NATURAL RUBBER LATEX FILM PRODUCT WITH IMPROVED TEAR STRENGTH

摘要

PURPOSE: To obtain improved tear strength and a good balance of other properties of a film prepd. by incorporating a high styrene content styrene-butadiene copolymer to a natural rubber latex compd. CONSTITUTION: A styrene-butadiene(SB) latex compounded with a natural rubber(NR) is a high styrene content SB latex. Such a latex contains at least 50 wt.%, e.g. max. up to approximately 90 wt.%, pref. approximately 75-85 wt.% styrene in the copolymer constituting SB and the remaining part in the copolymer is butadiene. The SB latex is used by a ratio of approximately 1-25 pts.wt. and pref. approximately 10-20 pts.wt. per 100 pts.wt. NR latex. When 5 pts.wt. SB copolymer are added to NR, tear strength of the latex film exhibits an increase of approximately 50%. When 10-15% SB copolymer are added, the value reaches 2 times of the value of an NR film alone.