Abstract: A thixotropy-imparting agent comprises chain clay mineral particles which have a thixotropic index (TI) of not smaller than 4.0 in a dispersion solution obtained by dispersing chain clay mineral particles at a concentration of 7% by weight in diethylhexyl phthalate (DOP) as a dispersing medium and not smaller than 3.0 in a dispersion solution obtained by dispersing chain clay mineral particles at a concentration of 3% by weight in water as a dispersion medium, and have a bulk density of not larger than 0.125 g/ml, and a particle size distribution of secondary particles as measured by a laser method, in which particle sizes of larger than 1.0 ?m but not larger than 30 ?m are not less than 70% by weight and particle sizes of not larger than 1.0 ?m are in a range of 5 to 30% by weight.

Abstract: Alkaline earth metal basic silicate particles having a silicate of an alkaline earth metal on the surfaces of the alkaline earth metal hydroxide particles, and having an SiO2/MO (M is an alkaline earth metal) molar ratio as a whole in a range of from 0.01 to 0.90. The particles are useful as a stabilizer for the chlorine-containing polymers.

Abstract: A zinc borate having a particular crystallite size and containing very little sodium components and a method of preparing the same. The zinc borate has a particular chemical composition, has a crystallite size of not smaller than 40 nm as found from diffraction peaks of indexes of planes of (020), (101) and (200) in the X-ray diffraction image (Cu-k&agr;) and contains sodium components in amounts of not larger than 100 ppm as measured by the atomic absorptiometric method.

Abstract: Alkaline earth metal basic silicate particles having a silicate of an alkaline earth metal on the surfaces of the alkaline earth metal hydroxide particles, and having an SiO2/MO (M is an alkaline earth metal) molar ratio as a whole in a range of from 0.01 to 0.90. The particles are useful as a stabilizer for the chlorine-containing polymers.

Abstract: A zinc borate having a particular crystallite size and containing very little sodium components and a method of preparing the same. The zinc borate has a particular chemical composition, has a crystallite size of not smaller than 40 nm as found from diffraction peaks of indexes of planes of (020), (101) and (200) in the X-ray diffraction image (Cu-k&agr;) and contains sodium components in amounts of not larger than 100 ppm as measured by the atomic absorptiometric method.