CA1111633A - Bodies with reversibly variable temperature-dependent light absorbence - Google Patents

Bodies with reversibly variable temperature-dependent light absorbence

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Publication number
CA1111633A
CA1111633A CA309,091A CA309091A CA1111633A CA 1111633 A CA1111633 A CA 1111633A CA 309091 A CA309091 A CA 309091A CA 1111633 A CA1111633 A CA 1111633A
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CA
Canada
Prior art keywords
matrix material
organic substance
absorbence
light
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA309,091A
Other languages
French (fr)
Inventor
Wolfgang Dabisch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TIPP-EX TECHNIK WOLFGANG DABISCH
Original Assignee
TIPP-EX TECHNIK WOLFGANG DABISCH
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Application filed by TIPP-EX TECHNIK WOLFGANG DABISCH filed Critical TIPP-EX TECHNIK WOLFGANG DABISCH
Application granted granted Critical
Publication of CA1111633A publication Critical patent/CA1111633A/en
Expired legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41MPRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/36Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties
    • B41M5/363Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties using materials comprising a polymeric matrix containing a low molecular weight organic compound such as a fatty acid, e.g. for reversible recording
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24SSOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S50/00Arrangements for controlling solar heat collectors
    • F24S50/80Arrangements for controlling solar heat collectors for controlling collection or absorption of solar radiation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24SSOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S80/00Details, accessories or component parts of solar heat collectors not provided for in groups F24S10/00-F24S70/00
    • F24S80/50Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings
    • F24S80/52Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings characterised by the material
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/12Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in colour, translucency or reflectance
    • G01K11/16Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in colour, translucency or reflectance of organic materials
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/0147Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on thermo-optic effects
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B10/00Integration of renewable energy sources in buildings
    • Y02B10/20Solar thermal
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/40Solar thermal energy, e.g. solar towers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S252/00Compositions
    • Y10S252/962Temperature or thermal history
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/22Nonparticulate element embedded or inlaid in substrate and visible
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/25Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

ABSTRACT OF THE DISCLOSURE

In order, in the case of bodies with reversibly-variable absorbence, to adjust the zone of transition from transparent to opaque or vice versa at desired goal temperatures and to give the bodies a preferred form,' such as sheet form, they consist of a substantially optically transparent polymeric and/or resinous matrix material (A) and an organic substance (B) which is embedded therein as a dispersed second phase and which is at least partially insoluble therein, and which melts or congeals at the goal temperature of light-absorbence variation at the goal temperature of light-absorbence variation, and the refractive index of which, either above or below the goal temperature of the light-absorbence variation, substantially agrees with the refractive index of the matrix material.
Such bodies are usable in sheet (or film) form, for example, for temperature-measuring devices, temperature-indicating devices, and slippery-ice warning devices, as well as for devices on glass windows for protection against solar irradiation.

Description

ti~3 - BF`N 6661 ~1-BOOIES WITEI REVEP~SIBL~ V~RI:~BLE
TEMPEE~TU~.E-DEPEND~NT LIGEIrl' ~BSOR~ENCE
.
Background o~ the Invention -The inv~ntion relates to bodi~s with reversibly variable tempe~ature-dependent licJht ~bsorbence. These are suited for cletermining tempera-ture, rneasuring tem-perature, and ~ernperature data like, for example, frost ~ warnincJ devices, slippery ice warning devices, devices for absorbing radiation o~ the sun, also for greenhouses, industrial structures, office and dwelling space, vehicles, etc., as well as for temperature indication in technical devices and apparatus.
10 Bodies with reversibly variable temperature-deperl-dent permeability to light are known ~rom Germall Patent No.
1,2~,391 and German published patent application No.
2,154,042, which bodies consist of reversibly thermo-coagulclble synthe~ic substances, hydrate salts and, if necessary, water, or of hydrated polymers and/or copol~mers of n-vinyl lactamens. In such bodles, the hydrate sal~s or hydrated synthetic substances give off ~Jater when a specific temperatllre is exceeded, ~7hich water is dispersed in small aropl~ts in the synthetic substance and thus pro-~0 duces turbidity of the body. The disadvan-tc~ge of such bodi.es with reversible temperature depend~nce resides in the fact that they exhibit vaxiati.on in light absorbence only upon being heated to relcatively high temperatures;
that always a transi.tion ~xom a transparent st-ate to an .opaque state is possible only in one cdirec-tion, that the reversibili.ty o variation in light absorption is depende~nt on atrnospheric moisture; and that no sharp sudden chanye in transparency occurs.
Further, from German publish~d patent appliccltio.n No. 1,812,319 is kltown a reflec-tor for slippery ice war~.tiny devi.ces ~Ihi.ch corlsi.C;t.s of a fluid in a capsule, the cor.t-~].atiotl poi.nt of thi..s fluid ~einy so adjus-ted that .it conge.lls densel.y above thc~ ~ree~;.ncJ F?oint o~ ~/ater ancl thus 10SF~S pern;eabil.i.t:y tc> licJilt. SUCh r.ef].ec:tc)i.~s ~Ire re:lal-.;.vely , ~ .
BFN 666~

expensive and are not suited to be installed on street guide-posts. They are susceptible to breakaye, since the capsules shatter in collisons or from wanton mishandling, and the fluid can run out; and finally, they have the disadvantage that because of their nature -they are not suited to keep the ~rost warning indicators invisible in non-dangerous temperature ran~es and ma~e them visible only in the warning range.
The problem forming the basis of the invention, consequently, resided in acquiring new bodies with rever~
sibly variable tem~erature-dependent ]ight absorbence in whichr as requiredr a transition from transparent to opaque or from opaque to transparent can be attained and the ~ variability in light absorbence to almost any clesired temperatures. A special problem resides in creating such bodies with reversibly variable temperature-dependent licJht absorbence which can be used as frost-indicating devices or slippery ice warnincJ devices and change from opaque to transparent in the vicinity of the freezing point of water and thus, in case of frost o-r slippery ice, permit warning - symbols, become visible or, if they themselves 2re formed as warning symbols, become visible by reason of turbidity.
A further problem resides in obtaining such bodies in which the transition from transparent to opaque or vice versa is as sharp as possible; which are neither dependent on atmosp}leric conditions like a-tmospheric moistu~e nor susceptible to clestruction; and which can be proauced ancl installed as simply as possihle and in abundance. Still a further problem resides in being able to give such bodies a pxeferred form, such as that of fil~ls (or foils, or -sheets).
Su~mary of the ~nvention . . ~
The bodies accordin~ to the invention ~ith xeversibl~ variable temperature~-dependent licJht absorbence made at least of a pol~ner ma-terial and/or resill mat~ri~l are ch~racterized by the fac~ that in a substcln~i~l]y opt:ical]y transpclrent- polyrner material arld/cir re3:in lnatrl~
3~ 3 ~ BFN 6661 ~3 material (A) they contain an oryani.c substance (B) at least partially insoluble in t~e latter, which, after being embedcled in the matrix material, melts or congeals at the goal -temperature of light absorbence variation, and whose re~ractive index ~ither above or below -the tem-perature of light-absorbence variation substantially agrees wi.th the refractive index of the matrix material, as a dispersed ~mbeddecl second phase.
When mention is made here of "absorbence", this conc~pt is intended to include the e~fects not only of absorption and scattering but also of refraction and reflection. The concept "light" signifies electromagne.tic waVes not only in the visible range but also, i~ occasion arisés, in the ultra-violet or infra-red rang~. Finally r when the organic substance (B) is cdefinea as being at leastt part.ially insoluble in the polymer material arld/or resin matrix material (.~), this i.s not intended to exclude the possibility that the substance (B) in the transparent state -- that is, in a state of hi.gh light transmission --can also be present in real solution in the matrix materi.al.
In temperature variations, these bodies accordingto the invention show, at a predetermined temperature, a reversible suclden chan~e ~rom transparent to opaque or from opaque to transparent. In other ~ords, at a predeter-mined temperature, these hodies possess a relatively sharp sudden change from opti.cal absorbence to hi~h light trans~
mission, or vice versa. This procedure is unlimiteclly reversible and is independent o~ any sort of atmospheric conditions.
Such bodies can be used, for exarnple, for ttempera-ture-measuxin~ devlces or warnincJ devices. For example, they can be uti].i.zed as slippery ice warning de~ices if the desired tempera-ture is set slightly above t.he ~reezing point of water. Here i-t is appropriate to use such substances for the matri.x rnatericll, and also Eor the embedded O.CCJclni C s~lbstancc, thclt, uL~on a:lt~r~.lt:io.~l o~
~.iy~l-t absorb~rlc~c! w~lerl t~}IC` t~m}?erc~l:.u~:-o ~ .s ~' Lo~7 t~

~ J3 ~
--~ .
BFN 66fil -4 desired temperature, a transi.tion from opaque to ligh~~transmitting ta]ces place; that is, the organic substance (B), af-ter being embedded in the matrix material, melts slightly above the freezing point o~ water and in the solid state has a refractive index which agxees as well as possible with tha-t of the matrix material.
Another area of application consists in -temper-ature warning systems; that is, for indicating an excess temperature i.n areas or receptacles which must be kept at 10 a specific temperature, as in air-conditioned areas, cold-storage rooms, or freezer compartments. In this case, it is appropriate, when the organic substance B, which is embedded in the matrix material and which has to melt at the desired temperature of light-absorbence ~axiation, has 15 a refractive index in the molten state which agrees as well as possible wi-th that of the matrix ma-terial, since, when the desired temperature is exceeded, an alteration in state .from opaque to transparent occurs, and warning si.gnals, which lie behind the body and which are no-t leyible in -the 20 normal state, become visible.
Another application i.s that of screening (or shielding) devices for solar and heat radiation for green-houses, hotbeds, industrial structures, office windows and windows in dwelling houses, vehicle wi.ndows, and the 25 like.
Detailed escription of the Preferred ~mbodirrlents _ _ _ _ _ _ _ _ For this applica.tion, the substances are so selected that, when the temperat~re falls below a determined desired temperature, the organic substance (B) embedded i 30 the matri.x ma-terial rnelts and in the molten st-ate has a refractive index substan-tially different frorn the refractive `index of the matrix material; in the solid state, on the other hand, has a refractive i.ndex which agrees as well as possible with the refractive inde~ of the matxi.x mal-exial.
. 35 In this case, the bocly accordi.ng to l:he invent.ion :i.s trans--parcnt be].ow khe desired ternpel-atl~7:c hul-. become-s l~ hi.d abrupt].~ W~lC?~ t~ric d~?c~ir:~d t~rrlpc!xature is C'~Cl~?~-'d~ cl~ld l-l-lc-~

aets as a shield agains-t further solar or hea-t i~radiation.
more sensitive reaction of the the~no-funetional body to solar i~radiation can be obtainedl for exa~nple, in that dark -- preferably blaek -- spots of eolor are plaeed on this body. If the the~no-functional body in the trc~ns-parent state is exposed to solar radiation, -the spots of color, which cover only a small portion of the surfaee o~
the thermo-funetional body~ become heated particularly rapidly through absorption of radiation. This heat is transmitted by means of heat- eonduction in the longitudinal direetion of the body -to ad~acent points, whereupon these points, because of the heightened temperature, ehange over into the seattering, absorbing state. Now in this state, ` more radiation is again absorbed, the hea~ thus originating is eondueted further, and so on.
When mention is made here of "~odies", this expr~ssion signifies an~ sort of molded article, like plates, sheets, lamina, bloeks, or cle~iees of an~ desired form; also coatings on other objects, as on sheets of syntheti.e (or plastic~ material, p]astic (or syn:thetic) plates, or glass plates. Since the matrix material eonsists of a syntheti.c (or plastic) material or of synlhetie resi.n, it can be formed in any m~nner. Ho~,~Yev~r, it is espeeially appropriate if the bodies according to the invention are present in -the form of sheets or eoa-t;.ngs on transparent objeets like glass plates or plates or sheets o~ synthetie ma',erial.
When mention is made above that the organie substanee (B), which is embedded in the matrix material (A) an~ ~hich is at least partially insoluble in the latter, is suppo~ed to r(,elt or concJea] at the goal temperature of vari.ati.on in licJht a.bsorbenee after being embedded in this matrix ma.terial, thi.s is in-tended to express that this meltinc.~ or concJealincJ point does not compulsorily have -to ~c3rce with t:he melti.ncJ or COncJeali.llc~ point o~ thc pure orcJanic subsL.ancc~ (~). Usuc-lll.y, tl-li.s mel.ti.rlg or concJcalir poinl: of the orcJan:i.c subst.clnc~e (1:~)/ l~e:l. it is en)beclclecl - -BFN 6661 ~~

in the matrix material (A), lies a ~ew Celsius degrees below that of the pure organic substance (B), khe deviation being dependent on the process by means oE
which the organic subs-tance (B) is united with the matrix material (A). When the organic substance (B) is united with the dissolved or molten matrix material (~), the deviation of th,e melting point usually lies within a range of S degrees Celsius, while in cases where the matrix material is polymerized from its monomers and a mixture of the same with organic subskance (B), the deviation can amount to up to 20 Celsius degrees. However, for an eXp~Qrt, it is simple to determine, wi.th -the a.id of a few experiments, how the melting point becomes lowered with a given method and the working of the organic substance into the matrix material, and wi~h the selection o~ a speci~ic matrix material and a specific organic substance. There--fore, in the selection of the organic substance-s (B), usually one would emplov a compound or a mi.xture of com-pounds which, as such, melts a few Celsius degrees above the goal temperature, so that khe goal temperature is att.ained as closely as possible, upon melting, t~rough lowering of the melting point upon working the organic substance into tl~e matrix material (A).
It also goes without sayincJ that melting of the organic substance (s) can and may take place over a limited range of tempera-ture; ho~7ever, the goal ten~perature must f~ll within this meltiny range or conyealiny range.
The refractive inde~ of the embeddecl organic substance ~Ei) shou].d subskantially ayree, either above or below the goal kemperature of light absorbence variation, with the refractive index o~ the matrix material. This si.gniies khat no complete iden-tily is requi.red. ~Iowever, the be-tter this agrcement, the sharper i.s the light absorbence variakion, and the more transplrellt the bocly ~S is, either above or below the goa.l tempera-tl:!re.
The sharpnesc: o the effecl: -~ khclt ;s, the variclti.on o~ li.yhk absor~ence -~ also deL)cn(.ls on hol,7 - ' BFN 666]. -7~

strongly the refractive inde~ of th~ organic substance varies with phase alter~tion; that is, with transition from solid to liquid or vice versa. ~n ord~r -to obtain an effect utilizabl~ in practice, it is suitable that this altera-tion of the refractive index of the organic sub-stance (B~ upon its phase alteration amount to at least 2~, preferably at least 5~, of -the initial value.
The organic substance (B~ is embedded in the matrix material (A) as a seconcd ~- that is, discrete --phase and is suitably finely divicled in the form o~ smallto very small droplets or crystallites, preferably in the order of size of, or smaller than, the wavelength of li~h~, the droplets converting into crystallites or the crystallites converting into droplets upon altera-tion oE
light absorbence. The degree of fineness of division of the organic substance in the matrix material can he adjusted accoxding to the effect desired and the purpose of use.
The organic substance (B) can be wor~ed into the matrix material in various ways and can be finely distrib-uted therein. One meLhod consists in mixing monornersand/or oligolllers and/or prepolyrtl~rs of the matrix material (A) with the organic substance (B) and, if necessary, adcling a hardener for the monomers, oligorners, or prepolymers and polymeri2ing this mi~ture, forming and shaping the matriY~ material~ The or3anic substance (B)-may ~e present, completely dissolvecl, in the monomers, oligomers, or prepolymers of the matrix material until incompatibility or d.ifficulty o~ solubilit~ or phase separation takes place at any point in time during poly-merization, so that then the matrix material and the organic substance are actuall~ present in the end procluct as two separate phases, of whi.ch the organic substance (B) is the inncr or clispersed phase, which usually is dispersed i.Il more or less finely divided folm in the ma-tri.x phase.
~nother method consists of miY~ing thc~ organic substance (13) ~i.th a soluti.on o~ the matr;.~. material in ~n or.c3arlic so1ve~ and f~ ally ~vaporaLi.r~g the .solvcrlt, giving . .. ~
`- BFN 6661 -8 form to the matrix material. fIere also, in dissolving, the organic substance can be entirely dissolved in the common solution but must precipitate (or clepos.it) in fine-particles form as the second phase upon evaporation of the solvent. It goes without sayiny that it is also possible so to select the substances that the organic substance (B) does not, on the whole, dissolve completely in the solution o:E matrlx ma~erial but rather always xemains dispersed therein as the second phase; care must be taken to achieve a fine-particle dispersion in the form of little droplets or crystallites, possibly by means of efficient stirring devices, ultra-sound, or e~fective comminution of the solid material.
A further method consists in mel-tiny the matrix material, then admixing or dispersing the organic sub-stance (B), ancl finally, a~ter the mixture has become uni~orm, cooling the matrix material ofr to gi~e it form.
"Giving form" can consist of allowing the matrix material, with the organic substance (B) finely distributed therein., to polymerize, harden, or congeal in a rorm;
shaping the matrix material in customary extruders with tnouthpieces into sheets or plates or o-ther molded artic1.es;
or using other cus-tomary forrning processes, such as sheet-forming processes; or allowing the matrix materia].
to form as a coating on another transparent body like a ~lass plate, and polymeriziny, or allowing a coating to form on this transparent body, like a ylass plate, by evaporation of the solvent or by congelation. Basically, all forming processes can be employed, since the matrix . 30 material is a polymer material or a resin material, yiving ~orm to which is known.
The matrix materials may be thermoplastic or duroplastic synthetic materials, or natural or synthetic resins; the~ can harden to elas-tomers or rjyid bodies; or even, within a certain extent, may relrla;n plastic or adhesive, a.s in the case of specifi.c resinoUc, mcltrix materials, ~or examp~.e. ~n thi'.: Ca'..C? nrld 0~ ten in other cases, it is suitable to enclose the matrix material, sandwich-like, between other transparent bodies like glass plates or sheets of plastic (or synthetic) material.
The most varied classes of materials ma~ be em-ployed as matrix materials, selection being made especially on one hand according to the refractive index and on the other hand according to the physical properties required for a special purpose of use. Thus it may be desired that the matrix material produce a rigid sheet or plate, for be-ing attached to street guide posts as slippery ice warningdevices, for example. However, it may also be desired that the matrix material produce a flexible sheet or an adhesive or plastic coating. On the basis of the conditions outlined above for the matrix material, it is easy for an expert to select, from the multitude o~ known polymers and resins, a suitable resinous material for a specific organic substance, or vice versa. For example, suitable matrix materials are polyesters, polyamides, polystyrol, polyacrylates, and poly- .
methacrylates, as well as silicon resins. Among the polyes-ters, the high-molecular linear saturated polyesters, par-ticularly such with molecular weights of 10,000 to 20,000, are especially suitable. A suitable matrix material is also a polyvinylidene chloride acrylonitrile copolymer which con-tains substantially no branch.ings (or ramifications) and unsaturatednesses.
It is favourable to keep the weight ratio of or-ganic substance (B) to matrix material (A) within the range of 1:3 to 1:16, preferably rom 1:6 to 1:12l so that 3 to 16, preferably 6 to 12, parts by weiyht of matrix. material will exist to 1 part by weight of the organic substance (B).
Examples of suitable organic substances (B) are alkanols, alkandiols, halogen alkanols or al.kandiols, alkyl-amines, alkanes, alkenes, alkynes, halogen alkanes, alkenes, or alkynes, saturated or unsaturated monocarboxylic or ~ g_ dicarboxylic acids or esters or amides of the same saturate~
or unsaturated halogen fatty acids or esters or amides of the same, arylcarboxylic acids or their esters or amides, thioalcohols, thiocarboxylic acids or their esters or amides, or carboxylic acid esters of thioalcohols, as well as mix-tures of ~he same, all of these compounds containing, appro-priately, 10 to ~0, preferably 10 to 30, carbon atoms. In the esters, the alcohol groups, for their part, may be satu-rated or unsaturated and/or halogen-substituted. The halogen atoms in these compounds are, suitably, chlorine or bromine, especially chlorine. Particularly favourable have been found to be such compounds as organic substance (B), which contain at least one straight -chain aliphatic group, sui-tably with 10 to 30 carbon atoms. In the aryl compounds, the aryl group is preferably phenyl or substituted phenyl.
Through suitable selection of the organic substance (B), the hysteresis of the body according to the invention with rever-sible temperature-dependent transparency can be adjusted as desired; that is, by the reversible alternation between solid and liquid state of the embedded organic substance (~), one can obtain a temperature difference between melting and congealing or a temperature difference of the variation in light absorbence in heating or coolin~. A relatively large hysteresis - that is, such a temperature difference of a few degress Celsius - is desired, for example, in the applica-tion of the invention to slippery ice warning devices. In this way it happens that the embedded organic substance (B) melts somewhat above its congealing point, so khat the slip-pery ice warniny still remains visible at temperatures at which normally no slippery ice will occur but can still be found locally in certain unfavourable spots.

In order to obtain as small a hysteresis as pos-sible, one uses, suitably, compounds with heteroatoms, like ~r~
'~

haloyen, nitrogen, oxygen, and sulfur, as the organic sub-stance (B).
A few organic substances incline toward the ......

-lOa-."~

BE`N 6661 11 formation of undercool~d melting. When it is desired to prevent this, lt can be appropria-te to add crystallization nuclei in the foIm of organic or inorganic crystallites to the organic substance (B), such as pulverized quar-tz, basalt, mica, or benzamide crystals. Such crystalli~a-tion nuclei effect spontaneous crystallization at the goal temperature of the light-absorbence variation.
In being employed as temperature-measuring or temperature-wa~ning systems, the bodies according to the invention can be used as a coating, a sheet, a plate, or other molded a~ticle in front o~ a panel with a print of a symbol, a specific eolor panel, a symbol, or a reflector, so that abo~e or below the point of light~absorbence . variati~n a type eharacter, a speci~ic color, a symbol, or a refleetion when irradiated with vehicle headlights, beeomes visible. The prin~ may, f-or example, be a speGi~ie temperature indication or the words "slippery iee" or the like.
It goes without sayin~ that it is also possible to emplo~ a combination of materials in ~7hich the dispersed substance (B) has the same reEractive inde~, above its phaseconversion point, as that of the resin matrix material tA) but below that point has a refractive index different from that of the resin matrix ma~erial ~).
The thermofunctional b~cly so obtained becc~mes opaque white in the warning range and forms a very clear contrast to a dark or reflecting background~ A thickness o~ the thermo-functional layer of only 0.005 to 0.050 ~m. suffices to attain an effective contrast. When the layer is placed on a thin, possibly self-adhesive film carrier, any pre-ferred letters or symhols can be stamped (or punched, or blanked) out without difficulty, which are very i.nsensi.tive and worth the price and have a small heat capacit~ because oE their small volume and therefore permit an almost inerti.aless a~aptalion to varyi.ng temperatures.
In cases o~ use as solar radiatlon .~h.i.elds or heat:-radiation sh:i.elds, the body accor(li.rlc~ ~o the invention consists of a coating on or between disks of window glass.
The following examples serve for further explana-tion of the invention.
EXAMPLE_l 10 parts by weight of a silicon resin, free from solvent, with a ref~active index nl0 = 1.43 ("Sylgard* 184 encapsulating agent" of the Dow Chemical firm) is stirred to homogeneity with 1 part by weight of hardener ("Sylgard*
184 curing agent" of the Dow Chemical firm). 5 parts by weight of this mixture is treated with 1 part by weight of octadecanic acid pentyl ester with a refractive index nl0 =
1.45 and nO, again stirred to homogeneity, and coated in a layer 0.5 mm. thick on a glass plate. After four hours' hardening of the silicon resin at 65 Centigrade, there originates a reversible ther~ofunctional layer which shows good transparency above 5 Centigrade and a strong opacity (light absorbence) below 5 Centigrade.

3 parts by weight of thermoplastic polyamide resin - namely, a condensation product of polymeric fatty acids with aliphatic diamines (Versalon* 1175 of the firm Schering AG) is melted at 150 Centigrade. WiththiS melt is stirred 1 part by weight of heptanic acid tetradecyl ester, and the melt is coated in a 0.1-mm.-thick layer on a glass plate.
After cooling to room temperature, there originates a rever-sibly thermofunctional layer, which shows opacity above 7 Centigrade and transparency below 7 Centigrade.

One part of phenyl acetic acid stearylester is dissolved in 20 parts by weight of a 15~ solution of a high-molecular, linear copolyester on the basis of aromatic di-carboxylic acid and aliphatic dioles ("Polyester Dynapol*
* Trade Mark L 206" of the Dynamit Nobel ~.irm) in trichloroethylene.
With the aid of a ~ire wiper (or doctor), this solution is coated as a 0.05-mm.-thick ~heet of polyterephthalic acid glycol ester in such a manner that a layer 0.02 mm.
thick results after evaporation of the solvent. The layer of thermofunctional transparency so produced showsopacity above 40 Centigrade and transparency below 40 Cenkigrade.

In 10 parts by weight of a 20% solution of a poly~
ester on the basis of a mixture of aromatic as well as non-aromatic dicarboxylic acids and aliphatic dioles ("Polyester CR 04-178"* of the sostik firm, Oberursel) in trichloroethy-lene is dissolved one part of an intimate mixture of 10 parts of acetic acid heptadecyl ester, 10 parts of hexadecaneic acid heptylester, and 1 part of octadecanic acid octadeca-nic acid octadecyl ester (as crystallization nucleus). With the aid of a wire doctor (or wiper), this solution is spread as a 0.075-mm.-thick film of polyterephthalic acid glycol ester in such a manner that, after evaporation of the sol-vent, a layer 0.02 mm. thick results. The layer oftemperature-dependent light absorbence so produced shows opacity above 18.0 Centigrade and transparency below 17.3 Centigrade. This narrow area between the conversion tem-peratures of heating or cooling is obtained by the addition of the octadecanic acid octadecyl ester as crystallization nucleus.
EX~MPLE 5 3 parts by weight of a thermoplastic polystyrol ("Hostyren* N 2000" of the firm of Hoechs-t AB) is melted at about 160 Centigrade. With this melt is stirred one part of heptanic acid tetradecyl ester, and the melt is coated as a layer 0.1 mm. thick on a glass plate. After cooliny * Trade Mark to room temperature there remains a reversibly thermofunc-tional layer which shows opacity above 7 Centigrade and transparency below 7 C.
4 parts by weight of a fusible polymethacrylate ("Plexigum* P28" of the firm of R~hm G.m.b.H., of Darmstadt) is melted at about 160 Centigrade. With this melt is stirred l part by weight of Eicosan, and the melt iS coated as a layer 0.07 mm. thick on a glass plate. After cooling to room temperature, there originates a layer, in accor-dance with the invention, which shows transparency above 35 Centigrade and opacity below 35 Centigrade.

-9 parts by weight of a linear saturated copoly-ester with a refractive index n25 = 1.52 ("Polyester RFF-221 174"* of the Bostik firm, Oberursell) is melted at about 160 Centigrade. With this melt is stirred 1 part by weight of octadecane with a refractive index n25 = 1.51 and n28 = 1.43, and the melt is coated on a glass plate as a layer 0.1 mm. thick. After cooling to room temperature, the result is a reversibly thermofunctional layer in which the octadecane melts at 25 Centigrade, so that the layer shows opacity above 25 degrees Centigrade and transparency below 25 Centigrade.

* Trade Mark ;, -14-

Claims (12)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A body with reversibly variable temperature dependent light absorbence made of at least a polymeric or resinous material, comprising a substantially optically transparent polymeric or resinous matrix material (A), which contains, embedded as a dispersed second phase, at least one organic substance (B), which is at least parti-ally insoluble in the former and which, after being embed-ded in the matrix material, melts or congeals at the goal temperature of light-absorbence variation, and the refrac-tive index of which, either above or below the goal tem-perature of light-absorbence variation, agrees substanti-ally with the refractive index of the matrix material.
2. A body according to Claim 1, wherein said matrix material (A) contains embedded therein an organic substance (B) whose refractive index varies, upon phase alteration, by at least 2%.
3. A body according to Claim 1, wherein said organic substance (B) is in the form of small droplets or crystallites finely distributed in the matrix material.
4. A body according to Claim 1, wherein said organic substance (B) is present in a weight ratio to said matrix material (A) of 1:3 to 1:16.
5. A body according to Claim 1, wherein said organic substance (B) is a material selected from the group consisting of alkanol, alkandiol, halogenated alkanol, halogenated alkandiol, alkylamine, alkane, alkene, alkyne, halogenated alkane, halogenated alkene, halogenated alkyne;
a saturated monocarboxylic acid, unsaturated monocarboxylic acid, saturated dicarboxylic acid, unsaturated dicarboxylic acid or esters or amides thereof; a saturated halogenated fatty acid, unsaturated halogenated fatty acid, esters or amides thereof; an arylcarboxylic acid or esters or ami-des thereof; a thioalcohol; a thiocarboxylic acid, es-ters or amides thereof; and a carboxylic acid ester of a thioalcohol, each of which possesses 10 to 30 carbon atoms.
6. A body according to Claim 1, wherein said organic substance (B) is a compound with at least one straight-line aliphatic group.
7. A body according to Claim 1, wherein said matrix material (A) is selected from the group consisting of a polyacrylate, polymethacrylate, polystyrene, silicon resin, polyvinyl chloride, polyvinylidene chloride, and polyvinylidene chloride-acrylonitrile copolymer.
8. A body according to Claim 1, wherein said organic substance (B) contains crystallization nuclei in the form of organic or inorganic crystallites which melt above the goal temperature of light-absorbence variation, and with the organic substance (B), forms no mixed crystal-lites.
9. The method of producing a body with rever-sibly variable temperature dependent light absorbence comprising the steps of:
a) mixing in a substantially optically transpa-rent polymeric or resinous matrix material (A), an organic substance (B) which is at least partially insoluble in said matrix material and which after being embedded in the mat-rix material, melts or congeals at the goal temperature of light-absorbence variation and the refractive index of which, either above or below the goal temperature of light-absorbence variation, agrees substantially with the refrac-tive index of said matrix material and b) forming said body of the mixture.
10. The method of Claim 9, wherein said matrix material (A) is polymerizable when mixed with said organic substance (B) and is, then, polymerized in the forming step.
11. The method of Claim 9, wherein said matrix material (A) is in an organic solution when mixed with said organic substance (B) and is, then, set by evaporation of said solvent in the forming step.
12. The method of Claim 9, wherein said matrix material (A) is in the form of a melt when mixed with said organic substance (B) and is, then, cooled in the forming step.
CA309,091A 1977-08-25 1978-08-10 Bodies with reversibly variable temperature-dependent light absorbence Expired CA1111633A (en)

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DE19772738253 DE2738253A1 (en) 1977-08-25 1977-08-25 BODY WITH REVERSIBLE TEMPERATURE-DEPENDENT TRANSPARENCY
DEP2738253.2 1977-08-25

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EP (1) EP0000868B1 (en)
JP (1) JPS54119377A (en)
AT (1) AT375183B (en)
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DE (2) DE2738253A1 (en)
IT (1) IT1159102B (en)
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Families Citing this family (99)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2907352A1 (en) * 1979-02-24 1980-08-28 Dabisch Tipp Ex Tech BODY WITH REVERSIBLE, FIXABLE AND TEMPERATURE VARIABLE LIGHT TEXT INK
US4280441A (en) * 1979-07-06 1981-07-28 Akzona Incorporated Temperature indicator
US4299727A (en) * 1980-01-07 1981-11-10 Akzona Incorporated Disposable reversible thermometer
US4333339A (en) * 1980-03-21 1982-06-08 Akzona Incorporated Steam trap monitor
US4695528A (en) * 1980-07-16 1987-09-22 Wolfgang Dabisch Process for forming images using body with reversible fixable and temperature-variable light extinctions
US4428321A (en) 1981-11-16 1984-01-31 Minnesota Mining And Manufacturing Co. Thermally-activated time-temperature indicator
US4471711A (en) * 1981-12-23 1984-09-18 Incom International Inc. Push-pull cable with color change temperature self-indicating means
EP0096503A3 (en) * 1982-05-25 1987-04-22 Unisys Corporation Heat sensitive film shutter
SE431258B (en) * 1982-07-02 1984-01-23 Tiru Maj Britt Ingegerd COMPOSITION WITH REGULATED CHANGE OF OPALESCENCE OR CLEARANCE AT SELECTED TEMPERATURES AND SETS FOR ITS PREPARATION AND USE OF THE COMPOSITION
DE3307567A1 (en) * 1983-03-03 1984-09-06 Siemens AG, 1000 Berlin und 8000 München HEAT RECOVERABLE OBJECT
DE3326021A1 (en) * 1983-07-20 1985-01-31 ANT Nachrichtentechnik GmbH, 7150 Backnang HEAT RECOVERABLE ITEM WITH TEMPERATURE INDICATION
DE3436477A1 (en) * 1984-10-05 1986-04-10 Röhm GmbH, 6100 Darmstadt GLAZINGS WITH TEMPERATURE CONTROLLED LIGHT TRANSMISSION
US4657345A (en) * 1985-03-11 1987-04-14 Barnes Engineering Company Laser shield and method of making same
JP2594263B2 (en) * 1986-11-25 1997-03-26 株式会社リコー Display device
JPS6414077A (en) * 1987-07-08 1989-01-18 Ricoh Kk Reversible composite thermal recording material
JPS6420193A (en) * 1987-07-15 1989-01-24 Ricoh Kk Data-recording material
DE8802656U1 (en) * 1988-02-29 1989-03-30 Holzer, Walter, Dr.H.C., 7758 Meersburg, De
US6090508A (en) * 1988-06-07 2000-07-18 Ricoh Company, Ltd. Optically anisotropic recording medium and method of recording and erasing information using the same
DE3831495C1 (en) * 1988-09-16 1989-12-07 Alfred Prof. Dr. 5100 Aachen De Boettcher Translucent heat insulation
JPH02187389A (en) * 1989-01-17 1990-07-23 Tomoegawa Paper Co Ltd Heat transfer sheet with reversible heat-sensitive recording layer
WO1990011898A1 (en) 1989-04-07 1990-10-18 Toppan Printing Co., Ltd. Composition for reversible thermal recording medium
JP2615200B2 (en) * 1989-05-31 1997-05-28 株式会社リコー Reversible thermosensitive recording material
DE69009687T2 (en) * 1989-11-17 1994-11-03 Oki Electric Ind Co Ltd Thermoreversible recording material, a device using the material and process for its production.
US5249000A (en) * 1989-11-17 1993-09-28 Oki Electric Industry Co., Ltd. Thermoreversible recording medium, apparatus utilizing the same and method for fabricating the same
DE4002518A1 (en) * 1990-01-29 1991-08-01 Fraunhofer Ges Forschung Cladding over heating of building - has outermost covering over transparent insulation, an air gap layer whose transparency depends on temp. and absorber background
JPH0775914B2 (en) * 1990-02-02 1995-08-16 日東電工株式会社 Reversible thermosensitive recording material
DE59008535D1 (en) * 1990-03-21 1995-03-30 Rxs Schrumpftech Garnituren Item with a temperature indicator.
US5711884A (en) * 1990-08-22 1998-01-27 University Of Pittsburgh Of The Commonwealth System Of Higher Education Method of filtering submicron particles with gel lattice membrane filter
JP3100450B2 (en) * 1991-01-11 2000-10-16 株式会社リコー Image recording method and apparatus used therefor
US5364829A (en) * 1991-08-30 1994-11-15 Matsushita Electric Industrial Co., Ltd. Rewritable recording medium and a method of recording in the same
EP0535930B1 (en) * 1991-10-04 1997-01-02 Oki Electric Industry Co., Ltd. Thermoreversible recording material, thermoreversible recording medium and recording method
AU669131B2 (en) * 1991-10-08 1996-05-30 Kabushiki Kaisha Ace Denken Card for recording number of game media, device for dispensing cards and device for taking cards in
US5620781A (en) * 1991-10-23 1997-04-15 Fuji Xerox Co., Ltd. Erasable display medium
US5278129A (en) * 1991-11-20 1994-01-11 Toppan Printing Co., Ltd. Rewritable thermosensitive recording medium
US5779365A (en) * 1992-11-25 1998-07-14 Minnesota Mining And Manufacturing Company Temperature sensor for medical application
JP3375995B2 (en) 1992-11-25 2003-02-10 ミネソタ マイニング アンド マニュファクチャリング カンパニー Medical temperature sensor
US5737102A (en) * 1992-12-30 1998-04-07 University Of Pittsburgh Of The Commonwealth System Of Higher Education Method of making an optically nonlinear switched optical device and related devices
ATE143475T1 (en) * 1993-03-17 1996-10-15 Sto Ag THERMAL INSULATION COMPOSITE SYSTEM
US5589237A (en) * 1993-06-25 1996-12-31 Fuji Xerox Co., Ltd. Reversible display medium
US5707543A (en) * 1994-05-11 1998-01-13 Fuji Xerox Co., Ltd. Reversible display medium
CA2161376C (en) * 1994-10-27 2005-01-11 Toshiaki Minami Reversible multi-color thermal recording medium
US5499597A (en) * 1994-11-01 1996-03-19 Kronberg; James W. Optical temperature indicator using thermochromic semiconductors
US5547283A (en) * 1994-11-01 1996-08-20 Kronberg; James W. Optical temperature sensor using thermochromic semiconductors
US5671211A (en) * 1994-11-24 1997-09-23 Fuji Xerox Co., Ltd. Data recording medium
JP2887083B2 (en) * 1994-12-02 1999-04-26 富士ゼロックス株式会社 Thermal recording type optical element
US5585418A (en) * 1995-06-15 1996-12-17 At Plastics Inc. Greenhouse film having variable light diffusion properties
US5982346A (en) * 1995-12-15 1999-11-09 Xerox Corporation Fabrication of a twisting ball display having two or more different kinds of balls
US5737115A (en) * 1995-12-15 1998-04-07 Xerox Corporation Additive color tristate light valve twisting ball display
US5717515A (en) * 1995-12-15 1998-02-10 Xerox Corporation Canted electric fields for addressing a twisting ball display
US5739801A (en) * 1995-12-15 1998-04-14 Xerox Corporation Multithreshold addressing of a twisting ball display
US5767826A (en) * 1995-12-15 1998-06-16 Xerox Corporation Subtractive color twisting ball display
US5760761A (en) * 1995-12-15 1998-06-02 Xerox Corporation Highlight color twisting ball display
US5751268A (en) * 1995-12-15 1998-05-12 Xerox Corporation Pseudo-four color twisting ball display
US5892497A (en) * 1995-12-15 1999-04-06 Xerox Corporation Additive color transmissive twisting ball display
US5717514A (en) * 1995-12-15 1998-02-10 Xerox Corporation Polychromal segmented balls for a twisting ball display
US5708525A (en) * 1995-12-15 1998-01-13 Xerox Corporation Applications of a transmissive twisting ball display
ES2120369B1 (en) * 1996-06-19 1999-04-01 Magic Dreams Cosmetica Infanti DEPILATION WAX CONTAINER WITH THERMAL INDICATOR.
DE19642886A1 (en) * 1996-10-17 1998-04-23 Fraunhofer Ges Forschung Process for the production of a thermo-optic variable polymer material and its application
US6014246A (en) * 1996-11-06 2000-01-11 University Of Pittsburgh Of The Commonwealth System Of Higher Education Thermally switchable optical devices
JPH10250239A (en) * 1997-03-11 1998-09-22 Hitachi Maxell Ltd Reversible thermal recording medium
US5900192A (en) * 1998-01-09 1999-05-04 Xerox Corporation Method and apparatus for fabricating very small two-color balls for a twisting ball display
US5976428A (en) * 1998-01-09 1999-11-02 Xerox Corporation Method and apparatus for controlling formation of two-color balls for a twisting ball display
FR2776232B1 (en) 1998-03-23 2001-05-18 Ricoh Kk REVERSIBLE THERMOSENSITIVE RECORDING MEDIUM AND IMAGE FORMATION AND ERASING METHOD USING THE SAME
US6348908B1 (en) 1998-09-15 2002-02-19 Xerox Corporation Ambient energy powered display
GB2348703A (en) * 1999-04-06 2000-10-11 Amg Innovations Ltd Temperature activatable indicia reveal cover
JP3781587B2 (en) 1999-07-22 2006-05-31 三菱製紙株式会社 Reversible thermosensitive recording material
US6440252B1 (en) 1999-12-17 2002-08-27 Xerox Corporation Method for rotatable element assembly
JP2001221718A (en) * 2000-02-08 2001-08-17 Canon Inc Device including reusable unit and management system therefor
AU2001238634A1 (en) 2000-02-23 2001-09-03 University Of Pittsburgh Of The Commonwealth System Of Higher Education Photochemically controlled photonic crystal diffraction
US6545671B1 (en) 2000-03-02 2003-04-08 Xerox Corporation Rotating element sheet material with reversible highlighting
US6498674B1 (en) 2000-04-14 2002-12-24 Xerox Corporation Rotating element sheet material with generalized containment structure
US6504525B1 (en) 2000-05-03 2003-01-07 Xerox Corporation Rotating element sheet material with microstructured substrate and method of use
US6362303B1 (en) 2000-05-19 2002-03-26 Pleotint, L.L.C. Thermoscattering materials and devices
US6847347B1 (en) * 2000-08-17 2005-01-25 Xerox Corporation Electromagnetophoretic display system and method
US6524500B2 (en) 2000-12-28 2003-02-25 Xerox Corporation Method for making microencapsulated gyricon beads
US6897848B2 (en) 2001-01-11 2005-05-24 Xerox Corporation Rotating element sheet material and stylus with gradient field addressing
US6690350B2 (en) 2001-01-11 2004-02-10 Xerox Corporation Rotating element sheet material with dual vector field addressing
US6970154B2 (en) 2001-01-11 2005-11-29 Jpmorgan Chase Bank Fringe-field filter for addressable displays
JP2002248863A (en) 2001-02-26 2002-09-03 Ricoh Co Ltd Reversible heat-sensitive recording medium and method for processing image thereof
US6699570B2 (en) 2001-11-06 2004-03-02 Xerox Corporation Colored cyber toner using multicolored gyricon spheres
US6561122B1 (en) * 2002-01-25 2003-05-13 Milliken & Company Transparent polypropylene formulations that become opaque upon exposure to sufficient heat
US7670623B2 (en) * 2002-05-31 2010-03-02 Materials Modification, Inc. Hemostatic composition
JP2004074583A (en) 2002-08-19 2004-03-11 Sony Corp Reversible multi-color recording medium and recording method using the recording medium
JP2004074584A (en) 2002-08-19 2004-03-11 Sony Corp Reversible multi-color recording medium and recording method using the recording medium
US7560160B2 (en) * 2002-11-25 2009-07-14 Materials Modification, Inc. Multifunctional particulate material, fluid, and composition
TW200501139A (en) * 2003-01-24 2005-01-01 Mitsubishi Chem Corp Information recording medium
US7007972B1 (en) 2003-03-10 2006-03-07 Materials Modification, Inc. Method and airbag inflation apparatus employing magnetic fluid
US6982501B1 (en) 2003-05-19 2006-01-03 Materials Modification, Inc. Magnetic fluid power generator device and method for generating power
US7200956B1 (en) 2003-07-23 2007-04-10 Materials Modification, Inc. Magnetic fluid cushioning device for a footwear or shoe
US7448389B1 (en) 2003-10-10 2008-11-11 Materials Modification, Inc. Method and kit for inducing hypoxia in tumors through the use of a magnetic fluid
CN1930005A (en) * 2004-02-09 2007-03-14 太阳化学公司 Reversible thermochromic systems
GB2472987A (en) * 2009-08-24 2011-03-02 Cambridge Entpr Ltd Composite optical materials, uses of composite optical materials and methods for the manufacture of composite optical materials
US9561615B2 (en) 2011-01-12 2017-02-07 Cambridge Enterprise Limited Manufacture of composite optical materials
EP2819650A1 (en) 2012-02-29 2015-01-07 B. Braun Melsungen AG Hormone containing emulsion comprising krill phospholipids
CN105143785A (en) * 2013-03-13 2015-12-09 沙特基础全球技术有限公司 Polyetherimides with improved melt stability and reduced corrosivity
EP3313937A1 (en) 2015-06-23 2018-05-02 BASF Coatings GmbH Aqueous resin solutions for passive opafication
WO2017209111A1 (en) 2016-05-30 2017-12-07 Ricoh Company, Ltd. Thermosensitive recording medium
US11324697B2 (en) 2017-08-10 2022-05-10 The Children's Medical Center Corporation Methods and compositions relating to emulsions comprising fish oil and/or omega-3 fatty acids
US20200256565A1 (en) * 2018-08-02 2020-08-13 Micheal Kieren Stovetop covering system

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE473772C (en) * 1926-08-07 1929-04-02 Telefunken Gmbh Arrangement for light control, especially for the purposes of picture telegraphy
US2261473A (en) * 1938-04-16 1941-11-04 George W Jennings Temperature indicator
US2269038A (en) * 1940-07-25 1942-01-06 Nashua Gummed & Coated Paper Temperature-indicating instrumentality
US2928791A (en) * 1953-02-12 1960-03-15 Joseph D Loconti Temperature indicators
NL280517A (en) * 1961-07-04 1900-01-01
US3445291A (en) * 1966-07-14 1969-05-20 Catalyst Research Corp Thermal battery with temperature indicating potting composition
GB1270928A (en) * 1968-04-18 1972-04-19 Hawker Siddeley Dynamics Ltd Improved temperature sensing device
US3620889A (en) * 1968-06-11 1971-11-16 Vari Light Corp Liquid crystal systems
DE1812319A1 (en) * 1968-12-03 1970-06-18 Basf Ag Reflectors for traffic purposes as a black ice warning device
US3585259A (en) * 1969-08-15 1971-06-15 Eastman Kodak Co Process for manufacturing friable solid polyester products
US3845662A (en) * 1970-03-24 1974-11-05 T Bei Method of and means for determining the threshold of surface temperatures of heated elements of machines, articles and other equipment
CH574613A5 (en) * 1970-11-04 1976-04-15 Kuehl Georg Walter
GB1367703A (en) * 1971-08-22 1974-09-18 Spezialfolien Leipzig Veb Temperature indicating articles
BE791100A (en) * 1971-11-11 1973-03-01 Bio Medical Sciences Inc TEMPERATURE INDICATOR COMPOSITION
DE2442176A1 (en) * 1973-09-07 1975-03-13 Takeda Chemical Industries Ltd TEMPERATURE-SENSITIVE POLYMER MATERIAL
US3956153A (en) * 1973-09-26 1976-05-11 Bio-Medical Sciences, Inc. Regenerative nucleating agents
US4022706A (en) * 1973-12-17 1977-05-10 Robert Parker Research, Inc. Cholesteric liquid crystal water base ink and laminates formed therefrom
US4154106A (en) * 1976-04-10 1979-05-15 Morishita Jintan Company, Limited Disposable clinical thermometer
CA1085277A (en) * 1976-05-27 1980-09-09 James D.B. Smith Carboxylic acid composition for forming thermoparticulating coating
US4150572A (en) * 1977-12-05 1979-04-24 Johnson & Johnson Reversible thermometer

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US4268413A (en) 1981-05-19
AT375183B (en) 1984-07-10
JPS54119377A (en) 1979-09-17
NO782695L (en) 1979-02-27
NO148234C (en) 1983-09-07
EP0000868A1 (en) 1979-03-07
IT1159102B (en) 1987-02-25
DE2738253A1 (en) 1979-03-01
NO148234B (en) 1983-05-24
IT7826881A0 (en) 1978-08-21
DE2860290D1 (en) 1981-02-19
EP0000868B1 (en) 1980-12-10
ATA543178A (en) 1983-11-15

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