Low birefringent copolymer

A technology of copolymer and acrylic acid, applied in instruments, optics, nonlinear optics, etc., can solve the problems of easy thermal yellowing and coloring of resins, and achieve the effects of excellent transparency, excellent heat resistance and low coloring.

Active Publication Date: 2008-07-23
NIPPON SHOKUBAI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, AS resin is prone to thermal yellowing, and there are problems such as coloring in the kneading process

Method used

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  • Low birefringent copolymer
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  • Low birefringent copolymer

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0094]

[0095] The preparation of the acrylic copolymer is not particularly limited. First, in the case of an acrylic copolymer having a structural unit providing a negative phase difference and a lactone ring structure as a structural unit providing a positive phase difference in the molecular chain, it can be obtained by The acrylic copolymer (a) having a structural unit providing a negative phase difference in the molecular chain and having a hydroxyl group and an ester group in the molecular chain is obtained by the polymerization process, and then the obtained acrylic copolymer (a) is heat-treated, It is obtained by performing a cyclocondensation process of introducing a lactone ring structure providing a positive retardation into an acrylic copolymer.

[0096] At this time, in the polymerization step, for example, the monomer component represented by the following formula (6) and the monomer represented by the following formula (7) can be obtained through the polymeriz...

Embodiment 1

[0228] First, add 7 kg of methyl methacrylate, 2 kg of 2-(hydroxymethyl) methyl acrylate, and 1 kg of styrene , 10kg of methyl isobutyl ketone, 5g of n-dodecyl mercaptan.

[0229] Nitrogen gas was introduced into the reaction vessel, and the temperature was raised to 105° C., 5 g of tert-amyl 3,5,5-trimethylhexanoate was added as a polymerization initiator under reflux, and at the same time, 230 g of formic acid was added dropwise over 2 hours. 10 g of tert-amyl 3,5,5-trimethylhexanoate was dissolved in methyl isobutyl ketone, solution polymerization was carried out at about 105-120° C. under reflux, and aging was carried out for 4 hours.

[0230] In the obtained acrylic copolymer solution, add 30 g of stearyl phosphate / dioctadecyl phosphate mixture (PhoslexA-18, manufactured by Sakai Chemical Industry Co., Ltd.), under reflux at about 90- The cyclocondensation reaction was carried out at 120° C. for 5 hours. Then, the obtained acrylic copolymer solution is introduced into t...

Embodiment 2

[0261] First, add 7950 g of methyl methacrylate, 1500 g of 2-(hydroxymethyl) methyl acrylate, and 550 g of styrene in a reaction vessel with a stirring device, a temperature sensor, a cooling pipe, and a nitrogen inlet pipe with a capacity of 30 L. , 10,000 g of toluene.

[0262] Nitrogen gas was introduced into the reaction vessel, and the temperature was raised to 105° C., 12 g of tert-amyl peroxyisononanoate as a polymerization initiator was added under reflux, and 24 g of peroxide dissolved in 136 g of toluene was added dropwise over 2 hours. A solution of tert-amyl isononanoate was oxidized and solution polymerized at about 105-110°C under reflux, followed by a further 4 hours of aging.

[0263] 10 g of octyl phosphate (Phoslex A-8, manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained acrylic copolymer solution, and cyclocondensation reaction was carried out at about 120° C. under pressure for 5 hours. Then, the obtained acrylic copolymer solution...

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Abstract

A low birefringent material which may comprise an acrylic copolymer having a lactone ring structure that can provide a positive phase difference and a structure unit that can provide a negative phase difference, the material satisfying the following requirements: (A) the material has a glass transition temperature (Tg) of 100 DEG C or higher; (B) a film comprising the material shows a total light transmission of 85% or higher; and (C) in a film comprising the material, the phase difference is 10 mm or less per 100 [mu]m of thickness of the film in the plane-wise direction, and the difference between the phase difference per 100 [mu]m of thickness of the film in the plane-wise direction after the film is stretched by 1.5 times and that before the film is stretched is 20 nm or less. The low birefringent material has excellent transparency and heat resistance, also has other desired properties including mechanical strength and molding processability, has a low staining property when no nitrogen atom is contained, and particularly has a high optical isotropy.

Description

technical field [0001] The present invention relates to a low-birefringence copolymer, and more specifically, to a low-birefringence material useful for optical applications and the like. Background technique [0002] The methacrylic resin represented by polymethyl methacrylate (PMMA) has excellent optical properties, especially high total light transmittance, low birefringence and low phase difference. Therefore, as a resin with high optical isotropy Materials that can be used for various optical purposes. However, in recent years, with the progress of flat display devices such as liquid crystal display devices, plasma display devices, and organic EL display devices, infrared sensors, and optical waveguides, optical materials are not only required to be excellent in transparency and heat resistance, but also must be So-called low-birefringence materials with high optical isotropy. [0003] In addition, as a thermoplastic resin having transparency and heat resistance, for ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F220/28C08F8/48C08F212/06
CPCC08F8/16C08F8/48C08F212/08C08F220/06C08F220/14C08F220/28C08F222/40C08F220/20C08F220/00C08F220/10G02F1/13
Inventor 上田贤一和泉博子中田善知前田顺启
Owner NIPPON SHOKUBAI CO LTD
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