Claims
- 1. A method of forming a temporary image on a surface using activating radiation which comprises the steps of:
- (a) forming a photochromic surface comprising a photochromic compound having the general formula (1) below and a support therefor, ##STR8## wherein X represents oxygen or >NR.sub.6, R.sub.6 being hydrogen, alkyl, aryl or aralkyl,
- R.sub.1 represents alkyl, aryl or aralkyl,
- Y and Y.sup.1 are the same or different and represent hydrogen, alkyl, halogen or alkoxy,
- Z represents hydrogen, halogen, alkyl, alkoxy or aryloxy,
- R.sub.5 represents hydrogen, alkyl, alkoxy or aryloxy,
- R.sub.4 represents alkyl, aryl or aralkyl and
- R.sub.2 and R.sub.3 represent the same or different alkyl, aryl, or aralkyl groups or one of R.sub.2 and R.sub.3 represents hydrogen and the other is alkyl, aryl or aralkyl, and
- (b) subjecting the photochromic surface to activating radiation using imaging means whereby areas of the surface exposed to the radiation exhibit a colour change or tone resulting from reversible photocyclisation of the photochromic compound.
- 2. The method of claim 1 wherein the activating radiation is U.V. light having a wavelength in the range of about 330 to 400 nm.
- 3. The method of claim 2 wherein the photochromic surface comprises light-transmissive matrix having said photochromic compound dispersed therein or coated thereon.
- 4. A method of forming a temporary image on a surface using activating radiation which comprises the steps of:
- (a) forming a photochromic surface comprising a photochromic compound having the general formula: ##STR9## wherein X represents oxygen or >NR.sub.6, R.sub.6 being hydrogen, alkyl or aryl,
- R.sub.1 represents hydrogen, alkyl or aryl,
- Y and Y.sup.1 are the same or different and represent hydrogen, alkyl or halogen,
- Z represents hydrogen, halogen or alkyl,
- R.sub.5 represents alkoxy or aryloxy,
- R.sub.4 represents alkyl or aryl and
- R.sub.2 and R.sub.3 represent the same or different alkyl, aralkyl or aryl groups or one of R.sub.2 and R.sub.3 represents hydrogen and the other is alkyl, or aryl and
- (b) subjecting the photochromic surface to activating radiation using imaging means whereby areas of the surface exposed to the radiation exhibit a colour change or tone resulting from reversible photocyclisation of the photochromic compound.
- 5. A photochromic image recording or display device which comprises a photochromic compound having the general formula (1) below: ##STR10## wherein X represents oxygen or >NR.sub.6, R.sub.6 being hydroge, alkyl, aryl or aralkyl,
- R.sub.1 represents alkyl, aryl or aralkyl,
- Y and Y.sup.1 are the same or different and represent hydrogen, alkyl, halogen or alkoxy,
- Z represents hydrogen, halogen, alkyl, alkoxy or aryloxy,
- R.sub.5 represents hydrogen, alkyl, alkoxy or aryloxy,
- R.sub.4 represents alkyl, aryl or aralkyl, and
- R.sub.2 and R.sub.3 represent the same or different alkyl, aryl, or aralkyl groups or one of R.sub.2 and R.sub.3 represent hydrogen and the other is alkyl, aryl or aralkyl, said photochromic compound being in the form of a coating on a support or dispersed in a light-transmitting matrix.
- 6. A photochromic image recording or display device which comprises a photochromic compound having the general formula: ##STR11## wherein X represents oxygen or >NR.sub.6, R.sub.6 being hydrogen, alkyl or aryl,
- R.sub.1 represents hydrogen, alkyl or aryl,
- Y and Y.sup.1 are the same or different and represent hydrogen, alkyl or halogen,
- Z represents hydrogen, halogen or alkyl,
- R.sub.5 represents alkoxy or aryloxy,
- R.sub.4 represents alkyl or aryl, and
- R.sub.2 and R.sub.3 represent the same or different alkyl, aryl or aralkyl groups or one of R.sub.2 and R.sub.3 represent hydrogen and the other is alkyl, or aryl said photochromic compound being in the form of a coating on a support or dispersed in a light-transmitting matrix.
Priority Claims (1)
Number |
Date |
Country |
Kind |
41233/73 |
Sep 1973 |
GBX |
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Parent Case Info
This is a divisional of application Ser. No. 801,915, filed May 31, 1977, which, in turn, is a continuation-in-part of application Ser. No. 502,095, filed Aug. 30, 1974, which is abandoned.
Non-Patent Literature Citations (4)
Entry |
Hart et al.: Chemical Communication, 1968, pp. 1627-1628. |
Santiago et al.: J. Am. Chem. Soc. 90 (1968), pp. 3654-3658. |
El-Assal et al.: J. Chem. Soc. (1963), pp. 2983-2988. |
Brunow et al.: Acta Chem. Scand. 22 (1965), pp. 590-595. |
Divisions (1)
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Number |
Date |
Country |
Parent |
801915 |
May 1977 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
502095 |
Aug 1974 |
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