| 摘要 |
Butadiene hydrocarbon polymers are plasticized by subjecting a mixture of the polymer latex and a plasticizer emulsion to a temperature between 30 DEG and -50 DEG F. to freeze the mixture but not to coagulate it and then to thaw it. The plasticizer, which may be any known one, is added in an amount of up to 50 parts by weight (dry) per 100 parts by weight (dry) of polymer either as an emulsion to the latex or is added per se and the mixture stirred p rapidly till the plasticizer is emulsified. In all the operations the amount of emulsifier present should not completely cover all the particles. Optionally a reinforcing pigment dispersion in an amount of up to 50 parts by wt. (dry) per 100 parts by wt. (dry) of polymer may be added and incorporated in the polymer latex by freezing and thawing either before, together with or after the plasticizer has been added. Specified materials are a pulverized limestone/silicate ore and polystyrene latex. The term butadiene hydrocarbon polymer is defined as any polymer containing more than 51% of 1,3-diene. U.S.A. Specification 3,031,427 is referred to.ALSO:Latex foams are made by beating air into an aqueous dispersion containing particles which comprise a mixture of butadiene hydrocarbon polymer and a plasticizer. The dispersion is made by subjecting the ploymer latex and a plasticizer emulsion to a freeze-thaw cycle as in Specification 758,622 with the amount of emsulsifier present in the mixture being insufficient to cover all the particles. Optionally a reinforcing agent such as polystyrene latex or a silicate dispersion may be incorporated in the mixture by freezing and thawing. The butadiene hydrocarbon polymer is defined as any polymer containing at least 51% of a 1, 3-diene. U.S.A. Specification 3,031,427 also is referred to.
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