초록 ▼

A flat plate made of a cycloolefin polymer comprising at least 30% by weight, based on the cyclopolefin polymer, of repeating units (A) having an alicyclic structure. The repeating units (A) comprises at least 30% by weight, based on the repeating units (A), of repeating units (A-i) having no norbor

A flat plate made of a cycloolefin polymer comprising at least 30% by weight, based on the cyclopolefin polymer, of repeating units (A) having an alicyclic structure. The repeating units (A) comprises at least 30% by weight, based on the repeating units (A), of repeating units (A-i) having no norbornane structure. The cycloolefin polymer has a weight average molecular weight of 5,000 to 50,000. The flat plate is especially useful as a light guide plate.

대표청구항 ▼

1. A flat plate made of a cycloolefin polymer comprising at least 30% by weight, based on the cycloolefin polymer, of repeating units (A) having an alicyclic structure; said repeating units (A) comprising at least 30% by weight, based on the repeating units (A), of the repeating units (A-i) having n

1. A flat plate made of a cycloolefin polymer comprising at least 30% by weight, based on the cycloolefin polymer, of repeating units (A) having an alicyclic structure; said repeating units (A) comprising at least 30% by weight, based on the repeating units (A), of the repeating units (A-i) having no norbornane structure and more than 0% hut not more than 70% by weight of repeating units (A-ii) having a norbornane structure, represented by the following formula (4):wherein R 35 through R 48 are independently selected from the group consisting of a hydrogen atom, an alkyl or alkenyl hydrocarbon, hydroxyl, ester, alkoxy, cyano, imido and silyl groups, a halogen atom, and alkyl or alkenyl hydrocarbon groups having a functional group as a substituent selected from the group consisting of hydroxyl, ester, alkoxy, cyano, imido and silyl groups; R 38 and R 39 , or R 40 and R 41 may form together an alkylidene group having 1 to 20 carbon atoms; e is an integer of 1 to 3; and represents a carbon-carbon single or double bond; and said cycloolefin polymer having a weight average molecular weight of 5,000 to 50,000, wherein an illuminating surface of the flat plate has a surface roughness of not larger than 5 μm as expressed in terms of maximum height (Rmax). 2. The flat plate according to claim 1, wherein the repeating units (A-i) having no norbornane structure are represented by the formula (2):R 21 through R 34 are independently selected from the group consisting of a hydrogen atom, an alkyl or alkenyl hydrocarbon, hydroxyl, ester, alkoxy, cyano, imido and silyl groups, a halogen atom, and an alkyl or alkenyl hydrocarbon group having a functional group as a substituent selected from the group consisting of hydroxyl, ester, alkoxy, cyano, imido and silyl groups; R 25 and R 27 , or R 26 and R 28 may form together an unsaturated bond; or R 25 and R 26 , or R 27 and R 28 may form together an alkylidene group; d is 0 or 1; andrepresents a carbon-carbon single or double bond. 3. The flat plate according to claim 1, wherein the repeating units (A-i) having no norbornane structure are represented by the formula (3): 4. The flat plate according to claim 1, wherein the repeating units (A-ii) having a norbornane structure are represented by the formula (5):wherein R 49 through R 62 are the same as R 35 through R 48 as defined in formula (4), respectively; R 52 and R 53 may form together an alkylidene group; and represents a carbon-carbon single or double bond. 5. The flat plate according to claim 1, wherein the repeating units (A-ii) having a norbornane structure are represented by the formula (6):wherein R 63 through R 66 are the same as R 38 through R 41 as defined in formula (4), respectively; and represents a carbon-carbon single or double bond. 6. The flat plate according to claim 1, wherein the cycloolefin polymer has a temperature of at least 280° C. at which the loss of polymer on heating reaches 5% by weight. 7. The flat plate according to claim 1, wherein the cycloolefin polymer has a melt viscosity of 1×10 2 to 1×10 5 poise as measured at a temperature of 260° C. 8. The flat plate according to claim 1, wherein the cycloolefin polymer contains not larger than 20% by weight, based on the cycloolefin polymer, of a fraction having a molecular weight of not larger than 1,000. 9. The flat plate according to claim 1, wherein the cycloolefin polymer contains 0.2% to 20% by weight, based on the cycloolefin polymer, of a fraction having a molecular weight of not larger than 1,000. 10. The flat plate according to claim 1, wherein the repeating units (A) having an alicyclic structure comprises, based on the repeating units (A), at least 70% by weight of repeating units (A-i) having no norbornane structure and more than 0% but not more than 30% by weight of repeating units (a-ii) having a norbornane structure. 11. A light guide plate composed of the flat plate as claimed in claim 1. 12. The lig ht guide plate according to claim 11, which has a wedge-shaped cross-section. 13. The light guide plate according to claim 11, which has a light reflection plane with a printed pattern. 14. The light guide plate according to claim 11, which has a light reflection plane with a plurality of V-shaped grooves. 15. The light guide plate according to claim 11, which has a wedge-shaped cross-section and a light reflection plane with a plurality of V-shaped grooves which have pitches gradually decreasing from the light-incident side end toward the tip end of the wedge-shaped cross-section. 16. The light guide plate according to claim 11, which has an illuminating surface with a surface area of 10 to 2,500 cm 2 and has a thickness of 0.5 to 10 mm.