GB767344A - Improvements relating to the production of melamine and/or cyanamide - Google Patents

Improvements relating to the production of melamine and/or cyanamide

Info

Publication number
GB767344A
GB767344A GB26988/54A GB2698854A GB767344A GB 767344 A GB767344 A GB 767344A GB 26988/54 A GB26988/54 A GB 26988/54A GB 2698854 A GB2698854 A GB 2698854A GB 767344 A GB767344 A GB 767344A
Authority
GB
United Kingdom
Prior art keywords
melamine
sept
ammonia
cyanamide
produced
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
GB26988/54A
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
Priority claimed from US381128A external-priority patent/US2760961A/en
Application filed by American Cyanamid Co filed Critical American Cyanamid Co
Publication of GB767344A publication Critical patent/GB767344A/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)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Catalysts (AREA)
  • Silicon Compounds (AREA)

Abstract

767,344. Melamine. AMERICAN CYANAMID CO. Sept. 17, 1954 [Sept. 18, 1953; Sept. 18, 1953; Sept. 18, 1953; Sept. 18, 1953; Sept. 18, 1953; Sept. 18, 1953], No. 26988/54. Addition to 718,934. Class 2 (3). [Also in Group III] Melamine, cyanamide and dicyandiamide are produced by heating urea or an intermediate thermal reaction product thereof to a temperature of at least 220‹ C. at atmospheric or superatmospheric pressure, preferably up to 750 p.s.i. in the presence of a catalyst consisting of an absorptive material having a surface area of 180-650 m<SP>2</SP>/gm. In the range 220-400‹ C., the product is mainly melamine. Above 400‹ C., the melamine begins to decompose to cyanamide and other products. Intermediate products specified are biuret, cyanuric acid, cyanic acid, ammelide, ammeline, melam, melem. A mixture of these may be produced by heating urea to 270‹ C. under pressure. Catalysts specified are silica, alumina, silicaalumina, titania, zirconia, and thoria gels, pumice, diatomite, infusorial earth, and clay and clay-like materials, e.g. kaolin, bentonite, bauxite, and fuller's earth. The clay and claylike material is preferably activated by pretreatment with silica. The catalysts may contain 2-20 per cent of water. The reaction product may be leached first with ether to remove cyanamide and then with hot water to remove melamine, which is precipitated on cooling, and the dicyandiamide recovered by evaporation of the remaining solution. Melamine may be continuously produced by passing urea or the like into the absorbent maintained at a temperature of 400‹ C. and subliming off the melamine produced in a current of ammonia at 400‹ C. The melamine may be condensed in a vessel maintained at 100‹ C. and the residual gas, consisting of ammonia and carbon dioxide, passed to an ammonium carbamate recovery unit. The melamine may be sublimed in the absence of a sweeping out gas. The absorbent may be fluidized, optionally in two or more stages. In a two-stage process the catalyst fluidized by means of ammonia is heated first at 220‹ C., ammonia and carbon dioxide being recovered, and then at 350‹ C. In a three-stage process, the catalyst is heated at 220‹ C. to form carbon dioxide, at 250‹ C. to form melamine without stripping it from the absorbent, and finally at 350-400‹ C. to strip the melamine formed.
GB26988/54A 1952-01-17 1954-09-17 Improvements relating to the production of melamine and/or cyanamide Expired GB767344A (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
GB767344A true GB767344A (en) 1957-01-30

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 Before (1)

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

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 (10)

* 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
US3093644A (en) * 1963-06-11 Preparation of melamine
US3095416A (en) * 1963-06-25 Urea to melamine process
US3152128A (en) * 1964-10-06 Preparation of melamine
US3210352A (en) * 1965-10-05 Preparation of melamine
DE1209570B (en) * 1964-03-28 1966-01-27 Basf Ag Process for the production of melamine
DE1215722B (en) * 1961-02-09 1966-05-05 Stamicarbon Process for the continuous production of melamine
DE1216316B (en) * 1960-07-14 1966-05-12 Stamicarbon Improved 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
FR2852011A1 (en) * 2003-03-07 2004-09-10 Atofina Preparation of melamine from cyanuric acid by sublimation and decomposition to cyanic acid and contact with an alumina-type catalyst

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179664A (en) * 1965-04-20 Processes for preparing melamine
US3009914A (en) * 1961-11-21 Melamine process
DE1138785B (en) * 1960-09-27 1962-10-31 Suddeutsche Kalkstickstoff Werke Aktiengesellschaft, Trostberg (Obb ) Process for the production of melamine.
NL8400717A (en) 1984-03-06 1985-10-01 Stamicarbon PROCESS FOR PREPARING CYANAMIDE.
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
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

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566224A (en) * 1951-08-28 Production of melamine
US2550659A (en) * 1951-04-24 Process for producing melamine
US2615018A (en) * 1952-10-21 Preparation of melamine
US2649446A (en) * 1953-08-18 Peocess for producing 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 (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3093644A (en) * 1963-06-11 Preparation of melamine
US3095416A (en) * 1963-06-25 Urea to melamine process
US3152128A (en) * 1964-10-06 Preparation of melamine
US3210352A (en) * 1965-10-05 Preparation of melamine
DE1216316B (en) * 1960-07-14 1966-05-12 Stamicarbon Improved process for the continuous production of melamine
US3054796A (en) * 1960-07-18 1962-09-18 Grace W R & Co Melamine process
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
FR2852011A1 (en) * 2003-03-07 2004-09-10 Atofina Preparation of melamine from cyanuric acid by sublimation and decomposition to cyanic acid and contact with an alumina-type catalyst

Also Published As

Publication number Publication date
BE516995A (en) 1954-11-26
NL87214C (en) 1958-01-15
DE942991C (en) 1956-05-09
FR1112418A (en) 1956-03-14
BE531929A (en) 1958-01-03
CH317446A (en) 1956-11-30
DE1028126B (en) 1958-04-17
GB718934A (en) 1954-11-24

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