Fluorescent compounds

Abstract

The present invention relates to fluorescent compounds with large Stokes-shift and a process for their preparation. More particularly, the present invention relates to fluorescent compounds that are colorless. The compounds may be used in compositions for inks, paints and plastics, especially in a wide variety of printing systems and are particularly well-suited for security applications.

Claims

1. A method of security printing, the method comprising: contacting a compound with a substrate; wherein said compound has a formula (I) ##STR00060## wherein R.sup.1 and R.sup.1 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy; R.sup.2 and R.sup.2 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.3 and R.sup.3 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.8alkoxy, R.sup.4 and R.sup.4 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, or one or more pairs of two substituents selected from the group consisting of R.sup.1 and R.sup.2, R.sup.1 and R.sup.2, R.sup.3 and R.sup.4, and R.sup.3 and R.sup.4 together form a group ##STR00061## wherein R.sup.105, R.sup.106, R.sup.107 and R.sup.108 are each independently H, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl interrupted by O, C.sub.1-C.sub.18alkoxy, or C.sub.1-C.sub.18alkoxy interrupted by O, and Y is a group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3, wherein Y.sup.1 and Y.sup.3 are independently of each other a substituted, or unsubstituted arylene group having 6 to 10 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 3 to 9 ring carbon atoms, Y.sup.2 is O, S, NR.sup.12, SO.sub.2, C(O), (CR.sup.8R.sup.9).sub.n4, O(CR.sup.10R.sup.11).sub.n5O, R.sup.8 and R.sup.9 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.10 and R.sup.11 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.12 is H, or a C.sub.1-C.sub.8alkyl group, or a C.sub.6-C.sub.10aryl group, n1 is 1, or 2, n2 is 0, or 1, n3 is 1, or 2, n4 is an integer of 1 to 4 and n5 is an integer of 1 to 4.

2. A method of improving a fastness property of a print, the method comprising: contacting a printing ink formulation comprising a compound with a substrate; wherein said compound has a formula (I) ##STR00062## wherein R.sup.1 and R.sup.1 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy; R.sup.2 and R.sup.2 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.3 and R.sup.3 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.4 and R.sup.4 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, or one or more pairs of two substituents selected from the group consisting of R.sup.1 and R.sup.2, R.sup.1 and R.sup.2, R.sup.3 and R.sup.4, and R.sup.3 and R.sup.4 together form a group ##STR00063## wherein R.sup.105, R.sup.106, R.sup.107 and R.sup.108 are each independently H, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl interrupted by O, C.sub.1-C.sub.18alkoxy, or C.sub.1-C.sub.18alkoxy interrupted by O, and Y is a group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3, wherein Y.sup.1 and Y.sup.3 are independently of each other a substituted, or unsubstituted arylene group having 6 to 10 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 3 to 9 ring carbon atoms, Y.sup.2 is O, S, NR.sup.12, SO.sub.2, C(O), (CR.sup.8R.sup.9).sub.n4, O(CR.sup.10R.sup.11).sub.n5O, R.sup.8 and R.sup.9 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.10 and R.sup.11 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.12 is H, or a C.sub.1-C.sub.8alkyl group, or a C.sub.6-C.sub.10aryl group, n1 is 1, or 2, n2 is 0, or 1, n3 is 1, or 2, n4 is an integer of 1 to 4 and n5 is an integer of 1 to 4.

3. A printing ink formulation, comprising: a) at least one compound, b) a polymeric binder, c) a solvent, d) optionally a colorant, and e) optionally a further additive; wherein said compound has a formula (I) ##STR00064## wherein R.sup.1 and R.sup.1 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy; R.sup.2 and R.sup.2 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.3 and R.sup.3 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.4 and R.sup.4 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, or one or more pairs of two substituents selected from the group consisting of R.sup.1 and R.sup.2, R.sup.1 and R.sup.2, R.sup.3 and R.sup.4, and R.sup.3 and R.sup.4 together form a group ##STR00065## wherein R.sup.105, R.sup.106, R.sup.107 and R.sup.108 are each independently H, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl interrupted by O, C.sub.1-C.sub.18alkoxy, or C.sub.1-C.sub.18alkoxy interrupted by O, and Y is a group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3, wherein Y.sup.1 and Y.sup.3 are independently of each other a substituted, or unsubstituted arylene group having 6 to 10 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 3 to 9 ring carbon atoms, Y.sup.2 is O, S, NR.sup.12, SO.sub.2, C(O), (CR.sup.8R.sup.9).sup.n4, O(CR.sup.10R.sup.11).sub.n5O, R.sup.8 and R.sup.9 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.10 and R.sup.11 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.12 is H, or a C.sub.1-C.sub.8alkyl group, or a C.sub.6-C.sub.10aryl group, n1 is 1, or 2, n2 is 0, or 1, n3 is 1, or 2, n4 is an integer of 1 to 4 and n5 is an integer of 1 to 4.

4. The printing ink formulation of claim 3, comprising a) 0.0001 to 25% by weight of the compound, b) 5 to 74% by weight of the polymeric binder, c) 1 to 94.9999% by weight of the solvent, d) 0 to 25% by weight of the colorant, and e) 0 to 25% by weight of the further additive, wherein the sum of components a) to e) is 100%.

5. A security document, comprising: a substrate and a compound of formula (I) ##STR00066## wherein R.sup.1 and R.sup.1 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy; R.sup.2 and R.sup.2 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.3 and R.sup.3 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, R.sup.4 and R.sup.4 are each independently hydrogen, C.sub.1-C.sub.18alkyl, substituted C.sub.1-C.sub.18alkyl, C.sub.6-C.sub.24aryl, substituted C.sub.6-C.sub.24aryl, C.sub.6-C.sub.24heteroaryl, substituted C.sub.6-C.sub.24heteroaryl, halogen, or C.sub.1-C.sub.18alkoxy, or one or more pairs of two substituents selected from the group consisting of R.sup.1 and R.sup.2, R.sup.1 and R.sup.2, R.sup.3 and R.sup.4, and R.sup.3 and R.sup.4 together form a group ##STR00067## wherein R.sup.105, R.sup.106, R.sup.107 and R.sup.108 are each independently H, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.18alkyl interrupted by O, C.sub.1-C.sub.18alkoxy, or C.sub.1-C.sub.18alkoxy interrupted by O, and Y is a group of formula (Y.sup.1).sub.n1(Y.sup.2).sup.n2(Y.sup.3).sub.n3, wherein Y.sup.1 and Y.sup.3 are independently of each other a substituted, or unsubstituted arylene group having 6 to 10 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 3 to 9 ring carbon atoms, Y.sup.2 is O, S, NR.sup.12, SO.sub.2, (CR.sup.8R.sup.9).sub.n4, O(CR.sup.10R.sup.11).sub.n5O, R.sup.8 and R.sup.9 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.10 and R.sup.11 are independently of each other H, or a C.sub.1-C.sub.8alkyl group, R.sup.12 is H, or a C.sub.1-C.sub.8alkyl group, or a C.sub.6-C.sub.10aryl group, n1 is 1, or 2, n2 is 0, or 1, n3 is 1, or 2, n4 is an integer of 1 to 4 and n5 is an integer of 1 to 4.

6. A security document, obtained by a printing process comprising contacting the printing ink formulation of claim 3 with a substrate.

7. The security document of claim 5, which is a bank note, a passport, a check, a voucher, an ID- or transaction card, a stamp or a tax label.

8. The method of claim 1, wherein the group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3 is at least one selected from the group consisting of ##STR00068##

9. The method of claim 2, wherein the group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3 is at least one selected from the group consisting of ##STR00069##

10. The printing ink formulation of claim 3, wherein the group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3 is at least one selected from the group consisting of ##STR00070##

11. The security document of claim 5, wherein the group of formula (Y.sup.1).sub.n1(Y.sup.2).sub.n2(Y.sup.3).sub.n3 is at least one selected from the group consisting of ##STR00071##

Description

EXAMPLES

Example 1

(1) ##STR00019##

(2) 18.5 parts of anthanilic acid are dissolved in 60 parts of pyridine at 22 C. Over a period of 2.5 hours 21.5 parts of thionyl chloride are added at 1-5 C. to the stirred solution. After a further hour of stirring the mixture is added to 28 parts of water. The mixture is heated for 30 minutes at 80 C. The mixture is filtered and washed with water to give 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-one as a yellow solid (81% yield).

(3) 19.9 parts of 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-one are dissolved in 68.1 parts of pyridine at 22 C. Over a period of 5 minutes 12.0 parts of biphenyl-4,4-disulphonyl chloride are added at 40 C. to the stirred solution. After a 2.0 hour of stirring the mixture is filtered and washed with water to give the product as yellow solid (54% yield).

Example 2

(4) ##STR00020##

(5) 24.3 parts of 3-amino-2-naphthoic acid are dissolved in 44.2 parts of pyridine at 22 C. Over a period of 2.5 hours 31.5 parts of thionyl chloride are added at 1-5 C. to the stirred solution. After a further hour of stirring the mixture is added to 28 parts of water. The mixture is heated for 30 minutes at 80 C. The mixture is filtered and washed with water to give 2-(3-amino-naphthalen-2-yl)-naphtho[2,3-d][1,3]oxazin-4-one2-as a yellow solid (28% yield).

(6) 5.6 parts of 2-(3-amino-naphthalen-2-yl)-naphtho[2,3-d][1,3]oxazin-4-one are dissolved in 91.6 parts of pyridine at 22 C. Over a period of 5 minutes 2.8 parts of biphenyl-4,4-disulphonyl chloride are added at 40 C. to the stirred solution. After a 2.0 hour of stirring the mixture is filtered and washed with water to give the product as yellow solid (27% yield).

(7) The compounds shown in the Table below are prepared in analogy to compounds A-1 and A-25.

(8) TABLE-US-00001 Fluorescence Compound R.sup.1 R.sup.2 R.sup.3 R.sup.4 Y colour.sup.4) A-1 H H H H YG A-2 H H H H G A-3 H H H H YG A-4 H H H H YG A-5 H H H H YG A-6 H H H H Y A-7 H H H H GYG A-8 H H H H YG A-9 H CH.sub.3 CH.sub.3 H 0 Y A-10 H CH.sub.3 CH.sub.3 H YG A-11 H CH.sub.3 CH.sub.3 H Y A-12 H CH.sub.3 CH.sub.3 H Y A-13 H CH.sub.3 CH.sub.3 H YG A-14 H CH.sub.3 CH.sub.3 H Y A-15 H CH.sub.3 CH.sub.3 H GYG A-16 H CH.sub.3 CH.sub.3 H GYG A-17 OCH.sub.3 H H OCH.sub.3 Y A-18 OCH.sub.3 H H OCH.sub.3 YG A-19 OCH.sub.3 H H OCH.sub.3 0 Y A-20 OCH.sub.3 H H OCH.sub.3 Y A-21 OCH.sub.3 H H OCH.sub.3 YG A-22 OCH.sub.3 H H OCH.sub.3 Y A-23 OCH.sub.3 H H OCH.sub.3 GYG A-24 OCH.sub.3 H H OCH.sub.3 GYG A-25 .sub.2) .sub.2) .sub.3) .sub.3) G A-26 .sub.2) .sub.2) .sub.3) .sub.3) G A-27 .sub.2) .sub.2) .sub.3) .sub.3) Y A-28 .sub.2) .sub.2) .sub.3) .sub.3) Y A-29 .sub.2) .sub.2) .sub.3) .sub.3) 0 Y A-30 .sub.2) .sub.2) .sub.3) .sub.3) Y A-31 .sub.2) .sub.2) .sub.3) .sub.3) Y A-32 .sub.2) .sub.2) .sub.3) .sub.3) Y A-33 H H H H YG A-34 H CH.sub.3 CH.sub.3 H YG A-35 OCH.sub.3 H H OCH.sub.3 YG A-36 .sub.2) .sub.2) .sub.3) .sub.3) YG

APPLICATION EXAMPLES

Application Example 1 (Printing)

(9) A fluorescent offset ink is prepared containing 10.0 weight percent on solids of the compound A-2 from example 1. The ink is prepared on a 3-roll mill and comprises 10 weight percent of high tack varnish (CAS 68458-35-5, alkyd resin), 86.5 weight percent of a commercial offset varnish and 1 weight percent of a drying agent (based on CAS 136-52-7; cobalt bis (2-ethylhexanoate) and oleic acid, CAS 112-80-1). The ink is printed by an offset printing equipment to banknote paper. The print is visually almost colorless, but is shows green fluorescence under UV-light (365 nm). The print exhibits excellent light fastness and very good resistance against all types of solvents, acids, bases, hydrogen peroxide, hypochlorite, sodium sulfite, boiling water etc.

Comparative Application Example 1 (Printing)

(10) By proceeding as indicated in Application Example 1, but using 2-(2-(2-naphtalenesulphonylamino)phenyl)-4H-3,1-benzoxazin-4-one (EP0314350) as fluorescent pigment with the structure indicated below, is likewise obtained a colorless offset print having excellent fastness to light.

(11) ##STR00059##

(12) Resistance against solvents like ethanol, white spirit, acids, bases, hydrogen peroxide synthetic sweat and detergents is excellent. But resistance against solvents like toluene, acetone, boiling water or against aggressive chemicals like hypochlorite is not sufficient for banknote printing.

(13) For testing procedure cf. Chemical and Physical Resistance in Extract of the ANNEX 13 of the Technical Specification for Euro banknote production (European Central Bank; July 2004).

(14) In the following Table the test results of the critical fastnesses are given for Application Example 1 and Comparative Application Example 1.

(15) TABLE-US-00002 Resistance Application Comparative Application against: Example 1 Example 1 Acetone 4 0 Toluene 4 0 Ethylacetate 4 0 sope 4 0

(16) Evaluation by UV-Light (365 nm)

(17) Ranking List According to the European Central Bank

(18) 4: no change or minor changes not visible with naked eyes

(19) 3: minor change

(20) 2: considerable change; less than 50% damaged

(21) 1: major change; more than 50% damaged

(22) 0: element disappeared