Substrate for heat-resistant electronic device
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.
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,
wherein the hollow particles are hollow silica particles, and the hollow silica particles are surface treated with a fluorine-based compound, and
wherein the hollow silica particles are included in an amount of greater than 30% by weight and less than 60% by weight with respect to the total weight of the heat resistant base, 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.
2 . The heat resistant base for electronic equipment of claim 1 , wherein the polyimide-based resin is a modified polyimide with a structure represented by the following Chemical Formula 4:
in the Chemical Formula 4,
D is a thermo-curable or photo-curable functional group,
R is a divalent or higher organic group,
n is an integer of 1 or greater,
X1, X2, X3 and X4 are each independently a tetravalent organic group derived from a tetracarboxylic dianhydride,
Y1, Y2 and Y3 are each independently a divalent organic group derived from a diamine,
p, q, r and v are each independently an integer of 0 or greater, but are not 0 at the same time, and
the value of p+q+r+v is an integer of 2 to 100.
3 . The heat resistant base for electronic equipment of claim 1 , 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).
4 . 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:
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.
5 . The heat resistant base for electronic equipment of claim 4 , 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.
6 . The heat resistant base for electronic equipment of claim 5 , wherein the divalent organic group having a fluorine atom-containing substituent is 2,2′-bis(trifluoromethyl)benzidine or 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.
7 . The heat resistant base for electronic equipment of claim 4 , 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.
8 . The heat resistant base for electronic equipment of claim 7 , 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.
9 . The heat resistant base for electronic equipment of claim 1 , 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.
10 . 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.
11 . The heat resistant base for electronic equipment of claim 10 , wherein the heat resistant base has a yellowness index value “YI value” of 5.0 or less.
12 . The heat resistant base for electronic equipment of claim 1 , wherein the heat resistant base is a basic structure of the electronic equipment.
13 . 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.