DOCSLIB.ORG

United States Patent (19) (11) 4,411,876 Sherif 45) Oct

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
United States Patent (19) (11) 4,411,876 Sherif 45) Oct United States Patent (19) (11) 4,411,876 Sherif 45) Oct. 25, 1983 54 PROCESS FOR THE MANUFACTURE OF 636182 12/1978 U.S.S.R. .............................. 423A311 TRIMAGNESUM PHOSPHATE OCTAHYDRATE OF HIGH PURTY OTHER PUBLICATIONS Bhaunagary et al., "Preparation of Tricalcium Phos phate by Hydrolysis of Dicalcium Phosphate with Cal (75) Inventor: Fawzy G. Sherif, Stony Point, N.Y. cium Hydroxide", J. Appl. Chem. Biotechnol., (1977), (73) Assignee: Stauffer Chemical Company, 27, 393-398. Westport, Conn. Chemical Abstracts, 81 (12), 71959c. 21 Appl. No.: 454,395 Chemical Abstracts, 78(22) 138447t. Primary Examiner-Edward J. Meros 22 Filed: Dec. 30, 1982 Assistant Examiner-Wayne A. Langel (51) Int. Cl. .............................................. CO1B 25/26 Attorney, Agent, or Firm-Vivienne T. White 52) U.S. Cl. .................................................... 423/311 (58) Field of Search ................................ 423/308, 311 57 ABSTRACT The invention is the production of crystalline tertiary 56) References Cited magnesium phosphate octahydrate having uniform and U.S. PATENT DOCUMENTS perfect crystal shape. The process comprises adding a 991,096 5/1911 Schrödter ........................... 423/31 monomagnesium phosphate solution to a magnesium 2,095,994 10/1937 MacIntire ...... ... 42.331 hydroxide slurry at a sufficient temperature and for a 3,194,632 7/1965 Baniel et al. ........................ 423/311 sufficient time to form the highly pure crystalline prod uct within a specified pH range. FOREIGN PATENT DOCUMENTS 44-4649 2/1969 Japan ................................... 423.31 9 Claims, No Drawings 4,411,876 1 2 phate compatibility of various samples of dicalcium PROCESS FOR THE MANUFACTURE OF phosphate dihydrate, TRIMAGNESUM PHOSPHATE The prior art teaches that dicalcium phosphate dihy OCTAHYDRATE OF HIGH PURITY drate may be stabilized by adding a small amount of an alkali metal pyrophosphate or tertiary magnesium phos BACKGROUND OF THE INVENTION phate to the mother liquor, at a controlled pH, during the preparation of the dicalcium phosphate. Specifi 1. Field of the Invention cally, it is taught that after precipitation of the dical The invention relates to a process for the production cium phosphate in the mother liquor, a small amount of of tertiary magnesium phosphate octahydrate and in O alkali metal pyrophosphate or tertiary magnesium phos particular to a process for the production of highly pure phate should be added and the entire slurry then heated crystalline tertiary magnesium phosphate octahydrate. for a short period of time, while maintaining the pH of 2. Related Art the mother liquor above 7. It is known to use tertiary magnesium phosphate The alkali metal pyrophosphate or tertiary magne (a/k/a tribasic magnesium, phosphate or trimagnesium 5 sium phosphate coats the surface of the dicalcium phos phosphate), or an alkali metal pyrophosphate as a stabi phate such that the coating significantly eliminates the lizer for dibasic calcium phosphate. reaction of the dicalcium phosphate with the mono It is well known that hardness and particle shape fluorophosphate thereby resulting in a dicalcium phos make dibasic calcium phosphate suitable for use as a phate which remains in the water soluble state. base for dentifrices. The required properties of a base The effect of tertiary magnesium phosphate as a stabi for a toothpaste are that, even when kept in the tube for lizer for dibasic calcium phosphate varies greatly with a long time, it does not harden, remains homogeneous, the method used for its production. does not form a coagulated mass, and does not separate Tertiary magnesium phosphate containing 0, 4, 8, and into a liquid and solid phase. However, the dihydrate of 22 molecules of water of crystallization has so far been dibasic calcium phosphate, when used as a base for a 25 reported, but only the octahydrate is used as a stabilizer toothpaste is so unstable that it often tends to harden, for dicalcium phosphate. It is also known to use tribasic coagulate, causing the toothpaste to separate into a magnesium phosphate as a fertilizer because of its high liquid and a solid phase. The water of crystallization of P2O5 content, and as an antacid. It has also been dis dibasic calcium phosphate is normally thermally unsta closed to use tribasic magnesium phosphate as a water ble and tends to evaporate readily when the compound 30 insoluble neutralizing agent in the growing of acid pro is allowed to stand in dry air at room temperature, leav ducing bacteria cultures. ing the anhydrous salt behind. The known production methods for the octahydrate With the advent of the use of monofluorophosphate include one in which an aqueous solution of magnesium additives in toothpaste formulations another problem sulfate and dibasic sodium phosphate is made weakly was encountered. It was found that the monofluoro alkaline with sodium bicarbonate and is then allowed to phosphate components would react with the dicalcium stand. Another method is one in which dibasic magne phosphate whereby the monofluorophosphate compo sium phosphate is boiled for a long time in a large quan nent was converted from a water/soluble form to a tity of water. water insoluble form. Since the beneficial effect of It has been disclosed to produce Mg3(PO4)2.8H2O by 40 the dehydration of Mg2(PO4)2.22H2O or by the hydro monofluorophosphate additives in toothpaste is under lysis of Mg2HPO4.3H2O. stood to be derived principally from the water-soluble It has also been disclosed to produce Mg3(PO4)2.8- form, it has become important to develop toothpaste H2O by reacting orthophosphoric acid, added drop formulations which permit an effective amount of wise, to magnesium oxide powder or magnesium hy monofluorophosphate component to remain in the 45 droxide powder with energetic stirring; see Japanese water-soluble state, Patent Application No. 39-57557/1964. This order of The term "monofluorophosphate compatibility' has addition, i.e., the acid to the base, is disclosed to be been used as a term-of-art to describe the tendency of necessary to produce the trimagnesium but not the such formulations to permit the monofluorophosphate dimagnesium phosphate. However, it is common to component to remain in the water soluble state. SO produce trimagnesium phosphate by this method, The monofluorophosphate compatibility of a particu which product is contaminated with unreacted lar formulation may be determined by a variety of meth Mg(OH)2 or with dimagnesium phosphate. These unde ods. Preferably, the monofluorophosphate compatibil sired components lead to caking. They may also alter ity of a formulation is determined by actually preparing the functional properties of the trimagnesium phos the toothpaste formulation, comprising a fluoride stabi- ss phate. Furthermore, the addition of the very strong acid lizer, placing it in storage for a predetermined period of to Mg(OH)2 has to occur at a very slow rate, otherwise time under controlled conditions, and then determining the pH falls very quickly forming the dimagnesium the amount of water-soluble monofluorophosphate phosphate. Therefore, this process takes several hours, which remains in the formulation. Alternatively, a sinnu normally 10-14 hours, to complete. lated formulation, such as the dicalcium phosphate di hydrate to be tested, glycerine, a known amount of a SUMMARY OF THE INVENTION monofluorophosphate component, such as sodium A novel process of producing trimagnesium phos monofluorophosphate and a stabilizer can be "quick phate octahydrate has been discovered which produces aged' by maintaining it at an elevated temperature for Mg3(PO4)2.8H2O crystals having good crystal shapes. one or more hours, and then determining the amount of 65 The process of the invention comprises the reaction of water-soluble monofluorophosphate remaining after monobasic monomagnesium phosphate with magne such conditioning. There are, of course, many other sium hydroxide at a temperature of from about 35 C. to methods for measuring the relative monofluorophos about 70° C. for a period of hours wherein the pH is 4,411,876 3 4. maintained at from about 6.7 to about 6.9 during the A terminal pH of from about 6.7 to about 6.9 for the process and the process pH is preferably 6.8. reaction slurry is generally acceptable with a pH of 6.8 being particularly desirable. At lower a pH of 4 or 6, for DETALED DESCRIPTION OF THE example, dimagnesium phosphate is formed instead of INVENTION trimagnesium phosphate. At higher a pH free untreated The invention is a process of producing highly pure Mg(OH)2 remains in the product. trimagnesium phosphate. The monomagnesium phosphate solution is generally Broadly the invention comprises the preparation of a added to the slurry over a period of time sufficient to monomagnesium phosphate solution followed by the complete the reaction and produce the pure trimagne addition of the monomagnesium phosphate solution to a 10 sium phosphate octahydrate product. A total reaction magnesium hydroxide slurry wherein the temperature time of from 5 to 7 hours is generally required. After the of the slurry is maintained at from about 35 to about 70 reaction is completed, the white solid product is filtered C. and preferably from about 40' to about 50 C. from the mother liquor. The reactions are thought to be as follows: Mg(OH)2 In practicing the invention it is desirable to use a and excess H3PO4 are mixed together to produce the 15 monomagnesium phosphate solution having as high a following: concentration of Mg and H3PO4 as possible to reduce the amount of filtrate recycled in the commercial pro cess and therefore reduce cost. At lower concentrations of Mg and H3PO4, the ratio of the filtered product to The clear slightly acidic monomagnesium phosphate the mother liquor will be too small, requiring larger solution produced has a pH of about 3 to about 3.5. It is equipment in handling of the filtrate. This is not eco then added to a slurry of Mg(OH)2 as shown.
Load more

Recommended publications
  • 2019 Trace Minerals
    United States Department of Agriculture Agricultural Marketing Service | National Organic Program Document Cover Sheet https://www.ams.usda.gov/rules-regulations/organic/national-list/petitioned Document Type: ☐ National List Petition or Petition Update A petition is a request to amend the USDA National Organic Program’s National List of Allowed and Prohibited Substances (National List). Any person may submit a petition to have a substance evaluated by the National Organic Standards Board (7 CFR 205.607(a)). Guidelines for submitting a petition are available in the NOP Handbook as NOP 3011, National List Petition Guidelines. Petitions are posted for the public on the NOP website for Petitioned Substances. ☒ Technical Report A technical report is developed in response to a petition to amend the National List. Reports are also developed to assist in the review of substances that are already on the National List. Technical reports are completed by third-party contractors and are available to the public on the NOP website for Petitioned Substances. Contractor names and dates completed are available in the report. Trace Minerals Livestock 1 Identification of Petitioned Substance 2 3 “Trace minerals” is a term for multiple nutritional elements added to livestock, poultry, and companion 4 animal diets in micro quantities only (i.e., measured in milligrams per pound or small units) (AAFCO 5 2019). While the Association of American Feed Control Officials (AAFCO) lists only cobalt, copper, iodine, 6 iron, manganese, and zinc as trace minerals added to animal feeds (AAFCO 2019), this technical report also 7 discusses chromium, molybdenum, and selenium, which are all commonly found in commercial trace 8 mineral products on the market for inclusion in animal feeds.
    [Show full text]
  • A Thesis Entitled Development of Novel Magnesium Phosphate Bone
    A Thesis entitled Development of Novel Magnesium Phosphate Bone Cement by Niloufar Rostami Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Bioengineering ________________________________________ Dr. Sarit B. Bhaduri, Committee Chair ________________________________________ Dr. Vijay K. Goel, Committee Member ________________________________________ Dr. Arunan Nadarajah, Committee Member ________________________________________ Dr. Mehdi Pourazady, Committee Member ________________________________________ Dr. Patricia R. Komuniecki, Dean College of Graduate Studies The University of Toledo December 2014 Copyright 2014, Niloufar Rostami This document is copyrighted material. Under copyright law, no parts of this document may be reproduced without the expressed permission of the author. An Abstract of Development of Novel Magnesium Phosphate Bone Cement by Niloufar Rostami Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Bioengineering The University of Toledo December 2014 This study aims to develop a novel magnesium phosphate based injectable cement for orthopedic applications. Magnesium phosphate cements (MPC) provide more favorable clinical performances including shorter setting time, and higher resorption rates and strength, as compared to the commonly used calcium phosphate cements. These features make magnesium cements great potential candidates for orthopedic and dental applications. In this study, the magnesium phosphate cement is prepared using a microwave assisted precipitation process. An experimental study is conducted to evaluate developed phases, setting times, injectability, and mechanical strength of the prepared cement. X-ray diffraction and SEM techniques are used to characterize the structure of powders with or without physiological conditions. Physiological conditions are simulated by soaking MPC pellets in Simulated Body Fluid (SBF).
    [Show full text]
  • A Process for the Manufacture of Highly Pure Trimagnesium
    Patentamt 0113153 JEuropâischesEuropean Patent Office ® Publication number: B1R1 — Officerit*: — européen„.... a — des*j — brevetsi ® EUROPEAN PATENT SPECIFICATION © Date of publication of patent spécification: 18.03.87 © Int. Cl.4: C01 B 25/34 (H) Application number: 83201865.9 ® Date offiling: 29.12.83 (H) A processforthe manufacture of highly pure trimagnesium phosphate octahydrate. (§) Priority: 30.12.82 US 454395 (73) Proprietor: STAUFFER CHEMICAL COMPANY Westport Connecticut 06880 (US) ® Date of publication of application: 11.07.84 Bulletin 84/28 @ Inventor: Sherif, Fawzy Gamaleldin 2 Babcock Court Stony Point, NY. 10980 (US) Publication of the grant of the patent: 18.03.87 Bulletin 87/12 @ Représentative: Urbanus, Henricus Maria, Ir. et al (§ï) Designated Contracting States: c/o Vereenigde Octrooibureaux Nieuwe BEDEFRGBITNLSE Parklaan 107 NL-2587 BP 's-Gravenhage (NL) (§) Références cited: CHEMICAL ABSTRACTS, vol. 71, no. 24, 15th December 1969, page 138, no. 114771y, Columbus, Ohio, USA CÛ m Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall û. be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been ui paid. (Art. 99(1 ) European patent convention). Courier Press, Leamington Spa, England. Background of the invention Field of the invention The invention relates to a process for the production of tertiary magnesium phosphate octahydrate and in particular to a process for the production of highly pure crystalline tertiary magnesium phosphate octahydrate.
    [Show full text]
  • The Phosphates of Magnesium and Iron' - by F
    THE PHOSPHATES OF MAGNESIUM AND IRON' - BY F. K. CAMERON AND J. M. BELL The behavior of phosphates of calcium in phosphoric acid solutions has been discussed in former papers from this labora- toryZ. Two crystalline phosphates of calcium have been shown to exist in equilibrium with solutions containing free phosphoric acid: monocalcium phosphate, which at 25' exists in equilibrium with solutions containing over 3 I 7 grams of phosphoric acid (PzO,) per liter; and dicalcium phosphate, which is stable below this concentration. At very low con- centrations (up to about 5 grams phosphoric acid per liter) the stable solid was found to be a solid solution consisting of lime and phosphoric acid. Both these crystalline phosphates of lime suffer decom- position when water is added to the solid, the resulting solu- tion becoming richer in phosphoric acid and the solid poorer in phosphoric acid than the original compounds. The phos- phates of magnesium are also decomposed by water, yielding solutions which are more strongly acid than the original solid, and the composition of the various acid solutions which can exist in contact with magnesium phosphates have been determined at 25O. In a similar way the phosphates of iron suffer decomposition when treated with pure water and com- positions of various acid solutions in contact with ferric phosphate have been determined at 25O. The composition of the solid in contact with these solutions is shown to be variable, that is, the solids are solid solutions. Phosphates of Mag.nesium.--Solid dimagnesium phosphate was added in excess to solutions of phosphoric acid in varying concentrations.
    [Show full text]
  • Essential Guide to Food Additives
    ESSENTIAL GUIDE TO FOOD ADDITIVES Third Edition Revised by Victoria Emerton and Eugenia Choi This edition first published 2008 by Leatherhead Publishing a division of Leatherhead Food International Ltd Randalls Road, Leatherhead, Surrey KT22 7RY, UK and Royal Society of Chemistry Thomas Graham House, Science Park, Milton Road, Cambridge, CB4 0WF, UK URL: http://www.rsc.org Registered Charity No. 207890 Third Edition 2008 ISBN No: 978-1-905224-50-0 A catalogue record of this book is available from the British Library © 2008 Leatherhead Food International Ltd The contents of this publication are copyright and reproduction in whole, or in part, is not permitted without the written consent of the Chief Executive of Leatherhead Food International Limited. Leatherhead Food International Limited uses every possible care in compiling, preparing and issuing the information herein given but accepts no liability whatsoever in connection with it. All rights reserved Apart from any fair dealing for the purposes of research or private study, or criticism or review as permitted under the terms of the UK Copyright, Designs and Patents Act, 1988, this publication may not be reproduced, stored or transmitted, in any form or by any means, without the prior permission in writing of the Chief Executive of Leatherhead Food International Ltd, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licencing Agency in the UK, or in accordance with the terms of the licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to Leatherhead Food International Ltd at the address printed on this page.
    [Show full text]
  • Derctuo Derctuo-020201231, by Kragen Javier Sitaker, 02020
    Derctuo ⁘⁛⁛⁘ Kragen Javier Sitaker Buenos Aires December, 02020 Public domain work ⁘⁛⁛⁘ Derctuo is a book of notes on various topics, mostly science and engineering with some math, from the first year of the COVID-19 pandemic, 02020 CE. Its primary published form is a gzipped tarball of 9MB of HTML files and sources, although there’s also an inferior PDF version of about 1000 pages for reading on hand computers or printing. It uses a page size slightly smaller than standard for improved readability on hand computers. My original plan was to write a reproducible computation system so that the book would be entirely reproducible from a minimal computational core, allowing all of its calculations to be not only verified but also easily extended, reused, and studied. I didn’t get very far on that plan. Instead it’s mostly just about a quarter million words of dead text, with some static inline images, plus a bundled library of source material, which is not included in the PDF version. It contains some novel discoveries, but some of it is just my notes from exploring the enormous feast of knowledge now available on the internet to anyone who takes the time to taste of it, and some other parts are explorations that didn’t pan out — left here only as a cautionary tale to the next explorer. There are lots of notes in here that aren’t “finished” in the usual sense; they end in the middle of a sentence, or say “XXX”, or have a note in them that the foregoing is wrong in such-and-such a way.
    [Show full text]
  • Provisional Peer-Reviewed Toxicity Values for Inorganic
    EPA/690/R-11/023F l Final 3-01-2011 Provisional Peer-Reviewed Toxicity Values for Inorganic Phosphates (Orthophosphoric Acid and Inorganic Phosphate Compounds, Including Ortho- and Condensed Phosphates) (Various CASRNs included in the text) Superfund Health Risk Technical Support Center National Center for Environmental Assessment Office of Research and Development U.S. Environmental Protection Agency Cincinnati, OH 45268 AUTHORS, CONTRIBUTORS, AND REVIEWERS CHEMICAL MANAGER Custodio V. Muianga, PhD, MPH National Center for Environmental Assessment, Cincinnati, OH DRAFT DOCUMENT PREPARED BY ICF International 9300 Lee Highway Fairfax, VA 22031 PRIMARY INTERNAL REVIEWERS Dan D. Petersen, PhD, DABT National Center for Environmental Assessment, Cincinnati, OH Anuradha Mudipalli, MSc, PhD National Center for Environmental Assessment, Research Triangle Park, NC This document was externally peer reviewed under contract to Eastern Research Group, Inc. 110 Hartwell Avenue Lexington, MA 02421-3136 Questions regarding the contents of this document may be directed to the U.S. EPA Office of Research and Development’s National Center for Environmental Assessment, Superfund Health Risk Technical Support Center (513-569-7300). TABLE OF CONTENTS COMMONLY USED ABBREVIATIONS .................................................................................... ii BACKGROUND .............................................................................................................................3 HISTORY ...................................................................................................................................3
    [Show full text]