TWI799158B - Retardation film, circular polarizing plate and manufacturing method of retardation film - Google Patents

Abstract

The invention provides a retardation film capable of suppressing the change of the retardation value in a high-temperature and high-humidity environment. The production method of the present invention is a production method for obtaining a retardation film whose in-plane retardation satisfies the relationship of Re(450)<Re(550), which includes heating the stretched film at a temperature above 105°C for 2 minutes or more step, the stretched film is heated from 30°C to Tg-25°C and then cooled to 30°C for 3 cycles of heating TMA test, the shrinkage rate in the direction of the slow axis is 0.4% or less, or when using In the humidified TMA test where the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH, the shrinkage rate in the slow axis direction is less than 0.7% .

Description

Retardation film, circular polarizing plate and manufacturing method of retardation film

The invention relates to a retardation film, a circular polarizing plate and a manufacturing method of the retardation film.

In recent years, with the popularity of thin displays, a display equipped with an organic EL (Electroluminescence, electroluminescence) panel has been proposed. The organic EL panel has a highly reflective metal layer, which is prone to problems such as reflection of external light or reflection of the background. Therefore, it is known to prevent these problems by disposing a circular polarizing plate having a λ/4 plate on the viewing side. In addition, in the retardation film used for the above-mentioned circular polarizing plate, the retardation value generally varies depending on the wavelength, and depending on the wavelength, a sufficient antireflection effect may not be obtained, causing discoloration to become a problem. Therefore, a so-called inversely dispersed retardation film in which the retardation value becomes larger as the wavelength becomes longer has been proposed (for example, Patent Document 1). [Prior Art Literature] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open No. 2006-171235

[Problems to be Solved by the Invention] However, the above-mentioned conventional retardation films with reverse dispersion properties may change the retardation value when used in a high-temperature environment and/or a high-humidity environment. As a result, there is Uneven phase difference occurs. The present invention is made in order to solve the above-mentioned previous problems, and its main purpose is to provide a retardation film that suppresses the change of the retardation value under a high-temperature and high-humidity environment, a circular polarizing plate with such a retardation film, and the present invention. A method of manufacturing a retardation film. [Technical means to solve the problem] The manufacturing method of the retardation film of the present invention is a manufacturing method of obtaining a retardation film whose in-plane retardation satisfies the relation of Re(450)<Re(550), which comprises stretching the film at 105°C The heat treatment step of heating at the above temperature for more than 2 minutes, the stretched film is heated from 30°C to Tg-25°C and then cooled to 30°C again for 3 cycles of heating TMA (Thermomechanical Analysis, thermomechanical analysis ) test, the shrinkage rate in the slow axis direction is less than 0.4%, or in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH In the changing humidified TMA test, the shrinkage rate in the slow axis direction is 0.7% or less. In one embodiment, the heating temperature in the above heat treatment step is set as T ₁ (°C), the heating time in the above heat treatment step is set as t ₁ (minutes), and the stretched film before the above heat treatment step is When the above-mentioned shrinkage rate in the above-mentioned heating TMA test is _A1 , it satisfies 10×t ₁ /{(Tg-T ₁ ) ² ×A ₁ ² }>2. In one embodiment, the heating temperature in the above heat treatment step is set as T ₁ (°C), the heating time in the above heat treatment step is set as t ₁ (minutes), and the stretched film before the above heat treatment step is When the aforementioned shrinkage rate in the aforementioned humidified TMA test is A ₂ , 10×t ₁ /{(Tg−T ₁ ) ² ×A ₂ ² }>0.9 is satisfied. The manufacturing method of the retardation film of the present invention is a method of obtaining a retardation film whose in-plane retardation satisfies the relationship of Re(450)<Re(550), which includes immersing the stretched film in warm water above 60°C for 3 minutes In the warm water treatment step above, the stretched film is subjected to a humidified TMA test in which the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, and 85°C/2%RH , The shrinkage rate in the slow axis direction is below 0.7%. In one embodiment, the immersion time in the warm water treatment step is t ₂ (minutes), and the shrinkage ratio of the stretched film before the warm water treatment step in the humidified TMA test is A ₃ , satisfy t ₂ /A ₃ ² >20. According to another aspect of the present invention, a retardation film is provided. Regarding the retardation film, the in-plane retardation satisfies the relationship of Re(450)<Re(550), and the heating TMA is repeated for 3 cycles in the steps of heating from 30°C to Tg-25°C and cooling to 30°C again. In the test, the shrinkage rate in the slow axis direction is less than 0.1%, and the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH In the humidified TMA test, the shrinkage rate in the slow axis direction is 0.2% or less. In one embodiment, the retardation film is formed of a resin selected from polycarbonate resins and polyester carbonate-based resins. In one embodiment, Re(450)/Re(550) of the retardation film is 0.8-0.9. In one embodiment, the photoelastic coefficient of the retardation film is 1×10 ⁻¹² (m ² /N) to 40×10 ⁻¹² (m ² /N). According to another aspect of the present invention, a circular polarizing plate is provided. The circular polarizing plate has a retardation layer comprising the above-mentioned retardation film and a polarizing element, and the angle formed by the retardation axis of the above-mentioned retardation layer and the absorption axis of the above-mentioned polarizing element is 35°-55°. In one embodiment, the above-mentioned circular polarizing plate is a single piece, and the in-plane retardation value of the center part of the above-mentioned retardation layer is set to R _A0 , and the in-plane retardation value of the apex part is set to R _B0 . The in-plane retardation value of the central part of the retardation layer after laminating glass on both sides and holding at 85°C for 240 hours is R _A1 , and the above-mentioned vertex after laminating glass on both sides and holding at 85°C for 240 hours The partial in-plane retardation value is set to R _B1 , and the in-plane retardation value of the above-mentioned central part of the above-mentioned retardation layer after laminating glass on both sides and maintaining at 65°C/90%RH for 240 hours is set to R _A2 , when the in-plane retardation value of the above-mentioned vertex after laminating glass on both sides and keeping it at 65°C/90%RH for 240 hours is R _B2 , (R _A1 －R _B1 )－(R _A0 －R _B0 ) is less than 3 nm in absolute value, and the absolute value of (R _A2 -R _B2 ) - (R _A0 -R _B0 ) is less than 3 nm. In one embodiment, the circular polarizing plate includes a protective film, the retardation layer, the polarizing element, and another retardation layer in which a refractive index ellipsoid has a relationship of nz>nx=ny in this order. [Effects of the Invention] According to the production method of the present invention, the shrinkage rate in the slow axis direction in the heating TMA test is 0.4% or less, or the shrinkage rate in the slow axis direction in the humidified TMA test is 0.7%. In the heat treatment step of heating the stretched film at a temperature above 105° C. for 2 minutes or more, a retardation film in which the change of the retardation value in a high-temperature and high-humidity environment is suppressed can be obtained.

(圓偏光板) 經由黏著劑將上述相位差膜以偏光元件之吸收軸與相位差膜之遲相軸所成之角度成為45°之方式貼合於上述偏光板之偏光元件側。繼而，將上述液晶固化層轉印於相位差膜之與偏光元件相反之側之面，藉此製作具有保護層/偏光元件/相位差層/第2相位差層之構成之圓偏光板。 ＜實施例2＞ 將延伸膜於125℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例3＞ 將延伸膜於125℃下加熱30分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例4＞ 將延伸膜於125℃下加熱60分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例5＞ 將延伸膜於125℃下加熱120分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例6＞ 將緩和溫度設為110℃，除此以外，與實施例1同樣地製作延伸膜。將該延伸膜供於上述(4)之加濕TMA試驗，結果尺寸變化率為0.50%。又，將該延伸膜供於上述(3)之加熱TMA試驗，結果尺寸變化率為0.08%。 使用上述延伸膜，除此以外，與實施例2同樣地製作相位差膜及圓偏光板。 ＜實施例7＞ 將緩和溫度設為80℃，除此以外，與實施例1同樣地製作延伸膜。將該延伸膜供於上述(4)之加濕TMA試驗，結果尺寸變化率為0.70%。又，將該延伸膜供於上述(3)之加熱TMA試驗，結果尺寸變化率為0.13%。 使用上述延伸膜，除此以外，與實施例2同樣地製作相位差膜及圓偏光板。 ＜實施例8＞ 將延伸膜於105℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例9＞ 將延伸膜於110℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例10＞ 將延伸膜於115℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例11＞ 將延伸膜於120℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例12＞ 將延伸膜於130℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例13＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中3分鐘(溫水處理)，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例14＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例15＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中30分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例16＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中60分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜實施例17＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中10分鐘，除此以外，與實施例6同樣地製作相位差膜及圓偏光板。 ＜實施例18＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中10分鐘，除此以外，與實施例7同樣地製作相位差膜及圓偏光板。 ＜實施例19＞ 使用市售之聚碳酸酯樹脂膜(帝人股份有限公司製造，製品名「PURE-ACE RM」，厚度50 μm)作為延伸膜。將該延伸膜供於上述(3)之加熱TMA試驗，結果尺寸變化率為0.22%。又，將該延伸膜供於上述(4)之加濕TMA試驗，結果尺寸變化率為0.10%。 繼而，將上述延伸膜於125℃下加熱(加熱處理)2分鐘，藉此獲得相位差膜。進而，使用上述相位差膜，除此以外，與實施例1同樣地製作圓偏光板。 ＜實施例20＞ 將延伸膜於125℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例21＞ 將延伸膜於125℃下加熱30分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例22＞ 將延伸膜於125℃下加熱60分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例23＞ 將延伸膜於125℃下加熱120分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例24＞ 將延伸膜於105℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例25＞ 將延伸膜於110℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例26＞ 將延伸膜於115℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜實施例27＞ 將延伸膜於120℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜比較例1＞ 將延伸膜於125℃下加熱1分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜比較例2＞ 將延伸膜於100℃下加熱10分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜比較例3＞ 將緩和溫度設為80℃，將緩和率設為0%，除此以外，與實施例1同樣地製作延伸膜。將該延伸膜供於上述(4)之加濕TMA試驗，結果尺寸變化率為0.90%。又，將該延伸膜供於上述(3)之加熱TMA試驗，結果尺寸變化率為0.18%。 使用上述延伸膜，除此以外，與實施例2同樣地製作相位差膜及圓偏光板。 ＜比較例4＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中1分鐘，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜比較例5＞ 代替上述加熱處理，將延伸膜浸漬於60℃之溫水中10分鐘，除此以外，與比較例3同樣地製作相位差膜及圓偏光板。 ＜比較例6＞ 不實施加熱處理，除此以外，與實施例1同樣地製作相位差膜及圓偏光板。 ＜比較例7＞ 將延伸膜於100℃下加熱10分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜比較例8＞ 將延伸膜於125℃下加熱1分鐘，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜比較例9＞ 不實施加熱處理，除此以外，與實施例19同樣地製作相位差膜及圓偏光板。 ＜評價＞ 關於實施例1～12、實施例19～27、比較例1～3、及比較例7～8，作為加熱處理條件之指標，算出 10×t ₁/{(Tg－T ₁) ²×A ₁ ²} 及 10×t ₁/{(Tg－T ₁) ²×A ₂ ²}。 此處，T ₁係設為加熱處理步驟中之加熱溫度(℃)，t ₁係設為加熱處理步驟中之加熱時間(分鐘)，A ₁係設為加熱處理步驟前之延伸膜之於加熱TMA試驗中之收縮率(%)，A ₂係設為加熱處理步驟前之延伸膜之於加濕TMA試驗中之收縮率(%)。 關於實施例13～18及比較例4～5，作為溫水處理條件之指標，算出 t ₂/A ₃ ²。 此處，t ₂係設為溫水處理步驟中之浸漬時間(分鐘)，A ₃係設為溫水處理步驟前之延伸膜之於加濕TMA試驗中之收縮率(%)。 將實施例1～27及比較例1～9之相位差膜供於加濕TMA試驗及加熱TMA試驗，並測定由各個試驗所得之尺寸變化率。 進而，對於實施例1～27及比較例1～9，測定加濕相位差不均及加熱相位差不均。 將各個結果示於表1中。 [表1]    相位差膜 處理條件 尺寸變化率(%) 相位差不均(nm) 加熱TMA試驗 加濕TMA試驗 種類 溫度(℃) 時間(分鐘) 指標 處理前 處理後 處理前 處理後 加熱後 加濕後 實施例1 PC樹脂 加熱 125 2 0.99 0.05 0.02 0.30 0.18 0.9 2.6 實施例2 PC樹脂 加熱 125 10 4.94 0.05 0.02 0.30 0.14 0.7 2 實施例3 PC樹脂 加熱 125 30 14.81 0.05 0.01 0.30 0.10 0.6 1.5 實施例4 PC樹脂 加熱 125 60 29.63 0.05 0.01 0.30 0.07 0.4 1.3 實施例5 PC樹脂 加熱 125 120 59.26 0.05 0.00 0.30 0.04 0.4 1 實施例6 PC樹脂 加熱 125 10 1.78 0.08 0.03 0.50 0.17 1 2.5 實施例7 PC樹脂 加熱 125 10 0.91 0.13 0.04 0.70 0.20 1.2 2.9 實施例8 PC樹脂 加熱 105 10 0.91 0.05 0.04 0.30 0.20 1.2 2.9 實施例9 PC樹脂 加熱 110 10 1.23 0.05 0.03 0.30 0.18 1.1 2.6 實施例10 PC樹脂 加熱 115 10 1.78 0.05 0.03 0.30 0.16 1 2.4 實施例11 PC樹脂 加熱 120 10 2.78 0.05 0.02 0.30 0.14 0.8 2.1 實施例12 PC樹脂 加熱 130 10 11.11 0.05 0.01 0.30 0.11 0.7 1.8 實施例13 PC樹脂 溫水 60 3 33.33 0.05 0.03 0.30 0.18 1 2.5 實施例14 PC樹脂 溫水 60 10 111.11 0.05 0.02 0.30 0.13 0.9 1.9 實施例15 PC樹脂 溫水 60 30 333.33 0.05 0.01 0.30 0.08 0.7 1.2 實施例16 PC樹脂 溫水 60 60 666.67 0.05 0.00 0.30 0.06 0.5 0.8 實施例17 PC樹脂 溫水 60 10 40.00 0.08 0.03 0.50 0.17 1 2.4 實施例18 PC樹脂 溫水 60 10 20.41 0.13 0.05 0.70 0.20 1.3 2.9 實施例19 PURE-ACE RM 加熱 125 2 1.84 0.22 0.10 0.10 0.07 2.4 1.2 實施例20 PURE-ACE RM 加熱 125 10 9.18 0.22 0.07 0.10 0.06 1.6 0.9 實施例21 PURE-ACE RM 加熱 125 30 27.55 0.22 0.04 0.10 0.05 0.9 0.8 實施例22 PURE-ACE RM 加熱 125 60 55.10 0.22 0.03 0.10 0.04 0.8 0.5 實施例23 PURE-ACE RM 加熱 125 120 110.19 0.22 0.03 0.10 0.03 0.7 0.5 實施例24 PURE-ACE RM 加熱 105 10 1.69 0.22 0.10 0.10 0.09 2.9 1.5 實施例25 PURE-ACE RM 加熱 110 10 2.30 0.22 0.09 0.10 0.08 2.6 1.3 實施例26 PURE-ACE RM 加熱 115 10 3.31 0.22 0.09 0.10 0.07 2.3 1.2 實施例27 PURE-ACE RM 加熱 120 10 5.17 0.22 0.08 0.10 0.06 2 0.9 比較例1 PC樹脂 加熱 125 1 0.49 0.05 0.04 0.30 0.25 1.3 4.2 比較例2 PC樹脂 加熱 100 10 0.69 0.05 0.04 0.30 0.22 1.4 3.5 比較例3 PC樹脂 加熱 125 10 0.55 0.18 0.05 0.90 0.24 1.5 3.7 比較例4 PC樹脂 溫水 60 1 11.11 0.05 0.04 0.30 0.25 1.4 3.8 比較例5 PC樹脂 溫水 60 10 12.35 0.18 0.05 0.90 0.24 1.4 3.5 比較例6 PC樹脂 無 - - - 0.05 0.05 0.30 0.30 1.6 4.8 比較例7 PURE-ACE RM 加熱 100 10 1.29 0.22 0.16 0.10 0.10 3.5 1.6 比較例8 PURE-ACE RM 加熱 125 1 0.92 0.22 0.16 0.10 0.09 3.5 1.6 比較例9 PURE-ACE RM 無 - - - 0.22 0.22 0.10 0.10 4.7 1.7 由表1可明確，實施例之相位差膜與比較例之相位差膜相比，加熱處理或溫水處理後之TMA試驗中之尺寸變化率較小，用於圓偏光板之情形之相位差不均亦較小。 [產業上之可利用性] 本發明之相位差膜可較佳地用於圓偏光板，本發明之圓偏光板可較佳地用於有機EL面板。 Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. (Definitions of terms and symbols) The definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index becomes maximum (that is, the direction of the retardation axis), and "ny" is in the plane positive to the retardation axis. The refractive index in the intersecting direction (that is, the direction of the phase axis), "nz" is the refractive index in the thickness direction. (2) In-plane retardation (Re) "Re(λ)" is the in-plane retardation measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured by light with a wavelength of 550 nm at 23°C. Re(λ) is obtained from the formula: Re=(nx-ny)×d when the thickness of the layer (film) is d (nm). (3) Retardation in the thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured by light with a wavelength of λ nm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured with light with a wavelength of 550 nm at 23°C. Rth(λ) is obtained from the formula: Rth=(nx-nz)×d when the thickness of the layer (film) is d (nm). (4) Nz Coefficient The Nz coefficient is obtained by Nz=Rth/Re. A. Manufacturing method of retardation film The manufacturing method of the present invention is used in the manufacture of a retardation film exhibiting so-called inverse dispersion wavelength dependence in which the in-plane retardation satisfies the relationship of Re(450)<Re(550). Manufacturing method. The manufacturing method of the retardation film which concerns on one Embodiment of this invention includes the heat processing process of heating a stretched film at the temperature of 105 degreeC or more for 2 minutes or more. In the heating TMA test of the above-mentioned stretched film, the steps of heating from 30°C to Tg-25°C and then cooling to 30°C are repeated for 3 cycles, the shrinkage rate in the direction of the slow axis is 0.4% or less, or when the environment is controlled In the humidified TMA test with sequential changes of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, and 85°C/2%RH, the shrinkage rate in the slow axis direction is 0.7% or less. Set the heating temperature in the heat treatment step as _T1 (°C), set the heating time in the heat treatment step as _t1 (minutes), and set the shrinkage rate of the stretched film before the heat treatment step in the heating TMA test as When A ₁ is used, it is preferable to satisfy 10×t ₁ /{(Tg−T ₁ ) ² ×A ₁ ² }>2. When the shrinkage rate in the humidified TMA test of the stretched film before the heat treatment step is _A2 , it is preferable to satisfy 10×t ₁ /{(Tg−T ₁ ) ² ×A ₂ ² }>0.9. The manufacturing method of the retardation film of another embodiment of this invention includes the warm water treatment process of immersing a stretched film in warm water of 60 degreeC or more for 3 minutes or more. Shrinkage in the slow axis direction of the stretched film above in a humidified TMA test in which the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH The rate is below 0.7%. When the immersion time in the warm water treatment step is set to t ₂ (minutes), and the shrinkage rate of the stretched film before the warm water treatment step in the humidified TMA test is set to A ₃ , it is preferable to satisfy t ₂ /A ₃ ² >20. In the conventional manufacturing method, depending on the material constituting the retardation film, the durability may not be sufficient, and as a result, the retardation value may change in a high-temperature and high-humidity environment. On the other hand, according to the production method of the present invention, a retardation film having high durability and a small dimensional change rate (shrinkage rate) in a high-temperature and high-humidity environment can be obtained independently of the material constituting the retardation film. This kind of retardation film can suppress the change of the retardation value under high temperature and high humidity environment. A-1. Stretched film As mentioned above, the shrinkage rate in the slow axis direction of the stretched film is repeated in the heating TMA test for 3 cycles of heating from 30°C to Tg-25°C and then cooling to 30°C. Below 0.4%, or in the humidified TMA test where the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH, the direction of the slow axis The shrinkage rate is below 0.7%. Typically, stretched films are produced by stretching a resin film in at least one direction. The resin film is formed of any appropriate resin as long as a stretched film (retardation film) exhibiting wavelength dependence of so-called reverse dispersion can be obtained by performing stretching treatment. Examples of the resin forming the resin film include polycarbonate resins, polyvinyl acetal resins, cellulose ester resins, polyester resins, and polyester carbonate resins. These resins may be used alone or in combination according to required properties. Any appropriate polycarbonate-based resin is used as the above-mentioned polycarbonate-based resin. For example, a polycarbonate resin containing a structural unit derived from a dihydroxy compound is preferable. Specific examples of dihydroxy compounds include: 9,9-bis(4-hydroxyphenyl) fluorene, 9,9-bis(4-hydroxy-3-methylphenyl) fluorene, 9,9-bis( 4-Hydroxy-3-ethylphenyl) fluorene, 9,9-bis(4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis(4-hydroxy-3-isopropylphenyl) ) terrene, 9,9-bis(4-hydroxy-3-n-butylphenyl) terrene, 9,9-bis(4-hydroxy-3-second butylphenyl) terrene, 9,9-bis( 4-Hydroxy-3-tert-butylphenyl) fluorine, 9,9-bis(4-hydroxy-3-cyclohexylphenyl) fluorine, 9,9-bis(4-hydroxy-3-phenylphenyl) ) fennel, 9,9-bis(4-(2-hydroxyethoxy) phenyl) terrene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl) terrene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylbenzene Base) terrene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl) terrene, 9,9-bis(4-(2-hydroxyethoxy)-3 -cyclohexylphenyl) fluorine, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl) fluorine, 9,9-bis(4-(2-hydroxyethoxy) -3,5-Dimethylphenyl) fluorine, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl) fluorine, 9,9- Bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl) fennel, etc. In addition to the structural units derived from the above-mentioned dihydroxy compounds, polycarbonate resins may also contain units derived from isosorbide, isomannitol, isoidide, spirodiol, dioxanediol, diethylene glycol, Structural units of dihydroxy compounds such as triethylene glycol, polyethylene glycol, and bisphenols. The details of the above-mentioned polycarbonate resin are described in, for example, JP-A-2012-67300, JP-A-3325560 and WO2014/061677. The description of this patent document is used as a reference in this specification. The glass transition temperature (Tg) of the polycarbonate resin is preferably from 110°C to 250°C, more preferably from 120°C to 230°C. If the glass transition temperature is too low, the heat resistance tends to deteriorate, and there is a possibility of dimensional change after film formation. When the glass transition temperature is too high, the molding stability at the time of film molding may be deteriorated, and the transparency of the film may be impaired. In addition, glass transition temperature was calculated|required based on JISK7121 (1987). Arbitrary appropriate methods can be employ|adopted as a formation method of the said resin film. For example, melt extrusion method (for example, T-die forming method), cast coating method (for example, casting method), calender forming method, hot pressing method, co-extrusion method, co-melting method, multi-layer extrusion, Inflation molding method, etc. Preferably, T-die molding, tape casting, and inflation molding are used. The thickness of the resin film (unstretched film) can be set to any appropriate value according to required optical characteristics, stretching conditions described below, and the like. Preferably it is 50 μm to 300 μm, more preferably 80 μm to 250 μm. Any appropriate stretching direction and stretching conditions (for example, stretching temperature, stretching ratio, stretching direction) may be employed for the stretching as long as the stretched film is obtained. Specifically, various stretching methods such as free-end extension, fixed-end extension-free-end shrinkage, and fixed-end shrinkage can be used alone, or these stretching methods can be used simultaneously or sequentially. Regarding the extending direction, it can also be performed in various directions or dimensions such as the horizontal direction, the vertical direction, the thickness direction, and the diagonal direction. The stretching temperature is preferably within the range of the glass transition temperature (Tg) of the resin film ±20°C. By properly selecting the above-mentioned stretching method and stretching conditions, a retardation film with desired optical properties (for example, refractive index ellipsoid, in-plane retardation, Nz coefficient) can be finally obtained. In one embodiment, the stretched film is produced by uniaxially stretching a resin film or uniaxially stretching a fixed end. As a specific example of uniaxial stretching, a method of stretching a resin film in the longitudinal direction (vertical direction) while running in the elongated direction is mentioned. The elongation ratio is preferably from 10% to 500%. In another embodiment, the stretched film is produced by continuously stretching a long resin film obliquely in a direction having an angle θ with respect to the long direction. By adopting oblique stretching, a long stretched film having an alignment angle of θ with respect to the long direction of the film can be obtained. For example, when laminating with a polarizing element, roll-to-roll can be implemented, and the manufacturing steps can be simplified. As a stretching machine used for diagonal stretching, for example, a tenter stretching machine that can apply a feed force, a stretching force, or a traction force at a lateral and/or longitudinal direction at different speeds can be mentioned. The tenter stretching machine includes a horizontal uniaxial stretching machine and a simultaneous biaxial stretching machine, and any suitable stretching machine can be used as long as the long resin film can be continuously stretched obliquely. As a method of oblique extension, for example, Japanese Patent Laid-Open No. 50-83482, Japanese Patent Laid-Open No. 2-113920, Japanese Patent Laid-Open No. 3-182701, and Japanese Patent Laid-Open No. 2000-9912 The method described in the gazette, Japanese Patent Laid-Open No. 2002-86554, Japanese Patent Laid-Open No. 2002-22944, etc. The thickness of the stretched film is preferably from 20 μm to 100 μm, more preferably from 30 μm to 80 μm. As the stretched film, a commercially available film may be used as it is, or a commercially available film may be subjected to secondary processing (for example, stretching treatment, surface treatment) according to the purpose. As a specific example of a commercially available film, Teijin Corporation's product name "PURE-ACE RM" is mentioned. In one embodiment, relaxation treatment is performed on the stretched film. Thereby, the stress generated by stretching can be relaxed, and the shrinkage rate in the direction of the slow axis in the above-mentioned heating TMA test can be reduced to 0.4%, or the shrinkage rate in the direction of the slow axis in the above-mentioned humidified TMA test can be reduced to 0.7. %the following. Arbitrary appropriate conditions can be adopted as the mild treatment conditions. For example, the stretched film is shrunk at a specific relaxation temperature and a specific relaxation rate (shrinkage rate) along the stretching direction. The relaxation temperature is preferably from 60°C to 150°C. The relaxation rate is preferably 3% to 6%. A-2. Heat treatment step As described above, in the heat treatment step, the stretched film is heated at a temperature of 105° C. or higher for 2 minutes or more. In one embodiment, the heating temperature in the heat treatment step is set to T ₁ (° C.), the heating time in the heat treatment step is set to t ₁ (minutes), and the stretched film before the heat treatment step is heated to TMA When the shrinkage rate in the test is set to A ₁ , the value represented by 10×t ₁ /{(Tg-T ₁ ) ² ×A ₁ ² } is preferably greater than 2. The above-mentioned value is preferably greater than 2 and less than 150, more preferably 3-50, and especially preferably 3-10. Furthermore, (Tg-T ₁ ) is preferably 5 or more. In another embodiment, when the shrinkage rate of the stretched film before the heat treatment step in the humidified TMA test is A ₂ , it is preferably 10×t ₁ /{(Tg-T ₁ ) ² ×A ₂ ² } indicates a value greater than 0.9. The said value is preferably 1-60, more preferably 1-20, and especially preferably 1-10. The heating temperature is preferably from 105°C to 140°C, more preferably from 110°C to 130°C, especially preferably from 115°C to 125°C. The heating time is preferably from 2 minutes to 150 minutes, more preferably from 3 minutes to 120 minutes, and especially preferably from 5 minutes to 60 minutes. In the heat treatment step, any appropriate heating mechanism can be used as long as the stretched film can be heated under the above heating conditions. Typically, the heating mechanism is an oven. When a stretched film is obtained by stretching a long resin film while moving it in the longitudinal direction, heat treatment may be performed while moving the obtained stretched film in this state. A-3. Warm water treatment step As described above, in the warm water treatment step, the stretched film is immersed in warm water of 60° C. or higher for 3 minutes or more. When the immersion time in the warm water treatment step is set to t ₂ (minutes), and the shrinkage rate of the stretched film before the warm water treatment step in the humidified TMA test is set to A ₃ , it is preferably t ₂ /A ₃ ² represents a value greater than 20. The above-mentioned value is preferably greater than 20 and not more than 1000, more preferably 25-500, and especially preferably 30-150. The temperature of warm water is preferably from 60°C to 90°C, more preferably from 65°C to 85°C, especially preferably from 68°C to 82°C. The dipping time is preferably from 3 minutes to 60 minutes, more preferably from 3 minutes to 30 minutes, and especially preferably from 5 minutes to 20 minutes. In the warm water treatment step, any appropriate warm water treatment mechanism can be used as long as the stretched film can be heated under the above-mentioned heating conditions. Typically, the above-mentioned warm water treatment means is a warm water bath adjusted to an appropriate temperature. When a stretched film is obtained by stretching a long resin film while moving it in the longitudinal direction, warm water treatment may be performed while moving the obtained stretched film in this state. B. Retardation film The retardation film of the present invention is a retardation film exhibiting wavelength dependence of so-called inverse dispersion in which the in-plane retardation satisfies the relationship of Re(450)<Re(550). In the heating TMA test of the above-mentioned retardation film, the steps of heating from 30°C to Tg-25°C and then cooling to 30°C were repeated for 3 cycles, the shrinkage rate in the direction of the retardation axis was 0.1% or less, and the shrinkage rate in the environment In the humidified TMA test changing in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH, the shrinkage rate in the slow axis direction is 0.2% or less. The shrinkage rate in the slow axis direction in the heating TMA test is preferably from 0% to 0.08%, more preferably from 0% to 0.05%. The shrinkage rate in the slow axis direction in the above-mentioned humidified TMA test is preferably from 0% to 0.15%, more preferably from 0% to 0.10%. The retardation film as described above can suppress the change of the retardation value in a high-temperature and high-humidity environment. The value of Re(450)/Re(550) of the retardation film is preferably from 0.8 to 0.9, more preferably from 0.83 to 0.87. The in-plane retardation Re(550) of the retardation film is preferably from 100 nm to 180 nm, more preferably from 135 nm to 155 nm. The photoelastic coefficient of the retardation film is preferably 1×10 ^-12 (m ² /N) to 40×10 ^-12 (m ² /N), more preferably 1×10 ^-12 (m ² /N) to 30 ×10 ^-12 (m ² /N), especially preferably 1×10 ^-12 (m ² /N) to 20×10 ^-12 (m ² /N). Such a retardation film can be obtained by the manufacturing method demonstrated in A term, for example. Retardation films can be used for circular polarizers. C. Circular Polarizing Plate The circular polarizing plate of the present invention has a retardation layer including the aforementioned retardation film, and a polarizing element. The angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizing element is 35°-55°, preferably 40°-50°, especially 43-47°, most preferably about 45°. Fig. 1 is a schematic cross-sectional view of a circular polarizing plate according to an embodiment of the present invention. The circular polarizing plate 100 sequentially includes a protective layer 10, a polarizing element 20, a retardation layer 30, and another retardation layer 40 (sometimes referred to as a second retardation layer) whose refractive index ellipsoid has a relationship of nz>nx=ny. ). In one embodiment, the circular polarizing plate 100 is in the shape of a single sheet. The retardation unevenness of the retardation layer 30 when the circular polarizing plate 100 is heated (heating retardation unevenness) is 3 nm or less. Furthermore, the retardation unevenness of the retardation layer 30 when the circular polarizing plate 100 is humidified (wetting retardation unevenness) is 3 nm or less. The uneven heating phase difference and the uneven humidifying phase difference are preferably from 0 nm to 2 nm, more preferably from 0 nm to 1 nm. The heating retardation unevenness can be determined as the absolute value of the value calculated by the following formula when, for example, glass is bonded to both sides of the circular polarizing plate 100 and heated (maintained at 85° C. for 240 hours). (R _A1 - R _B1 ) - (R _A0 - R _B0 ) Here, R _A0 is the in-plane retardation value at the center of the retardation layer 30, and R _B0 is the in-plane retardation at the apex of the retardation layer 30 R _A1 is the in-plane retardation value of the central part of the retardation layer 30 after the above-mentioned heating, and R _B1 is the in-plane retardation value of the above-mentioned apex part after the above-mentioned heating. The aforementioned humidity retardation unevenness can be used as the absolute value of the value calculated by the following formula when, for example, glass is attached to both sides of the circular polarizing plate 100 and humidified (maintained at 65°C/90%RH for 240 hours) And decided. (R _A2 - R _B2 ) - (R _A0 - R _B0 ) Here, R _A2 is the in-plane retardation value of the central part of the retardation layer 30 after the above-mentioned humidification, and R _B2 is the above-mentioned vertex after the above-mentioned humidification Partial in-plane phase difference. When the conventional circular polarizing plate is used in an image display device by laminating glass on both sides, the central portion of the retardation layer is less likely to be affected by the high-temperature and high-humidity environment. On the other hand, the end portion of the retardation layer is affected by The influence of high temperature and high humidity environment. As a result, the variation in the in-plane retardation value in the central part of the retardation layer is small, and the variation in the in-plane retardation value in the edge part of the retardation layer becomes large, which may cause uneven retardation. On the other hand, in the circular polarizing plate of the present invention, since the retardation layer includes the above-mentioned retardation film, variations in the in-plane retardation at the end of the retardation layer can be suppressed, and retardation unevenness can be suppressed. C-1. Polarizer As the polarizer, any appropriate polarizer can be used. For example, the resin film forming the polarizing element may be a single-layer resin film, or may be a laminate of two or more layers. Specific examples of polarizing elements including a single-layer resin film include highly hydrophilic polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films. Molecular film dyed with dichroic substances such as iodine or dichroic dyes and stretched, polyene-based alignment films such as dehydrated PVA or dehydrochlorinated polyvinyl chloride, etc. It is preferable to use a polarizing element obtained by dyeing a PVA-based film with iodine and uniaxially stretching it in terms of excellent optical characteristics. The above-mentioned dyeing with iodine is performed, for example, by immersing a PVA-based film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching can be performed after the dyeing treatment, or can be performed while dyeing. In addition, dyeing may be performed after elongation. Swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc. are performed on the PVA-based film as necessary. For example, by immersing the PVA-based film in water for washing before dyeing, not only can the dirt and anti-blocking agent on the surface of the PVA-based film be washed, but also the PVA-based film can be swollen to prevent uneven dyeing. Specific examples of polarizing elements obtained by using a laminate include: a laminate using a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material formed by coating A polarizing element obtained from a laminate of PVA-based resin layers on the resin substrate. A polarizing element obtained by using a laminate of a resin base material and a PVA-based resin layer coated and formed on the resin base material can be produced, for example, by applying a PVA-based resin solution to the resin base material and drying it. A PVA-based resin layer is formed on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; the laminate is stretched and dyed to make the PVA-based resin layer into a polarizing element. In this embodiment, typically, extending|stretching includes the process of immersing a laminated body in boric-acid aqueous solution, and extending it. Furthermore, the stretching may further include a step of stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in a boric acid aqueous solution, if necessary. The obtained resin substrate/polarizer laminate can be used directly (that is, the resin substrate can be used as a protective layer for the polarizer), or the resin substrate can be peeled off from the resin substrate/polarizer laminate, and An arbitrary appropriate protective layer according to the purpose is used on the peeling surface layer. The details of the manufacturing method of such a polarizing element are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580. The entire description of this publication is incorporated in this specification as a reference. The thickness of the polarizing element is, for example, 1 μm˜80 μm. In one embodiment, the thickness of the polarizing element is preferably 1 μm˜15 μm, further preferably 3 μm˜10 μm, especially preferably 3 μm˜8 μm. When the thickness of the polarizing element is within such a range, curling during heating can be favorably suppressed, and favorable appearance durability during heating can be obtained. C-2. Second Retardation Layer Regarding the second retardation layer, as described above, the refractive index ellipsoid has the relationship of nz>nx=ny, and can function as a so-called anode C plate. When the circular polarizing plate having such a second retardation layer is used in an organic EL panel, changes in reflectance and reflection hue can be suppressed. The retardation Rth(550) in the thickness direction of the second retardation layer is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, further preferably -90 nm to -200 nm, especially The best range is -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. That is, the in-plane retardation Re(550) of the second retardation layer may be less than 10 nm. The second retardation layer having the refractive index characteristic of nz>nx=ny can be formed of any appropriate material. Preferably, the second retardation layer can include a liquid crystal material fixed in a vertical alignment. The vertically aligned liquid crystal material (liquid crystal compound) can be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the method of forming the liquid crystal compound and the second retardation layer include the method of forming the liquid crystal compound and the retardation film described in [0020] to [0028] of JP-A-2002-333642. In this case, the thickness of the second retardation layer is preferably from 0.5 μm to 10 μm, more preferably from 0.5 μm to 8 μm, and still more preferably from 0.5 μm to 5 μm. As another preferred specific example, the second retardation layer may also include a retardation film made of fumaric diester resin described in Japanese Patent Laid-Open No. 2012-32784. In this case, the thickness is preferably from 5 μm to 80 μm, more preferably from 10 μm to 50 μm. C-3. Protective Layer The protective layer is formed of any appropriate protective film that can be used as a film for protecting a polarizing element. Specific examples of the material used as the main component of the protective film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, and polyamide-based resins. , Polyimide-based, polyether-based, poly-based, polystyrene-based, polynorthylene-based, polyolefin-based, (meth)acrylic-based, acetate-based transparent resins, etc. Also, thermosetting resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, silicone, etc. or ultraviolet curable resins can be mentioned. wait. In addition, glassy polymers, such as a siloxane polymer, are mentioned, for example. Moreover, the polymer film described in Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a resin combination including a thermoplastic resin having a substituted or unsubstituted imide group in a side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in a side chain can be used. As an example, the resin composition which has the alternating copolymer containing isobutylene and N-methylmaleimide, and an acrylonitrile-styrene copolymer is mentioned. The polymer film may be, for example, an extruded product of the aforementioned resin composition. The thickness of the protective film is preferably from 10 μm to 100 μm. The protective film may be laminated on the polarizing element via an adhesive layer (specifically, an adhesive layer or an adhesive layer), or may be laminated on the polarizing element in close contact (without an adhesive layer). The adhesive layer is formed of any appropriate adhesive. As an adhesive agent, the water-soluble adhesive agent whose main component is a polyvinyl-alcohol-type resin is mentioned, for example. The water-soluble adhesive mainly composed of a polyvinyl alcohol-based resin may further contain a metal compound colloid. The metal compound colloid may be one in which metal compound fine particles are dispersed in a dispersion medium, and may be electrostatically stabilized and permanently stable due to mutual repulsion of the same charges of the fine particles. The average particle size of the fine particles forming the metal compound colloid may be any appropriate value as long as it does not adversely affect optical properties such as polarization properties. It is preferably 1 nm to 100 nm, and more preferably 1 nm to 50 nm. This is because fine particles can be uniformly dispersed in the adhesive layer, adhesiveness can be ensured, and cracks can be suppressed. Furthermore, "crack point" refers to a local concave-convex defect generated at the interface between the polarizer and the protective film. The adhesive layer contains any suitable adhesive. Surface treatment such as hard coating treatment, anti-reflection treatment, anti-adhesion treatment, anti-glare treatment, etc. can also be performed on the surface of the protective film opposite to the polarizing element as required. Typically, the thickness of the protective film is 5 mm or less, preferably 1 mm or less, more preferably 1 μm to 500 μm, further preferably 5 μm to 150 μm. EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. The measuring method of each characteristic is as follows. In addition, unless otherwise indicated, "part" and "%" in an Example and a comparative example are based on weight. (1) Thickness was measured using a dial gauge (manufactured by PEACOCK, product name "DG-205 type pds-2"). (2) The retardation value was measured using Axoscan manufactured by Axometrics. (3) Dimensional change rate caused by heating (heating TMA test) The stretched film or retardation film obtained in the examples and comparative examples was cut into 20 mm (delay axis direction) × 4 mm (phase axis direction) direction) to make a measurement sample. Using a thermomechanical analysis device (manufactured by Hitachi High-Tech Science, model "TMA7100"), the steps of heating the measurement sample from 30°C to Tg-25°C and cooling to 30°C were repeated for 3 cycles. The dimensional change rate (shrinkage rate) in the longitudinal direction (slow axis direction) of the sample is measured. Furthermore, the heating rate was set at 5° C./min, and the holding time at each temperature was set at 10 minutes. (4) Dimensional change rate caused by humidification (humidification TMA test) The stretched film or retardation film obtained in the examples and comparative examples was cut into 20 mm (retardation axis direction) × 5 mm (further phase axis direction) to make measurement samples. Using a thermomechanical analysis device, after the environment is changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH, the longitudinal direction of the measured sample (late phase) The dimensional change rate (shrinkage rate) in the axial direction) is measured. Furthermore, the holding time at 25°C/25%RH is set to 60 minutes, the holding time at 85°C/2%RH is set to 60 minutes, and the holding time at 85°C/85%RH is set to 300 minutes . (5) Heating retardation unevenness The circular polarizing plates obtained in Examples and Comparative Examples were cut into 75 mm×150 mm in such a way that the absorption axis of the polarizing element becomes the short side direction, and the glass substrates were bonded together with an adhesive On both sides of the circular polarizing plate, make a measurement sample. For the measurement sample, measure the in-plane retardation value R _A0 from the central part, the in-plane retardation value R _B01 from the central part to the vertex in the slow axis direction, and the plane from the central part to the vertex in the advancing axis direction Internal phase difference R _B02 . Then, heat the measurement sample in an oven at 85°C for 240 hours. For the heated measurement sample, measure the in-plane retardation value R _A1 at the center, and the in-plane retardation from the center to the apex in the direction of the slow axis. value R _B11 , and the in-plane phase difference value R _B12 from the center part to the apex part located in the direction of the phase advance axis. The larger value among the absolute values of the values A and B obtained from the following formula was regarded as the heating phase difference unevenness. A=(R _A1 -R _B11 )-(R _A0 -R _B01 ) B=(R _A1 -R _B12 )-(R _A0 -R _B02 ) (6) Humidification phase difference is the same as (5) above Make a measurement sample of a circular polarizing plate, and measure the in-plane retardation value R _A0 from the central part, the in-plane retardation value R B01 from the central part to the vertex in the direction of the retardation axis, and the in-plane retardation value R _B01 from the central part to the direction of the advancing axis The in-plane phase difference value R _B02 of the vertex part. Next, humidify the measurement sample in an oven at 65°C/90% for 240 hours. For the humidified measurement sample, measure the in-plane retardation value R A2 in the central part, and measure the in-plane retardation value R _A2 from the central part to the apex in the slow axis direction. The in-plane phase difference value R _B21 , and the in-plane phase difference value R _B22 from the center part to the apex part in the direction of the phase advance axis. The greater value among the absolute values of the values C and D obtained from the following formula was regarded as the humidification phase difference unevenness. C=(R _A2 -R _B21 )-(R _A0 -R _B01 ) D=(R _A2 -R _B22 )-(R _A0 -R _B02 ) <Example 1> 1. Production of retardation film (polycarbonate Resin) Polymerization was performed using a batch polymerization device, which included two vertical reactors equipped with stirring blades and a reflux cooler controlled at 100°C. Add 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl) fluorine-9-yl]methane, 29.21 parts by mass (0.200 mol) of ISB (Isosorbide, isosorbide), SPG (Spiroglycol , spirodiol) 42.28 parts by mass (0.139 mol), DPC (Diphenyl Carbonate, diphenyl carbonate) 63.77 parts by mass (0.298 mol) and calcium acetate monohydrate as a catalyst 1.19×10 ^-2 parts by mass (6.78× 10 ^-5 mol). After the inside of the reactor was replaced with nitrogen under reduced pressure, it was heated with a heat medium, and stirring was started when the internal temperature became 100°C. 40 minutes after the start of the temperature rise, the internal temperature was brought to 220° C., and the temperature was controlled to maintain the temperature. At the same time, the pressure was reduced, and after reaching 220° C., it was brought to 13.3 kPa over 90 minutes. The phenol vapor produced by the polymerization reaction is introduced into the reflux cooler at 100°C, so that a certain amount of monomer components contained in the phenol vapor are returned to the reactor, and the uncondensed phenol vapor is introduced into the condenser at 45°C for recovery . After introducing nitrogen gas into the first reactor and temporarily restoring the pressure to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, temperature rise and pressure reduction in the second reactor were started, and it took 50 minutes to bring the inner temperature to 240° C. and the pressure to 0.2 kPa. Thereafter, polymerization is carried out until a specific stirring power is obtained. When the specific power is reached, nitrogen gas is introduced into the reactor for repressurization, the polyester carbonate produced is extruded into water, and the strands are cut to obtain pellets. (Resin film) After vacuum-drying the obtained polycarbonate resin at 80° C. for 5 hours, use a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250° C.), T-die (width 200 mm , set temperature: 250°C), cooling roll (set temperature: 120-130°C) and the film-making device of the coiler to produce a resin film with a thickness of 135 μm. (Retardation Film) The obtained elongated resin film was stretched in the width direction at a stretching temperature of 134° C. and a stretching ratio of 2.8 times, and then the stretched film was subjected to relaxation treatment in the width direction to produce a stretched film. The conditions of the relaxation treatment were set at a relaxation temperature of 130°C and a relaxation rate of 4.5%. When this stretched film was subjected to the humidified TMA test of (4) above, the dimensional change rate was 0.30%. Also, when this stretched film was subjected to the heating TMA test of (3) above, the dimensional change rate was 0.05%. Next, by heating (heat-processing) the said stretched film at 125 degreeC for 2 minutes, the retardation film of thickness 48 micrometers was obtained. 2. Production of circular polarizing plate (polarizing element) Prepare long amorphous polyethylene terephthalate (A-PET) film (manufactured by Mitsubishi Plastics Corporation, trade name "Novaclear", thickness: 100 μm) As a substrate, an aqueous solution of polyvinyl alcohol (PVA) resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gohsenol (registered trademark) NH-26") is applied and dried on one side of the substrate at 60°C. , and a PVA-based resin layer with a thickness of 7 μm was formed. The laminate obtained in this way was immersed in an insolubilization bath having a liquid temperature of 30° C. for 30 seconds (insolubilization step). Then, it was immersed in a dyeing bath having a liquid temperature of 30° C. for 60 seconds (dyeing step). Next, it was immersed in a crosslinking bath having a liquid temperature of 30° C. for 30 seconds (crosslinking step). Thereafter, while the laminate was immersed in a boric acid aqueous solution having a liquid temperature of 60° C., it was uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds. The time of immersion in the boric acid aqueous solution was 120 seconds, extending until just before the laminate was broken. Thereafter, after immersing the laminate in a cleaning bath, it was dried with warm air at 60° C. (washing and drying steps). In this manner, a long laminate (polarizer laminate) in which a polarizing element having a thickness of 5 μm was formed on a substrate was obtained. (Polarizing plate) A cycloolefin-based resin film (manufactured by ZEONOR Co., Ltd., trade name “ZEONOR FILM”, thickness: 25 μm) as a protective film was bonded to the surface of the above-mentioned laminate on the polarizing element side through an adhesive. And the said base material was peeled off from a polarizing element, and the polarizing plate was obtained by this. (The second retardation layer) 20 parts by weight of the side chain type liquid crystal polymer represented by the following chemical formula (I), and 80 parts by weight of a polymerizable liquid crystal (manufactured by BASF Corporation: trade name Paliocolor LC242) showing a nematic liquid crystal phase 5 parts by weight of a photopolymerization initiator (manufactured by BASF Corporation: trade name Irgacure 907) was dissolved in 400 parts by weight of cyclopentanone to prepare a liquid crystal coating liquid. Then, this coating solution was applied to a base film (northylene-based resin film: manufactured by Nippon Zeon Co., Ltd., trade name "ZEONOR") with a bar coater, and then heated and dried at 70°C. 4 minutes, thereby aligning the liquid crystal. The liquid crystal layer was irradiated with ultraviolet rays to harden the liquid crystal layer, thereby forming a liquid crystal solidified layer (thickness: 1 μm) serving as a retardation film on the substrate. Re(550) of this layer is 0 nm, Rth(550) is -71 nm (nx: 1.5326, ny: 1.5326, nz: 1.6550). [chemical 1]

(Circular Polarizing Plate) The retardation film was bonded to the polarizing element side of the polarizing plate through an adhesive so that the angle formed by the absorption axis of the polarizing element and the retardation axis of the retardation film was 45°. Then, transfer the above-mentioned liquid crystal solidified layer to the surface of the retardation film opposite to the polarizing element, thereby producing a circular polarizing plate having a composition of protective layer/polarizing element/retardation layer/second retardation layer. <Example 2> Except having heated the stretched film at 125 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 3> Except having heated the stretched film at 125 degreeC for 30 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 4> Except having heated the stretched film at 125 degreeC for 60 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 5> Except having heated the stretched film at 125 degreeC for 120 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 6> Except having set relaxation temperature as 110 degreeC, it carried out similarly to Example 1, and produced the stretched film. When this stretched film was subjected to the humidified TMA test of (4) above, the dimensional change rate was 0.50%. When this stretched film was subjected to the heating TMA test of (3) above, the dimensional change rate was 0.08%. Except having used the said stretched film, it carried out similarly to Example 2, and produced the retardation film and circularly polarizing plate. <Example 7> Except having set the relaxation temperature at 80 degreeC, it carried out similarly to Example 1, and produced the stretched film. When this stretched film was subjected to the humidified TMA test of (4) above, the dimensional change rate was 0.70%. Furthermore, when this stretched film was subjected to the heating TMA test of (3) above, the dimensional change rate was 0.13%. Except having used the said stretched film, it carried out similarly to Example 2, and produced the retardation film and circularly polarizing plate. <Example 8> Except having heated the stretched film at 105 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 9> Except having heated the stretched film at 110 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 10> Except having heated the stretched film at 115 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Example 11> Except having heated the stretched film at 120 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Example 12> Except having heated the stretched film at 130 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Example 13> Instead of the above heat treatment, a retardation film and a circular polarizing plate were produced in the same manner as in Example 1 except that the stretched film was immersed in 60° C. warm water for 3 minutes (warm water treatment). <Example 14> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Example 15> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 30 minutes, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Example 16> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 60 minutes, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Example 17> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 10 minutes, it carried out similarly to Example 6, and produced the retardation film and circular polarizing plate. <Example 18> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 10 minutes, it carried out similarly to Example 7, and produced the retardation film and circular polarizing plate. <Example 19> A commercially available polycarbonate resin film (manufactured by Teijin Co., Ltd., product name "PURE-ACE RM", thickness 50 μm) was used as a stretched film. When this stretched film was subjected to the heating TMA test of (3) above, the dimensional change rate was 0.22%. When this stretched film was subjected to the humidified TMA test of (4) above, the dimensional change rate was 0.10%. Next, the said stretched film was heated (heat-processed) at 125 degreeC for 2 minutes, and the retardation film was obtained. Furthermore, except having used the said retardation film, it carried out similarly to Example 1, and produced the circular polarizing plate. <Example 20> Except having heated the stretched film at 125 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the retardation film and circular polarizing plate. <Example 21> Except having heated the stretched film at 125 degreeC for 30 minutes, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Example 22> Except having heated the stretched film at 125 degreeC for 60 minutes, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Example 23> Except having heated the stretched film at 125 degreeC for 120 minutes, it carried out similarly to Example 19, and produced the retardation film and circular polarizing plate. <Example 24> Except having heated the stretched film at 105 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Example 25> Except having heated the stretched film at 110 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the phase difference film and circularly polarizing plate. <Example 26> Except having heated the stretched film at 115 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Example 27> Except having heated the stretched film at 120 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the phase difference film and circularly polarizing plate. <Comparative example 1> Except having heated the stretched film at 125 degreeC for 1 minute, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Comparative example 2> Except having heated the stretched film at 100 degreeC for 10 minutes, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Comparative example 3> The stretched film was produced similarly to Example 1 except having made relaxation temperature into 80 degreeC and relaxation rate into 0%. When this stretched film was subjected to the humidified TMA test of (4) above, the dimensional change rate was 0.90%. Furthermore, when this stretched film was subjected to the heating TMA test of (3) above, the dimensional change rate was 0.18%. Except having used the said stretched film, it carried out similarly to Example 2, and produced the retardation film and circularly polarizing plate. <Comparative example 4> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 1 minute, it carried out similarly to Example 1, and produced the retardation film and circular polarizing plate. <Comparative example 5> Instead of the above heat treatment, except having immersed the stretched film in 60 degreeC warm water for 10 minutes, it carried out similarly to the comparative example 3, and produced the retardation film and circular polarizing plate. <Comparative example 6> Except not having heat-processed, it carried out similarly to Example 1, and produced the retardation film and circularly polarizing plate. <Comparative example 7> Except having heated the stretched film at 100 degreeC for 10 minutes, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Comparative example 8> Except having heated the stretched film at 125 degreeC for 1 minute, it carried out similarly to Example 19, and produced the retardation film and circular polarizing plate. <Comparative example 9> Except not having heat-processed, it carried out similarly to Example 19, and produced the retardation film and circularly polarizing plate. <Evaluation> Regarding Examples 1 to 12, Examples 19 to 27, Comparative Examples 1 to 3, and Comparative Examples 7 to 8, 10×t ₁ /{(Tg−T ₁ ) ² was calculated as an index of heat treatment conditions. ×A ₁ ² } and 10×t ₁ /{(Tg-T ₁ ) ² ×A ₂ ² }. Here, _T1 is set as the heating temperature (°C) in the heat treatment step, _t1 is set as the heating time (minutes) in the heat treatment step, and _A1 is set as the heating time of the stretched film before the heat treatment step. The shrinkage rate (%) in the TMA test, _A2 is set as the shrinkage rate (%) of the stretched film before the heat treatment step in the humidified TMA test. Regarding Examples 13 to 18 and Comparative Examples 4 to 5, t ₂ /A ₃ ² was calculated as an index of warm water treatment conditions. Here, _t2 is the immersion time (minutes) in the warm water treatment step, and _A3 is the shrinkage rate (%) of the stretched film before the warm water treatment step in the humidified TMA test. The retardation films of Examples 1 to 27 and Comparative Examples 1 to 9 were subjected to a humidified TMA test and a heated TMA test, and the dimensional change rates obtained by the respective tests were measured. Furthermore, about Examples 1-27 and Comparative Examples 1-9, the humidification phase difference unevenness and the heating phase difference unevenness were measured. Each result is shown in Table 1. [Table 1] Retardation film processing conditions Dimensional change rate (%) Uneven phase difference (nm) Heated TMA test Humidified TMA test type temperature(℃) time (minutes) index before processing after treatment before processing after treatment after heating After humidification Example 1 PC resin heating 125 2 0.99 0.05 0.02 0.30 0.18 0.9 2.6 Example 2 PC resin heating 125 10 4.94 0.05 0.02 0.30 0.14 0.7 2 Example 3 PC resin heating 125 30 14.81 0.05 0.01 0.30 0.10 0.6 1.5 Example 4 PC resin heating 125 60 29.63 0.05 0.01 0.30 0.07 0.4 1.3 Example 5 PC resin heating 125 120 59.26 0.05 0.00 0.30 0.04 0.4 1 Example 6 PC resin heating 125 10 1.78 0.08 0.03 0.50 0.17 1 2.5 Example 7 PC resin heating 125 10 0.91 0.13 0.04 0.70 0.20 1.2 2.9 Example 8 PC resin heating 105 10 0.91 0.05 0.04 0.30 0.20 1.2 2.9 Example 9 PC resin heating 110 10 1.23 0.05 0.03 0.30 0.18 1.1 2.6 Example 10 PC resin heating 115 10 1.78 0.05 0.03 0.30 0.16 1 2.4 Example 11 PC resin heating 120 10 2.78 0.05 0.02 0.30 0.14 0.8 2.1 Example 12 PC resin heating 130 10 11.11 0.05 0.01 0.30 0.11 0.7 1.8 Example 13 PC resin warm water 60 3 33.33 0.05 0.03 0.30 0.18 1 2.5 Example 14 PC resin warm water 60 10 111.11 0.05 0.02 0.30 0.13 0.9 1.9 Example 15 PC resin warm water 60 30 333.33 0.05 0.01 0.30 0.08 0.7 1.2 Example 16 PC resin warm water 60 60 666.67 0.05 0.00 0.30 0.06 0.5 0.8 Example 17 PC resin warm water 60 10 40.00 0.08 0.03 0.50 0.17 1 2.4 Example 18 PC resin warm water 60 10 20.41 0.13 0.05 0.70 0.20 1.3 2.9 Example 19 PURE-ACE RM heating 125 2 1.84 0.22 0.10 0.10 0.07 2.4 1.2 Example 20 PURE-ACE RM heating 125 10 9.18 0.22 0.07 0.10 0.06 1.6 0.9 Example 21 PURE-ACE RM heating 125 30 27.55 0.22 0.04 0.10 0.05 0.9 0.8 Example 22 PURE-ACE RM heating 125 60 55.10 0.22 0.03 0.10 0.04 0.8 0.5 Example 23 PURE-ACE RM heating 125 120 110.19 0.22 0.03 0.10 0.03 0.7 0.5 Example 24 PURE-ACE RM heating 105 10 1.69 0.22 0.10 0.10 0.09 2.9 1.5 Example 25 PURE-ACE RM heating 110 10 2.30 0.22 0.09 0.10 0.08 2.6 1.3 Example 26 PURE-ACE RM heating 115 10 3.31 0.22 0.09 0.10 0.07 2.3 1.2 Example 27 PURE-ACE RM heating 120 10 5.17 0.22 0.08 0.10 0.06 2 0.9 Comparative example 1 PC resin heating 125 1 0.49 0.05 0.04 0.30 0.25 1.3 4.2 Comparative example 2 PC resin heating 100 10 0.69 0.05 0.04 0.30 0.22 1.4 3.5 Comparative example 3 PC resin heating 125 10 0.55 0.18 0.05 0.90 0.24 1.5 3.7 Comparative example 4 PC resin warm water 60 1 11.11 0.05 0.04 0.30 0.25 1.4 3.8 Comparative Example 5 PC resin warm water 60 10 12.35 0.18 0.05 0.90 0.24 1.4 3.5 Comparative Example 6 PC resin none - - - 0.05 0.05 0.30 0.30 1.6 4.8 Comparative Example 7 PURE-ACE RM heating 100 10 1.29 0.22 0.16 0.10 0.10 3.5 1.6 Comparative Example 8 PURE-ACE RM heating 125 1 0.92 0.22 0.16 0.10 0.09 3.5 1.6 Comparative Example 9 PURE-ACE RM none - - - 0.22 0.22 0.10 0.10 4.7 1.7 As can be seen from Table 1, compared with the retardation film of the comparative example, the retardation film of the embodiment has a smaller dimensional change rate in the TMA test after heat treatment or warm water treatment. The unevenness is also small. [Industrial Applicability] The retardation film of the present invention can be preferably used for a circular polarizing plate, and the circular polarizing plate of the present invention can be preferably used for an organic EL panel.

10: Protective layer 20: polarizing element 30: Retardation layer 40: The second retardation layer 100: circular polarizer

Fig. 1 is a schematic cross-sectional view of a circular polarizing plate according to an embodiment of the present invention.

10: Protective layer

20: polarizing element

30: Retardation layer

40: The second retardation layer

100: circular polarizer

Claims (7)

A circular polarizing plate, which is in the shape of a single sheet, has a retardation layer comprising a retardation film, and a polarizing element, and the angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizing element is 35° to 55° , set the in-plane retardation value at the center of the retardation layer as R _A0 , and set the in-plane retardation value at the apex as R _B0 , after laminating glass on both sides and keeping it at 85°C for 240 hours The in-plane retardation value of the central portion of the above-mentioned retardation layer is set as R _A1 , and the in-plane retardation value of the above-mentioned apex portion after bonding glass on both sides and maintaining at 85°C for 240 hours is set as R _B1 , and the The in-plane retardation value of the above-mentioned central part of the above-mentioned retardation layer after laminating glass on both sides and keeping it at 65°C/90%RH for 240 hours is set to R _A2 . When the in-plane retardation value of the above-mentioned apex after being kept under RH for 240 hours is set to R _B2 , the absolute value of (R _A1 -R _B1 )-(R _A0 -R _B0 ) is 3nm or less, (R _A2 -R _B2 )-(R _A0 -R _B0 ) has an absolute value of 3nm or less. The above retardation film system: the in-plane retardation satisfies the relationship of Re(450)<Re(550), and the temperature will rise from 30°C to Tg-25°C And the step of cooling to 30°C was repeated for 3 cycles in the heating TMA test, the shrinkage rate in the slow axis direction was less than 0.1%, and the environment was 25°C/25%RH, 85°C/2%RH, In the humidified TMA test with sequential changes of 85°C/85%RH and 85°C/2%RH, the shrinkage rate in the slow axis direction is 0.2% or less. Here, Re(450) and Re(550) respectively represent The in-plane retardation measured by light with wavelengths of 450nm and 550nm at 23°C. The circular polarizing plate according to claim 1, wherein the retardation film is formed of a resin selected from polycarbonate resins and polyester carbonate resins. The circular polarizing plate according to claim 1, wherein Re(450)/Re(550) of the retardation film is 0.8~0.9. The circular polarizing plate according to claim 2, wherein Re(450)/Re(550) of the retardation film is 0.8~0.9. The circular polarizing plate according to any one of claims 1 to 4, wherein the photoelastic coefficient of the retardation film is 1×10 ^-12 (m ² /N) to 40×10 ^-12 (m ² /N). The circular polarizing plate according to any one of claims 1 to 4, which sequentially has a protective film, the aforementioned retardation layer, the aforementioned polarizing element, and another retardation layer whose refractive index ellipsoid has a relationship of nz>nx=ny . The circular polarizing plate according to claim 5, which sequentially has a protective film, the aforementioned retardation layer, the aforementioned polarizing element, and another retardation layer whose refractive index ellipsoid has a relationship of nz>nx=ny.

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