orientation of the crystals in the film are improved, and rigidity and heat resistance at high temperatures are easily obtained.
  • it is 99.9% or less, the cost of polypropylene production is easily reduced, and the film is less likely to break during film formation.
  • the mesopentad fraction is measured by a nuclear magnetic resonance method (so-called NMR method).
  • a method of washing the obtained polypropylene resin powder with a solvent such as n-heptane, a method of appropriately selecting a catalyst and/or a co-catalyst, and a method of appropriately selecting components of the polypropylene resin composition are preferably adopted.
  • the melting temperature (Tm) of the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate measured by DSC is preferably 160 ° C, more preferably 161 ° C, even more preferably 162 ° C, even more preferably 163 ° C, and particularly preferably 164 ° C.
  • Tm is 160 ° C or more, rigidity and heat resistance at high temperatures are easily obtained.
  • the upper limit of Tm is preferably 170 ° C, more preferably 169 ° C, even more preferably 168 ° C, even more preferably 167 ° C, and particularly preferably 166 ° C.
  • Tm is 170 ° C or less, it is easy to suppress the increase in cost in terms of polypropylene production, and it is difficult to break during film formation.
  • the melting temperature can also be further increased by blending a crystal nucleating agent with the above-mentioned polypropylene resin.
  • Tm is the main endothermic peak temperature associated with melting, which is observed when 1 to 10 mg of a sample is packed in an aluminum pan and set in a differential scanning calorimeter (DSC), melted at 230°C for 5 minutes in a nitrogen atmosphere, cooled to 30°C at a scanning rate of -10°C/min, held for 5 minutes, and then heated at a scanning rate of 10°C/min.
  • DSC differential scanning calorimeter
  • the lower limit of the crystallization temperature (Tc) measured by DSC of the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate is preferably 105 ° C, more preferably 108 ° C, and even more preferably 110 ° C. If Tc is 105 ° C or more, crystallization is likely to proceed in the width direction stretching and the subsequent cooling process, and rigidity and heat resistance at high temperatures are likely to be obtained.
  • the upper limit of Tc is preferably 135 ° C, more preferably 133 ° C, even more preferably 132 ° C, even more preferably 130 ° C, particularly preferably 128 ° C, and most preferably 127 ° C.
  • Tc is 135 ° C or less, it is difficult to increase the cost in terms of polypropylene production, and it is difficult to break during film formation.
  • the crystallization temperature can also be further increased by blending a crystal nucleating agent with the above-mentioned polypropylene resin.
  • Tc is the main peak temperature of the exothermic peak observed when 1 to 10 mg of a sample is packed in an aluminum pan, set in a DSC, melted at 230°C for 5 minutes in a nitrogen atmosphere, and cooled to 30°C at a scanning rate of -10°C/min.
  • the melt flow rate (MFR) of the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate is preferably 4.0 to 30 g/10 min, more preferably 4.5 to 25 g/10 min, even more preferably 4.8 to 22 g/10 min, particularly preferably 5.0 to 20 g/10 min, and most preferably 6.0 to 18 g/10 min, when measured in accordance with condition M (230 ° C, 2.16 kgf) of JIS K 7210 (1995).
  • the melt flow rate (MFR) of the polypropylene resin is 4.0 g/10 min or more, it is easy to obtain a biaxially oriented polypropylene film for transfer substrate with low thermal shrinkage.
  • the melt flow rate (MFR) of the polypropylene resin is 30 g/10 min or less, it is easy to maintain the film formability of the film.
  • the lower limit of the melt flow rate (MFR) (230°C, 2.16 kgf) of the polypropylene resin constituting the film is preferably 5.0 g/10 min, 5.5 g/10 min, 6.0 g/10 min, 6.3 g/10 min, 6.5 g/10 min, 6.8 g/10 min, and 7.0 g/10 min in that order. If the melt flow rate (MFR) of the polypropylene resin is 5.0 g/10 min or more, the amount of low molecular weight components in the polypropylene resin constituting the film increases.
  • the lower limit of the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve of the polypropylene resin constituting the biaxially oriented polypropylene film for transfer substrate is preferably 35% by mass, more preferably 38% by mass, even more preferably 40% by mass, even more preferably 41% by mass, and particularly preferably 42% by mass.
  • the upper limit of the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve is preferably 65% by mass, more preferably 60% by mass, and even more preferably 58% by mass.
  • the amount of components with a molecular weight of 100,000 or less contained in the polypropylene resin can be easily adjusted without significantly changing the overall viscosity, so that it is easy to improve the film formability without significantly affecting the rigidity or heat shrinkage.
  • the lower limit of the weight average molecular weight (Mw)/number average molecular weight (Mn), which is an index of the breadth of the molecular weight distribution, of the polypropylene resin is preferably 3.5, more preferably 4, even more preferably 4.5, and particularly preferably 5.
  • the upper limit of Mw/Mn is preferably 30, more preferably 25, even more preferably 23, particularly preferably 21, and most preferably 20.
  • Mw/Mn can be obtained using gel permeation chromatography (GPC). When Mw/Mn is in the above range, it is easy to increase the amount of components having a molecular weight of 100,000 or less.
  • the molecular weight distribution of polypropylene resin can be adjusted by polymerizing components of different molecular weights in multiple stages in a series of plants, blending components of different molecular weights offline in a kneader, polymerizing by blending catalysts with different performance, or using a catalyst that can achieve the desired molecular weight distribution.
  • the shape of the molecular weight distribution obtained by GPC may be a gentle molecular weight distribution with a single peak in a GPC chart with the logarithm (logM) of molecular weight (M) on the horizontal axis and the differential distribution value (weight fraction per logM) on the vertical axis, or a molecular weight distribution with multiple peaks or shoulders.
  • the thickness of the biaxially oriented polypropylene film for transfer substrate is set according to each application, but in order to obtain the strength of the film, the lower limit of the film thickness is preferably 5 ⁇ m, more preferably 8 ⁇ m, even more preferably 10 ⁇ m, particularly preferably 12 ⁇ m, and most preferably 14 ⁇ m.
  • the film thickness is 5 ⁇ m or more, the rigidity of the film is easily obtained, the transfer layer is easily provided, and peeling during transfer is also easy. In addition, wrinkles are less likely to occur when winding.
  • the upper limit of the film thickness is preferably 120 ⁇ m, more preferably 100 ⁇ m, even more preferably 80 ⁇ m, particularly preferably 70 ⁇ m, and most preferably 60 ⁇ m.
  • the biaxially oriented polypropylene film for transfer substrate is usually produced as a roll having a width of about 2000 to 12000 mm and a length of about 1000 to 50000 m, and is wound into a film roll. Further, it is slit according to each application and supplied as a slit roll having a width of about 300 to 2000 mm and a length of about 500 to 5000 m. It is possible to obtain a longer film roll of the biaxially oriented polypropylene film for transfer substrate.
  • the lower limit of the thickness uniformity of the biaxially oriented polypropylene film for transfer substrate is preferably 0%, more preferably 0.1%, even more preferably 0.5%, and particularly preferably 1%.
  • the upper limit of the thickness uniformity is preferably 20%, more preferably 17%, even more preferably 15%, especially preferably 12%, and most preferably 10%. In the above range, defects are unlikely to occur during post-processing such as coating and printing, and it is easy to use in applications requiring precision.
  • the method for measuring the thickness uniformity is, for example, as follows.
  • the biaxially oriented polypropylene film for transfer substrate preferably has the following characteristics and structure.
  • the "longitudinal direction" of the biaxially oriented polypropylene film for transfer substrate is the direction corresponding to the flow direction in the film manufacturing process
  • the "width direction” is the direction perpendicular to the flow direction in the film manufacturing process.
  • the spin-spin relaxation time T2 observed by 1H -pulse NMR becomes slower in the order of crystal, intermediate phase, and amorphous.
  • the intermediate phase has a faster T2 than the amorphous phase, and is considered to be an amorphous phase with restricted mobility.
  • a highly oriented crystalline component (I) is generated, and an amorphous chain component (II) (corresponding to the above-mentioned intermediate phase) with restricted mobility is generated near the crystal.
  • an amorphous component (III) (corresponding to the above-mentioned amorphous) that is not restricted by the crystal is likely to be generated.
  • the unrestricted amorphous component (III) has high mobility, and at high temperatures it is likely to move to eliminate distortion, which is thought to cause shrinkage at high temperatures.
  • the restricted amorphous chain (II) is thought to be less likely to shrink at high temperatures because its movement is suppressed even at high temperatures compared to the amorphous component (III).
  • the upper limit of the ratio of the unconstrained amorphous component (III) determined by pulse NMR of the biaxially oriented polypropylene film for transfer substrate is preferably 7%, more preferably 6%, and even more preferably 5%.
  • it is effective to increase the area ratio during film formation, and to perform sequential biaxial stretching and then re-stretching in the width direction at high temperature. It is also effective to use a polypropylene raw material with a high mesopentad fraction.
  • a ratio of the unconstrained amorphous component (III) of 7% or less determined by pulse NMR means that there are few molecular chains with large distortion of the molecular orientation restrained by the entanglement points, and the film is less likely to shrink even when the crystals begin to melt.
  • the release layer or transfer layer is dried at high temperatures, when the transfer layer is heat treated, or when heat is applied during transfer, the film is less likely to wrinkle, change in dimensions, curl, or lose its flatness.
  • the ratio of the unconstrained amorphous component (III) exceeds 7% when the crystal component (I), the constrained amorphous component (II), and the unconstrained amorphous component (III) are separated by pulse NMR using the solid echo method, there are many molecular chains with large distortion of the molecular orientation constrained by the entanglement points, so that the film shrinks as soon as the crystals start to melt, and as a result, it is considered that the film is prone to wrinkles, dimensional changes, curling, and deterioration of flatness.
  • the ratio of the unconstrained amorphous component (III) it is practical to set it to 0.1% or more.
  • the ratio of the unconstrained amorphous component (III) is to be less than 0.1%, it is necessary to further stretch the film in the width direction at a high temperature after the successive biaxial stretching, and the tension during stretching due to melting decreases, which may cause breakage. In addition, the crystal orientation in the film may become weaker, resulting in a lower rigidity.
  • the upper limit of the thermal shrinkage rate in the longitudinal direction of the biaxially oriented polypropylene film for transfer substrate at 150 ° C. is preferably 10%, more preferably 8.0%, even more preferably 6.0%, particularly preferably 5.0%, and most preferably 4.0%.
  • the lower limit may be 0%, 1.0%, or 2.0%.
  • the upper limit of the thermal shrinkage rate in the width direction at 150 ° C. is preferably 25%, more preferably 20%, even more preferably 16%, even more preferably 15%, particularly preferably 12%, and most preferably 10%.
  • the lower limit may be 0%, 2.0%, or 4.0%.
  • the thermal shrinkage rate in the longitudinal direction is 10% or less and the thermal shrinkage rate in the transverse direction is 25% or less, wrinkles, dimensional changes, and deterioration of flatness are unlikely to occur in the film or laminate during release processing, processing of the transfer layer such as providing a transfer layer or heat treatment, and heating for transfer.
  • processing of the transfer layer such as providing a transfer layer or heat treatment, and heating for transfer.
  • the control range of the roll tension during processing is further expanded, and as a result, wrinkles, dimensional changes, and deterioration of flatness are unlikely to occur, which is preferable.
  • the lower limit of the stress (F5) at 5% elongation in the width direction of the biaxially oriented polypropylene film for transfer substrate at 23 ° C. is preferably 110 MPa, more preferably 120 MPa, even more preferably 140 MPa, even more preferably 160 MPa, particularly preferably 180 MPa, and most preferably 190 MPa.
  • the upper limit of F5 in the width direction at 23 ° C. is preferably 300 MPa, more preferably 290 MPa, and even more preferably 280 Pa. If it is 280 MPa or less, practical production is easy and the vertical-width balance is easily improved.
  • the lower limit of F5 in the longitudinal direction of the biaxially oriented polypropylene film for transfer substrate at 23°C is preferably 40 MPa, more preferably 42 MPa, even more preferably 46 MPa, and particularly preferably 48 MPa.
  • the upper limit of F5 in the longitudinal direction at 23°C is preferably 70 MPa, more preferably 65 MPa, even more preferably 62 MPa, and particularly preferably 60 MPa. At 70 MPa or less, practical manufacturing becomes easy and the length-width balance is easily improved.
  • the film is highly rigid, making it easier to maintain its shape and easy to perform release processing, and it is also easier to handle during processing and transfer of the transfer layer, and it is less likely to undergo dimensional changes or deterioration of flatness, making it easier to perform high-quality, high-precision transfer processing.
  • F5 can be set within the range by adjusting the stretch ratio and relaxation rate, or by adjusting the temperature during film formation.
  • the heat shrinkage rate (%) in the width direction at 150° C. and the stress (MPa) at 5% elongation in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage rate (%) in the width direction at 150°C ⁇ 4.0 + 140 This results in higher rigidity and a smaller thermal shrinkage rate at high temperatures, making it easier to maintain the shape of the film, and suppressing the occurrence of wrinkles in the film due to heat during the drying process of the release layer.
  • the film and laminate are less likely to wrinkle, change in size, or deteriorate in flatness, making handling easier, and facilitating high-quality, high-precision transfer. Wrinkles are caused by the shrinkage of the film due to heat and the deformation of the film due to tension during roll transport, and wrinkle occurrence can be suppressed by optimizing the balance between the two.
  • the control range of the roll tension during processing is wider, which is preferable because it results in less wrinkles, change in size, and deterioration of flatness.
  • the thermal shrinkage rate (%) in the width direction at 150° C. and the stress (MPa) at 5% elongation in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage rate (%) in the width direction at 150°C ⁇ 4.0 + 150
  • the heat shrinkage rate (%) in the width direction at 150° C. and the stress at 5% elongation (MPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 150°C ⁇ 4.0 + 160
  • the upper limit of the thermal shrinkage rate in the longitudinal direction of the biaxially oriented polypropylene film for transfer substrate at 120 ° C. is preferably 2.0%, more preferably 1.5%, even more preferably 1.2%, particularly preferably 1.0%, and most preferably 0.8%.
  • the lower limit may be 0% or 0.1%. If it is 2.0% or less, appearance defects such as vertical streaks are unlikely to occur during release processing and processing of the transfer layer.
  • the upper limit of the thermal shrinkage rate in the width direction at 120 ° C. is preferably 8.0%, more preferably 5.0%, even more preferably 3.5%, even more preferably 2.5%, particularly preferably 2.0%, more particularly preferably 1.5%, and most preferably 1.0%.
  • the lower limit may be 0%, 0.1%, or 0.2%. If it is less than the above, wrinkles, dimensional changes, and deterioration of flatness are unlikely to occur in the polypropylene film or laminated film during release processing, processing of the transfer layer, and heating for transfer, making it easier to perform high-quality and high-precision transfer.
  • the heat shrinkage rate at 120° C. can be kept within the range by adjusting the stretch ratio, stretching temperature and heat setting temperature.
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae.
  • Heat shrinkage (%) in the width direction at 120°C ⁇ 0.3 + 7.0 This results in higher rigidity and smaller thermal shrinkage at high temperatures, so that the film or laminate is less likely to wrinkle, change in size, or lose its flatness during release processing, processing of the transfer layer such as providing a transfer layer or heat treatment, or heating during transfer, and is easier to handle, facilitating high-quality, high-precision transfer. Also, it is easier to peel off smoothly.
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae.
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for transfer substrate satisfy the following formulae: Tensile modulus (GPa) in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 120°C ⁇ 0.3 + 9.0
  • the lower limit of the tensile modulus in the longitudinal direction of the biaxially oriented polypropylene film for transfer substrate at 23 ° C. is preferably 2.0 GPa, more preferably 2.1 GPa, even more preferably 2.2 GPa, even more preferably 2.3 GPa, particularly preferably 2.4 GPa, and most preferably 2.6 GPa.
  • the upper limit of the tensile modulus in the longitudinal direction is preferably 4.0 GPa, more preferably 3.8 GPa, even more preferably 3.7 GPa, particularly preferably 3.6 GPa, and most preferably 3.5 GPa. At 4.0 GPa or less, practical production is easy and the balance of the properties in the longitudinal direction and the width direction is easily improved.
  • the lower limit of the tensile modulus in the width direction of the biaxially oriented polypropylene film for transfer substrate at 23°C is preferably 5.0 GPa, more preferably 6.0 GPa, even more preferably 6.5 GPa, even more preferably 6.7 GPa, particularly preferably 7.0 GPa, even more particularly preferably 8.0 GPa, and most preferably 8.5 GPa.
  • the upper limit of the tensile modulus in the width direction is preferably 15 GPa, more preferably 13 GPa, and even more preferably 12 GPa. If it is 15 GPa or less, practical manufacturing is easy and the balance of the longitudinal and width direction properties is easily improved.
  • the tensile modulus By setting the tensile modulus at the above level or more, the shape of the film is easily maintained, and the film is not easily stretched even when a strong tension is applied to the film when providing the transfer layer, processing, or transferring, and handling is easy during processing and transferring of the transfer layer, and wrinkles, dimensional changes, and deterioration of flatness are less likely to occur in the film or laminate, making it easier to perform high-quality, high-precision transfer. In addition, smooth peeling is easy to perform during transfer.
  • the tensile modulus can be kept within the range by adjusting the stretch ratio and relaxation rate, and by adjusting the temperature during film formation.
  • the lower limit of the longitudinal tensile breaking strength of the biaxially oriented polypropylene film for transfer substrate at 23 ° C. is preferably 90 MPa, more preferably 100 MPa, even more preferably 110 MPa, and particularly preferably 115 MPa. If it is 90 MPa or more, wrinkles are unlikely to occur during release film processing, and film breakage is unlikely to occur during release processing.
  • the upper limit of the longitudinal tensile breaking strength is preferably 200 MPa as a practical value, more preferably 180 MPa, and even more preferably 160 MPa. If it is 200 MPa or less, the film is likely to break less.
  • the lower limit of the tensile breaking strength in the width direction of the biaxially oriented polypropylene film for transfer substrate at 23°C is preferably 250 MPa, more preferably 300 MPa, even more preferably 350 MPa, even more preferably 400 MPa, particularly preferably 420 MPa, even more particularly preferably 440 MPa, and most preferably 450 MPa.
  • the upper limit of the tensile breaking strength in the width direction is preferably 650 MPa as a practical value, more preferably 600 MPa, and even more preferably 550 MPa. If it is 650 MPa or less, the film is likely to break less.
  • the tensile breaking strength is 650 MPa or more, it is easy to apply strong tension to the film when providing the transfer layer, during processing, and during transfer, and wrinkles, dimensional changes, and deterioration of flatness of the film or laminate are unlikely to occur, handling is easy, and high-quality, high-precision transfer is easy to perform. In addition, the film is unlikely to break during release processing.
  • the tensile breaking strength can be kept within the range by adjusting the stretching ratio, stretching temperature, and heat setting temperature.
  • the lower limit of the longitudinal tensile breaking elongation of the biaxially oriented polypropylene film for transfer substrate at 23°C is preferably 150%, more preferably 180%, even more preferably 190%, particularly preferably 200%, and most preferably 210%. If it is 150% or more, the film tends to break less.
  • the upper limit of the longitudinal tensile breaking elongation at 23°C is preferably 300% as a practical value, and more preferably 280%.
  • the lower limit of the tensile elongation at break in the width direction of the biaxially oriented polypropylene film for transfer substrate at 23°C is preferably 15%, more preferably 20%, even more preferably 25%, and particularly preferably 30%. If it is 15% or more, the film is less likely to break.
  • the upper limit of the tensile elongation at break in the width direction at 23°C is preferably 60%, more preferably 55%, and even more preferably 50%.
  • the tensile elongation at break can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the lower limit of the refractive index (Nx) in the longitudinal direction of the biaxially oriented polypropylene film for transfer substrate is preferably 1.4950, more preferably 1.4970, even more preferably 1.4980, particularly preferably 1.4990, and most preferably 1.5000. If it is 1.4950 or more, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Nx) in the longitudinal direction is preferably 1.5100, more preferably 1.5070, and even more preferably 1.5050. If it is 1.5100 or less, the balance of the properties in the longitudinal direction and the width direction of the film is easily excellent.
  • the lower limit of the refractive index (Ny) in the width direction of the biaxially oriented polypropylene film for transfer substrate is preferably 1.5250, more preferably 1.5253, even more preferably 1.5255, even more preferably 1.5260, and especially preferably 1.5265. If it is 1.5250 or more, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Ny) in the width direction is preferably 1.5280, more preferably 1.5275, and further preferably 1.5270. If it is 1.5280 or less, the film tends to have an excellent balance of properties in the longitudinal direction and the width direction.
  • the lower limit of the refractive index (Nz) in the thickness direction of the biaxially oriented polypropylene film for transfer substrate is preferably 1.4960, more preferably 1.4965, even more preferably 1.4970, particularly preferably 1.4980, and most preferably 1.4990. If it is 1.4960 or more, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Nz) in the thickness direction is preferably 1.5020, more preferably 1.5015, and even more preferably 1.5010. If it is 1.5020 or less, the heat resistance of the film is easily increased.
  • the refractive index can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the lower limit of ⁇ Ny of the biaxially oriented polypropylene film for transfer substrate is preferably 0.0240, more preferably 0.0245, even more preferably 0.0247, even more preferably 0.0250, particularly preferably 0.0255, and most preferably 0.0260. If it is 0.0240 or more, the rigidity of the film tends to be high.
  • the upper limit of ⁇ Ny is preferably 0.0280 as a practical value, more preferably 0.0277, even more preferably 0.0273, and particularly preferably 0.0270. If it is 0.0280 or less, the thickness unevenness tends to be good. ⁇ Ny can be kept within the range by adjusting the stretching ratio, stretching temperature, and heat setting temperature of the film.
  • ⁇ Ny is calculated by the following formula, where Nx, Ny, and Nz are the refractive indexes along the longitudinal direction, width direction, and thickness direction of the film, respectively, and means the degree of width direction orientation in the overall orientation in the longitudinal direction, width direction, and thickness direction of the film.
  • ⁇ Ny Ny-[(Nx+Nz)/2]
  • the lower limit of the plane orientation coefficient ( ⁇ P) of the biaxially oriented polypropylene film for transfer substrate is preferably 0.0135, more preferably 0.0138, and even more preferably 0.0140. If it is 0.0135 or more, the balance in the plane direction of the film is good, and the thickness unevenness is also good.
  • the upper limit of the plane orientation coefficient ( ⁇ P) is preferably 0.0155 as a practical value, more preferably 0.0152, and even more preferably 0.0150. If it is 0.0155 or less, it is likely to have excellent heat resistance at high temperatures.
  • the plane orientation coefficient ( ⁇ P) can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the plane orientation coefficient ( ⁇ P) is calculated by the formula [(Nx+Ny)/2]-Nz.
  • the lower limit of the average refractive index of the biaxially oriented polypropylene film for transfer substrate is preferably 1.5080, more preferably 1.5081, even more preferably 1.5082, particularly preferably 1.5083, and most preferably 1.5090.
  • the upper limit of the average refractive index is preferably 1.5150 as a practical value, more preferably 1.5140, even more preferably 1.5135, and particularly preferably 1.5130. If it is 1.5080 or more, wrinkles, dimensional changes, and deterioration of flatness are unlikely to occur in the film or laminate during release processing, processing of the transfer layer such as providing a transfer layer or heat treatment, and heating during transfer, and handling is also easy, making it easier to perform high-quality, high-precision transfer.
  • the average refractive index can be within the range by adjusting the stretching ratio, stretching temperature, and heat setting temperature of the film.
  • the average refractive index is calculated by the following formula, with Nx, Ny, and Nz being the refractive indexes along the longitudinal direction, width direction, and thickness direction of the film, respectively.
  • Average refractive index (Nx+Ny+Nz)/3
  • the upper limit of the haze of the film is preferably 5.0%, more preferably 4.5%, even more preferably 4.0%, particularly preferably 3.5%, and most preferably 3.0%. If it is 5.0% or less, it is easy to use in applications where transparency is required.
  • the lower limit of the haze is preferably 0.1% as a practical value, more preferably 0.2%, even more preferably 0.3%, and particularly preferably 0.4%. If it is 0.1% or more, it is easy to manufacture.
  • the haze can be kept within the range by adjusting the cooling roll (CR) temperature, the width direction stretching temperature, the tenter width direction preheating temperature, the width direction stretching temperature, or the heat setting temperature, or the amount of the component having a molecular weight of 100,000 or less of the polypropylene resin, but it may become large by adding an antiblocking agent or providing a seal layer.
  • CR cooling roll
  • the upper limit of the half-width (Wh) of the diffraction peak derived from the oriented crystals in the width direction of the film is preferably 30 °, more preferably 28 °, more preferably 26 °, even more preferably 25 °, particularly preferably 24 °, more particularly preferably 23 °, and most preferably 22.0 °. If the half-width (Wh) is 30 ° or less, particularly 26 ° or less, the rigidity of the film is easily increased.
  • the lower limit of Wh is preferably 15 °, more preferably 16 °, and even more preferably 17 °.
  • the lower limit of the X-ray orientation degree calculated from the half-width (Wh) of the biaxially oriented polypropylene film for transfer substrate by the following formula is preferably 0.833, more preferably 0.844, even more preferably 0.856, still more preferably 0.861, particularly preferably 0.867, even more particularly preferably 0.872, and most preferably 0.878. By making it 0.833 or more, particularly 0.856 or more, it is easy to increase the rigidity.
  • X-ray orientation degree (180-Wh)/180
  • the upper limit of the degree of X-ray orientation is preferably 0.917, more preferably 0.911, and further preferably 0.906. By setting the degree to 0.917 or less, film formation is likely to be stable.
  • the loop stiffness stress is an index representing the stiffness of the film, which also depends on the thickness of the film, but the value of the slope a of the approximate straight line means a characteristic value specific to the film that does not depend on the thickness that determines the rigidity. S ⁇ 0.0010 ⁇ t3 ...(A)
  • the lower limit of the loop stiffness stress S (mN) in the width direction at 23 ° C. of the biaxially oriented polypropylene film for transfer substrate is 0.0010 ⁇ t 3 , preferably 0.0011 ⁇ t 3 , particularly preferably 0.0012 ⁇ t 3 , and most preferably 0.0013 ⁇ t 3 , when the thickness of the biaxially oriented polypropylene film is t ( ⁇ m). If it is 0.0010 ⁇ t 3 or more, the peeling force during the transfer process tends to be small, smooth peeling is possible, and peeling marks (streaky marks that occur when caught during peeling) are unlikely to occur.
  • the peeling force during the transfer process tends to be small, smooth peeling is possible, and peeling marks (streaky marks that occur when caught during peeling) are unlikely to occur.
  • peeling marks strip marks that occur when caught during peeling
  • the upper limit of the loop stiffness stress S (mN) in the width direction at 23° C. is preferably 0.0020 ⁇ t 3 , more preferably 0.0019 ⁇ t 3 , still more preferably 0.0018 ⁇ t 3 , and particularly preferably 0.0017 ⁇ t 3. If it is 0.0020 ⁇ t 3 or less, it is easy to manufacture in practice.
  • the biaxially oriented polypropylene film for transfer substrate preferably satisfies the following formula (B) in the relationship between the longitudinal loop stiffness stress S [mN] and the thickness t ( ⁇ m).
  • the cube of the thickness t ( ⁇ m) is plotted on the horizontal axis and the longitudinal loop stiffness stress [mN] is plotted on the vertical axis, and linear approximation is performed by the least squares method so that the intercept is 0, and the slope a of the approximate straight line is obtained. It is preferable that the slope a is 0.00030 or more.
  • the following formula (B) will be described below. S ⁇ 0.00030 ⁇ t3 ...(B)
  • the lower limit of the longitudinal loop stiffness stress S (mN) of the biaxially oriented polypropylene film for transfer substrate at 23 ° C. is preferably 0.00030 ⁇ t 3 , more preferably 0.00040 ⁇ t 3 , even more preferably 0.00045 ⁇ t 3, particularly preferably 0.00048 ⁇ t 3, and most preferably 0.00050 ⁇ t 3 , when the thickness of the biaxially oriented polypropylene film is t ( ⁇ m). If it is 0.00030 ⁇ t 3 or more, the peeling force during the transfer process tends to be small, smooth peeling is possible, and peeling marks (streaky marks that occur when caught during peeling) are unlikely to occur.
  • the upper limit of the longitudinal loop stiffness stress S (mN) at 23° C. is preferably 0.00080 ⁇ t 3 , more preferably 0.00075 ⁇ t 3 , even more preferably 0.00072 ⁇ t 3 , and particularly preferably 0.00070 ⁇ t 3. If it is 0.00080 ⁇ t 3 or less, it is easy to manufacture in practice.
  • the biaxially oriented polypropylene film for transfer substrate is preferably obtained by preparing an unstretched sheet made of a polypropylene resin composition mainly composed of the above-mentioned polypropylene resin, and biaxially stretching it.
  • any of the inflation simultaneous biaxial stretching method, the tenter simultaneous biaxial stretching method, and the tenter sequential biaxial stretching method can be used, but it is preferable to adopt the tenter sequential biaxial stretching method from the viewpoint of film formation stability and thickness uniformity.
  • it is preferable to stretch in the longitudinal direction and then in the width direction but a method of stretching in the width direction and then in the longitudinal direction may also be used.
  • the manufacturing method of the biaxially oriented polypropylene film for transfer substrate of the embodiment will be described below, but the method is not necessarily limited thereto.
  • the biaxially oriented polypropylene film for transfer substrate of the embodiment may have a layer having another function laminated on at least one side. Lamination may be performed on one side or both sides.
  • the above-mentioned polypropylene resin composition may be used as the resin composition of the other layer or the central layer. Also, it may be different from the above-mentioned polypropylene resin composition.
  • the number of layers to be laminated may be one, two, or three or more layers per side, but from the viewpoint of manufacturing, one or two layers per side are preferable.
  • a lamination method for example, coextrusion by the feed block method or the multi-manifold method is preferable.
  • a resin layer having easy slip properties containing particles or the like and a resin layer having releasability can be laminated within a range that does not deteriorate the properties.
  • corona treatment can be performed on one side or both sides.
  • a resin composition containing polypropylene resin is heated and melted in a single-screw or twin-screw extruder, extruded into a sheet from a T-die, and then cooled and solidified by being placed on a cooling roll.
  • a cooling roll In order to promote solidification, it is preferable to further cool the sheet cooled by the cooling roll, for example by immersing it in a water tank.
  • the sheet is stretched in the longitudinal direction between two pairs of heated stretching rolls by increasing the rotation speed of the rear stretching roll, resulting in a uniaxially stretched film.
  • the uniaxially stretched film is then preheated, and stretched widthwise at a specific temperature while holding the film ends in a tenter-type stretching machine to obtain a biaxially stretched film. This widthwise stretching process will be described in detail later.
  • the biaxially stretched film is heat-treated at a specific temperature to obtain a biaxially oriented film.
  • the film may be relaxed in the width direction.
  • the biaxially oriented polypropylene film for transfer substrate thus obtained can be subjected to a corona discharge treatment, for example, on at least one side, if necessary, and then wound up on a winder to obtain a film roll.
  • a polypropylene resin composition mainly composed of polypropylene resin is heated and melted in the range of 200°C to 300°C using a single-screw or twin-screw extruder, and the sheet-shaped molten polypropylene resin composition coming out of a T-die is extruded and brought into contact with a metal cooling roll to be cooled and solidified.
  • the obtained unstretched sheet is preferably further put into a water tank.
  • the temperature of the cooling roll, or the cooling roll and the water tank is preferably in the range of 10°C to Tc, and when it is desired to increase the transparency of the film, it is preferable to cool and solidify it using a cooling roll having a temperature in the range of 10 to 50°C. If the cooling temperature is 50°C or less, the transparency of the unstretched sheet is likely to be increased, more preferably 40°C or less, and even more preferably 30°C or less.
  • the cooling temperature In order to increase the degree of crystal orientation after sequential biaxial stretching, it may be preferable to set the cooling temperature to 40°C or more, but when a propylene homopolymer having a mesopent fraction of 97.5% or more is used as described above, it is more preferable to set the cooling temperature to 40°C or less in order to easily perform the stretching in the next step and to reduce thickness unevenness, and it is even more preferable to set the cooling temperature to 30°C or less.
  • the thickness of the unstretched sheet is preferably 3500 ⁇ m or less in terms of cooling efficiency, more preferably 3000 ⁇ m or less, and can be appropriately adjusted depending on the film thickness after sequential biaxial stretching.
  • the thickness of the unstretched sheet can be controlled by the extrusion speed of the polypropylene resin composition and the lip width of the T-die, etc.
  • the lower limit of the longitudinal stretching ratio is preferably 3.5 times, more preferably 3.8 times, and particularly preferably 4.2 times. In the above range, the strength is easily increased and the film thickness unevenness is also reduced.
  • the upper limit of the longitudinal stretching ratio is preferably 7.0 times, more preferably 6.0 times, and particularly preferably 5.0 times. In the above range, the width direction stretching in the width direction stretching step is easy, and the productivity is improved.
  • the lower limit of the longitudinal stretching temperature is preferably Tm-30°C, more preferably Tm-27°C, and even more preferably Tm-25°C. In the above range, the subsequent width direction stretching is easy, and the thickness unevenness is also reduced.
  • the upper limit of the longitudinal stretching temperature is preferably Tm-7°C, more preferably Tm-10°C, and even more preferably Tm-12°C. In the above range, the heat shrinkage rate is easily reduced, and the quality is less likely to be reduced due to the difficulty of applying the stretching roll to the stretching roll and the increase in surface roughness.
  • the longitudinal stretching may be carried out in two or more stages using three or more pairs of stretching rolls.
  • the heating temperature in the preheating step is preferably Tm to Tm + 25°C, more preferably Tm + 2 to Tm + 20°C, and even more preferably Tm + 3 to Tm + 15°C.
  • Tm + 25°C By setting the heating temperature in the preheating step to the melting point or higher, softening proceeds and widthwise stretching becomes easier.
  • Tm + 25°C or less By setting the heating temperature in the preheating step to Tm + 25°C or less, orientation proceeds during widthwise stretching, and rigidity is easily developed.
  • the preheating step is composed of multiple zones, the temperature of the zone with the highest temperature among them is the preheating temperature.
  • Transverse direction stretching process In the transverse stretching step after the preheating step, a preferred method is as follows.
  • stretching is preferably performed at a temperature of Tm-10°C or more and the preheating temperature or less.
  • the lower limit of the temperature in the width direction stretching step is more preferably Tm-9°C, even more preferably Tm-7°C, and particularly preferably Tm-5°C.
  • the upper limit of the temperature in the width direction stretching step is preferably Tm+10°C, even more preferably Tm+7°C, and particularly preferably Tm+5°C. When the width direction stretching temperature is in this range, stretching unevenness is less likely to occur.
  • a later stretching process in which stretching is performed at a lower temperature may be added following the width direction stretching in the above temperature range.
  • a section (early section) in which stretching is performed at a temperature of Tm-10°C or more and Tm+10°C or less a section (late section) in which stretching is performed at a temperature lower than the temperature in the early section and at Tm-70°C or more and Tm-5°C or less may be provided.
  • the lower limit of the stretching temperature in the late section is preferably Tm-65°C, more preferably Tm-60°C, and even more preferably Tm-55°C. When the stretching temperature in the late section is within this range, film formation is more likely to be stable.
  • the final width direction stretching ratio in the width direction stretching step is preferably 10 times or more, more preferably 11 times or more, and even more preferably 11.5 times or more. If it is 10 times or more, the rigidity of the film is easily increased and thickness unevenness is also easily reduced.
  • the upper limit of the width direction stretching ratio is preferably 20 times, more preferably 17 times, and even more preferably 15 times. If it is 20 times or less, the thermal shrinkage rate is easily reduced and the film is less likely to break during stretching. When a later section is added and/or when the later-described width direction re-stretching is performed, it is preferable that the total stretching ratio is within the above range.
  • the lower limit of the stretching ratio in the early stretching step is preferably 4 times, more preferably 5 times, even more preferably 6 times, and particularly preferably 6.5 times.
  • the upper limit of the stretching ratio at the end of the early section is preferably 15 times, more preferably 14 times, and even more preferably 13 times.
  • the cooling temperature at this time is preferably equal to or lower than the width direction stretching temperature, and is at least Tm-80°C and not more than Tm-15°C, more preferably at least Tm-80°C and not more than Tm-20°C, even more preferably at least Tm-80°C and not more than Tm-30°C, and particularly preferably at least Tm-70°C and not more than Tm-40°C.
  • the temperature at the end of the width direction stretching can be gradually decreased to the cooling temperature, but it can also be decreased in stages or in a single stage. Decreasing the temperature in stages or in a single stage is preferable because it is easier to increase the crystal orientation in the film.
  • width direction re-stretching After cooling the film, it is preferable to stretch it again in the width direction at a high temperature (hereinafter also referred to as width direction re-stretching).
  • the lower limit of the stretching temperature when stretching again in the width direction is preferably Tm - 5°C, more preferably Tm°C, even more preferably Tm + 5°C, even more preferably Tm + 7°C, and particularly preferably Tm + 9°C. If it is Tm - 5°C or higher, it is easy to increase the rigidity and to reduce the thermal shrinkage rate.
  • the upper limit of the width direction re-stretching temperature is preferably Tm + 20°C, more preferably Tm + 18°C, and even more preferably Tm + 16°C. If it is Tm + 20°C or lower, it is easy to increase the rigidity.
  • the lower limit of the widthwise re-stretching ratio at high temperature is preferably 1.05 times, more preferably 1.1 times, and even more preferably 1.15 times.
  • the upper limit of the widthwise re-stretching ratio at high temperature is preferably 2 times, more preferably 1.7 times, and even more preferably 1.5 times. If the re-stretching ratio is too large, the thermal shrinkage rate may become too large, thickness unevenness may occur, or the film may break.
  • the film is stretched once in the width direction and sufficiently oriented in the width direction, and then the film, which has sufficient tension even if the fixed crystal orientation melts by cooling, is stretched again at a high temperature of Tm + 5°C or higher, so that when stretched again, there is sufficient tension and there is little concern that thickness unevenness will occur or the film will break.
  • the stretching ratio at high temperatures should be at least 1.05 times, so long as it is sufficient to disentangle and align the molecular chains. A stretching ratio of 2 times or less makes it difficult for thickness unevenness to occur.
  • the molecules of the polypropylene resin are highly aligned in the main orientation direction (this corresponds to the width direction in the above-mentioned width stretching process), so that the crystal orientation in the obtained biaxially oriented film is strong, and it becomes easier to produce more crystals with a high melting point.
  • the biaxially stretched film can be heat-treated as necessary to further reduce the heat shrinkage.
  • the upper limit of the heat treatment temperature is preferably the high-temperature re-stretching temperature described above, more preferably the high-temperature re-stretching temperature -2°C, and even more preferably the high-temperature re-stretching temperature -3°C.
  • the lower limit of the heat treatment temperature is preferably Tm-3°C, more preferably Tm-2°C, and particularly preferably Tm°C.
  • the film may be relaxed (relaxed) in the width direction during heat treatment, but the upper limit of the relaxation rate is preferably 5%, more preferably 3%, and even more preferably 1%. Within the above range, the rigidity is unlikely to decrease, and the film thickness variation is likely to be small. When the rigidity is to be further increased, heat treatment may not be performed.
  • the cooling temperature at this time is preferably 10°C or more and 140°C or less, more preferably 20°C or more and 120°C or less, even more preferably 80°C or less, and particularly preferably 50°C or less.
  • the cooling temperature at this time is preferably 10°C or more and 140°C or less, more preferably 20°C or more and 120°C or less, even more preferably 80°C or less, and particularly preferably 50°C or less.
  • the state of the film can be fixed. It is preferable to subject the thus obtained biaxially oriented polypropylene film to corona discharge, plasma treatment, flame treatment, etc., as necessary.
  • the biaxially oriented polypropylene film for transfer substrate described above may be used as a transfer film without any particular release treatment, and the release property may be adjusted by corona treatment, flame treatment, plasma treatment, etc. Also, the release property may be adjusted in a gas atmosphere containing a fluorine-based compound or a silicone-based compound.
  • the following describes a release layer laminated polypropylene film for transfer according to an embodiment.
  • the release layer laminated polypropylene film for transfer has any of the biaxially oriented polypropylene films for transfer substrate described above and a release layer laminated on at least one surface of the biaxially oriented polypropylene film for transfer substrate.
  • a release agent may be applied to the surface of the biaxially oriented polypropylene film for transfer substrate.
  • a release agent is applied to the surface, it is preferable that the surface of the biaxially oriented polypropylene film for transfer substrate has a wet tension of 38 mN/m or more. If the wet tension is 38 mN/m or more, the adhesion with the release layer is improved. In order to make the wet tension 38 mN/m or more, it is preferable to perform a physicochemical surface treatment such as corona treatment, flame treatment, plasma treatment, etc.
  • the wet tension is preferably 44 mN/m or less, more preferably 43 mN/m or less, and even more preferably 42 mN/m or less.
  • the wet tension when the release agent is not applied may be less than 38 mN/m, and can be adjusted by the surface treatment conditions so as to obtain the required peelability, and surface treatment may not be performed.
  • the release agent may contain silicone resin, fluororesin, alkyd resin, amino resin, various waxes, aliphatic olefin, long-chain alkyl group-containing resin, etc., and each resin may be used alone or in combination of two or more types.
  • the silicone resin used as the release agent can be any silicone resin generally used for release agents, and can be selected from silicone resins generally used in the relevant field, as described in, for example, "Silicone Materials Handbook” (edited by Toray Dow Corning, August 1993). Generally, heat-curable or ionizing radiation-curable silicone resins (which encompass both resins and resin compositions) are used. For example, condensation reaction and addition reaction silicone resins can be used as heat-curable silicone resins, and ultraviolet or electron beam curable silicone resins can be used as ionizing radiation-curable silicone resins. These are applied onto the film substrate, and then dried or cured to form the release layer.
  • the above-mentioned curable silicone resin preferably has a degree of polymerization after curing of about 500,000 to 200,000, and particularly about 1,000 to 100,000.
  • Specific examples of these include the following resins: KS-718, KS-774, KS-775, KS-778, KS-779H, KS-830, KS-835, KS-837, KS-838, KS-839, KS-841, KS-843, and KS-845 manufactured by Shin-Etsu Chemical Co., Ltd.
  • the silicone resin of the above-mentioned addition reaction system is, for example, a resin in which polydimethylsiloxane with vinyl groups introduced at the end or side chain is reacted with hydrogen siloxane using a platinum catalyst to harden.
  • Examples include low-temperature addition cure types (LTC1006L, LTC1056L, LTC300B, LTC303E, LTC310, LTC314, LTC350G, LTC450A, LTC371G, LTC750A, LTC755, LTC760A, etc.) and thermal UV cure types (LTC851, BY24-510, BY24-561, BY24-562, etc.) manufactured by Dow Corning Toray Co., Ltd., and solvent addition + UV cure types (X62-5040, X62-5065, X62-5072T, KS5508, etc.) and dual cure cure types (X62-2835, X62-2834, X62-1980, etc.) manufactured by Shin-Etsu Chemical Co., Ltd.
  • low-temperature addition cure types LTC1006L, LTC1056L, LTC300B, LTC303E, LTC310, LTC314, LTC350G, LTC450A, LTC371G, LTC750A, LTC
  • An example of the silicone resin of the condensation reaction system is one in which a polydimethylsiloxane having an OH group at the end and a polydimethylsiloxane having an H group at the end are condensed using an organotin catalyst to form a three-dimensional crosslinked structure.
  • UV-curable or electron beam-curable silicone resins include, for example, the most basic types: resins that crosslink and harden through a radical reaction in the same way as normal silicone rubber crosslinks; resins that photocure by the introduction of acrylic groups; resin compositions in which UV decomposes onium salts to generate strong acids that cleave epoxy rings and crosslink; and resin compositions that crosslink through an addition reaction of thiols to vinyl siloxanes.
  • Electron beams have more energy than UV rays, so a radical-based crosslinking reaction occurs without the use of an initiator as in the case of UV curing.
  • Amino resins are resins obtained by the addition condensation reaction of aldehydes with compounds containing amino groups, such as urea, melamine, guanamine, and aniline, and examples of such resins include aniline aldehyde resins, urea resins, melamine resins, benzoguanamine resins, and acetoguanamine resins. Amino resins may be modified with long-chain alkyl groups. Long-chain alkyl groups are explained below.
  • Alkyd resin is a resin obtained by the condensation reaction of polyhydric alcohol and polybasic acid, and is a condensation product of polycarboxylic acid and polyhydric alcohol, with fatty acids etc. added if necessary.
  • polyhydric alcohols examples include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol; trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane; and polyhydric alcohols such as diglycerin, triglycerin, pentaerythritol, pentaerythritol, dipentaerythritol, mannitol, and sorbitol.
  • dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol
  • trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane
  • polyhydric alcohols such as diglycerin, trigly
  • Polybasic acids include saturated polybasic acids such as phthalic anhydride, terephthalic acid, succinic acid, adipic acid, and sebacic acid; unsaturated polybasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride, isophthalic acid, and trimellitic anhydride; and polybasic acids produced by the Diels-Alder reaction such as cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, and rosin-maleic anhydride adduct.
  • saturated polybasic acids such as phthalic anhydride, terephthalic acid, succinic acid, adipic acid, and sebacic acid
  • unsaturated polybasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride, isophthalic acid, and trimellitic anhydride
  • wax examples include paraffin wax, microcrystalline wax, palm wax, carnauba wax, candelilla wax, rice wax, soy wax, hazel wax, beeswax, and lanolin wax.
  • Aliphatic olefins include polyethylene-based, polypropylene-based, and polymethylpentene-based resins.
  • resins containing long-chain alkyl groups include those obtained by reacting a main chain polymer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl butyral, polyvinyl acetate, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resin, or reactive group-containing poly(meth)acrylic resin with a compound having a group reactive with the above polymer and a long-chain alkyl group, thereby introducing a pendant long-chain alkyl group into the polymer, as well as copolymers of long-chain alkyl (meth)acrylates and monomers copolymerizable therewith.
  • a main chain polymer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl butyral, polyvinyl acetate, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resin, or reactive group-containing poly(meth)acrylic resin
  • the long-chain alkyl group preferably has 6 to 32 carbon atoms, more preferably 8 to 26 carbon atoms, and even more preferably 10 to 22 carbon atoms.
  • groups that can react with the above polymer include isocyanate groups, glycidyl groups, carboxyl groups, acid chloride groups, and oxazoline groups, with isocyanate groups being particularly preferred. Specific examples include octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, and behenyl isocyanate.
  • release agents containing long-chain alkyl group-containing resins are commercially available, for example, under the name Resem (product name) from Chukyo Yushi Co., Ltd., Peloil (registered trademark) from Lion Specialty Chemicals Co., Ltd., and octadecyl isocyanate-modified polyethyleneimine (product name: RP-20) from Nippon Shokubai Co., Ltd.
  • Long-chain alkyl (meth)acrylates include hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, behenyl (meth)acrylate, etc.
  • Monomers that can be copolymerized with long-chain alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, vinyl acetate, styrene, acrylonitrile, etc.
  • hydroxyl group-containing (meth)acrylic monomers such as 2-hydroxyethyl acrylate, carboxyl group-containing (meth)acrylic monomers such as acrylic acid and methacrylic acid, maleic acid, maleic anhydride, fumaric acid, cyano group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, etc. may be copolymerized.
  • the resin of the release layer may be crosslinked.
  • the crosslinking agent may be an isocyanate compound, a glycidyl group-containing compound, an oxazoline group-containing compound, an amino resin, or the like, but is not limited thereto.
  • a double bond may be introduced into the precursor of the resin that will become the release layer, and a crosslinking reaction may be caused by ultraviolet light or an electron beam.
  • a release agent When using a release agent, one type may be used, or two or more types may be mixed. It is also possible to mix additives such as light release additives and heavy release additives in order to adjust the release force.
  • additives such as light release additives and heavy release additives in order to adjust the release force.
  • the resulting biaxially oriented polypropylene film with a release layer has particularly excellent releasability.
  • the release layer may contain particles with a particle size of 1 ⁇ m or less, but it is preferable that it does not substantially contain particles or other protrusions from the viewpoint of pinhole formation.
  • Additives such as adhesion improvers and antistatic agents may be added to the release layer.
  • the thickness of the release layer may be set according to the intended use, and is not particularly limited, but is preferably in the range of 0.005 to 2 ⁇ m after curing.
  • a release layer thickness of 0.005 ⁇ m or more is preferable because it maintains peeling performance.
  • a release layer thickness of 2 ⁇ m or less is preferable because it does not require too long a curing time and there is no risk of uneven thickness due to a decrease in the flatness of the release film.
  • Another layer may be provided between the biaxially oriented polypropylene film and the release layer.
  • the method of forming the release layer is not particularly limited, and a method is used in which a coating liquid in which a releasing resin is dissolved or dispersed is spread on one side of a biaxially oriented polypropylene film by coating, etc., and the solvent is removed by drying, and then the film is heated and dried, heat-cured, or cured with ultraviolet light.
  • the drying temperature during solvent drying and heat-curing is preferably 100 to 170°C. If the drying temperature is higher than 170°C, wrinkles may occur in the film due to heat. On the other hand, if the drying temperature is low, the heat-curing of the release layer may be insufficient and releasability may not be obtained.
  • biaxially oriented polypropylene films have lower thermal dimensional stability at high temperatures than biaxially oriented polyester films, so that heat-induced wrinkles and deterioration of flatness are likely to occur during drying of the release layer, but the biaxially oriented polypropylene film for transfer substrate of the embodiment can suppress the occurrence of wrinkles.
  • the heating and drying time is generally 10 to 60 seconds.
  • any known coating method can be used as the coating method for the coating liquid, for example, roll coating methods such as gravure coating and reverse coating, bar coating methods such as wire bars, die coating, spray coating, air knife coating, etc., which are conventionally known methods.
  • the release layer may be an underlayer of the transfer layer described below, but it may also be a release layer for preventing the transfer layer from sticking to the side of the biaxially oriented polypropylene film for transfer substrate opposite the transfer layer when the laminate of the biaxially oriented polypropylene film for transfer substrate and the transfer layer is wound into a roll.
  • the release layer may also be laminated on both sides of the biaxially oriented polypropylene film.
  • the transfer laminate film of the embodiment will be described below.
  • the transfer laminate film includes a biaxially oriented polypropylene film for transfer substrate and a transfer layer.
  • the transfer layer and the transfer target will be described.
  • the transfer layer include a printed layer such as a pattern or character; a decorative metal thin film; a thermal transfer ink layer; a photosensitive resin layer; an optical functional layer such as a retardation layer, a polarizing layer, a circularly polarized reflective layer, a hard coat layer, an anti-reflection layer, and a low-reflection layer; a conductive layer; a circuit; an adhesive layer; a pressure-sensitive adhesive layer; and a rubber sheet layer. It is preferable that the transfer layer includes at least one layer selected from these.
  • the biaxially oriented polypropylene film for transfer substrate of the embodiment has excellent heat resistance, and even under conditions exceeding 130°C during processing such as coating and drying, the film shrinks only slightly, and it can be used at temperatures exceeding 150°C for a short period of time, and further has excellent rigidity, so that the above-mentioned transfer layer and biaxially oriented polypropylene film for transfer substrate are a suitable combination.
  • it because it has excellent rigidity, it can be peeled off smoothly when the base film is peeled off, which also allows for high-speed transfer and increases productivity.
  • the printing layer is transferred to a molded product, etc., to impart design to the surface.
  • the printing layer can be provided by printing on a substrate film. Examples of printing methods include gravure printing, letterpress printing, offset printing, screen printing, inkjet printing, and pad printing.
  • the printing layer may be provided directly on the substrate film, or a protective layer may be provided on the substrate film and printed on.
  • the protective layer becomes the protective layer for the printing layer after transfer.
  • a UV absorber may be added to the protective layer.
  • the transfer target include paper, film, cloth, wood, glass, ceramics, metal, resin molded body, conductive thin film laminate, etc., and may be composite materials of these.
  • Wood, glass, ceramics, metal, and resin molded body may be plate-shaped or columnar, and may have a shape for a specific purpose such as a container or a part of an article.
  • a transfer laminate film is placed on the transfer target, and the transfer is performed using a heated roll or a heated mold.
  • a biaxially oriented polypropylene film for the transfer substrate, there is little dimensional change or deterioration of flatness even when drying at a higher temperature when providing the printing layer, and productivity can be increased. It also enables faster transfer printing, making it easier to perform highly accurate transfer printing without misalignment.
  • Decorative metal thin films are transferred to molded products, paper, films, etc. to impart design. The transfer may be performed over the entire surface of the object, or only a portion of the object.
  • Metals for decorative metal thin films include gold, silver, copper, aluminum, nickel, tin, etc.
  • Decorative metal thin films can be formed by laminating metal foils, or by methods such as vapor deposition and sputtering.
  • the decorative metal thin film may be directly in contact with the base film, and in the case of metal foil, may be provided via an adhesive layer, or may be provided on a protective layer provided on the base film.
  • the protective layer becomes a protective layer for the decorative metal thin film layer after transfer.
  • the protective layer may be colored and the metal thin film may be made of uncolored aluminum, etc., so that the appearance after transfer is gold or copper.
  • a printed layer may also be provided between the decorative metal thin film and the base film. Examples of objects to be transferred include the same as the printed layer.
  • Thermal transfer ink layer uses a heating head to print patterns, characters, etc. onto a receiver such as paper, film, or cloth.
  • the thermal transfer ink layer may be a melt ink layer or a sublimation dye-containing ink layer.
  • the temperature of the heating head can be increased, making it easier to print at higher speeds.
  • the photosensitive resin layer can be a resist layer, and may be negative or positive. It can be transferred to a transfer target having a conductive layer such as a thin copper film or an ITO layer on its surface, and used to form a pattern on the conductive layer. In forming a pattern, radiation exposure may be performed before or after peeling off the base film.
  • transfer targets having a conductive layer include films, glass plates, ceramic plates, resin plates, etc., on whose surfaces a conductive layer is provided, and the resin plate may be a composite plate with paper, glass fiber, etc.
  • the retardation layer is transferred to a polarizing plate or film, and becomes an optical compensation layer of an image display device, a ⁇ /4 layer, a ⁇ /2 layer, etc. of a circular polarizing plate, etc.
  • a liquid crystal compound is preferably used for the retardation layer, and the retardation is generated by the orientation of the liquid crystal compound.
  • the liquid crystal compound may be either a rod-shaped liquid crystal compound or a discotic liquid crystal compound, but it is preferable that the liquid crystal compound has a reactive group such as a double bond and can fix the orientation.
  • the orientation of the liquid crystal compound can be performed by rubbing the surface of the base film or the surface of the protective layer when the protective layer described below is provided, irradiating the liquid crystal compound with polarized light, providing an orientation control layer as a lower layer of the retardation layer and rubbing the orientation control layer, or irradiating polarized light to impart an orientation control function.
  • This orientation control is also considered to be part of the retardation layer.
  • the retardation layer may be a plurality of layers.
  • the retardation layer may be provided directly in contact with the base film, or may be provided on a protective layer provided on the base film.
  • the polarizing layer is a layer that converts natural light into linearly polarized light.
  • the liquid crystal compound is oriented in the same manner as the retardation layer.
  • the polarizing layer contains a dichroic dye, which is oriented along the orientation of the liquid crystal compound and exhibits a polarizing function. It is preferable to use multiple dichroic dyes so that the light is polarized over the entire visible light range.
  • Another form of the polarizing layer may be a wire grid type.
  • the circularly polarized reflective layer reflects one direction of the optical rotation and transmits optical rotation in multiple directions. It is preferable to use cholesteric liquid crystal.
  • the retardation layer, polarizing layer, and circularly polarized reflective layer may be combined and laminated.
  • the retardation layer, polarizing layer, and circularly polarized reflective layer may be provided in direct contact with the substrate film, or may be provided on a protective layer on the substrate film. Examples of objects to which the retardation layer, polarizing layer, and circularly polarized reflective layer are transferred include films, glass plates, and resin plates. The objects to be transferred are preferably transparent, but may be mirror-reflective depending on the application.
  • liquid crystal compounds In order to align these liquid crystal compounds, they are often heated to 110 to 140°C, but by using a biaxially oriented polypropylene film for transfer substrate, the dimensional change and deterioration of flatness due to heat during alignment and fixation of the liquid crystal compounds are small, and the liquid crystal can be oriented as designed, and a higher quality and uniform retardation layer, polarizing layer, and circularly polarized reflective layer can be provided.
  • the hard coat layer prevents the surface of the transfer target from being dented or scratched.
  • the low reflection layer is a layer with a lower refractive index than the transfer target provided on the surface of the transfer target to suppress surface reflection
  • the anti-reflection layer is a layer with a different refractive index provided on the surface of the transfer target to suppress reflection by interference of reflected light at multiple interfaces.
  • the transfer target may be a film, a glass plate, a resin plate, a resin molded body, etc.
  • the transfer target is preferably a transparent one, and a preferred example is one provided on the surface of an image display device. It may also be provided on the surface of a colored object to suppress surface reflection and make the color look vivid.
  • Curable resins are used for the hard coat layer, low reflection layer, and anti-reflection layer, but by using a biaxially oriented polypropylene film for transfer substrate, high dimensional stability and flatness are maintained even when irradiated with stronger radiation in the case of a radiation curable resin, or even when irradiated with higher temperatures in the case of a thermosetting resin, so high-speed processing is possible. Curable adhesives are also used during transfer, which similarly makes it easier to perform high-speed transfer.
  • the conductive layer provides conductivity to the surface of the transfer target. It is used as an antistatic layer, an electromagnetic shielding layer, and an electrode layer for image display cells such as liquid crystal cells in touch panels and liquid crystal display devices.
  • the conductive layer is preferably a transparent conductive layer, and examples of the conductive layer include metal oxide films such as ITO, conductive polymer films such as polyacetylene, polythiophene, and polyaniline, metal nanowire-dispersed polymer films, conductive pastes containing metal particles printed in a mesh shape, and metal foils etched into a mesh shape.
  • the transfer target can be a film, glass plate, resin plate, or resin molded body. By using a biaxially oriented polypropylene film for transfer substrates, high dimensional stability and flatness are maintained even when exposed to heat by deposition, sputtering, CVD, etc., making it possible to produce a high-quality conductive film.
  • the circuit is the conductive layer processed into a circuit shape, and is used to provide a touch sensor function, an antenna, or an electric or electronic circuit to the target object.
  • the conductive layer and circuit may be provided in contact with the base film, or a protective layer may be provided on the base film and the circuit may be provided on top of this.
  • the circuit may be processed into a circuit after the conductive layer is provided as described above, or may be printed as a circuit using conductive polymer or conductive paste. Examples of objects to be transferred include films, glass plates, ceramic plates, and resin plates, and the resin plate may be a composite plate containing paper, glass fiber, etc.
  • the adhesive layer is a layer that contains an adhesive.
  • Suitable adhesives include hot melt adhesives.
  • Hot melt adhesives include polyolefin-based, ethylene vinyl acetate-based, rubber-based, polyamide-based, polyester-based, and polyurethane-based adhesives.
  • the adhesive may be a reactive adhesive. A reactive adhesive is not solidified when laminated on the substrate film, but reacts and hardens after transfer.
  • a reactive adhesive is an adhesive that contains a reactive group
  • examples of the reactive group include an isocyanate group, a blocked isocyanate group, an oxirane group, an oxetane group, a carbodiimide group, an acryloyl group, an oxazoline group, a silyl group, and a cyanoacrylate group.
  • Adhesives that are heat-curable, moisture-curable, or radiation-curable can be used.
  • the appropriate reactive group can be selected from isocyanate, blocked isocyanate, oxirane, oxetane, carbodiimide, acryloyl, and oxazoline groups.
  • the appropriate reactive group can be selected from isocyanate, silyl, and cyanoacrylate groups.
  • the appropriate reactive group can be selected from oxirane, oxetane, and acryloyl groups.
  • a catalyst that acts as a catalyst when exposed to heat or radiation a heat-curable or radiation-curable adhesive can be made.
  • Reactive adhesives may be reacted with heat or radiation after the substrate film of the adhesive layer has been peeled off and the object to be bonded is placed on the surface, or radiation may be applied before the substrate film is peeled off, or the adhesive reaction may be initiated by heat during transfer, after which the substrate film is peeled off and the object to be bonded is placed on top.
  • the reaction is initiated when the adhesive layer absorbs moisture after the release film or substrate film on the opposite side of the adhesive layer is peeled off.
  • Hot melt adhesives may also have the above reactivity.
  • An adhesion-promoting coating may be applied to the adhesive layer or the object to be bonded during transfer to ensure stronger adhesion of the adhesive.
  • a barrier layer may be provided on the biaxially oriented polypropylene film for transfer substrates.
  • barrier layers include vapor deposition layers of aluminum, silicon oxide, aluminum oxide, etc., and barrier coat layers of inorganic layered compounds and polyvinylidene chloride, etc.
  • the adhesive layer is a layer that contains an adhesive.
  • adhesives include acrylic and rubber-based adhesives, and a suitable example is an acrylic optical adhesive.
  • a hot melt adhesive may also be used.
  • a transfer layer other than an adhesive layer or pressure-sensitive adhesive layer When a transfer layer other than an adhesive layer or pressure-sensitive adhesive layer is transferred to a transfer target object, it is attached to the transfer target object via an adhesive layer or pressure-sensitive adhesive layer.
  • the adhesive layer or pressure-sensitive adhesive layer may be provided on the transfer layer or the transfer target object when transferring, or may be provided on the transfer layer in advance. Note that if the transfer layer itself has adhesiveness or bonding properties to the transfer target object, or if the transfer target object itself has adhesiveness or bonding properties to the transfer layer, it is not necessarily necessary to provide an adhesive layer or pressure-sensitive adhesive layer. The same applies when the transfer layer and the transfer target object exhibit adhesiveness or bonding properties when heated.
  • rubber sheet layers include sheets of natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber, nitrile rubber, and polyisobutylene rubber.
  • Rubber sheet laminates are used, for example, as repair patches for rubber products and as rubber sheets for vulcanization adhesion. These rubbers are manufactured by kneading them using a calendar method and laminating them on a film with releasability to form a sheet, or by extruding them into a sheet from an extruder and laminating them on a film with releasability. Even at the temperatures used during lamination, wrinkles are unlikely to form and the laminate obtained is curl-free and has excellent flatness. Furthermore, when heated during transfer, the temperature can be raised, and the excellent rigidity allows for smooth peeling.
  • the transfer target is preferably any of paper, film, cloth, wood, glass, ceramics, metal, resin molded body, and conductive thin film laminate.
  • the biaxially oriented polypropylene film for transfer substrate of the embodiment is less likely to wrinkle, change in size, or deteriorate in flatness when the transfer layer is provided or processed, and not only does it improve the appearance quality of the transfer laminate film, but it can also be used as a transfer film for high-definition transfer applications. Furthermore, even at high temperatures during transfer, it is less likely to wrinkle or change in size, and not only does it improve the appearance quality, but it also enables high-precision transfer.
  • the biaxially oriented polypropylene film for thin film manufacturing is preferably used when the transfer layer is provided or the processing process includes a process in which the environment is at high temperature.
  • Specific processes include a drying process, a crosslinking reaction process, a phase conversion process, a phase separation process, and a surface flattening process.
  • Specific temperatures preferably include a process in an environment of 110°C or higher, more preferably 115°C or higher, even more preferably 120°C or higher, and particularly preferably 125°C or higher.
  • the upper limit of the environmental temperature is preferably 160°C, more preferably 155°C, and even more preferably 150°C.
  • the lower limit of the time for the step of reaching the above temperature is preferably 2 seconds, more preferably 5 seconds, and even more preferably 10 seconds.
  • the upper limit of the time is preferably 60 minutes, more preferably 45 minutes, and even more preferably 30 minutes.
  • the temperature exceeds 155°C, it is preferable to avoid more than 30 seconds, more preferably to avoid more than 20 seconds, and even more preferably to avoid more than 15 seconds.
  • the temperature exceeds 150°C, it is preferable to avoid more than 90 seconds, more preferably to avoid more than 60 seconds, and even more preferably to avoid more than 45 seconds.
  • the temperature exceeds 140°C it is preferable to avoid more than 3 minutes, more preferably to avoid more than 2 minutes, and even more preferably to avoid more than 1 minute.
  • the temperature exceeds 130°C, it is preferable to avoid more than 5 minutes, more preferably to avoid more than 4 minutes, and even more preferably to avoid more than 3 minutes.
  • the temperature of the molten transfer layer is preferably 180°C or less, more preferably 170°C or less, even more preferably 160°C or less, particularly preferably 150°C or less, and most preferably 145°C or less. However, if the temperature exceeds 150°C, it is preferable to pass the film through a cooling roll or cooling belt and cool it from the opposite side.
  • the temperature of the molten transfer layer is preferably 120°C or more, more preferably 125°C or more, and even more preferably 130°C or more.
  • the temperature of the heating body is preferably 120°C or higher, more preferably 125°C or higher, and even more preferably 130°C or higher.
  • the temperature of the heating body is preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower.
  • the contact time with the heating body is preferably 0.5 seconds or more, more preferably 1 second or more, even more preferably 1.5 seconds or more, and especially preferably 2 seconds or more.
  • the contact time is preferably 180 seconds or less, more preferably 120 seconds or less, even more preferably 90 seconds or less, and especially preferably 60 seconds or less.
  • the temperature of the heating body exceeds 155°C, it is preferable to avoid a time of 90 seconds or more, and if it exceeds 150°C, it is preferable to avoid a time of 60 seconds or more.
  • the film When performing deposition, sputtering, CVD, etc., it is preferable to cool the film so that the temperature does not exceed 150°C.
  • the transfer process is a heat transfer process
  • the temperature and time of the heating body such as a heat roll or a heat press mold
  • the transfer laminate film is preferably wound into a long roll.
  • a masking film surface protection film
  • Examples of masking films include polyester-based films, polypropylene-based films, and polyethylene-based films.
  • the masking film may be provided with a release layer and an adhesive layer.
  • the transfer method of the embodiment includes a step of bonding the transfer laminate film to the transfer target object, and a step of peeling the biaxially oriented polypropylene film for transfer substrate of the transfer laminate film from the transfer target object to which the transfer laminate film is bonded.
  • the transfer laminate film can be overlaid on the transfer target object and bonded using a heated roll or a heated mold.
  • the peeling step it is sufficient to peel at least the biaxially oriented polypropylene film for transfer substrate from the transfer target object, and if the transfer laminate film has a release layer, it is preferable to peel the biaxially oriented polypropylene film for transfer substrate and the release layer from the transfer target object.
  • the biaxially oriented polypropylene film for the thin film manufacturing process according to the embodiment of the second disclosure satisfies the following (1), (2), and (3).
  • the mesopentad fraction of the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process is 97.5% or more.
  • the relationship between the loop stiffness stress S [mN] in the width direction and the thickness t ( ⁇ m) satisfies the following formula (A).
  • the biaxially oriented polypropylene film for thin film manufacturing process of the embodiment is preferably made of a polypropylene resin composition containing polypropylene resin as a main component.
  • the term "main component" means that the proportion of polypropylene resin in the polypropylene resin composition is 90% by mass or more, more preferably 93% by mass or more, even more preferably 95% by mass or more, and particularly preferably 97% by mass or more. The proportion may be 100% by mass or less, or 99% by mass or less.
  • the polypropylene resin composition may contain additives.
  • the additives may include a crystal nucleating agent, an antioxidant, a heat stabilizer, a slipping agent, an antistatic agent, an antiblocking agent, a filler, a viscosity modifier, a color inhibitor, or a combination thereof.
  • the polypropylene resin may contain a polypropylene homopolymer, a copolymer of propylene and ethylene and/or an ⁇ -olefin having 4 or more carbon atoms, or a mixture thereof. Of these, a propylene homopolymer that does not substantially contain ethylene and/or an ⁇ -olefin having 4 or more carbon atoms is preferred.
  • the amount of ethylene and/or an ⁇ -olefin having 4 or more carbon atoms is preferably 1 mol% or less, more preferably 0.5 mol% or less, even more preferably 0.3 mol% or less, and particularly preferably 0.1 mol% or less, based on 100 mol% of all constituent units of the copolymer.
  • the amount of the component may be 0.01 mol% or more.
  • Examples of the ⁇ -olefin component having 4 or more carbon atoms constituting such a copolymer include 1-butene, 1-pentene, 3-methylpentene-1, 3-methylbutene-1, 1-hexene, 4-methylpentene-1, 5-ethylhexene-1, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-eicosene, etc.
  • the polypropylene resin may contain two or more different polypropylene homopolymers, copolymers with ethylene and/or ⁇ -olefins having 4 or more carbon atoms, or mixtures thereof.
  • the mesopentad fraction of a polypropylene resin (hereinafter sometimes abbreviated as [mmmm]%) is quantified based on the peak assignment of the 13 C-NMR spectrum, and means the ratio of five consecutive propylene monomer units in the polypropylene resin having the same stereostructure, and is an index of stereoregularity.
  • the mesopentad fraction of a polypropylene resin is 97.5% or more, preferably in the range of 97.5 to 99.9%, more preferably in the range of 98.0 to 99.7%, even more preferably in the range of 98.3 to 99.5%, and particularly preferably in the range of 98.5 to 99.3%.
  • the crystallinity of the polypropylene resin is increased, and the melting point, crystallinity, and crystal orientation of the crystals in the film are improved, and rigidity and heat resistance at high temperatures are easily obtained.
  • it is 99.9% or less, the cost of polypropylene production is easily reduced, and the film is less likely to break during film formation.
  • the mesopentad fraction is measured by a nuclear magnetic resonance method (so-called NMR method).
  • a method of washing the obtained polypropylene resin powder with a solvent such as n-heptane, a method of appropriately selecting a catalyst and/or a co-catalyst, and a method of appropriately selecting components of the polypropylene resin composition are preferably adopted.
  • the melting temperature (Tm) of the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process measured by DSC is preferably 160 ° C, more preferably 161 ° C, even more preferably 162 ° C, even more preferably 163 ° C, and particularly preferably 164 ° C. If Tm is 160 ° C or more, rigidity and heat resistance at high temperatures are easily obtained.
  • the upper limit of Tm is preferably 170 ° C, more preferably 169 ° C, even more preferably 168 ° C, even more preferably 167 ° C, and particularly preferably 166 ° C.
  • Tm is 170 ° C or less, it is easy to suppress the increase in cost in terms of polypropylene production, and it is difficult to break during film formation.
  • the melting temperature can also be further increased by blending a crystal nucleating agent with the above-mentioned polypropylene resin.
  • Tm is the main endothermic peak temperature associated with melting, which is observed when 1 to 10 mg of a sample is packed in an aluminum pan and set in a differential scanning calorimeter (DSC), melted at 230°C for 5 minutes in a nitrogen atmosphere, cooled to 30°C at a scanning rate of -10°C/min, held for 5 minutes, and then heated at a scanning rate of 10°C/min.
  • DSC differential scanning calorimeter
  • the lower limit of the crystallization temperature (Tc) measured by DSC of the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process is preferably 105 ° C, more preferably 108 ° C, and even more preferably 110 ° C. If Tc is 105 ° C or more, crystallization is likely to proceed in the width direction stretching and the subsequent cooling process, and rigidity and heat resistance at high temperatures are likely to be obtained.
  • the upper limit of Tc is preferably 135 ° C, more preferably 133 ° C, even more preferably 132 ° C, even more preferably 130 ° C, particularly preferably 128 ° C, and most preferably 127 ° C.
  • Tc is 135 ° C or less, it is difficult to increase the cost in terms of polypropylene production, and it is difficult to break during film formation.
  • the crystallization temperature can also be increased by blending a crystal nucleating agent with the above-mentioned polypropylene resin.
  • Tc is the main peak temperature of the exothermic peak observed when 1 to 10 mg of a sample is packed in an aluminum pan, set in a DSC, melted at 230°C for 5 minutes in a nitrogen atmosphere, and cooled to 30°C at a scanning rate of -10°C/min.
  • the melt flow rate (MFR) of the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process is preferably 4.0 to 30 g/10 min, more preferably 4.5 to 25 g/10 min, even more preferably 4.8 to 22 g/10 min, particularly preferably 5.0 to 20 g/10 min, and most preferably 6.0 to 18 g/10 min, when measured in accordance with condition M (230 ° C, 2.16 kgf) of JIS K 7210 (1995).
  • the melt flow rate (MFR) of the polypropylene resin is 4.0 g/10 min or more, it is easy to obtain a biaxially oriented polypropylene film for thin film manufacturing process with low thermal shrinkage.
  • the melt flow rate (MFR) of the polypropylene resin is 30 g/10 min or less, it is easy to maintain the film formability of the film.
  • the lower limit of the melt flow rate (MFR) (230°C, 2.16 kgf) of the polypropylene resin constituting the film is preferably 5.0 g/10 min, 5.5 g/10 min, 6.0 g/10 min, 6.3 g/10 min, 6.5 g/10 min, 6.8 g/10 min, and 7.0 g/10 min in that order. If the melt flow rate (MFR) of the polypropylene resin is 5.0 g/10 min or more, the amount of low molecular weight components in the polypropylene resin constituting the film increases.
  • the lower limit of the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve of the polypropylene resin constituting the biaxially oriented polypropylene film for thin film manufacturing process is preferably 35 mass%, more preferably 38 mass%, even more preferably 40 mass%, even more preferably 41 mass%, and particularly preferably 42 mass%.
  • the upper limit of the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve is preferably 65 mass%, more preferably 60 mass%, and even more preferably 58 mass%. If the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve is 65 mass% or less, the film strength is less likely to decrease.
  • the amount of components with a molecular weight of 100,000 or less contained in the polypropylene resin can be easily adjusted without significantly changing the overall viscosity, so that it is easy to improve the film formability without affecting the rigidity or heat shrinkage too much.
  • the lower limit of the weight average molecular weight (Mw)/number average molecular weight (Mn), which is an index of the breadth of the molecular weight distribution, of the polypropylene resin is preferably 3.5, more preferably 4, even more preferably 4.5, and particularly preferably 5.
  • the upper limit of Mw/Mn is preferably 30, more preferably 25, even more preferably 23, particularly preferably 21, and most preferably 20.
  • Mw/Mn can be obtained using gel permeation chromatography (GPC). When Mw/Mn is in the above range, it is easy to increase the amount of components having a molecular weight of 100,000 or less.
  • the molecular weight distribution of polypropylene resin can be adjusted by polymerizing components of different molecular weights in multiple stages in a series of plants, blending components of different molecular weights offline in a kneader, polymerizing by blending catalysts with different performance, or using a catalyst that can achieve the desired molecular weight distribution.
  • the shape of the molecular weight distribution obtained by GPC may be a gentle molecular weight distribution with a single peak in a GPC chart with the logarithm (logM) of molecular weight (M) on the horizontal axis and the differential distribution value (weight fraction per logM) on the vertical axis, or a molecular weight distribution with multiple peaks or shoulders.
  • the thickness of the biaxially oriented polypropylene film for thin film manufacturing process is set according to each application, but in order to obtain the strength of the film, the lower limit of the film thickness is preferably 5 ⁇ m, more preferably 8 ⁇ m, even more preferably 10 ⁇ m, particularly preferably 12 ⁇ m, and most preferably 14 ⁇ m.
  • the film thickness is 5 ⁇ m or more, the rigidity of the film is easily obtained, the thin film layer is easily provided, and the thin film layer is easily peeled off. In addition, wrinkles are less likely to occur when winding up.
  • the upper limit of the film thickness is preferably 120 ⁇ m, more preferably 100 ⁇ m, even more preferably 80 ⁇ m, particularly preferably 70 ⁇ m, and most preferably 60 ⁇ m.
  • the biaxially oriented polypropylene film for thin film manufacturing process is usually produced as a roll having a width of about 2000 to 12000 mm and a length of about 1000 to 50000 m, and is wound into a film roll.
  • the film is then slit according to the intended use and supplied as a slit roll having a width of 300 to 2000 mm and a length of 500 to 5000 m. It is possible to obtain a longer film roll from the biaxially oriented polypropylene film for thin film manufacturing processes.
  • the lower limit of the thickness uniformity of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 0%, more preferably 0.1%, even more preferably 0.5%, and particularly preferably 1%.
  • the upper limit of the thickness uniformity is preferably 20%, more preferably 17%, even more preferably 15%, especially preferably 12%, and most preferably 10%. In the above range, defects are unlikely to occur during post-processing such as coating and printing, and it is easy to use in applications requiring precision.
  • the thickness uniformity is measured, for example, as follows.
  • the biaxially oriented polypropylene film for thin film manufacturing process preferably has the following characteristics and structure.
  • the "longitudinal direction" of the biaxially oriented polypropylene film for thin film manufacturing process is the direction corresponding to the flow direction in the film manufacturing process
  • the "width direction” is the direction perpendicular to the flow direction in the film manufacturing process.
  • the spin-spin relaxation time T2 observed by 1H -pulse NMR becomes slower in the order of crystal, intermediate phase, and amorphous.
  • the intermediate phase has a faster T2 than the amorphous phase, and is considered to be an amorphous phase with restricted mobility.
  • a highly oriented crystalline component (I) is generated, and an amorphous chain component (II) (corresponding to the above-mentioned intermediate phase) with restricted mobility is generated near the crystal.
  • an amorphous component (III) (corresponding to the above-mentioned amorphous) that is not restricted by the crystal is likely to be generated.
  • the unrestricted amorphous component (III) has high mobility, and at high temperatures it is likely to move to eliminate distortion, which is thought to cause shrinkage at high temperatures.
  • the restricted amorphous chain (II) is thought to be less likely to shrink at high temperatures because its movement is suppressed even at high temperatures compared to the amorphous component (III).
  • the upper limit of the ratio of the unconstrained amorphous component (III) determined by pulse NMR of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 7%, more preferably 6%, and even more preferably 5%.
  • it is effective to increase the area ratio during film formation, and to perform sequential biaxial stretching and then re-stretching in the width direction at high temperature. It is also effective to use a polypropylene raw material with a high mesopentad fraction.
  • a ratio of the unconstrained amorphous component (III) of 7% or less determined by pulse NMR means that there are few molecular chains with large distortion of the molecular orientation restrained by the entanglement points, and the film is less likely to shrink even when the crystals begin to melt.
  • the laminated film or thin film layer is less likely to wrinkle, resulting in a film with little dimensional change or deterioration in flatness.
  • the ratio of the unconstrained amorphous component (III) exceeds 7% when the film is separated into the crystalline component (I), the constrained amorphous component (II), and the unconstrained amorphous component (III) as determined by pulse NMR using the solid echo method, there are many molecular chains with large distortion of the molecular orientation constrained by the entanglement points, so that the film shrinks as soon as the crystals start to melt, resulting in a film that is prone to wrinkles, dimensional changes, and deterioration of flatness.
  • the ratio of the unconstrained amorphous component (III) but a practical value is 0.1% or more.
  • the ratio of the unconstrained amorphous component (III) is to be less than 0.1%, it is necessary to further stretch the film in the width direction at a high temperature after the successive biaxial stretching, and the tension during stretching due to melting may decrease, causing breakage. The crystal orientation in the film may become weaker, resulting in reduced rigidity.
  • the upper limit of the longitudinal heat shrinkage rate of the biaxially oriented polypropylene film for thin film manufacturing process at 150 ° C is preferably 10%, more preferably 8.0%, even more preferably 6.0%, particularly preferably 5.0%, and most preferably 4.0% or less.
  • the lower limit may be 0%, 1.0%, or 2.0%.
  • the upper limit of the transverse heat shrinkage rate at 150 ° C is preferably 25%, more preferably 20%, even more preferably 16%, even more preferably 15%, particularly preferably 12%, and most preferably 10%.
  • the lower limit may be 0%, 2.0%, or 4.0%.
  • the thermal shrinkage rate in the longitudinal direction is 10% or less and the thermal shrinkage rate in the transverse direction is 25% or less, wrinkles, dimensional changes, and deterioration of flatness due to heat during release processing or processing of the thin film layer such as providing a thin film layer or heat treatment are unlikely to occur.
  • the thermal shrinkage rate in the longitudinal direction at 150 ° C is 8.0% or less and the thermal shrinkage rate in the transverse direction at 150 ° C is 15% or less, the control range of the roll tension during processing is further expanded, and as a result, wrinkles, dimensional changes, and deterioration of flatness are unlikely to occur, which is preferable.
  • the lower limit of the stress (F5) at 5% elongation in the width direction of the biaxially oriented polypropylene film at 23 ° C. in the thin film manufacturing process is preferably 110 MPa, more preferably 120 MPa, even more preferably 140 MPa, even more preferably 160 MPa, particularly preferably 180 MPa, and most preferably 190 MPa.
  • the upper limit of F5 in the width direction at 23 ° C. is preferably 300 MPa, more preferably 290 MPa, and even more preferably 280 Pa. If it is 280 MPa or less, practical manufacturing is easy and the vertical-width balance is easily improved.
  • the lower limit of F5 in the longitudinal direction of the biaxially oriented polypropylene film for thin film manufacturing process at 23°C is preferably 40 MPa, more preferably 42 MPa, even more preferably 46 MPa, and particularly preferably 48 MPa.
  • the upper limit of F5 in the longitudinal direction at 23°C is preferably 70 MPa, more preferably 65 MPa, even more preferably 62 MPa, and particularly preferably 60 MPa. At 70 MPa or less, practical manufacturing becomes easier and the longitudinal and width balance tends to improve.
  • F5 By setting F5 at the above level or more, the film is more rigid, making it easier to maintain the shape of the film and easier to perform release processing, and it is also easier to handle when processing the thin film layer and peeling the thin film, and it is less likely to undergo dimensional changes or deterioration of flatness, making it easier to obtain a uniform, high-quality thin film.
  • F5 can be set within the range by adjusting the stretch ratio and relaxation rate, or by adjusting the temperature during film production.
  • the heat shrinkage rate (%) in the width direction at 150° C. and the stress at 5% elongation (MPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulas. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage rate (%) in the width direction at 150°C ⁇ 4.0 + 140 This results in higher rigidity and a smaller thermal shrinkage rate at high temperatures, making it easier to maintain the shape of the film, and suppressing the occurrence of wrinkles in the film due to heat during the drying process of the release layer.
  • the heat shrinkage rate (%) in the width direction at 150° C. and the stress at 5% elongation (MPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulae. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 150°C ⁇ 4.0 + 150
  • the heat shrinkage rate (%) in the width direction at 150°C and the stress at 5% elongation (MPa) in the width direction at 23°C of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulae. Stress (MPa) at 5% elongation in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 150°C ⁇ 4.0 + 160
  • the upper limit of the longitudinal heat shrinkage rate of the biaxially oriented polypropylene film for thin film manufacturing process at 120 ° C. is preferably 2.0%, more preferably 1.5%, even more preferably 1.2%, particularly preferably 1.0%, and most preferably 0.8%.
  • the lower limit may be 0% or 0.1%. If it is 2.0% or less, appearance defects such as vertical streaks during release processing are unlikely to occur.
  • the upper limit of the widthwise heat shrinkage rate at 120 ° C. is preferably 8.0%, more preferably 5.0%, even more preferably 3.5%, even more preferably 2.5%, particularly preferably 2.0%, more particularly preferably 1.5%, and most preferably 1.0%.
  • the lower limit may be 0%, 0.1%, or 0.2%.
  • the heat shrinkage rate at 120° C. can be kept within the range by adjusting the stretch ratio, stretching temperature and heat setting temperature.
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulas.
  • Heat shrinkage (%) in the width direction at 120°C ⁇ 0.3 + 7.0 This results in higher rigidity and smaller thermal shrinkage at high temperatures, which means that the film or laminate with a thin film is less likely to develop wrinkles, dimensional changes, or deterioration in flatness during release processing and processing of the thin film layer, resulting in not only a better appearance but also the ability to easily obtain a uniform, high-quality thin film.
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulae: Tensile modulus (GPa) in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 120°C ⁇ 0.3 + 8.0
  • the heat shrinkage rate (%) in the width direction at 120° C. and the tensile modulus (GPa) in the width direction at 23° C. of the biaxially oriented polypropylene film for the thin film manufacturing process satisfy the following formulae: Tensile modulus (GPa) in the width direction at 23°C ⁇ Heat shrinkage (%) in the width direction at 120°C ⁇ 0.3 + 9.0
  • the lower limit of the tensile modulus in the longitudinal direction of the biaxially oriented polypropylene film for thin film manufacturing process at 23° C. is preferably 2.0 GPa, more preferably 2.1 GPa, even more preferably 2.2 GPa, even more preferably 2.3 GPa, particularly preferably 2.4 GPa, and most preferably 2.6 GPa.
  • the upper limit of the tensile modulus in the longitudinal direction is preferably 4.0 GPa, more preferably 3.8 GPa, even more preferably 3.7 GPa, particularly preferably 3.6 GPa, and most preferably 3.5 GPa. At 4.0 GPa or less, practical manufacturing is easy and the balance of the properties in the longitudinal direction and the width direction is easily improved.
  • the lower limit of the tensile modulus in the width direction at 23°C of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 5.0 GPa, more preferably 6.0 GPa, even more preferably 6.5 GPa, even more preferably 6.7 GPa, particularly preferably 7.0 GPa, even more particularly preferably 8.0 GPa, and most preferably 8.5 GPa.
  • the upper limit of the tensile modulus in the width direction is preferably 15 GPa, more preferably 13 GPa, and even more preferably 12 GPa. If it is 15 GPa or less, practical manufacturing is easy and the balance of the longitudinal and width direction properties is easily improved.
  • the tensile modulus By setting the tensile modulus at the above level or more, the shape of the film is easily maintained, the film is not easily stretched even when a strong tension is applied to the film when the thin film layer is provided, processed, or transferred, and handling is easy when the thin film layer is processed or transferred, and wrinkles, dimensional changes, and deterioration of flatness are less likely to occur in the film or laminate with the thin film layer, not only improving the appearance quality but also making it easier to manufacture a uniform, high-quality thin film.
  • the tensile modulus can be kept within the range by adjusting the stretch ratio and relaxation rate, and by adjusting the temperature during film formation.
  • the lower limit of the longitudinal tensile breaking strength of the biaxially oriented polypropylene film for thin film manufacturing process at 23° C. is preferably 90 MPa, more preferably 100 MPa, even more preferably 110 MPa, and particularly preferably 115 MPa.
  • the upper limit of the longitudinal tensile breaking strength is preferably 200 MPa, more preferably 180 MPa, and even more preferably 160 MPa as a practical value. If it is 200 MPa or less, the film is likely to break less.
  • the lower limit of the tensile breaking strength in the width direction at 23°C of the biaxially oriented polypropylene film for the thin film manufacturing process is preferably 250 MPa, more preferably 300 MPa, even more preferably 350 MPa, even more preferably 400 MPa, particularly preferably 420 MPa, even more particularly preferably 440 MPa, and most preferably 450 MPa.
  • the upper limit of the tensile breaking strength in the width direction is preferably 650 MPa as a practical value, more preferably 600 MPa, and even more preferably 550 MPa. If it is 650 MPa or less, the film is less likely to break.
  • the tensile breaking strength is above the above, high tension is easily applied during release processing, when providing a thin film layer, or during processing, and wrinkles, dimensional changes, and deterioration of flatness of the film or laminate are less likely to occur, handling is easier, and not only the appearance quality is improved, but also it is easy to manufacture a uniform and high-quality thin film.
  • the film is less likely to break during release processing.
  • the tensile breaking strength can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the lower limit of the longitudinal tensile elongation at break of the biaxially oriented polypropylene film for thin film manufacturing process at 23°C is preferably 150%, more preferably 180%, even more preferably 190%, particularly preferably 200%, and most preferably 210%. If it is 150% or more, the film tends to break less.
  • the upper limit of the longitudinal tensile elongation at break at 23°C is preferably 300% as a practical value, and more preferably 280%.
  • the lower limit of the tensile elongation at break in the width direction of the biaxially oriented polypropylene film for thin film manufacturing processes at 23°C is preferably 15%, more preferably 20%, even more preferably 25%, and particularly preferably 30%. If it is 15% or more, the film is less likely to break.
  • the upper limit of the tensile elongation at break in the width direction at 23°C is preferably 60%, more preferably 55%, and even more preferably 50%.
  • the tensile elongation at break can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the lower limit of the refractive index (Nx) in the longitudinal direction of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 1.4950, more preferably 1.4970, even more preferably 1.4980, particularly preferably 1.4990, and most preferably 1.5000. If it is 1.4950 or more, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Nx) in the longitudinal direction is preferably 1.5100, more preferably 1.5070, and even more preferably 1.5050. If it is 1.5100 or less, the film is likely to have an excellent balance of properties in the longitudinal direction and the width direction.
  • the lower limit of the refractive index (Ny) in the width direction of the biaxially oriented polypropylene film for thin film manufacturing processes is preferably 1.5250, more preferably 1.5253, even more preferably 1.5255, even more preferably 1.5260, and particularly preferably 1.5265. If it is 1.5250 or higher, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Ny) in the width direction is preferably 1.5280, more preferably 1.5275, and even more preferably 1.5270. If it is 1.5280 or less, the film is likely to have an excellent balance of properties in the longitudinal and width directions.
  • the lower limit of the refractive index (Nz) in the thickness direction of the biaxially oriented polypropylene film for the thin film manufacturing process is preferably 1.4960, more preferably 1.4965, even more preferably 1.4970, particularly preferably 1.4980, and most preferably 1.4990. If it is 1.4960 or higher, the rigidity of the film is easily increased.
  • the upper limit of the refractive index (Nz) in the thickness direction is preferably 1.5020, more preferably 1.5015, and even more preferably 1.5010. If it is 1.5020 or lower, the heat resistance of the film is easily increased.
  • the refractive index can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the lower limit of ⁇ Ny of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 0.0240, more preferably 0.0245, even more preferably 0.0247, even more preferably 0.0250, particularly preferably 0.0255, and most preferably 0.0260. If it is 0.0240 or more, the rigidity of the film tends to be high.
  • the upper limit of ⁇ Ny is preferably 0.0280 as a practical value, more preferably 0.0277, even more preferably 0.0273, and particularly preferably 0.0270. If it is 0.0280 or less, the thickness unevenness tends to be good. ⁇ Ny can be kept within the range by adjusting the stretching ratio, stretching temperature, and heat setting temperature of the film.
  • ⁇ Ny is calculated by the following formula, where Nx, Ny, and Nz are the refractive indexes along the longitudinal direction, width direction, and thickness direction of the film, respectively, and means the degree of width direction orientation in the overall orientation in the longitudinal direction, width direction, and thickness direction of the film.
  • ⁇ Ny Ny-[(Nx+Nz)/2]
  • the lower limit of the plane orientation coefficient ( ⁇ P) of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 0.0135, more preferably 0.0138, and even more preferably 0.0140. If it is 0.0135 or more, the balance in the plane direction of the film is good, and the thickness unevenness is also good.
  • the upper limit of the plane orientation coefficient ( ⁇ P) is preferably 0.0155 as a practical value, more preferably 0.0152, and even more preferably 0.0150. If it is 0.0155 or less, it is likely to have excellent heat resistance at high temperatures.
  • the plane orientation coefficient ( ⁇ P) can be kept within the range by adjusting the stretch ratio, stretching temperature, and heat setting temperature.
  • the plane orientation coefficient ( ⁇ P) is calculated by the formula [(Nx+Ny)/2]-Nz.
  • the lower limit of the average refractive index of the biaxially oriented polypropylene film for thin film manufacturing process is preferably 1.5080, more preferably 1.5081, even more preferably 1.5082, particularly preferably 1.5083, and most preferably 1.5090.
  • the upper limit of the average refractive index is preferably 1.5150 as a practical value, more preferably 1.5140, even more preferably 1.5135, and particularly preferably 1.5130. If it is 1.5080 or more, wrinkles, dimensional changes, and deterioration of flatness of the film or laminate during release processing and processing of the thin film layer are unlikely to occur, and handling is easy, not only improving the appearance quality but also facilitating the production of a uniform and high-quality thin film.
  • the average refractive index can be within the range by adjusting the stretching ratio, stretching temperature, and heat setting temperature of the film.
  • the average refractive index is calculated by the following formula, with the refractive indexes along the longitudinal direction, width direction, and thickness direction of the film being Nx, Ny, and Nz, respectively.
  • Average refractive index (Nx+Ny+Nz)/3
  • the upper limit of the haze of the film is preferably 5.0%, more preferably 4.5%, even more preferably 4.0%, particularly preferably 3.5%, and most preferably 3.0%. If it is 5.0% or less, it is easy to use in applications where transparency is required.
  • the lower limit of the haze is preferably 0.1% as a practical value, more preferably 0.2%, even more preferably 0.3%, and particularly preferably 0.4%. If it is 0.1% or more, it is easy to manufacture.
  • the haze can be kept within the range by adjusting the cooling roll (CR) temperature, the width direction stretching temperature, the tenter width direction preheating temperature, the width direction stretching temperature, or the heat setting temperature, or the amount of the component having a molecular weight of 100,000 or less of the polypropylene resin, but it may become large by adding an antiblocking agent or providing a seal layer.
  • CR cooling roll
  • the upper limit of the half-width (Wh) of the diffraction peak derived from the oriented crystals in the width direction of the film is preferably 30 °, more preferably 28 °, even more preferably 26 °, even more preferably 25 °, particularly preferably 24 °, more particularly preferably 23 °, and most preferably 22.0 °.
  • the half-width (Wh) is 30 ° or less, particularly 26 ° or less, the rigidity of the film is easily increased.
  • the lower limit of the half-width (Wh) is preferably 15 °, more preferably 16 °, and even more preferably 17 °.
  • the lower limit of the degree of X-ray orientation calculated from the half-width (Wh) of the biaxially oriented polypropylene film for thin film manufacturing process by the following formula is preferably 0.833, more preferably 0.844, even more preferably 0.856, still more preferably 0.861, particularly preferably 0.867, even more particularly preferably 0.872, and most preferably 0.878. By making it 0.833 or more, especially 0.856 or more, it is easy to increase the rigidity.
  • X-ray orientation degree (180-Wh)/180
  • the upper limit of the degree of X-ray orientation is preferably 0.917, more preferably 0.911, and further preferably 0.906. By setting it to 0.917 or less, film formation is likely to be stable.
  • the loop stiffness stress is an index representing the stiffness of the film, which also depends on the thickness of the film, but the value of the slope a of the approximated straight line means a characteristic value of the film that does not depend on the thickness and determines the rigidity. S ⁇ 0.0010 ⁇ t3 ...(A)
  • the lower limit of the loop stiffness stress S (mN) in the width direction at 23 ° C. of the biaxially oriented polypropylene film for thin film manufacturing process is 0.0010 ⁇ t 3 , preferably 0.0011 ⁇ t 3 , particularly preferably 0.0012 ⁇ t 3 , and most preferably 0.0013 ⁇ t 3 , where t ( ⁇ m) is the thickness of the biaxially oriented polypropylene film. If it is 0.0010 ⁇ t 3 or more, the peeling force when peeling the thin film tends to be small, smooth peeling is possible, and thin film breakage is unlikely to occur.
  • the upper limit of the loop stiffness stress S (mN) in the width direction at 23° C. is preferably 0.0020 ⁇ t 3 , more preferably 0.0019 ⁇ t 3 , still more preferably 0.0018 ⁇ t 3 , and particularly preferably 0.0017 ⁇ t 3. If it is 0.0020 ⁇ t 3 or less, it is easy to manufacture in practice.
  • the relationship between the longitudinal loop stiffness stress S [mN] and the thickness t ( ⁇ m) preferably satisfies the following formula (B).
  • the slope a is 0.00030 or more.
  • the lower limit of the longitudinal loop stiffness stress S (mN) of the biaxially oriented polypropylene film for thin film manufacturing process at 23 ° C. is preferably 0.00030 ⁇ t 3 , more preferably 0.00040 ⁇ t 3 , even more preferably 0.00045 ⁇ t 3 , particularly preferably 0.00048 ⁇ t 3 , and most preferably 0.00050 ⁇ t 3 , when the thickness of the biaxially oriented polypropylene film is t ( ⁇ m). If it is 0.00030 ⁇ t 3 or more, the peeling force when peeling the thin film from the film tends to be small, smooth peeling is possible, and peeling marks (streaky marks that occur when caught during peeling) are unlikely to occur.
  • the upper limit of the longitudinal loop stiffness stress S (mN) at 23° C. is preferably 0.00080 ⁇ t 3 , more preferably 0.00075 ⁇ t 3 , even more preferably 0.00072 ⁇ t 3 , and particularly preferably 0.00070 ⁇ t 3. If it is 0.00080 ⁇ t 3 or less, it is easy to manufacture in practice.
  • the biaxially oriented polypropylene film for thin film manufacturing process is preferably obtained by preparing an unstretched sheet made of a polypropylene resin composition mainly composed of the above-mentioned polypropylene resin, and biaxially stretching the sheet.
  • any of the inflation simultaneous biaxial stretching method, the tenter simultaneous biaxial stretching method, and the tenter sequential biaxial stretching method can be used, but it is preferable to adopt the tenter sequential biaxial stretching method from the viewpoint of film formation stability and thickness uniformity.
  • it is preferable to stretch in the longitudinal direction and then in the width direction but a method of stretching in the width direction and then in the longitudinal direction may also be used.
  • the biaxially oriented polypropylene film for thin film manufacturing process of the embodiment may have a layer having another function laminated on at least one side. Lamination may be performed on one side or both sides.
  • the above-mentioned polypropylene resin composition may be used as the resin composition of the other layer or the central layer. It may also be different from the above-mentioned polypropylene resin composition.
  • the number of layers to be laminated may be one, two, or three or more layers per side, but from the viewpoint of manufacturing, one or two layers per side are preferred.
  • a lamination method for example, coextrusion by the feed block method or the multi-manifold method is preferred.
  • a resin layer having easy slip properties containing particles or the like or a resin layer having releasability can be laminated to a degree that does not deteriorate the properties.
  • corona treatment can be performed on one side or both sides to adjust the releasability.
  • the biaxially oriented polypropylene film for thin film manufacturing process described above may be used as a film for thin film manufacturing process without any particular release processing, and the release property may be adjusted by corona treatment, flame treatment, plasma treatment, etc. Also, the release property may be adjusted in a gas atmosphere in which a fluorine-based compound or a silicone-based compound is present.
  • the release layer-laminated biaxially oriented polypropylene film for thin film manufacturing process according to the embodiment will be described below.
  • the release layer-laminated biaxially oriented polypropylene film for thin film manufacturing process has any of the biaxially oriented polypropylene films for thin film manufacturing process described above and a release layer laminated on at least one surface of the biaxially oriented polypropylene film for thin film manufacturing process.
  • a release agent may be applied to the surface of the biaxially oriented polypropylene film for thin film manufacturing process.
  • a release agent When a release agent is applied to the surface, it is preferable that the wet tension of the surface of the biaxially oriented polypropylene film for thin film manufacturing process is 38 mN/m or more. If the wet tension is 38 mN/m or more, the adhesion with the release layer is improved. In order to make the wet tension 38 mN/m or more, it is preferable to perform a physicochemical surface treatment such as corona treatment, flame treatment, plasma treatment, etc.
  • the wet tension is preferably 44 mN/m or less, more preferably 43 mN/m or less, and even more preferably 42 mN/m or less.
  • the wet tension when the release agent is not applied may be less than 38 mN/m, and can be adjusted by the surface treatment conditions so as to obtain the required peelability, and surface treatment may not be performed.
  • the release agent may contain silicone resin, fluororesin, alkyd resin, amino resin, various waxes, aliphatic olefin, long-chain alkyl group-containing resin, etc., and each resin may be used alone or in combination of two or more kinds.
  • the silicone resin used as the release agent may be a silicone resin generally used for release agents, and may be selected from among the silicone resins generally used in the relevant field described in "Silicone Materials Handbook" (edited by Toray Dow Corning, August 1993) and the like. Generally, heat-curing or ionizing radiation-curing silicone resins (which includes resins and resin compositions) are used.
  • condensation reaction type and addition reaction type silicone resins may be used as heat-curing silicone resins, and ultraviolet or electron beam curing silicone resins may be used as ionizing radiation-curing silicone resins. These are applied to the film, which is the substrate, and dried or cured to form a release layer.
  • the release agent since it is the same as the release agent used in the transfer release layer laminated polypropylene film, the description of the release agent in the first disclosure may be referred to.
  • the resin of the release layer may be crosslinked.
  • the crosslinking agent may be an isocyanate compound, a glycidyl group-containing compound, an oxazoline group-containing compound, an amino resin, or the like, but is not limited thereto.
  • a double bond may be introduced into the precursor of the resin that will become the release layer, and a crosslinking reaction may be caused by ultraviolet light or an electron beam.
  • a release agent When using a release agent, one type may be used, or two or more types may be mixed. It is also possible to mix additives such as light release additives and heavy release additives in order to adjust the release force.
  • additives such as light release additives and heavy release additives in order to adjust the release force.
  • the resulting biaxially oriented polypropylene film with a release layer has particularly excellent releasability.
  • the release layer may contain particles with a particle size of 1 ⁇ m or less, but it is preferable that it does not substantially contain particles or other protrusions from the viewpoint of pinhole formation.
  • Additives such as adhesion improvers and antistatic agents may be added to the release layer.
  • the thickness of the release layer may be set according to the intended use, and is not particularly limited, but is preferably in the range of 0.005 to 2 ⁇ m after curing.
  • a release layer thickness of 0.005 ⁇ m or more is preferable because it maintains peeling performance.
  • a release layer thickness of 2 ⁇ m or less is preferable because it does not require too long a curing time and there is no risk of uneven thickness due to a decrease in the flatness of the release film.
  • Another layer may be provided between the biaxially oriented polypropylene film and the release layer.
  • the method of forming the release layer is not particularly limited, and a coating liquid in which a releasing resin is dissolved or dispersed is spread on one side of a biaxially oriented polypropylene film by coating, etc., and the solvent is removed by drying, followed by heating, drying, heat curing, or ultraviolet curing.
  • the drying temperature during solvent drying and heat curing is preferably 100 to 170°C. If the drying temperature is higher than 170°C, wrinkles may occur in the film due to heat. On the other hand, if the drying temperature is low, the heat curing of the release layer may be insufficient and releasability may not be obtained.
  • biaxially oriented polypropylene films have lower thermal dimensional stability at high temperatures than biaxially oriented polyester films, so that heat-induced wrinkles and deterioration of flatness are likely to occur during drying of the coating film, but the biaxially oriented polypropylene film for thin film manufacturing process of the embodiment can suppress the occurrence of wrinkles.
  • the heating and drying time is generally 10 to 60 seconds.
  • any known coating method can be used as the coating method for the coating liquid, for example, roll coating methods such as gravure coating and reverse coating, bar coating methods such as wire bars, die coating, spray coating, air knife coating, etc., which are conventionally known methods.
  • the release layer may be an underlayer of the thin film layer, but it may also be a release layer for preventing the thin film layer from sticking to the side of the biaxially oriented polypropylene film for thin film manufacturing process opposite the thin film layer when the laminate of the biaxially oriented polypropylene film for thin film manufacturing process and the thin film layer is wound into a roll.
  • the release layer may also be laminated on both sides of the biaxially oriented polypropylene film.
  • the method for producing a thin film according to the embodiment preferably includes step 1A of preparing any of the biaxially oriented polypropylene films for the thin film production process described above, step 1B of providing a thin film layer on at least one surface of the biaxially oriented polypropylene film for the thin film production process, and step 1C of peeling the thin film layer from the biaxially oriented polypropylene film for the thin film production process.
  • the method for producing a thin film preferably includes step 2A of preparing any of the release layer-laminated biaxially oriented polypropylene films for the thin film production process described above, step 2B of providing a thin film layer on the release layer surface of the release layer-laminated biaxially oriented polypropylene film for the thin film production process, and step 2C of peeling the thin film layer from the release layer.
  • a biaxially oriented polypropylene film for the thin film production process or a release layer-laminated biaxially oriented polypropylene film for the thin film production process having a release layer on at least one surface thereof, and to provide a thin film layer on at least one surface.
  • step 1B of providing a thin film layer on at least one surface of the biaxially oriented polypropylene film for thin film manufacturing process it is preferable to apply a coating solution to at least one surface and dry the solvent of the coating solution.
  • step 2B of providing a thin film layer on the release layer surface of the release layer-laminated biaxially oriented polypropylene film for thin film manufacturing process it is preferable to apply a coating solution to at least one surface and dry the solvent of the coating solution.
  • Such a dried thin film layer becomes easier to peel off from the biaxially oriented polypropylene film or the release layer in step 1C or step 2C.
  • the thin film layer is preferably a resin thin film, which may be non-porous or porous.
  • the thin film layer can be formed by spreading a solution or dispersion containing the raw resin and, if necessary, additives on the substrate film and then removing the solvent; this method is generally called the solution method or casting method.
  • thin film layers include non-porous resin films used as insulating materials or barrier materials, polymer electrolyte membranes used in fuel cells, and porous membranes used in lithium ion batteries.
  • the thin film layer preferably includes any of a resin film, a polymer electrolyte membrane, and a porous membrane.
  • the resins that can be used as the material for the nonporous resin film include epoxy resins, phenoxy resins, polyester resins, wholly aromatic polyester resins, polyarylate resins, polycarbonate resins, polyurethane resins, fluorine resins, acrylic resins, polyolefin resins, polyimide resins, aromatic polyamide resins, polysulfone resins, polyether resins, polyethersulfone resins, ketone resins, polyetherketone resins, polyacrylonitrile resins, polyamideimide resins, polyaniline resins, polythiophene resins, and cellulose resins. These resins often use high-boiling point solvents, and the manufacturing method of the embodiment is preferably applied.
  • the resin of the resin film may be crosslinked.
  • the crosslinking may be self-crosslinking of the resin itself, or a crosslinking agent may be used.
  • the crosslinking agent There are no particular limitations on the crosslinking agent as long as it is capable of reacting with the reactive groups introduced into the resin, but examples include isocyanate compounds, melamine compounds, carbodiimide compounds, oxazoline compounds, epoxy resins, and compounds with multiple double bonds.
  • Crosslinked resin films are difficult to manufacture using a typical melt extrusion method, and may require high temperatures for the crosslinking reaction, so this is an example in which the manufacturing method of the embodiment is preferably applied.
  • a nonporous resin film can be obtained by dissolving or dispersing the resin material in a solvent, applying a coating solution containing a crosslinking agent, catalyst, and other additives as necessary onto a substrate film, drying and removing the solvent, and then peeling it off from the substrate.
  • crosslinking it can be done while laminated with the substrate film, or after peeling it off from the substrate.
  • the film can retain its shape even if it contains a solvent, it can be peeled off from the substrate while still containing the solvent, and then the residual solvent can be removed from the resin film.
  • polyimide for example, it can be coated and dried in the precursor state, the precursor film can be peeled off from the substrate film, and then the reaction can be completed.
  • Additives include particles, fillers, colorants, antioxidants, antistatic agents, etc.
  • the resin may also be a blend of multiple materials.
  • the solvent contains a solvent with a boiling point of 120°C or higher, more preferably a solvent with a boiling point of 130°C or higher, even more preferably a solvent with a boiling point of 140°C or higher, and particularly preferably a solvent with a boiling point of 150°C or higher.
  • solvents include acetylacetone (141°C), monoethanolamine (171°C), benzyl alcohol (205°C), n-butyl alcohol (117°C), butyl acetate (125°C), dibutyl ether (142°C), cyclohexanol (161°C), cyclohexanone (156°C), diethyl carbonate (127°C), diethylene glycol monobutyl ether (230°C), diethylene glycol monoethyl ether (196°C), diethylene glycol monomethyl ether (194°C), dimethylacetamide (163°C), dimethylformamide (153°C), dimethylsulfoxide (189°C), N-methylpyrrolidone (202°C), 2-chloroethanol (128°C), ethylene glycol (197°C), ethylene glycol monobutyl ether (171°C), ethylene glycol monobutyl ether acetate (19 2°C), ethylene glycol monoethyl ether (135
  • the resin film may be surface-treated while laminated on the base film.
  • surface treatments include corona treatment, plasma treatment, and surface coating.
  • surface coatings include wet processes in which a solution is applied, and dry processes such as vapor deposition and sputter CVD.
  • Representative surface coatings include easy-adhesion coatings and antistatic coatings in wet processes, and the application of conductive layers such as various metals such as gold, copper, and aluminum, and ITO in dry processes.
  • the resin film may be subjected to post-processing while laminated to the base film. Circuit formation can be performed by printing or etching, and after pattern formation, it can be peeled off from the base film. If the resin film is to be used laminated with another material, it may be attached to the other material while laminated on the base film, and the base film may then be peeled off.
  • the thickness of the nonporous resin film is preferably 0.5 ⁇ m or more, more preferably 1.0 ⁇ m or more, even more preferably 1.5 ⁇ m or more, and particularly preferably 2.0 ⁇ m or more.
  • the thickness is preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less, even more preferably 20 ⁇ m or less, and particularly preferably 15 ⁇ m or less.
  • it is possible to manufacture a uniform, high-quality film even with a resin film having a thickness of 10 ⁇ m or less, 7 ⁇ m or less, or 5 ⁇ m or less, and it is also preferable to use the method for manufacturing such thin resin films.
  • the resin used for the polymer electrolyte membrane may be one that has ionic groups introduced into the resin that is the material of the above-mentioned non-porous resin film.
  • the resin include ionic group-containing polyphenylene oxide, ionic group-containing polyether ketone, ionic group-containing polyether ether ketone, ionic group-containing polyether sulfone, ionic group-containing polyether ether sulfone, ionic group-containing polyether phosphine oxide, ionic group-containing polyether ether phosphine oxide, ionic group-containing polyphenylene sulfide, ionic group-containing polyamide, ionic group-containing polyimide, ionic group-containing polyether imide, ionic group-containing polyimidazole, ionic group-containing polyoxazole, and ionic group-containing polyphenylene, and other aromatic hydrocarbon-based polymers having
  • the polymer electrolyte membrane may be crosslinked.
  • the crosslinking method is the same as for the resin film.
  • the polymer electrolyte membrane may also use the various additives described above, or multiple resins.
  • the polymer electrolyte membrane can be obtained by dissolving an ionic group-containing resin in a solvent, adding a crosslinking agent, catalyst, and other additives as necessary, coating the coating solution on a substrate film, drying to remove the solvent, and then peeling it off from the substrate.
  • the solvent preferably contains a high-boiling point solvent as listed above for the resin film.
  • the precursor may be applied, dried, and then peeled off from the substrate film, after which the reaction may be completed.
  • the polymer electrolyte membrane is preferably completed by a solvent removal treatment in which the solvent is removed by heating or by desolvation with a liquid miscible with the solvent of the ionic group-containing polymer electrolyte, such as water; an acid treatment in which the ionic groups are converted to an acid form by contacting with an inorganic acid-containing acidic liquid, such as hydrochloric acid, nitric acid, or sulfuric acid; an acid removal treatment in which free acid in the membrane is removed by contacting with water, etc.; and a final drying treatment.
  • solvent removal treatment in which the solvent is removed by heating or by desolvation with a liquid miscible with the solvent of the ionic group-containing polymer electrolyte, such as water
  • an acid treatment in which the ionic groups are converted to an acid form by contacting with an inorganic acid-containing acidic liquid, such as hydrochloric acid, nitric acid, or sulfuric acid
  • an acid removal treatment in which free acid in the membrane is removed by contacting
  • the polymer electrolyte membrane is laminated to a reinforcing material, etc., it may be laminated to the reinforcing material while it is laminated to the substrate film, and then the substrate film may be peeled off.
  • the thickness of the polymer electrolyte membrane is preferably 1.0 ⁇ m or more, more preferably 3.0 ⁇ m or more, even more preferably 4.0 ⁇ m or more, and particularly preferably 5.0 ⁇ m or more.
  • the thickness is preferably 100 ⁇ m or less, more preferably 70 ⁇ m or less, even more preferably 60 ⁇ m or less, and particularly preferably 50 ⁇ m or less.
  • the porous film can be obtained by applying a solution in which the resin, which is the material of the non-porous resin film, is dissolved or dispersed in a solvent to a substrate film and making the film porous.
  • the method of making the film porous is preferably a method of layer separation, specifically, a method of dissolving the resin in a mixed solvent of a good solvent and a poor solvent for the resin, which is the material, and making the film porous by leaving a large amount of the poor solvent in the drying process, and a method of applying the solution to the substrate film and then contacting it with a poor solvent (coagulation liquid) such as water to make the film porous.
  • the solvent preferably contains the high boiling point solvents listed in the above resin film.
  • the porous film is obtained by drying, but it may be dried on the substrate film, or it may be peeled off from the substrate film with the solvent remaining, and then dried.
  • a precursor may be applied, and the precursor may be made into a porous film, and then peeled off, and the reaction may be completed.
  • the membrane When laminating the porous membrane to another material, the membrane may be laminated to the other material while still laminated to a base film, and then the base film may be peeled off.
  • the porous membrane may also contain the various additives described above, and may contain multiple resins.
  • the thickness of the porous membrane is preferably 2.0 ⁇ m or more, more preferably 5.0 ⁇ m or more, even more preferably 8.0 ⁇ m or more, and particularly preferably 10.0 ⁇ m or more.
  • the thickness is preferably 200 ⁇ m or less, more preferably 150 ⁇ m or less, even more preferably 100 ⁇ m or less, and particularly preferably 70 ⁇ m or less.
  • the thin film layer may be peeled off from the base film and rolled up as a thin film, or it may be transferred to another material and rolled up as a laminate with the other material. In addition, until the process of using the thin film, it may be rolled up as a laminate of the base film and the thin film layer and stored in a roll.
  • the biaxially oriented polypropylene film for thin film manufacturing of the embodiment is less likely to wrinkle, change in dimensions, or deteriorate in flatness when the thin film layer is applied or processed, which not only improves the appearance quality of the resulting thin film, but also makes it easier to manufacture thin films with uniform properties.
  • the biaxially oriented polypropylene film for thin film manufacturing of the embodiment is preferably used when the process of applying the thin film layer or the processing process includes a process in a high-temperature environment. Specific processes include a drying process, a crosslinking reaction process, a phase conversion process, a phase separation process, and a surface flattening process.
  • Specific temperatures preferably include a process in an environment of 110°C or higher, more preferably 115°C or higher, even more preferably 120°C or higher, and particularly preferably 125°C or higher.
  • the upper limit of the environmental temperature is preferably 160°C, more preferably 155°C, and even more preferably 150°C.
  • the lower limit of the time for the process in which the above temperature is reached is preferably 2 seconds, more preferably 5 seconds, and even more preferably 10 seconds.
  • the upper limit of the time is preferably 60 minutes, more preferably 45 minutes, and even more preferably 30 minutes. However, if the temperature exceeds 155°C, it is preferable to avoid more than 30 seconds, more preferably to avoid more than 20 seconds, and even more preferably to avoid more than 15 seconds.
  • the temperature of the heating body is preferably 120°C or more, more preferably 125°C or more, and even more preferably 130°C or more.
  • the temperature of the heating body is preferably 160°C or less, more preferably 155°C or less, and even more preferably 150°C or less.
  • the temperature of the molten thin film layer is preferably 180°C or less, more preferably 170°C or less, even more preferably 160°C or less, particularly preferably 150°C or less, and most preferably 145°C or less. However, if the temperature exceeds 150°C, it is preferable to pass the film through a cooling roll or cooling belt and cool it from the opposite side.
  • the temperature of the molten thin film layer is preferably 120°C or more, more preferably 125°C or more, and even more preferably 130°C or more.
  • the temperature of the heating body is preferably 120°C or higher, more preferably 125°C or higher, and even more preferably 130°C or higher.
  • the temperature of the heating body is preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower.
  • the contact time with the heating body is preferably 0.5 seconds or more, more preferably 1 second or more, even more preferably 1.5 seconds or more, and especially preferably 2 seconds or more.
  • the contact time is preferably 180 seconds or less, more preferably 120 seconds or less, even more preferably 90 seconds or less, and especially preferably 60 seconds or less.
  • the temperature of the heating body exceeds 155°C, it is preferable to avoid a time of 90 seconds or more, and if it exceeds 150°C, it is preferable to avoid a time of 60 seconds or more.
  • the thin film manufacturing film is preferably wound into a roll in a long length.
  • a masking film surface protection film
  • Examples of masking films include polyester-based films, polypropylene-based films, and polyethylene-based films.
  • the masking film may be provided with a release layer and an adhesive layer.
  • melt flow rate (MFR) was measured in accordance with JIS K7210 at a temperature of 230° C. and a load of 2.16 kgf.
  • Apparatus HLC-8321PC/HT (manufactured by Tosoh Corporation)
  • Detector RI
  • Solvent 1,2,4-trichlorobenzene + dibutylhydroxytoluene (0.05%)
  • Mn ⁇ (Ni ⁇ Mi)/ ⁇ Ni
  • Mass average molecular weight: Mw ⁇ (Ni ⁇ Mi 2 )/ ⁇ (Ni ⁇ Mi)
  • Mw ⁇ (Ni ⁇ Mi 2 )/ ⁇ (Ni ⁇ Mi)
  • the proportion (mass %) of components having a molecular weight of 100,000 or less was calculated from the integral curve of the molecular weight distribution obtained by GPC.
  • Crystallization temperature (Tc), melting temperature (Tm) Heat measurement was performed under a nitrogen atmosphere using a TA Instruments Q1000 differential scanning calorimeter. Approximately 5 mg was cut out from the pellets of polypropylene resin and sealed in an aluminum pan for measurement. After heating to 230°C and holding for 5 minutes, it was cooled to 30°C at a rate of -10°C/min, and the exothermic peak temperature was taken as the crystallization temperature (Tc).
  • the crystallization heat ( ⁇ Hc) was determined by setting a baseline so that the area of the exothermic peak was smoothly connected from the start of the peak to the end of the peak. It was held at 30°C for 5 minutes, heated to 230°C at 10°C/min, and the main endothermic peak temperature was taken as the melting temperature (Tm).
  • Tensile test The tensile strength of the film in the longitudinal direction and the transverse direction was measured at 23°C according to JIS K7127. A sample was cut out from the film to a size of 15 mm x 200 mm, and the distance between the chucks was 100 mm and set in a tensile tester (Instron 5965 dual column tabletop tester manufactured by Instron Japan Co., Ltd.). The tensile test was performed at a tensile speed of 200 mm/min. From the obtained strain-stress curve, the tensile modulus was calculated from the slope of the linear part at the beginning of elongation, and the stress at 5% elongation was taken as F5. The tensile breaking strength and tensile breaking elongation were respectively the strength and elongation at the time when the sample broke.
  • Heat shrinkage rate Measured according to JIS Z1712 by the following method. The film was cut into pieces of 20 mm width and 200 mm length in both the longitudinal and transverse directions, and was heated for 5 minutes by hanging in a hot air oven at 120° C. or 150° C. The length after heating was measured, and the heat shrinkage rate was calculated as the ratio of the shrunken length to the original length.
  • Refractive index, ⁇ Ny, plane orientation coefficient, average refractive index The refractive index was measured at a wavelength of 589.3 nm and a temperature of 23°C using an Abbe refractometer manufactured by Atago Co., Ltd.
  • the refractive indexes along the longitudinal direction and width direction of the film were designated as Nx and Ny, respectively, and the refractive index in the thickness direction was designated as Nz.
  • ⁇ Ny was calculated using Nx, Ny, and Nz according to the formula Ny-[(Nx+Nz)/2].
  • the plane orientation coefficient ( ⁇ P) was calculated using the formula [(Nx+Ny)/2]-Nz.
  • the average refractive index was calculated using the formula (Nx+Ny+Nz)/3.
  • the camera length was 300 mm, and the integral width of the detector was 2 mm.
  • the film was stacked to a thickness of 400 ⁇ m to prepare a sample.
  • the step interval was 0.5 °, and the measurement speed was 60 ° / min. From this azimuth angle dependence, the half-width Wh of the diffraction peak derived from the oriented crystal in the width direction of the film was obtained.
  • Ratio of Unconstrained Amorphous Component (III) Determined by Pulse NMR The film was cut and packed into a glass tube having an outer diameter of 10 mm to a height of 1 cm.
  • the spin-spin relaxation time T2 of 1H nuclei of the biaxially oriented polypropylene film was measured using the following measuring device and measuring conditions to obtain a decay curve of magnetization intensity.
  • the shortest component corresponds to the crystalline component (I)
  • the second and third shortest components correspond to the constrained amorphous component (II) and the unconstrained amorphous component (III), respectively.
  • a diagram showing the decay curve and each curve separated into the crystalline component (I), the amorphous component (II), and the unconstrained amorphous component (III) is shown in FIG. 1. The fitting and analysis were performed using the software (TD-NMR Analyzer) attached to the above-mentioned measuring apparatus according to the product manual.
  • the ratio of the unconstrained amorphous component (III) was calculated by the following formula (1), which is the ratio (%) of the amorphous component (III) to the total of the crystalline component (I), the constrained amorphous component (II), and the unconstrained amorphous component (III) obtained by the above method.
  • Ratio of unconstrained amorphous component (III) MIII/(MI+MII+MIII) (1)
  • MI Amount of crystalline component (I)
  • MII Amount of constrained amorphous component (II)
  • MIII Amount of unconstrained amorphous component (III)
  • loop stiffness stress, slope of approximate line a The measurement method of the loop stiffness stress S (mN) in the width direction and the slope a of the approximation line of formula (A) is as follows. Two strips of 110 mm x 25.4 mm were cut out with the width direction of the film as the long axis (loop direction) of the strip. These were clamped with a clip to prepare a measurement loop in which one side of the film becomes the inner surface of the loop and the other side becomes the inner surface of the loop.
  • the measurement loop was set in a state where the longitudinal direction was perpendicular to the chuck part of a loop stiffness tester DA manufactured by Toyo Seiki Co., Ltd., the clip was removed, and the loop stiffness stress was measured with a chuck interval of 50 mm, a pressing depth of 15 mm, and a compression speed of 3.3 mm/sec. The measurement was performed five times to measure the loop stiffness stress and thickness with one side of the film becoming the inner surface of the loop, and then five times to measure with the other side becoming the inner surface of the loop.
  • the cube of the thickness of each test piece was plotted on the horizontal axis and the loop stiffness stress on the vertical axis, and the least squares method was used to approximate a straight line with an intercept of 0 to determine the slope a.
  • the slope a of the approximation line of the loop stiffness stress S (mN) in the longitudinal direction and formula (B) was measured in the same manner as the above measurement method, except that two measurement loops were cut out with the long axis of the rectangular strip in the longitudinal direction of the film, and the two loops were set in a state where the width direction was perpendicular to the chuck portion.
  • the amount of liquid should be enough to form a thin layer without creating a puddle.
  • the wetting tension is judged by observing the liquid film of the test mixture in a bright place and the state of the liquid film after 3 seconds. If the liquid film does not break and the state at the time of application is maintained for 3 seconds or more, it is considered to be wet. If the wetting is maintained for 3 seconds or more, proceed to the next mixture with a higher surface tension, and conversely, if the liquid film breaks in 3 seconds or less, proceed to the next mixture with a lower surface tension. Repeat this operation to select a mixture that can accurately wet the surface of the test specimen in 3 seconds.
  • the release film was cut from a roll of biaxially oriented polypropylene film (hereinafter, sometimes referred to as release film) coated with the silicone-based release agent described in the examples to a width of 30 mm and a length of 80 mm so that the width direction was the long side, and used as a sample for measuring peel force. After removing electricity using a static eliminator (Keyence Corporation, SJ-F020), the film was peeled off using a peel tester (Kyowa Interface Science Co., Ltd., VPA-3) at a peel angle of 30 degrees, a peel temperature of 25°C, and a peel speed of 10 m/min.
  • release film biaxially oriented polypropylene film coated with the silicone-based release agent described in the examples
  • a double-sided adhesive tape (Nitto Denko Corporation, No. 535A) was attached to a SUS plate attached to the peel tester, half of the release film was fixed on the double-sided tape in such a way that the release layer was adhered to the double-sided tape, and the end of the release film on the side not adhered to the tape was pulled to peel it off.
  • the average peel force for peel distances of 20 mm to 70 mm was calculated, and this value was taken as the peel force.
  • the measurement was carried out five times in total, and the average value of the peel strength was used for evaluation.
  • the peel strength was evaluated according to the following criteria. ⁇ : 60 mN/mm or less. ⁇ : greater than 60 mN/mm.
  • the peel angle in this evaluation method refers to the angle in the direction in which the release film is pulled relative to the axis of the evaluation sample fixed to the peel tester.
  • release film curl From the roll of biaxially oriented polypropylene film (release film) coated with the silicone-based release agent described in the examples, the release film was cut into a size of 10 cm x 10 cm, and the release film sample was placed on a glass plate with the release surface facing up, and the height of the part floating from the glass plate was measured.
  • the curl generated in the release film was evaluated by the following method. The height of the part that was most raised from the glass plate was taken as the measured value. The curling was evaluated according to the following criteria. A: Curl is 5 mm or less. ⁇ : Curl is greater than 5 mm.
  • release film was unwound from a roll of biaxially oriented polypropylene film (hereinafter, sometimes referred to as release film) coated with the silicone-based release agent described in the examples, and the wrinkles generated on the release film were evaluated by the following method. That is, in a room with a temperature of 25°C and a humidity of 65%, a release film with a width of 60 cm was hung so that the film longitudinal direction was vertical, and a load of 10 N/m was applied and left to stand for 30 minutes.
  • release film biaxially oriented polypropylene film
  • a fluorescent lamp was projected onto the film surface from 45° above, 1 m away from the surface on which the number of continuous corrugated wrinkles in the longitudinal direction was counted, and the number of wrinkles was visually counted and evaluated from 45° below, 0.5 m away from the surface on which the wrinkles were counted.
  • the wrinkles were counted by counting the number of wrinkles in the film width direction, with each wrinkle that was convex in the longitudinal direction of the film relative to the surface being observed being counted as one wrinkle.
  • A The number of wrinkles is 10 or less per meter.
  • ⁇ The number of wrinkles is 11 or more per meter.
  • Example 1 Metal for producing biaxially oriented polypropylene film
  • the mixture was extruded into a sheet from a T-die at 250 ° C., brought into contact with a cooling roll at 20 ° C., and then placed in a water tank at 20 ° C. as it is. Thereafter, the film was stretched 4.5 times in the longitudinal direction at 142 ° C. with two pairs of rolls, then both ends were clipped and introduced into a hot air oven, preheated at 170 ° C., and then stretched 10 times in the width direction at 162 ° C. as the first stage. Immediately after stretching in the width direction, the film was cooled at 120 ° C.
  • WET coating amount
  • the release layer was dried for 20 seconds at a conveying tension of 2000 kPa and a drying temperature of 150 ° C. using an air floating conveying type drying device with a distance between the lower and upper air flow outlets of 38 cm, to obtain a release film with a mass of 0.03 g/m 2 after drying and curing of the release layer.
  • the film was cooled at a rate of 20 ° C./sec using a cooling roll at 50 ° C., and then wound up in a roll to obtain a release film roll.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film formation conditions.
  • the physical properties of the release film coated with the release agent were as shown in Table 3.
  • the release film had excellent releasability and was a smooth film without wrinkles, and exhibited excellent properties as a film for a transfer substrate.
  • the corona treatment was performed under the condition of an applied current value of 0.75 A.
  • Example 2 The same procedure as in Example 1 was carried out except that the film was re-stretched 1.2 times in the width direction at 165°C. The thickness of the obtained film was 18.4 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin, and Table 2 shows the film-forming conditions. As shown in Table 3, the physical properties of the film were very excellent in rigidity, had a low thermal shrinkage rate at high temperatures, and the release film coated with a release agent had excellent releasability and was a smooth film without wrinkles, and showed excellent properties as a film for a transfer substrate.
  • Example 3 The film was stretched in the longitudinal direction at 147°C, stretched 10 times in the width direction at 165°C as the first stage, and immediately after the width direction stretching, cooled at 120°C while being held by the clip, and then re-stretched 1.2 times in the width direction at 177°C.
  • the film was the same as in Example 1 except that it had a thickness of 18.9 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film formation conditions.
  • the physical properties of the film were high rigidity, low heat shrinkage at high temperatures, and the release film coated with a release agent had excellent releasability and was a smooth film without wrinkles, and showed excellent properties as a film for transfer substrate.
  • Example 4 The same procedure was followed as in Example 3, except that the film was re-stretched to 1.1 times the width at 177°C. The thickness of the obtained film was 20.6 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin, and Table 2 shows the film-forming conditions.
  • Table 1 shows the structure of the polypropylene resin, and Table 2 shows the film-forming conditions.
  • the physical properties of the film were high rigidity and low thermal shrinkage at high temperatures, and the release film coated with the release agent had excellent releasability and was a smooth film without wrinkles, and showed excellent properties as a film for transfer substrates.
  • Example 1 The film was stretched 12 times in the width direction at 162°C as the first stage, and immediately after the width direction stretching, the film was cooled at 100°C while being held by the clip, and then heat-set at 170°C while keeping the width constant.
  • the film was the same as in Example 1.
  • the thickness of the obtained film was 20.8 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film formation conditions. As shown in Table 3, the physical properties of the film were high in rigidity, but the thermal shrinkage rate at high temperatures was poor, and wrinkles occurred in the release film coated with a release agent, so that the film had poor processing suitability as a release film used for transfer.
  • Example 3 The film was stretched 12 times in the width direction at 168°C as the first stage, and immediately after the width direction stretching, the film was cooled at 100°C while being held by the clip, and then heat-set at 170°C while keeping the width constant.
  • the film was the same as in Example 1.
  • the thickness of the obtained film was 18.7 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film formation conditions. As shown in Table 3, the physical properties of the film were poor in rigidity, and wrinkles occurred in the release film coated with the release agent, so that the film had poor processing suitability as a release film to be used for transfer.
  • the film was stretched 4.5 times in the longitudinal direction at 130 ° C., and in the width direction stretching with a tenter, the preheating temperature was set to 168 ° C., and 8.2 times stretching was performed at 155 ° C. as the first stage of stretching.
  • the film was cooled at 120 ° C. while being held by the clip, and then re-stretched 1.2 times in the width direction at 170 ° C. Finally, it was cooled at room temperature.
  • the thickness of the obtained film was 18.8 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film formation conditions. As shown in Table 3, the physical properties of the film were high in thermal shrinkage at high temperatures and poor in rigidity. In addition, the film had poor releasability when coated with a release agent, and wrinkles occurred, making the film unsuitable for processing as a release film for transfer.
  • Example 5 A blend of PP-1 and PP-2 was used as the polypropylene resin in the same manner as in Example 1, and a film was obtained under the film-forming conditions shown in Table 2, in which the film was heat-treated at 168°C without re-stretching in the width direction. The thickness of the obtained film was 20.0 ⁇ m.
  • Table 1 shows the structure of the polypropylene resin
  • Table 2 shows the film-forming conditions.
  • the thermal shrinkage rate at high temperatures was low, but the rigidity was poor, and wrinkles occurred in the release film coated with the release agent, resulting in poor processing suitability as a release film to be used for transfer.
  • a transfer laminate was prepared using the film obtained in the example, and transfer was performed on an article.
  • the corona treatment conditions were adjusted.
  • a urethane acrylate-based hard coat agent (HX-RSC manufactured by Kyoeisha Chemical Co., Ltd.) was applied as a protective layer to one side of the biaxially oriented polypropylene film (without release coat) after corona treatment obtained in Example 1, and then irradiated with ultraviolet light after drying at 100°C to provide a protective layer with a thickness of 5 ⁇ m. Further, full-color printing was performed on the protective layer using an ink containing butyl acetate as a solvent, and then a toluene/MEK solution of Nichigo Polyester (registered trademark) SP-154 was applied as an adhesive layer, and after drying, the film was wound into a roll to obtain a laminate for transfer printing.
  • HX-RSC manufactured by Kyoeisha Chemical Co., Ltd.
  • the printing and drying of the adhesive were performed in an oven at 130°C, but there was no printing misalignment, and the obtained laminate had no wrinkles and excellent flatness.
  • the roll of the obtained laminate for transfer printing was unwound, and the film surface was passed through a silicone transfer roll heated to 150°C so that the film surface became the transfer roll, and the adhesive layer surface was pressed against a polycarbonate molded body to transfer the protective layer/printing layer/adhesive layer.
  • the contact time of the transfer roll was 3 seconds. During the transfer, the film and the protective layer were smoothly peeled off, the film contracted only slightly, and transfer printing was possible without transfer defects or misalignment.
  • Example 2 Metal thin film layer transfer
  • One side of the corona-treated biaxially oriented polypropylene film (without release coating) obtained in Example 1 was coated with a transparent yellow-colored acrylic resin solution and dried at 130°C for 30 seconds to provide a colored protective layer with a thickness of 5 ⁇ m.
  • Aluminum was then vacuum-deposited on the colored layer.
  • the coated film had no wrinkles and the flatness of the film after deposition was good.
  • the above adhesive layer was then provided on the aluminum deposition layer to obtain a roll-shaped laminate for transferring a metal thin film layer.
  • the obtained metal thin film layer laminate was unwound, and the adhesive layer surface was placed on a printed cardboard, and a mold heated to 150°C was pressed against the film surface for 3 seconds to hot stamp the metal thin film layer onto the printed cardboard.
  • a gold leaf-like pattern could be provided at a predetermined position on the cardboard.
  • the release surface of the biaxially stretched polypropylene film provided with the non-silicone release layer was coated with the following photosensitive resin solution obtained with reference to the examples in JP-A-2006-114735, and the solvent was removed to provide a photosensitive resin layer having a thickness of 30 ⁇ m.
  • a biaxially oriented polypropylene film provided with the silicone-based release layer of Example 2 was laminated as a protective film to the surface of the photosensitive resin layer opposite to the substrate to obtain a photosensitive resin laminate.
  • the obtained photosensitive resin laminate had no warping and was excellent in flatness.
  • the protective film was peeled off from the resulting photosensitive resin laminate, and the copper foil surface of the copper-clad film on the exposure device was pressed against the photosensitive resin layer surface, and then a negative was placed on the base film surface and the pressure was reduced to allow for close contact. After exposure from the negative side, the base film was peeled off and the uncured areas were removed with an aqueous sodium carbonate solution. A resist layer was created on the copper foil in which the photosensitive resin had hardened according to the pattern of the negative.
  • a solution for forming a retardation layer (liquid crystal compound alignment layer) having the following composition was applied to the surface that had been subjected to the rubbing treatment by a bar coating method.
  • Rod-shaped liquid crystal compound (BASF LC242) 24.15 parts by weight Surfactant (NEOS Ftergent FTX-209F) 0.12 parts by weight Reaction initiator (BASF IRGACURE379) 0.73 parts by weight Solvent (cyclopentyl methyl ether) 75.00 parts by weight Dry in an oven at 125 ° C.
  • a UV-curable adhesive was applied to a rectangular commercially available polarizing plate, and the retardation layer surface of the obtained retardation layer transfer laminate was bonded so that the MD direction of the biaxially oriented polypropylene film was parallel to the long side of the polarizing plate, and the adhesive was hardened by irradiating with ultraviolet light, and then the film was peeled off.
  • the alignment direction of the retardation layer was measured, it was found to be at an angle of 45 degrees to the long side of the polarizing plate as set, and a circular polarizing plate was obtained.
  • circuit A copper foil having a thickness of 10 ⁇ m was laminated to the release layer surface of the biaxially oriented polypropylene film provided with the silicone-based release layer obtained in Example 1 using an EVA-based hot melt adhesive. Then, a loop antenna pattern of a resist agent was printed on the copper foil by screen printing, the resist agent was cured, and the exposed copper foil was removed by etching. Then, after removing the resist agent, an adhesive was applied to obtain a circuit transfer laminate. The adhesive layer surface of the circuit transfer laminate was superimposed on a resin molded body, and then a silicone pad heated to 150° C. was pressed against the film surface for 5 seconds, and then the base film was peeled off. A molded body having a loop antenna circuit as designed was obtained.
  • the obtained reactive hot melt adhesive was melted at 130°C, and spread on the release layer of the biaxially oriented polypropylene film provided with the silicone-based release layer obtained in Example 4 using a slit die to provide a 25 ⁇ m thick adhesive layer, and then wound up after cooling.
  • the wound reactive hot melt adhesive transfer laminate was packaged with an aluminum-deposited polyester film together with a desiccant.
  • the obtained laminate for reactive hot melt adhesive transfer was wrinkle-free and excellent in flatness.
  • the laminate for reactive hot melt adhesive transfer was unwound, and the adhesive layer surface of the laminate was placed on the MDF board side, and the MDF board and the adhesive layer surface were bonded together using a roll heated to 150 ° C from the substrate film side.
  • the contact time with the heated roll was 3 seconds. After that, the substrate film was peeled off, and a cotton and nylon blended fabric was placed on the adhesive layer surface, and the cloth was attached to the MDF board using a roll heated to 150 ° C.
  • An acrylic adhesive was obtained by the following method with reference to International Publication No. 2012/029471. 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate were reacted to obtain an ethyl acetate solution of an acrylic polymer (solid content concentration 30%), and 0.15 parts of trimethylolpropane xylylene diisocyanate and 0.2 parts of an acetoacetyl group-containing silane coupling agent were added per 100 parts of solid content, and the mixture was diluted with ethyl acetate to obtain an adhesive solution with a solid content concentration of 12%.
  • the non-silicone release agent was applied to the biaxially stretched polypropylene film after corona treatment obtained in Example 4 to provide a release layer, and an acrylic adhesive solution was applied to the release layer surface of the obtained release film, dried at 130° C. for 5 minutes, and crosslinked to form an adhesive layer with a thickness of 17 ⁇ m.
  • the biaxially stretched polypropylene film provided with the silicone release agent obtained in Example 1 was laminated on the adhesive layer surface and wound up.
  • An optical adhesive transfer laminate with little shrinkage and excellent flatness was obtained.
  • the unwound optical adhesive transfer laminate was cut to the size of a commercially available polarizing plate, and after peeling off the protective film of the optical adhesive transfer laminate, the adhesive layer surface was attached to a polarizing plate.
  • the substrate film surface was then peeled off and attached to a glass plate simulating a liquid crystal cell.
  • the substrate film had a moderate stiffness and could be peeled off smoothly, and no peeling marks were observed on the adhesive layer.
  • the biaxially oriented polypropylene film for transfer substrate of the embodiment was usable for transfer in various applications.
  • the biaxially oriented polypropylene film of the comparative example is prone to wrinkles and deterioration of flatness due to heat in the drying process, etc., as can be seen from the evaluation of wrinkles in the biaxially oriented polypropylene film coated with a silicone-based release agent, and its applications are limited. Wrinkles and flatness were evaluated by placing the processed film or transfer laminate with the film face up on a table and looking at the reflected fluorescent light on the ceiling to evaluate the distortion of the film surface. Long distortions with a width of about 1 cm or less were considered to be wrinkles, while wide distortions, convex or concave distortions, and wavy distortions all over the surface were considered to have poor flatness.
  • the biaxially oriented polypropylene films of Examples 1 to 4 had high rigidity and low heat shrinkage at high temperatures. Furthermore, the biaxially oriented polypropylene films (release films) coated with a release agent had excellent releasability and were smooth films without wrinkles. Therefore, they had excellent properties as films for thin film manufacturing processes. On the other hand, as described above, the biaxially oriented polypropylene films of Comparative Examples 1 to 6 had low rigidity or high heat shrinkage at high temperatures. Furthermore, the release films coated with a release agent had wrinkles, so they were poor in processability as films for thin film manufacturing processes.
  • the following thin films were produced using the biaxially oriented polypropylene films obtained in Examples 1 to 4.
  • the corona treatment conditions were adjusted.
  • Thermosetting resin film The following phenoxy resin solution was applied to the release layer surface of the biaxially oriented polypropylene film having a silicone-based release layer obtained in Example 1 so that the thickness of the resin film after drying would be 5 ⁇ m. The film was then dried in a hot air drying oven at 100° C. for 30 seconds and then heated at 140° C. for 100 seconds to produce a laminated film. Polyvinyl butyral (Sekisui Chemical Co., Ltd.
  • Epoxy resin A Bisphenol A type epoxy resin (DIC Corporation "EPICLON (registered trademark) EXA-4850-1000") 37.9 parts by weight
  • Epoxy resin B Dicyclopentadiene type epoxy resin (DIC Corporation "EPICLON (registered trademark) HP-7200”) 24.7 parts by weight
  • Heat curing agent Novolac type phenolic resin (Showa Denko K.K. "Shounol (registered trademark) BRG-556") 18.3 parts by weight Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemical Industry Co., Ltd.
  • thermosetting resin film had no wrinkles, good flatness, and excellent appearance.
  • An aromatic polyamide solution (solid content concentration 10.5% by mass) obtained from 2-chloro-p-phenylenediamine and 4,4'-diaminodiphenyl ether (85 mol%/15 mol%) as aromatic diamine components and 2-chloroterephthalic acid dichloride as acid component was prepared in N-methyl-2-pyrrolidone.
  • the obtained aromatic polyamide solution was applied onto the corona-treated biaxially stretched polypropylene film (without release coat) obtained in Example 3, heated at 150°C for 60 seconds to evaporate the solvent, and then the biaxially stretched polypropylene film was peeled off.
  • the obtained aromatic polyamide film was introduced into a water tank and subjected to extraction treatment, and then the film was fixed with a clip and subjected to heat treatment in an oven at 250°C to obtain an aromatic polyamide film having a thickness of 5 ⁇ m.
  • the obtained aromatic polyamide film had no wrinkles, good flatness, and excellent appearance.
  • a release film having a mass of 0.03 g / m 2 after drying and hardening of the release layer.
  • the film was cooled at a speed of 20 ° C. / sec using a cooling roll at 50 ° C., and then wound up into a roll to obtain a release film roll.
  • the obtained solution was applied to the release layer surface of a biaxially stretched polypropylene film coated with the above non-silicone-based release agent, and after drying at 130°C for 10 minutes, it was immersed in a 20% by mass aqueous sulfuric acid solution at 30°C for 10 minutes, then immersed in pure water at 30°C for 40 minutes, and further dried at 40°C. Thereafter, the release film was peeled off to obtain a polymer electrolyte membrane with a thickness of 18 ⁇ m. The obtained polymer electrolyte membrane had no wrinkles, good flatness, and excellent appearance.
  • a resin solution was prepared by mixing and dissolving 100 parts by weight of polyamideimide solution [manufactured by Toyobo Co., Ltd., product name "Viromax HR11NN”], 30 parts by weight of polyvinylpyrrolidone (molecular weight 55,000), and a silicone-based surfactant.
  • This resin solution was applied to the release layer surface of the biaxially stretched polypropylene film coated with the silicone-based release agent of Example 4. After that, it was held in an atmosphere of 25°C and 95% RH for 3 minutes, immersed in water to solidify, and then dried in an oven with an inlet at 80°C and an outlet at 120°C, after which the release film was peeled off to obtain a porous film.
  • the obtained porous film had no wrinkles, good flatness, and excellent appearance.
  • the biaxially oriented polypropylene film of the embodiment was usable as a process film when manufacturing various thin films.
  • the biaxially oriented polypropylene film of the comparative example is subject to limitations, as it is prone to wrinkles and deterioration of flatness due to heat in the drying process, etc., as can be seen from the evaluation of wrinkles in the biaxially oriented polypropylene film coated with a silicone-based release agent.
  • the wrinkles and flatness of the thin film were evaluated by placing the laminate of the biaxially oriented polypropylene film and the thin film immediately before peeling the thin film on a table with the film facing up, and looking at the reflected fluorescent light on the ceiling, and evaluating the distortion of the film surface. Long distortions with a width of about 1 cm or less were considered to be wrinkles, while those with wide widths, convex or concave distortions, and those that were wavy all over were considered to have poor flatness.
  • the biaxially oriented polypropylene film for transfer substrates disclosed in the first disclosure has excellent heat resistance and rigidity, so the occurrence of wrinkles and deterioration of flatness are suppressed when forming a transfer layer or during heat treatment.
  • the film is thin, it is easy to peel off, and it can be suitably used as a film for transfer substrates for various applications.
  • the biaxially oriented polypropylene film for thin film manufacturing process of the second disclosure has excellent heat resistance and rigidity, so that the occurrence of wrinkles and deterioration of flatness are suppressed during the formation of a thin film or during heat treatment.
  • the film is thinned, it is easy to peel off, and it can be suitably used as a film for various types of thin film manufacturing processes.

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PCT/JP2024/022259 2023-06-23 2024-06-19 転写基材用または薄膜製造工程用二軸配向ポリプロピレンフィルム、離型層積層ポリプロピレンフィルム、転写用積層フィルム、転写方法、および薄膜の製造方法 Ceased WO2024262545A1 (ja)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010024354A (ja) * 2008-07-18 2010-02-04 Tohcello Co Ltd 二軸延伸ポリプロピレンフィルム及びその用途
JP2013210446A (ja) * 2012-03-30 2013-10-10 Sumitomo Chemical Co Ltd 偏光板
JP2018127620A (ja) * 2017-02-07 2018-08-16 東レ株式会社 二軸配向ポリプロピレンフィルム
WO2021261312A1 (ja) * 2020-06-25 2021-12-30 東洋紡株式会社 二軸配向ポリプロピレンフィルム
WO2022210693A1 (ja) * 2021-03-31 2022-10-06 東レ株式会社 ポリプロピレンフィルム
JP2023095425A (ja) * 2021-12-24 2023-07-06 東洋紡株式会社 離型用二軸配向ポリプロピレンフィルム及び離型フィルム

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010024354A (ja) * 2008-07-18 2010-02-04 Tohcello Co Ltd 二軸延伸ポリプロピレンフィルム及びその用途
JP2013210446A (ja) * 2012-03-30 2013-10-10 Sumitomo Chemical Co Ltd 偏光板
JP2018127620A (ja) * 2017-02-07 2018-08-16 東レ株式会社 二軸配向ポリプロピレンフィルム
WO2021261312A1 (ja) * 2020-06-25 2021-12-30 東洋紡株式会社 二軸配向ポリプロピレンフィルム
WO2022210693A1 (ja) * 2021-03-31 2022-10-06 東レ株式会社 ポリプロピレンフィルム
JP2023095425A (ja) * 2021-12-24 2023-07-06 東洋紡株式会社 離型用二軸配向ポリプロピレンフィルム及び離型フィルム

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