A problem is to provide a silver paste which can produce, without variation in resistivity value, a conductive silver coating film exhibiting resistivity substantially equivalent to the resistance value of bulk silver in low-temperature sintering. The problem is solved by providing a silver paste including a silver nanoparticle aqueous dispersion prepared by using a compound having a polyethyleneimine skeleton as a protective agent, a compound having a functional group reactable with nitrogen atoms in the polyethyleneimine, and at least one compound selected from the group consisting of a compound having an amine functional group and a compound having an amide functional group.

Described herein are compositions, methods, and systems for printing metal three-dimensional objects. In an example, described is a method of printing a three-dimensional object comprising: (i) depositing a metal powder build material, wherein the metal powder build material has an average particle size of from about 10 μm to about 250 μm; (ii) selectively applying a binder fluid on at least a portion of the metal powder build material, wherein the binder fluid comprises an aqueous liquid vehicle and latex polymer particles dispersed in the aqueous liquid vehicle; (iii) heating the selectively applied binder fluid on the metal powder build material to a temperature of from about 40° C. to about 180° C.; and (iv) repeating (i), (ii), and (iii) at least one time to form the three-dimensional object.

One aspect of the present invention is a lubricant to be incorporated into a powder metallurgical mixed powder containing an iron-based powder. The lubricant includes a flaky organic material having an average particle diameter of from 0.1 μm to less than 3 μm. Another aspect of the present invention is a powder metallurgical mixed powder which contains an iron-based powder and the lubricant. Yet another aspect of the present invention is a method for producing a sintered compact. The method includes the step of mixing materials to give a powder metallurgical mixed powder containing an iron-based powder and the lubricant. The powder metallurgical mixed powder is compacted using a die to give a powder compact. The powder compact is sintered to give a sintered compact.

The present invention provides a magnetic core having insulating properties, and a method for manufacturing the magnetic core. Provided is a magnetic core manufactured by compression molding and subsequent thermal curing of an iron-based soft magnetic powder having a resin coating formed on particle surfaces thereof. The iron-based soft magnetic powder is one in which the particle surfaces have been coated with an inorganic insulator; the resin coating is an uncured resin coating formed by dry blending the powder with a thermosetting resin at a temperature equal to or greater than the softening point of the thermosetting resin and lower than the thermal curing initiation temperature of the resin; the compression molding is carried out by using a mold to produce a compression molded body; and the thermal curing is carried out at a temperature equal to or greater than the thermal curing initiation temperature of the thermosetting resin.

The present invention provides a magnetic core having insulating properties, and a method for manufacturing the magnetic core. Provided is a magnetic core manufactured by compression molding and subsequent thermal curing of an iron-based soft magnetic powder having a resin coating formed on particle surfaces thereof. The iron-based soft magnetic powder is one in which the particle surfaces have been coated with an inorganic insulator; the resin coating is an uncured resin coating formed by dry blending the powder with a thermosetting resin at a temperature equal to or greater than the softening point of the thermosetting resin and lower than the thermal curing initiation temperature of the resin; the compression molding is carried out by using a mold to produce a compression molded body; and the thermal curing is carried out at a temperature equal to or greater than the thermal curing initiation temperature of the thermosetting resin.

A molding composition contains a powder, a wax, an adhesive component, a molding component, and a plasticizer, in which a melt flow rate of the adhesive component at 190° C. is 200 g/10 min or more, and a density of the plasticizer is 1.0 g/cm.sup.3 or less.

A metal paste contains (A) 75% to 90% by weight of at least one metal that is present in the form of particles comprising a coating that contains, at least one organic compound, (B) 0% to 12% by weight of at least one metal precursor, (C) 6% to 20% by weight of a mixture of at least two organic solvents, and (D) 0% to 10% by weight of at least one sintering aid. 30% to 60% by weight of the solvent mixture (C) consists of at least one 1-hydroxyalkane with 16-20 C-atoms that is non-substituted except for a methyl substitution on the penultimate C-atom.

The three-dimensional printing process for obtaining a manufactured article with material effect comprises: a supply step of an image (1) in digital format reproducing a wooden surface portion provided with a plurality of grains (2), comprising a plurality of pixels; an identification step of a color range datum of each of pixels by means of a software; a transformation step of the color range datum into a depth spatial datum to produce a three-dimensional digital model of a manufactured article with material effect (3) provided with an outer surface (4) reproducing the grains (2) by means of a plurality of grooves (5) with variable depth; a three-dimensional printing step of the model to obtain the manufactured article with material effect (3) by means of a molding device (10, 13); and a painting step of the outer surface (4) by means of a paint (9), the paint (9) accumulating in the grooves (5) and reproducing the color range of the grains (2).

The three-dimensional printing process for obtaining a manufactured article with material effect comprises: a supply step of an image (1) in digital format reproducing a wooden surface portion provided with a plurality of grains (2), comprising a plurality of pixels; an identification step of a color range datum of each of pixels by means of a software; a transformation step of the color range datum into a depth spatial datum to produce a three-dimensional digital model of a manufactured article with material effect (3) provided with an outer surface (4) reproducing the grains (2) by means of a plurality of grooves (5) with variable depth; a three-dimensional printing step of the model to obtain the manufactured article with material effect (3) by means of a molding device (10, 13); and a painting step of the outer surface (4) by means of a paint (9), the paint (9) accumulating in the grooves (5) and reproducing the color range of the grains (2).

A powder for molding is a mixture of first constituent particles, which are made up of first metal base particles, and second constituent particles, which are made up of second metal base particles. A first lubricant concentration that is a mass proportion of a first internal lubricant adhered to the surface of the first metal base particles with respect to the total of the first constituent particles, is greater than a second lubricant concentration that is a mass proportion of a second internal lubricant that is adhered to the surface of the second metal base particles with respect to the total of the second constituent particles.