SUBSTRATE FOR HEAT-RESISTANT ELECTRONIC DEVICE

Abstract

The present disclosure proposes an improved heat resistant base for electronic equipment having transparency, heat resistance and mechanical strength and also having superior optical properties and quality, and thereby capable of replacing a transparent glass base.

The present disclosure is accomplished by the heat resistant base for electronic equipment including a polyimide-based resin and a hollow particle, wherein a plurality of the hollow particles are dispersed and present in the polyimide-based resin, and the hollow particle has an average particle diameter of greater than or equal to 10 nm and less than or equal to 300 nm.

Claims

1. A heat resistant base for electronic equipment, the base comprising: a polyimide-based resin; and hollow particles, wherein the hollow particles are dispersed in the polyimide-based resin; and the hollow particles have an average particle diameter of greater than or equal to 10 nm and less than or equal to 300 nm.

2. The heat resistant base for electronic equipment of claim 1, wherein the polyimide-based resin is a modified polyimide containing a terminal group represented by the following Chemical Formula 1: ##STR00012## in the Chemical Formula 1, D is a thermo-curable or photo-curable functional group; R is a divalent or higher organic group; and n is an integer of at least 1.

3. The heat resistant base for electronic equipment of claim 2, wherein the thermo-curable or photo-curable functional group in the terminal group of the Chemical Formula 1 is from a reaction of a terminal group of an acid dianhydride of a polyimide, and a compound of the following Chemical Formula 2:
O═C═N—RD].sub.n  [Chemical Formula 2] in the Chemical Formula 2, D, R and n are as defined in claim 2.

4. The heat resistant base for electronic equipment of claim 12, wherein the polyimide-based resin is a modified polyimide that is from a reaction of 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB) and 4,4′-oxydiphthalic anhydride (ODPA).

5. The heat resistant base for electronic equipment of claim 1, wherein the polyimide-based resin comprises a polyimide including a structure of the following Chemical Formula A and a polyamic acid including a structure of the following Chemical Formula B: ##STR00013## in the Chemical Formulae A and B, X is a tetravalent organic group derived from an acid dianhydride; and Y is a divalent organic group derived from a diamine.

6. The heat resistant base for electronic equipment of claim 5, wherein, in the Chemical Formula A and Chemical Formula B, X is a tetravalent organic group having a fluorine atom-containing substituent; Y is a divalent organic group having a fluorine atom-containing substituent; or, both X and Y are organic groups having a fluorine atom-containing substituent.

7. The heat resistant base for electronic equipment of claim 6, wherein the divalent organic group having a fluorine atom-containing substituent is 2,2′-bis(trifluoromethyl)benzidine or 2,2-bis[4-(-aminophenoxy)phenyl]hexafluoropropane.

8. The heat resistant base for electronic equipment of claim 5, wherein, in the Chemical Formulae A and B, X is a tetravalent organic group having a fluorine atom-containing substituent, or a tetravalent organic group not having a fluorine atom-containing substituent.

9. The heat resistant base for electronic equipment of claim 8, wherein the tetravalent organic group not having a fluorine atom-containing substituent is from a compound selected from 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,3,3′,4′-biphenyltetracarboxylic dianhydride, pyromellitic anhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 2,3,3′,4′-oxydiphthalic anhydride and mixtures thereof.

10. The heat resistant base for electronic equipment of claim 1, wherein the hollow particles are hollow silica particles.

11. The heat resistant base for electronic equipment of claim 10, wherein the hollow silica particles have an average particle diameter of greater than or equal to 40 nm and less than or equal to 150 nm.

12. The heat resistant base for electronic equipment of claim 1, wherein the hollow particles are hollow silica particles, and the polyimide-based resin has a refractive index of greater than or equal to 1.40 and less than or equal to 1.55 at a wavelength of 632.8 nm after curing.

13. The heat resistant base for electronic equipment of claim 1, wherein the heat resistant base has, a light transmittance of at least 85%; a haze of 1.0% or less; an initial color b* of 1.0 or less, wherein b* is Blue/Yellow Value, a* is Red/Green Value and L* is Lightness according to CIE 1976 L*a*b* color space; and a difference of 0.5 or less between the initial color b*, and a color b* after being exposed to an ultraviolet lamp in a UVB wavelength region for at least 72 hours.

14. The heat resistant base for electronic equipment of claim 1, wherein the heat resistant base is a basic structure of the electronic equipment.

15. The heat resistant base for electronic equipment of claim 1, wherein the heat resistant base is for supporting a basic structure in a display, a lens, a thin film transistor (TFT), a polarizing plate, an alignment film, a color filter, an optical compensation film, an anti-reflection film, an anti-glare film, a surface treatment film, an anti-static film, a separator, a capacitor, a vibration element or an actuator.

16. The heat resistant base for electronic equipment of claim 13, wherein the heat resistant base has a yellowness index value “YI value” of 5.0 or less.

Description

EXAMPLE

[0206] Hereinafter, the present disclosure will be described in detail by describing operations and effects of the disclosure through the following specific examples. The corresponding examples form one example of the present disclosure, and technological ideas covered by the scope of the present disclosure may all be readily implemented from the corresponding examples. Meanwhile, the examples present just one aspect of the present disclosure, and the scope of a right of the present disclosure is not limited and specified by the presence of the corresponding examples.

Example 1

[0207] Preparation of Modified Polyimide Resin A1

[0208] After dissolving 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB) (1 mol) in DEF (80 g), 4,4′-oxydiphthalic anhydride (ODPA) (1.1 mol) was added thereto, and the mixture was introduced to N,N-diethylformamide (DEF) (50 g). The result was polymerized for 24 hours at 50° C. to obtain a solution including polyamic acid.

[0209] To the solution, toluene (40 g) was introduced, and, after installing a Dean-Stark distillation apparatus to remove water, the result was refluxed for 12 hours at 180° C. to obtain a polyimide solution. In the polyimide solution, precipitates were produced using a methanol solvent and then dried, and after dissolving the dried polyimide in DEF (50 g), 2-methacryloyloxyethyl isocyanate (MOI) (3 moles) was added thereto, then DEF (30 g) was introduced thereto, and the result was reacted for 24 hours at room temperature. Precipitates were produced using methanol, and then dried to obtain a modified polyimide resin A1.

[0210] Preparation of Thermo-curable Coating Composition a1

[0211] To the modified polyimide resin A1 (10 g), an urethane acryl oligomer SP260 (manufactured by Soltech Ltd.) (5 g) was introduced, and after introducing dipentaerythritol hexaacrylate (DPHA) (4 g) thereto, DEF was introduced to a thermal initiator (2,2′-azobis(2,4-dimethylvaleronitrile), V65 (manufactured by Wako Pure Chemical Industries Ltd.), 10 hours, half-life temperature 50° C.) (1 g) so that the solid content becomes 30% by weight, and the result was mixed to obtain a thermo-curable coating composition a1.

[0212] Preparation of Hollow Particle Silica Particle Dispersion Liquid b1

[0213] The surface of a hollow silica particle B1 having an average particle diameter of 80 nm was treated with a fluorine-based compound using a sol-gel reaction to obtain 20% by weight of a hollow silica particle dispersion liquid b1 in methyl isobutyl ketone (MIBK).

[0214] Preparation of Base

[0215] The thermo-curable coating composition a1 and the hollow silica particle dispersion liquid 131 were mixed such that the solid of the thermo-curable coating composition a1 and the hollow silica particle dispersion liquid 131 have a weight ratio of 70:30, and stirred to obtain a composition. The composition was coated on a peeling agent-coated glass substrate using spin coating. After that, the result was dried for 10 minutes at 100° C. in an oven under the nitrogen atmosphere, and, after raising the temperature to 350° C. at a temperature raising rate of 5° C./minute, heat treated for 30 minutes. After taking out from the oven, the result was peeled from the glass substrate to obtain a single layered polymer film base having a thickness of 20 μm.

Example 2

[0216] Preparation of Thermo-curable Coating Composition a2

[0217] To the modified polyimide resin A1 (10 g), an urethane acryl oligomer SU5260 (manufactured by Soltech Ltd.) (5 g) was introduced, and after introducing dipentaerythritol hexaacrylate (DPHA) (4 g) thereto, DEF was introduced to a thermal initiator (2,2′-azobis(2,4-dimethylvaleronitrile), V65 (manufactured by Wako Pure Chemical Industries Ltd.), 10 hours, half-life temperature 50° C.) (1 g) so that the solid content becomes 30% by weight, and the result was mixed to obtain a thermo-curable coating composition a2.

[0218] Preparation of Base

[0219] The thermo-curable coating composition a2 and the hollow silica particle dispersion liquid 131 were mixed such that the solid of the thermo-curable coating composition a2 and the hollow silica particle dispersion liquid 131 have a weight ratio of 60:40, and stirred to obtain a composition. Using the composition, a single layered polymer film base having a thickness of 20 μm was prepared in the same manner as in Example 1.

Comparative Example 1

[0220] A single layered polymer film base having a thickness of 20 μm was prepared in the same manner as in Example 1 except that only the curable coating composition was coated on a glass substrate without mixing the hollow silica particles.

Comparative Example 2

[0221] A single layered polymer film base having a thickness of 20 μm was prepared in the same manner as in Example 2 except that only the curable coating composition was coated on a glass substrate without mixing the hollow silica particles.

[0222] [Evaluation Test: Evaluation Test of Optical Properties]

[0223] For each of the polymer film bases obtained in Examples 1 and 2 and Comparative Examples 1 and 2, optical properties of the film such as transmittance and yellowness index were measured using the following method.

[0224] The transmittance was measured using a spectrophotometer (manufactured by JASCO, model V-770). In addition, the yellowness index (“YI”) was measured by installing an integration sphere unit in the spectrophotometer and using a color evaluation (color diagnosis) program VWCD-960. These results are as shown in Table 1.

[0225] [Result]

[0226] As described in the following [Table 1], in Example 1 and Comparative Example 1, and in Example 2 and Comparative Example 2 having the same base thickness, transmittance (at 550 nm) (%) and transmittance (at 460 nm) (%) were far superior in Example 1 in terms of transparency, and as for “YI”, it was understood that Examples 1 and 2 clearly had a lower degree of coloration compared to Comparative Examples 1 and 2.

TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 1 Example 2 Polyimide Resin Al Al Al Al Thermo-curable al a2 al a2 Coating Composition Hollow Silica B1 B1 None None Particle Hollow Silica b1 b1 None None Particle Dispersion Liquid Weight Ratio of 70:30 60:40 100:0 100:0 Solid of Thermo- curable Coating Composition and Hollow Silica Particle Dispersion Liquid Base Thickness 20 20 20 20 (unn) Transmittance 90 89 86 85 (at 550 nm) (%) Transmittance 88 88 82 80 (at 460 nm) (%) Yl 2.5 2.6 6.0 6.3