TW202112922A

TW202112922A - Biaxially oriented polyester film and method of producing the same

Info

Publication number: TW202112922A
Application number: TW109101873A
Authority: TW
Inventors: 玉利昇; 後藤考道; 春田雅幸
Original assignee: 日商東洋紡股份有限公司
Priority date: 2019-08-06
Filing date: 2020-01-20
Publication date: 2021-04-01

Abstract

Provided is a biaxially oriented polyester film having good bag breaking resistance and excellent film forming properties. A biaxially oriented film comprising a polyester resin composition containing 75 to 100% by mass of the polybutylene terephthalate resin (A) and satisfying (1) to (3), (1) The piercing strength of the biaxially oriented polyester film measured by a piercing test according to JIS-Z1707 is 0.50 N / μm or more. (2) In the width direction of the biaxially oriented polyester film, sampling was performed at a position of 10 mm from the left and right ends toward the center, and the highest value among the measured densities measured according to JIS-K7112 was 1.40 g / cm³ or less. (3) Intrinsic viscosity of biaxially oriented polyester film is 0.7 dl / g or more.

Description

雙軸配向聚酯膜以及雙軸配向聚酯膜之製造方法Biaxially oriented polyester film and manufacturing method of biaxially oriented polyester film

本發明係關於一種雙軸配向聚酯膜以及雙軸配向聚酯膜之製造方法。The invention relates to a biaxially aligned polyester film and a method for manufacturing the biaxially aligned polyester film.

聚對苯二甲酸丁二酯(以下，將聚對苯二甲酸丁二酯簡稱為PBT)樹脂相較於聚對苯二甲酸乙二酯(以下，將聚對苯二甲酸乙二酯簡稱為PET)樹脂，耐衝擊性優異，故而於食品包裝用膜、真空隔熱材料之外裝材料、拉製成形用膜、罐的內袋用膜等領域中亦研究應用。Polybutylene terephthalate (hereinafter, polybutylene terephthalate is abbreviated as PBT) resin is compared to polyethylene terephthalate (hereinafter, polyethylene terephthalate is abbreviated as PBT) resin PET) resin has excellent impact resistance, so it has also been researched and applied in the fields of food packaging film, vacuum insulation material outer packaging material, stretch forming film, and can inner bag film.

例如，於專利文獻1中，揭示有藉由相對於PET樹脂將PBT樹脂設為40重量%至80重量%，將長度方向及寬度方向的拉伸彈性模數設為2.3GPa至3.5GPa，能夠較佳地用作罐的內袋用聚酯膜。For example, Patent Document 1 discloses that by setting the PBT resin to 40% by weight to 80% by weight relative to the PET resin, and setting the tensile modulus of elasticity in the longitudinal direction and the width direction to 2.3GPa to 3.5GPa, it is possible to It is preferably used as a polyester film for the inner bag of a can.

於專利文獻2中，揭示有一種由PBT樹脂所構成之雙軸延伸膜，該膜的4個方向(0°(長度方向)、45°、90°(寬度方向)、135°)的拉伸斷裂強度分別為215MPa以上、228MPa以上、240MPa以上及221MPa以上，且4個方向(0°(長度方向)、45°、90°(寬度方向)、135°)的拉伸斷裂強度中，最大值與最小值之比為1.12以下。另外，揭示有一種包裝材料，使用該雙軸延伸膜作為基材層，自外側起由基材層-氣體阻隔層-密封劑層之構成所構成。並且，揭示有藉由將該包裝材料於5℃×40%RH條件下彎曲1000次時的針孔數設為3個以下，能夠較佳地用作保香性優異之液體填充用包裝材料。Patent Document 2 discloses a biaxially stretched film composed of PBT resin, which stretches in 4 directions (0° (length direction), 45°, 90° (width direction), 135°) The breaking strength is 215 MPa or more, 228 MPa or more, 240 MPa or more and 221 MPa or more, and the maximum tensile breaking strength in 4 directions (0° (length direction), 45°, 90° (width direction), 135°) The ratio to the minimum value is 1.12 or less. In addition, a packaging material is disclosed that uses the biaxially stretched film as a base layer and is composed of a base layer, a gas barrier layer, and a sealant layer from the outside. Furthermore, it is disclosed that by setting the number of pinholes when the packaging material is bent 1000 times under the conditions of 5°C×40%RH to 3 or less, it can be preferably used as a packaging material for liquid filling with excellent fragrance retention.

於專利文獻3中，揭示有藉由PBT樹脂為60質量%以上，且長度方向及寬度方向的降伏應力設為70MPa以上、斷裂強度設為160MPa以上、斷裂伸長率設為100%以上，能夠較佳地用於尼龍膜或其他柔軟膜用途。 [先前技術文獻] [專利文獻]In Patent Document 3, it is disclosed that the PBT resin is 60% by mass or more, the yield stress in the longitudinal and width directions is 70 MPa or more, the breaking strength is 160 MPa or more, and the elongation at break is 100% or more. Ideally used for nylon film or other soft film applications. [Prior Technical Literature] [Patent Literature]

[專利文獻1]日本專利第6195765號公報。 [專利文獻2]日本專利第6347499號公報。 [專利文獻3]日本專利第5994864號公報。[Patent Document 1] Japanese Patent No. 6195765. [Patent Document 2] Japanese Patent No. 6347499. [Patent Document 3] Japanese Patent No. 5994864.

[發明所欲解決之課題][The problem to be solved by the invention]

PBT樹脂由於結晶化速度快，故而於澆鑄時亦進行結晶化。尤其是，進行澆鑄而獲得之膜的端部因製造上的理由而存在與中央部相比變厚之傾向。因此，於進行澆鑄而獲得之膜的端部，結晶化變得更顯著。於上述之專利文獻1、3中，於澆鑄時進行了利用冷卻輥之急冷處理，但於膜中央部與端部為相同的冷卻條件，因此厚度厚之端部與中央部相比成為緩冷狀態，進一步進行結晶化。因此，推測於後續的延伸步驟中，端部的延伸應力變大，容易導致斷裂。另外，於專利文獻2中，由於冷卻水為20℃之相對較高溫，故而推測冷卻不充分而進行結晶化，推測於後續的延伸步驟中，延伸應力變大而容易導致斷裂。Since PBT resin has a fast crystallization rate, it also undergoes crystallization during casting. In particular, the end portion of the film obtained by casting tends to be thicker than the center portion due to manufacturing reasons. Therefore, the crystallization becomes more remarkable at the end of the film obtained by casting. In the above-mentioned Patent Documents 1 and 3, the rapid cooling process using cooling rolls is performed during casting, but the cooling conditions are the same at the center and the ends of the film, so the thicker ends are slowly cooled compared to the center. State, further crystallization. Therefore, it is inferred that in the subsequent extension step, the extension stress at the end portion becomes larger, which is likely to cause breakage. In addition, in Patent Document 2, since the cooling water has a relatively high temperature of 20°C, it is presumed that the cooling is insufficient and the crystallization proceeds, and it is presumed that in the subsequent elongation step, the elongation stress becomes large and the fracture is likely to be caused.

本發明係鑒於上述課題而完成。亦即，本發明的目的在於提供一種具有良好的耐破袋性且製膜性優異之雙軸配向聚酯膜。另外，本發明的目的在於提供一種雙軸配向聚酯膜之製造方法，能夠獲得該雙軸配向聚酯膜。 [用以解決課題之手段]The present invention has been completed in view of the above-mentioned problems. That is, the object of the present invention is to provide a biaxially oriented polyester film having good bag breaking resistance and excellent film forming properties. In addition, the object of the present invention is to provide a method for manufacturing a biaxially oriented polyester film, which can be obtained. [Means to solve the problem]

本發明者等人對雙軸配向聚酯膜進行了努力研究。結果發現，藉由採用下述構成，能獲得具有良好的耐破袋性且製膜性優異之雙軸配向聚酯膜，從而完成了本發明。The inventors of the present invention conducted diligent research on the biaxially aligned polyester film. As a result, it was found that by adopting the following structure, a biaxially oriented polyester film having good bag breaking resistance and excellent film forming properties can be obtained, and the present invention has been completed.

亦即，本發明的雙軸配向聚酯膜的特徵在於：包含含有聚對苯二甲酸丁二酯樹脂(A)75質量%至100質量%之聚酯樹脂組成物，且滿足下述要件(1)至要件(3)。 (1)以依據JIS-Z1707之穿刺試驗所測定之雙軸配向聚酯膜的穿刺強度為0.50N/μm以上。 (2)於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別依據JIS-K7112所測定之密度中最高值為1.40g/cm³ 以下。 (3)雙軸配向聚酯膜的固有黏度為0.7dl/g以上。That is, the biaxially oriented polyester film of the present invention is characterized in that it contains a polyester resin composition containing 75% to 100% by mass of polybutylene terephthalate resin (A), and satisfies the following requirements ( 1) To essentials (3). (1) The puncture strength of the biaxially aligned polyester film measured by the puncture test in accordance with JIS-Z1707 is 0.50 N/μm or more. (2) In the width direction of the biaxially oriented polyester film, samples are taken from the left and right ends to the central part of 10 mm respectively, and the highest value of the density measured in accordance with JIS-K7112 is 1.40 g/cm ³ or less. (3) The inherent viscosity of the biaxially aligned polyester film is 0.7 dl/g or more.

根據前述構成，由於包含含有聚對苯二甲酸丁二酯樹脂(A)75質量%以上之聚酯樹脂組成物，故而能夠提高穿刺強度，能夠使耐破袋性良好。另外，由於前述穿刺強度為0.50N/μm以上，故而能夠使耐破袋性良好。另外，由於前述密度為1.4g/cm³ 以下，故而端部的結晶化得到抑制。結果，能夠抑制製造該雙軸配向聚酯膜時的延伸步驟中，於端部產生過度的應力，能夠使製膜性良好。另外，由於前述固有黏度為0.7dl/g以上，故而於將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥而獲得未延伸片時，能夠抑制未延伸片的結晶化，尤其能夠使厚度厚之端部的降伏應力不會變得過高。結果，能夠於延伸步驟中不易斷裂。According to the aforementioned configuration, since the polyester resin composition containing 75% by mass or more of the polybutylene terephthalate resin (A) is included, the puncture strength can be improved, and the bag breakage resistance can be improved. In addition, since the aforementioned puncture strength is 0.50 N/μm or more, it is possible to make the bag breakage resistance good. In addition, since the aforementioned density is 1.4 g/cm ³ or less, the crystallization of the ends is suppressed. As a result, it is possible to prevent excessive stress from being generated at the end portion in the stretching step when manufacturing the biaxially oriented polyester film, and it is possible to improve the film formability. In addition, since the aforementioned intrinsic viscosity is 0.7 dl/g or more, when the resin composition for the production of biaxially oriented polyester film is cast on a cooling roll to obtain an unstretched sheet, the crystallization of the unstretched sheet can be suppressed, especially The yield stress at the thick end will not become too high. As a result, it can be difficult to break during the stretching step.

此外，本發明的雙軸配向聚酯膜係假定製造後(澆鑄及延伸處理後)的膜、亦即未進行分切處理等之膜(銑輥狀態的膜)。但本發明的雙軸配向聚酯膜只要包含含有聚對苯二甲酸丁二酯樹脂(A)75質量%至100質量%之聚酯樹脂組成物，且滿足上述要件(1)至要件(3)，則膜的形態並無特別限定，例如亦包括藉由分切處理等而成為小輥之膜、以及單片之膜。In addition, the biaxially oriented polyester film of the present invention assumes a film after production (after casting and stretching treatment), that is, a film that has not been subjected to a slitting treatment or the like (a film in the state of a milling roll). However, the biaxially oriented polyester film of the present invention only needs to contain a polyester resin composition containing 75% to 100% by mass of the polybutylene terephthalate resin (A) and satisfy the above-mentioned requirements (1) to (3). ), the form of the film is not particularly limited. For example, it also includes a film made into a small roll by a slitting process, etc., and a single-piece film.

前述構成中，較佳為前述聚酯樹脂組成物含有聚對苯二甲酸丁二酯樹脂(A)以外的聚酯樹脂(B)。In the aforementioned configuration, the polyester resin composition preferably contains a polyester resin (B) other than the polybutylene terephthalate resin (A).

若前述聚酯樹脂組成物含有聚對苯二甲酸丁二酯樹脂(A)以外的聚酯樹脂(B)，則能夠調整進行雙軸延伸時的製膜性及所獲得之膜的力學特性。If the aforementioned polyester resin composition contains a polyester resin (B) other than the polybutylene terephthalate resin (A), it is possible to adjust the film formability during biaxial stretching and the mechanical properties of the obtained film.

前述構成中，較佳為於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別求出使用傅立葉轉換型紅外光譜法光譜強度中之全反射法所獲得之1450±10cm^-1 之峰值的吸收強度A與1410±10cm^-1 之峰值的吸收強度B之比A/B時，最高值為0.62以下。In the aforementioned configuration, it is preferable to sample a position of 10 mm from the left and right ends to the center in the width direction of the biaxially aligned polyester film, and obtain the total reflection in the spectral intensity using Fourier transform infrared spectroscopy. When the ratio A/B of the absorption intensity A at the peak of 1450±10cm ^-1 ^{and the absorption intensity B at the peak of 1410±10cm -1 obtained} by the method is A/B, the maximum value is 0.62 or less.

前述吸收強度A係源自PBT的α型結晶的亞甲基之吸收，前述吸收強度B係源自苯環的碳鍵之吸收，吸收強度比A/B的值表示配向係數，配向係數越小，表示結晶性越低，配向係數越高，表示結晶性越高。若前述比A/B的最高值為0.62以下，則結晶性不會變得過高，因此延伸時的應力得到抑制，變得不易斷裂。The aforementioned absorption strength A is derived from the absorption of the methylene group of the α-type crystal of PBT, and the aforementioned absorption strength B is derived from the absorption of the carbon bond of the benzene ring. The value of the absorption intensity ratio A/B represents the alignment coefficient, and the smaller the alignment coefficient , Indicates that the lower the crystallinity, the higher the alignment coefficient, the higher the crystallinity. If the maximum value of the aforementioned ratio A/B is 0.62 or less, the crystallinity does not become too high, so the stress during stretching is suppressed, and it becomes difficult to break.

前述構成中，較佳為雙軸配向聚酯膜的面配向度ΔP為0.145至0.160。In the foregoing configuration, it is preferable that the surface alignment degree ΔP of the biaxially oriented polyester film is 0.145 to 0.160.

若前述面配向度ΔP為0.145以上，則面配向適度高，穿刺強度變得充分，耐破袋性更優異。若前述面配向度ΔP為0.160以下，則能夠將熱收縮率維持得低，能夠使熱穩定性更良好。If the aforementioned degree of surface alignment ΔP is 0.145 or more, the surface alignment is moderately high, the puncture strength becomes sufficient, and the bag break resistance is more excellent. If the surface orientation degree ΔP is 0.160 or less, the thermal shrinkage rate can be maintained low, and the thermal stability can be improved.

另外，本發明的雙軸配向聚酯膜之製造方法的特徵在於具有：步驟A，係將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥而形成未延伸片；以及步驟B，係對前述冷卻輥上的前述未延伸片吹送風；並且前述步驟B係於將未延伸片全寬設為100%時，將吹送至中央之風的溫度設為X，將吹送至兩端部之溫度設為Y時，前述X為15℃以下，且前述Y為較前述X低之溫度；前述端部至少包含自端緣起10%以內的區域。In addition, the manufacturing method of the biaxially oriented polyester film of the present invention is characterized by having: step A, casting the resin composition for manufacturing the biaxially oriented polyester film on a cooling roll to form an unstretched sheet; and step B, The air is blown to the unstretched sheet on the cooling roll; and the foregoing step B is to set the temperature of the wind blown to the center as X when the full width of the unstretched sheet is set to 100%, and blow to the ends of the unstretched sheet. When the temperature is set to Y, the aforementioned X is 15° C. or less, and the aforementioned Y is a temperature lower than the aforementioned X; the aforementioned end includes at least a region within 10% from the end edge.

根據前述構成，對冷卻輥上的未延伸片吹送15℃以下之風，將未延伸片的B面(與接觸於冷卻輥之面為相反的面)進行急冷，藉此能夠減少結晶度，使製膜性良好。另外，多數情況下，未延伸片的端部的厚度較中央部厚。因此，藉由將端部(至少自端緣起10%以內的區域)較中央更強烈地進行急冷，能夠將端部的結晶化抑制為與中央部相當，使製膜性良好。According to the aforementioned structure, the unstretched sheet on the cooling roll is blown with a wind of 15°C or less, and the surface B of the unstretched sheet (the surface opposite to the surface contacting the cooling roll) is quenched, thereby reducing the crystallinity and making Good film forming properties. In addition, in many cases, the thickness of the end portion of the unstretched piece is thicker than the center portion. Therefore, by quenching the end portion (at least the region within 10% from the end edge) more intensely than the center portion, the crystallization of the end portion can be suppressed to be equivalent to the center portion, and the film forming properties can be improved.

前述構成中，較佳為前述Y為10℃以下。若前述Y為10℃以下，則未延伸片的B面端部的結晶度不會變得過高，製膜性變得更良好。 [發明功效]In the aforementioned configuration, it is preferable that the aforementioned Y is 10°C or less. If the aforementioned Y is 10°C or less, the crystallinity of the B surface end of the unstretched sheet will not become too high, and the film formability will become better. [Efficacy of invention]

根據本發明，能夠提供一種具有良好的耐破袋性且製膜性優異之雙軸配向聚酯膜。另外，能夠提供一種雙軸配向聚酯膜之製造方法，能夠獲得該雙軸配向聚酯膜。According to the present invention, it is possible to provide a biaxially oriented polyester film having good bag breaking resistance and excellent film forming properties. In addition, a method for manufacturing a biaxially aligned polyester film can be provided, and the biaxially aligned polyester film can be obtained.

以下，對本發明的實施形態進行說明。Hereinafter, an embodiment of the present invention will be described.

本實施形態的雙軸配向聚酯膜的特徵在於：包含含有聚對苯二甲酸丁二酯樹脂(A)75質量%至100質量%之聚酯樹脂組成物，且滿足下述要件(1)至要件(3)。 (1)以依據JIS-Z1707之穿刺試驗所測定之雙軸配向聚酯膜的穿刺強度為0.50N/μm以上。 (2)於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別依據JIS-K7112所測定之密度中最高值為1.40g/cm³ 以下。 (3)雙軸配向聚酯膜的固有黏度為0.7dl/g以上。The biaxially oriented polyester film of this embodiment is characterized in that it contains a polyester resin composition containing 75% to 100% by mass of polybutylene terephthalate resin (A), and satisfies the following requirements (1) To essentials (3). (1) The puncture strength of the biaxially aligned polyester film measured by the puncture test in accordance with JIS-Z1707 is 0.50 N/μm or more. (2) In the width direction of the biaxially oriented polyester film, samples are taken from the left and right ends to the central part of 10 mm respectively, and the highest value of the density measured in accordance with JIS-K7112 is 1.40 g/cm ³ or less. (3) The inherent viscosity of the biaxially aligned polyester film is 0.7 dl/g or more.

[雙軸配向聚酯膜的組成] 前述聚酯樹脂組成物係以PBT樹脂(A)作為主要構成成分，前述聚酯樹脂組成物中的PBT樹脂(A)的含有率為75質量%以上。較佳為85質量%以上，更佳為90質量%以上。藉由設為75質量%以上，能夠使穿刺強度充分，能夠提高耐破袋性。用作主要構成成分之PBT樹脂(A)中，作為二羧酸成分之對苯二甲酸較佳為90莫耳%以上，更佳為95莫耳%以上，進而較佳為98莫耳%以上，最佳為100莫耳%。作為二醇成分之1,4-丁二醇較佳為90莫耳%以上，更佳為95莫耳%以上。[Composition of biaxially aligned polyester film] The said polyester resin composition system has PBT resin (A) as a main component, and the content rate of the PBT resin (A) in the said polyester resin composition is 75 mass% or more. It is preferably 85% by mass or more, and more preferably 90% by mass or more. By setting it to 75% by mass or more, the puncture strength can be made sufficient, and the bag breaking resistance can be improved. In the PBT resin (A) used as the main constituent, terephthalic acid as the dicarboxylic acid component is preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 98 mol% or more , The best is 100 mol%. The 1,4-butanediol as the diol component is preferably 90 mol% or more, and more preferably 95 mol% or more.

前述PBT樹脂(A)的固有黏度的下限較佳為0.80dl/g，更佳為0.95dl/g，進而較佳為1.0dl/g。藉由將PBT樹脂(A)的固有黏度設為0.80dl/g以上，能夠提高製膜而獲得之膜的固有黏度，能夠提高耐破袋性及製膜性。前述PBT樹脂(A)的固有黏度的上限較佳為1.3dl/g。藉由設為1.3dl/g以下，能夠抑制膜延伸時的應力變得過高，而使製膜性良好。進而，於使用固有黏度高之PBT樹脂之情形時，樹脂的熔融黏度變高，因此必須使擠出溫度成為高溫，但藉由使用固有黏度為1.3dl/g以下之PBT樹脂(A)，亦可不進行高溫擠出，而能夠抑制產生分解物。The lower limit of the inherent viscosity of the aforementioned PBT resin (A) is preferably 0.80 dl/g, more preferably 0.95 dl/g, and still more preferably 1.0 dl/g. By setting the intrinsic viscosity of the PBT resin (A) to 0.80 dl/g or more, the intrinsic viscosity of the film obtained by film formation can be increased, and the bag breaking resistance and film forming properties can be improved. The upper limit of the intrinsic viscosity of the aforementioned PBT resin (A) is preferably 1.3 dl/g. By setting it to 1.3 dl/g or less, it is possible to suppress the stress during film stretching from becoming too high, and the film formability can be improved. Furthermore, when using a PBT resin with a high intrinsic viscosity, the melt viscosity of the resin becomes higher, so the extrusion temperature must be increased to a high temperature. However, it is also possible to use PBT resin (A) with an intrinsic viscosity of 1.3dl/g or less. High temperature extrusion is not required, and the generation of decomposition products can be suppressed.

以調整進行雙軸延伸時的製膜性及所獲得之膜的力學特性為目的，前述聚酯樹脂組成物較佳為含有PBT樹脂(A)以外的聚酯樹脂(B)。作為前述聚酯樹脂(B)，可列舉選自以下之樹脂中的至少一種樹脂：PET、聚萘二甲酸乙二酯、聚萘二甲酸丁二酯、聚對苯二甲酸丙二酯等聚酯樹脂；或者有選自由間苯二甲酸、鄰苯二甲酸、萘二羧酸、聯苯二羧酸、環己烷二羧酸、己二酸、壬二酸及癸二酸所組成之群組中的至少1種二羧酸共聚而成之PBT樹脂；有選自由乙二醇、1,3-丙二醇、1,2-丙二醇、新戊二醇、1,5-戊二醇、1,6-己二醇、二乙二醇、環己二醇、聚乙二醇、聚四亞甲基二醇及聚碳酸酯所組成之群組中的至少1種二醇成分共聚而成之PBT樹脂；有選自由間苯二甲酸、鄰苯二甲酸、萘二羧酸、聯苯二羧酸、環己烷二羧酸、己二酸、壬二酸及癸二酸所組成之群組中的至少1種二羧酸共聚而成之PBT樹脂；或有選自1,3-丁二醇、1,3-丙二醇、1,2-丙二醇、新戊二醇、1,5-戊二醇、1,6-己二醇、二乙二醇、環己二醇、聚乙二醇、聚四亞甲基二醇及聚碳酸酯所組成之群組中的至少1種二醇成分共聚而成之PET樹脂。For the purpose of adjusting the film formability during biaxial stretching and the mechanical properties of the obtained film, the polyester resin composition preferably contains a polyester resin (B) other than the PBT resin (A). As the aforementioned polyester resin (B), at least one resin selected from the group consisting of PET, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate and the like can be mentioned. Ester resin; or selected from the group consisting of isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, cyclohexane dicarboxylic acid, adipic acid, azelaic acid and sebacic acid PBT resin made by copolymerization of at least one dicarboxylic acid in the group; there are selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,2-propanediol, neopentyl glycol, 1,5-pentanediol, 1, PBT made by copolymerization of at least one diol component in the group consisting of 6-hexanediol, diethylene glycol, cyclohexanediol, polyethylene glycol, polytetramethylene glycol and polycarbonate Resin; selected from the group consisting of isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, cyclohexane dicarboxylic acid, adipic acid, azelaic acid and sebacic acid PBT resin made by copolymerization of at least one dicarboxylic acid; or selected from 1,3-butanediol, 1,3-propanediol, 1,2-propanediol, neopentyl glycol, 1,5-pentanediol , 1,6-hexanediol, diethylene glycol, cyclohexanediol, polyethylene glycol, polytetramethylene glycol and polycarbonate composed of at least one diol component copolymerized and Chengzhi PET resin.

其中，由於以PET作為主成分之樹脂的熔點高而耐熱性優異，與PBT樹脂之相容性良好而透明性優異，故而較佳為PET樹脂或經共聚之PET樹脂，尤佳為PET樹脂。Among them, since the resin with PET as the main component has a high melting point, excellent heat resistance, good compatibility with PBT resin and excellent transparency, PET resin or copolymerized PET resin is preferred, and PET resin is particularly preferred.

作為前述聚酯樹脂(B)的添加量，相對於前述聚酯樹脂組成物整體，較佳為25質量%以下，更佳為20質量%以下，進而較佳為15質量%以下，尤佳為10質量%以下。若前述聚酯樹脂(B)的添加量為25質量%以下，則能夠進一步提高穿刺強度，耐破袋性更優異。另外，能夠將透明性保持得高。前述聚酯樹脂(B)的添加量相對於前述聚酯樹脂組成物整體，可設為0質量%以上、5質量%以上、10質量%以上等。The addition amount of the polyester resin (B) is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, with respect to the entire polyester resin composition. 10% by mass or less. If the addition amount of the aforementioned polyester resin (B) is 25% by mass or less, the puncture strength can be further improved, and the bag breakage resistance can be more excellent. In addition, transparency can be maintained high. The addition amount of the said polyester resin (B) can be set to 0 mass% or more, 5 mass% or more, 10 mass% or more with respect to the said whole polyester resin composition.

前述聚酯樹脂(B)的固有黏度的下限較佳為0.5dl/g，更佳為0.6dl/g，進而較佳為0.8dl/g。前述聚酯樹脂(B)的固有黏度的上限較佳為1.3dl/g。藉由將前述聚酯樹脂(B)的固有黏度設為上述數值範圍內，能夠與PBT樹脂(A)更良好地混合。The lower limit of the inherent viscosity of the aforementioned polyester resin (B) is preferably 0.5 dl/g, more preferably 0.6 dl/g, and still more preferably 0.8 dl/g. The upper limit of the inherent viscosity of the aforementioned polyester resin (B) is preferably 1.3 dl/g. By setting the inherent viscosity of the aforementioned polyester resin (B) within the above-mentioned numerical range, it is possible to mix with the PBT resin (A) more satisfactorily.

前述雙軸配向聚酯膜中，除前述聚酯樹脂組成物以外，亦可含有先前公知的添加劑，例如滑劑、穩定劑、著色劑、抗氧化劑、抗靜電劑、紫外線吸收劑等。The biaxially oriented polyester film may contain previously known additives such as lubricants, stabilizers, colorants, antioxidants, antistatic agents, and ultraviolet absorbers in addition to the polyester resin composition.

於將前述雙軸配向聚酯膜整體設為100質量%時，前述聚酯樹脂組成物的含量較佳為99.5質量%以上，更佳為99.6質量%以上，進而較佳為99.7質量%以上。於將前述雙軸配向聚酯膜整體設為100質量%時，前述聚酯樹脂組成物的含量較佳為100質量%以下，更佳為99.9質量%以下，進而較佳為99.8質量%以下。When the entire biaxially aligned polyester film is 100% by mass, the content of the polyester resin composition is preferably 99.5% by mass or more, more preferably 99.6% by mass or more, and still more preferably 99.7% by mass or more. When the entire biaxially oriented polyester film is 100% by mass, the content of the polyester resin composition is preferably 100% by mass or less, more preferably 99.9% by mass or less, and still more preferably 99.8% by mass or less.

前述滑劑能夠調整膜的動摩擦係數，可列舉：二氧化矽、碳酸鈣、氧化鋁等無機系滑劑、有機系滑劑。更佳為二氧化矽、碳酸鈣，其中，就降低霧度之方面而言，尤佳為二氧化矽。藉由這些滑劑，能夠表現出透明性及滑動性。The aforementioned slip agent can adjust the dynamic friction coefficient of the film, and examples thereof include inorganic slip agents such as silica, calcium carbonate, and alumina, and organic slip agents. Silicon dioxide and calcium carbonate are more preferable, and among them, silicon dioxide is particularly preferable in terms of reducing haze. With these lubricants, transparency and sliding properties can be expressed.

前述雙軸配向聚酯膜中的滑劑的含量的下限較佳為100質量ppm，更佳為800質量ppm。藉由設為100質量ppm以上，能夠提高滑動性。前述滑劑的含量的上限較佳為20000質量ppm，更佳為1000質量ppm，尤佳為1800質量ppm。藉由設為20000質量ppm以下，能夠維持透明性。The lower limit of the content of the slip agent in the aforementioned biaxially aligned polyester film is preferably 100 ppm by mass, more preferably 800 ppm by mass. By setting it as 100 mass ppm or more, the sliding properties can be improved. The upper limit of the content of the aforementioned lubricant is preferably 20,000 ppm by mass, more preferably 1,000 ppm by mass, and particularly preferably 1,800 ppm by mass. By setting it as 20,000 ppm by mass or less, transparency can be maintained.

[雙軸配向聚酯膜的特性] 如上所述，前述雙軸配向聚酯膜滿足下述要件(1)。 (1)以依據JIS-Z1707之穿刺試驗所測定之雙軸配向聚酯膜的穿刺強度為0.50N/μm以上。前述穿刺強度較佳為0.55N/μm以上，進而較佳為0.60N/μm以上。由於前述穿刺強度為0.50N/μm以上，故而能夠使耐破袋性良好。另外，前述穿刺強度較佳為0.90N/μm以下，更佳為0.85N/μm以下，進而較佳為0.80N/μm以下。若為0.9N/μm以下，則熱收縮率得到抑制，熱穩定性更優異。此外，本說明書中，所謂「穿刺強度為0.50N/μm以上」，係指於雙軸配向聚酯膜的任何部分皆「穿刺強度為0.50N/μm以上」。[Characteristics of biaxially aligned polyester film] As described above, the aforementioned biaxially aligned polyester film satisfies the following requirement (1). (1) The puncture strength of the biaxially aligned polyester film measured by the puncture test in accordance with JIS-Z1707 is 0.50 N/μm or more. The aforementioned puncture strength is preferably 0.55 N/μm or more, and more preferably 0.60 N/μm or more. Since the aforementioned puncture strength is 0.50 N/μm or more, it is possible to make the bag breakage resistance good. In addition, the aforementioned puncture strength is preferably 0.90 N/μm or less, more preferably 0.85 N/μm or less, and still more preferably 0.80 N/μm or less. If it is 0.9 N/μm or less, the thermal shrinkage rate is suppressed, and the thermal stability is more excellent. In addition, in this specification, the "puncture strength of 0.50 N/μm or more" means that any part of the biaxially oriented polyester film has a "puncture strength of 0.50 N/μm or more".

另外，如上所述，前述雙軸配向聚酯膜滿足下述要件(2)。 (2)於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別依據JIS-K7112所測定之密度中最高值為1.40g/cm³ 以下。前述密度(前述密度中最高值)較佳為1.39g/cm³ ，進而較佳為1.38g/cm³ 。由於前述密度為1.4g/cm³ 以下，故而端部的結晶化得到抑制。結果，能夠抑制製造該雙軸配向聚酯膜時的延伸步驟中，於端部產生過度的應力，而能夠使製膜性良好。另外，前述密度較佳為1.28g/cm³ 以上，更佳為1.29g/cm³ 以上，進而較佳為1.30g/cm³ 以上。若為1.28g/cm³ 以上，則結晶性適度高，力學強度變得更良好。此外，若端部的密度(對於自左右端分別朝向中央部為10mm之位置進行取樣之部分的密度)為1.4g/cm³ 以下，則當然相較於取樣部位更靠中央部側的密度會滿足1.4g/cm³ 以下。In addition, as described above, the aforementioned biaxially oriented polyester film satisfies the following requirement (2). (2) In the width direction of the biaxially oriented polyester film, samples are taken from the left and right ends to the central part of 10 mm respectively, and the highest value of the density measured in accordance with JIS-K7112 is 1.40 g/cm ³ or less. The aforementioned density (the highest value among the aforementioned densities) is preferably 1.39 g/cm ³ , and more preferably 1.38 g/cm ³ . Since the aforementioned density is 1.4 g/cm ³ or less, crystallization at the ends is suppressed. As a result, it is possible to prevent excessive stress from being generated at the end in the stretching step when manufacturing the biaxially oriented polyester film, and it is possible to improve the film forming properties. In addition, the aforementioned density is preferably 1.28 g/cm ³ or more, more preferably 1.29 g/cm ³ or more, and still more preferably 1.30 g/cm ³ or more. If it is 1.28 g/cm ³ or more, the crystallinity is moderately high, and the mechanical strength becomes better. In addition, if the density at the end (the density of the part where sampling is 10 mm from the left and right ends to the central part) is 1.4 g/cm ³ or less, of course, the density on the central part side will be higher than that of the sampling part. Meet 1.4g/cm ³ or less.

另外，如上所述，前述雙軸配向聚酯膜滿足下述要件(3)。 (3)雙軸配向聚酯膜的固有黏度為0.7dl/g以上。前述固有黏度較佳為0.75dl/g以上，進而較佳為0.80dl/g以上。由於前述固有黏度為0.7dl/g以上，故而於將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥而獲得未延伸片時，能夠抑制未延伸片的結晶化，尤其能夠使厚度厚之端部的降伏應力不會變得過高。結果，能夠於延伸步驟中不易斷裂。另外，前述固有黏度較佳為1.20dl/g以下，更佳為1.15dl/g以下，進而較佳為1.10dl/g以下。若前述固有黏度為1.20dl/g以下，則延伸時的應力不會變得過高，製膜性變得更良好。In addition, as described above, the aforementioned biaxially oriented polyester film satisfies the following requirement (3). (3) The inherent viscosity of the biaxially aligned polyester film is 0.7 dl/g or more. The aforementioned intrinsic viscosity is preferably 0.75 dl/g or more, and more preferably 0.80 dl/g or more. Since the aforementioned intrinsic viscosity is 0.7 dl/g or more, when the resin composition for the manufacture of biaxially oriented polyester film is cast on a cooling roll to obtain an unstretched sheet, the crystallization of the unstretched sheet can be suppressed, and the thickness can be increased. The yield stress at the thick end will not become too high. As a result, it can be difficult to break during the stretching step. In addition, the aforementioned intrinsic viscosity is preferably 1.20 dl/g or less, more preferably 1.15 dl/g or less, and still more preferably 1.10 dl/g or less. If the inherent viscosity is 1.20 dl/g or less, the stress during stretching does not become too high, and the film formability becomes better.

前述雙軸配向聚酯膜較佳為於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別求出使用傅立葉轉換型紅外光譜法光譜強度中之全反射法所獲得之1450±10cm^-1 之峰值的吸收強度A與1410±10cm^-1 之峰值的吸收強度B之比A/B時，最高值為0.62以下。前述比A/B(前述比A/B的最高值)更佳為0.61以下，進而較佳為0.60以下。若前述比A/B為0.62以下，則結晶性不會變得過高，因此延伸時的應力得到抑制，變得不易斷裂。前述比A/B較佳為0.52以上，更佳為0.53以上，進而較佳為0.54以上。若為0.52以上，則結晶性不會過低，力學強度更良好。此外，若雙軸配向聚酯膜的B面的比A/B為0.62以下，則當然F面的比A/B亦滿足0.62以下。The aforementioned biaxially oriented polyester film is preferably in the width direction of the biaxially oriented polyester film. Samples are taken from the left and right ends to a position of 10 mm from the center, respectively, and the spectral intensity of Fourier transform infrared spectroscopy is obtained. When the ratio A/B of the absorption intensity A at the peak ^{of 1450±10cm -1} obtained by the total reflection method to ^{the absorption intensity B at the peak of 1410±10cm -1} is A/B, the maximum value is 0.62 or less. The aforementioned ratio A/B (the highest value of the aforementioned ratio A/B) is more preferably 0.61 or less, and still more preferably 0.60 or less. If the aforementioned ratio A/B is 0.62 or less, the crystallinity does not become too high, so the stress during stretching is suppressed, and it becomes difficult to break. The aforementioned ratio A/B is preferably 0.52 or more, more preferably 0.53 or more, and still more preferably 0.54 or more. If it is 0.52 or more, the crystallinity will not be too low, and the mechanical strength will be more favorable. In addition, if the ratio A/B of the B side of the biaxially oriented polyester film is 0.62 or less, of course, the ratio A/B of the F side also satisfies 0.62 or less.

前述雙軸配向聚酯膜較佳為面配向度ΔP為0.145至0.160。前述面配向度ΔP更佳為0.1455以上，進而較佳為0.146以上。若為0.145以上，則面配向適度高，穿刺強度變得充分，耐破袋性更優異。前述面配向度ΔP更佳為0.157以下，進而較佳為0.154以下。若為0.160以下，則能夠將熱收縮率維持得低，能夠使熱穩定性更良好。The aforementioned biaxially aligned polyester film preferably has a plane alignment degree ΔP of 0.145 to 0.160. The aforementioned degree of surface alignment ΔP is more preferably 0.1455 or more, and still more preferably 0.146 or more. If it is 0.145 or more, the surface alignment is moderately high, the puncture strength becomes sufficient, and the bag burst resistance is more excellent. The aforementioned degree of plane alignment ΔP is more preferably 0.157 or less, and still more preferably 0.154 or less. If it is 0.160 or less, the thermal shrinkage rate can be maintained low, and thermal stability can be made more favorable.

前述雙軸配向聚酯膜在MD方向於150℃加熱15分鐘後的熱收縮率的下限較佳為0.5%。更佳為0.8%，進而較佳為1.2%。若為0.5%以上，則能夠提高穿刺強度，能夠將耐破袋性維持得高。前述雙軸配向聚酯膜在MD方向於150℃加熱15分鐘後的熱收縮率的上限較佳為3.5%。更佳為3.0%，進而較佳為2.5%。若為3.5%以下，則能夠抑制於後續加工中施加熱時膜大幅收縮，從而加工變得更容易。The lower limit of the thermal shrinkage rate of the aforementioned biaxially oriented polyester film after heating at 150° C. for 15 minutes in the MD direction is preferably 0.5%. It is more preferably 0.8%, and still more preferably 1.2%. If it is 0.5% or more, the puncture strength can be improved, and the bag breaking resistance can be maintained high. The upper limit of the thermal shrinkage rate of the aforementioned biaxially oriented polyester film after heating at 150° C. for 15 minutes in the MD direction is preferably 3.5%. It is more preferably 3.0%, and still more preferably 2.5%. If it is 3.5% or less, the film can be prevented from shrinking significantly when heat is applied in subsequent processing, and processing becomes easier.

前述雙軸配向聚酯膜的厚度的下限較佳為5μm。更佳為7μm，進而較佳為9μm。若為5μm以上，則能夠使作為膜之強度充分。前述雙軸配向聚酯膜的厚度的上限較佳為40μm。更佳為30μm，進而較佳為20μm。The lower limit of the thickness of the aforementioned biaxially aligned polyester film is preferably 5 μm. It is more preferably 7 μm, and still more preferably 9 μm. If it is 5 μm or more, the strength as a film can be made sufficient. The upper limit of the thickness of the aforementioned biaxially aligned polyester film is preferably 40 μm. It is more preferably 30 μm, and still more preferably 20 μm.

前述雙軸配向聚酯膜較佳為遍及整個膜為相同組成。The aforementioned biaxially aligned polyester film preferably has the same composition throughout the entire film.

對於前述雙軸配向聚酯膜，亦可積層印刷層。作為形成印刷層之印刷油墨，可較佳地使用水性及溶媒系的含樹脂之印刷油墨。此處，作為印刷油墨所使用之樹脂，可例示：丙烯酸系樹脂、胺基甲酸酯系樹脂、聚酯系樹脂、氯乙烯系樹脂、乙酸乙烯酯共聚樹脂及這些之混合物。印刷油墨中，亦可含有抗靜電劑、光線阻斷劑、紫外線吸收劑、塑化劑、滑劑、填料、著色劑、穩定劑、潤滑劑、消泡劑、交聯劑、耐黏連劑、抗氧化劑等公知的添加劑。For the aforementioned biaxially oriented polyester film, a printing layer may also be laminated. As the printing ink for forming the printing layer, water-based and solvent-based resin-containing printing inks can be preferably used. Here, as the resin used in the printing ink, acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures of these can be exemplified. Printing inks may also contain antistatic agents, light blockers, ultraviolet absorbers, plasticizers, slip agents, fillers, colorants, stabilizers, lubricants, defoamers, crosslinkers, and anti-blocking agents , Antioxidants and other well-known additives.

作為用以設置印刷層之印刷方法，並無特別限定，可使用膠版印刷法、凹版印刷法、網版印刷法等公知的印刷方法。印刷後的溶媒的乾燥可使用熱風乾燥、熱輥乾燥、紅外線乾燥等公知的乾燥方法。The printing method for providing the printing layer is not particularly limited, and known printing methods such as an offset printing method, a gravure printing method, and a screen printing method can be used. For drying the solvent after printing, a known drying method such as hot air drying, hot roll drying, and infrared drying can be used.

另外，對於前述雙軸配向聚酯膜，只要無損本發明的目的，則可實施電暈放電處理、輝光放電處理、火焰處理、表面粗面化處理，另外，亦可實施公知的錨固塗佈處理、印刷、裝飾等。In addition, for the aforementioned biaxially aligned polyester film, as long as the purpose of the present invention is not impaired, corona discharge treatment, glow discharge treatment, flame treatment, surface roughening treatment can be carried out, and well-known anchor coating treatment can also be carried out. , Printing, decoration, etc.

可於前述雙軸配向聚酯膜的至少單面設置無機薄膜層或如鋁箔之金屬箔等氣體阻隔層。An inorganic thin film layer or a gas barrier layer such as a metal foil such as aluminum foil can be provided on at least one side of the aforementioned biaxially aligned polyester film.

使用無機薄膜層作為氣體阻隔層之情形時的無機薄膜層，為由金屬或無機氧化物所構成之薄膜。形成無機薄膜層之材料只要能夠形成為薄膜，則並無特別限制，就氣體阻隔性之觀點而言，可較佳地列舉氧化矽(矽氧)、氧化鋁(鋁氧)、氧化矽與氧化鋁之混合物等無機氧化物。尤其是，就能夠兼顧薄膜層的柔軟性及緻密性之方面而言，較佳為氧化矽與氧化鋁之複合氧化物。When an inorganic thin film layer is used as the gas barrier layer, the inorganic thin film layer is a thin film composed of metal or inorganic oxide. The material for forming the inorganic thin film layer is not particularly limited as long as it can be formed into a thin film. From the viewpoint of gas barrier properties, silicon oxide (silicon oxide), aluminum oxide (aluminum oxide), silicon oxide, and oxide Inorganic oxides such as a mixture of aluminum. In particular, a composite oxide of silicon oxide and aluminum oxide is preferred in terms of the flexibility and compactness of the thin film layer.

該複合氧化物中，氧化矽與氧化鋁之混合比較佳為以金屬份之重量比計，Al為20%至70%之範圍。若Al濃度為20%以上，則能夠進一步提高水蒸氣氣體阻隔性。另一方面，若為70%以下，則能夠使無機薄膜層柔軟，能夠抑制於印刷或層壓等二次加工時膜遭破壞而氣體阻隔性降低。此外，此處所謂之氧化矽，係指SiO或SiO₂ 等各種矽氧化物或這些之混合物，所謂氧化鋁，係指AlO或Al₂ O₃ 等各種鋁氧化物或這些之混合物。In the composite oxide, the mixing ratio of silicon oxide and aluminum oxide is preferably in the range of 20% to 70% in terms of the weight ratio of the metal content. If the Al concentration is 20% or more, the water vapor gas barrier properties can be further improved. On the other hand, if it is 70% or less, the inorganic thin film layer can be made soft, and it can be suppressed that the film is broken during secondary processing such as printing or lamination, and the gas barrier properties are reduced. In addition, the term “ _{silica oxide” here refers to various silicon oxides such as SiO or SiO 2} or a mixture of these, and the term “alumina” refers to _{various aluminum oxides such as AlO or Al 2} O ₃ or a mixture of these.

無機薄膜層的膜厚通常為1nm至100nm，較佳為5nm至50nm。若無機薄膜層的膜厚為1nm以上，則更容易獲得令人滿意的氣體阻隔性。另一方面，若為100nm以下，則於耐彎曲性及製造成本之方面有利。The thickness of the inorganic thin film layer is usually 1 nm to 100 nm, preferably 5 nm to 50 nm. If the thickness of the inorganic thin film layer is 1 nm or more, it is easier to obtain satisfactory gas barrier properties. On the other hand, if it is 100 nm or less, it is advantageous in terms of bending resistance and manufacturing cost.

作為形成無機薄膜層之方法，並無特別限制，例如適宜採用真空蒸鍍法、濺鍍法、離子鍍覆法等物理蒸鍍法(PVD(Physical Vapor Deposition；物理氣相沈積)法)、或者化學蒸鍍法(CVD(Chemical Vapor Deposition；化學氣相沈積)法)等公知的蒸鍍法即可。以下，以氧化矽-氧化鋁系薄膜為例，說明形成無機薄膜層之典型的方法。例如，於採用真空蒸鍍法之情形時，作為蒸鍍原料，可較佳地使用SiO₂ 與Al₂ O₃ 之混合物、或SiO₂ 與Al之混合物等。作為這些蒸鍍原料，通常使用粒子，此時，各粒子的大小較理想為蒸鍍時的壓力不變化之程度的大小，較佳的粒徑為1mm至5mm。加熱可採用電阻加熱、高頻感應加熱、電子束加熱、雷射加熱等方式。另外，亦可採用反應性蒸鍍，該反應性蒸鍍係導入氧、氮、氫、氬、二氧化碳、水蒸氣等作為反應氣體，或使用臭氧添加、離子輔助等方法。進而，可對被蒸鍍體(供應於蒸鍍之積層膜)施加偏壓，或者將被蒸鍍體進行加熱或冷卻等，成膜條件亦可任意地變更。此種蒸鍍材料、反應氣體、被蒸鍍體之偏壓、加熱、冷卻等於採用濺鍍法或CVD法之情形時亦可同樣地變更。進而，亦可於上述無機薄膜層上積層印刷層。The method of forming the inorganic thin film layer is not particularly limited. For example, a physical vapor deposition method (PVD (Physical Vapor Deposition; physical vapor deposition) method) such as a vacuum vapor deposition method, a sputtering method, an ion plating method, etc. is suitably used, or A known vapor deposition method such as a chemical vapor deposition method (CVD (Chemical Vapor Deposition) method) may be sufficient. Hereinafter, a typical method of forming an inorganic thin film layer will be explained by taking a silicon oxide-alumina based thin film as an example. For example, when a vacuum evaporation method is used, a _{mixture of SiO 2} and Al ₂ O ₃ or a mixture of SiO ₂ and Al can be preferably used as the evaporation material. As these vapor deposition raw materials, particles are generally used. In this case, the size of each particle is preferably such that the pressure during vapor deposition does not change, and the preferred particle size is 1 mm to 5 mm. Heating can use resistance heating, high frequency induction heating, electron beam heating, laser heating, etc. In addition, it is also possible to use reactive vapor deposition, which introduces oxygen, nitrogen, hydrogen, argon, carbon dioxide, water vapor, etc. as a reactive gas, or uses methods such as ozone addition, ion assist, and the like. Furthermore, a bias voltage can be applied to the vapor-deposited body (the laminated film supplied for vapor deposition), or the vapor-deposited body can be heated or cooled, etc., and the film formation conditions can also be changed arbitrarily. Such vapor deposition materials, reaction gases, and the bias voltage, heating, and cooling of the vapor-deposited body can be changed in the same way when the sputtering method or the CVD method is used. Furthermore, a printing layer may be laminated on the above-mentioned inorganic thin film layer.

本實施形態中，較佳為於前述氣體阻隔層上設置保護層。由金屬氧化物所構成之氣體阻隔層並非完全緻密的膜，而是散佈有微小的缺損部分。於金屬氧化物層上塗敷後述之特定的保護層用樹脂組成物而形成保護層，藉此保護層用樹脂組成物中的樹脂滲透至金屬氧化物層的缺損部分，結果能獲得氣體阻隔性穩定之效果。此外，藉由於保護層本身亦使用具有氣體阻隔性之材料，積層膜的氣體阻隔性能亦大幅提高。In this embodiment, it is preferable to provide a protective layer on the aforementioned gas barrier layer. The gas barrier layer made of metal oxide is not a completely dense film, but is scattered with tiny defects. The metal oxide layer is coated with the specific resin composition for a protective layer described later to form a protective layer, whereby the resin in the resin composition for the protective layer penetrates into the defect part of the metal oxide layer, resulting in stable gas barrier properties The effect. In addition, since the protective layer itself also uses a material with gas barrier properties, the gas barrier performance of the laminated film is also greatly improved.

作為前述保護層，可列舉：於胺基甲酸酯系、聚酯系、丙烯酸系、鈦系、異氰酸酯系、亞胺系、聚丁二烯系等樹脂中，添加有環氧系、異氰酸酯系、三聚氰胺系等硬化劑之層。作為形成保護層時所使用之溶媒(溶劑)，例如可列舉：苯、甲苯等芳香族系溶劑；甲醇、乙醇等醇系溶劑；丙酮、甲基乙基酮等酮系溶劑；乙酸乙酯、乙酸丁酯等酯系溶劑；乙二醇單甲醚等多元醇衍生物等。Examples of the aforementioned protective layer include: urethane-based, polyester-based, acrylic-based, titanium-based, isocyanate-based, imine-based, and polybutadiene-based resins, with epoxy-based and isocyanate-based resins added , Melamine series and other hardener layer. The solvent (solvent) used when forming the protective layer includes, for example, aromatic solvents such as benzene and toluene; alcohol solvents such as methanol and ethanol; ketone solvents such as acetone and methyl ethyl ketone; ethyl acetate, Ester solvents such as butyl acetate; polyol derivatives such as ethylene glycol monomethyl ether, etc.

前述之胺基甲酸酯樹脂由於胺基甲酸酯鍵的極性基與無機薄膜層相互作用，並且藉由存在非晶部分而亦具有柔軟性，故而即便於施加彎曲負載時，亦能夠抑制對無機薄膜層之損傷，故而較佳。胺基甲酸酯樹脂的酸值較佳為10mgKOH/g至60mgKOH/g之範圍內。更佳為15mgKOH/g至55mgKOH/g之範圍內，進而較佳為20mgKOH/g至50mgKOH/g之範圍內。若胺基甲酸酯樹脂的酸值為前述範圍，則於製成水分散液時，液穩定性提高，另外，保護層能夠均勻地堆積於高極性的無機薄膜上，因此塗佈外觀變得良好。The aforementioned urethane resin has flexibility due to the interaction of the polar groups of the urethane bond with the inorganic thin film layer and the presence of amorphous parts. Therefore, even when a bending load is applied, the resistance to the The damage of the inorganic thin film layer is therefore preferable. The acid value of the urethane resin is preferably in the range of 10 mgKOH/g to 60 mgKOH/g. It is more preferably in the range of 15 mgKOH/g to 55 mgKOH/g, and still more preferably in the range of 20 mgKOH/g to 50 mgKOH/g. If the acid value of the urethane resin is in the aforementioned range, the liquid stability is improved when it is made into an aqueous dispersion. In addition, the protective layer can be uniformly deposited on the high-polarity inorganic film, so the coating appearance becomes good.

前述之胺基甲酸酯樹脂的玻璃轉移溫度(Tg)較佳為80℃以上，更佳為90℃以上。藉由將Tg設為80℃以上，能夠減少濕熱處理過程(升溫～保溫～降溫)中的分子運動所致之保護層的膨潤。The glass transition temperature (Tg) of the aforementioned urethane resin is preferably 80°C or higher, more preferably 90°C or higher. By setting the Tg to 80°C or higher, it is possible to reduce the swelling of the protective layer caused by the molecular motion in the heat treatment process (heating-keeping warm-cooling).

就氣體阻隔性提高之方面而言，前述之胺基甲酸酯樹脂更佳為使用含有芳香族或芳香脂肪族二異氰酸酯成分作為主要構成成分之胺基甲酸酯樹脂。其中，尤佳為含有間苯二甲基二異氰酸酯成分。藉由使用上述樹脂，能夠藉由芳香環彼此的堆疊效果而進一步提高胺基甲酸酯鍵的凝聚力，結果能獲得良好的氣體阻隔性。In terms of improving gas barrier properties, the aforementioned urethane resin is more preferably a urethane resin containing an aromatic or aromatic aliphatic diisocyanate component as a main component. Among them, it is particularly preferable to contain a metaxylylene diisocyanate component. By using the above-mentioned resin, the cohesive force of the urethane bond can be further improved by the stacking effect of the aromatic rings, and as a result, good gas barrier properties can be obtained.

本實施形態中，較佳為將胺基甲酸酯樹脂中的芳香族或芳香脂肪族二異氰酸酯的比率設為聚異氰酸酯成分100莫耳%中為50莫耳%以上(50莫耳%至100莫耳%)之範圍。芳香族或芳香脂肪族二異氰酸酯的合計量的比率較佳為60莫耳%至100莫耳%，更佳為70莫耳%至100莫耳%，進而較佳為80莫耳%至100莫耳%。作為此種樹脂，可較佳地使用由三井化學股份有限公司市售之「Takelac(註冊商標)WPB」系列。若芳香族或芳香脂肪族二異氰酸酯的合計量的比率為50莫耳%以上，則能獲得更良好的氣體阻隔性。In this embodiment, it is preferable to set the ratio of the aromatic or aromatic aliphatic diisocyanate in the urethane resin to 50 mol% or more in 100 mol% of the polyisocyanate component (50 mol% to 100%). Mole%) range. The ratio of the total amount of aromatic or aromatic aliphatic diisocyanate is preferably 60 mol% to 100 mol%, more preferably 70 mol% to 100 mol%, and still more preferably 80 mol% to 100 mol% ear%. As such a resin, the "Takelac (registered trademark) WPB" series commercially available from Mitsui Chemicals Co., Ltd. can be preferably used. If the ratio of the total amount of aromatic or aromatic aliphatic diisocyanates is 50 mol% or more, better gas barrier properties can be obtained.

就與無機薄膜層之親和性提高之觀點而言，前述胺基甲酸酯樹脂較佳為具有羧酸基(羧基)。為了於胺基甲酸酯樹脂中導入羧酸(鹽)基，例如導入作為多元醇成分之二羥甲基丙酸、二羥甲基丁酸等具有羧酸基之多元醇化合物作為共聚成分即可。另外，若於合成含羧酸基之胺基甲酸酯樹脂後，藉由鹽形成劑進行中和，則能夠獲得水分散體之胺基甲酸酯樹脂。作為鹽形成劑的具體例，可列舉：氨、三甲基胺、三乙基胺、三異丙基胺、三正丙基胺、三正丁基胺等三烷基胺類、N-甲基嗎啉、N-乙基嗎啉等N-烷基嗎啉類、N-二甲基乙醇胺、N-二乙基乙醇胺等N-二烷基烷醇胺類等。這些可單獨使用，亦可併用2種以上。From the viewpoint of improving the affinity with the inorganic thin film layer, the aforementioned urethane resin preferably has a carboxylic acid group (carboxyl group). In order to introduce a carboxylic acid (salt) group into the urethane resin, for example, a polyol compound having a carboxylic acid group such as dimethylol propionic acid and dimethylol butyric acid as a polyol component is introduced as a copolymerization component. can. In addition, if the urethane resin containing a carboxylic acid group is synthesized and neutralized with a salt forming agent, the urethane resin of an aqueous dispersion can be obtained. Specific examples of the salt forming agent include trialkylamines such as ammonia, trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, and tri-n-butylamine, and N-methyl N-alkylmorpholines such as morpholine and N-ethylmorpholine; N-dialkylalkanolamines such as N-dimethylethanolamine and N-diethylethanolamine. These can be used individually or in combination of 2 or more types.

亦可於前述雙軸配向聚酯膜積層其他素材之層，作為積層方法，可於製作雙軸配向聚酯膜後貼合，或於製膜中貼合。Layers of other materials can also be laminated on the aforementioned biaxially oriented polyester film. As a lamination method, it can be laminated after the biaxially oriented polyester film is made, or in film making.

前述雙軸配向聚酯膜例如可於前述雙軸配向聚酯膜設置無機蒸鍍層，進而形成稱為密封劑之熱密封性樹脂層(亦稱為密封劑層)，用作包裝材料。通常藉由擠出層壓法或乾式層壓法形成熱密封性樹脂層。作為形成熱密封性樹脂層之熱塑性聚合物，只要能夠充分地展現密封劑接著性即可，可使用HDPE(High Density Polyethylene；高密度聚乙烯)、LDPE(Low Density Polyethylene；低密度聚乙烯)、LLDPE(Linear Low Density Polyethylene；線性低密度聚乙烯)等聚乙烯樹脂類、聚丙烯樹脂。也可使用乙烯-乙酸乙烯酯共聚物、乙烯-α-烯烴無規共聚物、離子聚合物樹脂等。The aforementioned biaxially oriented polyester film may be provided with an inorganic vapor deposition layer on the aforementioned biaxially oriented polyester film to form a heat-sealable resin layer (also referred to as a sealant layer) called a sealant for use as a packaging material. The heat-sealable resin layer is usually formed by an extrusion lamination method or a dry lamination method. As the thermoplastic polymer forming the heat-sealable resin layer, as long as it can fully exhibit the adhesiveness of the sealant, HDPE (High Density Polyethylene; high-density polyethylene), LDPE (Low Density Polyethylene; low-density polyethylene), Polyethylene resins and polypropylene resins such as LLDPE (Linear Low Density Polyethylene). Ethylene-vinyl acetate copolymers, ethylene-α-olefin random copolymers, ionomer resins, etc. can also be used.

密封劑層可為單層膜，亦可為多層膜，根據所需功能而進行選擇即可。例如，就賦予防濕性之方面而言，可使用隔設有乙烯-環狀烯烴共聚物或聚甲基戊烯等樹脂之多層膜。另外，密封劑層亦可調配阻燃劑、滑動劑、抗黏連劑、抗氧化劑、光穩定劑、黏著賦予劑等各種添加劑。密封劑層的厚度較佳為10μm至100μm，更佳為20μm至60μm。The sealant layer may be a single-layer film or a multilayer film, and it may be selected according to the required function. For example, in terms of imparting moisture resistance, a multilayer film in which a resin such as an ethylene-cyclic olefin copolymer or polymethylpentene is interposed can be used. In addition, the sealant layer can also be formulated with various additives such as flame retardants, sliding agents, anti-blocking agents, antioxidants, light stabilizers, and adhesion imparting agents. The thickness of the sealant layer is preferably 10 μm to 100 μm, more preferably 20 μm to 60 μm.

前述雙軸配向聚酯膜能夠用於食品、醫藥品、工業製品等之包裝領域。尤其是，前述雙軸配向聚酯膜可用作包裝用積層體的基材膜(基材層)。作為包裝用積層體的層構成，若由“／”表示層的交界，則例如可列舉：基材層／氣體阻隔層／保護層、基材層／氣體阻隔層／保護層／接著劑層／密封劑層、基材層／氣體阻隔層／保護層／接著劑層／樹脂層／接著劑層／密封劑層、基材層／接著劑層／樹脂層／氣體阻隔層／保護層／接著劑層／密封劑層、基材層／氣體阻隔層／保護層／印刷層／接著劑層／密封劑層、基材層／印刷層／氣體阻隔層／保護層／接著劑層／密封劑層、基材層／氣體阻隔層／保護層／接著劑層／樹脂層／印刷層／接著劑層／密封劑層、基材層／接著劑層／樹脂層／印刷層／氣體阻隔層／保護層／接著劑層／密封劑層、基材層／印刷層／氣體阻隔層／保護層／接著劑層／樹脂層／接著劑層／密封劑層、基材層／印刷層／接著劑層／樹脂層／氣體阻隔層／保護層／接著劑層／密封劑層、基材層／接著劑層／樹脂層／氣體阻隔層／保護層／印刷層／接著劑層／密封劑層等。The aforementioned biaxially oriented polyester film can be used in the packaging fields of food, medicine, industrial products, and the like. In particular, the aforementioned biaxially oriented polyester film can be used as a base film (base layer) of a laminate for packaging. As the layer structure of the laminate for packaging, if the boundary between the layers is indicated by "/", for example: base layer/gas barrier layer/protective layer, base layer/gas barrier layer/protective layer/adhesive layer/ Sealant layer, base material layer/gas barrier layer/protective layer/adhesive layer/resin layer/adhesive layer/sealant layer, base material layer/adhesive layer/resin layer/gas barrier layer/protective layer/adhesive Layer/sealant layer, base material layer/gas barrier layer/protective layer/printed layer/adhesive layer/sealant layer, base material layer/printed layer/gas barrier layer/protective layer/adhesive layer/sealant layer, Base material layer/gas barrier layer/protective layer/adhesive layer/resin layer/printed layer/adhesive layer/sealant layer, base material layer/adhesive layer/resin layer/printed layer/gas barrier layer/protective layer/ Adhesive layer/sealant layer, substrate layer/printed layer/gas barrier layer/protective layer/adhesive layer/resin layer/adhesive layer/sealant layer, substrate layer/printed layer/adhesive layer/resin layer /Gas barrier layer/protective layer/adhesive layer/sealant layer, base material layer/adhesive layer/resin layer/gas barrier layer/protective layer/printing layer/adhesive layer/sealant layer, etc.

使用前述雙軸配向聚酯膜之積層體可較佳地用於包裝製品、各種標籤材料、蓋材、片成型品、層壓管等用途。尤其是，可用於包裝用袋(例如枕形袋、自立袋或四方袋等袋)。積層體的厚度可根據積層體的用途而適宜決定。例如以5μm至500μm、較佳為以10μm至300μm左右的厚度的膜或片狀的形態使用。The laminate using the aforementioned biaxially oriented polyester film can be preferably used for packaging products, various label materials, cover materials, sheet molded products, laminated tubes, and the like. In particular, it can be used for packaging bags (such as pillow bags, self-supporting bags, or square bags). The thickness of the laminate can be appropriately determined according to the use of the laminate. For example, it is used in the form of a film or sheet having a thickness of about 5 μm to 500 μm, preferably about 10 μm to 300 μm.

[雙軸配向聚酯膜之製造方法] 作為用以獲得前述雙軸配向聚酯膜之較佳的方法，就寬度方向的厚度精度之觀點而言，較佳為T字模方式。於吹脹(inflation)方式中，起因於該雙軸配向聚酯膜之製造方法而延伸倍率不易提高，容易產生寬度方向的厚度不良。另外，作為用以獲得前述雙軸配向聚酯膜之較佳的方法，先前提出有於將熔融聚酯樹脂組成物澆鑄於冷卻輥時，藉由利用靜態混合器等來將相同組成的樹脂多層化為8層以上而抑制結晶化從而獲得均勻的未延伸片之方法，但就設備的簡便性及保養性之方面而言，較佳為利用以下所記載之獲得均質的未延伸片之澆鑄方法，於熔融擠出時積層為未達8層。積層數進而較佳為3層以下。就設備的維護之方面而言，最佳為單層。於欲改善膜的表面的特性之情形時，較佳為2種2層、2種3層、或3種3層之層構成。由於PBT樹脂的結晶化速度快，故而所獲得之未延伸片的固有黏度的下限較佳為0.70dl/g，更佳為0.75dl/g，進而較佳為0.80dl/g，尤佳為0.90dl/g。若為0.70dl/g以上，則澆鑄時的結晶化得到抑制，未延伸片的降伏應力變低。尤其是使厚度厚之端部的降伏應力變低。結果，有於延伸時不易產生斷裂之傾向。所獲得之未延伸片的固有黏度的上限較佳為1.2dl/g，進而較佳為1.1dl/g。若為1.2dl/g以下，則延伸時的應力不會變得過高，製膜性變得更良好。[Manufacturing method of biaxially aligned polyester film] As a preferable method for obtaining the aforementioned biaxially oriented polyester film, from the viewpoint of thickness accuracy in the width direction, the T-type method is preferable. In the inflation method, due to the manufacturing method of the biaxially aligned polyester film, the stretching ratio is not easily increased, and thickness defects in the width direction are likely to occur. In addition, as a preferred method for obtaining the aforementioned biaxially oriented polyester film, it has previously been proposed that when the molten polyester resin composition is cast on a cooling roll, a static mixer or the like is used to multi-layer resins of the same composition. It is a method to obtain a uniform unstretched sheet by reducing crystallization into 8 layers or more. However, in terms of the simplicity and maintenance of the equipment, it is preferable to use the casting method described below to obtain a uniform unstretched sheet , The build-up is less than 8 layers during melt extrusion. The number of stacked layers is more preferably 3 layers or less. In terms of equipment maintenance, a single layer is best. When it is desired to improve the characteristics of the surface of the film, it is preferably a 2-type 2-layer, 2-type 3-layer, or 3-type 3-layer structure. Since the crystallization speed of PBT resin is fast, the lower limit of the inherent viscosity of the obtained unstretched sheet is preferably 0.70 dl/g, more preferably 0.75 dl/g, still more preferably 0.80 dl/g, and particularly preferably 0.90 dl/g. If it is 0.70 dl/g or more, crystallization during casting is suppressed, and the yield stress of the unstretched sheet becomes low. In particular, the yield stress at the thick end is reduced. As a result, it tends to be less likely to break during extension. The upper limit of the inherent viscosity of the obtained unstretched sheet is preferably 1.2 dl/g, and more preferably 1.1 dl/g. If it is 1.2 dl/g or less, the stress during stretching does not become too high, and the film formability becomes better.

模具溫度的下限較佳為240℃，更佳為245℃，尤佳為250℃。若為240℃以上，則噴出更穩定，能夠使厚度更均勻。另外，若為240℃以上，則能夠防止樹脂之熔融擠出步驟內所滯留之PET樹脂成為未熔融物而混入至膜中，損害膜的品質。樹脂熔融溫度的上限較佳為280℃，更佳為275℃，最佳為270℃。若為280℃以下，則能夠抑制樹脂之分解，能夠防止膜變脆。另外，能夠抑制澆鑄時的結晶化的進行，能夠使製膜性更良好。模具溫度的上限較佳為280℃，更佳為275℃以下，進而較佳為270℃以下。若為280℃以下，則能夠抑制厚度變得不均勻。另外，能夠抑制引起樹脂劣化、因模唇污染等而導致外觀不良。另外，能夠抑制所獲得之膜的固有黏度降低。另外，澆鑄時的結晶化的進行得到抑制，製膜性變得更良好。The lower limit of the mold temperature is preferably 240°C, more preferably 245°C, and particularly preferably 250°C. If it is 240°C or higher, the ejection is more stable and the thickness can be made more uniform. In addition, if it is 240° C. or higher, it is possible to prevent the PET resin remaining in the melt extrusion step of the resin from becoming an unmelted substance and being mixed into the film, thereby impairing the film quality. The upper limit of the resin melting temperature is preferably 280°C, more preferably 275°C, and most preferably 270°C. If it is 280°C or less, the decomposition of the resin can be suppressed and the film can be prevented from becoming brittle. In addition, the progress of crystallization during casting can be suppressed, and the film forming properties can be made better. The upper limit of the mold temperature is preferably 280°C, more preferably 275°C or lower, and still more preferably 270°C or lower. If it is 280°C or less, it is possible to suppress the thickness from becoming uneven. In addition, it is possible to prevent deterioration of the resin and poor appearance due to contamination of the die lip. In addition, it is possible to suppress the decrease in the inherent viscosity of the obtained film. In addition, the progress of crystallization during casting is suppressed, and film forming properties become better.

樹脂之熔融擠出步驟中的螺桿的轉速的下限較佳為70rpm，更佳為80rpm，尤佳為90rpm。若為70rpm以上，則噴出更穩定，厚度變得更均勻。另外，樹脂之混合變得更充分，能夠進一步抑制外觀不良。樹脂之熔融擠出步驟中的螺桿的轉速的上限較佳為150rpm，更佳為130rpm，尤佳為110rpm。若為150rpm以下，則能夠抑制因剪切發熱而熔融樹脂進行分解，能夠抑制所獲得之膜的固有黏度降低。另外，澆鑄時的結晶化的進行得到抑制，製膜性變得更良好。The lower limit of the rotation speed of the screw in the resin melt extrusion step is preferably 70 rpm, more preferably 80 rpm, and particularly preferably 90 rpm. If it is 70 rpm or more, the ejection becomes more stable and the thickness becomes more uniform. In addition, the mixing of the resin becomes more sufficient, and the appearance defect can be further suppressed. The upper limit of the rotation speed of the screw in the resin melt extrusion step is preferably 150 rpm, more preferably 130 rpm, and particularly preferably 110 rpm. If it is 150 rpm or less, it is possible to suppress decomposition of the molten resin due to shear heat generation, and it is possible to suppress a decrease in the intrinsic viscosity of the obtained film. In addition, the progress of crystallization during casting is suppressed, and film forming properties become better.

冷卻輥溫度的上限較佳為40℃，更佳為10℃以下。若為40℃以下，則已熔融的聚酯樹脂組成物冷卻固化時的結晶度不會變得過高，延伸變得更容易。另外，能夠提高層壓強度，能夠使耐破袋性更良好。冷卻輥溫度的下限較佳為0℃。若為0℃以上，則能夠充分地發揮已熔融的聚酯樹脂組成物冷卻固化時的結晶化抑制之效果。另外，於將冷卻輥的溫度設為上述範圍之情形時，較佳為預先降低冷卻輥附近的環境的濕度以防止結露。The upper limit of the cooling roll temperature is preferably 40°C, more preferably 10°C or less. If it is 40°C or less, the crystallinity of the melted polyester resin composition when it is cooled and solidified does not become too high, and it becomes easier to stretch. In addition, the lamination strength can be improved, and the bag breaking resistance can be made better. The lower limit of the cooling roll temperature is preferably 0°C. If it is 0°C or higher, the effect of suppressing crystallization when the melted polyester resin composition is cooled and solidified can be sufficiently exhibited. In addition, when the temperature of the cooling roll is in the above-mentioned range, it is preferable to lower the humidity of the environment near the cooling roll in advance to prevent condensation.

將熔融聚酯樹脂組成物澆鑄於冷卻輥表面時，由於高溫的樹脂接觸於表面，故而冷卻輥表面的溫度上升。通常，冷卻輥係於內部通過配管流通冷卻水而進行冷卻，但必須減少冷卻輥表面的寬度方向的溫度差，例如確保充分的冷卻水量、研究配管的配置、以及進行維護以使沈澱物(sludge)不附著於配管等。尤其是，於不使用藉由進行多層化(例如8層以上)而獲得均勻的未延伸片之方法之情形時，未延伸片容易進行結晶化，故而必須注意。此時，未延伸片的厚度較佳為15μm至2500μm之範圍。更佳為500μm以下，進而較佳為300μm以下。When the molten polyester resin composition is cast on the surface of the cooling roll, the temperature of the surface of the cooling roll rises because the high-temperature resin contacts the surface. Generally, the cooling roll is cooled by circulating cooling water through pipes. However, it is necessary to reduce the temperature difference in the width direction of the cooling roll surface, such as ensuring a sufficient amount of cooling water, studying the arrangement of pipes, and performing maintenance to prevent sludge. ) Does not attach to piping, etc. In particular, when a method of obtaining a uniform unstretched sheet by multi-layering (for example, 8 layers or more) is not used, the unstretched sheet is easy to crystallize, so care must be taken. At this time, the thickness of the unstretched sheet is preferably in the range of 15 μm to 2500 μm. It is more preferably 500 μm or less, and still more preferably 300 μm or less.

熔融聚酯樹脂組成物自模具噴出後至接觸於冷卻輥為止的時間(以下，亦稱為接觸時間)較佳為0.1秒至1.0秒之範圍內，更佳為0.2秒至0.5秒之範圍內。前述接觸時間係藉由(氣隙)/(噴出速度)所獲得之值。此處，氣隙係指噴出口12與冷卻輥20的面之距離。The time (hereinafter, also referred to as contact time) of the molten polyester resin composition after it is ejected from the mold until it comes into contact with the cooling roll is preferably in the range of 0.1 second to 1.0 second, more preferably in the range of 0.2 second to 0.5 second . The aforementioned contact time is a value obtained by (air gap)/(discharge speed). Here, the air gap refers to the distance between the ejection port 12 and the surface of the cooling roller 20.

就減少未延伸片的結晶度，提高延伸性(製膜性)之觀點而言，較佳為於將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥之後(步驟A之後)，對於冷卻輥上的未延伸片的B面同樣進行急冷。進而，為了進一步提高延伸性，較佳為將未延伸片的B面的端部較中央部更強烈地進行急冷。具體而言，於將未延伸片全寬設為100%時，將吹送至中央之風的溫度設為X，將吹送至兩端部之溫度設為Y時，前述X為15℃以下，且前述Y成為較前述X低之溫度。另外，多數情況下，未延伸片的端部的厚度較中央部厚。因此，藉由將端部較中央部更強烈地進行急冷，能夠將結晶化抑制為與中央部相當，使製膜性良好。進行急冷之方法並無特別限定，就設備的簡便性及保養性之方面而言，較佳為吹送由多風道送風機產生之冷卻風之方法。前述X更佳為5℃以下。前述X較佳為-5℃以上。若前述X為-5℃以上，則能充分地獲得未延伸片的B面的結晶化抑制效果。前述端部較佳為至少自端緣起10%以內的區域。前述端部更佳為自端緣起15%以內的區域，進而較佳為自端緣起20%以內的區域，尤佳為自端緣起25%以內的區域。From the viewpoint of reducing the crystallinity of the unstretched sheet and improving the extensibility (film forming properties), it is preferable to cast the resin composition for the production of the biaxially oriented polyester film on a cooling roll (after step A), The B side of the unstretched sheet on the cooling roll is also quenched. Furthermore, in order to further improve the extensibility, it is preferable to quench the end portion of the B surface of the unstretched sheet more strongly than the central portion. Specifically, when the full width of the unstretched sheet is set to 100%, the temperature of the wind blowing to the center is set to X, and the temperature of blowing to both ends is set to Y, the aforementioned X is 15°C or less, and The aforementioned Y becomes a lower temperature than the aforementioned X. In addition, in many cases, the thickness of the end portion of the unstretched piece is thicker than the center portion. Therefore, by quenching the end portion more intensely than the central portion, crystallization can be suppressed to be equivalent to that of the central portion, and the film forming properties can be improved. The method of rapid cooling is not particularly limited, but in terms of the simplicity and maintenance of the equipment, a method of blowing the cooling air generated by the multi-air blower is preferred. The aforementioned X is more preferably 5°C or lower. The aforementioned X is preferably -5°C or higher. If the aforementioned X is -5°C or higher, the effect of suppressing the crystallization of the B surface of the unstretched sheet can be sufficiently obtained. The aforementioned end is preferably at least an area within 10% of the end edge. The aforementioned end is more preferably an area within 15% from the end edge, more preferably an area within 20% from the end edge, and particularly preferably an area within 25% from the end edge.

前述Y較佳為10℃以下，更佳為5℃以下。若前述Y為10℃以下，則未延伸片的B面端部的結晶度不會變得過高，製膜性變得更良好。前述Y較佳為-5℃以上。若前述Y為-5℃以上，則能充分地獲得未延伸片的B面的結晶化抑制效果。The aforementioned Y is preferably 10°C or lower, more preferably 5°C or lower. If the aforementioned Y is 10°C or less, the crystallinity of the B surface end of the unstretched sheet will not become too high, and the film formability will become better. The aforementioned Y is preferably -5°C or higher. If the aforementioned Y is -5°C or higher, the effect of suppressing the crystallization of the B surface of the unstretched sheet can be sufficiently obtained.

圖1係用以說明對冷卻輥上的未延伸片的B面吹送來自多風道送風機之冷卻風之方法之前視示意圖，圖2係圖1的側視圖。如圖1、圖2所示，模具10係以使噴出口12與冷卻輥20的面成為對向之方式配置。噴出口12與冷卻輥20的面之距離(最短距離)並無特別限定，一般為2cm至10cm左右。另外，於冷卻輥20的外周面上配設有多風道送風機30。關於多風道送風機30的位置，於側視圖(圖2)中，於相對於冷卻輥20的中心，將模具10的位置設為0°時，相對於冷卻輥20的旋轉方向(圖2中為右旋轉方向)，較佳為設置於0°至45°之範圍，更佳為設置於10°至35°之範圍內。若將多風道送風機30配置於前述範圍內，則能夠將澆鑄於冷卻輥20上之未延伸片40的B面於澆鑄後立即進行冷卻。另外，自雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥之時間點(觸碰之時間點)至前述風吹送至該部分為止的時間較佳為2.0秒以內，更佳為1.0秒以內，進而較佳為0.5秒以內。若自雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥之時間點(觸碰之時間點)至前述風吹送至該部分為止的時間(該部分移動至多風道送風機30的正下方為止的時間)為2.0秒以內，則能夠將未延伸片40的B面於澆鑄後立即進行冷卻。Fig. 1 is a schematic front view for explaining the method of blowing cooling air from a multi-air duct blower to the B side of the unstretched sheet on the cooling roll, and Fig. 2 is a side view of Fig. 1. As shown in FIGS. 1 and 2, the mold 10 is arranged so that the ejection port 12 and the cooling roll 20 face each other. The distance (shortest distance) between the ejection port 12 and the surface of the cooling roll 20 is not particularly limited, but is generally about 2 cm to 10 cm. In addition, a multi-channel blower 30 is arranged on the outer peripheral surface of the cooling roll 20. Regarding the position of the multi-air duct blower 30, in the side view (FIG. 2), when the position of the mold 10 is set to 0° relative to the center of the cooling roll 20, it is relative to the rotation direction of the cooling roll 20 (FIG. 2) It is the right rotation direction), preferably set in the range of 0° to 45°, more preferably set in the range of 10° to 35°. If the multi-channel air blower 30 is arranged in the aforementioned range, the B surface of the unstretched sheet 40 cast on the cooling roll 20 can be cooled immediately after casting. In addition, the time from the point when the resin composition for manufacturing the biaxially oriented polyester film is cast on the cooling roll (the point in time when touched) to the point where the wind blows to this part is preferably within 2.0 seconds, more preferably 1.0 Within seconds, more preferably within 0.5 seconds. If the resin composition for the production of biaxially aligned polyester film is cast on the cooling roll (the time of touching) to the time until the aforementioned wind blows to this part (this part moves to just below the multi-channel blower 30) If the time until it is within 2.0 seconds, the surface B of the unstretched sheet 40 can be cooled immediately after casting.

多風道送風機30的橫寬(圖1中的左右方向的長度)較佳為成為受到澆鑄之未延伸片40的寬度以上。藉由將多風道送風機30的橫寬設為受到澆鑄之未延伸片40的寬度以上，容易充分地獲得結晶化抑制效果直至未延伸片40的B面的端部。The horizontal width (the length in the left-right direction in FIG. 1) of the multi-channel air blower 30 is preferably equal to or greater than the width of the unstretched piece 40 to be cast. By setting the horizontal width of the multi-channel air blower 30 to be greater than the width of the unstretched sheet 40 to be cast, it is easy to sufficiently obtain the crystallization suppressing effect up to the end of the B surface of the unstretched sheet 40.

多風道送風機30較佳為於將未延伸片全寬設為100%時，能夠使吹送至中央部之風的溫度、與吹送至左端部20%的部分及右端部20%的部分之溫度為不同之構成。具體而言，可列舉以下之方法：設定為將多風道送風機30的吹出口藉由間隔板等分割為複數個之構成，自各吹出口吹出不同溫度的風。吹出口的分割態樣並無特別限定，可均等地分割，亦可各吹出口的寬度各不相同。The multi-channel blower 30 is preferably capable of setting the temperature of the wind blown to the center part and the temperature of the part blown to 20% of the left end and 20% of the right end when the full width of the unstretched sheet is set to 100%. It is a different composition. Specifically, the following method can be exemplified: a configuration in which the blowing port of the multi-channel air blower 30 is divided into a plurality of pieces by a partition plate or the like, and air of different temperatures is blown from each blowing port. The split state of the blower outlet is not particularly limited, and it may be equally divided, or the width of each blower outlet may be different.

多風道送風機的一例示於圖3。圖3係表示多風道送風機的一例之仰視圖(自冷卻輥面側觀察之圖)。本實施形態的多風道送風機30中，橫寬係設定成為與未延伸片40為相同寬度(圖2)，如圖3所示，多風道送風機30的吹出口藉由間隔板32而分割為5份。具體而言，多風道送風機30的吹出口係自圖3的左側向右側依序分割為吹出口31-1至吹出口31-5。An example of a multi-channel air blower is shown in FIG. 3. Fig. 3 is a bottom view showing an example of the multi-channel air blower (a view viewed from the side of the cooling roll surface). In the multi-channel air blower 30 of this embodiment, the horizontal width is set to be the same width as the unextended piece 40 (FIG. 2 ). As shown in FIG. 3, the air outlet of the multi-channel air blower 30 is divided by a partition plate 32 For 5 servings. Specifically, the air outlet of the multi-channel air blower 30 is divided into the air outlet 31-1 to the air outlet 31-5 in order from the left side to the right side in FIG. 3.

多風道送風機30的縱寬(圖1中的上下方向的長度)較佳為30cm以上至80cm以下，更佳為50cm以上至60cm以下。另外，未延伸片40於冷卻輥20上移動之速度較佳為20m/分鐘至100m/分鐘，更佳為40m/分鐘至80m/分鐘。藉由將多風道送風機30的縱寬設為前述數值範圍內，並將未延伸片40的速度設為前述數值範圍內，能夠將合適量的冷卻風吹送至未延伸片40的B面。The vertical width (the length in the vertical direction in FIG. 1) of the multi-channel air blower 30 is preferably 30 cm or more and 80 cm or less, more preferably 50 cm or more and 60 cm or less. In addition, the moving speed of the unstretched sheet 40 on the cooling roll 20 is preferably 20 m/min to 100 m/min, more preferably 40 m/min to 80 m/min. By setting the vertical width of the multi-channel blower 30 within the aforementioned numerical range and setting the speed of the unstretched sheet 40 within the aforementioned numerical range, a suitable amount of cooling air can be blown to the B side of the unstretched sheet 40.

多風道送風機30距離冷卻輥20之高度的上限為20cm以下，更佳為10cm以下。若為20cm以下，則冷卻效率提高，能充分地獲得未延伸片40的端部的結晶化抑制效果。多風道送風機30距離冷卻輥20之高度的下限並無特別限制，較理想為不接觸於未延伸片40之範圍。The upper limit of the height of the multi-channel blower 30 from the cooling roller 20 is 20 cm or less, more preferably 10 cm or less. If it is 20 cm or less, the cooling efficiency is improved, and the effect of suppressing crystallization at the end of the unstretched sheet 40 can be sufficiently obtained. The lower limit of the height of the multi-channel air blower 30 from the cooling roller 20 is not particularly limited, and it is preferably a range that does not touch the unextended sheet 40.

來自多風道送風機30之冷卻風的風速的上限較佳為200m/min，更佳為180m/min以下。若為200m/min以下，則能夠抑制澆鑄已熔融的片形成用樹脂組成物時的接地點因冷卻風而搖晃。冷卻風的風速的下限較佳為50m/min。若為50m/min以上，則能充分地獲得未延伸片40的端部的結晶化抑制效果。The upper limit of the wind speed of the cooling air from the multi-channel air blower 30 is preferably 200 m/min, more preferably 180 m/min or less. If it is 200 m/min or less, it is possible to suppress shaking of the ground point when the molten resin composition for sheet formation is cast. The lower limit of the wind speed of the cooling wind is preferably 50 m/min. If it is 50 m/min or more, the effect of suppressing crystallization at the end of the unstretched sheet 40 can be sufficiently obtained.

上述之中，本實施形態的雙軸配向聚酯膜之製造方法較佳為具有：步驟A，係將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥而形成未延伸片；以及步驟B，係對前述冷卻輥上的前述未延伸片吹送風；並且前述步驟B係於將未延伸片全寬設為100%時，將吹送至中央之風的溫度設為X，將吹送至兩端部之溫度設為Y時，前述X為15℃以下，且前述Y為較前述X低之溫度；前述端部至少包含自端緣起10%以內的區域。Among the above, the manufacturing method of the biaxially oriented polyester film of this embodiment preferably includes: step A, casting the resin composition for manufacturing the biaxially oriented polyester film on a cooling roll to form an unstretched sheet; and Step B is to blow air to the unstretched sheet on the cooling roll; and the foregoing step B is to set the temperature of the wind blown to the center as X when the full width of the unstretched sheet is set to 100%, and blow to two When the temperature of the end is set to Y, the aforementioned X is 15°C or less, and the aforementioned Y is a temperature lower than the aforementioned X; the aforementioned end includes at least an area within 10% from the end edge.

其次，對延伸方法進行說明。延伸方法可為同步雙軸延伸亦可為逐步雙軸延伸，並無特別限定。Next, the extension method will be explained. The extension method may be synchronous biaxial extension or gradual biaxial extension, and is not particularly limited.

長度方向(以下，亦稱為MD方向)的延伸溫度的下限較佳為55℃，更佳為60℃。若為55℃以上，則能夠進一步抑制斷裂。另外，能夠防止縱向的配向變得過強，能夠抑制MD方向的熱收縮率變大。MD方向的延伸溫度的上限較佳為100℃，更佳為95℃。若為100℃以下，則能夠充分地賦予配向，能夠進一步提高力學特性。The lower limit of the extension temperature in the longitudinal direction (hereinafter also referred to as the MD direction) is preferably 55°C, more preferably 60°C. If it is 55°C or higher, fracture can be further suppressed. In addition, it is possible to prevent the alignment in the longitudinal direction from becoming too strong, and it is possible to suppress an increase in the thermal shrinkage rate in the MD direction. The upper limit of the stretching temperature in the MD direction is preferably 100°C, more preferably 95°C. If it is 100° C. or less, the alignment can be sufficiently imparted, and the mechanical properties can be further improved.

MD方向的延伸倍率的下限較佳為2.5倍，尤佳為2.7倍。若為2.5倍以上，則能夠充分地賦予配向，能夠進一步提高力學特性。另外，若為2.5倍以上，則能夠抑制厚度不均，能夠防止膜輥的鬆弛。 MD方向的延伸倍率的上限較佳為3.8倍，更佳為3.6倍，尤佳為3.4倍。若為3.8倍以下，則能充分地獲得力學強度及厚度不均改善之效果。The lower limit of the stretching ratio in the MD direction is preferably 2.5 times, and particularly preferably 2.7 times. If it is 2.5 times or more, the alignment can be sufficiently imparted, and the mechanical properties can be further improved. Moreover, if it is 2.5 times or more, thickness unevenness can be suppressed, and the slack of a film roll can be prevented. The upper limit of the stretching ratio in the MD direction is preferably 3.8 times, more preferably 3.6 times, and particularly preferably 3.4 times. If it is 3.8 times or less, the effect of improving mechanical strength and thickness unevenness can be sufficiently obtained.

寬度方向(以下，亦稱為TD方向)的延伸溫度的下限較佳為55℃，更佳為60℃。若為55℃以上，則能夠不易引起斷裂。另外，能夠防止橫向的配向變得過強，能夠抑制TD方向的熱收縮率變大。 TD方向的延伸溫度的上限較佳為100℃，更佳為95℃。若為100℃以下，能夠充分地賦予配向，能夠進一步提高力學特性。The lower limit of the stretching temperature in the width direction (hereinafter, also referred to as the TD direction) is preferably 55°C, more preferably 60°C. If it is 55°C or higher, it is less likely to cause breakage. In addition, it is possible to prevent the alignment in the lateral direction from becoming too strong, and it is possible to suppress an increase in the thermal shrinkage in the TD direction. The upper limit of the stretching temperature in the TD direction is preferably 100°C, more preferably 95°C. If it is 100° C. or less, the alignment can be sufficiently imparted, and the mechanical properties can be further improved.

TD方向的延伸倍率的下限較佳為3.5倍，更佳為3.6倍，尤佳為3.7倍。若為3.5倍以上，則能夠增大寬度方向的配向度，能夠提高力學強度。 TD方向的延伸倍率的上限較佳為5.0倍，更佳為4.6倍，尤佳為4.3倍。若為5.0倍以下，則能充分地獲得力學強度及厚度不均改善之效果。The lower limit of the stretching ratio in the TD direction is preferably 3.5 times, more preferably 3.6 times, and particularly preferably 3.7 times. If it is 3.5 times or more, the degree of alignment in the width direction can be increased, and the mechanical strength can be improved. The upper limit of the stretching ratio in the TD direction is preferably 5.0 times, more preferably 4.6 times, and particularly preferably 4.3 times. If it is 5.0 times or less, the effect of improving mechanical strength and thickness unevenness can be sufficiently obtained.

熱固定溫度的下限較佳為170℃，更佳為180℃。若為170℃以上，則能夠進一步減少熱收縮率。熱固定溫度的上限較佳為220℃。若為220℃以下，則能夠抑制膜熔融、或穿刺強度降低。The lower limit of the heat fixing temperature is preferably 170°C, more preferably 180°C. If it is 170°C or higher, the thermal shrinkage rate can be further reduced. The upper limit of the heat fixation temperature is preferably 220°C. If it is 220° C. or less, it is possible to suppress the melting of the film and the decrease in the puncture strength.

鬆弛率的下限較佳為0.5%。若為0.5%以上，則能夠將TD方向的熱收縮率保持得低。鬆弛率的上限較佳為10%。若為10%以下，則能夠防止產生鬆弛等，能夠提高平面性。The lower limit of the relaxation rate is preferably 0.5%. If it is 0.5% or more, the thermal shrinkage rate in the TD direction can be kept low. The upper limit of the relaxation rate is preferably 10%. If it is 10% or less, it is possible to prevent generation of slack and the like, and to improve flatness.

鬆弛步驟的溫度的下限較佳為130℃，更佳為150℃。若為130℃以上，則於進行鬆弛時膜充分地收縮，能夠充分地獲得熱收縮率降低效果。鬆弛步驟溫度的上限較佳為190℃，更佳為170℃。若為190℃以下，則能夠抑制因褶皺等而產生膜的平面性的惡化。The lower limit of the temperature of the relaxation step is preferably 130°C, more preferably 150°C. If it is 130° C. or higher, the film fully shrinks during relaxation, and the thermal shrinkage rate reduction effect can be sufficiently obtained. The upper limit of the relaxation step temperature is preferably 190°C, more preferably 170°C. If it is 190°C or less, it is possible to suppress the deterioration of the flatness of the film due to wrinkles or the like.

以上，說明了本實施形態的雙軸配向聚酯膜之製造方法。 [實施例]In the above, the manufacturing method of the biaxially oriented polyester film of this embodiment was demonstrated. [Example]

其次，藉由實施例更詳細地說明本發明，但本發明並不限定於以下之例。此外，膜之評價係藉由以下之測定法進行。 [膜的厚度] 依據JIS K7130-1999 A法，使用度盤規進行測定。Next, the present invention will be explained in more detail with examples, but the present invention is not limited to the following examples. In addition, the evaluation of the film was performed by the following measurement method. [Thickness of film] According to JIS K7130-1999 A method, use a dial gauge for measurement.

[膜的穿刺強度] 自實施例、比較例中所製作之膜，分別切取縱5mm×橫5mm之樣品，該樣品以膜寬度方向的中央位置及自左右端分別朝向中央部距離10mm之位置作為中心。聚酯膜的穿刺強度係藉由下式以1μm換算來算出利用JIS-Z1707中所記載之試驗法所測定之值。穿刺強度(N/μm)＝穿刺強度實測值/膜的厚度[Puncture strength of membrane] From the films produced in the Examples and Comparative Examples, a sample of 5 mm in length x 5 mm in width was cut out, and the center of the sample was centered on the center position in the width direction of the film and the position at a distance of 10 mm from the left and right ends to the center. The puncture strength of the polyester film is a value measured by the test method described in JIS-Z1707 calculated by the following formula in 1 μm conversion. Puncture strength (N/μm) = measured value of puncture strength/thickness of film

[傅立葉轉換型紅外光譜法(全反射法)] 自實施例、比較例中所製作之膜，分別切取縱5mm×橫5mm之樣品，該樣品以自膜寬度方向的左右端部朝向中央部距離10mm之位置作為中心。使用Varian公司製造的Varian3100FT-IR，以鑽石作為介質結晶來密接於膜表層，一邊與MD方向平行地入射光線，一邊藉由全反射法測定光譜強度。分光器的解析度設為4cm^-1 、光譜累計次數設為64次而進行測定。光譜強度係設為各波數下的吸光度。藉由下式而算出。測定係對B面進行。吸光度比(A/B)＝吸光度A(1450±10cm^-1 之峰值的光譜強度)/吸光度B(1410±10cm^-1 之峰值的光譜強度)[Fourier Transform Infrared Spectroscopy (Total Reflection Method)] From the films produced in the Examples and Comparative Examples, a sample of 5 mm in length × 5 mm in width was cut out, and the sample was spaced from the left and right ends in the width direction of the film toward the center. The 10mm position is taken as the center. Using Varian 3100FT-IR manufactured by Varian, diamond was used as a medium crystal to adhere to the surface of the film, and the spectral intensity was measured by the total reflection method while incident light parallel to the MD direction. The resolution of the spectrometer was set to 4 cm ^-1 , and the number of times of spectrum integration was set to 64, and the measurement was performed. The spectral intensity is the absorbance at each wave number. Calculated by the following formula. The measurement is performed on the B side. Absorbance ratio (A/B) = Absorbance A (spectral intensity of the peak at ^{1450±10cm -1} )/Absorbance B (spectral intensity of the peak at ^{1410±10cm -1)}

[膜的面配向度ΔP] 自實施例、比較例中所製作之膜，分別切取縱5mm×橫5mm之樣品，該樣品以膜寬度方向的中央位置及自左右端分別朝向中央部距離10mm之位置作為中心。針對樣品，藉由JIS K 7142-1996 A法，將鈉D射線作為光源，使用二碘甲烷作為接觸液，藉由阿貝折射率計測定膜長度方向的折射率(Nx)、寬度方向的折射率(Ny)、厚度方向的折射率(Nz)，藉由下式算出ΔP。面配向度(ΔP)＝[(Nx＋Ny)/2]－Nz[Film orientation degree ΔP] From the films produced in the Examples and Comparative Examples, a sample of 5 mm in length x 5 mm in width was cut out, and the center of the sample was centered on the center position in the width direction of the film and the position at a distance of 10 mm from the left and right ends to the center. For the sample, according to the JIS K 7142-1996 A method, using sodium D-ray as the light source and diiodomethane as the contact liquid, the refractive index (Nx) in the length direction of the film and the refraction in the width direction were measured by an Abbe refractometer. The ratio (Ny) and the refractive index (Nz) in the thickness direction are calculated by the following formula to calculate ΔP. Surface orientation degree (ΔP)=[(Nx＋Ny)/2]－Nz

[膜的固有黏度] 自實施例、比較例中所製作之膜，分別切取縱5mm×橫5mm之樣品，該樣品以膜寬度方向的中央位置及自左右端分別朝向中央部距離10mm之位置作為中心。針對樣品，固有黏度係使用紫山科學機器製作所(股份有限)公司製造的自動黏度測定裝置「SS-600-L1」而測定。作為溶媒液，使用對氯苯酚/1,1,2,2-四氯乙烷＝6/4(質量比)之混合液。[Intrinsic viscosity of film] From the films produced in the Examples and Comparative Examples, a sample of 5 mm in length x 5 mm in width was cut out, and the center of the sample was centered on the center position in the width direction of the film and the position at a distance of 10 mm from the left and right ends to the center. For the sample, the intrinsic viscosity was measured using an automatic viscosity measuring device "SS-600-L1" manufactured by Zishan Scientific Machine Manufacturing Co., Ltd. (Co., Ltd.). As the solvent, a mixed solution of p-chlorophenol/1,1,2,2-tetrachloroethane=6/4 (mass ratio) was used.

[膜的密度] 自實施例、比較例中所製作之膜，切取縱5mm×橫5mm之樣品，該樣品以自膜寬度方向的左右端部朝向中央部距離10mm之位置作為中心。關於樣品的密度，藉由JIS K 7112之D法(密度梯度法)而測定。測定條件如下所述。表1中顯示了左端、右端之2個樣品中測定值最高的樣品。 [測定條件] 梯度液：硝酸鈣四水合物梯度管內的溫度：30℃ 樣品尺寸：5mm×5mm 浸漬時間：16小時[Density of film] From the films produced in the Examples and Comparative Examples, a sample of 5 mm in length × 5 mm in width was cut out, and the sample was centered at a distance of 10 mm from the left and right ends in the width direction of the film toward the center. The density of the sample was measured by the D method (density gradient method) of JIS K 7112. The measurement conditions are as follows. Table 1 shows the sample with the highest measured value among the two samples at the left and right ends. [Measurement conditions] Gradient solution: calcium nitrate tetrahydrate Temperature in gradient tube: 30℃ Sample size: 5mm×5mm Immersion time: 16 hours

[評價用層壓積層體之製作] 於聚酯膜的B面側，使用胺基甲酸酯系2液硬化型接著劑(將三井化學股份有限公司製造的「Takelac(註冊商標)A525S」與「Takenate(註冊商標)A50」以13.5：1(質量比)之比率進行調配)，藉由乾式層壓法，貼合厚度70μm之無延伸聚丙烯膜(東洋紡股份有限公司製造的「P1147」)作為熱密封性樹脂層，於40℃實施4天老化，藉此獲得層壓積層體。此外，由胺基甲酸酯系2液硬化型接著劑所形成之接著劑層的乾燥後的厚度均為約4μm。[Production of laminated laminate for evaluation] On the B surface side of the polyester film, a urethane-based two-component curing adhesive (Mitsui Chemicals Co., Ltd. "Takelac (registered trademark) A525S" and "Takenate (registered trademark) A50" are used with 13.5 : 1 (mass ratio) ratio), by dry lamination, a 70μm thick non-stretched polypropylene film ("P1147" manufactured by Toyobo Co., Ltd.) is laminated as a heat-sealable resin layer at 40°C Aging was carried out for 4 days, thereby obtaining a laminated body. In addition, the thickness after drying of the adhesive layer formed of the urethane-based two-liquid curing adhesive is about 4 μm.

[評價用蒸煮處理完畢製袋品之製作] 分別切取縱15cm×橫15cm之樣品，該樣品係以前述層壓積層體的寬度方向的中央位置及自左右端部朝向中央部距離30cm之位置作為中心。針對所切取之樣品，以密封劑成為內側之方式將2片重疊，將三邊以160℃之密封溫度、密封寬度1.0cm進行熱密封，藉此獲得內部尺寸13cm之三邊密封袋。此外，作為前述三邊密封袋係製作出：將自中央位置切取之2片貼合而成之袋、將自左側切取之2片貼合而成之袋、將自右側切取之2片貼合而成之袋。於所獲得之三邊密封袋中填充水250mL後，利用熱密封將第四邊之口封閉，製作填充有水之四邊密封袋。將所獲得之填充有水之四邊密封袋於130℃之熱水中浸漬30分鐘而獲得蒸煮處理完畢之袋。[Production of bag-making products after retort treatment for evaluation] A sample of 15 cm in length x 15 cm in width was cut out, and the sample was centered on the center position in the width direction of the above-mentioned laminated body and the position at a distance of 30 cm from the left and right ends to the center. Regarding the cut sample, overlap the two sheets so that the sealant becomes the inside, heat-sealing the three sides at a sealing temperature of 160°C and a sealing width of 1.0 cm, thereby obtaining a three-side sealed bag with an inner size of 13 cm. In addition, as the aforementioned three-sided sealed bag, a bag made of two pieces cut from the center, a bag made of two pieces cut from the left side, and two pieces cut from the right side glued together. The bag is made. After filling the obtained three-side sealed bag with 250 mL of water, the mouth of the fourth side was sealed by heat sealing to make a four-side sealed bag filled with water. The obtained four-side sealed bag filled with water was immersed in hot water at 130° C. for 30 minutes to obtain a bag that has been retorted.

[耐破袋性之評價] 將前述之蒸煮處理完畢之填充有水之袋於室溫5℃、相對濕度35%之環境下，自高度100cm之位置以使袋的面成為水平之方式掉落10次至混凝土板上，繼而，以使袋的面成為垂直之方式掉落10次，算出未產生破裂之袋的比率。此外，用於試驗之袋的數量係設為水平方向、垂直方向各20個。[Evaluation of bag breaking resistance] Drop the water-filled bag from a height of 100cm at a temperature of 5°C and a relative humidity of 35% on the concrete slab 10 times from a position with a height of 100cm, and then the bag filled with water after the above-mentioned retort treatment is completed. , Drop 10 times so that the surface of the bag becomes vertical, and calculate the ratio of the bag that did not break. In addition, the number of bags used for the test was set to 20 in the horizontal direction and 20 in the vertical direction.

[製膜性之評價] 於製作各實施例、比較例的膜時，將30分鐘以上無斷裂而能夠連續製膜之情形評價為〇，將於30分鐘以內產生至少1次斷裂之情形評價為×。[Evaluation of Film Formability] When the films of the respective Examples and Comparative Examples were produced, the case where the film could be continuously formed without breaking for more than 30 minutes was evaluated as ○, and the case where at least one breaking occurred within 30 minutes was evaluated as ×.

[實施例1] 使用單軸擠出機，將包含PBT樹脂(由對苯二甲酸//丁二醇＝100//100(莫耳%)所構成且固有黏度1.28dl/g)及PET樹脂(由對苯二甲酸//乙二醇＝100//100(莫耳%)所構成且固有黏度0.62dl/g，且調配有二氧化矽粒子)之雙軸配向聚酯膜製造用之樹脂組成物於290熔融後，自250℃之T字模進行澆鑄，一邊藉由靜電密接法使之密接於10℃之冷卻輥，一邊對B面自多風道送風機吹送冷風而獲得未延伸片。所獲得之未延伸片的寬度為160cm。多風道送風機係如圖1所示之結構，自吹出口31-1、吹出口31-5(以下，亦稱為吹出口1、吹出口5)吹送10℃之冷風，自吹出口31-2至吹出口31-4(以下，亦稱為吹出口2至吹出口4)吹送15℃之冷風。本實施例中，吹出口1、吹出口5的寬度分別設為40cm，吹出口2至吹出口4的橫寬分別設為32cm。對於未延伸片當中之自左右端分別朝向中央部為32cm之位置之範圍係吹送來自吹出口1或吹出口5之風，對於較前述位置更靠中央部側係吹送來自吹出口2至吹出口4之風。此時，多風道送風機的縱寬為50cm，未延伸片的移動速度為60m/分鐘。另外，自雙軸配向聚酯膜製造用之樹脂組成物澆鑄至冷卻輥之時間點(觸碰之時間點)至風吹送至該部分為止的時間為1.0秒。此外，關於雙軸配向聚酯膜製造用之樹脂組成物中的二氧化矽粒子的含量，於將雙軸配向聚酯膜製造用之樹脂組成物當作整體(100質量%)時，以二氧化矽濃度計為0.16質量%。[Example 1] Using a single-screw extruder, the PBT resin (consisting of terephthalic acid//butanediol = 100//100 (mol%) and an inherent viscosity of 1.28dl/g) and PET resin (consisting of terephthalic acid) Formic acid//ethylene glycol = 100//100 (mole%) and the intrinsic viscosity 0.62dl/g, and the resin composition for the manufacture of biaxially oriented polyester film with silica particles is melted at 290 After that, it was cast from a T-mold at 250°C, and while being adhered to a cooling roll at 10°C by an electrostatic adhesion method, cold air was blown from the multi-air duct blower to the B side to obtain an unstretched sheet. The width of the obtained unstretched sheet was 160 cm. The multi-channel air blower has the structure shown in Figure 1. It blows cold air at 10°C from the blowing outlet 31-1 and the blowing outlet 31-5 (hereinafter, also referred to as the blowing outlet 1, the blowing outlet 5), and the blowing outlet 31- 2 Blow 15°C cold air to blower port 31-4 (hereinafter, also referred to as blower port 2 to blower port 4). In this embodiment, the widths of the air outlet 1 and the air outlet 5 are each set to 40 cm, and the widths of the air outlet 2 to the air outlet 4 are each set to 32 cm. For the unstretched sheet, the area from the left and right ends to the center of 32 cm is blowing the wind from the blowing outlet 1 or the blowing outlet 5. For the center side of the position, the blowing is blowing from the blowing outlet 2 to the blowing outlet. 4 winds. At this time, the vertical width of the multi-air duct blower was 50 cm, and the moving speed of the unstretched sheet was 60 m/min. In addition, the time from the moment when the resin composition for the production of the biaxially oriented polyester film was cast to the time when the cooling roll was touched (the time when it was touched) to when the wind was blown to this part was 1.0 second. In addition, regarding the content of silica particles in the resin composition for the production of biaxially oriented polyester film, when the resin composition for the production of the biaxially oriented polyester film is taken as a whole (100% by mass), the The silica concentration was 0.16 mass%.

繼而，將所獲得之未延伸片於70℃之溫度下沿長度方向(MD方向)以3.3倍進行延伸，繼而，通入拉幅機於80℃沿寬度方向(TD方向)以4.0倍進行延伸，於200℃實施3秒之熱固定處理及1秒之9%之緩和處理，獲得厚度15μm之雙軸配向聚酯膜。雙軸配向聚酯膜製造用之樹脂組成物中的樹脂組成及製膜條件示於表1。另外，所獲得之膜的物性及評價結果示於表1。Then, the obtained unstretched sheet was stretched 3.3 times in the length direction (MD direction) at a temperature of 70°C, and then stretched 4.0 times in the width direction (TD direction) at 80°C through a tenter , Heat-fixing treatment for 3 seconds and 9% relaxation treatment for 1 second at 200°C, to obtain a biaxially oriented polyester film with a thickness of 15μm. Table 1 shows the resin composition and film forming conditions in the resin composition for the production of biaxially oriented polyester film. In addition, the physical properties and evaluation results of the obtained film are shown in Table 1.

[實施例2至實施例4] 如表1所記載般變更樹脂組成，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜的物性及評價結果示於表1。[Example 2 to Example 4] Except having changed the resin composition as described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The physical properties and evaluation results of the obtained film are shown in Table 1.

[實施例5] 如表1所記載般變更模具溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜的物性及評價結果示於表1。[Example 5] Except changing the mold temperature as described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The physical properties and evaluation results of the obtained film are shown in Table 1.

[實施例6] 如表1所記載般變更熱處理溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜的物性及評價結果示於表1。[Example 6] Except changing the heat treatment temperature as described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The physical properties and evaluation results of the obtained film are shown in Table 1.

[實施例7] 如表1所記載般變更樹脂組成，除此以外，與實施例6同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜的物性及評價結果示於表1。[Example 7] Except having changed the resin composition as described in Table 1, film formation was performed in the same manner as in Example 6 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The physical properties and evaluation results of the obtained film are shown in Table 1.

[比較例1] 將多風道送風機的吹出口1、吹出口5的冷風溫度變更為表1所記載之溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於膜端部的密度大且結晶性差大，故而製膜性不良。[Comparative Example 1] Except having changed the cold air temperature of the blower outlet 1 of the multi-channel air blower 1 and the blower outlet 5 to the temperature described in Table 1, film formation was performed in the same manner as in Example 1, and a biaxially oriented polyester film with a thickness of 15 μm was obtained. The film obtained had a high density at the end of the film and a large difference in crystallinity, and thus had poor film forming properties.

[比較例2] 將自熔融樹脂的模具接觸於冷卻輥之時間變更為表1所記載之時間，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於膜端部的密度大且結晶性差大，故而製膜性不良。[Comparative Example 2] Except having changed the time when the mold from the molten resin was in contact with the cooling roll to the time described in Table 1, film formation was carried out in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The film obtained had a high density at the end of the film and a large difference in crystallinity, and thus had poor film forming properties.

[比較例3] 將模具溫度變更為表1所記載之溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於膜的固有黏度低，膜端部的密度大且結晶性差大，故而製膜性不良，不僅如此，由於穿刺強度低，故而耐破袋性不良。[Comparative Example 3] Except having changed the mold temperature to the temperature described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. Due to the low inherent viscosity of the film, the high density at the end of the film and the large difference in crystallinity, the obtained film has poor film-forming properties. Not only that, but also has poor bag-break resistance due to low puncture strength.

[比較例4] 將熱處理溫度變更為表1所記載之溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於穿刺強度低，故而耐破袋性不良。[Comparative Example 4] Except having changed the heat treatment temperature to the temperature described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The obtained film has low puncture strength, and therefore has poor bag-break resistance.

[比較例5] 將樹脂組成變更為表1所記載之比率，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於穿刺強度低，故而耐破袋性不良。[Comparative Example 5] Except having changed the resin composition to the ratio described in Table 1, film formation was performed in the same manner as in Example 1 to obtain a biaxially oriented polyester film with a thickness of 15 μm. The obtained film has low puncture strength, and therefore has poor bag-break resistance.

[比較例6] 將樹脂組成變更為表1所記載之比率，及將多風道送風機的吹出口1、吹出口5的冷風溫度變更為表1所記載之溫度，除此以外，與實施例1同樣地進行製膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於膜端部的密度大且結晶性差大，故而製膜性不良。[Comparative Example 6] The resin composition was changed to the ratio described in Table 1, and the temperature of the cold air at the blower outlet 1 and the blower outlet 5 of the multi-channel blower was changed to the temperature described in Table 1, except that it was produced in the same manner as in Example 1. Film to obtain a biaxially aligned polyester film with a thickness of 15 μm. The film obtained had a high density at the end of the film and a large difference in crystallinity, and thus had poor film forming properties.

[比較例7] 實施例1中，未進行利用多風道送風機之未延伸膜B面之冷卻，除此以外，與實施例1同樣地製作雙軸延伸膜，獲得厚度15μm之雙軸配向聚酯膜。所獲得之膜由於膜端部的密度大且結晶性差大，故而製膜性不良。[Comparative Example 7] In Example 1, a biaxially stretched film was produced in the same manner as in Example 1 except that cooling of the B side of the unstretched film by a multi-air blower was not performed to obtain a biaxially oriented polyester film with a thickness of 15 μm. The film obtained had a high density at the end of the film and a large difference in crystallinity, and thus had poor film forming properties.

[表1]

[Table 1]

10:模具 12:噴出口 20:冷卻輥 30:多風道送風機 31(31-1,31-2,31-3,31-4,31-5):吹出口 32:間隔板 40:未延伸片10: Mould 12: Ejector 20: cooling roll 30: Multi-air duct blower 31 (31-1, 31-2, 31-3, 31-4, 31-5): blowout outlet 32: Spacer 40: Unextended piece

[圖1]係用以說明對冷卻輥上的未延伸片的B面吹送來自多風道送風機之冷卻風之方法之前視示意圖。 [圖2]係圖1的側視圖。 [圖3]係表示多風道送風機的一例之仰視圖。[Fig. 1] It is a schematic front view for explaining the method of blowing cooling air from a multi-air duct blower to the B side of the unstretched sheet on the cooling roll. [Fig. 2] is a side view of Fig. 1. [Fig. 3] A bottom view showing an example of a multi-channel air blower.

10:模具 10: Mould

12:噴出口 12: Ejector

20:冷卻輥 20: cooling roll

30:多風道送風機 30: Multi-air duct blower

40:未延伸片 40: Unextended piece

Claims

一種雙軸配向聚酯膜，包含含有聚對苯二甲酸丁二酯樹脂(A)75質量%至100質量%之聚酯樹脂組成物；滿足下述要件(1)至要件(3)； (1)以依據JIS-Z1707之穿刺試驗所測定之雙軸配向聚酯膜的穿刺強度為0.50N/μm以上； (2)於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別依據JIS-K7112所測定之密度中最高值為1.40g/cm³ 以下； (3)雙軸配向聚酯膜的固有黏度為0.7dl/g以上。A biaxially aligned polyester film, comprising a polyester resin composition containing 75% to 100% by mass of polybutylene terephthalate resin (A); meeting the following requirements (1) to (3); 1) The puncture strength of the biaxially oriented polyester film measured by the puncture test according to JIS-Z1707 is 0.50 N/μm or more; (2) In the width direction of the biaxially oriented polyester film, the Sampling was performed at a position of 10 mm in the center, and the highest value of the density measured according to JIS-K7112 was 1.40 g/cm ³ or less; (3) The inherent viscosity of the biaxially oriented polyester film was 0.7 dl/g or more.

如請求項1所記載之雙軸配向聚酯膜，其中前述聚酯樹脂組成物含有聚對苯二甲酸丁二酯樹脂(A)以外的聚酯樹脂(B)。The biaxially oriented polyester film according to claim 1, wherein the polyester resin composition contains a polyester resin (B) other than the polybutylene terephthalate resin (A).

如請求項1所記載之雙軸配向聚酯膜，其中於雙軸配向聚酯膜的寬度方向上，對於自左右端分別朝向中央部為10mm之位置進行取樣，分別求出使用傅立葉轉換型紅外光譜法光譜強度中之全反射法所獲得之1450±10cm^-1 之峰值的吸收強度A與1410±10cm^-1 之峰值的吸收強度B之比A/B時，最高值為0.62以下。The biaxially oriented polyester film described in claim 1, wherein in the width direction of the biaxially oriented polyester film, samples are taken at a position 10 mm from the left and right ends to the center respectively, and the Fourier transform infrared When the ratio of the absorption intensity A of the peak ^{of 1450±10cm -1} obtained by the total reflection method in the spectral intensity to the ^{absorption intensity B of the peak of 1410±10cm -1} is A/B, the maximum value is 0.62 or less.

如請求項1至3中任一項所記載之雙軸配向聚酯膜，其中雙軸配向聚酯膜的面配向度ΔP為0.145至0.160。The biaxially oriented polyester film according to any one of claims 1 to 3, wherein the plane alignment degree ΔP of the biaxially oriented polyester film is 0.145 to 0.160.

一種雙軸配向聚酯膜之製造方法，具有：步驟A，係將雙軸配向聚酯膜製造用之樹脂組成物澆鑄於冷卻輥而形成未延伸片；步驟B，係對前述冷卻輥上的前述未延伸片吹送風；前述步驟B係於將未延伸片全寬設為100%時，將吹送至中央之風的溫度設為X，將吹送至兩端部之溫度設為Y時，前述X為15℃以下，且前述Y為較前述X低之溫度；前述端部至少包含自端緣起10%以內的區域。A manufacturing method of biaxially aligned polyester film, which has: Step A: Casting the resin composition for manufacturing the biaxially oriented polyester film on a cooling roll to form an unstretched sheet; Step B, blowing air to the unstretched sheet on the cooling roll; In the aforementioned step B, when the full width of the unstretched sheet is set to 100%, the temperature of the wind blowing to the center is set to X, and when the temperature blowing to both ends is set to Y, the aforementioned X is 15°C or less, and The aforementioned Y is a lower temperature than the aforementioned X; The aforementioned end includes at least an area within 10% from the end edge.

如請求項5所記載之雙軸配向聚酯膜之製造方法，其中前述Y為10℃以下。The method for producing a biaxially oriented polyester film as described in claim 5, wherein the aforementioned Y is 10°C or less.