JPH11286558A - Flat plate and light guide plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat plate excellent in light transmissivity, low water absorptivity, mechanical strength, and thin and scarce in color change, and a precise light guide plate having the same properties. SOLUTION: This flat plate consists of a cyclic olefin polymer having weight average molecular weight of 5,000 to 50,000 which comprises 30 wt.% or more of a repeating unit having an alicyclic structure (A) and 30 wt.% or more of which repeating unit is free from nonbornane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat plate which is excellent in light transmittance, low water absorption and mechanical strength, is thin and has little discoloration. This flat plate is useful, for example, as a light guide plate.

[0002]

2. Description of the Related Art Conventionally, a light guide plate used for a liquid crystal substrate, a light diffusion plate, etc., has excellent light transmittance, is a thin plate, and
There is a demand for characteristics that cause less deformation due to water absorption. As a light guide plate that meets this demand, for example, a light guide plate having a norbornane ring structure obtained by metathesis polymerization of 8-methyl-8-methoxycarbonyltetracyclododeca-3-ene and improving fluidity during molding. Intrinsic viscosity 0.2 ~
An injection molded article of a cyclic olefin polymer specified as 1.5 dl / g has been proposed (Japanese Patent Laid-Open No. Hei 7-118344).
No.). However, in this injection molded product, (1)
When the molecular weight of the cyclic olefin-based polymer is reduced to sufficiently increase the fluidity and produce a thin flat plate, the mechanical strength is reduced, and there are problems such as cracking at the time of molding and brittleness of the molded product. 2) When the molecular weight of the cyclic olefin polymer is increased to improve the mechanical strength, the flowability deteriorates and the sheet cannot be thinned. And other problems.

[0003]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a flat plate which is excellent in light transmittance, low water absorption, mechanical strength, thin and has little discoloration. is there. Another object of the present invention is to provide a light guide plate which is excellent in light transmittance, low water absorption, and mechanical strength, and which is thin and has little discoloration.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to overcome the problems of the prior art, and as a result,
By injection molding using a cyclic olefin polymer having a specific molecular weight and containing a specific repeating unit having no norbornane structure, it is excellent in light transmittance, low water absorption and mechanical strength, and at a low temperature. It has been found that a thin flat plate with little discoloration can be obtained due to the good fluidity of the resin. The present invention has been completed based on these findings.

Thus, according to the present invention, the repeating unit (A) having an alicyclic structure is at least 30% by weight, and at least 30% by weight of the repeating unit (A) having an alicyclic structure is a norbornane structure. (A-)
i) having a weight average molecular weight of 5,000 to 50,000
A flat plate comprising a cyclic olefin-based polymer that is 0 is provided. According to the present invention, there is also provided a light guide plate made of such a flat plate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Cyclic olefin polymer The cyclic olefin polymer used in the present invention contains a repeating unit (A) having an alicyclic structure in an amount of 30% by weight or more and a repeating unit having the alicyclic structure. It is characterized in that (A) contains 30% by weight or more of (Ai) having no norbornane structure. The alicyclic structure in the repeating unit (A) may be contained in any of the main chain and / or the side chain, but is contained in the main chain particularly when high mechanical strength and transparency are required. Are preferred. The alicyclic structure may be either saturated or unsaturated, and when high mechanical strength is required, a saturated alicyclic structure is preferred.
Specific examples include a cycloalkane and a cycloalkene structure, and a cycloalkane structure is preferred. Also,
The number of carbon atoms constituting the alicyclic structure may be appropriately selected depending on the purpose of use, but is usually 4 to 30, preferably 5
When the number is in the range of from 20 to 20, more preferably in the range of from 5 to 15, the mechanical strength is particularly good and preferable.

These repeating units (A) having an alicyclic structure may be used alone or in combination of two or more. The content ratio of the repeating unit (A) having an alicyclic structure in the cyclic olefin-based polymer is appropriately selected according to the purpose of use, but needs to be 30 to 100% by weight, and preferably 50 to 100% by weight. %, More preferably in the range of 70-100% by weight, most preferably 100% by weight. If the proportion of the repeating unit (A) having an alicyclic structure in the cyclic olefin-based thermoplastic resin (I) is excessively small, characteristics such as mechanical strength and light transmittance are inferior, which is not preferable.

[0008] The repeating unit (Ai) having an alicyclic structure having no norbornane structure is not particularly limited.

[0009]

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[R ^{1 to} R ²⁰ each independently represent a hydrogen atom, a hydrocarbon group, a hydroxyl group, a halogen atom, an ester group,
An alkoxy group, a cyano group, an imide group, a silyl group, or a functional group (a functional group selected from a hydroxyl group, an ester group, an alkoxy group, a cyano group, an imide group, and a silyl group)
Represents a hydrocarbon group substituted with Where R ⁸ and R ¹⁰ ,
Alternatively, R ⁹ and R ¹¹ may form an unsaturated bond together, or R ⁸ and R ⁹ or R ¹⁰ and R ¹¹ may form an alkylidene group. a is 0 or 1,
b is 0 or 1, and c is 0, 1 or 2. ‥‥‥ represents a carbon-carbon single bond or a double bond. ].

R ^{1 to} R ²⁰ in the formula (1) each independently represent a hydrogen atom, a hydrocarbon group, a hydroxyl group, a halogen atom, an ester group, an alkoxy group, a cyano group, an imide group, a silyl group, or a functional group. (Selected from among a hydroxyl group, an ester group, an alkoxy group, a cyano group, an imide group and a silyl group), preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom It is. The number of carbon atoms of the hydrocarbon group is usually in the range of 1 to 20, preferably 1 to 10, and more preferably 1 to 6. Specific examples of the hydrocarbon group include an alkyl group and an alkenyl group, and are preferably an alkyl group,
Among them, an alkyl group having 1 to 6 carbon atoms is particularly preferable. Examples of the hydrocarbon group substituted with a functional group include:
Examples thereof include an ester group-containing alkyl group having 1 to 20, preferably 1 to 10, and more preferably 1 to 6 carbon atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

In the formula (1), R ⁸ and R ¹⁰ or R ⁹
And R ¹¹ may together form an unsaturated bond,
Further, R ⁸ and R ⁹ or R ¹⁰ and R ¹¹ may form an alkylidene group. The carbon number of the alkylidene group is
Usually 1 to 20, preferably 1 to 10, more preferably 1
-6. A in the formula (1) is 0 or 1, and preferably 0. B in the formula (1) is 0 or 1
And preferably 1. C in the formula (1) is 0, 1
Or 2, preferably 0. ‥ in equation (1)
‥‥ represents a carbon-carbon single bond or a double bond. Usually, when the proportion of the single bond is 95% or more, preferably 98% or more, and more preferably 99% or more, excellent light transmittance is obtained, and It is. The repeating unit having an alicyclic structure having no norbornane structure represented by the formula (1) (A-
Among i), those represented by the following formula (2) are preferable, and those represented by the following formula (3) are more preferable.

[0013]

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Examples and preferred ranges of R ^{21 to} R ³⁴ in the formula (2) are the same as those of R ¹ in the formula (1). Further, R ²⁵ and R ²⁷ or R ²⁶ and R ²⁸ in the formula (2) may form an unsaturated bond together, and R ²⁵ and R ²⁶ , or R ²⁷ and R ²⁸ And may form an alkylidene group. The number of carbon atoms of the alkylidene group is usually 1-2.
0, preferably 1 to 10, more preferably 1 to 6. D in the formula (2) is 0 or 1, and is preferably 0. In the formula (2), を represents a carbon-carbon single bond or a double bond.
Above, preferably 98% or more, more preferably 99% or more, is excellent in light transmittance and is suitable.

[0015]

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‥‥‥ in the formula (3) represents a carbon-carbon single bond or a double bond.
Above, preferably 98% or more, more preferably 99% or more, it is particularly excellent in light transmittance and is suitable. Specific examples of the repeating unit (Ai) having an alicyclic structure having no norbornane structure include ethyl norbornene, dicyclopentadiene, dihydrodicyclopentadiene,
Dimethyldicyclopentadiene, methyldicyclopentadiene, 5-ethylidene-bicyclo [2.2.1] -hept-2-ene, 5-ethyl-bicyclo [2.2.1]
-Hept-2-ene, tetracyclo [7.4.0.0
^2,7 . 1 ^{10, 13]} - tetradec-11-ene and tetracyclo [7.4.0.0 ^2,7. 1 ^{10, 13]} - trideca -
Those derived from 2,4,6,11-tetraene are exemplified.

These repeating units (Ai) having no norbornane structure may be contained alone or in combination of two or more. The proportion of the repeating unit (A-i) having no norbornane structure in the repeating unit (A) having an alicyclic structure is from 30 to 10
0% by weight, preferably 50 to 100% by weight, more preferably 70 to 100% by weight, particularly preferably 80 to 100% by weight.
% By weight. Those having no norbornane structure in the repeating unit (A) having an alicyclic structure (A-i)
If the ratio is too small, the mechanical strength is inferior, and there are problems such as cracking during molding, and the molded product being brittle and unable to be thinned. If the cyclic olefin-based polymer has a large number of these alicyclic structure repeating units having no norbornane structure, there is an advantage that necessary mechanical strength can be secured even if the molecular weight is reduced to improve fluidity. The repeating unit other than the repeating unit (A-i) having no norbornane structure in the repeating unit (A) having an alicyclic structure, that is, the repeating unit (A-ii) having a norbornane structure is not particularly limited. Is, for example, the following equation (4)

[0018]

Embedded image It is represented by

Examples and preferred ranges of R ^{35 to} R ⁴⁸ in the formula (4) are the same as those of R ¹ in the formula (1). Further, R ³⁸ and R ⁴⁰ or R ³⁹ and R ⁴¹ in the formula (4) may form an unsaturated bond together, and R ³⁸ and R ³⁹ , or R ⁴⁰ and R ⁴¹ And may form an alkylidene group. The number of carbon atoms of the alkylidene group is usually 1-2.
0, preferably 1 to 10, more preferably 1 to 6. E in the formula (4) is an integer of 1 to 3, and is preferably 1. ‥‥‥ in the formula (4) represents a carbon-carbon single bond or a double bond.
% Or more, preferably 98% or more, more preferably 99%
The above cases are particularly excellent in light transmittance and are suitable. Of the repeating units (A-ii) having an alicyclic structure having a norbornane structure represented by the formula (4), preferred are represented by the following formula (5), and more preferred are represented by the following formula (6).

[0020]

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Examples and preferred ranges of R ^{49 to} R ⁶² in the formula (5) are the same as those of R ¹ in the formula (1). Further, R ⁵² and R ⁵⁴ or R ⁵³ and R ⁵⁵ in the formula (5) may form an unsaturated bond together, and R ⁵² and R ⁵³ , or R ⁵⁴ and R ⁵⁵ And may form an alkylidene group. The number of carbon atoms of the alkylidene group is usually 1-2.
0, preferably 1 to 10, more preferably 1 to 6. In the formula (5), ‥‥‥ represents a carbon-carbon single bond or a double bond, and the ratio of the single bond is usually 95% or more, preferably 98% or more, more preferably 99% or more.

[0022]

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Examples and preferred ranges of R ^{63 to} R ⁶⁶ in the formula (6) are the same as those of R ¹ in the formula (1). Further, R ⁶³ and R ⁶⁵ , or R ⁶⁴ and R ⁶⁶ in the formula (6) may form an unsaturated bond together, and R ⁶³ and R ⁶⁴ , or R ⁶⁵ and R ⁶⁶ And may form an alkylidene group. The number of carbon atoms of the alkylidene group is usually 1-2.
0, preferably 1 to 10, more preferably 1 to 6. In the formula (6), ‥‥‥ represents a carbon-carbon single bond or a double bond, and the ratio of the single bond is usually 95% or more, preferably 98% or more, more preferably 99% or more.

Specific examples of the repeating unit (A-ii) having an alicyclic structure having a norbornane structure include 8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] −
Dodeca-3-ene, 8-ethylidene-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodec-3-ene,
8-methyl-tetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] -dodec-3-ene and tetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] -dodec-3-ene and the like. These repeating units (A-ii) having a norbornane structure may be used alone or in combination of two or more. The content of the repeating unit (A-ii) having a norbornane structure is determined by the repeating unit (A-ii) having no norbornane structure.
0 to 70% by weight, preferably 0 to 50% by weight, more preferably 0 to 30% by weight, particularly preferably 0 to 70% by weight in the remainder of i), that is, in the repeating unit (A) having a completely alicyclic structure.
-20% by weight.

The repeating unit (B) other than the repeating unit (A) having the alicyclic structure in the cyclic olefin polymer used in the present invention is not particularly limited, but is usually a chain-like unit. And repeating units. As the chain repeating unit, for example, a unit represented by the following formula (7) is used.

[0026]

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[0027] R ⁶⁷ to R ⁷⁰ in the formula (7) is the same as R ¹ in formula (1), preferably a hydrogen atom. Specific examples of the linear repeating unit (D) represented by the formula (7) include α-olefins such as ethylene, propylene, 1-butene and 1-pentene; and aromatic vinyls such as styrene and α-methylstyrene. , Cyclobutene, cyclopentene, cycloolefins such as cyclohexene, 1,4-
Examples include a repeating unit derived from a non-conjugated diene such as hexadiene.

The molecular weight of the cyclic olefin polymer used in the present invention is determined by gel permeation chromatography (GPC) using cyclohexane (toluene when insoluble in cyclohexane) as a solvent. 5,000 ~ 50,000
0, preferably 7,000 to 45,000, more preferably 10,000 to 40,000. If the weight average molecular weight of the cyclic olefin-based polymer is too small, the mechanical strength is poor. Conversely, if the weight average molecular weight is too large, the fluidity is poor.

The 5% loss on heating of the cyclic olefin polymer used in the present invention is preferably at least 280 ° C.
More preferably 360 ° C. or higher, still more preferably 400 ° C.
° C or higher. If the heating weight loss temperature is too low, for the purpose of improving fluidity during injection molding, decomposition occurs when performing injection molding at a high resin temperature, and bubbles due to decomposition gas are included in the molded light guide plate, There is a problem that silver streaks occur. When the 5% heating loss temperature is in the above range, decomposition does not occur even if the resin temperature is increased for the purpose of increasing the fluidity of the resin during injection molding, and inclusion of bubbles and generation of silver can be avoided. is there.

The melt viscosity of the cyclic olefin polymer used in the present invention at a temperature of 260 ° C. is usually 1 × 10
² to 1 × 10 ⁵ poise, preferably 1 × 10 ² to 1 × 10 ³
Poise. If the melt viscosity is too high, the moldability of the resin will decrease during injection molding, and short shots will occur, especially in the case of large molded products, and fine patterns that change the direction of light rays as a function of the light guide plate. Transfer failure occurs. When the melt viscosity is in the above range, such inconvenience does not occur, and the light guide plate has excellent moldability and is suitable.

The proportion of the component having a molecular weight of at most 1,000 as measured by GPC in the cyclic olefin polymer used in the present invention is not particularly limited, but is usually at most 20% by weight, preferably at most 20% by weight. When the content is 10% by weight or less, more preferably 5% by weight or less, particularly preferably 3% by weight or less, the mechanical strength is enhanced, and the mechanical strength and the formability are well-balanced. Molecular weight 1,000
The lower limits of the amounts of the following components are not particularly limited, but are generally preferably 0.2% by weight or more.

Production of Cyclic Olefin Polymer The production of the above-mentioned cyclic olefin polymer used in the present invention can be carried out according to a conventional method. Then, a method of performing a hydrogenation reaction can be employed as needed. The alicyclic olefin-based monomer (a) is preferably a repeating unit having no norbornane structure, and is, for example, the following formula (8), preferably the following formula (9), more preferably the following formula (10) The olefin monomer (a-i) represented by the formula (1) is used. When these olefin-based monomers (a-i) are a repeating unit having no norbornane structure in metathesis polymerization (the above-mentioned A-
What is i) is known in, for example, Japanese Patent No. 2534086 and Japanese Patent Publication No. 7-121981.

[0033]

Embedded image [Wherein, R ^{1 to} R ²⁰ , a, b, and c are the same as the symbols in the formula (1). ]

[0034]

Embedded image [Wherein, R ^{21 to} R ³⁴ and d are the same as the symbols in the formula (2). ]

[0035]

Embedded image

These equations (8), (9) or (1)
The olefin-based monomers (ai) represented by 0) can be used alone or in combination of two or more. The ratio of the olefin monomer (ai) represented by the formula (8), the formula (9) or the formula (10) in the cyclic olefin monomer (a) having an alicyclic structure is 30 to 100. % By weight, preferably 50 to
It is 100% by weight, more preferably 70-100% by weight, particularly preferably in the range of 80-100% by weight, most preferably 100% by weight. In the alicyclic olefin monomer (a), the remainder other than the olefin monomer (ai) represented by the formula (8), (9) or (10) is usually represented by the following formula (11). Preferably, the following formula (12):
More preferably, an alicyclic olefin monomer (a-ii) represented by the following formula (13) is used.

[0037]

Embedded image [Wherein, R ^{35 to} R ⁴⁸ and e are the same as the symbols in the formula (4). ]

[0038]

Embedded image [Wherein, R ^{49 to} R ⁶² are the same as the symbols in the formula (5). ]

[0039]

Embedded image

Wherein R ^{63 to} R ⁶⁶ are the same as the symbols in the formula (6). These cyclic olefin-based monomers (a) having an alicyclic structure can be used alone or in combination of two or more. The proportion of the cyclic olefin monomer (a) having an alicyclic structure in all the monomers is 3
0-100% by weight, preferably 50-100% by weight, more preferably 70-100% by weight, most preferably 100% by weight. As the remaining monomer (b) other than the cyclic olefin monomer (a) having an alicyclic structure, a chain monomer is usually used. The chain monomer is represented, for example, by the following formula (14).

[0041]

Embedded image [Wherein, R ^{67 to} R ⁷⁰ are the same as the symbols in the formula (7). ]

Suitable monomer combinations include:
(1) dicyclopentadiene [olefin monomer (a)] + Ethyl - tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -
Dodeca-3-ene [olefin-based monomer (b)],
(2) dicyclopentadiene [olefin-based monomer (a)] + ethylnorbornene (ethyl-bicyclo [2.
2.1] - hept-2-ene) [olefin monomer (a)], (3) dicyclopentadiene [olefin monomer (a)] + tetracyclo [4.4.0.1 ^{2, 5} .1 ^7,10] - dodeca-3-ene [olefin monomer (b)] + ethyl - tetracyclo ^{[4.4.0.1 2,5 .1 7, 10]} - dodeca-3-ene
[Olefin-based monomer (b)], (4) dicyclopentadiene [olefin-based monomer (a)] + tetracyclo
[7.4.0.1 ^2,7 .1 ^10,13] - trideca -2,4,6,11-
Ene [olefin monomer (b)] + tetracyclo [4.
4.0.1 ^2,5 .1 ^7,10] - dodeca-3-ene [olefin monomer (b)], (5) tetracyclo [7.4.0.1 ^2,7 .1 ^10,13]
- trideca -2,4,6,11- ene [olefin monomer (a)] + tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] - dodeca-3-ene [olefin monomer (b)], etc. Is mentioned.

Examples of the metathesis catalyst include, for example, tongue
Group VI metals such as stainless steel (W) and molybdenum (Mo)
Compounds and compounds of Group IV metals such as titanium (Ti)
Can be used, preferably a tungsten (W) compound
Or molybdenum (Mo) compound, more preferably
Is a tungsten (W) compound. tungsten
Specific examples of the (W) compound include WBr_Two, WBr_Three, W
Br₆, WCl_Two, WCl_Four, WCl_Five, WCl₆, WF_Two,
WF_Four, WF₆, WI_Two, WI_Four, WI₆, WOBr_Four, WO
Cl_Four, WOF_Four, WO_Two, H_TwoWO_Four, NaWO_Four, K_TwoW
O_Four, (NH_Four)_TwoWO_Four, CaWO_Four, CuWO_Four, MgW
O_Four, (CO)_FiveWC (, OCH_Three) (CH_Three), (C
O_Five) WC (OC_TwoH_Five) (CH_Three), (CO_Five) WC (O
C_TwoH_Five) (C_FourH_Five), But among these,
Also WBr_Two, WBr_Three, WBr₆, WCl_Two, WCl_Four, W
Cl_Five, WCl₆, WF_Two, WF_Four, WF₆, WI _Two, W
I_Four, WI₆, WOBr_Four, WOCl_Four , WOF_FourEtc. are good
Best, WBr_Two, WBr_Three, WBr₆, WCl_Two, WCl
_Four, WCl_Five, WCl₆, WF_Two, WF_Four, WF ₆, WI_Two,
WI_Four, WI₆Is more preferred. These metathesis catalysts
Can be used alone or in combination of two or more
Can be used. The amount of metathesis catalyst used is usually
0.1 to 1.5 parts by weight per 100 parts by weight of all monomers,
Preferably 0.1 to 1.0 part by weight, more preferably
0.1 to 0.5 parts by weight.

In conducting metathesis polymerization, it is common to use a co-catalyst together with the above-mentioned metathesis catalyst. Examples of the co-catalyst include an organic aluminum compound and an organic tin compound, and an organic aluminum compound is preferable. Specific examples of the organoaluminum compound include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, and triisobutylaluminum, and alkylaluminum halides such as diethylaluminum chloride and ethylaluminum dichloride. However, preferred are triethylaluminum, triisobutylaluminum and diethylaluminum chloride. These co-catalysts can be used alone or in combination of two or more. The amount of the cocatalyst used is usually 0.01 to 30 mol per 1 mol of the metathesis catalyst,
Preferably 0.1 to 20 mol, more preferably 1 to
When the amount is 10 mol, the generation of a gel is small, the polymerization activity is high, and a high molecular weight product is easily obtained, which is preferable.

In the combination of the metathesis catalyst and the cocatalyst, a combination of a tungsten (W) compound and an organoaluminum compound is particularly preferable. However,
It has a preferred repeating unit (A-i) having no norbornane structure in the present invention, and has a high molecular weight (specifically, a weight average molecular weight of 5,000 to 50,000, preferably 7,000 to 45). 000, more preferably 10,000
00 to 40,000) and low in low molecular weight components (specifically, the proportion of components having a molecular weight of 1,000 or less is usually 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight. %, Particularly preferably 3% by weight or less.) When producing a cyclic olefin-based polymer, it is preferable to use a regulator in addition to the tungsten (W) -based compound and the organoaluminum compound.

As the modifier, at least one polar compound selected from polar compounds containing active hydrogen such as alcohols and amines and polar compounds not containing active hydrogen such as ethers, esters, ketones and nitriles is used. Can be. The active hydrogen-containing polar compound is effective for preventing gelation and obtaining a high molecular weight polymer, and among them, alcohol is preferable. Further, the polar compound containing no active hydrogen is effective in suppressing the production of low molecular weight components in the polymer, among which ether,
Esters and ketones are preferred, and ketones are particularly preferred.

Examples of the alcohol include saturated alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, isopentanol, hexanol and cyclohexanol, and unreacted alcohols such as phenol and benzyl alcohol. Saturated alcohols and the like can be mentioned, and preferred are propanol, isopropanol, butanol and isobutanol.

Examples of the ether include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, ethylene glycol dibutyl ether and triethylene glycol dibutyl ether. Of these, diisopropyl ether and diethyl ether are preferable.

Examples of the ester include methyl formate,
Ethyl formate, methyl acetate, ethyl acetate, propyl acetate,
Isopropyl acetate, methyl benzoate, ethyl benzoate,
Examples thereof include propyl benzoate and isopropyl benzoate, and among them, methyl acetate and ethyl acetate are preferable. Ketones include, for example, acetone, methyl ethyl ketone, diethyl ketone, methyl phenyl ketone, diphenyl ketone, etc. Among them, acetone and methyl ethyl ketone are preferable. As nitrile,
For example, acetonitrile, benzonitrile, t-butyronitrile and the like can be mentioned, among which benzonitrile and t-butyronitrile are preferable.

These adjusting agents can be used alone or in combination of two or more. In particular, in the present invention, it is preferable to combine a polar compound containing active hydrogen and a polar compound not having active hydrogen, and particularly a combination of alcohol and ketone, alcohol and nitrile, alcohol and ether, and alcohol and ester. The amount of the modifier used is usually 0.01 to 20 mol, preferably 0.1 to 10 mol, more preferably 1 to 5 per 1 mol of the metathesis catalyst.
mol range.

The polymerization reaction is usually carried out in the presence of a solvent. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as n-pentane, hexane and heptane, and cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane and cyclooctane. And preferably, toluene, cyclohexane,
Cyclooctane and the like, and more preferably toluene and cyclohexane. These solvents can be used alone or in combination of two or more, and the amount of the solvent used is usually 10 to 1,000 parts by weight, preferably 50 to 700 parts by weight, per 100 parts by weight of the monomer. , More preferably in the range of 100 to 500 parts by weight.

The polymerization conditions are such that the polymerization temperature is usually -10 ° C.
200 ° C., preferably 0 ° C. to 100 ° C., more preferably 10 ° C. to 80 ° C., and the polymerization time is usually 30 minutes to 10 hours, preferably 1 hour to 7 hours, more preferably 2 hours to 5 hours. Time range. If the polymerization temperature is too high, components having a molecular weight of 1,000 or less increase, and if the polymerization temperature is too low, the reaction rate is too slow to increase the reaction rate.

After the completion of the polymerization reaction, a hydrogenation catalyst can be added to carry out the hydrogenation reaction. The hydrogenation catalyst is not particularly limited as long as it is generally used in hydrogenating an olefin compound, and a heterogeneous catalyst or a homogeneous catalyst is generally used. As the heterogeneous catalyst, for example, nickel, palladium, platinum, or these metals are carbon, silica, diatomaceous earth, alumina,
Solid catalysts supported on a carrier such as titanium oxide: nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium / alumina and the like.

As the homogeneous catalyst, for example, a catalyst comprising a combination of a transition metal compound and an alkylaluminum metal compound or alkyllithium, for example, cobalt acetate /
Triethylaluminum, cobalt acetate / triisobutylaluminum, nickel acetate / triethylaluminum, nickel acetate / triisobutylaluminum, nickel acetylacetonate / triethylaluminum,
Nickel acetylacetonate / triisobutylaluminum, titanocene chloride / n-butyllithium,
A catalyst comprising a combination of zirconocene chloride / n-butyllithium and the like can be mentioned.

Each of these hydrogenation catalysts can be used alone.
Alternatively, two or more kinds can be used in combination. The amount of the hydrogenation catalyst to be used is generally 0.01 to 100 parts by weight, preferably 0.1 to 50 parts by weight, more preferably 1 to 30 parts by weight, per 100 parts by weight of the polymer. The hydrogenation reaction is usually carried out under a hydrogen pressure of 1 to 150 kg / cm ² ,
To 250 ° C, preferably 20 to 200 ° C, 1
The reaction is performed for a reaction time of from 20 hours to 20 hours.

The cyclic olefin polymer used in the present invention can be obtained by filtration after the hydrogenation reaction to remove the hydrogenation catalyst, followed by coagulation and drying. When a homogeneous catalyst is used as the hydrogenation catalyst, after the hydrogenation reaction,
The catalyst can be obtained by adding alcohol or water to deactivate the catalyst and insolubilizing the solvent, followed by filtration, coagulation and drying.

Other Polymer Components Other polymers can be added to the cyclic olefin polymer used in the present invention, if desired.
Examples of other polymers include rubbery polymers and other resins. Examples of the rubbery polymer include diene rubbers such as natural rubber, polybutadiene rubber, polyisoprene rubber, acrylonitrile / butadiene copolymer rubber; styrene / butadiene copolymer rubber, styrene / isoprene copolymer rubber, styrene /
Butadiene / isoprene terpolymer rubber; hydrogenated diene rubber; saturated polyolefin such as ethylene / α-olefin copolymer such as ethylene / propylene copolymer, and propylene / other α-olefin copolymer Rubber; ethylene-propylene-diene copolymer, α-
Α- such as olefin / diene copolymer, isobutylene / isoprene copolymer, isobutylene / diene copolymer
Olefin / diene polymer rubbers; special rubbers such as urethane rubber, silicone rubber, polyether rubber, acrylic rubber, propylene oxide rubber, and ethylene acrylic rubber; styrene / butadiene / styrene block copolymer rubber; styrene / isoprene / styrene Thermoplastic elastomers such as block copolymer rubbers; hydrogenated thermoplastic elastomers; urethane-based thermoplastic elastomers;
Polyamide-based thermoplastic elastomers; 1,2-polybutadiene-based thermoplastic elastomers;

Examples of other resins include polyolefins such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, polypropylene, syndiotactic polypropylene, polybutene, and polypentene; polyethylene terephthalate, polybutylene Polyesters such as terephthalate;
Polyamides such as nylon 6 and nylon 66; ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, polystyrene, syndiotactic polystyrene, polyphenylene sulfide, polyphenylene ether, polyamide, polyester, polycarbonate and the like.

These other polymers can be used alone or in combination of two or more. The compounding amount of the other polymer is usually 100 parts by weight or less, preferably 70 parts by weight or less, more preferably 50 parts by weight or less, and most preferably 30 parts by weight or less based on 100 parts by weight of the cyclic olefin-based thermal polymer. .

Blending agent A blending agent can be added to the cyclic olefin polymer used in the present invention, if necessary. The compounding agent is not particularly limited as long as it is generally used in the resin industry. For example, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, plasticizers, antistatic agents and light diffusing agents And the like. Examples of the antioxidant include a phenolic antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant. Among them, a phenol-based antioxidant is preferable, and an alkyl-substituted phenol-based antioxidant is preferable. Particularly preferred.

As the phenolic antioxidant, those conventionally known can be used. For example, 2-t-butyl-6-
(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- (1- (3,5-di-t-amyl-
Acrylate compounds described in JP-A-63-179953 and JP-A-1-168463, such as 2-hydroxyphenyl) ethyl) phenyl acrylate;

Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,
2′-methylene-bis (4-methyl-6-t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane,
5-trimethyl-2,4,6-tris (3,5-di-t
-Butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ', 5'-di-t-butyl-
4'-hydroxyphenyl) propionate) methane [that is, pentaerythryl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate]], triethylene glycol bis (3
Alkyl-substituted phenolic compounds such as-(3-t-butyl-4-hydroxy-5-methylphenyl) propionate); 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bis Octylthio-1,
3,5-triazine, 6- (4-hydroxy-3,5-
Dimethylanilino) -2,4-bis-octylthio-
Examples thereof include triazine group-containing phenol compounds such as 1,3,5-triazine.

The phosphorus-based antioxidant is not particularly limited as long as it is generally used in the general resin industry. For example, triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris (Nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-
Di-t-butylphenyl) phosphite, tris (2-
t-butyl-4-methylphenyl) phosphite, tris (cyclohexylphenyl) phosphite, 2,2-
Methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 9,10-dihydro-9-oxa-
10-phosphaphenanthrene-10-oxide, 1
0- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9 Monophosphite compounds such as -oxa-10-phosphaphenanthrene;

4,4'-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite), 4,4'-isopropylidene-bis (phenyl-
Di-alkyl (C12-C15) phosphite), 4,
4'-isopropylidene-bis (diphenylmonoalkyl (C12-C15) phosphite), 1,1,3-tris (2-methyl-4-di-tridecylphosphite-
5-t-butylphenyl) butane, tetrakis (2,4
-Di-t-butylphenyl) -4,4'-biphenylenediphosphite, cyclic neopentanetetraylbis (isodecylphosphite), cyclic neopentanetetraylbis (nonylphenylphosphite), cyclic neo Pentanetetraylbis (2,
4-di-t-butylphenyl phosphite), cyclic neopentanetetraylbis (2,4-dimethylphenylphosphite), cyclic neopentanetetraylbis (2,6-di-t-butylphenylphosphite) ) And the like. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, and tris (2,4-
Di-t-butylphenyl) phosphite and the like are particularly preferred.

Examples of the sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl
3,3′-thiodipropionate, laurylstearyl 3,3′-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl)-
2,4,8,10-tetraoxaspiro [5,5] undecane and the like.

As the light stabilizer, for example, 2,2,6
6-tetramethyl-4-piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-
4-hydroxybenzyl) -2-n-butylmalonate, 4- (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2,6,6-
Hindered amine light stabilizers such as tetramethylpiperidine are preferably used.

As the ultraviolet absorber, for example, 2- (2
-Hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5)
-Methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di -T-butyl-2-hydroxyphenyl) -2H-benzotriazole, 5-chloro-2
-(3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-
benzotriazole ultraviolet absorbers such as t-amyl-2-hydroxyphenyl) -2H-benzotriazole; 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate, 2,4
-Di-t-butylphenyl-3,5-di-t-butyl-
4-hydroxybenzoate, hexadecyl-3,5-
Di-tert-butyl-4-hydroxybenzoate, 2-
(2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H -Benzotriazole, 2-
Bezoate UV absorbers such as (2-hydroxy-4-octylphenyl) -2H-benzotriazole;

2,4-dihydroxybenzophenone, 2
-Hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy- Benzophenone ultraviolet absorbers such as 2-hydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone; ethyl-2-cyano-3,3 Acrylate UV absorbers such as -diphenyl acrylate, 2'-ethylhexyl-2-cyano-3,3-diphenyl acrylate; [2,2'-thiobis (4-t-octylphenolate)]-2-ethylhexylamine nickel Such as nickel complex UV absorbers And the like.

In general, inorganic fine particles can be used as the lubricant. Here, as the inorganic fine particles, the first, second, fourth, sixth, seventh, eighth to tenth, and eleventh groups of the periodic table are used.
Oxides, hydroxides, sulfides, nitrides, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates of Group 12, 13 and 14 elements, Examples include particles of titanates, borates and their hydrated compounds, composite compounds centered on them, and natural minerals.

Examples of the plasticizer include tricresyl phosphate, trixylyl phosphate, triphenyl phosphate, triethylphenyl phosphate, diphenylcresyl phosphate, monophenyl dicresyl phosphate, and dicresyl monoxylenyl. Phosphate, arylalkyl phosphate, diphenyl monoxylenyl phosphate, monophenyl dixylenyl phosphate, tributyl phosphate, triethyl phosphate, trichloroethyl phosphate, trioctyl phosphate, tris (isopropylphenyl) phosphate, etc. A phosphate triester plasticizer;

Dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-phthalate
Phthalate plasticizers such as octyl, di-2-ethylhexyl phthalate, diisononyl phthalate, octyldecyl phthalate and butylbenzyl phthalate; monobasic acid esters such as butyl oleate and glycerin monooleate Plasticizers; fatty acid dibasic acid ester plasticizers such as dibutyl adipate; dihydric alcohol ester plasticizers; oxyacid ester plasticizers; and the like, and among them, phosphate triester plasticizers are preferable. , Tricresyl phosphate and tricillyl phosphate are particularly preferred.

Further, as the softening agent or plasticizer, a hydrocarbon polymer which is liquid at room temperature and whose main skeleton is mainly a CC or C = C structure is preferably used. Among liquid hydrocarbon polymers, a linear or branched liquid hydrocarbon polymer having no hydrocarbon ring in the main chain is preferable. Also, because the resulting composition has excellent weather resistance,
Those having no C ＝ C structure are preferred. The molecular weight of the liquid hydrocarbon polymer is preferably 10,000 or less,
More preferably 200 to 8,000, particularly preferably 3
The range is from 00 to 4,000. As a specific example of the liquid hydrocarbon polymer, squalane (C ₃₀ H ₆₂ , Mw = 42
2.8), liquid paraffin (white oil, JIS
ISO VG10, ISO V specified in K2231
G15, ISO VG32, ISO VG68, ISO
VG100, VG8 and VG12), polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene and the like. Among them, squalane, liquid paraffin and polyisobutene are preferred.

Examples of the antistatic agent include alkyl sulfonates such as sodium alkyl sulfonate and phosphonium alkyl sulfonate; and glycerin esters of stearic acid. These compounding agents can be used alone or in combination of two or more. The amount of other ingredients used
It is appropriately selected within a range that does not impair the object of the present invention.

[0074] The flat panel and the light guide plate present invention, the term "flat" means a molded article having a flat shape, the length of the minimum width of the major surface (e.g., when the main surface is a rectangle the shorter side Further, when the main surface is circular or elliptical, the ratio L / L of the diameter or minor diameter) L to the maximum thickness (that is, the maximum length in the direction perpendicular to the main surface) T
T refers to two or more. The size and shape of the flat plate are not particularly limited, and are appropriately selected according to the purpose of use. The shape is usually selected from a square, a rectangle, a polygon having five or more corners, a perfect circle, an oval, and the like. The size ranges from a minimum width L of the main surface of about 0.5 mm to 100 c.
It can be widely applied to m or more. The thickness D of the flat plate is also appropriately selected according to the purpose of use, but is usually 0.5 to 10 mm, preferably 0.6 to 5.0.
mm, more preferably in the range of 0.8 to 2.0 mm.

Usually, the molded article has a retardation caused by the birefringence of light. The flat plate of the present invention has a retardation in the thickness direction of usually 100 nm or less, preferably 70 nm or less.
Or less, more preferably 50 nm or less. It is preferable that the phase difference in the thickness direction be in such a range, because higher luminance and reduction of luminance unevenness can be more preferably achieved in an optical member, for example, a light guide plate. Note that the phase difference in the thickness direction is measured by a method described later. Examples of a method for imparting a small phase difference to a flat plate such as a light guide plate as described above include, for example, a method of annealing a molded product to reduce birefringence, and a method of concentrating birefringence such as an injection molded product. Method to selectively use a site with relatively small birefringence by cutting and removing the vicinity of the injection gate by cutting, etc., and to reduce the occurrence of birefringence during molding by improving the fluidity of the cyclic olefin-based polymer And the like.

The flat molded article of the present invention preferably has a high surface accuracy, and its characteristic is the maximum height Rmax of the main surface.
It is preferable that the value is usually 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less. It is preferable that the flat surface has such a range of surface accuracy, because it is possible to suppress the occurrence of a shadow on the light emitting surface and to improve the luminance in an optical member, for example, a light guide plate. Such Rm
Means for achieving the ax value include, for example, a method of polishing the surface of the molded body, selection of molding conditions suitable for the resin used, suppression of occurrence of molding defects such as burning during molding, and surface accuracy. A method of removing foreign matter in a molded article by performing a filter treatment in advance in a polymer production stage or a melting stage before molding to prevent contamination in the molded article, and the like. .

The flat plate made of the cyclic olefin-based polymer of the present invention can be made thin, and has a light transmittance,
Since it is excellent in low water absorption, mechanical strength, and discoloration resistance, it is suitable as a light guide plate used for optical applications, for example, a light source device of an information display device. The “light guide plate” is an optical element that, unlike a lens, passes light from a light source through the plate and uniformly emits light from a main surface (light emission surface) of the plate without uneven brightness. For example, the light guide plate of the edge light type planar light source device of the information display device passes light incident on the incident end from the fluorescent lamp along the longitudinal direction of the light guide plate, and further bends the light at a right angle to the incident direction to emit light on the display. This is a plate for emitting light uniformly from the light exit surface. For example, in the edge light type planar light source device 10 shown in FIG. 1, the light guide plate 2 is combined with a fluorescent lamp 4, a reflector 3, a reflection sheet 6 and a diffusion sheet 5 to form an edge light type planar light source device (backlight). (Unit) 10. The backlight unit 10 is provided with a condensing prism sheet (not shown) on the diffusion sheet 5 as required, and further combined with a liquid crystal, a color filter, and other sheets to constitute a flat panel display unit. , Notebook PCs, car navigation systems, flat-screen TVs and other displays. The light reflected by the lamp reflector 3 from the fluorescent lamp 4 and introduced into one end of the light guide plate 2 penetrates through the light guide plate 2 and is reflected by the lower surface (reflection surface) of the light guide plate 2. The light exits upward at a right angle, passes through the diffusion sheet 5, and is guided to the display surface.

The light guide plate 2 may be a flat plate, but preferably has a wedge-shaped cross section whose thickness gradually decreases from the incident side end to the opposite end. The light guide plate 2 has a printing method in which a print pattern is formed on the lower surface (reflection surface) in order to reflect light toward the emission surface,
V-groove type in which a number of fine V-grooves are drilled (FIG. 1,
2 and 3) are preferably used. The light guide plate of the present invention is suitable for any of these methods, but is particularly suitable for a V-groove method. That is, in the printing method,
The reflection efficiency of light to the exit surface tends to be low,
Production requires a molding step and a pattern printing step, but the cyclic olefin-based polymer used in the present invention excels in following the irregularities on the mold surface during molding. This is because a light guide plate having the V-groove method can be integrally formed only by the molding process, and the light reflection efficiency to the light exit surface is good.

As shown in the partially enlarged view of FIG. 1, a large number of fine V-grooves extending in a direction perpendicular to the incident direction and parallel to each other are formed on the reflection surface of the V-groove type light guide plate 2. Has been established. The pitch of the V-groove is such that the wedge-shaped cross-section from the incident side end (rightward in FIG. 1) so that the light reflected by the V-groove is uniformly emitted over the entire main surface of the light guide plate 2.
May be configured to gradually decrease toward. In the edge light type planar light source device 1 shown in FIG. 2 as well, light incident on the incident surface 2a from the lamp 4 is guided in the longitudinal direction, further reflected on the reflecting surface 2c, and emitted from the light emitting surface 2b without uneven brightness. Thus, the light guide plate 2 gradually decreases in thickness toward the end 2d, and has a wedge-shaped cross section as a whole. A V-shaped groove 22 is formed on the light reflecting surface 2c of the light guide plate, and the V-shaped groove 22 is configured such that the pitch gradually decreases toward the end 2d.

The size of the light guide plate having a wedge-shaped cross section is
The area of the main surface is usually 10 to 2,500 cm ² , preferably 100 to 2,500 cm ² , more preferably ² to 2,500 cm ² .
00 to 2,500 cm ² , more preferably 500 to 2,500 cm ²
2,500 cm ² . The thickness is usually 0.5-5mm
It is. The apex angle of the V groove (shown as α in the partially enlarged view of FIG. 1) is usually 100 to 170 degrees, preferably 120 to 170 degrees.
At 50 degrees, the depth of the V-groove is usually 0.1 to 100 μm, preferably 1 to 50 μm, and the pitch of the V-groove gradually decreases from the incident end to the opposite end. The pitch ratio is 1/20 to 1/2, preferably 1 /
It is in the range of 10 to 1/3, and the maximum pitch is usually 0.1 to 10 mm, preferably 0.2 to 5 mm.
The angle of inclination (θ2 in FIG. 2) of the reflection surface of the light guide plate is 0.1 to 1
The range is 5 ^o .

The configuration of the light guide plate 2 shown in FIGS. 3 and 4 is substantially the same as that shown in FIGS. 1 and 2. In the light guide plate 2 having this wedge-shaped cross section, the pitch P1 between the adjacent V-grooves 22 is usually 50 to 1 near the incident end 2a.
000 μm, preferably 100 to 5,000 μm,
It is more preferably 500 to 2,000 μm, and usually about 10 to 1,000 μm, preferably 30 to 500 μm, more preferably 50 to 10 near the end 2 d on the facing surface side.
0 μm. Pitch P on 2a side between adjacent V-grooves 22
The ratio of the pitch P1 on the 1d to 2d side is preferably 10/1 to 3/1. The width P2 of the V groove 22 is usually 10 μm to 5 m
m, preferably 30 μm to 2 mm, more preferably 50 μm
μm to 1 mm. The depth H1 of the V groove 22 is usually 1 to 5
It is 00 μm, preferably 10 to 100 μm, more preferably 30 to 80 μm. The angle θ of the V groove 22 is 70 to 1
50 °, preferably 90-130 °, more preferably 1
00 to 120 °.

As shown in FIG. 4, raised portions 24 are formed in the vicinity of both edges of the V-shaped groove 22, and the height H2 thereof is usually 1
It is 0 to 150 μm, preferably 20 to 120 μm, more preferably 25 to 100 μm. Height H of raised portion 24
2 is 10 to 500%, preferably 20 to 300%, more preferably 30 to 200% with respect to the depth H1 of the V groove 22.
%. The width P3 of the raised portion 24 is usually 10 to 1,000.
μm, preferably 50-600 μm, more preferably 1 μm
It is 00 to 400 μm. Also, the cross-sectional area S of the V groove 22
22 (for one piece of S22) and the cross-sectional area S2 of the raised portion 24
4 (for one S24) is from 10/1 to 10/10
0, preferably 10/2 to 10/50, more preferably 10/5 to 10/20.

In the light guide plate of the present invention, as shown in FIG. 5, unevenness 11 for condensing light is provided integrally on the light emitting surface side of the light guide plate 2 of the planar light source device 1 to reduce the number of parts. It is possible to reduce the number and simplify the assembly. In addition,
The technique for forming the light guide plate as shown in FIGS. 1 to 5 can be applied to other cyclic olefin-based polymers.

The light guide plate and other flat plates of the present invention can be obtained by molding a composition comprising the above-mentioned cyclic olefin polymer and other necessary components into a flat plate shape. The molding method may be a conventional method, for example, an injection molding method, an inflation molding method, a compression molding method, an extrusion method, a casting method, a continuous extrusion method, and the like.
The injection molding method is preferable because of its excellent fluidity and workability. The injection molding conditions are appropriately selected according to the specifications of the flat molded product, but the resin temperature is usually 100 to 400 ° C, preferably 150 to 350 ° C, more preferably 200 to 30 ° C.
When the temperature is within the range of 0 ° C., the fluidity and discoloration resistance are highly balanced and suitable. However, it is not preferable to produce a light guide plate from a flat plate produced by stretching. When using a flat plate as the light guide plate, it is usually preferable that the phase difference caused by birefringence in the thickness direction is small,
If a stretched flat plate is used as the light guide plate, the resin is oriented in the stretching direction, and the phase difference in the thickness direction increases.

In particular, since the light guide plate of the present invention is made of a cyclic olefin polymer, it has excellent fluidity and strength at the time of melting, and the V-shaped groove 22 and the raised portion 24 shown in FIGS. To obtain a highly accurate light guide plate having a V-shaped groove 22 and a raised portion 24 having a good shape without causing transfer failure and without chipping or deformation at the time of mold release even when integrally molded by injection molding. Can be.

[0086]

The present invention will be described more specifically below with reference to examples and comparative examples. Parts and% are based on weight unless otherwise specified. The measuring method followed the following method. (1) Weight average molecular weight The weight average molecular weight in terms of polyisoprene was calculated by gel permeation chromatography (GPC) using cyclohexane (toluene when insoluble in cyclohexane) as a solvent. (2) Low-Molecular-Weight Ingredient The proportion of a polyisoprene-equivalent molecular weight of 1,000 or less was calculated by gel permeation chromatography (GPC) using a gel containing cyclohexane (toluene when insoluble in cyclohexane) as a solvent. (3) Hydrogenation rate The hydrogenation rate was measured by ¹ H-NMR. (4) Glass transition temperature The glass transition temperature was measured by the DSC method.

(5) Mechanical strength (A) Cracking test at the time of molding During the molding of 10 flat plates, it was observed whether cracks or cracks were formed when the flat plate was taken out of the mold, and 10 cracks or cracks were formed. 0 out of 10 sheets are good (good) 1 to 3 out of 10 pieces have cracks or cracks ○ (good) 4 out of 10 pieces have 6 pieces or less cracks or cracks Was evaluated as △ (slightly poor), and those having cracks or cracks in 7 or more out of 10 were evaluated as × (defective). In addition, the crack test was repeated, and the rate of occurrence of cracks and cracks (%) was determined. (B) Drop test A 3/4 inch radius missile-type weight (weight 50
g) was dropped naturally from a height of 1 m, and observed for cracks or cracks.
◎ (very good), 1 to 3 out of 10 cracks or cracks, ○ (good), 4 out of 10
以上 (slightly poor) when cracks or cracks were found in more than 6 or less pieces x (bad) when cracks or cracks were found in all 10 pieces
And In addition, the drop test was repeatedly performed to determine the rate of occurrence of cracks and cracks (%).

(6) Moisture Absorption Deformation Test The flat plate was allowed to stand for 1 week in a constant temperature and high humidity bath at a temperature of 23 ° C. and a humidity of 60%, and the flat plate was checked for any moisture absorption deformation (warpage). A sample having no warpage was evaluated as ○ (good), and a sample having warpage was evaluated as x (bad). (7) △ YI measurement Using a color difference meter (SM color computer) manufactured by Suga Test Instruments Co., Ltd., measure the △ YI value, which is an index of tint, and the value is less than 0.5. ◎ (very good), those in the range of 0.5 or more and less than 0.8 were （(good), those in the range of 0.8 or more and less than 1.1 were Δ (somewhat poor), and those of 1.1 or more Those were marked as x. (8) Bright point and shade point The presence or absence of a bright point and a shade point on the effective light emitting surface of the light guide plate was visually evaluated. (9) Surface roughness Rmax Measured using a contact surface roughness meter (resolution 0.02 μm) (unit: μm). (10) Phase difference in the thickness direction The birefringence of the light guide plate was measured using a birefringence measurement device (ADR-100XY, manufactured by Oak). The results of the birefringence measurement in the examples were obtained by measuring three arbitrary points 1 cm inward from the pressure end of the light guide plate, and calculating the average value (unit: nm).

(Synthesis of Polymer) Reference Example 1 5 g of dicyclopentadiene monomer and 12 g of cyclohexane were placed in a 1-liter flask purged with nitrogen.
0.5 g of tri-i-butylaluminum [iBu ₃ Al] as a polymerization catalyst, 0.57 mol of isobutyl alcohol and 0.189 mmol of acetone as a reaction regulator, and 4.55 mmol of 1-hexene as a molecular weight regulator were added. . To this, 0.076 mmol of tungsten hexachloride was added, and the mixture was stirred at 60 ° C. for 5 minutes. Next, while maintaining the reaction system at 60 ° C., a mixed solution of 45 g of dicyclopentadiene monomer, 0.114 mmol of tungsten hexachloride, and cyclohexane was continuously dropped into the system. After dropping, 3 more
The ring-opening polymerization was completed by stirring for 0 minutes. The thus obtained ring-opened polymer had a weight average molecular weight (Mw) of 16,
000. Gas chromatography analysis of the reaction solution did not detect a peak of unreacted monomer, and thus it was confirmed that the reaction rate was 100%.
The repeating unit having a bicyclic alicyclic structure having no norbornane structure was 100% by weight.

This polymerization reaction solution was transferred to a 1-liter autoclave, and 160 g of cyclohexane was added. As a hydrogenation catalyst, 2.5 g of diatomaceous earth-supported nickel catalyst and activated alumina (surface area: 320 cm ² / g,
Pore volume 0.8 cm ³ / g, average particle size 15 [mu] m, manufactured by Mizusawa Chemical Co., Neobido D powder) was added 2.5g, after the reactor was replaced with hydrogen, pressurized by about 10 kg / cm ^2, stirring The temperature was raised to 160 ° C. When the temperature was stabilized, the hydrogen pressure was maintained at 40 kg / cm ² and the reaction was carried out for 8 hours while replenishing the hydrogen consumed in the reaction process. After the hydrogenation reaction, after filtering off the hydrogenation catalyst and activated alumina,
Further, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as an antioxidant was added to this hydrogenated polymer solution in an amount of 100 parts by weight of the hydrogenated polymer. On the other hand, 0.1 part by weight was added, and the solvent was removed at 380 ° C. under reduced pressure drying. Then
The molten resin was pelletized by an extruder under a nitrogen atmosphere. The polymer thus obtained is converted into a polymer (A)
And The weight average molecular weight (Mw) of the polymer (A) is 3
The proportion of components having a molecular weight of 3,000 and a molecular weight of 1,000 or less was 0.5% by weight. The hydrogenation ratio of the polymer (a) was 99.9%, and the glass transition temperature was 97 ° C.

Reference Example 2 A ring-opened polymer was synthesized and hydrogenated in the same manner as in Reference Example 1, except that acetone as a reaction regulator was not used and the reaction temperature was 70 ° C. The polymer thus obtained is referred to as a polymer (B). The weight average molecular weight (Mw) of the polymer (B) was 32,400, and the molecular weight was 1,000.
The component of 0 or less was 10.0% by weight. Hydrogenation rate is 9
9.9%, and the glass transition temperature was 97 ° C. The repeating unit having a bicyclic alicyclic structure having no norbornane structure was 100% by weight.

Reference Example 3 The monomers were dicyclopentadiene and 6-methyl-1,4: 5,8-dimethano-1,
A ring-opened polymer was synthesized and hydrogenated in the same manner as in Reference Example 1, except that the mixture was changed to a 70:30 mixture of 4,4a, 5,6,7,8,8a-octahydronaphthalene. The polymer thus obtained is referred to as a polymer (C). The weight average molecular weight (Mw) of the polymer (C) was 36,000, and the ratio of components having a molecular weight of 1,000 or less was 0.5% by weight. The hydrogenation ratio of the polymer (C) was 99.9%, and the glass transition temperature was 110 ° C. The repeating unit having a bicyclic alicyclic structure having no norbornane structure was 70% by weight.

[Reference Example 4] 25 parts of tetracyclododecene (TCD), 25 parts of dicyclopentadiene (DCP) and 1-hexene were added to a reactor which was sufficiently dried and purged with nitrogen, based on the total amount of the monomer and 1 part. Mole%, and toluene 30
0 parts were charged. Next, 16 parts of a 1 molar triethylaluminum toluene solution, 4 parts of triethylamine and 3 parts of a 1 molar titanium tetrachloride toluene solution were added, and reacted at 25 ° C. for 2 hours. The reaction solution was poured into acetone / isopropyl alcohol (1/1) to coagulate the polymer, and the precipitate was separated by filtration and dried to obtain 74 parts of a polymer. The yield was 74%. As a result of analyzing the obtained polymer by proton NMR spectrum, the weight ratio of the TCD component to the DCP component in the polymer was 25:75. 50 parts of the above polymer was dissolved in 500 parts of cyclohexane, and a hydrogenation reaction was carried out at a hydrogen pressure of 60 kg / cm ² and a temperature of 140 ° C. for 4 hours using 5 parts of a palladium / carbon catalyst. After filtering the obtained polymer solution to remove the catalyst, acetone / isopropyl alcohol (1/1) was used.
The mixture was poured into 1) to solidify the polymer, and the precipitate was separated by filtration and dried to obtain 43 parts of a polymer. This polymer was designated as polymer (D). Weight average molecular weight (Mw) of polymer (D)
Was 68,000, and the ratio of components having a molecular weight of 1,000 or less was 0.6% by weight. The hydrogenation ratio of the polymer (D) was 99.9%, and the glass transition temperature was 127 ° C. The repeating unit having a bicyclic alicyclic structure having no norbornane structure was 75% by weight.

Reference Example 5 8-Methyl-8-methoxyca
Rubonyltetracyclo [4.4.0.1^2,5 . 1 ^7,8 ]
100 g of dodeca-3-ene, 1,2-dimethoxyethane
60 g, cyclohexane 240 g, 1-hexene 9 g,
And 0.96 mol / l of diethylaluminum chloride
3.4 ml of a toluene solution of
Added to the toclave. Meanwhile, in another flask,
Nustene, 0.05 mol / l 1,2-didimethoxy
20 ml of ethane solution and 0.1 mol / l of paraaldehyde
Was mixed with 10 ml of a 1,2-didimethoxyethane solution of
Was. 4.9 ml of this mixed solution was placed in the autoclave.
Added to the mixture. After sealing, heat the mixture to 80 ° C
Stirring was performed for 2.5 hours.

To the obtained polymer solution, a mixed solvent of 1/8 (weight ratio) of 1,2-didimethoxyethane and cyclohexane was added to reduce the polymer / solvent ratio to 1/9 (weight ratio). 20 g of triethanolamine was added and stirred for 10 minutes. To this polymerization solution, 500 g of methanol was added, and 3
Stir for 0 minutes and let stand. Except for the upper layer which is separated into two layers,
Methanol was added again, and the mixture was stirred and allowed to stand, and then the upper layer was removed.
The same operation was further repeated twice, and the obtained lower layer was appropriately diluted with cyclohexane and 1,2-didimethoxyethane to obtain a cyclohexane-1,2-didimethoxyethane solution having a polymer concentration of 10%. 20 g of palladium / silica magnesia [manufactured by Nikki Chemical Co., Ltd., palladium amount = 5%] was added to this solution, and hydrogen pressure was set at 40 kg in an autoclave.
After reacting at 165 ° C. for 4 hours at 165 ° C./cm ² , the hydrogenation catalyst was removed by filtration to obtain a hydrogenated polymer solution.

Further, pentaerythrityl-tetrakis [3- (3,5), an antioxidant, was added to this hydrogenated polymer solution.
-Di-t-butyl-4-hydroxyphenyl) propionate] was added to 100 parts by weight of the hydrogenated polymer, and the solvent was removed at 380 ° C under reduced pressure. Next, the molten resin was pelletized by an extruder under a nitrogen atmosphere, and an intrinsic viscosity of 0.48 dl / g (30
C. in chloroform), a polymer having a hydrogenation rate of 99.5% and a glass transition temperature of 168 ° C. was obtained. This polymer was designated as polymer (E). The repeating unit having a bicyclic alicyclic structure having no norbornane structure was 0% by weight.

[Examples 1 to 3] (Preparation of flat plate) Polymers (A) to
(C) was mixed with pentaerythrityl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
[Propionate] was added, and the mixture was heated and kneaded (resin temperature: 250 ° C.) and pelletized. Using these pellets, a resin temperature of 280 ° C., 15
A flat plate of cm × 15 cm × 1 mm was formed. Each of the obtained flat plates was sufficiently excellent in light transmittance.
Using this flat plate, mechanical strength, ΔYI, and moisture absorption deformation were measured. Table 1 shows the results.

Using the above pellets, a light guide plate having a wedge-shaped cross section as shown in FIG. 1 and having the following specifications was extruded. Diagonal length 11 inches, thickness on the incident side end 3 mm, thickness on the opposite side 0.8 mm, V groove depth 5 μm, V groove apex angle α140 degrees, V groove maximum pitch (incident side end pitch ) 1mm, minimum pitch (opposite pitch)
0.2 mm. Using this light guide plate, a backlight unit as shown in FIG. 1 was prepared, light was emitted at a lamp current of 5 mA, and the luminance of the light exit surface of the light guide plate was measured. The measurement of brightness
The measurement was performed at 9 points uniformly distributed in the effective light emitting area excluding the peripheral edge width of the light guide plate of 10 mm. Any polymer (A)
The light guide plate manufactured from (C) also has an average luminance of 1,500 c.
d / m ² or more, and luminance unevenness was less than 20%.

Comparative Example 1 A flat plate was formed in the same manner as in Example 1 except that the polymer (D) produced in Reference Example 4 was used and the resin temperature was changed to 350 ° C. Using this flat plate, mechanical strength, ΔYI, and moisture absorption deformation were measured. Table 1 shows the results. Comparative Example 2 Using the polymer (E) produced in Reference Example 5,
A flat plate was formed in the same manner as in Example 1 except that the resin temperature was changed to 320 ° C. Using this flat plate, mechanical strength, ΔYI,
Hygroscopic deformation was measured. Table 1 shows the results.

[0100]

[Table 1]

As shown in Table 1, the thin flat plate of the present invention (Example 1)
3) are excellent in mechanical strength, resistance to discoloration, and resistance to deformation due to moisture absorption. In particular, when a polymer having a large number of repeating units having no norbornane structure was used, superior mechanical strength (drop resistance test) was exhibited (Example 1 = Example 2> Example 3> Comparative Example 1). ) And those using a polymer having a low molecular weight component having a low molecular weight of 1,000 or less have more excellent mechanical strength (comparison between Example 1 and Example 2). On the other hand, it was found that the polymer using a polymer having a norbornane structure in all the repeating units was insufficient in all of the mechanical strength, the discoloration resistance, and the moisture absorption deformation resistance (Comparative Example 2). Those using a polymer having an excessively high molecular weight are inferior in discoloration resistance (Comparative Example 1).

[0102]

EFFECT OF THE INVENTION 30 repeating units having an alicyclic structure
At least 30% by weight of the repeating unit having no norbornane structure, and
The flat plate of the present invention comprising a cyclic olefin polymer having a weight average molecular weight in a predetermined range has light transmittance, low water absorption,
It is excellent in mechanical strength and discoloration resistance, and can be made thin. Therefore, by utilizing such characteristics, it is suitably used for optical applications, particularly for a light guide plate of a planar light source device (flat panel display) of an information display device such as a notebook computer, a car navigation system, and a thin television.

Preferred Embodiment The repeating unit (A) having an alicyclic structure is 30% by weight or more, and 30% by weight or more of the repeating unit (A) having an alicyclic structure has no norbornane structure. Unit (A-i), and the weight average molecular weight is from 5,000 to
Preferred embodiments of the flat plate of the present invention comprising a cyclic olefin polymer having a molecular weight of 50,000 are summarized as follows.

(1) The alicyclic structure in the repeating unit (A) is a saturated alicyclic structure having 4 to 30, preferably 5 to 20, and more preferably 5 to 15 carbon atoms. And it is included in the main chain of the polymer. (2) The content of the repeating unit (A) having an alicyclic structure in the cyclic olefin-based thermoplastic resin (I) is preferably 50 to 100% by weight, and more preferably 70 to 100% by weight.
%, Particularly preferably in the range of 100% by weight. (3) The proportion of the repeating unit (Ai) having no norbornane structure in the repeating unit (A) having an alicyclic structure is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, Particularly preferably, it is in the range of 80 to 100% by weight.

(4) The repeating unit (Ai) having no norbornane structure is represented by the formula (1), more preferably the formula (2), and further preferably the formula (3). In the formula (1), R ^{1 to} R ²⁰ each independently represent a hydrogen atom, a hydrocarbon group, a hydroxyl group, a halogen atom, an ester group, an alkoxy group, a cyano group, an imide group,
A hydrocarbon group substituted with a silyl group or a functional group (hydroxyl group, ester group, alkoxy group, cyano group, imide group, silyl group), preferably a hydrogen atom or usually 1
A hydrocarbon group having from 20 to 20, preferably 1 to 10, and more preferably 1 to 6, carbon atoms, more preferably a hydrogen atom.

Where R⁸And R^TenOr R⁹And R¹¹And
May together form an unsaturated bond,⁸
And R⁹Or R^TenAnd R¹¹And 1 to 20, preferably
A compound having 1 to 10, more preferably 1 to 6 carbon atoms
A alkylidene group may be formed. a is 0 or 1
And preferably 0, b is 0 or 1, and
Preferably 1 and c is 0, 1 or 2;
Or 0.‥‥‥Is a carbon-carbon single bond or double
Represents a bond. In the above formula (2), R^{twenty one}~ R ³⁴Is
R in the above formula (1)¹And R⁸And R²⁷,
Or R⁹And R²⁸And together form an unsaturated bond
And R⁸And R²⁶Or R²⁷And R²⁸And
1-20, preferably 1-10, more preferably 1-6
May form an alkylidene group having
No. d is 0 or 1, preferably 0,‥‥
‥Represents a carbon-carbon single bond or a double bond. The formula
In (3),‥‥‥Is a carbon-carbon single bond or two
Represents a heavy bond.

(5) In the repeating unit (A) having an alicyclic structure, the repeating unit other than the repeating unit (Ai) having no norbornane structure, that is, the repeating unit (A-ii) having a norbornane structure is , The formula (4), more preferably the formula (5), and still more preferably the formula (6). In the above equation (4),
R ^{35 to} R ⁴⁸ are the same as those of R ¹ in the formula (1);
e is an integer of 1 to 3, preferably 1, and ‥‥‥ represents a carbon-carbon single bond or a double bond. In the formula (5), R ^{49 to} R ⁶² are the same as those of R ¹ in the formula (1), and ‥‥‥ represents a carbon-carbon single bond or a double bond. In the formula (6), R ^{63 to} R ⁶⁶ are represented by the formula (1)
They are the same as those in R ¹ of, ‥‥‥ carbon - represents a single bond or a double bond of carbon.

(6) The repeating unit (A) having the alicyclic structure in the cyclic olefin-based thermoplastic resin (I)
The remaining repeating unit (B) other than the above is a chain repeating unit represented by the formula (7). In the formula (7), R ^{67 to} R ⁷⁰ are the same as R ¹ in the formula (1), and are preferably a hydrogen atom.

(7) The molecular weight of the cyclic olefin-based polymer is 5, as a weight average molecular weight in terms of polyisoprene measured by gel permeation chromatography (GPC) using cyclohexane (toluene when insoluble in cyclohexane) as a solvent. 000 to 50,000, preferably 7,000 to 45,000, more preferably 10,
000-40,000. (8) The proportion of the component of the cyclic olefin polymer having a molecular weight of 1,000 or less as measured by GPC is preferably 20% by weight or less, more preferably 10% by weight or less,
The content is more preferably 5% by weight, particularly preferably 3% by weight or less.

(9) 5% of the cyclic olefin polymer
The heating weight loss temperature is 280 ° C or more, more preferably 360 ° C.
C. or higher, more preferably 400 C. or higher.
The flat plate as described. (10) When the temperature of the cyclic olefin polymer is 260 ° C
Melt viscosity 1 × 10 ^Two~ 1 × 10^FivePoise, more preferred
Or 1 × 10^Two~ 1 × 10^Three2. A poise according to claim 1.
Slab. (11) Molecular weight of the cyclic olefin polymer is 1000
The following component ratio is usually 20% by weight or less, preferably
% By weight or less, more preferably 5% or less, particularly preferably
The flat plate according to claim 1, wherein the content is 3% by weight or less.

(12) The flat plate and the light guide plate of the present invention
The retardation in the thickness direction is usually 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less. (13) In the flat plate and the light guide plate of the present invention, the surface roughness of the main surface portion is usually 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm as the maximum height (Rmax).
It is as follows. (14) The light guide plate has a wedge-shaped cross section in which a number of fine V-shaped grooves are formed in the reflection surface. (15) The light guide plate has a wedge-shaped cross section in which a printing pattern is formed on the reflection surface. (16) The light guide plate has a wedge-shaped cross section, and a large number of V-shaped grooves are provided on the reflection surface, and the pitch of the V-shaped grooves gradually decreases from the incident surface toward the tip of the wedge-shaped cross section. (17) The area of the main surface of the light guide plate is 10 to 2,500 c.
m ² and a thickness of 0.5 to 10 mm.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flat panel display edge light type planar light source device (backlight unit) provided with a light guide plate of the present invention.

FIG. 2 is a cross-sectional view showing an example of a light source and a light guide plate constituting an edge light type planar light source device.

FIG. 3 is a cross-sectional view showing another example of the light source and the light guide plate that constitute the edge light type planar light source device.

FIG. 4 is an enlarged view of a portion II in FIG. 3;

FIG. 5 is a perspective view showing a light exit surface of a light guide plate of the edge light type planar light source device.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1,10 Planar light source device 2 Light guide plate 3 Reflector 4 Fluorescent lamp 5 Diffusion sheet 6 Reflection sheet 22 V-shaped groove 24 Ridge

Claims (4)

[Claims] 1. The repeating unit (A) having an alicyclic structure is at least 30% by weight, and at least 30% by weight of the repeating unit (A) having an alicyclic structure has no norbornane structure. (Ai) A flat plate made of a cyclic olefin polymer having a weight average molecular weight of 5,000 to 50,000. 2. The repeating unit (A-) comprising only the repeating unit (A) having an alicyclic structure, wherein 70% by weight or more of the repeating unit (A) having an alicyclic structure has no norbornane structure. The flat plate according to claim 1, comprising the cyclic olefin-based polymer (i). 3. A repeating unit having no norbornane structure
The position (Ai) is represented by the following formula (2).
3. The flat plate according to claim 1 or 2. Embedded image [R^{twenty one}~ R³⁴Is independently a hydrogen atom,
Hydrocarbon group, hydroxyl group, halogen atom, ester group,
Coxy group, cyano group, imide group, silyl group, or functional
Groups (hydroxyl, ester, alkoxy, cyano,
Substituted with a functional group selected from a mid group and a silyl group)
Represents a treated hydrocarbon group. Where R^{twenty five}And R²⁷Or
R²⁶And R²⁸May form an unsaturated bond with
And R^{twenty five}And R ²⁶Or R²⁷And R²⁸And archi
It may form a redene group. a is 0 or 1, b is
0 or 1, and c is 0, 1, or 2.‥‥‥Is carbon
-Represents a single or double bond of carbon. ]. 4. A light guide plate comprising the flat plate according to claim 1, 2 or 3.