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CN107710032B - White reflective film for large displays - Google Patents

White reflective film for large displays Download PDF

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Publication number
CN107710032B
CN107710032B CN201680037837.0A CN201680037837A CN107710032B CN 107710032 B CN107710032 B CN 107710032B CN 201680037837 A CN201680037837 A CN 201680037837A CN 107710032 B CN107710032 B CN 107710032B
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thermoplastic resin
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CN107710032A (en
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浅井真人
仓垣雅弘
冈田真一郎
大泽利洋
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Toyobo Film Solutions Ltd
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Teijin Film Solutions Ltd
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Priority claimed from JP2015142209A external-priority patent/JP2017026676A/en
Priority claimed from JP2015167587A external-priority patent/JP2017044886A/en
Priority claimed from JP2016077384A external-priority patent/JP6837285B2/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/18Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00Reflectors for light sources
    • F21V7/22Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
    • F21V7/28Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by coatings
    • F21V7/30Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by coatings the coatings comprising photoluminescent substances
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/06Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/36Layered products comprising a layer of synthetic resin comprising polyesters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00Reflectors for light sources
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00Reflectors for light sources
    • F21V7/22Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/08Mirrors
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00Properties of the layers or laminate
    • B32B2307/40Properties of the layers or laminate having particular optical properties
    • B32B2307/416Reflective

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Laminated Bodies (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

本发明的课题在于提供一种具有优异的反射特性的同时,不易热变形的白色反射膜。该课题是由具有下述反射层A的白色反射膜达成,反射层A满足以下a、b的任一个,a.包含热塑性树脂组合物A1,所述热塑性树脂组合物A1是在热塑性树脂A中含有碳酸钙粒子,该碳酸钙粒子的含量相对于上述热塑性树脂组合物A1的质量为10质量%~70质量%,或者b.包含热塑性树脂组合物A2,所述热塑性树脂组合物A2是在热塑性树脂A中含有碳酸钙粒子以及与该热塑性树脂A不相容的树脂,该碳酸钙粒子的含量相对于上述热塑性树脂组合物A2的质量为5质量%~69质量%,该不相容树脂的含量相对于上述热塑性树脂组合物A2的质量为1质量%~40质量%,上述碳酸钙粒子与上述不相容树脂的含量之和相对于上述热塑性树脂组合物A2的质量为10质量%~70质量%,并且上述碳酸钙粒子的平均粒径为0.1μm~1.2μm,从小粒径侧累积而得的10%体积粒径D10、50%体积粒径D50以及90%体积粒径D90满足(D90‑D10)/D50≦1.6,膜的反射率在60%以上。

Figure 201680037837

An object of the present invention is to provide a white reflective film that is not easily thermally deformed while having excellent reflective properties. This problem is achieved by a white reflective film having a reflective layer A that satisfies any one of the following a and b, a. contains a thermoplastic resin composition A1 in which the thermoplastic resin A1 is contained Contains calcium carbonate particles, the content of the calcium carbonate particles is 10% by mass to 70% by mass relative to the mass of the thermoplastic resin composition A1, or b. The thermoplastic resin composition A2 is contained in the thermoplastic resin composition A2. Resin A contains calcium carbonate particles and resins incompatible with the thermoplastic resin A, and the content of the calcium carbonate particles is 5% by mass to 69% by mass relative to the mass of the thermoplastic resin composition A2. The content is 1% by mass to 40% by mass relative to the mass of the thermoplastic resin composition A2, and the sum of the content of the calcium carbonate particles and the incompatible resin is 10% by mass to 70% by mass relative to the mass of the thermoplastic resin composition A2 % by mass, and the average particle diameter of the calcium carbonate particles is 0.1 μm to 1.2 μm, and the 10% volume particle diameter D10, 50% volume particle diameter D50 and 90% volume particle diameter D90 accumulated from the small particle diameter side satisfy (D90 ‑D10)/D50≦1.6, the reflectivity of the film is above 60%.

Figure 201680037837

Description

大型显示器用白色反射膜White reflective film for large displays

技术领域technical field

本发明涉及可适用作反射板的大型显示器用白色反射膜。The present invention relates to a white reflective film for large-scale displays that can be used as a reflective plate.

背景技术Background technique

面光源是在背面配置反射板,由该反射板将光源发出的光反射至前面从而提高光的提取效率,进而提高亮度。In the surface light source, a reflector is arranged on the back side, and the reflector plate reflects the light emitted by the light source to the front side, thereby improving the light extraction efficiency and further improving the brightness.

例如液晶显示装置(以下也称为LCD。)的背光单元中具有如下类型:在液晶显示面板的背面具备光源以及反射膜的直下型,和在液晶显示面板的背面配置背面具备反射板的导光板,在该导光板的侧面具备光源的侧光型。作为光源,现今一直使用有CCFL,但近年来出于低功耗化或薄型化的需求,使用有发光二极管(以下也称LED。),侧光型LED背光源或直下型LED背光源成为主流。侧光型背光源具有使LCD更薄型化的优点,另一方面,直下型LED背光源具有不使用导光板而为低成本的优点。For example, the backlight unit of a liquid crystal display device (hereinafter also referred to as LCD.) has the following types: a direct type having a light source and a reflective film on the back of the liquid crystal display panel, and a light guide plate having a reflective plate on the back of the liquid crystal display panel. , and a side-light type with a light source provided on the side of the light guide plate. As a light source, CCFLs have been used today, but in recent years, light emitting diodes (hereinafter also referred to as LEDs) are used due to the demand for low power consumption and thinning, and edge-type LED backlights or direct-type LED backlights have become mainstream. . The edge type backlight has the advantage of making the LCD thinner, while the direct type LED backlight has the advantage of being low-cost without using a light guide plate.

面光源也可以用作对屋内外进行照明的照明用用途。The surface light source can also be used for lighting purposes for lighting inside and outside the house.

作为反射板,一直使用有例如在聚酯等热塑性树脂中添加无机粒子或不相容树脂,将其拉伸制膜而在内部形成空隙的含空隙膜(专利文献1~5)。As a reflector, for example, a void-containing film in which an inorganic particle or an incompatible resin is added to a thermoplastic resin such as polyester and stretched to form a void therein has been used (Patent Documents 1 to 5).

然而,这样的反射板存在由光源或外部环境发出的热或湿度而变形弯曲的情况(以下也将该弯曲称为“热变形”。)。反射板弯曲的话,会成为面光源的亮度不均,例如L CD画面中的明亮程度不均。However, such a reflection plate may be deformed and bent by heat or humidity emitted from a light source or an external environment (this bending is also referred to as "thermal deformation" hereinafter). If the reflector is curved, the brightness of the surface light source will be uneven, for example, the brightness of the LCD screen will be uneven.

因此为了解决热变形问题,专利文献6中提出了通过将金属层形成在由粒子所形成的凹凸面上的反射面,即便是弯曲也不易成为亮度不均的思想。此外,还讨论了在LCD的底面构件形成突起部以支撑反射板(专利文献7),以及通过在反射板上加入吸收弯曲的狭缝(专利文献8),从而改善反射板的弯曲。然而,这些加工均存在耗费成本的问题。Therefore, in order to solve the problem of thermal deformation, Patent Document 6 proposes an idea that uneven brightness is less likely to occur even when curved by forming a metal layer on a reflective surface formed by particles on a concavo-convex surface. In addition, forming protrusions on the bottom surface member of the LCD to support the reflective plate (Patent Document 7), and improving the curvature of the reflective plate by adding bending-absorbing slits in the reflective plate (Patent Document 8) have also been discussed. However, these processes all have the problem of being expensive.

【专利文献1】日本专利特开2004-330727号公报[Patent Document 1] Japanese Patent Laid-Open No. 2004-330727

【专利文献2】日本专利特开2011-11370号公报[Patent Document 2] Japanese Patent Laid-Open No. 2011-11370

【专利文献3】日本专利特开2011-232369号公报[Patent Document 3] Japanese Patent Laid-Open No. 2011-232369

【专利文献4】日本专利特开2013-88715号公报[Patent Document 4] Japanese Patent Laid-Open No. 2013-88715

【专利文献5】日本专利特开2013-88716号公报[Patent Document 5] Japanese Patent Laid-Open No. 2013-88716

【专利文献6】日本专利特开2002-100227号公报[Patent Document 6] Japanese Patent Laid-Open No. 2002-100227

【专利文献7】日本专利特开2013-229185号公报[Patent Document 7] Japanese Patent Laid-Open No. 2013-229185

【专利文献8】日本专利特开2014-22060号公报[Patent Document 8] Japanese Patent Laid-Open No. 2014-22060

发明内容SUMMARY OF THE INVENTION

发明要解决的课题The problem to be solved by the invention

大型显示器由于背侧机箱(back chassis)中有电路基板等,因而有凹陷。本发明人发现这种凹陷易于滞留热,由该热进一步使热变形问题变得显著,故而着眼于此。A large display has a recess due to a circuit board or the like in the back chassis. The inventors of the present invention have found that such depressions tend to retain heat, and this heat further increases the problem of thermal deformation, and has focused on this.

鉴于上述背景技术,本发明的课题在于提供一种具有优异的反射特性的同时,用作大型显示器也不易热变形的白色反射膜。In view of the above-mentioned background art, an object of the present invention is to provide a white reflective film that has excellent reflective properties and is not easily thermally deformed when used as a large-scale display.

解决课题的方法solution to the problem

本发明人着眼于含空隙膜中空隙的存在更易于产生热变形。然而,单纯降低空隙会降低反射特性故并不优选。此外,作为空隙形成剂的无机粒子的重量,重量太重也易于产生热变形,本发明人也着眼于此。The present inventors focused on the presence of voids in the void-containing film that is more prone to thermal deformation. However, simply reducing the voids is not preferable because the reflection characteristics are lowered. In addition, the weight of the inorganic particles as the void-forming agent is too heavy, and thermal deformation is liable to occur, and the inventors of the present invention also paid attention to this.

即本发明为了达成上述课题,采用以下构成。That is, in order to achieve the above-mentioned subject, this invention employs the following structures.

1.一种大型显示器用白色反射膜,其是具有反射层A的白色反射膜,1. A white reflective film for large-scale displays, which is a white reflective film having a reflective layer A,

所述反射层A满足下述a、b中的任意一个:The reflective layer A satisfies any one of the following a and b:

a.包含热塑性树脂组合物A1,所述热塑性树脂组合物A1是在热塑性树脂A中含有碳酸钙粒子,该碳酸钙粒子的含量相对于所述热塑性树脂组合物A1的质量为10质量%以上、70质量%以下,a. comprising a thermoplastic resin composition A1 that contains calcium carbonate particles in the thermoplastic resin A, and the content of the calcium carbonate particles is 10% by mass or more relative to the mass of the thermoplastic resin composition A1, 70% by mass or less,

或者,or,

b.包含热塑性树脂组合物A2,所述热塑性树脂组合物A2是在热塑性树脂A中含有碳酸钙粒子以及与该热塑性树脂A不相容的树脂,该碳酸钙粒子的含量相对于所述热塑性树脂组合物A2的质量为5质量%以上、69质量%以下,该不相容树脂的含量相对于所述热塑性树脂组合物A2的质量为1质量%以上、40质量%以下,所述碳酸钙粒子与所述不相容树脂的含量之和相对于所述热塑性树脂组合物A2的质量为10质量%以上、70质量%以下,b. comprising a thermoplastic resin composition A2 that contains calcium carbonate particles in the thermoplastic resin A and a resin incompatible with the thermoplastic resin A, the content of the calcium carbonate particles is relative to the thermoplastic resin The mass of the composition A2 is 5 mass % or more and 69 mass % or less, the content of the incompatible resin is 1 mass % or more and 40 mass % or less with respect to the mass of the thermoplastic resin composition A2, and the calcium carbonate particles The sum of the content with the incompatible resin is 10 mass % or more and 70 mass % or less with respect to the mass of the thermoplastic resin composition A2,

所述碳酸钙粒子的平均粒径为0.1μm以上、1.2μm以下,从小粒径侧累积而得的10%体积粒径D10、50%体积粒径D50以及90%体积粒径D90满足(D90-D10)/D50≦1.6,The average particle diameter of the calcium carbonate particles is 0.1 μm or more and 1.2 μm or less, and the 10% volume particle diameter D10, 50% volume particle diameter D50 and 90% volume particle diameter D90 accumulated from the small particle diameter side satisfy (D90- D10)/D50≦1.6,

膜的反射率在60%以上。The reflectance of the film is above 60%.

2.上述1所述的白色反射膜,所述反射层A为a.包含热塑性树脂组合物A1,所述热塑性树脂组合物A1是在热塑性树脂A中含有碳酸钙粒子,该碳酸钙粒子的含量相对于所述热塑性树脂组合物A1的质量为10质量%以上、70质量%以下。2. The white reflective film described in 1 above, wherein the reflective layer A is a. It contains a thermoplastic resin composition A1 that contains calcium carbonate particles in the thermoplastic resin A, and the content of the calcium carbonate particles is It is 10 mass % or more and 70 mass % or less with respect to the mass of the thermoplastic resin composition A1.

3.上述1所述的白色反射膜,所述反射层A为b.包含热塑性树脂组合物A2,所述热塑性树脂组合物A2是在热塑性树脂A中含有碳酸钙粒子以及与该热塑性树脂A不相容的树脂,该碳酸钙粒子的含量相对于所述热塑性树脂组合物A2的质量为5质量%以上、69质量%以下,该不相容树脂的含量相对于所述热塑性树脂组合物A2的质量为1质量%以上、40质量%以下,所述碳酸钙粒子与所述不相容树脂的含量之和相对于所述热塑性树脂组合物A2的质量为10质量%以上、70质量%以下。3. The white reflective film described in 1 above, wherein the reflective layer A is b. It contains a thermoplastic resin composition A2 that contains calcium carbonate particles in the thermoplastic resin A and is incompatible with the thermoplastic resin A. Compatible resin, the content of the calcium carbonate particles is 5 mass % or more and 69 mass % or less relative to the mass of the thermoplastic resin composition A2, and the content of the incompatible resin is relative to the thermoplastic resin composition A2. The mass is 1 mass % or more and 40 mass % or less, and the sum of the content of the calcium carbonate particles and the incompatible resin is 10 mass % or more and 70 mass % or less with respect to the mass of the thermoplastic resin composition A2.

4.上述1~3的任意一项所述的大型显示器用白色反射膜,其具有所述反射层A,且还在膜的至少一个表面具有表面层C,4. The white reflective film for large-scale displays according to any one of 1 to 3 above, which has the reflective layer A and further has a surface layer C on at least one surface of the film,

所述表面层C包含含有表面层粒子的热塑性树脂组合物C,该表面层粒子的平均粒径为2.0μm以上、50.0μm以下,相对于该热塑性树脂组合物C的体积,该表面层粒子的含量是3体积%以上、50体积%以下。The surface layer C includes a thermoplastic resin composition C containing surface layer particles, the average particle diameter of the surface layer particles is 2.0 μm or more and 50.0 μm or less, and relative to the volume of the thermoplastic resin composition C, the surface layer particles have an average particle diameter of 2.0 μm or more. The content is not less than 3% by volume and not more than 50% by volume.

5.上述1~4的任意一项所述的白色反射膜,所述热塑性树脂A是共聚聚对苯二甲酸乙二醇酯。5. The white reflective film according to any one of 1 to 4 above, wherein the thermoplastic resin A is a copolymerized polyethylene terephthalate.

6.上述5所述的白色反射膜,所述共聚聚对苯二甲酸乙二醇酯的共聚量相对于该共聚聚对苯二甲酸乙二醇酯的总酸成分100摩尔%为1摩尔%以上、20摩尔%以下。6. The white reflective film according to 5 above, wherein the copolymerization amount of the copolymerized polyethylene terephthalate is 1 mol % with respect to 100 mol % of the total acid content of the copolymerized polyethylene terephthalate more than 20 mol% or less.

7.上述1~6的任意一项所述的白色反射膜,相对于白色反射膜的厚度100%,所述反射层A的厚度比例在50%以上。7. The white reflective film according to any one of 1 to 6 above, wherein the ratio of the thickness of the reflective layer A to 100% of the thickness of the white reflective film is 50% or more.

8.上述1~7的任意一项所述的白色反射膜,其进一步具有热塑性树脂B或者包含热塑性树脂组合物B的支撑层B。8. The white reflective film according to any one of 1 to 7 above, further comprising a thermoplastic resin B or a support layer B containing the thermoplastic resin composition B.

9.使用上述1~8的任意一项所述的白色反射膜的面光源。9. A surface light source using the white reflective film according to any one of 1 to 8 above.

与此相对,专利文献1中使用粒度分布的标准偏差小的硫酸钡,由于硫酸钡的比重较大,故易于产生热变形。此外,专利文献2~5中使用碳酸钙粒子,虽然对其90%体积粒径D90与10%体积粒径D10之比D90/D10进行了公开,但实际上没有研究本发明那样狭区域的粒度分布。另外各专利文献均没有意识到热变形课题,更没有以这样的观点进行讨论。On the other hand, in Patent Document 1, barium sulfate with a small standard deviation of particle size distribution is used, and since the specific gravity of barium sulfate is large, thermal deformation tends to occur. In addition, in Patent Documents 2 to 5, calcium carbonate particles are used, and although the ratio D90/D10 of the 90% volume particle diameter D90 to the 10% volume particle diameter D10 is disclosed, the particle size in a narrow region as in the present invention is not actually studied. distributed. In addition, each patent document does not recognize the subject of thermal deformation, and does not discuss it from such a viewpoint.

发明效果Invention effect

根据本发明,可以提供一种具有优异的反射特性的同时,用于大型显示器也不易热变形的白色反射膜。According to the present invention, it is possible to provide a white reflective film that is not easily thermally deformed for large-scale displays while having excellent reflective properties.

附图说明Description of drawings

【图1】本发明中的粘贴评价中使用的构成体的示意图。FIG. 1 is a schematic diagram of a structure used for the sticking evaluation in the present invention.

符号说明Symbol Description

1机箱1 Chassis

2白色反射膜、导光板、光学片的层叠物2 Laminates of white reflective film, light guide plate and optical sheet

3正三角形型台3 equilateral triangle table

4负重4 weights

具体实施方式Detailed ways

本发明的白色反射膜具有:The white reflective film of the present invention has:

(方式a)包含热塑性树脂组合物A1的反射层A,所述热塑性树脂组合物A1是在热塑性树脂A中含有特定形态的碳酸钙粒子,或者(Form a) The reflective layer A comprising a thermoplastic resin composition A1 containing calcium carbonate particles in a specific form in the thermoplastic resin A, or

(方式b)包含热塑性树脂组合物A2的反射层A,所述热塑性树脂组合物A2是在热塑性树脂A中含有特定形态的碳酸钙粒子以及与该热塑性树脂A不相容的树脂(以下也称为不相容树脂。)。(Mode b) Reflective layer A comprising a thermoplastic resin composition A2 containing calcium carbonate particles in a specific form and a resin incompatible with the thermoplastic resin A in the thermoplastic resin A (hereinafter also referred to as for incompatible resins.).

以下对构成本发明的各构成成分进行详细说明。Hereinafter, each constituent element constituting the present invention will be described in detail.

[反射层A][Reflection Layer A]

本发明中的反射层A是包含热塑性树脂组合物A1或热塑性树脂组合物A2,所述热塑性树脂组合物A1是在热塑性树脂A中含有碳酸钙粒子,所述热塑性树脂组合物A2是在热塑性树脂A中含有碳酸钙粒子和不相容树脂,所述碳酸钙粒子以及/或者不相容树脂作为空隙形成剂发挥功能而使层中含有空隙,从而呈现出白色的层。另外,也存在将热塑性树脂组合物A1与热塑性树脂组合物A2总称为热塑性树脂组合物A的情况。反射层A通过该空隙发挥反射功能。反射层A的波长550nm中的反射率优选80%以上,进一步优选90%以上,特别优选95%以上。据此,易于使白色反射膜的反射率在优选范围内。The reflective layer A in the present invention contains a thermoplastic resin composition A1 or a thermoplastic resin composition A2, the thermoplastic resin composition A1 contains calcium carbonate particles in the thermoplastic resin A, and the thermoplastic resin composition A2 is in the thermoplastic resin. A contains calcium carbonate particles and an incompatible resin, and the calcium carbonate particles and/or the incompatible resin function as a void-forming agent to include voids in the layer, thereby exhibiting a white layer. In addition, the thermoplastic resin composition A1 and the thermoplastic resin composition A2 may be collectively referred to as the thermoplastic resin composition A in some cases. The reflection layer A exhibits a reflection function through the voids. The reflectance of the reflection layer A at a wavelength of 550 nm is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. Accordingly, it is easy to make the reflectance of the white reflective film within a preferable range.

反射层A如上所述在层中具有空隙,优选该空隙的体积相对于反射层A的体积所占的比例,即空隙体积率在15体积%以上、70体积%以下。通过使之在该范围内,可以增加提高反射率的效果,易于获得上述的反射率。此外,还可增加提高拉伸制膜性的效果。空隙体积率过低时,具有难以获得优选的反射率的倾向。基于这样的观点,反射层A中的空隙体积率进一步优选30体积%以上,特别优选40体积%以上。另一方面,空隙体积率过高时,具有提高拉伸制膜性的效果降低的倾向。基于这样的观点,反射层A中的空隙体积率进一步优选65体积%以下,特别优选60体积%以下。The reflection layer A has voids in the layer as described above, and the volume ratio of the voids to the volume of the reflection layer A, that is, the void volume ratio is preferably 15% by volume or more and 70% by volume or less. By setting it within this range, the effect of improving the reflectance can be increased, and the above-mentioned reflectance can be easily obtained. In addition, the effect of improving stretch film formability can be increased. When the void volume ratio is too low, it tends to be difficult to obtain a preferable reflectance. From such a viewpoint, the void volume ratio in the reflection layer A is more preferably 30% by volume or more, and particularly preferably 40% by volume or more. On the other hand, when the void volume ratio is too high, the effect of improving stretch film formability tends to decrease. From such a viewpoint, the void volume ratio in the reflection layer A is more preferably 65% by volume or less, particularly preferably 60% by volume or less.

空隙体积率通过调整反射层A中的碳酸钙粒子的大小或量、不相容树脂的种类或量来达成。The void volume ratio is achieved by adjusting the size or amount of calcium carbonate particles in the reflective layer A, and the type or amount of incompatible resins.

(热塑性树脂A)(thermoplastic resin A)

作为构成反射层A的热塑性树脂A,可列举例如聚酯、聚烯烃、聚苯乙烯、丙烯酸构成的热塑性树脂。其中,基于获得机械特性以及热稳定性优异的白色反射膜的观点,优选聚酯。As thermoplastic resin A which comprises the reflection layer A, the thermoplastic resin which consists of polyester, polyolefin, polystyrene, and acrylic is mentioned, for example. Among them, polyester is preferable from the viewpoint of obtaining a white reflective film excellent in mechanical properties and thermal stability.

作为该聚酯,优选使用包含二羧酸成分和二醇成分的聚酯。作为该二羧酸成分,可列举对苯二甲酸成分、间苯二甲酸成分、2,6-萘二羧酸成分、4,4’-二苯基二羧酸成分、己二酸成分、癸二酸成分。作为二醇成分,可列举乙二醇成分、1,4-丁二醇成分、1,4-环己烷二甲醇成分、1,6-己二醇成分。这些聚酯之中,优选芳香族聚酯,特别优选聚对苯二甲酸乙二醇酯。聚酯以及优选的聚对苯二甲酸乙二醇酯可以是均聚物,但基于将膜进行单轴或双轴拉伸时结晶化得到抑制、增加提高拉伸制膜性效果的点,优选共聚聚酯以及进一步优选共聚聚对苯二甲酸乙二醇酯。作为共聚成分,可以列举上述的二羧酸成分或二醇成分,但基于耐热性高、提高拉伸制膜性效果高的观点,优选间苯二甲酸成分、2,6-萘二羧酸成分。共聚成分的含有比例以聚酯的总二羧酸成分100摩尔%为基准,例如1摩尔%以上,优选2摩尔%以上,进一步优选3摩尔%以上,特别优选7摩尔%以上,此外,例如20摩尔%以下,优选18摩尔%以下,进一步优选15摩尔%以下,特别优选11摩尔%以下。通过使共聚成分的比例在该范围内,提高拉伸制膜性的效果优异。此外,热尺寸稳定性优异。进一步,可进一步提高热变形的抑制效果。As the polyester, a polyester containing a dicarboxylic acid component and a diol component is preferably used. As the dicarboxylic acid component, a terephthalic acid component, an isophthalic acid component, a 2,6-naphthalenedicarboxylic acid component, a 4,4'-diphenyldicarboxylic acid component, an adipic acid component, and a decane are mentioned. Diacid components. As a diol component, an ethylene glycol component, a 1, 4- butanediol component, a 1, 4- cyclohexane dimethanol component, and a 1, 6- hexanediol component are mentioned. Among these polyesters, aromatic polyesters are preferable, and polyethylene terephthalate is particularly preferable. Polyesters and preferably polyethylene terephthalate may be homopolymers, but are preferred because crystallization is suppressed when the film is uniaxially or biaxially stretched, and the effect of improving the stretchable film formability is increased. Copolyesters and further preferably copolyethylene terephthalate. Examples of the copolymerization component include the above-mentioned dicarboxylic acid components and diol components, but from the viewpoints of high heat resistance and high effect of improving stretch film-forming properties, isophthalic acid components and 2,6-naphthalenedicarboxylic acid are preferred. Element. The content ratio of the copolymerization component is based on 100 mol % of the total dicarboxylic acid content of the polyester, for example, 1 mol % or more, preferably 2 mol % or more, more preferably 3 mol % or more, particularly preferably 7 mol % or more, and, for example, 20 mol % or more. mol% or less, preferably 18 mol% or less, more preferably 15 mol% or less, particularly preferably 11 mol% or less. By making the ratio of a copolymerization component into this range, the effect of improving stretch film formability is excellent. In addition, thermal dimensional stability is excellent. Furthermore, the effect of suppressing thermal deformation can be further enhanced.

该热塑性树脂A的熔点优选200℃以上、280℃以下。据此更易于抑制热变形。过低的话,具有热变形的抑制效果变低的倾向,过高的话,具有操作性变难的倾向。基于该观点,更优选205℃以上,进一步优选210℃以上,此外,更优选275℃以下,进一步优选265℃以下。The melting point of the thermoplastic resin A is preferably 200°C or higher and 280°C or lower. Accordingly, it is easier to suppress thermal deformation. If it is too low, the effect of suppressing thermal deformation tends to be low, and if it is too high, workability tends to be difficult. From this viewpoint, 205°C or higher is more preferable, 210°C or higher is still more preferable, and 275°C or lower is more preferable, and 265°C or lower is still more preferable.

另外,作为构成本发明中的反射层A的热塑性树脂A,可以是作为优选的热塑性树脂的聚酯与不同于该聚酯的其他热塑性树脂的混合物。In addition, as the thermoplastic resin A constituting the reflective layer A in the present invention, a mixture of polyester, which is a preferable thermoplastic resin, and other thermoplastic resins other than the polyester may be used.

(碳酸钙粒子)(Calcium Carbonate Particles)

本发明中,反射层A含有具备特定形态的碳酸钙粒子作为空隙形成剂。In the present invention, the reflection layer A contains calcium carbonate particles having a specific form as a void-forming agent.

本发明中的碳酸钙粒子的平均粒径为0.1μm以上、1.2μm以下,此外,(D90-D10)/D50为1.6以下。此处,D10、D50以及D90是分别从碳酸钙粒子的小粒径侧累积而得的10%体积粒径、50%体积粒径以及90%体积粒径。通过采用这样形态的碳酸钙粒子,可以在具有高反射率的同时抑制热变形。即,存在粗大空隙的话,易于由此引起热变形,而通过采用平均粒径小且粒度分布尖锐的碳酸钙粒子制作内部存在大量比较小的空隙The calcium carbonate particles in the present invention have an average particle diameter of 0.1 μm or more and 1.2 μm or less, and (D90-D10)/D50 is 1.6 or less. Here, D10, D50, and D90 are the 10% volume particle diameter, the 50% volume particle diameter, and the 90% volume particle diameter, which are accumulated from the small particle diameter side of the calcium carbonate particles, respectively. By adopting the calcium carbonate particles of such a form, thermal deformation can be suppressed while having high reflectance. That is, if there are coarse voids, thermal deformation is likely to be caused by this, and by using calcium carbonate particles with a small average particle size and a sharp particle size distribution, there are a large number of relatively small voids inside.

(以下也称微空隙。)的膜的形态,可抑制粗大空隙引起的热变形。如果粒度分布较宽,则存在粗大粒子,据此易于形成粗大空隙。此外同时,可抑制空隙与热塑性树脂界面上的量的减少,获得高反射率。进一步,由于碳酸钙粒子的比重相对较小,粒子与热塑性树脂的质量差或者密度差小,故空隙以外的部分不易产生局部的密度差。由此也可以抑制热变形。(Hereinafter, also referred to as microvoids.) The form of the film can suppress thermal deformation due to coarse voids. If the particle size distribution is broad, there are coarse particles, whereby coarse voids tend to be formed. In addition, at the same time, a decrease in the amount of voids at the interface of the thermoplastic resin can be suppressed, and a high reflectance can be obtained. Furthermore, since the specific gravity of the calcium carbonate particles is relatively small, and the difference in mass or density between the particles and the thermoplastic resin is small, local density differences are less likely to occur in parts other than voids. Thereby, thermal deformation can also be suppressed.

碳酸钙粒子的平均粒径过大,具有易于形成粗大空隙的倾向,无法抑制热变形。因此平均粒径优选1.1μm以下,更优选1.0μm以下,进一步优选0.95μm以下,特别优选0.9μm以下。另一方面,过小的话,粒子相互之间会凝聚成为形成粗大空隙的原因,并且很难获得这样的碳酸钙粒子。基于该观点,平均粒径优选0.3μm以上,更优选0.5μm以上,进一步优选0.6μm以上。The average particle diameter of the calcium carbonate particles is too large, so that coarse voids tend to be easily formed, and thermal deformation cannot be suppressed. Therefore, the average particle diameter is preferably 1.1 μm or less, more preferably 1.0 μm or less, still more preferably 0.95 μm or less, and particularly preferably 0.9 μm or less. On the other hand, if the particle size is too small, the particles will agglomerate with each other to form coarse voids, and it will be difficult to obtain such calcium carbonate particles. From this viewpoint, the average particle diameter is preferably 0.3 μm or more, more preferably 0.5 μm or more, and further preferably 0.6 μm or more.

此外,在另一方式中,碳酸钙粒子的平均粒径过大的话,不易抑制热变形,反之过小的话,存在易于凝聚形成粗大空隙,难以抑制热变形的情况,考虑到抑制热变形与提高反射率的平衡,以及成本方面,也存在优选某种程度较大粒径的情况。基于这样的观点,碳酸钙粒子的平均粒径优选1.2μm以下,更优选1.18μm以下,进一步优选1.15μm以下,此外,优选0.6μm以上,更优选0.8μm以上,进一步优选1.01μm以上,特别优选1.02μm以上,最优选1.05μm以上。In another aspect, if the average particle size of the calcium carbonate particles is too large, it is difficult to suppress thermal deformation, and if it is too small, it is easy to aggregate to form coarse voids, and it may be difficult to suppress thermal deformation. In terms of the balance of reflectance and cost, there are cases where a certain particle size is preferably larger. From such a viewpoint, the average particle diameter of the calcium carbonate particles is preferably 1.2 μm or less, more preferably 1.18 μm or less, still more preferably 1.15 μm or less, and more preferably 0.6 μm or more, more preferably 0.8 μm or more, still more preferably 1.01 μm or more, particularly preferably 1.02 μm or more, most preferably 1.05 μm or more.

基于上述的观点,(D90-D10)/D50优选为较小,更优选1.5以下,进一步优选1.4以下。下限理论上为0,实际上优选0.1以上。From the above-mentioned viewpoints, (D90-D10)/D50 is preferably small, more preferably 1.5 or less, and further preferably 1.4 or less. The lower limit is theoretically 0, and practically preferably 0.1 or more.

为了满足上述的形态,本发明中,作为碳酸钙粒子,特别优选合成碳酸钙构成的粒子(以下也称合成碳酸钙粒子。)。作为碳酸钙粒子,存在天然碳酸钙构成的粒子(以下也称天然碳酸钙粒子。)和合成碳酸钙粒子,通常使用天然碳酸钙粒子。但是,天然碳酸钙粒子存在难以满足上述形态的倾向,具有难以达成本发明课题的倾向。In order to satisfy the above-mentioned aspect, in the present invention, as the calcium carbonate particles, particles composed of synthetic calcium carbonate (hereinafter, also referred to as synthetic calcium carbonate particles.) are particularly preferable. As the calcium carbonate particles, there are particles composed of natural calcium carbonate (hereinafter also referred to as natural calcium carbonate particles.) and synthetic calcium carbonate particles, and natural calcium carbonate particles are usually used. However, natural calcium carbonate particles tend to be difficult to satisfy the above-mentioned form, and there is a tendency that it is difficult to achieve the subject of the present invention.

作为使聚酯树脂中含有碳酸钙粒子的方法,可以使用现有公知的各种方法。作为代表性的方法,可列举下述的方法。As a method of incorporating calcium carbonate particles in the polyester resin, various conventionally known methods can be used. As a representative method, the following method can be mentioned.

(1)在合成聚酯树脂时的酯化阶段或酯交换反应结束后添加的方法。(1) The method of adding in the esterification stage or after completion|finish of transesterification reaction at the time of synthesizing polyester resin.

(2)向获得的聚酯树脂中添加,进行熔融混炼的方法。(2) A method of adding to the obtained polyester resin and performing melt-kneading.

(3)在上述(1)或者(2)的方法中,在聚酯树脂中添加大量碳酸钙粒子制造母粒,将其与作为稀释聚合物的聚酯树脂进行混炼,从而使聚酯树脂中含有规定量的碳酸钙粒子的方法。(3) In the method of (1) or (2) above, a large amount of calcium carbonate particles are added to polyester resin to produce a master batch, which is kneaded with polyester resin as a diluent polymer to make polyester resin A method of containing a predetermined amount of calcium carbonate particles.

(4)将上述(3)中的母粒直接使用的方法。(4) A method of using the master batch in the above (3) as it is.

(碳酸钙粒子的表面处理)(Surface treatment of calcium carbonate particles)

本发明中的碳酸钙粒子优选通过表面处理剂实施表面处理。据此,使碳酸钙粒子表面的Ca活性失活,可以获得表面Ca活性失活的碳酸钙粒子,进一步抑制产生气痕。作为该表面处理剂,可列举磷酸、亚磷酸、膦酸或者它们的衍生物等磷化合物,以及硬脂酸等脂肪酸、硅烷偶联剂等。本发明中,优选通过磷化合物进行表面处理,作为该磷化合物,具体地优选可列举磷酸、亚磷酸、磷酸三甲酯、磷酸三丁酯、磷酸三苯酯、磷酸单或二甲基酯、亚磷酸三甲酯、甲基膦酸、甲基磺酸二乙酯、苯基膦酸二甲酯、苯基膦酸二乙酯等。其中,优选磷酸、亚磷酸以及其酯形成性衍生物。本发明中,最优选通过磷酸三甲基酯进行表面处理。这些磷化合物可以单独使用,也可2种以上并用。The calcium carbonate particles in the present invention are preferably surface-treated with a surface-treating agent. According to this, by deactivating the Ca activity on the surface of the calcium carbonate particles, the calcium carbonate particles whose surface Ca activity is deactivated can be obtained, and the generation of gas marks can be further suppressed. Examples of the surface treatment agent include phosphorus compounds such as phosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof, fatty acids such as stearic acid, and silane coupling agents. In the present invention, the surface treatment is preferably performed by a phosphorus compound, and as the phosphorus compound, phosphoric acid, phosphorous acid, trimethyl phosphate, tributyl phosphate, triphenyl phosphate, mono- or dimethyl phosphate, Trimethyl phosphite, methylphosphonic acid, diethyl methanesulfonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, etc. Among them, phosphoric acid, phosphorous acid, and ester-forming derivatives thereof are preferred. In the present invention, surface treatment by trimethyl phosphate is most preferable. These phosphorus compounds may be used alone or in combination of two or more.

碳酸钙粒子的表面处理方法没有特别限定,可以采用现有公知的方法。例如通过磷化合物实施表面处理时,优选采用将磷化合物与碳酸钙粒子进行物理混合的方法(物理混合方法)。作为该物理混合方法,没有特别限定,例如可列举使用辊转动磨机、高速旋转式粉碎机、球磨机、喷射磨机等各种粉碎机,将碳酸钙进行粉碎的同时通过磷化合物进行表面处理的方法,或者使用容器自身转动的容器旋转型混合机、在固定容器内具有旋转叶片或吹入气流的容器固定型混合机等进行表面处理的方法。具体地优选诺塔混合机、螺旋带式混合机、亨舍尔混合机等混合机。The surface treatment method of the calcium carbonate particles is not particularly limited, and conventionally known methods can be employed. For example, when the surface treatment is performed with a phosphorus compound, a method of physically mixing the phosphorus compound and calcium carbonate particles (physical mixing method) is preferably employed. The physical mixing method is not particularly limited. For example, various types of pulverizers, such as a rolling mill, a high-speed rotary pulverizer, a ball mill, and a jet mill, are used to pulverize calcium carbonate and surface-treated with a phosphorus compound. method, or a method of surface treatment using a container rotary mixer in which the container itself rotates, a container stationary mixer provided with a rotating blade in a fixed container, or an air flow blowing. Specifically, mixers such as a Nauta mixer, a spiral ribbon mixer, and a Henschel mixer are preferable.

此外此时的处理条件没有特别限定,基于碳酸钙粒子对聚酯的分散性、聚酯高温滞留时产生异物、发泡的观点,处理温度优选30℃以上,进一步优选50℃以上,特别优选90℃以上。处理时间优选5小时以内,进一步3小时以内,特别优选2小时以内。此外,磷化合物可以同时与碳酸钙粒子混合,此外还可以预先装入碳酸钙粒子后添加磷化合物。此时,磷化合物可以滴加、喷雾,进一步还可以是溶解或分散于水或醇等之物。The treatment conditions at this time are not particularly limited, but the treatment temperature is preferably 30° C. or higher, more preferably 50° C. or higher, and particularly preferably 90° C. ℃ above. The treatment time is preferably within 5 hours, further within 3 hours, particularly preferably within 2 hours. In addition, the phosphorus compound may be mixed with the calcium carbonate particles at the same time, or the phosphorus compound may be added after preliminarily loading the calcium carbonate particles. In this case, the phosphorus compound may be added dropwise or sprayed, and may be dissolved or dispersed in water, alcohol, or the like.

此外,本发明中,还可以将碳酸钙粒子的表面处理剂添加进聚酯,进行混合,接着向其中添加碳酸钙粒子,进行碳酸钙的表面处理。例如可以在聚酯的制造、即聚合反应结束之前的任意阶段,或聚合反应结束后进行熔融混炼为止的阶段,添加表面处理剂。Further, in the present invention, the surface treatment agent of calcium carbonate particles may be added to polyester and mixed, and then calcium carbonate particles may be added thereto to perform surface treatment of calcium carbonate. For example, the surface treatment agent may be added at any stage before the production of the polyester, that is, before the completion of the polymerization reaction, or at the stage until the melt-kneading is performed after the completion of the polymerization reaction.

上述表面处理工序中的表面处理剂的添加量只要是能使碳酸钙粒子表面的Ca活性充分失活的量即可,例如相对于碳酸钙粒子的质量,磷元素的量为0.1质量%以上的量。另一方面,添加过多的话,膜中会残留大量磷化合物,从环境的角度不优选,此外从可以抑制挤出机内等碳酸钙粒子相互之间凝聚的观点,优选5质量%以下,更优选2质量%以下,进一步优选1质量%以下,特别优选0.5质量%以下。The addition amount of the surface treatment agent in the above-mentioned surface treatment step may be an amount sufficient to deactivate the Ca activity on the surface of the calcium carbonate particles, for example, the amount of phosphorus element is 0.1 mass % or more relative to the mass of the calcium carbonate particles quantity. On the other hand, if it is added too much, a large amount of phosphorus compound will remain in the film, which is not preferable from the viewpoint of the environment, and from the viewpoint of suppressing aggregation of calcium carbonate particles in the extruder and the like, it is preferably 5 mass % or less, and more 2 mass % or less is preferable, 1 mass % or less is more preferable, and 0.5 mass % or less is especially preferable.

(不相容树脂)(incompatible resin)

本发明的方式b中,反射层A含有不相容树脂作为空隙形成剂。In the aspect b of the present invention, the reflection layer A contains an incompatible resin as a void-forming agent.

作为该不相容树脂,只要是与构成反射层A的热塑性树脂A不相容即无特别限定。例如,热塑性树脂A为聚酯时,优选聚乙烯、聚丙烯、聚甲基戊烯等聚烯烃树脂、环烯烃树脂、聚苯乙烯树脂、聚丙烯酸酯树脂、聚碳酸酯树脂、聚丙烯腈树脂、聚苯硫醚树脂、氟树脂等。这些可以单独使用,也可2种以上并用。此外,可以是均聚物,也可以是共聚物。特别地,优选与热塑性树脂A、作为该热塑性树脂A优选的聚酯的临界表面张力差大的树脂。此外,优选经拉伸后的热处理不易变形的树脂。具体地,优选聚烯烃系树脂。作为聚烯烃系树脂,可列举聚乙烯、聚丙烯、聚甲基戊烯等聚烯烃树脂,以及它们的共聚物。其中特别优选作为环烯烃共聚物的乙烯与双环烯烃的共聚物。The incompatible resin is not particularly limited as long as it is incompatible with the thermoplastic resin A constituting the reflective layer A. For example, when the thermoplastic resin A is polyester, polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, cycloolefin resins, polystyrene resins, polyacrylate resins, polycarbonate resins, and polyacrylonitrile resins are preferred. , polyphenylene sulfide resin, fluororesin, etc. These may be used alone or in combination of two or more. In addition, it may be a homopolymer or a copolymer. In particular, a resin having a large difference in critical surface tension with the thermoplastic resin A and polyester which is preferable for the thermoplastic resin A is preferable. In addition, resins that are not easily deformed by heat treatment after stretching are preferred. Specifically, polyolefin-based resins are preferred. Examples of the polyolefin-based resin include polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, and copolymers thereof. Among them, a copolymer of ethylene and a bicyclic olefin is particularly preferable as the cyclic olefin copolymer.

此外,不相容树脂的玻璃化转变温度优选180℃以上、220℃以下,进一步优选190℃以上、220℃以下。玻璃化转变温度低于180℃的区域,具有在膜制造工序中的热处理工序中,拉伸时出现的空隙变形,引起空隙大小的不均一性,易于形成粗大空隙的倾向,提高抑制热变形的效果趋于变低。此外,高于220℃的区域,与构成反射层A的热塑性树脂A熔融混炼时,具有不相容树脂没有充分熔融难以促进微分散化的倾向,由此提高抑制热变形的效果趋于变低。另外,控制不相容树脂的玻璃化转变温度的方法,例如可以通过控制直链烯烃部与环烯烃部的共聚比例任意进行变更,该直链烯烃部例如乙烯部,该环烯烃部例如亚甲基-降冰片烯部;例如为了提高玻璃化转变温度,可以通过提高环烯烃部的共聚比例来达成。Further, the glass transition temperature of the incompatible resin is preferably 180°C or higher and 220°C or lower, and more preferably 190°C or higher and 220°C or lower. In the region where the glass transition temperature is lower than 180°C, there is void deformation that occurs during stretching in the heat treatment process in the film production process, causing unevenness in the size of the voids, and tends to form coarse voids. The effect tends to be lower. In addition, in the region higher than 220°C, when melt-kneading with the thermoplastic resin A constituting the reflective layer A, the incompatible resin tends not to be sufficiently melted to promote microdispersion, thereby improving the effect of suppressing thermal deformation. Low. In addition, the method of controlling the glass transition temperature of the incompatible resin can be arbitrarily changed, for example, by controlling the copolymerization ratio of a linear olefin part such as an ethylene part and a cyclic olefin part such as methylene and a cyclic olefin part. Base-norbornene moiety; for example, in order to increase the glass transition temperature, it can be achieved by increasing the copolymerization ratio of the cycloolefin moiety.

作为优选使用的不相容树脂,可列举宝理塑料株式会社的TOPAS(注册商标)COC系列,例如Grade 6017S-04等。As an incompatible resin used preferably, Polyplastics Co., Ltd.'s TOPAS (registered trademark) COC series, for example, Grade 6017S-04, etc., can be mentioned.

(方式a中的碳酸钙粒子的含量)(content of calcium carbonate particles in mode a)

方式a中,反射层A包含含有碳酸钙粒子的热塑性树脂组合物A1,该热塑性树脂组合物A1中的碳酸钙粒子的含量以该热塑性树脂组合物A1的质量为基准,在10质量%以上、70质量%以下。据此易于达成上述优选的空隙体积率,进而获得高反射率。此外,热变形得到抑制。进一步,可以增加提高拉伸制膜性的效果。含量过少的话,反射率变低。另一方面,含有率过多的话,空隙过多无法抑制热变形。基于这样的观点,含量优选15质量%以上、更优选20质量%以上,此外,优选60质量%以下、更优选50质量%以下。In the mode a, the reflective layer A comprises a thermoplastic resin composition A1 containing calcium carbonate particles, and the content of the calcium carbonate particles in the thermoplastic resin composition A1 is based on the mass of the thermoplastic resin composition A1, 10% by mass or more, 70 mass% or less. According to this, it is easy to achieve the above-mentioned preferable void volume ratio, thereby obtaining a high reflectance. Furthermore, thermal deformation is suppressed. Furthermore, the effect of improving stretch film formability can be increased. When the content is too small, the reflectance becomes low. On the other hand, when the content rate is too large, the thermal deformation cannot be suppressed due to too many voids. From such a viewpoint, the content is preferably 15% by mass or more, more preferably 20% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less.

(方式b中的碳酸钙粒子和不相容树脂的含量)(content of calcium carbonate particles and incompatible resin in mode b)

方式b中,构成反射层A的热塑性树脂组合物A2中的碳酸钙粒子的含量以该热塑性树脂组合物A2的质量为基准,为5质量%以上、69质量%以下。据此易于达成上述优选的空隙体积率,进而获得高反射率。此外,热变形得到抑制。进一步,可以增加提高拉伸制膜性的效果。含量过少的话,反射率变低。另一方面,含有率过多的话,空隙过多无法抑制热变形。基于这样的观点,含量优选10质量%以上、更优选15质量%以上,此外,优选60质量%以下、更优选50质量%以下。In the form b, the content of the calcium carbonate particles in the thermoplastic resin composition A2 constituting the reflective layer A is 5 mass % or more and 69 mass % or less based on the mass of the thermoplastic resin composition A2. According to this, it is easy to achieve the above-mentioned preferable void volume ratio, thereby obtaining a high reflectance. Furthermore, thermal deformation is suppressed. Furthermore, the effect of improving stretch film formability can be increased. When the content is too small, the reflectance becomes low. On the other hand, when the content rate is too large, the thermal deformation cannot be suppressed due to too many voids. From such a viewpoint, the content is preferably 10% by mass or more, more preferably 15% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less.

方式b中,构成反射层A的热塑性树脂组合物A2中的不相容树脂的含量以该热塑性树脂组合物A2的质量为基准,在1质量%以上、40质量%以下。据此,在热变形得到抑制的同时也易于获得上述优选的空隙体积率,进而可以获得高反射率。据此易于达成上述优选的空隙体积率,进而获得高反射率。进一步,可以增加提高拉伸制膜性的效果。含量过少的话,反射率变低。另一方面,含有率过多的话,空隙过多无法抑制热变形。此外,膜中会存在大量耐热性较低的不相容树脂,因此,亦有难以抑制热变形的倾向。基于这样的观点,含量优选5质量%以上、更优选10质量%以上,此外,优选35质量%以下、更优选30质量%以下。In the form b, the content of the incompatible resin in the thermoplastic resin composition A2 constituting the reflective layer A is 1 mass % or more and 40 mass % or less based on the mass of the thermoplastic resin composition A2. According to this, the above-mentioned preferable void volume ratio can be easily obtained while thermal deformation is suppressed, and a high reflectance can be obtained. According to this, it is easy to achieve the above-mentioned preferable void volume ratio, thereby obtaining a high reflectance. Furthermore, the effect of improving stretch film formability can be increased. When the content is too small, the reflectance becomes low. On the other hand, when the content rate is too large, the thermal deformation cannot be suppressed due to too many voids. In addition, a large amount of incompatible resins with low heat resistance exist in the film, and therefore, it also tends to be difficult to suppress thermal deformation. From such a viewpoint, the content is preferably 5% by mass or more, more preferably 10% by mass or more, and is preferably 35% by mass or less, more preferably 30% by mass or less.

方式b中,构成反射层A的热塑性树脂组合物A2中的碳酸钙粒子与不相容树脂含量之和以该热塑性树脂组合物A2的质量为基准,在10质量%以上、70质量%以下。据此,在热变形得到抑制的同时也易于获得上述优选的空隙体积率,进而可以获得高反射率。进一步,可以增加提高拉伸制膜性的效果。总含量过少的话,反射率变低。另一方面,总含有率过多的话,基于与上述的碳酸钙粒子的含量过多或不相容树脂的含量过多时相同的理由,无法抑制热变形。基于这样的观点,含量优选15质量%以上、更优选20质量%以上,此外,优选65质量%以下、更优选60质量%以下。In the form b, the sum of the content of calcium carbonate particles and incompatible resin in the thermoplastic resin composition A2 constituting the reflective layer A is 10 mass % or more and 70 mass % or less based on the mass of the thermoplastic resin composition A2. According to this, the above-mentioned preferable void volume ratio can be easily obtained while thermal deformation is suppressed, and a high reflectance can be obtained. Furthermore, the effect of improving stretch film formability can be increased. When the total content is too small, the reflectance becomes low. On the other hand, when the total content rate is too high, thermal deformation cannot be suppressed for the same reason as when the content of the calcium carbonate particles described above is too large or the content of the incompatible resin is too large. From such a viewpoint, the content is preferably 15% by mass or more, more preferably 20% by mass or more, and is preferably 65% by mass or less, more preferably 60% by mass or less.

(其他成分)(other ingredients)

反射层A、即可构成反射层A的热塑性树脂组合物A,在不损害本发明目的的范围内,可以含有其他成分,例如紫外线吸收剂、抗氧化剂、抗静电剂、荧光增白剂、蜡。此外,只要不阻碍本发明的目的,还可以含有不同于上述碳酸钙粒子或不相容树脂的粒子或树脂等的空隙形成剂。The reflective layer A, that is, the thermoplastic resin composition A that constitutes the reflective layer A, may contain other components, such as ultraviolet absorbers, antioxidants, antistatic agents, fluorescent whitening agents, waxes, within the scope of not impairing the purpose of the present invention. . Further, as long as the object of the present invention is not inhibited, a void-forming agent such as particles or resins other than the above-mentioned calcium carbonate particles or incompatible resins may be contained.

[支撑层B][Support Layer B]

本发明的白色反射膜除了上述反射层A,还可以进一步具有支撑层B,该支撑层B包含热塑性树脂B或者在热塑性树脂B中添加有粒子等的热塑性树脂组合物B。通过该支撑层B可以提高拉伸制膜性,进一步抑制热变形。优选在反射层A的至少一面设置空隙少于反射层A或耐热性尽可能高的组成构成的支撑层B,可以进一步抑制热引起的局部变形,进一步抑制热变形。The white reflective film of the present invention may further include, in addition to the above-mentioned reflective layer A, a support layer B containing a thermoplastic resin B or a thermoplastic resin composition B obtained by adding particles or the like to the thermoplastic resin B. With this support layer B, stretch film-forming properties can be improved, and thermal deformation can be further suppressed. Preferably, at least one surface of the reflective layer A is provided with a support layer B having a composition with fewer voids than the reflective layer A or as high heat resistance as possible, so that local deformation caused by heat can be further suppressed, and thermal deformation can be further suppressed.

以下,对本发明中的支撑层B进行详述。Hereinafter, the supporting layer B in the present invention will be described in detail.

(热塑性树脂B)(thermoplastic resin B)

作为构成本发明中的支撑层B的热塑性树脂B,可以使用与构成上述反射层A的热塑性树脂A相同的热塑性树脂。其中,基于获得机械特性以及热稳定性优异的白色反射膜的观点,优选聚酯。As the thermoplastic resin B constituting the support layer B in the present invention, the same thermoplastic resin as the thermoplastic resin A constituting the reflective layer A described above can be used. Among them, polyester is preferable from the viewpoint of obtaining a white reflective film excellent in mechanical properties and thermal stability.

作为该聚酯,可以使用与上述的反射层A中的聚酯相同的聚酯。这些聚酯之中,基于获得机械特性以及热稳定性优异的白色反射膜的观点,优选芳香族聚酯,特别优选聚对苯二甲酸乙二醇酯。聚酯以及优选的聚对苯二甲酸乙二醇酯可以是均聚物,但基于将膜进行单轴或双轴拉伸时结晶化得到抑制,增加提高拉伸制膜性效果的点,优选共聚聚酯以及进一步优选共聚聚对苯二甲酸乙二醇酯。作为该共聚成分,反射层A中可以列举上述二羧酸成分或二醇成分,基于耐热性高、提高拉伸制膜性的效果高的观点,优选间苯二甲酸成分、2,6-萘二羧酸成分。共聚成分的含有比例以聚酯的总二羧酸成分100摩尔%为基准,例如为1摩尔%以上,优选2摩尔%以上,进一步优选3摩尔%以上,特别优选12摩尔%以上,此外,例如为20摩尔%以下,优选18摩尔%以下,进一步优选17摩尔%以下,特别优选16摩尔%以下。通过使共聚成分的比例在该范围内,提高拉伸制膜性的效果优异。此外,热尺寸稳定性优异。进一步,可以进一步提高抑制热变形的效果。As this polyester, the same polyester as the polyester in the above-mentioned reflection layer A can be used. Among these polyesters, from the viewpoint of obtaining a white reflective film excellent in mechanical properties and thermal stability, aromatic polyesters are preferred, and polyethylene terephthalate is particularly preferred. Polyester and preferably polyethylene terephthalate may be homopolymers, but crystallization is suppressed when the film is uniaxially or biaxially stretched, and the effect of improving the stretchable film formability is increased. Copolyesters and further preferably copolyethylene terephthalate. As the copolymerization component, the above-mentioned dicarboxylic acid component or diol component in the reflective layer A is exemplified, and the isophthalic acid component, 2,6- Naphthalene dicarboxylic acid component. The content ratio of the copolymerization component is based on 100 mol % of the total dicarboxylic acid content of the polyester, for example, 1 mol % or more, preferably 2 mol % or more, more preferably 3 mol % or more, particularly preferably 12 mol % or more. It is 20 mol% or less, preferably 18 mol% or less, more preferably 17 mol% or less, and particularly preferably 16 mol% or less. By making the ratio of a copolymerization component into this range, the effect of improving stretch film formability is excellent. In addition, thermal dimensional stability is excellent. Furthermore, the effect of suppressing thermal deformation can be further enhanced.

该热塑性树脂B的熔点优选190℃以上、280℃以下。据此,更易于抑制热变形。太低的话具有热变形的抑制效果变低的倾向,过高的话具有操作处理变难的倾向。从该观点出发,更优选195℃以上,进一步优选200℃以上,此外,更优选275℃以下,进一步优选270℃以下。The melting point of the thermoplastic resin B is preferably 190°C or higher and 280°C or lower. According to this, it becomes easier to suppress thermal deformation. If it is too low, the effect of suppressing thermal deformation tends to be low, and if it is too high, it tends to be difficult to handle. From this viewpoint, 195°C or higher is more preferable, 200°C or higher is still more preferable, and 275°C or lower is more preferable, and 270°C or lower is still more preferable.

另外,作为构成本发明中的支撑层B的热塑性树脂B,可以是优选的热塑性树脂如聚酯与不同于该聚酯的其他热塑性树脂的混合物。In addition, as the thermoplastic resin B constituting the support layer B in the present invention, there may be a mixture of a preferred thermoplastic resin such as polyester and other thermoplastic resins other than the polyester.

(其他成分)(other ingredients)

支撑层B也可包含热塑性树脂组合物B,所述热塑性树脂组合物B是在不损害本发明的目的的范围内,在上述的热塑性树脂B中含有任意成分。作为该任意成分,可列举例如紫外线吸收剂、抗氧化剂、抗静电剂、荧光增白剂、蜡等。The support layer B may contain the thermoplastic resin composition B which contains arbitrary components in the above-mentioned thermoplastic resin B within the range which does not impair the objective of this invention. As this optional component, an ultraviolet absorber, an antioxidant, an antistatic agent, a fluorescent whitening agent, a wax, etc. are mentioned, for example.

此外,支撑层B在不损害本发明的目的的范围内,可以含有反射层A中列举的空隙形成剂作为任意成分,通过采用这样的形态,可以增加提高反射率的效果。相反,减少支撑层B中的空隙形成剂的含量,或不含有空隙形成剂的话,可以增加提高拉伸制膜性的效果。从此观点出发,支撑层B中的空隙体积率、该空隙体积率是支撑层B中的空隙的体积相对于支撑层B的体积的比例优选为0体积%以上、小于15体积%,进一步优选5体积%以下,特别优选3体积%以下。特别本发明中,基于可以同时提高反射特性与提高拉伸制膜性的效果的点,特别优选同时采用上述反射层A中优选的空隙体积率与该支撑层B中优选的空隙体积率。Further, the support layer B may contain the void-forming agent listed in the reflection layer A as an optional component within a range that does not impair the object of the present invention, and by adopting such a form, the effect of improving the reflectance can be increased. Conversely, when the content of the void-forming agent in the support layer B is reduced, or the void-forming agent is not contained, the effect of improving the stretch film formability can be increased. From this viewpoint, the void volume ratio in the support layer B, which is the ratio of the volume of the voids in the support layer B to the volume of the support layer B, is preferably 0% by volume or more and less than 15% by volume, and more preferably 5% by volume. Volume % or less, particularly preferably 3 volume % or less. In particular, in the present invention, the preferred void volume ratio in the above-mentioned reflection layer A and the preferred void volume ratio in the support layer B are particularly preferably used at the same time because the effects of improving the reflection characteristics and the stretchable film formability can be simultaneously improved.

[表面层C][Surface layer C]

本发明的白色反射膜可以在膜的至少一方的表面具有包含含有表面层粒子的热塑性树脂组合物C的表面层C。通过该表面层C,可以赋予以下功能:赋予反射光以扩散性、接触导光板时确保与导光板的间隔、抑制导光板划伤。为了获得这样的效果,表面层C在膜中处于反射面侧,是背光单元中的光源侧或者导光板侧。此外,为了获得这样的效果,该表面层粒子的平均粒径为2.0μm以上、50.0μm以下,此外,含量相对于热塑性树脂组合物C的体积为3体积%以上、50体积%以下。The white reflective film of this invention may have the surface layer C containing the thermoplastic resin composition C containing surface layer particle|grains on at least one surface of a film. The surface layer C can impart functions of imparting diffusivity to reflected light, securing a distance from the light guide plate when touching the light guide plate, and suppressing scratches on the light guide plate. In order to obtain such an effect, the surface layer C is on the reflective surface side in the film, which is the light source side or the light guide plate side in the backlight unit. In addition, in order to obtain such an effect, the average particle diameter of the surface layer particles is 2.0 μm or more and 50.0 μm or less, and the content is 3 volume % or more and 50 volume % or less with respect to the volume of the thermoplastic resin composition C.

此外,为了发挥上述效果,优选在反射层A的相反侧的表面,表面层C的表面由上述表面层粒子形成突起,作为该表面的形态,优选中心线平均粗糙度Ra在0.1μm以上、6.0μm以下的范围,十点平均粗糙度Rz在3.0μm以上、40.0μm以下的范围。该Ra与Rz优选双方均在该范围内。In addition, in order to exert the above-mentioned effects, it is preferable that the surface layer C has protrusions formed by the surface layer particles on the surface opposite to the reflective layer A, and as the form of the surface, the centerline average roughness Ra is preferably 0.1 μm or more and 6.0 μm or more. In the range of μm or less, the ten-point average roughness Rz is in the range of 3.0 μm or more and 40.0 μm or less. Both of the Ra and Rz are preferably within this range.

以下对本发明中的表面层C进行详述。The surface layer C in the present invention will be described in detail below.

(热塑性树脂C)(thermoplastic resin C)

作为构成本发明中的表面层C的热塑性树脂C,可以使用与构成上述反射层A的热塑性树脂A相同的热塑性树脂。其中,基于获得机械特性以及热稳定性优异的白色反射膜的观点,优选聚酯。As the thermoplastic resin C constituting the surface layer C in the present invention, the same thermoplastic resin as the thermoplastic resin A constituting the reflection layer A described above can be used. Among them, polyester is preferable from the viewpoint of obtaining a white reflective film excellent in mechanical properties and thermal stability.

作为该聚酯,可以使用与上述的反射层A中的聚酯相同的聚酯。这些聚酯之中,基于获得机械特性以及热稳定性优异的白色反射膜的观点,优选芳香族聚酯,特别优选聚对苯二甲酸乙二醇酯。聚酯以及优选的聚对苯二甲酸乙二醇酯可以是均聚物,但基于将膜进行单轴或双轴拉伸时结晶化得到抑制,增加提高拉伸制膜性效果的点,优选共聚聚酯以及进一步优选共聚聚对苯二甲酸乙二醇酯。作为该共聚成分,反射层A中可列举上述二羧酸成分或二醇成分,但基于耐热性高、增加提高拉伸制膜性效果的观点,优选间苯二甲酸成分、2,6-萘二羧酸成分。共聚成分的含有比例以聚酯的总二羧酸成分100摩尔%为基准,例如为1摩尔%以上,优选2摩尔%以上,进一步优选3摩尔%以上,特别优选12摩尔%以上,此外,例如20摩尔%以下,优选18摩尔%以下,进一步优选17摩尔%以下,特别优选16摩尔%以下。通过使共聚成分的比例在该范围内,提高拉伸制膜性的效果优异。此外,热尺寸稳定性优异。进一步,可以进一步提高抑制热变形的效果。As this polyester, the same polyester as the polyester in the above-mentioned reflection layer A can be used. Among these polyesters, from the viewpoint of obtaining a white reflective film excellent in mechanical properties and thermal stability, aromatic polyesters are preferred, and polyethylene terephthalate is particularly preferred. Polyester and preferably polyethylene terephthalate may be homopolymers, but crystallization is suppressed when the film is uniaxially or biaxially stretched, and the effect of improving the stretchable film formability is increased. Copolyesters and further preferably copolyethylene terephthalate. As the copolymerized component, the above-mentioned dicarboxylic acid component or diol component can be mentioned in the reflection layer A, but from the viewpoint of high heat resistance and increased effect of improving stretch film formability, isophthalic acid component, 2,6- Naphthalene dicarboxylic acid component. The content ratio of the copolymerization component is based on 100 mol % of the total dicarboxylic acid content of the polyester, for example, 1 mol % or more, preferably 2 mol % or more, more preferably 3 mol % or more, particularly preferably 12 mol % or more. 20 mol% or less, preferably 18 mol% or less, more preferably 17 mol% or less, particularly preferably 16 mol% or less. By making the ratio of a copolymerization component into this range, the effect of improving stretch film formability is excellent. In addition, thermal dimensional stability is excellent. Furthermore, the effect of suppressing thermal deformation can be further enhanced.

该热塑性树脂C的熔点优选225℃以上、260℃以下。据此,更易于抑制热变形。太低的话具有热变形的抑制效果变低的倾向,过高的话具有操作处理变难的倾向。从该观点出发,更优选230℃以上、进一步优选235℃以上,此外,更优选258℃以下、进一步优选256℃以下。The melting point of the thermoplastic resin C is preferably 225°C or higher and 260°C or lower. According to this, it becomes easier to suppress thermal deformation. If it is too low, the effect of suppressing thermal deformation tends to be low, and if it is too high, it tends to be difficult to handle. From this viewpoint, it is more preferably 230°C or higher, still more preferably 235°C or higher, and more preferably 258°C or lower, still more preferably 256°C or lower.

另外,作为构成本发明中的表面层C的热塑性树脂C,可以是优选的热塑性树脂如聚酯与不同于该聚酯的其他热塑性树脂的混合物。In addition, as the thermoplastic resin C constituting the surface layer C in the present invention, a mixture of a preferred thermoplastic resin such as polyester and other thermoplastic resins other than the polyester may be used.

(表面层粒子)(surface layer particles)

本发明中,通过具有表面层C可以赋予反射光扩散性。此外,还可以赋予在接触导光板时确保与导光板的间隔、抑制导光板划伤的效果。In the present invention, by having the surface layer C, reflected light diffusivity can be imparted. In addition, the effect of securing the distance from the light guide plate when touching the light guide plate and suppressing scratches on the light guide plate can also be imparted.

首先,对赋予反射光扩散性时优选的表面层粒子的实施方式进行说明。本方式适合直下型背光单元,特别是具备具有透镜罩的光源的直下型背光单元,该光源优选LED光源。First, an embodiment of the surface layer particles that is preferable for imparting reflected light diffusivity will be described. This method is suitable for a direct type backlight unit, especially a direct type backlight unit having a light source having a lens cover, and the light source is preferably an LED light source.

此时,为了进一步获得上述效果,表面层C的外侧表面的Ra优选0.1μm以上,更优选0.2μm以上,此外,优选3.0μm以下,更优选2.7μm以下。Rz优选3.0μm以上,更优选4.0μm以上,此外,优选15.0μm以下,更优选13.0μm以下。另外,该表面形态参照后述的表面层粒子的平均粒径或含量适当调整即可达成。In this case, in order to further obtain the above-mentioned effects, Ra of the outer surface of the surface layer C is preferably 0.1 μm or more, more preferably 0.2 μm or more, and preferably 3.0 μm or less, more preferably 2.7 μm or less. Rz is preferably 3.0 μm or more, more preferably 4.0 μm or more, and preferably 15.0 μm or less, more preferably 13.0 μm or less. In addition, the surface morphology can be achieved by appropriately adjusting with reference to the average particle diameter or content of the surface layer particles described later.

此时,作为用于表面层C的表面层粒子,优选平均粒径为2.0μm以上、40.0μm以下。通过采用这样的形态,易于提高反射光的扩散性。平均粒径过小的话,具有不易形成突起的倾向,反射光的扩散性变小的倾向。从该观点出发,表面层粒子的平均粒径更优选2.5μm以上,进一步优选3.0μm以上,进一步优选3.5μm以上,特别优选4.0μm以上。另一方面,使用的表面层粒子过大的话,具有在生产膜时易于堵塞过滤器等的倾向,此外,具有表面层粒子易于从表面层C脱落的倾向。从该观点出发,更优选35.0μm以下,进一步优选30.0μm以下,进一步优选25.0μm以下,特别优选20.0μm以下。In this case, as the surface layer particles used for the surface layer C, the average particle diameter is preferably 2.0 μm or more and 40.0 μm or less. By adopting such a form, it becomes easy to improve the diffusivity of reflected light. When the average particle diameter is too small, the protrusions tend to be less likely to be formed, and the diffusivity of reflected light tends to decrease. From this viewpoint, the average particle diameter of the surface layer particles is more preferably 2.5 μm or more, still more preferably 3.0 μm or more, still more preferably 3.5 μm or more, and particularly preferably 4.0 μm or more. On the other hand, when the surface layer particles used are too large, the filter or the like tends to be easily clogged during film production, and the surface layer particles tend to fall off from the surface layer C easily. From this viewpoint, it is more preferably 35.0 μm or less, still more preferably 30.0 μm or less, still more preferably 25.0 μm or less, and particularly preferably 20.0 μm or less.

此外,为了进一步发挥表面层C的上述功能,优选表面层C中的表面层粒子的含量以表面层C(即可为构成表面层C的热塑性树脂组合物C的体积)为基准在3体积%以上、50体积%以下。含量过少的话,具有反射光的扩散性表小的倾向。另一方面,过多的话,具有易于堵塞过滤器的倾向,此外还具有表面层粒子易于脱落的倾向。从该观点出发,含量更优选5体积%以上,进一步优选6体积%以上,特别优选10体积%以上,此外,更优选45体积%以下,进一步优选40体积%以下,进一步优选35体积%以下,特别优选30体积%以下。In addition, in order to further exert the above-mentioned function of the surface layer C, the content of the surface layer particles in the surface layer C is preferably 3% by volume based on the surface layer C (that is, the volume of the thermoplastic resin composition C constituting the surface layer C). more than 50% by volume. When the content is too small, the diffusivity of reflected light tends to be small. On the other hand, when it is too large, the filter tends to be easily clogged, and the surface layer particles tend to fall off easily. From this viewpoint, the content is more preferably 5% by volume or more, more preferably 6% by volume or more, particularly preferably 10% by volume or more, and more preferably 45% by volume or less, still more preferably 40% by volume or less, and still more preferably 35% by volume or less, It is especially preferable that it is 30 volume% or less.

本发明中表面层C中使用的表面层粒子不论种类,可以是有机粒子或无机粒子或有机无机复合粒子。更具体地,对特别优选的形态进行说明的话,作为优选的有机粒子,可列举例如聚四氟乙烯那样的含氟树脂粒子、高耐热尼龙粒子、高耐热丙烯酸粒子等。此外,作为优选的无机粒子,可列举氧化钛粒子、硫酸钡、碳酸钙、氧化锌粒子、氧化锆、氧化铝粒子、二氧化硅粒子等。The surface layer particles used in the surface layer C in the present invention may be organic particles, inorganic particles, or organic-inorganic composite particles regardless of the type. More specifically, when a particularly preferable aspect is described, preferable organic particles include, for example, fluorine-containing resin particles such as polytetrafluoroethylene, highly heat-resistant nylon particles, and highly heat-resistant acrylic particles. Further, as preferable inorganic particles, titanium oxide particles, barium sulfate, calcium carbonate, zinc oxide particles, zirconium oxide, alumina particles, silica particles and the like can be mentioned.

其中,优选凝聚粒子,进一步优选凝聚无机粒子,特别优选凝聚二氧化硅粒子。通过采用该优选的表面层粒子,可以获得更优选的扩散性。可以考虑是因为本发明中,采用凝聚粒子作为表面层C的表面层粒子,即使在凝聚颗粒中也可以期望光扩散,进而可以进一步提高反射光的扩散性,故而优选。此外,通过采用凝聚粒子,还具有进一步抑制制膜拉伸时的断裂问题、抑制使用自回收原材料生产膜时的断裂问题及对光学特性的影响等的效果。Among them, aggregated particles are preferable, aggregated inorganic particles are more preferable, and aggregated silica particles are particularly preferable. By using this preferable surface layer particle, more preferable diffusibility can be obtained. In the present invention, the use of aggregated particles as the surface layer particles of the surface layer C is considered to be preferable because light diffusion can be expected even in the aggregated particles, and the diffusivity of reflected light can be further improved. In addition, the use of aggregated particles has the effect of further suppressing the problem of breakage during film forming and stretching, and suppressing the problem of breakage when producing a film using self-recovered raw materials, and the influence on optical properties, and the like.

此外,上述的无机粒子以及高耐热尼龙粒子、高耐热丙烯酸粒子还具有即便加热加工,也不易熔融或产生气体的效果。进一步,从形成表面层C时粒度分布或形状不易产生变化的点考虑也优选。In addition, the above-mentioned inorganic particles, high heat-resistant nylon particles, and high heat-resistant acrylic particles also have the effect of being less likely to melt or generate gas even if they are heated and processed. Furthermore, it is also preferable from the viewpoint that the particle size distribution and the shape are not easily changed when the surface layer C is formed.

接着,对赋予确保与导光板的距离、抑制导光板划伤的功能时优选的表面层粒子的实施方式进行说明。本方式特别适合于具备导光板的侧光型背光单元。Next, an embodiment of a surface layer particle that is preferable when the function of securing the distance to the light guide plate and suppressing the scratches of the light guide plate is provided will be described. This method is particularly suitable for an edge-light type backlight unit provided with a light guide plate.

此时,为了进一步获得上述效果,优选表面层C的外侧表面的Ra在1.0μm以上,更优选1.5μm以上,此外,优选6.0μm以下,更优选5.5μm以下。Rz优选6.0μm以上,更优选6.5μm以上,此外,优选40.0μm以下,更优选35.0μm以下。另外,该表面的形态可以参照后述的表面层粒子的平均粒径或含量适宜地调整即可达成。In this case, in order to further obtain the above-mentioned effects, Ra of the outer surface of the surface layer C is preferably 1.0 μm or more, more preferably 1.5 μm or more, and preferably 6.0 μm or less, more preferably 5.5 μm or less. Rz is preferably 6.0 μm or more, more preferably 6.5 μm or more, and preferably 40.0 μm or less, more preferably 35.0 μm or less. In addition, the morphology of the surface can be achieved by appropriately adjusting with reference to the average particle diameter and content of the surface layer particles to be described later.

此时作为表面层C中使用的表面层粒子,其平均粒径优选3.0μm以上、50.0μm以下。通过采用这样的形态,易于确保与导光板的距离以及抑制导光板划伤。平均粒径过小的话具有难以形成突起的倾向,难以确保与导光板的距离的倾向。此外,还倾向于划伤导光板。从该观点出发,表面层粒子的平均粒径更优选3.5μm以上,进一步优选4.0μm以上,进一步优选4.5μm以上,特别优选5.0μm以上。另一方面,使用的表面层粒子过大的话具有生产膜时易于堵塞过滤器的倾向,此外,还倾向于表面层粒子易于脱落以及由此引起的导光板划伤。从该观点出发,更优选48.0μm以下,进一步优选46.0μm以下,进一步优选44.0μm以下,特别优选42.0μm以下。In this case, as the surface layer particles used in the surface layer C, the average particle diameter is preferably 3.0 μm or more and 50.0 μm or less. By adopting such a form, it becomes easy to secure the distance from the light guide plate and to suppress scratches on the light guide plate. When the average particle diameter is too small, it tends to be difficult to form protrusions, and it tends to be difficult to secure the distance from the light guide plate. In addition, there is a tendency to scratch the light guide plate. From this viewpoint, the average particle diameter of the surface layer particles is more preferably 3.5 μm or more, still more preferably 4.0 μm or more, still more preferably 4.5 μm or more, and particularly preferably 5.0 μm or more. On the other hand, when the particles of the surface layer used are too large, the filter tends to clog during film production, and the particles of the surface layer tend to fall off and cause scratches on the light guide plate. From this viewpoint, it is more preferably 48.0 μm or less, still more preferably 46.0 μm or less, still more preferably 44.0 μm or less, and particularly preferably 42.0 μm or less.

此外,为了进一步易于满足表面层C表面中的上述表面形态,优选表面层C中的表面层粒子的含量以表面层C(即可为构成表面层C的热塑性树脂组合物C)的体积为基准,为3体积%以上、50体积%以下。含量过少的话倾向于难以确保与导光板的距离或抑制导光板划伤。另一方面,过多的话,倾向于易于堵塞过滤器,此外表面层粒子倾向于易于脱落。从该观点出发,含量更优选5体积%以上,进一步优选6体积%以上,特别优选10体积%以上,此外,更优选45体积%以下,进一步优选40体积%以下,进一步优选35体积%以下,特别优选30体积%以下。In addition, in order to further easily satisfy the above-mentioned surface morphology on the surface of the surface layer C, the content of the surface layer particles in the surface layer C is preferably based on the volume of the surface layer C (that is, the thermoplastic resin composition C constituting the surface layer C) , is 3 volume % or more and 50 volume % or less. When the content is too small, it tends to be difficult to secure the distance from the light guide plate or to suppress scratches on the light guide plate. On the other hand, when it is too large, the filter tends to be easily clogged, and the surface layer particles tend to fall off easily. From this viewpoint, the content is more preferably 5% by volume or more, more preferably 6% by volume or more, particularly preferably 10% by volume or more, and more preferably 45% by volume or less, still more preferably 40% by volume or less, and still more preferably 35% by volume or less, It is especially preferable that it is 30 volume% or less.

本发明中用于表面层C的表面层粒子不论其种类,可以是有机粒子或无机粒子或有机无机复合粒子。更具体地,对特别优选的形态进行说明的话,作为优选的有机粒子,可列举例如聚四氟乙烯那样的含氟树脂粒子、高耐热尼龙粒子、高耐热丙烯酸粒子等。此外,作为优选的无机粒子,优选凝聚无机粒子。作为该凝聚无机粒子,可列举凝聚氧化钛粒子、凝聚硫酸钡粒子、凝聚碳酸钙粒子、凝聚氧化锌粒子、凝聚氧化锆、凝聚氧化铝粒子、凝聚二氧化硅粒子等。其中,优选凝聚二氧化硅粒子。The surface layer particles used for the surface layer C in the present invention may be organic particles, inorganic particles, or organic-inorganic composite particles regardless of their types. More specifically, when a particularly preferable aspect is described, preferable organic particles include, for example, fluorine-containing resin particles such as polytetrafluoroethylene, highly heat-resistant nylon particles, and highly heat-resistant acrylic particles. Further, as preferable inorganic particles, aggregated inorganic particles are preferable. The aggregated inorganic particles include aggregated titanium oxide particles, aggregated barium sulfate particles, aggregated calcium carbonate particles, aggregated zinc oxide particles, aggregated zirconia particles, aggregated alumina particles, aggregated silica particles, and the like. Among them, aggregated silica particles are preferred.

通过采用这样优选的表面层粒子,确保与导光板的距离以及抑制导光板划伤的效果更优异。可以考虑是因为本发明中,采用凝聚粒子作为无机粒子,表面层粒子变为合适的柔软度,在确保与导光板的距离的同时,可以进一步提高抑制导光板划伤的效果,故而优选。此外,通过采用凝聚粒子,还具有进一步抑制制膜拉伸时的断裂问题、抑制使用自回收原材料生产膜时的断裂问题及对光学特性的影响等的效果。By adopting such preferable surface layer particles, the effect of securing the distance to the light guide plate and suppressing the scratches of the light guide plate is more excellent. In the present invention, the use of aggregated particles as the inorganic particles is considered to be preferable because the surface layer particles have suitable softness, and the effect of suppressing scratches on the light guide plate can be further improved while securing the distance from the light guide plate. In addition, the use of aggregated particles has the effect of further suppressing the problem of breakage during film forming and stretching, and suppressing the problem of breakage when producing a film using self-recovered raw materials, and the influence on optical properties, and the like.

此外,上述的无机粒子以及高耐热尼龙粒子、高耐热丙烯酸粒子还具有即便加热加工,也不易熔融或产生气体的效果。进一步,从形成表面层C时粒度分布或形状不易产生变化的点考虑也优选。In addition, the above-mentioned inorganic particles, high heat-resistant nylon particles, and high heat-resistant acrylic particles also have the effect of being less likely to melt or generate gas even if they are heated and processed. Furthermore, it is also preferable from the viewpoint that the particle size distribution and the shape are not easily changed when the surface layer C is formed.

(其他成分)(other ingredients)

表面层C可以包含热塑性树脂组合物C,所述热塑性树脂组合物C是在不损害本发明的目的的范围内,在上述的热塑性树脂C中含有任意成分。作为该任意成分,可列举例如紫外线吸收剂、抗氧化剂、抗静电剂、荧光增白剂、蜡等。The surface layer C may contain the thermoplastic resin composition C which contains arbitrary components in the above-mentioned thermoplastic resin C within the range which does not impair the objective of this invention. As this optional component, an ultraviolet absorber, an antioxidant, an antistatic agent, a fluorescent whitening agent, a wax, etc. are mentioned, for example.

此外,在不损害本发明的目的的范围内,表面层C可以含有反射层A中列举的空隙形成剂作为任意成分,通过采用这样的形态,可以增加提高反射率的效果。反之,减少表面层C中的空隙形成剂的含量,或不含有空隙形成剂的话,可以增加提高拉伸制膜性的效果。从此观点出发,表面层C中的空隙体积率、该空隙体积率是表面层C中的空隙体积相对于表面层C的体积的比例优选0体积%以上、小于15体积%,进一步优选5体积%以下,特别优选3体积%以下。特别本发明中,由于可以同时增加反射特性与提高拉伸制膜性的效果,特别优选同时采用上述反射层A中的优选空隙体积率与该表面层C中的优选空隙体积率。In addition, the surface layer C may contain the void-forming agent listed in the reflection layer A as an optional component within the range that does not impair the object of the present invention, and by adopting such a form, the effect of improving the reflectance can be increased. Conversely, when the content of the void-forming agent in the surface layer C is reduced, or the void-forming agent is not contained, the effect of improving the stretch film-forming property can be increased. From this viewpoint, the void volume ratio in the surface layer C, which is the ratio of the void volume in the surface layer C to the volume of the surface layer C, is preferably 0% by volume or more and less than 15% by volume, more preferably 5% by volume Below, 3 volume % or less is especially preferable. In particular, in the present invention, the preferred void volume ratio in the above-mentioned reflection layer A and the preferred void volume ratio in the surface layer C are particularly preferably used simultaneously, since the effects of increasing the reflection characteristics and improving the stretchable film formability can be achieved simultaneously.

[层构成][layer composition]

本发明中白色反射膜的厚度优选155μm以上、350μm以下。此处该厚度为在白色反射膜仅由反射层A构成时为反射层A的厚度。据此可以增加提高反射率的效果。此外,可以增加提高抑制热变形的效果。过薄的话,提高反射率的效果低,此外,提高抑制热变形的效果低,另一方面过厚的话效率差。基于这样的观点,更优选160μm以上,进一步优选170μm以上,特别优选180μm以上,此外,更优选340μm以下,进一步优选330μm以下,特别优选320μm以下。In the present invention, the thickness of the white reflective film is preferably 155 μm or more and 350 μm or less. The thickness here is the thickness of the reflective layer A when the white reflective film is composed of only the reflective layer A. Accordingly, the effect of improving the reflectance can be increased. In addition, the effect of improving the suppression of thermal deformation can be increased. If it is too thin, the effect of improving the reflectance is low, and the effect of improving the thermal deformation suppression is low. On the other hand, if it is too thick, the efficiency is low. From such a viewpoint, it is more preferably 160 μm or more, still more preferably 170 μm or more, particularly preferably 180 μm or more, and more preferably 340 μm or less, still more preferably 330 μm or less, and particularly preferably 320 μm or less.

反射层A在以白色反射膜整体的厚度为100%时的厚度比例优选50%以上即可,更优选60%以上,进一步优选70%以上,此外,更优选95%以下,进一步优选90%以下。此处该厚度比例在具有多个反射层A时为其总厚度的比例。此外,具有支撑层B时,其厚度比例优选5%以上,更优选10%以上,此外,优选50%以下,更优选40%以下,进一步优选30%以下。此处该厚度比例在具有多个支撑层B时为其总厚度的比例。据此,可以使反射特性或拉伸制膜性等各特性的平衡趋于良好。此外,在能良好平衡的同时,进一步增加提高抑制热变形的效果。The thickness ratio of the reflective layer A when the thickness of the entire white reflective film is taken as 100% is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, and more preferably 95% or less, still more preferably 90% or less . Here, the thickness ratio is the ratio of the total thickness when there are a plurality of reflective layers A. FIG. Further, when the support layer B is provided, the thickness ratio thereof is preferably 5% or more, more preferably 10% or more, and is preferably 50% or less, more preferably 40% or less, and further preferably 30% or less. The thickness ratio here is the ratio of the total thickness when there are a plurality of support layers B. FIG. Thereby, the balance of each characteristic, such as reflection characteristic and stretch film formability, can be made favorable. In addition, the effect of suppressing thermal deformation is further increased while being well balanced.

本发明中的支撑层B的厚度优选2μm以上、80μm以下。此处该厚度在膜中具有多个支撑层B时为其总厚度。据此,可以增加提高拉伸制膜性的效果,此外,可以提高抑制热变形的效果。进一步可以减小热收缩。支撑层B过薄的话,具有提高拉伸制膜性的效果降低的倾向。此外,具有抑制热变形的效果降低的倾向。另一方面,即便是过厚上述效果也不会再变化,效率差。基于这样的观点,支撑层B的厚度(总厚度)更优选5μm以上,进一步优选10μm以上,此外,更优选70μm以下,进一步优选65μm以下。The thickness of the support layer B in the present invention is preferably 2 μm or more and 80 μm or less. The thickness here is the total thickness when there are multiple support layers B in the film. According to this, the effect of improving the stretch film formability can be increased, and the effect of suppressing thermal deformation can be increased. Further, thermal shrinkage can be reduced. When the support layer B is too thin, the effect of improving the stretch film formability tends to decrease. In addition, the effect of suppressing thermal deformation tends to decrease. On the other hand, even if it is too thick, the above-mentioned effects will not change, and the efficiency will be poor. From such a viewpoint, the thickness (total thickness) of the support layer B is more preferably 5 μm or more, further preferably 10 μm or more, and more preferably 70 μm or less, further preferably 65 μm or less.

此外,在反射层A的反射面侧具有支撑层B时,该支撑层B的厚度影响反射率。In addition, when the support layer B is provided on the reflection surface side of the reflection layer A, the thickness of the support layer B affects the reflectance.

即,反射层A的反射面侧的支撑层B的厚度过厚时,具有提高反射率的效果降低的倾向。另一方面,过薄的话,具有抑制反射层A的碳酸钙粒子脱落的效果、抑制反射层A的碳酸钙造成的装置或其他构件划伤的效果变低的倾向。基于这样的观点,支撑层B的厚度优选1μm以上、40μm以下,更优选2.5μm以上,进一步优选5μm以上,此外,更优选35μm以下,进一步优选32.5μm以下。此处该厚度是指1层支撑层B的厚度。That is, when the thickness of the support layer B on the reflective surface side of the reflective layer A is too thick, the effect of improving the reflectance tends to decrease. On the other hand, if it is too thin, the effect of suppressing the dropping of calcium carbonate particles in the reflective layer A and the effect of suppressing scratches on devices or other members caused by the calcium carbonate in the reflective layer A tend to be low. From such a viewpoint, the thickness of the support layer B is preferably 1 μm or more and 40 μm or less, more preferably 2.5 μm or more, still more preferably 5 μm or more, and more preferably 35 μm or less, and still more preferably 32.5 μm or less. Here, the thickness refers to the thickness of one supporting layer B.

白色反射膜具有反射层A和支撑层B时,以A表示反射层A、B表示支撑层B时,其层叠构成可列举B/A的2层构成、A/B/A或B/A/B的3层构成、B/A/B/A或B/A/B’/A的4层构成、还有同样地具有A和B的5层以上的多层构成。另外,上述中B’表示与支撑层B同样构成的另外设置的支撑层B’。特别优选B/A的2层构成、A/B/A、B/A/B的3层构成。最优选B/A/B的3层构成,拉伸制膜性更优异。此外,表背面的支撑层B为相近厚度范围的话,不易产生卷曲等问题。When the white reflective film has a reflective layer A and a supporting layer B, when A represents the reflective layer A and B represents the supporting layer B, the lamination structure includes a two-layer structure of B/A, A/B/A or B/A/ A 3-layer structure of B, a 4-layer structure of B/A/B/A or B/A/B'/A, and a multi-layer structure of 5 or more layers having A and B similarly. In addition, in the above, B' represents a separately provided support layer B' having the same configuration as the support layer B. As shown in FIG. In particular, the two-layer structure of B/A and the three-layer structure of A/B/A and B/A/B are preferable. The three-layer structure of B/A/B is most preferable, and the stretch film-forming property is more excellent. In addition, when the support layers B on the front and back surfaces are in a similar thickness range, problems such as curling are less likely to occur.

本发明中,除了反射层A与支撑层B以外,只要不有损本发明的目的,可以具有其他的层。例如可以具有赋予抗静电性或导电性、紫外线耐久性等功能的层。该层优选涂布层。此外,可以在反射面侧的至少一面的最表面具有用于赋予反射光以扩散性,或确保与导光板的距离的、含有珠粒的珠层。另外,表面层C是珠层优选的一种形态。In the present invention, in addition to the reflective layer A and the support layer B, as long as the object of the present invention is not impaired, other layers may be provided. For example, it may have a layer that imparts functions such as antistatic properties, conductivity, and UV resistance. This layer is preferably a coating layer. In addition, the outermost surface of at least one surface on the reflective surface side may have a bead layer containing beads for imparting diffusivity to reflected light or securing a distance from the light guide plate. In addition, the surface layer C is a preferred form of the bead layer.

具有表面层C时,本发明中的表面层C的厚度优选5μm以上、70μm以下。此处该厚度是指膜中具有多个表面层C时成为光源侧或者导光板侧的1层的厚度。据此更易于发挥表面层C的上述效果。过薄的话,表面层粒子易于发生脱落,另一方面过厚的话,具有难以形成突起的倾向,倾向于不易获得上述效果。此外经济上效率差。基于这样的观点,进一步优选10μm以上,此外,60μm以下。When the surface layer C is provided, the thickness of the surface layer C in the present invention is preferably 5 μm or more and 70 μm or less. The thickness here refers to the thickness of one layer on the light source side or the light guide plate side when there are a plurality of surface layers C in the film. Accordingly, the above-described effects of the surface layer C are more easily exhibited. If it is too thin, the surface layer particles tend to fall off. On the other hand, if it is too thick, it tends to be difficult to form protrusions, and the above-mentioned effects tend to be difficult to obtain. In addition, it is economically inefficient. From such a viewpoint, 10 μm or more is more preferable, and 60 μm or less.

白色反射膜具有反射层A与表面层C时,以A表示反射层A、C表示支撑层C时,其层叠构成可列举C/A的2层构成、C/A/C的3层构成、C/A/C/A或C/A/C’/A的4层构成、还有同样的具有A与C的5层以上的多层构成。另外,上述中不位于表面的C表示与表面层C相同构成的内面层C。此外C’表示与表面层C同样构成的另外设置的表面层C’。特别优选C/A的2层构成、C/A/C的3层构成。最优选C/A/C的3层构成,拉伸制膜性更优异。此外,表背面的表面层C为相近厚度范围的话,不易产生卷曲等问题。When the white reflective film has a reflective layer A and a surface layer C, when A represents the reflective layer A and C represents the support layer C, the lamination structure includes a two-layer structure of C/A, a three-layer structure of C/A/C, A four-layer structure of C/A/C/A or C/A/C'/A, and a similar five-layer or more multi-layer structure including A and C are also available. In addition, C which is not located on the surface in the above shows the inner surface layer C having the same structure as the surface layer C. As shown in FIG. In addition, C' represents a separately provided surface layer C' having the same configuration as that of the surface layer C. In particular, a two-layer structure of C/A and a three-layer structure of C/A/C are preferable. The three-layer structure of C/A/C is most preferable, and the stretch film-forming property is more excellent. In addition, when the surface layers C on the front and back surfaces are in a similar thickness range, problems such as curling are less likely to occur.

此外,白色反射膜具有反射层A、支撑层B以及表面层C时,以B表示支撑层B时,其层叠构成可列举C/B/A或C/A/B的3层构成、C/A/B/A或C/B/A/B的4层构成、C/B/A/B/A或C/B/A/B’/A的5层构成、还有同样的具有A与B的6层以上的多层构成的至少一方的表面上具有表面层C的多层构成。另外,上述中B’表示与支撑层B同样构成的另外设置的支撑层B’。特别优选C/B/A、C/A/B的3层构成、C/A/B/A、C/B/A/B的4层构成。最优选C/B/A/B的4层构成,拉伸制膜性更优异。此外,表背面的支撑层B为相近厚度范围的话,不易产生卷曲等问题。In addition, when the white reflective film has a reflective layer A, a support layer B, and a surface layer C, and when B represents the support layer B, the lamination structure includes a three-layer structure of C/B/A or C/A/B, C/B/A 4-layer configuration of A/B/A or C/B/A/B, 5-layer configuration of C/B/A/B/A or C/B/A/B'/A, and the same At least one of the six or more layers of the multilayer structure of B has a multilayer structure of the surface layer C on the surface. In addition, in the above, B' represents a separately provided support layer B' having the same configuration as the support layer B. As shown in FIG. In particular, a three-layer structure of C/B/A and C/A/B, and a four-layer structure of C/A/B/A and C/B/A/B are preferable. The four-layer structure of C/B/A/B is most preferable, and the stretch film-forming property is more excellent. In addition, when the support layers B on the front and back surfaces are in a similar thickness range, problems such as curling are less likely to occur.

[膜的制造方法][Manufacturing method of film]

以下对一例制造本发明的白色反射膜的方法进行说明。An example of the method for producing the white reflective film of the present invention will be described below.

在制造本发明的白色反射膜时,优选通过熔融挤出法形成反射层A。此外,白色反射膜是反射层A与支撑层B的层叠构成时,或者反射层A与表面层C的层叠构成时,或者反射层A与支撑层B与表面层C的层叠构成时,优选通过共挤出法将这些各层层叠进行制造。据此提高拉伸制膜性的效果增加。此外,反射层A与支撑层B,或者反射层A与表面层C,或者反射层A与支撑层B与表面层C优选通过共挤出法直接层叠。这样通过共挤出法进行层叠,可以提高各层的界面密接性,无需贴合膜,制膜后无需经过重新形成支撑层B或表面层C的工序,价格便宜,容易量产。When producing the white reflective film of the present invention, the reflective layer A is preferably formed by a melt extrusion method. In addition, when the white reflective film is formed by laminating the reflective layer A and the supporting layer B, or when the reflective layer A and the surface layer C are laminated, or when the reflective layer A, the supporting layer B, and the surface layer C are formed by laminating, it is preferable to use the These layers are laminated and produced by co-extrusion. Accordingly, the effect of improving stretch film formability increases. In addition, the reflection layer A and the support layer B, or the reflection layer A and the surface layer C, or the reflection layer A and the support layer B and the surface layer C are preferably directly laminated by a coextrusion method. Lamination by co-extrusion in this way can improve the interfacial adhesion of each layer, and there is no need for laminating films, and there is no need to re-form the support layer B or surface layer C after the film is formed. The process is cheap and easy to mass produce.

以下对一例本发明的白色反射膜的更具体的制法进行说明,但本发明并不限于该制法,此外参考下述对其他方式进行同样的制造。此时,不含挤出工序时,以下的“熔融挤出温度”解读为例如“熔融温度”即可。另外,此处,使用的聚酯的熔点为Tm(单元:℃)、玻璃化转变温度为Tg(单元:℃)。Hereinafter, an example of a more specific production method of the white reflective film of the present invention will be described, but the present invention is not limited to this production method, and the same production is performed for other modes with reference to the following. In this case, when the extrusion process is not included, the following "melt extrusion temperature" may be interpreted as, for example, "melting temperature". Here, the melting point of the polyester used is Tm (unit: °C), and the glass transition temperature is Tg (unit: °C).

具有反射层A与支撑层B,且作为构成反射层A的热塑性树脂A以及构成支撑层B的热塑性树脂B采用聚酯,采用共挤出法作为层叠方法时,首先,准备好混合有作为用于形成反射层A的热塑性树脂组合物A(采用聚酯作为热塑性树脂A时也称为聚酯组合物A)的聚酯、碳酸钙粒子、含有不相容树脂时作为不相容树脂的环烯烃、其他任意成分的化合物。此外,准备好混合有作为用于形成支撑层B的热塑性树脂组合物B(采用聚酯作为热塑性树脂B时也称为聚酯组合物B)的聚酯、其他任意成分的化合物。此处对于支撑层B,可以使用不添加其他任意成分的热塑性树脂B,作为该热塑性树脂B,例如可使用聚酯。将这些聚酯组合物干燥充分除去水分后使用。It has a reflective layer A and a supporting layer B, and polyester is used as the thermoplastic resin A constituting the reflective layer A and the thermoplastic resin B constituting the supporting layer B, and co-extrusion is used as the lamination method, first, prepare a mixture of Polyester, calcium carbonate particles, and rings of an incompatible resin when the thermoplastic resin composition A (also referred to as polyester composition A when polyester is used as the thermoplastic resin A) forming the reflective layer A Olefins and other compounds with arbitrary components. Further, a compound in which polyester and other optional components are mixed as the thermoplastic resin composition B for forming the support layer B (when polyester is used as the thermoplastic resin B, also referred to as polyester composition B) is prepared. Here, for the support layer B, the thermoplastic resin B to which other optional components are not added can be used, and as the thermoplastic resin B, polyester can be used, for example. These polyester compositions are used after drying to sufficiently remove moisture.

此外,具有反射层A与表面层C,且作为构成反射层A的热塑性树脂A以及构成表面层C的热塑性树脂C采用聚酯,采用共挤出法作为层叠方法时,首先,准备好混合有作为用于形成反射层A的热塑性树脂组合物A(采用聚酯作为热塑性树脂A时也称为聚酯组合物A)的聚酯、碳酸钙粒子、其他任意成分的化合物。此外,准备好混合有作为用于形成表面层C的热塑性树脂组合物C(采用聚酯作为热塑性树脂C时也称为聚酯组合物C)的聚酯、表面层粒子、其他任意成分的化合物。将这些聚酯组合物干燥充分除去水分后使用。In addition, when the reflective layer A and the surface layer C are provided, and polyester is used as the thermoplastic resin A constituting the reflective layer A and the thermoplastic resin C constituting the surface layer C, and the co-extrusion method is used as the lamination method, first, a mixture of Compounds of polyester, calcium carbonate particles, and other optional components as the thermoplastic resin composition A for forming the reflective layer A (also referred to as polyester composition A when polyester is used as the thermoplastic resin A). In addition, a compound containing polyester, surface layer particles, and other optional components as thermoplastic resin composition C for forming surface layer C (also referred to as polyester composition C when polyester is used as thermoplastic resin C) is prepared. . These polyester compositions are used after drying to sufficiently remove moisture.

接着,将干燥后的聚酯组合物分别投入挤出机进行熔融挤出。熔融挤出温度需要在T m以上,Tm+40℃程度即可。Next, the dried polyester composition is put into an extruder and melt-extruded. The melt extrusion temperature needs to be higher than Tm, and Tm+40°C is sufficient.

此外此时,用于膜制造的聚酯组合物、特别是反射层A中使用的聚酯组合物A,优选使用线径15μm以下的不锈钢细丝构成的平均网目10μm以上、100μm以下的无纺布型过滤器进行过滤。通过进行该过滤,能抑制通常易于凝聚而成为粗大凝聚粒子的粒子的凝聚,可以获得粗大异物少的膜。然后,通过抑制凝聚的粒子,易于形成微空隙,热变形得到进一步抑制。另外,无纺布的平均网目优选15μm以上,进一步优选20μm以上,此外,优选50μm以下,进一步优选40μm以下。此外,对于热塑性树脂组合物C,优选35μm以上,进一步优选40μm以上,此外,优选70μm以下,进一步优选60μm以下。过滤后的聚酯组合物以熔融的状态,通过使用进料块的同时多层挤出法、即共挤出法,从模头以多层状态被挤出,制造未拉伸层叠片。从模头挤出的未拉伸层叠片通过流延滚筒冷却固化,成为未拉伸层叠膜。In addition, in this case, the polyester composition used for film production, in particular, the polyester composition A used in the reflection layer A is preferably made of stainless steel filaments having a wire diameter of 15 μm or less and having an average mesh size of 10 μm or more and 100 μm or less. Filtration with a woven filter. By performing this filtration, it is possible to suppress the aggregation of particles that generally tend to aggregate and become coarse aggregated particles, and a membrane with few coarse foreign substances can be obtained. Then, by suppressing the aggregated particles, microvoids are easily formed, and thermal deformation is further suppressed. In addition, the average mesh of the nonwoven fabric is preferably 15 μm or more, more preferably 20 μm or more, and more preferably 50 μm or less, further preferably 40 μm or less. Further, the thermoplastic resin composition C is preferably 35 μm or more, more preferably 40 μm or more, and more preferably 70 μm or less, and further preferably 60 μm or less. The filtered polyester composition is extruded from a die in a multi-layered state by a simultaneous multilayer extrusion method using a feed block, that is, a co-extrusion method, to produce an unstretched laminate sheet. The unstretched laminated sheet extruded from the die is cooled and solidified by a casting drum, and becomes an unstretched laminated film.

接着,将该未拉伸层叠膜用辊加热、红外线加热等进行加热,在制膜机械轴方向(以下也称为纵方向或者长度方向或者MD。)上拉伸获得纵拉伸膜。该拉伸优选利用2个以上的辊的周速差进行。纵拉伸后的膜接着被导向拉幅机,在与纵方向和厚度方向垂直的方向(以下也称横方向或者宽度方向或者TD。)上拉伸,制作双轴拉伸膜。Next, this unstretched laminated film is heated with roll heating, infrared heating, etc., and is stretched in the film-forming machine axis direction (hereinafter also referred to as longitudinal direction or longitudinal direction or MD.) to obtain a longitudinally stretched film. This stretching is preferably performed using the difference in peripheral speed between two or more rolls. The longitudinally stretched film is then guided to a tenter and stretched in a direction perpendicular to the longitudinal direction and the thickness direction (hereinafter also referred to as the transverse direction or the width direction or TD.) to produce a biaxially stretched film.

作为拉伸温度,优选在聚酯的Tg以上、优选构成反射层A的聚酯的Tg以上、Tg+30℃以下的温度进行,拉伸制膜性更优异,此外空隙易于很好地形成。此外,作为拉伸倍率,在纵方向、横方向上优选2.5~4.3倍,进一步优选2.7~4.2倍。拉伸倍率太低的话具有膜的厚度均匀变差的倾向,此外具有不易形成空隙的倾向,另一方面过高的话倾向于制膜中易于发生断裂。另外,实施纵拉伸后再进行横拉伸的逐次双轴拉伸时,优选第二阶段(即此时为横拉伸)相比于第一阶段的拉伸温度高10~50℃左右。这是由于经过第一阶段的拉伸进行了取向,单轴膜的Tg升高。The stretching temperature is preferably higher than Tg of polyester, preferably higher than Tg and lower than Tg+30°C of polyester constituting the reflective layer A, since the stretching film-forming property is more excellent, and voids are easily formed well. Moreover, as a draw ratio, 2.5-4.3 times are preferable in a longitudinal direction and a transverse direction, and 2.7-4.2 times are more preferable. If the draw ratio is too low, the uniformity of the film thickness tends to be deteriorated, and there is a tendency that voids are not easily formed. In addition, in the case of successive biaxial stretching in which longitudinal stretching is performed followed by transverse stretching, the stretching temperature in the second stage (ie, transverse stretching in this case) is preferably about 10 to 50°C higher than that in the first stage. This is because the Tg of the uniaxial film is increased due to the orientation through the first-stage stretching.

此外,优选在各拉伸前对膜进行预热。例如横拉伸的预热处理是从高于聚酯(这是优选构成反射层A的聚酯)的Tg+5℃的温度开始,慢慢升温即可。横拉伸过程中的升温可以是连续性的或阶段性的(也称逐次),通常是逐次升温。例如将拉幅机的横拉伸区域沿膜移动的方向分为多块,向每块区域通入规定温度的加热媒体使之升温。Furthermore, it is preferable to preheat the film before each stretching. For example, the preheating treatment for transverse stretching may be started from a temperature higher than the Tg+5°C of polyester (which is preferably the polyester constituting the reflective layer A), and the temperature may be gradually increased. The temperature rise in the transverse stretching process can be continuous or stepwise (also called successively), and usually the temperature rises successively. For example, the transverse stretching area of a tenter is divided into a plurality of blocks in the direction of film movement, and a heating medium of a predetermined temperature is passed through each block to raise the temperature.

双轴拉伸后的膜接着依次进行热固定、热松弛的处理制作双轴取向膜,从熔融挤出至拉伸,这些处理均在移动膜的同时进行。The biaxially stretched film is then sequentially subjected to heat-fixing and heat-relaxing treatments to produce a biaxially oriented film, and these treatments are performed while moving the film from melt extrusion to stretching.

在使用夹具将双轴拉伸后的膜的两端固定的情况下,以聚酯的熔点为Tm,在(Tm-10℃)~(Tm-100℃)下定幅或者减少10%以下的宽度,热处理0.01~100秒,进行热固定,降低热收缩率。另外,该熔点优选是构成反射层A的聚酯的熔点。该热处理温度过高的话具有膜的平面性变差的倾向,厚度不均倾向于变大。另一方面太低的话,具有热收缩率变大的倾向。此外,据此可以进一步提高抑制热变形的效果。When both ends of the biaxially stretched film are fixed using clips, the melting point of polyester is taken as Tm, and the width is fixed or reduced by 10% or less at (Tm-10°C) to (Tm-100°C) , heat treatment for 0.01 to 100 seconds, thermal fixation is performed, and thermal shrinkage is reduced. In addition, the melting point is preferably the melting point of the polyester constituting the reflection layer A. When the heat treatment temperature is too high, the flatness of the film tends to deteriorate, and the thickness unevenness tends to increase. On the other hand, when it is too low, there exists a tendency for a thermal contraction rate to become large. In addition, according to this, the effect of suppressing thermal deformation can be further enhanced.

此外,为了调整热收缩量,切断固定的膜的两端,调整膜纵方向的拉伸速度,可以在纵方向上使之松弛。作为松弛的方法,可以调整拉幅机出口侧的辊群的速度。作为松弛的比例,降低辊群相对于拉幅机的膜线速度的速度,优选实施0.1~2.5%,进一步优选0.2~2.3%,特别优选0.3~2.0%的速度降低来进行膜松弛(以下也将该值称为“松弛率”),通过控制松弛率来调整纵方向的热收缩率。此外,据此可以进一步提高抑制热变形的效果。对于膜横方向,在直至将两端切断的过程中减少宽度,可以获得所望的热收缩率。In addition, in order to adjust the amount of heat shrinkage, both ends of the fixed film can be cut, and the stretching speed in the longitudinal direction of the film can be adjusted to relax the film in the longitudinal direction. As a relaxation method, the speed of the roll group on the exit side of the tenter can be adjusted. As the ratio of relaxation, the speed of the roll group relative to the film linear speed of the tenter is lowered, preferably 0.1 to 2.5%, more preferably 0.2 to 2.3%, and particularly preferably 0.3 to 2.0% to lower the speed of the film to relax the film (hereinafter referred to as the This value is referred to as "relaxation rate"), and the thermal shrinkage rate in the longitudinal direction is adjusted by controlling the relaxation rate. In addition, according to this, the effect of suppressing thermal deformation can be further enhanced. In the film transverse direction, a desired thermal shrinkage rate can be obtained by reducing the width until both ends are cut.

另外,双轴拉伸时,除了上述那样的纵-横的逐次双轴拉伸法以外,还可以是横-纵的逐次双轴拉伸法。此外,可以使用同时双轴拉伸法进行制膜。同时双轴拉伸法的情况下,拉伸倍率在纵方向、横方向上均为例如2.7~4.3倍,优选2.8~4.2倍。In addition, in the case of biaxial stretching, in addition to the above-described longitudinal-horizontal sequential biaxial stretching method, a lateral-longitudinal sequential biaxial stretching method may be used. In addition, film formation can be performed using a simultaneous biaxial stretching method. In the case of the simultaneous biaxial stretching method, the stretching ratio is, for example, 2.7 to 4.3 times, preferably 2.8 to 4.2 times, in both the longitudinal direction and the transverse direction.

这样可以获得本发明的白色反射膜。In this way, the white reflective film of the present invention can be obtained.

[白色反射膜的特性][Characteristics of white reflective film]

(反射率、正面亮度)(Reflectivity, front brightness)

本发明的白色反射膜的反射率在60%以上。优选70%以上,更优选80%以上,进一步优选90%以上,特别优选95%以上,最优选97%以上。反射率在上述范围的话,在用于液晶显示装置或照明等时,可以获得高亮度。该反射率可以通过以下方式达成:增加反射层A的空隙体积率等优选的方式,增加反射层A的厚度,此外,具有支撑层B或表面层C时,使这些层中含有空隙形成剂、相对于反射层A减薄反射面侧的支撑层B或表面层C的厚度等各层形态等优选的方式。The reflectance of the white reflective film of the present invention is 60% or more. It is preferably 70% or more, more preferably 80% or more, further preferably 90% or more, particularly preferably 95% or more, and most preferably 97% or more. When the reflectance is within the above-mentioned range, high luminance can be obtained when used in a liquid crystal display device, illumination, or the like. This reflectivity can be achieved by increasing the thickness of the reflective layer A, preferably by increasing the void volume ratio of the reflective layer A, and, in the case of having a support layer B or a surface layer C, by including a void-forming agent, Preferred embodiments such as the thickness of each layer form, such as the thickness of the support layer B or the surface layer C on the reflective surface side, are made thinner than the reflective layer A.

此外,正面亮度可以通过后述的测定方法求得,优选2000cd/m2以上,更优选3000cd/m2以上,进一步优选4000cd/m2以上,特别优选4400cd/m2以上。In addition, the front luminance can be obtained by the measurement method described later, and is preferably 2000 cd/m 2 or more, more preferably 3000 cd/m 2 or more, still more preferably 4000 cd/m 2 or more, and particularly preferably 4400 cd/m 2 or more.

另外,此处反射率或正面亮度的值是对作为白色反射膜的反射面所使用的面进行测定所得的值。In addition, the value of reflectance or front luminance here is the value obtained by measuring the surface used as a reflection surface of a white reflective film.

(热变形)(Thermal deformation)

本发明的目的在于抑制热变形。热变形是指,驱动例如电视或显示器等制品中的液晶显示器等显示装置的电路或者由背光单元或光源产生的热,或者来自于使用环境的热或湿度,使制品中具备的白色反射膜发生弯曲乃至变形的现象。白色反射膜发生热变形的话,会成为亮度不均的原因,直接导致画质降低的问题。An object of the present invention is to suppress thermal deformation. Thermal deformation means that the circuit for driving a display device such as a liquid crystal display in a product such as a TV or a monitor, or the heat generated by the backlight unit or light source, or the heat or humidity from the use environment, cause the white reflective film included in the product to occur. Bending and even deformation. If the white reflective film is thermally deformed, it will cause uneven brightness and directly lead to the problem of degradation of image quality.

[用途][use]

本发明的白色反射膜是大型显示器用。此处大型显示器是指30寸以上,优选32寸以上,更优选40寸以上,进一步优选42寸以上的液晶显示器。这样的大型显示器在背部机箱上设置有用于组装电路等的凹陷或者隔板。因此,由上述原因等产生的热会局部滞留于该凹陷,进而易于发生热变形。显示器的尺寸越大,为了确保亮度而所必要的光源的数量就多,故而电路等也变得复杂,进而滞留的热变多,倾向于易于发生热变形。因此,现有的技术中,对于抑制这样的大型显示器中的热变形非常困难。与此相对,本发明在这样的大型显示器中,也能良好地抑制热变形。The white reflective film of the present invention is used for large-scale displays. The large-scale display here refers to a liquid crystal display of 30 inches or more, preferably 32 inches or more, more preferably 40 inches or more, and further preferably 42 inches or more. Such large-scale displays are provided with recesses or partitions for assembling circuits and the like in the rear chassis. Therefore, the heat generated by the above-mentioned reasons or the like is locally retained in the depressions, and thermal deformation tends to occur. The larger the size of the display, the larger the number of light sources necessary to ensure brightness, the complicated circuit and the like, and the more accumulated heat, which tends to be prone to thermal deformation. Therefore, in the conventional technology, it is very difficult to suppress thermal deformation in such a large-scale display. On the other hand, according to the present invention, also in such a large-scale display, thermal deformation can be suppressed favorably.

实施例Example

以下通过实施例对本发明进行详细说明。另外,各特性值通过以下的方法进行测定。The present invention will be described in detail below by means of examples. In addition, each characteristic value was measured by the following method.

(1)光线反射率(1) Light reflectivity

在分光光度计(岛津制作所制UV-3101PC)上安装积分球,在波长550nm下测定将BaSO4白板设为100%时的反射率,将该值作为反射率。另外,测定是在作为反射面使用的一侧、即光源侧表面进行。An integrating sphere was attached to a spectrophotometer (UV-3101PC, manufactured by Shimadzu Corporation), and the reflectance when the BaSO 4 white plate was set to 100% was measured at a wavelength of 550 nm, and this value was taken as the reflectance. In addition, the measurement was performed on the side used as a reflection surface, ie, the light source side surface.

(2)粒子的平均粒径(2) Average particle size of particles

使用岛津制作所制激光散射式粒度分布测定装置SALD-7000进行测定。测定前在乙二醇中的分散是称量粒子粉体使其相当于5质量%浆料浓度,在搅拌机中搅拌10分钟,冷却至常温后,供给至流槽(flow cell)式供给装置。此处作为搅拌机,例如使用Nationa lMXV253型料理用搅拌机。然后,该供给装置中进行30秒的超声波处理脱泡后供于测定。另外,该超声波处理中的超声波的强度是超声波处理装置的旋钮处于显示MAX值的位置的60%的位置。由粒度分布测定结果求得50%体积粒径(D50),将其作为平均粒径。此外,同样地求得10%体积粒径(D10)以及90%体积粒径(D90)。The measurement was performed using a laser scattering particle size distribution analyzer SALD-7000 manufactured by Shimadzu Corporation. For dispersion in ethylene glycol before measurement, the particle powder was weighed so as to correspond to a slurry concentration of 5% by mass, stirred in a mixer for 10 minutes, cooled to normal temperature, and then supplied to a flow cell type supply device. Here, as a mixer, for example, a Nationa lMXV253 cooking mixer is used. Then, after degassing by ultrasonic treatment for 30 seconds in this supply device, it was used for measurement. In addition, the intensity of the ultrasonic waves in the ultrasonic treatment is such that the knob of the ultrasonic treatment apparatus is at a position of 60% of the position where the MAX value is displayed. The 50% volume particle diameter (D50) was obtained from the result of particle size distribution measurement, and this was taken as the average particle diameter. In addition, the 10% volume particle diameter (D10) and the 90% volume particle diameter (D90) were similarly obtained.

(3)粒子以及不相容树脂的含量(3) Content of particles and incompatible resins

(3-1)粒子的含量(3-1) Content of particles

将膜在500℃的温度下焚烧6小时,测定其前后的重量,将残余灰分的重量作为粒子的含量。另外,层叠体中各层的粒子含量是将各层分离后进行上述操作而求得。The film was incinerated at a temperature of 500° C. for 6 hours, the weights before and after that were measured, and the weight of the residual ash was taken as the content of particles. In addition, the particle content of each layer in a laminated body was calculated|required by carrying out the said operation after isolate|separating each layer.

(3-2)不相容树脂的含量(3-2) Content of incompatible resin

秤量膜后,溶解于六氟异丙醇(HFIP)/氯仿的质量比50/50的混合溶剂中,存在不溶成分时,通过离心分离将该不溶成分分离提取后,测定质量,通过元素分析、FT-IR、NMR法测定该成分的结构和质量分率。对上层成分也作同样的分析,可以确定聚酯成分以及其他成分的质量分率和结构。从上层成分馏去溶剂后,溶解于HFIP/重氯仿的质量比50/50的混合溶剂后,测定1H-NMR谱。After weighing the membrane, it was dissolved in a mixed solvent of hexafluoroisopropanol (HFIP)/chloroform in a mass ratio of 50/50. If there was an insoluble component, the insoluble component was separated and extracted by centrifugation, the mass was measured, and elemental analysis, The structure and mass fraction of this component were measured by FT-IR and NMR methods. The same analysis is performed for the upper layer components, and the mass fraction and structure of the polyester component and other components can be determined. After distilling off the solvent from the upper layer component, it was dissolved in a mixed solvent of HFIP/heavy chloroform in a mass ratio of 50/50, and then the 1 H-NMR spectrum was measured.

从获得的氢谱求得各成分特有的吸收峰面积强度,通过其比例及质子数算出混合的摩尔比。进一步从相当于聚合物的单位单元的式量来算出质量比。如此确定各成分的质量分率和结构。The absorption peak area intensity specific to each component was obtained from the obtained hydrogen spectrum, and the molar ratio of the mixture was calculated from the ratio and the number of protons. Furthermore, the mass ratio was calculated from the formula amount corresponding to the unit unit of the polymer. The mass fraction and structure of each component are thus determined.

另外,层叠体中各层的粒子含量是将各层分离后进行上述操作而求得。In addition, the particle content of each layer in a laminated body was calculated|required by carrying out the said operation after isolate|separating each layer.

(4)膜厚度以及层构成(4) Film thickness and layer composition

将白色反射膜用切片机切片露出截面,对该截面使用日立制作所制S-4700型场发射扫描电子显微镜,以倍率500倍进行观察,分别求得膜整体、反射层A、支撑层B、表面层C的厚度。厚度的测定是取n=7测定任意位置作为平均值求得。求得各层的厚度(μm)之后算出各层的厚度比。The white reflective film was sliced with a microtome to expose the cross-section, and the cross-section was observed using an S-4700 field emission scanning electron microscope manufactured by Hitachi, Ltd. at a magnification of 500 times, and the entire film, the reflective layer A, the support layer B, the Thickness of surface layer C. The measurement of thickness was calculated|required by taking n=7 and measuring arbitrary positions as an average value. After the thickness (µm) of each layer was obtained, the thickness ratio of each layer was calculated.

(5)空隙体积率的计算(5) Calculation of void volume ratio

从求空隙体积率的层的聚合物、添加粒子、其他各成分的密度及混合比例,求得计算密度。同时,剥离该层等进行分离,测定质量以及体积,从中算出实际密度,通过下述式基于计算密度和实际密度求得。The calculated density was obtained from the densities and mixing ratios of the polymer, added particles, and other components of the layer for which the void volume ratio was obtained. Simultaneously, this layer is peeled off and separated, the mass and volume are measured, and the actual density is calculated therefrom, which is obtained by the following formula based on the calculated density and the actual density.

空隙体积率=100×(1-(实际密度/计算密度))Void volume ratio=100×(1-(actual density/calculated density))

另外,双轴拉伸后的间苯二甲酸共聚聚对苯二甲酸乙二醇酯的密度为1.39g/cm3,碳酸钙粒子的密度为2.7g/cm3,硫酸钡粒子的密度为4.5g/cm3,环烯烃共聚物不相容树脂的密度为1.02g/cm3In addition, the density of the isophthalic acid copolymer polyethylene terephthalate after biaxial stretching was 1.39 g/cm 3 , the density of calcium carbonate particles was 2.7 g/cm 3 , and the density of barium sulfate particles was 4.5 g/cm 3 , the density of the cyclic olefin copolymer incompatible resin was 1.02 g/cm 3 .

此外,仅分离测定空隙体积率的层,求得每单位体积的质量,从而求得实际密度。体积按照以下测得的厚度及质量作为面积×厚度算出:将样本切出为面积3cm2,使用电测微计(日本安立公司制K-402B)对该尺寸的厚度进行测定,测定10点取其平均值作为厚度。质量使用电子天秤进行秤量。Further, only the layer for which the void volume ratio was measured was separated, and the mass per unit volume was obtained to obtain the actual density. The volume was calculated as area×thickness from the thickness and mass measured as follows: A sample was cut out to an area of 3 cm 2 , and the thickness of this dimension was measured using an electric micrometer (K-402B, manufactured by Anritsu Co., Ltd., Japan), and the measurement was taken at 10 points. Its average value was taken as the thickness. Mass is measured using an electronic balance.

另外,作为含有凝聚粒子的其他粒子的比重,使用通过以下的量筒法求得的堆密度的值。将容积1000ml的量筒中填充绝干状态的粒子,测定整体的重量,从该整体的重量减去量筒的重量求得该粒子的重量,测定该量筒的容积,通过该粒子的重量(g)除以该容积(cm3)而求得。In addition, as the specific gravity of other particles including aggregated particles, the value of the bulk density obtained by the following graduated cylinder method was used. Fill a measuring cylinder with a volume of 1000 ml with absolutely dry particles, measure the weight of the whole, subtract the weight of the measuring cylinder from the whole weight to obtain the weight of the particles, measure the volume of the measuring cylinder, divide by the weight (g) of the particles Obtained by this volume (cm 3 ).

(6)熔点、玻璃化转变温度(6) Melting point and glass transition temperature

使用差示扫描量热仪(TA Instruments 2100DSC),以升温速度20℃/分进行测定。The measurement was performed at a temperature increase rate of 20°C/min using a differential scanning calorimeter (TA Instruments 2100DSC).

(7)正面亮度(7) Front brightness

(7-1)正面亮度1(7-1) Front brightness 1

从LG公司生产的侧光型LED液晶电视(LG42LE5310AKR)(42寸)中取出反射膜,替换为实施例中所得的各种反射膜,将反射面侧设置为画面侧,配合原本具备的扩散膜以及棱镜片,以背光单元的状态使用亮度计(大塚电子制Model MC-940)测定亮度。Take out the reflective film from the edge-lit LED LCD TV (LG42LE5310AKR) (42 inches) produced by LG, replace it with various reflective films obtained in the examples, set the reflective surface side as the screen side, and match the original diffuser film As for the prism sheet, the luminance was measured using a luminance meter (Model MC-940, manufactured by Otsuka Electronics Co., Ltd.) in the state of the backlight unit.

(7-2)正面亮度2(7-2) Front brightness 2

从LG公司生产的直下LED光型液晶电视(LG LN5400)(42寸)中取出反射膜,替换为实施例中所得的各种反射膜,将反射面侧设置为画面侧,配合原本具备的扩散膜以及棱镜片,以背光单元的状态使用亮度计(大塚电子制Model MC-940)测定亮度。Take out the reflective film from the direct-lit LED light type LCD TV (LG LN5400) (42 inches) produced by LG, replace it with various reflective films obtained in the examples, set the reflective surface side as the screen side, and match the original diffuser The luminance of the film and the prism sheet was measured using a luminance meter (Model MC-940, manufactured by Otsuka Electronics Co., Ltd.) in the state of the backlight unit.

(8)拉伸制膜性(8) Stretch film formability

对使用拉幅机通过连续制膜法对实施例中所述的膜进行制膜时的制膜稳定性进行观察,以下述基准进行评价。The film-forming stability at the time of film-forming the film described in the Example was observed by the continuous film-forming method using a tenter, and it evaluated based on the following criteria.

◎:可以8小时以上稳定制膜。◎: Stable film formation is possible for more than 8 hours.

○:可以3小时以上小于8小时内稳定制膜。○: The film can be stably formed within 3 hours or more and less than 8 hours.

△:不足3小时断裂过1次。△: Break once in less than 3 hours.

×:不足3小时即发生数次断裂,无法稳定制膜。×: Breaks occurred several times in less than 3 hours, and stable film formation was not possible.

(9)热变形评价(9) Thermal deformation evaluation

将LG公司生产的侧光型LED液晶电视(LG42LE5310AKR)(42寸)分解,从中取出原本具备的反射膜,替换配置为实施例的白色反射膜,组装成电视,以该状态下将电视亮灯显示为白色,于温度50℃、湿度80%RH的环境中保管72小时,评价其前后的亮度不均。Disassemble the edge-lit LED LCD TV (LG42LE5310AKR) (42 inches) produced by LG, take out the original reflective film, replace the white reflective film of the example, assemble it into a TV, and turn on the TV in this state It appeared white, and was stored in an environment with a temperature of 50° C. and a humidity of 80% RH for 72 hours, and the brightness unevenness before and after was evaluated.

(9-1)亮度不均评价1(9-1) Evaluation of uneven brightness 1

目测判断亮度不均,基于以下的基准进行评价The uneven brightness was visually judged and evaluated based on the following criteria

○:完全没有看到亮度不均。○: Brightness unevenness was not observed at all.

△:勉强看到亮度不均。△: Brightness unevenness is barely seen.

×:看见显著的亮度不均。×: Significant unevenness in luminance was seen.

(9-2)亮度不均评价2(9-2) Evaluation of uneven brightness 2

使用亮度计(柯尼卡美能达公司制造CA-2000)测定画面内平均的任意的10点的亮度,以画面内的[(最高亮度-最低亮度)/平均亮度]的值进行评价。上述的值在5%以下时可以判定为由热变形引起的亮度不均少,为良好的状态。优选4%以下,进一步优选3%以下。An arbitrary 10-point luminance averaged in the screen was measured using a luminance meter (CA-2000, manufactured by Konica Minolta), and evaluated by the value of [(highest luminance - lowest luminance)/average luminance] in the screen. When the above-mentioned value is 5% or less, it can be judged that there is little unevenness in luminance due to thermal deformation, and it is a good state. 4% or less is preferable, and 3% or less is more preferable.

(10)导光板粘贴评价(10) Evaluation of light guide plate sticking

从LG公司生产的LED液晶电视(LG42LE5310AKR)上取出机箱,放置在水平的桌上使电视内部侧朝上,在其上以表面层面朝上的方式放置与机箱几乎等大小的反射膜,进一步再在其上放置电视原本具备的导光板以及3片光学片,该3片光学片是指2片扩散膜以及1片棱镜。接着,在该面内,包含机箱的凹凸最突出的部分的区域上,如图1所示,放置具备3根直径5mm的圆柱状支脚的正三角形型台,在该台上进一步放置15kg的负重,目测观察该3根支脚所包围的区域,没有异常明亮的部分为“无粘着斑”、即评价为○。此外,具有异常明亮的部分时,在3片光学片上进一步放置电视原本具备的DBEF片,同样目测进行观察,异常明亮的部分没有消除的为“有粘着斑”、即评价为×,异常明亮的部分消除的为“几乎没有粘着斑”、即评价为△。另外,该3根支脚所包围的区域为各边长为10cm的略正三角形。Take out the case from the LED LCD TV (LG42LE5310AKR) produced by LG, place it on a horizontal table with the inside of the TV facing up, and place a reflective film almost the same size as the case on it with the surface up. Put the light guide plate originally equipped with the TV and 3 optical sheets on it, and the 3 optical sheets refer to 2 diffusers and 1 prism. Next, on this surface, on the area including the most protruding parts of the chassis, as shown in Fig. 1, a equilateral triangle-shaped table with three cylindrical legs with a diameter of 5 mm was placed, and a load of 15 kg was further placed on the table. , the area surrounded by the three legs was visually observed, and the part with no abnormally bright part was "no adhesion spots", that is, it was evaluated as ○. In addition, when there are abnormally bright parts, the DBEF sheet originally provided in the TV is further placed on the three optical sheets, and the same visual observation is carried out. Partially eliminated was "hardly no adhesion spots", that is, it was evaluated as Δ. In addition, the area enclosed by the three legs is an approximately equilateral triangle with a side length of 10 cm.

<制造例1:间苯二甲酸共聚聚对苯二甲酸乙二醇酯1的合成><Production example 1: Synthesis of isophthalic acid copolymer polyethylene terephthalate 1>

将对苯二甲酸二甲酯136.5质量份、间苯二甲酸二甲酯13.5质量份(即间苯二甲酸成分相对于获得的聚酯的总酸成分100摩尔%为9摩尔%)、乙二醇98质量份、二乙二醇1.0质量份、乙酸锰0.05质量份、乙酸锂0.012质量份加入具备精馏塔、馏出冷凝器的烧瓶中,在搅拌的同时,加热到150~240℃,馏出甲醇进行酯交换反应。甲醇馏出后,添加磷酸三甲酯0.03质量份、二氧化锗0.04质量份,将反应物移到反应器。接着在搅拌的同时将反应器内慢慢减压到0.3mmHg,同时升温至292℃,进行缩聚反应,获得间苯二甲酸共聚聚对苯二甲酸乙二醇酯1。该聚合物的熔点是235℃。136.5 parts by mass of dimethyl terephthalate, 13.5 parts by mass of dimethyl isophthalate (that is, the isophthalic acid component is 9 mol % with respect to 100 mol % of the total acid content of the polyester obtained), ethylene glycol 98 parts by mass of alcohol, 1.0 part by mass of diethylene glycol, 0.05 part by mass of manganese acetate, and 0.012 part by mass of lithium acetate were added to a flask equipped with a rectifying column and a distillation condenser, and heated to 150-240° C. while stirring, Methanol was distilled off for transesterification. After methanol was distilled off, 0.03 parts by mass of trimethyl phosphate and 0.04 parts by mass of germanium dioxide were added, and the reactants were transferred to the reactor. Next, the inside of the reactor was gradually depressurized to 0.3 mmHg while stirring, and the temperature was raised to 292° C. to carry out a polycondensation reaction to obtain isophthalic acid copolymerized polyethylene terephthalate 1. The melting point of this polymer is 235°C.

<制造例2:间苯二甲酸共聚聚对苯二甲酸乙二醇酯2的合成><Production example 2: Synthesis of isophthalic acid copolymer polyethylene terephthalate 2>

除了变更为对苯二甲酸二甲酯129.0质量份、间苯二甲酸二甲酯21.0质量份(即间苯二甲酸成分相对于获得的聚酯的总酸成分100摩尔%为14摩尔%),其他与上述制造例1相同地获得间苯二甲酸共聚聚对苯二甲酸乙二醇酯2。该聚合物的熔点是215℃。Except for changing to 129.0 parts by mass of dimethyl terephthalate and 21.0 parts by mass of dimethyl isophthalate (that is, the isophthalic acid component is 14 mol % with respect to 100 mol % of the total acid content of the polyester obtained), Otherwise, it carried out similarly to the said manufacture example 1, and obtained isophthalic-acid co-polyethylene terephthalate 2. The melting point of this polymer is 215°C.

<制造例3:粒子母料切片1的制作><Production Example 3: Production of Particle Masterbatch Chip 1>

使用上述获得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯1的一部分,以及作为空隙形成剂的平均粒径0.9μm、(D90-D10)/D50为1.4的合成碳酸钙粒子,通过日本神户制钢公司制NEX-T60串联式挤出机以合成碳酸钙粒子的含量相对于获得的母料切片的质量为60质量%的量进行混合,在树脂温度260℃下进行挤出,制作含合成碳酸钙粒子的粒子母料切片1。另外,该合成碳酸钙粒子通过磷酸三甲酯进行了表面处理。Using a part of the isophthalic acid-copolymerized polyethylene terephthalate 1 obtained above, and synthetic calcium carbonate particles having an average particle diameter of 0.9 μm as a void former and (D90-D10)/D50 of 1.4, The NEX-T60 tandem extruder manufactured by Kobe Steel Co., Ltd. mixed the content of synthetic calcium carbonate particles in an amount of 60% by mass relative to the mass of the obtained master batch chips, and extruded at a resin temperature of 260°C to produce Particle Masterbatch Chip 1 with Synthetic Calcium Carbonate Particles. In addition, the synthetic calcium carbonate particles were surface-treated with trimethyl phosphate.

<制造例4:粒子母料切片2的制作><Production Example 4: Production of Particle Masterbatch Chip 2>

使用上述获得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯2替代间苯二甲酸共聚聚对苯二甲酸乙二醇酯1,除此之外与上述制造例3同样地制作含合成碳酸钙粒子的粒子母料切片2。A compound containing isophthalic acid was prepared in the same manner as in Production Example 3, except that the isophthalic acid copolyethylene terephthalate 2 obtained above was used in place of the isophthalic acid copolyethylene terephthalate 1. Calcium carbonate particle particle master batch slice 2.

<制造例5:粒子母料切片3的制作><Production Example 5: Production of Particle Masterbatch Chip 3>

将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径6.5μm的粒子作为粒子A,以在获得的粒子母料切片中的浓度为8质量%的量通过双轴挤出机与上述获得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯2进行混合,在熔融温度250℃下进行挤出,制作粒子母料切片3。AY-601 (that is, agglomerated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles with an average particle diameter of 6.5 μm by wind as particle A, and the concentration in the obtained particle master batch chips was 8 The amount of mass % was mixed with the isophthalic acid co-polyethylene terephthalate 2 obtained above with a twin-screw extruder, and extruded at a melting temperature of 250° C. to prepare particle master batch chips 3 .

<制造例6:珠层中使用的粒子1的制造><Production Example 6: Production of Particle 1 Used in Bead Layer>

将对苯二甲酸二甲酯150质量份、乙二醇98质量份、二乙二醇1.0质量份、乙酸锰0.05质量份、乙酸锂0.012质量份加入具备精馏塔、馏出冷凝器的烧瓶中,在搅拌的同时,加热到150~240℃,馏出甲醇进行酯交换反应。甲醇馏出后,添加磷酸三甲酯0.03质量份、二氧化锗0.04质量份,将反应物移到反应器。接着在搅拌的同时将反应器内慢慢减压到0.3mmHg,同时升温至292℃,进行缩聚反应,获得聚对苯二甲酸乙二醇酯3。将获得的聚对苯二甲酸乙二醇酯3从股束状模头中挤出,冷却后切断成颗粒状。调整股束的形状,其结果是该颗粒的形状为近似长方体的形状,其平均为4mm×3mm×2mm。接着,将该获得的颗粒在烘箱内170℃下加热3小时使之干燥结晶化,使用株式会社MATSUBO生产的雾化粉碎机TAP-1以液氮冷却的同时进行粉碎,获得平均粒径60μm的聚酯粒子。进一步将该聚酯粒子风力分级,获得平均粒径43μm的粒子1,其为非球状粒子。150 parts by mass of dimethyl terephthalate, 98 parts by mass of ethylene glycol, 1.0 part by mass of diethylene glycol, 0.05 part by mass of manganese acetate, and 0.012 part by mass of lithium acetate were added to a flask equipped with a rectification column and a distillation condenser While stirring, the mixture was heated to 150 to 240° C., methanol was distilled off, and the transesterification reaction was carried out. After methanol was distilled off, 0.03 parts by mass of trimethyl phosphate and 0.04 parts by mass of germanium dioxide were added, and the reactants were transferred to the reactor. Next, the inside of the reactor was gradually depressurized to 0.3 mmHg while stirring, and the temperature was raised to 292° C. to carry out a polycondensation reaction to obtain polyethylene terephthalate 3 . The obtained polyethylene terephthalate 3 was extruded from a strand-shaped die, and after cooling, it was cut into pellets. The shape of the strands was adjusted, and as a result, the shape of the particles was approximately a rectangular parallelepiped shape, which averaged 4 mm x 3 mm x 2 mm. Next, the obtained particles were dried and crystallized by heating at 170° C. in an oven for 3 hours, and pulverized while cooling with liquid nitrogen using an atomizing pulverizer TAP-1 manufactured by MATSUBO Co., Ltd. to obtain particles with an average particle size of 60 μm. Polyester particles. Further, the polyester particles were air-classified to obtain particles 1 having an average particle diameter of 43 μm, which were non-spherical particles.

[实施例1-1][Example 1-1]

(白色反射膜的制造)(Manufacture of white reflective film)

分别使用上述所得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯1与粒子母料切片1作为反射层(A层)的原料,使用间苯二甲酸共聚聚对苯二甲酸乙二醇酯2与粒子母料切片2作为支撑层(B层)的原料,将各层按照表1所记载的构成进行混合,投入挤出机,将A层通过平均网目30μm的无纺布型过滤器以熔融挤出温度255℃,B层通过平均网目30μm的无纺布型过滤器以熔融挤出温度230℃,使用3层进料块装置进行合流,使之形成如表1所示的B层/A层/B层的层构成,保持该层叠状态通过模头成形为片状。此时调整各挤出机的吐出量使B层/A层/B层的厚度比在双轴拉伸后为10/80/10。进一步将该片通过表面温度25℃的冷却滚筒进行冷却固化制作未拉伸膜。使该未拉伸膜通过73℃的预热区、接着75℃的预热区,导入保持为92℃的纵拉伸区,在纵方向上拉伸3.0倍,以25℃的辊群冷却。接着,通过夹具保持膜两端的同时使之通过115℃的预热区,导入保持为130℃的横拉伸区,在横方向上拉伸3.6倍。其后在拉幅机内连续进行155℃下热处理10秒,200℃下热固定10秒,155℃下热处理10秒,接着以缩幅率2%、缩幅温度130℃进行横方向的缩幅,然后切掉膜两端,以纵松弛率2.5%进行热松弛,冷却至室温,获得厚度300μm的膜。获得的膜的评价结果如表1所示。The isophthalic acid copolyethylene terephthalate 1 and the particle master batch chip 1 obtained above were used as the raw materials of the reflective layer (layer A), and the isophthalic acid copolyethylene terephthalate was used Ester 2 and particle master batch chips 2 were used as raw materials for the support layer (layer B), each layer was mixed according to the composition described in Table 1, put into an extruder, and layer A was filtered through a non-woven fabric with an average mesh size of 30 μm The melt extrusion temperature is 255°C, and the B layer passes through a non-woven filter with an average mesh of 30 μm at a melt extrusion temperature of 230°C, using a 3-layer feed block device for confluence, so that it forms as shown in Table 1. The layer structure of B layer/A layer/B layer is kept in this laminated state, and it is molded into a sheet shape by a die. At this time, the discharge amount of each extruder was adjusted so that the thickness ratio of B layer/A layer/B layer after biaxial stretching was 10/80/10. Further, the sheet was cooled and solidified by a cooling roll having a surface temperature of 25°C to produce an unstretched film. The unstretched film was passed through a preheating zone at 73°C, followed by a preheating zone at 75°C, introduced into a longitudinal stretching zone maintained at 92°C, stretched 3.0 times in the longitudinal direction, and cooled with a 25°C roll group. Next, the film was passed through a preheating zone at 115° C. while being held by clips at both ends, introduced into a lateral stretching zone kept at 130° C., and stretched 3.6 times in the lateral direction. Thereafter, heat treatment at 155°C for 10 seconds in a tenter, heat fixation at 200°C for 10 seconds, and heat treatment at 155°C for 10 seconds, followed by narrowing down in the transverse direction at a narrowing rate of 2% and a narrowing temperature of 130°C Then, both ends of the film were cut off, thermally relaxed at a longitudinal relaxation rate of 2.5%, and cooled to room temperature to obtain a film with a thickness of 300 μm. Table 1 shows the evaluation results of the obtained films.

[实施例1-2~1-9、1-11、比较例1-1~1-6][Examples 1-2 to 1-9, 1-11, Comparative Examples 1-1 to 1-6]

除了使粒子的形态、膜的构成如表1所示以外,与实施例1-1同样地获得白色反射膜。获得的膜的评价结果如表1所示。另外,使用的合成碳酸钙粒子通过磷酸三甲基进行了表面处理。A white reflective film was obtained in the same manner as in Example 1-1, except that the form of the particles and the composition of the film were as shown in Table 1. Table 1 shows the evaluation results of the obtained films. In addition, the synthetic calcium carbonate particles used were surface-treated with trimethyl phosphate.

实施例1-11中膜的总厚度为188μm。The total thickness of the films in Examples 1-11 was 188 μm.

[比较例1-7][Comparative Example 1-7]

除了使用平均粒径0.9μm、(D90-D10)/D50为1.4的硫酸钡粒子替代碳酸钙粒子作为空隙形成剂以外,与制造例3、4同样地制作粒子母料切片,除了膜的构成如表1所示以外,与实施例1-1同样地获得白色反射膜。获得的膜的评价结果如表1所示。另外,该硫酸钡粒子通过重复进行风力分级获得。The particle master batch chips were prepared in the same manner as in Production Examples 3 and 4, except that barium sulfate particles having an average particle diameter of 0.9 μm and (D90-D10)/D50 of 1.4 were used instead of calcium carbonate particles as the void-forming agent, except that the film composition was as follows: Except as shown in Table 1, it carried out similarly to Example 1-1, and obtained the white reflection film. Table 1 shows the evaluation results of the obtained films. In addition, the barium sulfate particles are obtained by repeating air classification.

[实施例1-10][Example 1-10]

在与实施例1-1同样地获得的双轴拉伸膜的一个面上,使用直接凹版涂布装置,将用于形成下述珠层的涂液1所示的组成构成的涂液以湿厚度15g/m2的涂布量进行涂布后,于烘箱内100℃下进行干燥获得具有珠层的白色反射膜。获得的膜的评价结果见表1。另外,评价中将珠层侧作为反射面。On one side of the biaxially stretched film obtained in the same manner as in Example 1-1, a coating liquid having a composition shown in Coating Liquid 1 for forming a bead layer below was wetted using a direct gravure coating apparatus. After coating with a thickness of 15 g/m 2 , drying was performed at 100° C. in an oven to obtain a white reflective film with a bead layer. The evaluation results of the obtained films are shown in Table 1. In addition, in the evaluation, the bead layer side was used as a reflective surface.

<涂液1、固体成分浓度30质量%><Coating liquid 1, solid content concentration 30 mass %>

·粒子:上述制造例6所得的粒子1(非球状粒子)···7.5质量%Particles: Particles 1 (non-spherical particles) obtained in Production Example 6 above... 7.5% by mass

·丙烯酸树脂(热塑性树脂):DIC公司制ACRYDIC A-817BA(固体成分浓度50质量%)···30质量%Acrylic resin (thermoplastic resin): ACRYDIC A-817BA (solid content concentration: 50 mass %) manufactured by DIC Corporation: 30 mass %

·交联剂:日本聚氨酯工业公司制Coronate HL(异氰酸酯系交联剂、固体成分浓度75质量%)···10质量%・Crosslinking agent: Coronate HL (Isocyanate-based crosslinking agent, solid content concentration 75% by mass) manufactured by Nippon Polyurethane Industry Co., Ltd.... 10% by mass

·稀释溶剂:乙酸丁酯···52.5质量%Dilution solvent: Butyl acetate...52.5% by mass

另外,涂液1中各成分的固体成分比例如下。In addition, the solid content ratio of each component in the coating liquid 1 is as follows.

·粒子:25质量%· Particles: 25% by mass

·丙烯酸树脂(热塑性树脂):50质量%Acrylic resin (thermoplastic resin): 50% by mass

·交联剂:25质量%Crosslinking agent: 25% by mass

【表1】【Table 1】

Figure BDA0001526755760000311
Figure BDA0001526755760000311

[实施例2-1][Example 2-1]

(白色反射膜的制造)(Manufacture of white reflective film)

分别使用上述所得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯1与粒子母料切片1以及不相容树脂(环烯烃共聚物、Tg=210℃、宝理塑料株式会社制“TOPAS”)作为反射层(A层)的原料,使用间苯二甲酸共聚聚对苯二甲酸乙二醇酯2与粒子母料切片2作为支撑层(B层)的原料,将各层按照表2所记载的构成进行混合,投入挤出机,将A层通过平均网目30μm的无纺布型过滤器以熔融挤出温度255℃,B层通过平均网目30μm的无纺布型过滤器以熔融挤出温度230℃,使用3层进料块装置进行合流,使之形成如表2所示的B层/A层/B层的层构成,保持该层叠状态通过模头成形为片状。此时调整各挤出机的吐出量使B层/A层/B层的厚度比在双轴拉伸后为10/80/10。进一步将该片通过表面温度25℃的冷却滚筒进行冷却固化制作未拉伸膜。使该未拉伸膜通过73℃的预热区、接着75℃的预热区,导入保持为92℃的纵拉伸区,在纵方向上拉伸3.0倍,以25℃的辊群冷却。接着,通过夹具保持膜两端的同时使之通过115℃的预热区,导入保持为130℃的横拉伸区,在横方向上拉伸3.6倍。其后在拉幅机内连续进行155℃下热处理10秒,200℃下热固定10秒,155℃下热处理10秒,接着以缩幅率2%、缩幅温度130℃进行横方向的缩幅,然后切掉膜两端,以纵松弛率2.5%进行热松弛,冷却至室温,获得厚度300μm的膜。获得的膜的评价结果如表2。The isophthalic acid copolymer polyethylene terephthalate 1 obtained above, the particle master batch chip 1 and the incompatible resin (cyclic olefin copolymer, Tg=210°C, "TOPAS" manufactured by Polyplastics Co., Ltd.) were used, respectively. ”) as the raw material of the reflective layer (layer A), use isophthalic acid copolyethylene terephthalate 2 and particle master batch chips 2 as the raw material of the support layer (layer B), each layer according to Table 2 The composition described above was mixed, put into an extruder, layer A was passed through a non-woven filter with an average mesh of 30 μm at a melt extrusion temperature of 255°C, and layer B was passed through a non-woven filter with an average mesh of 30 μm. The melt extrusion temperature was 230°C, and the three-layer feed block apparatus was used for confluence to form a layer structure of B layer/A layer/B layer as shown in Table 2, and the laminated state was maintained and formed into a sheet shape by a die. At this time, the discharge amount of each extruder was adjusted so that the thickness ratio of B layer/A layer/B layer after biaxial stretching was 10/80/10. Further, the sheet was cooled and solidified by a cooling roll having a surface temperature of 25°C to produce an unstretched film. The unstretched film was passed through a preheating zone at 73°C, followed by a preheating zone at 75°C, introduced into a longitudinal stretching zone maintained at 92°C, stretched 3.0 times in the longitudinal direction, and cooled with a 25°C roll group. Next, the film was passed through a preheating zone at 115° C. while being held by clips at both ends, introduced into a lateral stretching zone kept at 130° C., and stretched 3.6 times in the lateral direction. Thereafter, heat treatment at 155°C for 10 seconds in a tenter, heat fixation at 200°C for 10 seconds, and heat treatment at 155°C for 10 seconds, followed by narrowing down in the transverse direction at a narrowing rate of 2% and a narrowing temperature of 130°C Then, both ends of the film were cut off, thermally relaxed at a longitudinal relaxation rate of 2.5%, and cooled to room temperature to obtain a film with a thickness of 300 μm. The evaluation results of the obtained films are shown in Table 2.

[实施例2-2~2-17、比较例2-1~2-6][Examples 2-2 to 2-17, Comparative Examples 2-1 to 2-6]

除了使粒子的形态、膜的构成如表2所示以外,与实施例2-1同样地获得白色反射膜。获得的膜的评价结果如表2所示。另外,使用的合成碳酸钙粒子通过磷酸三甲酯进行了表面处理。A white reflective film was obtained in the same manner as in Example 2-1, except that the form of the particles and the composition of the film were as shown in Table 2. Table 2 shows the evaluation results of the obtained films. In addition, the used synthetic calcium carbonate particles were surface-treated with trimethyl phosphate.

实施例2-17中膜的总厚度为188μm。The total thickness of the films in Examples 2-17 was 188 μm.

[实施例2-18][Example 2-18]

在与实施例2-1同样地获得的双轴拉伸膜的一个面上,使用直接凹版涂布装置,将用于形成上述珠层的涂液1所示的组成构成的涂液以湿厚度15g/m2的涂布量进行涂布后,于烘箱内100℃下进行干燥获得具有珠层的白色反射膜。获得的膜的评价结果见表2。另外,评价中将珠层侧作为反射面。On one side of the biaxially stretched film obtained in the same manner as in Example 2-1, a coating liquid having a composition shown in Coating Liquid 1 for Forming the Bead Layer was applied to a wet thickness using a direct gravure coating apparatus. After coating with a coating amount of 15 g/m 2 , it was dried in an oven at 100° C. to obtain a white reflective film with a bead layer. The evaluation results of the obtained films are shown in Table 2. In addition, in the evaluation, the bead layer side was used as a reflective surface.

[比较例2-7][Comparative Example 2-7]

除了使用平均粒径0.9μm、(D90-D10)/D50为1.4的硫酸钡粒子替代碳酸钙粒子作为空隙形成剂以外,与制造例3、4同样地制作粒子母料切片,除了膜的构成如表2所示以外,与实施例2-1同样地获得白色反射膜。获得的膜的评价结果如表2。另外,该硫酸钡粒子通过重复进行风力分级获得。The particle master batch chips were prepared in the same manner as in Production Examples 3 and 4, except that barium sulfate particles having an average particle diameter of 0.9 μm and (D90-D10)/D50 of 1.4 were used instead of calcium carbonate particles as the void-forming agent, except that the film composition was as follows: Except as shown in Table 2, a white reflective film was obtained in the same manner as in Example 2-1. The evaluation results of the obtained films are shown in Table 2. In addition, the barium sulfate particles are obtained by repeating air classification.

【表2】【Table 2】

Figure BDA0001526755760000331
Figure BDA0001526755760000331

[实施例3-1][Example 3-1]

(白色反射膜的制造)(Manufacture of white reflective film)

分别使用上述所得的间苯二甲酸共聚聚对苯二甲酸乙二醇酯1与粒子母料切片1作为反射层(A层)的原料,使用间苯二甲酸共聚聚对苯二甲酸乙二醇酯2与粒子母料切片3作为表面层(C层)的原料,将各层按照表3所记载的构成进行混合,投入挤出机,将A层通过平均网目30μm的无纺布型过滤器以熔融挤出温度255℃,C层通过平均网目50μm的无纺布型过滤器以熔融挤出温度230℃,使用3层进料块装置进行合流,使之形成如表3所示的C层/A层/C层的层构成,保持该层叠状态通过模头成形为片状。此时调整各挤出机的吐出量使C层/A层/C层的厚度比在双轴拉伸后为10/80/10。进一步将该片通过表面温度25℃的冷却滚筒进行冷却固化制作未拉伸膜。使该未拉伸膜通过73℃的预热区、接着75℃的预热区,导入保持为92℃的纵拉伸区,在纵方向上拉伸3.0倍,以25℃的辊群冷却。接着,通过夹具保持膜两端的同时使之通过115℃的预热区,导入保持为130℃的横拉伸区,在横方向上拉伸3.6倍。其后在拉幅机内连续进行155℃下热处理10秒,200℃下热固定10秒,155℃下热处理10秒,接着以缩幅率2%、缩幅温度130℃进行横方向的缩幅,然后切掉膜两端,以纵松弛率2.5%进行热松弛,冷却至室温,获得厚度300μm的膜。获得的膜的评价结果如表3所示。The isophthalic acid copolyethylene terephthalate 1 and the particle master batch chip 1 obtained above were used as the raw materials of the reflective layer (layer A), and the isophthalic acid copolyethylene terephthalate was used Ester 2 and particle master batch chips 3 were used as raw materials for the surface layer (layer C), each layer was mixed according to the composition described in Table 3, put into an extruder, and layer A was filtered through a non-woven fabric with an average mesh size of 30 μm The melt extrusion temperature was 255°C, and the C layer was passed through a non-woven filter with an average mesh of 50 μm at a melt extrusion temperature of 230°C, and a 3-layer feed block device was used. The layered configuration of layer C/layer A/layer C is formed into a sheet shape by a die while maintaining this laminated state. At this time, the discharge rate of each extruder was adjusted so that the thickness ratio of the C layer/A layer/C layer after biaxial stretching was 10/80/10. Further, the sheet was cooled and solidified by a cooling roll having a surface temperature of 25°C to produce an unstretched film. The unstretched film was passed through a preheating zone at 73°C, followed by a preheating zone at 75°C, introduced into a longitudinal stretching zone maintained at 92°C, stretched 3.0 times in the longitudinal direction, and cooled with a 25°C roll group. Next, the film was passed through a preheating zone at 115° C. while being held by clips at both ends, introduced into a lateral stretching zone kept at 130° C., and stretched 3.6 times in the lateral direction. Thereafter, heat treatment at 155°C for 10 seconds in a tenter, heat fixation at 200°C for 10 seconds, and heat treatment at 155°C for 10 seconds, followed by narrowing down in the transverse direction at a narrowing rate of 2% and a narrowing temperature of 130°C Then, both ends of the film were cut off, thermally relaxed at a longitudinal relaxation rate of 2.5%, and cooled to room temperature to obtain a film with a thickness of 300 μm. Table 3 shows the evaluation results of the obtained films.

[实施例3-2~3-15、比较例3-1~3-10][Examples 3-2 to 3-15, Comparative Examples 3-1 to 3-10]

除了使粒子的形态、膜的构成如表3所示以外,与实施例3-1同样地获得白色反射膜。获得的膜的评价结果如表3所示。另外,使用的合成碳酸钙粒子通过磷酸三甲酯进行了表面处理。A white reflective film was obtained in the same manner as in Example 3-1, except that the form of the particles and the composition of the film were as shown in Table 3. Table 3 shows the evaluation results of the obtained films. In addition, the used synthetic calcium carbonate particles were surface-treated with trimethyl phosphate.

实施例3-10中膜的总厚度为188μm。The total thickness of the films in Examples 3-10 was 188 μm.

另外,表面层C中使用的各表面层粒子如下。与制造例5同样地,作为粒子母料切片使用。In addition, each surface layer particle used for the surface layer C is as follows. In the same manner as in Production Example 5, it was used as a particle master batch chip.

粒子B:将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径5.0μm的粒子Particle B: AY-601 (that is, aggregated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles having an average particle diameter of 5.0 μm by wind

粒子C:将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径18.2μm的粒子Particle C: AY-601 (that is, aggregated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles having an average particle diameter of 18.2 μm by wind

粒子D:将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径35.3μm的粒子Particle D: AY-601 (that is, aggregated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles having an average particle diameter of 35.3 μm by wind

粒子E:将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径1.0μm的粒子Particle E: AY-601 (that is, aggregated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles having an average particle diameter of 1.0 μm by wind

粒子F:将东曹-二氧化硅公司株式会社制AY-601(即为凝聚二氧化硅)以风力分级为平均粒径52.0μm的粒子Particle F: AY-601 (that is, aggregated silica) manufactured by Tosoh Silica Co., Ltd. was classified into particles having an average particle diameter of 52.0 μm by wind

[比较例3-11][Comparative Example 3-11]

除了使用平均粒径0.9μm、(D90-D10)/D50为1.4的硫酸钡粒子替代碳酸钙粒子作为空隙形成剂以外,与制造例3同样地制作粒子母料切片,除了膜的构成如表3所示以外,与实施例3-1同样地获得白色反射膜。获得的膜的评价结果如表3。另外,该硫酸钡粒子通过重复进行风力分级获得。The particle master batch chips were prepared in the same manner as in Production Example 3, except that barium sulfate particles having an average particle diameter of 0.9 μm and (D90-D10)/D50 of 1.4 were used instead of calcium carbonate particles as the void-forming agent, except that the film composition was as shown in Table 3. Except as shown, a white reflective film was obtained in the same manner as in Example 3-1. The evaluation results of the obtained films are shown in Table 3. In addition, the barium sulfate particles are obtained by repeating air classification.

【表3】【table 3】

Figure BDA0001526755760000361
Figure BDA0001526755760000361

产业上的可利用性Industrial Availability

本发明的白色反射膜在具有优异的反射特性的同时,即便是用于大型显示器,也可以抑制由电路或光源产生的热,或来自于使用环境的热或湿度所引起的热变形。据此,可以抑制白色反射膜弯曲所产生的亮度不均,产业上的可利用性高。The white reflective film of the present invention has excellent reflective properties, and can suppress heat generated by circuits or light sources, or thermal deformation caused by heat or humidity in a use environment even when used in large-scale displays. Thereby, it is possible to suppress unevenness in luminance due to the curvature of the white reflective film, and the industrial applicability is high.

Claims (8)

1.一种大型显示器用白色反射膜,其是具有反射层A的白色反射膜,1. A white reflective film for large-scale displays, which is a white reflective film having a reflective layer A, 所述反射层A满足:包含聚酯组合物A2,所述聚酯组合物A2是在聚酯中含有碳酸钙粒子以及与该聚酯不相容的树脂,该碳酸钙粒子的含量相对于所述聚酯组合物A2的质量为5质量%以上、69质量%以下,该不相容树脂的含量相对于所述聚酯组合物A2的质量为1质量%以上、40质量%以下,所述碳酸钙粒子与所述不相容树脂的含量之和相对于所述聚酯组合物A2的质量为10质量%以上、70质量%以下,The reflective layer A satisfies: it comprises a polyester composition A2, wherein the polyester composition A2 contains calcium carbonate particles in polyester and a resin incompatible with the polyester, and the content of the calcium carbonate particles is relative to the content of the polyester. The mass of the polyester composition A2 is 5 mass % or more and 69 mass % or less, the content of the incompatible resin is 1 mass % or more and 40 mass % or less with respect to the mass of the polyester composition A2, and the The sum of the content of calcium carbonate particles and the incompatible resin is 10% by mass or more and 70% by mass or less with respect to the mass of the polyester composition A2, 所述不相容的树脂包含环烯烃共聚物,所述不相容的树脂的玻璃化转变温度为190℃以上、220℃以下,The incompatible resin includes a cyclic olefin copolymer, and the glass transition temperature of the incompatible resin is 190°C or higher and 220°C or lower, 所述碳酸钙粒子的平均粒径为0.1μm以上、1.2μm以下,从小粒径侧累积而得的10%体积粒径D10、50%体积粒径D50以及90%体积粒径D90满足(D90-D10)/D50≦1.6,The average particle diameter of the calcium carbonate particles is 0.1 μm or more and 1.2 μm or less, and the 10% volume particle diameter D10, 50% volume particle diameter D50 and 90% volume particle diameter D90 accumulated from the small particle diameter side satisfy (D90- D10)/D50≦1.6, 膜的反射率在60%以上。The reflectance of the film is above 60%. 2.根据权利要求1所述的白色反射膜,其特征在于,该碳酸钙粒子的含量相对于所述聚酯组合物A2的质量为10质量%以上、60质量%以下,该不相容树脂的含量相对于所述聚酯组合物A2的质量为5质量%以上、35质量%以下,所述碳酸钙粒子与所述不相容树脂的含量之和相对于所述聚酯组合物A2的质量为15质量%以上、65质量%以下。2 . The white reflective film according to claim 1 , wherein the content of the calcium carbonate particles is 10 mass % or more and 60 mass % or less with respect to the mass of the polyester composition A2, and the incompatible resin The content of the calcium carbonate particles and the incompatible resin is 5 mass % or more and 35 mass % or less relative to the mass of the polyester composition A2, and the sum of the content of the calcium carbonate particles and the incompatible resin is relative to the polyester composition A2. The mass is 15 mass % or more and 65 mass % or less. 3.根据权利要求1或2所述的大型显示器用白色反射膜,其特征在于,具有所述反射层A,且还在膜的至少一个表面具有表面层C,3. The white reflective film for large-scale displays according to claim 1 or 2, characterized in that it has the reflective layer A, and further has a surface layer C on at least one surface of the film, 所述表面层C包含含有表面层粒子的热塑性树脂组合物C,该表面层粒子的平均粒径为2.0μm以上、50.0μm以下,相对于该热塑性树脂组合物C的体积,该表面层粒子的含量在3体积%以上、50体积%以下。The surface layer C includes a thermoplastic resin composition C containing surface layer particles, the average particle diameter of the surface layer particles is 2.0 μm or more and 50.0 μm or less, and relative to the volume of the thermoplastic resin composition C, the surface layer particles have an average particle diameter of 2.0 μm or more. The content is not less than 3% by volume and not more than 50% by volume. 4.根据权利要求1或2所述的白色反射膜,其特征在于,所述聚酯是共聚聚对苯二甲酸乙二醇酯。4. The white reflective film according to claim 1 or 2, wherein the polyester is a copolymerized polyethylene terephthalate. 5.根据权利要求4所述的白色反射膜,其特征在于,所述共聚聚对苯二甲酸乙二醇酯的共聚量相对于该共聚聚对苯二甲酸乙二醇酯的全部酸成分100摩尔%为1摩尔%以上、20摩尔%以下。5 . The white reflective film according to claim 4 , wherein the copolymerization amount of the copolymerized polyethylene terephthalate is 100 with respect to the total acid component of the copolymerized polyethylene terephthalate. 6 . The mol % is 1 mol % or more and 20 mol % or less. 6.根据权利要求1或2所述的白色反射膜,其特征在于,相对于白色反射膜的厚度100%,所述反射层A的厚度比例在50%以上。6 . The white reflective film according to claim 1 , wherein the ratio of the thickness of the reflective layer A to 100% of the thickness of the white reflective film is 50% or more. 7 . 7.根据权利要求1或2所述的白色反射膜,其特征在于,其还具有热塑性树脂B或包含热塑性树脂组合物B的支撑层B。7 . The white reflective film according to claim 1 , further comprising a thermoplastic resin B or a support layer B containing the thermoplastic resin composition B. 8 . 8.一种面光源,其使用权利要求1或2所述的白色反射膜。8. A surface light source using the white reflective film of claim 1 or 2.
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