CN1023231C - Light modulating materials comprising liquid crystal microdroplets dispersed in birefringent polymeric matrix - Google Patents
Light modulating materials comprising liquid crystal microdroplets dispersed in birefringent polymeric matrix Download PDFInfo
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Abstract
A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the liquid crystal phase structure and configuration of the light shutter device.
Description
The present invention relates to the liquid crystal light-modulating prepared material, particularly contain the light modulating materials of the liquid crystal droplet of disperse in the synthetic resins matrix of birefringent, energy transmissive.
Phase-splitting dispersed liquid crystal droplet in the lucite matrix and the advantage that light modulating materials had that obtains are at as a reference United States Patent (USP) 4,671,618; 4,673,255; 4,685,771; With 4,688, discuss in 900.This class material is called as liquid crystal (PDLC) material of polymkeric substance disperse.
The method of phase-splitting can be by polymerization (PIPS), and thermoinduction (TIPS) or solvent evaporation (SIPS) realize.As at United States Patent (USP) 4,685, disclosed in 771 and 4,688,900, in these technology, adopted Resins, epoxy.For the PIPS method, adopt additional solidifying agent, for example aliphatic amide or use UV-light carries out polymerization to obtain liquid crystal droplet in the thermofixation polymeric epoxy resin to matrix component and the uncured Resins, epoxy that contains liquid crystal.For the TIPS method, contain the matrix component of liquid crystal and be heated to produce thermoplastic Resins, epoxy through the non-crosslinked solidifying agent of unary alkylamine and so on is cured modified, cooling then is to produce liquid crystal droplet in the thermoplasticity polymeric epoxy resin.
The light modulating materials that can link up on electricity that obtains with the phase-splitting technology adopts the liquid crystal that presents positive dielectric anisotropy.This class material is opaque to incident light when added electric field not, and is transparent to incident light when electric field is arranged.
The mechanical encapsulation technology is used to make the device (seeing French Patent 2,139,537) that is positive dielectric anisotropy (seeing United States Patent (USP) 4,435,047) and negative dielectric anisotropic that adopts liquid crystal.Adopt device substantially transparent when field-free of negative dielectric anisotropy liquid crystal, when having, increase its opaqueness with alive effect.
The various technology that contain the light modulating materials of liquid crystal droplet in the transparent resin matrix that are produced on, all can adopt technology with the effective refractive index of droplet and matrix refractive index match and mismatch to obtain suitable viewing angle simultaneously, wherein, infiltrate indicating meter, window of this material etc., can make it to do to such an extent that easily observe or transparent.For example, at the PDLC material is when being made by the liquid crystal with positive dielectric anisotropy, general and the matrix refractive index match of its normal refraction rate, like this, owing to droplet refractive optical axis is parallel to electric field and perpendicular to observation surface arranging, then there are being under the field condition indicating meter or the window can be in sight or seem transparent.Under no field condition, not parallel arrangement of optical axis or random orientation, then incident light is scattered and makes indicating meter or window seem opaque.
When the normal refraction rate of liquid crystal and matrix refractive index match, in above-mentioned window or indicating meter, device seem the most transparent (having under the field condition) during observation on facing usually perpendicular to the direction of an electric field on observation surface.Adding high spud angle will increase " optical haze " and reduce transparency, becomes when enough big opaque basically at the inclination angle.The generation of this optical haze is because observation angle is got over offset from perpendicular, and the mismatch of the extraordinary refractive index of the liquid crystal droplet of seeing and matrix specific refractory power is just big more.
Have been found that the liquid crystal light-modulating prepared material that to make a kind of the above-mentioned type now, its essentially no optical haze and all transparent on all observation angles.This by adopt birefringent material as matrix and make droplet normal and extraordinary refractive index and matrix normally and extraordinary refractive index be complementary and realize.When the optical axis of droplet and matrix is arranged being aligned or when parallel, material is transparent, and no matter how observation angle does not see the mismatch of specific refractory power yet.The observing angle of baze-free is ± 90 ° from observing surperficial vertical line.Since the reflection on surface, for example in substrate internal surface and the issuable reflection of outside surface, actual visual field is about ± 60 °.
Novel material can be worked in the ordinary way, then it have under the field condition transparent and opaque under no field condition.In addition, find also that novel material also can be made with opposite or " fault secure " mode to work that then material is transparent and opaque when having when field-free.
The present invention includes a kind of optical modulation liquid-crystal apparatus that contains novel PDLC material.Novel material comprises the liquid crystal droplet of disperse in a kind of matrix of birefringent energy printing opacity, the effective refractive index of droplet and matrix mates on all directions of incident light, thereby field condition is being arranged or do not having the transparent and baze-free of device under a kind of situation among the field condition, and field condition is being arranged or do not having effective refractive index mismatch under the another kind of situation among the field condition, thereby device is opaque.In specific embodiment of the present invention that will narrate below, one of liquid crystal of droplet and matrix is a kind of liquid crystalline polymers.
One embodiment of the present of invention more specifically comprise a kind of optical modulation liquid crystal device, it contains a kind of material that is made of the combinations of low molecular weight liquid crystals droplet of disperse in the transparent liquid crystal polymer matrix, the polymerizable mesogenic matrix has with respect to the localized optical axis of this material surface, normal and the extraordinary refractive index of liquid crystal droplet respectively with matrix normally and extraordinary refractive index be complementary, thereby this material transparent and baze-free on all incident light directions when the optical axis of droplet is parallel to the arrangement of matrix optical axis, and material is opaque when the effective refractive index mismatch of droplet and matrix.A kind of matrix of particularly suitable is the liquid crystal side based polyalcohol.
According to another aspect of the present invention, provided a kind of manufacturing can show the optical modulation liquid crystal material of the baze-free transparency on all directions of incident light method, it is included in the step that forms the liquid crystal droplet of phased disperse in a kind of polymer matrix of birefringent light-permeable, droplet and matrix have the normal and extraordinary refractive index that is complementary, and the matrix optical axis observed surperficial localization step with respect to material, just can obtain the transparency of baze-free by the droplet optical axis being parallel to matrix optical axis location like this, and just make material become opaque by the effective refractive index mismatch that makes droplet and matrix.In a most preferred embodiment, this method is to realize by the lower molecular weight drop that forms phased disperse in a kind of liquid crystalline polymers matrix, medium unit in the matrix has positive dielectric anisotropy, selects liquid crystal drop and matrix to make it the normal and unusual specific refractory power of coupling.
Just as is known to the person skilled in the art, the extraordinary refractive index n of single shaft liquid crystal
eCan be used as the line polarized light that electric vector is parallel to its optical axis measures.Like this, the optical axis of the optical axis of double refraction matrix and new PDLC material liquid crystal droplet should be on the same direction with respect to separately extraordinary refractive index.Equally, the normal refraction rate direction that should be understood that double refraction matrix and droplet is by determining perpendicular to the electric vector of optical axis vibration separately.
The polymeric liquid crystal is known in prior art.Polymeric liquid crystal or liquid crystalline polymers are the combinations of medium unit and main polymer chain.Medium unit and main polymer chain can by dual mode in conjunction with and produce two kinds of liquid crystalline polymerss: a kind of is that medium unit is included in the main polymer chain, a kind of be medium unit be attached to main polymer chain side group (side chain) on.The structure of liquid crystalline polymers, performance and general synthetic method are at " Pure ﹠amp; Appl Chem. ", 57 volumes 1009(1985) with " Polymer Liquid Crystals ", were discussed in the academic communication nineteen eighty-two supplementary issue.
The present invention adopts main chain or side chain polymer as droplet or matrix.Liquid crystal is side chain polymer preferably, because be easier to the location than backbone units under the effect on the scene of side chain medium unit.Compare with existing PDLC material, adopting the characteristics of the new PDLC material of suitable liquid crystal wire side group polymkeric substance among the present invention is the full visual field of baze-free (acerous dependency), the optionally opposite or mode of operation of " fault secure ", and the electrical response characteristics of the less driving voltage of needs that has improved.
The liquid crystalline polymers matrix of selecting for use can be by making through any suitable synthetic prepolymer of intermediary's solidifying agent solidified, or made by the uncured resin that contains medium unit, and resin is solidified by suitable solidifying agent.For example, a kind of liquid crystal side group PDLC material is with the PIPS method liquid crystal and intermediary's solidifying agent and uncured synthetic resins to be mixed, and solidifies with the polymerization that impels matrix and the formation of association droplet to make again.With liquid crystal and solidifying agent with contain intermediary's side chain, uncured synthetic resins mixes liquid crystalline side-chain PDLC material with the PIPS method, solidifies with the polymerization that impels matrix and the formation of association droplet to make again.To certain temperature, resin and liquid crystal form homogeneous solution to the also available TIPS method of liquid crystalline side-chain PDLC material under this temperature, this solution cooling are made with the formation droplet again with liquid crystal and the mixture heating up of polymerization synthetic resin that contains liquid crystalline side-chain.The also available SIPS method of liquid crystalline side-chain PDLC material is removed solvent and is made to impel droplet to form from liquid crystal and the solution of resin that contains medium unit.
The matrix of selecting for use comprises the thermoplastic liquid crystal side group synthetic polymer of modification, Resins, epoxy for example, polyvinyl butyral acetal, polyvinyl acetate, polyvinyl formal, polycarbonate, polyvinyl methyl ketone, polymethyl acrylate, poly-cyclohexyl methacrylic acid ester, poly-isobutyl-methacrylic acid ester, and polymethylmethacrylate, or other equivalent.The liquid crystal side group preferably includes a cyaniding xenyl.Cyaniding xenyl part is preferably separated so that intermediary's part is located on a common direction by a sufficiently long soft alkyl unit, interval and main polymer chain.An example of suitable intermediary's solidifying agent is a cyaniding xenyl alcoxyl amine.
The medium unit of liquid crystalline polymers matrix can be located in a different manner.When medium unit had positive dielectric anisotropy, alternating-electric field or magnetic field can make optical axis be parallel to and locate, promptly usually perpendicular to the direction location of observing the surface.By the crosslinking polymerization matrix, material is operated in below the second-order transition temperature, or the glass substrate that material is housed is carried out surface treatment just can after the disappearance on the scene this location situation is still kept.
Become when opaque by transparent at said apparatus, the effective refractive index of droplet changes.This may occur in several different situations.The change of first orientation structure for example becomes a kind of radial structure, and it changes the numerical value of droplet effective refractive index.Various types of droplet orientation structures have been listed in the document.Should be understood that the surface condition of the elasticity of the size of the orientation of droplet structure and droplet, liquid crystal and polymkeric substance generation is relevant under field-free state.The another kind of mechanism that changes the droplet specific refractory power is the surface restraint condition effect that is subjected to aspheric surface or droplet limit wall, and causes the change of droplet direction of optic axis.In phase process, produce the non-spherical droplet of random orientation often, and when field-free, cause the random orientation of droplet optical axis.This situation makes the droplet effective refractive index change with respect to the polymeric matrix specific refractory power.And under no field condition, make material become opaque.
A kind of light dispensing device that adopts novel baze-free PDLC material of the present invention as window or photoswitch, can make and work in normal way, and it is opaque under no field condition, and is having the next one-tenth of field condition transparent or printing opacity.This is to realize perpendicular to the observation watch planar orientation by the optical axis that makes the double refraction matrix.Having under the field condition, alternating-electric field makes the optical axis of the liquid crystal droplet with positive dielectric anisotropy be parallel to the optical axis of matrix and locatees, promptly perpendicular to observing the surface.Because the normal and extraordinary refractive index of droplet and matrix is complementary respectively, material is being arranged under the state to all equal baze-frees of incident light direction.Under field-free state, the orientation structural change of droplet, then the effective refractive index of droplet for all incident light directions all with the effective refractive index mismatch of matrix, thereby incident light is scattered, material is opaque.
New PDLC material of the present invention also can be made with opposite mode or fault secure mode and work, and makes material transparent under field-free state, and have under the state opaque.In the embodiment of a novel material with opposite mode work, adopt any above-mentioned technology to make the matrix of liquid crystal droplet phase-splitting disperse, preferably in the liquid crystalline polymers matrix at the double refraction printing opacity.The same with other embodiment of the present invention, the normal and extraordinary refractive index of droplet respectively with matrix normally and extraordinary refractive index be complementary.After material is made, apply the opposite tangential force of direction so that the inclined light shaft of matrix in observing surface alignment.Tangential force also makes elongation of droplet and makes its optical axis be parallel to the optical axis location of matrix.Make like this droplet and matrix effective refractive index coupling so that under no field condition material to all transparent and baze-frees of incident light direction.When material is dressed up an optical switch device and when adding a field on perpendicular to the direction of observing the surface, had positive dielectric anisotropy or negative dielectric anisotropic according to droplet, droplet will be distinguished parallel or perpendicular to the direction location of field.Under any situation, the field causes the effective refractive index mismatch of the effective refractive index and the matrix of droplet, thus material scattering light and opaque.
Among another reverse or the embodiment with the material of fault secure mode work, liquid crystal droplet has dipolar configuration and has negative dielectric anisotropy.Liquid crystal droplet phase-splitting disperse in the double refraction matrix, the liquid crystalline polymers matrix of its medium unit preferably in the matrix with positive dielectric anisotropy.In the matrix forming process, make the matrix optical axis arrange the location by applying alternating-electric field.Bipolar liquid crystal droplet comes into line with matrix naturally, so that the optical axis of droplet and matrix is perpendicular to the observation surface of material.Since normal and the extraordinary refractive index and the matrix of droplet normally and extraordinary refractive index be complementary respectively, formed material under no field condition to all incident light directions all transparent and baze-free.Having under the field condition, the liquid crystal droplet of negative dielectric anisotropic is arranged the location in the electric field action lower edge perpendicular to the direction of field, thereby causes the refractive index mismatch of matrix and droplet on all viewing angles.The material of opposite way work can use various minutes phase methods such as SIPS, TIPS or PIPS, make with the combinations of low molecular weight liquid crystals with negative dielectric anisotropic, and arranges on the liquid crystal side group of polymeric matrix observation surface perpendicular to material under the effect of alternating-electric field.
Use made in accordance with the present invention combinations of low molecular weight liquid crystals in full visual field PDLC material or device can be according to added frequency with its dielectric anisotropy from the positive negative type that switches to.For example, this class liquid crystal presents negative dielectric anisotropy when high frequency, and is positive dielectric anisotropy when low frequency.Similarly, polymer liquid crystal also can be according to its dielectric anisotropy Symbol Type of frequency shift.
In droplet, use the so-called crossover frequency liquid crystal of this class to make window or the device made have the enhanced contrast, and make liquid crystal droplet be easy to relative matrix liquid crystal side group arrangement location.This is because under a given frequency, the liquid crystal composition in the matrix can be arranged along a certain direction, and the liquid crystal composition in the droplet can be along arranging with the vertical direction of first direction under same frequency.
By accompanying drawing given below and invention most preferred embodiment, those skilled in the art can draw further feature of the present invention, advantage and to further understanding of the present invention.
Fig. 1 (A) and 1(B) be respectively have and no field condition under the partial cross section sketch of optical switch device, device comprises one deck light adjusting of the present invention material, it is represented by the several schematic liquid crystal droplet that is contained in the liquid crystalline polymers matrix.
Fig. 2 (A) is an equipment synoptic diagram along different measurement of incidence direction Fig. 1 (A) device transparencies.
Fig. 2 (B) is that the similar curve of PDLC optical switch device when clear state made from optically isotropic polymkeric substance compared, the graphic representation of the transmittance that PDLC optical switch device of the present invention changes with input angle.
The drawn optical switch device of a kind of opposite mode of operation or fail-safe of Fig. 3 (A) and Fig. 3 (B), wherein the optical axis of droplet and matrix by the tangential force effect oblique arrangement, device is respectively and field-free situation among the figure.
Fig. 1 represents how liquid crystal PDLC light modulating materials of the present invention is made, making it having under field condition material transparent to all incident directions of light, and therefore with have PDLC material isotropic optical property, that adopt ordinary hot solidity or thermoplasticity synthetic resins to make and compare and do not have optical haze.The visual field of the existing PDLC material made from isotropic polymer owing to inevitably under field condition is arranged in the wide angular field of view refractive index mismatch be restricted.This is to obtain the transparency when having because the extraordinary refractive index of liquid crystal is arranged perpendicular to material surface usually.And when increasing with the viewing angle of vertical direction, noticeable mismatch has increased between the e optical index of the specific refractory power of matrix and droplet.The full visual field that the PDLC material of the present invention of the double refraction light-transmission substrate of employing liquid crystal polymer resin and so on is had is owing to the matrix itself that contains liquid crystal droplet is the liquid crystal that identical optical character is arranged with droplet, so the effective refractive index of droplet may be on all incident light directions and the specific refractory power of matrix be complementary, therefore all do not have scattering of light and optical haze in any direction.When the normal and extraordinary refractive index of droplet was mated with the normal and extraordinary refractive index of polymeric matrix respectively, the effective refractive index of matrix and droplet just was complementary on all incident light directions, and the optical axis of droplet is parallel to the optical axis arrangement of matrix.
In Fig. 1 (A), contain total the representing of optical switch device of the novel baze-free PDLC of the present invention material with numeral 10.Device 10 comprises a pair of glass or plastic base 11, and a kind of birefringent polymer matrix 14 that contains phase-splitting dispersed liquid crystal droplet 16.Internal surface at glass substrate 11 has the transparent electrode coating 12 that is connected on the AC power that voltage is V.According to most preferred embodiment of the present invention, matrix 14 is the polymkeric substance that contain the liquid crystal side group with positive dielectric anisotropy.The normal refraction rate n of droplet 16
oWith extraordinary refractive index n
eRespectively with the normal refraction rate n of double refraction matrix 14
o' and extraordinary refractive index n
e' be complementary.
Shown in Fig. 1 (A), the optical axis that is in unidirectional matrix 14 and droplet 16 with separately extraordinary refractive index is arranged in parallel.Because the optical axis of droplet is parallel to the optical axis of polymeric matrix, and the normal and extraordinary refractive index of droplet and matrix mates respectively, and then the effective refractive index of droplet is complementary with the matrix specific refractory power on all directions.Like this, having under the field condition of Fig. 1 (A), device 10 internal surface and outside surfaces except substrate 11 exist the surface reflection, and the incident light of all directions is not had scattering and transparent.
Select by the liquid crystal side group to side chain polymer matrix 14, the combinations of low molecular weight liquid crystals that makes it with droplet 16 is similar material, and the specific refractory power of droplet and matrix specific refractory power are complementary.When the bigger positive dielectric anisotropy of needs, preferably adopt cyaniding xenyl material.In the manufacturing processed of device 10, can make the optical axis of droplet and matrix arrange the location by applying electric field or magnetic field.For example, matrix 14 be positive dielectric anisotropy have the liquid crystal side based polyalcohol time, by being in nematic comparatively high temps at polymer liquid crystal when, add suitable voltage of alternating current, the optical axis of side group is arranged perpendicular to the observation surface of device 10 to electrode 12.By surface with currently known methods treatment substrate 12, or cooling and device is operated in below the second-order transition temperature of polymer liquid crystal of this arrangement, and/or by making this crosslinked polymer just can make unidirectional array state still maintenance after removing voltage of alternating current of matrix.Crosslinked is by giving polymer pendant groups a unsettled part, two keys preferably, by uv-radiation, thermal radiation, Raolical polymerizable etc. or similarly method make its part similar produce crosslinked and realization to another.
The photoswitch performance of the device 10 of Fig. 1 (A) can obtain when obtaining the droplet structure shown in Fig. 1 (B) explaining at electric power disconnection.In the device 10 ' of Fig. 1 (B), no field condition lower substrate 14 keeps its ordered state, and its effective refractive index is constant.And the nematic phase oriented structure of droplet 16 ' changes, thus changed effective refractive index and with the matrix refractive index mismatch.This mismatch causes scattering of light in all incident light directions.It is radial that the oriented structure of the middle droplet 16 ' of Fig. 1 (B) is painted as, but should be understood that this structure can be that any other can change the type of effective refractive index equally.For example,, when device is switched to no field condition, cause direction of optic axis to change if the droplet shape is not spherical, thus cause that the droplet effective refractive index changes and with the matrix refractive index mismatch.
Referring now to Fig. 2 (A), a kind of layout of coming the PDLC optical switch device transmitance of measuring apparatus 10 1 classes along different incident light directions shown in it.Laser apparatus 15 emission light beams arrive detector 16 places of measuring transmittance by device 10.Device 10 is positioned to laser beam and becomes different angle θ.Input angle θ is to measure perpendicular to the direction on device 10 surfaces.
Fig. 2 (B) is the curve of the transmissivity T of various input angle θ F.When sample when the vertical incidence direction is rotated given angle, measure its percentage transmittance.Curve (a) is made by the present invention, the curve of the liquid crystal side basic ring epoxy resins PDLC material of refractive index match.Curve (b) is a United States Patent (USP) 4,671,618; 4,673,255; The curve of the PDLC material that disclosed isotropy Resins, epoxy is made in 4,685,771 and 4,688,900.Dash line and dotted line are used for comparing.Curve (b) shows that having optically isotropic body material transmittance percentage ratio falls sharply in the both sides several years of vertical incidence scope.And curve (a) shows, the material that the present invention adopts the double refraction transparent base to make just begins to fall sharply owing to the reflection of glass substrate internal surface and outside surface when vertical direction is made an appointment with ± 60 °.If there is not this reflection, curve (a) will be a straight line substantially, express the scope iuuminting rate no change from ° angle, vertical incidence ± 90.
Fig. 3 illustrates the optical switch device of a kind of opposite mode of operation or fault secure mode.In Fig. 3 (A), adopt total the representing of the optical switch device of novel baze-free PDLC material of the present invention under field-free state or vitreous state with numeral 20.Device 20 comprises a pair of glass or the plastic base 21 that scribbles transparency electrode 22, and the birefringent polymer matrix 24 that contains the liquid crystal droplet 26 of disperse.According to a most preferred embodiment of the present invention, matrix is a kind of polymer liquid crystal, and it arranges the location along the direction that favours substrate 21 surperficial vertical lines under by the tangential force effect shown in arrow 23 and 23 '.Tangential forces also makes liquid crystal droplet 26 elongate and arrange the location.The normal refraction rate n of droplet 26
oWith extraordinary refractive index n
eRespectively with the normal refraction rate n of double refraction matrix 24
o' and extraordinary refractive index n
e' be complementary.Can find out also that from Fig. 3 (A) optical axis of matrix 24 and droplet 26 is arranged parallel to each other.Because the droplet optical axis is parallel to the optical axis of polymeric resin matrix, and the mutual respectively coupling of the normal and extraordinary refractive index of droplet and matrix, then the effective refractive index of the effective refractive index of droplet and matrix is complementary on all directions.Like this, under the no field condition of Fig. 3 (A), device 20 exists the surface reflection except internal surface and outside surface at glass or plastic base 21, and the incident light of all directions is not all had scattering and transparent.
Droplet be by Fig. 3 (A) in during dipolar configuration shown in the number designation 26, can make the droplet optical axis arrange the location by tangential forces corresponding to the matrix optical axis, but should be understood that, droplet also can be other any effective refractive index that under the tangential force effect of substrate, can cause droplet all incident light directions all with the structure of matrix refractive index match.
Be to be further appreciated that, also may have this material, even wherein do not add tangential force to substrate, the optical axis of bipolar droplet also can natural partly and the same the lining up of the partial optical axis of polymeric matrix.In this case, the effective refractive index of droplet will be complementary to the incident light of all directions and the effective refractive index of birefringent polymer matrix, the material that obtains like this is transparent for all view directions, and irrelevant with respect to the orientation of vertical incidence light with optical axis.
When voltage is the power supply of V when receiving the droplet composition that produces Fig. 3 (B) on the transparency electrode 22, the switch performance of device 20 among Fig. 3 (A) has been described.In the device 20 ' shown in Fig. 3 (B), matrix 24 keeps the orientation under the conducting state constant, and its effective refractive index is also constant.The nematic phase oriented structure of droplet 26 ' becomes its optical axis and is parallel to the electric field arrangement, changes its effective refractive index thus and makes it and the matrix refractive index mismatch.This mismatch causes all direction incident scatterings of light.
Example one
A kind of liquid crystalline epoxy polymkeric substance is mixed by the solidifying agent B9-10 that will wait 1: 1 uncured Resins, epoxy of weight ratio (MK-107, Wilmington Chem produce) and a kind of intermediary ehter bond and prepares, and its molecular formula is:
Mixture heating up obtains limpid uniform solution to more than the temperature of fusion (110 ℃) of solidifying agent after mixing one minute.Solution was cured under about 90 ℃ about 48 hours.The Resins, epoxy liquid crystalline polymers of having solidified is mixed with weight ratio with combinations of low molecular weight liquid crystals (E-7 is produced by EM Chem) and is dissolved in (trichloromethane accounts for 85% by weight) in the trichloromethane at 1: 1.Solution is placed rotary-type mixing tank mixed for several minutes, inhale uniform one deck of formation on one the 26 μ m liner on the substrate that moves on to the band indium-tin oxide electrode again.It is opaque that solvent evaporation is become up to resulting material, made residual solvent evaporation in 5 minutes by heating on an about hot-plate of 125 ℃.A conducting electrode glass substrate through preheating is placed on the mixture again and forms a sandwich structure, the chien shih sample is cooled to room temperature when about 5 minutes.Sample appearance becomes translucent white shape.It is limpid or transparent at the voltage of alternating current that adds 85V60Hz on the electrode sample to be become behind several minutes.Adopt polarizing microscope liquid crystal droplet unidirectional lining up under electric field action of polymer liquid crystal and disperse as can be seen under awl light polarization figure.Remove voltage then sample in time, become the opaque and white shape less than a second.Add voltage of alternating current then sample become within less than a second transparent again.During adding 85V voltage, it is limpid that sample keeps, though under the visual angle that tilts also baze-free.By the light transmission sample that helium/neon laser is sent, be mapped to when sample and on the detector with the measure sample transmittance, just can measure the angular correlation of sample transmittance under vitreous state when the direction of laser beam changes.The between perpendiculars angle of beam direction and glass substrate is changing in ° scope of vertical incidence direction ± 85, and except the reflection of glass baseplate surface, transmittance is without any reducing (the results are shown in Figure 2).
Example 2
A kind of epoxy resin by using liquid crystal polymkeric substance prepares by waiting heavy Resins, epoxy to mix with the amine hardener that connects ether.Combinations of low molecular weight liquid crystals is added in the mixture by weight 1: 1, and the mixture of gained is placed on and is heated on the glass substrate that scribbles tin indium oxide more than 110 ℃ and forms homogeneous solution.After mixing about 2 minutes, the liner of several 26 μ m is placed on the solution, again a glass substrate that scribbles tin indium oxide through preheating is placed on the sample.Sample solidified about 48 hours down at 90 ℃.And then process slowly was cooled to room temperature in about 30 minutes.Under polarizing microscope, can observe the big nematic phase droplet that diameter is about 3-5 μ m, and the nematic phase oriented structure that can be observed droplet is a radial structure.
Example 3
Heavy Resins, epoxy and amine curing compound such as weigh up and combine on the sheet glass that is coated onto the ITO coating with 1: 1 ratio with combinations of low molecular weight liquid crystals.Whole sheet glass heats under 115 ℃-120 ℃ and made material mixing about 1.5 to 3 minutes.Ito glass sheet through preheating is placed on the sample, and sample was annealed 48 hours down at 90 ℃.
Adding 60Hz, during the voltage of alternating current of 85V, the PDLC of gained presents the wide vision of baze-free.
Those skilled in the art can make various improvement to the present invention according to above-mentioned disclosed content.Should be understood that in the claim scope of being carried, the present invention also can realize by the mode beyond above-mentioned.
Claims (21)
1, a kind of optical modulation liquid crystal material, comprise the mesomorphic phase that is dispersed in the double refraction light penetrating copolymer, the effective refractive index of this mesomorphic phase and this polymkeric substance is all mated on all incident light directions, then described material is transparent and baze-free under a kind of state that has among a state or the field-free state, if above-mentioned effective refractive index is not all matched on all incident light directions, then described material is opaque under the another kind of state that has among a state or the field-free state.
2, press the material of claim 1, wherein mesomorphic phase has normal and extraordinary refractive index, they are complementary with the normal and extraordinary refractive index of polymkeric substance respectively, when the optical axis of mesomorphic phase and polymkeric substance is parallel, this material is transparent and baze-free, when the optical axis of mesomorphic phase and polymkeric substance was not parallel, this material was opaque.
3, by the material of claim 1, wherein polymkeric substance is a liquid crystalline polymers.
4, by the material of claim 3, wherein polymkeric substance contains the liquid crystal side group.
5, by the material of claim 1, wherein polymkeric substance contains poly epoxy liquid crystal side group.
6, by the material of claim 4, wherein at least a liquid crystal side group contains the cyanobiphenyl base.
7, by the material of claim 1, wherein mesomorphic phase demonstrates the dielectric anisotropy that relies on frequency.
8, a kind of optical modulation liquid crystal material, comprise and be dispersed in the first kind optical birefringence phase of second kind of optical birefringence in mutually, a kind of in mutually of described first and second optical birefringences contained the polymer phase of group (mesogenic moieties) in the middle of the band, its optical axis the is parallel surface of this material, another kind in described first and second double refractions mutually contains mesomorphic phase, normal and the extraordinary refractive index of the first and second double refraction phases matches each other, when the optical axis of mesomorphic phase and middle group is parallel to each other, this material all is transparent and baze-free in all viewing angles, when the optical axis of mesomorphic phase and middle group was not parallel, this material was opaque.
9, by the material of claim 8, wherein second double refraction is made up of the polymkeric substance of band liquid crystal side group mutually substantially, and first double refraction is made up of liquid crystal mutually substantially.
10, by the material of claim 9, wherein the polymkeric substance with the liquid crystal side group contains the liquid crystal side group of being with active part, and this active part can be cross-linked to each other.
11, by the material of claim 10, wherein active part is cross-linked to each other, and makes the liquid crystal side group permanently locate arrangement.
12, a kind of fail-safe optical modulation liquid crystal material, comprise the liquid crystal droplet that presents negative dielectric anisotropic in the synthetic resin based body of liquid crystal side group that is dispersed in printing opacity, normal and the extraordinary refractive index of this droplet respectively with matrix normally and extraordinary refractive index be complementary, the liquid crystal side group presents positive dielectric anisotropy, the observation surface of the optical axis of matrix and droplet and material is perpendicular, thereby material is transparent under field-free state, is opaque having under the state.
13, a kind of fail-safe optical modulation liquid crystal material, comprise the synthetic resin based body of printing opacity liquid crystal side group that contains the brilliant droplet of phase dispersant liquid, normal and the extraordinary refractive index of droplet and matrix is mated respectively, the optical axis of droplet and matrix is arranged in parallel on the direction that favours the incident light visual angle, droplet can respond the outfield that is applied, thereby destroy being arranged in parallel of droplet optical axis, so material is opaque having under the state.
14, a kind of preparation all has the method for the optical modulation liquid crystal material of the baze-free transparency to all incident light directions, be included in and form phase dispersive liquid crystal droplet in the birefringent light penetrating copolymer matrix, by applying electric field or magnetic field to this material, make the optical axis of matrix be parallel to the material surface arrangement, make droplet and matrix have the normal and extraordinary refractive index of coupling, by making polymeric matrix crosslinked, arrange with the fixing base optical axis, still can keep after removing original optical axis to arrange with convenient electric field or magnetic field, thereby, the optical axis that is parallel to matrix by the optical axis that makes droplet is arranged, can obtain the baze-free transparency, if the effective refractive index of droplet and matrix is lost, material then is opaque.
15, a kind of optical modulation liquid crystal material, comprise the liquid crystal that is contained in the dispersion amount in a kind of double refraction solid substrate, normal and the extraordinary refractive index of the liquid crystal of described dispersion amount respectively with matrix normally and extraordinary refractive index be complementary, thereby when the optical axis of droplet and matrix was parallel, this material was a printing opacity.
16, by the material of claim 1, wherein said polymkeric substance comprises a kind of polymeric matrix, and mesomorphic phase comprises the liquid crystal droplet that is dispersed in the polymeric matrix.
17, by the material of claim 8, wherein first double refraction is mesomorphic phase mutually, and second double refraction is polymer phase mutually.
18, a kind of optical modulation liquid crystal material, comprise and be dispersed in the first optical birefringence phase of second optical birefringence in mutually, one of described first and second double refraction phases comprise the polymer phase that has middle group, and another in described first and second double refractions mutually comprises mesomorphic phase mutually
Normal and the extraordinary refractive index of mesomorphic phase and being complementary of above-mentioned middle group,
The optical axis of mesomorphic phase and middle group is parallel under the situation that does not have electric field or magnetic field, thereby the effective refractive index of mesomorphic phase and middle group all mates on all incident light directions,
Described mesomorphic phase can respond extra electric field or magnetic field makes the liquid crystal optic axis reorientation, has destroyed and the liquid crystalline polymers parallel relation of optical axis mutually, thereby has made material light transmission under the state arranged not as the light transmission under the field-free state.
19, the method for preparing the optical modulation liquid crystal material, this material is by a kind of liquid crystal components and be selected from monomer with middle group and have that second component of solution of the polymkeric substance of centre group forms, select these components that their normal and extraordinary refractive index each other are complementary, this method comprises the steps:
Make the optical axis of liquid crystal components parallel with the optical axis of middle group,
Solidify second component, so that the optical axis arrangement mode is not still remained unchanged when having electric field or magnetic field to exist.
20, by the method for claim 19, the step that wherein is arranged in parallel comprises to described component and applies electric field or magnetic field.
21, by the method for claim 19, wherein curing schedule comprise make in the middle of group crosslinked.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US18021588A | 1988-04-11 | 1988-04-11 | |
| US267,232 | 1989-03-20 | ||
| US324,051 | 1989-03-20 | ||
| US180,215 | 1989-03-20 | ||
| US07/324,051 US4994204A (en) | 1988-11-04 | 1989-03-20 | Light modulating materials comprising a liquid crystal phase dispersed in a birefringent polymeric phase |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1040213A CN1040213A (en) | 1990-03-07 |
| CN1023231C true CN1023231C (en) | 1993-12-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 89103574 Expired - Fee Related CN1023231C (en) | 1988-04-11 | 1989-04-11 | Light modulating materials comprising liquid crystal microdroplets dispersed in birefringent polymeric matrix |
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| Country | Link |
|---|---|
| CN (1) | CN1023231C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101061422B (en) * | 2005-01-21 | 2016-01-06 | 乐金显示有限公司 | Liquid crystal display and the transfer table with this liquid crystal display |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4497212B2 (en) * | 2008-02-20 | 2010-07-07 | ソニー株式会社 | Light source system |
| US7837897B2 (en) * | 2009-04-27 | 2010-11-23 | Polytronix, Inc. | Polymeric dispersed liquid crystal light shutter device |
| CN101928570B (en) * | 2010-05-19 | 2013-01-09 | 江苏和成显示科技股份有限公司 | Composition for preparing polymer dispersed liquid crystal |
| US9429787B2 (en) | 2012-02-29 | 2016-08-30 | Boe Technology Group Co., Ltd. | Transparent display unit |
| CN102654687B (en) * | 2012-02-29 | 2015-06-03 | 京东方科技集团股份有限公司 | Transparent display device |
| DE102017214093B3 (en) * | 2017-08-11 | 2018-11-29 | Continental Automotive Gmbh | Flat light modulation device with switchable multistable transmittances and / or multi-stable scattering properties with respect to visible light and vehicle with a flat light modulation device |
| CN108761848A (en) * | 2018-05-02 | 2018-11-06 | 上海大学 | A kind of all -fiber electro-optic modulation system |
-
1989
- 1989-04-11 CN CN 89103574 patent/CN1023231C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101061422B (en) * | 2005-01-21 | 2016-01-06 | 乐金显示有限公司 | Liquid crystal display and the transfer table with this liquid crystal display |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1040213A (en) | 1990-03-07 |
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