US20030175480A1 - Microcup compositions having improved flexure resistance and release properties - Google Patents

Microcup compositions having improved flexure resistance and release properties Download PDF

Info

Publication number
US20030175480A1
US20030175480A1 US10/386,622 US38662203A US2003175480A1 US 20030175480 A1 US20030175480 A1 US 20030175480A1 US 38662203 A US38662203 A US 38662203A US 2003175480 A1 US2003175480 A1 US 2003175480A1
Authority
US
United States
Prior art keywords
electrophoretic display
rubber material
rubber
composition
microcup
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/386,622
Inventor
Xianhai Chen
Mary Chan-Park
Xiaojia Wang
Rong-Chang Liang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US10/386,622 priority Critical patent/US20030175480A1/en
Publication of US20030175480A1 publication Critical patent/US20030175480A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00Stock material or miscellaneous articles
    • Y10S428/913Material designed to be responsive to temperature, light, moisture
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/23Sheet including cover or casing
    • Y10T428/234Sheet including cover or casing including elements cooperating to form cells
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/23Sheet including cover or casing
    • Y10T428/234Sheet including cover or casing including elements cooperating to form cells
    • Y10T428/236Honeycomb type cells extend perpendicularly to nonthickness layer
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24479Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24479Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
    • Y10T428/24562Interlaminar spaces
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24479Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
    • Y10T428/24612Composite web or sheet

Definitions

  • the electrophoretic display is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. This general type of display was first proposed in 1969.
  • An electrophoretic display typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes. One of the electrodes is typically transparent. A dispersion composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates.
  • the pigment particles migrate to one side by attraction to the plate of polarity opposite that of the pigment particles.
  • the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color.
  • Intermediate color density (or shades of grey) due to intermediate pigment density at the transparent plate may be obtained by controlling the plate charge through a range of voltages.
  • the partition-type electrophoretic display see M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979)
  • the microencapsulated electrophoretic display as described in U.S. Pat. No. 5,961,804 and U.S. Pat. No. 5,930,026).
  • a partition-type electrophorectic display there are partitions between the two electrodes for dividing the space into smaller cells in order to prevent undesired movements of the particles such as sedimentation.
  • the microencapsulated electrophoretic display has a substantially two dimensional arrangement of microcapsules each having therein an electrophoretic composition of a dielectric fluid and a dispersion of charged pigment particles that visually contrast with the dielectric solvent.
  • the improved electrophoretic display comprises cells formed from micrcups of well-defined shape, size, and aspect ratio and filled with charged pigment particles dispersed in a dielectric solvent.
  • Multifunctional UV curable compositions have been employed to fabricate the microcup array for the improved electrophoretic display.
  • the microcup structure formed tends to be quite brittle.
  • the internal stress in the cups due to the high degree of crosslinking and shrinkage often results in undesirable cracking and delamination of the microcups from the conductor substrate during demolding.
  • the microcup array prepared from the multifunctional UV curable compositions also showed a poor flexure resistance.
  • Suitable rubber materials for this purpose include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives.
  • SBR styrene-butadiene rubber
  • PBR polybutadiene rubber
  • NBR acrylonitrile-butadiene rubber
  • SBS styrene-butadiene-styrene block copolymer
  • SIS styrene-isoprene-styrene block copolymer
  • polybutadiene dimethacrylate CN301 and CN302 from Sartomer
  • Ricacryl 3100 from Ricon Resins Inc.
  • graft (meth)acrylated hydrocarbon polymer Rostomer
  • Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.
  • methacrylate terminated butadiene-acrylonitrile copolymers Hycar VTBNX 1300 ⁇ 33, 1300 ⁇ 43 from B F Goodrich
  • FIGS. 1A and 1B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask of conductor film coated with a thermoset precursor (“top exposure”).
  • FIGS. 2A and 2B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure of the base conductor film coated with a thermoset precursor, in which the base conductor pattern on a transparent substrate serves a substitute for a photomask and is opaque to the radiation (“bottom exposure”).
  • FIGS. 3A and 3B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure combining the top and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”).
  • microcup Unless defined otherwise in this specification, all technical terms are used herein according to their conventional definitions as they are commonly used and understood by those of ordinary skill in the art.
  • the terms “microcup”, “cell”, “well-defined”, “aspect ratio” and “imagewise exposure” in the context of the present application are as defined in the copending applications identified above, as are the dimensions of the microcups.
  • the microcups may be prepared by microembossing or by photolithography.
  • the male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating.
  • a master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 ⁇ ) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal.
  • a master is then ready for electroforming.
  • a typical material used for electroforming is nickel cobalt.
  • the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp.324 (1992).
  • the floor of the mold is typically between about 50 to 400 microns.
  • the master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol.3.099, pp76-82 (1997).
  • the mold can be made by photomachining, using plastics, ceramics or metals.
  • the male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferably about 4 to 50 microns.
  • the male mold may be in the form of a belt, a roller, or a sheet.
  • the belt type of mold is preferred.
  • Micro-cups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed-in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001.
  • the latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or liquid crystal displays.
  • the mold Prior to applying a UV curable resin composition, the mold may be prepared with a mold release to aid in the demolding process, if desired.
  • the UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates.
  • the UV curable resin is dispensed by any appropriate means, such as coating, dipping, pouring and the like, over the male mold.
  • the dispenser may be moving or stationary.
  • a conductor film is overlaid on the UV curable resin.
  • suitable conductor films include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites.
  • Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the micro-cups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means.
  • the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin, which should have a good release property from the mold surface.
  • FIGS. 1, 2 and 3 The photolithographic processes for preparation of the microcup array are described in FIGS. 1, 2 and 3 .
  • the microcup array 10 may be prepared by exposure of a radiation curable material 11 a coated by known methods onto a conductor electrode film 12 to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask 16 to form walls 11 b corresponding to the image projected through the mask 16 .
  • the base conductor film 12 is preferably mounted on a supportive substrate base web 13 , which may comprise a plastic material.
  • the dark squares 14 represent the opaque area and the space between the dark squares represents the opening (transparent) area 15 of the mask 16 .
  • the UV radiates through the opening area 15 onto the radiation curable material 11 a.
  • the exposure is preferably directly onto the radiation curable material 11 a, i.e., the UV does not pass through the substrate 13 or base conductor 12 (top exposure). For this reason, neither the substrate 13 nor the conductor 12 needs to be transparent to the UV or other radiation wavelengths employed.
  • the exposed areas 11 b become hardened and the unexposed areas 11 c (protected by the opaque area 14 of the mask 16 are then removed by an appropriate solvent or developer to form the microcups 17 .
  • the solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone, toluene, acetone, isopropanol or the like.
  • FIGS. 2A and 2B and 3 A and 3 B Two alternative methods for the preparation of the microcup array of the invention by imagewise exposure are illustrated in FIGS. 2A and 2B and 3 A and 3 B. These methods employ UV exposure through the substrate web, using the conductor pattern as a mask.
  • the conductor film 22 used is pre-patterned to comprise cell base electrode portions 24 corresponding to the floor portions of the microcups 27 .
  • the base portions 24 are opaque to the UV wavelength (or other radiation) employed.
  • the spaces 25 between conductor base portions 22 are substantially transparent or transmissive to the UV light.
  • the conductor pattern serves as a photomask.
  • the radiation curable material 21 a is coated upon the substrate 23 and conductor 22 as described in FIG. 2A.
  • the material 21 a is exposed by UV light projected “upwards” (through substrate 23 ) and cured where not shielded by the conductor 22 , i.e., in those areas corresponding to the space 25 .
  • the uncured material 21 c is removed from the unexposed areas as described above, leaving the cured material 21 b to form the walls of the microcups 27 .
  • FIG. 3A illustrates a combination method which uses both the top and bottom exposure principals to produce the microcup array 30 of the invention.
  • the base conductor film 32 is also opaque and line-patterned.
  • the radiation curable material 31 a which is coated on the base conductor 32 and substrate 33 , is exposed from the bottom through the conductor line pattern 32 which serves as the first photomask.
  • a second exposure is performed from the “top” side through the second photomask 36 having a line pattern perpendicular to the conductor lines 32 .
  • the spaces 35 between the lines 34 are substantially transparent or transmissive to the UV light.
  • the wall material 31 b is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup 37 .
  • the unexposed area is then removed by a solvent or developer as described above to reveal the microcups 37 .
  • the radiation curable material used in the processes described above is a thermoplastic or thermoset precursor, such as multifunctional acrylate or methacrylate, vinylether, epoxide and their oligomers, polymers and the like. Multifunctional acrylates and their oligomers are the most preferred. A combination of multifunctional epoxide and multifunctional acrylate is also very useful to achieve desirable physico-mechanical properties.
  • Suitable rubber materials have a Tg (glass transition temperature) lower than 0° C.
  • Unsaturated rubber materials are preferred and rubber materials having uncapped or side chain unsaturated groups such as vinyl, acrylate, methacrylate, allyl groups are particularly preferred. More specifically, suitable rubber materials include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives.
  • SBR styrene-butadiene rubber
  • PBR polybutadiene rubber
  • NBR acrylonitrile-butadiene rubber
  • SBS styrene-butadiene-styrene block copolymer
  • SIS styrene-isoprene-st
  • polybutadiene dimethacrylate CN301 and CN302 from Sartomer
  • Ricacryl 3100 from Ricon Resins Inc.
  • graft (meth)acrylated hydrocarbon polymer Rostomer
  • Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.
  • methacrylate terminated butadiene-acrylonitrile copolymers Hycar VTBNX 1300 ⁇ 33, 1300 ⁇ 43 from B F Goodrich
  • the percentage of rubber component in the UV curable formulation can be in the range from 1 wt-% to 30 wt-%, preferably from 5 wt-% to 20 wt-%, even more preferably from 8-15 wt-%.
  • the rubber components can be soluble or dispersible in the formulation. Ideally, the rubber component is soluble in the formulation before UV curing and phase separates into microdomains after UV curing.
  • Ebercryl® 600 (UCB), 40 parts of SR-399 (Sartomer®), 10 parts of Ebecryl 4827 (UCB), 7 parts of Ebecryl 1360 (UCB), 8 parts of HDDA (UCB), and 0.05 parts of Irgacure® 369 (Ciba Specialty Chemicals), 0.01 parts of isopropyl thioxanthone (Aldrich) were mixed homogeneously and used to prepare the microcup arrary by either the microembossing or photolithographic process.
  • Example 2-7 The same procedure as Example 1 was repeated except that 6, 7, 8, 10, 11 or 14 phr (parts per hundred resin) of Hycar® VTBNX 1300 ⁇ 33 were added to the compositions of Examples 2-7, respectively.
  • microcup compositions of Examples 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 ⁇ m, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ⁇ 5 mW/cm 2 .
  • the coated samples were then 90 degree hand bended to determine the flexure resistance, after the untreated PET was removed. It was found that the flexure resistance of formulations containing more than 8 phr of Hycar VTBNX 1300 ⁇ 33 (Examples 4, 5, 6, 7) was improved significantly (Table 1).
  • Example 1-7 The microcup compositions of the Example 1-7 were coated onto 2 mil PET film with a targeted thickness of about 50 ⁇ m, microembossed with a Ni—Co male mold of 60 ⁇ 60 ⁇ 35 ⁇ m with partition lines of 10 ⁇ m width, UV cured for 20 seconds, and removed from the mold with a 2′′ peeling bar at a speed of about 4-5 ft/min.
  • the formulations containing more than 6 phr of rubber (Examples 2-7) showed significantly improved demoldability (Table 1). Little defect or contamination on the mold was observed for formulations containing 10-15 phr of rubber (Examples 5, 6, 7) after at least 100 molding-demolding cycles.
  • Example 1-7 The microcup compositions of Example 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 ⁇ m, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ⁇ 5 mW/cm 2 .
  • the untreated PET cover sheet was removed.
  • a 15 wt % solution of the sealing material (Kraton® FG-1901X from Shell) in 20/80 (v/v) toluene/hexane was then coated onto the cured microcup layer and dried in 60° C. oven for 10 minutes. The thickness of the dried sealing layer was controlled to be about 5 ⁇ m.
  • a 3M 3710 Scotch® tape was laminated at room temperature onto the sealing layer by a Eagle®35 laminator from GBC at the heavy gauge setting. The T-peel adhesion force was then measured by Instron® at 500 mm/min. The adhesion forces listed in Table 1 were the average of at least 5 measurements. It was found that adhesion between the sealing layer and the cured microcup layer was significantly improved by incorporating rubber into the microcup.
  • Example 8 The same procedure as in Example 8 was repeated except that 5.47 parts of poly(butadiene-co-acrylonitrile) diacrylate (Monomer-Polymer & Dajac Labs, Inc.) was added to the composition. No observable defect on the microcup array or contamination on the Ni—Co male mold was found after about 10 molding-demolding cycles.
  • poly(butadiene-co-acrylonitrile) diacrylate Monomer-Polymer & Dajac Labs, Inc.
  • the electrophoretic fluid prepared in Examples 10 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 11 phr of Hycar® VTBNX 1300 ⁇ 33 (Example 6) on a ITO/PET conductor film.
  • the volatile cosolvent was allowed to evaporate to expose a partially filled microcup array.
  • a 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil.
  • the overcoated microcups were then dried at room temperature.
  • a seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was formed on the microcup array.
  • the electrophoretic fluid prepared in Example 11 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 12 phr of Hycar® VTBNX 1300 ⁇ 33 on a ITO/PET conductor film.
  • the volatile cosolvent was allowed to evaporate to expose a partially filled microcup array.
  • a 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil.
  • the overcoated microcups were then dried at room temperature.
  • a seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was form on the microcup array.

Abstract

This invention relates to a novel composition suitable for use in the manufacture of electrophoretic display cells. The mechanical properties of the cells are significantly improved with this composition in which a rubber material is incorporated.

Description

    BACKGROUND
  • The electrophoretic display is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. This general type of display was first proposed in 1969. An electrophoretic display typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes. One of the electrodes is typically transparent. A dispersion composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates. [0001]
  • When a voltage difference is imposed between the two electrodes, the pigment particles migrate to one side by attraction to the plate of polarity opposite that of the pigment particles. Thus the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color. Intermediate color density (or shades of grey) due to intermediate pigment density at the transparent plate may be obtained by controlling the plate charge through a range of voltages. [0002]
  • There are several types of electrophoretic displays available in the art, for example, the partition-type electrophoretic display (see M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979)) and the microencapsulated electrophoretic display (as described in U.S. Pat. No. 5,961,804 and U.S. Pat. No. 5,930,026). In a partition-type electrophorectic display, there are partitions between the two electrodes for dividing the space into smaller cells in order to prevent undesired movements of the particles such as sedimentation. The microencapsulated electrophoretic display has a substantially two dimensional arrangement of microcapsules each having therein an electrophoretic composition of a dielectric fluid and a dispersion of charged pigment particles that visually contrast with the dielectric solvent. [0003]
  • Furthermore, an improved electrophoretic display (EPD) technology was recently disclosed in the co-pending applications, U.S. Ser. No. 09/518,488, filed on Mar. 3, 2000, U.S. Ser. No. 09/759,212, filed on Jan. 11, 2001, U.S. Ser. No. 09/606,654, filed on Jun. 28, 2000 and U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001, all of which are incorporated herein by reference. The improved electrophoretic display comprises cells formed from micrcups of well-defined shape, size, and aspect ratio and filled with charged pigment particles dispersed in a dielectric solvent. [0004]
  • SUMMARY OF THE INVENTION
  • Multifunctional UV curable compositions have been employed to fabricate the microcup array for the improved electrophoretic display. However, the microcup structure formed tends to be quite brittle. The internal stress in the cups due to the high degree of crosslinking and shrinkage often results in undesirable cracking and delamination of the microcups from the conductor substrate during demolding. The microcup array prepared from the multifunctional UV curable compositions also showed a poor flexure resistance. [0005]
  • It has now been found that resistance toward flexure or stress may be significantly reduced if a rubber component is incorporated into the microcup composition. Two other key properties: demoldability during microembossing and adhesion between the sealing layer and the microcups have also been considerably improved with the composition containing this additional rubber component. [0006]
  • Suitable rubber materials for this purpose include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives. Particularly useful are functionalized rubbers such as polybutadiene dimethacrylate (CN301 and CN302 from Sartomer, Ricacryl 3100 from Ricon Resins Inc.), graft (meth)acrylated hydrocarbon polymer (Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.), and methacrylate terminated butadiene-acrylonitrile copolymers (Hycar VTBNX 1300×33, 1300×43 from B F Goodrich).[0007]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIGS. 1A and 1B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask of conductor film coated with a thermoset precursor (“top exposure”). [0008]
  • FIGS. 2A and 2B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure of the base conductor film coated with a thermoset precursor, in which the base conductor pattern on a transparent substrate serves a substitute for a photomask and is opaque to the radiation (“bottom exposure”). [0009]
  • FIGS. 3A and 3B show alternative processing steps for preparing the microcups involving imagewise photolithographic exposure combining the top and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”).[0010]
  • DETAILED DESCRIPTION OF THE INVENTION
  • Unless defined otherwise in this specification, all technical terms are used herein according to their conventional definitions as they are commonly used and understood by those of ordinary skill in the art. The terms “microcup”, “cell”, “well-defined”, “aspect ratio” and “imagewise exposure” in the context of the present application are as defined in the copending applications identified above, as are the dimensions of the microcups. [0011]
  • The microcups may be prepared by microembossing or by photolithography. [0012]
  • I. Preparation of Microcups by Microembossing [0013]
  • Preparation of the Male Mold [0014]
  • The male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating. A master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 Å) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal. A master is then ready for electroforming. A typical material used for electroforming is nickel cobalt. Alternatively, the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp.324 (1992). The floor of the mold is typically between about 50 to 400 microns. The master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol.3.099, pp76-82 (1997). Alternatively, the mold can be made by photomachining, using plastics, ceramics or metals. [0015]
  • The male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferably about 4 to 50 microns. The male mold may be in the form of a belt, a roller, or a sheet. For continuous manufacturing, the belt type of mold is preferred. [0016]
  • Micro-cup Formation [0017]
  • Micro-cups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed-in the co-pending application, U.S. Ser. No. 09/784,972, filed on Feb. 25, 2001. The latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or liquid crystal displays. Prior to applying a UV curable resin composition, the mold may be prepared with a mold release to aid in the demolding process, if desired. The UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates. The UV curable resin is dispensed by any appropriate means, such as coating, dipping, pouring and the like, over the male mold. The dispenser may be moving or stationary. A conductor film is overlaid on the UV curable resin. Examples of suitable conductor films include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites. Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the micro-cups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means. If the male mold is metallic and opaque, the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin, which should have a good release property from the mold surface. [0018]
  • II. Preparation of Microcup Array by Photolithography [0019]
  • The photolithographic processes for preparation of the microcup array are described in FIGS. 1, 2 and [0020] 3.
  • II(a) Top Exposure [0021]
  • As shown in FIGS. 1A and 1B, the [0022] microcup array 10 may be prepared by exposure of a radiation curable material 11 a coated by known methods onto a conductor electrode film 12 to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask 16 to form walls 11 b corresponding to the image projected through the mask 16. The base conductor film 12 is preferably mounted on a supportive substrate base web 13, which may comprise a plastic material.
  • In the [0023] photomask 16 in FIG. 1A, the dark squares 14 represent the opaque area and the space between the dark squares represents the opening (transparent) area 15 of the mask 16. The UV radiates through the opening area 15 onto the radiation curable material 11 a. The exposure is preferably directly onto the radiation curable material 11 a, i.e., the UV does not pass through the substrate 13 or base conductor 12 (top exposure). For this reason, neither the substrate 13 nor the conductor 12 needs to be transparent to the UV or other radiation wavelengths employed.
  • As shown in FIG. 1B, The exposed [0024] areas 11 b become hardened and the unexposed areas 11 c (protected by the opaque area 14 of the mask 16 are then removed by an appropriate solvent or developer to form the microcups 17. The solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone, toluene, acetone, isopropanol or the like.
  • II(b) Bottom Exposure or Combined Exposure [0025]
  • Two alternative methods for the preparation of the microcup array of the invention by imagewise exposure are illustrated in FIGS. 2A and 2B and [0026] 3A and 3B. These methods employ UV exposure through the substrate web, using the conductor pattern as a mask.
  • Turning first to FIG. 2A, the [0027] conductor film 22 used is pre-patterned to comprise cell base electrode portions 24 corresponding to the floor portions of the microcups 27. The base portions 24 are opaque to the UV wavelength (or other radiation) employed. The spaces 25 between conductor base portions 22 are substantially transparent or transmissive to the UV light. In this case, the conductor pattern serves as a photomask. The radiation curable material 21 a is coated upon the substrate 23 and conductor 22 as described in FIG. 2A. The material 21 a is exposed by UV light projected “upwards” (through substrate 23) and cured where not shielded by the conductor 22, i.e., in those areas corresponding to the space 25. As shown in FIG. 2B, the uncured material 21 c is removed from the unexposed areas as described above, leaving the cured material 21 b to form the walls of the microcups 27.
  • FIG. 3A illustrates a combination method which uses both the top and bottom exposure principals to produce the [0028] microcup array 30 of the invention. The base conductor film 32 is also opaque and line-patterned. The radiation curable material 31 a, which is coated on the base conductor 32 and substrate 33, is exposed from the bottom through the conductor line pattern 32 which serves as the first photomask. A second exposure is performed from the “top” side through the second photomask 36 having a line pattern perpendicular to the conductor lines 32. The spaces 35 between the lines 34 are substantially transparent or transmissive to the UV light. In this process, the wall material 31 b is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup 37.
  • As shown in FIG. 3B, the unexposed area is then removed by a solvent or developer as described above to reveal the [0029] microcups 37.
  • The radiation curable material used in the processes described above is a thermoplastic or thermoset precursor, such as multifunctional acrylate or methacrylate, vinylether, epoxide and their oligomers, polymers and the like. Multifunctional acrylates and their oligomers are the most preferred. A combination of multifunctional epoxide and multifunctional acrylate is also very useful to achieve desirable physico-mechanical properties. [0030]
  • It has now been found that addition of a rubber component significantly improves the quality of the microcups, such as resistance toward flexure or stress, demoldability during the microembossing step, and adhesion between the sealing layer and the microcups. [0031]
  • Suitable rubber materials have a Tg (glass transition temperature) lower than 0° C. Unsaturated rubber materials are preferred and rubber materials having uncapped or side chain unsaturated groups such as vinyl, acrylate, methacrylate, allyl groups are particularly preferred. More specifically, suitable rubber materials include SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives. Particularly useful are functionalized rubbers such as polybutadiene dimethacrylate (CN301 and CN302 from Sartomer, Ricacryl 3100 from Ricon Resins Inc.), graft (meth)acrylated hydrocarbon polymer (Ricacryl 3500 and Ricacryl 3801 from Ricon Resins, Inc.), and methacrylate terminated butadiene-acrylonitrile copolymers (Hycar VTBNX 1300×33, 1300×43 from B F Goodrich). [0032]
  • The percentage of rubber component in the UV curable formulation can be in the range from 1 wt-% to 30 wt-%, preferably from 5 wt-% to 20 wt-%, even more preferably from 8-15 wt-%. The rubber components can be soluble or dispersible in the formulation. Ideally, the rubber component is soluble in the formulation before UV curing and phase separates into microdomains after UV curing. [0033]
  • EXAMPLES Example 1
  • Microcup Composition Without Rubber [0034]
  • 35 parts by weight of Ebercryl® 600 (UCB), 40 parts of SR-399 (Sartomer®), 10 parts of Ebecryl 4827 (UCB), 7 parts of Ebecryl 1360 (UCB), 8 parts of HDDA (UCB), and 0.05 parts of Irgacure® 369 (Ciba Specialty Chemicals), 0.01 parts of isopropyl thioxanthone (Aldrich) were mixed homogeneously and used to prepare the microcup arrary by either the microembossing or photolithographic process. [0035]
  • Example 2-7
  • Rubber-Containing Microcup Compositions [0036]
  • The same procedure as Example 1 was repeated except that 6, 7, 8, 10, 11 or 14 phr (parts per hundred resin) of Hycar® VTBNX 1300×33 were added to the compositions of Examples 2-7, respectively. [0037]
  • Comparison of Flexure Resistance [0038]
  • The microcup compositions of Examples 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 μm, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ˜5 mW/cm[0039] 2. The coated samples were then 90 degree hand bended to determine the flexure resistance, after the untreated PET was removed. It was found that the flexure resistance of formulations containing more than 8 phr of Hycar VTBNX 1300×33 (Examples 4, 5, 6, 7) was improved significantly (Table 1).
  • Comparison of Release Properties Between the Cured Microcup and the Ni—Co Microembossing Male Mold [0040]
  • The microcup compositions of the Example 1-7 were coated onto 2 mil PET film with a targeted thickness of about 50 μm, microembossed with a Ni—Co male mold of 60×60×35 μm with partition lines of 10 μm width, UV cured for 20 seconds, and removed from the mold with a 2″ peeling bar at a speed of about 4-5 ft/min. The formulations containing more than 6 phr of rubber (Examples 2-7) showed significantly improved demoldability (Table 1). Little defect or contamination on the mold was observed for formulations containing 10-15 phr of rubber (Examples 5, 6, 7) after at least 100 molding-demolding cycles. [0041]
  • Comparison of Adhesion Between the Microcup and the Sealing Layers [0042]
  • The microcup compositions of Example 1-7 were coated onto 2 mil PET film with a targeted dry thickness of about 30 μm, covered by untreated PET, and then cured for 20 seconds under UV light at an intensity of ˜5 mW/cm[0043] 2. The untreated PET cover sheet was removed. A 15 wt % solution of the sealing material (Kraton® FG-1901X from Shell) in 20/80 (v/v) toluene/hexane was then coated onto the cured microcup layer and dried in 60° C. oven for 10 minutes. The thickness of the dried sealing layer was controlled to be about 5 μm. A 3M 3710 Scotch® tape was laminated at room temperature onto the sealing layer by a Eagle®35 laminator from GBC at the heavy gauge setting. The T-peel adhesion force was then measured by Instron® at 500 mm/min. The adhesion forces listed in Table 1 were the average of at least 5 measurements. It was found that adhesion between the sealing layer and the cured microcup layer was significantly improved by incorporating rubber into the microcup.
    TABLE 1
    T Peel Adhesion Between the Cured Microcup Material and the Sealing
    Layer
    Hycar Adhesion
    VTBNX (peel) to
    Example 1300x33 sealing layer Flexure Release
    Number (phr) (gm/12.5 mm) Resistance from the mold
    1 0 431 +/− 33 poor, bending fair, some
    line defects
    broke
    2 6 513 +/− 12 fair, bending Good, no
    line broke defect after 50
    cycles
    3 7 fair-good good
    bending line
    broke
    4 8 Good, bending good-
    mark excellent
    5 10 543 +/− 20 Excellent, no Excellent, no
    bending mark defect after
    100 cycles
    6 11 excellent excellent
    7 14 536 +/− 12 excellent excellent
  • Example 8
  • Microcup Composition Without Rubber [0044]
  • 36 parts by weight of Ebercryl® 830 (UCB), 9 parts of SR-399 (Sartomer®), 1.2 parts of Ebecryl 1360 (UCB), 3 parts of HDDA (UCB), 1.25 parts of Irgacure® 500 (Ciba Specialty Chemicals), and 25 parts of MEK (Aldrich) were mixed homogeneously and used to prepare the microcup array by microembossing as described previously, except that the UV curing time was 1 minute. This example showed some defect on the microcup or contamination on a Ni—Co male mold of 60×60×50 μm with 10 μm partition lines after about 10 molding-demolding cycles. [0045]
  • Example 9
  • Microcup Composition With Rubber [0046]
  • The same procedure as in Example 8 was repeated except that 5.47 parts of poly(butadiene-co-acrylonitrile) diacrylate (Monomer-Polymer & Dajac Labs, Inc.) was added to the composition. No observable defect on the microcup array or contamination on the Ni—Co male mold was found after about 10 molding-demolding cycles. [0047]
  • Example 10
  • Pigment Dispersion [0048]
  • 6.42 Grams of Ti Pure R706 was dispersed with a homogenizer into a solution containing 1.94 grams of Fluorolink® D from Ausimont, 0.22 grams of Fluorolink® 7004 also from Ausimont, 0.37 grams of a fluorinated copper phthalocyanine dye from 3M, and 52.54 grams of perfluoro solvent HT-200 (Ausimont). [0049]
  • Example 11
  • Pigment Dispersion [0050]
  • The same as in Example 10, except the Ti Pure R706 and Fluorolink were replaced by polymer coated TiO[0051] 2 particles PC-9003 from Elimentis (Hihstown, N.J.) and Krytox® (Du Pont) respectively.
  • Example 12
  • Microcup Sealing and Electrophoretic Cell [0052]
  • The electrophoretic fluid prepared in Examples 10 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 11 phr of Hycar® VTBNX 1300×33 (Example 6) on a ITO/PET conductor film. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was formed on the microcup array. No observable entrapped air bubbles in the sealed microcups were found under microscope. The sealed microcup array was then post treated by UV radiation or thermal baking to further improve the barrier properties. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after being aged in a 66° C. oven for 5 days. [0053]
  • Example 13
  • Microcup Sealing and Electrophoretic Cell [0054]
  • The electrophoretic fluid prepared in Example 11 was diluted with a volatile perfluoro cosolvent (FC-33 from 3M) and coated onto a microcup array containing 12 phr of Hycar® VTBNX 1300×33 on a ITO/PET conductor film. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene in heptane was then overcoated onto the partially filled cups by a Universal Blade Applicator with an opening of 6 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 5-6 microns thickness with acceptable adhesion was form on the microcup array. No observable entrapped air bubbles in the sealed microcups were found under microscope. The sealed microcup array was then post treated by UV radiation or thermal baking to further improve the barrier properties. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after aged in a 66° C. oven for 5 days. [0055]
  • While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be. substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, materials, compositions, processes, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. For example, it should be noted that the method of the invention for making microcups may also be used for manufacturing microcup arrays for liquid crystal displays. Similarly, the microcup selective filling, sealing and ITO laminating methods of the invention may also be employed in the manufacture of liquid crystal displays. [0056]
  • It is therefore wished that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification. [0057]

Claims (15)

What is claimed is:
1. An electrophoretic display comprising cells formed from a composition comprising a radiation curable material and a rubber material.
2. The electrophoretic display of claim 1 wherein the radiation curable material is a thermoplastic or thermoset precursor.
3. The electrophoretic display of claim 2 wherein said thermoplastic or thermoset precursor is multifunctional acrylate or methacrylate, vinylether, epoxide and their oligomers, polymers and the like.
4. The electrophoretic display of claim 3 wherein said thermoplastic or theormoset precursor is a multifunctional acrylate and its oligomers.
5. The electrophoretic display of claim 2 wherein said radiation curable material is a combination of multifunctional epoxide and multifunctional acrylate.
6. The electrophoretic display of claim 1 wherein the rubber material has a glass transition temperature lower than about 0° C.
7. The electrophoretic display of claim 6 wherein the rubber material is unsaturated.
8. The electrophoretic display of claim 7 wherein the rubber material has uncapped or side chain unsaturated groups such as vinyl, acrylate, methacrylate or allyl groups.
9. The electrophoretic display of claim 1 wherein said rubber material is selected from a group consisting of SBR (styrene-butadiene rubber), PBR (polybutadiene rubber), NBR (acrylonitrile-butadiene rubber), SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and their derivatives.
10. The electrophoretic display of claim 9 wherein said rubber material is polybutadiene dimethacrylate, graft (meth)acrylated hydrocarbon polymer or methacrylate terminated butadiene-acrylonitrile copolymers.
11. The electrophoretic display of claim 1 wherein said composition comprising from about 1 to about 30% by weight of the rubber material.
12. The electrophoretic display of claim 11 wherein said composition comprising from about 5 to about 20% by weight of the rubber material.
13. The electrophoretic display of claim 12 wherein said composition comprising from about 8 to about 15% by weight of the rubber material.
14. A process for the manufacture of an electrophoretic display which process comprises forming microcups by microembossing using a composition comprising a radiation curable material and a rubber material.
15. A process for the manufacture of an electrophoretic display which process comprises forming microcups by photolithography using a composition comprising a radiation curable material and a rubber material.
US10/386,622 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties Abandoned US20030175480A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/386,622 US20030175480A1 (en) 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/840,756 US6753067B2 (en) 2001-04-23 2001-04-23 Microcup compositions having improved flexure resistance and release properties
US10/386,622 US20030175480A1 (en) 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/840,756 Division US6753067B2 (en) 2001-04-23 2001-04-23 Microcup compositions having improved flexure resistance and release properties

Publications (1)

Publication Number Publication Date
US20030175480A1 true US20030175480A1 (en) 2003-09-18

Family

ID=25283136

Family Applications (4)

Application Number Title Priority Date Filing Date
US09/840,756 Expired - Lifetime US6753067B2 (en) 2001-04-23 2001-04-23 Microcup compositions having improved flexure resistance and release properties
US10/386,622 Abandoned US20030175480A1 (en) 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties
US10/386,895 Abandoned US20030175481A1 (en) 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties
US10/621,192 Expired - Lifetime US6833177B2 (en) 2001-04-23 2003-07-15 Microcup compositions having improved flexure resistance and release properties

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/840,756 Expired - Lifetime US6753067B2 (en) 2001-04-23 2001-04-23 Microcup compositions having improved flexure resistance and release properties

Family Applications After (2)

Application Number Title Priority Date Filing Date
US10/386,895 Abandoned US20030175481A1 (en) 2001-04-23 2003-03-11 Microcup compositions having improved flexure resistance and release properties
US10/621,192 Expired - Lifetime US6833177B2 (en) 2001-04-23 2003-07-15 Microcup compositions having improved flexure resistance and release properties

Country Status (9)

Country Link
US (4) US6753067B2 (en)
EP (1) EP1390809B1 (en)
JP (1) JP4422965B2 (en)
KR (1) KR20030090768A (en)
CN (1) CN1172215C (en)
AT (1) ATE278205T1 (en)
DE (1) DE60201442T2 (en)
TW (1) TWI308249B (en)
WO (1) WO2002086613A2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10401668B2 (en) 2012-05-30 2019-09-03 E Ink California, Llc Display device with visually-distinguishable watermark area and non-watermark area
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US10698265B1 (en) 2017-10-06 2020-06-30 E Ink California, Llc Quantum dot film
US10802373B1 (en) 2017-06-26 2020-10-13 E Ink Corporation Reflective microcells for electrophoretic displays and methods of making the same
US10921676B2 (en) 2017-08-30 2021-02-16 E Ink Corporation Electrophoretic medium
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector

Families Citing this family (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6831770B2 (en) * 2000-03-03 2004-12-14 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6885495B2 (en) * 2000-03-03 2005-04-26 Sipix Imaging Inc. Electrophoretic display with in-plane switching
US7158282B2 (en) * 2000-03-03 2007-01-02 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US20070237962A1 (en) 2000-03-03 2007-10-11 Rong-Chang Liang Semi-finished display panels
US7715088B2 (en) 2000-03-03 2010-05-11 Sipix Imaging, Inc. Electrophoretic display
US8361356B2 (en) 2001-06-04 2013-01-29 Sipix Imaging, Inc. Composition and process for the sealing of microcups in roll-to-roll display manufacturing
TWI310098B (en) * 2002-05-03 2009-05-21 Sipix Imaging Inc Methods of surface modification for improving electrophoretic display performance
US6767942B2 (en) 2002-07-18 2004-07-27 Xerox Corporation Coatings having fully fluorinated co-solubilizer, metal material and fluorinated solvent
TW575646B (en) * 2002-09-04 2004-02-11 Sipix Imaging Inc Novel adhesive and sealing layers for electrophoretic displays
US7166182B2 (en) * 2002-09-04 2007-01-23 Sipix Imaging, Inc. Adhesive and sealing layers for electrophoretic displays
TWI300157B (en) * 2002-09-10 2008-08-21 Sipix Imaging Inc Electrochromic or electrodeposition display and process for their preparation
US7616374B2 (en) * 2002-09-23 2009-11-10 Sipix Imaging, Inc. Electrophoretic displays with improved high temperature performance
US8023071B2 (en) * 2002-11-25 2011-09-20 Sipix Imaging, Inc. Transmissive or reflective liquid crystal display
TWI297089B (en) * 2002-11-25 2008-05-21 Sipix Imaging Inc A composition for the preparation of microcups used in a liquid crystal display, a liquid crystal display comprising two or more layers of microcup array and process for its manufacture
US9346987B2 (en) * 2003-01-24 2016-05-24 E Ink California, Llc Adhesive and sealing layers for electrophoretic displays
TWI230832B (en) * 2003-01-24 2005-04-11 Sipix Imaging Inc Novel adhesive and sealing layers for electrophoretic displays
US7572491B2 (en) * 2003-01-24 2009-08-11 Sipix Imaging, Inc. Adhesive and sealing layers for electrophoretic displays
US9039401B2 (en) 2006-02-27 2015-05-26 Microcontinuum, Inc. Formation of pattern replicating tools
US9307648B2 (en) 2004-01-21 2016-04-05 Microcontinuum, Inc. Roll-to-roll patterning of transparent and metallic layers
FR2872590B1 (en) * 2004-07-02 2006-10-27 Essilor Int METHOD FOR PRODUCING AN OPHTHALMIC GLASS AND OPTICAL COMPONENT SUITABLE FOR CARRYING OUT SAID METHOD
PT1763699E (en) * 2004-07-02 2011-11-24 Essilor Int Method for producing a transparent optical element, an optical component involved into said method and the thus obtained optical element
US20060033676A1 (en) * 2004-08-10 2006-02-16 Kenneth Faase Display device
US7042614B1 (en) 2004-11-17 2006-05-09 Hewlett-Packard Development Company, L.P. Spatial light modulator
FR2879757B1 (en) * 2004-12-17 2007-07-13 Essilor Int METHOD FOR PRODUCING A TRANSPARENT OPTICAL ELEMENT, OPTICAL COMPONENT INVOLVED IN THIS METHOD AND OPTICAL ELEMENT THUS OBTAINED
US7463409B2 (en) * 2004-12-20 2008-12-09 Palo Alto Research Center Incorporated Flexible electrophoretic-type display
FR2888951B1 (en) * 2005-07-20 2008-02-08 Essilor Int RANDOMIZED PIXELLIZED OPTICAL COMPONENT, METHOD FOR MANUFACTURING THE SAME, AND USE THEREOF IN THE MANUFACTURE OF A TRANSPARENT OPTICAL ELEMENT
FR2888950B1 (en) * 2005-07-20 2007-10-12 Essilor Int TRANSPARENT PIXELLIZED OPTICAL COMPONENT WITH ABSORBENT WALLS ITS MANUFACTURING METHOD AND USE IN FARICATION OF A TRANSPARENT OPTICAL ELEMENT
FR2888948B1 (en) * 2005-07-20 2007-10-12 Essilor Int PIXELLIZED TRANSPARENT OPTIC COMPONENT COMPRISING AN ABSORBENT COATING, METHOD FOR PRODUCING THE SAME AND USE THEREOF IN AN OPTICAL ELEMENT
FR2888947B1 (en) * 2005-07-20 2007-10-12 Essilor Int OPTICAL CELL COMPONENT
FR2901367B1 (en) * 2006-05-17 2008-10-17 Essilor Int IMPLEMENTING A TRANSPARENT OPTICAL ELEMENT COMPRISING A SUBSTANCE CONTAINED IN CELLS
CN100412677C (en) * 2006-06-12 2008-08-20 天津大学 Preparation of microcheck method electrophoresis display
WO2008014519A2 (en) * 2006-07-28 2008-01-31 Microcontinuum, Inc. Addressable flexible patterns
TW200811569A (en) * 2006-08-21 2008-03-01 Prime View Int Co Ltd E-ink display panel
FR2907559B1 (en) * 2006-10-19 2009-02-13 Essilor Int ELECRO-COMMANDABLE OPTICAL COMPONENT COMPRISING A SET OF CELLS
US7774106B2 (en) * 2006-12-22 2010-08-10 Pratt - Whitney Canada Corp. Cruise control FADEC logic
FR2910642B1 (en) * 2006-12-26 2009-03-06 Essilor Int TRANSPARENT OPTICAL COMPONENT WITH TWO CELL ARRAYS
FR2911404B1 (en) * 2007-01-17 2009-04-10 Essilor Int TRANSPARENT OPTICAL COMPONENT WITH CELLS FILLED WITH OPTICAL MATERIAL
US8940117B2 (en) 2007-02-27 2015-01-27 Microcontinuum, Inc. Methods and systems for forming flexible multilayer structures
US8804941B2 (en) * 2007-07-13 2014-08-12 Plumchoice, Inc. Systems and methods for hybrid delivery of remote and local technical support via a centralized service
US9873001B2 (en) 2008-01-07 2018-01-23 Salutaris Medical Devices, Inc. Methods and devices for minimally-invasive delivery of radiation to the eye
JP5173444B2 (en) * 2008-01-07 2013-04-03 株式会社アルバック Sealing panel manufacturing method and plasma display panel manufacturing method using the same
JP5173504B2 (en) * 2008-03-17 2013-04-03 株式会社アルバック Sealing panel manufacturing method and plasma display panel manufacturing method using the same
US8266858B2 (en) * 2010-02-17 2012-09-18 Unisaf Enterprise Company Limited Waterproof heat-insulation construction method and module
US8845912B2 (en) 2010-11-22 2014-09-30 Microcontinuum, Inc. Tools and methods for forming semi-transparent patterning masks
US9388307B2 (en) * 2012-11-27 2016-07-12 E Ink California, Llc Microcup compositions
TWI493270B (en) 2012-12-28 2015-07-21 E Ink Holdings Inc Display device and fabrication method of display device
US9589797B2 (en) 2013-05-17 2017-03-07 Microcontinuum, Inc. Tools and methods for producing nanoantenna electronic devices
US10043284B2 (en) 2014-05-07 2018-08-07 Varian Medical Systems, Inc. Systems and methods for real-time tumor tracking
US9919165B2 (en) 2014-05-07 2018-03-20 Varian Medical Systems, Inc. Systems and methods for fiducial to plan association
WO2021241129A1 (en) 2020-05-29 2021-12-02 三井化学株式会社 Sealant for display devices

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4268339A (en) * 1979-07-17 1981-05-19 General Electric Company Process for radiation cured continuous laminates
US5182332A (en) * 1989-08-02 1993-01-26 Mitsubishi Rayon Co., Ltd. Dental composition
US6287490B2 (en) * 1997-04-18 2001-09-11 Ivoclar Ag Method for manufacturing a dental prosthesis
US20020126249A1 (en) * 2001-01-11 2002-09-12 Rong-Chang Liang Transmissive or reflective liquid crystal display and novel process for its manufacture

Family Cites Families (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3612758A (en) 1969-10-03 1971-10-12 Xerox Corp Color display device
US3668106A (en) 1970-04-09 1972-06-06 Matsushita Electric Ind Co Ltd Electrophoretic display device
US3697679A (en) 1970-07-01 1972-10-10 Ampex Automatic threading video recorder
US4093534A (en) 1974-02-12 1978-06-06 Plessey Handel Und Investments Ag Working fluids for electrophoretic image display devices
US4071430A (en) 1976-12-06 1978-01-31 North American Philips Corporation Electrophoretic image display having an improved switching time
US4285801A (en) 1979-09-20 1981-08-25 Xerox Corporation Electrophoretic display composition
JPS59171930A (en) 1983-03-18 1984-09-28 Matsushita Electric Ind Co Ltd Electrophoresis display element
US4741988A (en) 1985-05-08 1988-05-03 U.S. Philips Corp. Patterned polyimide film, a photosensitive polyamide acid derivative and an electrophoretic image-display cell
US4735778A (en) * 1985-08-28 1988-04-05 Kureha Kagaku Kohyo Kabushiki Kaisha Microtiter plate
US4680103A (en) 1986-01-24 1987-07-14 Epid. Inc. Positive particles in electrophoretic display device composition
JP2777729B2 (en) 1989-04-26 1998-07-23 エヌオーケー株式会社 Electrophoretic display device and method of manufacturing the same
US4995718A (en) 1989-11-15 1991-02-26 Honeywell Inc. Full color three-dimensional projection display
US5326865A (en) 1990-06-08 1994-07-05 Hercules Incorporated Arylazo and poly(arylazo) dyes having at least one core radical selected from naphthyl or anthracyl and having at least one 2,3-dihydro-1,3-dialkyl perimidine substituent
CA2114650C (en) 1991-08-29 1999-08-10 Frank J. Disanto Electrophoretic display panel with internal mesh background screen
US5279511A (en) 1992-10-21 1994-01-18 Copytele, Inc. Method of filling an electrophoretic display
JPH08510790A (en) 1993-05-21 1996-11-12 コピイテル,インコーポレイテッド Method for preparing electrophoretic dispersion containing two types of particles having different colors and opposite charges
US5380362A (en) 1993-07-16 1995-01-10 Copytele, Inc. Suspension for use in electrophoretic image display systems
US5616449A (en) * 1993-11-01 1997-04-01 Polaroid Corporation Lithographic printing plates with dispersed rubber additives
US6111598A (en) 1993-11-12 2000-08-29 Peveo, Inc. System and method for producing and displaying spectrally-multiplexed images of three-dimensional imagery for use in flicker-free stereoscopic viewing thereof
US5403518A (en) 1993-12-02 1995-04-04 Copytele, Inc. Formulations for improved electrophoretic display suspensions and related methods
US5699097A (en) 1994-04-22 1997-12-16 Kabushiki Kaisha Toshiba Display medium and method for display therewith
JPH10501301A (en) 1994-05-26 1998-02-03 コピイテル,インコーポレイテッド Fluorinated dielectric suspensions for electrophoretic image displays and related methods
US6017584A (en) 1995-07-20 2000-01-25 E Ink Corporation Multi-color electrophoretic displays and materials for making the same
US6120839A (en) 1995-07-20 2000-09-19 E Ink Corporation Electro-osmotic displays and materials for making the same
US6120588A (en) 1996-07-19 2000-09-19 E Ink Corporation Electronically addressable microencapsulated ink and display thereof
US5835174A (en) 1995-10-12 1998-11-10 Rohm And Haas Company Droplets and particles containing liquid crystal and films and apparatus containing the same
US6037058A (en) 1995-10-12 2000-03-14 Rohms And Haas Company Particles and droplets containing liquid domains and method for forming in an acueous medium
US5773375A (en) * 1996-05-29 1998-06-30 Swan; Michael D. Thermally stable acoustical insulation
US5930026A (en) 1996-10-25 1999-07-27 Massachusetts Institute Of Technology Nonemissive displays and piezoelectric power supplies therefor
US5961804A (en) 1997-03-18 1999-10-05 Massachusetts Institute Of Technology Microencapsulated electrophoretic display
US6252624B1 (en) 1997-07-18 2001-06-26 Idemitsu Kosan Co., Ltd. Three dimensional display
US6067185A (en) 1997-08-28 2000-05-23 E Ink Corporation Process for creating an encapsulated electrophoretic display
US5914806A (en) 1998-02-11 1999-06-22 International Business Machines Corporation Stable electrophoretic particles for displays
WO1999056171A1 (en) 1998-04-27 1999-11-04 E-Ink Corporation Shutter mode microencapsulated electrophoretic display
US6184856B1 (en) 1998-09-16 2001-02-06 International Business Machines Corporation Transmissive electrophoretic display with laterally adjacent color cells
US6312304B1 (en) 1998-12-15 2001-11-06 E Ink Corporation Assembly of microencapsulated electronic displays
US6327072B1 (en) 1999-04-06 2001-12-04 E Ink Corporation Microcell electrophoretic displays
JP2001056653A (en) * 1999-06-11 2001-02-27 Ricoh Co Ltd Display liquid for electrophoresis display, display particles, display medium utilizing the foregoing same, display device, display method, display, recording sheet, display and reversible display type signboard
JP5394601B2 (en) 1999-07-01 2014-01-22 イー インク コーポレイション Electrophoretic medium provided with spacer
JP4400018B2 (en) * 1999-08-06 2010-01-20 セイコーエプソン株式会社 Electrophoretic display device
US6337761B1 (en) 1999-10-01 2002-01-08 Lucent Technologies Inc. Electrophoretic display and method of making the same
US6930818B1 (en) 2000-03-03 2005-08-16 Sipix Imaging, Inc. Electrophoretic display and novel process for its manufacture
US6750844B2 (en) 2000-06-14 2004-06-15 Canon Kabushiki Kaisha Electrophoretic display device and process for production thereof
DE60120315T2 (en) 2000-10-04 2007-05-16 Seiko Epson Corp. Electrophoretic device and its production method
US6663820B2 (en) * 2001-03-14 2003-12-16 The Procter & Gamble Company Method of manufacturing microneedle structures using soft lithography and photolithography

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4268339A (en) * 1979-07-17 1981-05-19 General Electric Company Process for radiation cured continuous laminates
US5182332A (en) * 1989-08-02 1993-01-26 Mitsubishi Rayon Co., Ltd. Dental composition
US6287490B2 (en) * 1997-04-18 2001-09-11 Ivoclar Ag Method for manufacturing a dental prosthesis
US20020126249A1 (en) * 2001-01-11 2002-09-12 Rong-Chang Liang Transmissive or reflective liquid crystal display and novel process for its manufacture

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10831052B2 (en) 2012-05-30 2020-11-10 E Ink California, Llc Display device with visually-distinguishable watermark area and non-watermark area
US10401668B2 (en) 2012-05-30 2019-09-03 E Ink California, Llc Display device with visually-distinguishable watermark area and non-watermark area
US11372306B2 (en) 2017-06-26 2022-06-28 E Ink Corporation Reflective microcells for electrophoretic displays and methods of making the same
US10802373B1 (en) 2017-06-26 2020-10-13 E Ink Corporation Reflective microcells for electrophoretic displays and methods of making the same
US10921676B2 (en) 2017-08-30 2021-02-16 E Ink Corporation Electrophoretic medium
US10698265B1 (en) 2017-10-06 2020-06-30 E Ink California, Llc Quantum dot film
US11493805B2 (en) 2017-10-06 2022-11-08 E Ink California, Llc Quantum dot film with sealed microcells
WO2020033787A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US11314098B2 (en) 2018-08-10 2022-04-26 E Ink California, Llc Switchable light-collimating layer with reflector
WO2020033175A1 (en) 2018-08-10 2020-02-13 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11397366B2 (en) 2018-08-10 2022-07-26 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11435606B2 (en) 2018-08-10 2022-09-06 E Ink California, Llc Driving waveforms for switchable light-collimating layer including bistable electrophoretic fluid
US11656526B2 (en) 2018-08-10 2023-05-23 E Ink California, Llc Switchable light-collimating layer including bistable electrophoretic fluid
US11719953B2 (en) 2018-08-10 2023-08-08 E Ink California, Llc Switchable light-collimating layer with reflector

Also Published As

Publication number Publication date
ATE278205T1 (en) 2004-10-15
US20030175481A1 (en) 2003-09-18
US6833177B2 (en) 2004-12-21
KR20030090768A (en) 2003-11-28
US20020176963A1 (en) 2002-11-28
JP4422965B2 (en) 2010-03-03
WO2002086613A3 (en) 2003-12-11
US20040013855A1 (en) 2004-01-22
DE60201442D1 (en) 2004-11-04
EP1390809B1 (en) 2004-09-29
TWI308249B (en) 2009-04-01
EP1390809A2 (en) 2004-02-25
US6753067B2 (en) 2004-06-22
DE60201442T2 (en) 2005-10-13
WO2002086613A2 (en) 2002-10-31
CN1172215C (en) 2004-10-20
CN1381760A (en) 2002-11-27
JP2004536332A (en) 2004-12-02

Similar Documents

Publication Publication Date Title
US6753067B2 (en) Microcup compositions having improved flexure resistance and release properties
KR100859305B1 (en) Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US6672921B1 (en) Manufacturing process for electrophoretic display
US7233429B2 (en) Electrophoretic display
US6788449B2 (en) Electrophoretic display and novel process for its manufacture
US6987605B2 (en) Transflective electrophoretic display
US6865012B2 (en) Electrophoretic display and novel process for its manufacture
JP2005509690A5 (en)
US8361356B2 (en) Composition and process for the sealing of microcups in roll-to-roll display manufacturing
US20030043450A1 (en) Electrophoretic display with sub relief structure for high contrast ratio and improved shear and/or compression resistance
JP2004536344A (en) In-plane switching electrophoretic display
JPH0980216A (en) Production of color filter

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION