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Title:
【発明の名称】強発熱硬化性の尿素-ホルムアルデヒド樹脂の製造方法
Document Type and Number:
Japanese Patent JP2895079
Kind Code:
B2
Abstract:
A urea-formaldehyde resin which cures highly exothermally is obtained by condensation of urea with formaldehyde in an alkaline medium and is characterised in that it is obtained by… a) condensation in a first condensation step I of from 0.2 to 0.7 mol, preferably 0.5 mol, of urea with from 1.2 to 3 mol, preferably from 1.7 to 2.2 mol, of formaldehyde in the form of solid paraformaldehyde, in an exclusively alkaline medium at an initial pH of 8 - 12, preferably 9 - 11,… b) in the presence of from 1 to 10 mmol of NaOH and from 10 to 80 mmol of NH3, or… in the presence of from 2.5 to 50 mmol of guanidine base and from 0 to 80 mmol of NH3… per mole of formaldehyde,… c) at a condensation temperature (I) of from 90 to 110 DEG C,… d) for a condensation time (I) of from 10 to 100 minutes, preferably from 15 to 70 minutes,… e) subsequently adding, in a second condensation step II, a further 0.2 to 0.7 mol, preferably 0.5 mol, of urea,… f) at a condensation temperature (II) of from 105 to 120 DEG C,… g) for a further condensation time (II) of from 1.5 to 5 hours. …The resin has advantages in environmental friendliness, freedom from effluent, reduced energy and plant costs, improved drying of the foams and increased economic efficiency.

Inventors:
BORUFU DEIITORITSUHI SHERUHORUN
Application Number:
JP30901588A
Publication Date:
May 24, 1999
Filing Date:
December 08, 1988
Export Citation:
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Assignee:
BORUFU DEIITORITSUHI SHERUHORUN
International Classes:
C08J9/12; C08G12/04; C08G12/12; C08G12/40; C08J9/14; (IPC1-7): C08G12/12; C08J9/12
Domestic Patent References:
JP58213030A
JP54162790A
JP4876990A
JP50119892A
Foreign References:
Other References:
沼田勇記「プラスチック材料講座2:ユリア樹脂」昭和36年9月15日 日刊工業新聞社 P.55−67
Attorney, Agent or Firm:
Toshio Yano (1 outside)



 
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