Low birefringent copolymer

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

Active Publication Date: 2011-06-22
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 retardation and a lactone ring structure as a structural unit providing a positive retardation in the molecular chain, An acrylic copolymer (a) having a structural unit providing a negative retardation in the molecular chain and a hydroxyl group and an ester group in the molecular chain is obtained from the polymerization process, and then the obtained acrylic copolymer (a) is subjected to heat treatment, It is obtained by performing a cyclization condensation step of introducing a lactone ring structure that provides a positive phase difference in an acrylic copolymer.

[0096] At this time, in the polymerization step, for example, the monomer component of the monomer represented by the following formula (6) and the monomer represented by the following formula (7) can be mixed to obtain the in the molecular ...

Embodiment 1

[0228] First, a 30-liter reaction vessel with a stirring device, temperature sensor, cooling tube, and nitrogen introduction tube is charged with 7 kg of methyl methacrylate, 2 kg of 2-(hydroxymethyl) acrylate, and 1 kg of styrene. , 10kg of methyl isobutyl ketone, 5g of n-dodecyl mercaptan.

[0229] Nitrogen was introduced into the reaction vessel and the temperature was raised to 105°C. Under reflux, 5 g of tert-amyl 3,5,5-trimethylhexanoate was added as a polymerization initiator. At the same time, it was added dropwise to 230 g of methylbenzene over 2 hours. A solution of 10 g of tert-amyl 3,5,5-trimethylhexanoate is dissolved in the base isobutyl ketone, and solution polymerization is carried out at about 105-120°C under reflux, and then maturing for 4 hours.

[0230] 30 g of stearyl phosphate / di(octadecyl) phosphate mixture (Phoslex A-18, manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained acrylic copolymer solution, and the mixture was refluxed at ab...

Embodiment 2

[0261] First, a 30-liter reaction vessel with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube was charged with 7950 g of methyl methacrylate, 1500 g of 2-(hydroxymethyl) acrylate, and 550 g of styrene. , 10,000g of toluene.

[0262] Nitrogen was introduced into the reaction vessel and the temperature was raised to 105°C. 12g of tert-amyl peroxyisononanoate as a polymerization initiator was added under reflux. At the same time, 24g of peroxide was dissolved in 136g of toluene over 2 hours. The solution of tert-amyl isononanoate is oxidized, and solution polymerization is performed at about 105-110°C under reflux, and then matured for 4 hours.

[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 the reaction was subjected to cyclization condensation reaction at about 120°C under pressure for 5 hours. Then, the obtained acrylic copolymer sol...

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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 lighttransmission 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 lowbirefringent 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 low-birefringence copolymers, and more specifically to low-birefringence materials useful in optical applications and the like. Background technique [0002] Methacrylic resins represented by polymethyl methacrylate (PMMA) have excellent optical properties, especially high total light transmittance, low birefringence and low phase difference, so they are highly optically isotropic Material, can be used for various optical purposes. However, in recent years, with the advancement of flat-panel display devices such as liquid crystal display devices, plasma display devices, organic EL display devices, infrared sensors, and optical waveguides, optical materials are required not only to be excellent in transparency and heat resistance, but also to be So-called low birefringence material with high optical isotropy. [0003] In addition, as a thermoplastic resin having transparency and heat resistance, for example, JP 2000-230016 A ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F220/28C08F8/48C08F212/06
CPCC08F212/08C08F8/16C08F220/06C08F220/14C08F220/28C08F8/48C08F222/40C08F220/20C08F220/00C08F220/10G02F1/13
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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