Patent ID: 6753356
Filing Date: 2004-06-22
Classification: C08J

Abstract:
A process for foaming polyurethanes, comprising: adding to compositions used to make solid polymers azeotropic or near azeotropic foaming agent compositions as substitutes for CFC 11 to give a homogeneous foam having a density of about 30 kg/cm3, said foaming agent compositions based on difluoromethoxy-bis(difluoromethyl ether) and/or 1-difluoromethoxy-1,1,2,2-tetrafluoroethyl difluoromethyl ether, said foaming agent compositions selected from the group consisting of;composition% by weightI)difluoromethoxyâ€‚1-95bis(difluoromethyl ether)(HCF2OCF2OCF2H);n-pentane99-5â€‚II)difluoromethoxyâ€‚1-99bis(difluoromethyl ether)(HCF2OCF2OCF2H);Iso-pentane99-1â€‚III)difluoromethoxyâ€‚1-60bis(difluoromethyl ether)(HCF2OCF2OCF2H);dimethyl ketone (acetone)99-40VI)difluoromethoxyâ€‚1-86bis(difluoromethyl ether)(HCF2OCF2OCF2H);methoxymethyl methylether99-14VII)difluoromethoxy30-99bis(difluoromethyl ether)(HCF2OCF2OCF2H);n-hexane70-1â€‚VIII)1-difluoromethoxyâ€‚1-931,1,2,2-tetrafluoroethyldifluoromethyl ether(HCF2OCF2CF2OCF2H);n-pentane99-7â€‚IX)1-difluoromethoxy30-991,1,2,2-tetrafluoroethyldifluoromethyl ether(HCF2OCF2CF2OCF2H);dimethyl ketone (acetone)70-1â€‚X)1-difluoromethoxy15-991,1,2,2-tetrafluoroethyldifluoromethyl ether(HCF2OCF2CF2OCF2H);n-hexane85-1â€‚XI)1-difluoromethoxyâ€‚5-991,1,2,2-tetrafluoroethyldifluoromethyl ether(HCF2OCF2CF2OCF2H);ethyl alcohol95-1â€‚XII)difluoromethoxy-bisâ€‚1-64(difluoromethyl ether)(HCF2OCF2OCF2H);1,1,1,3,3-pentafluorobutane98-1â€‚(CF3CH2CF2CH3, HFC 365 mfc)a hydrocarbon selected fromn-pentane or isopentaneâ€ƒâ€ƒâ€‰1-35 andXIII)difluoromethoxy-bisâ€‚1-22(difluoromethyl ether)(HCF2OCF2OCF2H);1,1,1,4,4,4-hexafluorobutane98-43(CF3CH2CH2CF3, HFC 356 ffa)a hydrocarbon selected fromn-pentane or isopentaneâ€‚1-35wherein(1) in the foaming agent compositions II, III and VI, up to 40% by weight of the difluoromethoxy-bis(difluoromethyl ether) is optionally substituted with 1-difluoro methoxy-1,1,2,2-tetrafluoroethyldifluoromethyl ether; (2) in the foaming agent composition IX, up to 40% by weight of 1-difluoromethoxy-1,1,2,2-tetrafluoroethyldifluoromethyl ether is optionally substituted by difluoromethoxy-bis(difluoromethyl) ether; (3) in the foaming agent compositions I and VII, up to 50% by weight of difluoromethoxy-bis(difluoromethyl ether) is optionally substituted by 1-difluoromethoxy-1,1,2,2-tetrafluoroethyldifluoromethyl ether; (4) in the foaming agent compositions VIII and X, up to 50% by weight of 1-difluoromethoxy-1,1,2,2-tetrafluoroethyldifluoromethyl ether is optionally substituted with difluoromethoxy-bis(difluoromethyl) ether.