JPS5952217A - Reflective polarizing plate - Google Patents

Abstract

PURPOSE:To obtain a reflective polarizing plate having superior heat stability and strength, etc., by laminating an adhesive layer, a polarizing film, a reflective metallic vapor deposited layer, an adhesive layer, and a nondirectionally or biaxially stretched plastic film on a nondirectionally or uniaxially stretched plastic film in this order. CONSTITUTION:A polarizing film 2 obtd. by adsorbing I2 or a dichroic dye to a PVA type film or the like and orienting it is pasted to a substrate 1 of a nondirectionally or uniaxially stretched polyester film or the like using a polyester type adhesive 4 or the like. On the polarizing film 2 a reflective metallic layer 3 is formed by vapor depositing Al or the like, and then, a plastic film 5 uniaxially or biaxially or nondirectionally stretched (it may be the same as the film 1) is pasted to the layer 3. As a result, the reflective film 3 is prevented from wrinkling and scratching, and from light scattering due to direct contact with the films 2, 3, hence, it has a superior reflection effect, and the obtained reflective polarizing plate is superior in heat stability, mechanical strength, etc., and usable for a liquid crystal display device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel reflective polarizing plate, and more specifically, it provides a reflective polarizing plate having excellent thermal stability (dimensional stability) and mechanical strength.

The usage status of polarizing plates in liquid crystal display devices is that in the current mainstream TN (twisted nematic) type, they are used above and below the liquid crystal display device, and the absorption axes of the polarizing plates are perpendicular to each other. ζ), and furthermore,
To increase the brightness, reflective M foil is usually pasted with adhesive on one side (opposite the visible side) of the lower polarizing plate.

In addition, as an alternative to Al foil, a reflective metal material provided by vacuum deposition or the like has also been proposed.

However, in the case of these reflective objects, for example, when bonding AJ foil with adhesive, are there problems such as wrinkles and flaking of the AJ foil and an increase in the bonding process? ), and polarizing plates formed by directly forming reflective metal objects have weak strength of the metal layer itself, so they are easily scratched during assembly or operation of the liquid crystal display device, which reduces the reflective ability. There was a drawback.

The present invention is a reflective polarizing plate having a novel reflective function that solves the drawbacks of the prior art, has good thermal stability and mechanical strength17, and has polarization properties equivalent to or better than conventional polarizing plates. The object of the present invention is to provide a product having the above characteristics. The gist is that a plastic film (or sheet) stretched in no direction or only in one direction, an adhesive layer, a polarizing film, a reflective metal vapor deposited layer, and a contact M1
! Layer K, a vertically and horizontally stretched plastic film or a plastic film (or sheet) stretched in the horizontal direction or only in one direction, is laminated in this order.

A detailed explanation will be given below using the drawings. In the drawing, 1
2 is a polarizing film, and 3 is a reflective metal F deposited directly on the film 2 (preferably 200 to 3000 people). ), 4 adhesive layers, and 5 are vertically and horizontally stretched plastic films, or plastic films or sheets stretched in no direction or only in one direction (thickness preferably from 10 to 800 μm).

Plastic films or sheets stretched in no direction or only in one direction include plastic materials such as polyester, polyether-nulphone, polysulfone, polymethylpentene, and polyamide. Films or sheets that are stretched only in the vertical or horizontal directions are used; ~23°C for 60 minutes
The use of a polyester film or sheet that is heat-set at 0''G for 5 minutes and stretched in one direction westward is particularly preferred from the viewpoint of chemical resistance.

The plastic film or sheet stretched in only one direction is bonded to the polarizing film described below so that the stretching direction and the absorption axis direction are parallel or perpendicular to each other.

Note that for the non-directional plastic film or sheet formed on one surface of the polarizing film, instead of forming a film of plastic material in advance and laminating it C1, it is also possible to dissolve the plastic material in an appropriate solvent and then laminate it. It can be formed by

As a vertically and horizontally stretched plastic film or sheet,
A polyester film or sheet made of polyester is stretched in the longitudinal and transverse directions (stretched by about 1.5 to 7 times each and heated). Polyethersulfone, polysulfone, Bo! 1 methylpentene, polystyrene, polyolefin iso, polyamide, polymethyl methacrylate,
A vertically and horizontally stretched film or sheet of polyvinyl chloride, acetate, etc. is used.

The polarizing film adsorbs iodine and/or dichroic dyes of hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and saponified ethylene-vinyl acetate copolymer films. Oriented iodine and/or dichroic dye-based polarizing film, polyvinyl alcohol film dehydrated to form polyene and oriented polyene polarizing film, polyvinyl chloride film dehydrochlorinated to form polyene. Examples include polyene-based polarizing films oriented by polyurethane, and those having a thickness of 10 to 80 μm are generally used.

As the reflective metal vapor deposited layer, an AIK;

The above-mentioned pasting of the plastic film 1 and the polarizing film 2 or the all-1-layer vapor deposition layer 3 and the plastic film? ) The adhesive composition used for lamination has, in addition to adhesive properties, approximately 2
It is necessary that the polarizing film has optical transparency at a thickness of ~50 μm and that the polarizing properties of the polarizing film do not disappear or deteriorate due to the contained components, such as polyester adhesives, polyacrylic adhesives, and epoxy adhesives. , cyanoacrylate adhesives, polyurethane adhesives, and spirane adhesives.

The reflective polarizing plate configured in this way is installed in a liquid crystal display device as a pair with a normal polarizing plate on the side opposite to the visible side, so that one side of the reflective polarizing plate is in contact with the surface of the liquid crystal display device. be incorporated so that it is

Since the uninvented reflective polarizing plate is structured like a son, there is no need for complicated work such as attaching the reflective plate when mounting.
It has the characteristic that the reflective layer will not be scratched. Moreover, since the reflective image (vapor deposition) is provided directly on the polarizing film, there is no light scattering and a good reflection effect can be obtained.

[Brief explanation of the drawing]

The drawing is a side view showing an example of the invention. 2...Polarizing film, 3...Reflective metal vapor deposited layer Patent applicant Nitto Electric Industry Co., Ltd. Representative Kamigata Sanbe 123-

Claims (1)

[Claims] 1) A plastic film (or sheet) stretched in no direction or only in one direction, an adhesive layer, a polarizing film, a reflective metal vapor deposited layer 1, an adhesive layer, and the vertical and horizontal axes. Stretched plastic film or plastic film (or sheet) stretched in no direction or only in one direction is pasted in this order! ] Combined reflective polarizing plate. 2) The reflective polarizing plate according to claim 1, wherein the plastic film (or sheet) is a polyester film (or sheet).