What is claimed is:
1. A cellulose ester film comprising a polymer prepared by polymerizing at least one ethylenically unsaturated monomer selected from the group consisting of vinyl esters, vinyl esters having a functional group, acrylic esters, and acrylic esters having a functional group, the polymer having a weight average molecular weight of not more than 5,000.
2. The cellulose ester film of claim 1, wherein the polymer contains an alkyl acrylate monomer in an amount of not less than 30 weight % or an alkyl methacrylate monomer in an amount of not less than 30 weight %.
3. The cellulose ester film of claim 2, wherein the polymer contains a methyl acrylate monomer in an amount of not less than 30 weight %
4. The cellulose ester film of claim 1, wherein the polymer has a water solubilizing group.
5. The cellulose ester film of claim 4, wherein the water solubilizing group is a hydroxyl group.
6. The cellulose ester film of claim 1, wherein the molecular weight of the functional group of the vinyl esters having a functional group or the acrylic esters having a functional group is from 10 to 150.
7. The cellulose ester film of claim 1, wherein the content of said polymer in the cellulose ester film is 0.5 to 30 weight % based on the cellulose ester film.
8. The cellulose ester film of claim 1, wherein the rate of mass change of the cellulose ester film is not more than 2%, the rate of mass change being represented by the following formula:
Rate of mass change (%)(y-zy)100
wherein y is the weight of the cellulose ester film measured at 233 C. and at 553% RH, and z is the weight of the cellulose ester film measured at 233 C. and at 553% RH after the film has been stored at 803 C. and at 903% RH for 48 hours, and then stored at 233 C. and at 553% RH for 24 hours.
9. The cellulose ester film of claim 1, wherein the moisture vapor transmittance of the cellulose ester film with a thickness of 40 m is not more than 250 gm224 h at 805 C. and at 905% RH.
10. The cellulose ester film of claim 1, wherein the film further contains fine particles.
11. The cellulose ester film of claim 1, wherein the thickness of the cellulose ester film is 30 to 150 m.
12. The cellulose ester film of claim 1, wherein the cellulose ester film is a film for use in a liquid crystal display.
13. The cellulose ester film of claim 12, wherein the cellulose ester film is a film for use in a protective film of a polarizing plate.
14. A cellulose ester dope for preparing the cellulose ester film of claim 1 according to a solution casting film forming method.
15. A polarizing plate comprising a first protective film, a polarizing film and a second protective film, wherein at least one of the first protective film and the second protective film is the cellulose ester film of claim 1.
16. A liquid crystal display comprising a first polarizing plate, a second polarizing plate, and a liquid crystal cell provided between the first and second polarizing plates, the second polarizing plate being arranged on the viewer side of the display, wherein the first polarizing plate has a first film, a second film and a first polarizing film between the first and second films so that the second film is provided on the first polarizing film on the liquid crystal cell side, the second polarizing plate has a third film, a fourth film and a second polarizing film between the third and fourth films so that the third film is provided on the second polarizing film on the liquid crystal cell side, and at least one of the first, second, third and fourth films is the cellulose ester film of claim 1.
17. A method for preparing a cellulose ester film, the method comprising the steps of a) casting the cellulose ester dope of claim 14 on a metal support to form a cellulose ester web, b) peeling the web from the metal support, and c) drying the peeled web in a drying apparatus to obtain a cellulose ester film.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A lighted sign comprising a front face having at least a translucent portion, a skirt at least partly surrounding said front face and extending rearwardly with respect thereto, the skirt defining a contour of the lighted sign, the contour being at least partly opaque, a light diffuser located behind said skirt, the skirt extending laterally outwardly relative to the light diffuser and defining therewith a rearwardly open gap, and a light source within the lighted sign, the light source lighting both 1) said translucent portion of said front face and 2) the light diffuser, at least a portion of the light transmitted laterally outwardly through the light diffuser coming out rearwardly from the lighted sign through said rearwardly open gap; wherein a rim projects forwardly from a periphery of the front face, thereby providing for a recessed front surface, and wherein said skirt projects integrally rearwardly from said rim.
2. A lighted sign as defined in claim 1, wherein said light diffuser extends rearwardly outwardly of said skirt, and wherein said light diffuser is not visible through said skirt.
3. A lighted sign as defined in claim 1, wherein said light diffuser has a color different than a color of said translucent portion of said front face.
4. A lighted sip as defined in claim 1, wherein the light diffuser is hidden behind an opaque zone of the skin.
5. A lighted sign as defined in claim 1, wherein the skin and the light diffuser have an overlapping area in a depthwise direction, the light diffuser having a rear end portion which extends rearwardly beyond the skin, the light being at least partly blocked in the overlapping area by the skin while being allowed to pass laterally out or the sign through the rear end portion of the light diffuser.
6. A lighted sign comprising a front face having at least a translucent portion, a skirt at least partly surrounding said front face and extending rearwardly with respect thereto, the skirt defining a contour of the lighted sign, the contour being at least partly opaque, a light diffuser located behind said skirt, the skirt extending laterally outwardly relative to the light diffuser and defining therewith a rearwardly open gap, and a light source within the lighted sign, the light source lighting both 1) said translucent portion of said front face and 2) the light diffuser, at least a portion of the light transmitted laterally outwardly through the light diffuser coming out rearwardly from the lighted sign through said rearwardly open gap; wherein a light reflective device is mounted on an internal surface of the skirt and oriented to redirect the light onto an external surface of the front face of the lighted sign through a translucent surface between the front face and the skirt.
7. A lighted sign comprising a housing defining an internal volume for accommodating a light source, said housing having a front face having a main translucent zone surrounded by an opaque zone, the opaque zone defining the outline of the sign, and a sidewall disposed inboard of said outline and extending rearwardly from said front face, said sidewall having a rear translucent portion through which light from said light source can pass, and a skirt surrounding said sidewall and defining therewith a rearwardly open gap to allow the light passing through the rear translucent portion of the sidewall to come out rearwardly of the lighted sign to provide a contrasting illuminated background for said outline of the sign; wherein a rim projects forwardly from a periphery of the front face, thereby providing for a recessed front surface, and wherein said skirt projects integrally rearwardly from said rim.
8. A lighted sign as defined in claim 7, wherein said front face has a front panel having a peripheral rearwardly skirt, the outline being defined by said skirt, and wherein said rear translucent portion of said sidewall extends rearwardly beyond said skirt, said sidewall being hidden behind said skirt from a front point of view.
9. A lighted sign as defined in claim 8, wherein the skirt and the sidewall have an overlapping area in a depthwise direction, the sidewall having a rear end portion which extends rearwardly beyond the skirt, the light being at least partly blocked in the overlapping area by the skirt while being allowed to pass laterally out of the sign through the rear end portion of the sidewall.