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US5322675A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of preparing calcium phosphate

Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1993-01-14
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Granted: 1994-06-21
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Expires: 2013-01-14
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Abstract

Abstract Powdery calcium carbonate and a powdery dihydrate of calcium monohydrogenohosphate are weighed to get a Ca/P ratio of 1.45 to 1.67. The powdery mixture thus prepared is then added pure water at a temperature of 30 DEG C. or higher to obtain an aqueous slurry having a concentration of about 10% by weight. Thereafter, the aqueous slurry is subjected to a rotational attrition by using a ball mill to conduct a mechanochemical reaction of the calcium carbonate with the dihydrate of calcium monohydrogenphosphate. The slurry is then dried completely at 80 DEG C., followed by pulverization to yield a dry powder of calcium phosphate hydrate. The dry powder is calcinated at a temperature ranging from 720 DEG to 1,150 DEG C. for 1-10 hours or more to give calcium phosphate powder, which is molded in a desired shape and is sintered at a certain temperature to obtain a sintered body of calcium phosphate. The calcium phosphate and the sintered body thereof, thus prepared, have an assured biological safety in that the calcium phosphate is free from hemolysis, antigenicity and cytotoxicity.

Inventors

  • 👤 Yasuharu Hakamatsuka
  • 👤 Hiroyuki Irie
  • 👤 Sukezo Kawamura
  • 👤 Motohiro Toriyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 09:34
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/447; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/327

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 308 words
A method of preparing calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing about 10% by weight of the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted, at 80° C.; (e) pulverizing the dried slurry to obtain a powdery substance; and (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.
Claim 2
Independent Claim 308 words
A method of preparing calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing about 10% by weight of the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted, at 80° C.; (e) pulverizing the dried slurry to obtain a powdery substance; and (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.
Claim 3
Dependent Claim 21 words
The method according to claim 1, wherein said powdery calcium carbonate has a particle diameter of not more than 0.5 μm.
Claim 4
Dependent Claim 12 words
The method according to claim 2, wherein the Ca/P ratio is 1.5.
Claim 5
Dependent Claim 24 words
The method according to claim 3, wherein step (c) is carried out for 24 hours and step (d) is carried out for 8 hours.
Claim 6
Dependent Claim 18 words
The method according to claim 1, wherein the water is at a temperature of 30° to 50° C.
Claim 7
Dependent Claim 18 words
The method according to claim 1, wherein the calcining is carried out at 1150° C. for one hour.
Claim 8
Dependent Claim 18 words
The method according to claim 1, wherein the calcining is carried out at 1000° C. for three hours.
Claim 9
Dependent Claim 18 words
The method according to claim 1, wherein the calcining is carried out at 900° C. for eight hours.
Claim 10
Dependent Claim 18 words
The method according to claim 1, wherein the calcining is carried out at 720° C. for ten hours.
Claim 11
Independent Claim 335 words
A method of preparing a sintered body of calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing about 10% by weight of the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted, at 80° C.; (e) pulverizing the dried slurry to obtain a powdery substance; (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° c.; (g) molding the calcium phosphate into a desired shape, and (h) sintering the molded calcium phosphate to obtain a sintered body of the calcium phosphate.
Claim 12
Independent Claim 335 words
A method of preparing a sintered body of calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing about 10% by weight of the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted, at 80° C.; (e) pulverizing the dried slurry to obtain a powdery substance; (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° c.; (g) molding the calcium phosphate into a desired shape, and (h) sintering the molded calcium phosphate to obtain a sintered body of the calcium phosphate.
Claim 13
Dependent Claim 21 words
The method according to claim 10, wherein said powdery calcium carbonate has a particle diameter of not more than 0.5 μm.
Claim 14
Dependent Claim 12 words
The method according to claim 11, wherein the Ca/P ratio is 1.5.
Claim 15
Dependent Claim 24 words
The method according to claim 12, wherein step (c) is carried out for 24 hours and step (d) is carried out for 8 hours.
Claim 16
Dependent Claim 18 words
The method according to claim 10, wherein the water is at a temperature of 30° to 50° C.
Claim 17
Independent Claim 300 words
A method of preparing calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted; (e) pulverizing the dried slurry to obtain a powdery substance; and (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.
Claim 18
Independent Claim 300 words
A method of preparing calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 30° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted; (e) pulverizing the dried slurry to obtain a powdery substance; and (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.
Claim 19
Dependent Claim 21 words
The method according to claim 15, wherein said powdery calcium carbonate has a particle diameter of not more than 0.5 μm.
Claim 20
Dependent Claim 19 words
The method according to claim 15, wherein the aqueous slurry contains about 10% by weight of the powdery materials.
Claim 21
Independent Claim 328 words
A method of preparing a sintered body of calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 90+° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted; (e) pulverizing the dried slurry to obtain a powdery substance; (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.; (g) molding the calcium phosphate into a desired shape, and (h) sintering the molded calcium phosphate to obtain a sintered body of the calcium phosphate.
Claim 22
Independent Claim 328 words
A method of preparing a sintered body of calcium phosphate comprising: (a) weighing powdery materials comprising powdery calcium carbonate and powdery calcium monohydrogenphosphate or a powdery dihydrate thereof such that a Ca/P ratio of the powdery materials is 1.45 to 1.67; (b) adding water at a temperature of not lower than 90+° C. to the weighed powdery materials from step (a) to prepare an aqueous slurry containing the powdery materials; (c) subjecting the aqueous slurry to a rotational attrition by using a ball mill to carry out a mechanochemical reaction of said calcium carbonate with said calcium monohydrogenphosphate or a dehydrate thereof; (d) drying the aqueous slurry, thus mechanochemically reacted; (e) pulverizing the dried slurry to obtain a powdery substance; (f) calcining the powdery substance under conditions of calcination temperature and calcination period of time to obtain a biologically safe calcium phosphate free from all of hemolysis, antigenicity and cytotoxicity, said calcining being carried out at a calcination temperature of 720° to 1,150° C. for a calcination period of time of 1 to 10 hours, said calcining being carried out for a calcination period of time of at least one hour when said calcining is carried out at 1,150° C. and the calcination period of time being related to the calcination temperature such that the calcination period of time is increased with a decrease in said calcination temperature, said calcining being carried out for a calcination period of time of at least 3 hours when said calcining is carried out 1000° C., said calcining being carried out for a calcination period of time of at least 8 hours when said calcining is carried out at 900° C. and said calcining being carried out for a calcination period of time of at least 10 hours when said calcining is carried out at 720° C.; (g) molding the calcium phosphate into a desired shape, and (h) sintering the molded calcium phosphate to obtain a sintered body of the calcium phosphate.
Claim 23
Dependent Claim 21 words
The method according to claim 18, wherein said powdery calcium carbonate has a particle diameter of not more than 0.5 μm.
Claim 24
Dependent Claim 19 words
The method according to claim 18, wherein the aqueous slurry contains about 10% by weight of the powdery materials.

References Cited (Backward Citations)

US4717556A Cited
US4880610A Cited
US5047031A Cited
US5053212A Cited

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