Reversibly thermochromic compositions

1. A reversibly thermochromic system comprising

a) a 6,11-dihydroxy-naphthacene-5,12-dione and

b) a base with a molecular weight of at least 300,

wherein the base b) is an secondary or tertiary amine

where the secondary or tertiary amine is of formula NHR 26 R 27 or NHR 26 R 27 R 28 where

R 26 , R 27 and R 28 are independently C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 2 -C 30 alkenyl, C 8 -C 12 aralkenyl, C 2 -C 30 alkynyl or C 8 -C 12 aralkynyl, which are unsubstituted or substituted by one or more COO—R 21 , CONR 21 R 22 , OCO—R 23 , NR 21 CO—R 23 , NR 23 R 21 , O—R 23 , S—R 23 , SO—R 23 and/or S(═O) 2 —R 23 ; or the aralkyl, aralkenyl and aralkynyl are substituted by C 1 -C 30 alkyl, C 2 -C 30 alkenyl and/or C 2 -C 30 alkynyl,

R 23 is C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkenyl or C 8 -C 12 aralkynyl and R 21 and R 22 are independently H or as defined for R 23 or

the secondary or tertiary amine is of formula III

wherein G 4 , G 5 , G 6 and G 7 are independently methyl or ethyl,

E is hydrogen, C 1 -C 18 alkyl or C 3 -C 18 alkenyl and

E 10 is a carbon atom which is unsubstituted or substituted by OH, ═O or by one or two organic residues containing in total 1-500 carbon atoms,

wherein said reversibly thermochromic system demonstrates a reversibly thermochromic property.

2. A reversibly thermochromic system of claim 1 , wherein component a) is a compound of formula (I) or one of the tautomers thereof

wherein

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 independently are H, C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, C 1 -C 30 alkylsulfoxyl, C 1 -C 30 alkylsulfonyl, C 2 -C 30 alkenyl, C 8 -C 12 aralkenyl, C 2 -C 30 alkenyloxy, C 2 -C 30 alkenylthio, C 2 -C 30 alkenylsulfoxyl, C 2 -C 30 alkenylsulfonyl, C 2 -C 30 alkynyl, C 8 -C 12 aralkynyl, C 2 -C 30 alkynyloxy, C 2 -C 30 alkynylthio, C 2 -C 30 alkynylsulfoxyl, C 2 -C 30 alkynylsulfonyl, C 6 -C 10 aryl, C 6 -C 10 aryloxy, C 6 -C 10 arylthio, C 6 -C 10 arylsulfoxyl, C 6 -C 10 arylsulfonyl, halogen, NO 2 , CN, COO—R 9 , OCO—R 10 , CO—NR 9 R 11 or NR 12 CO—R 13 , whereby the alkyl, alkenyl, alkynyl, aryl and aralkyl are substituted or unsubstituted,

or R 2 , R 3 , R 6 and/or R 7 are hydroxy;

or two adjacent groups of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 form a 5- or 6-membered alicyclic or heterocyclic ring structure together with the two carbon atoms they are directly connected to;

or two of the substituents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are defined as follows:

one substituent is the group

and the other substituent is the group

 so the part of the one substituent with the open bracket and the part of the other substituent with the open bracket form together with the part of the molecule they are both attached to a monomer unit that is x times part in an oligomer or polymer;

R 10 and R 13 are independently C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkenyl, C 8 -C 12 aralkynyl or an organic polymer, whereby the alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl and aralkynyl are substituted or unsubstituted;

R 9 is H or as defined for R 10 ;

R 11 and R 12 are independently H or C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkenyl or C 8 -C 12 aralkynyl, whereby the alkyl, alkenyl, alkynyl, aryl aralkyl, aralkenyl and aralkynyl are substituted or unsubstituted;

V is independently CH 2 , S, SO or SO 2 ;

G is C 1 -C 30 alkylene;

L and L′ are A or B; if L is A, then L′ is B; if L is B, then L ′ is A;

A is 0, S or NR 14 ;

R 14 is H, C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkynyl or C 8 -C 12 aralkenyl;

B is CO;

G 2 is C 1 -C 30 alkylene; said alkylene is optionally interrupted by O, S, SO, SO 2 , NR 14 or G 2 is one of the groups

R 15 is H or CH 3 ;

q, r and s are independently integers from 1 to 20;

R 16 is NH 2 , NHR 14 or

R 17 and R 18 are independently as defined for R 14 or

R 19 and R 20 are independently C 1 -C 20 alkylene;

G 3 has the same meanings as G 2 ;

T is H, if L is A; T is OH, if L=B;

x and y are independently integers from 1 to 20;

z is an integer from 0 to 20;

the substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl and aralkynyl are substituted by halogen, hydroxy, nitro, cyano, COO—R 21 , CONR 21 R 22 , OCO—R 23 , NR 21 CO—R 23 , NR 21 R 22 , O—R 23 S—R 23 SO—R 23 and/or S(═O) 2 —R 23 ; or the substituted aryl, aralkyl, aralkenyl and aralkynyl are substituted by C 1 -C 30 alkyl, C 2 -C 30 alkenyl and/or C 2 -C 30 alkynyl;

R 23 is C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 312 aralkenyl or C 8 -C 12 aralkynyl; and

R 21 and R 22 are independently H or as defined for R 23 .

3. A reversibly thermochromic system of claim 2 , wherein

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 independently are H, C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, C 1 -C 30 alkylsulfoxyl, C 1 -C 30 alkylsulfonyl, C 2 -C 30 alkenyl, C 8 -C 12 aralkenyl, C 2 -C 30 alkenyloxy, C 2 -C 30 alkenylthio, C 2 -C 30 alkenylsulfoxyl, C 2 -C 30 alkenylsulfonyl, C 2 -C 30 alkynyl, C 8 -C 12 aralkynyl, C 2 -C 30 alkynyloxy, C 2 -C 30 alkynylthio, C 2 -C 30 alkynylsulfoxyl, C 2 -C 30 alkynylsulfonyl, C 6 -C 10 aryl, C 6 -C 10 aryloxy, C 6 -C 10 arylthio, C 6 -C 0 arylsulfoxyl, C 6 -C 10 arylsulfonyl, halogen, NO 2 , CN, COO—R 9 , OCO—R 10 , CO—NR 9 R 11 or NR 12 CO—R 13 , whereby the alkyl, alkenyl, alkynyl, aryl and aralkyl are substituted or unsubstituted,

or R 2 , R 3 , R 6 and/or R 7 are hydroxy:

or two adjacent groups of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 form a 5- or 6-membered alicyclic or heterocyclic ring structure together with the two carbon atoms they are directly connected to, whereby the ring structure optionally contains one or two carbonyl groups and/or one or two hetero atoms, that are O, N, S, Se and/or P; the said ring structure is unsubstituted or substituted by C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, unsubstituted or substituted C 6 -C 10 aryl, halogen, hydroxy, nitro, cyano, COO—R 21 , CONR 21 R 22 , OCO—R 23 NR 21 CO—R 23 NR 21 R 22 , O—R 23 , S—R 23 , SO—R 23 , S(═O) 2 —R 23 an organic poly- or oligomer, and/or an anellated 5- or 6-membered saturated or unsaturated ring structure that contains C and optionally one or two carbonyl groups and/or one or two hetero atoms, that are O, N, S, Se and/or P, the said anellated ring structure is unsubstituted or substituted by C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, halogen, hydroxy, nitro, cyano, COO—R 21 , CONR 21 R 22 , OCO—R 23 , NR 21 COR 23 , NR 21 R 22 , O—R 23 , S—R 23 , SO—R 23 , S(═O) 2 —R 23 , and/or anellated 5- or 6-membered saturated or unsaturated ring structure that contains C and optionally one or two carbonyl groups and/or one or two hetero atoms, that are O, N, S, Se and/or P;

or two of the substituents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are defined as follows:

one substituent is the group

 and the other substituent is the group

 so the part of the one substituent with the open bracket and the part of the other substituent with the open bracket form together with the part of the molecule they are both attached to a monomer unit that is x times part in an oligomer or polymer; and

q, r and s are independently integers from 1 to 5.

4. A reversibly thermochromic system of claim 3 , wherein

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 independently are H, C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, C 1 -C 30 alkylsulfoxyl, C 1 -C 30 alkylsulfonyl, C 2 -C 30 alkenyl, C 8 -C 12 aralkenyl, C 2 -C 30 alkenyloxy, C 2 -C 30 alkenylthio, C 2 -C 30 alkenylsulfoxyl, C 2 -C 30 alkenylsulfonyl, C 2 -C 30 alkynyl, C 8 -C 12 aralkynyl, C 2 -C 30 alkynyloxy, C 2 -C 30 alkynylthio, C 2 -C 30 alkynylsulfoxyl, C 2 -C 30 alkynylsulfonyl, C 6 -C 10 aryl, C 6 -C 10 aryloxy, C 6 -C 10 arylthio, C 6 -C 0 arylsulfoxyl, C 6 -C 10 arylsulfonyl, halogen, NO 2 , CN, COO—R 9 , OCO—R 10 , CO—NR 9 R 11 or NR 12 CO—R 13 , whereby the alkyl, alkenyl, alkynyl, aryl and aralkyl are substituted or unsubstituted,

or R 2 , R 3 , R 6 and/or R 7 are hydroxy;

or R 2 and R 3 form together the group CO—O—CO or CO—NR 24 —CO;

or R 2 and R 3 are defined as follows:

one substituent is the group

 and the other substituent is the group

 so the part of the one substituent with the open bracket and the part of the other substituent with the open bracket form together with the part of the molecule they are both attached to a monomer unit that is x times part in an oligomer or polymer;

R 24 is C 2 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkenyl, C 8 -C 12 aralkynyl or

q is an integer from 2 to 4;

r and s are independently integers from 1 to 3;

W is C 6 -C 10 arylene, C 1 -C 30 alkylene, C 1 -C 30 alk-1-enylene, NR 11 or O; and

R 25 is H or C 1 -C 4 alkyl.

5. A reversibly thermochromic system of claim 4 , wherein

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 independently are H, C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 1 -C 30 alkoxy, C 1 -C 30 alkylthio, C 1 -C 30 alkylsulfoxyl, C 1 -C 30 alkylsulfonyl, C 6 aryl, C 6 arylthio, C 6 arylsulfoxyl, C 6 arylsulfonyl, halogen, COO—R 9 or OCO—R 10 , whereby the alkyl and aryl are substituted or unsubstituted,

or R 2 and R 3 form together the group CO—O—CO or CO—NR 24 —CO;

or R 2 and R 3 are defined as follows:

one substituent is the group

 and the other substituent is the group

 so the part of the one substituent with the open bracket and the part of the other substituent with the open bracket form together with the part of the molecule they are both attached to a monomer unit that is x times part in an oligomer or polymer;

R 10 is C 1 -C 30 alkyl or C 6 aryl, whereby the alkyl and aryl is substituted or unsubstituted;

R 9 is H or as defined for R 10 ;

R 24 is unsubstituted or substituted C 2 -C 30 alkyl or C 6 aryl;

V is SO 2 ;

G 1 is C 2 -C 10 alkylene;

L and L′ are A or B; if L is A, then L′ is B; if L is B, then L′ is A;

A is O;

B is CO;

G 2 is C 2 -C 10 alkylene;

G 3 has the same meanings as G 2 ;

T is H, if L is A; T is OH, if L=B;

x and y are independently integers from 1 to 10;

z is an integer from 0 to 10;

the substituted alkyl and substituted aryl are substituted by hydroxy, COO—R 21 , OCO—R 23 and/or O—R 23 ; or the aryl is substituted by C 1 -C 15 alkyl;

R 23 is C 1 -C 15 alkyl; and

R 21 is H or as defined for R 23 .

6. A reversibly thermochromic system of claim 1 , wherein the ratio of component a) to component b) is 2:1 to 1:100 by weight.

7. A reversibly thermochromic composition, comprising

i) a reversibly thermochromic system as defined in claim 1 and

ii) a carrier material.

8. A reversibly thermochromic composition of claim 7 , wherein the ratio of component i) to component ii) is 1:10000 to 1:1.

9. A reversibly thermochromic composition of claim 7 , comprising as carrier material ii) polymers, solvents and/or waxes.

10. A reversibly thermochromic composition of claim 7 , comprising as carrier material ii) plastic articles, films, papers, fibers, solvents, waxes, coatings and/or inks.

11. A reversibly thermochromic composition of claim 7 , comprising further additives selected from the group consisting of antioxidants, UV-absorbers, light stabilizers, metal deactivators, processing stabilizers, thiosynergists, peroxide scavengers, oxygen scavengers, basic co-stabilizers, nucleating agents, fillers, reinforcing agents, flameproofing agents and additional colorants, with the proviso that the additional colorants do not suppress and do not mask the thermochromic effect.

12. A reversibly thermochromic composition of claim 11 , comprising as further additives phenolic antioxidants, aminic antioxidants, phosphites, phosphonites, hydroxylamines, nitrones, benzofuranones, indolinones, 2-(2-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, 2-(2-hydroxyphenyl)-1,3,5-triazines, oxamides, sterically hindered amines, pigments and/or dyes.

13. A process for reversibly thermochromically coloring a carrier by applying thereto/incorporating therein the reversibly thermochromic system of claim 1 comprising a 6,11-dihydroxy-naphthacene-5,12-dione and a base with a molecular weight of at least 300,

wherein the base is an secondary or tertiary amine

where the secondary or tertiary amine is of formula NHR 26 R 27 or NHR 26 R 27 R 28 where

R 26 , R 27 and R 28 are independently C 1 -C 30 alkyl, C 7 -C 12 aralkyl, C 2 -C 30 alkenyl, C 8 -C 12 aralkenyl, C 2 -C 30 alkynyl or C 8 -C 12 aralkynyl, which are unsubstituted or substituted by one or more COO—R 21 , CONR 21 R 22 , OCO—R 23 , NR 21 CO—R 23 , NR 23 R 21 , O—R 23 , S—R 23 , SO—R 23 and/or S(═O) 2 —R 23 ; or the aralkyl, aralkenyl and aralkynyl are substituted by C 1 -C 30 alkyl, C 2 -C 30 alkenyl and/or C 2 -C 30 alkynyl,

R 23 is C 1 -C 30 alkyl, C 2 -C 30 alkenyl, C 2 -C 30 alkynyl, C 6 -C 10 aryl, C 7 -C 12 aralkyl, C 8 -C 12 aralkenyl or C 8 -C 12 aralkynyl and R 21 and R 22 are independently H or as defined for R 23 or

the secondary or tertiary amine is of formula III

wherein G 4 , G 5 , G 6 and G 7 are independently methyl or ethyl,

E is hydrogen, C 1 -C 18 alkyl or C 3 -C 18 alkenyl and

E 10 is a carbon atom which is unsubstituted or substituted by OH, ═O or by one or two organic residues containing in total 1-500 carbon atoms.