Summary of the invention
Technical matters to be solved by this invention is: provide a kind of method manufacturing scattering polaroid based on heat-curable glue technology, and namely polyvinyl alcohol (PVA) folder polymer dispersed nematic liquid crystal oriented film manufactures the method for scattering polaroid.Goods press from both sides polymer dispersed liquid crystal film by two polyvinyl alcohol (PVA) to form interlayer film, Triafol T diaphragm in stretched rear compound, forms 5 layers of compound film; goods have translucent appearance, there is light transmission shaft, and natural light is incident; half Transmission light, half light scattering.Polarized light is incident, and polarization direction is parallel with light transmission shaft, the strong transmission weak scattering of light beam, and polarization direction is orthogonal with light transmission shaft, the weak transmission of light beam strong scattering.This scattering polaroid is transparent rear projection screen new technology, and scattering polaroid and reflective polarizers are fit together, and is exactly transparent front projection screen new technology.
The present invention solves this technical problem adopted technical scheme: with two polyvinyl alcohol film folder polymer dispersed liquid crystal layers, after stretched, then two transparent Triafol T film protective films in compound.Scattering polaroid manufacture method of the present invention adopts heat-curable glue phase detachment technique, and core technology has the technological process such as preparation prepolymer and liquid crystal mixed liquor, coating overlay film, heating, solidification, stretching and compound.Described prepolymer preparation is that the birefraction of described Nematic phase liquid crystal material is about n with heat-curable glue prepolymer and Nematic phase liquid crystal material mixing composition liquid crystal glue
o=1.5, n
e=1.7, birefringence rate variance is about 0.2, and after heat-curable glue prepolymer cures, refractive index is about 1.5.Described coating overlay film is on accurate laminating machine, and two volume polyvinyl alcohol (PVA) uncoilings are pressed from both sides in the thick roller of laminating machine, the perfusion of liquid crystal glue is applied between two polyvinyl alcohol (PVA), is combined into 3 layers of doubling film through laminating machine.Described heating is that 3 layers of doubling film are delivered into oven heats to 80 ~ 90 DEG C, triggers thermal initiator and starts cross-linking reaction, and rolling obtains the polyvinyl alcohol (PVA) folder polymer dispersed liquid-crystal film of not fully solidification, and goods are mist degree slightly, more transparent.Described solidification is that the polyvinyl alcohol (PVA) through heating of rolling folder polymer dispersed liquid-crystal film is placed a few days, thermal initiator has continued to cause heat curing effect, solidify completely, liquid crystal is separated out and is formed liquid crystal droplet from polymkeric substance, obtain polyvinyl alcohol (PVA) folder polymer dispersed liquid-crystal film, goods mist degree is slightly large, in dim translucent.Described stretching is the uncoiling of polyvinyl alcohol (PVA) folder polymer dispersed liquid-crystal film, stretcher adds hot-stretch more than 3 times by the thick roller of many group heating again film, thick roller heating-up temperature is at 60 ~ 70 DEG C, form oriented film, goods are that mist degree decreases, the translucent that transmittance increases.Described compound is on equipment complex, and Triafol T diaphragm in the compound of oriented film upper and lower both sides, obtains 5 layers of compound adhesive sheet articles.
Starting material used in above-mentioned scattering polaroid preparation method easily purchase commodity as polyvinyl alcohol (PVA) film, Nematic phase liquid crystal material and Triafol T film are on market, heat-curable glue prepolymer can be that existing Polymer Dispersed Liquid Crystal electric-controlled light-regulating film produces practical formulation, and involved coating overlay film, heating, stretching and equipment complex are known general plastic molding and processing equipment.
The principle of scattering polaroid of the present invention: described Polymer Dispersed Liquid Crystal oriented film scattering polaroid is translucent state under normal conditions, liquid crystal droplet can imagine the prolate spheroid be reduced to along direction, face, ellipsoid axial ratio more than about 3 to 1, in liquid crystal droplet, liquid crystal molecule is along ellipsoid long axis direction roughly orientation, therefore liquid crystal droplet shows as the character of anisotropy uniaxial crystal, as selective polymer refractive index n
pwith liquid crystal ordinary refraction index n
oequal, when light normal incidence is by Polymer Dispersed Liquid Crystal thin layer, polarization direction is along the light scattering of draw direction, and the Transmission light in stretched vertically direction, polarization direction, namely stretched vertically direction is light transmission shaft direction.This is that liquid crystal is two-fold material, be then parallel to the refractive index n of liquid crystal molecule because liquid crystal molecule in liquid crystal droplet is roughly along draw direction orientation
ewith refractive index polymer n
punequally cause light scattering, and perpendicular to the refractive index n of liquid crystal molecule
owith refractive index polymer n
pequally cause Transmission light, namely possess the odd number solution of scattering polarizing device.
The characteristic of heat-curable glue Polymer Dispersed Liquid Crystal oriented film scattering polaroid of the present invention, by the ratio of telomerized polymer and liquid crystal, can reach transmittance 50 ~ 70%, mist degree less than 50%, the technical indicators such as degree of polarization 70 ~ 90%.Individual scattering polaroid is transparent rear projection screen technology, in single chip liquid crystal projector or single piece of silicon, liquid crystal projector carries absorption polaroid, emergent light is complete polarized light, scattering polaroid is used as screen, projected light polarization direction is orthogonal with scattering polaroid light transmission shaft, transmitted light is not had to waste, there is total scattering, back projection imaging is super clear, than other transparent projection screens film technologies (as holographic film), there is image-forming principle technical advantage, be applicable to being applied on the show window of market, back projection effect is magical.It is transparent front projection screen technology that scattering polaroid and reflective polarizers are fit together, and is applicable to being attached on meeting room French window, and orthogonal projection effect is magical.
The method that heat-curable glue technology of the present invention manufactures scattering polaroid with before inventor disclosed in compared with " a kind of scattering spread glass and its preparation method and application ", there is new feature: the present inventor has first invented scattering spread glass, and found that it makes the special applications of transparent projection screens, be devoted to the industrialization of scattering spread glass, and then invention scattering polaroid again.Scattering spread glass is glass laminating goods, naturally has the merits and demerits of glass product, and scattering polaroid is multilayer film compound adhesive sheet articles, certainly has again the merits and demerits that film product is obvious.
The method that heat-curable glue technology of the present invention manufactures scattering polaroid with before inventor disclosed in compared with " a kind of scattering polaroid and its preparation method and application ", there is new feature: former technology is the method manufacturing scattering polaroid based on ultraviolet cured adhesive technology, there is ultraviolet photoetching phase separation process, new technology is the method manufacturing scattering polaroid based on heat-curable glue technology, replaces heating and curing process.Require different from manufacture electric-controlled light-regulating membrane process, the manufacture of scattering polaroid, not to the rigors of polymer dispersed liquid crystal layer thickness, can not put wadding plastic microsphere, controls doubling layer roughly thickness by adjustable liquid crystal display adhesiveness and the thick roller gap of laminating machine.
Embodiment
Scattering polaroid process for making:
The first step, preparation heat-curable glue prepolymer adds the liquid crystal glue mixed liquor of liquid crystal, the mass ratio about 3 ~ 4 to 1 of heat-curable glue prepolymer and liquid crystal, heat-curable glue prepolymer formulation is as follows: urethane acrylate 30%, methacrylate 66%, cumyl peroxide 1%, benzophenone 3%, liquid crystal is PDLC-005 (supply of Shijiazhuang Luquan novel electron material factory).
Second step, make polyvinyl alcohol (PVA) folder heat-curable glue polymer dispersed liquid crystal layer film, accurate laminating machine is filled into the mixed liquor of heat-curable glue prepolymer and liquid crystal between two polyvinyl alcohol films, be combined into doubling film, deliver into 80 ~ 90 DEG C of oven heats, trigger thermal initiator to work initiation cross-linking reaction, rolling obtains the polyvinyl alcohol (PVA) folder polymer dispersed liquid-crystal film of fully solidification, and goods are the doubling laminated film that slightly mist degree is more transparent.
3rd step, solidification doubling film, the thermal initiator that the heat that is subject to goods after rolling triggers continues to play a role, namely solidify completely after leaving standstill a few days, be separated, occur the liquid crystal droplet wrapped up by polymer dispersed, goods are the dim translucent doubling laminated film that mist degree is larger, polymer dispersed liquid crystal layer thickness 0.08 ~ 0.12mm.
4th step, stretching polyethylene alcohol folder polymer dispersed liquid-crystal film, the uncoiling of polyvinyl alcohol (PVA) folder polymer dispersed liquid-crystal film, by how group roller is film stretching more than 3 times on stretcher, the thick roller that stretches heating 60 ~ 70 DEG C.Unfolded expansion by a special roller, eliminate fold, form the stretched film of regime width thickness, stretching doubling laminated film mist degree reduces, more transparent, stretching post-consumer polymer dispersed LCD layer thickness 0.02 ~ 0.04mm.
5th step, composite protection film, on equipment complex, Triafol T diaphragm on stretching doubling Film laminated, rolling obtains compound adhesive sheet articles.