MIXED MATERIAL WITH HIGH EXPANSION RATE FOR PRODUCING POROUS METALLIC SINTERED BODY

Abstract

A mixed material having a high expansion rate for producing a porous metallic sintered body including: a conventional mixed material for producing a porous metallic sintered body which is formed of a mixture including a composition of 0.05 to 10% by mass of a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms, 0.5 to 20% by mass of a water-soluble resin binder, and 5 to 80% by mass of a metal powder having an average particle size within a range of 0.5 to 500 m, and water as the balance; and a gas, wherein the mixed material contains the gas so that the proportion of the gas is within a range of 2 to 50% by volume while the remainder is the conventional mixed material for producing a porous metallic sintered body.

Claims

1. A method for producing a mixed material for producing a porous metallic sintered body, the method comprising the steps of: preparing a slurry composed of 0.05 to 10% by mass of a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms used as a foaming agent, 0.5 to 20% by mass of a water-soluble resin binder, 5 to 80% by mass of a metal powder having an average particle size within a range of 0.5 to 500 m, and water as a balance; and preparing the mixed material by supplying gas to the slurry, wherein a proportion of the gas is within a range of 2 to 50% by volume, with respect to a total volume of the mixed material, the gas is at least one selected from a group consisting of air, oxygen, nitrogen, argon, helium, carbon dioxide, and hydrogen, the mixed material is prepared by stirring the slurry with a stirring device, while simultaneously supplying the gas to the slurry through holes, and the gas shortens a process of foaming the slurry.

2. The method for producing the mixed material according to claim 1, wherein the slurry composed of 0.05 to 10% by mass of a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms used as a foaming agent, 0.5 to 20% by mass of a water-soluble resin binder, 5 to 80% by mass of a metal powder having an average particle size within a range of 0.5 to 500 m, 0.05 to 5% by mass of a surfactant, and water as a balance.

3. The method for producing the mixed material according to claim 1, wherein the slurry composed of 0.05 to 10% by mass of a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms used as a foaming agent, 0.5 to 20% by mass of a water-soluble resin binder, 5 to 80% by mass of a metal powder having an average particle size within a range of 0.5 to 500 m, 0.1 to 15% by mass of at least one plasticizer selected from the group consisting of a polyhydric alcohol, a fat and oil, an ether, and an ester, and water as a balance.

4. The method for producing the mixed material according to claim 1, wherein the slurry composed of 0.05 to 10% by mass of a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms used as a foaming agent, 0.05 to 5% by mass of a surfactant, 0.5 to 20% by mass of a water-soluble resin binder, 5 to 80% by mass of a metal powder having an average particle size within a range of 0.5 to 500 m, 0.1 to 15% by mass of at least one plasticizer selected from the group consisting of a polyhydric alcohol, a fat and oil, an ether, and an ester, and water as a balance.

5. The method for producing the mixed material according to claim 1, wherein the mixed material is prepared so that uniform size pores are formed in the slurry.

6. The method for producing the mixed material according to claim 1, wherein a time required for completing the process of foaming of the mixed material is within a range of 1 to 8 minutes.

Description

EXAMPLE 1

[0062] To a slurry obtained by mixing the Ag powder having an average particle size of 10 m, hydroxypropylmethylcellulose serving as a water-soluble resin binder, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. By stirring this mixture using a mixer, a conventional mixed material A for producing a porous metallic sintered body was produced which was formed of 60% by mass of Ag powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of hydroxypropylmethylcellulose as a water-soluble resin binder, and water as the balance.

[0063] To a slurry obtained by mixing the Ag powder having an average particle size of 10 m, hydroxypropylmethylcellulose serving as a water-soluble resin binder, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. While stirring this mixture using a mixer, air was supplied to the mixture from a pipe provided with 50 minute holes having a diameter of 0.5 mm By continuing the stirring process while adjusting the amount of air supplied, mixed materials of Present Invention 1 to 5 for producing a porous metallic sintered body and Comparative Mixed Materials 1 and 2 for producing a porous metallic sintered body were produced, all of which were formed of a slurry composed of 60% by mass of Ag powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of hydroxypropylmethylcellulose as a water-soluble resin binder, and water as the balance, as well as air, which was introduced to the slurry so that the respective mixed materials each contained the amount of air shown in Table 1 while the remainder was the conventional mixed material A for producing a porous metallic sintered body.

[0064] These mixed materials for producing a porous metallic sintered body, that is, the conventional mixed material A for producing a porous metallic sintered body, the comparative mixed materials 1 and 2 for producing a porous metallic sintered body, and the mixed materials of present inventions 1 to 5 for producing a porous metallic sintered body were respectively applied on one entire surface of a polyethylene terephthalate (PET) resin sheet having dimensions of 200 mm (longitudinal)200 mm (transverse)1 mm (thickness) so that the thickness of the resulting coating film was 0.3 mm This coating film was retained under the conditions of a humidity of 90% and a temperature of 45 C., and the time required for the coating film to expand so as to achieve a thickness of 1.2 mm was measured. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Constitution of mixed material of the Time required for present invention for producing a porous coating film with a metallic sintered body thickness of 0.3 mm Mixed material (% by volume) to expand so as to for producing a Conventional mixed material achieve a thickness porous metallic A for producing a porous of 1.2 mm sintered body Air content metallic sintered body (min) Note Present 1 2.1 Remainder 8 invention 2 5.0 Remainder 5 3 20.1 Remainder 3 4 35.0 Remainder 2 5 49.8 Remainder 2 Comparative 1 1.3* Remainder 24 2 51.6* Remainder 2 Difficult coating control Conventional 1 100 61

[0065] From the results shown in Table 1, it is apparent that the time required for the coating films obtained by using the mixed materials of present inventions 1 to 5 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm was shortened to a great extent, as compared to the time required for the coating film obtained by using only the conventional mixed material A for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm However, it took a somewhat longer time for the coating film obtained by using the comparative mixed material 1 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm. On the other hand, when the comparative mixed material 2 for producing a porous metallic sintered body, which had an air content of more than 50% by volume, was used, it was difficult to control the coating process due to the large extent of unevenness formed on the coating film surface, and thus the use was not preferable.

EXAMPLE 2

[0066] To a slurry obtained by mixing the Ti powder having an average particle size of 10 m, methylcellulose serving as a water-soluble resin binder, sodium dodecylbenzenesulfonate serving as a surfactant, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. By stirring this mixture using a mixer, a conventional mixed material B for producing a porous metallic sintered body was produced which was formed of 60% by mass of Ti powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of methylcellulose as a water-soluble resin binder, 2.0% by mass of sodium dodecylbenzenesulfonate as a surfactant, and water as the balance.

[0067] To a slurry obtained by mixing the Ti powder having an average particle size of 10 m, methylcellulose serving as a water-soluble resin binder, sodium dodecylbenzenesulfonate serving as a surfactant, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. While stirring this mixture using a mixer, air was supplied to the mixture from a pipe provided with 50 minute holes having a diameter of 0.5 mm By continuing the stirring process while adjusting the amount of air supplied, mixed materials of the present inventions 6 to 10 for producing a porous metallic sintered body and comparative mixed materials 3 and 4 for producing a porous metallic sintered body were produced, all of which were formed of a slurry composed of 60% by mass of Ti powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of methylcellulose as a water-soluble resin binder, and water as the balance, as well as air, which was introduced to the slurry so that the respective mixed materials each contained the amount of air shown in Table 2 while the remainder was the conventional mixed material B for producing a porous metallic sintered body.

[0068] These mixed materials for producing a porous metallic sintered body, that is, the conventional mixed material B for producing a porous metallic sintered body, the comparative mixed materials 3 and 4 for producing a porous metallic sintered body, and the mixed materials of present inventions 6 to 10 for producing a porous metallic sintered body were respectively applied on a surface of the PET resin sheet so that the thickness of the resulting coating film was 0.3 mm This coating film was retained under the conditions of a humidity of 90% and a temperature of 45 C., and the time required for the coating film to expand so as to achieve a thickness of 1.2 mm was measured. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Constitution of mixed material of the present invention for producing a porous Time required for metallic sintered body coating film with a (% by volume) thickness of 0.3 mm Mixed material for Conventional mixed to expand so as producing a porous material B for producing a to achieve a metallic sintered porous metallic sintered thickness of 1.2 mm body Air content body (min) Note Present 6 2.2 Remainder 7 invention 7 5.1 Remainder 5 8 20.1 Remainder 2 9 35.1 Remainder 1 10 48.9 Remainder 1 Comparative 3 1.3* Remainder 14 4 51.6* Remainder 1 Difficult coating control Conventional 2 100 20

[0069] From the results shown in Table 2, it is apparent that the time required for the coating films obtained by using the mixed materials of present inventions 6 to 10 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm was shortened to a great extent, as compared to the time required for the coating film obtained by using only the conventional mixed material B for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm

[0070] However, it took a somewhat longer time for the coating film obtained by using the comparative mixed material 3 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm. On the other hand, when the comparative mixed material 4 for producing a porous metallic sintered body, which had an air content of more than 50% by volume, was used, it was difficult to control the coating process due to the large extent of unevenness formed on the coating film surface, and thus the use was not preferable.

EXAMPLE 3

[0071] To a slurry obtained by mixing the Ni powder having an average particle size of 10 m, hydroxypropylmethylcellulose serving as a water-soluble resin binder, glycerin serving as a plasticizer, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. By stirring this mixture using a mixer, a conventional mixed material C for producing a porous metallic sintered body was produced which was formed of 60% by mass of Ni powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of hydroxypropylmethylcellulose as a water-soluble resin binder, 2.5% by mass of glycerin as a plasticizer, and water as the balance.

[0072] Further, to a slurry obtained by mixing the Ni powder having an average particle size of 10 m, hydroxypropylmethylcellulose serving as a water-soluble resin binder, glycerin serving as a plasticizer, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. While stirring this mixture using a mixer, air was supplied to the mixture from a pipe provided with 50 minute holes having a diameter of 0.5 mm By continuing the stirring process while adjusting the amount of air supplied, the mixed materials of present inventions 11 to 15 for producing a porous metallic sintered body and comparative mixed materials 5 and 6 for producing a porous metallic sintered body were produced, all of which were formed of a slurry composed of 60% by mass of Ni powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of hydroxypropylmethylcellulose as a water-soluble resin binder, 2.5% by mass of glycerin as a plasticizer, and water as the balance, as well as air, which was introduced to the slurry so that the respective mixed materials each contained the amount of air shown in Table 3 while the remainder was the conventional mixed material C for producing a porous metallic sintered body.

[0073] These mixed materials for producing a porous metallic sintered body, that is, the conventional mixed material C for producing a porous metallic sintered body, the comparative mixed materials 5 and 6 for producing a porous metallic sintered body, and the mixed materials of present inventions 11 to 15 for producing a porous metallic sintered body were respectively applied on a surface of the PET resin sheet so that the thickness of the resulting coating film was 0.3 mm This coating film was retained under the conditions of a humidity of 90% and a temperature of 45 C., and the time required for the coating film to expand so as to achieve a thickness of 1.2 mm was measured. The results are shown in Table 3.

TABLE-US-00003 TABLE 3 Constitution of mixed material of the Time required for present invention for producing a porous coating film with a metallic sintered body (% by volume) thickness of 0.3 mm Mixed material for Conventional mixed to expand so as producing a porous material C for producing a to achieve a metallic sintered porous metallic sintered thickness of 1.2 mm body Air content body (min) Note Present 11 2.0 Remainder 8 invention 12 5.2 Remainder 4 13 20.1 Remainder 3 14 34.9 Remainder 3 15 47.9 Remainder 3 Comparative 5 1.3* Remainder 31 6 51.6* Remainder 3 Difficult coating control Conventional 3 Remainder 85

[0074] From the results shown in Table 3, it is apparent that the time required for the coating films obtained by using the mixed materials of present inventions 11 to 15 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm was shortened to a great extent, as compared to the time required for the coating film obtained by using only the conventional mixed material C for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm However, it took a somewhat longer time for the coating film obtained by using the comparative mixed material 5 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm. On the other hand, when the comparative mixed material 6 for producing a porous metallic sintered body, which had an air content of more than 50% by volume was used, it was difficult to control the coating process due to the large extent of unevenness formed on the coating film surface, and thus the use was not preferable.

EXAMPLE 4

[0075] To a slurry obtained by mixing the SUS 316 powder having an average particle size of 10 m, methylcellulose serving as a water-soluble resin binder, sodium dodecylbenzenesulfonate serving as a surfactant, glycerin serving as a plasticizer, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. By stirring this mixture using a mixer, a conventional mixed material D for producing a porous metallic sintered body was produced which was formed of 60% by mass of SUS 316 powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of methylcellulose as a water-soluble resin binder, 2.0% by mass of sodium dodecylbenzenesulfonate as a surfactant, 2.5% by mass of glycerin as a plasticizer, and water as the balance.

[0076] Further, to a slurry obtained by mixing the SUS 316 powder having an average particle size of 10 m, methylcellulose serving as a water-soluble resin binder, sodium dodecylbenzenesulfonate serving as a surfactant, glycerin serving as a plasticizer, and water which were prepared earlier, hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent) was further added, thereby preparing a mixture. While stirring this mixture using a mixer, air was supplied to the mixture from a pipe provided with 50 minute holes having a diameter of 0.5 mm By continuing the stirring process while adjusting the amount of air supplied, mixed materials of present inventions 16 to 20 for producing a porous metallic sintered body and comparative mixed materials 7 and 8 for producing a porous metallic sintered body were produced, all of which were formed of a slurry composed of 60% by mass of SUS 316 powder having an average particle size of 10 m, 1.8% by mass of hexane as a non-water-soluble hydrocarbon-based organic solvent having 5 to 8 carbon atoms (foaming agent), 6.5% by mass of methylcellulose as a water-soluble resin binder, 2.5% by mass of glycerin as a plasticizer, and water as the balance, as well as air, which was introduced to the slurry so that the respective mixed materials each contained the amount of air shown in Table 4 while the remainder was the conventional mixed material D for producing a porous metallic sintered body.

[0077] These mixed materials for producing a porous metallic sintered body, that is, the conventional mixed material D for producing a porous metallic sintered body, the comparative mixed materials 7 and 8 for producing a porous metallic sintered body, and the mixed materials of present inventions 16 to 20 for producing a porous metallic sintered body were respectively applied on a surface of the PET resin sheet so that the thickness of the resulting coating film was 0.3 mm This coating film was retained under the conditions of a humidity of 90% and a temperature of 45 C., and the time required for the coating film to expand so as to achieve a thickness of 1.2 mm was measured. The results are shown in Table 4.

TABLE-US-00004 TABLE 4 Constitution of mixed material of the present invention for producing a porous Time required for metallic sintered body coating film with a (% by volume) thickness of 0.3 mm Mixed material for Conventional mixed to expand so as producing a porous material D for producing a to achieve a metallic sintered porous metallic sintered thickness of 1.2 mm body Air content body (min) Note Present 16 2.5 Remainder 7 invention 17 5.0 Remainder 5 18 19.9 Remainder 3 19 35.0 Remainder 2 20 49.7 Remainder 1 Comparative 7 1.1* Remainder 18 8 51.0* Remainder 1 Difficult coating control Conventional 4 100 27

[0078] From the results shown in Table 4, it is apparent that the time required for the coating films obtained by using the mixed materials of present inventions 16 to 20 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm was shortened to a great extent, as compared to the time required for the coating film obtained by using only the conventional mixed material D for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm However, it took a somewhat longer time for the coating film obtained by using the comparative mixed material 7 for producing a porous metallic sintered body to expand so as to achieve a thickness of 1.2 mm. On the other hand, when the comparative mixed material 8 for producing a porous metallic sintered body, which had an air content of more than 50% by volume was used, it was difficult to control the coating process due to the large extent of unevenness formed on the coating film surface, and thus the use was not preferable.

INDUSTRIAL APPLICABILITY

[0079] By using the mixed materials of the present invention for producing a porous metallic sintered body, since they foam in an even shorter time period as compared to the conventional mixed materials for producing a porous metallic sintered body, it is possible to produce a porous metal having minute pores with uniform size within an even shorter time period. Therefore, the present invention is highly useful industrially.