JP2002220525A - Optical polymer sheet and display element substrate produced using the sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical polymer sheet which can be applied to a liquid crystal element substrate or the like, has good transparency, heat resistance, solvent resistance and liquid crystal resistance, and has excellent adhesivity to inorganic films. SOLUTION: This optical polymer sheet comprises 99 to 70 pts.wt. of a dicyclopentadiene skeleton-having monomer represented by the general formula (1) [X1 and X2 are each a group of formula (3) or a group of formula (4)] and 1 to 30 pts.wt. of a polycarbonate resin which contains repeating units represented by the general formula (2) (R1, R2, R3 and R4 are each H, a 1 to 7C alkyl or an aralkyl, and may be identical or different each other) and is not dissolved in dimethyl sulfoxide (DMSO), when heated at 60 deg.C for 1 hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to transparency, heat resistance,
The present invention relates to a resin composition having excellent solvent resistance and liquid crystal resistance, a polymer sheet for an optical material obtained by curing the resin composition, and a substrate for a thin film transistor display element. It can be suitably used for lenses, optical disk substrates, optical waveguides, plastic liquid crystal substrates, plastic color filters, plastic solar cell substrates, touch panels, optical elements, and the like.

[0002]

2. Description of the Related Art Liquid crystals, plasma displays, electroluminescence (EL), fluorescent display tubes, light emitting diodes
A glass plate is often used as a display substrate such as a glass substrate. However, considering a large area, it is easy to crack,
In recent years, many attempts have been made to use a plastic material instead of a glass plate due to problems such as being unbendable, having a large specific gravity, and being unsuitable for weight reduction. These plastic materials are inferior to the glass plate in solvent resistance, liquid crystal resistance, heat resistance, and the like. Therefore, attempts have been made to compensate for these disadvantages by providing various inorganic and / or organic barrier layers. However, especially in the manufacturing process of a TFT liquid crystal display substrate, unlike a liquid crystal display substrate such as TN or STN, dimethyl sulfoxide (hereinafter abbreviated as DMSO) used for removing a resist and a developer for photolithography are used. It must have resistance to tetramethylammonium hydroxide (hereinafter abbreviated as TMAH) and also to liquid crystal mixture itself used for a display element, and there is no plastic material suitable for a TFT liquid crystal display substrate. .

[0003]

The problem to be solved by the present invention is to improve the transparency applicable to a liquid crystal display element substrate and the like.
An object of the present invention is to provide an optical polymer sheet having heat resistance, solvent resistance, and liquid crystal resistance, and having excellent adhesion to an inorganic film such as a gas / water vapor impermeable barrier and a transparent electrode.

[0004]

Means for Solving the Problems The present inventors have found that a transparent plastic sheet obtained by crosslinking a polyfunctional acrylate or polyfunctional methacrylate monomer is excellent in solvent resistance, liquid crystal resistance, heat resistance, etc. In addition, it was found that by co-polymerizing a solvent having solvent resistance with a polycarbonate resin, it was possible to impart properties excellent in adhesion to an inorganic film. That is, the present invention provides (1)
It contains 99 to 70 parts by weight of a monomer having a dicyclopentadiene skeleton represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and is heated at 60 ° C. for 1 hour in dimethyl sulfoxide (DMSO). An optical polymer sheet comprising 1 to 30 parts by weight of a polycarbonate resin which does not dissolve even

[0005]

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[0006]

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(2) The polymer sheet for optical use according to claim 1, which has been crosslinked by one or more crosslinking methods selected from organic peroxides, electron beams and ultraviolet rays.
A substrate for a display element using the optical polymer sheet according to any one of claims 1 to 4, and (4) a substrate for a thin film transistor display element using the optical polymer sheet according to claim 1 or 2.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate resin of the present invention has the general formula (3)

[0009]

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The bisphenol (c) represented by the following formula is used. Here, various bisphenols (c) represented by the general formula (3) can be applied. Specific examples include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5 -Dimethylphenyl) fluorene, 9,9-bis (4-hydroxy-3-ethylphenyl) fluorene, and the like. Among these, 9,9-bis (4-hydroxyphenyl) fluorene is particularly preferred. These bisphenols may be used alone,
Also, two or more kinds may be used in combination.

The polycarbonate resin of the present invention may be a copolymer of bisphenol (c) represented by the general formula (3) and another bisphenol. Other bisphenols include bis (4-hydroxyphenyl) methane [commonly known as bisphenol F], 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl) propane [commonly known as bisphenol A] , 1,
1-bis (4-hydroxyphenyl) cyclohexane,
4,4-dihydroxydiphenyl ether, 4,4-dihydroxydiphenylsulfone [commonly known as bisphenol S], 4,4-dihydroxydiphenylsulfide,
4,4-dihydroxybiphenol and the like.
Further, the polycarbonate resin of the present invention may contain an unsaturated group in order to improve crosslinkability. Examples of the polycarbonate resin containing an unsaturated group include those having an unsaturated group added to the terminal and those copolymerized with bisphenol containing an unsaturated group. Examples of the terminal unsaturated group include an allyl group, an acryl group, a methacryl group, and a maleimide group. Examples of bisphenols containing an unsaturated group include bis (3-allyl-4-hydroxyphenyl) methane (commonly called diallyl bisphenol F),
1,1-bis (3-allyl-4-hydroxyphenyl)
Ethane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane (commonly called diallylbisphenol A),
Bis (3-allyl-4-hydroxyphenyl) ether, bis (3-allyl-4-hydroxyphenyl) sulfone (commonly called diallylbisphenol S), bis (3-allyl-4-hydroxyphenyl) sulfide, 3,3-
Diallyl-4, 4-hydroxybiphenol and the like can be exemplified.

The polycarbonate resin of the present invention can be produced by a method commonly used in the production of ordinary polycarbonates,
For example, it can be synthesized using an interfacial polycondensation method using phosgene or a phosgene derivative and a transesterification method (transesterification method). Among these, the interfacial polycondensation method is preferred. As an interfacial polycondensation method using phosgene or a phosgene derivative, for example, bisphenol (c)
Phosgene or a phosgene derivative is introduced into a mixed solution of an alkaline aqueous solution containing a predetermined ratio of phenol and phosgene or phosgene, or a polycarbonate oligomer of bisphenol (c) is previously reacted with bisphenol (c) Derivatives are synthesized beforehand, and these inert organic solvents and bisphenol (c)
And a method of reacting with an alkaline aqueous solution containing a predetermined ratio of Examples of the phosgene derivative include phosgene, triphosgene, bromophosgene, bis (2,4,6-trichlorophenyl) carbonate, and trichloromethyl formate. Of these, phosgene or triphosgene is particularly preferred.

The number average molecular weight of the polycarbonate resin of the present invention is preferably 5,000 to 200,000, and 10,000 to 15
It is more preferably 10,000, and most preferably 15,000 to 100,000. If the number average molecular weight is low, the polymer tends to be brittle, and if it is too high, the viscosity tends to be high and moldability tends to be poor.

The monomer having a dicyclopentadiene skeleton according to the present invention has a structure represented by the general formula (1), and each of X ¹ and X ² may be a methylene oxide-modified acryloyl or methacryloyl group. Of these, a methylene oxide-modified acryloyl group (—CH ₂ OCOCHCH ₂ ) is preferred.

A monomer (a) having a dicyclopentadiene skeleton used in the present invention and a polycarbonate resin (b)
Is a percentage by weight of (a) / (b), and is 99/1 to 7
0/30, preferably 98/2 to 80/20
Is more preferable, and 97/3 to 85/15 is still more preferable. When the ratio of (a) is low, the adhesion to the inorganic film for suppressing gas / water vapor permeability tends to be poor,
If it is too high, the compatibility with (b) becomes poor, and a solvent is required for uniform blending. (A) and (b)
Is preferably 60 to 130 ° C., and 70 to 130 ° C.
-120 ° C is more preferred, and 80-110 ° C is still more preferred. If the temperature is too low, the compatibility will be poor,
Conversely, if it is too high, the monomer may gel.

The monomer (a) having a dicyclopentadiene skeleton of the present invention and the polycarbonate resin (b) are
It can be blended without solvent, and the film thickness can be made uniform at the time of molding, and the surface roughness as seen when using the solvent, an increase in outgas due to the residual solvent, and a lack of morphology in the direction in which the solvent evaporates. There is no problem such as uniformity.

As a method for crosslinking the monomer having a dicyclopentadiene skeleton and the polycarbonate resin, any method can be applied as long as it can be polymerized by the reaction of unsaturated groups. Among them, from the viewpoint of transparency, organic peroxides, electron beams, and ultraviolet rays are preferred, and crosslinking by heating using an organic peroxide is particularly preferred. The polycarbonate copolymer composition of the present invention is an organic peroxide, an electron beam,
A member having excellent solvent resistance can be obtained by crosslinking with ultraviolet light or the like. As an example of a method of forming the member, directly cast on a roll or a belt, and further, using two opposed flat plates that can transmit an electron beam or ultraviolet light made of polished glass or the like, form a cavity with a spacer or the like, The resin can be injected into an injection mold having a peripheral portion sealed, cross-linked by irradiation with an electron beam or ultraviolet light, or heated to be molded. Alternatively, after the resin composition is extruded, the resin composition may be cross-linked by electron beam, ultraviolet light, or heating to be molded.

(Crosslinking of Organic Peroxide) Crosslinking with an organic peroxide can be directly applied to the usual crosslinking method with an organic peroxide applied to unsaturated polyesters and the like. As the organic peroxide used in the present invention, known compounds such as dialkyl peroxide, acyl peroxide, hydroperoxide, ketone peroxide and peroxyester can be used. Specifically, dicumyl peroxide, α, α′-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane,
2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, di-t-hexyl peroxide,
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, t-butylperoxy-2
-Ethylhexanoate, t-butylperoxyisopropyl monocarbonate and the like.

The compounding amount of the organic peroxide is (a) + (b)
0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of If the amount of the organic peroxide is too small, sufficient crosslinking cannot be obtained and the solvent resistance tends to be poor. If the amount is too large, the appearance of the crosslinked product tends to deteriorate.

(Crosslinking by Electron Beam) The polycarbonate resin composition of the present invention can be crosslinked by radiation such as an electron beam. The irradiation amount of the electron beam is 100 kGy to 2000
The range of kGy is preferable, and 500 kGy to 1500 kG
The range of y is more preferable, but there is no particular problem if the properties of the obtained crosslinked product do not deviate from the intended range. As the radiation, electron beams from various electron beam accelerators are preferable, but α-rays, β-rays, γ-rays from radioisotopes are preferable.
Radiation such as radiation can also be used.

(Crosslinking by Ultraviolet Light) The polycarbonate resin composition of the present invention can be crosslinked by ultraviolet light by adding a photopolymerization initiator. Examples of the photopolymerization initiator include benzophenone, benzoin methyl ether, benzoin methyl ether, benzoin isopropyl ether, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethyl Benzoyldiphenylphosphine oxide and the like. Two or more of these photopolymerization initiators may be used in combination.

The amount of the photopolymerization initiator added is (a) + (b)
The amount is preferably 0.02 to 5 parts by weight, more preferably 0.05 to 1 part by weight, based on 100 parts by weight. If the amount of the photopolymerization initiator is small, there is a tendency that crosslinking cannot be sufficiently performed,
If it is too large, the hue tends to deteriorate. The irradiation amount of the ultraviolet ray is arbitrary as long as the photopolymerization initiator generates a radical, but may be 0.1 to match the type and amount of the photopolymerization initiator.
It is preferable to irradiate in the range of -200 J.

In the present invention, thermal polymerization may be used in combination with irradiation of an electron beam or ultraviolet rays for the purpose of promptly completing crosslinking. That is, the composition is heated to 30 to 300 ° C. simultaneously with or after the irradiation with the electron beam or ultraviolet light. in this case,
An organic peroxide may be added. In the present invention, the completion of the polymerization reaction and the internal strain generated during the polymerization can be reduced by heating the crosslinked product after the crosslinking by irradiation with an electron beam or an ultraviolet ray. The heating temperature is preferably selected as appropriate according to the composition of the crosslinked product and the glass transition temperature.

In order to improve heat stability, weather resistance, durability, water resistance, corrosion resistance and the like, the polycarbonate copolymer composition of the present invention contains, in addition to the above-mentioned components, an ultraviolet absorber and a light stabilizer. , Antioxidants, defoamers, leveling agents, release agents,
Additives such as ion scavengers can be added to further improve performance.

[0025]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. [Synthesis of Polycarbonate Resin] In a 1 L four-necked flask (with a stirrer, a reflux tube, a gas introduction tube, and a dropping funnel), 14.0 g of bisphenolfluorene, 04.0 ml of tetrabutylammonium bromide were added to 240 ml of a 1M aqueous sodium hydroxide solution. .007 g was dissolved, and 200 ml of 1,2-dichloroethane was added to the solution. Next, a solution in which 4.158 g of triphosgene was dissolved in 50 ml of 1,2-dichloroethane was added dropwise over 1 hour, and the mixture was stirred for 30 minutes to carry out a reaction. After the reaction is completed, the organic phase is separated, washed with water,
Poured into methyl ethyl ketone. The precipitate was filtered, washed with acetone and dried. As a result, a polycarbonate resin having a number average molecular weight of 23,000 and a glass transition temperature Tg = 281 ° C. was obtained.

<Example 1> The above polycarbonate resin 1
g, dicyclopentadienyl diacrylate (Toagosei
Irgacure 18 as a photopolymerization initiator in 19 g
After adding 0.1 g of 4 (manufactured by Ciba Specialty Chemical) and stirring and mixing at 100 ° C. for 20 minutes, the mixture was poured into a 0.4 mm-thick frame formed on a release-treated glass plate. 1000mJ / c after placing the mold release glass from above
The sheet was cured by irradiating it with UV light of m ^2, the sheet was peeled from the glass, and further heat-treated on a stainless steel plate in an oven at 240 ° C. under a nitrogen atmosphere for 3 hours to obtain a sheet having a thickness of 0.4 mm.

Example 2 Polycarbonate resin was replaced with 2
g, and a sheet was obtained in the same manner as in Example 1 except that the amount of dicyclopentadienyl diacrylate was changed to 18 g.

Example 3 1 g of polycarbonate resin,
To 19 g of dicyclopentadienyl diacrylate was added 0.1 g of perhexa 25B (manufactured by Shikoku Chemicals) as an organic peroxide, and the mixture was stirred and mixed at 100 ° C. for 20 minutes, and then formed on a release-treated glass plate. Was injected into a 0.4 mm thick frame. After putting the mold release glass from the top,
Cured in an oven under a nitrogen atmosphere at 110 ° C. for 3 hours, peeled the sheet from the glass, and further cured on a stainless steel plate for 250 hours.
Heat treated in an oven under nitrogen atmosphere for 3 hours.
A 4 mm sheet was obtained.

<Example 4> 1 g of a polycarbonate resin,
19 g of dicyclopentadienyl diacrylate was injected into a 0.4 mm thick frame formed on a glass plate subjected to a mold release treatment. After placing the release-treated glass from the upper part, it is cured by irradiating it with an electron beam of about 500 kGy from the upper part, the sheet is peeled from the glass, and then 270 on a stainless steel plate.
Heat treated in an oven under nitrogen atmosphere for 3 hours.
A 4 mm sheet was obtained.

Comparative Example 1 10 g of polycarbonate resin
Was dissolved in 30 g of chloroform, cast on a glass plate subjected to a mold release treatment, and dried in an oven under a nitrogen atmosphere.
The sheet was peeled off by heating and drying at 00 ° C. for 3 hours, and further heat-treated on a stainless steel plate in an oven under a nitrogen atmosphere at 240 ° C. for 3 hours to obtain a sheet having a thickness of 0.4 mm.

Comparative Example 2 Irgacure 1 was added to 20 g of dicyclopentadienyl diacrylate as a photopolymerization initiator.
84 g was added, and the mixture was stirred and mixed at 100 ° C. for 20 minutes.
Was injected into the frame. After placing the release-treated glass from above, it is cured by irradiating with 1000 mJ / cm ² UV light, the sheet is peeled off from the glass, and further heat-treated on a stainless steel plate at 240 ° C. in an oven under a nitrogen atmosphere for 3 hours. And a sheet having a thickness of 0.4 mm.

The sheet prepared as described above was evaluated for color, solvent resistance (DMSO), alignment agent resistance, liquid crystal resistance, heat resistance (Tg), and adhesion to the inorganic film by the following methods. did.

<Evaluation Method> Color: The appearance was visually observed. Solvent resistance: 40 ° C. dimethyl sulfoxide (DM
SO) The sample was immersed in the solution and left for 60 minutes. After taking out the sample, the external appearance was visually observed. Alignment agent resistance: A sample is placed on a spin coater. After dropping CRD-8201 (manufactured by Sumitomo Bakelite) on the surface, spin coating was performed at 2500 rpm. 18
After drying at 0 ° C. for 60 minutes, the appearance was visually observed. Liquid crystal resistance: ZLI-47 manufactured by Merck on the surface of the substrate
92 is dropped. Put in an oven at 120 ° C. and leave for 60 minutes. After removing the sample, the external appearance is visually observed. Heat resistance (Tg): The maximum value of tan δ at 1 Hz of a viscoelasticity measuring device DMS-210 (manufactured by Seiko Instruments) was defined as the glass transition point (Tg). Adhesion with Inorganic Film: After repeating the treatment of the sheet provided with the inorganic film by sputtering twice at 210 ° C. × 2 hours and hot water at 95 ° C. × 30 minutes twice, the occurrence of cracks in the inorganic film by an electron microscope (SEM) Was observed. Table 1 shows the evaluation results.

[0034]

[Table 1]

As is evident from the results in Table 1, Examples 1 to 4 all have improved DMSO resistance and NMP resistance, which are disadvantages of the conventional polycarbonate comprising bisphenolfluorene, and have a Tg. It had heat resistance of 250 ° C. or more, transparency of 88% or more in light transmittance, and liquid crystal resistance. In addition, even when an inorganic film for suppressing gas / water vapor permeability was laminated, cracks did not occur and adhesion to the inorganic film was good. From the above results, it has been clarified that the optical polymer sheet of the present invention is a sheet suitable for a display element substrate, particularly a TFT liquid crystal display substrate.

Example 5 A sheet-like substrate was prepared by the method shown in Examples 1-4, and a silicon oxide-based inorganic layer was deposited as an oxygen and water vapor barrier. Using this as a polymer substrate, a thin film transistor (hereinafter abbreviated as TFT) array was produced in accordance with the method described in Japanese Patent Application Publication No. 10-512104. During this manufacturing process, DMSO was used as a solvent for removing the resist and TMA was used as a developing solution for photolithography.
Although H was used, no modification such as blistering or clouding was observed on the polymer substrate. Further, a color filter substrate was produced by the same photolithography technique. Again, DMSO and TMAH were used,
As with the TFT array, no denaturation such as blistering or clouding was observed.

Next, after washing both substrates of the TFT and the color filter, an orientation film treatment is performed, an epoxy adhesive is applied to the color filter side by screen printing, a spacer is sprayed on the TFT substrate, and the two are laminated. Was.
Thereafter, liquid crystal was injected from the previously opened gap between the substrates by a vacuum injection method. As is well known, the liquid crystal injection method is a method in which a gap (opening) between both substrates is immersed in liquid crystal and injected by a pressure difference, and a substrate portion around the opening is always immersed in liquid crystal. After this operation, no denaturation was observed on both substrates. As described above, by using the optical polymer sheet of the present invention for a display element substrate, a good TF can be obtained.
It was proved that a T liquid crystal cell could be obtained.

[0038]

The optical polymer sheet of the present invention is excellent in transparency, solvent resistance, liquid crystal resistance, heat resistance, and adhesion to an inorganic film, and is suitably used for a liquid crystal display substrate instead of a glass substrate. The liquid crystal display device manufactured using the optical polymer sheet of the present invention showed good performance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/18 CFD C08J 5/18 CFD G02B 1/04 G02B 1/04 F term (Reference) 4F071 AA33 AA50 AH19 BA02 BB12 BC01 BC02 4J002 BG04X BG05X CG01W EH076 EK017 EK037 EK047 EK087 FD147 FD206 GP00 4J011 PA89 PC02 PC08 QA18 RA07 RA10 SA06 SA22 SA34 SA61 SA84 UA01 UA03 UA04 VA01 WA01 4A0 DB07 GA07 BB12A BB12B GA02 HC01 HC03 HC05B

Claims (4)

[Claims] 1. A composition comprising 99 to 70 parts by weight of a monomer having a dicyclopentadiene skeleton represented by the following general formula (1), a repeating unit represented by the following general formula (2), and a dimethyl sulfoxide (DMSO) at 60 ° C. An optical polymer sheet comprising 1 to 30 parts by weight of a polycarbonate resin which does not dissolve even when heated for 1 hour. Embedded image Embedded image 2. The optical polymer sheet according to claim 1, which has been crosslinked by one or more crosslinking methods selected from organic peroxides, electron beams and ultraviolet rays. 3. A display element substrate using the optical polymer sheet according to claim 1 or 2. 4. A substrate for a thin-film transistor display device, comprising the optical polymer sheet according to claim 1.