US2697024A - Dental polishing agent and method of producing same - Google Patents
Dental polishing agent and method of producing same Download PDFInfo
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- US2697024A US2697024A US284646A US28464652A US2697024A US 2697024 A US2697024 A US 2697024A US 284646 A US284646 A US 284646A US 28464652 A US28464652 A US 28464652A US 2697024 A US2697024 A US 2697024A
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- dicalcium phosphate
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K8/00—Cosmetics or similar toiletry preparations
- A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
- A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
- A61K8/24—Phosphorous; Compounds thereof
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q11/00—Preparations for care of the teeth, of the oral cavity or of dentures; Dentifrices, e.g. toothpastes; Mouth rinses
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/32—Phosphates of magnesium, calcium, strontium, or barium
- C01B25/322—Preparation by neutralisation of orthophosphoric acid
Definitions
- This invention relates to an improved dental polishing agent for use in the compounding of tooth paste or tooth powder.
- the dental polishing agent herein contemplated is an improved form of anhydrous dicalcium phosphate.
- anhydrous dicalcium phosphate to be useful as a dental polishing agent should have a polishing power of from about 2 to about 15 and preferably from about 10 to about 13 by the scale hereinafter described. Moreover, it should meet the above polishing power requirements and at the same time have an improved cleaning and stain-removing action over the dihydrate or the anhydrous product of the prior art. In addition, it should combine the above properties in a product which, when used in a dentifrice, does not produce an unpleasant taste or feel in the mouth.
- Anhydrous dicalcium phosphate produced by the methods of the prior art has a polishing power of about 20 to about 30 which is too high to meet the current specifications for a satisfactory dental polishing agent.
- this material when used in a dentifrice, it is so highly abrasive that it has a deleterious effect on the dentine of the teeth. Consequently, there is an urgent demand in the dentifrice art for an anhydrous dicalcium phosphate having a polishing power within the limits of about 2 to about 15, which also possesses all of the previously known desirable properties of the above anhydrous salt.
- the primary object of the present invention to provide an anhydrous dicalcium phosphate having a polishing power within the current specifications for a satisfactory dental polishing agent.
- An additional object of the invention is to provide an anhydrous dicalcium phosphate which has a polishing power within the limits of about 2 to about 15 and an improved cleaning and stain-removing action over the dihydrate and the anhydrous dicalcium phosphate of the prior art.
- a further object of the invention is to provide an anhydrous dicalcium phosphate having a polishing power of from about 2 to about 15 which, when used in a dentifrice, does not produce an unpleasant feel or taste in the mouth.
- a still further object of the invention is to provide a method of producing anhydrous dicalcium phosphate having the above combination of properties.
- anhydrous dicalcium phosphate can be produced in a form that is eminently suitable for use as a dental polishing agent.
- This new form of anhydrous dicalcium phosphate is a pseudomorph of dicalcium phosphate dihydrate, i. e., it has the same apparent crystal formation as the dihydrate.
- it has the very desirable property of having a polishing power within the range of about 2 to about 15 which is well within the present requirements of the dentifrice art.
- a slurry of dicalcium phosphate dihydrate crystals having a particle size within the range of about 2 to about 38 microns is prepared by precipitation, after which the crystals are separated and converted to the anhydrous state by heating.
- the reaction temperature was maintained at about 45 C.
- the slurry of dicalcium phosphate dihydrate thus produced was ball milled and then pumped to a spray drier where it was spray dried using an air inlet temperature of about 625 F. and an air outlet temperature of about 260 F.
- the spray dried product was characterized by having an ignition loss of 8.8%, a polishing power of 9 and a particle size such that on addition to a 325 mesh screen only 2.88% by weight of material was retained.
- Example II One gallon of 75% HsPO4 was diluted to 23% P205 acid and then neutralized with an 8.74% CaO slurry, the resulting reaction temperature being maintained below 45 C. by means of a cooling coil.
- the slurry of dicalcium phosphate dihydrate thus produced was removed from the reactor and ball milled for 30 minutes. After the last mentioned operation, phosphoric acid was added until 10 milliliters of the solution was titratable to a phenolphthalein end point with 1.16 milliliters of 0.1212 N NaOH.
- the slurry was then spray dried using an air inlet temperature of about 600 F. and an air outlet temperaure of about 300 F.
- the spray dried product on testing by the method hereinafter described was found to have a polishing power of 8.5.
- Example 111 A dilute lime slurry containing about 8.74% CaO was added to a 23% P205 phosphoric acid solution with agitation to form a slurry of dicalcium phosphate dihydrate, the lime addition being carried out until 1.26 milliliters of 0.1367 N NaOH titrated 10 milliliters of a sample of the slurry to a phenolphthalein end point.
- the above slurry was transferred to a spraydrier and dried using an air inlet temperature of about 800 F. and an air outlet temperature of about 370 F.
- the spray dried product thus obtained had an ignition loss of 8.3% and a polishing power of 27.
- Example IV 15.9 lbs. of lime containing 73% CaO was mixed with a sufficient amount of water to produce a 8.74% CaO slurry. This slurry was added to 27.4 lbs. of 75 HaPO4 night. The dried product was then slurried in water,
- Example V The procedure describedin Example IV was repeated except that the milling step was omitted.
- the product thus obtained had a polishing power of 41.5.
- Example VI tdilute'lime slurry containing 8.74% CaO was added to a dilute phosphoric acid solution which was-heated to a temperature of C., the above solution being prepared by diluting 177 grams of HsPO4 with water ;to 8.”'P2Q5 content of 15% P205.
- the lime slurry was addeduntil a slurry of dicalcium phosphate was produced 'whose mother liquor titrated to a phenolphthalein end :point with 6 cc. of 0.1 N NaOH per 10 cc. of liquor.
- a dilute solution or slurry of lime is reacted with dilute phosphoric acid in substantially the proportions calcu- -lated to yield dicalcium phosphate 2H2O, the reaction being carried out at a temperature which is maintained below about 45 C. More specifically, these materials arereacted together in the proportions yielding a mother liquorthat -is-titratable to a phenolphthalein. end point with about 1 to about 2 milliliters and preferably with not more than 1.5 milliliters of 0.1507 N NaOI-I.
- the product of the above reaction may be rapidly cooledto yield very fine crystals having a particle size -Within the range of about 2 to about 38 microns or it may be crystallized at room temperature and then converted .
- Air inlet temperature About 500 F. to about 1000 F.
- Air outlet temperature About 280 F. to about 380 F.
- the invention is not limited to these conditions ,as;the inlet and outlet temperatures may be varied widely so ,long ;as anhydrous dicalcium phosphate having .an ignition loss of not over 12% is obtained.
- the relatively coarse slurry of dicalcium phosphate dihydrate crystals may be filtered, centrifuged or treated in any other suitable manner for separating the crystals which rn ay then be milled to a particle size within the limits. of -..:a bo,u t.2-to about 38 microns.
- the milled dicalcium phos- ;;:phate,.dihydrate, is then subjected to slow drying forabout 10 to about 48 hours at a temperature of about 65 C.
- the milled dihydrate is heated to a temperature of about 75 C. for about 30 hours and then for about /2 hour at 300 C. to convert it into a relatively soft anhydrous product.
- the brush is adjusted so that it touches the copper strip along the entire length of the brush. Once this has been achieved, the brush is rigidly fixed in position.
- the sample to be tested is prepared by adding twenty grams of the powdered material to a 150 milliliter beaker and then mixing therewith glycerine until the resulting paste flows readily upon tilting the beaker.
- the paste thus prepared is poured into the above trough and the brush lowered into contact with the copper strip.
- the brushholder is reciprocated 14,400 times in about to 123 minutes so that including the forward and reverse motions of the brush a total of 28,800 strokes are applied to the copper strip.
- the copper strip is removed, washed with water and then with ethyl alcohol.
- the washed strip is then dried for 5 minutes at 60 C., cooled in a dessicator and reweighed.
- the loss in weight in milligrams represents the polishing power.
- the abrasive material being tested is said to have a polishing power of 10.
- the ignition loss as used herein represents the loss in weight of the anhydrous dicalcium phosphate product when heated for /2 hour at 800 C.
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Description
United States Patent 0.
DENTAL POLISHING AGENT AND METHOD OF PRODUCING SAME Henry V. Moss, Anniston, Ala., and Theodore W. Schilb, Centerville, Ohio, assignors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application April 26, 1952, Serial No. 284,646
g] 9 Claims. (Cl. 23109) This invention relates to an improved dental polishing agent for use in the compounding of tooth paste or tooth powder. The dental polishing agent herein contemplated is an improved form of anhydrous dicalcium phosphate.
According to the present requirements of the trade, anhydrous dicalcium phosphate to be useful as a dental polishing agent should have a polishing power of from about 2 to about 15 and preferably from about 10 to about 13 by the scale hereinafter described. Moreover, it should meet the above polishing power requirements and at the same time have an improved cleaning and stain-removing action over the dihydrate or the anhydrous product of the prior art. In addition, it should combine the above properties in a product which, when used in a dentifrice, does not produce an unpleasant taste or feel in the mouth.
Anhydrous dicalcium phosphate produced by the methods of the prior art has a polishing power of about 20 to about 30 which is too high to meet the current specifications for a satisfactory dental polishing agent. Thus, when this material is used in a dentifrice, it is so highly abrasive that it has a deleterious effect on the dentine of the teeth. Consequently, there is an urgent demand in the dentifrice art for an anhydrous dicalcium phosphate having a polishing power within the limits of about 2 to about 15, which also possesses all of the previously known desirable properties of the above anhydrous salt.
It is, therefore, the primary object of the present invention to provide an anhydrous dicalcium phosphate having a polishing power within the current specifications for a satisfactory dental polishing agent.
An additional object of the invention is to provide an anhydrous dicalcium phosphate which has a polishing power within the limits of about 2 to about 15 and an improved cleaning and stain-removing action over the dihydrate and the anhydrous dicalcium phosphate of the prior art.
A further object of the invention is to provide an anhydrous dicalcium phosphate having a polishing power of from about 2 to about 15 which, when used in a dentifrice, does not produce an unpleasant feel or taste in the mouth.
A still further object of the invention is to provide a method of producing anhydrous dicalcium phosphate having the above combination of properties.
Other objects and advantages will become apparent to those skilled in the art as the description of the invention proceeds.
We have made the surprising discovery that by following the method hereinafter described, anhydrous dicalcium phosphate can be produced in a form that is eminently suitable for use as a dental polishing agent. This new form of anhydrous dicalcium phosphate is a pseudomorph of dicalcium phosphate dihydrate, i. e., it has the same apparent crystal formation as the dihydrate. Moreover, it has the very desirable property of having a polishing power within the range of about 2 to about 15 which is well within the present requirements of the dentifrice art.
In accordance with the above method, a slurry of dicalcium phosphate dihydrate crystals having a particle size within the range of about 2 to about 38 microns is prepared by precipitation, after which the crystals are separated and converted to the anhydrous state by heating. In another embodiment, a slurry of relatively coarse 2,697,024 Patented Dec. 14, 1954 2 crystals of dicalcium phosphate dihydrate is produced and milled so as to reduce the size of the crystals to a value within the above limits, whereupon the slurry of fractured crystals is spray dried at a temperature producing anhydrous dicalcium phosphate having an ignition loss 3.295 kilograms of lime containing 73% CaO was slurried with 6.5 gallons of water and the resulting product added to 5:1 kilograms of 61.6% P205 phosphoric acid which had been diluted with water to a concentration of 23% P205 acid, the lime being added until 10 milli liters of the resulting slurry was titratable with 2 milliliters of 0.1507 N NaOH to a phenolphthalein end point. During the above operation, the reaction temperature was maintained at about 45 C. The slurry of dicalcium phosphate dihydrate thus produced was ball milled and then pumped to a spray drier where it was spray dried using an air inlet temperature of about 625 F. and an air outlet temperature of about 260 F. The spray dried product was characterized by having an ignition loss of 8.8%, a polishing power of 9 and a particle size such that on addition to a 325 mesh screen only 2.88% by weight of material was retained.
Example II One gallon of 75% HsPO4 was diluted to 23% P205 acid and then neutralized with an 8.74% CaO slurry, the resulting reaction temperature being maintained below 45 C. by means of a cooling coil. The slurry of dicalcium phosphate dihydrate thus produced was removed from the reactor and ball milled for 30 minutes. After the last mentioned operation, phosphoric acid was added until 10 milliliters of the solution was titratable to a phenolphthalein end point with 1.16 milliliters of 0.1212 N NaOH. The slurry was then spray dried using an air inlet temperature of about 600 F. and an air outlet temperaure of about 300 F. The spray dried product on testing by the method hereinafter described was found to have a polishing power of 8.5.
Example 111 A dilute lime slurry containing about 8.74% CaO was added to a 23% P205 phosphoric acid solution with agitation to form a slurry of dicalcium phosphate dihydrate, the lime addition being carried out until 1.26 milliliters of 0.1367 N NaOH titrated 10 milliliters of a sample of the slurry to a phenolphthalein end point. The above slurry was transferred to a spraydrier and dried using an air inlet temperature of about 800 F. and an air outlet temperature of about 370 F. The spray dried product thus obtained had an ignition loss of 8.3% and a polishing power of 27.
It is evident from Examples I and II which resulted in the production of a product having a polishing power within the desired range that milling is an essential step of the process since this step was missing from Example IIIand the polishing power of the resulting product was too high.
Example IV 15.9 lbs. of lime containing 73% CaO was mixed with a sufficient amount of water to produce a 8.74% CaO slurry. This slurry was added to 27.4 lbs. of 75 HaPO4 night. The dried product was then slurried in water,
,milled in .a ball mill, filtered and heated in a pan for about 36 hours at 75 C. The product thereby obtained had a polishing power of 8.5.
Example V .The procedure describedin Example IV was repeated except that the milling step was omitted. The product thus obtained had a polishing power of 41.5.
The results obtained by the methods described in Ex- :amples IV and V further illustrate that it is essential ;to
.substantially reduce the particle size of the crystals in order to produce a product having a polishing power with- .in the desired range.
Example VI tdilute'lime slurry containing 8.74% CaO was added to a dilute phosphoric acid solution which was-heated to a temperature of C., the above solution being prepared by diluting 177 grams of HsPO4 with water ;to 8."'P2Q5 content of 15% P205. The lime slurry was addeduntil a slurry of dicalcium phosphate was produced 'whose mother liquor titrated to a phenolphthalein end :point with 6 cc. of 0.1 N NaOH per 10 cc. of liquor.
One half of the slurry of anhydrous dicalcium phosphate crystals was ball milled to a particle size within the range of 2 to 38 microns. The ground crystals were separated from their motherliquor andthen pan dried slowly at a temperature of 70 C. This sample had an ignition loss of 8.3% and a polishing power of 25.3.
The other half of the slurry of crystals was separated from its mother liquor, pan dried slowly at 70 C. and
subsequently milled to a particle size within the range of'2 to 38 microns. The ignition loss for this sample was L 9% and the polishing power was 28.1.
The above example demonstrates that if the dicalcium phosphate is initially precipitated in the anhydrous state and then ground to a particle size within the limits of 2 to 38 microns, separated and finally dried, an excessively abrasive product is obtained; it also shows that if the :dicalcium phosphate is precipitated in the anhydrous state, separated, then dried and finally ground to the above particle size, the product still does not possess the desired low polishing power.
Incarrying out the method of the instant invention,
a dilute solution or slurry of lime is reacted with dilute phosphoric acid in substantially the proportions calcu- -lated to yield dicalcium phosphate 2H2O, the reaction being carried out at a temperature which is maintained below about 45 C. More specifically, these materials arereacted together in the proportions yielding a mother liquorthat -is-titratable to a phenolphthalein. end point with about 1 to about 2 milliliters and preferably with not more than 1.5 milliliters of 0.1507 N NaOI-I.
The product of the above reaction may be rapidly cooledto yield very fine crystals having a particle size -Within the range of about 2 to about 38 microns or it may be crystallized at room temperature and then converted .Air inlet temperature About 500 F. to about 1000 F. Preferably about 600 F. to about 800 F. Air outlet temperature About 280 F. to about 380 F.
The invention, however, is not limited to these conditions ,as;the inlet and outlet temperatures may be varied widely so ,long ;as anhydrous dicalcium phosphate having .an ignition loss of not over 12% is obtained.
Asa modification of the above'described procedure, the relatively coarse slurry of dicalcium phosphate dihydrate crystals may be filtered, centrifuged or treated in any other suitable manner for separating the crystals which rn ay then be milled to a particle size within the limits. of -..:a bo,u t.2-to about 38 microns. The milled dicalcium phos- ;;:phate,.dihydrate,is then subjected to slow drying forabout 10 to about 48 hours at a temperature of about 65 C.
p to about C. and then for about A hour to about 1 hour at 325 C. to about 250 C. to convert it to the anhydrous state in which it then possesses a polishing power within the desired limits. More specifically, the milled dihydrate is heated to a temperature of about 75 C. for about 30 hours and then for about /2 hour at 300 C. to convert it into a relatively soft anhydrous product.
holder, moistened and then lowered against the copper strip, the brush being adjusted so that it touches the copper strip along the entire length of the brush. Once this has been achieved, the brush is rigidly fixed in position.
The sample to be tested is prepared by adding twenty grams of the powdered material to a 150 milliliter beaker and then mixing therewith glycerine until the resulting paste flows readily upon tilting the beaker. The paste thus prepared is poured into the above trough and the brush lowered into contact with the copper strip.
The brushholder is reciprocated 14,400 times in about to 123 minutes so that including the forward and reverse motions of the brush a total of 28,800 strokes are applied to the copper strip.
At the end of the foregoing operation, the copper strip is removed, washed with water and then with ethyl alcohol. The washed strip is then dried for 5 minutes at 60 C., cooled in a dessicator and reweighed. The loss in weight in milligrams represents the polishing power. Thus, if the copper strip losses 10 milligrams in weight, the abrasive material being tested is said to have a polishing power of 10.
The ignition loss as used herein represents the loss in weight of the anhydrous dicalcium phosphate product when heated for /2 hour at 800 C.
The expression about 2 to about 38 microns mentioned earlier herein has reference to particle size as measured by sedimentation rate and calculations based on Stokes law of falling spheres [see method of Hinkley, Industrial and Engineering Chemistry (Analytical Edition) volume 14, pp. 10-13, 1952; and also method described by Colbeck and Harner found in industrial and Engineering Chemistry, volume 19, page 58, 1927].
The above description and examples are intended to be illustrative only. Any modification or variation therefrom which conforms to the spirit of the invention is intended to be included within the scope of the claims.
What we claim is:
1. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 2-to about 15, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals having a particle size within the range of about 2 to about 38 microns and then converting said product to the anhydrous state by heating.
2. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 10 to about 13, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals having a particle size within the range of about 2 to about 38 microns and then converting said product to the anhydrous state by heating.
3. The method-of. producing anhydrous dicalcium phosphate having :a polishing power within the range of about 2 to.about 15, which comprises preparing a slurry .of dicalcium phosphate dihydrate crystals having a particle size within the range of about 2 to about 38 microns and then spray drying said slurry at a temperature sufficient to produce anhydrous dicalcium phosphate.
4. The-method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 2 to about 15, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals, milling said slurry soas to reduce'the particle size of said crystals to a value withinthe-range .of about..2.to ,about,38.microns and then spray drying said product at a temperature producing anhydrous dicalcium phosphate.
5. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about to about 13, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals, milling said slurry so as to reduce the particle size of said crystals to a value within the range of about 2 to about 38 microns and then spray drying said product at a temperature producing anhydrous dicalcium phosphate.
6. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 2 to about 15, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals, milling said slurry so as to reduce the particle size of said crystals to a value within the range of about 2 to about 38 microns and then spray drying said product under conditions yielding a product having an ignition loss not in excess of 12% by weight.
7. The method defined in claim 6 wherein the spray drying operation is carried out at a temperature producing a product having an ignition loss of from about 8% to about 9% by weight.
8. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 2 to about 15, which comprises preparing a slurry of di calcium phosphate dihydrate crystals, milling said product so as to reduce the particle size of said crystals to a value within the range of about 2 to about 38 microns and then converting the resulting product to anhydrous dicalcium phosphate by heating.
9. The method of producing anhydrous dicalcium phosphate having a polishing power within the range of about 2 to about 15, which comprises preparing a slurry of dicalcium phosphate dihydrate crystals, milling said slurry so as to reduce the particle size of said crystals to a value within the range of about 2 to about 38 microns, separating said crystals, heating said separated crystals to a temperature of about 75 C. for about hours and then at 300 C. for about /2 hour to convert said crystals to the anhydrous state.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,818,114 Carothers et a1 Aug. 11, 1931 2,277,854 Lecoq Mar. 31, 1942 2,296,494 Block Sept. 22, 1942
Claims (1)
1. THE METHOD OF PRODUCING ANHYDROUS DICALCIUM PHOSPHATE HAVING A POLISHING POWER WITHIN THE RANGE OF ABOUT 2 TO ABOUT 15, WHICH COMPRISES PREPARING A SLURRY OF DICALCIUM PHOSPHATE DIHYDRATE CRYSTALS HAVING A PARTICLE SIZE WITHIN THE RANGE OF ABOUT 2 TO ABOUT 38 MICRONS AND THEN COVERTING SAID PRODUCT TO THE ANHYDROUS STATE BY HEATING.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US284646A US2697024A (en) | 1952-04-26 | 1952-04-26 | Dental polishing agent and method of producing same |
| DEM18239A DE958243C (en) | 1952-04-26 | 1953-04-21 | Process for the production of anhydrous dicalcium phosphate with a cleaning force between 2 and 15, preferably between 10 and 13 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US284646A US2697024A (en) | 1952-04-26 | 1952-04-26 | Dental polishing agent and method of producing same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2697024A true US2697024A (en) | 1954-12-14 |
Family
ID=23090990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US284646A Expired - Lifetime US2697024A (en) | 1952-04-26 | 1952-04-26 | Dental polishing agent and method of producing same |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2697024A (en) |
| DE (1) | DE958243C (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2876168A (en) * | 1956-08-20 | 1959-03-03 | Procter & Gamble | Calcium pyrophosphate abrasive and dentifrice containing the same |
| US2901400A (en) * | 1955-12-30 | 1959-08-25 | Monsanto Chemicals | Cryptocrystalline calcium pyrophosphate and dentifrice composition comprising the same |
| US2943982A (en) * | 1955-10-10 | 1960-07-05 | Clarence W Dahlin | Processing of dicalcium phosphate and composition thereof |
| US3065053A (en) * | 1960-02-23 | 1962-11-20 | Sylvania Electric Prod | Homogeneous precipitation of dibasic alkaline earth phosphates |
| US3279992A (en) * | 1962-05-18 | 1966-10-18 | Monsanto Co | Fluoridation |
| US3647371A (en) * | 1968-08-07 | 1972-03-07 | Monsanto Co | Method for preparation of dicalcium phosphate |
| US5486365A (en) * | 1993-09-17 | 1996-01-23 | Fuji Chemical Industry Co., Ltd. | Calcium hydrogen phosphate, a method for preparing it, and an excipient utilizing it |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1189527B (en) * | 1959-06-30 | 1965-03-25 | Stauffer Chemical Co | Process for the production of stabilized dicalcium phosphate |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1818114A (en) * | 1926-06-11 | 1931-08-11 | Swann Res Inc | Method for the production of dried acid calcium phosphate |
| US2277854A (en) * | 1939-05-10 | 1942-03-31 | Lecoq Louis Paul Victor | Colloidal tertiary calcium phosphate |
| US2296494A (en) * | 1939-09-14 | 1942-09-22 | Blockson Chemical Co | Manufacture of anhydrous di-calcium phosphate |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE572056C (en) * | 1929-06-21 | 1933-04-22 | I G Farbenindustrie Akt Ges | Process for dewatering dicalcium phosphate containing water of crystallization |
-
1952
- 1952-04-26 US US284646A patent/US2697024A/en not_active Expired - Lifetime
-
1953
- 1953-04-21 DE DEM18239A patent/DE958243C/en not_active Expired
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1818114A (en) * | 1926-06-11 | 1931-08-11 | Swann Res Inc | Method for the production of dried acid calcium phosphate |
| US2277854A (en) * | 1939-05-10 | 1942-03-31 | Lecoq Louis Paul Victor | Colloidal tertiary calcium phosphate |
| US2296494A (en) * | 1939-09-14 | 1942-09-22 | Blockson Chemical Co | Manufacture of anhydrous di-calcium phosphate |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2943982A (en) * | 1955-10-10 | 1960-07-05 | Clarence W Dahlin | Processing of dicalcium phosphate and composition thereof |
| US2901400A (en) * | 1955-12-30 | 1959-08-25 | Monsanto Chemicals | Cryptocrystalline calcium pyrophosphate and dentifrice composition comprising the same |
| US2876168A (en) * | 1956-08-20 | 1959-03-03 | Procter & Gamble | Calcium pyrophosphate abrasive and dentifrice containing the same |
| US3065053A (en) * | 1960-02-23 | 1962-11-20 | Sylvania Electric Prod | Homogeneous precipitation of dibasic alkaline earth phosphates |
| US3279992A (en) * | 1962-05-18 | 1966-10-18 | Monsanto Co | Fluoridation |
| US3647371A (en) * | 1968-08-07 | 1972-03-07 | Monsanto Co | Method for preparation of dicalcium phosphate |
| US5486365A (en) * | 1993-09-17 | 1996-01-23 | Fuji Chemical Industry Co., Ltd. | Calcium hydrogen phosphate, a method for preparing it, and an excipient utilizing it |
Also Published As
| Publication number | Publication date |
|---|---|
| DE958243C (en) | 1957-02-14 |
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