Process for producing capacitors

1. A process for producing capacitor anodes comprising niobium suboxide, said process comprising the following steps in the following order:

(a) first mixing niobium suboxide particles of the formula

NbO x

wherein 0.7<x<2.1,

with at least one valve metal powder to form a niobium suboxide particles mixture wherein said niobium suboxide particles mixture consists essentially of niobium suboxide particles and valve metal powder(s) and said valve metal being a pressing and sintering aid.

(a) pressing niobium suboxide particles mixture to form powder preforms; and

(b) sintering the powder preforms to form porous anode bodies.

2. The process of claim 1 wherein the valve metal is niobium metal powder.

3. The process of claim 1 wherein the valve metal and the niobium suboxide particles are mixed in a weight ratio from 0.1 to 2.

4. The process of claim 1 wherein the valve metal and the niobium suboxide particles are mixed and agglomerated together prior to being sintered.

5. The process as claimed in claim 1 , wherein said niobium suboxide particles mixture consists of niobium suboxide particles and valve metal powder(s).

6. The process of claim 1 wherein the niobium suboxide is represented by the following formula,

NbO x

wherein 0.7<x<1.3.

7. The process as claimed in claim 1 , wherein x is greater than 0.7 and less than 1.05.

8. The process as claimed in claim 1 , wherein x is greater than 1.0 and less than 1.05.

9. The process of claim 1 wherein the niobium suboxide is represented by the following formula,

NbO x

wherein 1.3<x<2.1, and

the sintering step is carried out in the presence of hydrogen.

10. The process of claim 9 wherein the mixture of niobium suboxide and said valve metal has a mean composition represented by the following formula

NbO y

wherein0.7<y<1.3.