| 摘要 |
<p>Certain piperidine compounds having the formula (I) are used to protect natural or synthetic, organic or inorganic pigments or pigment mixtures in natural or synthetic polymer or prepolymer substrates against the negative effects of heat and/or light on light-fastness or colour stability, in particular against colour changes or light-induced discoloration. In the formula (I), R1 stands for hydrogen, hydroxyl, low-molecular alkyl, low-molecular alkoxy or acyl; R2 stands for a rest of aromatic character with one or two cores and optional substituents; R3 stands for oxygen, -NH- or -N(C1-4-alkyl)-; and all R8 independently represent hydrogen or methyl. Also disclosed is a master batch composition with at least one piperidine compound of formula (I), optionally at least one inorganic or organic pigment and a natural or synthetic material that is identical to or compatible with the natural or synthetic polymer or prepolymer substrate that is to be pigmented. In a process for protecting organic or inorganic pigments or pigment mixtures in synthetic polymer or prepolymer substrates against the negative effects of heat and/or light on light-fastness or colour stability, in particular against changes of colour or light-induced discoloration, an amount of at least one piperidine compound of formula (I) sufficient for stabilisation purposes is added as such or in the form of a master batch composition to the pigment or pigment mixture to be stabilised, or to the natural or synthetic polymer or prepolymer substrate that contains the pigment or pigment mixture.</p> |
