CN-116867832-B - Cyclic olefin copolymer, hydrogenated product thereof, and optical element

Abstract

The invention provides a resin which can achieve high refractive index, high heat resistance and low birefringence. The cyclic olefin copolymer hydride of the present invention is obtained by hydrogenating a cyclic olefin copolymer which contains a structural unit derived from 1-naphthylnorbornene and a structural unit derived from 2-naphthylnorbornene and has an average endo form ratio of 1-naphthylnorbornene to 2-naphthylnorbornene of 50mol% or more. The cyclic olefin copolymer hydride of the present invention can be preferably used as a material for optical elements such as optical lenses.

Inventors

• Shan Tiansheng
• SUDEJI HIRONARI

Assignees

• 日本瑞翁株式会社

Dates

Publication Date

20260505

Application Date

20220222

Priority Date

20210226

Claims (5)

1. 1. A cyclic olefin copolymer comprising a structural unit derived from 1-naphthylnorbornene and a structural unit derived from 2-naphthylnorbornene, wherein the average endo-form ratio of the 1-naphthylnorbornene and the 2-naphthylnorbornene is 50mol% or more, The average endo-form ratio is a ratio of a total of structural units derived from endo-1-naphthalene norbornene and structural units derived from endo-2-naphthalene norbornene to a total of structural units derived from exo-1-naphthalene norbornene, structural units derived from endo-1-naphthalene norbornene, structural units derived from exo-2-naphthalene norbornene and structural units derived from endo-2-naphthalene norbornene, The total proportion of the structural units derived from 1-naphthylnorbornene and the structural units derived from 2-naphthylnorbornene in the total structural units of the cyclic olefin copolymer is 30mol% or more and 70mol% or less, The proportion of the structural unit derived from 1-naphthylnorbornene to the total of the structural unit derived from 1-naphthylnorbornene and the structural unit derived from 2-naphthylnorbornene is 1mol% or more and 30mol% or less, The cyclic olefin copolymer is a ring-opening polymer.
2. 2. The cyclic olefin copolymer according to claim 1, further comprising structural units derived from norbornene-based monomers other than 1-naphthyl norbornene and 2-naphthyl norbornene.
3. 3. A cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer according to claim 1 or 2.
4. 4. The cyclic olefin copolymer hydride according to claim 3, wherein the glass transition temperature of the cyclic olefin copolymer hydride is 135 ℃ or higher.
5. 5. An optical element comprising the cyclic olefin copolymer hydride of claim 3 or 4.

Description

Cyclic olefin copolymer, hydrogenated product thereof, and optical element Technical Field The present invention relates to a cyclic olefin copolymer, a hydride of the cyclic olefin copolymer, and an optical element. Background In recent years, polymers obtained by polymerizing cyclic olefins have been attracting attention as materials for optical elements and medical containers. For example, patent document 1 discloses a norbornene ring-opening polymer (copolymer) having excellent transparency and heat resistance, high solubility in an organic solvent, and specific birefringence and wavelength dependence. Patent document 2 discloses a cycloolefin copolymer that effectively develops the inverse wavelength dispersion of birefringence, and a film formed from the copolymer. Patent document 3 discloses a cyclic olefin copolymer having a high refractive index and being able to adjust the abbe number to be low, and a medical container having little discoloration due to electron beam or gamma irradiation and excellent transparency. Prior art literature Patent literature Patent document 1, japanese patent laid-open No. 2009-46615; Patent document 2, japanese patent laid-open publication No. 2009-46614; Patent document 3 International publication No. 2019/107363. Disclosure of Invention Problems to be solved by the invention Here, in order to improve the degree of freedom in design for optical elements such as optical lenses in a wide range of applications, a resin having a high refractive index and high heat resistance and having a small birefringence even when the optical element is produced is required. However, the conventional polymer described above cannot achieve a combination of high refractive index, high heat resistance and low birefringence (for example, stress birefringence). Accordingly, an object of the present invention is to provide a resin which can achieve a high refractive index, high heat resistance and low birefringence. Solution for solving the problem The present inventors have conducted intensive studies with a view to solving the above-mentioned problems. Then, the present inventors have newly found that a hydrogenated cyclic olefin copolymer obtained by hydrogenating a cyclic olefin copolymer obtained by polymerizing a monomer composition comprising a mixture of 1-naphthalene norbornene and 2-naphthalene norbornene having a predetermined average endo-type (endo) ratio can achieve a high refractive index, high heat resistance and low birefringence, and completed the present invention. That is, an object of the present invention is to advantageously solve the above-mentioned problems, and a cyclic olefin copolymer of the present invention is characterized by comprising a structural unit derived from 1-naphthylnorbornene and a structural unit derived from 2-naphthylnorbornene, wherein the average endo (endo) volume ratio of the 1-naphthylnorbornene and the 2-naphthylnorbornene is 50mol% or more. If such a cyclic olefin copolymer is hydrogenated, a resin (cyclic olefin copolymer hydride) which can achieve a high refractive index, high heat resistance and low birefringence can be provided. Therefore, the cyclic olefin copolymer of the present invention is useful as a raw material for resins capable of achieving a high refractive index, a high heat resistance and a low birefringence. In the present invention, the "average endo (endo) body ratio of 1-naphthylnorbornene and 2-naphthylnorbornene" can be determined by, for example, the method described in examples. The cyclic olefin copolymer of the present invention preferably has a total ratio of structural units derived from 1-naphthylnorbornene and structural units derived from 2-naphthylnorbornene of 30mol% or more and 70mol% or less in all structural units. If the ratio of the total of the structural units derived from 1-naphthyl norbornene and the structural units derived from 2-naphthyl norbornene is within the above-mentioned range, a resin having a high refractive index, high heat resistance and low birefringence at a higher level can be obtained. In the present invention, the "ratio of each structural unit" can be measured by a Nuclear Magnetic Resonance (NMR) method. The cyclic olefin copolymer of the present invention preferably has a proportion of structural units derived from 1-naphthylnorbornene to the total of structural units derived from 1-naphthylnorbornene and structural units derived from 2-naphthylnorbornene of 1mol% or more and 30mol% or less. If the proportion of the structural unit derived from 1-naphthyl norbornene is within the above range, a resin which combines high refractive index, high heat resistance and low birefringence at a higher level can be obtained. Further, the cyclic olefin copolymer of the present invention preferably further comprises a structural unit derived from a norbornene-based monomer other than 1-naphthylnorbornene and 2-naphthylnorbornene. Further, the cyclic olefin copolymer of the present invent