Abstract: This invention relates to a manufacturing method and a hermetic glass-to-metal seal suitable for a component in an electric circuit such as a liquid tantalum electrolytic capacitor. The method comprises the steps of fusing a raw material glass in order to form a glass tube; setting a bead, obtained by cutting the glass tube across the axis, in the opening to be sealed, for example, the opening of a member which forms a circuit component; and heating the assembly of the members which composes the circuit component including the bead, above the melting temperature of the bead, with a longitudinal conductor piercing through the bead. This simplified method of manufacturing a hermetic glass-to-metal seal accomplishes a perfect sealing since the sealing glass includes no undesirable impurities such as binder, and since the thermal expansion coefficient of the sealing glass is close to that of the metals used to construct the circuit components, and the sealing glass is stable to electrolyte.

Abstract: A valve nozzle is used at an end of a hot runner or an injection molding machine for an injection molding. The valve nozzle comprises a cylinder as a body of the nozzle, and a piston. The cylinder has a gate and has a larger inner diameter at the rear end and a smaller inner diameter at the front end. The piston has a passage in the piston and has a large outer diameter at the rear end and a smaller outer diameter at the front end.

Abstract: A gate of a mold for an injection molding machine comprises a valve cone having a circular cone shape or a pyramid shape and a valve seat corresponding to the valve cone wherein the valve cone is pushed toward the valve seat by a spring in the direction reverse to the injecting direction.

Abstract: A process for producing an aromatic amine comprises heating an aromatic sulfonate and a metal amide in liquid ammonia in a closed reactor at a temperature of at least 40.degree. C to produce a metal arylamide and reacting the resultant metal arylamide with water or lower aliphatic alcohol to produce an aromatic amine.

Abstract: In nitrating an aromatic compound having at least one of ortho-para orientation substituents, a process which is characterized in that nitration is carried out in the presence of an aromatic sulfonic acid supported on a solid carrier in a weight ratio of 1 : 1 to 1 : 20.