Abstract: Photochromatic compounds belonging to the groups of chromenes and spiro-pyrans having general formula (I)

Abstract: Photochromatic compounds belonging to the groups of chromenes and spiro-pyrans having general formula (I).

Abstract: Photochromic compounds belonging to the group of spiro-isoindolino-oxazines having general formula (I). The above photochromatic compounds having general formula (I) have excellent photochromic characteristics, excellent stress resistance and high dyability characteristics.

Abstract: Compounds belonging to the group of enamines consisting of derivatives of &bgr;-keto-esters or &bgr;-keto-amides or 1,3-diketones with primary or secondary aliphatic or aromatic amines carrying at least one sterically hindered amine group having general formula (I) in the molecule. The compounds having general formula (I) can be used as antioxidants or light stabilizers for organic polymers.

Abstract: A description follows of photochromatic and thermochromatic compounds, belonging to the group of spiro-indoline-oxazines, and their application in polymeric materials.

Abstract: Polymeric compositions comprising a polymer and photochromic compounds belonging to the class of spiro-pyrans, having the general formula (I): ##STR1##

Abstract: Photochromic products belonging to the group of chromenes having general formula (I): ##STR1##

Abstract: Photochromic compounds belonging to the class of spiro-pyrans, having the general formula (I): ##STR1##

Abstract: Stabilizing mixture for photochromatic substances containing a cyclic amine chosen from 1,4-diazabicyclo-(2.2.2)octane and quinuclidine, or their derivatives, and at least one sterically hindered amine.

Abstract: A photochromatic compound represented by the following general formula (I): ##STR1## where: R.sub.1 and R.sub.2 independently represent a linear, branched or cyclic C1-C10 alkyl radical, H, OH, F, Cl, Br, NH.sub.2, N(R.sub.4).sub.2, COOH, OR.sub.4 or COOR.sub.4 where R.sub.4 is a C1-C10 linear, branched or cyclic alkyl radical, or an aryl radical;R.sub.3 is a variously substituted mono or polycondensed heterocyclic or aryl radical.A compound (I) demonstrates marked photochromatic characteristics both when in an organic solvent solution and when incorporated into polymer matrices.

Abstract: A photochromatic composition, endowed with a high light fatigue resistance contains a photochromatic compound belonging to the class of spirooxazines and an U.V.-stabilizer consisting of a sterically hindered amine to be defined by means of formula (I): ##STR1## wherein: R is either hydrogen or a methyl group,x is either oxygen or nitrogen,m is a number comprised within the range of from 2 to 10, andn is a number coprised within the range of from 1 to 100.A photochromatic article made from a thermoplastic material, endowed with a high light fatigue resistance, contains a thermoplastic material and the hereinabove disclosed photochromatic composition.

Abstract: New compounds of the spiro-indoline-oxazine class possessing photochromatic and photosensitizing charecteristics are definable by the general formula (I): ##STR1## where the substituents R, R.sup.1 -R.sup.7 and A are as defined in the description. The process for preparing the compounds (I) is described, as is their use as photochromic agents able to confer photochromatic characteristics on the articles in which they are incorporated, and as photosensitizing agents.

Abstract: A photochromatic composition contains at least two photochromatic compounds, defined by the general formula: ##STR1## wherein the various substituents from R.sub.1 to R.sub.7 and X are as defined in the specification.In such a mixture, at least one photochromatic compound is defined by the general formula, wherein R.sub.7 represents a hydrogen atom, and at least one further compound is also defined by the general formula, wherein R.sub.7 represents an -NR.sub.8 R.sub.9, with R.sub.8 and R.sub.9 having the meaning as defined in the text.