发明名称 |
VERFAHREN ZUR HERSTELLUNG VON WAERMEHAERTBAREN HARNSTOFF-FORMALDEHYD-HARZEN UND DEREN VERWENDUNG |
摘要 |
<p>A method for preparing thermosettable urea-formaldehyde resins having a urea to formaldehyde molar ratio of 1:1 to 1:1.5 wherein urea and formaldehyde are first reacted in an aqueous solution at a molar ratio of 1:1.5 to 1:4 in the pH range between 7.5 to 10, and then condensing the reactants in a pH range from 4 to 6 to a precipitation number of 1:1.5 to 1:10, thereafter adjusting the pH to 7 to 10 and adding the remaining urea to obtain a molar ratio of 1:1 to 1:1.5 and continuing the reaction until a precipitation number of 1:0.5 to 1:3 is obtained. The products obtained have a uniform molecular weight and good penetration properties when used to impregnate supporting webs for coating wood-based panels.</p> |
申请公布号 |
DD144170(A5) |
申请公布日期 |
1980.10.01 |
申请号 |
DD19790213464 |
申请日期 |
1979.06.07 |
申请人 |
TH.GOLDSCHMIDT AG,DE |
发明人 |
SCHAMBERG,ECKEHARD,DE;HOLTSCHMIDT,ULRICH,DE;HELLWIG,DIETER,DE |
分类号 |
C08G12/00;C08G12/12;C08L61/24;C09D161/20;D21H17/50;(IPC1-7):C08G12/12 |
主分类号 |
C08G12/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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