TW202223460A - Phase difference film, circularly polarizing plate, and method for manufacturing phase difference film - Google Patents

Abstract

The present invention provides a phase difference film capable of minimizing a change in a phase difference value under high temperature and high humidity environment. A manufacturing method according to the present invention is used to produce a phase difference film with an in-plane retardation that satisfies the relationship of Re(450) < Re(550). The manufacturing method includes a heat treatment step of heating a stretched film for two minutes or longer at a temperature of 105°C or higher, the stretched film exhibiting a shrinkage of 0.4% or less along the slow axis in the TMA of heating which repeats the cycle of heating and cooling the stretched film between 30 DEG C and Tg - 25 DEG C three times or the stretched film exhibiting a shrinkage of 0.7% or less along the slow axis in the TMA of humidification which changes the environment in order of 25 DEG C/25%RH, 85 DEG C/2%RH, 85 DEG C/85%RH, and 85 DEG C/2%RH.

Description

Retardation film, circular polarizing plate and method for producing retardation film

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

In recent years, with the popularization of thin-type displays, a display equipped with an organic EL (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 such problems by arranging a circularly polarizing plate having a λ/4 plate on the viewing side. In addition, regarding the retardation film used for the above-mentioned circularly polarizing plate, the retardation value usually varies depending on the wavelength, and depending on the wavelength, a sufficient antireflection effect may not be obtained, resulting in a problem of fading. Therefore, a so-called reverse dispersion retardation film has been proposed in which the retardation value increases as the wavelength increases (for example, Patent Document 1). [Prior Art Literature] [Patent Literature] [Patent Document 1] Japanese Patent Laid-Open No. 2006-171235

[Problem to be Solved by the Invention] However, the retardation value of the conventional reverse dispersive retardation film as described above may change when used in a high-temperature environment and/or a high-humidity environment. As a result, there are Uneven phase difference occurs. The present invention is made in order to solve the above-mentioned problems, and its main object is to provide a retardation film in which the change in the retardation value under a high temperature and high humidity environment is suppressed, a circularly polarizing plate having such a retardation film, and the like A method of manufacturing a retardation film. [Technical Means for Solving the Problem] The method for producing a retardation film of the present invention is a method for obtaining a retardation film in which the in-plane retardation satisfies the relation of Re(450)<Re(550), which comprises subjecting the stretched film to a temperature of 105° C. The heating 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 for 3 cycles of repeated heating TMA (Thermomechanical Analysis, Thermomechanical Analysis ) in the test, the shrinkage rate in the slow axis direction is 0.4% or less, or the environment is in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, 85°C/2%RH In the modified humidification TMA test, the shrinkage in the slow axis direction was 0.7% or less. 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 (min), and the stretched film before the heat treatment step is set to When the said shrinkage rate in the said heating TMA test is set to A1, ₁₀ * _t1 /{(Tg-T1) ₂ * ^A12 _} > ² is satisfied. 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 (min), and the stretched film before the heat treatment step is set to When the above-mentioned shrinkage ratio in the above-mentioned humidification TMA test is set to 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 manufacturing method of obtaining a retardation film whose in-plane retardation satisfies the relation of Re(450)<Re(550), which comprises immersing the stretched film in warm water of 60°C or higher for 3 minutes In the above warm water treatment steps, the stretched film was subjected to a humidification TMA test in which the environment was changed in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, and 85°C/2%RH , the shrinkage in the slow axis direction is 0.7% or less. In one embodiment, the immersion time in the warm water treatment step is t ₂ (minutes), and the shrinkage rate in the humidification TMA test of the stretched film before the warm water treatment step is A. When ₃ , t ₂ /A ₃ ² >20 is satisfied. According to another aspect of the present invention, a retardation film is provided. With regard to this retardation film, the in-plane retardation satisfies the relation of Re(450)<Re(550), and the heating TMA for 3 cycles was repeated in the step of heating from 30°C to Tg-25°C and then cooling to 30°C again. In the test, the shrinkage rate in the direction of the slow axis is 0.1% or less, 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 in the slow axis direction was 0.2% or less. In one Embodiment, the said retardation film is formed from the resin chosen from polycarbonate resin and polyester carbonate resin. In one Embodiment, Re(450)/Re(550) of the said 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 polarizer is provided. The circularly polarizing plate has a retardation layer including the 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°˜55°. In one embodiment, the circularly polarizing plate is in a single-piece shape, and the in-plane retardation value of the center portion of the retardation layer is R _A0 , the in-plane retardation value of the vertex portion is R _B0 , and The in-plane retardation value of the center portion of the retardation layer after laminating glass on both sides and holding at 85°C for 240 hours is set as R _A1 , and the vertex after laminating glass on both sides and holding at 85°C for 240 hours will be The in-plane retardation value of the part is set to R _B1 , and the in-plane retardation value of the center part of the above-mentioned retardation layer after the glass is bonded on both sides and kept at 65°C/90% RH for 240 hours is set to be R _A2 , when the in-plane retardation value of the above-mentioned vertex part after the glass is bonded on both sides and kept at 65°C/90%RH for 240 hours is set as R _B2 , (R _A1 -R _B1 )-(R _A0 -R _B0 ) is 3 nm or less in absolute value, and the absolute value of (R _A2 -R _B2 ) - (R _A0 -R _B0 ) is 3 nm or less. In one embodiment, the circularly polarizing plate includes a protective film, the retardation layer, the polarizer, and another retardation layer in which the refractive index ellipsoid has a relationship of nz>nx=ny in this order. [Effect of the Invention] According to the manufacturing 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 humidification TMA test is 0.7%. The following heat treatment step of heating the stretched film at a temperature of 105° C. or more for 2 minutes or more can obtain a retardation film in which the change in the retardation value under a high temperature and high humidity environment is suppressed.

(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. (Definition 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 the largest (that is, the direction of the retardation axis), and "ny" is the in-plane positive with the retardation axis The refractive index in the intersecting direction (ie, the direction of the advance 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 with light having 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 with light with a wavelength of λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured with light having 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 for the manufacture of retardation films exhibiting wavelength dependence of so-called reverse dispersion, in which the in-plane retardation satisfies the relation 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 in which the above stretched film was heated from 30°C to Tg-25°C and then cooled to 30°C for 3 cycles, the shrinkage in the slow axis direction was 0.4% or less, or the environment was 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 in the slow axis direction is less than 0.7%. Let the heating temperature in the heat treatment step be T ₁ (° C.), the heating time in the heat treatment step be t ₁ (min), and the shrinkage rate of the stretched film before the heat treatment step in the heating TMA test is set to When A ₁ is used, 10×t ₁ /{(Tg−T ₁ ) ² ×A ₁ ² }>2 is preferably satisfied. When the shrinkage ratio in the humidification TMA test of the stretched film before the heat treatment step is A ₂ , 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. The shrinkage of the above stretched film in the direction of the slow axis in the humidification 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 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 in the humidification TMA test of the stretched film before the warm water treatment step 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 be insufficient, and as a result, the retardation value may change in a high-temperature and high-humidity environment. In contrast, according to the manufacturing method of the present invention, a retardation film having high durability and a small dimensional change rate (shrinkage rate) under a high temperature and high humidity environment can be obtained independently of the material constituting the retardation film. Such a retardation film can suppress the change of the retardation value in a high temperature and high humidity environment. A-1. Stretched film As described above, in the heating TMA test in which the stretched film was heated from 30°C to Tg-25°C and then cooled to 30°C for 3 cycles, the shrinkage in the slow axis direction was 0.4% or less, or in the humidification 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 direction of the slow phase axis The shrinkage rate is below 0.7%. Typically, a stretched film is produced by stretching a resin film in at least one direction. The resin film may be 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 the stretching treatment. As resin which forms a resin film, a polycarbonate resin, a polyvinyl acetal resin, a cellulose ester resin, a polyester resin, and a polyester carbonate resin are mentioned, for example. These resins can be used alone or in combination according to the desired properties. Arbitrary appropriate polycarbonate-type resin is used as said polycarbonate-type resin. For example, a polycarbonate resin containing a structural unit derived from a dihydroxy compound is preferable. Specific examples of the dihydroxy compound include 9,9-bis(4-hydroxyphenyl) fluoride, 9,9-bis(4-hydroxy-3-methylphenyl) fluoride, 9,9-bis( 4-Hydroxy-3-ethylphenyl) fluoride, 9,9-bis(4-hydroxy-3-n-propylphenyl) fluoride, 9,9-bis(4-hydroxy-3-isopropylphenyl) ) fluoride, 9,9-bis(4-hydroxy-3-n-butylphenyl) fluoride, 9,9-bis(4-hydroxy-3-2-butylphenyl) fluoride, 9,9-bis( 4-Hydroxy-3-tert-butylphenyl) stilbene, 9,9-bis(4-hydroxy-3-cyclohexylphenyl) stilbene, 9,9-bis(4-hydroxy-3-phenylphenyl) ) fluoride, 9,9-bis(4-(2-hydroxyethoxy) phenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl) benzene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylbenzene) base) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3 -Cyclohexylphenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy) -3,5-Dimethylphenyl) fluoride, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl) fluoride, 9,9- Bis(4-(3-Hydroxy-2,2-dimethylpropoxy)phenyl)pyrene and the like. In addition to the structural units derived from the above-mentioned dihydroxy compounds, the polycarbonate resin may also contain ingredients derived from isosorbide, isomannitol, isoiditol, spiroglycol, diethylene glycol, diethylene glycol, Structural units of dihydroxy compounds such as triethylene glycol, polyethylene glycol, and bisphenols. The details of the polycarbonate resin described above are described in, for example, Japanese Patent Laid-Open No. 2012-67300, Japanese Patent No. 3325560, and WO2014/061677. The description of this patent document is incorporated in this specification as a reference. The glass transition temperature (Tg) of the polycarbonate resin is preferably 110°C or higher and 250°C or lower, more preferably 120°C or higher and 230°C or lower. When the glass transition temperature is too low, the heat resistance tends to be deteriorated, and there is a possibility that a dimensional change occurs after the film is formed. 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, the glass transition temperature is calculated|required based on JISK7121 (1987). As a method for forming the above-mentioned resin film, any appropriate method can be adopted. For example, melt extrusion method (for example, T-die molding method), casting method (for example, casting method), calender molding method, hot pressing method, co-extrusion method, co-melting method, multilayer extrusion method, Inflation molding, etc. Preferably, a T-die molding method, a casting method, and an inflation molding method are used. The thickness of the resin film (unstretched film) can be set to any appropriate value according to required optical properties, the following stretching conditions, and the like. It is preferably 50 μm to 300 μm, more preferably 80 μm to 250 μm. As long as the above-described stretched film can be obtained, any appropriate stretching direction and stretching conditions (for example, stretching temperature, stretching ratio, stretching direction) can be adopted for the above-described stretching. Specifically, various extension methods such as free-end extension, fixed-end extension-free-end shrinkage, and fixed-end shrinkage can be used alone, or these extension 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 in the range of the glass transition temperature (Tg) of the resin film ±20°C. A retardation film having desired optical properties (eg, refractive index ellipsoid, in-plane retardation, Nz coefficient) can be finally obtained by appropriately selecting the above-mentioned stretching method and stretching conditions. In one embodiment, the stretched film is produced by uniaxially stretching a resin film or by uniaxially stretching a fixed end. As a specific example of uniaxial stretching, a method of extending the resin film in the longitudinal direction (longitudinal direction) is mentioned while running the resin film in the longitudinal direction. The stretching ratio is preferably 10% to 500%. In another embodiment, the stretched film is produced by continuously extending the elongated resin film obliquely in the direction whose angle is θ with respect to the elongated direction. By adopting the oblique stretching, an elongated stretched film having an alignment angle of θ relative to the longitudinal direction of the film can be obtained. For example, when laminating with a polarizer, roll-to-roll can be performed, thereby simplifying the manufacturing process. As a stretching machine for oblique stretching, for example, a tenter-type stretching machine which can add a feed force, a stretching force, or a pulling force at different speeds on the left and right to the transverse direction and/or the longitudinal direction is exemplified. The tenter-type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, and any appropriate stretching machine can be used as long as the elongated resin film can be continuously stretched obliquely. As a method of obliquely extending, 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 can be mentioned. The method described in the gazette, Japanese Patent Laid-Open No. 2002-86554, Japanese Patent Laid-Open No. 2002-22944, and the like. The thickness of the stretched film is preferably 20 μm to 100 μm, more preferably 30 μm to 80 μm. As a stretched film, a commercially available film may be used as it is, or a commercially available film may be subjected to secondary processing (eg, stretching treatment, surface treatment) according to the purpose and used. As a specific example of a commercially available film, the brand name "PURE-ACE RM" by Teijin Corporation is mentioned. In one embodiment, a relaxation treatment is performed on the stretched film. Thereby, the stress caused by elongation can be alleviated, and the shrinkage rate in the slow axis direction in the above-mentioned heating TMA test can be made to be 0.4% or less, or the shrinkage rate in the slow axis direction in the above-mentioned humidification TMA test can be made 0.7. %the following. Arbitrary appropriate conditions can be employ|adopted as relaxation processing 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 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 more 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 used to heat the TMA. When the shrinkage ratio 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 more than 2 and less than 150, more preferably 3-50, still more preferably 3-10. Furthermore, (Tg-T ₁ ) is preferably 5 or more. In another embodiment, when the shrinkage ratio in the humidified TMA test of the stretched film before the heat treatment step is A ₂ , it is preferably 10×t ₁ /{(Tg−T ₁ ) ² ×A ₂ ² } represents a value greater than 0.9. The above-mentioned value is preferably 1-60, more preferably 1-20, particularly preferably 1-10. The heating temperature is preferably 105°C to 140°C, more preferably 110°C to 130°C, and particularly preferably 115°C to 125°C. The heating time is preferably 2 minutes to 150 minutes, more preferably 3 minutes to 120 minutes, and particularly preferably 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 above-mentioned heating mechanism is an oven. When a stretched film is obtained by extending a long resin film while moving in the long direction, the obtained stretched film may be moved while maintaining this state, and heat treatment may be performed. 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 in the humidification TMA test of the stretched film before the warm water treatment step 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 more than 20 and 1000 or less, more preferably 25-500, still more preferably 30-150. The temperature of the warm water is preferably 60°C to 90°C, more preferably 65°C to 85°C, particularly preferably 68°C to 82°C. The immersion time is preferably 3 minutes to 60 minutes, more preferably 3 minutes to 30 minutes, and particularly preferably 5 minutes to 20 minutes. In the warm water treatment step, as long as the stretched film can be heated under the above heating conditions, any appropriate warm water treatment mechanism can be used. Typically, the above-mentioned warm water treatment mechanism is a warm water bath adjusted to an appropriate temperature. When a stretched film is obtained by extending the long resin film while moving in the long direction, the obtained stretched film may be moved while keeping this state, and the warm water treatment may be performed. B. Retardation Film The retardation film of the present invention is a retardation film that exhibits wavelength dependence of so-called reverse dispersion, in which the in-plane retardation satisfies the relation of Re(450)<Re(550). In the heating TMA test in which the above retardation film was heated from 30°C to Tg-25°C and then cooled to 30°C for 3 cycles, the shrinkage rate in the direction of the retardation axis was 0.1% or less. In the humidified TMA test in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, and 85°C/2%RH, the shrinkage in the slow axis direction is less than 0.2%. The shrinkage rate in the slow axis direction in the above-mentioned heating TMA test is preferably 0% to 0.08%, more preferably 0% to 0.05%. The shrinkage rate in the slow axis direction in the above-mentioned humidification TMA test is preferably 0% to 0.15%, more preferably 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 0.8 to 0.9, more preferably 0.83 to 0.87. The in-plane retardation Re(550) of the retardation film is preferably 100 nm to 180 nm, more preferably 135 nm to 155 nm. The photoelastic coefficient of the retardation film is preferably 1×10 ^-12 (m ² /N)～40×10 ^-12 (m ² /N), more preferably 1×10 ^-12 (m ² /N)～30 ×10 ^-12 (m ² /N), particularly preferably 1 × 10 ^-12 (m ² /N) to 20 × 10 ^-12 (m ² /N). The above retardation film can be obtained by, for example, the manufacturing method described in the item A. The retardation film can be used for circularly polarizing plates. C. Circularly polarizing plate The circularly polarizing plate of this invention has the retardation layer which consists of the said 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°, particularly preferably 43-47°, and most preferably about 45°. FIG. 1 is a schematic cross-sectional view of a circularly polarizing plate according to an embodiment of the present invention. The circularly 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 polarizer 100 is a single piece. The retardation unevenness (heating retardation unevenness) of the retardation layer 30 when the circularly polarizing plate 100 is heated is 3 nm or less. Furthermore, the retardation unevenness (humidification retardation unevenness) of the retardation layer 30 when the circularly polarizing plate 100 is humidified is 3 nm or less. The uneven heating phase difference and the uneven humidifying phase difference are preferably 0 nm to 2 nm, more preferably 0 nm to 1 nm. The above-mentioned 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 surfaces of the circular polarizing plate 100 and heated (retained at 85° C. for 240 hours). (R _A1 −R _B1 )−(R _A0 −R _B0 ) Here, R _A0 is the in-plane retardation value of the center portion of the retardation layer 30 , and R _B0 is the in-plane retardation value of the vertex portion of the retardation layer 30 . R _A1 is the in-plane retardation value of the center portion of the retardation layer 30 after the heating, and R _B1 is the in-plane retardation value of the vertex portion after the heating. The above-mentioned humidification retardation unevenness can be used as the absolute value of the value calculated by the following formula when, for example, glass is laminated on both sides of the circular polarizing plate 100 and humidified (kept at 65°C/90%RH for 240 hours). And decide. (R _A2 −R _B2 )−(R _A0 −R _B0 ) Here, R _A2 is the in-plane retardation value of the central portion of the retardation layer 30 after the humidification, and R _B2 is the vertex after the humidification. The in-plane phase difference value of the part. When the conventional circular polarizing plate is used in an image display device with glass or the like on both sides, the central part of the retardation layer is not easily affected by the high temperature and high humidity environment, while the ends of the retardation layer are Influence of high temperature and high humidity environment. As a result, the variation of the in-plane retardation value at the center portion of the retardation layer is small, and the variation of the in-plane retardation value at the end portion of the retardation layer is large, and there is a possibility that the retardation is uneven. On the other hand, in the circularly polarizing plate of the present invention, by including the retardation film in the retardation layer, the variation of the in-plane retardation at the end portion of the retardation layer can be suppressed, and the uneven retardation can be suppressed. C-1. Polarizing element As the polarizing element, any suitable polarizing element 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 polarizers comprising a single-layer resin film include polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films with high hydrophilicity. Molecular films are dyed and stretched with dichroic substances such as iodine or dichroic dyes, polyene-based alignment films such as PVA dehydration products or polyvinyl chloride dehydrochlorination products. From the viewpoint of being excellent in optical properties, it is preferable to use a polarizing element obtained by dyeing a PVA-based film with iodine and uniaxially extending it. The above-mentioned dyeing with iodine is performed, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment, or may be carried out while dyeing. Moreover, you may dye|stain after extending|stretching. The PVA-based film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment, and the like as necessary. For example, by immersing the PVA film in water and washing it before dyeing, not only the dirt and anti-blocking agent on the surface of the PVA film can be removed, but also the PVA film can be swelled to prevent uneven dyeing. Specific examples of the polarizing element obtained by using the laminate include a laminate using a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and coating A polarizing element obtained by a laminate of PVA-based resin layers of the resin substrate. A polarizing element obtained by using a laminate of a resin substrate and coating a PVA-based resin layer formed on the resin substrate can be produced, for example, by the following steps: apply a PVA-based resin solution to the resin substrate and dry it Then, 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 extended and dyed to form the PVA-based resin layer into a polarizing element. In the present embodiment, the stretching typically includes a step of immersing the layered body in an aqueous solution of boric acid and stretching it. Further, the stretching may further include, if necessary, a step of conducting the air-stretching of the laminated body at a high temperature (eg, 95° C. or higher) before conducting the stretching in the boric acid aqueous solution. The obtained laminate of resin substrate/polarizing element can be used directly (that is, the resin substrate can be used as a protective layer of the polarizing element), or the resin substrate can be peeled off from the laminate of resin substrate/polarizing element, and In the peeling area layer, an arbitrary appropriate protective layer is used according to the purpose. The details of the manufacturing method of such a polarizing element are described in Unexamined-Japanese-Patent No. 2012-73580, for example. The entire description of this gazette is incorporated herein by reference. The thickness of the polarizing element is, for example, 1 μm to 80 μm. In one embodiment, the thickness of the polarizing element is preferably 1 μm to 15 μm, more preferably 3 μm to 10 μm, and particularly preferably 3 μm to 8 μm. When the thickness of the polarizing element is in such a range, curling during heating can be suppressed favorably, 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 a relationship of nz>nx=ny, and can function as a so-called anode C plate. The circularly polarizing plate which has such a 2nd retardation layer can suppress the change of the reflectance and reflection hue when it is used for an organic EL panel. 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 Preferably -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 may include a liquid crystal material fixed to a vertical alignment. The liquid crystal material (liquid crystal compound) that can be vertically aligned can be either a liquid crystal monomer or a liquid crystal polymer. As a specific example of the formation method of this liquid crystal compound and this 2nd retardation layer, the formation method of the liquid crystal compound and retardation film described in Unexamined-Japanese-Patent No. 2002-333642 [0020] - [0028] is mentioned. In this case, the thickness of the second retardation layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm, and still more preferably 0.5 μm to 5 μm. As another preferred specific example, the second retardation layer may include a retardation film formed of a fumaric acid diester resin described in Japanese Patent Laid-Open No. 2012-32784. In this case, the thickness is preferably 5 μm to 80 μm, more preferably 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 the polarizer. 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, polyether, polyether, polystyrene, polynorene, polyolefin, (meth)acrylic, acetate and other transparent resins. Moreover, thermosetting resins, such as (meth)acrylic type, urethane type, (meth)acrylate urethane type, epoxy type, silicone type, etc., or ultraviolet-curable resin can also be mentioned. Wait. In addition, glass-type polymers, such as a siloxane-type polymer, can also be 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 containing 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 the side chain can be used As the material, for example, a resin composition having an alternating copolymer containing isobutylene and N-methylmaleimide, and an acrylonitrile-styrene copolymer can be mentioned. The polymer film may be, for example, an extruded product of the above-mentioned resin composition. The thickness of the protective film is preferably 10 μm to 100 μm. The protective film may be laminated on the polarizing element via an adhesive layer (specifically, an adhesive layer and 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 suitable adhesive. As an adhesive agent, the water-soluble adhesive agent which has a polyvinyl alcohol-type resin as a main component is mentioned, for example. It is preferable that 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 the mutual repulsion of the same charge of the fine particles. The average particle diameter 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. Preferably it is 1 nm - 100 nm, More preferably, it is 1 nm - 50 nm. This is because the fine particles can be uniformly dispersed in the adhesive layer, the adhesiveness can be ensured, and cracks can be suppressed. Furthermore, "crack point" refers to a local unevenness defect generated at the interface between the polarizing element and the protective film. The adhesive layer contains any suitable adhesive. Surface treatments such as hard coating treatment, anti-reflection treatment, anti-stick treatment, and anti-glare treatment can also be applied to the surface of the protective film on the opposite side of 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, and still more preferably 5 μm to 150 μm. [Examples] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. In addition, unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight. (1) Thickness was measured using a dial gauge (manufactured by PEACOCK, product name "DG-205 type pds-2"). (2) The phase difference value was measured using Axoscan manufactured by Axometrics. (3) Dimensional change rate due to heating (heating TMA test) The stretched films or retardation films obtained in Examples and Comparative Examples were cut into 20 mm (slow axis direction)×4 mm (advanced axis direction) direction) to prepare a measurement sample. Using a thermomechanical analyzer (manufactured by Hitachi High-Tech Science, model "TMA7100"), the step of heating the measurement sample from 30°C to Tg-25°C and then cooling to 30°C was repeated for 3 cycles. The dimensional change rate (shrinkage rate) in the longitudinal direction (slow axis direction) of the sample was measured. In addition, the temperature increase rate was made into 5 degreeC/min, and the holding time in each temperature was made into 10 minutes. (4) Dimensional change rate due to humidification (humidification TMA test) The stretched films or retardation films obtained in Examples and Comparative Examples were cut into 20 mm (in the direction of the slow axis) × 5 mm (in the direction of the slow axis) phase axis direction) to prepare a measurement sample. Use a thermomechanical analyzer to change the environment in the order of 25°C/25%RH, 85°C/2%RH, 85°C/85%RH, and 85°C/2%RH, and then measure the length direction (latency phase) of the sample. The dimensional change rate (shrinkage rate) in the axial direction) was 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) Uneven heating retardation The circularly polarizing plates obtained in the Examples and Comparative Examples were cut into 75 mm×150 mm so that the absorption axis of the polarizing element became the short side direction, and the glass substrates were attached to each other through an adhesive. On both sides of the circular polarizing plate, a measurement sample was made. For the measurement sample, the in-plane retardation value R _A0 at the center portion, the in-plane retardation value R _B01 between the center portion and the vertex portion located in the slow axis direction, and the plane from the center portion to the vertex portion located in the advance axis direction are measured. Internal phase difference value R _B02 . Next, the measurement sample was heated in an oven at 85° C. for 240 hours, and for the measurement sample after heating, the in-plane retardation value R _A1 in the central part and the in-plane retardation between the central part and the vertex part located in the slow axis direction were measured. The value R _B11 , and the in-plane phase difference value R _B12 from the center portion to the vertex portion located in the direction of the advance axis. The larger value among the absolute values of the values A and B obtained by the following equations was used 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 unevenness is the same as (5) above A measurement sample of the circularly polarizing plate was produced, and the in-plane retardation value R _A0 in the central part, the in-plane retardation value R B01 from the central part to the vertex part located in the direction of the retardation axis, and the in-plane retardation value R _B01 from the central part to the direction of the advanced phase axis were measured. The in-plane phase difference value R _B02 of the vertex portion of . Then, the measurement sample was humidified in an oven at 65°C/90% for 240 hours. For the measurement sample after humidification, the in-plane retardation value R _A2 in the central part was measured, and the central part to the vertex located in the direction of the slow axis was measured. The in-plane phase difference value R _B21 , and the in-plane phase difference value R _B22 from the center portion to the vertex portion located in the direction of the advance axis. The larger value among the absolute values of the values C and D obtained by the following equation was used 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) The polymerization was carried out using a batch polymerization apparatus comprising two vertical reactors equipped with stirring blades and a reflux cooler controlled at 100°C. 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)perpen-9-yl]methane, 29.21 parts by mass (0.200 mol) of ISB (Isosorbide), and 29.21 parts by mass (0.200 mol) of SPG (Spiroglycol) were added. , spiroglycol) 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 reached 100°C. 40 minutes after the start of the temperature increase, the internal temperature was controlled to reach 220°C, and the pressure was reduced while maintaining the temperature. After reaching 220°C, the temperature was adjusted to 13.3 kPa over 90 minutes. The phenol vapor produced by the polymerization reaction is introduced into a reflux cooler at 100°C, so that a certain amount of monomer components contained in the phenol vapor is returned to the reactor, and the uncondensed phenol vapor is introduced into a condenser at 45°C for recovery. . After introducing nitrogen gas into the first reactor, the pressure was temporarily restored to atmospheric pressure, and then the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was 240° C. and the pressure was 0.2 kPa over 50 minutes. Thereafter, polymerization is performed until a specific stirring power is obtained. When a specific power is reached, nitrogen gas is introduced into the reactor for repressurization, the resulting polyester carbonate 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, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C) and a T-die (width 200 mm) were used. , set temperature: 250 ℃), cooling roll (set temperature: 120 ~ 130 ℃) and film forming device of the winder, to produce a resin film with a thickness of 135 μm. (Retardation Film) The obtained elongated resin film was stretched at a stretching temperature of 134° C. and a stretching ratio of 2.8 times in the width direction, and then, the stretched film was subjected to a relaxation treatment in the width direction, thereby producing 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%. This stretched film was subjected to the humidification TMA test of the above (4), and as a result, the dimensional change rate was 0.30%. In addition, when this stretched film was subjected to the heating TMA test of the above (3), the dimensional change rate was 0.05%. Next, by heating (heating) the said stretched film at 125 degreeC for 2 minutes, the retardation film of thickness 48 micrometers was obtained. 2. Fabrication of circular polarizing plate (polarizing element) Prepare a long strip of amorphous polyethylene terephthalate (A-PET) film (manufactured by Mitsubishi Plastics, 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") was 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 layered body obtained in this way was immersed in an insolubilization bath having a liquid temperature of 30° C. for 30 seconds (insolubilization step). Next, it was immersed in the dyeing bath of the liquid temperature of 30 degreeC for 60 second (dyeing process). Next, it was immersed for 30 seconds in a crosslinking bath having a liquid temperature of 30°C (crosslinking step). Then, uniaxially extending in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds while immersing the layered body in an aqueous solution of boric acid having a liquid temperature of 60°C. The time of immersion in the boric acid aqueous solution was 120 seconds, and it extended until just before fracture of the laminated body. After that, the layered body was immersed in a washing bath, and then dried with warm air at 60°C (washing and drying step). In this way, an elongated laminate (polarizer laminate) in which a polarizing element having a thickness of 5 μm was formed on the substrate was obtained. (Polarizing plate) A cycloolefin-based resin film (manufactured by Zeon Corporation, Japan, trade name "ZEONOR FILM", thickness 25 μm) as a protective film was attached to the polarizer side surface of the above-mentioned laminate through an adhesive. And the said base material was peeled from a polarizing element, and the polarizing plate was obtained by this. (Second retardation layer) 20 parts by weight of a side chain type liquid crystal polymer represented by the following chemical formula (I) and 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Paliocolor LC242) and 5 parts by weight of a photopolymerization initiator (manufactured by BASF: Irgacure 907, trade name) was dissolved in 400 parts by weight of cyclopentanone to prepare a liquid crystal coating liquid. Then, the coating liquid was applied to a base film (nor-alkene-based resin film: manufactured by Nippon Zeon Corporation, trade name "ZEONOR") by 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 cure the liquid crystal layer, thereby forming a liquid crystal cured layer (thickness: 1 μm) serving as a retardation film on the substrate. The Re(550) of this layer was 0 nm and the Rth(550) was -71 nm (nx: 1.5326, ny: 1.5326, nz: 1.6550). [hua 1]

(Circular polarizing plate) The above-mentioned retardation film was bonded to the polarizing element side of the above-mentioned 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, the said liquid crystal cured layer was transcribe|transferred to the surface opposite to the polarizing element of the retardation film, and the circular polarizing plate with the structure of protective layer/polarizing element/retardation layer/second retardation layer was produced. <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 the circular 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 the circular 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 the circular 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 the circular polarizing plate. <Example 6> Except having made the relaxation temperature 110 degreeC, it carried out similarly to Example 1, and produced the stretched film. This stretched film was subjected to the humidification TMA test of the above (4), and as a result, the dimensional change rate was 0.50%. In addition, when this stretched film was subjected to the heating TMA test of the above (3), the dimensional change rate was 0.08%. A retardation film and a circularly polarizing plate were produced in the same manner as in Example 2, except that the stretched film was used. <Example 7> Except having made the relaxation temperature 80 degreeC, it carried out similarly to Example 1, and produced the stretched film. This stretched film was subjected to the humidification TMA test of the above (4), and as a result, the dimensional change rate was 0.70%. In addition, when this stretched film was subjected to the heating TMA test of the above (3), the dimensional change rate was 0.13%. A retardation film and a circularly polarizing plate were produced in the same manner as in Example 2, except that the stretched film was used. <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 the circular 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 the circular 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 the 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 the 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 the circular polarizing plate. <Example 13> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the stretched film was immersed in warm water at 60° C. for 3 minutes (warm water treatment) instead of the above-mentioned heat treatment. <Example 14> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the stretched film was immersed in warm water at 60° C. for 10 minutes instead of the above-mentioned heat treatment. <Example 15> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the stretched film was immersed in warm water at 60° C. for 30 minutes instead of the above-mentioned heat treatment. <Example 16> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the stretched film was immersed in warm water at 60° C. for 60 minutes instead of the above-mentioned heat treatment. <Example 17> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 6, except that the stretched film was immersed in warm water at 60° C. for 10 minutes instead of the above-mentioned heat treatment. <Example 18> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 7, except that the stretched film was immersed in warm water at 60° C. for 10 minutes instead of the above-mentioned heat treatment. <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. This stretched film was subjected to the heating TMA test of (3) above, and as a result, the dimensional change rate was 0.22%. In addition, when this stretched film was subjected to the humidification TMA test of the above (4), the dimensional change rate was 0.10%. Next, the said stretched film was heated (heat-processing) for 2 minutes at 125 degreeC, and the retardation film was obtained by this. Furthermore, except having used the said retardation film, it carried out similarly to Example 1, and produced the circularly 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 the 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 the circular 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 the circular 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 the circularly 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 the circular 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 retardation film and the circular 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 the circular 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 retardation film and the circular 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 the circular 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 the circular polarizing plate. <Comparative Example 3> A stretched film was produced in the same manner as in Example 1, except that the relaxation temperature was set to 80° C. and the relaxation rate was set to 0%. This stretched film was subjected to the humidification TMA test of the above (4), and as a result, the dimensional change rate was 0.90%. In addition, when this stretched film was subjected to the heating TMA test of the above (3), the dimensional change rate was 0.18%. A retardation film and a circularly polarizing plate were produced in the same manner as in Example 2, except that the stretched film was used. <Comparative Example 4> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the stretched film was immersed in warm water at 60° C. for 1 minute instead of the above-mentioned heat treatment. <Comparative Example 5> A retardation film and a circularly polarizing plate were produced in the same manner as in Comparative Example 3, except that the stretched film was immersed in warm water at 60° C. for 10 minutes instead of the above-mentioned heat treatment. <Comparative Example 6> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 1, except that the heat treatment was not performed. <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 the circular 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 the circular polarizing plate. <Comparative Example 9> A retardation film and a circularly polarizing plate were produced in the same manner as in Example 19, except that the heat treatment was not performed. <Evaluation> About 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, T ₁ is the heating temperature (° C.) in the heat treatment step, t ₁ is the heating time (min) in the heat treatment step, and A ₁ is the heating time of the stretched film before the heat treatment step. For the shrinkage ratio (%) in the TMA test, A2 is set as the shrinkage ratio (% ₎ in the humidification TMA test of the stretched film before the heat treatment step. Regarding Examples 13 to 18 and Comparative Examples 4 to 5, t ₂ /A ₃ ² was calculated as an index of the warm water treatment conditions. Here, t ₂ is the immersion time (min) in the warm water treatment step, and A ₃ is the shrinkage rate (%) in the humidification TMA test of the stretched film before the warm water treatment step. The retardation films of Examples 1 to 27 and Comparative Examples 1 to 9 were subjected to the humidification TMA test and the heating TMA test, and the dimensional change rate obtained by each test was measured. Furthermore, about Examples 1-27 and Comparative Examples 1-9, the humidification phase difference unevenness and the heating phase difference unevenness were measured. The respective results are shown in Table 1. [Table 1] retardation film Processing conditions Dimensional change rate (%) Uneven phase difference (nm) Heated TMA test Humidification TMA test type temperature(℃) time (minutes) index Before processing After processing Before processing After processing 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 It can be seen from Table 1 that the dimensional change rate in the TMA test after heat treatment or warm water treatment of the retardation films of the examples is smaller than that of the retardation films of the comparative examples. The unevenness is also small. [Industrial Applicability] The retardation film of the present invention can be preferably used for a circularly polarizing plate, and the circularly 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: 2nd retardation layer 100: Circular polarizer

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

10: Protective layer

20: Polarizing element

30: retardation layer

40: 2nd retardation layer

100: Circular polarizer

Claims (8)

A retardation film whose in-plane retardation satisfies the relation of Re(450)<Re(550), In the heating TMA test in which the step of heating from 30°C to Tg-25°C and then cooling to 30°C was repeated for 3 cycles, the shrinkage in the slow axis direction was 0.1% or less, and In the humidification 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 0.2 %the following, Here, Re(450) and Re(550) represent the in-plane retardation measured with light with wavelengths of 450 nm and 550 nm, respectively, at 23°C. The retardation film according to claim 1, which is formed of a resin selected from polycarbonate resins and polyester carbonate-based resins. As in the retardation film of claim 1, its Re(450)/Re(550) is 0.8-0.9. As in the retardation film of claim 2, its Re(450)/Re(550) is 0.8-0.9. The retardation film according to any one of claims 1 to 4, which has a photoelastic coefficient of 1×10 ^-12 (m ² /N) to 40×10 ^-12 (m ² /N). A circularly polarizing plate having a retardation layer comprising the retardation film as claimed in any one of claims 1 to 5, and a polarizing element, The angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizer is 35° to 55°. For the circular polarizing plate of claim 6, which is a single piece, the in-plane retardation value of the central portion of the retardation layer is set as R _A0 , the in-plane retardation value of the vertex portion is set as R _B0 , and the The in-plane retardation value of the center portion of the retardation layer after laminating glass on both sides and holding at 85°C for 240 hours is set as R _A1 , and the vertex after laminating glass on both sides and holding at 85°C for 240 hours will be The in-plane retardation value of the part is set as R _B1 , and the in-plane retardation value of the central part of the above-mentioned retardation layer after the glass is bonded on both sides and kept at 65°C/90% RH for 240 hours is set as R _A2 , when the in-plane retardation value of the above-mentioned vertex portion after the glass is bonded on both sides and kept at 65°C/90%RH for 240 hours is set as R _B2 , (R _A1 -R _B1 )-(R _A0 -R _B0 ) is 3 nm or less in absolute value, and the absolute value of (R _A2 -R _B2 ) - (R _A0 -R _B0 ) is 3 nm or less. The circularly polarizing plate according to claim 6 or 7, comprising in this order a protective film, the retardation layer, the polarizing element, and another retardation layer whose refractive index ellipsoid has a relationship of nz>nx=ny.

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