Abstract: A method of forming a urea formaldehyde resin includes the step of heating solid paraformaldehyde to a temperature of 60 to 120.degree. C. Urea is added to the heated paraformaldehyde to form a urea mixture, which is dry mixed and heated until a temperature of 80 to 110.degree. C. has been reached. After this, a methanolic quanine base is added to the urea mixture to form a quanine-urea-formaldehyde mixture, which is heated until the quanine-urea-formaldehyde mixture is liquefied and cooled to 65.degree. C. Then, the quanine-urea-formaldehyde mixture is heated until it boils, at which point it is condensed for a period of 30 to 100 minutes. After this, additional urea is added to the liquified urea mixture to form a urea enriched mixture. The urea enriched mixture is condensed for 90 to 180 minutes. After condensation, the urea enriched mixture is buffered with lactic acid to form a buffered mixture. This buffered mixture is cooled.

Abstract: A polysulfide sealing composition is described which contains, in addition to the hardening agents and optional fillers, softeners and other conventional additives, a mixture of a solid polysulfide rubber with terminal SH groups and a liquid polysulfide polymer with terminal SH groups, wherein the weight ratio of the respective solid and liquid polysulfide is 100:5 to 15. The composition may be used for the manufacture of insulating glass units.