WO2022124056A1 - Laminate and production method for same, and polyimide film and production method for same - Google Patents

Laminate and production method for same, and polyimide film and production method for same Download PDF

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Publication number
WO2022124056A1
WO2022124056A1 PCT/JP2021/042661 JP2021042661W WO2022124056A1 WO 2022124056 A1 WO2022124056 A1 WO 2022124056A1 JP 2021042661 W JP2021042661 W JP 2021042661W WO 2022124056 A1 WO2022124056 A1 WO 2022124056A1
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Prior art keywords
glass substrate
polyimide
polyimide layer
less
polyimide film
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PCT/JP2021/042661
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French (fr)
Japanese (ja)
Inventor
健一 福川
穣 久宗
達宣 浦上
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三井化学株式会社
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Publication of WO2022124056A1 publication Critical patent/WO2022124056A1/en

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    • 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
    • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material 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
    • B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/28—Surface treatment of glass, not in the form of fibres or filaments, by coating with organic material
    • C03C17/32—Surface treatment of glass, not in the form of fibres or filaments, by coating with organic material with synthetic or natural resins

Definitions

  • the present invention relates to a laminate, a method for producing the same, a polyimide film, and a method for producing the same.
  • the present invention provides the following laminates.
  • the glass substrate has a glass substrate and a polyimide layer laminated on the glass substrate, and when the surface roughness of the glass substrate is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and the glass substrate has.
  • the present invention provides the following method for producing a laminate.
  • the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 or more and 1000 protrusions having a height of 1/2 or more of the maximum height difference Sz per 5 ⁇ m ⁇ 5 ⁇ m. It includes a step of preparing a glass substrate having less than one piece, a step of applying a varnish containing a polyimide precursor and / or a polyimide on the glass substrate, and a step of curing the varnish to form a polyimide layer. , A method for manufacturing a laminate.
  • the present invention also provides the following method for producing a polyimide film and a polyimide film.
  • a method for producing a polyimide film which comprises a step of peeling the glass substrate and the polyimide layer of the laminate to obtain a polyimide film.
  • the glass substrate is recovered to form a second glass substrate, and a second varnish containing a polyimide precursor and / or a polyimide is applied onto the second glass substrate.
  • FIG. 1A is a photograph of the range of 5 ⁇ m ⁇ 5 ⁇ m when the surface of the glass substrate used in Example 9 is observed by AFM
  • FIG. 1B shows the glass substrate and the polyimide layer of the laminate produced in Example 9. It is a photograph of the range of 5 ⁇ m ⁇ 5 ⁇ m when the surface of the polyimide layer at the time of peeling was observed by AFM.
  • the reason is considered as follows.
  • a varnish is applied on a glass substrate and heated to cure it. Then, when this is cooled, residual stress is generated in the polyimide layer. At this time, if a smooth glass substrate is used as the support, the residual stress is generated in the entire polyimide layer.
  • a glass substrate having specific protrusions is used as the support, residual stress is concentrated around the protrusions. Then, when the glass substrate and the polyimide layer are peeled off, the peeling easily occurs in the vicinity of the protrusions. Further, at this time, since the glass substrate has an appropriate number of protrusions, peeling is likely to occur in the entire laminated body.
  • the glass substrate and the polyimide layer will be described in detail.
  • the glass substrate in the laminate of the present invention has a maximum height difference Sz of 4 nm or more and 20 nm or less when the surface roughness is measured, and is 1/2 of the maximum height difference Sz per 5 ⁇ m ⁇ 5 ⁇ m. It has 100 or more and 1000 or less protrusions having a height of the above.
  • the glass substrate may have the above-mentioned protrusions on the entire surface, but for example, the above-mentioned protrusions may be provided only in the region where the polyimide layer is laminated. Further, the glass substrate may have protrusions on both sides, or may have protrusions only on the surface on which the polyimide layer is laminated. Further, the glass substrate may be composed of one layer or two or more layers.
  • the maximum height difference Sz in the present specification refers to the top of the highest mountain in the region and the bottom of the lowest valley in the region when the surface roughness is observed for the region 2 ⁇ m ⁇ 2 ⁇ m including the protrusions of the glass substrate. Is the difference in height.
  • the highest mountain and the lowest valley do not necessarily have to be adjacent to each other.
  • the maximum height difference Sz can be measured by, for example, an atomic force microscope (hereinafter, also referred to as “AFM”).
  • the maximum height difference Sz may be 4 nm or more and 20 nm or less, preferably 5 nm or more and 18 nm or less, and more preferably 6 nm or more and 15 nm or less.
  • the maximum height difference Sz is 4 nm or more, the residual stress of the polyimide layer tends to concentrate in the vicinity of the protrusions as described above.
  • the maximum height difference Sz is 20 nm or less, the anchor effect is difficult to be exhibited between the glass substrate and the polyimide layer, and the glass substrate is easily peeled off.
  • the number of protrusions is calculated by taking a photograph of the surface of the glass substrate per 5 ⁇ m ⁇ 5 ⁇ m with AFM and counting the number of protrusions present in the photograph. Further, when counting the number of protrusions, not counting the number of tops, but counting the number of convex regions having a height of 1/2 or more of the maximum height difference Sz. Therefore, one protrusion may have a plurality of tops.
  • the total area of the region existing in the horizontal plane 2 nm lower than the highest protrusion means the total area of the glass substrate existing on the cut surface when the glass substrate is horizontally cut at a position 2 nm lower than the highest protrusion.
  • the area when the glass substrate is viewed in a plan view means the area when the glass substrate is viewed in a plan view regardless of the presence or absence of protrusions and the height.
  • the value is used when the measurement is performed in the range of 2 ⁇ m ⁇ 2 ⁇ m.
  • AFM identifies the tallest protrusion present in the 2 ⁇ m ⁇ 2 ⁇ m region.
  • the total cross-sectional area is calculated assuming that the glass substrate is cut in a horizontal plane 2 nm lower than the height of the protrusion. Then, the total area is divided by the plan-viewing area (2 ⁇ m ⁇ 2 ⁇ m) of the glass substrate to calculate the above ratio.
  • the contact angle of the glass substrate with water at 25 ° C. is preferably 10 ° or more and 90 ° or less, and more preferably 15 ° or more and 70 ° or less. More preferably, it is 15 ° or more and 45 ° or less. If the contact angle between the glass substrate and water is too large, the varnish may be repelled when the polyimide is formed, and the smoothness of the polyimide layer may be impaired. Further, if the contact angle with water is too small, it tends to be difficult to peel off the polyimide layer.
  • the thickness of the glass substrate is not particularly limited, and is preferably 50 ⁇ m or more and 5000 ⁇ m or less, and more preferably 500 ⁇ m or more and 2000 ⁇ m or less.
  • the thickness of the glass substrate is 50 ⁇ m or more, the glass substrate is less likely to bend and its strength is increased.
  • the thickness of the glass substrate is 2000 ⁇ m or less, the handleability of the laminated body is improved.
  • plan view shape of the glass substrate is not particularly limited and may be, for example, a rectangle, but other shapes may be used.
  • the area thereof is not particularly limited and is appropriately selected according to the use of the laminated body, but the length is usually preferably 10 mm or more and 2000 mm or less, and more preferably 30 mm or more and 500 mm or less.
  • the width is preferably 10 mm or more and 2000 mm or less, and more preferably 30 mm or more and 500 mm or less.
  • the polyimide layer may be arranged on the entire surface of the glass substrate, or may be arranged only on a part of the glass substrate. Further, the plan view shape is not particularly limited, and may be a desired shape such as a rectangular shape or a circular shape.
  • the above-mentioned glass substrate is prepared.
  • an inspection may be performed such as specifying the maximum height difference Sz on the surface of the glass substrate or counting the number of protrusions on the surface of the glass substrate. Further, based on the result of the inspection, a glass substrate may be selected in which the maximum height difference Sz is in a predetermined range and the number of protrusions per 5 ⁇ m ⁇ 5 ⁇ m is in a predetermined range. Further, for those which do not meet the standard, for example, etching treatment with hydrofluoric acid, laser irradiation, or the like may be performed, or the surface may be polished.
  • a step of confirming or sorting whether the contact angle of the glass substrate with water at 25 ° C. is 10 ° or more and 90 ° or less may be performed.
  • the varnish can be uniformly applied without repelling the varnish in the varnish application step described later.
  • the varnish may be a commercially available product.
  • examples of commercially available varnishes containing polyamic acid include ECRIOS VICT-LA, ECRIOS VICT-Bnp, ECRIOS VICT-Cz, ECRIOS VICT-E (all manufactured by Mitsui Chemicals, ECRIOS is a registered trademark of the same company); UPIA series ( UBE Kosan Co., Ltd., UPIA is a registered trademark of the company), etc. are included.
  • examples of commercially available varnishes containing polyimide are PIVAR MP17 and PIVAR MP20A (both manufactured by Mitsui Chemicals, PIVAR is a registered trademark of the company); Neoprim varnish (manufactured by Mitsubishi Gas Chemicals, Neoprim is a registered trademark of the company). ); PIAD (manufactured by Arakawa Kogyo Co., Ltd.), Pyre-M. L. (IST, Pyre-ML is a registered trademark of the company); PIX-8144 (manufactured by HD Microsystems) and the like are included.
  • the temperature at which the temperature rise ends (maximum reached) is usually preferably a higher temperature, specifically, a temperature 10 ° C. or higher higher than the glass transition temperature Tg of polyimide.
  • a higher temperature specifically, a temperature 10 ° C. or higher than the glass transition temperature Tg of polyimide.
  • the heating time after the temperature rise is completed can be, for example, about 1 second to 10 hours.
  • a varnish containing polyimide when applied in the varnish coating step, it is preferable to heat the varnish to a temperature higher than the boiling point of the solvent in the polyimide varnish, and the temperature is maintained at a temperature 10 ° C. or higher higher than the glass transition temperature Tg of the polyimide for a certain period of time. Is particularly preferable. This makes it easy for the solvent in the varnish to escape sufficiently.
  • the heating time can be, for example, about 1 second to 10 hours.
  • the method of peeling the glass substrate and the polyimide layer is not particularly limited, and a method of causing a chemical change between the glass substrate and the polyimide layer to peel the glass substrate may be used, but the polyimide layer or the glass substrate may be chemically peeled off.
  • a method of mechanically peeling the glass substrate and the polyimide layer without causing a change is more preferable.
  • mechanical peeling means peeling by applying force from either or both of the glass substrate and the polyimide layer so that the peeling occurs at the interface between the glass substrate and the polyimide layer.
  • An example of the method of mechanically peeling includes a method of fixing a glass substrate, attaching a tape to at least one end of the polyimide film, and then moving the tape in a direction of pulling it away from the glass substrate.
  • the tape may be attached not only to one end but also to a wider area, for example, the entire surface.
  • examples of the method of causing a chemical change between the glass substrate and the polyimide layer to peel off include laser irradiation treatment and flash light irradiation treatment.
  • the polyimide layer near the interface between the glass substrate and the polyimide layer is partially decomposed or altered to facilitate the separation between the glass substrate and the polyimide layer.
  • the polyimide layer after peeling from the glass substrate (hereinafter, also referred to as "polyimide film”) has a recess corresponding to the protrusion of the glass substrate.
  • the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 recesses having a depth of 1/2 or more of the maximum height difference Sz per 5 ⁇ m ⁇ 5 ⁇ m. It has 1000 or more and 1000 or less.
  • the maximum height difference Sz is preferably 5 nm or more and 18 nm or less, and more preferably 6 nm or more and 15 nm or less.
  • the total area of the openings is calculated assuming that the polyimide film is cut on a horizontal plane 2 nm higher than the depth of the recess. Then, the total area is divided by the plan-viewing area (2 ⁇ m ⁇ 2 ⁇ m) of the polyimide film to calculate the ratio.
  • the polyimide film (polyimide layer) and the peeled glass substrate can be used as a support for repeatedly forming the polyimide layer.
  • a second glass substrate from which the polyimide film (polyimide layer) has been peeled off is collected, and the polyimide precursor and / or the polyimide is contained on the glass substrate (also referred to as “second glass substrate” in the present specification).
  • the step of obtaining the polyimide film may be performed.
  • the second varnish may be the same as or different from the varnish applied in the varnish application step of the above-mentioned method for producing a laminated body.
  • the method of applying and curing the second varnish is the same as the varnish applying step and the varnish curing step of the above-mentioned manufacturing method of the laminated body.
  • the method of peeling the second glass substrate and the second polyimide layer is the same as described above, and can be performed by, for example, mechanical peeling.
  • the glass substrate from which the second polyimide layer has been peeled off can be recovered, and the production of the polyimide film (polyimide layer) can be further repeated.
  • the glass substrate can be easily peeled off from the polyimide layer. Therefore, it is possible to perform peeling without damaging the element portion, and a flexible electronic element can be easily obtained.
  • Example 1 Preparation of glass substrate A white plate glass 1 (52 mm x 76 mm, thickness 1 mm) manufactured by Matsunami Glass Industry Co., Ltd. and having a model number S9111 was prepared as a glass substrate.
  • AFM5300E manufactured by Hitachi High-Tech Science Co., Ltd.
  • the number was measured.
  • a Si cantilever having a back surface Al coat was used as the cantilever.
  • AFM5300E (manufactured by Hitachi High-Tech Science Co., Ltd.) calculated the total area of the glass substrate existing on the surface 2 nm lower than the highest protrusion on the surface of the glass substrate in the range of 2 ⁇ m ⁇ 2 ⁇ m, and the ratio ((highest)). The total area of the glass substrate existing on the surface 2 nm lower than the protrusion / 4 ⁇ m 2 ) ⁇ 100) was calculated. The results are shown in Table 1.
  • a masking tape (Capton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the above-mentioned glass substrate so as to have a strip-shaped opening having a width of 10 mm and a length of 40 mm. Then, about 5 g of varnish 1 polyamic acid (manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-LA) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds.
  • the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 220 ° C. at a heating rate of 2 ° C./min under an air stream, and subsequently maintained at 220 ° C. It was baked for 1.5 hours.
  • the polyamic acid in the polyamic acid varnish 1 was imidized, and a laminated body in which a glass substrate and a strip-shaped polyimide layer were laminated was obtained.
  • the thickness of the polyimide layer was 11 to 13 ⁇ m.
  • Example 2 The glass substrate (white plate glass 1) was peeled off from the laminate prepared in Example 1 and the polyamic acid varnish 1 was applied again on the glass substrate to prepare a laminate under the same conditions.
  • Example 3 A glass substrate (white plate glass 1) similar to that in Example 1 was prepared.
  • Masking tape Kerpton (registered trademark) tape manufactured by Toray DuPont
  • varnish 2 polyamic acid manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-Bnp
  • spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds.
  • Example 4 A glass substrate (white plate glass 1) similar to that in Example 1 was prepared.
  • Masking tape Kerpton (registered trademark) tape manufactured by Toray DuPont
  • varnish 3 polyamic acid manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-Cz
  • spin coating was performed at a rotation speed of 1000 rpm for 15 seconds and then at 1200 rpm for 5 seconds.
  • the masking tape was immediately peeled off and placed in a forced exhaust type drying inert oven, heated from 50 ° C to 350 ° C at a heating rate of 2 ° C / min under a nitrogen stream, and subsequently maintained at 350 ° C. It was baked for 1 hour.
  • the polyamic acid in the polyamic acid varnish 3 was imidized, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained.
  • the thickness of the polyimide layer was 12 ⁇ m.
  • Example 5 A glass substrate (white plate glass 1) similar to that in Example 1 was prepared.
  • Masking tape Kerpton (registered trademark) tape manufactured by Toray DuPont
  • varnish 4 polyamic acid manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-E
  • spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds.
  • the masking tape was immediately peeled off and placed in a forced exhaust type drying inert oven, heated from 50 ° C to 350 ° C at a heating rate of 2 ° C / min under a nitrogen stream, and subsequently maintained at 350 ° C. It was baked for 1 hour.
  • the polyamic acid in the polyamic acid varnish 4 was imidized, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained.
  • the thickness of the polyimide layer was 8 ⁇ m.
  • Example 6 A glass substrate (white plate glass 1) similar to that in Example 1 was prepared.
  • Masking tape Kerpton (registered trademark) tape manufactured by Toray DuPont
  • PIVAR polyimide varnish 1
  • spin coating was performed at a rotation speed of 1200 rpm for 15 seconds and then at 1400 rpm for 5 seconds.
  • the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 180 ° C.
  • the thickness of the polyimide layer was 14 ⁇ m.
  • Example 7 A glass substrate (white plate glass 1) similar to that in Example 1 was prepared.
  • Masking tape Kerpton (registered trademark) tape manufactured by Toray DuPont
  • PAVAR polyimide varnish 2
  • MP20A polyimide varnish 2
  • spin coating was performed at a rotation speed of 1200 rpm for 15 seconds and then at 1400 rpm for 5 seconds.
  • the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 250 ° C.
  • the thickness of the polyimide layer was 13 ⁇ m.
  • Example 8 After forming the laminate in the same manner as in Example 1, the laminate was placed in a vacuum oven and annealed at a vacuum degree of 0.2 kPa and 160 ° C. for 1 hour. After the annealing was completed, the decompression was immediately released and the temperature was returned to room temperature.
  • Example 9 A laminated body was produced in the same manner as in Example 1 except that white plate glass 2 (manufactured by Schott, B270, 100 mm ⁇ 100 mm, thickness 0.8 mm) was used as the glass substrate.
  • white plate glass 2 manufactured by Schott, B270, 100 mm ⁇ 100 mm, thickness 0.8 mm
  • Example 11 A laminated body was produced in the same manner as in Example 1 except that white plate glass 4 (manufactured by Schott, B270, 210 mm ⁇ 297 mm, polished to a thickness of 1.1 mm to 0.8 mm) was used as the glass substrate.
  • white plate glass 4 manufactured by Schott, B270, 210 mm ⁇ 297 mm, polished to a thickness of 1.1 mm to 0.8 mm
  • Example 1 A laminated body was produced in the same manner as in Example 1 except that alkaline glass (manufactured by AGC, 100 mm ⁇ 100 mm, thickness 0.7 mm) was used as the glass substrate.
  • alkaline glass manufactured by AGC, 100 mm ⁇ 100 mm, thickness 0.7 mm
  • Example 2 A laminated body was produced in the same manner as in Example 8 except that alkaline glass (manufactured by AGC, 100 mm ⁇ 100 mm, thickness 0.7 mm) was used as the glass substrate.
  • alkaline glass manufactured by AGC, 100 mm ⁇ 100 mm, thickness 0.7 mm
  • Example 3 As the glass substrate, a laminate was produced in the same manner as in Example 1 except that a substrate (manufactured by GDLAB GK, 100 mm ⁇ 100 mm, thickness 0.7 mm) having a surface coated silicon-based component on alkaline glass was used.
  • a strip-shaped polyimide layer having a width of 10 mm and a length of 40 mm is formed on the glass substrate of the laminate produced in each Example or Comparative Example. Then, the double-sided tape was folded back and attached to the end 1 cm square of the strip-shaped polyimide layer to reinforce the gripped portion. Then, the gripped portion is sandwiched between a small desktop testing machine (manufactured by Shimadzu Corporation, EZ-S) equipped with an adhesive tape peeling test device, and a 1 mm cutter blade is inserted at the interface between the glass substrate and the polyimide layer to peel it off. Gave me a chance. Then, a 90 ° peel test was carried out in accordance with JIS Z0237 (2009).
  • the glass substrate can be easily peeled off from the polyimide layer without causing damage to the polyimide layer even without using a dedicated device or the like. Therefore, it is useful for manufacturing various flexible electronic devices.

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  • Engineering & Computer Science (AREA)
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Abstract

The present invention addresses the problem of providing a laminate that makes it possible for a polyimide film and a glass substrate to be peeled apart without damaging the polyimide film or an element part, even if a dedicated device or the like is not used. A laminate that has a glass substrate and a polyimide layer that is layered on the glass substrate. When the surface roughness of the glass substrate has been measured, the maximum height difference Sz is 4–20 nm, and, per 5 μm×5 μm, the glass substrate has 100–1000 protrusions that have a height of at least 1/2 of the maximum height difference Sz.

Description

積層体およびその製造方法、ならびにポリイミドフィルム、およびその製造方法Laminates and their manufacturing methods, and polyimide films and their manufacturing methods
　本発明は、積層体およびその製造方法、ならびにポリイミドフィルム、およびその製造方法に関する。 The present invention relates to a laminate, a method for producing the same, a polyimide film, and a method for producing the same.
　近年、電子ペーパーの実用化にともない、ポリイミド等のフレキシブルな樹脂フィルム上にＴＦＴ素子等の半導体デバイスを形成することが試みられている。ただし、可撓性を有する樹脂フィルムだけでは撓んだりしやすく、搬送等が困難となることがある。そこで通常、ガラス基板上に樹脂層を形成し、樹脂層をガラス基板によって支持した状態で素子部を形成する。ガラス基板を支持体として使用すると、フラットパネルディスプレイ等を製造するための既存のプロセス技術および設備を流用できるとの観点でも好都合である。そして、素子部の形成後、樹脂層とガラス基板とを剥離することで、フレキシブルな素子が得られる。 In recent years, with the practical application of electronic paper, attempts have been made to form semiconductor devices such as TFT elements on a flexible resin film such as polyimide. However, the flexible resin film alone is liable to bend, which may make transportation difficult. Therefore, usually, a resin layer is formed on a glass substrate, and an element portion is formed in a state where the resin layer is supported by the glass substrate. Using a glass substrate as a support is also convenient from the viewpoint that existing process techniques and equipment for manufacturing flat panel displays and the like can be diverted. Then, after the element portion is formed, the resin layer and the glass substrate are peeled off to obtain a flexible element.
　しかしながら、一般的なガラス基板上に樹脂層、特にポリイミド層を形成すると、ガラス基板とポリイミド層との剥離が難しい、という課題があった。そして、剥離の際にかかる荷重によって、ポリイミド層が変形したり、損傷したり、さらには素子を損傷したりすること等があった。そこで、ポリイミド層とガラス基板との剥離技術が種々検討されている。 However, when a resin layer, particularly a polyimide layer, is formed on a general glass substrate, there is a problem that it is difficult to separate the glass substrate and the polyimide layer. Then, the polyimide layer may be deformed or damaged due to the load applied at the time of peeling, or the element may be damaged. Therefore, various techniques for peeling the polyimide layer and the glass substrate have been studied.
　例えば、ガラス基板とその上に配置された樹脂層との界面にレーザーを照射し、アブレーションを生じさせて剥離する技術が提案されている（例えば、特許文献１）。一方、ガラス基板と樹脂層との間に、フラッシュ光を照射し、これらの界面における密着性を弱める技術も提案されている（例えば、特許文献２）。 For example, a technique has been proposed in which the interface between a glass substrate and a resin layer arranged on the glass substrate is irradiated with a laser to cause ablation and peel off (for example, Patent Document 1). On the other hand, a technique of irradiating a flash light between a glass substrate and a resin layer to weaken the adhesion at these interfaces has also been proposed (for example, Patent Document 2).
特開２００３－１６３３３８号公報Japanese Patent Application Laid-Open No. 2003-163338 特開２０１４－１０７３１４号公報Japanese Unexamined Patent Publication No. 2014-107314
　しかしながら、レーザー光やフラッシュ光を照射するためには、専用の装置が必要である。またこれらの方法では、工程数が多く、ランニングコストが増大するという課題がある。 However, in order to irradiate laser light or flash light, a dedicated device is required. Further, these methods have a problem that the number of steps is large and the running cost increases.
　本発明は上記課題を鑑みてなされたものである。本発明は、専用の装置等を用いない場合でも、さらにはポリイミド層の損傷を抑制させつつ、ポリイミド層とガラス基板との剥離を容易に行うことが可能な積層体やその製造方法、当該積層体から得られるポリイミドフィルムやその製造方法等を提供する。 The present invention has been made in view of the above problems. The present invention is a laminate capable of easily peeling the polyimide layer from the glass substrate while suppressing damage to the polyimide layer even when a dedicated device or the like is not used, a method for manufacturing the laminate, and the laminate. Provided are a polyimide film obtained from a body, a method for producing the same, and the like.
　本発明は、以下の積層体を提供する。
　［１］ガラス基板と、前記ガラス基板に積層されたポリイミド層と、を有し、前記ガラス基板の表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、前記ガラス基板は、５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有する、積層体。 The present invention provides the following laminates.
[1] The glass substrate has a glass substrate and a polyimide layer laminated on the glass substrate, and when the surface roughness of the glass substrate is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and the glass substrate has. A laminated body having 100 or more and 1000 or less protrusions having a height of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm.
　［２］前記ガラス基板表面の最も高い突起から２ｎｍ低い水平面に存在する領域の合計面積が、前記ガラス基板を平面視したときの面積に対して３％以下である、［１］に記載の積層体。 [2] The lamination according to [1], wherein the total area of the regions existing in the horizontal plane 2 nm lower than the highest protrusion on the surface of the glass substrate is 3% or less with respect to the area when the glass substrate is viewed in a plan view. body.
　本発明は、以下の積層体の製造方法を提供する。
　［３］表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有するガラス基板を準備する工程と、前記ガラス基板上に、ポリイミド前駆体および／またはポリイミドを含むワニスを塗布する工程と、前記ワニスを硬化させて、ポリイミド層を形成する工程と、を含む、積層体の製造方法。 The present invention provides the following method for producing a laminate.
[3] When the surface roughness is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 or more and 1000 protrusions having a height of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm. It includes a step of preparing a glass substrate having less than one piece, a step of applying a varnish containing a polyimide precursor and / or a polyimide on the glass substrate, and a step of curing the varnish to form a polyimide layer. , A method for manufacturing a laminate.
　［４］前記ガラス基板の２５℃における水との接触角が、１０°～９０°である、［３］に記載の積層体の製造方法。 [4] The method for manufacturing a laminate according to [3], wherein the contact angle of the glass substrate with water at 25 ° C. is 10 ° to 90 °.
　本発明は、以下のポリイミドフィルムの製造方法、およびポリイミドフィルムも提供する。
　［５］上記積層体の、前記ガラス基板と前記ポリイミド層とを剥離し、ポリイミドフィルムを得る工程を有する、ポリイミドフィルムの製造方法。
　［６］前記ポリイミドフィルムを得る工程が、前記ガラス基板と前記ポリイミド層とを、機械的に剥離する工程である、［５］に記載のポリイミドフィルムの製造方法。
　［７］前記ポリイミドフィルムを得る工程後、前記ガラス基板を回収して第２のガラス基板とし、前記第２のガラス基板上に、ポリイミド前駆体および／またはポリイミドを含む第２のワニスを塗布する工程と、前記第２のワニスを硬化させて、第２のポリイミド層を形成する工程と、前記第２のガラス基板と前記第２のポリイミド層とを剥離し、第２のポリイミドフィルムを得る工程と、を有する、［５］または［６］に記載のポリイミドフィルムの製造方法。
　［８］表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の深さの凹部を１００個以上１０００個以下有する、ポリイミドフィルム。
　［９］前記ポリイミドフィルムの最も深い凹部から２ｎｍ高い水平面に存在する開口部の合計面積が、前記ポリイミドフィルムを平面視したときの面積に対して３％以下である、［８］に記載のポリイミドフィルム。 The present invention also provides the following method for producing a polyimide film and a polyimide film.
[5] A method for producing a polyimide film, which comprises a step of peeling the glass substrate and the polyimide layer of the laminate to obtain a polyimide film.
[6] The method for producing a polyimide film according to [5], wherein the step of obtaining the polyimide film is a step of mechanically peeling the glass substrate and the polyimide layer.
[7] After the step of obtaining the polyimide film, the glass substrate is recovered to form a second glass substrate, and a second varnish containing a polyimide precursor and / or a polyimide is applied onto the second glass substrate. A step of curing the second varnish to form a second polyimide layer, and a step of peeling the second glass substrate and the second polyimide layer to obtain a second polyimide film. The method for producing a polyimide film according to [5] or [6].
[8] When the surface roughness is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 or more and 1000 recesses having a depth of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm. The polyimide film having the following.
[9] The polyimide according to [8], wherein the total area of the openings existing in the horizontal plane 2 nm higher than the deepest recess of the polyimide film is 3% or less with respect to the area when the polyimide film is viewed in a plan view. the film.
　本発明は、以下のフレキシブル・エレクトロニクス素子の製造方法も提供する。
　［１０］上記［１］または［２］に記載の積層体の、前記ポリイミド層上に、素子部を形成する工程と、前記素子部の形成後、前記ポリイミド層と前記ガラス基板とを剥離する工程と、を有する、フレキシブル・エレクトロニクス素子の製造方法。 The present invention also provides the following method for manufacturing a flexible electronic device.
[10] The step of forming an element portion on the polyimide layer of the laminate according to the above [1] or [2], and after forming the element portion, the polyimide layer and the glass substrate are peeled off. A method for manufacturing a flexible electronic element, which comprises a process.
　本発明の積層体によれば、専用の装置等を用いない場合でも、さらにはポリイミド層に損傷を抑制して、ポリイミド層とガラス基板との剥離を容易に行うことが可能である。 According to the laminate of the present invention, it is possible to easily peel off the polyimide layer and the glass substrate by suppressing damage to the polyimide layer even when a dedicated device or the like is not used.
図１Ａは、実施例９で使用するガラス基板の表面をＡＦＭで観察したときの５μｍ×５μｍの範囲の写真であり、図１Ｂは、実施例９で作製した積層体のガラス基板およびポリイミド層を剥離したときのポリイミド層の表面をＡＦＭで観察したときの５μｍ×５μｍの範囲の写真である。FIG. 1A is a photograph of the range of 5 μm × 5 μm when the surface of the glass substrate used in Example 9 is observed by AFM, and FIG. 1B shows the glass substrate and the polyimide layer of the laminate produced in Example 9. It is a photograph of the range of 5 μm × 5 μm when the surface of the polyimide layer at the time of peeling was observed by AFM.
　本明細書において、「～」を用いて表される数値範囲は、「～」の前後に記載される数値を下限値及び上限値として含む範囲を意味する。本明細書に段階的に記載されている数値範囲において、ある数値範囲で記載された上限値又は下限値は、他の段階的な記載の数値範囲の上限値又は下限値に置き換えてもよい。 In the present specification, the numerical range represented by using "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value. In the numerical range described in the present specification stepwise, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in another stepwise description.
　本発明の積層体は、ガラス基板とポリイミド層とを含む。当該ポリイミド層は、各種フレキシブル・エレクトロニクス素子用の基板等に用いられる。ただし、ポリイミド層や積層体の用途はフレキシブル・エレクトロニクス素子用の基板に限定されない。 The laminate of the present invention includes a glass substrate and a polyimide layer. The polyimide layer is used for a substrate or the like for various flexible electronic devices. However, the use of the polyimide layer or the laminate is not limited to the substrate for the flexible electronic element.
　前述のように、従来、支持体となるガラス基板等の上にポリイミド層を形成し、ガラス基板によってポリイミド層を支持した状態でフレキシブル・エレクトロニクス素子の素子部等を形成することがあった。一方で、ポリイミド層をガラス基板から剥離して、各種フィルムとして使用することもあった。いずれの用途においても、ガラス基板上にポリイミド層を形成すると、これらの密着性が高く、ガラス基板とポリイミド層との剥離が難しい、という課題があった。 As described above, conventionally, a polyimide layer may be formed on a glass substrate or the like as a support, and an element portion or the like of a flexible electronics element may be formed while the polyimide layer is supported by the glass substrate. On the other hand, the polyimide layer may be peeled off from the glass substrate and used as various films. In any of the applications, when the polyimide layer is formed on the glass substrate, there is a problem that the adhesion between them is high and it is difficult to peel off the glass substrate and the polyimide layer.
　なお、上記ガラス基板としては、硬度の高いアルカリガラス基板、または無アルカリガラスを使用することが一般的であった。一方、ガラス基板の一種に、硬度や剛性がアルカリガラスより低い白板ガラスと称する種類のガラスがある。ただし、白板ガラスは、生産工程やその管理方法が他のガラス基板と異なり、例えばガラス基板内に気泡等が含まれることがある。さらに、強度も他のガラス基板より低いことが多く、厳密な光学用途や大判ガラス化して生産するには適さない傾向にあった。 As the glass substrate, it was common to use an alkaline glass substrate having a high hardness or non-alkali glass. On the other hand, as a kind of glass substrate, there is a kind of glass called white plate glass whose hardness and rigidity are lower than those of alkaline glass. However, the white plate glass is different from other glass substrates in the production process and its management method, and for example, bubbles may be contained in the glass substrate. Furthermore, the strength is often lower than that of other glass substrates, and it tends to be unsuitable for strict optical applications and large-format vitrification.
　本発明者らが検討したところ、従来、支持体として使用されてきたガラス基板は、表面が平滑であり、その上に形成したポリイミド層を形成すると、剥離が難しい。これに対し、表面に特定の突起を有するガラス基板によれば、特別な装置等を用いることなく、容易に剥離できることが見出された。具体的には、表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ、５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有するガラス基板によれば、ガラス基板とポリイミド層とを容易に剥離できることが明らかとなった。 As a result of the study by the present inventors, the glass substrate conventionally used as a support has a smooth surface, and when a polyimide layer formed on the glass substrate is formed, it is difficult to peel off. On the other hand, it was found that a glass substrate having a specific protrusion on the surface can be easily peeled off without using a special device or the like. Specifically, when the surface roughness is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 protrusions having a height of 1/2 or more of the maximum height difference Sz are formed per 5 μm × 5 μm. It was clarified that the glass substrate and the polyimide layer can be easily peeled off from the glass substrate having 1000 or more and 1000 or less.
　その理由は、以下のように考えられる。ポリイミド層を形成する際、ガラス基板上にワニスを塗布し、これを加熱して硬化させる。そして、これを冷却すると、ポリイミド層内に残留応力が発生する。このとき、支持体として平滑なガラス基板を用いると、当該残留応力がポリイミド層全体に発生する。一方、支持体として、特定の突起を有するガラス基板を用いると、残留応力が突起の周辺に集中する。そして、ガラス基板とポリイミド層とを剥離する際、当該突起の近傍で容易に剥離が生じる。またこのとき、ガラス基板が適度な数の突起を有するため、積層体全体で、剥離が生じやすくなる。以下、当該ガラス基板およびポリイミド層について、詳しく説明する。 The reason is considered as follows. When forming the polyimide layer, a varnish is applied on a glass substrate and heated to cure it. Then, when this is cooled, residual stress is generated in the polyimide layer. At this time, if a smooth glass substrate is used as the support, the residual stress is generated in the entire polyimide layer. On the other hand, when a glass substrate having specific protrusions is used as the support, residual stress is concentrated around the protrusions. Then, when the glass substrate and the polyimide layer are peeled off, the peeling easily occurs in the vicinity of the protrusions. Further, at this time, since the glass substrate has an appropriate number of protrusions, peeling is likely to occur in the entire laminated body. Hereinafter, the glass substrate and the polyimide layer will be described in detail.
　・ガラス基板
　本発明の積層体におけるガラス基板は、表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ、５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有する。 -Glass substrate The glass substrate in the laminate of the present invention has a maximum height difference Sz of 4 nm or more and 20 nm or less when the surface roughness is measured, and is 1/2 of the maximum height difference Sz per 5 μm × 5 μm. It has 100 or more and 1000 or less protrusions having a height of the above.
　ガラス基板は、全面に上記突起を有していてもよいが、例えばポリイミド層を積層する領域のみに、上記突起を有していてもよい。また、ガラス基板は、両面に突起を有していてもよく、ポリイミド層を積層する面のみに、突起を有していてもよい。さらに、ガラス基板は１層で構成されていてもよく、２層以上から構成されていてもよい。 The glass substrate may have the above-mentioned protrusions on the entire surface, but for example, the above-mentioned protrusions may be provided only in the region where the polyimide layer is laminated. Further, the glass substrate may have protrusions on both sides, or may have protrusions only on the surface on which the polyimide layer is laminated. Further, the glass substrate may be composed of one layer or two or more layers.
　本明細書における最大高低差Ｓｚとは、ガラス基板の突起を含む領域２μｍ×２μｍについて表面粗さを観察したときに、当該領域における最も高い山の頂部と、当該領域における最も低い谷の底部との高さの差である。なお、最も高い山および最も低い谷は、必ずしも隣り合っている必要はない。当該最大高低差Ｓｚは、例えば原子間力顕微鏡（以下、「ＡＦＭ」とも称する）で測定できる。 The maximum height difference Sz in the present specification refers to the top of the highest mountain in the region and the bottom of the lowest valley in the region when the surface roughness is observed for the region 2 μm × 2 μm including the protrusions of the glass substrate. Is the difference in height. The highest mountain and the lowest valley do not necessarily have to be adjacent to each other. The maximum height difference Sz can be measured by, for example, an atomic force microscope (hereinafter, also referred to as “AFM”).
　ここで、上記最大高低差Ｓｚは、４ｎｍ以上２０ｎｍ以下であればよいが、５ｎｍ以上１８ｎｍ以下が好ましく、６ｎｍ以上１５ｎｍ以下がより好ましい。最大高低差Ｓｚが４ｎｍ以上であると、上述のように、突起の近傍に、ポリイミド層の残留応力が集中しやすくなる。一方で最大高低差Ｓｚが２０ｎｍ以下であると、ガラス基板とポリイミド層との間でアンカー効果が発現し難く、容易に剥離しやすくなる。 Here, the maximum height difference Sz may be 4 nm or more and 20 nm or less, preferably 5 nm or more and 18 nm or less, and more preferably 6 nm or more and 15 nm or less. When the maximum height difference Sz is 4 nm or more, the residual stress of the polyimide layer tends to concentrate in the vicinity of the protrusions as described above. On the other hand, when the maximum height difference Sz is 20 nm or less, the anchor effect is difficult to be exhibited between the glass substrate and the polyimide layer, and the glass substrate is easily peeled off.
　また、本明細書では、ガラス基板の表面に存在する、上記最大高低差Ｓｚの１／２以上の高さを有する凸部を突起とする。当該突起の形状は特に制限されず、例えば円錐状や角錐状であってもよく、円柱状や円錐台状、角柱状、角錐台状等であってもよい。また、柱状や錐台状の天面の一部に窪みを有する形状であってもよい。突起の数は、ＡＦＭでガラス基板表面の５μｍ×５μｍ当たりの写真を撮像し、当該写真中に存在する突起の数を数えて算出する。また、突起の数を数える際には、頂部の数を数えるのではなく、最大高低差Ｓｚの１／２以上の高さを有する凸状の領域の数を数える。したがって、１つの突起に複数の頂部があってもよい。 Further, in the present specification, a convex portion existing on the surface of the glass substrate and having a height of 1/2 or more of the maximum height difference Sz is used as a protrusion. The shape of the protrusion is not particularly limited, and may be, for example, a conical shape or a pyramidal shape, or may be a cylindrical shape, a conical trapezoidal shape, a prismatic shape, a pyramidal trapezoidal shape, or the like. Further, it may have a shape having a dent in a part of the top surface having a columnar shape or a frustum shape. The number of protrusions is calculated by taking a photograph of the surface of the glass substrate per 5 μm × 5 μm with AFM and counting the number of protrusions present in the photograph. Further, when counting the number of protrusions, not counting the number of tops, but counting the number of convex regions having a height of 1/2 or more of the maximum height difference Sz. Therefore, one protrusion may have a plurality of tops.
　ここで、ガラス基板の表面５μｍ×５μｍ当たりに存在する突起の数は、１００個以上１０００個以下であればよいが、１２０個以上５００個以下が好ましく、１４０個以上２５０個以下がより好ましい。５μｍ×５μｍ当たりに存在する突起の数が１００個以上であると、ガラス基板とポリイミド層とを剥離しやすくなる。一方、５μｍ×５μｍ当たりに存在する突起の数が１０００個以下であると、ガラス基板とポリイミド層との間でアンカー効果が生じ難くなり、この場合も剥離しやすくなる。 Here, the number of protrusions existing per 5 μm × 5 μm on the surface of the glass substrate may be 100 or more and 1000 or less, but 120 or more and 500 or less are preferable, and 140 or more and 250 or less are more preferable. When the number of protrusions existing per 5 μm × 5 μm is 100 or more, the glass substrate and the polyimide layer can be easily peeled off. On the other hand, when the number of protrusions existing per 5 μm × 5 μm is 1000 or less, the anchor effect is less likely to occur between the glass substrate and the polyimide layer, and in this case as well, peeling is likely to occur.
　また、上記ガラス基板では、最も高い突起から２ｎｍ低い水平面に存在する領域の合計面積が、ガラス基板を平面視したときの面積に対して３％以下であることが好ましく、２％以下がより好ましく、１％以下がさらに好ましい。 Further, in the glass substrate, the total area of the region existing in the horizontal plane 2 nm lower than the highest protrusion is preferably 3% or less, more preferably 2% or less with respect to the area when the glass substrate is viewed in a plan view. 1% or less is more preferable.
　最も高い突起から２ｎｍ低い水平面に存在する領域の合計面積とは、最も高い突起から２ｎｍ低い位置で、水平にガラス基板を切断したとき、当該切断面に存在するガラス基板の面積の合計をいう。一方、ガラス基板を平面視したときの面積とは、突起の有無や高さに関係なく、ガラス基板を平面視したときの面積をいう。ただし、ガラス基板全体について、上記水平面に存在する領域の合計面積を算出することは難しい。そこで、本明細書では２μｍ×２μｍの範囲で測定を行ったときの値とする。具体的には、ＡＦＭで２μｍ×２μｍの領域内に存在する最も高い突起を特定する。そして、当該突起の高さから２ｎｍ低い水平面でガラス基板を切断したと仮定したときの断面積の合計を算出する。そして、当該合計面積を、ガラス基板の平面視面積（２μｍ×２μｍ）で除し、上記割合を算出する。 The total area of the region existing in the horizontal plane 2 nm lower than the highest protrusion means the total area of the glass substrate existing on the cut surface when the glass substrate is horizontally cut at a position 2 nm lower than the highest protrusion. On the other hand, the area when the glass substrate is viewed in a plan view means the area when the glass substrate is viewed in a plan view regardless of the presence or absence of protrusions and the height. However, it is difficult to calculate the total area of the regions existing on the horizontal plane for the entire glass substrate. Therefore, in the present specification, the value is used when the measurement is performed in the range of 2 μm × 2 μm. Specifically, AFM identifies the tallest protrusion present in the 2 μm × 2 μm region. Then, the total cross-sectional area is calculated assuming that the glass substrate is cut in a horizontal plane 2 nm lower than the height of the protrusion. Then, the total area is divided by the plan-viewing area (2 μm × 2 μm) of the glass substrate to calculate the above ratio.
　当該数値は、個々の突起の太さと相関する。個々の突起が太い場合には、上記数値が大きくなりやすい。上記数値を３％以下とすると、ポリイミド層の残留応力が突起周辺に集中しやすくなり、ポリイミド層がより剥離しやすくなる。 The value correlates with the thickness of each protrusion. If the individual protrusions are thick, the above values tend to be large. When the above value is 3% or less, the residual stress of the polyimide layer is likely to be concentrated around the protrusions, and the polyimide layer is more likely to be peeled off.
　さらに、ガラス基板の２５℃における水との接触角は、１０°以上９０°以下が好ましく、１５°以上７０°以下がより好ましい。１５°以上４５°以下がさらに好ましい。ガラス基板と水との接触角が大きすぎると、ポリイミドを形成する際に、ワニスをはじいてしまい、ポリイミド層の平滑性等が損なわれることがある。また、水との接触角が小さすぎると、ポリイミド層を剥離し難くなりやすい。 Further, the contact angle of the glass substrate with water at 25 ° C. is preferably 10 ° or more and 90 ° or less, and more preferably 15 ° or more and 70 ° or less. More preferably, it is 15 ° or more and 45 ° or less. If the contact angle between the glass substrate and water is too large, the varnish may be repelled when the polyimide is formed, and the smoothness of the polyimide layer may be impaired. Further, if the contact angle with water is too small, it tends to be difficult to peel off the polyimide layer.
　ここで、ガラス基板の種類は、上述の最大高低差Ｓｚや所定の数の突起を有していれば特に制限されず、例えばアルカリガラス基板であってもよく、無アルカリガラス基板であってもよく、白板ガラス基板であってもよい。ただし、通常、一般的なアルカリガラス基板や無アルカリガラス基板で上記数値を満たすものは少ないことから、アルカリガラス基板や無アルカリガラス基板を使用する際には、表面に突起を設けるための加工が必要である。一方で、白板ガラス基板では、上述の最大高低差Ｓｚや所定の数の突起を有するものがあり、これをそのまま使用してもよい。上述のように、白板ガラス基板の表面には、気泡由来の突起が生じやすく、他の種類のガラス基板より上述の最大高低差Ｓｚや所定の突起の数を満たしやすいと考えられる。なお、白板ガラス基板においても、必要に応じて、表面を研磨して最大高低差Ｓｚを調整したり、表面に突起を設けるための加工等を行ったりしてもよい。 Here, the type of the glass substrate is not particularly limited as long as it has the above-mentioned maximum height difference Sz and a predetermined number of protrusions, and may be, for example, an alkaline glass substrate or a non-alkali glass substrate. It may be a white plate glass substrate. However, since there are few general alkaline glass substrates and non-alkali glass substrates that satisfy the above values, when using an alkali glass substrate or non-alkali glass substrate, processing for providing protrusions on the surface is usually performed. is necessary. On the other hand, some whiteboard glass substrates have the above-mentioned maximum height difference Sz and a predetermined number of protrusions, and these may be used as they are. As described above, protrusions derived from bubbles are likely to occur on the surface of the white plate glass substrate, and it is considered that the above-mentioned maximum height difference Sz and a predetermined number of protrusions are more likely to be satisfied than other types of glass substrates. Even in the white plate glass substrate, the surface may be polished to adjust the maximum height difference Sz, or processing for providing protrusions on the surface may be performed, if necessary.
　上記ガラス基板に突起を設けるための加工の一例として、フッ酸によるエッチング処理や、レーザー照射、フォトリソグラフィー、または、これらを複数組み合わせた方法等が含まれる。 Examples of processing for providing protrusions on the glass substrate include etching treatment with hydrofluoric acid, laser irradiation, photolithography, or a method in which a plurality of these are combined.
　ここで、ガラス基板の厚みは特に制限されず、５０μｍ以上５０００μｍ以下が好ましく、５００μｍ以上２０００μｍ以下がより好ましい。ガラス基板の厚みが５０μｍ以上であると、ガラス基板が撓みにくくなったり、強度が高まったりする。一方、ガラス基板の厚みが２０００μｍ以下であると、積層体の取り扱い性が良好になる。 Here, the thickness of the glass substrate is not particularly limited, and is preferably 50 μm or more and 5000 μm or less, and more preferably 500 μm or more and 2000 μm or less. When the thickness of the glass substrate is 50 μm or more, the glass substrate is less likely to bend and its strength is increased. On the other hand, when the thickness of the glass substrate is 2000 μm or less, the handleability of the laminated body is improved.
　また、ガラス基板の平面視形状は特に制限されず、例えば矩形とすることができるが、その他の形状であってもよい。また、その面積も特に制限されず、積層体の用途に合わせて適宜選択されるが、通常長さは１０ｍｍ以上２０００ｍｍ以下が好ましく、３０ｍｍ以上５００ｍｍ以下がより好ましい。また、幅は１０ｍｍ以上２０００ｍｍ以下が好ましく、３０ｍｍ以上５００ｍｍ以下がより好ましい。 Further, the plan view shape of the glass substrate is not particularly limited and may be, for example, a rectangle, but other shapes may be used. Further, the area thereof is not particularly limited and is appropriately selected according to the use of the laminated body, but the length is usually preferably 10 mm or more and 2000 mm or less, and more preferably 30 mm or more and 500 mm or less. The width is preferably 10 mm or more and 2000 mm or less, and more preferably 30 mm or more and 500 mm or less.
　・ポリイミド層
　上記ガラス基板上に配置されるポリイミド層は、ポリイミドを主に含む層であれば特に制限されず、ポリイミド層を構成するポリイミドの構造は特に制限されない。ポリイミドの構造は、ポリイミド層の用途や所望の物性（例えば透明性や耐熱性等）に応じて適宜選択される。ただし、ポリイミド層は、ポリアミド酸を含むワニスや、ポリイミドを含むワニスから形成された層であることが特に好ましい。このようなポリイミド層は、ポリイミド層形成時に、上述のガラス基板の突起周辺に残留応力が生じやすく、上述のガラス基板から剥離しやすい。 -Polyimide layer The polyimide layer arranged on the glass substrate is not particularly limited as long as it is a layer mainly containing polyimide, and the structure of the polyimide constituting the polyimide layer is not particularly limited. The structure of the polyimide is appropriately selected according to the use of the polyimide layer and desired physical properties (for example, transparency, heat resistance, etc.). However, the polyimide layer is particularly preferably a varnish containing polyamic acid or a layer formed from a varnish containing polyimide. Such a polyimide layer tends to generate residual stress around the protrusions of the above-mentioned glass substrate when the polyimide layer is formed, and easily peels off from the above-mentioned glass substrate.
　ポリイミド層中には、ポリイミドを１種のみ含んでいてもよく、２種以上含んでいてもよい。また、本発明の目的および効果を損なわない範囲において、ポリイミド以外の成分を一部に含んでいてもよい。ポリイミド以外の成分の例には、他の樹脂や各種添加剤等が含まれる。ただし、ポリイミド層中のポリイミドの含有量は２０質量％以上が好ましく、４０質量％以上であることがより好ましい。 The polyimide layer may contain only one type of polyimide, or may contain two or more types of polyimide. Further, a component other than polyimide may be partially contained as long as the object and effect of the present invention are not impaired. Examples of components other than polyimide include other resins and various additives. However, the content of polyimide in the polyimide layer is preferably 20% by mass or more, more preferably 40% by mass or more.
　当該ポリイミド層の厚みは、１μｍ以上１００μｍ以下が好ましく、５μｍ以上５０μｍ以下がより好ましい。ポリイミド層の厚みが、１μｍ以上であると、ガラス基板から剥離した際に、十分な強度を維持できる。一方、ポリイミド層の厚みが５０μｍ以下であると、ポリイミド層を基板とした素子の厚みを薄くできる。また、フレキシブル性等も高まる。 The thickness of the polyimide layer is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less. When the thickness of the polyimide layer is 1 μm or more, sufficient strength can be maintained when peeled from the glass substrate. On the other hand, when the thickness of the polyimide layer is 50 μm or less, the thickness of the element using the polyimide layer as a substrate can be reduced. In addition, flexibility and the like are also enhanced.
　ポリイミド層は、ガラス基板の全面に配置されていてもよく、一部のみに配置されていてもよい。また、その平面視形状も特に制限されず、例えば矩形状であってもよく、円形状等、所望の形状であってもよい。 The polyimide layer may be arranged on the entire surface of the glass substrate, or may be arranged only on a part of the glass substrate. Further, the plan view shape is not particularly limited, and may be a desired shape such as a rectangular shape or a circular shape.
　・積層体の製造方法
　上述のポリイミド積層体の製造方法は特に制限されない。ただし、ガラス基板の表面の最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有するガラス基板を準備する工程（以下、「ガラス基板準備工程」とも称する）と、当該ガラス基板上に、ポリイミド前駆体および／またはポリイミドを含むワニスを塗布する工程（以下、「ワニス塗布工程」とも称する）と、当該ワニスを硬化させて、ポリイミド層とする工程（以下、「ワニス硬化工程」とも称する）と、を含む方法が好ましい。 -Method for manufacturing the laminate The above-mentioned method for manufacturing the polyimide laminate is not particularly limited. However, a glass having a maximum height difference Sz of 4 nm or more and 20 nm or less on the surface of the glass substrate and having 100 or more and 1000 or less protrusions having a height of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm. A step of preparing a substrate (hereinafter, also referred to as a “glass substrate preparation step”) and a step of applying a varnish containing a polyimide precursor and / or a polyimide on the glass substrate (hereinafter, also referred to as a “varnish coating step”). A method including a step of curing the varnish to form a polyimide layer (hereinafter, also referred to as a “varnish curing step”) is preferable.
　上述のように、このような方法でポリイミド層を形成すると、ワニス硬化工程後、ポリイミド層の残留応力がガラス基板の突起周辺に集中しやすくなり、ガラス基板とポリイミド層とを剥離しやすくなる。 As described above, when the polyimide layer is formed by such a method, the residual stress of the polyimide layer tends to be concentrated around the protrusions of the glass substrate after the varnish curing step, and the glass substrate and the polyimide layer are easily peeled off.
　基板準備工程では、上述のガラス基板を準備する。なお、ガラス基板準備工程では、ガラス基板の表面における最大高低差Ｓｚを特定したり、ガラス基板表面の突起の数を数えたりする検査を行ってもよい。また、検査の結果に基づき、最大高低差Ｓｚが所定の範囲であり、かつ５μｍ×５μｍ当たりにおける突起の数が所定の範囲であるガラス基板を選別したりする作業を行ってもよい。さらに、基準に満たないものに対して、例えばフッ酸によるエッチング処理やレーザー照射等を行ったりしてもよく、表面を研磨したりする作業を行ってもよい。 In the substrate preparation process, the above-mentioned glass substrate is prepared. In the glass substrate preparation step, an inspection may be performed such as specifying the maximum height difference Sz on the surface of the glass substrate or counting the number of protrusions on the surface of the glass substrate. Further, based on the result of the inspection, a glass substrate may be selected in which the maximum height difference Sz is in a predetermined range and the number of protrusions per 5 μm × 5 μm is in a predetermined range. Further, for those which do not meet the standard, for example, etching treatment with hydrofluoric acid, laser irradiation, or the like may be performed, or the surface may be polished.
　また基板準備工程では、ガラス基板の２５℃における水との接触角が、１０°以上９０°以下であるかを確認したり選別したりする工程を行ってもよい。ガラス基板と水との接触角が当該範囲であると、後述のワニス塗布工程で、ワニスをはじくことなく、均一に塗布できる。 Further, in the substrate preparation step, a step of confirming or sorting whether the contact angle of the glass substrate with water at 25 ° C. is 10 ° or more and 90 ° or less may be performed. When the contact angle between the glass substrate and water is within the range, the varnish can be uniformly applied without repelling the varnish in the varnish application step described later.
　ワニス塗布工程では、ポリアミド酸および／またはポリイミドを含むワニスを塗布する。当該ワニスは、テトラカルボン酸二無水物およびジアミンを溶媒中で反応させて調製してもよく、ポリアミド酸やポリイミドを準備し、これを溶媒に溶解または分散させてもよい。 In the varnish application step, a varnish containing polyamic acid and / or polyimide is applied. The varnish may be prepared by reacting tetracarboxylic acid dianhydride and diamine in a solvent, or polyamic acid or polyimide may be prepared and dissolved or dispersed in the solvent.
　使用する溶媒は、ポリアミド酸またはポリイミドを十分に溶解または分散させることが可能なものであれば特に制限されず、公知の溶媒を使用できる。 The solvent used is not particularly limited as long as it can sufficiently dissolve or disperse polyamic acid or polyimide, and known solvents can be used.
　なお、ワニスは市販品であってもよい。ポリアミド酸を含む市販のワニスの例には、ＥＣＲＩＯＳ　ＶＩＣＴ－ＬＡ、ＥＣＲＩＯＳ　ＶＩＣＴ－Ｂｎｐ、ＥＣＲＩＯＳ　ＶＩＣＴ－Ｃｚ、ＥＣＲＩＯＳ　ＶＩＣＴ－Ｅ（いずれも三井化学社製、ＥＣＲＩＯＳは同社の登録商標）；ＵＰＩＡシリーズ（宇部興産社製、ＵＰＩＡは同社の登録商標）等が含まれる。 The varnish may be a commercially available product. Examples of commercially available varnishes containing polyamic acid include ECRIOS VICT-LA, ECRIOS VICT-Bnp, ECRIOS VICT-Cz, ECRIOS VICT-E (all manufactured by Mitsui Chemicals, ECRIOS is a registered trademark of the same company); UPIA series ( UBE Kosan Co., Ltd., UPIA is a registered trademark of the company), etc. are included.
　一方、ポリイミドを含む市販のワニスの例には、ＰＩＶＡＲ　ＭＰ１７、ＰＩＶＡＲ　ＭＰ２０Ａ（いずれも三井化学社製、ＰＩＶＡＲは同社の登録商標）；ネオプリムワニス（三菱瓦斯化学社製、ネオプリムは同社の登録商標）；ＰＩＡＤ（荒川工業社製）、Ｐｙｒｅ－Ｍ．Ｌ．（Ｉ．Ｓ．Ｔ．社製、Ｐｙｒｅ－Ｍ．Ｌ．は同社の登録商標）；ＰＩＸ－８１４４（ＨＤマイクロシステムズ社製）等が含まれる。 On the other hand, examples of commercially available varnishes containing polyimide are PIVAR MP17 and PIVAR MP20A (both manufactured by Mitsui Chemicals, PIVAR is a registered trademark of the company); Neoprim varnish (manufactured by Mitsubishi Gas Chemicals, Neoprim is a registered trademark of the company). ); PIAD (manufactured by Arakawa Kogyo Co., Ltd.), Pyre-M. L. (IST, Pyre-ML is a registered trademark of the company); PIX-8144 (manufactured by HD Microsystems) and the like are included.
　上記ワニスの塗布方法は特に制限されず、例えばスピンコート法、バーコート法、ディップコート法、スリットコート法、スプレーコート法、グラビアコート法、ダイコート法等が含まれる。 The method for applying the varnish is not particularly limited, and includes, for example, a spin coating method, a bar coating method, a dip coating method, a slit coating method, a spray coating method, a gravure coating method, a die coating method, and the like.
　ワニス硬化工程では、ワニス塗布工程で塗布したワニスを硬化させる。これにより、所望のポリイミド層が形成される。ワニスの硬化方法は、ワニスの種類に応じて適宜選択される。例えば、ワニス塗布工程でポリアミド酸を含むワニスを塗布した場合には、ポリイミド酸をイミド化させる温度まで加熱する。 In the varnish curing process, the varnish applied in the varnish application process is cured. As a result, the desired polyimide layer is formed. The varnish curing method is appropriately selected according to the type of varnish. For example, when a varnish containing a polyamic acid is applied in the varnish application step, it is heated to a temperature at which the polyimide acid is imidized.
　このときの平均昇温速度は、５０～３６０℃の範囲で、例えば０．２５～５０℃／分とすることができ、好ましくは１～１０℃／分、より好ましくは２～５℃／分である。昇温速度は、一定としてもよく、２段階以上に変えてもよい。２段階以上に変える場合は、各昇温速度を０．２５～５０℃／分とすることが好ましい。得られるポリイミド層の透明性が高くなる。さらに、昇温は、連続的でも段階的（逐次的）でもよいが、連続的とすることが、得られるポリイミド層の外観不良やイミド化反応に伴う白化を抑制できる点から好ましい。なお、塗膜は必ずしも３００℃まで加熱する必要はない。昇温終了温度が３００℃未満である場合、１５０℃からその昇温終了温度までの範囲における平均昇温速度を０．２５～５０℃／分とすることが好ましい。 The average heating rate at this time can be in the range of 50 to 360 ° C., for example, 0.25 to 50 ° C./min, preferably 1 to 10 ° C./min, and more preferably 2 to 5 ° C./min. Is. The rate of temperature rise may be constant or may be changed to two or more steps. When changing to two or more steps, it is preferable to set each heating rate to 0.25 to 50 ° C./min. The transparency of the obtained polyimide layer is increased. Further, the temperature rise may be continuous or stepwise (sequential), but it is preferable to raise the temperature continuously from the viewpoint that the appearance of the obtained polyimide layer may be poor and whitening due to the imidization reaction can be suppressed. The coating film does not necessarily have to be heated to 300 ° C. When the temperature rise end temperature is less than 300 ° C., the average temperature rise rate in the range from 150 ° C. to the temperature rise end temperature is preferably 0.25 to 50 ° C./min.
　昇温終了（到達最高）温度は、通常、高めの温度、具体的にはポリイミドのガラス転移温度Ｔｇより１０℃以上高い温度とすることが好ましい。昇温終了（到達最高）温度をポリイミドのガラス転移温度以上とすることで、塗膜に含まれる残存溶剤を除去しやすくなる。昇温終了後の加熱時間は、例えば１秒～１０時間程度とすることができる。 The temperature at which the temperature rise ends (maximum reached) is usually preferably a higher temperature, specifically, a temperature 10 ° C. or higher higher than the glass transition temperature Tg of polyimide. By setting the temperature at which the temperature rise ends (maximum reached) to the glass transition temperature of the polyimide or higher, it becomes easy to remove the residual solvent contained in the coating film. The heating time after the temperature rise is completed can be, for example, about 1 second to 10 hours.
　一方、ワニス塗布工程でポリイミドを含むワニスを塗布した場合には、ポリイミドワニス中の溶媒の沸点以上に加熱することが好ましく、ポリイミドのガラス転移温度Ｔｇより１０℃以上高い温度で一定時間維持することが特に好ましい。これにより、ワニス中の溶媒が十分に抜けやすくなる。加熱時間は、例えば１秒～１０時間程度とすることができる。 On the other hand, when a varnish containing polyimide is applied in the varnish coating step, it is preferable to heat the varnish to a temperature higher than the boiling point of the solvent in the polyimide varnish, and the temperature is maintained at a temperature 10 ° C. or higher higher than the glass transition temperature Tg of the polyimide for a certain period of time. Is particularly preferable. This makes it easy for the solvent in the varnish to escape sufficiently. The heating time can be, for example, about 1 second to 10 hours.
　上記加熱によるワニスの硬化後（ポリイミド層の形成後）、通常当該積層体を室温まで冷却する。このとき、上述のようにポリイミド層に残留応力が生じやすく、当該残留応力がガラス基板の突起の周囲に集中しやすくなる。なお、冷却時の降温速度は特に制限されない。 After the varnish is cured by the above heating (after the polyimide layer is formed), the laminate is usually cooled to room temperature. At this time, as described above, residual stress is likely to occur in the polyimide layer, and the residual stress is likely to be concentrated around the protrusions of the glass substrate. The temperature lowering rate during cooling is not particularly limited.
　・積層体の用途
　上記積層体は、ポリイミド上記ガラス基板からポリイミド層を剥離して使用してもよく、ガラス基板によってポリイミド層を支持したまま使用してもよい。例えば、ガラス基板とポリイミド層とを剥離後、ポリイミド層上に各種素子部を形成して、フレキシブル・エレクトロニクス素子を作製してもよい。一方、後述のように、積層体の状態、すなわちガラス基板とポリイミド層とを積層した状態で、ポリイミド層上に素子部を形成する工程を行ってもよい。 -Application of Laminate The laminate may be used by peeling the polyimide layer from the polyimide glass substrate, or may be used while the polyimide layer is supported by the glass substrate. For example, after peeling the glass substrate and the polyimide layer, various element portions may be formed on the polyimide layer to manufacture a flexible electronic element. On the other hand, as described later, a step of forming an element portion on the polyimide layer may be performed in a state of a laminated body, that is, a state in which a glass substrate and a polyimide layer are laminated.
　ガラス基板とポリイミド層とを剥離する方法は特に制限されず、ガラス基板とポリイミド層との間に化学的変化を生じさせて剥離する方法であってもよいが、ポリイミド層やガラス基板に化学的変化を生じさせることなく、ガラス基板とポリイミド層とを機械的に剥離する方法がより好ましい。本明細書において、機械的に剥離するとは、ガラス基板およびポリイミド層の界面で剥離が生じるように、ガラス基板およびポリイミド層のいずれか一方、または両方から力を加えて、剥離することをいう。機械的に剥離する方法の一例には、ガラス基板を固定し、かつポリイミド膜の少なくとも一端にテープを貼り付けた後、当該テープをガラス基板から引き離す方向に移動させる方法が含まれる。なお、テープは一端だけでなく、より広い面積、例えば全面に貼り付けてもよい。 The method of peeling the glass substrate and the polyimide layer is not particularly limited, and a method of causing a chemical change between the glass substrate and the polyimide layer to peel the glass substrate may be used, but the polyimide layer or the glass substrate may be chemically peeled off. A method of mechanically peeling the glass substrate and the polyimide layer without causing a change is more preferable. As used herein, mechanical peeling means peeling by applying force from either or both of the glass substrate and the polyimide layer so that the peeling occurs at the interface between the glass substrate and the polyimide layer. An example of the method of mechanically peeling includes a method of fixing a glass substrate, attaching a tape to at least one end of the polyimide film, and then moving the tape in a direction of pulling it away from the glass substrate. The tape may be attached not only to one end but also to a wider area, for example, the entire surface.
　一方、ガラス基板とポリイミド層との間に化学的変化を生じさせて剥離する方法の例には、レーザー照射処理やフラッシュ光照射処理が挙げられる。これらの方法では、ガラス基板およびポリイミド層の界面近傍の、ポリイミド層を一部分解したり変質させたりすることで、ガラス基板とポリイミド層とを剥離しやすくする。 On the other hand, examples of the method of causing a chemical change between the glass substrate and the polyimide layer to peel off include laser irradiation treatment and flash light irradiation treatment. In these methods, the polyimide layer near the interface between the glass substrate and the polyimide layer is partially decomposed or altered to facilitate the separation between the glass substrate and the polyimide layer.
　上記ガラス基板から剥離後のポリイミド層（以下、「ポリイミドフィルム」とも称する）は、上記ガラス基板の突起に対応する凹部を有している。具体的には、表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の深さの凹部を１００個以上１０００個以下有する。最大高低差Ｓｚは、５ｎｍ以上１８ｎｍ以下が好ましく、６ｎｍ以上１５ｎｍ以下がより好ましい。一方、凹部の数は、１２０個以上５００個以下が好ましく、１４０個以上２５０個以下がより好ましい。最大高低差Ｓｚの測定方法や、凹部の個数の算出方法は、上述のガラス基板の最大高低差Ｓｚの測定方法や、凸部の個数の算出方法と同様である。 The polyimide layer after peeling from the glass substrate (hereinafter, also referred to as "polyimide film") has a recess corresponding to the protrusion of the glass substrate. Specifically, when the surface roughness is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and 100 recesses having a depth of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm. It has 1000 or more and 1000 or less. The maximum height difference Sz is preferably 5 nm or more and 18 nm or less, and more preferably 6 nm or more and 15 nm or less. On the other hand, the number of recesses is preferably 120 or more and 500 or less, and more preferably 140 or more and 250 or less. The method for measuring the maximum height difference Sz and the method for calculating the number of concave portions are the same as the method for measuring the maximum height difference Sz of the glass substrate and the method for calculating the number of convex portions.
　さらに、当該ポリイミドフィルムの最も深い凹部から２ｎｍ高い水平面に存在する開口部の合計面積が、ポリイミドフィルムを平面視したときの面積に対して３％以下であることが好ましく、２％以下がより好ましく、１％以下がさらに好ましい。本明細書でいう「開口部」とは、上記水平面においてポリイミドが存在しない部分、つまり空隙となっている部分をいう。上記水平面に存在する開口部の合計面積についても、上述のガラス基板の表面形状を測定する方法と同様に測定できる。具体的には、ポリイミドフィルムをＡＦＭで観察し、２μｍ×２μｍの領域内に存在する最も深い凹部を特定する。そして、当該凹部の深さから２ｎｍ高い水平面でポリイミドフィルムを切断したと仮定したときの開口部の面積の合計を算出する。そして、当該合計面積を、ポリイミドフィルムの平面視面積（２μｍ×２μｍ）で除し、割合を算出する。 Further, the total area of the openings existing in the horizontal plane 2 nm higher than the deepest recess of the polyimide film is preferably 3% or less, more preferably 2% or less with respect to the area when the polyimide film is viewed in a plan view. 1% or less is more preferable. As used herein, the term "opening" refers to a portion of the horizontal plane in which polyimide does not exist, that is, a portion that is a void. The total area of the openings existing in the horizontal plane can also be measured in the same manner as the method for measuring the surface shape of the glass substrate. Specifically, the polyimide film is observed by AFM to identify the deepest recess existing in the region of 2 μm × 2 μm. Then, the total area of the openings is calculated assuming that the polyimide film is cut on a horizontal plane 2 nm higher than the depth of the recess. Then, the total area is divided by the plan-viewing area (2 μm × 2 μm) of the polyimide film to calculate the ratio.
　ポリイミドフィルムが、このような凹部を有すると、当該ポリイミドフィルム上に素子部を形成する際、もしくは形成した後にポリイミドフィルムが光を反射し難くなり、ポリイミドフィルムを様々な用途に使用しやすくなる。 When the polyimide film has such a recess, it becomes difficult for the polyimide film to reflect light when or after forming an element portion on the polyimide film, and the polyimide film can be easily used for various purposes.
　なお、ポリイミドフィルム（ポリイミド層）と剥離したガラス基板は、繰り返しポリイミド層を形成するための支持体として使用可能である。例えば、ポリイミドフィルム（ポリイミド層）を剥離したガラス基板を回収し、当該ガラス基板（本明細書では、「第２のガラス基板」とも称する）上に、ポリイミド前駆体および／またはポリイミドを含む第２のワニスを塗布する工程と、当該第２のワニスを硬化させて、第２のポリイミド層を形成する工程と、上記第２のガラス基板と上記第２のポリイミド層とを剥離し、第２のポリイミドフィルムを得る工程と、を行ってもよい。上記第２のワニスは、上述の積層体の製造方法のワニス塗布工程で塗布するワニスと同一であってもよく、異なっていてもよい。また、当該第２のワニスの塗布方法や硬化方法は、上述の積層体の製造方法のワニス塗布工程やワニス硬化工程と同様である。また、第２のガラス基板と第２のポリイミド層との剥離方法も上述と同様であり、例えば機械的剥離によって行うことができる。なお、第２のポリイミド層を剥離したガラス基板を回収し、ポリイミドフィルム（ポリイミド層）の作製をさらに繰り返すことができる。 The polyimide film (polyimide layer) and the peeled glass substrate can be used as a support for repeatedly forming the polyimide layer. For example, a second glass substrate from which the polyimide film (polyimide layer) has been peeled off is collected, and the polyimide precursor and / or the polyimide is contained on the glass substrate (also referred to as “second glass substrate” in the present specification). The step of applying the varnish, the step of curing the second varnish to form the second polyimide layer, and the step of peeling the second glass substrate and the second polyimide layer to form a second polyimide layer. The step of obtaining the polyimide film may be performed. The second varnish may be the same as or different from the varnish applied in the varnish application step of the above-mentioned method for producing a laminated body. Further, the method of applying and curing the second varnish is the same as the varnish applying step and the varnish curing step of the above-mentioned manufacturing method of the laminated body. Further, the method of peeling the second glass substrate and the second polyimide layer is the same as described above, and can be performed by, for example, mechanical peeling. The glass substrate from which the second polyimide layer has been peeled off can be recovered, and the production of the polyimide film (polyimide layer) can be further repeated.
　このように繰り返し、ガラス基板上にポリイミド層を作製してポリイミドフィルム（ポリイミド層）を得る場合、厚さや組成が同一である、一種類のポリイミドフィルムを繰り返し作製してもよく、厚さや組成等が互いに異なる、複数種類のポリイミドフィルムを作製してもよい。 When a polyimide layer is repeatedly produced on a glass substrate in this way to obtain a polyimide film (polyimide layer), one type of polyimide film having the same thickness and composition may be repeatedly produced, such as thickness and composition. You may make a plurality of kinds of polyimide films which are different from each other.
　・積層体を用いたフレキシブル・エレクトロニクス素子の製造方法
　上述の積層体をそのまま、フレキシブル・エレクトロニクス素子の製造に使用する場合、まず、積層体のポリイミド層上に素子部を形成する工程を行い、その後、ポリイミド層とガラス基板とを剥離する工程を行う。 -Manufacturing method of flexible electronics element using a laminated body When the above-mentioned laminated body is used as it is for manufacturing a flexible electronic element, first, a step of forming an element portion on the polyimide layer of the laminated body is performed, and then. , Perform a step of peeling the polyimide layer and the glass substrate.
　当該方法によれば、剛性を有するガラス基板によって支持しながら、素子部を形成することが可能である。したがって、素子部の形成時に、ポリイミド層が撓んだりすること等がなく、所望の位置に精度よく素子部を形成することが可能である。 According to this method, it is possible to form an element portion while being supported by a rigid glass substrate. Therefore, the polyimide layer does not bend when the element portion is formed, and the element portion can be accurately formed at a desired position.
　一方で、素子部を形成した後は、ポリイミド層からガラス基板を容易に剥離可能である。したがって、素子部を破損させること等なく、剥離を行うことが可能であり、フレキシブル・エレクトロニクス素子が容易に得られる。 On the other hand, after the element portion is formed, the glass substrate can be easily peeled off from the polyimide layer. Therefore, it is possible to perform peeling without damaging the element portion, and a flexible electronic element can be easily obtained.
　以下において、実施例を参照して本発明を説明する。実施例によって、本発明の範囲は限定されない。 Hereinafter, the present invention will be described with reference to examples. Examples do not limit the scope of the invention.
　［実施例１］
　・ガラス基板の準備
　松浪硝子工業社製、型番Ｓ９１１１の白板ガラス１（５２ｍｍ×７６ｍｍ、厚み１ｍｍ）をガラス基板として準備した。当該ガラス基板について、ＡＦＭ５３００Ｅ（日立ハイテクサイエンス株式会社製）を用いて、表面の最大高低差Ｓｚ、および５μｍ×５μｍ当たりに存在する、最大高低差Ｓｚの１／２以上の高さを有する突起の数を測定した。なお、測定の際、カンチレバーは背面Ａｌコートを有するＳｉ製カンチレバーを用いた。測定モードはＤＦＭモード（表面形状象）とし、測定環境は室温、大気中で観測した。なお、最大高低差Ｓｚは、２μｍ×２μｍ当たりの表面粗さを測定し、ガラス基板の表面において、最も高い点と最も低い点との高低差を算出して求めた。一方、５μｍ×５μｍ当たりに存在する、最大高低差Ｓｚの１／２以上の高さを有する突起の数は、ＡＦＭで撮影した画像（５μｍ×５μｍ）中の突起の数を数えた。結果を表１に示す。 [Example 1]
-Preparation of glass substrate A white plate glass 1 (52 mm x 76 mm, thickness 1 mm) manufactured by Matsunami Glass Industry Co., Ltd. and having a model number S9111 was prepared as a glass substrate. For the glass substrate, using AFM5300E (manufactured by Hitachi High-Tech Science Co., Ltd.), a protrusion having a maximum height difference Sz on the surface and a protrusion having a height of 1/2 or more of the maximum height difference Sz existing per 5 μm × 5 μm. The number was measured. At the time of measurement, a Si cantilever having a back surface Al coat was used as the cantilever. The measurement mode was DFM mode (surface shape elephant), and the measurement environment was room temperature and the atmosphere. The maximum height difference Sz was obtained by measuring the surface roughness per 2 μm × 2 μm and calculating the height difference between the highest point and the lowest point on the surface of the glass substrate. On the other hand, the number of protrusions having a height of 1/2 or more of the maximum height difference Sz existing per 5 μm × 5 μm was counted as the number of protrusions in the image (5 μm × 5 μm) taken by AFM. The results are shown in Table 1.
　さらに、ＡＦＭ５３００Ｅ（日立ハイテクサイエンス株式会社製）により、２μｍ×２μｍの範囲について、ガラス基板表面の最も高い突起から２ｎｍ低い面に存在する、ガラス基板の合計面積を算出し、その割合（（最も高い突起から２ｎｍ低い面に存在するガラス基板の合計面積／４μｍ２）×１００）を算出した。結果を表１に示す。 Furthermore, AFM5300E (manufactured by Hitachi High-Tech Science Co., Ltd.) calculated the total area of the glass substrate existing on the surface 2 nm lower than the highest protrusion on the surface of the glass substrate in the range of 2 μm × 2 μm, and the ratio ((highest)). The total area of the glass substrate existing on the surface 2 nm lower than the protrusion / 4 μm 2 ) × 100) was calculated. The results are shown in Table 1.
　・ポリイミド層の形成
　上述のガラス基板の一部に幅１０ｍｍ、長さ４０ｍｍの短冊状の開口部を有するようにマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリアミド酸ワニス１（三井化学社製、ＥＣＲＩＯＳ（登録商標）　ＶＩＣＴ－ＬＡ）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１３００ｒｐｍで１５秒間、続けて１５００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥オーブンの中に置き、空気気流下、５０℃から２２０℃まで、昇温速度２℃／分で加熱し、続けて２２０℃に保持したまま１．５時間焼成した。これにより、ポリアミド酸ワニス１中のポリアミド酸がイミド化し、ガラス基板と短冊状のポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、１１～１３μｍであった。 -Formation of a polyimide layer A masking tape (Capton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the above-mentioned glass substrate so as to have a strip-shaped opening having a width of 10 mm and a length of 40 mm. Then, about 5 g of varnish 1 polyamic acid (manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-LA) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 220 ° C. at a heating rate of 2 ° C./min under an air stream, and subsequently maintained at 220 ° C. It was baked for 1.5 hours. As a result, the polyamic acid in the polyamic acid varnish 1 was imidized, and a laminated body in which a glass substrate and a strip-shaped polyimide layer were laminated was obtained. The thickness of the polyimide layer was 11 to 13 μm.
　［実施例２］
　上記実施例１で作製した積層体からガラス基板（白板ガラス１）を剥離し、再度当該ガラス基板上にポリアミド酸ワニス１を塗布して、同様の条件で積層体を作製した。 [Example 2]
The glass substrate (white plate glass 1) was peeled off from the laminate prepared in Example 1 and the polyamic acid varnish 1 was applied again on the glass substrate to prepare a laminate under the same conditions.
　［実施例３］
　実施例１と同様のガラス基板（白板ガラス１）を準備した。当該ガラス基板の一部にマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリアミド酸ワニス２（三井化学社製、ＥＣＲＩＯＳ（登録商標）　ＶＩＣＴ－Ｂｎｐ）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１３００ｒｐｍで１５秒間、続けて１５００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥イナートオーブンの中に置き、窒素気流下、５０℃から２８０℃まで、昇温速度２℃／分で加熱し、続けて２８０℃に保持したまま２時間焼成した。これにより、ポリアミド酸ワニス２中のポリアミド酸がイミド化され、ガラス基板とポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、１３μｍであった。 [Example 3]
A glass substrate (white plate glass 1) similar to that in Example 1 was prepared. Masking tape (Kapton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the glass substrate. Then, about 5 g of varnish 2 polyamic acid (manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-Bnp) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying inert oven, heated from 50 ° C to 280 ° C at a heating rate of 2 ° C / min under a nitrogen stream, and subsequently maintained at 280 ° C. It was baked for 2 hours. As a result, the polyamic acid in the polyamic acid varnish 2 was imidized, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained. The thickness of the polyimide layer was 13 μm.
　［実施例４］
　実施例１と同様のガラス基板（白板ガラス１）を準備した。当該ガラス基板の一部にマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリアミド酸ワニス３（三井化学社製、ＥＣＲＩＯＳ（登録商標）　ＶＩＣＴ－Ｃｚ）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１０００ｒｐｍで１５秒間、続けて１２００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥イナートオーブンの中に置き、窒素気流下、５０℃から３５０℃まで、昇温速度２℃／分で加熱し、続けて３５０℃に保持したまま１時間焼成した。これにより、ポリアミド酸ワニス３中のポリアミド酸がイミド化され、ガラス基板とポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、１２μｍであった。 [Example 4]
A glass substrate (white plate glass 1) similar to that in Example 1 was prepared. Masking tape (Kapton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the glass substrate. Then, about 5 g of varnish 3 polyamic acid (manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-Cz) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1000 rpm for 15 seconds and then at 1200 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying inert oven, heated from 50 ° C to 350 ° C at a heating rate of 2 ° C / min under a nitrogen stream, and subsequently maintained at 350 ° C. It was baked for 1 hour. As a result, the polyamic acid in the polyamic acid varnish 3 was imidized, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained. The thickness of the polyimide layer was 12 μm.
　［実施例５］
　実施例１と同様のガラス基板（白板ガラス１）を準備した。当該ガラス基板の一部にマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリアミド酸ワニス４（三井化学社製、ＥＣＲＩＯＳ（登録商標）　ＶＩＣＴ－Ｅ）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１３００ｒｐｍで１５秒間、続けて１５００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥イナートオーブンの中に置き、窒素気流下、５０℃から３５０℃まで、昇温速度２℃／分で加熱し、続けて３５０℃に保持したまま１時間焼成した。これにより、ポリアミド酸ワニス４中のポリアミド酸がイミド化され、ガラス基板とポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、８μｍであった。 [Example 5]
A glass substrate (white plate glass 1) similar to that in Example 1 was prepared. Masking tape (Kapton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the glass substrate. Then, about 5 g of varnish 4 polyamic acid (manufactured by Mitsui Chemicals, Inc., ECRIOS (registered trademark) VICT-E) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1300 rpm for 15 seconds and then at 1500 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying inert oven, heated from 50 ° C to 350 ° C at a heating rate of 2 ° C / min under a nitrogen stream, and subsequently maintained at 350 ° C. It was baked for 1 hour. As a result, the polyamic acid in the polyamic acid varnish 4 was imidized, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained. The thickness of the polyimide layer was 8 μm.
　［実施例６］
　実施例１と同様のガラス基板（白板ガラス１）を準備した。当該ガラス基板の一部にマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリイミドワニス１（三井化学社製、ＰＩＶＡＲ（登録商標）　ＭＰＥ３０８）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１２００ｒｐｍで１５秒間、続けて１４００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥オーブンの中に置き、空気気流下、５０℃から１８０℃まで、昇温速度５℃／分で加熱し、続けて１８０℃に保持したまま１時間焼成した。これにより、ポリイミドワニス１中の溶媒が除去され、ガラス基板とポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、１４μｍであった。 [Example 6]
A glass substrate (white plate glass 1) similar to that in Example 1 was prepared. Masking tape (Kapton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the glass substrate. Then, about 5 g of polyimide varnish 1 (PIVAR (registered trademark) MPE308 manufactured by Mitsui Chemicals, Inc.) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1200 rpm for 15 seconds and then at 1400 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 180 ° C. at a heating rate of 5 ° C./min under an air stream, and subsequently maintained at 180 ° C. It was baked for 1 hour as it was. As a result, the solvent in the polyimide varnish 1 was removed, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained. The thickness of the polyimide layer was 14 μm.
　［実施例７］
　実施例１と同様のガラス基板（白板ガラス１）を準備した。当該ガラス基板の一部にマスキングテープ（東レ・デュポン社製、カプトン（登録商標）テープ）を貼付した。そして、ポリイミドワニス２（三井化学社製、ＰＩＶＡＲ（登録商標）　ＭＰ２０Ａ）を約５ｇ、上記ガラス基板上に滴下した。そして、回転数１２００ｒｐｍで１５秒間、続けて１４００ｒｐｍで５秒間スピンコートした。その後、速やかに、マスキングテープを剥離して強制排気型乾燥オーブンの中に置き、空気気流下、５０℃から２５０℃まで、昇温速度５℃／分で加熱し、続けて２５０℃に保持したまま１時間焼成した。これにより、ポリイミドワニス２中の溶媒が除去され、ガラス基板とポリイミド層とが積層された積層体が得られた。ポリイミド層の厚みは、１３μｍであった。 [Example 7]
A glass substrate (white plate glass 1) similar to that in Example 1 was prepared. Masking tape (Kapton (registered trademark) tape manufactured by Toray DuPont) was attached to a part of the glass substrate. Then, about 5 g of polyimide varnish 2 (PIVAR (registered trademark) MP20A manufactured by Mitsui Chemicals, Inc.) was dropped onto the glass substrate. Then, spin coating was performed at a rotation speed of 1200 rpm for 15 seconds and then at 1400 rpm for 5 seconds. After that, the masking tape was immediately peeled off and placed in a forced exhaust type drying oven, heated from 50 ° C. to 250 ° C. at a heating rate of 5 ° C./min under an air stream, and subsequently maintained at 250 ° C. It was baked for 1 hour as it was. As a result, the solvent in the polyimide varnish 2 was removed, and a laminated body in which the glass substrate and the polyimide layer were laminated was obtained. The thickness of the polyimide layer was 13 μm.
　［実施例８］
　上記実施例１と同様に積層体を形成後、当該積層体を真空オーブン中に載置し、真空度０．２ｋＰａ、１６０℃で１時間のアニーリングを行った。アニーリング終了後、速やかに減圧を解除し、常温に戻した。 [Example 8]
After forming the laminate in the same manner as in Example 1, the laminate was placed in a vacuum oven and annealed at a vacuum degree of 0.2 kPa and 160 ° C. for 1 hour. After the annealing was completed, the decompression was immediately released and the temperature was returned to room temperature.
　［実施例９］
　ガラス基板として、白板ガラス２（Ｓｃｈｏｔｔ社製、Ｂ２７０、１００ｍｍ×１００ｍｍ、厚み０．８ｍｍ）を用いた以外は、実施例１と同様に積層体を作製した。 [Example 9]
A laminated body was produced in the same manner as in Example 1 except that white plate glass 2 (manufactured by Schott, B270, 100 mm × 100 mm, thickness 0.8 mm) was used as the glass substrate.
　［実施例１０］
　ガラス基板として、白板ガラス３（Ｓｃｈｏｔｔ社製、Ｂ２７０、２１０ｍｍ×２９７ｍｍ、厚み２．０ｍｍ）を用いた以外は、実施例１と同様に積層体を作製した。図１Ａに、ポリイミド層形成前のガラス基板の表面をＡＦＭで観察したときの５μｍ×５μｍの範囲の写真を示す。また図１Ｂに、作製した積層体のガラス基板およびポリイミド層を剥離したときのポリイミド層の表面をＡＦＭで観察したときの５μｍ×５μｍの範囲の写真を示す。図１Ａに示すように、白板ガラス３は、所望の高さの突起を有しており、かつ当該白板ガラス３から剥離したポリイミド層には当該突起に対応する凹部が形成された。 [Example 10]
A laminated body was produced in the same manner as in Example 1 except that white plate glass 3 (manufactured by Schott, B270, 210 mm × 297 mm, thickness 2.0 mm) was used as the glass substrate. FIG. 1A shows a photograph in the range of 5 μm × 5 μm when the surface of the glass substrate before forming the polyimide layer was observed by AFM. Further, FIG. 1B shows a photograph in the range of 5 μm × 5 μm when the surface of the polyimide layer when the glass substrate and the polyimide layer of the produced laminate were peeled off was observed by AFM. As shown in FIG. 1A, the white plate glass 3 has protrusions having a desired height, and the polyimide layer peeled from the white plate glass 3 is formed with recesses corresponding to the protrusions.
　［実施例１１］
　ガラス基板として、白板ガラス４（Ｓｃｈｏｔｔ社製、Ｂ２７０、２１０ｍｍ×２９７ｍｍ、厚み１．１ｍｍを０．８ｍｍまで研磨したもの）を用いた以外は、実施例１と同様に積層体を作製した。 [Example 11]
A laminated body was produced in the same manner as in Example 1 except that white plate glass 4 (manufactured by Schott, B270, 210 mm × 297 mm, polished to a thickness of 1.1 mm to 0.8 mm) was used as the glass substrate.
　［比較例１］
　ガラス基板として、アルカリガラス（ＡＧＣ社製、１００ｍｍ×１００ｍｍ、厚み０．７ｍｍ）を用いた以外は、実施例１と同様に積層体を作製した。 [Comparative Example 1]
A laminated body was produced in the same manner as in Example 1 except that alkaline glass (manufactured by AGC, 100 mm × 100 mm, thickness 0.7 mm) was used as the glass substrate.
　［比較例２］
　ガラス基板として、アルカリガラス（ＡＧＣ社製、１００ｍｍ×１００ｍｍ、厚み０．７ｍｍ）を用いた以外は、実施例８と同様に積層体を作製した。 [Comparative Example 2]
A laminated body was produced in the same manner as in Example 8 except that alkaline glass (manufactured by AGC, 100 mm × 100 mm, thickness 0.7 mm) was used as the glass substrate.
　［比較例３］
　ガラス基板として、アルカリガラスにシリコン系成分を表面コーティングした基板（ＧＤＬＡＢ合同会社製、１００ｍｍ×１００ｍｍ、厚み０．７ｍｍ）を用いた以外は、実施例１と同様に積層体を作製した。 [Comparative Example 3]
As the glass substrate, a laminate was produced in the same manner as in Example 1 except that a substrate (manufactured by GDLAB GK, 100 mm × 100 mm, thickness 0.7 mm) having a surface coated silicon-based component on alkaline glass was used.
　［評価］
　各実施例または比較例で作製した積層体のガラス基板上には、幅１０ｍｍ、長さ４０ｍｍの短冊状のポリイミド層が形成されている。そして、当該短冊状のポリイミド層の端部１ｃｍ四方に、両面テープを折り返して貼り付け、掴み部位を補強した。そして、当該掴み部位を、粘着テープ引きはがし試験装置を備えた、小型卓上試験機（島津製作所社製、ＥＺ－Ｓ）に挟み、ガラス基板とポリイミド層との界面に１ｍｍカッター刃を入れ、剥離のきっかけを与えた。そして、ＪＩＳ　Ｚ０２３７（２００９年）に合わせた９０°ピール試験を実施した。試験速度は、３００ｍｍ/分、試験感度は０．０１Ｎとした。そして、ガラス板からポリイミド層を剥離する際に必要な試験力を測定し、安定して剥離できている１０ｍｍの長さの試験力を平均して剥離強度とした。 [evaluation]
A strip-shaped polyimide layer having a width of 10 mm and a length of 40 mm is formed on the glass substrate of the laminate produced in each Example or Comparative Example. Then, the double-sided tape was folded back and attached to the end 1 cm square of the strip-shaped polyimide layer to reinforce the gripped portion. Then, the gripped portion is sandwiched between a small desktop testing machine (manufactured by Shimadzu Corporation, EZ-S) equipped with an adhesive tape peeling test device, and a 1 mm cutter blade is inserted at the interface between the glass substrate and the polyimide layer to peel it off. Gave me a chance. Then, a 90 ° peel test was carried out in accordance with JIS Z0237 (2009). The test speed was 300 mm / min and the test sensitivity was 0.01 N. Then, the test force required for peeling the polyimide layer from the glass plate was measured, and the test force having a length of 10 mm that was able to be stably peeled was averaged to obtain the peel strength.
　また、得られた数値を以下の基準で評価した。
　〇：数値が０．２Ｎ／ｃｍ以下である場合
　△：数値が０．２Ｎ／ｃｍ超１．５Ｎ／ｃｍ以下である場合
　×：数値が１．５Ｎ／ｃｍ超である場合 In addition, the obtained values were evaluated according to the following criteria.
〇: When the numerical value is 0.2 N / cm or less Δ: When the numerical value is more than 0.2 N / cm and 1.5 N / cm or less ×: When the numerical value is more than 1.5 N / cm
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表１に示されるように、ガラス基板の最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ５μｍ×５μｍ当たりの突起の数が１００個以上１０００個以下であると、積層体の形成後、各種条件で作製したポリイミド層を容易に剥離できた（実施例１～１０）。またこのとき、ガラス基板の水との接触角が１０°以上９０°以下であると、ポリイミドワニスをはじくことなく表面に濡れ広がらせることができ、所望のポリイミド層が得られた。 As shown in Table 1 above, when the maximum height difference Sz of the glass substrate is 4 nm or more and 20 nm or less, and the number of protrusions per 5 μm × 5 μm is 100 or more and 1000 or less, after the laminated body is formed, The polyimide layer produced under various conditions could be easily peeled off (Examples 1 to 10). At this time, when the contact angle of the glass substrate with water was 10 ° or more and 90 ° or less, the polyimide varnish could be wetted and spread on the surface without repelling, and a desired polyimide layer was obtained.
　これに対し、ガラス基板の最大高低差Ｓｚが４ｎｍ未満である場合、また最大高低差Ｓｚが２０ｎｍ超である場合のいずれにおいても、ポリイミド層を剥離することが難しかった（比較例１～３）。また特に、最大高低差Ｓｚが大きい場合には、突起の数が少ないにも関わらず、ポリイミド層が破断した（比較例３）。ガラス基板とポリイミド層との間でアンカー効果が生じたと考えられる。 On the other hand, it was difficult to peel off the polyimide layer in both cases where the maximum height difference Sz of the glass substrate was less than 4 nm and the maximum height difference Sz was more than 20 nm (Comparative Examples 1 to 3). .. In particular, when the maximum height difference Sz is large, the polyimide layer is broken even though the number of protrusions is small (Comparative Example 3). It is considered that the anchor effect occurred between the glass substrate and the polyimide layer.
　本出願は、２０２０年１２月１０日出願の特願２０２０－２０４９４２号に基づく優先権を主張する。これらの出願明細書に記載された内容は、すべて本願明細書に援用される。 This application claims priority based on Japanese Patent Application No. 2020-204942 filed on December 10, 2020. All the contents described in these application specifications are incorporated herein by reference.
　本発明の積層体によれば、専用の装置等を用いない場合でも、ポリイミド層に損傷を生じさせることなく、ポリイミド層からガラス基板を容易に剥離させることが可能である。したがって、各種フレキシブル・エレクトロニクス素子の作製に有用である。 According to the laminate of the present invention, the glass substrate can be easily peeled off from the polyimide layer without causing damage to the polyimide layer even without using a dedicated device or the like. Therefore, it is useful for manufacturing various flexible electronic devices.

Claims (10)

  1. 　ガラス基板と、前記ガラス基板に積層されたポリイミド層と、を有し、
    　前記ガラス基板の表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、
    　前記ガラス基板は、５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有する、
    　積層体。     It has a glass substrate and a polyimide layer laminated on the glass substrate.
    When the surface roughness of the glass substrate was measured, the maximum height difference Sz was 4 nm or more and 20 nm or less.
    The glass substrate has 100 or more and 1000 or less protrusions having a height of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm.
    Laminated body.
  2. 　前記ガラス基板表面の最も高い突起から２ｎｍ低い水平面に存在する領域の合計面積が、前記ガラス基板を平面視したときの面積に対して３％以下である、
    　請求項１に記載の積層体。     The total area of the region existing in the horizontal plane 2 nm lower than the highest protrusion on the surface of the glass substrate is 3% or less with respect to the area when the glass substrate is viewed in a plan view.
    The laminate according to claim 1.
  3. 　表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、かつ５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の高さの突起を１００個以上１０００個以下有するガラス基板を準備する工程と、
    　前記ガラス基板上に、ポリイミド前駆体および／またはポリイミドを含むワニスを塗布する工程と、
    　前記ワニスを硬化させて、ポリイミド層を形成する工程と、
    　を含む、
    　積層体の製造方法。     When the surface roughness is measured, the maximum height difference Sz is 4 nm or more and 20 nm or less, and each 5 μm × 5 μm has 100 or more and 1000 or less protrusions having a height of 1/2 or more of the maximum height difference Sz. The process of preparing the glass substrate and
    A step of applying a polyimide precursor and / or a varnish containing polyimide on the glass substrate, and
    The step of curing the varnish to form a polyimide layer and
    including,
    A method for manufacturing a laminate.
  4. 　前記ガラス基板の２５℃における水との接触角が、１０°～９０°である、
    　請求項３に記載の積層体の製造方法。     The contact angle of the glass substrate with water at 25 ° C. is 10 ° to 90 °.
    The method for manufacturing a laminate according to claim 3.
  5. 　請求項１または２に記載の積層体の、前記ガラス基板と前記ポリイミド層とを剥離し、ポリイミドフィルムを得る工程を有する、
    　ポリイミドフィルムの製造方法。     A step of peeling the glass substrate and the polyimide layer of the laminate according to claim 1 or 2 to obtain a polyimide film.
    Method for manufacturing polyimide film.
  6. 　前記ポリイミドフィルムを得る工程が、前記ガラス基板と前記ポリイミド層とを、機械的に剥離する工程である、
    　請求項５に記載のポリイミドフィルムの製造方法。     The step of obtaining the polyimide film is a step of mechanically peeling the glass substrate and the polyimide layer.
    The method for producing a polyimide film according to claim 5.
  7. 　前記ポリイミドフィルムを得る工程後、前記ガラス基板を回収して第２のガラス基板とし、前記第２のガラス基板上に、ポリイミド前駆体および／またはポリイミドを含む第２のワニスを塗布する工程と、
    　前記第２のワニスを硬化させて、第２のポリイミド層を形成する工程と、
    　前記第２のガラス基板と前記第２のポリイミド層とを剥離し、第２のポリイミドフィルムを得る工程と、
    　を有する、
    　請求項５または６に記載のポリイミドフィルムの製造方法。     After the step of obtaining the polyimide film, the glass substrate is recovered to form a second glass substrate, and a second varnish containing a polyimide precursor and / or a polyimide is applied onto the second glass substrate.
    The step of curing the second varnish to form the second polyimide layer and
    A step of peeling the second glass substrate and the second polyimide layer to obtain a second polyimide film, and
    Have,
    The method for producing a polyimide film according to claim 5 or 6.
  8. 　表面粗さを測定したとき、最大高低差Ｓｚが４ｎｍ以上２０ｎｍ以下であり、
    　５μｍ×５μｍ当たりに、前記最大高低差Ｓｚの１／２以上の深さの凹部を１００個以上１０００個以下有する、
    　ポリイミドフィルム。     When the surface roughness was measured, the maximum height difference Sz was 4 nm or more and 20 nm or less.
    It has 100 or more and 1000 or less recesses having a depth of 1/2 or more of the maximum height difference Sz per 5 μm × 5 μm.
    Polyimide film.
  9. 　前記ポリイミドフィルムの最も深い凹部から２ｎｍ高い水平面に存在する開口部の合計面積が、前記ポリイミドフィルムを平面視したときの面積に対して３％以下である、
    　請求項８に記載のポリイミドフィルム。     The total area of the openings existing in the horizontal plane 2 nm higher than the deepest recess of the polyimide film is 3% or less with respect to the area when the polyimide film is viewed in a plan view.
    The polyimide film according to claim 8.
  10. 　請求項１または２に記載の積層体の前記ポリイミド層上に、素子部を形成する工程と、
    　前記素子部の形成後、前記ポリイミド層と前記ガラス基板とを剥離する工程と、
    　を有する、フレキシブル・エレクトロニクス素子の製造方法。     A step of forming an element portion on the polyimide layer of the laminate according to claim 1 or 2.
    A step of peeling the polyimide layer and the glass substrate after forming the element portion,
    A method for manufacturing a flexible electronic device.
PCT/JP2021/042661 2020-12-10 2021-11-19 Laminate and production method for same, and polyimide film and production method for same WO2022124056A1 (en)

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