Method for marking sites

Method for determining changes of a site, comprising:

• a) treating the site with a composition;
• b) exposing the site thus treated and/or the untreated areas adjacent thereto to UV light;
• and
• c) determining the deviation of the light intensity of the emitted light of the site immediately after the treatment with the composition from the light intensity of the emitted light of the site at a later time,
• wherein the composition is an aqueous dispersion comprising:
• a1) at least one binder,
• a2) at least one substance emitting visible light on UV exposure and
• a3) optionally a dispersant,
• wherein the composition comprises a polyurethane as the binder of the component a1) and said polyurethane is obtained by reaction with component i)–iv):
• i) diisocyanates containing 4 to 50 carbon atoms
• ii) diols having a molecular weight of 500 to 4 000 g/mol
• iii) diols as chain extenders having a molecular weight of 62 to 500 g/mol
• iv) mono- and polyols and/or mono- and polyamines having primary and/or secondary amino groups, which also have a group having a hydrophilizing effect.

Method for determining changes of a site, comprising:

• a) treating the site with a composition;
• b) exposing the site thus treated and/or the untreated areas adjacent thereto to UV light;
• arid
• c) determining the deviation of the light intensity of the emitted light of the site immediately after the treatment with the composition from the light intensity of the emitted light of the site at a later time
• wherein the composition is an aqueous dispersion comprising:
• a1) at least one binder,
• a2) at least one substance emitting visible light on UV exposure and
• a3) optionally a dispersant,
• wherein said substance a2) emitting visible light on UV exposure is a flavonic acid derivative of the formula (VI)
• in which
• R10, R11 and R12, independently of one another, denote phenoxy, mono- or disulphonated phenoxy, phenylamino, mono- or disulphonated phenylamino, phenylamino substituted by C1–C3-alkyl, cyano, halogen, COOR, CONH—R, —NH—COR SO2NH—R, O—R, morpholino, piperidino, pyrrolidino, —O—C1–C4-alkyl, —NH(C1–C4-alkyl), —NH(C1–C4-alkyl)2, —NH—C2–C4-alkylene-O—C2–C4-alkylene-OR, —NH(C2–C4-hydroxyalkyl)2, —NHC2–C4-akylene-=—C2–C4-alkylene-OR, an amino acid or an amino acid amide, from the amino group of which a hydrogen atom was removed;
• —NHCH2CH2OH, —N(CH2CH2OH)2, —N(CH)3CH2CH2OH, —NH2, —CH3, —S—C1–C4-alkyl, —S-aryl, —Cl, —NHCH2CH2SO3H, —NH(CH2CH2SO3H)2, —N(CH2CH2OH)CH2CH2CONH2, in
• which 13 represents H or C1–C3-alkyl and M has the meaning described above, or
• the substance a2) emitting visible light on UV exposure is a flavonic acid derivative of the formula (VII)
• in which
• R13 and R14, independently of one another, denote hydrogen, phenyl, monosulphonated phenyl, methyl, ethyl, propyl, methoxy or ethoxy.

An aqueous dispersion comprising:

• a1) at least one binder,
• a2) at least one substance emitting visible light on UV exposure and
• a3) optionally a dispersant,
• wherein the composition comprises a polyurethane as the binder of the component a1) and said polyurethane is obtained by reaction with component i)–iv):
• i) diisocyanates containing 4 to 50 carbon atoms
• ii) diols having a molecular weight of 500 to 4 000 g/mol
• iii) diols as chain extenders having a molecular weight of 62 to 500 g/mol
• iv) mono- and polyols and/or mono- and polyamines having primary and/or secondary amino groups, which also have a group having a hydrophilizing effect.