GB718934A - Improvements relating to the preparation of cyanamide and cyanamide polymers from urea - Google Patents

Improvements relating to the preparation of cyanamide and cyanamide polymers from urea

Info

Publication number
GB718934A
GB718934A GB989/53A GB98953A GB718934A GB 718934 A GB718934 A GB 718934A GB 989/53 A GB989/53 A GB 989/53A GB 98953 A GB98953 A GB 98953A GB 718934 A GB718934 A GB 718934A
Authority
GB
United Kingdom
Prior art keywords
cyanamide
melamine
dissolve
dicyandiamide
dicyanamide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB989/53A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wyeth Holdings LLC
Original Assignee
American Cyanamid Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by American Cyanamid Co filed Critical American Cyanamid Co
Priority claimed from US381128A external-priority patent/US2760961A/en
Publication of GB718934A publication Critical patent/GB718934A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
    • C07D251/40—Nitrogen atoms
    • C07D251/54—Three nitrogen atoms
    • C07D251/56—Preparation of melamine
    • C07D251/60—Preparation of melamine from urea or from carbon dioxide and ammonia
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C3/00—Cyanogen; Compounds thereof
    • C01C3/16—Cyanamide; Salts thereof

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
  • Phenolic Resins Or Amino Resins (AREA)
  • Catalysts (AREA)
  • Silicon Compounds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

A product containing melamine together with cyanamide and dicyanamide may be produced by heating urea in the presence of silica gel at 275-650 DEG C. and at atmospheric pressure. The constituents of the reaction product may be separated by extracting the reaction mass first with ether to dissolve the cyanamide, then with hot water to dissolve the dicyanamide and melamine. On cooling the aqueous solution the melamine crystallizes out leaving the dicyanamide in solution.ALSO:Cyanamide and its polymers are prepared by heating urea in the presence of silica gel at a temperature of 275-650 DEG C. and at atmospheric pressure. A reaction temperature of 340-360 DEG C. is preferred. The reaction product which according to the example also contains dicyandiamide and melamine may be isolated by extracting the reaction mass with hot water only, or by extracting first with ether to dissolve the cyanamide followed by extraction with hot water to dissolve the dicyandiamide and melamine. The hot aqueous solution of dicyandiamide and melamine may be cooled whereupon melamine crystallizes out and the residual solution concentrated by evaporation in order to recover the dicyandiamide.
GB989/53A 1952-01-17 1953-01-13 Improvements relating to the preparation of cyanamide and cyanamide polymers from urea Expired GB718934A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US317446XA 1952-01-17 1952-01-17
US381128A US2760961A (en) 1953-09-18 1953-09-18 Preparation of melamine

Publications (1)

Publication Number Publication Date
GB718934A true GB718934A (en) 1954-11-24

Family

ID=31980755

Family Applications (2)

Application Number Title Priority Date Filing Date
GB989/53A Expired GB718934A (en) 1952-01-17 1953-01-13 Improvements relating to the preparation of cyanamide and cyanamide polymers from urea
GB26988/54A Expired GB767344A (en) 1952-01-17 1954-09-17 Improvements relating to the production of melamine and/or cyanamide

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB26988/54A Expired GB767344A (en) 1952-01-17 1954-09-17 Improvements relating to the production of melamine and/or cyanamide

Country Status (6)

Country Link
BE (2) BE516995A (en)
CH (1) CH317446A (en)
DE (2) DE942991C (en)
FR (1) FR1112418A (en)
GB (2) GB718934A (en)
NL (1) NL87214C (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3054796A (en) * 1960-07-18 1962-09-18 Grace W R & Co Melamine process
US3095416A (en) * 1963-06-25 Urea to melamine process
US4625061A (en) * 1984-03-06 1986-11-25 Stamicarbon B.V. Process for preparing cyanamide
CN115944942A (en) * 2022-12-06 2023-04-11 四川金象赛瑞化工股份有限公司 Preparation method of cyanamide substance

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3152128A (en) * 1964-10-06 Preparation of melamine
US3210352A (en) * 1965-10-05 Preparation of melamine
US3093644A (en) * 1963-06-11 Preparation of melamine
US3179664A (en) * 1965-04-20 Processes for preparing melamine
US3009914A (en) * 1961-11-21 Melamine process
DE1216316B (en) * 1960-07-14 1966-05-12 Stamicarbon Improved process for the continuous production of melamine
DE1138785B (en) * 1960-09-27 1962-10-31 Suddeutsche Kalkstickstoff Werke Aktiengesellschaft, Trostberg (Obb ) Process for the production of melamine.
DE1215722B (en) * 1961-02-09 1966-05-05 Stamicarbon Process for the continuous production of melamine
DE1294386B (en) * 1961-09-29 1969-05-08 Lentia Gmbh Chem Und Pharm Erz Process for the production of melamine
DE1209570B (en) * 1964-03-28 1966-01-27 Basf Ag Process for the production of melamine
FR2852011B1 (en) * 2003-03-07 2006-07-07 PROCESS FOR THE PRODUCTION OF MELAMINE FROM CYANURIC ACID AND APPLICATION FOR THE PURIFICATION OF MELAMINE CONTAINING CYANURIC ACID AS IMPURITY
CN107840811A (en) * 2017-12-15 2018-03-27 黄河三角洲京博化工研究院有限公司 A kind of preparation method of dicyandiamide

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2550659A (en) * 1951-04-24 Process for producing melamine
US2649446A (en) * 1953-08-18 Peocess for producing melamine
US2566224A (en) * 1951-08-28 Production of melamine
US2615018A (en) * 1952-10-21 Preparation of melamine
US2566228A (en) * 1951-08-28 Production of melamine
GB639962A (en) * 1946-03-27 1950-07-12 Du Pont Process for the production of melamine

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3095416A (en) * 1963-06-25 Urea to melamine process
US3054796A (en) * 1960-07-18 1962-09-18 Grace W R & Co Melamine process
US4625061A (en) * 1984-03-06 1986-11-25 Stamicarbon B.V. Process for preparing cyanamide
CN115944942A (en) * 2022-12-06 2023-04-11 四川金象赛瑞化工股份有限公司 Preparation method of cyanamide substance
CN115944942B (en) * 2022-12-06 2024-04-12 四川金象赛瑞化工股份有限公司 Preparation method of cyanamide substance

Also Published As

Publication number Publication date
GB767344A (en) 1957-01-30
DE942991C (en) 1956-05-09
DE1028126B (en) 1958-04-17
FR1112418A (en) 1956-03-14
BE516995A (en) 1954-11-26
BE531929A (en) 1958-01-03
NL87214C (en) 1958-01-15
CH317446A (en) 1956-11-30

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