WO2011054731A1 - Fluorescent materials - Google Patents

Abstract

Fluorescent colorants are provided, a process for their preparation and their use. The colorants comprise a polyhedral oligomeric silsesquioxane moiety (POSS) having covalently attached an organic chromophoric moiety, wherein said silsesquioxane moiety has a cage structure comprising at least 9 silicon atoms within its cage structure.

Description

Fluorescent Materials

The present invention relates to fluorescent polyhedral oligomeric silsesquioxane (POSS) colorants, a process for their preparation and their use. Further, the invention relates to a composition comprising an organic material and said colorant, especially a coating composition.

Fluorescent colorants are highly recommended in decorative, electronic, industrial, security and home and personal care markets delivering effects to the customers. These applications require stabilized, migration-free and heat resistant fluorescent colorants that can be specifically modified like pigments to adapt to desired

applications.

However, the fluorescent signal from a solid dyestuff is weak, and the dye molecules in solid, in solvent or polymer matrix are susceptible to migration, decomposition by heat and irreversible photodegradation. It is a known fact that almost all fluorescent dyes in application (solution, polymer, paint, ink or matrix) are self-quenching if the

concentration of dye gets high enough. This means, that the dye itself decreases the fluorescence intensity by promoting decay from the excited state without emitting a photon.

Different approaches have emerged in recent years for synthesizing fluorescent materials for use in a range of demanding applications. In the first approach, the fluorescent dye is linked to a polymer matrix. In the second, the fluorescent dye is encapsulated in a polymer matrix of at least one kind of polymer prior to the end application to prevent dye molecules as good as possible from migration and self- quenching. In addition, in order to avoid, e.g., swelling or porosity change with pH changes, agglomeration in aqueous medium etc. that are associated with the above two approaches, functionalized silica and alumina nanoparticles to which dyes are bound had been manufactured for use as coloring materials for organic materials as disclosed in WO 2006/125736 A1 . The particles have many desirable characteristics including increased fluorescence, but they are not soluble in many materials.

A further approach is the use of polyhedral oligomeric silsesquioxanes (POSS) structures as building block unit for fluorescent colorants. POSS structures are a class of condensed three dimensional oligomeric organosiliceous compounds with cage frameworks having different degrees of symmetry. Colorant-functionalized POSS compounds based on the fully condensed, well-defined cage of RsSisO^ are known. For example, US 2005/0123760 A1 discloses lumophore-functionalized POSS compounds capable of emitting white light. WO 2007/147742 A1 describes colored silsesquioxanes having attached eight dye residues. These compounds do not show any fluorescence. WO 2008/017593 A1 discloses fluorescent colorants attached to a POSS useful in printing inks, coatings and the coloration of plastics. However, colorants based on the above-mentioned well-defined RsSisO^ cage do still not meet the requirement of migration stability, especially in coating applications.

It was therefore an objective of the present invention to provide fluorescent colorants which can readily be obtained by a straightforward process and which colorants have improved properties such as excellent migration stability, light stability and

fluorescence of high intensity.

Accordingly, in a first aspect the invention relates to a fluorescent compound of formula

POSS - E — D [Q]_X

(I), wherein

E is a direct bond or a linking group,

D is an organic chromophoric moiety,

Q is -E-POSS', said POSS' independently has the same or a different meaning as POSS of formula (I),

x + y is a number of from 1 to 4 and x is a number of from 0 to 3, and

POSS and POSS' are independently from each other a polyhedral oligomeric silsesquioxane moiety having a cage structure comprising at least 9 silicon atoms within its cage structure. The ratio of the sum of POSS moieties (including POSS') to the sum of chromophoric moieties is suitably such that the fluorescence of the inventive compounds is in no way affected. Preferably, said ratio is of from 1 :4 to 4:1 , more preferably 1 :2 to 2:1 , most preferably 1 :1 to 2:1. The POSS or POSS' moiety comprises preferably 9 to 32, more preferably 9 to 16 silicon atoms within the cage structure. Within the cage structure one or more silicon atoms may be replaced with a metal forming a metalla-silsesquioxane.

A silsesquioxane is the general name for a family of polycyclic compounds comprising silicon and oxygen. Polyhedral oligomeric silsesquioxanes are abbreviated "POSS". POSS molecules in accordance with the invention are defined as having a three dimensional cage structure, either complete cages, wherein all sides are completed and all Si atoms are completely saturated, or incompletely condensed cages, wherein Si-X or S1X2 groups, in particular Si-OH or Si(OH)2 groups, may be present which are capable of forming additional Si-O-Si linkages via elimination of H2O. Metalla- silsesquioxanes include the above POSS molecules wherein at least one Si atom of the cage structure is replaced with a metal atom. A POSS moiety can be derived from the above-defined POSS molecule by abstracting at least one H corresponding to the sum of comprised chromophoric moieties.

A "chromophoric moiety" is a radical of molecule or aggregate of molecules that can absorb electromagnetic radiation, such as a moiety comprising a dye molecule bound to the POSS moiety via E. Further definitions which will be used below are:

Alkyl, e.g., Ci-C4alkyl, d-Csalkyl, CiCi2alkyl or Ci-Cisalkyl, may be within the given limits of carbon atoms linear or branched, where possible. Examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, n- hexyl, 2,2-dimethylpropyl, 1 ,1 ,3,3-tetramethylpentyl, 1 -methylhexyl,

1 ,1 ,3,3,5,5-hexamethylhexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl,

1 - methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, n-nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. Alkoxy is alkyl-

0-; alkylthio is alkyl-S-.

Alkylene, e.g., Ci-Cisalkylene, Ci-Csalkylene, Ci-C₄alkylene or Cs-Cisalkylene, may be derived from above-defined alkyl by abstracting a hydrogen atom from any terminal carbon atom of the alkyl. Examples are methylene, ethylene, n-, isopropylene, n-, iso-, sec-, tert-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, n-nonylene, n- decylene, n-undecylene, n-dodecylene, n-tridecylene, n-tetradecylene, n-penta- decylene, n-hexydecylene, n-heptydecylene, n-octadecylene. Where indicated as interrupted, any alkylene moiety of more than one, especially more than 2 carbon atoms may be interrupted by a group such as N(R²), O, CO, COO, CON(R²), wherein R² is independently and in each occurrence H, Ci-Ci2alkyl, C5-Ci2cycloalkyl or C6-, Cio- or Ci2aryl, preferably phenyl or naphthyl. If two or more interrupting groups of the type N(R²) or O occur in one radical, they often are identical. Cycloalkyi, e.g., C5-Ci2cycloalkyl, preferably Cs-Crcycloalkyl, may be within the given limits of carbon atoms cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,

methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl and dimethylcyclohexyl, preferably cyclohexyl. The cycloalkyi group, in particular a cyclohexyl group, may be condensed one or twice by phenyl which may be substituted one to three times with Ci-C₄alkyl and halogen.

Cycloalkylene, e.g., C5-Ci2cycloalkylene, may be derived from above-defined cycloalkyi by abstracting a hydrogen atom from any carbon atom of the cycloalkyi. Alkenyl, e.g., C3-Cisalkenyl, may be within the given limits of carbon atoms straight- chain or branched, where possible. Examples are allyl, methallyl, isopropenyl,

2- butenyl, 3-butenyl, isobutenyl, n-penta-2,4-dienyl, 3-methyl-but-2-enyl, n-oct-2-enyl, n-dodec-2-enyl, isododecenyl, oleyl, n-dodec-2-enyl or n-octadec-4-enyl. The term "alkenyl" also comprises residues with more than one double bond that may be conjugated or non-conjugated, for example, may comprise one double bond. Alkenylene, e.g., C₃-Ci₈alkenylene, may be derived from above-defined alkenyl by abstracting a hydrogen atom from any terminal carbon atom of the alkenylene.

Cycloalkenyl, e.g., C₅-Ci₂cycloalkenyl, may be within the given limits of carbon atoms, for example, cyclopentenyl, cyclohexenyl, methylcyclopentenyl, dimethylcyclopentenyl and methylcyclohexenyl. Cycloalkenyl may comprise more than one double bond that may be conjugated or non-conjugated, for example may comprise one double bond.

Alkynyl, e.g., C3-Cisalkynyl, may be within the given limits of carbon atoms straight- chain or branched, where possible. Examples are 1-propyn-3-yl, 1-butyn-4-yl,

1-pentyn-5-yl, 2-methyl-3-butyn-2-yl, 1 ,4-pentadiyn-3-yl, 1 ,3-pentadiyn-5-yl, 1-hexyn-6- yl, cis-3-methyl-2-penten-4-yn-1-yl, trans-3-methyl-2-penten-4-yn-1-yl, 1 ,3-hexadiyn-5- yl, 1-octyn-8-yl, 1-nonyn-9-yl or 1-decyn-10-yl. The term "alkynyl" also comprises residues with more than one triple bond and residues with a triple bond and a double bond, all of which may be conjugated or non-conjugated. For instance, alkynyl comprises one triple bond.

Aralkyl, e.g., Cz-Cisaralkyl, may be within the given limits of carbon atoms, for example, benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl (phenethyl), α,α-dimethylbenzyl, co-phenyl- butyl, ω,ω-dimethyl-co-phenyl-butyl, ω-phenyl-dodecyl, in which both the aliphatic and the aromatic hydrocarbon group may be unsubstituted or substituted. Preferred examples are benzyl, phenethyl and α,α-dimethylbenzyl.

Aralkylene, e.g., Cz-Cisaralkylene, may be derived from above-defined arlkylene by abstracting a hydrogen atom from any carbon atom of the aryl. Examples are -(CH2)i-4- phenylene, preferably -Chb-phenylene-.

Aryl, e.g., C6-Ci8aryl or C6-Ci2aryl, may be within the given limits of carbon atoms, for example, phenyl, indenyl, azulenyl, naphthyl, biphenylyl, terphenylyl, as-indacenyl, s- indacenyl, acenaphthylenyl, phenanthryl, fluoranthenyl, triphenylenyl, chrysenyl, naphthacen, picenyl, perylenyl, pentaphenyl, hexacenyl, pyrenyl, or anthracenyl, preferably phenyl, 1-naphthyl, 2-naphthyl, 9-phenanthryl, 2- or 9-fluorenyl, 3- or 4-biphenylyl, preferably the above-mentioned mono- or bicyclic heterocyclic radicals, which may be unsubstituted or substituted.

Arylene, e.g., C6-Ci2arylene, may be derived from above-defined aryl by abstracting a hydrogen atom from any carbon atom of the aryl. Examples are phenylene or naphthylene, e.g., o-phenylene, m-phenylene, p-phenylene, or 1 ,4-naphthylene. Heteroaryl, e.g., C2-Ci8heteroaryl, is a ring, wherein nitrogen, oxygen or sulfur are the possible hetero atoms, and is typically an unsaturated heterocyclic radical with five to 18 atoms having at least six conjugated π-electrons such as thienyl, benzo[b]thienyl, dibenzo[b,d]thienyl, thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl, isobenzo- furanyl, 2H-chromenyl, xanthenyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl, 1 H-pyrrolizinyl, isoindolyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, 3H- indolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl or phenoxazinyl.

The above-mentioned groups may be substituted by one or more substituents.

Possible substituents are d-Csalkyl, OH, SH, Ci-Csalkoxy, d-Csalkylthio, halogen, CN, COR⁴, COOR⁴, CONR⁴R⁵, NR⁴R⁵, wherein R⁴ and R⁵ independently are

Ci-Ci2alkyl, Ci-Ci2haloalkyl, Cs-doaryl, C5-Ci2cycloalkyl, or R⁴ and R⁵ form an organic bridging group completing, together the nitrogen atom, they are bonding to, a heterocyclic ring of 5 to 7 ring atoms in total, e.g., forming a morpholine or piperidine ring, preferably R⁴ and R⁵ are Ci-C6alkyl, halogen, phenyl, cyclopentyl, cyclohexyl. If a substituent occurs more than one time in a group, it can be different in each occurrence.

Halogen denotes I, Br, CI, or F, especially Br or CI. The term "amino group or an amino-substituted group" encompasses amino groups which are linked to the chromophoric moiety D, such as -NH-, -NR³- or an amino group attached to a linking group E, such as -E-NH- or -E-NR³-, and amino groups such as - NH2, -NHR³, or an amino group attached to a linking group E; wherein R³ is Ci-Cisalkyl, C5-Ci2cycloalkyl or C6-Ci2aryl. The N atom of the amino group or of the amino- substituted group may be part of the chromophoric moiety, for example, part of the ring system of the chromophoric moiety, in the inventive fluorescent compound.

A preferred embodiment relates to a compound, wherein the POSS and/or POSS' moieties are a structure of formula

[(R¹ _m Yn Xo SiOi.₅)r (R¹p X_q SiO)s ] (II), wherein

R¹ is independently from each other C-i-C-isalkyl, C5-Ci2cycloalkyl, Cs-Cisalkenyl, C5-Ci2cycloalkenyl, Cs-Cisalkynyl, d-dsaralkyl, C6-Ci8aryl or C2-Ci8heteroaryl;

Y is an amino group or an amino-substituted group;

X is independently from each other OH, CI, Br, I or Ci-Cisalkoxy, preferably OH, m, n and o are independently 0 or 1 , wherein m+n+o = 1 ;

p and q are independently 0, 1 or 2, wherein p+q = 2;

r+s is a number of 9 to 32, wherein s < r, and the chromophoric moiety is bound to at least one amino group of Y.

Preferably, Y is selected from -E-NH-D; -E-NR³-D or Y', wherein Y' is -E-NH₂ or -E- NHR³ and R³ is Ci-Cisalkyl, C5-Ci2cycloalkyl or C6-Ci2aryl, wherein E is as defined above.

The compound is more preferred, where each Y is bound to a chromophoric moiety D.

The structure described above may include, for example, units such as (YS1O1.5), (R¹SiOi.₅), (XSiOi.s), (R¹X SiO), (R¹ ₂ SiO) or (X₂SiO), wherein R may have

independently and in each occurrence the same or different meaning and the above- mentioned groups may be unsubstituted or substituted. Preferably, R¹ is d-Csalkyl, such as methyl, ethyl, propyl, butyl, or Cs-Crcycloalkyl, such as cyclopentyl, cyclohexyl, or cycloheptyl, or C6-Ci2aryl, such as phenyl, biphenylyl or naphthyl.

A more preferred compound comprises a cage structure of silicon and oxygen atoms having at least 9 up to 16 silicon atoms, especially 9, 10, 1 1 , 12, 13 or 14, within this cage, i.e. r+s is of from 9 to 16 according to formula (II).

Further preferred are compounds comprising a so-called siloxane-extended POSS and/or POSS' moieties, wherein the cage structure comprises one or more of siloxane

R¹

I

o \ o

R

units such as

Accordingly, in a preferred aspect the invention relates to a compound, wherein the POSS and/or POSS' moieties comprise at least one siloxane of formula (R¹2 SiO), wherein R¹ may be the same or different, preferably the same.

Further preferred are so-called silicate-extended POSS and/or POSS' moieties, wherein the cage structure comprises one or more of silicate units such as

Accordingly, in a preferred aspect the invention relates to a compound, wherein the POSS and/or POSS' moieties comprise at least one silicate selected from formulae (XS1O1.5), (X2S1O) or (R¹XSiO), wherein R¹ may be the same or different, preferably the same.

For example, one or more silicon atoms may be replaced within the cage structure of the inventive compounds with a metal M selected from the group consisting of Al, Ga, Sn, Fe, Ge, Ti and Zr, preferably Al, Ti and Zr. In that case the structure described above may include one or more units such as (MO2), (XMO1.5), (X2MO) or (X3MO0.5).

In case of a metalla-silsesquioxane, usually 1 to 4 silicon atoms are replaced in the inventive compounds, more preferably 1 to 2, most preferably 1.

Two silicate extended POSS moieties which may have the same or different meaning may be condensed via one or more Si-O-Si linkages to form double or triple cages. In case of two Si-O-Si linkages are formed, three POSS moieties may be within one compound. It is also possible that two successive silicon atoms of the same POSS moiety may be linked to two successive silicon atoms of another POSS moiety.

Fluorescent compounds are preferred, wherein the linking group E is Ci-Cisalkylene, C3-Ci2alkenylene, C5-Ci2cycloalkylene, C6-Ci2arylene; Cz-Cisaralkylene, or C3- C-isalkylene which is interrupted by N(R²), O, CO; COO; CON(R²); wherein R² is H; Ci- Ci2alkyl; C5-Ci2cycloalkyl or C6-, C10- or Ci2aryl. In particular, E is Ci-Cisalkylene, especially d-Csalkylene, or 0-, m-, p-phenylene.

Reactive chromophores imparting fluorescence properties are well-known in the art, for example, from "Molecular Probes Handbook of Fluorescent Probes and Research

Chemicals", 6^th ed., R.P. Haugland, 1996. A chromophoric moiety may be a radical of a colorant, such as a pyrene, anthracene, naphthalene, acridine, stilbene, indole or benzindole, oxazole or benzoxazole, thiazole or benzothiazole, diazole, e.g. 4-amino-7- nitrobenz-2-oxa-1 ,3-diazole (NBD), cyanine, phthalocyanine, porphyrin, porphycene, salicylate, anthranilate, azulene, perylene, pyridine, quinoline, coumarin (including hydroxycoumarin and aminocoumarin and fluorinated derivatives thereof), phthalimide, naphthalimide, diphenylmaleimide, acetoacetamide, perylenemonoimide,

naphtholactam, azlactone, xanthene, benzothioxanthene and benzoxanthene

(benzo[a]xanthene, benzo[b]xanthene, benzo[c]xanthene, rhodamine, fluoresceine), oxazine, thiazine, phenoxazine, benzo[a]phenoxazine, benzo[b]phenoxazine, benzo[c]phenoxazine, diketopyrrolopyrrole, quinacridone, azo dye, and the like, see, for example, US 5,830,912; US 5,433,896; US 4,810,636; and US 4,812,409.

Advantageously, the chromophoric moiety D is a radical of a chromophore selected from the group consisting of an azo dye, benzoxanthene, naphthalimide,

diketopyrrolopyrrole, perylene, quinacridone, diphenylmaleimide, acetoacetamide, perylenemonoimide, and phthalimide, preferably a perylene, benzoxanthene, naphthalimide, quinacridone, diketopyrrolopyrrole and phthalocyanine. When more than one D is present, each D is selected independently from each other, for example, D may be the same moiety. In one particular embodiment of the invention the chromophoric moiety is derived from a chromophore which is part of a pigment, or typically found as part of a pigment particle. Thus, an easily handled, fluorescent colorant soluble in a variety of polymers, inks and other vehicles is readily derived from an insoluble solid. In such an embodiment, the chromophoric moiety is derived, for example, from a xanthene, perylene, benzoxanthene, naphthalimide, diketopyrrolopyrrole, quinacridone or phthalocyanine pigment, and in a particular embodiment, the chromophoric moiety is derived from a perylene, benzoxanthene, naphthalimide or diketopyrrolopyrrole pigment.

Particularly useful radicals for D are those of formula

O

⁰ (VII)

wherein R⁶ and R⁷ together with the residue of formula -N(CO-)2 form the radical of a perylene, benzoxanthene or naphthalimide dye.

Examples of such radicals of formula (VII) include the following:

nd diphenylmaleimide dyes:

(VII-1 ), (VII-2),

wherein the rings A and B can be unsubstituted or substituted by d-Csalkyl, Ci- Cealkoxy, amino, mono- or di(Ci-C8alkyl)amino, halogen or sulfo.

- Radicals derived from benzoxanthene dyes:

wherein R⁸ is d-Csalkyl, d-Csalkoxy, Ci-Csthioalkyl, amino, mono- or di(Ci-Csalkyl) amino, or halogen, and

R⁹ is -0-, -S-, -NH-, or -N(R¹⁰)-, wherein R¹⁰ is Ci-C₈alkyl, hydroxy- Ci-C₈alkyl, or C₆

- Radicals derived from perylene dyes

wherein R¹¹ and R¹² independently from each other are H; Ci-CsalkyI; phenyl or naphthyl which can be substituted by Ci-Csalkyl, Ci-Csalkoxy or halogen; cyano; nitro; halogen; -OR¹⁴; -COR¹⁴; -COOR¹⁴; -OCOR¹⁴; -CONR ⁴R¹⁵; -OCONR ⁴R¹⁵; -NR ⁴R¹⁵; - NR ⁴COR¹⁵; -NR ⁴COOR¹⁵; -NR ⁴S0₂R¹⁵; -S0₂R¹⁴; -S0₃R¹⁴; -S0₂NR ⁴R¹⁵ or -N=N-R¹⁴; and R¹⁴ and R¹⁵ are independently from each other and in each occurrence H; Ci- Cealkyl; or phenyl which can in turn be further substituted by Ci-Csalkyl, Ci-Csalkoxy or halogen;

R¹³ is H; Ci-Cisalkyl, which can be substituted by halogen, phenyl or naphthyl, whereby phenyl or naphthyl can in turn be further substituted by Ci-Csalkyl or Ci- Csalkoxy; allyl which can be substituted one to three times with Ci-C4alkyl; Cs- C7cycloalkyl; Cs-Czcycloalkyl, which can be condensed one or two times by phenyl which can be substituted one to three times with Ci-C4alkyl, halogen, nitro or cyano; C3-Ciealkenyl which can be substituted by halogen; or Cs-Cisalkynyl which can be substituted by halogen, preferably, R¹³ is Ci-Cisalkyl, which can be substituted by halogen, phenyl or naphthyl, whereby phenyl or naphthyl can in turn be further substituted by Ci-Csalkyl or Ci-Csalkoxy, more preferably R¹³ is Ci-Cisalkyl;

R¹¹ and R¹² are preferably, independently from each other, H; Ci-Csalkyl; phenyl or naphthyl which can be substituted by Ci-Csalkyl, Ci-Csalkoxy or halogen; cyano; halogen; amino; hydroxyl; or -COOR¹⁴, wherein R¹⁴ is as defined above; for example R¹¹ and R¹² are H or -COOR¹⁴.

The perylene compounds and their preparation are known, for example, from US 6,326,494, as well as from "Synthesis of Diazodibenzoperylenes...", F. Wurthner et al, J. Org. Chem., 67, 2002, 3037-3044, and "Hierarchical Self-Organisation of Perylene Bisimide...", F. Wurthner et at, Chem. Eur., 6(21 ), 2000, 3871 -3886.

Other examples of radicals useful as D include the following:

wherein R¹¹ , R¹² and R¹³ are as defined above, and

A¹ and A³ are each independently from each other -S-, -S-S-, -CH=CH-,

R¹⁶OOC-C(-)=C(-)-COOR¹⁶, -N=N- or -N(R¹⁷)-, or a linkage selected from organic radicals of formulae

wherein R¹⁷ is H, Ci-Cisalkyl or C5-Ci2cycloalkyl,

R¹⁶ is unsubstituted or substituted Ci-Cisalkyl, C5-Ci2cycloalkyl, phenyl, benzyl, -CO-Ci-C4alkyl, -CO-C6H5 or Ci-C4alkylcarboxylic acid (Ci-C4alkyl) ester, and A² is a linkage of formula

, wherein R¹⁷ is as defined above; - Radicals derived from diketopyrrolopyrroles of formula:

wherein R¹⁸ and R¹⁹ are independently from each other an organic group, and

Ar¹ and Ar² are independently from each other C6-Ci8aryl or C2-Ci8heteroaryl, which can optionally be substituted; preferably, Ar¹ and Ar² are phenyl; 1 - or 2-naphthyl; 3- or 4-biphenylyl; 9-phenanthryl; or 2- or 9-fluorenyl, for example, Ar¹ and Ar² are phenyl, 4- biphenylyl or naphthyl.

Ar¹ and Ar² can be unsubstituted or substituted with, for example, Ci-CsalkyI; Ci- Ci2alkoxy; halogen; cyano; amino; N-mono- or N,N-di-(Ci-Ci2alkyl)amino;

phenylamino, N,N-di-phenylamino, naphthylamino or N,N-di-naphthylamino, wherein phenyl or naphthyl can be further substituted with, for example, Ci-CsalkyI, Ci-Csalkoxy or halogen.

R¹⁸ and R¹⁹ may be the same or different and are, for example, selected from Ci- Ciealkyl, which can be substituted with F, CI, Br or OH; allyl, which can be substituted with Ci-C4alkyl; Cs-Crcycloalkyl, which can be condensed one or two times by phenyl which can be substituted with Ci-C4alkyl, halogen, or cyano; Cs-Cisalkenyl, C3- Cisalkynyl, a ketone, aldehyde, ester, or carbamoyl group. Preferably, R¹⁸ and R¹⁹ are Ci-Ci8alkyl, optionally substituted with F, CI, Br or OH.

D may be derived from an azo dye (formula (XIV) including an azomethine dye (formula XVa) and a disazomethine compound (formula XVb), for example:

B¹ -N=N— B

(XIV),

B¹ -C=N— B B 1 C= -N— N=C— B

H H H

(XVa) and (XVb), wherein B¹ and B² independently from each other are C6-Ci8aryl or C2-Cisheteroaryl, preferably phenyl, naphthyl, imidazole or pyridazine, each of which can be substituted by d-Cealkyl, Ci-C₈alkoxy, phenyl, halogen, -NR²⁰R²¹, or -OR²⁰, wherein R²⁰ and R²¹ are H, Ci-CsalkyI, Ci-Cshydroxyalkyl or phenyl, which phenyl can be further substituted with one of substituents given above for B¹ and B².

With the processes as described herein, generally mixtures of compounds of formula (I) are obtained. If necessary, the compounds can be isolated by methods known to the person skilled in the art, e.g. distillation, chromatography etc.. However, in the context of the present invention isolation of a single component of the prepared mixture is not necessary by all means, as the mixtures of the invention can be used as such, as they exhibit excellent fluorescent properties and meet the requirement of low migration.

Accordingly, in a further aspect the invention relates to a mixture comprising fluorescent compounds of formula (I) in any aspects, as described above. Said mixture may also comprise fluorescent compounds comprising a polyhedral oligomeric silsesquioxane moiety (POSS) having covalently attached an organic chromophoric moiety, wherein said silsesquioxane moiety has a cage structure comprising 6, 7 or 8 silicon atoms within its cage structure, for example derived from ReSisO^ cage.

The mixture may also comprise fluorescent compounds comprising a polyhedral oligomeric metalla-silsesquioxane moiety having covalently attached an organic chromophoric moiety, wherein said silsesquioxane moiety has a cage structure comprising 6, 7 or 8 silicon atoms, wherein one or more silicon atoms are replaced with a metal. The metal may be as defined above. Due to their molecular structure the inventive compounds have a defined molecular weight. Typically, the inventive compounds have a molecular weight of at most 5000 g/mol, preferably between 700 to 3000 g/mol.

Preferably, the invention relates to a mixture wherein fluorescent compounds having cages of 10 to 12 silicon atoms are predominant. In general, said compounds are present in the inventive mixture in an amount of at least 20% by weight, based on the total weight of the composition, preferably more than 30%, more preferably more than 50% by weight.

Examples of possible POSS / POSS' structures are of the following formulae:

Fully condensed silsesquioxanes, e.g.

(XVI-2).

Silica extended silsesquioxanes, e.g.

Siloxane extended silsesquioxanes, e.g.:

Incompletely condensed silsesquioxanes, e.g.:

In the formula (XVI-1 ) to (XVI-1 1 ) the asterix ^* denote the position of different groups R¹, Y linked the chromophoric moiety as defined above and optionally not reacted groups Y'. The inventive compounds may be synthesized by autocatalytic polycondensation of silanes, in particular, by reacting an amino-functionalized silane with at least one further silane to form an amino-functionalized POSS, followed by reacting with a fluorescent colorant. The first step is generally performed such that the rate constants regarding the hydrolysation of the silanes used are approximately in the range. Thus, it can be achieved that the amino-functionalized POSS have a distribution of substituents according to the initial composition of silanes. Prior art, e.g. DE 10 2005 024 815 and DE 10 2005 024 814, discloses a one-pot reaction to form a composition comprising functionalized polyhedral silsesquioxanes, in particular silsesquioxanes having a polymerizable groups, under base or acid catalysis. In a further aspect, the invention relates to a process for preparing a fluorescent compound of formula (I) as described above, which process comprises the steps of a) reacting an amino-functionalized silane with at least one co-reactive silane having at least one group R¹, and

b) treating the product of step a) with a colorant,

wherein step a) is carried out without addition of a further base or acid.

The invention also relates to a process for preparing a mixture comprising fluorescent compound of formula (I), as described above, which process comprises the steps of a) reacting an amino-functionalized silane with at least one co-reactive silane having at least one group R¹, and

b) treating the product of step a) with a colorant,

wherein step a) is carried out without addition of a further base or acid.

In case of forming a metalla-silsesquioxane an appropriate amount of the co-reactive silane of step a) is replaced with an organometallic compound, such as organic titania, organic zirconia or organic alumina.

Preferred is a process, wherein

the amino-functionalized silane is of formula (III) Y'SiZ¹Z²Z³,

the co-reactive silane is of formula (IV), (V) or (VI)

R SiZ Z²Z³ (IV), R ₂ SiZ Z² (V) or SiZ Z²Z³Z⁴ (VI),

Z¹, Z², Z³ and Z⁴ are independently a hydrolyzable group, and

E and R¹ are as defined above; and

R³ is Ci-Cisalkyl, C5-Ci2cycloalkyl or C6-Ci2aryl.

In a preferred embodiment of the invention the amino-functionalized silane is an aminosilane of formula (III'), H2lM-E-SiZ¹Z²Z³, wherein E is Ci-Cisalkylene, preferably Ci-Csalkylene, or o-, m-, p-phenylene, and Z¹ = Z² = Z³ are -OH, d-dsalkoxy or Ci- C₄alkoxy which is substituted by Ci-C₄alkoxy. Particularly preferred are aminoalkyltrialkoxysilanes, i.e. in which E is d-Csalkylene and Z¹ = Z² = Z³ are Ci-C4alkoxy such as 3-amino-n-propyltrimethoxysilane and 3- amino-n-propyltriethoxysilane, most preferred is 3-amino-n-propyltriethoxysilane. Also preferred are amino-phenyl-trialkoxysilanes, in which E is o-, m-, p-phenylene, and Z¹ = Z² = Z³ are Ci-Cisalkoxy or with Ci-C4alkoxy substituted Ci-C4alkoxy, such as o-aminophenyl-, m-aminophenyl-, p-aminophenyl-trialkoxysilanes, preferably p- aminophenyl-trialkoxysilanes. In particular preferred are p-aminophenyl- trialkoxysilanes.

Also mixtures of aminoalkyltrialkoxysilanes and aminoaryltnalkoxysilanes can be used.

Co-reactive silanes of formula (III), (IV), (V) or (VI) are known and commercially available or can be synthesized by known methods.

Preferred organic silanes R¹SiZ¹Z²Z³ of formula (IV) are silanes, wherein Z¹ = Z² = Z³ are -OH, Ci-Cisalkoxy or Ci-C4alkoxy which is substituted Ci-C4alkoxy. Particularly preferred are alkyltrialkoxysilanes, such as methyl, ethyl, n-propyl-, isopropyl-, n-butyl- trialkoxysilanes, and aryltrialkoxysilanes, such as phenyltrialkoxysilanes, wherein phenyl may be substituted by Ci-C4alkyl or halogen.

Preferred organic silanes R¹2 SiZ¹Z² of formula (V) are silanes, wherein Z¹ = Z² = Z³ are -OH, Ci-Cisalkoxy or Ci-C4alkoxy which is substituted Ci-C4alkoxy. Particularly preferred are dialkyldialkoxysilanes, wherein R¹ is independently methyl, ethyl, n- propyl, isopropyl or n-butyl, and diaryldialkoxysilanes, such as diphenyldialkoxysilanes, wherein phenyl may be substituted by Ci-C4alkyl or halogen.

Preferred organic silanes SiZ¹Z²Z³Z⁴ of formula (VI) are e.g. unsubstituted or substituted tetra-d-Csalkoxysilanes such as tetramethoxysilane, tetraethoxysilane (TEOS), tetra-n-propoxysilane, tetra-n-butoxysilane; tetrakis(methoxyethoxy)silane, tetrakis(ethoxyethoxy)silane, tetrakis(methoxyethoxyethoxy)silane,

tetrakis(methoxypropoxy)silane, tetrakis(2-methyl-hexoxy)silane, di-Ci-C4alkyl-tetra-Ci- Cealkoxydisilanes such as dimethyltetraethoxydisiloxane; tetra-Ci-C4acyloxysilanes such as tetraacetoxysilane; tetra-C2-C4alkenyloxysilanes such as tetraallyloxysilane, as well as mixtures thereof, preferably tetraethoxysilane (TEOS) and tetra-n- propoxysilane.

As co-reactive organic alumina such as tri-Ci-C4alkoxy aluminate like tri-n-, -iso- propoxy aluminate, tri-n-butoxy aluminate, but also alkoxy alumina-silica compounds like di-Ci-C4alkoxy aluminoxy tri-Ci-C4alkoxy silanes such as di-butoxy-aluminoxy- triethoxysilane, can be used. As co-reactive organic zirconia such as tetra-Ci-C4alkoxy zirconate like tetra-n-butoxy zirconate, tetraethoxy zirconate, tetra-n-, -isopropoxy zirconate, can be used.

As co-reactive organic titania such as tetra-Ci-C4alkoxy titanate like tetra-n-butyl titanate, tetraethoxy titanate, tetramethoxy titanate, tetra-n-, -iso-propoxy titanate, can be used.

The molar ratio of amino-functionalized silane of formula (III) to co-reactive silane may usually be varied in a wide range. Preferably, the molar ratio of amino-functionalized silane of formula (III) to co-reactive silane of formulae (IV), (V) and/or (VI) is of from

1 :10 to 10:1 , more preferably from 1 :7 to 7:1 , more preferably 1 :7 to 1 :1. If present, the silane of formula (IV) is often used in excess compared to the amino-functionalized silane. In case where silanes of formula (IV) and (VI) are present in step a) the molar ratio of (lll):(IV) may be of from 1 :10 to 1 :1 , preferably from 1 :7 to 1 :3, and the molar ratio of from (lll):(VI) may be of from 10:1 to 5:3, preferably from 5:1 to 5:3.

Step b), i.e. the reaction of the amino-functionalized POSS with a reactive fluorescent chromophore comprising D, i.e. colorant, may be performed via known methods. For example, known methods of preparing a substituted amine, amide, imide, urea or thiourea linkages can be readily employed to couple the desired aminofunctionalized POSS and the chromophore. For example, the inventive compound may be prepared by the reaction of an amino- functionalized POSS obtained by step a) with a reactive colorant (D-hal):

POSS-E-NH2 + D-hal → POSS - E -NHD + H-hal As reactive colorant D-hal known colorants can be used, preferably chemically reactive colorants as mentioned above are used. In particular, preferred are colorants selected from xanthene, perylene, benzoxanthene, naphthalimide, diketopyrrolopyrrole, quinacridone and phthalocyanine. For example, the inventive compound may be prepared by the reaction of an amino- functionalized POSS with a reactive colorant comprising a cyclic anhydride to form an imide within the colorant molecule. In principle, all colorants containing a cyclic anhydride may be used, for example, naphthalic anhydride, N-alkyl-3,4,9,10-perylene tetracarboxylic monoimide monoanhydride or 3,4,9,10-perylene tetracarboxylic dianhydride. The inventive compound may also be prepared by the reaction of an amino- functionalized POSS with a reactive colorant comprising a lactone to form an amide within the colorant molecule. In principle, all colorants containing a lactone may be used, for example, a rhodamine and fluoresceine based compound such as rhodamine B, fluoresceine and the like. According to the process disclosed in WO 03/022848 the fluorescent compounds may be prepared by reacting a substituted diketopyrrolopyrrole

by reacting

wherein A¹, A², A³ may be suitable substituents, with an amino-functionalized POSS. The inventive compound may also be prepared by the reaction of an amino- functionalized POSS with a reactive dyestuff comprising an isothiocyanate group D- N=C=S or an active ester like succinimidyl-ester:

D-N=C=S + R1 R2R3S1-E-N H2 ► D-NH-C(=S)-NH-E-SiRiR₂R₃

Such reactions are well-known in the art, and e.g. a similar reaction is described in Langmuir, 8(12), 1992, 2924.

As reactive dyestuff succinimidylesters and all isothiocyanato group containing dyestuffs can be used such as rhodamine derivatives, preferably tetraethylrhodamine- 5/6-isothiocyanate (TRITC), fluoresceine-5-isothiocyanate (FITC), 7-dimethylamino-4- methylcoumarin-3- isothiocyanate (DACITC), eosin-5-isothiocyanate, erythrosin-5- isothiocyanate, malachite green isothiocyanate and the like. Of course, it is also possible to prepare inventive compounds by using appropriately functionalized POSS and a colorant having a reactive amino group. Appropriately functionalized POSS may have OH, SH, halogen, NCO, NCS and the like.

Preferably, the molar ratio of amino-functionalized silane of formula (III) to colorant is chosen in the range of 1 :1 to 1 :10, more preferably from 1 :1 to 1 :5.

Preferred solvents are organic solvents, in particular polar solvents such as acetonitrile, alcohols like ethanol, methanol, 1 -propanol, 2-propanol, 1 -methoxy-2-propanol, tetrahydrofurane (THF), dioxane, pyridine, N-methylpyrrolidone (NMP),

dimethylformamide (DMF), dimethylacetamide (DMA), ketones like tert- butylmethylketone, preferably ethanol and 2-propanol for step a) and NMP and DMF for step b). Of course, also mixtures of solvents can be used, too. Naturally, other solvents can be used as long as they do not interfere negatively with the reaction. Preferably, step a) is carried out in the presence of water, i.e. water is added in addition to the solvent.

Generally, the reaction is carried out in a temperature range from 0 °C to the boiling point of the reaction mixture, which as a rule is in the range of the boiling point of the used solvent or solvent mixture.

Step a) of the above-mentioned process is of particular interest, if silica-extended amino-functionalized polyhedral oligomeric silsesquioxanes are prepared as precursors. In that case, an amino-functionalized silane as mentioned above may be reacted with silanes of formula (IV), for example, a monoalkyi- or monoaryl-substituted trialkoxysilane, and a silane of formula (VI), for example, a tetraalkyl- or tetraaryl- substituted silane.

Accordingly, in a further aspect, the invention relates to a process for preparing an amino-functionalized polyhedral oligomeric silsesquioxane, wherein said

silsesquioxane has a cage structure comprising at least 9 silicon atoms within its cage structure, which process comprises

reacting an amino-functionalized silane Y'SiZ¹Z²Z³ of formula (III) with at least one silane of formula R¹SiZ¹Z²Z³ (III) and at least one silane of formula SiZ¹Z²Z³Z⁴ (V), wherein

Z¹, Z², Z³ and Z⁴ are independently from each other a hydrolyzable group;

E and R¹ are as defined above; and

R³ is Ci-Cisalkyl, Cs-docycloalkyl or C6-Ci2aryl.

In a further aspect, the invention relates to a fluorescent compound of formula (I), as defined above,

obtainable by a process which process comprises the steps of

a) reacting an amino-functionalized silane having a group Y with at least one co- reactive silane having at least one group R¹, and

b) treating the product of step a) with a colorant,

wherein step a) is carried out without addition of a base or acid.

Further, the invention also relates to a mixture of compounds of formula (I) as described above, obtainable by a process which process comprises the steps of a) reacting an amino-functionalized silane having a group Y with at least one co- reactive silane having at least one group R¹, and

b) treating the product of step a) with a colorant,

wherein step a) is carried out without addition of a base or acid. In a further aspect, the invention relates to a process for preparing a polyfunctional polyhedral oligomeric silsesquioxane comprising treating an amino-functionalized silane in a solvent at elevated temperature, wherein no further base or acid is added. The fluorescent colorants of the present invention can be used in any application wherein pigments and dyes are encountered and are of course valuable in applications where the fluorescence of the colorant provides a useful function as in security marking or bioassays, or imparts a particularly desired color or effect. The colorants are employed in general by methods known per se, for example,

(a) for mass coloring polymers;

(b) for the preparation of paints, paint systems, coating compositions, paper colors, printing colors, inks including ink-jet applications and writing purposes, as well as in electrophotography, e.g. for dry copier systems and laser printers;

(c) for photoresists for color filters (polymer/paint formulation for displays, electronic applications);

(d) for security marking purposes, such as for checks, check cards, currency notes, coupons, documents, identity papers and the like, where a special unmistakable color impression is to be achieved;

(e) as an additive to colorants, such as pigments and dyes, where a specific color shade is to be achieved, in particular, where luminous shades are desired;

(f) for marking objects for machine recognition of these objects via the fluorescence, for example for machine recognition of objects for sorting, examples including the recycling of plastics, alphanumerical prints or barcodes;

(g) for the production of passive display elements for a multitude of display, notice and marking purposes, e.g. passive display elements, notices and traffic signs, such as traffic lights, safety equipment;

(h) for marking with fluorescence in the solid state;

(i) for decorative and artistic purposes;

(j) for modifying inorganic substrates such as aluminum oxide, silicon dioxide, titanium dioxide, tin oxide, magnesium oxide (including "stone wood"), silicates, clay minerals, calcium-, gypsum- or cement-containing surfaces, for example coatings or plaster surfaces;

(k) in optical light collection systems, in fluorescence solar collectors (see Nachr.

Chem. Tech. Lab. 1980, 28, 716), in fluorescence-activated displays (see Elektronik 1977, 26, 6), in cold light sources used for light-induced polymerization for the preparation of plastics, for testing of materials, for example in the production of semiconductor circuits, for analyzing microstructures of integrated semiconductor components, in photoconductors, in photographic processes, in display, illumination or image converter systems, where excitation is effected by electrons, ions or UV radiation, e.g., in fluorescent displays, Braun tubes or in fluorescent lamps, as part of an integrated semiconductor circuit containing dyes as such or in combination with other semiconductors, for example in the form of an epitaxy, in chemiluminescence systems, e.g., in chemiluminescent flashlights, in luminescence immunoassays or other luminescence detection processes, as signal paints, for marking signs and other objects for which a particular visual color impression is to be achieved, in dye lasers, preferably as fluorescent dyes for generating laser beams, as optical recording medium and also as Q-switches;

(I) for converting the frequency of light, e.g., for turning short-wave light into long-wave visible light or for doubling or tripling the frequency of laser light in non-linear optics; (m) for tracer purposes, e.g., in biochemistry, medicine, technology and natural science, where the novel colorants can be linked covalently to the substrates or via secondary valences, such as hydrogen bonds or hydrophobic interactions (adsorption); (n) in cosmetics, e.g. hair dyeing, make-up, and the like; and

(o) in highly sensitive detection processes (see Z. Analyt. Chem. 1985, 320, 361 ), in particular as fluorescent colorants in scintillators.

For example, the compounds of the present invention are used as highly fluorescent colorants for coating, plastics and ink applications, especially in coating and ink applications. In a further aspect, the invention relates to a composition comprising a

a) an organic material, preferably a high molecular weight organic material, and b) a fluorescent compound as described in any aspects above, preferably a mixture comprising fluorescent compounds. The fluorescent compounds of the present invention are either soluble or readily and evenly dispersed in a wide variety of solvents and polymers providing evenly colored systems which retain their color under aging or weathering conditions longer than commonly encountered dyes. The fluorescence of these colored systems is much higher than systems colored by known pigments comprising similar chromophores and this fluorescence is likewise retained under aging or weathering conditions longer than commonly encountered fluorescent dyes.

The use of the fluorescent compounds of the invention is not limited by the manner in which they are incorporated into the final application.

In any composition comprising the present fluorescent compounds, one would naturally expect to find other commonly encountered components including stabilizers, for example antioxidants, UV absorbers, hindered amine or other light stabilizers, phosphites or phosphonites, benzofuran-2-ones, thiosynergists, polyamide stabilizers, metal stearates; also other fluorescent materials, processing aids, solvents etc., nucleating agents, fillers, reinforcing agents, lubricants, emulsifiers, dyes, pigments, dispersents, optical brighteners, flame retardants, antistatic agents, blowing agents and the like.

The amount of the fluorescent compounds of the present invention used in an application will vary greatly depending on the end use and effect desired. Typical load levels are well known to the practitioner or are readily found in the literature and would be adequate starting points for those formulating with the present fluorescent compounds. The fluorescent compounds of the invention can therefore be used in almost any concentration depending on the end use application. While almost any amount of the novel compounds can be incorporated into a high molecular weight organic material, typically the novel fluorescent compounds are used in an amount of 0.01 to 30% by weight, for example 0.1 to 10% by weight, based on the high molecular weight organic material to be colored.

For example, fluorescent compounds of the invention are used to color high molecular weight organic material which may be in the form plastic materials, melts or of spinning solutions, paint systems, coating materials or printing inks, for example, a coating composition comprising an organic film-forming binder and a fluorescent colorant of the invention. Depending on the end use requirement, it may be expedient to use the novel compounds as toners or in the form of preparations. The high molecular weight organic material to be colored in accordance with the invention may be of natural or synthetic origin and usually has a molecular weight in the range of from 10³ to 10⁸ g/mol.

The novel compounds are particularly suitable for the mass coloration of thermoplastic, thermoset and elastomeric polymers which may also be cross-linked. These polymers may be in the form of, for example, molded articles, extruded workpieces, films, sheets, etc., as well as part of paint systems, powder coating compositions, printing inks and other coating materials.

The coloring of the high molecular weight organic materials with the novel compounds is conveniently effected by directly incorporating a said compound by itself or in the form of a masterbatch. Standard incorporation techniques are employed, for example, incorporating the novel colorants into the substrates using roll mills, mixing or milling apparatus. The colored material is then brought into the desired final form by methods which are known per se, e.g., by calendering, molding, extruding, coating, casting, melt mixing, blending, dissolution, injection molding etc. For coloring paint systems, coating materials and printing inks, the novel compounds, together with optional additives such as fillers, other pigments, siccatives or

plasticizers, are finely dispersed or dissolved in suitable carrier such as an organic solvent, water or powder. The procedure may be such that the individual components by themselves, or also several components together, are dispersed or dissolved in the carrier and thereafter all the components are mixed. Accordingly, a preferred embodiment is a composition, wherein the composition is a coating composition and component (a), i.e. the organic high molecular weight material is an organic film-forming binder.

Examples of organic film-forming binders are epoxy resins, polyurethane resins, amino resins, acrylic resins, acrylic copolymer resins, polyvinyl resins, phenolic resins, styrene/butadiene copolymer resins, vinyl/acrylic copolymer resins, polyester resins, UV-curable resins or alkyd resins, or a mixture of two or more of these resins, or an aqueous basic or acidic dispersion of these resins or mixtures of these resins, or an aqueous emulsion of these resins or mixtures of these resins.

Of particular interest are organic film-forming binders for aqueous coating

compositions, such as alkyd resins; acrylic resins, two-component epoxy resins;

polyurethane resins; polyester resins, which are usually saturated; water-dilutable phenolic resins or derived dispersions; water-dilutable urea resins; resins based on vinyl/acrylic copolymers; and hybrid systems based on, for example, epoxy acrylates.

In a further aspect, the invention is directed to the use of the fluorescent compound as described above for coloring an organic material, in particular to use of a mixture of fluorescent compounds as described above for coloring an organic material.

Other applications for the inventive compounds will be apparent to those skilled in the art, and the invention is not limited to the applications disclosed herein.

The inventive fluorescent compounds exhibit improved quantum efficiency, an excellent migration stability, an excellent thermostability as well as excellent storage stability.

Further, the inventive compounds are soluble in many organic solvents and substrates.

The preferences referring to the compounds of formula (I) as described above and in the context of the whole text are intended not to refer to the compounds as such only, but to all categories of the claims, that is to the mixtures comprising said compounds, to compositions comprising said compounds and organic material as well as to the process or use claims.

The examples which follow illustrate the invention, without limiting it. "%" are by weight where not otherwise specified. Examples

1 ) Synthesis of aminofunctionalized POSS as intermediates

Example 1

54 g (0.3 mol) of 3-aminopropyl trimethoxysilane are dissolved in 1 10 g of 2-propanol, followed by adding a mixture of 13.5 g (0.75 mol) of demineralized water and 15 g of 2- propanol within 3 minutes under stirring. The mixture is heated to reflux for 36 hours under stirring, and then 90 g of the solvent are distilled off under nitrogen atmosphere (1013 hPa). 100 g of 2-propanol are added to the residue, and the solvent is distilled off again to dryness. The product is obtained as a clear, transparent viscous paste.

2⁹Si-NMR indicates a total transformation of 3-aminopropyl trimethoxy silane in POSS- cages of different sizes ranging from 7 to 15 Si-membered cages (main components having 10 to 12 Si atoms).

Example 2

63 g (0.35 mol) of 3-aminopropyl trimethoxysilane are dissolved in 125 g of 2-propanol, followed by adding a mixture of 20 g (1.1 1 mol) of demineralized water and 15 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 6 hours under stirring, cooled down to 35°C, and then, a mixture of 10.3 g (0.05 mol) of tetraethoxysilane in 15 g of 2-propanol is added. The mixture is heated to reflux for 30 hours. Then, 90 g of the solvent is distilled off under nitrogen atmosphere (1013 hPa). 100 g of 2-propanol are added, and the solvent is distilled off to dryness. A clear, transparent viscous paste is obtained. ²⁹Si-NMR indicates the presence of silicate units (Q structures) besides silsesquioxane units (T structures). Example 3

63 g (0.35 mol) of 3-aminopropyl trimethoxysilane are dissolved in 125 g of 2-propanol, followed by adding a mixture of 20 g (1.1 1 mol) of demineralized water and 25 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 6 hours under stirring, cooled down to 35°C, and then, a mixture of 20.6 g (0.1 mol) of tetraethoxysilane in 35 g of 2-propanol is added. The mixture is heated to reflux for 30 hours. Then, 120 g of the solvent is distilled off under nitrogen atmosphere (1013 hPa). 100 g of 2-propanol are added, and the solvent is distilled off to dryness. A clear, transparent viscous paste is obtained. Example 4

36 g (0.2 mol) of 3-aminopropyl trimethoxysilane and 36 g (0,2 mol) of i-butyl trimethoxysilane are dissolved in 125 g of 2-propanol, followed by adding a mixture of 20 g (1.1 1 mol) of demineralized water and 25 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 6 hours under stirring, cooled down to 35°C, and then, a mixture of 10.3 g (0.05 mol) of tetraethoxysilane in 25 g of 2-propanol is added. The mixture is heated to reflux for 30 hours. Then, 90 g of the solvent is distilled off under nitrogen atmosphere (1013hPa). 1 10 g of 2-propanol are added, and the solvent is distilled off to dryness. A clear, transparent viscous paste is obtained. ²⁹Si- NMR indicates the presence of silicate units (Q structures) besides silsesquioxane units (T structures). Example 5

18 g (0.1 mol) of 3-aminopropyl trimethoxysilane and 54 g (0.3 mol) of i-butyl trimethoxysilane are dissolved in 125 g of 2-propanol, followed by adding a mixture of 21 g (1.16 mol) of demineralized water and 30 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 6 hours under stirring, cooled down to 35°C, and then, a mixture of 20.6 g (0.1 mol) of tetraethoxysilane in 30 g of 2-propanol is added. The mixture is heated to reflux for 30 hours. Then, 120 g of the solvent is distilled off under nitrogen atmosphere (1013 hPa). 120 g of 2-propanol are added, and the solvent is distilled off to dryness. A clear, transparent viscous paste is obtained. Example 6

18 g (0.1 mol) of 3-aminopropyl trimethoxysilane, 54 g (0,3 mol) of i-butyl

trimethoxysilane and 6 g (0.05 mol) of dimethyldimethoxy silane are dissolved in 140 g of 2-propanol, followed by adding a mixture of 21 g (1.16 mol) of demineralized water and 30 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 48 hours under stirring. Then, 120 g of the solvent is distilled off under nitrogen atmosphere (1013hPa). 120 g of 2-propanol are added, and the solvent is distilled off to dryness. A clear, transparent viscous paste is obtained.

Example 7

The procedure of Synthesis Example 6 is repeated except from that 12 g (0.1 mol) of dimethyldimethoxy silane are used. A clear, transparent viscous paste is obtained.

2) Synthesis of fluorescent compounds

4.5 g (0,015 mol) of 2 (prepared according to Example 1 (a) of WO 2008/138727 A1 ) are dissolved in 10 ml of N-methyl-2-pyrrolidone (NMP) at 88°C, the solution is added to a solution of 15 g (0.017 mol) of 3-aminopropyl-hepta-i-butyl POSS 1 (AM0265 Hybrid Plastics) in 40 g of NMP and stirred at 88°C for 24 hours. Then, the brownish solution is cooled down to 30°C and diluted with 100 ml of 2-propanol. 1 .5 I of demineralized water are added, wherein a yellow product is precipitated. Addition of 50 ml of saturated sodium chloride solution enables further precipitation. The suspension is stirred for 12 hours, and the solid is filtered off. The press cake is washed three times with 100 ml of water, air dried and at a reduced pressure at 60°C for 24 hours. 3 is obtained as a yellow fluorescent solid. Yield: 17.4 g.

2 g (8.62 mmol) of 4-chloronaphthalic anhydride are dissolved in 10 ml NMP at 88°C, the solution is added to a solution of 15 g (17 mmol) of 1 (AM0265 from Hybrid

Plastics) in 30 g of NMP and 25 g of 2-propanol and stirred at 88°C for 24 hours. Then, the brownish yellow solution is cooled down to 30°C and diluted with 100 ml of 2- propanol. 1 .5 I of demineralized water are added, wherein a yellow product is precipitated. Addition of 50 ml of saturated aqueous sodium chloride solution enables further precipitation. The suspension is stirred for 12 hours, and the solid is filtered off. The press cake is washed three times with 100 ml of water, air dried and at a reduced pressure at 60°C for 24 hours. 2 is obtained as a yellow fluorescent solid. Yield: 15.3 g. Example 8

9 g (0.05 mol) of 3-aminopropyl trimethoxysilane and 63 g (0.35 mol) of i-butyl trimethoxysilane are dissolved in 170 g of 2-propanol, followed by adding a mixture of 21 g (1.16 mol) of demineralized water and 40 g of 2-propanol within 3 minutes under stirring. The obtained mixture is heated to reflux for 24 hours under stirring, cooled down to 35°C, and then a mixture of 10.3 g (0.05 mol) of tetraethoxysilane in 20 g of 2- propanol is added under stirring. The mixture is heated again to reflux for 30 hours. Then, 180 g of the solvent are distilled off under nitrogen atmosphere (1013 hPa). 150 g of 2-propanol are added to the residue, and the solvent is distilled off again nearly to dryness. The resulting clear, transparent viscous paste is diluted with 60 ml of 2- propanol and 60 g of NMP and stirred at 65°C until a solution is obtained.

Then, 4.64 g (0,02 mol) of 4-chloronaphthalic anhydride are added under stirring, and temperature is raised to 88°C. After 24 hours the brownish solution is cooled down to 30°C, diluted with 300 ml of 2-propanol and stirred. 2.5 I of demineralized water are added wherein a yellow product is precipitated. Addition of 50 ml of saturated sodium chloride solution enables further precipitation. The yellow suspension is stirred for additional 12 hours and filtered off. The press cake is washed three times with 300 ml of water, dried at air and finally at reduced pressure at 60°C for 24 hours. A yellow fluorescent product is obtained which is soluble in THF, chloroform. Yield: 50g.

Example 9

9 g (0.05 mol) of 3-aminopropyl trimethoxysilane and 63 g (0.35 mol) of i-butyl trimethoxysilane are dissolved in 170 g of 2-propanol, followed by adding a mixture of 21 g (1.16 mol) of demineralized water and 40 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 24 hours under stirring, cooled down to 35°C and then a mixture of 20.8 g (0.1 mol) of tetraethoxysilane in 35 g of 2-propanol is added. The mixture is heated again to reflux for 30 hours. Then, 180 g of the solvent are distilled off under nitrogen atmosphere (1013hPa). 150 g of 2-propanol are added to the residue, and the solvent is distilled off again nearly to dryness. The resulting clear, transparent viscous paste is diluted with 60 ml of 2-propanol and 60 g of NMP and stirred at 65°C until a solution is obtained.

Then, 4.64 g (0.02 mol) of 4-chloronaphthalic anhydride are added under stirring, and temperature is raised to 89°C. After 24 hours the brownish solution is cooled down to 30°C, diluted with 300 ml of 2-propanol. 2.5 I of demineralized water are added, wherein a yellow product is precipitated. Addition of 50 ml of saturated sodium chloride solution enables further precipitation. The yellow suspension is stirred for 12 hours, and the product is filtered off. The press cake is washed three times with 300 ml of water, dried at air and finally at a reduced pressure at 60°C for 24 hours. A yellow fluorescent product is obtained which is soluble in THF and chloroform. Yield: 58 g.

Example 10

18 g (0.1 mol) of 3-aminopropyl trimethoxysilane and 54 g (0.3 mol) of i-butyl trimethoxysilane are dissolved in 125 g of 2-propanol, followed by adding a mixture of 21 g (1.16 mol) of demineralized water and 30 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 18 hours under stirring, cooled down to 35°C and then, a mixture of 20.6 g (0,1 mol) of tetraethoxysilane in 30 g of 2-propanol is added. The mixture is heated again to reflux for 30 hours. Then, 120 g of the solvent is distilled off under nitrogen atmosphere (1013 hPa). 120 g of 2-propanol are added to the residue, and the solvent is distilled off again nearly to dryness. The resulting clear, transparent viscous paste is diluted with 90 g of NMP and stirred at 65°C until a solution is obtained. Then, 12 g (0.04 mol) of 4-chloronaphthal pentylimide are added under stirring, and temperature is raised to 89°C. After 24 hours the brownish solution is cooled down to 30°C, diluted with 300 ml of 2-propanol. Then, 2.5 I of demineralized water are added, wherein a yellow product is precipitated. Addition of 50 ml of saturated sodium chloride solution enables further precipitation. The suspension is stirred for 12 hours, and the product is filtered off. The press cake is washed three times with 300 ml of water, dried at air and further at a reduced pressure at 60°C for 24 hours. A yellow fluorescent product is obtained which is soluble in THF and chloroform. Yield: 56 g. Example 1 1

9 g (0.05 mol) of 3-aminopropyl trimethoxysilane and 63 g (0.35 mol) of isobutyl trimethoxysilane are dissolved in 150 g of neat 2-propanol, followed by adding a mixture of 21 g (1 .16 mol) of demineralized water and 30 g of 2-propanol within 3 minutes under stirring. The mixture is heated to reflux for 48h under stirring. Then, 150 g of the solvent are distilled off under nitrogen atmosphere (1013hPa). 150 g of 2- propanol are added to the residue, and the solvent is distilled off again nearly to dryness. The resulted clear, transparent viscous paste is diluted with 90 g of NMP and stirred at 65°C until a solution is obtained.

Then, 12 g (0.04 mol) of 4-chloronaphthal pentylimide are added under stirring, and the temperature is raised to 89°C. After 24 hours the brownish solution is cooled down to 30°C, diluted with 300 ml of 2-propanol. Then, 2.5 I of demineralized water are added, wherein a yellow product is precipitated. Addition of 50 ml of saturated sodium chloride solution enables further precipitation. The suspension is stirred for 12 hours, and the product is filtered off. The press cake is washed three times with 300 ml of water, air dried and finally at a reduced pressure at 60°C for 24 hours. A yellow fluorescent product is obtained which is soluble in THF, chloroform. Yield: 48 g.

Application Example: Migration resistance

0.2 g of the product of Examples 8 to 1 1 , 26.6 g of PVC (EVIPOL^®SH 7020, EVC GmbH, Frankfurt/Main) and 14.6 g of a mixture of stabilizer consisting of 92.21 % of a softening agent (diisodecyl phthalate, Vestinol, Huls Chemie), 4.19% of a rheology stabilizer (Rheoplast^®39, Ciba) and 3.60% of a Ba/Zn stabilizer (lrgastab^®BZ 561 , Ciba) are calandered to a PVC-foil having a thickness of 0.5 mm and a content of 0,5% by weight, based on the total weight of the foil, of the corresponding Example. A migration test (measured during 24 hours at 80°C and a pressure of 1 kg/cm², with heat stress during 30 min at 180°C) showed no or essentially no migration which results are illustrated in Table 1 : Table 1 :

Migration scale from 1 to 5, wherein 5 = very good, i.e. no migration; 1 = bad.

Claims

Claims 29

1. A fluorescent compound of formula

(I), wherein

E is a direct bond or a linking group,

D is an organic chromophoric moiety,

Q is -E-POSS', said POSS' independently has the same or different meaning as the POSS of formula (I),

x + y is a number of from 1 to 4 and x is a number of from 0 to 3; and

POSS and POSS' are independently from each other a polyhedral oligomeric silsesquioxane moiety having a cage structure comprising at least 9 silicon atoms within its cage structure.

2. A compound according to claim 1 , wherein the POSS and/or POSS' moieties are a structure of formula [(R¹m Yn Xo SiOi.₅)r (R¹ _P Xq SiO)_s ] (II), wherein

R¹ is independently from each other Ci-Cisalkyl, C5-Ci2cycloalkyl, Cs-Cisalkenyl, C5-Ci2cycloalkenyl, Cs-Cisalkynyl, C7-Cisaralkyl, C6-Ci8aryl or C2-Ci8heteroaryl;

Y is an amino group or an amino substituted group,

X is independently from each other OH, CI, Br, I, or d-dsalkoxy,

m, n and o are independently 0 or 1 , wherein m+n+o = 1 ;

p and q are independently 0, 1 or 2, wherein p+q = 2;

r+s is a number of 9 to 32, wherein s < r, and

the chromophoric moiety is bound to at least one amino group of Y.

3. A compound according to claim 1 or 2, wherein the ratio of the sum of POSS and POSS' moieties to the sum of chromophoric moieties is 1 :2 to 2:1.

4. A compound according to claims 2 or 3, wherein the POSS and/or POSS' moieties comprise at least one siloxane unit of formula (R¹2 SiO), wherein R¹ may have the same or different meaning, preferably the same.

5. A compound according to claims 2 or 3, wherein the POSS and/or POSS' moieties comprise at least one silicate unit selected from formulae (XS1O1.5), (X2S1O) or (R XSiO).

6. A compound according to claims 1 to 5, wherein the linking group is Ci-Cisalkylene, C3-Ci2alkenylene, C5-Ci2cycloalkylene, C6-Ci2arylene; Cz-Cisaralkylene, or C3- dsalkylene which is interrupted by N(R²), O, CO; COO; CON(R²), wherein R² is H, Ci- Ci2alkyl, C5-Ci2cycloalkyl or C6-, C10- or Ci2aryl.

7. A compound according to claims 1 to 6, wherein the chromophoric moiety D is a radical of a chromophore selected from the group consisting of azo dyes,

benzoxanthenes, naphthalimides, diketopyrrolopyrroles, perylenes, quinacridones, diphenylmaleimides, acetoacetamides, perylenemonoimides and phthalimides.

8. A mixture comprising compounds according to claims 1 to 7.

9. A process for preparing a compound according to claims 1 to 7, which process comprises the steps of

a) reacting an amino-functionalized silane with at least one co-reactive silane having a group R¹, and

b) treating the product of step a) with a colorant,

wherein step a) is carried out without addition of a further base or acid.

10. A process according to claim 9, wherein

the amino-functionalized silane is of formula (III) Y'SiZ¹Z²Z³,

the co-reactive silane is of formula (IV), (V) or (VI)

R SiZ Z²Z³ (IV), R ₂ SiZ Z² (V) or SiZ Z²Z³Z⁴ (VI),

Z¹, Z², Z³ and Z⁴ are independently a hydrolyzable group, and

E is as defined in claim 1 ;

R³ is Ci-Cisalkyl, C5-Ci2cycloalkyl or C6-Ci2aryl, and

R¹ is independently from each other as defined in claim 2.

1 1 . A process according to claim 10, wherein the molar ratio of the amino- functionalized silane of formula (III) : co-reactive silane is of from 1 : 10 to 10:1.

12. A composition comprising

a) an organic material, and

b) a compound according to claims 1 to 7 or a mixture according to claim 8.

13. A composition according to claim 12, wherein the composition is a coating composition and component (a) is an organic film-forming binder.

14. The use of the compound according to claims 1 to 7 or a mixture according to claim 8 for coloring an organic material.