Abstract: There is provided a conductive filler with high heat resistance which can be melt-bonded under reflow heat treatment conditions for a lead-free solder and, after the bonding, does not melt under the same heat treatment conditions. The conductive filler is characterized in that, as measured by differential scanning calorimetry, it has at least one metastable metal alloy phase observed as an exothermic peak and has at least one melting point observed as an endothermic peak in each of the 210 to 240° C. range and the 300 to 450° C. range, and that the filler, upon heat treatment at 246° C., gives a bonded object which has, as measured by differential scanning calorimetry, no melting point observed as an endothermic peak in the 210 to 240° C. range or has a melting endotherm calculated from an endothermic peak area in the 210 to 240° C. range, the melting endotherm being 90% or less of the melting endotherm of the filler before bonding calculated from an endothermic peak area in the 210 to 240° C. range.

Abstract: There is provided a conductive filler with high heat resistance which can be melt-bonded under reflow heat treatment conditions for a lead-free solder and, after the bonding, does not melt under the same heat treatment conditions. The conductive filler is characterized in that, as measured by differential scanning calorimetry, it has at least one metastable metal alloy phase observed as an exothermic peak and has at least one melting point observed as an endothermic peak in each of the 210 to 240° C. range and the 300 to 450° C. range, and that the filler, upon heat treatment at 246° C., gives a bonded object which has, as measured by differential scanning calorimetry, no melting point observed as an endothermic peak in the 210 to 240° C. range or has a melting endotherm calculated from an endothermic peak area in the 210 to 240° C. range, the melting endotherm being 90% or less of the melting endotherm of the filler before bonding calculated from an endothermic peak area in the 210 to 240° C. range.

Abstract: Disclosed are metal alloy particles containing substantially no lead, each exhibiting a plurality of different melting points including an original lowest melting point (a) and a highest melting point, wherein, when the metal alloy particles are subjected to differential scanning calorimetry (DSC), at least one exothermic peak is observed in the DSC, wherein each of the metal alloy particles exhibits the original lowest melting point (a) at least at a surface portion thereof, and wherein, when each metal alloy particle is heated at a temperature equal to or higher than the original lowest melting point (a) to melt at least a surface portion of each metal alloy particle, followed by cooling to room temperature to thereby solidify the melted portion of each metal alloy particle, the resultant solid metal alloy particle having experienced the melting and solidification exhibits an elevated lowest melting point (a?) higher than the original lowest melting point (a).

Abstract: Disclosed are metal alloy particles containing substantially no lead, each exhibiting a plurality of different melting points including an original lowest melting point (a) and a highest melting point, wherein each of the metal alloy particles exhibits the original lowest melting point (a) at least at a surface portion thereof, and wherein, when each metal alloy particle is heated at a temperature equal to or higher than the original lowest melting point (a) to melt at least a surface portion of each metal alloy particle, followed by cooling to room temperature to thereby solidify the melted portion of each metal alloy particle, the resultant solid metal alloy particle having experienced the melting and solidification exhibits an elevated lowest melting point (a′) higher than the original lowest melting point (a).

Abstract: A photosensitive and heat-sensitive polymer having conjugated polyenes and sulfonic acid groups and an absorbance ratio of a strong band in the region of 1200 cm.sup.-1 to 1300 cm.sup.-1 assignable to sulfonic acid groups adjacent to conjugated polyenes of at least 3 sequence lengths to a strong band near 1050 cm.sup.-1 assignable to sulfonic acid groups in the IR spectrum of at least 0.6.

Abstract: A photosensitive and heat-sensitive polymer having conjugated polyenes and sulfonic acid groups and an absorbance ratio of a strong band in the region of 1200 cm.sup.-1 to 1300 cm.sup.-1 assignable to sulfonic acid groups adjacent to conjugated polyenes of at least 3 sequence lengths to a strong band near 1050 cm.sup.-1 assignable to sulfonic acid groups in the IR spectrum of at least 0.6.

Abstract: A photosensitive and heat-sensitive polymer having conjugated polyenes and sulfonic acid groups and an absorbance ratio of a strong band in the region of 1200 cm.sup.-1 to 1300 cm.sup.-1 assignable to sulfonic acid groups adjacent to conjugated polyenes of at least 3 sequence lengths to a strong band near 1050 cm.sup.-1 assignable to sulfonic acid groups in the IR spectrum of at least 0.6. The photosensitive and heat-sensitive polymer is obtained by the sulfonation of a polymer of an ethylenically unsaturated monomer having a number average molecular weight of at least 10,000 or a polymer having conjugated polyenes and a number average molecular weight of at least 10,000 and selected from specified polymers and copolymers. The photosensitive and heat-sensitive polymer is useful for information recording materials capable of being recorded by a laser beam or a thermal head for preparing printing plates, especially offset printing plates.

Abstract: A process for the separation of one rare earth metal from another in a mixture of rare earth metals by chromatographic displacement using a complexing agent and a cation exchanger, which process comprises using a cation exchanger having a micro-void volume void ratio of 0.5 to 0.95, preferably 0.5 to 0.88.