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Optical film and method for manufacturing optical film

A manufacturing method and technology for optical films, applied in the field of optical films, can solve the problems of increased retardation, no mention of sliding property, retardation, etc., and achieve low retardation characteristics, excellent roll stability, and excellent brittleness resistance. Effect

Pending Publication Date: 2021-06-04
KONICA MINOLTA INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, with the method disclosed in Patent Document 1, although the low birefringence and brittleness of the film are improved, inorganic fine particles are contained as a material for the purpose of imparting low birefringence in the film, and the disclosed film is not yet available. Stretched films, no mention is made of slippery properties of stretched films
[0008] The inventors of the present invention have studied a film stretched by adding inorganic particles to low-birefringence acrylic resin and rubber particles. As a result, it has been found that the above-mentioned film has improved brittleness, but the phase difference increases and the slipperiness It is also insufficient, and a good roll laminate cannot be obtained when manufacturing a long and wide optical film
[0009] The inventors of the present invention further studied an optical film composed of acrylic resin, rubber particles, and inorganic particles. As a result, it was found that in an optical film having such a structure, the rubber particles are deformed by absorbing the stress during stretching. Phase difference appears, and the formation of surface irregularities caused by inorganic particles is insufficient
Regarding the development of retardation caused by rubber particles, when rubber particles with low birefringence are used, the retardation development can be improved even if the particles are deformed, but no effective means has been found for the improvement of sliding properties caused by the formation of surface irregularities. this is the status quo

Method used

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  • Optical film and method for manufacturing optical film
  • Optical film and method for manufacturing optical film
  • Optical film and method for manufacturing optical film

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preparation example Construction

[0197] The solvent used for the preparation of the dope contains at least an organic solvent (good solvent) capable of dissolving the (meth)acrylic resin. Examples of good solvents include chlorine-based organic solvents such as dichloromethane, and non-chlorinated organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, dichloromethane is preferable.

[0198] As a solvent used for the preparation of dope, a poor solvent may be contained further. Examples of poor solvents include linear or branched aliphatic alcohols having 1 to 4 carbon atoms. When the ratio of the alcohol in the dope increases, the membrane-like product tends to gel, and the peeling from the metal support becomes easy. Examples of straight-chain or branched-chain aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, and tert-butanol. Among these, ethanol is preferable in view of the stability of th...

Embodiment

[0230] Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these Examples. In addition, in an Example, the expression of "part" or "%" is used, and unless otherwise indicated, it means "part by mass" or "% by mass".

[0231] "Preparation of (meth)acrylic resin"

[0232] (Meth)acrylic resins 1 to 5 having the following compositions were synthesized according to a conventionally known synthesis method.

[0233] [Synthesis of (meth)acrylic resin 1]

[0234] According to conventional methods, synthesized (methyl ) Acrylic resin 1. The weight average molecular weight Mw of the (meth)acrylic resin 1 was 2 million.

[0235] [Synthesis of (meth)acrylic resin 2]

[0236] According to the conventional method, synthesized (methyl methacrylate) (methyl methacrylate) (50 mole %) / N-phenylmaleimide (25 mole %) / 2-ethylhexyl acrylate (25 mole %) ) Acrylic resin 2. The weight average molecular weight Mw of the (meth)ac...

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Abstract

The subject of the present invention is to provide an optical film and a manufacturing method thereof. The optical film contains a (meth) acrylic resin, and has excellent brittleness resistance, low phase difference characteristics, and excellent roll stability. The optical film according to the present invention is characterized by containing inorganic particles and a (meth) acrylic resin, with respect to all structural units constituting the (meth) acrylic resin, the (meth) acrylic resin is a copolymer containing 50-95% by mass of a structural unit derived from methyl methacrylate, 1-25% by mass of a structural unit derived from phenylmaleimide, and 1-25% by mass of a structural unit derived from an alkyl acrylate, and further contains rubber particles. The value of the ratio of the average primary particle diameter of the rubber particles to the secondary particle diameter of the inorganic particles in the film is within the range of 5.0-50% by number of the number of secondary particles of the inorganic particles in the range represented by formula (1). (Formula 1) 0.9 < = (average primary particle diameter of rubber particles) / (secondary particle diameter of inorganic particles) < = 1.1.

Description

technical field [0001] The present invention relates to optical films and methods for their manufacture. More specifically, it relates to an optical film containing a (meth)acrylic resin, excellent in brittleness, low retardation characteristics, and excellent in roll stability, and a method for producing the same. Background technique [0002] In recent years, not only liquid crystal display devices as display devices, polarizer protective films for organic electroluminescent display devices, optical films such as retardation films, base films for touch panels, and base films such as gas barrier base films , and substrate films for nanoimprinting, substrate films for flexible electronic circuits, etc., there is a great demand for flexible resin films that achieve high transparency, high functionality, and light weight. [0003] Among these, acrylic resins are preferably used as optical films because they exhibit excellent transparency and dimensional stability in addition ...

Claims

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Application Information

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IPC IPC(8): C08L33/12C08L51/04C08K7/18C08J5/18G02B1/10
CPCC08J5/18G02B1/10C08J2333/12C08J2451/04C08K7/18C08K2201/011C08L33/12C08L21/00C08K3/36
Inventor 森田亮藤枝奈奈惠
Owner KONICA MINOLTA INC
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