MULTIPLE AND SINGLE LAYERS LIQUID CRYSTAL DISPERSION DEVICES FOR COMMON AND DIRECT GLAZING APPLICATIONS AND METHODS THEREOF

Abstract

Means and methods for manufacturing a multilayer of liquid crystal dispersion film using releasable supporting films and means and methods for manufacturing a haze-free and low-cost multi liquid crystal-layer PDLC, LCDP, PSLC or polymer network using reliable supporting films.

Claims

1.-131. (canceled)

132. A haze-free liquid crystal selected from a group consisting of a multilayer of liquid crystal dispersion in a polymer matrix film, a haze-free direct-glazing liquid crystal dispersion in a polymer matrix, and a layer of liquid crystal dispersion in a polymer matrix; said haze-free liquid crystal is prepared by a method selected from a group consisting of method for manufacturing a haze-free multilayer of liquid crystal dispersion in a polymer matrix film; a method for manufacturing a haze-free direct-glazing liquid crystal dispersion in a polymer matrix; and a method for manufacturing a layer of liquid crystal dispersion in a polymer matrix; wherein said method for manufacturing a haze-free multilayer of liquid crystal dispersion in a polymer matrix film, comprising the steps of: a. providing materials for producing a PDLC, LCDP, PSLC or polymer network film, comprising: i. at least one first releasable supporting film; ii. at least one liquid crystal dispersion; iii. at least one second supporting film; b. allocating said liquid crystal dispersion between said at least one first releasable supporting film and said at least one second supporting film, thereby forming a PDLC, LCDP, PSLC or polymer network film; c. curing said PDLC, LCDP, PSLC or polymer network film by means of UV light, electron beam light or heat; d. detaching said at least one releasable supporting film; e. providing materials for producing at least one second layer of liquid crystal in said PDLC, LCDP, PSLC or polymer network film, comprising: i. a third supporting film; ii. a second liquid crystal dispersion; f. allocating said second liquid crystal dispersion between said third supporting film and said PDLC film, thereby forming a multilayer PDLC film; g. curing said multilayer PDLC, LCDP, PSLC or polymer network film by means of UV or electron beam light; any of said supporting films can be releasable supporting films; said steps of curing are partially completed in order to achieve a semi-rigid layer of liquid crystal; and a final step of detaching said releasable supporting films and enclosing the remaining said liquid crystal layers in two metallized supporting glasses, thereby making a low-cost haze free direct-glazing PDLC; and wherein said method for manufacturing a haze-free direct-glazing liquid crystal dispersion in a polymer matrix, comprising the steps of: h. providing materials for producing a PDLC, LCDP, PSLC or polymer network film, comprising: i. at least two releasable supporting films; and ii. at least one liquid crystal dispersion; i. allocating said liquid crystal dispersion between said at least two releasable supporting films, thereby forming a PDLC, LCDP, PSLC or polymer network film; j. curing said PDLC, LCDP, PSLC or polymer network film by means of UV light, electron beam light or heat; k. detaching said at least two releasable supporting films; l. providing at least two metallized coated glasses; m. enclosing said liquid crystal dispersion between said at least two metallized coated glasses, thereby making a low-cost haze free direct-glazing PDLC; n. adapting said low-cost haze free direct-glazing PDLC to the desired thickness; said step of curing is partially completed in order to achieve a semi-rigid layer of liquid crystal; and wherein said method for manufacturing a layer of liquid crystal dispersion in a polymer matrix, comprising the steps of: o. providing materials for producing a PDLC, LCDP, PSLC or polymer network film, comprising: i. at least two releasable supporting films; and ii. at least one liquid crystal dispersion; p. allocating said liquid crystal dispersion between said at least two releasable supporting films, thereby forming a PDLC, LCDP, PSLC or polymer network film; q. curing said PDLC, LCDP, PSLC or polymer network film by means of UV light, electron beam light or heat; r. detaching said at least two releasable supporting films; said step of curing is partially completed in order to achieve a semi-rigid layer of liquid crystal.

133. The haze-free liquid crystal of claim 132, wherein said liquid crystal device selected from a group consisting of PDLC, LCDP, PSLC or polymer network.

134. The haze-free liquid crystal of claim 132, wherein said liquid crystal type is nematic, cholesteric (chiral nematic or smectic).

135. The haze-free liquid crystal of claim 132, wherein said liquid crystal is characterized by a morphology in polymer matrix of nano-droplets, micro-droplets or macro-droplets.

136. The haze-free liquid crystal of claim 132, wherein said liquid crystal could be made by phase separation methods.

137. The haze-free liquid crystal of claim 132, wherein said liquid crystal could be made by micro-encapsulation methods.

138. The haze-free liquid crystal of claim 132, wherein said liquid crystal dispersion comprises highly adhesive and cross-linkable elastomer or composites of elastomer/plastic materials.

139. The haze-free liquid crystal of claim 132, wherein said liquid crystal dispersion comprises comprise acrylic, urethane, epoxy or their composite types.

140. The haze-free liquid crystal of claim 132, wherein said step of providing liquid crystal dispersion further comprises a step of introducing dichroic organic and metal-organic dye into said liquid crystal dispersion.

141. The haze-free liquid crystal of claim 132, wherein said releasable supporting are about 10-50 micron thick.

142. The haze-free liquid crystal of claim 132, wherein said step of providing liquid crystal dispersion further comprises a step of introducing nematic mixtures for static solar-reflection mode into said liquid crystal dispersion.

143. The haze-free liquid crystal of claim 132, wherein said step of providing liquid crystal dispersion further comprises a step of introducing broad-band cholesteric materials for dynamic solar-reflection mode into said liquid crystal dispersion.

144. The haze-free liquid crystal of claim 132, wherein said step of providing liquid crystal dispersion further comprises a step of introducing metal-organic mesogens into said liquid crystal dispersion.

145. The haze-free liquid crystal of claim 132, further comprising a step of providing a dimmer and switch adapted for driving a capacitive or complex capacitive-resistive load.

146. The haze-free liquid crystal of claim 132, wherein said supporting films can be coated with an enhanced reflective film.

147. The haze-free liquid crystal of claim 132, wherein said multilayer PDLC film comprises a pattern.

148. The haze-free liquid crystal of claim 132, wherein said multilayer PDLC, LCDP, PSLC or polymer network film comprises a low-definition display or signage.

149. The haze-free liquid crystal of claim 132, wherein said multilayer PDLC film is bi-stable.

150. The haze-free liquid crystal of claim 132, wherein said PDLC reduces it thickness from about 50-100 micron to 50-10 micron due to the final matrix curing and cross-linking by lamination under heat and pressure.

151. The haze-free liquid crystal of claim 132, wherein said film can be a stand-alone device or retrofitted into an already existing surface.

152. A method for manufacturing a low-cost and haze-free multilayer of liquid crystal dispersion in a polymer matrix film, comprising the steps of: a. providing materials for producing a PDLC, LCDP, PSLC or polymer network film, comprising: i. at least one first releasable supporting film; ii. at least one liquid crystal dispersion; iii. at least one second supporting film; b. allocating said liquid crystal dispersion between said at least one first releasable supporting film and said at least one second supporting film, thereby forming a PDLC, LCDP, PSLC or polymer network film; c. curing said PDLC, LCDP, PSLC or polymer network film by means of UV light, electron beam light or heat; d. detaching said at least one releasable supporting film; e. providing materials for producing at least one second layer of liquid crystal in said PDLC, LCDP, PSLC or polymer network film, comprising: i. a third supporting film; ii. a second liquid crystal dispersion; f. allocating said second liquid crystal dispersion between said third supporting film and said PDLC film, thereby forming a multilayer PDLC film; g. curing said multilayer PDLC, LCDP, PSLC or polymer network film by means of UV or electron beam light; wherein any of said supporting films can be releasable supporting films; wherein said steps of curing are partially completed in order to achieve a semi-rigid layer of liquid crystal; and wherein a final step of detaching said releasable supporting films and enclosing the remaining said liquid crystal layers in two metallized supporting glasses, thereby making a low-cost haze free direct-glazing PDLC.

153. A method for manufacturing a low-cost haze-free direct-glazing liquid crystal dispersion in a polymer matrix, comprising the steps of: a. providing materials for producing a PDLC, LCDP, PSLC or polymer network film, comprising: i. at least two releasable supporting films; and ii. at least one liquid crystal dispersion; b. allocating said liquid crystal dispersion between said at least two releasable supporting films, thereby forming a PDLC, LCDP, PSLC or polymer network film; c. curing said PDLC, LCDP, PSLC or polymer network film by means of UV light, electron beam light or heat; d. detaching said at least two releasable supporting films; wherein said step of curing are partially completed in order to achieve a semi-rigid layer of liquid crystal.

154. The method of claim 153, further comprising: e. providing at least two metallized coated glasses; f. enclosing said liquid crystal dispersion between said at least two metallized coated glasses, thereby making a low-cost haze free direct-glazing PDLC; and g. adapting said low-cost haze free direct-glazing PDLC to the desired thickness.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0088] FIG. 1 is a schematic representation of one method to manufacture one preferred embodiment of the present invention;

[0089] FIG. 2 is a schematic representation of another method to manufacture another preferred embodiment of the present invention;

[0090] FIG. 3 is a schematic representation of another method to manufacture another preferred embodiment of the present invention;

[0091] FIG. 4 is a schematic representation of a method to manufacture another preferred embodiment of the present invention characterized by being haze-free.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0092] The following description is provided, so as to enable any person skilled in the art to make use of the invention and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, are adapted to remain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide a multilayer of liquid crystal in PDLC films. Thus a novel method for creating such films has been obtained.

[0093] In the following, the present invention along with embodiments thereof will be described in detail with reference to the drawings.

[0094] Retrofit(ting): refers hereinafter to the modification of a conventional window or surface by combining the same in some manner with an enhancement, i.e., a switchable glazing, non-switchable light modulating device, etc.

[0095] Referring now to FIG. 1, a schematic illustration of the method 100 for manufacturing one embodiment of the present invention is presented. In this example, a roll-to-roll continuous manufacturing process for the preparation of liquid crystal film is used. One roll is composed by PET-ITO 10 film and the second roll is the novel PET release 11 film. Formulation A 12 is poured between the PET-ITO 10 film and the PET release 11 film. In this example curing is made by means of UV 13. The resulting PDLC (14 PDLC A) is thereby comprised by PET-ITO 10 film, the Formulation A 12 and the PET release 11 film.

[0096] The second step of the present invention method comprises the removal 15 of the PET release 11 film from the PDLC A 14. In this example, this process happens when passing in a second roll-to-roll machine when adding the second layer of liquid crystal. So, in one roll there is the previously made PDLC A 14, while the second roll is PET-ITO 10 (or any other support film). A second formulation, Formulation B 16, is poured between PDLC A 14 without the PET release 11 film and the PET-ITO 10. Then the film is cured, again in this case by means of UV 13. The resulting PDLC (17 PDLC A-B) is thereby comprised by PET-ITO 10 film, the Formulation A 12, the Formulation B 16 and PET-ITO 10 film.

[0097] Referring now to FIG. 2, a schematic illustration of the method 200 for manufacturing one embodiment of the present invention is presented. In this example, a roll-to-roll continuous manufacturing process for the preparation of liquid crystal film is used. Both rolls are composed by the novel PET release 20 film. Formulation A 21 is poured between the PET release 11 films. In this example curing is made by means of UV 22. The resulting PDLC (23 PDLC A) is thereby comprised by the Formulation A 21 and two PET release 20 films.

[0098] The second step of the present invention method comprises the removal 24 of one of the PET release 20 films from the PDLC A 23. In this example, this process happens when passing in a second roll-to-roll machine when adding the second layer of liquid crystal. So, in one roll there is the previously made PDLC A 23, while the second roll is PET release 20 film (or any other support film). A second formulation, Formulation B 25, is poured between PDLC A 23 without one PET release 11 film and the PET release 20 film. Then the film is cured, again in this case by means of UV 22. The resulting PDLC (26 PDLC A-B) is thereby comprised by PET release 20 film, the Formulation A 12, the Formulation B 16 and PET release 20 film.

[0099] The aforementioned examples provided in FIG. 1 and FIG. 2 can be repeated n times, in order to add n layers of different morphology of liquid crystal, as necessary.

[0100] It is another scope of the present invention to provide a method to manufacture a double-release single-layer and/or multi-layer PDLC preform film for direct glazing. The main characteristics of said film is that is manufactured at low-cost materials (no ITO-PET and two ITO-glasses), the process is simple and at low costs (double-release), the result is a simple and low-cost PDLC glazing (direct PDLC layer lamination on two ITO-glasses) with a significant PDLC haze reduction during glazing (LC droplet deformation), which provides the final product of a low-cost PDLC film and glazing product.

[0101] One example of the manufacture process is summarized as follows: [0102] 1. Coating of a mixture of liquid crystal and a UV-curable/themoset prepolymers between two non-metallized release sheets, each having 10-50 micron thickness. [0103] 2. The prepolymers will consist of highly adhesive and cross-linkable elastomer or composites of elastomer/plastic materials. [0104] 3. The prepolymers of PDLC preform will comprise acrylic, urethane, epoxy or their composite types. [0105] 4. Phase separation & partial UV curing of the UV-curable portion of PDLC layer to produce a partially-cured PDLC preform film. [0106] 5. The partially-cured PDLC preform could consist of single-layer or multi-layers with various morphologies. [0107] 6. The morphology of LC inclusions in single-layer or multi-layers PDLC preform could be nano-droplet, micro-droplet or macro-droplet. [0108] 7. The thickness of the partially-cured PDLC layer of preform would be within 50-100 microns range. [0109] 8. Collection of preform PDLC film on double-release for on roll or sheet for direct glazing.

[0110] Another example for a process for direct glazing of low-cost and haze-free PDLC glass: [0111] 1. Peeling off the two release sheets from preform PDLC film. [0112] 2. Placing the free-standing PDLC preform layer between two metallized glass supports [0113] 3. Final curing of thermoset portion of PDLC preform layer(s) and LC droplets deformation from spherical to non-spherical or discotic shapes by glass lamination under heat & vacuum pressure. [0114] 4. The final matrix curing and cross-linking by lamination under heat and pressure will cause the reduction of PDLC layer(s) thickness and deformation of LC droplets (layer before 50-100, after 10-50 um). [0115] 5. The deformed shapes of LC droplets will result to extreme reduction or total elimination of haze in the direct glazed PDLC glass. [0116] 6. The process cost of direct glazing of PDLC preform will be much less than standard PDLC lamination process. [0117] 7. The direct glaze PDLC glass will be a low-cost and haze-free product.

[0118] Referring now to FIG. 3, a schematic illustration of the method of manufacturing a direct glaze PDLC at low-cost and haze-free. In this figure two examples of PDLC are shown, one with one formulation (formulation A-31) of liquid crystal 30a and another with two adjacent formulations (formulation A-31 and B-33) 30b, as previously described in FIG. 2. Both PDLCs comprise PET release sheets 32 on both sides. The next step is to separate the PET-release sheets from the formulations. Then, the just separated formulations are sandwiched between two metallized coated glasses 34.

[0119] Referring now to FIG. 4a-b, a schematic illustration of the method of eliminating the haze in the low-cost direct glaze PDLC. As shown in FIG. 4a, once we have the PDLC 40 with two releasing sheets 42, the same release sheets 42 are peeled away leaving only the layer of liquid crystal 41. At this point the liquid crystal layer 41 can be stretched (see arrows), or it can be enclosed between two metallized coated glasses 43 and pressed until the final required thickness, as shown in FIG. 4b. This pressure flattens the liquid crystal domains reducing the haze.

[0120] In a preferred embodiment, the low-cost and haze-free PDLC can be enclosed between two glasses or may be retrofitted on existing interior and exterior architectural glazing, automotive windows, and other interior glazing. A transparent adhesive may be used to stick the panel to the window, which may be integrated with the panel or separately provided. The panel may also be applied to original windows before installation.

[0121] It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.