Dupont-mitsui Fluorochemicals Company, Ltd.

Other

Nippon Hodo Co., Ltd.

Murakashi Lime Industry Co., Ltd.

Dupont-mitsu Fluorochemicals Co., Ltd.

Nippo Corporation

Aso Cement Co., Ltd.

Masatsune Ogura

Tetsuya Shimoda

Teruo Urano

Hiroshi Miyaji

Katuaki Ishikawa

Shizuo Chiba

Hirofumi Tsutsumi

Susumu Okazaki

Kayoko Ohtera

Tomohiro Gocho

Yasunobu Mochizuki

Hirohumi Aso Cement Co Ltd Tsutsumi

A method of dusting-preventive treatment in which a powder having dusting property is treated with fibril-forming PTFE (polytetrafluoroethylene) to impart non-dusting property thereto and the non-dusting property of the powder, after having been reduced during transportation, are economically and advantageously recovered or improved through a relatively simple step. The method comprises: a first dusting-preventive treatment step in which fibril-forming polytetrafluoroethylene is added to a powder having dusting property, and a compression/shear force is exerted to the mixture at a temperature in the range of 20 to 200&#xb0; C. to thereby regulate powder so as to have a flow value of 150 mm to 200 mm; and a second dusting-preventive treatment step in which a compression/shear force is exerted again at a temperature in the range of 50 to 150&#xb0; C., without newly adding fibril-forming polytetrafluoroethylene, to the resultant powder after the powder treated in the first step has deteriorated in dusting-preventive property during transportation with transporting means due to such an external force that the polytetrafluoroethylene fibrils partly cleave or powder particles partly fall off polytetrafluoroethylene fibril nets.

Method of dusting-preventive treatment of powder having dusting property

The present invention provides a dusting-inhibited cement composition, which hardly forms dust and further capable of improving strength of concrete or mortar obtained therefrom. A dusting-inhibited cement composition according to the present invention comprises 100 weight parts of cement, 0.01&tilde;0.1 weight parts of fibrillatable polytetrafluoroethylene and 0.001&tilde;1.0 weight parts of alcohol base antifoamer and/or silicone base antifoamer.

Dusting-inhibited cement composition improved in strength

Aqueous emulsion of fluorine-containing polymer

Dust-preventing method

Aqueous emulsion of fluorocarbon polymer and method for producing the

Dust-control treatment of dusty powder, which mainly passes through a 100 mesh sieve, such as pigment and fertilizer, is achieved by, firstly blending the dusty powder with fibrillatable polytetrafluoroethylene and a pair of materials capable of initiating an exothermic reaction upon contact, and then subjecting the blended material to compression-shear under the exothermic reaction and raising the temperature of the blended material to 50.degree.-300.degree. C. The polytetrafluoroethylene fibrillates during the compression-shear and the formed fibrils enclose the dusty powder to turn it to a dust-controlled one.

Method for dust-control treatment

It is an object of the present invention to provide a soil-stabilizing agent with less emission of dust, good reactivity, good behavior at mixing and good dispersibility and a method for soil stabilizing treatment capable of restraining the emission of dust in the procedure of sprinkling and mixing of the soil-stabilizing agent to soil. The soil-stabilizing agent according to the present invention comprises a mixture of a material mainly composed of quick lime and/or calcined dolomite and fibrillatable polytetrafluoroethylene resin. And the method for soil-stabilizing treatment according to the present invention comprises the following steps; adding a mixture of a material mainly composed of quick lime and/or calcined dolomite and fibrillatable polytetrafluoroethylene resin to soil, and mixing them under the hydration heat generated by the reaction between the quick lime and/or calcined dolomite with moisture in the soil to form hydrated material. When PTFE is in partially fibrillated state, emission of dust while sprinkling (primary dust) from the soil-stabilizing agent will be restrained as the particles of quick lime and/or calcined dolomite are enclosed in a cobweb-like net of the partially fibrillated PTFE, and emission of dust while mixing (secondary dust) is further restrained by a cobweb-like net of PTFE fibrillated further by mixing under hydration heat generated by the reaction of quick lime and/or calcined dolomite with moisture in the soil.

Soil-stabilizing agent and a method for soil-stabilizing treatment

A partially fluorinated alumina catalyst having a determined component, which is obtained by calcining an Al.sub.2 O.sub.3.nH.sub.2 O(n=0 to 3) containing fibril of polytetrafluoroethylene, provides an excellent catalyst for the isomerization of HCFCs.

Process for isomerization of hydrochlorofluorocarbons

Growing community of inventors

Ichikawa, Japan

Masatsune Ogura