申请人:Fischer Walter
公开号:US20110180767A1
公开(公告)日:2011-07-28
A reversible thermochromic system comprising a) a compound of the formula (IA) or a tautomer thereof or a compound of the formula (IB) or a tautomer thereof (IA) (IB) wherein R
1
is C
1
-C
18
alkyl, C
2
-C
18
alkenyl, C
3
-C
12
cycloalkyl, C
3
-C
12
cycloalkyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; phenyl, phenyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; or C
7
-C
12
phenylalkyl; R
2
is hydrogen or a group —SO
2
—R; R
3
and R
4
independently of one another are hydrogen, C
1
-C
18
alkyl, C
2
-C
18
alkenyl, C
3
-C
12
cycloalkyl, C
3
-C
12
cycloalkyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; phenyl, phenyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; or C
7
-C
12
phenylalkyl; and R is C
1
-C
18
alkyl, C
2
-C
18
alkenyl, C
3
-C
12
cycloalkyl, C
3
-C
12
cycloalkyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; phenyl, phenyl substituted by 1, 2 or 3 C
1
-C
4
alkyl; or C
7
-C
12
phenylalkyl; and b) a compound containing a group of the formula (III).