Photothermographic reducing agents with bicyclic or tricyclic substitution
View Patent ↗Bis phenol reducing agents incorporating bicyclic and tricyclic substituents ortho to the hydroxyl groups on the aromatic rings have been found to provide photothermographic materials with improved silver efficiency and stability without significant loss in sensitometric properties.
1. A photothermographic material comprising a support and having on at least one side thereof a photothermographic layer and comprising, in reactive association:
a. a photosensitive silver halide
b. a non-photosensitive source of reducible silver ions,
c. a polymeric binder, and
d. one or more ortho-substituted bis-phenol reducing agents for the reducible silver ions, each of said reducing agents having a bicyclic or tricyclic substituent ortho to one or both hydroxyl groups on the aromatic rings,
wherein said one or more of said reducing agents are represented by the following Structure (I)
wherein R 1 and R 1 ′ each represent the same or different isobornyl, norbornyl, benzonorbornyl, adamantyl, bicyclo[3.2.1]octyl, benzobicyclo[3.2.1]octyl, benzo[3,4]bicyclo[3.2.1]oct-3-enyl, bicyclo[2.2.2]octyl, bicyclo[3.2.2]nonyl, benzobicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl, bicyclo[4.3.1]decyl, bicyclo[4.4.1]undecyl, bicyclo[5.4.1]dodecyl, tricyclo [5.3.1.0(1.5)]undecyl, tricyclo[5.2.1.0(2,6)]decyl, tricyclo[5.4.0.0(2,9)]undecyl groups, R 2 and R 2 ′ independently represent a hydrogen atom or a group that can be a substituent on a benzene ring, Z represents —S— or a —CHR 3 — group wherein R 3 represents hydrogen, a substituted or unsubstituted linear, branched, or cyclic, bicyclic, or tricyclic alkyl, cycloalkyl, alkenyl, aralkyl, heterocyclic, aryl, or heteroaryl group, and X 1 and X 1 ′ independently represent a hydrogen atom or a group that can be a substituent on a benzene ring.
2. The material of claim 1 wherein said one or more of said reducing agents are represented by the compounds (o-BTBP-1) to (o-BTBP-25) in the following TABLE I:
TABLE I
Compound
R 1 , R 1 ′
R 2 , R 2 ′
Z
o-BTBP-1
Isobornyl
Me
CH 2
o-BTBP-2
Isobornyl
Me
S
o-BTBP-3
Isobornyl
Et
CH(CH 2 CH 2 Ph)
o-BTBP-4
Isobornyl
Me
7,7-dimethylbicyclo[2.2.1]
hepta-2,5-dien-1-yl
o-BTBP-5
Norbornyl
Me
CH 2
o-BTBP-6
Benzonorbornyl
Me
CH 2
o-BTBP-7
Adamantyl
Me
CH 2
o-BTBP-8
Bicyclo[2.1.1]hexyl
Me
CH 2
o-BTBP-9
Bicyclo[2.1.1]hexyl
Me
CH(n-Pr)
o-BTBP-10
Bicyclo[2.1.1]hexyl
Me
Ph
o-BTBP-11
Bicyclo[3.2.1]octyl
Et
CH 2
o-BTBP-12
Benzobicyclo[3.2.1]octyl
hydroxymethyl
CHMe
o-BTBP-13
Benzo[3,4]bicyclo[3.2.1]oct-3-enyl
Me
S
o-BTBP-14
Bicyclo[2.2.2]octyl
Me
CHBu
o-BTBP-15
Bicyclo[3.2.2]nonyl
Me
CH(i-Pr)
o-BTBP-16
Benzobicyclo[2.2.2]octyl
Et
S
o-BTBP-17
Bicyclo[3.3.1]nonyl
2-hydroxyethyl
CH 2
o-BTBP-18
Bicyclo[3.3.2]decyl
hydroxymethyl
CHMe
o-BTBP-19
Bicyclo[4.3.1]decyl
iso-Propyl
CH 2
o-BTBP-20
Bicyclo[4.4.1]undecyl
Me
CH(cyclohexyl)
o-BTBP-21
Bicyclo[5.4.1]dodecyl
Me
CH(cyclohexenyl)
o-BTBP-22
Tricyclo[5.3.1.0(1,5)]undecyl
Me
CH 2
o-BTBP-23
Tricyclo[5.2.1.0(2,6)]decyl
Me
CH 2
o-BTBP-24
Tricyclo[5.4.0.0(2,9)]undecyl
Me
CH 2
o-BTBP-25
Norbornyl
Et
S
3. The material of claim 1 wherein R 1 and R 1 ′ are the same or different adamantyl, norbornyl, or isobornyl group, R 2 and R 2 ′ are independently hydrogen or an alkyl, cycloalkyl, or aralkyl group, and Z represents —CH(R 3 )— wherein R 3 is hydrogen or an alkyl, cycloalkyl, alkenyl, or aryl group, and X 1 and X 1 ′ are hydrogen.
4. The material of claim 1 wherein said one or more reducing agents having bicyclic or tricyclic substituents are present in an amount of from about 0.1 to about 0.5 mol/mol of total silver.
5. The material of claim 4 wherein total silver is less than 2 g/m 2 .
6. The material of claim 1 that provides a black-and-white image and is sensitized to a wavelength of from about 600 to about 1200 nm.
7. The material of claim 1 wherein said photosensitive silver halide is silver bromide or silver iodobromide having up to 50 mol % silver iodide, and said non-photosensitive source of reducible silver ions is a fatty acid silver carboxylate including silver behenate, and said polymeric binder is a hydrophobic polymer binder or a water-dispersible polymeric latex.
8. The material of claim 1 further comprising an additional reducing agent that is a hindered bis-phenol, one or more hindered mono-phenol reducing agents, or one or more hindered bis-phenol reducing agents not incorporating said bicyclic and tricyclic substituents ortho to the hydroxyl group on the aromatic ring, or a combination thereof.
9. The material of claim 1 having the same or different photothermographic layer on both sides of said support, and wherein said one or more reducing agents having bicyclic or tricyclic substituents are present on both sides of said support.
10. The material of claim 1 wherein said binder is gelatin or a water-dispersible polymer latex, and further comprising a development accelerator.
11. The material of claim 1 having one or more photo-thermographic layers on only one side of said support, and said material having a total absorbance at the exposure wavelength of at least 0.6 on that side of said support, and a total absorbance of at least 0.2 at the exposure wavelength on the backside of said support.
12. The photothermographic material of claim 1 further comprising a contrast enhancing agent.
13. The photothermographic material of claim 1 further comprising a co-developer reducing agent.
14. The photothermographic material of claim 12 wherein said co-developer reducing agent comprises one or more trityl hydrazides, formyl phenyl hydrazides, 2-substituted malondialdehydes, 4-substituted isoxazoles, and substituted acrylonitrile compounds.
15. The photothermographic material of claim 14 further comprising one or more hydroxylamines, alkanolamines, ammonium phthalamate compounds, hydroxamic acids, N-acylhydrazines, or hydrogen atom donor compounds.
16. A method of forming a visible image comprising:
A) imagewise exposing the photothermographic material of claim 1 to electromagnetic radiation to form a latent image, and
B) simultaneously or sequentially, heating said exposed photothermographic material to develop said latent image into a visible image.
17. The method of claim 16 wherein said development is carried out for 25 seconds or less.
18. The method of claim 16 wherein said imagewise exposing is carried out using laser imaging at from about 700 to about 950 nm.
19. A black-and-white photothermographic material comprises a support and having on at least one side thereof a photothermographic layer and comprising, in reactive association:
a. a photosensitive silver bromide or iodobromide having up to 40 mol % silver iodide,
b. a non-photosensitive source of reducible silver ions, comprising at least silver behenate,
c. a polyvinyl butyral or polyvinyl acetal binder, and
d. a reducing agent composition comprising one or more reducing agents for the reducible silver ions represented by Structure (II)
wherein R 1 and R 1 ′ are each a substituted or unsubstituted bicyclic or tricyclic ring groups selected from isobornyl norbornyl, benzonorbornyl, adamantyl, bicyclo[3.2.1]octyl, benzobicyclo[3.2.1]octyl, benzo[3.4]bicyclo[3.2.1]oct-3-enyl, bicyclo[2.2.2]octyl, bicyclo[3.2.2]nonyl, benzobicyclo[2.2.2]octyl bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl, bicyclo[4.3.1]decyl, bicyclo[4.4.1]undecyl, bicyclo[5.4.1]dodecyl, tricyclo [5.3.1.0(1.5)]undecyl, tricyclo[5.2.1.0(2,6)]decyl, and tricyclo[5.4.0.0(2,9)]undecyl, R 2 and R 2 ′ are each hydrogen, or an alkyl group having from 1 to 6 carbon atoms, and R 3 is hydrogen or an alkyl group having from 1 to 12 carbon atoms,
said material optionally further comprising a protective overcoat disposed over said photothermographic layer.
20. The material of claim 19 comprising one or more reducing agents that include the compounds (o-BTBP-1) to (o-BTBP-25) in the following TABLE I:
TABLE I
Compound
R 1 , R 1 ′
R 2 , R 2 ′
Z
o-BTBP-1
Isobornyl
Me
CH 2
o-BTBP-2
Isobornyl
Me
S
o-BTBP-3
Isobornyl
Et
CH(CH 2 CH 2 Ph)
o-BTBP-4
Isobornyl
Me
7,7-dimethylbicyclo[2.2.1]
hepta-2,5-dien-1-yl
o-BTBP-5
Norbornyl
Me
CH 2
o-BTBP-6
Benzonorbornyl
Me
CH 2
o-BTBP-7
Adamantyl
Me
CH 2
o-BTBP-8
Bicyclo[2.1.1]hexyl
Me
CH 2
o-BTBP-9
Bicyclo[2.1.1]hexyl
Me
CH(n-Pr)
o-BTBP-10
Bicyclo[2.1.1]hexyl
Me
Ph
o-BTBP-11
Bicyclo[3.2.1]octyl
Et
CH 2
o-BTBP-12
Benzobicyclo[3.2.1]octyl
hydroxymethyl
CHMe
o-BTBP-13
Benzo[3,4]bicyclo[3.2.1]oct-3-enyl
Me
S
o-BTBP-14
Bicyclo[2.2.2]octyl
Me
CHBu
o-BTBP-15
Bicyclo[3.2.2]nonyl
Me
CH(i-Pr)
o-BTBP-16
Benzobicyclo[2.2.2]octyl
Et
S
o-BTBP-17
Bicyclo[3.3.1]nonyl
2-hydroxyethyl
CH 2
o-BTBP-18
Bicyclo[3.3.2]decyl
hydroxymethyl
CHMe
o-BTBP-19
Bicyclo[4.3.1]decyl
iso-Propyl
CH 2
o-BTBP-20
Bicyclo[4.4.1]undecyl
Me
CH(cyclohexyl)
o-BTBP-21
Bicyclo[5.4.1]dodecyl
Me
CH(cyclohexenyl)
o-BTBP-22
Tricyclo[5.3.1.0(1,−.5)]undecyl
Me
CH 2
o-BTBP-23
Tricyclo[5.2.1.0(2,6)]decyl
Me
CH 2
o-BTBP-24
Tricyclo[5.4.0.0(2,−.9)]undecyl
Me
CH 2
o-BTBP-25
Norbornyl
Et
S.
21. The material of claim 20 further comprising an additional reducing agent that is a hindered bis-phenol that does not have said bicyclic or tricyclic substituent ortho to the hydroxyl group on the phenol ring(s) or a hindered mono-phenol.
22. The material of claim 21 wherein said one or more reducing agents comprising said bicyclic or tricyclic substituent ortho to the hydroxyl group on the phenol rings is present in an amount of from about 0.1 and to about 0.4 mol/mol of total silver, and said additional reducing agent is present in an amount of from about 0.001% to about 20% based on total dry weight of the photothermographic layer.