Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1990-06-07
1993-03-02
Schofer, Joseph L.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
526 90, 526281, F08F 800, C08F 464, C08F23200, C08G 6108
Patent
active
051910268
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a novel ring-opening hydrogenated copolymer excellent in thermal resistance, optical property and moldability. In more particular, it relates to a polycyclic norbornene or its derivative ring-opening hydrogenated copolymer and a process for producing the same.
BACKGROUND ART
Polymers hitherto mainly used as optical materials are polymethyl methacrylate and polycarbonate. However, the former has a problem of rather high water absorption and the latter has a problem of development of birefringence in injection molding. Accordingly, it is becoming difficult for these polymers to meet recent requirements, which are becoming increasingly more severe.
In recent years, polymers which use polycyclic norbornene or allied monomers have been developed as polymeric materials improved in said properties in question. For example, Japanese Patent Application Kokai (Laid-Open) No. 60-26024 describes that the hydrogenated products of ring-opening polymers of tetracyclododecenes or of ring-opening copolymers of tetracyclododecenes and norbornenes are excellent in transparency, water resistance and thermal resistance.
However, the hydrogenated products of ring-opening polymers of tetracyclododecenes are not fully satisfactory in moldability and their birefringence values are not so small as can meet the property requirement sufficiently. The hydrogenated products of ring-opening copolymers of tetracyclododecenes and norbornenes also have similar problems. Although hydrogenated products of this kind having a high proportion of norbornenes in copolymerization of 40-50% by mole are somewhat improved in said properties, they have a low glass transition temperature (Tg) of 90.degree.-100.degree. C. and hence their thermal resistance is not fully satisfactory.
Japanese Patent Application Kokoku (Post-Exam. Publn.) No. 58-43412 describes that the hydrogenated product of dicyclopentadiene ring-opening polymer can be easily heat-melt processed to give a tough, transparent sheet. The hydrogenated product, however, is unsatisfactory in thermal resistance for use as optical disks because it has a low glass transition temperature (Tg) of about 95.degree. C.
On the other hand, polymers or copolymers obtained by using polycyclic norbornene or allied monomers, when they have not been hydrogenated, are poor in resistance to oxidative degradation and hence unsuitable for use as optical materials.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a novel polymeric material which is excellent in thermal resistance, optical property and moldability.
Another object of the present invention is to provide a polycyclic norbornene ring-opening hydrogenated copolymer which has a high glass transition temperature and can give moldings with little of optical strain.
The present inventors have made extensive study to develop a novel synthetic resin suitable as optical polymer or as the raw material thereof by using polycyclic norbornene or allied monomers. As the result it has been found out that the hydrogenation products of ring-opening copolymers obtainable by ring-opening copolymerization of tetracyclododecenes with dicyclopentadienes and, as required, norbornenes are excellent in thermal properties and moldability and give moldings with little of optical strain. The present invention has been accomplished on the basis of above finding.
Thus, it has been found out that a polycyclic norbornene or its derivative ring-opening hydrogenated copolymer can attain the above-mentioned objects which comprises 90-10% by mole of a repeating unit represented by the following formula [I] or the alkyl-substituted derivative thereof, at least a repeating unit represented by the following formula [II] or the alkyl-substituted derivative thereof and, as desired, at least one repeating unit selected from a repeating unit represented by the following formula [III], the alkyl-substituted derivative thereof or the alkylidenesubstituted derivative thereof, has an intrinsic viscosity [.eta.]
REFERENCES:
patent: 4080491 (1978-03-01), Kobayashi et al.
WPIL , File Supplier, Accession No. 89-072686, Derwent Publications, Ltd., London, GB for JP-A-1024 826 (Mitsubishi Chem.) of Jan. 26, 1989.
Kohara Teiji
Natsuume Tadao
Nishi Yoshikatsu
Oshima Masayoshi
Cheng Wu C.
Nippon Zeon Co. Ltd.
Schofer Joseph L.
LandOfFree
Ring-opening hydrogenated copolymer and process for producing th does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ring-opening hydrogenated copolymer and process for producing th, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ring-opening hydrogenated copolymer and process for producing th will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-127275