Light-diffusing films, backlight display devices comprising the light-diffusing films, and methods of making the same
View Patent ↗A light-diffusing film comprises about 90 wt. % to about 99.999 wt. % polycarbonate, wherein the polycarbonate comprises a yellowness index of about 0.8 to about 1.5 as measured in accordance with ASTM E313-73 (D1925); about 0.001 wt. % to about 3 wt. % light-diffusing particles; wherein weight percents are based on a total weight of the light-diffusing film; and wherein the light-diffusing film comprises a light transmission of about 45% to about 65% as measured in accordance with ASTM D1003-00, and a hiding power of 0 to about 0.5.
1. A light-diffusing film comprising:
about 90 wt. % to about 99.999 wt. % polycarbonate, wherein the polycarbonate comprises a yellowness index of about 0.8 to about 1.5 as measured in accordance with ASTM E313-73 (D1925);
about 0.001 wt. % to about 3 wt. % light-diffusing particles; and
wherein weight percents are based on a total weight of the light-diffusing film;
wherein the light-diffusing film comprises a light transmission of about 45% to about 65% as measured in accordance with ASTM D1003-00, and a hiding power of 0 to about 0.5 that is mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
wherein: L i (on) is luminance above i th cold cathode fluorescent lamp, L j (off) is luminance at a midpoint between cold cathode fluorescent lamp j and cold cathode fluorescent lamp j+1, and n equals number of CCFL lamps; and
wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4% as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.
2. The light-diffusing film of claim 1 , wherein the light-diffusing film comprises about 0.20 wt. % to about 2 wt. % light-diffusing particles.
3. The light-diffusing film of claim 1 , wherein the light-diffusing film does not comprise any dyes or colorants.
4. The light-diffusing film of claim 1 , wherein the polycarbonate comprises a yellowness index of about 0.9 to about 1.3.
5. The light-diffusing film of claim 1 , wherein the light-diffusing particles comprise a polyorgano silsesquioxane.
6. The light-diffusing film of claim 1 , wherein the light-diffusing particles comprise poly(methyl methacrylate).
7. The light-diffusing sheet of claim 1 , wherein the light-diffusing sheet comprises an average surface roughness (Ra) of about 0.01 micrometers to about 2.0 micrometers as measured in accordance with JIS B0601.
8. The light-diffusing film of claim 1 , wherein the light-diffusing film is a solid unitary film.
9. The light diffusing film of claim 1 , wherein the light-diffusing film 13 points average luminance is greater than or equal to 100.8% compared to the polycarbonate film 13 points average luminance.
10. The light diffusing film of claim 9 , wherein the light-diffusing film 13 points average luminance is greater than or equal to 102.0% compared to the polycarbonate film 13 points average luminance.
11. The light diffusing film of claim 1 , wherein the polycarbonate was produced by an interfacial reaction.
12. A light-diffusing film comprising: about 90 wt. % to about 99.999 wt. % polycarbonate comprising a yellowness index of about 0.8 to about 1.5 as measured in accordance with ASTM E313-73 (D1925); and about 0.001 wt. % to about 3 wt. % light-diffusing particles comprising polyalkyl silsesquioxane, wherein the alkyl group is selected from the group consisting of methyl, a C12 to C18 alkyl, hydride, phenyl, vinyl, and cyclohexyl, and a combination comprising at least one of the foregoing, wherein weight percents are based on a total weight of the light-diffusing film; wherein the light-diffusing particles have an average particle size of less than or equal to about 5 micrometers and have a refractive index of about 1.3 to about 1.7 when measured at a wavelength of 589 nanometers; wherein the light-diffusing film has a hiding power of 0 to about 0.5, mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
where L i (on)=Luminance above i th cold cathode fluorescent lamp (CCFL), L j (off)=Luminance at the midpoint between lamp j and lamp j+1, and n=number of CCFL lamps; and wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4%, as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.
13. The light-diffusing film of claim 12 , wherein the light-diffusing film does not comprise any dyes or colorants.
14. The light-diffusing film of claim 12 , wherein the polycarbonate comprises a yellowness index of about 0.9 to about 1.3.
15. A backlight display device, comprising:
a liquid crystal display;
a light source disposed in optical communication with the liquid crystal display; and
a light-diffusing film disposed between the liquid crystal display and the light source, wherein the light-diffusing film comprises
about 90 wt. % to about 99.999 wt. % polycarbonate, wherein the polycarbonate comprises a yellowness index of about 0.8 to about 1.3 as measured in accordance with ASTM E313-73 (D1925); and
about 0.001 wt. % to about 3 wt. % light-diffusing particles;
wherein weight percents are based on a total weight of the light-diffusing film;
wherein the light-diffusing film comprises a light transmission of about 45% to about 65% as measured according to ASTM D 1003-00 and a hiding power of 0 to about 0.5 that is mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
wherein: L i (on) is luminance above i th cold cathode fluorescent lamp, L j (off) is luminance at a midpoint between cold cathode fluorescent lamp j and cold cathode fluorescent lamp j+1, and n equals number of CCFL lamps; and
wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4% as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.
16. A liquid crystal displaytelevision comprising the backlight display device of claim 15 .
17. The backlight display device of claim 15 , wherein the light-diffusing film does not comprise any dyes or colorants.
18. A light-diffusing film comprising:
about 90 wt. % to about 99.999 wt. % polycarbonate, wherein the polycarbonate comprises a yellowness index of about 0.8 to about 1.3 as measured in accordance with ASTM E313-73 (D1925); and
about 0.001 wt. % to about 3 wt. % light-diffusing particles;
wherein weight percents are based on a total weight of the light-diffusing film;
wherein the light-diffusing film comprises a hiding power of 0 to about 0.5 that is mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
wherein: L i (on) is luminance above i th cold cathode fluorescent lamp, L j (off) is luminance at a midpoint between cold cathode fluorescent lamp j and cold cathode fluorescent lamp j+1, and n equals number of CCFL lamps; and
wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4% as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.
19. A backlight display device, comprising:
a liquid crystal display;
a light source disposed in optical communication with the liquid crystal display; and
a light-diffusing film disposed between the liquid crystal display and the light source, wherein the light-diffusing film was produced from
about 90 wt. % to about 99.999 wt. % polycarbonate powder; and
about 0.001 wt. % to about 3 wt. % light-diffusing particles;
wherein weight percents are based on a total weight of the light-diffusing film;
wherein the light-diffusing film comprises a hiding power of 0 to about 0.5 that is mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
wherein: L i (on) is luminance above i th cold cathode fluorescent lamp, L j (off) is luminance at a midpoint between cold cathode fluorescent lamp j and cold cathode fluorescent lamp j+1, and n equals number of CCFL lamps; and
wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4% as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.
20. The device of claim 19 , wherein the polycarbonate powder comprised a yellowness index of about 0.8 to about 1.3 as measured in accordance with ASTM E313-73 (D1925).
21. The device of claim 19 , wherein the polycarbonate powder comprised a yellowness index of about 0.8 to about 1.3 as measured in accordance with ASTM E313-73 (D1925).
22. A backlight display device, comprising:
a liquid crystal display;
a light source disposed in optical communication with the liquid crystal display; and
a light-diffusing film disposed between the liquid crystal display and the light source, wherein the light-diffusing film was produced from
about 90 wt. % to about 99.999 wt. % polycarbonate; and
about 0.001 wt. % to about 3 wt. % light-diffusing particles;
wherein weight percents are based on a total weight of the light-diffusing film;
wherein the light-diffusing film does not comprise any dyes or colorants;
wherein the light-diffusing film comprises a hiding power of 0 to about 0.5 that is mathematically described by the following equation:
Hiding
power
(
%
)
=
1
-
∑
i
=
1
n
-
1
L
i
(
on
)
∑
j
=
1
n
-
1
L
j
(
off
)
×
100
wherein: L i (on) is luminance above i th cold cathode fluorescent lamp, L j (off) is luminance at a midpoint between cold cathode fluorescent lamp j and cold cathode fluorescent lamp j+1, and n equals number of CCFL lamps; and
wherein the light-diffusing film has a 13 points average luminance that is greater than a 13 points average luminance of a polycarbonate film, as determined by a 13 points test using a Topcon BM-7 instrument, wherein the polycarbonate film comprises about 3.5 wt % acrylate particles based on a total weight of the polycarbonate film, and the polycarbonate film has a thickness of 2 millimeters and a transmission of 50.4% as determined in accordance with ASTM D1003-00 and as measured with instrument Macbeth 7000A, D65 light source illuminant, 10° observer.