Abstract: The invention relates to photochromic plastic objects comprising a plastic material and at least two photochromic pyran derivatives, which are introduced therein and, in each case, have an aryl group, which is linked to the carbon atom adjacent to the pyran oxygen atom and is substituted with at least one group containing at least one nitrogen atom, the longest wavelength absorption maximum of the light-stimulated form of the one pyran derivative lying above 550 nm and the longest wavelength absorption of the light-stimulated form of the other pyran derivative lying below 550 nm and the pyran derivative, absorbing at the shorter wavelength, being selected from 3[H]-naphtho[2,1-b]pyrans and the pyran derivative, absorbing at the longer wavelength, being selected from indeno[2,1-f]naphtho[1,2-b]pyrans or spiro-9-fluoreno[1,2-b]pyrans.

Abstract: Photochromic spirofluorenopyran compounds corresponding to the general formula (I): in which B, B′, R1 to R4 and G have the meanings defined herein. The compounds of the invention are useful in the production of photochromic articles, particularly articles made of synthetic resin materials, and exhibit rapid darkening and brightening rates, as well as long useful service lives. By appropriate selection of substituents, it is possible to adjust the properties of the compounds such as absorption maxima (color), brightening rate, etc.

Abstract: What is described here are photochromic naphthopyrane dyes with different substituents whose properties can be set by controlled selection of the substituents. In this manner it is possible to take an influence on the migration characteristics, the absorption characteristics and the brightening rate and kinetics. The inventive compounds display good darkening and brightening properties at a very good service life.The invention excels itself by the fact that a method is made available which is substantially improved over prior art, in addition to the surprising influence on specific properties of the inventive compounds. The described compounds are suitable for application in synthetic materials of any kind.A photochromic object is also the subject matter of the invention, which comprises one or several photochromic naphthopyrane dyes as well as at least one polymer material, with the photochromic object being producible by mass-dyeing or superficial dyeing.