Abstract: Disclosed is a filler for a heat-sensitive recording paper comprising finely divided amorphous silica having a BET specific surface area of 10 to 100 m.sup.2 /g and a bulk density of 0.14 to 0.30 g/cc, said finely divided amorphous silica having such a secondary particle size distribution that secondary particles having a size smaller than 4 microns, as measured by the centrifugal precipitation method, occupy at least 90% by weight of the total particles.This filler is excellent in the effects of preventing the background coloration, improving the lubricating property, preventing the adhesion of scum and improving the image density.

Abstract: Disclosed is a filler for a heat-sensitive recording paper comprising finely divided amorphous silica having a BET specific surface area of 10 to 100 m.sup.2 /g and a bulk density of 0.14 to 0.30 g/cc, said finely divided amorphous silica having such a secondary particle size distribution that secondary particles having a size smaller than 4 microns, as measured by the centrifugal precipitation method, occupy at least 90% by weight of the total particles.This filler is excellent in the effects of preventing the background coloration, improving the lubricating property, preventing the adhesion of scum and improving the image density.

Abstract: Disclosed is an abrasion-resistant granular zeolite formed from a mixture of a synthetic zeolite and a clay binder, said granular zeolite comprising a core composed of a synthetic zeolite clay binder mixture containing the synthetic zeolite at a content higher than the average synthetic zeolite content in the granular zeolite and a shell composed of a synthetic zeolite-clay binder mixture containing the clay binder at a content higher than the average clay binder content in the granular zeolite.This granular zeolite is excellent in both the zeolitic characteristics such as adsorbability and ion exchange capacity and the mechanical strength characteristics such as abrasion resistance and compression strength.

Abstract: A color developer for pressure-sensitive recording paper which is derived from a clay mineral having a layer-structure composed of regular tetrahedrons of silica and which shows(A) the diffraction pattern attributable to the crystals of layer-structure composed of regular tetrahedrons of silica when subjected to an electron diffraction analysis, but(B) substantially no diffraction pattern attributable to the crystals of said layer-structure when subjected to an X-ray diffraction analysis, and which(C) contains as the constituting elements besides oxygen, at least silicon, magnesium and/or aluminum.This color developer is produced by acid-treating a clay mineral having a layer-structure composed of regular tetrahedrons of silica until its SiO.sub.2 content reaches 82-96.5% by weight on dry basis (drying at 105.degree. C.

Abstract: A detergent builder consisting essentially of an inorganic fine powder composed mainly of an alkali metal aluminosilicate having an X-ray diffraction pattern substantially the same as that of zeolite of the type A and having a degree of crystallization in the range of from 35 to 75%, wherein the inorganic fine powder has a primary particle size smaller than 1.mu. and a secondary particle size smaller than 4.mu., the inorganic fine powder has a buffer capacity (S) of at least 132 ml/100 g of solids, the buffer capacity being expressed by an amount of hydrochloric acid necessary for lowering the pH of a 1% aqueous dispersion of said inorganic fine powder from 9.0 to 6.75 when the dispersion is titrated with 0.4 N hydrochloric acid at a rate of 20 to 50 ml/hr, and wherein the inorganic fine powder has a calcium ion binding property (C. I.) of at least 70 mg/g as expressed as CaO.

Abstract: A detergent builder consisting essentially of an inorganic fine powder composed mainly of an alkali metal aluminosilicate having an X-ray diffraction pattern substantially the same as that of zeolite of the type A and having a degree of crystallization in the range of from 35 to 75%, wherein the inorganic fine powder has a primary particle size smaller than 1.mu. and a secondary particle size smaller than 4.mu., the inorganic fine powder has a buffer capacity (S) of at least 132 ml/100 g of solids, the buffer capacity being expressed by an amount of hydrochloric acid necessary for lowering the pH of a 1% aqueous dispersion of said inorganic fine powder from 9.0 to 6.75 when the dispersion is titrated with 0.4 N hydrochloric acid at a rate of 20 to 50 ml/hr, and wherein the inorganic fine powder has a calcium ion binding property (C. I.) of at least 70 mg/g as expressed as CaO.

Abstract: A detergent builder consisting essentially of an inorganic fine powder composed mainly of an alkali metal aluminosilicate having an X-ray diffraction pattern substantially the same as that of zeolite of the type A and having a degree of crystallization in the range of from 35 to 75%, wherein the inorganic fine powder has a primary particle size smaller than 1 .mu. and a secondary particle size smaller than 4 .mu., the inorganic fine powder has a buffer capacity (S) of at least 132 ml/100 g of solids, the buffer capacity being expressed by an amount of hydrochloric acid necessary for lowering the pH of a 1% aqueous dispersion of said inorganic fine powder from 9.0 to 6.75 when the dispersion is titrated with 0.4N hydrochloric acid at a rate of 20 to 50 ml/hr, and wherein the inorganic fine powder has a calcium ion binding property (C. I.) of at least 70 mg/g as expressed as CaO.