Raman-active taggants and thier recognition

Abstract

An organic or organoelement, linear or branched, monomeric or polymeric composition of matter having a Raman-active component in the form of particles. The particles having a maximum dimension of 50 μm. The Raman-active compound is applied to a substrate. When the Raman-active compound is exposed to a laser light wavelength which is batochromically well beyond a spectral region of maximum absorbance of said Raman-active compound, Raman scattering can be detected.

What is claimed is:  
     
         1 . An organic or organoelement, linear or branched, monomeric or polymeric composition of matter, comprising: 
 a Raman-active compound in the form of particles, whose maximum dimension is 50 μm, wherein said Raman-active compound is applied to a substrate or compatibilized with a substrate, said Raman-active compound having a characteristic that, when said Raman-active compound applied to a substrate is then exposed to a laser light wavelength which is batochromically shifted well beyond a spectral region of maximum absorbance of said Raman-active compound, at any incident intensity of said laser light higher than 1.0 mW but lower than that capable of inducing photothermal degradation of said Raman-active compound or said substrate, Raman scattering can be detected in a 2300-1900 cm −1  Raman shifts region at a level of at least 0.001 fW above an intensity of a background signal of said substrate.    
     
     
         2 . The composition of  claim 1 , wherein said laser light has a wavelength from about 750 nm to about 1500 nm.  
     
     
         3 . The composition of  claim 1 , wherein said substrate does not contain any acetylenic moieties within its structure.  
     
     
         4 . The composition of  claim 3 , wherein said substrate comprises paper.  
     
     
         5 . The composition of  claim 3 , wherein said substrate comprises a polymer.  
     
     
         6 . The composition of  claim 3 , wherein said substrate comprises a metal.  
     
     
         7 . The composition of  claim 3 , wherein said substrate comprises a metalloid.  
     
     
         8 . A flowable or solid composition of matter, comprising: 
 from 0.1 up to 100 percent by weight of one or more organic or organoelement, linear or branched, monomeric or polymeric compositions comprising: 
 a) at least one acetylenic moiety in any position within a molecule of said one or more organic or organoelement, linear or branched, monomeric or polymeric compositions; and  
 b) a Raman-active compound in the form of a layer whose thickness is more than 0.3 μm and less than 1000 μm, wherein said Raman-active compound is applied onto a sheet material, laminated between two layers of a sheet material or covered with a sheet material, and said Raman-active compound having a characteristic that, when exposed to a laser light wavelength which is batochromically shifted well beyond a spectral region of maximum absorbance of said Raman-active compound, at any incident intensity of said laser light higher than 1.0 mW but lower than that capable of inducing photothermal degradation of said Raman-active compound or said sheet material, Raman scattering can be detected in a 2300-1900 cm −1  Raman shifts region at a level of at least 0.01% of a dynamic range of a detector of a spectrometer above an intensity of a background signal of said sheet material.  
   
     
     
         9 . The flowable or solid composition of  claim 8 , wherein a difference between a maximum absorbance of said Raman-active compound and said laser light wavelength is at least 50 nm.  
     
     
         10 . The flowable or solid composition of  claim 8 , wherein said sheet material does not contain any acetylenic moieties within its structure.  
     
     
         11 . The flowable or solid composition of  claim 10 , wherein said sheet material comprises paper.  
     
     
         12 . The flowable or solid composition of  claim 10 , wherein said sheet material comprises a polymer.  
     
     
         13 . The flowable or solid composition of  claim 12 , wherein said thickness of said sheet material is less than 100 μm.  
     
     
         14 . The flowable or solid composition of  claim 8 , wherein at least one of said one or more compounds comprises a thermochromic polydiacetylene Raman-active compound.  
     
     
         15 . The flowable or solid composition of  claim 8 , wherein at least one of said one or more compounds comprises a topochemically polymerizable diacetylene monomer Raman-active compound, said Raman-active compound having a characteristic that it is polymerized to a specified degree of conversion into a polymer within a range of from 0.1 percent to 100 percent.  
     
     
         16 . The flowable or solid composition of  claim 8 , wherein said laser light has a wavelength from about 750 nm to about 1500 nm.  
     
     
         17 . A method of security marking, comprising the steps of: 
 a) applying to a genuine item a marking composition comprising a Raman-active composition, wherein said Raman-active composition, when illuminated with monochromatic near infrared radiation, generates a detectable Raman spectrum, thereby forming a machine-readable security mark on said genuine item;    b) illuminating said security mark on said genuine item with monochromatic near infrared radiation; and    c) quantitatively measuring with a spectrometer a spectrum of Raman scattered radiation from said Raman-active composition while said security mark is illuminated with monochromatic near infrared radiation;    d) wherein said Raman-active composition comprises from 0.1 to 100 percent by weight of one or more Raman-active compounds selected from the group consisting of: 
 1) R 1 —(C≡C) n —X 1 —Y 1 —R 2 , wherein n is an integer of 1 or 2; R 1  is H, a transition metal atom such as copper or silver, n-alkyl or substituted alkyl, aryl or substituted aryl; X 1  is absent or represents a molecular bridge such as n-alkylene, substituted alkylene, cycloalkylene, alkenylene, arylene and substituted arylene; Y 1  is absent or represents —H, —O—, —S—, —CO—, —CO—CO—, —OCO—, —NH—, —NHCO—, —NHCOO—, —CONHCOO—, —NHCONH—, a sulfonyl group, —HC═N—, —N═N—, >C═C<, >C═C—C═C<, —Ph—C≡C—Ph—, —C≡C—Ph—C≡C—, or —C≡C—M—C≡C—, wherein M is Hg, Pt, Ni, Pd, Si, Ge; and R 2  represents —H, or an n-alkyl, substituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, a substituted or unsubstituted heterocyclic structure, oxygen or sulfur, such as piperidinoxyl, carbazole, dehydropiperidinoxyl, carbolinoxyl, pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, or the like, with examples of substituents residing on the said substituted alkyls, aryls, alkylenes, arylenes, arylalkyls and heterocyclic structures including but not limited to halogen atoms, cyano group, vinyl group, mercapto group, hydroxy group, amine group, aldehyde group, carboxylic acid group, nitrile group, diazo group, nitro group, or azide group;  
 2) R 1 —(C≡C) n —X 2 —Y 2 -Z-Y 3 —X 3 —(C≡C) m—R   3 , wherein integer n is equal to or different from m and each, independently of the other, is 1 or 2; R 1  is equal to or different from R 3  and each, independently of the other, is H, a transition metal atom, n-alkyl or substituted alkyl, aryl or substituted aryl; X 2  is equal to X 3  and both simultaneously are either absent or represent a molecular bridge such as n-alkylene, substituted alkylene, arylene, substituted arylene, a substituted or unsubstituted heterocyclic structure, wherein the hetero atom is nitrogen, oxygen or sulfur, such as pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, piperidinoxyl, dehydropiperidinoxyl, carbolinoxyl, carbazole, and the like; Y 2  is equal to Y 3  and both simultaneously are either absent or represent —S—, —O—, —CO—, —OCO—, —CO—CO—, —NH—, —NHCO—, —NHCOO—, —CONHCOO—, —NHCONH—, a sulfonyl group, —C≡C—, >C═N—, —N═N—, >C═C<, >C═C—C═C<, —C≡C—Ph—C≡C—, —C≡C—C≡C—, or —Ph—C≡C—Ph—; Z is nil or represents a molecular bridge such as n-alkylene, substituted alkylene, cycloalkylene, arylene, substituted arylene, a substituted or unsubstituted heterocyclic structure, wherein the hetero atom is nitrogen, oxygen, sulfur, or the like, such as pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, piperidinoxyl, dehydropiperidinoxyl, carbolinoxyl, carbazole, and the like, a covalently bound element such as Hg, Pd, Pt, Ni, Si, Ge, or a moiety such as —S—, —O—, —CO—, —OCO—, —CO—CO—, —C≡C—, >C═N—, —N═N—, >C═C<, >C═C—C═C<, —C≡C—Ph—C≡C—, —Ph—C≡C—Ph—, and the like, with examples of substituents residing on the said substituted alkyls, aryls, alkylenes, arylenes, arylalkyls and heterocyclic structures including but not limited to halogen atoms, cyano group, vinyl group, mercapto group, hydroxy group, amine group, aldehyde group, carboxylic acid group, nitrile group, diazo group, nitro group, or azide group;  
 3) R 4 —Y 4 —X 4 —(C≡C)—X 5 —Y 5 —R 5 , wherein n is an integer from 1 to 4, X 4  is equal to or different from X 5  and each, independently of the other, is absent or represents a molecular bridge such as n-alkylene, substituted alkylene, preferably with from about 1 to about 12 carbon atoms, cycloalkylene, arylene, substituted arylene, preferably with from about 6 to about 18 carbon atoms, Y 4  is equal to or different from Y 5  and each, independently of the other, is absent or represents a moiety such as H, —OH, —COH, —COOH, —NH 2 , —NO 2 , —C≡N, —CH═CH 2 , phenyl, sulfonyl group, —S—, —O—, —CO—, —OCO—, —NH—, —NHCO—, —NHCOO—, —CONHCOO—, —NHCONH—, —C≡C—, >C═N—, —N═N—, >C═C<, >C═C—C═C<, —C≡C—C≡C—, —C≡C—Ph—C≡C—, —Ph—C≡C—Ph—, —C≡C—C≡C—C≡C—, —C≡C—C≡C—C≡C—C≡C—, and —C≡C—C≡C—M—C≡C≡C— moiety wherein M is an element such as Hg, Ni, Pd, Pt, Si, Ge or the like, and R 4  is equal to or different from R 5  and each, independently of the other, is absent or represents a functional group such as —H, —OH, —COH, —COOH, —NH 2 , —NO 2 , —C≡N, —CH═CH 2 , —C≡CH, —C≡C—C≡CH, —C≡C—Ph—C—≡CH, —Ph—C≡C—Ph, or an organic residue such as n-alkyl, substituted alkyl, preferably with from about 1 to about 12 carbon atoms, cycloalkyl, aryl, substituted aryl, preferably with from about 6 to about 18 carbon atoms, arylalkyl, substituted arylalkyl, preferably with from about 7 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic structure, preferably of from about 5 to about 15 members wherein the hetero atom is nitrogen, oxygen or sulfur, such as pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, carbazole, piperidinoxyl, dehydropiperidinoxyl, carbolinoxyl and the like, with examples of substituents residing on the said substituted alkyls, aryls, alkylenes, arylenes, arylalkyls and heterocyclic structures including but not limited to halogen atoms, cyano group, vinyl group, mercapto group, hydroxy group, amine group, aldehyde group, carboxylic acid group, nitrile group, diazo group, nitro group, or azide group;  
 4) R 6 —CH═C(CN)—COO—R 7 , wherein R 6  is equal to or different from R 7  and each, independently of the other, represents —H or a residue such as n-alkyl, substituted alkyl, preferably with from about 1 to about 12 carbon atoms, cycloalkyl, aryl, substituted aryl, preferably with from about 6 to about 18 carbon atoms, arylalkyl, substituted arylalkyl, preferably with from about 7 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic ring, preferably of from about 5 to about 7 members wherein the hetero atom is nitrogen, oxygen or sulfur, such as pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, carbazole, piperidinoxyl, carbolinoxyl and the like, or terminal functional groupings such as —CH═CH 2 , —HC═CH—HC═CH 2 , —C≡CH, —C≡C—C≡CH, —Ph—C≡CH, and —Ph—C≡C—Ph;  
 5) a compound represented by the general formula:  
                     
  wherein l and m are integers which are equal to or different from each other, and each, independently of the other, is 0, 1, 2 or 4; n is an integer preferably with from about 5 to about 10,000, Z 1  represents an atom such as mercury, nickel, platinum, palladium, silicon, germanium or the like, Z 2  represents an atom such as silicon or germanium, Z 3  is absent or represents arylene, substituted arylene, preferably with from about 6 to about 30 carbon atoms, or a substituted or unsubstituted heteroarylene structure, preferably of from about 5 to about 17 members wherein the hetero atom is nitrogen, oxygen or sulfur, R 8  is equal to or different from R 9  and each, independently of the other, is absent or represents an organic residue such as n-alkyl, substituted alkyl, preferably with from about 3 to about 16 carbon atoms, cycloalkyl, aryl, substituted aryl, preferably with from about 6 to about 30 carbon atoms, arylalkyl, substituted arylalkyl, preferably with from about 7 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic ring, preferably of from about 5 to about 7 members wherein the hetero atom is nitrogen, oxygen or sulfur, or a complexation ligand such as, e.g. trans-trialkylphosphine, and the like;  
 6) a compound represented by the general formula:  
                     
  wherein l and m are integers which are equal to or different from each other, and each, independently of the other, is 0, 1, 2 or 4; n is an integer preferably with from about 5 to about 10,000, Z 1  represents an atom such as mercury, nickel, platinum, palladium, silicon, germanium or the like, Z 2  represents an atom such as silicon or germanium, Z 3  is absent or represents arylene, substituted arylene, preferably with from about 6 to about 30 carbon atoms, or a substituted or unsubstituted heteroarylene structure, preferably of from about 5 to about 17 members wherein the hetero atom is nitrogen, oxygen or sulfur, R 8  is equal to or different from R 9  and each, independently of the other, is absent or represents an organic residue such as n-alkyl, substituted alkyl, preferably with from about 3 to about 16 carbon atoms, cycloalkyl, aryl, substituted aryl, preferably with from about 6 to about 30 carbon atoms, arylalkyl, substituted arylalkyl, preferably with from about 7 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic ring, preferably of from about 5 to about 7 members wherein the hetero atom is nitrogen, oxygen or sulfur, or a complexation ligand such as, e.g. trans-trialkylphosphine, and the like;  
 7) a compound represented by the general formula:  
                     
  wherein l and m are integers which are equal to or different from each other, and each, independently of the other, is 0, 1, 2 or 4; n is an integer preferably with from about 5 to about 10,000, Z 1  represents an atom such as mercury, nickel, platinum, palladium, silicon, germanium or the like, Z 2  represents an atom such as silicon or germanium, Z 3  is absent or represents arylene, substituted arylene, preferably with from about 6 to about 30 carbon atoms, or a substituted or unsubstituted heteroarylene structure, preferably of from about 5 to about 17 members wherein the hetero atom is nitrogen, oxygen or sulfur, R 8  is equal to or different from R 9  and each, independently of the other, is absent or represents an organic residue such as n-alkyl, substituted alkyl, preferably with from about 3 to about 16 carbon atoms, cycloalkyl, aryl, substituted aryl, preferably with from about 6 to about 30 carbon atoms, arylalkyl, substituted arylalkyl, preferably with from about 7 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic ring, preferably of from about 5 to about 7 members wherein the hetero atom is nitrogen, oxygen or sulfur, or a complexation ligand such as, e.g. trans-trialkylphosphine, and the like;  
 8) a compound represented by the general formula:  
                     
  wherein n is an integer preferably from about 5 to about 100,000, R 10  and R 11  are the same or different and each, independently of the other, represents n-alkyl, preferably with from about 1 to about 18 carbon atoms, substituted alkyl, preferably with from about 3 to about 30 carbon atoms, unsubstituted and substituted phenyl preferably with from about 6 to about 30 carbon atoms, aryl, substituted aryl, preferably with from about 12 to about 30 carbon atoms, arylalkyl, or substituted arylalkyl, preferably with from about 13 to about 30 carbon atoms;  
 9) a large spheroidal carbon molecule or a new allotropic form of carbon such as fullerene C60, C70, C72, C80, C140, C180, C240, C260, C320, C420, C432, C500, C504, C540, C560, C576, C620, C720, C740, C780, C860, C980, C1040, C1260, and the like, or the so called Goldberg polyhedron, or the so called carbon nanotube, or helical nanotube, or the so called carbon nanotorus;  
 10) a compound represented by the general formula:  
                     
  wherein n is an integer preferably from about 3 to about 100,000, R 12  and R 13  may be the same or different and, independently of each other, is H, n-alkyl preferably with from about 1 to about 8 carbon atoms or substituted alkyl, preferably with from about 3 to about 12 carbon atoms, or phenyl;  
 11) a compound represented by the general formula:  
                     
  wherein integer l is equal to or different from m and each, independently of the other, is 0, 1, 2, 3 or 4, n is an integer preferably from about 5 to about 100,000, X 6  is equal to or different from Y 6  and each, independently of the other, is absent or represents a moiety such as >C═C<, —CO—, —CO—CO—, —CH 2 —, —O—, —S—, —SO 2 —, —NH—, —NHCO—, —NHCOO—, —CONHCOO—, —NHCONH—, sulfonyl group, >C═N—, —N═N—, >C═C—C═C<, —Ph—C≡C—Ph—, p- or m-phenylene, diphenyleneoxide, tetraaryl substituted phenylene, cycloalkylene, arylene, substituted arylene, preferably with from about 6 to about 30 carbon atoms, a substituted or unsubstituted heterocyclic structure, preferably of from about 5 to about 15 members, wherein the hetero atom is nitrogen, oxygen or sulfur, such as pyrrolidine, pyridine, piperidine, piperazine, quinoline, isoquinoline, quinuclidine, pyrazole, triazole, tetrazole, triazine, imidazole, pyrimidine, pyradizine, pyrazine, oxazole, isoxazole, morpholine, piperidinoxyl, dehydropiperidinoxyl, carbolinoxyl, carbazole, and the like, with examples of suitable substituents residing on the said structures including but not limited to halogen atoms, cyano group, vinyl group, mercapto group, hydroxy group, amine group, aldehyde group, carboxylic acid group, nitrile group, diazo group, nitro group, or azide group, R 14  is equal to or different from R 15  and each, independently of the other, is absent or represents from one up to four substituents such as phenyl, alkyl preferably with from about 1 to about 12 carbon atoms, halogen atoms, cyano group, vinyl group, mercapto group, hydroxy group, amine group, aldehyde group, carboxylic acid group, nitrile group, diazo group, nitro group, or azide group; or  
 12) a compound represented by the general formula:  
                     
  where R 16  and R 17  are typically independently selected from alkyl and substituted alkyl groups, preferably monosubstituted alkyl groups, including urethane-modified alkyl, arylsulfonyl-modified alkyl, heterocyclic-substituted alkyl, ether-substituted alkyl, ester-substituted alkyl, amide-substituted alkyl, urea-substituted alkyl, carboxy-substituted alkyl, hydroxy-substituted alkyl, and the like, or in an alternative embodiment, R 16  and R 17  are independently selected from macromolecular residues having average degree of polymerization from 10 up to 100,000 and represented by polyalkylenes, polyoxymethylenes, polyoxypropylenes, polyethers, polyesters, polyurethanes, polyamides and polyetheramides.  
   
     
     
         18 . The method of  claim 17 , wherein said Raman-active composition is present in said marking composition in an amount from about 1 to about 100 percent by weight.  
     
     
         19 . The method of  claim 17 , wherein said Raman-active composition is present in said marking composition in an amount from about 50 to about 100 percent by weight.  
     
     
         20 . The method of  claim 17 , wherein said mark on said genuine item is illuminated with monochromatic near infrared radiation having a wavelength from about 750 to about 1500 nm.  
     
     
         21 . The method of  claim 20 , wherein said mark on said genuine item is illuminated with monochromatic radiation from a solid-state Nd:YAG laser.  
     
     
         22 . The method of  claim 20 , wherein said mark on said genuine item is illuminated with monochromatic radiation from a single-mode diode laser.  
     
     
         23 . The method of  claim 17 , wherein a spectrum of Raman scattered radiation from said Raman-active composition is quantitatively measured with a NIR-FT Raman spectrometer.  
     
     
         24 . The method of  claim 17 , wherein a spectrum of Raman scattered radiation from said Raman-active composition is quantitatively measured with a portable fiber optic Raman spectrometer.  
     
     
         25 . The method of  claim 17 , wherein a spectrum of Raman scattered radiation from said Raman-active composition is quantitatively measured with a portable fiber optic Raman spectrometer furnished with a waveguide evanescent probe.  
     
     
         26 . A method of security marking, comprising the steps of: 
 (a) applying to a genuine item a marking composition comprising an fluorescence-active composition, wherein said fluorescence-active composition, when illuminated with near infrared radiation, generates a detectable composite emission spectrum, thereby forming a machine-readable security mark on said genuine item;    (b) illuminating said security mark on said genuine item with monochromatic near infrared radiation; and    (c) simultaneously and quantitatively measuring with a spectrometer said composite emission spectrum of Raman scattered radiation and of laser induced fluorescence from said fluorescence-active composition while said security mark is illuminated with monochromatic near infrared radiation, wherein fluorescence-active composition is essentially an inorganic anti-Stokes up-converting phosphor selected from the group consisting of:   M (1−x) R x Z 3 ; or  (1)M 2( 1−x)R 2x O 2 S;  (2)    wherein 
 M comprises at least one rare earth element selected from the group consisting of cerium, gadolinium, yttrium, lanthanum, niodymium, holmium, samarium, europium, ytterbium, erbium, lutetium and mixtures thereof;  
 R is a dopant selected from the group comprising neodymium, thulium, erbium, holmium, samarium, or mixtures thereof;  
 x is a value in the range from 0.005 to 1.0;  
 Z is a halogen selected from the group consisting of chlorine, bromine, fluorine and iodine; and  
 said fluorescence-active composition is present in said marking composition along with from 0.1 to 100 percent by weight of one or more Raman-active compounds, the latter being represented by the general formulae as specified in  claim 17 .  
   
     
     
         27 . The method of  claim 26 , wherein said composite emission spectrum is quantitatively measured with a Raman spectrometer.  
     
     
         28 . The method of  claim 26 , wherein said composite emission spectrum is quantitatively measured with a Raman spectrometer furnished with InGaAs detector.  
     
     
         29 . The method of  claim 26 , wherein said composite emission spectrum is quantitatively measured with a Raman spectrometer furnished with Ge detector.  
     
     
         30 . The method of  claim 26 , wherein said composite emission spectrum is excited by a Nd:YAG laser.  
     
     
         31 . The method of  claim 26 , wherein said monochromatic near infrared radiation source is a diode laser.  
     
     
         32 . The method of  claim 26 , wherein at least one of said Raman-active compounds is represented by a thermochromic polydiacetylene.  
     
     
         33 . The method of  claim 26 , wherein said fluorescence-active composition comprises one of the Raman-active compounds of  claim 17  along with one fluorescence-active compound.  
     
     
         34 . The method of  claim 26 , wherein said fluorescence-active composition comprises more than one and less than nine Raman-active compounds of  claim 17  along with one fluorescence-active compound.  
     
     
         35 . The method of  claim 17 , wherein said Raman-active composition comprises more than two and less than six of said Raman-active compounds.  
     
     
         36 . The method of  claim 17 , wherein said Raman-active composition comprises two of said Raman-active compounds.  
     
     
         37 . An irradiation-developable Raman-active mark comprising a diacetylene solid-state polymerizable monomer.  
     
     
         38 . The mark of  claim 37 , wherein said mark is produced by an ink-jet printer.  
     
     
         39 . A thermally-developable Raman-active mark comprising a diacetylene solid-state polymerizable monomer.  
     
     
         40 . The mark of  claim 39 , wherein said mark is produced by an ink-jet printer.  
     
     
         41 . A Raman-active security mark which is thermochromic, pH-chromic, piezo-chromic or solvatochromic.  
     
     
         42 . The security mark of  claim 41 , wherein said mark is quantitatively Raman-detectable at discrete specified temperatures.  
     
     
         43 . The security mark of  claim 42 , wherein said temperature is selected from within a range of about −200° C. to about +300° C.