CN1015110B - Improvements to liquid crystal light-modulating materials - Google Patents

Abstract

The spontaneous formation of liquid crystal microdroplets by regulated phase separation from a solution of their isotropic state in matrix-producing composition, the matrix being solid and light transmissive synthetic resin, during solidification of such matrix yields a light modulating material consisting essentially of microdroplets (11) of liquid crystal dispersed in the matrix (10).

Description

Improvements to liquid crystal light-modulating materials

In general, the present invention relates to liquid crystal light control system technology, or rather, relate to the manufacturing of new liquid crystal material, this material comprises a kind of liquid crystal particle suspension of can light transferring, and these liquid crystal particles form naturally and are retained in the synthetic polymer matrix, for example: be used for showing.

The latest developments of commercial liquid crystal display device manufacturing all trend towards adopting the scattering of light character of utilizing liquid crystal and the material of developing, this liquid crystal material is mixed with the whole bag of tricks or mix on differing materials, as the thing of plastic sheet one class.

Suggestion available material type comprises the liquid crystal material of capsule sealing and has the material that the liquid crystal imbibition is arrived micropore wherein.

The method of a used encapsulated liquid crystals is by French Patent 2,139,537 is open, and it is to use a kind of immiscible tackiness agent, as polyvinyl alcohol, generate nematic or cholesteryl liquid crystal water-based emulsion, mixture is in addition emulsification under high-speed stirring, to generate the liquid crystal that is sealed by tackiness agent, and be applied on the clean plastic substrate of band conductive electrode, at United States Patent (USP) 4,435, similar technology is disclosed in 047.

Another existing method is with the micropore opening of plastic sheet or that link to each other, is filled with the liquid crystal of nematic or its alloytype, and is also at United States Patent (USP) 4,048, open in 358.

Available technology adopting is mechanically held back liquid crystal some shortcoming, can produce a capsule diameter gap than broad by the sealing method with emulsifying effect, thereby limit device performance, must be with magnitude classification.Another shortcoming by the sealing method of emulsifying effect is, moisture content left in device can influence switch performance, thereby device uses alternating-current only, and without direct-current drive.By mixing holding back of cellular plastic micropore can appear sealing, to prevent the loss of liquid crystal.

Electricity is regulated these light scatterings between scattering of light and light transmission, can make this device, or its imaging part, and there have a state to present to be opaque, and at another state, then present transparent.As use the hotwork thermal conditioning, it is that light-scattering state carries out the transition to isotropic light transmission state that this heat can cause from the liquid crystals attitude, then can make material become transparent (Clear) from opaque.

The operation of most of this display modes depends on that all external electric field of constant employing or thermal source are to keep image.Though for example, demonstration time and temperature (will produce multiple letter and number character with this understanding, subsequently by to various visual constant energy supplies and deenergize when being erased) just need this operating method, but under many circumstances, an advantage point is that the not only available ratio of a kind of technique of display is easier to preparation, but also can show that not relying on constant impressed field characterizes by its image.Another advantage point is that its lcd technology can have switching time and the better transparency faster than former institute is obtainable.

Therefore, be different from present invention, prior art is mechanically liquid crystal to be divided into a large amount of granules again, (a), or (b) be embedded in the substrate material with small amount of fines and (can be transformed into polymeric thin slice or analogue after this) with each particulate outsourcing or be sealed in the polymeric sheath (also can gather together subsequently generate one adherent and the thin slice or the analogue of support arranged).The advantage of the present invention that surpasses above-mentioned technology then is that preparation is simple, is easy to control liquid crystal size and its discontinuity, and theoretic unlimited display size, can be clearer when other advantages are introduced afterwards.

Below with all respects of the present invention of saying, all be relevant when transmitance matrix immobilized arranged, from a kind of liquid crystal the composition solution that produces synthetic resins matrix, the process of generation liquid crystal particle naturally.The particulate of this generation is to distribute quite evenly, and size is also quite uniform, and for for simplicity, we claim that this generative process is " being separated " process.Matrix available heat solidity or thermoplastic resin (polymkeric substance).

At this, an aspect is the relevant material that contains the scattering of light liquid crystal particle; But it can cause material inverse conversion between scattering of light and light transmission state with heat, electricity, magnetic or electromagnetism addressing.Moreover this material has photoresponse to tension force, promptly under tension force, can the polarizer effect, and the one-component of this polarizer transmission plano-polarized light, and another component of scattering.In addition, in the presence of electric field or magnetic field, but its phase separation can make this material play the polarizer effect of electrical addressing.

New light-scattering material, thermoplastic is characterized in that being easy to manufacturing and only just can reprocess with heating and cooling in this way.Another aspect of the present invention is that material can make from thermoplastic resin, and liquid crystal has the transformation temperature from liquid crystalization to isotropic phase more than the matrix softening temperature; It has shown the memory that a kind of reversible is not subjected to the outfield to be influenced (storage of thermoplastic image).

A further aspect of the invention is the themoplastic display material, and the ordinary refraction index of its liquid crystal approaches to be dissolved with the specific refractory power of the matrix of some liquid crystal especially; This material can have inferior millisecond switching time, the transparency greater than 90% and electric light memory.Can process this material and have high resistivity and specific inductivity, thereby it can play the electric capacity effect, when charging between two electrodes, can keep electric charge, even and after voltage was closed, the optical axis of liquid crystal particle was still aligned and image can also keep for some time (electrostatic image storage).

Another aspect of the present invention is a kind of light modulating materials, wherein particle size is when being separated, and increases by the control liquid crystal particle and regulates; Particulate increases when having arrived a selected mean diameter, by matrix immobilized and restrain.When using manufactured, can see that liquid crystal particle size and spacing are uniform, diameter range is about more than 0.2 micron.Temperature, selecting for use of relative concentration and material determined last particle size and population density.Thereby, can make the manufacturing of liquid crystal device have optimum display performance, as contrast gradient and time of response.

Except that above-mentioned modulation material, a further aspect of the invention is to the device of light conversion and electroresponse of light polar and electrical addressing, a kind of light modulating materials is arranged, as the present invention made thin slice or film in its structure.And the others that have again of the present invention broadly are to be used for phase disengagement method of the present invention, light modulating materials, the specific phase isolation technique, and the many improvement that relate to, as the control of particle size, component is selected for use, material reprocessing, make its auroral polesization or particularly make from each side's luminous energy always transparent, and in the electric field of orientation or magnetic field solidification matrix.This discussed in the above, also discussed during later on about light modulating materials again.

To further recognize some other feature and advantage from the most preferred embodiment of the present invention that describes below and accompanying drawing to one skilled in the art.

At Fig. 1,2,4,5(a), 6(a), 6(b), 9,10,11,13A and 13B, schematically drawn the three-dimensional fragment of sheeting of the present invention with cross sectional elevation, have the several representative liquid crystal particle and be included in resin (polymkeric substance) matrix, the continuum of the thin slice that invention is arranged is provided.

At Fig. 3,5(b), 7(a), 7(b) and 8 in, this sheet material has been formed a unit of this shown device.

Particularly Fig. 1 illustrates the particulate that isotropic phase is arranged on the clean thin slice.

Fig. 2 illustrates the liquid crystal particle that the liquid crystalization phase is arranged on the opaque thin slice.

Fig. 3 illustrates the electric actuator of being furnished with clean thin slice.

Fig. 4 illustrates the thin slice of stretched state.

Fig. 5 (a) illustrates the thin slice that has been separated in the field that adds to the thin slice in-plane.

Fig. 5 (b) illustrates the electric actuator of (a) thin slice of being furnished with Fig. 5.

Fig. 6 (a) illustrates the thin slice after the slaking in perpendicular to the field of this thin film planar.

Fig. 6 (b) illustrates the thin slice at Fig. 6 (a) in the added field of thin film planar direction.

Fig. 7 (a) illustrates at the thin slice that is subjected under the stressed condition.

Fig. 7 (b) illustrates the electric actuator of (a) thin slice of being furnished with Fig. 7.

Fig. 8 illustrates one section thermoplastic thin slice between the fax moving electrode.

Fig. 9 illustrates the thin slice of Fig. 8 that electric field is removed.

Figure 10 illustrates and contains the thin slice that smectic shape liquid crystal A is in the particulate of opaque burnt cone structure state.

The thin slice of Figure 10 that Figure 11 illustrates in vitreous state.

Figure 12 is the photomicrography of material of the present invention.

Figure 13 A and 13B roughly illustrate scattering of light or the visual angle that is incident on the liquid crystal particle.

Figure 14 illustrates liquid crystal and produces the phase equilibrium diagram of the binary mixture of matrix components.

Figure 15 illustrates liquid crystal and produces the phase equilibrium diagram of the tertiary mixture of matrix components.

Figure 16 is the sequence of steps synoptic diagram of preparation material of the present invention.

Figure 17 is the graph of a relation of the speed of cooling of particulate mean diameter and material of the present invention.

Realize best mode of the present invention

This term as " producing the component of synthetic resins matrix " used in specification sheets and claim or " producing the component of matrix " is meant the material of determining to provide cured resin (polymkeric substance) product.Better produce and have or do not have dissolved liquid crystal base component and generate the solid light modulating materials, it seems it all is quite high flowing water.

This solid resin that is used for the object of the invention can be provided by following generation matrix components:

(I) a kind of useful solid-state resin and mixture of certain chemical agent of can be grouped to, for example, by addition or polycondensation, the liquid mixture of epoxy or polyurethane resin and its a kind of solidifying agent (promptly typically, make the size of particulate and position no longer adding under the stress situation, be fixed on the Optical devices).Better polyurethane resin has high tensile strength and tear strength, and a kind of component of suitable generation polyurethane is based on tolylene diisocyanate, polyether glycol class, the mixture of the different Ortho-Chloro aniline of methylene-bis and other various polyvalent alcohols.A kind of unsaturated polyester resin in cinnamic solution, also can provide thermosetting matrix at polymerisable monomer.

(II) a kind of thermoplastic resin (polymkeric substance), it is through the solubilized liquid crystal of heating, and does not cause and the liquid crystal degraded then, can be cast into particulate form, becomes useful solid state when cooling.These thermoplastic resins typically comprise some thermoplastic Resins, epoxy, various polymkeric substance or multipolymer, and they contain vinyl butyral, alkyl acrylate, vinylbenzene and alkanisation vinylbenzene, iso-butylene, vinylchlorid, divinyl, methyl butene and ethene ethyl ester;

(III) a kind of thermoplastic resin (polymkeric substance), it can make homogeneous phase solution with liquid crystal and volatile solvent under the temperature that does not make the liquid crystal degraded, reliable then evaporating solvent in case of necessity, can adopt to add gentle may final refrigerative method curing, cast particulate, (also not having degraded).

(IV) polymerisable monomer, dipolymer, oligopolymer and prepolymer and composition thereof, it is at liquid solubilized liquid crystal, under the condition that is not causing the liquid crystal degraded, casts particulate when aggregating into useful solid.The component that this polymerizable produces matrix comprises vinylbenzene, alkyl acrylate, divinyl and various dipolymer, oligopolymer and contain one or more and plant this monomeric monomeric unit.

Volatile solvent as mentioned herein, from Practical significance, under normal pressure, its boiling point preferably is not higher than 100 ℃, but in some instances, higher boiling point is as also allowing to 150 ℃.This volatile solvent again can be in order to temperature and the dissolving of help liquid crystal that is controlled at the dissolving liquid crystal in the polymerization operation of the present invention.

" be separated " and told about in the above.This be one easily method indicating the anisotropic liquid crystal particulate concisely when matrix immobilized, Lock-in from equal phased soln in producing synthetic resins matrix component, and exist with isotropic phase.Have the several different methods that has been separated of adjusting to realize, this depends on how to produce this curing polymeric matrices from this solution, can adopt following one or more methods:

I) a kind of composition or several mixture of ingredients that produce matrix components are carried out polymerization, through heating, catalysis, katalysis include but not limited to adopt UV-light typically, electron beam or introducing free radical catalyst, or other effective catalytic species;

II) a kind of thermoplastic of cooling produces matrix components (thermally gelling);

III) evaporating volatile solvent from a kind of solution of general solid thermoplastic synthetic resins certain solvent that produces matrix components, this solution can dissolve liquid crystal, evaporation can be chosen wantonly to heat and/or cool off and help or control, and this resin can or be made by polymerization on request with the resin of preformed state.

Before being separated, the dissolved liquid crystal does not show scatter incident light, and solution also is transparent.

" solidify synthetic resins (polymkeric substance) matrix " is matrix not being had in the presence of stress machinery or electricity, for some practical use on optical modulation device, and the fixing matrix of liquid crystal particle size and shape.After this curing, just can use stress special machinery or electricity, so that the special operational performance to be provided to matrix.Obviously use high temperature and can get rid of employing low temperature softening thermoplastic matrix, that just requires another kind of type, as thermosetting.Being solidificated in this and can be described as " slaking " again, " condensing " or " sclerosis " of synthetic resins (polymkeric substance) matrix.The solid state substrate that generates can be flexible, elastic or inflexible, in other words, is quite solid in matrix with particle size and stationkeeping.

As be used for claim and specification sheets, and " thermoplastic resin " speech refers to general use, comprises that any synthetic resins is polymkeric substance, this polymkeric substance can thermoplastic, uses cooling curing then.When this was understood that in heating, " thermoplastic " a kind of thermoplastic resin can take place in a transition temperature range, and a tangible boundary line not necessarily must be arranged.

This term of " homogeneous phase solution " or " single-phase " solution is meant liquid crystal and produces transparent and uniform soluble mixture between matrix components.Solution can be liquor, solid solution, or be situated between between the two.When being separated, homogeneous solution separates mutually, and some liquid crystal is separated out with particulate at least at that time.Be separated and proceed, matrix begins sclerosis.So far, phase separation stops, and generates a stable rich solution crystalline phase with the particulate form appearance, and a polymer-rich phase that occurs with matrix form, and particulate in embedding in this matrix." plasticizing effect " is meant the transition of the thermoplastic resin that is caused by liquid crystal or the reduction of softening temperature, and it becomes the liquid crystal of still staying in this solution resin behind the particulate to cause by the part liquid crystal that is separated." plasticizing " resin may show physical properties.As refractive index n s and softening temperature, and electrical property, as resistivity and specific inductivity owing to there has been the dissolved liquid crystal to exist, these character can with the different in kind of original simple polymkeric substance.

" resistivity " and " specific inductivity " is meant the electrical property of liquid crystalization attitude plastic substance of the present invention, and be used in and generally be familiar with occasion and do not consider measuring system, the resistivity of material of the present invention and the product of specific inductivity are to express with time unit, and represent the storage time of material." electrostatic image storage medium " is meant that it approximately is one second or greater than one second material that the present invention has storage time, thereby, when material when conductive electrode is switched on, will play the electrical condenser effect, when removing voltage, still can keep electric charge." electrostatic image storage " is meant the image storage of material of the present invention, the selected zone of some of material or material wherein, when between transparent conductive electrode during making alive, can become transparent and transmissive state, and some selected zone of material or material wherein, when removing voltage the storage time of material, still keep clear thorough and transparent, unless, be transformed into opaque not transmissive state through short circuit, transparent up to turning to, this place's material keeps opaque.

" switching time " is meant that material of the present invention causes its transparent time of response to institute's making alive pulse, and refers to that material becomes the opaque time material through short circuit.To the ON(cleaning) switching time of attitude is general than opaque to OFF() attitude for lacking.To electrostatic image storage medium of the present invention, than storage time, be very short switching time.

" transparency " or " coefficient of transparency " is meant that light permeable material and light under the situation of this material not see through the ratio of electrode.

The physical principle of the present invention operation be based on the liquid crystal particle of birefringence can scattering the ability of transmissive light again, this depends on the relation of the optical index of liquid crystal and matrix.The scattering of light liquid crystal has the extra-ordinary index of refraction ne that measures along its major axis, than its ordinary index of refraction n in square with the axis plane surveying _oGreatly.Major axis is the optical axis of liquid crystal.Scattering of light liquid crystal with positive dielectric anisotropy plays response to added its optical axis electric field parallel with direction of an electric field that make; And the diffusing liquid crystal of the light with negative dielectric anisotropy plays response to added its optical axis and the vertical electric field of direction of an electric field of making.

Light is incident on and contains not mutually continuously on the material of liquid crystal dots, then scattering or transmission, and this depends on the relation between specific refractory power.For example, have in application on the nematic liquid crystal device of positive dielectric anisotropy, matrix is made up of a kind of resin, its refractive index n _sCome down to ordinary index of refraction n with liquid crystal _oEquate.Do not applying under the electric field situation, the liquid crystal that then is trapped in the general spheroidal particle does not have best alignment direction, so incident light is at the resin refractive index n _sExtra-ordinary index of refraction n with liquid crystal _eBetween aim at improper and scattering adds electric field, make all molecular energies aim at, to each each other amount of liquid crystal, the extra-ordinary index of refraction (optical axis) is the result all aim at.When optical axis is vertical with the plane of incident light projection, then can make particulate that this light is had refractive index n _o; Because n _oBe substantially equal to n _s, incident light can mate then between specific refractory power and is through, thus material the display is transparent.For example on time, then the plane polarization incident light component perpendicular to tension direction promptly is through by stretching this material when the optical axis of liquid crystal, thereby and another component because specific refractory power very and scattering reaches the light polarization effect.

Liquid crystal may have the diffusing rate n of ordinary folding _o, with the refractive index n of matrix _sBe complementary, then incident light is at n _sAnd n _oBetween when not running into effective difference, look Chang Buneng and see scattering.In order to improve the contrast between light transmission and the scattering state, wish n _oAnd n _sBetween difference is arranged slightly.

As long as the liquid crystal particle size is at the order of magnitude of lambda1-wavelength, this wavelength is about 0.2-10 micron or bigger, as 50 microns, and as long as n _eAnd n _sOr n _oBetween difference be large enough to an effective difference, cause the light inhomogeneity with the scattering that enables to see for oneself, just can be used for effective scattering that scattering of light shows.

Under the demonstration situation of depending on temperature variation to respond, in the folding rate of loosing of the liquid crystal of its isotropic phase is to be complementary to the specific refractory power of matrix or similar, thereby material can the transmission incident light, and in the specific refractory power of liquid crystalization phase, it generally is unusual specific refractory power, concerning the specific refractory power of matrix, be unmatched.Thereby, incident light be scattering and material opaque.

The material that depends on temperature variation to respond can adopt nematic according to the present invention, cholesteric, or multiple different smectic shape liquid crystal, with and the mixture formed prepare.Can use in the heat-photoeffect of arbitrary temperature and a kind ofly under this temperature, can obtain by the liquid crystal from the liquid crystalization phase transformation to isotropic phase.This process is a reversible, thereby when the temperature decline of material, to liquid crystals phase transit time, material turns to opaque state from vitreous state from isotropy.The thermo-optical device that can respond differing temps can use have different isotropy-liquid crystal of liquid crystals phase transformation temperature prepares.

As a kind of material that responds because of temperature variation, the invention provides several characteristics, it is different widely comparing with device with the material of prior art, and has some important advantages.The operation of prior art cholesteryl liquid crystal device for example has been disclosed in the U.S.'s 3,872,050 patent, and it is based on cloth loudspeaker lattice (Bragg) scattering of light, and this moment, the pitch length and the wavelength difference of incident light of temperature variant cholesteric helix line were few.Those prior aries such as being disclosed in the U.S. 4,279,152, require to change the order of dye molecule with the operation of liquid crystal material phase change device, to change optical absorption property.In the material of the present invention, the temperature between White-opalescent state and vitreous state differentiate be by isotropic phase to liquid crystals mutually the width of transition regulate, improved even so also differentiate than the temperature of habitual cholesteric device.This device depends on that the pitch length of the width of visible spectrum and cholesteric helix line is with variation of temperature.Another advantage of the present invention is that the contrast of seeing for oneself between ON and OFF state is by contrasting in isotropic phase and controlling in the scattering of light character of the dispersed LCD of liquid crystals in mutually, and in the cholesteryl liquid crystal temperature indicator of prior art, visual contrast is that the bragg scattering character by the cholesteric material of reversing contrasts its a kind of background substrate and regulates.

The present invention allows the liquid crystal and the mesomorphic phase that have wide range of applications again, comprise and have high thermostability and the liquid crystal of high life, the cholesteryl liquid crystal indicator of prior art has been placed restrictions in cholesteric or chiral material, and they have suitable temperature-dependent pitch length.This stability of liquid crystal is poor.Thereby, limited with the display life that they are done.

The material of electricity or electromagnetic response can be used nematic liquid crystal, or its effect is similar to the mixture of nematic liquid crystal and includes the smectic shape liquid crystal of iron-electric liquid crystal.Best is that liquid crystal comprises cyanobiphenyl, and can mix with cyano terphenyl and ester.As be meant nematic liquid crystal and liquid crystal compound at this exhausted " nematic " noun with nematic liquid crystal character.The liquid crystal that is dispersed in the resinous substrates is placed between two conductive surfaces, and one or two are transparent.When the voltage suitable in addition to conductive surface, material promptly is transformed into vitreous state from the White-opalescent state.When voltage was removed, this process was a reversible.If needed, can in liquid crystal, be equipped with a kind of pleochroic dyestuff, to improve the visual contrast between the transparent and opaque state of electric responsive material.As use black dyes, then material presents black at opaque state.

As electric responsive material, the present invention has it to be different from other known feature and advantage that include the voltage or the current-responsive material of liquid crystal.Use material of the present invention, on the electrical conductor of material surface, add and exchange or direct voltage source, the very folding that can aim at the optical axis of the nematic liquid crystal particulate that shows positive dielectric anisotropy and the liquid crystal parallel rate of loosing with electric field, thereby light is through.After electric field removed, the surface interaction between resinous substrates and dispersive nematic liquid crystal can be rapidly returns to situation about applying before the electric field with the random aligning of optical axis, owing to the extra-ordinary index of refraction reaches scattering of light.The number of dispersive liquid crystal particle is big and size is little, can provide a bigger surface-area and volumetric ratio between matrix and liquid crystal, so that change effect.A key character of the present invention is that particulate moulding rapidly is to produce quick switching time.To material of the present invention, vitreous state can be decided to be about 1-10 millisecond to the time of response of opaque state.After a kind of polygenetic dye is allocated liquid crystal into, principle of operation still shows different with object-main body that other allocate polygenetic dye into, this is that matrix-liquid crystal surfactant interacts and the big surface/volumetric ratio of dispersed LCD, thereby has recovered the nematic orientation and also the object dye component is returned to random opaque tendency after removing the electric field that applies.This and known " phase change " two looks show structure cell in pairs than, at this, a kind of cholesteric component is added liquid crystal, to cause the random aligning of dyestuff at opaque state.

To a certain embodiments of electroresponse demonstration structure cell, allocate a kind of tension foil or film into.In the presence of electric field, the surperficial perpendicular very folding of this electric field aligning and thin slice or the film rate of loosing does not have the polarising incident light through structure cell and transmission.Do not having under the electric field situation, then very the diffusing rate of folding is parallel with tension direction, and the result is the one-component transmission of plane polarization incident light, and another component scattering.Compare with the 10-100 millisecond of expanded material not the switching time of expanded material is 1 millisecond approximately, and this structure cell can play the photoconverter effect as allocating second polarizer into.

Another embodiment of electroresponse polarization material can be used on the liquid crystal particle in the flexible thermosetting polyurethane film that is clipped between sheet glass that solidified and makes.Sheet glass is relatively moved in the other direction, just give film with tension force.The tensile thin films scattering has been arranged along tension axis polarising light, and seen through perpendicular to tension axis polarising light.Apply electric field energy film is transformed into unpolarized transmissive state.No tension force film is applied electric field, then can be converted to unpolarized transmissive state from unpolarized scattering state.

A key character of the present invention is that in the presence of magnetic field that adds enough intensity or electric field, be separated component that produces matrix and the new technology of dissolving liquid crystal are so that the liquid crystal in particulate is aimed in phase separation.When in a single day process was finished, aligning was exactly nonvolatil, when removing electric field, still existed.This electric field one is aimed at phenomenon and is made and make the convertible light polarizer possibility that becomes.A kind of can making by in dielectric susceptibility and diamagnetic substance susceptibility, selecting to have positive anisotropic liquid crystal at the convertible light polarizer of polarization light under the not alive situation.Be dissolved in the liquid crystal film that produces in the matrix components, in the presence of the magnetic field of pointing to the thin film planar direction, be separated.After matrix sclerosis, the optical axis of liquid crystal particle obtains aiming at entirely in thin film planar, this material, and a film for example can polarization light.The film of slaking is placed between transparency electrode, and adds enough strong voltage, make that just polarization effect is switched off.

But the liquid crystal that the switchable polarizer of a polarization light in the presence of impressed field can be selected to have positive dielectric anisotropy makes, and is separated in alternating-current field, and this alternating-current field passes to voltage to the film conductive surface and produces.After film sclerosis, the optical axis of liquid crystal particle all with the vertical direction of film surface in aimed at.This film is transparent and non-polarizable.As to film surface added electric field or magnetic field, can guide film to change to polarization state.

Optical switchable polarizer can make by being separated liquid crystal and generation matrix components, and its condition is for will make added electric field or magnetic field enough strong, so that the liquid crystal particle optical axis is positioned at the film surface vertical direction.The film that generates was both transparent, did not polarize again.The high-strength magnetic width of cloth is penetrated the particulate optical axis is redirected, thereby film becomes opaque and scattering of light.

Display material with improved light scattering property, the available film that contains the liquid crystal particle that shows positive dielectric anisotropy makes, and film is imposed in addition distortion of compressive tension.The distortion liquid crystal extra-ordinary index of refraction parallel with film surface aligns, but random at thin film planar.There is not in the presence of the electric field this thin films scattering light and opaque; By adding the voltage of enough intensity, as voltage of alternating current, be converted to direction with Surface Vertical with optical axis with liquid crystal, this film can be transformed into vitreous state.The demonstration that makes from this material improves to some extent compared with the demonstration contrast gradient that makes from spheroidal particle, and this is based on this film specific refractory power misalignment when scattering state and has reached maximum.Be used in the interelectrode thermofixation solution of the sclerosis that contains identical structure cell, can make compressive tension easily, promptly by suitably regulating solidification value, so that the compressive strain of just having inducted of contrast thermal expansivity is arranged between such structure cell wall and the material that is separated.

Concerning electroresponse was used, be the refractive index n that is subjected to particle size, contains the resinous substrates that remaining liquid crystal exists as solute with isotropic phase always the switching time of material _sRelative value and the ordinary index of refraction n of liquid crystal _oThe influence of relative value.For example, big particle size and n _sValue is greater than n _o, generally form longer switching time.Generally speaking, do not change other character significantly, liquid-crystal refractive-index can not change to some extent, thereby is used to show that purposes is little.The specific refractory power that meticulous adjusting is embedded with the matrix of liquid crystal is convenient in the present invention.Refractive index n _sAvailable specific method is regulated the ordinary index of refraction n with liquid crystal _oBe complementary or do not match.The transparency of this adjusting adjustable material and switching time are so that material is the specific end use optimization.

For example, flat pannel display, as TV, the image of being given birth on display screen is improved with the speed that eye-observation does not go out, requires the order of magnitude of switching time at an about millisecond.It is that vitreous state has high transparency that this demonstration requires again at ON, for will obtain high brightness or contrast gradient on the image that shows.Flat pannel display has adopted light-scattering material of the present invention just can show these desired characteristics, because the refractive index value of matrix to the ordinary index of refraction of liquid crystal, is adjustable.

Other application shows as alphanumeric time-temperature, and at this, image also do not require and be improved to high switching speed, and requires a bigger visual angle, so that image can be from the next door that shows and not to Nogata always.Light-scattering material of the present invention can provide big visual angle, when the specific refractory power relative value of matrix through changing, aim at the good effective refractive index that occurs by liquid crystal particle to cooperate, become an angle with optical axis, that is, its specific refractory power is between ordinary and unusual specific refractory power.

Novel liquid crystals thermoplastic materials can have this discovery of the electrical property of change, makes to make liquid crystal device, and this device combines quick switching time and the high-clarity of electrostatic image storage is arranged.Because providing is uncomplicated not expensive again manufacturing course, this device has been simplified the manufacturing of flat pannel display, and the novel optical operating gear is provided, and wherein memory can periodicly recover, and exists with long-term maintenance image.

Better the type of liquid crystal is when added electric field or magnetic field, aims at according to its selected direction.The aligning of liquid crystal particle optical axis can be finished, and the major axis of all particulates points to same direction in thin slice or film at this moment; When each liquid crystal molecule roughly points to same direction, also can finish above-mentioned aligning.In the liquid crystal particle thin slice or film of nematic misalignment, each molecule in a given particulate generally is that sensing is unidirectional, and still, the direction of indication is still different because of particulate.Each molecule of smectic shape liquid crystal particle does not point to same direction at the misalignment state, but set coking taper sub-district; Each particulate shows a total burnt pyramidal structure., except that the directivity order, also have part positional order at the liquid crystal of smectic shape phase, they not only refer generally to same direction, and sequence the position by level.At the liquid crystal molecule of smectic shape A phase generally is parallel to each other and be vertical to each layer in a specified layer.Liquid crystal molecule in smectic shape C phase is longer than the thickness of this layer, thereby, we can say that molecule is to specific angle of this layer inclination; Smectic shape C phase liquid crystal has positional order, no matter the molecule in this order is middle-level is still general with identical angle inclination between level between telling.

Apply electric field to having the isotropic nematic liquid crystal particulate of positive dielectric, can make particulate directed parallel, but do not influence its positional order with electric field.Remove electric field and again directional recovery is arrived original random aligning.Smectic shape A liquid crystal particle is applied electric field in misalignment or burnt taper attitude, can cause the liquid crystal molecule aligning, and parallel with electric field, and the level aligning is vertical with electric field; Even electric field is removed, aim at still existence.Because the smectic shape liquid crystal of level not added electric field also can store, adopt heating, can get back to burnt wimble structure.Apply electric field to material surface (as film) or to its selected zone, can reach the storage of thermoplastic image.This district can be any required shape, for example alphanumeric character or similarly thing, or it can comprise whole surface.

Under the situation of nematic liquid crystal particle film with positive dielectric anisotropy, can obtain the storage of thermoplastic image by selected a kind of nematic liquid crystal, this liquid crystal has the transformation temperature more than thermoplastic matrix softening temperature from liquid crystals to isotropic phase, softening then matrix, apply field to aim at the liquid crystal particle in the matrix of having softened, the matrix of in the presence of electric field, rehardening at last, thereby the particulate in the matrix of having hardened is still aimed at after electric field is removed.The electric field that the film surface vertical direction is applied can be aimed at the optical axis of liquid crystal particle, promptly to Surface Vertical in the selected district of direction of an electric field.Aim at good nematic liquid crystal can with the matrix phase mutual effect of having softened, electric field exists under, reharden like this, can make on the scene the removing of optical axis of liquid crystal particle in the selected district after, according to their parallel alignment part of direction reservation perpendicular to film surface.

The situation of smectic shape liquid crystal particle film in this way can obtain the storage of thermoplastic image, if at a simple applied field in selected district to aim at burnt wimble structure particulate, then the field is removed.Particulate can be aimed to same direction to the field that the film surface vertical direction applies, promptly aligned perpendicular is in the direction on surface.

The light of the selected district of each on material vertical incidence (being perpendicular to surperficial aligned at these district's liquid crystal) will can not detect the ordinary index of refraction n of liquid crystal _oRefractive index n with resin _sBetween effective difference; It seems that these districts be transparent, also will keep transparent for a long time.On the contrary, the light (is random aligned at this district's liquid crystal particle) that is incident on non-selected district is then at the extra-ordinary index of refraction n of liquid crystal _eRefractive index n with resin _sBetween, can be subjected to very big difference; It seems that these non-selected districts be opaque, also will keep opaque for a long time.For example, selected district is in the shape of alphanumeric character, and this character will it seems it is transparent, and will be opaque around the district of character.When the whole surface of the soften film of nematic liquid crystal is exposed in an aligned electric field or the magnetic field, and reharden under the existence on the scene, it is transparent that whole film can keep.Similarly, nearly the whole surface of crystalline liquid crystal film is exposed in the aligned field, can make whole film transparent.Transparent smectic shape film can further be handled, and reaches opaque character in transparent background, as long as a selected zone of required character shape is heated.This makes gets back to burnt awl scattering state at the smectic shape liquid crystal in selected district.

The thermoplastic image can be wiped, and whole film just can be got back to scattering, opaque state through heating.To the nematic film, Heating temperature should be more than resin softening point.More than softening temperature, heat film, can reverse conformational change, and cause liquid crystal particle to get back to random arrangement.Reharden to and form a kind of scatter incident light and it seems opaque material.

The nematic liquid crystal particulate can be elongated with mechanical tension, and as stretching or shearing, at this moment matrix is softish, and the also available tension force that keeps when film rehardens elongates.In case film rehardens, just can remove tension force, and particulate is elongated still along the mechanical tension direction.For example, when the mechanical tension aligning was parallel to the particulate of slice surfaces, thin slice can polarized incident light.

It is opaque that electromagnetic beam can be used to change a transparent film.The energy that film matrix absorbed can make it softening.Thereby the liquid crystal in film is got back to random scattering state entirely.A kind of dyestuff that can absorb electromagnetic radiation can mix in the film.For example, can allocate a kind of dyestuff that absorbs the infrared radiation scope into.Film with this dyestuff, the available infrared component of penetrating electromagnetic radiation that is absorbed into is heated, and the electric component of incident electromagnetic radiation then is used for being aligned in the optical axis of particulate in the thin film planar.After the width of cloth is penetrated the source and is removed, then the film scattering, and remain on scattering state.

Adopt technology of the present invention to make display device, can form liquid crystal display device, as contrast gradient and time of response with optimized display characteristic with the control particle size.

For real rigidity thermosetting matrix, for once control particle size basically.For the thermoplastic matrix of available heating reprocessing, or particulate dissolved again, be separated again, or simply particulate strengthened, and no longer all dissolve them, change at this process for subsequent treatment of first subsubmicron mean diameter Chang Keyong of the gained that is separated for the first time.

Usually, less particulate can produce switching time faster when added electric field, but needs a bigger threshold transition voltage compared with bigger particulate.Do not wish simultaneously to be subjected to the constraint of any special principle of operation, this phenomenon it seems be because microparticle surfaces interacts and the outfield between competition: particulate is littler, and surface/volumetric ratio is bigger, thereby the surface influence is bigger.Bigger particulate shows lower threshold voltage, because the surface force that will overcome is less.

Technology of the present invention makes the selection of switching time depend on that the end-use of display device has had possibility.In needs quick switching time, as in image improvement being come the also fast flat pannel display that can observe than naked eyes, technology of the present invention can produce small particle.Do not needing quick switching time,, also can use technology of the present invention and make bigger particulate as the application scenario of various alphanumeric times and temperature demonstration.

In general, light scattering efficiency increases near the scattering light wavelength with mean particle dia; Scattering efficiency has increased, and has just increased the contrast between ON and OFF electricity transformation condition.When the bigger contrast of needs, show a kind of narrow wavelength spectrum source of employing as projection type, technology of the present invention can be produced the particulate near wavelength.

The present invention can make the optical gate that electromagnetic spectrum is not a visible-range again, and as in infrared or ultraviolet range, its method is for can generate the particulate that its diameter approximates the wavelength of infrared or ultraviolet radiation greatly.

More much easier according to the demonstration that method of the present invention is made than using the method that has earlier.Can produce demonstration from a thermoplastic materials, as long as it is heated to softening point temperature, fold up then between alternate conductive glass that selected thickness arranged or plastic plate and get final product.As the demonstration of another shape of needs or thickness, above-mentioned demonstration can be taken apart and be heated to softening and moulding liquid crystal-thermoplastic resin again, is made into needed shape and thickness, then the display material with desirable feature is made in its cooling.This material helps hot melt to handle, and wherein, promptly generates homogeneous solution as long as the liquid crystal of hot thermoplastic resin and heat contacts with each other, and as a slice is thin, the resin flake of heating is immersed in the liquid crystal bath of heat.Then, need only reheat to can simply reprocessing display material more than the softening temperature.This reprocessing and the ability of utilizing have again reduced loss and have improved the efficient of the course of processing.

The accompanying drawing of having a talk now, Fig. 1 illustration a kind of display material preferably of the present invention, it is by solid, the light transmission matrix 10 that contains liquid crystal particle 11 is formed.As shown in Figure 1, liquid crystal components is heated, so that liquid crystal is transparent and isotropic phase.Selected liquid crystal is so that its optical index n at isotropic phase _iThe refractive index n that is worth similar transparent resin _s, thereby incide light on the material, as I _o, the not scattering by it rapidly is as I _TThe state of the material shown on Fig. 1 is in vitreous state.

Fig. 2 illustration same material, but difference is a liquid crystal components 11 ' be in the liquid crystals phase.Liquid crystals can be nematic mutually, cholesteric or smectic shape phase or their mixture.When at the liquid crystals phase time, optical index, i.e. extra-ordinary index of refraction n _e, be different with the specific refractory power with matrix 10 of isotropic phase, cause incident light I _o, can be by the scattering of liquid crystal institute, as I _sAt the resinous substrates refractive index n _sWith liquid-crystal refractive-index n _e, and when mismatching between liquid crystal particle scattering of light character, can make material scattering light.Regard as at the material of opaque state shown in Figure 2 and to be the White-opalescent structure.The matrix that contains liquid crystal can be converted to the White-opalescent state from vitreous state when temperature descends, so that liquid crystal is changed to the liquid crystals phase from isotropy.

Can respond the thermal response material of differing temps, available liquid crystal with different isotropy-liquid crystals phase transformation temperature and preparation easily.According to the nematic liquid crystal of present existence, be possible obtain a kind of liquid crystal, from-30 ℃ to 250 ℃ any temperature have isotropy-nematic phase transition.

Fig. 3 illustration a kind of electroresponse device 15, can be between opaque and vitreous state reversibly conversion.Residuite 16 contains liquid crystal particle 17, and this liquid crystal has ordinary index of refraction n _o, similar to the specific refractory power of matrix, this residuite 16 is interposed in 18 of electrical conductor, and one of electrical conductor or two are transparent.Voltage source 19 is connected to conductor 18 by switch 20, and OFF and ON position 21 and 22 are arranged respectively on the switch 20.As shown in Figure 3, when closing switch 20, when electric field was added on liquid crystal-matrix material, this material was that to be in light transmission be vitreous state.The electric field that adds in the direction perpendicular to film surface has the liquid crystal of aligning extra-ordinary index of refraction n _eEffect, thereby, make at I _oNot scattering of incident light ground by display unit 15 and at I _TGo out.When electric brake 20 is placed on OFF position 21, when power supply 19 opened circuit, the surface interaction on the particulate wall of liquid crystal and interlaminar resin made particulate get back to its random direction again, can see on Fig. 2.Thereby the liquid crystal-matrix material of device becomes the White-opalescent structure.

Fig. 4 illustration photoresponse, it can from display material of the present invention in addition mechanical tension stretch and obtain, indicated as arrow 30.Matrix is represented by label 32, represents with label 34 according to draw direction extended liquid crystal particle.Liquid crystal can be a nematic, smectic shape or cholesteric, or at the mixture of liquid crystals phase.Liquid crystal ordinary, refractive index n _oPreferably and the refractive index n of matrix _sSimilar.

Can form the liquid crystal particle distortion to material extending.Spheroidal particle just becomes ellipse, and its long axis of ellipse is parallel with draw direction.The distortion meeting of this particulate oneself is aimed at liquid crystal in the particulate and transverse.The result is behind all liquid crystal particles that stretch, with its optical axis and its extra-ordinary index of refraction n thus _eAim at draw direction.As at I _oThe component of unpolarized incident light can be parallel with draw direction, parallel with the optical axis of particulate again.These components will be at the refractive index n of liquid crystal particle _eThe refractive index n of matrix on every side _eBetween big difference arranged and be scattered.With the orthogonal incident light component of draw direction can run into one with specific refractory power like the matrix phase by film, film plays the light polarizer effect at this.Except that polarization effect, find again, the liquid crystal-matrix material that is embedded in the electroresponse structure cell is imposed mechanical tension, as shown in Figure 3, can reduce extra show and go switching time between a state.

Scattering polarizer 50 of Fig. 5 (a) illustration is when material of the present invention is to be separated or when hardening, it is as shown in arrow 52 to obtain this polarizer 50(in the presence of electric field or magnetic field).Solid, residuite are represented with label 54, and are had it by a direction aligned of thin film planar extra-ordinary index of refraction n _eLiquid crystal particle, represent by label 56.Liquid crystal has positive anisotropy on dielectric and diamagnetic susceptibility.Exist down as the alternating-electric field of the intensity that is enough to the directional crystal particulate or magnetic field, be separated or during process of setting, remove the field after, particulate still can keep orientation direction.Film plays the light polarizer effect at this, and is similar to the polarizer of oriented film described in top Fig. 4.

Unpolarized incident light such as I _oComponent, parallel with the aligning direction of the extra-ordinary index of refraction, will be scattered, as I _s, this is owing to the refractive index n in matrix _sWith aligned liquid crystal particle optical axis n _eBetween mismatch due to.At the polarized incident light that is orthogonal with aligning direction, with can not be at the general refractive index n of particulate 56 _oRefractive index n with matrix _sBetween have difference, and at I _TTransmission-polarizing is gone out.The scattering polarizer 50 of Fig. 5 (a), and the oriented film of Fig. 4, can shown in Fig. 5 (b), be transformed into the non-polarized light transmissive state, this contain particulate (as 56 ') matrix 54 be interposed in 58 of 2 electrical conductor, these two electrical conductor are preferably transparent.Voltage source 60 connects electrical conductor 58.Apply electric field energy the effect of aiming at extra-ordinary index of refraction vertical thin-film surface is arranged.Thereby, can make not polarization and passing through of incident light.When power supply 60 is placed on electric brake 62 on the OFF position and after the outage, particulate is loose to the balance direction, shown in Fig. 4 and Fig. 5 (a), and this display material again can polarized incident light.

Fig. 6 (a) illustration film 70, this film be with material of the present invention in the presence of the alternating-electric field or magnetic field represented by arrow 72, be separated or harden and make.Solid substrate is represented by label 74.Have itself and the vertically aligned extra-ordinary index of refraction n of film surface _eLiquid crystal particle represent by label 76.This liquid crystal has positive dielectric or diamagnetic anisotropy.Incident light is as I _o, at the extra-ordinary index of refraction n of particulate _eRefractive index n with matrix _eBetween do not meet mismatch, and at I _TNot scattering and transmission.This film is transparent.Fig. 6 (b) illustration the film of Fig. 6 (a), the influence that this thin film planar is subjected to shown in arrow 80.This can be magnetic field, electric field or as by electromagnetic field that high-intensity light source produced.This extra show has the extra-ordinary index of refraction n that is aligned in thin film planar _eEffect.To between the particulate extra-ordinary index of refraction and substrate refractive index, run into mismatch and will be scattered at the non-polarized incident light component that is parallel to the direction of aiming at the extra-ordinary index of refraction.The non-polarized incident light component that is orthogonal to the direction of aiming at the extra-ordinary index of refraction will can not run into this mismatch and promptly at I _TPass through this device with polarized light.

Fig. 7 (a) illustration film 90, it ought of the present inventionly have the soft thermosetting material of nematic liquid crystal of positive dielectric anisotropy, and tension force makes by pushing in addition, this extruding is when a certain temperature is separated or hardens, so that in the thermal expansivity of matrix 92 with shrink to lose to allot between the thermal expansivity of structure cell wall 94 and give birth to.Discoid liquid crystal particle has its extra-ordinary index of refraction, has aimed to make it parallel with film surface and irregular at thin film planar, and the discoid liquid crystal particle of this kind is represented with label 96.Owing to have mismatch between the extra-ordinary index of refraction of particulate 96 and matrix 92 specific refractory poweres, incident light is just with scattering, and that this device presents is opaque.The discoid particulate of Fig. 7 (a) is compared with the spheroidal particle of Fig. 2, and its dispersion effect will have raising, and this is because to all particulates 96, n _eOn thin film planar.Fig. 7 (b) show be interposed in conducting electrode 94 ' contain particulate 96 ' resin 92.In conducting electrode 94 ' apply voltage can make the extra-ordinary index of refraction by aiming at the vertical direction of film surface.The incident light of device to particulate 96 ' specific refractory power and the specific refractory power of matrix 92 between can not detect difference, then will not scattering and transmission, thus form transparent device.This class film has the demonstration contrast gradient of having improved than spheroidal particle film.

Usually, liquid crystal-matrix material is a kind of flexible solid and can cuts, and casts or be reprocessed into film or big part.This thermal response material is at high resolution, all can use on high visual contrast thermometer or the temperature indicator, for example, can be used for medical science or other technology, Frozen Food Packaging, site etc. is determined in the detection of icing on Refrigeration Technique, the road surface and medically be used for detecting the thermogram of chest cancer.This material also can be used for the high contrast of hot addressing, wide visual angle and flat pannel display.This demonstration can be carried out electrical addressing with impedance or Joule-Thomson effect device, changes the temperature of material with the part.This material can also be used the high-strength beam addressing, with the local heating material surface.

As at Fig. 3,5(b) and 7(b) in illustrative electroresponse and polarizer, available transparent conducting coating deposits on material surface or brushes and makes, or solidify be interposed in two between the thin plate that contains transparent conducting coating resin and make.Visual contrast between opaque and vitreous state can adopt a suitable background (as dark or the light) improve.

Be that black or colored electrical-optical show under opaque state, can in liquid crystal, add two look dyestuffs and make.For example, at Fig. 3 or 7(b) in electrical-optical show, be black when not having voltage, be white when applying voltage, its available pleochroic nematic liquid crystal of black that contains is made.When solidifying in transparent resin, and during the adularescent background, this liquid crystal can reach the demonstration of white under the black prospect.

Illustrative scattering polarizer film can be used as the strain monitoring device on Fig. 4, is placed on should change direction on the film and has controlled film polarising direction.Change institute executes the strained direction or size can cause polarization direction or degree change.The variation of polarization can be looked film by the polariscope sight and monitor.

Can by under the situation about existing in Fig. 4 or Fig. 5 (b) field shown in going up respectively by stretching or the electrically addressable scattering polarizer is made in slaking.On of these films, its transparent conductive body is applied enough big voltage, can aligned perpendicular in the particulate optical axis of film surface, and make polarization effect conversion, and the film bleach.This material is applicable to display window or other device, polarization effect can be converted to and not have in this requirement.

The optics fertile material can prepare with film, and this film is by solidifying, or by strain, so that extra-ordinary index of refraction n under the existence on the scene _eMake with the film surface perpendicular alignmnet.This film is transparent and astigmatic thoroughly with general light intensity.Enough high-intensity incident light can make the liquid crystal reorientation, thereby the particulate optical axis is switched to the thin film planar direction.This film becomes scattered beam opaque.Film will be used as device for non-linear optical the high-strength magnetic ripple will be made the protection coating, or as the optical computing device.The nonlinear optical response also might make high-intensity incident light that the specific refractory power of liquid-crystal refractive-index with respect to resin changed.

When making material of the present invention with thermoplastic resin, this material has the advantage of storage characteristics.Fig. 8 illustration the preparation of thermoplastic materials, this material will show and form correlated opaque and clear area, for example be used for alphanumeric demonstration.As shown in Figure 3, be heated to the above temperature of resin 130 softening temperatures, but be lower than the thin slice of the transformation temperature from liquid crystals to isotropic phase of liquid crystal, be placed on 140,142 of conducting electrode necessarily requiring form in the quasi-electric field.This thin slice also can be heated to more than the transformation temperature from liquid crystals to isotropic phase, allows it be cooled to below the transformation temperature from isotropic phase to the liquid crystals phase then, but for alignment procedures will be more than the matrix softening temperature.The optical axis of the particulate 134 of softening matrix 130 is aimed at by direction of an electric field, and is promptly vertical with slice surfaces.The optical axis of particulate 138 is not placed under the electric field, then misalignment.Be cooled to below the softening point temperature subsequently, and protect electric field simultaneously, generate material as shown in Figure 9.

Fig. 9 shows the material of Fig. 8, matrix 150 reharden and electric field remove later state.Be incident on only transmission or scattering on the material, depend between the specific refractory power of matrix and liquid crystal and feel to have or not coupling or mismatch by incident light.Has the incident light I on the matrix 150 of aiming at particulate 154 optical axises _o, do not run into refractive index n _sAnd n _oMismatch, thereby transmission, this makes the zone of containing particulate 154 become transparent.Be incident on the incident light I on the matrix 150 of the particulate 152 that has irregular orientation _o', at refractive index n _sExtra-ordinary index of refraction n with whole irregular direction _eBetween can run into big difference, and be scattered, as I _s' shown in, cause this zone to become opaque.

Material shown on Fig. 8 and 9 has some purposes.For example, can be used as temperature monitor, surpass this monitor of a certain selected temperature as the envrionment temperature of material and show a visual alarm signal.Even this temperature is got back to below the selected temperature, still can see guard signal.For example be 0 ℃ matrix with a kind of softening temperature.A resin film can be fixed on a kind of frozen goods, as food product pack.Film can be made the suitable image that for example has " OK ".As long as film remains on below 0 ℃, will always can see " OK " image., be raised to more than 0 ℃, even image just disappears and the freezing more subsequently image of article also can not reproduce as the article temperature.

Material of the present invention can be as the mark that can disappear.Apply suitable voltage and heat and an image can be imprinted on the material.This material can keep image up to heating again.Seven grades of electrodes that alphanumeric information may be configured as form write out.When the film heating with postcooling the time, by the method for certain suitable direct addressing being write out a character with voltage.This mark is used for souvenir commodity price on shelf.This material also can be placed between the plastic tab of the conductive surface that has into form.On plastic sheet, add a thin metal layer and can be used to do resistive heating.Employing is with the film heating and cooling time, and to the method for suitable one-level charging, image just can be imprinted on this mark.Can make mark with a simple handpiece addressing at the electrical pickoff of this marker edge.When the current flow heats film was provided, this parts programable was charged to suitable one-level.This provides a promptly simple again rapidly device that shows the retail price that improves.

Material of the present invention also can be used to make multiplexed flat pannel display, and it is than having more picture elements with the resulting flat pannel display of device that lacks storage characteristics of the present invention.Material of the present invention does not also require that a kind of active matrix is to keep image.And, only be that the picture elements that will be changed in image just need be addressed.Under there is situation in the outfield, by heating and cooling, can generate clean picture elements, do not having to generate opaque picture elements with heating and cooling in the presence of the outfield.

Figure 10 represents matrix 170, and it contains the particulate of smectic shape A liquid crystal 174.As shown in figure 10, liquid crystal is that it does not have best aligning direction in burnt taper attitude, thereby, n _eBe irregular orientation in the substrate.Incident light on this material is as I _o, at n _sAnd n _eBetween feel its mismatch, then be scattered, as I _sThis material is opaque.

Figure 11 represents the material of Figure 10,, is subjected to electric field E and removes state behind the field in illustrative direction at the resin 180 that contains smectic shape A liquid crystal particle 184.Each level is all by aiming at perpendicular to the direction of institute's extra show, the major axis of liquid crystal molecule then with the film surface quadrature.Generally speaking, incident light I _o' at refractive index n _oAnd n _sBetween do not feel its mismatch, then at I _TThe scattering by material, the material of Figure 11 is transparent.

An important characteristic of the present invention provides the method for preparing liquid crystal-thermoplastic based material, and this material has very high liquid crystal to polymer ratio.This liquid crystal should show positive dielectric anisotropy, and nematic preferably.This ratio at least 1: 1, preferably about 1.5-2.0: 1.The liquid crystal of high density generates high correlated demonstration between transparent and zone of opacity, make to show that being easy to identification reads.Table I A has summed up in the example XXX below according to the polymkeric substance of the made various materials of the present invention various ratios to liquid crystal.Table I B has then listed the character of the electric convertible structure cell of material on the table I A and ratio made.(table is seen the literary composition back)

I B can see from table, and polymkeric substance and liquid crystal proportion are approximately greater than 1: 1 pair of structure cell first with can not form macroscopical visible for No. three and be separated.

A critical nature of liquid crystals-polymeric material of the present invention is that the polymkeric substance that is separated generates closed form matrix in a kind of agglutinating structure cell around liquid crystal particle.

Figure 12 is the microphotogram of example XX XII material, represents a structure like pellet porous, and this structure is to be separated and to be generated by polyisobutene methyl esters and liquid crystal E7.Closed form matrix makes the amount of liquid crystal that is trapped in the material reach maximum in the structure cell, and generates solid film, can not allow liquid crystal run off away.

The refractive index n of polymkeric substance _pBy being adjusted to n in the plasticising that is separated and particulate took place between the rise period with liquid crystal _sValue.Transparency is subjected to the n of matrix _sThe n of (wherein being dissolved with liquid crystal) and liquid crystal _oThe influence of relative value.For example, at the situation of the device of using the benzonitrile nematic liquid crystal, n _o≌ 1.51; So, reach the transparency of general incident light maximum, the n of matrix _sShould be as far as possible near 1.51.The dissolved liquid crystal may be worth close to this.

Equally, n _sAnd n _oRelative value influenced have the nematic liquid crystal particulate device of thermoplastic matrix of (showing positive dielectric isotropy) be transparent from ON() opaque to OFF() electric switching time of state.Table II A and II B have summed up n _pValue and with the character of various polymers and the prepared structure cell of liquid crystal E7, as listing with example XX III below.(table is seen the literary composition back)

The effect of dissolving liquid crystal is to improve or to reduce the refractive index n of polymkeric substance _p, and generate a kind of liquid-crystal refractive-index n that approaches _oThe effective refractive index n of matrix _s

Dissolving amount of liquid crystal in polymkeric substance can be done further control by speed of cooling in phase separation.The general generation of speed of cooling has material and a large amount of materials that dissolved liquid crystal of fine particles fast, and slowly speed of cooling then generally generates thick particulate, and the dissolving amount of liquid crystal in matrix is also less.Cyanogen hexichol liquid crystal solute such as E7 in the listed polymkeric substance of II A table have raising pure, the refractive index n of unadulterated polymkeric substance _pRefractive index n to real polymeric matrix _sEffect; To n _pThe degree that improves then depends on concentration and the n that dissolves liquid crystal _pInitial value.

Be illustrated in the situation of among Figure 13 A demonstration being looked at straight from the direction of A, then require refractive index polymer n _pIn the scope of 1.49-1.50, thereby, the last refractive index n of matrix _sWill be as far as possible near n _o=1.51.To the demonstration of watching from the side, shown in Figure 13 B, its refractive index n of polymkeric substance _pMore preferably greater than n _o, but be generally less than n _eThereby, substrate refractive index n _sCan with the effective refractive index n of liquid crystal _xCoupling.This demonstration is the easiest reads from direction B, shown in Figure 13 B.As on table II B, polycarbonate, its n _p=1.585, can be created in and become 30 ° of best image of watching with normal.13B with the aid of pictures again, effective refractive index n _xAvailable following formula comes proximate calculation:

nx≌ (n _en _o)/(n ₀ ²sin ² _a+n ² _ecos ²a)

At this,

sina= (sine)/(n _s)

θ is the visual angle; α is from n _eTo effective n _xThe angle; C is the polarization of incident light direction.

A key character of the present invention has provided the material that high resistivity and specific inductivity are arranged, and lives forever the storage time with generation.The structure cell that mixes this material can keep electric charge, and this electric charge has kept the optical axis of particles of material on aligned position again, opens circuit or disappears until electric charge.When keeping electric charge, external electric field is not depended in the storage of this material demonstration image.Its work principle is, the material film that is placed on the electrically conducting transparent interpolar has been formed a structure cell, plays a part capacitor C and internal resistance R, applies voltage electrical condenser is charged, and electric charge still exists when removing voltage, and the vitreous state of this film can keep for some time that approximates R * C product.The product value of R * C does not generally depend on the size or the shape of electrical condenser, and only depends on the electrical property of liquid crystal-matrix material: C=ε A/d, wherein, ε is the specific inductivity of material, and A is a membrane surface area, and d is a thickness, with R=ρ d/A, wherein ρ is the resistivity of material; Therefore, discharge time, the product of ε * ρ is the character of material, rather than the function of unit cell dimension or shape.The table III has been summed up the storage time (ε ρ) (table is seen the literary composition back) of the various materials of being made in the example XX III below according to the present invention.

Liquid crystals-polymeric material that other demonstrations have prolonged storage time will be mentioned in example.

Liquid crystal can dissolve rapidly, thereby, only need mild stirring to generate a homogeneous solution.Remove the air filled cavity that may occur when stirring, solution can be before solidification matrix, in addition centrifugation or be placed in the vacuum chamber.The size and the spacing of particulate depend on a number of factors, as the temperature that is separated, setting rate, and the type of polymkeric substance and used liquid crystal material, the relative proportion of these materials, and curing mode and speed are below with more detailed telling about.

The phase equilibrium diagram that liquid crystal and production thermoplastic materials are formed the binary mixture of resin schematically is illustrated among Figure 14.T ₁Be such temperature, more than the temperature, liquid crystals-resin compound can be formed single-phase, homogeneous solution in any component at this; T ₂It is the temperature of mixture solidified.The B district is separated before solidifying and forms the miscibility gap of particulate.A district in the miscibility gap outside is a homogeneous phase solution.The mixture that Y point illustration is one 50/50 will enter miscibility gap, that is, begin to be separated and in temperature T ₁Generate particulate down in the original place.X ₁The mixture that the some illustration is one about 67/33 is at T ₃It will be homogeneous solution; X ₂The point illustration mixture will enter miscibility gap, or at T ₄Under generate particulate.And X ₃Point illustration mixture will be at T ₂Solidify.

Be separated for solvent evaporation, best, thermoplastic resin will dissolve in solvent or the solvent mixture, and liquid crystal can mix with it.Figure 15 illustration solvent, the phase equilibrium diagram of the tertiary mixture of liquid crystal and resin.Ratio in the A district, mixture are uniform; Ratio in the B district, mixture are in the compatibility zone and formed particulate.By solvent evaporation, mixture is from Z ₁The point beginning is along Z ₁, Z ₂Line proceeds to have last component Z with generation ₃Film.

Solvent evaporation is useful for the film that coated on the article contains liquid crystal., be placed on liquid crystal-polymeric material electroresponse device between transparent electrode plate as the sheet form of needs, it but is very difficult making thin slice by solvent evaporation between plate.In this situation, solvent evaporation can generate the thermoplastic materials of monoblock by being separated.This then material is placed between plate, and it is flowed between plate, last cooling curing it.

The solvent evaporation technology is particularly useful to the resin that this high transformation temperature is arranged, the T of this temperature on Figure 14 ₁Or be higher than T ₁The time, liquid crystal can be degraded.Generate the monoblock thermoplastic materials by solvent evaporation, liquid crystal plays the effect of matrix softening agent, and the softening temperature of reduction matrix is to the degradation temperature of liquid crystal.For the thermoplastic materials that high destructive melt temperature is arranged, homogeneous solution preferably prepares by by weight 1 part of polymkeric substance being dissolved in about 5 parts of suitable solvents at least 1 part of liquid crystal.In case this material begins preparation with solvent evaporation, all are the processing of material subsequently, forms or reprocessing as structure cell, and reliable thermoplastic and cooling are finished, to dissolve and to regenerate or the size of conversion liquid crystal particle simply.The plastifying effect is because the liquid crystal of a part in solution stayed in the matrix.So in this situation, plasticization effect provides a kind of material, this material can be softened with heavily covering and harden, and the liquid crystal of not degrading.

A kind of suitable thermoplastic resin is a kind of improved Resins, epoxy, and its softening temperature is arranged in the scope that requires.A kind of general thermoset epoxy resin can convert a kind of thermoplastic resin with selected softening temperature to, and it is by replacing crosslinking and curing agent with non-crosslinked tackiness agent (solidifying agent) as monoalkylamine.The remollescent temperature takes place reliably selects solidifying agent to regulate.Use the short chain monoalkylamine and can produce the epoxy resin product that has than with the higher softening temperature of the solidification point of long-chain monoalkylamine, than generating epoxy resin product higher softening temperature is arranged with hexylamine as using propylamine.Alkyl branch can reduce its softening temperature.Come highly as its softening temperature of Resins, epoxy that makes from n-Butyl Amine 99 than what the TERTIARY BUTYL AMINE from side chain generated.

Solidified Resins, epoxy has not determined the chain length of the cured resin of generation to the ratio of monoalkylamine.Is 1: 1 o'clock at the Resins, epoxy equivalent to alkylamine equivalent ratio, and main chain length is the longest.When ratio departed from out 1: 1, for how with resin or use alkylamine, then backbone length can shorten more.

Can make the final character of matrix be fit to special requirement to the proportioning of Resins, epoxy by selecting what type alkylamine and alkylamine.Use long backbone length and short alkylamine chain length, can obtain a kind of harder and inflexible resin.For example, 1: 1 product with the propylamine proportioning can generate firmer cured resin than 1: 1 product with the hexylamine proportioning.

Softening range has determined can write/wipe the temperature of phenomenon.At this, " writing " means under the situation of field with the optical axis of aligning particulate that adds an one-tenth form, heating liquid crystal-polymer matrix material, and in the presence of this outfield, cooled off and then write out the image that occurs with this form type; " wipe " and mean one of heating, and cooled off in the presence of the outfield not having, so that optical axis is got back to random state thereon with the material of image.With long backbone length and short alkyl chain length, can obtain higher writing/wipe temperature.Producing higher writing/wipe temperature the storage time of image, and promptly main chain is long and can extend under the kindred circumstances that alkyl chain is short.

Other chemical agents beyond the alkylamine also can be used, and are a large amount of crosslinked and stop softening as long as they do not form.These suitable chemical agents are have only two reactive hydrogens the sort of, as glycols and two acids.

Curing resin material is changed the effect of its backbone length in softening range, can use by various EPON828(lot number #8GHJ-52-Miller Stephenson Co., Inc., Danbury, CT06810) resin to the various ratio manufacturings of hexylamine (HA) judges, and sees Table I

These three kinds of resins solidified 3 days at 65 ℃, were cooled to room temperature, and macroscopic observation shows that these three kinds all is equally quite hard curing.These three kinds of resins are at baking box internal heating to 82 ℃, and 10 minutes, macroscopic observation the results are shown in Table II.

Display characteristic is changed the effect of the backbone length of the curing resin material contain liquid crystal, can relatively contain the 33% liquid crystal E7(that has an appointment with in the example X III below) and the mixture of about 67%EPON828 and hexylamine (HA) (in the ratio of various EPON/HA) estimate; EPON to the per-cent of the various ratios of HA and liquid crystal in the table III, with only being that cured resin shows with same ratio.

These mixtures solidified 3 days at 50 ℃.Room temperature (R.T.) and in the result of 50 ℃ of macroscopic observations that the EPON/HA mixture is done in table IV A.Table IV B has then described at 3 ℃, the scattering of light character of room temperature and 50 ℃, and the mixture E PON/HA/E7 of table III is in the physical conditions of 3 ℃ and room temperature.

OP=is opaque

The POP=part is opaque

Cl=is transparent

Various amine are to the scattering of light character of various liquid crystal in EPON828, image storage time and write/wipe Temperature Influence, available 67%EPON/ amine with 1: 1 equivalence ratio one 33% liquid crystal of preparation (weight) estimate.Various mixture main bodys were solidified 4 hours at 65 ℃, and were cooled to room temperature.Table V A and table V B have summed up the scattering of light character in room temperature.Be hard and be difficult to distortion in room temperature with straight chain propylamine to the made resin of hexylamine (1,2 and 4), and heptyl amice (5) resin is easier to distortion, octylame (6) resin is clamminess.

The transparent S=scattering of C=

The translucent S/PS=of X=has the scattering that is separated

Liquid crystal in table V A is as follows:

E-7, as in the example 1 below, have one from crystallization to nematic liquid crystal phase transformation temperature-10 ℃ and liquid crystal to 60.5 ℃ of isotropic phase transformation temperatures.

E-31 is the patent mixture of EM chemical company, is made up of cyanobiphenyl and non-cyanobiphenyl ester, has from crystallization to nematic crystallization phases transformation temperature-9 ℃ and from liquid crystal to the isotropic phase transformation temperature 61.5 ℃.

E-44 also is the patent mixture of EM chemical company, and by cyanobiphenyl, cyano terphenyl and non-cyanobiphenyl ester are formed, and has from crystallization to nematic transformation temperature-60 ℃ and from liquid crystal to the isotropic phase transformation temperature 100 ℃.

K-12, by 4-cyanogen-4 '-the butyl hexichol forms, and has 48 ℃ of transformation temperatures from crystallization to the nematic liquid crystal phase.

K-18, by 4-cyano group-4 '-hexyl biphenyl forms, and has from crystallization to 14.5 ℃ of nematic liquid crystal phase transformation temperatures and from liquid crystal to the isotropic phase transformation temperature 29 ℃.

The transparent S=scattering of C=

The translucent S/PS=of X=has the scattering that is separated

Liquid crystal in table V B is as follows:

K-21, by 4-cyano group-4 '-heptyl biphenyl forms, and has from crystallization to 30 ℃ of nematic liquid crystal phase transformation temperatures and from liquid crystal to the isotropic phase transformation temperature 42.8 ℃.

K-24, by 4-cyano group-4 '-octyl group biphenyl forms, and has from crystallization to 21.5 ℃ of smectic shape A mesomorphic phase transformation temperatures 40.5 ℃ from smectic shape C to 33.5 ℃ of nematic liquid crystal phase transformation temperatures with from nematic liquid crystal to the isotropic phase transformation temperature.

M-15,4-cyano group-4 '-penta oxygen biphenyl is formed, and has from crystallization to 48 ℃ of nematic liquid crystal phase transformation temperatures and from liquid crystal to the isotropic phase transformation temperature 68 ℃.

M-18, by 4-cyano group-4 '-own oxygen biphenyl forms, and has from crystallization to 57 ℃ of nematic liquid crystal phase transformation temperatures and from liquid crystal to the isotropic phase transformation temperature 75.5 ℃.

M-24, by 4-cyano group-4 '-Xin oxygen biphenyl forms, and has from crystallization to 54.5 ℃ of smectic shape A mesomorphic phase transformation temperatures 80.0 ℃ from smectic shape A to 67.0 ℃ of nematic liquid crystal phase transformation temperatures with from nematic to the isotropic phase transformation temperature.

To image storage time be to use mixture 1-2 and 4-6 between the electrode slice of form to prepare with writing/wipe the sample that temperature makes qualitative evaluation, as shown in example X VII below.Storage time (image decay) and write/wipe temperature and increase with alkylamine and shorten, also shorten with the decline of resin hardness.

General step shown in the preparation of light-scattering material of the present invention is included on Figure 16.With reference to Figure 16, can find, select the processing of parent material and mixture, enter be separated after, but before matrix immobilized, can also control the rate of growth of particulate.

The character of parent material, promptly liquid crystal and resin (polymkeric substance) influence the solvability of liquid crystal in polymkeric substance, and have determined the composition of homogeneous solution and the point that is separated, and put the speed that it carries out at this.The relative concentration of parent material has also influenced phase separation speed.The variation of solidification value has changed solvability, and the speed of polymerization and liquid crystal come out to the speed of spread of particles from polymkeric substance.The speed of cooling of liquid crystal thermoplastic solution has influenced the rate of growth of particulate.

Thermoplastic materials, can reversibility ground melt and dissolved as the Resins, epoxy of thermoplastic improvement in differing temps, and be cooled to solid-state with controllable speed with different.When cooling off the homogeneous phase solution of a liquid crystal and thermoplastic materials, can reach a temperature, wherein liquid crystal and polymkeric substance are immiscible, and are separated.The molecular-weight average of this temperature and polymkeric substance is relevant with the concentration of liquid crystal.Can know from Figure 17 and to see, the temperature that slowly descends can have time enough by molecule to each deposition location diffusion, thereby form bigger particulate.Data on Figure 17 are to obtain from following example XXX I and XX XII.Fast as cooling time, then just curing of matrix for a long time before reaching hot running balance.Thereby particulate is not free to be increased, and a large amount of liquid crystal molecule is trapped in the solid substrate.The speed of cooling role of thermoplastic materials is similar to the curing or the polymerization temperature of thermosetting polymer.

Different thermosetting polymers as Resins, epoxy, solidifies under friction-motion speed, and its size of the particulate of generation can have the above difference of two orders of magnitude.The table V has been summed up this effect of two kinds of Resins, epoxy.

Can see from the table V, under same concentration and temperature, particulate being twice that EPON828 generates than Bostik.Can know more in the example below and see that when reaching the about 40-50% of maximum value, the relative concentration of liquid crystal just has relation with particle size in these systems, begin that channel information is arranged this moment.

Best way of the present invention will be come further illustration and description with following object lesson.Prepare all will use in the light modulating materials each time and be separated.

The example I

High reduced temperature responsive materials can be made with the epoxy material of two kinds of components, and the one, liquid crystal, another is the Resins, epoxy that the commerce that Bostik went out of Emhart chemistry group is named as Bostik7575.The A of its Resins, epoxy partly be dihydroxyphenyl propane and epichlorohydrin etc. molar mixture.B partly is a kind of fatty polyamine solidifying agent.The mixture (weight) that liquid crystal (E-8 of EM industrial) is made up of following chemicals; 4 ' just-pentane-4 '-cyanobiphenyl (5CB), 43%(weight); 4 ' just-third oxygen-4-cyanobiphenyl (30CB), 17%(weight); 4 '-just-and penta oxygen-4-cyanobiphenyl (50CB), 13%(weight); 4-just-Xin oxygen-4-cyanobiphenyl (80CB), 17%(weight) and 4 '-just-pentyl-4-cyano terphenyl (5CT), 10%(weight).

The A of Resins, epoxy and B part and liquid crystal, according to the A part of prescription 33-1/3%, the liquid crystal of the B of 33-1/3% part and 33-1/3% equal proportion by measure mixes.These three kinds of components were slowly stirred 3 minutes when mixing, and made into homogeneous phase solution.Solution centrifugal separates 1 minute to remove the air filled cavity that enters in whipping process then.On sheet glass, uncured material is spread out into uniform thickness with the preparation sample.After solidifying 48 hours, be the sample of 200 micron thickness approximately, and be pure white opaque structure (opaque state).The sample thin film of its thickness between 10 to 200 microns also is white, but opaque slightly.From glass surface film is torn, to form the solid toughness material.When these films are heated to nematic-isotropic phase transformation temperature near 80 ℃, their can become suddenly thorough clearly or transparent (clean state).Keep transparent at 80 ℃ with upper film, and be cooled to below 80 ℃, then get back to complete opaque state.Film thickness is depended in contrast between opaque and vitreous state.200 ± 100 microns thickness has shown visual contrast between opaque and vitreous state.By the cleaning of film and the nematic-isotropic phase transformation temperature of opaque state demonstration is very near the nematic-isotropic phase transformation temperature of liquid crystal before being dispensed into Resins, epoxy.

The example II

Be used in the same material of describing in the example I and can make the electroresponse device.In this example, the uncured mixture of example I is interposed between two sheet glass after centrifugation, on the surface of its contiguous mixture the Indium sesquioxide conductive coating is arranged.Between sheet glass with a layer insulating (tetrafluoroethylene strip) with the control film thickness to about 75 microns.After solidifying 24 hours, film has pure white opaque structure (opaque state).When to the conductive surface of sheet glass in addition during 100 volts alternating-current, material becomes transparent (vitreous state).Between cleaning and opaque state, show relatively poor visual contrast less than 10 microns film thicknesses, and need a less changing voltage.Display background is dark or reflective in this way, then can improve the ON-OFF visual contrast.

Can observe at an area is 2.0cm ²Sample apply 100 volts of voltages, be 5 * 10 at the given driving power of vitreous state ^-6Watt can draw 5 * 10 ^-8The peace electric current.

The example III

Can be produced on opaque state again to liquid crystal compound interpolation blue dyes is opaque blueness, is transparent electroresponse visitor-main device in vitreous state.Blue dyes be 1-(right-just-butyl phenyl amino)-the 4-hydroxyanthraquinone.According to weight ratio, blue dyes and liquid crystal are respectively: 1.5% and 98.5%, and dyestuff is added in the liquid crystal compound in the example I.This mixture and then with the A part of following proportioning (capacity) 33-1/3%, the A part and the partly mixing mutually of B of the blue dyes of the B of 33-1/3% part and 33-1/3% and liquid crystal and the Resins, epoxy of example I.As in the example II, material solidifies having between two blocks of sheet glass of surface conduction coating.In this example, between transparent and opaque state,, can obtain bigger visual contrast with less film thickness and lower in addition to conductive surface thus voltage.As long as applying 25 volts of voltages in about 10 microns demonstration, thickness it can be become vitreous state.

The example IV

With the liquid crystal compound of example I and one two component fast-curing epoxy resin (trade name EPO-TEK302), can make the temperature response film, this Resins, epoxy is made up of bisphenol a resin (A part) and a kind of aliphatic firming agent (B part).Resins, epoxy and liquid crystal mix with following proportioning (capacity); 25%A part, 25%B part and 50% liquid crystal.Adoptable film preparation program is all the same with the example I.Solidifying two days later, film when liquid crystal isotropy-nematic transformation temperature is below 80 ℃, the opaque structure of adularescent, and more than the temperature, be vitreous state at this.

The example V

With liquid crystal 4 '-the poly-supernatant liquid of octyl group-4-cyanobiphenyl (K-24 of EM industrial) mixes with following proportioning (capacity) mutually with one two component epoxy, can make the mechanical stress with light polarization character and the material of temperature response; 33-1/3%A part, 33-1/3%B part and 33-1/3% liquid crystal.Resins, epoxy by bisphenol-A epoxy compound and epichlorohydrin etc. molar mixture (A part) and a kind of fatty amide hardener (B part) form, it can be buied from the Bostik company of Milan, ITA.Prepared two samples, made liquid crystal with K-24 for one, another is with 75%K-24 and 25%(capacity) mixture of ar-methoxy-benzylidene-right-butylaniline.The whipping procedure of mixture and example I identical.Allow mixture solidify between microscope slide He under the plastic housing, to produce the about 50 microns film of thickness.In case mixture is cured, plastic housing is very easy to be removed, so film is easy to peel off from glass substrate.One smooth equably, and shinny promptly obtains with toughness material, and it is opaque in room temperature.

This film is pressed folk prescription when stretching, and it becomes more transparent.Can see by direction linear polarization by the light of oriented film perpendicular to draw direction.When material being heated to the temperature of liquid crystal, no matter material becomes transparent and all do not see polarization phenomena in state of nature or stretched state at isotropic phase.Except stretching, tangential strain power or only be that folk prescription also can produce same polarization effect to pressurization in addition.

The example VI

Mix following article according to following order, can prepare has the electroresponse of light polarization character structure cell: Resins, epoxy B part, 32.5%(weight); Nematic liquid crystal, 33.5%; Interval insulant 0.7%; Resins, epoxy A part, 33.3%.Used Resins, epoxy with in the example V, describe identical.Nematic liquid crystal (as the E-7 that buys from EM industrial) is 4 '-just-and amyl group-4-cyano group-biphenyl (5CB), 51%(weight), 4 '-just-and heptyl-4-cyano group-biphenyl (7CB), 21%; 4 '-just-and octyloxy-4-cyano group-biphenyl, 16%; With 4 '-just-and amyl group-4-cyano group-terphenyl, 12% mixture.Interval insulant is a kind of powder, and its granular size is 26 microns (as the AlufritPS-26 by the supply of Atomergic chemical company).When the mixture of liquid crystal and Resins, epoxy still is in uncured flow state, it is placed between two blocks of sheet glass, transparent conductive coating is arranged above the sheet glass, can pass to voltage to this coating.Material solidified 5 days at-24 ℃ then.When heating to room temperature, the different coefficient of expansion of sheet glass and epoxy matrix material makes matrix and the liquid crystal particle that is distributed in the matrix produce strain, thereby, light by material is linear polarization, and this can be from making light disappear and being confirmed through orthogonal polariscope.Then, conductive coating is passed to 30 volts alternating-current, responsive materials just is transformed into transmitted ray, only is in faint polarising state.

The example VII

A kind of response structure cell can also make from tough epoxy resin-LCD panel, and this is stretched, and is interposed in two electrically conducting transparent surfaces.Flexible Resins, epoxy-LCD panel is partly made by at first mixed liquid crystal and Resins, epoxy B, adds the A part with 1: 1: 1 proportioning then.Used liquid crystal identical with in the example IV.A partly be dihydroxyphenyl propane and epichlorohydrin etc. molar mixture; B partly is chemical curing agent (the two all can be bought from the Bostik company in gondola Milan).Resins, epoxy-liquid crystal compound is allowed to condition at two and apart solidifies between 50 microns synthetic glass sheet.After solidifying one day, then take out the opaque white color toughness sheet that generates from the synthetic glass sheet.This sheet is interposed between two blocks of sheet glass according to an about 5-10% of direction stretching.Each piece sheet glass is coated with transparent conducting coating in one side.This inserts and puts is to constitute like this, promptly will make conductive coating towards drawing sheet.A linearly polarizing film will be got same direction with the tensile sheet that inserts and puts, and disappears to greatest extent to reach transmitted ray, then attached to inserting and putting on the sheet glass.

Do the another one structure cell again by foregoing method, only the opaque white color toughness flake was not stretched before being interposed in the conductive glass sheet.

When one 200 volts voltages were added to the structure cell of expanded material, the time of response between opaque and vitreous state was the numbers of poles of a millisecond.The time of response of the structure cell of making of expanded material not then is the 25-40 millisecond.

The example VIII

The suspension of liquid crystal can solidify a kind of Resins, epoxy-dispensing liquid crystal and makes with ultraviolet light in toughness solids epoxy matrix.This Formulaion of epoxy resin is 3.8 gram resins (EPON828 of shell chemical company), the epoxy hardener (the trade mark FC-508 of 3M company) that 0.4 gram activate through ultraviolet light and the mixture of 0.9 trimethylene glycol that restrains.Liquid crystal identical with described in the example VI.A kind of solution can at first mix 0.3 gram Resins, epoxy and prepare with 0.1 gram liquid crystal.Then this solution was solidified 30 minutes under ultraviolet light.The material that solidified is an opaque white color, but when heating, promptly under nematic liquid crystal isotropy transformation temperature, become transparent, thereby, can play the transformation of thermal response light.Toughness solid and the opaque suspension material partially transparent that when stretching, also becomes.Can see see through the position stretch the transmitted ray of material will be by linear polarization, and when an orthogonal polarizer was placed on expanded material front or back, light can disappear.This material only needs than its original length stretching 5-10%, to show polarization effect.As extruding or other mechanical distortions a little, also show polarization effect.When seeing through a crossed polarizers, this material can play the transformation of mechanical response light.

The example IX

The A and the B part (the Bostik S.P.A. in gondola Milan) that are applied in the identical liquid crystal described in the example VII and Bostik can prepare scattering polarizer.The B part of Bostik and the ratio of A part are respectively 1: 0.94; The A part, the mixture 33%(weight of B part and liquid crystal) the E-7 making.0.1%(weight) interval insulant adds in this mixture and goes.Interval insulant is a powder, and its granular size is 26 microns supplied goods title Alufrit PS-26 of (by Atomergic) chemical company).Mixture is stirred, and centrifugation several times, to obtain homogeneous phase and gasless solution, various components being mixed entirely back 10 minutes, then this solution is interposed between two conductive glass sheets.26 microns the film that generates is by comprising in the magnetic field that the thin film planar direction is placed on one 47 kilogauss, and (claiming to solidify direction in the back) also placed 41 hours at this under 15 ℃.Behind magnetic field taking-up and cool to room temperature, the solid film that can see generation is opaque, and when watching with a linear absorption polarizing filter, its polarization is parallel with the curing direction.Become with to solidify direction vertical as the polarization with spectral filter, then film just becomes transparent.

The polarization properties of film also can be used under normal condition of incidence from the next polarized light of high-intensity light source and further measure.When light beam be perpendicular to solidify direction and during polarization the transmission light intensity be to be parallel to the curing direction and the ratio of transmitted intensity during polarization when light beam, be measured as 30.To perpendicular to the direction added electric field of film the time, material is changed to unpolarized (transmission) state.Time of response is less than 0.3 millisecond; Film is back to the needed time of polarization state and is less than 3.0 milliseconds.When unpolarized state is converted to polarization state, can weaken through the light intensity of film transmission.At incident light when solidifying the direction polarization, this reduction reach two orders of magnitude and when incident light by perpendicular to the direction of curing direction during polarization, only about 3 times.

The example X

Can make similar in appearance to the polarizer of example I, the mixture below only using, rather than E-7, this mixture be by 67%E-20(43.96%4 '-just-amyl group-4 '-cyanobiphenyl; 40.78%4 '-just-heptyl-4 '-cyanobiphenyl, 9.22%4 '-just-octyloxy-4-cyanobiphenyl; 6.05%4 '-just-amyl group-4-cyano terphenyl; BDH chemical company supply), with 33%10CB(4 '-methoxyl group-4-cyanobiphenyl) mix mutually, in addition deuterate forms on the methoxyl group position.This film shows as same polarization properties is arranged in the example I.One by the same bulk sample of forming with the example I under the same terms, at the NMR(nucleus magnetic resonance) solidify in the Glass tubing.The deuterate MR spectroscopy figure of this sample gets between 45 ℃ at 10 ℃, and it solidifies direction has and be parallel to static magnetic field, also have perpendicular to this.Deuterate spectrogram form has shown that liquid crystal molecule is tending towards an average orientation so that long molecular axis in solidification process along field direction.

The example XI

With having prepared two kinds of films as identical composition in the example IX and, in electric field, having solidified 43 hours at 9 ℃.In solidification process, the voltage of alternating current that adds 100 volts of its oscillation frequency and be 1 kilo hertz is on the transparent conductor on one of them film surface.Another film does not then solidify in the presence of electric field.After the curing, film is observed its optical property, in room temperature, solidified film in electric field, electric field solidified film is more not transparent than having.Lock in this alternating-current field energy optical axis curing medium of having represented in solidification process, to add according to directional bearing with particulate.

The example XII

Use E-7 and make liquid crystal and Conuthane TU50A, A and B part (the Conap company in the Bai Faluo city of New York) are made polyurethane, have made scattering polarizer.A partly is a kind of prepolymer, and it is generated by excess toluene vulcabond and polyethers glycol reaction, and the mixture of B partly is 4-4 '-methylene-bis different-neighbour-chloro-aniline and various polyols.A mixes with 1: 0.94 ratio respectively mutually with the B part.The A and the B mixture partly that contain 35%E-7 and 65% have been made.To 26 microns Alufrit spacer of this mixture-as in the example IX, add.To the sample centrifugation to remove bubble.Mixture is interposed between the conductive glass sheet, and makes 26 micron films.The thing that inserts and puts that forms solidifies a whole night at 65 ℃.When solidifying, it is opaque and device scattering in room temperature that the particulate of generation forms one.To film tension force a little, can be optically active to light by film.When watching with a linear absorption polarizing filter, when consistent with applying tension direction, device is opaque in the spectral filter polarization direction; And device is transparent when this both direction is orthogonal.But this device electricity consumption is changed.Film to 26 micron thickness must apply general 26 volts voltage, just can be converted to vitreous state fully from scattering state.In these two tension force and relaxed state, apply electric field and can make device in about 4 milliseconds, promptly play response.Depend primarily on tension force the time of relaxation of device.A strained device is lax in about 5 milliseconds, and not strained device needs 18 milliseconds to come lax.

Example X III

Convertible light-scattering film can lean on from containing liquid crystal and preparing with the evaporation of the solution of a large amount of preparations of hexylamine solidified EPON828.4 gram EPON828 and 1.124 amine (HA) of restraining oneself mix (1: 1 equivalence ratio) mutually.1.179 the EPON/HA mixture of gram is added among the liquid crystal E-7 of 0.595 gram; Mixture solidifies a whole night at 65 ℃, and makes it be cooled to room temperature.0.0188 the curing mixture fritter of gram mixes with 1.925 gram acetone again.Because the immiscibility of E-7 and acetone, the solution of generation become vaporific in vain.So, must add 0.206 gram methyl alcohol, it is thorough clearly that this solution could become.This solution stirring 5 minutes, after this, solution is thorough clearly, does not have significantly not dissolved material.Be poured over solution on the conductive glass substrate and allow its dry 3 minutes.The dry film that generates is scattering of light and opaque.

Can make convertible structure cell with this film,, and on spacing piece, clamp second conductive surface, insert and put thing with one-tenth as long as 26 microns spacing pieces are placed on the film top.What generate inserts and puts thing 85 ℃ of heating 5 minutes, clamped to touch spacing piece until second conductive surface, is cooled to room temperature then.The film energy scattered beam of 26 micron thickness, and be opaque.Adding 30 volts can make film be converted to vitreous state.

Example X IV

The scattering of light structure cell can prepare by the transparent poly-acetyl polymer class particle (Aldridge chemical company) of heating, at 10 milliliters of tubule bottle internal heating to 200 ℃, as in the example X III, press polymkeric substance 2: 1 ratio (weight) of liquid crystal is added liquid crystal E-7 then.Mixture is stirred, and makes it be cooled to room temperature, and cooling material is a White-opalescent.It is respectively to cut 20 milligrams fritter from massive material that two structure cells prepare simultaneously, every fritter is placed between conducting strip, in 10 microns spacing pieces are arranged.Conducting strip is clamped, be placed on one 200 ℃ the heating stand, until the material bleach.Promptly a structure cell is cooled to 3 ℃ then.Another structure cell slowly cools off a whole night after the outage of heating stand.The refrigerative structure cell compares with slow refrigerative structure cell rapidly, is the more transparent slightly band blueness slightly that also shows.Blue expression particle size is very little.This structure cell can be converted to vitreous state with 100 volt-amperes.Slowly the refrigerative structure cell then is converted to vitreous state with 50 volt-amperes.

Example X V

Scrape 0.292 gram polystyrene from a bulk of transparent polystyrene, be placed in one 10 milliliters the little phial, wherein add 0.143 gram E-7-as in the example X III.Little phial was placed in 170 ℃ the baking box 15 minutes.Polystyrene is not melt and dissolved, and liquid crystal is absorbed in the polystyrene and goes in its isotropic state.Tubule bottle cool to room temperature takes out material, cuts in half with razor.Can see that it is opaque and scattering that about 7 mm thick upper layers are arranged.This upper layer scales off on the electrode glass sheet of the one-tenth form that is placed on 18 millimeters spacing pieces, covers with second sheet glass to be clamped, and makes as the thing that inserts and puts in the example X III.Insert and put thing and be heated to 170 ℃, move and film former until this laminar flow that is scraped, like this, sheet glass can clamp and touch spacing piece, then, makes it be cooled to room temperature.At room temperature, an opaque film of scattering of light can be seen, vitreous state can be converted to 70 volts of electric currents.

Example X VI

Prepare a kind of resin (equivalence ratio of EPON and hexylamine is 1: 1.374) with mixing 1.850 gram EPON828 and 0.715 amine of restraining oneself.Mixture solidified 3 days at 65 ℃ in 10 milliliters of tubule bottles.In room temperature, solidify material is hard solid; When being heated to 50 ℃, be difficult to change shape.Solidify material be heated to 130 ℃ 10 minutes, just become can mobile viscous liquid.Be heated to 130 ℃ as the E-7 liquid crystal in the example X III, it, then, mixes with the viscous liquid that solidified more than the isotropy transformation temperature mutually at it.The mixture of a heat is interposed between sheet glass, makes it be cooled to room temperature; Another part also is interposed between sheet glass, but is placed on immediately in 0 ℃ the refrigerator.The sheet glass that is cooled to room temperature is opaque and scattering of light.The sheet glass that is cooled to 0 ℃ is transparent and light transmissive.These two kinds of sheet glass are all examined under a microscope with the 120X amplification then.The film that allows to be cooled to room temperature contains the big or small liquid crystal particle (about 0.7 to 1.5 micron) of micron; And the film that is cooled to 0 ℃ does not show particulate.

Example X VII

Thoroughly mix 1 equivalent EPON828 and 1 equivalent hexylamine mixture with preparation uncured resin and tackiness agent.This mixture is added liquid crystal E-7, form one 33% solution (weight).Mixture is sealed in 10 milliliters the little phial, 65 ℃ of a large amount of curing a whole night.The material that generates is promptly nonelastic, and is milky (scattering) in room temperature.

Material is heated in little phial, and keeps 5 minutes at about 100 ℃, but becomes softening to flow state.Part material topples over out formation one film between sheet glass, makes with 26 microns glass partition sheets to be spaced apart 26 microns.Conductive electrode is installed on the sheet glass, lines up character ZERO form.Every micron film thickness is set up 3 volts electric field on the film both sides, about 80 volts altogether.Then, make film be cooled to room temperature, under the situation that electric field exists, allow film reharden.Remove electric field, the film of generation shows the clean transparent image of a ZERO form, is the zone of opaque light scattering on every side.ZERO kept clear 2 days, and can show does not have decay tendency 2 hours.Whole decay after 7 days and be back to opaque state.

Example X VIII

As preparing described in example X VII and solidifying material of main part.Get 1cm ³The material that solidified cuts from material of main part with razor, and is placed on the formatted sheet glass electrode with 26 microns glass partition sheets of described in example 1 one.The electrode of second band sheet glass is placed on this material.Fix in position becomes one to insert and put thing.This inserts and puts thing with the heating of blowing hot-air device, flow with the formation film until material, and sheet glass can clamp to touch spacing piece.An about electric field of 70 volts is set up on both sides on film, and makes film be cooled to room temperature, and rehardens.The film role that generates is as in example X VII.

Example X IX

The film that the ZERO format pattern is arranged above the example X VII is heated with about 100 ℃ of temperature in baking oven and can be wiped in 2 minutes.When film was cooled to room temperature under not having the electric field situation, film became opaque.The method of application example X VII is printed an image storage, and postheating to 100 ℃ is wiped this image, is cooled off under the electric field not having subsequently again, and this circulation can successfully repeat 10 times in 7 day time, did not see tangible unfavorable effect.

The example XX

The film that the ZERO format pattern arranged above the example X VII at the baking oven internal heating to about 100 ℃, to wipe image, in addition about 70 volts electric field on film again, another ZERO form in the printing is until cool to room temperature.Film demonstrates the transparent image of a ZERO, is opaque scattering of light zone on every side.The electrode that will have form is taken away, and film is placed in 0 ℃ the refrigerator.It is clear that the ZERO form keeps in zone of opacity, can show that not having the decay tendency reaches 30 days.

Example X XI

By mixing 20%(weight) the Displaytech company in ferrous-Boulder city, electric liquid crystal W-7(Colorado produce) and 80%(weight)

Equivalent EPON828/ hexylamine resin, can prepare light-scattering film.Mixture solidified 4 hours at 65 ℃.Curing mixture is heated into VISCOUS FLOW, be allowed to condition between sheet glass flow (this sheet glass with 26 microns spacing pieces at interval), be cooled to room temperature again, made the film between sheet glass.The film that generates is opaque and produces scattering of light.

Example X XII

Mix 2.893 gram EPON(1.61 * 10 ^-2Equivalent) and 0.812 amine (1.61 * 10 of restraining oneself ^-2Equivalent), gets its 0.327 gram sample then, further mix with 0.170 gram liquid crystal M-24 again, with the preparation light-scattering film.This mixture solidifies a night at 65 ℃ in batch, as prepare 26 microns structure cells in the example X VIII.The structure cell that generates is opaque, and scattering of light is arranged.Apply 1000 volts of voltages, structure cell is switchable to vitreous state, and after voltage was removed, structure cell still kept vitreous state.Heat structure cell with heat gun then, and allow it be cooled to room temperature, to get back to opaque state.Under 400 volts of voltages, this same structure cell reheat is to vitreous state and cooling again.At the room temperature structure cell is transparent, is exactly not making alive of several hrs, and it also keeps transparent.

Example XX III

Polyvinylformal (the Aldrich chemical company supply in the Milwaukee city of University of Wisconsin-Madison Xin Zhou) mutually mixes with proportioning (weight) with chloroform with liquid crystal E-7 at 1: 1.5: 5.0, and stirs until generating transparent homogeneous phase solution.Solution is poured on the sheet glass, and chloroform evaporated has generated opaque solid liquid crystals-plastic material.This material until softening, and is interposed between the sheet glass that has transparency conductive electrode, and makes it be cooled to room temperature with suitable speed, to generate opaque scattering of light structure cell at the high-temperature cabinet internal heating.Structure cell is wrapped in the thin paper (the trade name KIMWIPES of the Kimberly-Clark company supply in the Roswell city of Georgia State, USA), reaches adiabatic and structure cell is placed between two aluminium blocks in room temperature, can obtain suitable speed of cooling.

The transparency of film is measured according to laxative remedy: structure cell is placed in the laser beam of the chopping the light with photodetector, adds 50 volts of voltages and make structure cell convert transparent state to, measure the light quantity of transmission, compared by the light quantity of sheet glass transmission again with only.The transparency coefficient of polyvinylformal structure cell is 96%.Note by photodetector from ON state to the switching time of OFF state, in room temperature less than 1.0 milliseconds.

Example XX IV

Polyisobutene acid methyl esters (supply of U.S. Aldrich chemical company) mixes (weight) with liquid crystal E-7 and acetone mutually with 1: 1.5: 5.0 proportioning, as generate opaque structure cell in example XX III.Transparency coefficient is greater than 90%, about 2.0 milliseconds in the switching time that room temperature records.

Example XX V

Polyvinylformal (by the supply of U.S. Aldrich chemical company) structure cell is used liquid crystal E-20 as in example XX III, and E-31 and E-40 make (cyanobiphenyl and the ester patent mixture that are EM chemical company entirely).In fact can see to example X III in similar switching time and the transparency reported.

Example XX VI

Polyvinylformal (Aldrich chemical company) mixes with 1.0: 1.5: 5.0 proportioning (weight) mutually with liquid crystal E-20 and chloroform, generates transparent homogeneous phase solution.Solvent is evaporated, to generate the bulk opaque material.Three parts of taking out material are placed on three covers respectively and have between the sheet glass of transparency conductive electrode.Sheet glass until material softening, and flows evenly cooling then, such opaque scattering of light structure cell in generation and the example XX III at the high-temperature cabinet internal heating between sheet glass.The thickness of structure cell by each structure cell never transparent translation to scattering required voltage amount measure.Three changing voltage threshold values that structure cell produced are respectively 400 volts, 200 volts and 80 volts.When its changing voltage threshold value, each structure cell is all becoming transparent less than 1.0 milliseconds.After removing voltage, it is transparent that structure cell still keeps.Two thicker structure cells (400 volts and 200 volts) are arranged before reaching opaque state, can keep transparent about 1 minute; And thin structure cell (80 volts) keeps transparent only several seconds.After these three structure cells reach opaque state entirely, can be converted to vitreous state again and opened circuit by adding separately threshold voltage.Structure cell is opened circuit, can make each structure cell arrive opaque state in time internal conversion less than 1.0 milliseconds.

Example XX VII

Polyisobutene acid methyl esters (supply of Aldrich chemical company) mixes with 1: 2: 5 proportioning mutually with liquid crystal E-7 and trichloromethane, generates homogeneous phase solution.Then, solvent evaporation generates as the structure cell in the example XX III, and difference is that transparency conductive electrode becomes the alphanumeric character form.Structure cell is added 200 volts of voltages, can with film in the opaque background zone never transparent translation to alphanumeric character clearly.Remove voltage, character image can keep about 10 seconds.

Example XX VIII

Polyisobutene acid methyl esters mixes with 1: 2: 5 proportioning mutually with liquid crystal E-20 and trichloromethane.As described in example XX VII, the structure cell of using the material that generated to make can keep the alphanumeric character image about 10 seconds.

Example XX IX

Polypropylene butyraldehyde (Aldrich) and liquid crystal E-7 are with proportioning 1: 2(weight) mix mutually.Mixture heating up is to about 150 ℃, until generating transparent homogeneous phase solution.Solvent is extruded having between the sheet glass of transparency electrode, is cooled to room temperature with suitable speed, as in the example XX III.The transparency of film is 90% approximately, and be 5 milliseconds switching time approximately.

The example XXX

Showing the mentioned electric light structure cell of I A and I B in the above can be according to the method for example XX III, is that 1: 5 ratio makes with following solvent in polymkeric substance and solvent.

Polymer solvent

Polyethylene ethyl ester acetone

The polyvinylformal chloroform

The polycarbonate chloroform

Polyethylene butyraldehyde acetone

Polyethylene methyl ketone chloroform

Polymethylmethacrylate toluene

Poly-cyclohexyl methacrylic acid ester methylene dichloride

The polyisoprene chloroform

Poly-ethyl propylene acid esters (high molecular) acetone

Poly-isobutyl-methacrylic acid ester acetone

Poly-methyl methacrylic acid ester acetone

Example XX XI

Application of differential cooling thermoplastic-liquid crystal solution can prepare an improved epoxy-liquid crystal structure cell earlier and measure to reach control particle growth rate.The supply of 1 normal EPON828(Miller-Stephenson company) mixes mutually with 1 normal hexylamine and liquid crystal E-7; The formation plastics are 60 to the proportioning of liquid crystal: 40(weight).Mixture becomes piece to solidify a whole liquid at 65 ℃, generates the solid white material.Prepare material from this piece and cut out a fritter, be placed on 26 microns at interval, and have between the sheet glass of transparency conductive electrode.Sheet glass is placed on microscopical being on 80 ℃ the heating stand (Mettler FPS), and is clamped, can flow until material, and sheet glass contact interval sheet.Structure cell 80 ℃ of generations is thorough clearly and transparent.This heating stand is programmed with the speed cooling by control, and same structure cell is heated to 80 ℃, and with the friction-motion speed cooling, its result is summarized in the following table VI.

The table VI

The speed of cooling average particle

(℃/minute) diameter (micron)

0.2 8

1.0 3.9

2.0 2.8

4.0 2.5

Can see that from the table VI slowly cooling forms very big particulate, this is only useful to the modulation longer wavelength, and cooling can cause than small particle fast, is used to modulate the light of shorter wavelength.

Example XX XII

Improved epoxy-liquid crystal structure cell can prepare by laxative remedy: with 40%(weight) liquid crystal and 60%(weight) its equivalent be that 1: 1 EPON828 and t-butylamine mixture mixes mutually, 60 ℃ of curing mixture a whole nights, as in the example XX XI, preparing structure cell.Structure cell heating for multiple times and cool off with friction-motion speed.In the following table VII, conclude its result.

The table VII

The rate of cooling average particle diameter

(℃/minute) (micron)

0.2 8

1.0 3.9

2.0 3.0

4.0 2.6

Out-of-control cooling for example, is placed on structure cell on the aluminium block, the particulate of generation, and its size too little (less than 1 micron) is difficult to measure with opticmicroscope.

Example XXX III

Measure the particle growth speed of controlling by the differential solidification value of resin-liquid crystal solution by preparation epoxy-liquid crystal structure cell.With EPON828, Capcure 3-800(Miller-Stephenson company supply) and liquid crystal E-7 mix at 1: 1: 1 with equivalence ratio, mixture is placed on 26 microns at 4 groups of intervals and has between the sheet glass of transparency conductive electrode.Each piece sheet glass is placed in the baking oven of controlled temperature system, allows it solidify a whole night, until being separated and curing is completely.The result of solidifying these structure cells in differing temps is summarised in the following table VIII.

(percentage ratio of %=qualified particulate in magnitude range)

0.2 micron 0.8 micron 1.1 microns 0.9 micron of mean diameter

(micron)

Can see from the table VIII, quicken the curing speed of resin 70 ℃ curing, and formed littler particulate.

Result on the VIII calculates by the particle number in tally's quadrature at table, and in a magnitude range normalization method particle number, with percentage ratio shown in obtaining.Comparatively high temps solidify also influence positional number that nucleus forms and in each structure cell the relative density of particulate, see Table IX.

The table IX

Solidification value (℃) particle number

(in every micron quadrature)

60℃ 0.0138

50℃ 0.0154

40℃ 0.0203

Example XXX IV

Control in the epoxy-liquid crystal structure cell of particulate rate of growth in example X V by relative concentration and to have done evaluation.Increase to about 40%(weight from about 20%) the E-7 mixture done preparation, and 60 ℃ of curing.The table X has been summed up the relation of particle size and liquid crystal relative concentration.

The table X

% liquid crystal diameter (micron)

＜20% no liquid crystal generates

～25-35% ～1.30

＞40% particle coagulation

Example XXX V

Leaning on differential solidification value and relative concentration to control the particulate rate of growth can estimate by preparing epoxy-liquid crystal structure cell earlier.The Bostik S.P.A. of Bostik(Milan, ITA, company) 1: 1 A mixes with liquid crystal E-7 mutually with the B part, is 35% and 40% liquid crystal to its weight ratio of plastics with generation.Mixture is poured between sheet glass, and solidifies, up to being opaque entirely at all temps.The table XI has been summed up the mean particle dia scope (micron) of two mixtures relation to solidification value.

35%(weight) it almost is the particulate of same diameter that E-7 generates, no matter be what solidification value, its diameter all is 0.6 micron approximately.And 40%(weight) particulate that dirty E-7 generates, its size raises with solidification value and reduces.

Example XXX VI

By relative concentration control particulate rate of growth, available Bostik estimates at epoxy-liquid crystal structure cell, as in example XXX III.Prepared and contained E-7 amount and increase to about 50%(weight from about 10%) mixture, and in self-vulcanizing.The table XII has been summed up the particle size scope of liquid crystal and the relation of relative concentration.

The table XII

% liquid crystal particle diameter (micron)

＜12 no particulates generate

14-16 0.2

22-35 0.5

37-43 1.0

＞44 particle coagulations

Example XXX VII

In example XXX IV, epoxy-liquid crystal structure cell fades to about 45%(weight from 14% approximately with the relative concentration of E-7) make.Sample is divided into three groups, respectively at 40 ℃, and 60 ℃ and 80 ℃ of curing.Table X III A, B and C have summed up this result.

Table X III A

40 ℃ of curing

% liquid crystal mean diameter (micron)

＜15 no particulates generate

16-20 ～0.2

24-35 ～0.5

36-38 ～0.1

＞38 particle coagulations

Table X III B

60 ℃ of curing

% liquid crystal mean diameter (micron)

＜22 no particulates generate

24 ～0.2

26-35 ～0.5

36-38 ～0.1

＞38 particle coagulations

Table X III C

80 ℃ of curing

% liquid crystal mean diameter (micron)

＜28 no particulates generate

32 ～0.2

36-38 ～0.5

42-47 ～1.0

＞47 particle coagulations

Many improvement of the present invention and modification are conspicuous for the technician in the aforementioned detailed disclosed optical arena.So, it should be understood that in affiliated claim scope the present invention can also otherwise put into practice except above-mentioned special diagram with describing.

Table I A

The polymer liquid crystal ratio

1, polyvinyl acetate E7 1:＜1

2, polyvinyl acetate E7 is 1: 1.5

3, polyvinylformal E7 is 1: 0.6

4, polyvinylformal E7 is 1: 1.8

5, polycarbonate E7 is 1: 1.8

6, polyethylene butyraldehyde E7 1: 1.5-2.0

7, polyethylene methyl ketone E31 is 1: 2.0

8, polymethyl acrylate E20 is 1: 1.5

9, polyisobutene acid cyclohexyl E31 is 1: 2.0

10, polyisoprene E20 is 1: 2.0

11, polyisobutene acetoacetic ester (high molecular) E20 is 1: 2.0

12, polyisobutene acid isobutyl ester E20 is 1: 2.0

Table I B

Polymkeric substance structure cell character

1, polyvinyl acetate does not have and is separated

2, polyvinyl acetate is good

3, polyvinylformal does not have and is separated

4, polyvinylformal is excellent

5, polycarbonate is good

6, the polyethylene butyraldehyde is excellent

7, the polyethylene methyl ketone is excellent

8, polymethyl acrylate is excellent

9, polyisobutene acid cyclohexyl is good

10, polyisoprene is good

11, polyisobutene acetoacetic ester (high molecular) is good

12, polyisobutene acid isobutyl ester is good

These character that are listed in structure cell among the table I B have been done evaluation below:

Well excellent

Transparency＜60%～70-90%＞90%

Switching time 50-100 millisecond 10-50 millisecond＜10 milliseconds

The medium paramount height of contrast gradient

Table II A

Polymkeric substance n _pSwitching time

1.501＜1.0 milliseconds of polyvinylformals

1.49～2.0 milliseconds of polyisobutene acid methyl esters

1.485＞2.0 milliseconds of polyethylene butyraldehyde

1.585＞10 milliseconds of polycarbonate

Polyvinyl acetate 1.467～10-20 millisecond

Table II B

The clarity in polymers visual angle

Polyvinylformal＞95% is vertical

Polyisobutene acid methyl esters～95% is vertical

Polyethylene butyraldehyde～90% is vertical

Polycarbonate～55% one-tenth 30 ° of angle

Polyvinyl acetate～70% is vertical

The table III

Polymer liquid crystal ratio storage time (ε ρ)

Polymethyl acrylate E20 1: 2＜1 second

Polyisobutene acid cyclohexyl E31 1: 2＞1 second

Polyisoprene E20 1: 2＞1 second

Polyisobutene acid isobutyl ester E20 1: 2＞1 second

Polyethylene butyraldehyde E7 1: 1.5-2.0＞1 second

Polyethylene methyl ketone E20 1: 2＞1 second

The table I

Mixture E PON HA EPON(equivalent)

(weight, gram) (weight, gram) HA(equivalent)

1 1.850 0.715 1∶1.374

2 2.492 0.770 1∶1.100

3 2.489 0.734 1∶1.050

The table II

Mixture relative hardness profile

1 the softest viscous liquid

2 moderate tack liquid

3 ebonite solids

The table III

Mixture E PON(equivalent) E7

The HA(equivalent) %(weight)

1 1∶0.753 33.6

2 1∶0.899 34.6

3 1∶1.008 33.2

4 1∶1.107 33.4

5 1∶1.284 33.7

6 1∶1.502 33.2

7 1∶0.509 33.2

Table IV A

50 ℃ of mixture room temperatures

1 rigid solid is easily deformable

2 rigid solids are difficult to distortion

The very difficult distortion of 3 rigid solids

4 rigid solids are difficult to distortion

5 sticking slightly, gluey soft, can stretch

6 pliable and tough, gluey soft, can stretch

7 viscosity, glue are easy to stretch

Table IV B

The scattering of light physical condition

50 ℃ of 3 ℃ of room temperatures of 3 ℃ of room temperatures

1 OP OP Cl ebonite shape

2 OP OP Cl are hard, gluey

3 OP OP Cl are soft firmly

4 OP OP Cl are hard, gluey

5 OP OP Cl are hard, gluey soft, gluey

The soft viscous liquid of 6 OP OP Cl

The soft viscous liquid of 7 POP Cl Cl

Table V A

The amine liquid crystal

E-7 E-31 E-44 E-12 E-18

1 propylamine S/PS C S/PS C X

2 just-butylamine S/PS X S/PS C S

3 different-butylamine S/PS C S/PS C S/PS

4 hexylamine S/PS C S C X

5 heptyl amice S X S C C

6 octylame C C C C C

Table V B

The amine liquid crystal

K-21 K-24 M-15 M-18 M-24

1 propylamine S/PS S/PS C S S

2 just-butylamine S S/PS C S S

3 different-butylamine S/PS S/PS C C S

4 hexylamine S S C S S

5 heptyl amice X/PS S S S S

6 octylame C C C C S

The table V

Epoxy resin cure time liquid crystal mean diameter

(at 40 ℃)

24 hours 35%E7～1.2 of EPON828

1 hour 35%E7～0.6 of Bostik

The table VIII

Solidification value

70 ℃ 60 ℃ 50 ℃ 40 ℃ of particle size

(micron) % % % %

＞0.1 6.1 - - -

0.1-0.2 64.2 - - -

0.2-0.3 21.4 10.0 0.6 0.9

0.3-0.5 8.3 14.9 2.9 5.1

0.5-0.7 - 17.5 5.2 11.6

0.7-0.9 - 18.9 13.8 19.5

0.9-1.1 - 19.6 24.2 36.0

1.1-1.3 - 12.1 30.0 17.6

1.3-1.5 - 6.7 17.4 8.4

1.5-1.7 - 0.3 4.7 0.9

1.7-1.9 - - 1.2 -

1.9 - - - -

The table XI

Solidification value

40 ℃ 60 ℃ 80 ℃ of room temperatures

35%E-7 0.6±0.3 0.6±0.3 0.7±0.4 0.5±0.2

40%E-7 4.0 2.5±1.0 1.2±0.3 0.8

Claims (59)

1, a kind of light modulating materials, comprise and the mutual dispersive mesomorphic phase of the solid resin of printing opacity, wherein this mesomorphic phase is nematic or smectic shape function, and the normal light refractive index of this mesomorphic phase is complementary with resin specific refractory power mutually, thereby incident light can see through described material, maybe can change the orientations of liquid crystal director, incident light is scattered, it is characterized in that, described mesomorphic phase dissolves in the composition that forms described resin, and this mesomorphic phase is the spontaneous formation by being separated from solution in the consolidation process of described resin formation composition.

2, by the material of claim 1, it is characterized in that described resin is to exist with a kind of resinous substrates form mutually, described mesomorphic phase is to exist with the particulate form that is scattered among this matrix.

3, by the material of claim 1, it is characterized in that described liquid crystal director normally is randomly-oriented, it is scattered incident light; And they can orientations in the presence of the electric or magnetic field, makes at least one composition transmission of incident light cross this material.

4, by the material of claim 2, it is characterized in that described liquid crystal director normally is randomly-oriented, it is scattered incident light; And they can orientations in the presence of the electric or magnetic field, makes at least one composition transmission of incident light cross this material.

5, by the material of claim 1, it is characterized in that described liquid crystal director normal circumstances is the surface that is parallel to this material, and they can be arranged in the presence of the electric or magnetic field perpendicular to this surface orientation.

6, by the material of claim 2, it is characterized in that described liquid crystal director normal circumstances is the surface that is parallel to this material, and they can be arranged in the presence of the electric or magnetic field perpendicular to this surface orientation.

7,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 1.

8,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 2.

9,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 3.

10,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 4.

11,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 5.

12,, it is characterized in that this mesomorphic phase shows positive dielectric anisotropy by the material of claim 6.

13, by each material among the claim 1-12, it is characterized in that this mesomorphic phase comprises a kind of cyanobiphenyl.

14, by each material among the claim 1-12, it is characterized in that this resin is a kind of thermosetting resin mutually.

15, by the material of claim 13, it is characterized in that this resin is a kind of thermosetting resin mutually.

16, by each material among the claim 1-12, it is characterized in that this resin is a kind of thermoplastic resin mutually.

17, by the material of claim 13, it is characterized in that this resin is a kind of thermoplastic resin mutually.

18, by each material among the claim 1-12, it is characterized in that described resin comprises Resins, epoxy, urethane resin, polycarbonate resin, polyethylene butyral resin, polyvinyl methyl ketone resin, polyvinylformal resin mutually, or contain the polymkeric substance of at least a the following units: low-level chain triacontanol (C _1-8) and low alkyl group (C _1-8) ester that vinylformic acid became, the vinylbenzene that replaces, vinylbenzene, isoprene, methyl butene, divinyl, iso-butylene or the lower alkanols alkanoic acid (C of replacement _1-4) vinyl ester.

19, press the material of claim 13, it is characterized in that described resin comprises Resins, epoxy, urethane resin, polycarbonate resin, polyethylene butyral resin, polyvinyl methyl ketone resin, polyvinylformal resin mutually, or contain the polymkeric substance of at least a the following units: low-level chain triacontanol (C _1-4) and low alkyl group (C _1-8) ester that vinylformic acid became, the vinylbenzene that replaces, vinylbenzene, isoprene, methyl butene, divinyl, iso-butylene or the lower alkanols alkanoic acid (C of replacement _1-8) vinyl ester.

20, by each material among the claim 1-12, the transition temperature that the liquid crystal that it is characterized in that described mesomorphic phase is converted to isotropic phase is higher than the softening temperature of this resin phase.

21, by the material of claim 13, the transition temperature that the liquid crystal that it is characterized in that described mesomorphic phase is converted to isotropic phase is higher than the softening temperature of this resin phase.

22, by each material among the claim 1-12, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

23, by the material of claim 13, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

24, by the material of claim 14, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

25, by the material of claim 15, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

26, by the material of claim 16, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

27, by the material of claim 17, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

28, by the material of claim 18, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

29, by the material of claim 19, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

30, by the material of claim 20, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

31, by the material of claim 21, it is characterized in that the specific refractory power of described resin phase is very approaching with the normal light refractive index of this mesomorphic phase, be enough to make after these material two ends apply changing voltage, make at least 90% normal incident light see through.

32, by each material among the claim 1-12, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

33, press the material of claim 13, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

34, press the material of claim 14, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

35, press the material of claim 15, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

36, press the material of claim 16, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

37, press the material of claim 17, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

38, press the material of claim 18, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

39, press the material of claim 19, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

40, press the material of claim 20, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

41, press the material of claim 21, it is characterized in that the specific refractory power of described resin phase and the normal light refractive index of this mesomorphic phase differ bigger, be enough to make after these material two ends apply changing voltage, for the incident light during less than 90 ° of angles shows the maximum transparency with this material surface.

42, by each material among the claim 1-12, it is characterized in that described resin is a kind of thermoplastic resin, the content of described liquid crystal in this material is at least about 50%(weight).

43, by the material of claim 13, it is characterized in that described resin is a kind of thermoplastic resin, the content of described liquid crystal in this material is at least about 50%(weight).

44, by each material among the claim 1-12, it is characterized in that described resin is a kind of thermoplastic resin, the content of described liquid crystal in this material is at least about 50%(weight), be that also the resistivity of this material and the mathematical product of its specific inductivity were at least several seconds, make when this material places between two electrodes, will keep certain electric charge and continue for some time.

45, press the material of claim 13, it is characterized in that described resin is a kind of thermoplastic resin, the content of described liquid crystal in this material is at least about 50%(weight), be that also the resistivity of this material and the mathematical product of its specific inductivity were at least several seconds, make when this material places between two electrodes, will keep certain electric charge and continue for some time.

46, press the material of claim 1 or 2, it is characterized in that by in the presence of electric field or magnetic field, this matrix being cured, thereby make this liquid crystal director along a direction orientations, described electric field or magnetic field will be enough to cause this orientation, and described material has response to the electric or magnetic field that can change above-mentioned liquid crystal aligning arrangement effectively.

47, a kind of method for preparing each described light modulating materials among the claim 1-46, this method may further comprise the steps:

Prepare the homogeneous solution that a kind of liquid crystal and synthetic resins form composition, the specific refractory power of the normal light refractive index of described liquid crystal and this resin formation composition of solidified is complementary, thereby incident light can see through this material, maybe can change the orientations of liquid crystal director, incident light is scattered, and

Cause being separated of described liquid crystal by this resin formation composition is solidified, thereby produce and the mutual dispersive mesomorphic phase of solidified resin.

48, by the method for claim 47, wherein said causing is separated and the step of spontaneous this mesomorphic phase of formation is to be undertaken by the polymerization of this resin formation composition.

49, press the method for claim 47, the step of wherein said preparation liquid crystal and resin formation composition homogeneous solution is to use a kind of solvent to carry out, and the wherein said step that is separated with spontaneous this mesomorphic phase of formation that causes is undertaken by extracting this solvent.

50, press the method for claim 47, the step of wherein said preparation liquid crystal and resin formation composition homogeneous solution is carried out to dissolve this liquid crystal by heating this resin formation composition, and wherein said causing is separated and the step of spontaneous this mesomorphic phase of formation is to be undertaken by the temperature that reduces said composition.

51, by each method among the claim 47-50, wherein said mesomorphic phase is to be scattered in particulate form in the resinous substrates, and comprise when forming liquid crystal particle, control the step that particulate increases by finishing to be separated with selected median size.

52, by each method among the claim 47-50, wherein also comprise this material of heating so that this liquid crystal is dissolved in the step of this matrix, and reduce temperature then so that the step that liquid crystal is separated.

53,, wherein also comprise this matrix of thermoplastic, make liquid crystal director orientation and make this matrix step of curing more thereafter in remollescent matrix by each method among the claim 47-50.

54, by the method for claim 53, wherein this matrix is to be enough to make this liquid crystal director to carry out cooling off in the presence of the electric field of orientations or the magnetic field.

55, by the method for claim 53, wherein make this liquid crystal director orientation by the described thermoplastic matrix that stretches.

56, by the method for claim 53, wherein said to make this matrix form composition step of curing be to be enough to make this liquid crystal director to carry out carrying out in the presence of the electric field of orientations or the magnetic field.

57, the purposes of each described light modulating materials among the claim 1-46, this purposes are to be applied to contiguous described material surface to be provided with the electroresponse formula optic modulating device that can set up the electrode device of electric field from these material two ends.

58, by the purposes of claim 57, wherein said light modulating materials is to use with the form of tensile sheet stock or film, and described sheet stock or film can make incident light see through when no electric field and polarization, and when electric field is arranged, non-polarized light are seen through.

59, press the purposes of claim 57, wherein said light modulating materials is to use with the form of a thin layer, particulate in this thin layer is a direction orientations along this layer plane at polarization state, and unpolarized, light transmission attitude be along and this layer plane vertical direction orientations.

Images