JP5487557B2 - Planarized film and method for producing the same - Google Patents

Description

  The present invention relates to a flattened film and a method for producing the same.

  In a gas barrier sheet used as a packaging material for foods and pharmaceuticals, a gas barrier layer is formed on a plastic film substrate in order to prevent the influence of oxygen and water vapor, which are factors that deteriorate the quality of contents. However, the gas barrier layer may not be able to sufficiently cover the surface of the plastic film substrate due to the unevenness on the surface of the plastic film substrate, and there is a problem that it is not easy to obtain sufficient gas barrier properties.

  Regarding such a problem, in Patent Document 1, a base film having a smooth surface on one side or both sides having an average surface roughness SRa of 20 nm or less measured for an area of 200 μm × 200 μm or more, and a smooth surface of the base film A gas barrier film comprising a gas barrier layer made of an inorganic compound formed in is described.

  In this document, in particular, a base film obtained by a predetermined method of reducing the amount of base film additive and quenching the film is extremely excellent in surface smoothness. And although the reason for this is not clear, when the film obtained under the condition with few additives is rapidly cooled, the crystallization of the resin component in the film is suppressed, thereby maintaining the smoothness of the surface. It is thought that it is a thing.

In Patent Document 2, a scratch resisting layer (scratch prevention layer) 110 is provided on both sides of a substrate (base material) 105, and a polymer smoothing layer (flattening layer) 115 is provided on the scratch resisting layer 110. Further, a barrier assembly in which a first barrier stack (barrier stack) 120 is stacked thereon is disclosed.
JP 2001-310412 A (Claim 1, paragraphs 0045 to 0052) US Pat. No. 6,413,645 (col. 2-4, FIG. 1)

  As described above, it is important to provide the gas barrier layer on a flat surface. However, as a result of examination by the present inventors, there is a problem that the flatness of the gas barrier layer cannot always be ensured by the methods of Patent Documents 1 and 2. It turned out to be. Furthermore, if a scratch preventing layer (hereinafter sometimes referred to as a hard coat layer) or a planarizing layer is provided on the substrate, the surface roughness of the scratch preventing layer surface or the planarizing layer surface may be increased. It has also been found that there is a problem of reduced transparency. In addition, it has also been found that the methods described in Patent Documents 1 and 2 have problems with the transparency of the base material and thus the gas barrier sheet over time.

  That is, in paragraphs 0045 and 0046 of Patent Document 1, when the substrate is made of resin, additives in the substrate (such as an anti-blocking agent, a thermal stabilizer, an antioxidant, and a chlorine scavenger) bleed out. As described, the amount to be added increases and the smoothness of the surface is inhibited, the bleed-out of the additive causes the occurrence of irregularities on the surface of the substrate. In this document, the unevenness of the substrate surface is suppressed by suppressing the amount of this bleed out.

  However, since the additive is an indispensable material for ensuring various performances such as antioxidant performance and light resistance performance, it is practically difficult to remove it from the base material. For this reason, it is difficult to completely suppress the bleed-out of the additive in the base material that must contain the additive. Therefore, even when the bleedout of the additive is suppressed to some extent, the bleedout of the additive may already be observed on the surface of the base material when the base material is manufactured. And it is the reality that the suppression of the unevenness | corrugation of a base-material surface becomes inadequate with the additive which may exist in the base-material surface immediately after such base-material manufacture.

  Further, when a hard coat layer or a planarizing layer is produced on a substrate, the substrate may be exposed to a high temperature. Under such a high temperature (particularly, a temperature higher than the glass transition temperature Tg of the substrate), Bleeding out of additives from the material is promoted. For this reason, immediately after the production of the base material, even when the additive bleed-out to the surface of the base material is suppressed, the bleed-out of the additive is promoted when the gas barrier sheet is produced. . As a result, when the hard coat layer or the planarizing layer is provided, irregularities on the surface of the substrate are generated, and as a result, the surface roughness of the hard coat layer or the planarizing layer is increased. In addition, the bleed-out of such an additive is observed as a white spot when observed with an optical microscope, which causes a decrease in the transparency of the substrate.

  In addition, after the production of the gas barrier sheet, the bleed out of the additive to the substrate surface progresses over time as the sheet is used. Due to such bleedout of the additive over time, the white spots are observed on the surface of the base material, which may cause the transparency of the gas barrier sheet to be impaired.

  Such problems of the formation of irregularities on the surface of the base material due to bleeding out of the surface of the base material, and the decrease in the transparency of the base material, and thus the gas barrier sheet, are now being used as substrates for electronic devices instead of glass substrates. This is particularly noticeable in certain gas barrier sheets. That is, the electronic device substrate is required to have higher gas barrier properties and transparency than food, pharmaceutical packaging and the like. Therefore, it is necessary to suppress the unevenness of the substrate surface more than before, and there is a high demand for suppressing a decrease in transparency of the substrate surface over time. For example, in an application such as an organic EL element, there is a problem that irregularities (protrusions) are generated in the transparent conductive layer (electrode) due to the irregularities of the base material, and the current is short-circuited.

  The present invention has been made in order to solve the above-described problems, and reduces unevenness on the surface of the base material and further unevenness (surface roughness) of the flattening layer and the like due to bleeding out of the additive during the production of the flattening film. It aims at providing the planarization film which has high flatness by doing. In addition, the present invention was made to solve the above-described problems, and suppresses the decrease in transparency of the substrate due to the bleeding out of the additive during the production of the flattened film, and the time after the production. It aims at providing the planarization film which becomes possible [suppressing the fall of the transparency of the base material by bleed-out].

  The present invention has been made to solve the above-described problems, and removes irregularities on the surface of the substrate caused by the bleed-out of the additive after the manufacture of the substrate. An object of the present invention is to provide a method for producing a flattened film having high flatness by reducing irregularities on the surface of the substrate due to bleed-out and thus irregularities (surface roughness) such as a flattened layer. In addition, the present invention was made to solve the above-described problems, and suppresses the decrease in transparency of the substrate due to the bleeding out of the additive during the production of the flattened film, and the time after the production. It aims at providing the manufacturing method of the planarization film which becomes possible [suppressing the fall of the transparency of the base material by bleed-out].

  As a result of intensive studies by the present inventor, in order to ensure the flatness of the base material, the unevenness of the substrate due to the bleedout of the additive is reduced once before the flattened film is manufactured, It was found that it is effective to suppress the formation of irregularities due to the bleed-out of the additive. And in the method of providing the planarization layer directly on the substrate, which has been conventionally performed to planarize the substrate, the bleedout of the additive from the substrate is changed by heating when the planarization layer is formed. It was also found that as a result of the formation of the unevenness of the base material by being promoted, the surface flatness of the flattening layer becomes insufficient, and a decrease in transparency due to contamination of the base material surface occurs.

  In view of the above knowledge, this inventor discovered that the said subject can be solved by providing a predetermined additive barrier layer between a base material and a planarization layer.

  The planarization film of the present invention for solving the above problems is a base material, an additive barrier layer provided in contact with the base material, a planarization layer provided on the additive barrier layer, The additive barrier layer is formed at a temperature lower than the glass transition temperature of the substrate.

  According to this invention, since the additive barrier layer is formed at a temperature lower than the glass transition temperature of the substrate, the additive barrier layer is formed in a stable state so that the additive barrier layer is formed. The additive bleed-out is suppressed, and the additive barrier layer provided in contact with the substrate suppresses the bleed-out. As a result, a flattened film having high flatness is provided by reducing unevenness on the surface of the substrate due to bleeding out of the additive during the production of the flattened film, and thus unevenness (surface roughness) such as the flattened layer. be able to. Furthermore, it becomes possible to suppress the decrease in the transparency of the substrate due to the bleed-out of the additive during the production of the flattened film, and the decrease in the transparency of the substrate due to the bleed-out over time after the manufacture. A planarizing film can be provided.

  In the planarization film of this invention, it is preferable that the said planarization layer is formed at the temperature more than the glass transition temperature of the said base material.

  According to this invention, since the planarization layer is formed at a temperature equal to or higher than the glass transition temperature of the substrate, the substrate is exposed to a temperature equal to or higher than the glass transition temperature during the formation of the planarization layer. Bleeding out of the additive is promoted, but the additive barrier layer suppresses this, and as a result, the irregularity of the substrate surface due to the bleeding out of the additive at the time of manufacturing, and thus the unevenness of the planarizing layer, etc. Reduction of (surface roughness) and suppression of a decrease in transparency of the substrate due to bleeding out of the additive during production can be more effectively performed.

  In the flattened film of the present invention, the substrate is preferably made of resin.

  According to this invention, since the substrate is made of resin, the additive contained in the substrate is more likely to bleed out, and as a result, the significance of providing the additive barrier layer is increased.

  In the flattened film of the present invention, the additive barrier layer is preferably formed from a curable resin that cures at a temperature lower than the glass transition temperature of the substrate.

  According to this invention, since the additive barrier layer is formed from a curable resin that cures at a temperature lower than the glass transition temperature of the substrate, the thermal influence on the substrate is reduced, and as a result, the addition Bleeding out of the additive from the base material after forming the agent barrier layer can be more effectively suppressed.

  In the planarization film of this invention, it is preferable that the said planarization layer is formed from curable resin hardened | cured at the temperature more than the glass transition temperature of the said base material.

  According to this invention, since the planarization layer is formed from a curable resin that is cured at a temperature equal to or higher than the glass transition temperature of the base material, the additive is likely to bleed out from the base material when the planarization layer is formed. As a result, the significance of using the additive barrier layer becomes greater.

  In the planarized film of the present invention, the additive barrier layer preferably has a thickness of 0.5 μm or more and 15 μm or less.

  According to this invention, since the thickness of the additive barrier layer is not less than 0.5 μm and not more than 15 μm, the effect of the additive barrier layer suppressing the bleed out of the additive from the base material is increased, and as a result Further, it becomes easier to suppress bleeding out of the additive at the time of production and after the production.

  In the planarization film of the present invention, it is preferable that the maximum protrusion length (Rmax) of the surface of the planarization layer is 2 nm or more and 20 nm or less.

  According to this invention, since the maximum protrusion length (Rmax) on the surface of the planarizing layer is 2 nm or more and 20 nm or less, the planarity of the planarizing layer is improved, and as a result, a planarized film having high planarity is obtained. Will be.

  In order to solve the above problems, a method for producing a flattening film of the present invention includes a base material, an additive barrier layer provided in contact with the base material, and a flattening provided on the additive barrier layer. A substrate cleaning step performed at a temperature lower than the glass transition temperature of the base material, and the additive barrier layer at a temperature lower than the glass transition temperature of the base material. And an additive barrier layer forming step for forming the flattening layer and a flattening layer forming step for forming the flattening layer.

  According to this invention, the substrate cleaning step performed at a temperature lower than the glass transition temperature of the substrate, the additive barrier layer forming step of forming the additive barrier layer at a temperature lower than the glass transition temperature of the substrate, A flattening layer forming step for forming a flattening layer, so that the additive can be washed away without causing a bleedout of a new additive on the surface of the substrate, and the surface of the substrate is cleaned and cleaned and cleaned. Since the additive barrier layer is formed while the material is stable, the bleed out of the new additive is suppressed, and the additive barrier layer provided in contact with the substrate suppresses the bleed out. It becomes. As a result, the unevenness of the substrate surface caused by the bleed-out of the additive after the manufacture of the substrate is removed, and the unevenness of the substrate surface due to the bleed-out of the additive during the manufacture of the flattened film, and thus the unevenness of the flattened layer, etc. By reducing (surface roughness), a method for producing a flattened film having high flatness can be provided. Furthermore, it becomes possible to suppress the decrease in the transparency of the substrate due to the bleed-out of the additive during the production of the flattened film, and the decrease in the transparency of the substrate due to the bleed-out over time after the manufacture. A method for producing a flattened film can be provided.

  In the method for producing a planarizing film of the present invention, it is preferable that the planarizing layer forming step forms the planarizing layer at a temperature equal to or higher than the glass transition temperature of the substrate.

  According to this invention, since the planarization layer forming step forms the planarization layer at a temperature equal to or higher than the glass transition temperature of the substrate, the substrate is exposed to a high temperature during the planarization layer formation, and the additive Even when the bleedout is promoted, the additive barrier layer provided in contact with the base material suppresses the bleed out, and as a result, the base material by the bleed out of the additive during manufacturing. It is possible to more effectively suppress the surface unevenness and the unevenness (surface roughness) of the flattening layer and the like and the suppression of the decrease in transparency of the base material due to the bleeding out of the additive during production.

  In the method for producing a flattened film of the present invention, it is preferable that the substrate is cleaned using an organic solvent in the substrate cleaning step.

  According to the present invention, since the substrate is washed using an organic solvent in the substrate washing step, the additive on the substrate surface can be easily washed away, and as a result, the additive is added to the cleaner substrate surface. A barrier layer can be formed.

  In the manufacturing method of the flattening film of this invention, it is preferable that the said base material is resin.

  According to this invention, since the substrate is made of resin, the additive contained in the substrate is more likely to bleed out, and as a result, the significance of providing the additive barrier layer is increased.

  In the method for producing a flattened film of the present invention, in the additive barrier layer forming step, the additive barrier layer is preferably formed of a curable resin that cures at a temperature lower than the glass transition temperature of the substrate.

  According to this invention, in the additive barrier layer forming step, the additive barrier layer is formed of a curable resin that is cured at a temperature lower than the glass transition temperature of the substrate, so that there is little thermal influence on the substrate. As a result, bleeding out of the additive from the base material when forming the additive barrier layer can be more effectively suppressed.

  In the planarization film manufacturing method of the present invention, it is preferable that in the planarization layer forming step, the planarization layer is formed of a curable resin that cures at a temperature equal to or higher than the glass transition temperature of the substrate.

  According to this invention, in the flattening layer forming step, the flattening layer is formed of a curable resin that cures at a temperature equal to or higher than the glass transition temperature of the base material. As a result, the significance of using the additive barrier layer becomes greater.

  According to the flattened film of the present invention, a flattened film having high flatness can be provided. Furthermore, the planarization film which becomes possible [suppressing the fall of the transparency of a base material] can be provided.

  According to the method for producing a flattened film of the present invention, a method for producing a flattened film having high flatness can be provided. Furthermore, the manufacturing method of the planarization film which becomes possible [suppressing the fall of the transparency of a base material] can be provided.

  Next, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

[Flattened film]
FIG. 1 is a schematic cross-sectional view showing an example of a flattened film. The planarizing film 1 has a base material 2, an additive barrier layer 3 provided in contact with the base material 2, and a planarizing layer 4 provided on the additive barrier layer 3. The additive barrier layer 3 is formed at a temperature lower than the glass transition temperature Tg of the substrate 2. As a result, the additive barrier layer 3 is formed while the base material 2 is stable, so that bleeding out of a new additive is suppressed, and the additive barrier layer 3 provided in contact with the base material 2 The above bleed out will be suppressed. As a result, the flattening film having high flatness can be obtained by reducing the unevenness (surface roughness) of the surface of the base material 2 and the flattening layer 4 due to the bleeding out of the additive during the production of the flattening film 1. 1 can be provided. Furthermore, the suppression of the decrease in the transparency of the substrate 2 due to the bleed-out of the additive during the production of the flattened film 1 and the decrease in the transparency of the substrate 2 due to the bleed-out after the production can be suppressed. A flattened film 1 that can be provided can be provided.

(Base material)
The substrate 2 can be used without particular limitation as long as it has a glass transition temperature Tg. As the base material 2, a sheet-like or film-like one is mainly used, but a non-flexible substrate or a flexible substrate can be used according to a specific application or purpose. For example, non-flexible substrates such as a glass substrate, a hard resin substrate, a wafer, a printed substrate, various cards, and a resin sheet may be used.

  The substrate 2 is preferably made of resin. Thereby, the additive contained in the base material 2 is more likely to bleed out, and as a result, the significance of providing the additive barrier layer 3 is increased.

  Examples of the resin constituting the substrate 2 include polyethylene terephthalate (PET), polyamide, polyolefin, polyethylene naphthalate (PEN), polycarbonate, polyacrylate, polymethacrylate, polyurethane acrylate, polyethersulfone, polyimide, polynorbornene, poly Examples include ether imide, polyarylate, and cyclic polyolefin. Further, a glass cloth impregnated with a resin may be used. In the case where the substrate 2 is made of a resin, a material having heat resistance of preferably 100 ° C. or higher, particularly preferably 150 ° C. or higher is appropriate.

  Although there is no restriction | limiting in particular also about the thickness of the base material 2, From a viewpoint of a flexibility and a form retainability, it is 6 micrometers or more normally, Preferably it is 12 micrometers or more, Usually, it is set as the range of 400 micrometers or less, Preferably it is 250 micrometers or less.

  The base material 2 contains additives for ensuring various performances. A conventionally well-known thing can be used suitably as such an additive, for example, a blocking inhibitor, a heat stabilizer, antioxidant, a chlorine capture agent etc. can be mentioned.

  Examples of the anti-blocking agent contained in the substrate 2 include organic or anti-blocking agents such as liquid or solid paraffin, synthetic wax, polyethylene wax, natural wax, silicone, fatty acid amide, talc (talc), Examples thereof include inorganic blocking inhibitors such as diatomaceous earth, kaolin (ceramic clay), silicon oxide, aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, and zeolite. These may be used as a mixture. Such an antiblocking agent is preferably in the form of spherical particles, and the particle size is usually 0.1 μm or more and 6 μm or less.

  Examples of the heat stabilizer contained in the substrate 2 include 2,6-di-tert-butyl-4-methylphenol (BHT). Examples of the antioxidant include tetrakis- {methylene- (3,5-di-3-butyl-4-hydrocinnamate)} butane (“Irganox 1010”).

  Examples of the chlorine scavenger contained in the substrate 2 include calcium stearate.

  The additive contained in the substrate 2 is usually contained in the substrate 2 in an amount of 0.01 wt% or more and 10 wt% or less. In the present invention, by using the additive barrier layer 3, bleeding out of the additive from the substrate 2 can be suppressed. For this reason, it is basically not necessary to reduce the content of the additive in order to suppress the bleed out amount. Therefore, the present invention also has an advantage that the base material 2 can contain an appropriate amount of a desired additive so that the base material 2 can exhibit sufficient performance.

  When the base material 2 is used as a substrate of a light emitting element such as an organic EL display that requires transparency, the base material 2 is preferably colorless and transparent. More specifically, for example, it is preferable that the substrate 2 has a transparency with an average light transmittance of 80% or more within a range of 400 nm to 700 nm. Since such light transmittance is influenced by the material and thickness of the base material 2, both are considered.

  When a resin-made material is used as the substrate 2, the production method thereof can also be produced by a conventionally known general method. In the present invention, by using the additive barrier layer 3, bleeding out of the additive from the substrate 2 can be suppressed. For this reason, it is basically unnecessary to manufacture the substrate 2 by a special method. Therefore, in this invention, the advantage that the manufacturing method of the base material 2 is not restrict | limited is also exhibited.

  When using the resin as the base material 2, a stretched film may be used. The stretching method may be a conventionally known general method. Although a draw ratio can be suitably selected according to resin used as the raw material of the base material 2, it is preferable to set it as 2-10 times in a vertical axis direction and a horizontal axis direction, respectively.

  The surface of the substrate 2 is subjected to surface treatment such as corona treatment, flame treatment, plasma treatment, glow discharge treatment, roughening treatment, heat treatment, chemical treatment, UV irradiation treatment, atmospheric pressure plasma treatment, and easy adhesion treatment. May be. As a specific method of such surface treatment, a conventionally known method can be appropriately used.

  The glass transition temperature Tg of the base material 2 can be measured by a conventionally known method. Examples of such a method include a method of measuring using a differential scanning calorimeter (DSC). When the glass transition temperature Tg of the base material 2 formed of a typical resin is exemplified, the polyethylene terephthalate (PET) base material is 78 ° C., the polyethylene naphthalate (PEN) base material is 117 ° C. (123 depending on the grade of the base material manufacturer) ° C), polycarbonate (PC) substrate is 150 ° C, polyethersulfone substrate is 223 ° C, polyimide substrate is 400 ° C, and cyclic polyolefin substrate is 165 ° C.

(Additive barrier layer)
The additive barrier layer 3 is formed at a temperature lower than the glass transition temperature Tg of the substrate 2. It can be formed at a temperature lower than the glass transition temperature Tg, and it is sufficient that the base material 2 is not thermally affected (additive bleed out phenomenon), and the material used for the additive barrier layer 3 is particularly limited. Not. Typical examples of such a material include inorganic materials and organic materials. In the case of forming with an inorganic material, the additive barrier layer 3 made of a necessary material may be formed on the substrate 2 by using a low temperature vapor deposition method or an ion plating method. When an organic material is used, the additive barrier layer 3 is preferably formed from a curable resin that cures at a temperature lower than the glass transition temperature Tg of the substrate 2. Thereby, the thermal influence given to the substrate is reduced, and as a result, the bleeding out of the additive from the substrate 2 after the formation of the additive barrier layer 3 can be more effectively suppressed.

  As the curable resin that can be used for the additive barrier layer 3, for example, acrylates such as dipentaerystol hexaacrylate, diethylene glycol diacrylate, and methacrylate resins are preferably used. From the viewpoint of effectively suppressing the out, it is also preferable to use an acrylate resin such as epoxy acrylate, urethane acrylate, or cyclic acrylate. As the acrylate resin, a material that can be cured at a temperature lower than the glass transition temperature Tg of the substrate 2 may be appropriately selected.

  When a curable resin is used as the material for the additive barrier layer 3, a known photopolymerization initiator or photosensitizer can be used in combination. Such photopolymerization initiators and photosensitizers are preferably used when polymerizing (curing) a curable resin by irradiating ultraviolet rays. The addition amount of the photopolymerization initiator and the photosensitizer is generally 0.1 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the curable resin. In addition to these materials, various inorganic and organic additives such as a solvent, a curing catalyst, a wettability improver, a plasticizer, an antifoaming agent, and a thickener can be added as necessary.

  The additive barrier layer 3 needs to be able to form a good film at a temperature lower than the glass transition temperature Tg of the substrate 2. More specifically, the good film means that the adhesiveness to the base material 2 and the planarizing layer 4 that may be provided on the base material 2 is good. The desired performance is not determined solely by the material. For example, a combination with a solvent used for film formation (for example, boiling point, viscosity, etc.), a film formation method (for example, coating method, vapor deposition method, etc.), and drying / curing conditions at the time of manufacture can be appropriately selected. It becomes important. These points will be described in detail in the description of the manufacturing method. In consideration of bleeding out of the additive, the temperature at which the additive barrier layer 3 is formed is usually 2 ° C. or lower, preferably 5 ° C. or lower, more preferably Tg or lower than Tg. The temperature is 10 ° C. or lower, more preferably 15 ° C. or lower than Tg. Here, since the temperature at the time of forming the additive barrier layer 3 is the temperature of the base material itself, the temperature of the atmosphere at the time of forming the additive barrier layer 3 is slightly higher than the above temperature range. Also good.

  The thickness of the additive barrier layer 3 is preferably 0.5 μm or more and 15 μm or less. The thickness is preferably 1 μm or more, more preferably 5 μm or more. Thereby, the effect which the additive barrier layer 3 suppresses the bleeding out of the additive from the base material 2 becomes large, As a result, it becomes easier to suppress the bleeding out of the additive at the time of manufacturing and after the manufacturing. .

  The additive barrier layer 3 preferably has high adhesiveness with the substrate 2 and the planarization layer 4 provided thereon. The adhesiveness of the additive barrier layer 3 can be evaluated by, for example, a cross cut test. In the present invention, the cross-cut test is performed in accordance with the description of JIS-K5400, 8.5.1. Specifically, using a cutter guide with a gap interval of 2 mm, cuts reaching the base material 2 and the like through the additive barrier layer 3 are made vertically and horizontally to form 100 grids, and cellophane adhesive tape (Nichiban Co., Ltd.) Paste No. 405 (24 mm width) on the cut surface of the mass, rub it completely with an eraser, and then peel it off vertically. Then, the surface after peeling is visually observed, and the layer residual ratio in 100 squares (the part peeled even in a part of the square is treated as the number of peeled) is used as a measure of adhesiveness, and the adhesiveness (%) = (1- (Peeled square / 100 square)) × 100 is calculated and evaluated.

  And, for example, preparing a sample for adhesion measurement provided with the additive barrier layer 3 on the substrate 2, and performing the above-described cross-cut test immediately after the production of the sample for adhesion measurement, after the heat resistance test, If both are performed, not only the adhesiveness between the base material 2 and the additive barrier layer 3 in the state after production, but also the durability of the adhesiveness can be evaluated. And, as a method of the moisture and heat resistance test, for example, a temperature and humidity chamber adjusted to an environment of a temperature of 60 ° C./humidity of 95% RH is used, and a sample for adhesion measurement is held in the temperature and humidity chamber for 1000 hours. Can be done.

  The additive barrier layer 3 preferably has an adhesiveness of 95% or more immediately after production and after the heat and humidity resistance test in the cross-cut test.

  When the additive barrier layer 3 is used as a substrate of a light emitting element such as an organic EL display that requires transparency, the additive barrier layer 3 is preferably colorless and transparent. More specifically, for example, it is preferable that the additive barrier layer 3 has a transparency with an average light transmittance of 80% or more within a range of 400 nm to 700 nm. Since such light transmittance is influenced by the material and thickness of the additive barrier layer 3, it is configured in consideration of both.

  The surface of the additive barrier layer 3 is subjected to surface treatment such as corona treatment, flame treatment, plasma treatment, glow discharge treatment, roughening treatment, heating treatment, chemical treatment, UV irradiation treatment, atmospheric pressure plasma treatment, and easy adhesion treatment. May be performed. As a specific method of such surface treatment, a conventionally known method can be appropriately used.

(Flattening layer)
Although there is no restriction | limiting in particular in the planarization layer 4, It is preferable that it is formed at the temperature more than the glass transition temperature Tg of the base material 2. FIG. Thereby, the base material 2 is exposed to a temperature equal to or higher than the glass transition temperature Tg when the planarizing layer 4 is formed, and the additive bleed out from the base material 2 is promoted. As a result, it is possible to reduce the unevenness on the surface of the base material 2 and the unevenness (surface roughness) of the planarizing layer 4 and the like due to the bleeding out of the additive at the time of manufacturing, and the bleeding out of the additive at the time of manufacturing. It is possible to more effectively suppress the decrease in transparency of the substrate 2.

  Examples of the material of the planarizing layer 4 include sol-gel materials, curable resins (ultraviolet curable resins, thermosetting resins), and photoresist materials. Of these materials, the planarization layer 4 is preferably formed from a curable resin that cures at a temperature equal to or higher than the glass transition temperature Tg of the substrate 2. As a result, the additive is likely to bleed out from the substrate 2 when the planarizing layer 4 is formed, and as a result, the significance of using the additive barrier layer 3 is further increased. Examples of such curable resins include siloxane-based sol-gel materials, cardo polymer-containing materials, arylate resins, transparent polyimide resins, and acrylate-based resins having a cyclic skeleton, reactive prepolymers having an epoxy group, oligomers, and / or Or an ionizing radiation curable resin that is a mixture of monomers as appropriate, or a thermoplastic resin such as urethane, polyester, acrylic, butyral, vinyl, etc., if necessary It has a polymerizable unsaturated bond in the molecule, such as a liquid composition that has become liquid, and is irradiated with ultraviolet rays (UV) or electron beams (EB) to cause a crosslinking polymerization reaction, resulting in a three-dimensional high Examples thereof include a resin that changes to a molecular structure.

  As a material for the planarizing layer 4, it is also preferable to use a sol-gel material using a sol-gel method. The sol-gel method includes at least a silane coupling agent having an organic functional group and a hydrolyzable group and a crosslinkable compound having an organic functional group that reacts with the organic functional group of the silane coupling agent. It refers to the coating method of the paint composition and the coating film. As the silane coupling agent having an organic functional group and a hydrolyzable group, conventionally known silane coupling agents can be appropriately used. For example, aminoalkyl dialkoxysilanes and aminoalkyltrialkoxy disclosed in JP-A-2001-207130. Silane may be used. Examples of the crosslinkable compound having an organic functional group that reacts with the organic functional group of the silane coupling agent include functional groups capable of reacting with amino groups such as glycidyl group, carboxyl group, isocyanate group, and oxazoline group. The thing which has can be mentioned. Conventionally known materials can be used as appropriate. Furthermore, various inorganic and organic additives such as a solvent, a curing catalyst, a wettability improver, a plasticizer, an antifoaming agent, and a thickener are added to the coating composition as necessary. Can do. Further, as the material of the planarizing layer 4, it is also preferable to contain a conventionally known cardo polymer.

  The thickness of the planarization layer 4 is usually 0.5 μm or more and usually 10 μm or less from the viewpoint of ensuring the smoothness of the surface.

  The maximum protrusion length (Rmax) on the surface of the planarizing layer 4 is preferably 2 nm or more and 20 nm or less. Thereby, the flatness of the flattening layer is improved, and as a result, a flattened film having a high flatness can be obtained. The measurement of the surface roughness of the planarization layer 4 is not particularly limited, and, for example, a Nanopics-1000 manufactured by Seiko Instruments Inc. is used as an atomic force microscope (AFM), and conforms to JIS B0601-1982. Thus, a method of measuring the maximum protrusion length (Rmax) in the range of 20 μm can be mentioned.

(Other)
As mentioned above, although the planarization film 1 was demonstrated, the planarization film of this invention is not restricted to the said structure. Specifically, another layer may be appropriately inserted between the additive barrier layer and the planarization layer from the viewpoint of ensuring the adhesion between the additive barrier layer and the planarization layer. Moreover, you may form suitably another layer in the surface in which the additive barrier layer is not formed in a base material. Furthermore, another layer may be provided on the planarization layer. Examples of such other layers include conventionally known anchor coat layers, gas barrier layers, transparent conductive layers, hard coat layers, antireflection layers, antistatic layers, antifouling layers, antiglare layers, and color filters. be able to. Among these, an antireflection layer, an antistatic layer, an antifouling layer, an antiglare layer, and a color filter may obtain a desired function by being bonded to a planarization film via an optical adhesive.

  As an example of the other layers, a gas barrier layer will be described below.

  Examples of the material used for the barrier layer include silicon oxide, aluminum oxide, magnesium oxide, indium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and the like; silicon nitride, aluminum nitride, Examples thereof include nitrides such as boron nitride and magnesium nitride; carbides such as silicon carbide; sulfides and the like. In addition, oxynitrides which are two or more kinds of composites selected from these materials, oxycarbides further containing carbon, inorganic nitride carbides, inorganic oxynitride carbides, and the like can also be used.

More specifically, the materials used for the cas barrier layer include inorganic oxides (MO _x ), inorganic nitrides (MN _y ), inorganic carbides (MC _z ), inorganic oxide carbides (MO _x C _z ), and inorganic nitride carbides. (MN _y C _z ), inorganic oxynitride (MO _x N _y ), inorganic oxynitride carbide (MO _x N _y C _z ), and preferable M is a metal element such as Si, Al, Ti, etc. is there. Among these, a film made of silicon oxide with M as Si exhibits a highly transparent gas barrier property, while silicon nitride exhibits a higher gas barrier property and is preferably used. Particularly preferably, it is a composite of silicon oxide and silicon nitride (inorganic oxynitride (MO _x N _y )). When the content of silicon oxide is large, the transparency is improved, and when the content of silicon nitride is large, a gas barrier is formed. Improves.

  The gas barrier layer is formed using a method such as a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, or a plasma CVD method. These methods may be appropriately selected in consideration of the type of base material and gas barrier layer, the type of film forming material, the ease of film formation, the process efficiency, and the like.

  The thickness of the gas barrier layer is usually 10 nm or more and 500 nm or less. Within this range, it is easy to adjust the color and secure productivity while ensuring gas barrier properties and flexibility.

  As described above, the types of other layers that can be used and the variations related to the lamination can be appropriately selected within the scope of the gist of the present invention.

  The flattened film of the present invention is not only a packaging material such as food and pharmaceuticals, but also a conventional glass such as a touch panel, a display film substrate, a lighting film substrate, a solar cell film substrate, and a circuit board film substrate. It can be used as a material relating to a member for an electronic device that can be bent and is light and not cracked, which can be replaced with the one used as a supporting substrate.

[Method for producing flattened film]
A method for producing a planarizing film according to the present invention includes a substrate, an additive barrier layer provided in contact with the substrate, and a planarizing layer provided on the additive barrier layer. It is a manufacturing method, and is a base material washing step performed at a temperature lower than the glass transition temperature Tg of the base material, and an additive barrier layer forming step for forming the additive barrier layer at a temperature lower than the glass transition temperature Tg of the base material. And a planarization layer forming step of forming a planarization layer. This makes it possible to wash out the additive without causing a new additive to bleed out on the surface of the base material, so that the surface of the base material is cleaned and the additive barrier layer can be formed in a clean and stable state. As a result, the bleeding out of the new additive is suppressed, and the additive barrier layer provided in contact with the substrate suppresses the bleeding out. As a result, the unevenness of the substrate surface caused by the bleed-out of the additive after the manufacture of the substrate is removed, and the unevenness of the substrate surface due to the bleed-out of the additive during the manufacture of the flattened film, and thus the unevenness of the flattened layer, etc. By reducing (surface roughness), a method for producing a flattened film having high flatness can be provided. Furthermore, it becomes possible to suppress the decrease in the transparency of the substrate due to the bleed-out of the additive during the production of the flattened film, and the decrease in the transparency of the substrate due to the bleed-out over time after the manufacture. A method for producing a flattened film can be provided. Hereinafter, each step will be described.

(Substrate cleaning process)
The substrate cleaning step is performed at a temperature lower than the glass transition temperature Tg of the substrate. Since the details of the base material have already been described, the description here is omitted, but for example, the base material is preferably made of resin. Thereby, the additive contained in the base material is more likely to bleed out, and as a result, the significance of providing the additive barrier layer is increased.

  The substrate cleaning step is performed at a temperature lower than the glass transition temperature Tg of the substrate. That is, it controls so that the temperature of a base material may not become more than the glass transition temperature Tg through a base-material washing | cleaning process. Specifically, the cleaning process temperature is set to a temperature lower than the glass transition temperature Tg of the substrate. If the temperature is Tg or higher, bleeding out of the base material additive is promoted at the stage of the cleaning process, and the meaning of cleaning is lost. Since the additive is washed away from the substrate surface by washing at a low temperature, the adhesion between the substrate and the additive barrier layer is easily improved. In consideration of bleeding out of the additive, the temperature during washing is usually 10 ° C. or lower, preferably 15 ° C. or lower than Tg.

  In the substrate cleaning step, it is preferable to clean the substrate using an organic solvent. As a result, the additive on the substrate surface can be easily washed away, and as a result, the additive barrier layer can be formed on a cleaner substrate surface. Thus, it is preferable to use an organic solvent in order to remove fine particle components such as additives present on the substrate surface. Examples of such an organic solvent include methyl ethyl ketone, acetone, isopropyl alcohol, ethanol, methanol, toluene, hexane, ethyl acetate, and propylene glycol monomethyl ether acetate (PGMEA). From the viewpoint of industrial production, methyl ethyl ketone, acetone, isopropyl alcohol, and ethanol are preferably used.

  Examples of the cleaning method in the substrate cleaning step include brush cleaning, shower cleaning, and ultrasonic cleaning. Among these, ultrasonic cleaning is preferred industrially. However, in ultrasonic cleaning, the temperature of the cleaning bowl may become high, so temperature management is important so as not to exceed the glass transition temperature Tg of the substrate. It becomes.

  In the substrate cleaning step, after the substrate is cleaned, if a cleaning liquid such as an organic solvent remains on the substrate, drying may be appropriately performed. The drying method is not particularly limited as long as the adsorbed liquid component can be sufficiently removed, but examples of the method that can be easily performed at a low temperature include vacuum drying. As described above, the drying temperature is lower than the glass transition temperature Tg of the substrate.

(Additive barrier layer forming step)
The additive barrier layer forming step is performed by forming the additive barrier layer at a temperature lower than the glass transition temperature Tg of the substrate. The additive barrier layer forming step is not particularly limited as long as the additive barrier layer is formed at a temperature lower than the glass transition temperature Tg of the base material using the above-described inorganic material or organic material.

  The additive barrier layer is usually formed by washing the surface of the substrate, coating the material constituting the additive barrier layer, and then drying and curing as necessary. As a method for forming the additive barrier layer, any method can be used as long as it can form a coating film uniformly and thinly. In the wet coating method, a spin coat method, a gravure coat method, a (kiss) reverse coat method, a comma coat method, a lip The coating method, the CAP (capillary) coating method, the knife coating method, the dip coating method, and the like, and the dry coating method include the vacuum deposition method, the sputtering method, the ion plating method, the thermal CVD method, the plasma CVD method, etc. Are used as appropriate.

  The additive barrier layer is preferably formed of a curable resin that cures at a temperature lower than the glass transition temperature Tg of the substrate. Thereby, the thermal influence given to the base material is reduced, and as a result, the bleeding out of the additive from the base material when forming the additive barrier layer can be more effectively suppressed. When a curable resin is used, the resin material before curing may be dissolved in a solvent and then applied using the wet coating method.

  As a solvent in the case of using the wet coating method, a low-boiling solvent, a high-boiling solvent, and the like are used in order to form a uniform additive barrier layer by controlling the evaporation rate of the solvent at a temperature lower than the glass transition temperature Tg of the substrate. Are preferably mixed as appropriate. Examples of the low boiling point solvent include ethanol, methanol, ethyl acetate, hexane, and methyl ethyl ketone (MEK). Examples of the high boiling point solvent include toluene, xylene, N-methylpyrrolidone (NMP), and Examples thereof include propylene glycol monomethyl ether acetate (PGMEA). In such a mixed solvent, a high boiling point solvent is usually contained in an amount of 10% by weight to 80% by weight.

  Drying and curing in the additive barrier layer forming step is performed at a temperature lower than the glass transition temperature Tg of the substrate. Specifically, considering the bleed out of the additive, the temperature is usually 2 ° C. lower than Tg, preferably 5 ° C. lower than Tg, more preferably 10 ° C. lower than Tg, more preferably Is carried out at a temperature 15 ° C. lower than Tg. Here, the control in the manufacturing process may be appropriately performed so that the temperature of the additive barrier layer does not exceed the glass transition temperature Tg of the substrate. For example, adopting a method of drying and curing the additive barrier layer while setting the substrate on a metal drum and cooling the substrate from the back side, controlling the angle and position of hot air applied to the additive barrier layer Or the like may be used as appropriate.

  In the additive barrier layer forming step, the surface treatment described above may be appropriately performed on the surface of the obtained additive barrier layer.

(Planarization layer forming process)
In the planarization layer forming step, a planarization layer is formed. The method for forming the flattening layer is not particularly limited as long as it is performed using the materials described above, but the flattening layer is preferably formed at a temperature equal to or higher than the glass transition temperature Tg of the substrate. Thus, even when the substrate is exposed to a high temperature during the planarization layer formation and the additive bleed-out is promoted, the additive barrier layer provided in contact with the substrate prevents the above bleed-out. As a result, unevenness of the substrate surface due to the bleed-out of the additive during manufacture, as well as reduction of unevenness (surface roughness) of the planarizing layer, etc., and transparency of the substrate due to bleed-out of the additive during manufacture Can be more effectively suppressed.

  In order to form the planarization layer, a method of coating the material constituting the planarization layer on the additive barrier layer and then drying and curing as necessary is used. As a method for forming the flattening layer, any method can be used as long as it can be formed uniformly and thinly. The wet coating method includes a spin coating method, a gravure coating method, a (kiss) reverse coating method, a comma coating method, and a lip coating method. , CAP (capillary) coating method, knife coating method, dip coating method and the like, and dry coating methods include vacuum deposition method, sputtering method, ion plating method, thermal CVD method, plasma CVD method, etc. Used as appropriate.

  The planarizing layer is preferably formed of a curable resin that cures at a temperature equal to or higher than the glass transition temperature Tg of the substrate. As a result, the additive is likely to bleed out from the base material when the planarizing layer is formed, and as a result, the significance of using the additive barrier layer becomes greater.

  When a curable resin is used, the resin material before curing may be dissolved in a solvent and then applied using the wet coating method. As the solvent, conventionally known solvents may be used as appropriate.

  As described above, the drying / curing in the planarization layer forming step is preferably performed at a temperature equal to or higher than the glass transition temperature Tg of the substrate. Since there is no restriction | limiting in particular about such a method, a conventionally well-known method can be used suitably.

(Other processes)
As described above, the laminated form of the flattened film of the present invention can be appropriately selected within the scope of the gist of the present invention. Therefore, a process other than the processes described above may be appropriately performed according to the stacked form. For example, when a gas barrier layer, an anchor coat layer, or the like is inserted between the additive barrier layer and the planarization layer, a film forming process of these layers may be appropriately performed.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

[Example 1]
As the substrate, a PET film having a thickness of 188 μm (Toyobo Co., Ltd .: E-5101, Tg: 78 ° C.) was used. This base material is presumed to contain an appropriate amount of a desired additive such as an antioxidant in order to obtain practically usable properties such as light resistance and oxidation resistance.

(Substrate cleaning process)
The substrate was immersed in a solution of methyl ethyl ketone and subjected to ultrasonic cleaning for 5 minutes at room temperature. Thereafter, drying was performed in a clean oven at 50 ° C./30 minutes.

(Additive barrier layer forming step)
As a material for forming the additive barrier layer, an acrylic resin (main agent: hardener: diluent = 5: 1: 6) manufactured by Dainichi Seika Kogyo Co., Ltd. was used. This acrylic resin uses a urethane acrylate material. Moreover, as a diluent, ethyl acetate was used as a low boiling point solvent, toluene was used as a high boiling point solvent, and the mixing ratio was set to 1/1. The additive barrier layer was formed by applying the above material on one side of the substrate with a spin coater so as to have a thickness of 2 μm, and then curing at a baking temperature of 70 ° C. for 30 minutes.

(Planarization layer forming process)
A cardo polymer (manufactured by Nippon Steel Chemical Co., Ltd.) was used as a material for forming the planarization layer. The planarizing layer was formed by applying the above material on one surface of the additive barrier layer with a spin coater so as to have a thickness of 1 μm, followed by curing at a baking temperature of 150 ° C. for 60 minutes.

(Measurement of surface roughness of flattening layer)
The surface roughness of the flattened film obtained as described above was measured. Specifically, as an atomic force microscope (AFM), a Nanopics-1000 manufactured by Seiko Instruments Inc. is used, and the maximum protrusion length (Rmax) is set in a range of 20 μm in accordance with JIS B0601-1982. The surface roughness was evaluated by measuring. As a result, the maximum protrusion length (Rmax) of the planarizing layer was 8 nm.

(Evaluation of additive barrier properties of additive barrier layer)
The flattened film was observed with an optical microscope, and after confirming that there were no white spots on the substrate, the flattened film was held in an environment of 80 ° C./90% RH for 10 days. Thereafter, the surface of the flattened film was observed with an optical microscope. As a result, generation of white spots due to bleeding out of the additive from the substrate was not observed.

(Evaluation of adhesiveness of additive barrier layer)
Separately, a sample without a planarizing layer was manufactured, and the adhesiveness of the additive barrier layer was performed. Evaluation of adhesiveness performed the crosscut test based on description of 8.5.1 of JIS-K5400. Specifically, using a cutter guide with a gap interval of 2 mm, cuts reaching the base material through the additive barrier layer are made vertically and horizontally to form 100 grids, and cellophane adhesive tape (No. 405 manufactured by Nichiban Co., Ltd.) 24 mm width) was attached to the cut surface of the mass and rubbed with an eraser to completely adhere, and then peeled off vertically. Then, the surface after peeling is visually observed, and the layer residual ratio in 100 squares (the part peeled even in a part of the square is treated as the number of peeled) is used as a measure of adhesiveness, and the adhesiveness (%) = (1- (Peeled cells / 100 cells)) × 100 was calculated and evaluated.

  The cross-cut test was performed both immediately after the production of the sample and after the wet heat resistance test. As a method of the moisture and heat resistance test, the sample was held for 1000 hours in a thermo-hygrostat adjusted to an environment of temperature 60 ° C./humidity 95% RH. As a result, the adhesiveness immediately after production was 100%, and the adhesiveness after the wet heat resistance test was 100%.

[Example 2]
A PEN film having a thickness of 100 μm (manufactured by SKC Korea, SKYNEX, Tg: 123 ° C.) was used as the substrate. This base material is presumed to contain an appropriate amount of a desired additive such as an antioxidant in order to obtain practically usable properties such as light resistance and oxidation resistance.

(Substrate cleaning process)
The substrate cleaning step was performed in the same manner as in Example 1 except that drying was performed in a clean oven at 90 ° C./15 minutes.

(Additive barrier layer forming step)
The additive barrier layer was formed in the same manner as in Example 1 except that the additive barrier layer was formed by curing at a baking temperature of 90 ° C. for 30 minutes.

(Planarization layer forming process)
A planarizing layer was formed in the same manner as in Example 1 except that the planarizing layer was formed by curing at a baking temperature of 180 ° C. for 60 minutes.

(Measurement of surface roughness of flattening layer)
When the surface roughness of the flattened film obtained as described above was measured in the same manner as in Example 1, the maximum protrusion length (Rmax) was 6 nm.

(Evaluation of additive barrier properties of additive barrier layer)
The additive barrier property of the additive barrier layer was evaluated in the same manner as in Example 1. As a result, generation of white spots due to bleeding out of the additive from the substrate was not observed.

(Evaluation of adhesiveness of additive barrier layer)
A sample not provided with a planarizing layer was prepared separately, and the adhesion was evaluated in the same manner as in Example 1. As a result, the adhesiveness immediately after production was 100%, and the adhesiveness after the wet heat resistance test was 100%.

[Example 3]
A planarized film was produced in the same manner as in Example 1 except that, in the additive barrier layer forming step, the additive barrier layer was formed by the following materials and film forming method. The contents of the additive barrier layer forming step, which is the difference from Example 1, will be described below.

(Additive barrier layer forming step)
The following compositions were mixed together to prepare a coating solution containing an ultraviolet curable resin.
Dipentaerystol hexaacrylate: 30 parts by weight Diethylene glycol diacrylate: 5 parts by weight Irgacure 651 (manufactured by Ciba Geigy): 2 parts by weight Methyl acetate: 10 parts by weight

The said coating liquid was apply | coated with the wire bar, the solvent content was evaporated at 75 degreeC / 2min, and the application layer was formed. Next, an ultraviolet ray of a high pressure mercury lamp (120 W / cm ² ) was irradiated from the coating layer side under conditions of an integrated light quantity of about 400 mJ / cm ² to cure, thereby forming an additive barrier layer of 5 μm. The curing temperature was set to 70 ° C.

(Measurement of surface roughness of flattening layer)
When the surface roughness of the flattened film obtained as described above was measured in the same manner as in Example 1, the maximum protrusion length (Rmax) was 10 nm.

(Evaluation of additive barrier properties of additive barrier layer)
The additive barrier property of the additive barrier layer was evaluated in the same manner as in Example 1. As a result, generation of white spots due to bleeding out of the additive from the substrate was not observed.

(Evaluation of adhesiveness of additive barrier layer)
A sample not provided with a planarizing layer was prepared separately, and the adhesion was evaluated in the same manner as in Example 1. As a result, the adhesiveness immediately after production was 100%, and the adhesiveness after the wet heat resistance test was 100%.

[Comparative Example 1]
A flattened film was produced in the same manner as in Example 1 except that the additive barrier layer was not formed.

(Measurement of surface roughness of flattening layer)
When the surface roughness of the flattened film was measured in the same manner as in Example 1, the maximum protrusion length (Rmax) was 215 nm.

(Evaluation of additive barrier properties of additive barrier layer)
Before the evaluation of the additive barrier property of the additive barrier layer, many white spots were observed due to the bleeding out of the additive from the substrate immediately after the production of the flattened film.

[Comparative Example 2]
Example 1 except that in the additive barrier layer forming step, the hard coat layer was formed by a predetermined method using the material used for the hard coat layer instead of the additive barrier layer, as shown below. A flattened film was produced in the same manner as described above. The contents of the hard coat layer forming step, which is the difference from Example 1, will be described below.

(Hard coat layer forming process)
A coating solution for forming a hard coat layer was produced by the following method. First, Snowtex O-40, which is colloidal silica manufactured by Nissan Chemical Co., Ltd., was weighed into a 300 g flask, and 135 g of γ-glycidoxypropyltrimethoxysilane and 49 g of methyltrimethoxysilane were gradually added while cooling and stirring. . And it stirred for 1 hour after completion | finish of addition. On the way, the cooling was stopped when the temperature of the mixed liquid disappeared. Thereafter, while stirring the mixed solution, 450 g of isopropanol was added as a diluent solvent, and then 60 g of 4-hydroxybutyl acrylate was added. Furthermore, 0.4 g of leveling agent L-7001 made by Nippon Unicar Co., Ltd. was added and stirred for 20 minutes. Through the above operation, a coating liquid for forming a hard coat layer was obtained.

  The coating liquid for forming a hard coat layer obtained as described above was applied on a substrate with a wire bar and then cured at 120 ° C. for 1 hour. The thickness of the obtained hard coat layer was 5 μm.

(Measurement of surface roughness of flattening layer)
When the surface roughness of the flattened film was measured in the same manner as in Example 1, the maximum protrusion length (Rmax) was 136 nm.

(Evaluation of additive barrier properties of additive barrier layer)
Before the evaluation of the additive barrier property of the additive barrier layer, the hard coat layer was formed at a temperature equal to or higher than the glass transition temperature Tg of the base material. As a result, the additive bleeded out from the base material immediately after the flattened film was produced. Many white spots were observed.

[Reference Example 1]
Two types of substrates were used, one immediately after production (base material A) and one held for 240 hours in the environment of 40 ° C./90% RH (base material B) after production, and the substrate washing step. A flattened film was produced in the same manner as in Example 1 except that it was not performed.

(Measurement of surface roughness of flattening layer)
When the surface roughness of the flattened film was measured in the same manner as in Example 1, the maximum protrusion length (Rmax) of the flattened film produced using the substrate A was 18 nm, and produced using the substrate B. The maximum protrusion length (Rmax) of the flattened film was 97 nm.

(Evaluation of additive barrier properties of additive barrier layer)
For the planarized film produced using the substrate A, the additive barrier property of the additive barrier layer was evaluated in the same manner as in Example 1. As a result, generation of white spots due to bleeding out of the additive from the substrate was not observed.

  For the flattened film manufactured using the base material B, white spots are generated by bleeding out of the additive from the base material immediately after the flattened film is manufactured before the evaluation of the additive barrier property of the additive barrier layer. Many were observed. This is because the additive bleeded out of the base material and white spots were generated by holding the base material in an environment of 40 ° C./90% RH for 240 hours.

(Evaluation of adhesiveness of additive barrier layer)
A sample not provided with a planarizing layer was prepared separately, and the adhesion was evaluated in the same manner as in Example 1. As a result, both the sample using the base material A and the sample using the base material B had 100% adhesiveness immediately after production and 100% adhesiveness after the wet heat resistance test.

It is typical sectional drawing which shows an example of the planarization film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flattening film 2 Base material 3 Additive barrier layer 4 Flattening layer

Claims (13)

A planarizing film comprising a base material, an additive barrier layer provided in contact with the base material, and a planarizing layer provided on the additive barrier layer,
The flattening film, wherein the additive barrier layer is formed at a temperature lower than the glass transition temperature of the substrate.   The planarizing film according to claim 1, wherein the planarizing layer is formed at a temperature equal to or higher than the glass transition temperature of the substrate.   The flattening film of Claim 1 or 2 whose said base material is resin.   The flattening film according to any one of claims 1 to 3, wherein the additive barrier layer is formed of a curable resin that is cured at a temperature lower than a glass transition temperature of the substrate.   The planarizing film according to any one of claims 2 to 4, wherein the planarizing layer is formed from a curable resin that cures at a temperature equal to or higher than the glass transition temperature of the substrate.   The flattening film according to claim 1, wherein the additive barrier layer has a thickness of 0.5 μm or more and 15 μm or less.   The flattening film according to any one of claims 1 to 6, wherein a maximum protrusion length (Rmax) of the surface of the flattening layer is 2 nm or more and 20 nm or less. A method for producing a planarized film comprising a substrate, an additive barrier layer provided in contact with the substrate, and a planarized layer provided on the additive barrier layer,
A substrate washing step performed at a temperature lower than the glass transition temperature of the substrate;
An additive barrier layer forming step of forming the additive barrier layer at a temperature lower than the glass transition temperature of the substrate;
A planarization layer forming step of forming the planarization layer;
A method for producing a flattened film, comprising:   The method for producing a flattened film according to claim 8, wherein the flattened layer forming step forms the flattened layer at a temperature equal to or higher than a glass transition temperature of the substrate.   The method for producing a flattened film according to claim 8 or 9, wherein in the substrate cleaning step, the substrate is cleaned using an organic solvent.   The manufacturing method of the planarization film of any one of Claims 8-10 whose said base material is resin.   The flatness according to any one of claims 8 to 11, wherein, in the additive barrier layer forming step, the additive barrier layer is formed of a curable resin that is cured at a temperature lower than a glass transition temperature of the base material. A method for producing a film.   The planarization film according to any one of claims 9 to 12, wherein in the planarization layer forming step, the planarization layer is formed of a curable resin that cures at a temperature equal to or higher than the glass transition temperature of the substrate. Production method.

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