Imaging element having improved durability
View Patent ↗The invention provides an imaging element comprising a support having thereon, in order, at least one imaging layer, at least one interlayer containing a lubricant which provides scratch-resistance and at least one outermost layer containing a different lubricant which provides abrasion-resistance and a method of processing the element. The element has increased durability, especially with regard to scratch- and abrasion- (especially photoabrasion-) resistance, whilst retaining performance and ease of manufacture. Preferably the element is for use in the manufacture of printed circuit boards or the production of printing plates, wherein abrasion and scratches are particularly acute.
1. An imaging element comprising a support having thereon, in order, at least one imaging layer, at least one interlayer containing a lubricant which provides scratch-resistance, which is a higher fatty acid or a derivative thereof or a higher alcohol or a derivative thereof and at least one outermost layer containing a lubricant which provides abrasion-resistance which is different from the lubricant providing scratch resistance.
2. The element of claim 1 wherein said lubricant which provides abrasion-resistance is a silicone-based lubricant.
3. The element of claim 2 wherein said lubricant which provides abrasion-resistance is a siloxane having the formula (I):
wherein each R 1 is independently an unsubstituted or substituted alkyl group having from 1 to 8 carbon atoms or an unsubstituted or substituted alkoxy group having from 1 to 8 carbon atoms, R 2 R 3 , R 4 and R 5 each represents an unsubstituted or substituted alkyl, cycloalkyl, alkoxyalkyl, arylalkyl, alkoxy aryloxyalkyl, glycidyloxyalkyl group or aryl group, and n and m each represents a positive integer of from 0 to 2,500, with the proviso that both m and n cannot be 0.
4. The element of claim 3 wherein in formula (I), each R 1 is the same and is an unsubstituted alkyl group having from 1 to 3 carbon atoms or an alkoxy group having either 1 or 2 carbon atoms.
5. The element of claim 3 wherein in formula (I) R 2 , R 3 , R 4 and R 5 each represents an unsubstituted alkyl group.
6. The element of claim 3 wherein m is 0 and n is an integer from 2-500.
7. The element of claim 3 wherein said lubricant which provides abrasion-resistance has a viscosity of 350 centistokes and an average molecular weight of 13,700 and has the formula:
wherein n is an average of 183.
8. The element of claim 1 wherein said lubricant which provides abrasion-resistance is present in a concentration of from about 35 to about 65 mg/m 2 .
9. The element of claim 1 wherein said lubricant providing scratch resistance is a metal salt of a higher fatty acid, a higher fatty acid ester, a higher fatty acid amide or a polyhydric alcohol ester of a higher fatty acid.
10. The element of claim 9 wherein said lubricant is a derivative of a fatty acid selected from the class consisting of palmitic, stearic, oleic, linoleic, linolenic or tauric acids.
11. The element of claim 10 wherein said lubricant comprises ‘Spermalube’.
12. The element of claim 1 wherein said lubricant which provides scratch-resistance is present in a concentration of from about 15 to about 30 mg/m 2 .
13. The element of claim 1 wherein said element is selected from the class consisting of photographic, electrostatographic, photothermographic, electrothermographic, dielectric recording and thermal-dye-transfer imaging elements.
14. The element of claim 13 wherein said element is a black-and-white photographic element in which at least one of the imaging layers comprises a radiation-sensitive silver halide emulsion layer.
15. The element of claim 14 wherein said silver halide emulsion comprises a silver chlorobromide emulsion.
16. The element of claim 1 wherein said element includes a nucleator capable of providing high contrast development in a latent-image forming layer.
17. The element of claim 16 which includes a booster.
18. A method for processing the imaging element of claim 1 , which comprises developing said element with an alkaline developing solution.
19. The method of claim 18 wherein said lubricant which provides abrasion-resistance is a siloxane having the formula (I):
wherein each R 1 is independently an unsubstituted or substituted alkyl group having from 1 to 8 carbon atoms or an unsubstituted or substituted alkoxy group having from 1 to 8 carbon atoms, R 2 R 3 , R 4 and R 5 each represents an unsubstituted or substituted alkyl, cycloalkyl, alkoxyalkyl, arylalkyl, alkoxy aryloxyalkyl, glycidyloxyalkyl group or aryl group, and n and m each represents a positive integer of from 0 to 2,500, with the proviso that both m and n cannot be 0.
20. The method of claim 18 wherein said lubricant which provides scratch resistance is a derivative of a fatty acid selected from the class consisting of palmitic, stearic, oleic, linoleic, linolenic or tauric acids.