| abstract |
Cement articles, having excellent bending strength and Charpy impact strength, are manufactured with an extremely strong polypropylene fiber having good dispersion. The extremely strong fiber which is made of the polypropylene fiber has a narrow molecular weight distribution and a high stereoregularity and is drawn at a high temperture and treated with normal alkylphosphate alkaline metal salt. The extremely strong polypropylene fiber is a drawn thread of highly crystalline polypropylene having Q<5, 97<HI<100, 94<IPF<100, with Q being the ratio of weight average molecular weight to number-average molecular weight, HI being the insoluble content of boiling n-heptane in wt % and IPF being the isotactic pentad fraction in mol %. The fiber comprises from 0.05% to 10 wt % of alkylphosphate alkaline metal salt and has strong breakage strength, greater than 6 g/denier. |