What is claimed is:
1. An aqueous based nanoparticulate dispersion of silver carboxylate particles having on the surface of said particles a surface modifier which is a nonionic oligomeric surfactant based on vinyl polymer with an amido function.
2. A dispersion according to claim 1 wherein said dispersion also contains about 1-20% by weight of carboxylic acid by weight of silver carboxylate.
3. A dispersion according to claim 1 wherein said silver carboxylate is a silver salt of a long chain fatty acid.
4. A dispersion according to claim 3 said silver salt is a salt of a long chain fatty acid containing 8 to 30 carbon atoms.
5. A dispersion according to claim 3 wherein said silver carboxylate is silver behenate.
6. A dispersion according to claim 1 wherein said surface modifier is acrylamide, methacrylamide or a derivative thereof.
7. A dispersion according to claim 6 wherein said surface modifier is dodecylthiopolyacrylamide.
8. An aqueous based oxidation-reduction imaging forming composition comprising (i) a nanoparticulate dispersion of silver carboxylate particles having on the surface of the particles a surface modifier which is a nonionic oligomeric surfactant based on vinyl polymer with an amido function and (ii) an organic reducing agent.
9. An oxidation-reduction imaging forming composition according to claim 1 wherein said dispersion also contains about 1-20% by weight of carboxylic acid by weight of silver carboxylate.
10. An oxidation-reduction imaging forming composition according to claim 9 wherein said silver carboxylate is a silver salt of a long chain fatty acid.
11. An oxidation-reduction imaging forming composition according to claim 10 said silver salt is a salt of a long chain fatty acid containing 8 to 30 carbon atoms.
12. An oxidation-reduction imaging forming composition according to claim 11 wherein said silver carboxylate is silver behenate.
13. An oxidation-reduction imaging forming composition according to claim 9 wherein said surface modifier is acrylamide, methacryalmide or a derivative thereof.
14. An oxidation-reduction imaging forming composition according to claim 11 wherein said surface modifier is dodecylthiopolyacrylamide.
15. A thermographic element comprising a support having thereon an imaging layer comprising an aqueous based oxidation-reduction imaging forming composition comprising (i) a nanoparticulate dispersion of silver carboxylate particles having on the surface of the particles a surface modifier which is a which is a nonionic oligomeric surfactant based on vinyl polymer with an amido function and (ii) an organic reducing agent.
16. A thermographic element according to claim 16 wherein said dispersion also contains about 1-20% by weight of carboxylic acid by weight of silver carboxylate.
17. An aqueous based photothermographic composition comprising a) a photosensitive silver halide emulsion containing a peptizer and b) an oxidation-reduction imaging forming composition comprising (i) a nanoparticulate dispersion of silver carboxylate particles having on the surface of the particles a surface modifier which is a nonionic oligomeric surfactant based on a vinyl polymer with an amido function and (ii) an organic reducing agent.
18. A photothermographic composition according to claim 17 wherein said dispersion also contains about 1-20% by weight of carboxylic acid by weight of silver carboxylate.
19. A photothermographic composition according to claim 17 wherein said silver carboxylate is a silver salt of a long chain fatty acid.
20. A photothermographic composition according to claim 19 said silver salt is a salt of a long chain fatty acid containing 8 to 30 carbon atoms.
21. A photothermographic composition according to claim 20 wherein said silver carboxylate is silver behenate.
22. A photothermographic composition according to claim 17 wherein said surface modifier is acrylamide, methacrylamide or a derivative thereof.
23. A photothermographic composition according to claim 17 wherein said surface modifier is dodecylthiopolyacrylamide.
24. A photothermographic element comprising a support having thereon an aqueous photothermographic composition comprising a) a photosensitive silver halide emulsion containing a peptizer and b) an oxidation-reduction imaging forming composition comprising (i) a nanoparticulate dispersion of silver carboxylate particles having on the surface of the particles a surface modifier which is a nonionic oligomeric surfactant based on a vinyl polymer with an amido function and (ii) an organic reducing agent.
25. A photothermographic element according to claim 24 wherein said dispersion also contains about 1-20% by weight of carboxylic acid by weight of silver carboxylate.
26. A photothermographic element according to claim 24 wherein said silver carboxylate is a silver salt of a long chain fatty acid.
27. A photothermographic element according to claim 26 said silver salt is a salt of a long chain fatty acid containing 8 to 30 carbon atoms.
28. A photothermographic element according to claim 27 wherein said silver carboxylate is silver behenate.
24. A photothermographic element according to claim 20 wherein said surface modifier is acrylamide, methacrylamide or a derivative thereof.
25. A photothermographic element according to claim 24 wherein said surface modifier is dodecylthiopolyacrylamide.
26. A photothermographic element according to claim 24 further comprising a protective layer.
27. A controlled precipitation method of making nanoparticulate silver carboxylate particles having on the surface of the particles surface modifier which is a nonionic oligomeric surfactant based on a vinyl polymer with an amido function, said method comprising the steps of:
d) introducing said surface modifier, water and carboxylic acid into a vessel;
e) solubilizing said carboxylic acid by introducing a basic salt;
f) introducing a water soluble silver salt so as to precipitate said silver carboxylate particles;
recovering said particles.
The claims below are in addition to those above.
All refrences to claims which appear below refer to the numbering after this setence.
1. An apparatus for forming a sheet metal blank into a pot including a bottom, a wall and a drawn edge, said apparatus comprising:
a punch with a bottom forming area forming the bottom and a wall forming area forming the wall;
an annular blank holder surrounding said punch and having a supporting surface for placing the drawn edge;
an inner die with a bottom forming area;
an outer die with a wall forming area and a clamping area for gripping the drawn edge and for pressing the drawn edge against the supporting surface of said annular blank holder; and
a drive respectively associated with at least two parts including the punch, the annular blank holder, the inner die and the outer die, all of which are involved in a drawing process, wherein said drive moves said at least two parts simultaneously with different respective speeds in the drawing direction during a specific phase of the forming.
2. An apparatus for forming a sheet metal blank into a pot including a bottom, a wall and a drawn edge, said apparatus comprising:
a punch with a bottom forming area forming the bottom and a wall forming area forming the wall;
an annular blank holder surrounding said punch and having a supporting surface for placing the drawn edge;
an inner die with a bottom forming area;
an outer die with a wall forming area and a clamping area for gripping the drawn edge and for pressing the drawn edge against the supporting surface of said annular blank holder; and
a drive respectively associated with at least two parts including the punch, the annular blank holder, the inner die and the outer die, all of which are involved in a drawing process, wherein said drive moves said at least two parts simultaneously with different respective speeds in the drawing direction during a specific phase of the forming, wherein said drive is respectively associated with the inner die, and the outer die and the annular blank holder, in which the inner die overtakes the outer die in a first phase, and the outer die overtakes the inner die in a subsequent phase.
3. The apparatus according to claim 2, wherein said drive is respectively associated with the inner die, and the outer die and the annular blank holder, in which the outer die overtakes the inner die in a first phase, and the inner die overtakes the outer die in a subsequent phase.
4. The apparatus according to claim 2, wherein said annular blank holder, said outer die and said punch are movable by the drive in a drawing direction.
5. The apparatus according to claim 2, wherein said wall forming area of the punch extends conically towards the bottom forming area of the punch.
6. The apparatus according to claim 4, wherein said wall forming area of the outer die tapers in the drawing direction.
7. The apparatus according to claim 2, wherein said apparatus includes a plurality of drawing stations which together form an installation.
8. A method for forming a sheet metal blank into a pot with a bottom, a wall, and a drawn edge by using a drawing apparatus, including:
a punch with a bottom forming area forming the bottom and a wall forming area forming the wall;
an annular blank holder surrounding said punch and having a supporting surface for placing the drawn edge;
an inner die with a bottom forming area; and
an outer die with a wall forming area and a clamping area for gripping the drawn edge and for pressing the drawn edge against the supporting surface of said annular blank holder, the method comprising the steps of:
placing a sheet metal blank or a pre-shaped workpiece produced therefrom inside said drawing apparatus;
moving the inner die, the outer die, and the annular blank holder in the drawing direction together with a clamped sheet metal blank or with a clamped pre-shaped workpiece during a first forming phase; and
moving the inner die to overtake the outer die during a phase of a forming process.
9. A method for forming a sheet metal blank into a pot with a bottom, a wall, and a drawn edge by using a drawing apparatus, including:
a punch with a bottom forming area forming the bottom and a wall forming area forming the wall;
an annular blank holder surrounding said punch and having a supporting surface for placing the drawn edge;
an inner die with a bottom forming area; and
an outer die with a wall forming area and a clamping area for gripping the drawn edge and for pressing the drawn edge against the supporting surface of said annular blank holder, the method comprising the steps of:
placing a sheet metal blank or a pre-shaped workpiece produced therefrom inside said drawing apparatus;
moving the inner die, the outer die, and the annular blank holder in the drawing direction together with a clamped sheet metal blank or with a clamped pre-shaped workpiece during a first forming phase; and
moving the outer die to overtake the inner die, as the inner die maintains a non-zero velocity, during a phase of a forming process.
10. The method according to claim 8, including the further steps of:
moving said inner die and said outer die in the same direction at equal velocity during an initial phase;
moving said inner die and said outer die in the same direction during a middle phase, but the inner die travels at higher velocity than the outer die; and
keeping the inner die stationary in an final phase, while the outer die continues to move at constant velocity.
11. The method according to claim 9, including the further steps of:
moving said inner die and said outer die in the same direction at equal velocity during an initial phase;
moving said inner die and said outer die in the same direction during a middle phase, but the inner die travels at higher velocity than the outer die; and
keeping the inner die stationary in an final phase, while the outer die continues to move at constant velocity.