JP2003029663A - Transparent insulating substrate and active matrix and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic transparent insulating substrate having excellent heat resistance which can be used for an active matrix substrate as the structural member of a display device. SOLUTION: The transparent insulating substrate is produced by using a resin of a random copolymer consisting of 2-4C α-olefins and cyclic olefins expressed by a specified general formula with a higher content of the cyclic olefins and having >=230 deg.C glass transition temperature and by the molding method by dissolving carbon dioxide in the above resin and then carrying out injection molding of the resin in dies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent insulating substrate made of a cyclic olefin resin and having excellent heat resistance, an active matrix substrate using the substrate, and a liquid crystal display device constructed by using the active matrix substrate. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a glass substrate has been used as a transparent insulating substrate which is a constituent member of a display element such as a liquid crystal display element, an organic electroluminescence (EL) element and a field emission display (FED) display element. Since it is lighter than the glass substrate and has excellent impact resistance and workability, it is desired to change to a plastic substrate. For example, JP-A-59-204545 discusses the use of a transparent plastic substrate instead of a glass substrate.

On the other hand, as a liquid crystal display element, an active matrix type liquid crystal display element in which a thin film transistor (TFT) is provided in each pixel and each pixel is driven by a scanning signal and a data signal has a high display quality, and thus is the mainstream in the future. Is expected to become. In this type of liquid crystal display element, an active matrix substrate having a thin film transistor array formed on a transparent insulating substrate and an opposite substrate having transparent electrodes formed on the transparent insulating substrate are arranged to face each other, and a liquid crystal material is sealed in the gap. I will do it. Therefore, the transparent insulating substrate that constitutes the active matrix substrate is required to have high heat resistance due to the formation of an insulating film, and the plastic substrate, which is inferior in heat resistance to glass, is deformed during processing and is difficult to use. Is. Therefore, Japanese Patent Laid-Open No. 4-238322 discloses a combination in which a plastic film is used for the counter substrate and a glass substrate is used for the active matrix substrate.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a lightweight plastic transparent insulating substrate having excellent heat resistance, transparency and workability, and using the substrate to form an active matrix substrate without causing deformation. However, it is to construct a liquid crystal display element that is lightweight and has excellent impact resistance.

[0005]

Means for Solving the Problems The present inventors have found that heat resistance,
As a result of intensive studies on transparent insulating substrate materials having excellent transparency, a random copolymer containing α-olefin such as ethylene and cyclic olefin such as norbornene as a monomer component has a large content of cyclic olefin and a glass transition temperature. A copolymer having a high composition is suitable as a transparent insulating substrate material for an active matrix substrate, and
A heat resistant resin such as a random copolymer composed of the α-olefin and the cyclic olefin is originally difficult to injection-mold, but by dissolving carbon dioxide in the molten resin,
The present invention has been achieved by finding that a shape suitable for an active matrix substrate can be easily formed.

That is, the first aspect of the present invention is to randomly contain a linear or branched α-olefin having at least 2 to 4 carbon atoms and a cyclic olefin represented by the following general formula (1) as monomer components. A transparent insulating substrate which is a copolymer and is formed by molding a cyclic olefin resin having a glass transition temperature of 230 ° C. or higher.

[0007]

[Chemical 2]

In the above formula, n is 0, 1, or 2, and R ^{1 to} R ⁸ are each independently hydrogen, a halogen atom,
Is a hydrocarbon group, R ^{9 to} R ¹² are each independently hydrogen,
A halogen atom, a hydrocarbon group, or a hydrocarbon group in which only R ⁹ or R ^{10 and} only R ¹¹ or R ¹² are substituted with a double bond, and R ^{9 to} R ¹² are bonded to each other to form a monocycle or It may form a polycycle, and the monocycle or polycycle may have a double bond. Further, the above hydrocarbon group may be substituted with a halogen atom.

The transparent insulating substrate of the present invention preferably has a surface smoothness Ra of 20 nm or less, and preferably by dissolving carbon dioxide in the cyclic olefin resin and injecting the resin into a mold. It is a molded body that is injection molded.

A second aspect of the present invention is a thin film transistor having at least a gate electrode, a gate insulating film, a semiconductor layer, a source electrode and a drain electrode on the transparent insulating substrate of the present invention, and electrically connected to the drain electrode. And an active matrix substrate according to the present invention, and a counter electrode substrate in which at least a transparent electrode is provided on a plastic transparent insulating substrate. Then, a liquid crystal display element is characterized in that a liquid crystal material is sealed in the gap.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The cyclic olefin resin constituting the transparent insulating substrate of the present invention comprises at least a linear or branched α-olefin having 2 to 4 carbon atoms and the following general formula (1).
It is a random copolymer containing a cyclic olefin represented by

[0012]

[Chemical 3]

In the above formula, n is 0, 1, or 2, and R ^{1 to} R ⁸ are each independently hydrogen, a halogen atom,
Is a hydrocarbon group, R ^{9 to} R ¹² are each independently hydrogen,
A halogen atom, a hydrocarbon group, or a hydrocarbon group in which only R ⁹ or R ^{10 and} only R ¹¹ or R ¹² are substituted with a double bond, and R ^{9 to} R ¹² are bonded to each other to form a monocycle or It may form a polycycle, and the monocycle or polycycle may have a double bond. Further, the above hydrocarbon group may be substituted with a halogen atom.

Examples of the linear or branched α-olefin having 2 to 4 carbon atoms include ethylene, propylene and 1
-Butene and the like. These linear or branched α-olefins may be used alone or in combination of two or more. Among these, ethylene alone,
Alternatively, it is preferable to use ethylene as a main component.

In the above general formula (1), the halogen atom is any one of fluorine, chlorine, bromine and iodine atoms. The hydrocarbon group represented by R ^{1 to} R ¹² has 1 carbon atom.
-20 alkyl groups, C3-15 cycloalkyl groups, and aromatic groups. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, and an octyl group. A cycloalkyl group is a cyclohexyl group, an aromatic group is a phenyl group, and a naphthyl group. And the like. These hydrocarbon groups may be substituted with a halogen atom.

Specific examples of the cyclic olefin represented by the above general formula (1) include bicyclo [2.
2.1] hept-2-ene (hereinafter referred to as norbornene), 5-methylbicyclo [2.2.1] hept-2-
Ene, 5,6-dimethylbicyclo [2.2.1] hept-2-ene, 5-ethylbicyclo [2.2.1] hept-2-ene, 5-n-butylbicyclo [2.2.1]. ] Hept-2-ene, 5-isobutylbicyclo [2.2.
1] hept-2-ene, tricyclo [4.3.0.1 ^2,
5 ] -3-decene, tricyclo [4.4.0.1 ^2,5 ]-
3-undecene, tetracyclo [4.4.0.1 ^2,5 .
1 ^7,10 ] -3-dodecene (hereinafter referred to as tetracyclododecene), 8-methyltetracyclo [4.4.0.
1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-propyltetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] -3-Dodecene, 8-butyltetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-isobutyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3
-Dodecene, 8-ethylidene tetracyclo [4.4.
0.1 ^2,5 . 1 ^7,10 ] -3-Dodecene, 8-chlorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 .
0 ^9,13 ] -4-pentadecene, pentacyclo [6.6.
1.1 ^3,6 . 0 ^2,7 . 0 ^9,14] -4-hexadecene, hexacyclo [6.6.1.1 ^3,6. 1 ^10,13 . 0 ^2,7 . 0
^9,14] -4-heptadecene, and the like. These cyclic olefins may be used alone or in combination of two or more. Among these cyclic olefins, norbornene and tetracyclodecene are preferable, and norbornene is particularly preferable.

In addition to the above α-olefin and cyclic olefin, cyclic copolymers such as cyclohexene and styrene may be added to the random copolymer according to the present invention, as long as the object of the present invention is not impaired. It is also possible to copolymerize an aromatic vinyl compound such as However, it is desirable that the above-mentioned α-olefin and the cyclic olefin represented by the general formula (1) are contained in the monomer component in an amount of 80 mol% or more.

The transparent insulating substrate of the present invention is molded by using the above-mentioned specific random copolymer cyclic olefin resin, and its glass transition temperature is 230 ° C. or higher, preferably 250 ° C. or higher. Glass transition temperature is 230
If the temperature is lower than ° C, the heat resistance is insufficient, and the substrate cannot withstand the heat treatment in the TFT array forming step when forming an active matrix substrate using the substrate. The upper limit of the glass transition temperature is preferably 350 ° C, and if it exceeds the temperature, molding such as injection molding and extrusion molding becomes difficult. The glass transition temperature of the resin according to the present invention is determined by the differential scanning calorimeter (DS
C) It measures. Therefore, it is necessary to set the copolymerization composition of the random copolymer so that the final glass transition temperature of the cyclic olefin resin is 230 ° C. or higher, preferably 350 ° C. or lower. The composition depends on the type of α-olefin and cyclic olefin used, but preferably 1 to 40 mol% of α-olefin,
Cyclic olefin is 60 to 99 mol%. The weight average molecular weight (Mw) of the copolymer is 5000 to 5000.
It is preferably in the range of 00.

The random copolymer according to the present invention comprises the aforementioned linear or branched α-olefin having 2 to 4 carbon atoms and the cyclic olefin represented by the above general formula (1).
It is obtained by addition-polymerizing another copolymerizable monomer as required, and a metallocene catalyst, for example, can be used as a polymerization catalyst for the addition-polymerization.

As the metallocene catalyst, a metallocene compound (a) of a transition metal, which is conventionally known as a single-site catalyst, an organoaluminum oxy compound (b) and / or
Alternatively, a catalyst composed of the organic boron compound (c) is preferably used. Specific examples of the metallocene compound (a) include transition metal compounds represented by the following general formula (2) or (3).

[0021]

[Chemical 4]

In the above general formula (2), M ¹ represents titanium, zirconium or hafnium, and preferably zirconium. X ¹ and X ² are hydrogen, halogen, and a carbon number of 1 to
The alkyl group having 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, the arylalkyl group having 7 to 40 carbon atoms, and the alkylaryl group having 7 to 40 carbon atoms may be the same or different from each other.

R ¹³ and R ¹⁴ are each an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms, which may be the same or different.

R ¹⁵ and R ¹⁶ represent a hydrocarbon group having a cyclopentadienyl structure capable of forming a sandwich structure with the central metal M ¹ and may be the same or different. Specifically, an indenyl group or a substituted product thereof and a fluorenyl group or a substituted product thereof are preferable.

Specific examples of the compound represented by the general formula (2) include diphenylmethylene-bis (1-indenyl) zirconium dichloride, isopropylidene-bis (1-indenyl) zirconium dichloride, cyclohexylidene-bis (1-). Indenyl) zirconium dichloride, diphenylmethylene-bis (9-fluorenyl) zirconium dichloride, isopropylidene-bis (9-fluorenyl) zirconium dichloride, cyclohexylidene-bis (9-fluorenyl) zirconium dichloride and the like can be mentioned.

In the above general formula (3), M ² represents titanium, zirconium or hafnium, and preferably zirconium.

Each R independently represents hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 7 to 4 carbon atoms.
It represents an arylalkyl group having 0, an alkylaryl group having 7 to 40 carbon atoms or an alkylsilyl group having 1 to 20 carbon atoms.

L represents a monovalent bidentate chelate anionic ligand having oxygen as a coordinating atom, which is produced from a compound represented by the following general formula (4), (5) or (6).

[0029]

[Chemical 5]

In the above formula, R ¹⁷ and R ¹⁹ may be the same or different, and are an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an alkyl group having 7 to 40 carbon atoms. A substituent selected from an arylalkyl group, an alkylaryl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, and R
¹⁸ is hydrogen, an alkyl group having 1 to 20 carbon atoms, and 6 to 6 carbon atoms
It is a substituent selected from an aryl group having 20 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, and an alkylaryl group having 7 to 40 carbon atoms. In addition, R ¹⁷ and R ¹⁸ may combine with each other to form a ring.

R ²⁰ and R ²² are selected from an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, and an alkylaryl group having 7 to 40 carbon atoms. Is a substituent, R ²¹ is hydrogen, carbon number 1
Is a substituent selected from an alkyl group having 20 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, and an alkylaryl group having 7 to 40 carbon atoms. Also,
R ²⁰ and R ²¹ may combine with each other to form a ring.

R ²³ , R ²⁴ , R ²⁶ and R ²⁷ may be the same or different, and are an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms and 7 to 7 carbon atoms. A substituent selected from an arylalkyl group having 40 carbon atoms and an alkylaryl group having 7 to 40 carbon atoms, R ²⁵ is hydrogen or 1 carbon atom
Is a substituent selected from an alkyl group having 20 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, and an alkylaryl group having 7 to 40 carbon atoms. Also,
R ²³ and R ²⁵ may combine with each other to form a ring.

X is hydrogen, an alkyl group having 1 to 20 carbon atoms,
It is composed of an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, or halogen. m represents an integer of 1 to 3. L
Alternatively, when there are a plurality of Xs, they may be the same or different, independently of each other.

Specific examples of the compound represented by the above general formula (3) are shown below. _{^{Cp * Zr (MeOCOCHCOOMe) Cl 2}} 1,2,3,4-Me 4 CpZr (MeOCOCHCO
OMe) Cl ₂ Cp ^* Zr (EtOCOCHCOOEt) Cl ₂ 1,2,3,4-Me ₄ CpZr (EtOCOCHCO
OEt) Cl ₂ Cp ^* Zr (PhOCOCHCOOPh) Cl ₂ 1,2,3,4-Me ₄ CpZr (PhOCOCHCO
OPh) Cl ₂ Cp ^* Zr (Me ₂ NCOCHCONMe ₂ ) Cl ₂ 1,2,3,4-Me ₄ CpZr (Me ₂ NCOCHCO
NMe ₂ ) Cl ₂ Cp ^* Zr (Et ₂ NCOCHCONEt ₂ ) Cl ₂ 1,2,3,4-Me ₄ CpZr (Et ₂ NCOCHCO
NEt ₂ ) Cl ₂ Cp ^* Zr (Ph ₂ NCOCHCONPh ₂ ) Cl ₂ 1,2,3,4-Me ₄ CpZr (Ph ₂ NCOCHCO
NPh ₂ ) Cl ₂ Cp ^* Zr (PhCOCHCOPh) Cl ₂ 1,2,3,4-Me ₄ CpZr (PhCOCHCOP
h) Cl ₂ Cp ^* Zr (PhCOCHCOMe) Cl ₂ 1,2,3,4-Me ₄ CpZr (PhCOCHCOM
e) Cl _2, 1,2,3,4-Me ₄ CpZr (MeOCOCHCO
Me) Cl ₂ Cp ^* Zr (EtOCOCHCOMe) Cl ₂ 1,2,3,4-Me ₄ CpZr (EtOCOCHCO
Me) Cl ₂ , Cp ^* Zr ((O =) C ₆ H ₉ COMe) Cl ₂

1,2,3,4-Me ₄ CpZr ((O
=) C ₆ H ₉ COMe) Cl ₂ CpZr (MeOCOCHCOOMe) Cl ₂ MeCpZr (MeOCOCHCOOMe) Cl ₂ 1,3-Me ₂ CpZr (MeOCOCHCOOMe)
Cl _2, 1,2,3-Me ₃ CpZr (MeOCOCHCOOM
e) Cl ₂ Cp ^* Zr (MeOCOCHCOOMe) Cl ₂ CpZr (EtOCOCHCOOEt) Cl ₂ MeCpZr (EtOCOCHCOOEt) Cl ₂ 1,3-Me ₂ CpZr (EtOCOCHCOOEt)
Cl _2, 1,2,3-Me ₃ CpZr (EtOCOCHCOOE
t) Cl ₂ Cp ^* Zr (EtOCOCHCOOEt) Cl ₂ CpZr (PhOCOCHCOOPh) Cl ₂ MeCpZr (PhOCOCHCOOPh) Cl ₂ 1,3-Me ₂ CpZr (PhOCOCHCOOPh)
Cl _2, 1,2,3-Me ₃ CpZr (PhOCOCHCOOP
h) Cl ₂ Cp ^* Zr (PhOCOCHCOOPh) Cl ₂ CpZr (Me ₂ NCOCHCONMe ₂ ) Cl ₂ MeCpZr (Me ₂ NCOCHCONMe ₂ ) Cl ₂ 1,3-Me ₂ CpZr (Me ₂ NCOCHCONM
_{e 2) Cl 2 1,2,3-Me} 3 CpZr (Me 2 NCOCHCONM
e ₂ ) Cl ₂

Cp ^* Zr (Me ₂ NCOCHCONM
e ₂ ) Cl ₂ CpZr (Et ₂ NCOCHCONEt ₂ ) Cl ₂ MeCpZr (Et ₂ NCOCHCONEt ₂ ) Cl ₂ 1,3-Me ₂ CpZr (Et ₂ NCOCHCONE
_{t 2) Cl 2 1,2,3-Me} 3 CpZr (Et 2 NCOCHCONE
t ₂ ) Cl ₂ Cp ^* Zr (Et ₂ NCOCHCONEt ₂ ) Cl ₂ CpZr (Ph ₂ NCOCHCONPh ₂ ) Cl ₂ MeCpZr (Ph ₂ NCOCHCONPh ₂ ) Cl ₂ 1,3-Me ₂ CpZr (Ph ₂ NCOCHCONP
_{h 2) Cl 2 1,2,3-Me} 3 CpZr (Ph 2 NCOCHCONP
^{_{h 2) Cl 2 Cp * Zr}} (Ph 2 NCOCHCONPh 2) Cl 2 CpZr (MeOCOCHCOOMe) Cl 2 CpZr (EtOCOCHCOOEt) Cl 2 CpZr (PhOCOCHCOOPh) Cl 2 CpZr (Me 2 NCOCHCONMe 2) Cl 2 CpZr (Et 2 NCOCHCONEt 2) _{Cl 2 CpZr (Ph 2 NCOCHCONPh 2} ) Cl 2 CpZr (PhCOCHCOPh) Cl 2 CpZr (PhCOCHCOMe) Cl 2 CpZr (MeOCOCHCOMe) Cl 2 CpZr (EtOCOCHCOMe) Cl 2 CpZr ((O =) C 6 H 8 COMe) Cl 2

In the structural formulas of the above specific examples, Cp is a cyclopentadienyl group, Cp ^* is a pentamethylcyclopentadienyl group, Ph is a phenyl group, Me is a methyl group,
Et represents an ethyl group.

Examples of the organoaluminum oxy compound (b) include at least one of the organoaluminum oxy compounds represented by the following general formulas (7), (8), (9) and (10).

[0039]

[Chemical 6]

In the above general formulas (7) to (10), R ^{28 to} R
³⁸ may be the same or different, each having 1 to 1 carbon atoms.
The hydrocarbon group of 8 and q represent the integer of 1-50.

Specific examples of these organoaluminum oxy compounds include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, isobutylaluminoxane, methylethylaluminoxane, methylbutylaluminoxane and methylisobutylaluminoxane. In particular, methylaluminoxane, isobutylaluminoxane and methylisobutylaluminoxane can be preferably used.

The alkyl aluminum oxy compound may contain an alkyl aluminum compound such as trimethyl aluminum, triethyl aluminum and triisobutyl aluminum.

Examples of the organic boron compound (c) include at least one compound selected from the organic boron compounds represented by the following general formulas (11) or (12).

(BR ³⁹ R ⁴⁰ R ⁴¹ ) _k (11) A (BR ⁴² R ⁴³ R ⁴⁴ R ⁴⁵ ) _k (12) In the general formulas (11) and (12), R ^{39 to} R ⁴⁵ are the same. Or may be different, and is a halogenated aryl group having 1 to 14 carbon atoms, a halogenated aryloxy group, or a hydrocarbon group, and A is a quaternary amine, a quaternary ammonium salt, a carbocation, or a metal having a valence of +1 to +4. It is a cation, and k represents an integer of 1 to 4.

Specific examples of the organic boron compound (c) include trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, triphenylphosphonium tetrakis (pentafluorophenyl).
Examples thereof include borate and triphenylcarbenium tetrakis (pentafluorophenyl) borate. Most preferred is triphenylcarbenium tetrakis (pentafluorophenyl) borate.

The preferred catalyst composition ratio of the transition metal metallocene compound (a) to the organoaluminum oxy compound (b) and / or the organoboron compound (c) is (a) :( b).
Or / and (c) = 1: 0.01 to 1: 10000. The catalyst may be prepared in advance by mixing in a suitable solvent under an atmosphere of an inert gas such as nitrogen or argon, or the components of (a), (b) or / and (c) may be separately prepared. It may be prepared in the reactor by implanting it in the reactor in which the monomer coexists. Suitable solvents for catalyst preparation include hydrocarbon solvents such as alkanes such as hexane and cyclohexane, and aromatic solvents such as toluene, benzene and ethylbenzene. Further, it is preferable to remove water and the like from these solvents in a pretreatment. The catalyst preparation temperature is -2.
The optimum temperature is 0 ° C to 150 ° C.

The method for copolymerizing the cyclic olefin resin constituting the transparent insulating substrate of the present invention is carried out in the presence of a monomer and a catalyst under reduced pressure, atmospheric pressure, or pressure under conditions of bulk, solution and slurry. It can be performed by any of the methods.

The temperature range suitable for copolymerization is -30 ° C to 260 ° C, preferably 0 ° C to 200 ° C.
Is. In addition, the copolymerization may be carried out in an atmosphere of an inert gas such as nitrogen or argon, or may be carried out in an atmosphere of ethylene, and ethylene and / or α-olefins and the above inert gas may be used. It does not matter even in a mixed atmosphere. Further, hydrogen may be allowed to coexist in addition to the above gas for controlling the molecular weight. Further, the catalyst component may be supported on a suitable carrier such as alumina, magnesium chloride or silica. Also, if desired,
A solvent may be used in the copolymerization. Suitable solvents for use in the copolymerization include hexane, cyclohexane, and other hydrocarbon solvents such as alkanes, and aromatic solvents such as toluene, benzene, and ethylbenzene.

A suitable catalyst amount in such copolymerization is [weight of polymer produced (kg)] / [catalyst (a) component 1 mol] =
It is an amount that gives a polymer of about 10 kg / 1 mol to 1,000,000 kg / 1 mol.

As a method for separating the polymer after the copolymerization of the cyclic olefin resin used in the present invention, for example, a polar solvent which is a poor solvent such as acetone or an alcohol mixed with an acid or an alkali is added to the copolymerization solution to carry out the copolymerization. Examples thereof include a method of precipitating and collecting the coalescence, a method of charging the reaction solution in hot water with stirring, and a method of distilling and collecting with the solvent, a method of directly heating the reaction solution and distilling the solvent.

In the present invention, a heat stabilizer, an antioxidant, a UV inhibitor, a lubricant and the like can be mixed and added to the cyclic olefin resin, if necessary. For example, examples of the antioxidant include a phenolic antioxidant, a phosphoric acid antioxidant, and a sulfur antioxidant,
Of these, phenolic antioxidants are preferably used. The antioxidants may be used alone or in combination of two or more. The blending amount is selected within the range that does not impair the object of the present invention and that the effect of the additive is expressed,
With respect to 100 parts by weight of the cyclic olefin resin, preferably 0.001 to 5 parts by weight, more preferably 0.01 to 1
Parts by weight.

Further, to the cyclic olefin resin according to the present invention, other polymer materials, inorganic reinforcing materials and the like can be mixed and added within a range not impairing the purpose. Examples of the inorganic material include glass fiber, glass wool, fullerene, carbon nanotube, talc, mica, kaolin, silica and alumina.

The method for molding the transparent insulating substrate of the present invention is not particularly limited, and known methods may be used, such as injection molding method, extrusion molding method, compression molding method, cast molding method and the like.

In the case of injection molding, it is preferable to dissolve carbon dioxide in a molten resin, reduce the melt viscosity, and inject it into a mold. At this time, it is preferable to suppress the foaming by injecting a gas such as carbon dioxide or nitrogen into the mold.

The surface smoothness (R
a) is preferably 20 nm or less, more preferably 15 nm or less.

The surface of the transparent insulating substrate of the present invention is subjected to discharge treatment, flame treatment, ozone treatment, ionizing actinic ray treatment, plasma treatment, oxidation in order to improve adhesion with other thin film materials provided on the surface. At least one or a plurality of treatments can be used in combination.

The thickness of the transparent insulating substrate of the present invention is 0.05 m.
It is preferably m or more and 1.0 mm or less, more preferably 0.1 mm or more and 0.7 mm or less, and particularly preferably 0.1 mm or more and 0.4 mm or less.

Since the transparent insulating substrate of the present invention has a glass transition temperature of 230 ° C. or higher and is excellent in heat resistance, it can sufficiently withstand a heat treatment process such as formation of an insulating film. Therefore, a T having at least a gate electrode, a gate insulating film, a semiconductor layer, a source electrode and a drain electrode on the transparent insulating substrate of the present invention.
By providing the FT and the pixel electrode electrically connected to the drain electrode without deforming the substrate, a lightweight active matrix substrate can be formed.

In the process of forming each member of the active matrix substrate, it is necessary to control the substrate temperature so that it does not exceed the glass transition temperature of the cyclic olefin resin. In addition to this, an undercoat layer or the like can be provided if necessary. Such an active matrix substrate is useful as an active driving substrate in a display element such as a liquid crystal display element, an organic EL display element, an FED display element. For example, when used as a liquid crystal display element, a liquid crystal alignment film can be formed after further forming a top coat layer on this substrate. Further, a polarizing plate can be provided on this substrate. Further, the transparent insulating substrate of the present invention,
It can also be used for a simple matrix substrate that constitutes a liquid crystal display element or the like.

In the liquid crystal display device of the present invention, the active matrix substrate of the present invention and a counter electrode substrate, which is separately formed and at least a transparent electrode is provided on a plastic transparent insulating substrate, are arranged to face each other, and a liquid crystal material is placed in the gap. It is composed by enclosing. The configuration of the liquid crystal display element will be described below.

In the liquid crystal display device of the present invention, the transparent insulating substrate forming the active matrix substrate and the transparent insulating substrate forming the counter electrode substrate are the same whether they are formed of the same material or different materials. It may be manufactured by a process or a different process, and its thickness may be the same or different.

Therefore, the resin material of the transparent insulating substrate constituting the counter electrode substrate according to the present invention is not particularly limited, and conventionally used polycarbonate, polymethylmethacrylate, polyethersulfone, so-called cyclic olefin resin. A conventionally known addition-copolymerization of norbornenes and α-olefins or a hydrogenated norbornene ring-opening metathesis polymer can be used.

Further, as in the case of the active matrix substrate of the present invention, a linear or branched α- having 2 to 4 carbon atoms is used.
When a random copolymer of an olefin and a cyclic olefin resin represented by the general formula (1) is used, its glass transition temperature is preferably 130 ° C or higher. More preferably 15
It is 0 ° C or higher. If the glass transition temperature is less than 130 ° C., it will be difficult to form and place a transparent electrode described later. The upper limit of the glass transition temperature is 350 ° C. Glass transition temperature is 350
When the temperature exceeds ℃, molding such as injection molding and extrusion molding becomes difficult. Therefore, when the above-mentioned cyclic olefin resin is used for the plastic transparent insulating substrate that constitutes the counter electrode substrate, the α-olefin used and the copolymerization composition of the cyclic olefin are determined according to the type thereof, but the α-olefin is preferably 1-55 mol%, cyclic olefin 45-99
It is mol%. Further, the weight average molecular weight M of the copolymer
It is preferable that w is in the range of 5,000 to 500,000. When the counter electrode substrate is formed of a cyclic olefin resin, it may be the same as or different from the cyclic olefin resin forming the opposing active matrix substrate.

If necessary, the transparent insulating substrate for the counter electrode substrate may be provided with a hard coat layer and a barrier layer for preventing infiltration of water and the like. Examples of the hard coat layer include a siloxane layer formed by a sol-gel reaction of a known organic silicate compound and a SiO _x layer. The barrier layer is made of an organic polymer such as polyvinyl alcohol or EVOH (polyethylene vinyl alcohol),
Any of inorganic thin films such as SiO _x may be used. By using a hard coat layer having a barrier property, it is possible to combine the hard coat layer and the barrier layer into one layer.

The material of the transparent electrode formed on the counter electrode substrate is not particularly limited, but for example, ITO,
Tin oxide, indium oxide, or the like is used and is provided by sputtering, patterning, or the like. An alignment film, a black matrix, a color filter, or the like can be provided on this substrate.

The active matrix substrate and the counter electrode substrate are bonded together via a spacer, and liquid crystal is injected into the gap and sealed to form a liquid crystal display element.

Since the substrate of the liquid crystal display device of the present invention is made of plastic, weight reduction and high impact resistance are realized, and it is very useful as a liquid crystal display device for portable use.

[0068]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these.

The various properties of the cyclic olefin resin and the properties of the substrate in this example were measured as follows.

(A) Copolymer composition Macromolecules, 31, 4674 (19)
98) and using a ¹³ C-NMR spectrum. The NMR measurement was performed in a d ₆ -benzene / 1,2,4-trichlorobenzene (1/1 vol ratio) solution.

(B) Molecular weight At 140 ° C. by GPC method, o-dichlorobenzene was used as a measuring solvent, UV / RI was used for detection, and polystyrene conversion was used.

(C) Glass transition temperature (Tg) Using a differential scanning calorimeter (DSC), under a nitrogen atmosphere, 20
It was determined at a temperature rising rate of ° C / min.

(D) Surface smoothness (Ra) The arithmetic mean roughness Ra was determined according to JIS B 0601.

(Metallocene Compound Production Example 1) In advance, -2
Dimethyl malonate (2.25 mmol) was slowly added dropwise to dehydrated diethyl ether (20 ml) in which NaH (2.25 mmol) cooled to 0 ° C was dispersed, and the temperature was raised to 0 ° C with stirring. A dehydrated toluene solution (20 m) containing methylcyclopentadienyl zirconium trichloride (2.25 mmol) was added to the obtained dispersion.
1) was added dropwise and stirred for 2 hours. The solvent was evaporated, the mixture was extracted with dehydrated toluene, filtered, and the filtrate was concentrated and recrystallized to obtain complex-1.

(Metallocene Compound Production Example 2) In advance, -2
2-Acetylcyclohexanone (2.25 mmol) was slowly added dropwise to dehydrated diethyl ether (20 ml) in which NaH (2.25 mmol) cooled to 0 ° C was dispersed, and the temperature was raised to 0 ° C with stirring. A dehydrated toluene solution (2 containing cyclopentadienyl zirconium trichloride (2.25 mmol) was added to the obtained dispersion liquid.
0 ml) was added dropwise and the mixture was stirred for 2 hours. The solvent was distilled off, the mixture was extracted with dehydrated toluene, filtered, and the filtrate was concentrated and recrystallized.
Complex-2 was obtained.

(Resin Production Example 1) 250 ml of a purified norbornene toluene solution (100 g of norbornene) was introduced into a 2000 ml autoclave whose interior was degassed in vacuum and purged with nitrogen. Then, 100 ml of a purified toluene solution containing 5 mmol of MMAO (methylaluminoxane manufactured by Tosoh Akzo) was introduced into the autoclave, and then 0.37 MPa of ethylene gas was introduced. Keeping the internal temperature of the autoclave at 80 ° C, the metal complex is
100 ml of a purified toluene solution containing 5 μmol of 1 was added to the autoclave to start the polymerization reaction. While maintaining the internal temperature and ethylene pressure of the autoclave, stirring 60
Polymerization was carried out for a minute to obtain cyclic olefin resin-1.

The cyclic olefin resin-1 thus obtained had a norbornene content of 85 mol% and a glass transition temperature of 253.
C., the weight average molecular weight Mw was 38,000.

(Resin Production Example 2) Ethylene pressure was 0.29 M
Polymerization was performed in the same manner as in Resin Production Example 1 except that Pa was used to obtain cyclic olefin resin-2.

The cyclic olefin resin-2 thus obtained had a norbornene content of 91 mol% and a glass transition temperature of 275.
C., the weight average molecular weight Mw was 34,000.

(Resin Production Example 3) Complex-2 as a metal complex
Was used, and polymerization was carried out in the same manner as in Resin Production Example 1 except that the ethylene pressure was changed to 0.52 MPa, to give a cyclic olefin resin-3.
Got

The cyclic olefin resin-3 thus obtained had a norbornene content of 55 mol% and a glass transition temperature of 154.
C., the weight average molecular weight Mw was 72,000.

(Example 1) Resin The cyclic olefin resin-1 obtained in Production Example 1 was used as a raw material and injection-molded using the mold shown in FIG. In FIG. 1, 1 is a mold, 1a is a fixed mold, 1b
Is a movable mold, 2 is a mold cavity, 3 is a parting surface,
4 is a carbon dioxide supply / discharge line, 5 is a sprue, 6
Is a runner, 7 is an ejector pin, 8 is a sealing material, 9
Is a solenoid valve for supply, 10 is a solenoid valve for opening, 11 is a space for releasing carbon dioxide in the mold cavity 2, 12
Is a slit. Hereinafter, the injection molding process of this embodiment will be described.

First, with the mold 1 shown in FIG. 1 closed, the supply solenoid valve 9 on the carbon dioxide supply / discharge line 4 is opened to supply carbon dioxide into the mold cavity 2. When carbon dioxide is supplied into the cylinder of the injection molding machine to absorb and dissolve the carbon dioxide in the molten resin and the resin is injected into the mold cavity 2, the carbon dioxide supply / discharge line 4
By opening the solenoid valve 10 for opening which is connected to at the same time as the resin filling, the carbon dioxide in the mold cavity 2 has a flow reverse to that at the time of supply and passes through the slit 12 to supply carbon dioxide. It returns to the discharge line 4 and is discharged to the outside of the mold.

The cavity of the mold used in this example has a rectangular flat plate shape, and its dimension is 40 on the long side.
mm, the short side portion is 30 mm, and the thickness is 200 μm.

Specific molding conditions will be described below. Molding machine: Sumitomo Heavy Industries, Ltd. SG125M-HP Molding machine cylinder temperature: 400 ℃ Injection speed: 500 mm / sec Resin holding pressure: 7.8 MPa (hydraulic oil pressure) Resin holding time: 3 sec Cooling time: 10 sec Mold temperature: 110 ℃ Carbon dioxide injection pressure into the mold cavity: 0.5 MPa Carbon dioxide injection pressure into the molding machine cylinder: 8 MPa

R of the transparent insulating substrate obtained under the above injection conditions
a was 3 nm.

Example 2 The same procedure as in Example 1 was carried out except that the cyclic olefin resin-2 obtained in Resin Production Example 2 was used as the raw material and the carbon dioxide injection pressure into the molding machine cylinder was changed to 12.6 MPa. Injection molding was carried out to obtain a transparent insulating substrate.

Ra of the obtained transparent insulating substrate was 5 nm.
Met.

Example 3 An inorganic gas barrier layer made of SiO _x was formed on one surface of the transparent insulating substrate obtained in Example 1 by a sputtering method. Subsequently, a siloxane-based hard coat containing methyltrimethoxysilicate as a main component was applied by a dip method and cured at 150 ° C. for 1 hour.

Subsequently, T of the sectional structure schematically shown in FIG.
An FT array was formed on the substrate. In FIG. 2, 21 is a gate electrode, 22 is a gate insulating film, 23 is a semiconductor layer, 24 is a pixel electrode, 25 is a drain electrode, 26 is a source electrode, 27
Is a protective film and 28 is a transparent insulating substrate.

First, a Ta metal film was formed by sputtering, and then the metal film was etched by a photolithography technique to form a gate electrode 21. Then, the gate insulating film 22 made of SiO _{x is} formed by the CVD method.
Was formed. Further, an amorphous silicon (a-Si) film was formed by the CVD method and phosphorus was doped. The a-Si film was etched by using a photolithography technique to form the semiconductor layer 23. Subsequently, ITO was sputtered and a pixel electrode 24 was formed by a photolithography process. Then, after forming aluminum by sputtering, a source electrode 26 and a drain electrode 25 were formed by using a photolithography technique. Finally, a SiN _x film is formed by CVD and patterned by photolithography technology,
A protective film 27 was formed to obtain an active matrix substrate.

The active matrix substrate obtained as described above is the transparent insulating substrate 28 in the TFT forming process.
A good substrate was obtained without any deformation or cracking of the thin film.

Example 4 An inorganic gas barrier layer made of SiO _x was formed on one surface of the transparent insulating substrate obtained in Example 2 by the sputtering method. Subsequently, a siloxane-based hard coat containing methyltrimethoxysilicate as a main component was applied by a dip method and cured at 150 ° C. for 1 hour. Then, a TFT array was formed in the same procedure as in Example 3 to obtain an active matrix substrate.

The obtained active matrix substrate is TF
A good substrate was obtained without deformation of the transparent insulating substrate or generation of cracks in the thin film in the T formation step.

Comparative Example 1 An attempt was made to form a TFT array in the same manner as in Example 3 except that a polycarbonate sheet having a thickness of 200 μm was used as a transparent insulating substrate. However, since the heat resistance of the substrate is insufficient, TF
Forming a T-array has been difficult.

Example 5 An inorganic gas barrier layer made of SiO _x was formed on one surface of a 200 μm thick sheet-like substrate made of the cyclic olefin resin-3 obtained in Resin Production Example 3 by a sputtering method. Subsequently, a siloxane-based hard coat containing methyltrimethoxysilicate as a main component was applied by a dip method and cured at 120 ° C. for 2 hours. A color filter is formed on this substrate, and a transparent electrode made of ITO is formed by sputtering,
A counter electrode substrate was formed.

The active matrix substrate obtained in Example 3 and the counter electrode substrate prepared in this example were each coated with a polyimide solution, dried and baked, and then rubbed to form an alignment film.

Subsequently, a sealing material made of an ultraviolet curable resin is printed on the outer periphery of the active matrix substrate, a gap agent in which polymer beads are dispersed is applied, the active matrix substrate and the counter electrode substrate are bonded together, and ultraviolet rays are irradiated. The sealing material was cured to form a cell.
Finally, a liquid crystal material was injected into the cell by a vacuum method and the injection port was sealed to produce a plastic liquid crystal display element.

The liquid crystal display device obtained as described above was a good panel with no problem in appearance.

[0100]

Since the transparent insulating substrate of the present invention is transparent and has excellent heat resistance, it does not deform even in the process of forming a TFT array, and an active matrix substrate can be easily used in place of a conventional glass substrate. Can be formed. Therefore, it becomes possible to provide a display element such as a liquid crystal display element which is lighter in weight and excellent in impact resistance by using the active matrix substrate.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a mold structure used for resin injection molding in an example of the present invention.

FIG. 2 is a schematic cross-sectional view showing the structure of a TFT array of an active matrix substrate manufactured in an example of the present invention.

[Explanation of symbols]

1 Mold 1a Fixed Mold 1b Movable Mold 2 Mold Cavity 3 Mold Parting Surface 4 Carbon Dioxide Supply / Discharge Line 5 Sprue 6 Runner 7 Ejector Pin 8 Sealant 9 Supply Solenoid Valve 10 Open Solenoid Valve 11 Mold Cavity Space for letting out carbon dioxide inside 12 Slit 21 Gate electrode 22 Gate insulating film 23 Semiconductor layer 24 Pixel electrode 25 Drain electrode 26 Source electrode 27 Protective film 28 Transparent insulating substrate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1333 500 G02F 1/1333 500 5F110 G09F 9/35 G09F 9/35 H01L 29/786 C08F 210: 00 // (C08F 232/00 B29K 23:00 210: 00) C08L 45:00 B29K 23:00 H01L 29/78 626C C08L 45:00 F Term (reference) 2H090 JA06 JB03 JC07 JC08 JC09 JD17 4F071 AA15X AA20X AA39X AA76 AF30 AH13 BB05 BC03 4F206 AA03E JA07 JF06 4J100 AA01Q AA02Q AA03Q AR05P AR11P DA25 DA62 JA46 5C094 AA15 AA36 BA03 BA43 CA19 DA14 DA15 DB04 EA04 EA07 EB01 5F110 AA30 BB01 CC05 CC07 DD01 DD06 DD12 DD13 DD17 EE04 EE44 FF02 FF29 GG02 GG15 GG32 GG44 HK03 HK33 NN02 NN24 NN35 NN72

Claims (5)

[Claims] 1. A random copolymer containing, as a monomer component, a linear or branched α-olefin having at least 2 to 4 carbon atoms and a cyclic olefin represented by the following general formula (1): A transparent insulating substrate formed by molding a cyclic olefin resin having a glass transition temperature of 230 ° C. or higher. [Chemical 1] (In the formula, n is 0, 1, or 2, and R ^{1 to} R ^1
8 independently represents hydrogen, a halogen atom, or a hydrocarbon group, and R ^{9 to} R ¹² each independently represents hydrogen, a halogen atom, a hydrocarbon group, or only R ⁹ or R ^{10, and} only R ¹¹ or R ^12. Is a hydrocarbon group substituted with a double bond,
R ^{9 to} R ¹² may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond. Further, the above hydrocarbon group may be substituted with a halogen atom. ) 2. The transparent insulating substrate according to claim 1, wherein the surface smoothness Ra is 20 nm or less. 3. The transparent insulating substrate according to claim 1, which is injection-molded by dissolving carbon dioxide in the cyclic olefin resin and injecting the resin into a mold. 4. A thin film transistor having at least a gate electrode, a gate insulating film, a semiconductor layer, a source electrode and a drain electrode on the transparent insulating substrate according to claim 1, and an electrically connected drain electrode. An active matrix substrate provided with connected pixel electrodes. 5. The active matrix substrate according to claim 4 and a counter electrode substrate provided with at least a transparent electrode on a plastic transparent insulating substrate are arranged so as to face each other, and a liquid crystal material is sealed in a gap therebetween. Liquid crystal display device.