Asahi Glass Company, Limited

Hachirou Hirano

Shigeru Sakurai

Kunihiko Terase

Shintaro Kikuchi

Hisakazu Arima

Hiroo Mori

Fumiaki Nakashima

Masaharu Tanaka

Toshiya Matsubara

Hiroshi Funaki

Yoshinori Kon

Katsumasa Nakahara

Hisao Inokuma

Takako Hirano, Legal Representative

Masako Wakabayashi

A method for evaluating the caking property of sodium hydrogencarbonate crystal particles, characterized in that sodium hydrogencarbonate crystal particles are hermetically sealed in a packaging material having a water vapor transmission rate of at least 3 g/(m&#xb7;24 h) (at 40&#xb0; C. with a relative humidity difference of 90%) as stipulated in JIS K7129 and left at rest at a temperature of from 17 to 35&#xb0; C. at a carbon dioxide gas concentration of from 0.03 to 0.05 vol % at a relative humidity of from 40 to 95% for from 2 weeks to 3 months, and the proportion of agglomerated sodium hydrogencarbonate crystal particles is determined to evaluate the caking tendency. A novel test method for evaluating the caking property of sodium hydrogencarbonate crystal particles, capable of providing results of the caking property test with high reproducibility, quantitatively with high versatility, can be provided.

Method for evaluating caking property of sodium hydrogencarbonate crystal particles

A process for producing sodium hydrogencarbonate crystal particles having a low caking property, which entails subjecting sodium hydrogencarbonate crystal particles having an average particle size of from 50 to 500 &#x3bc;m based on the mass to heat treatment at a temperature of from 70 to 95&#xb0; C. by a heating gas having a carbon dioxide gas concentration of at most the concentration calculated by the formula: Carbon dioxide gas concentration=0.071&#xd7;e&#xd7;R, where T (&#xb0; C.) is the temperature of sodium hydrogencarbonate crystals, and R (%) is the relative humidity around the crystals at the temperature of the crystals, provided that the upper limit of the carbon dioxide gas concentration is 100 vol % to form anhydrous sodium carbonate on the surface of the sodium hydrogencarbonate crystal particles with a content of anhydrous sodium carbonate of from 0.03 to 0.4 mass % in the sodium hydrogencarbonate crystals.

Process for producing sodium hydrogencarbonate crystal particles having low caking property

A process for producing a silica-alumina composite sol, which comprises mixing a silica hydrogel and an aluminum salt which, when dissolved in water, gives an acidic solution.

Recording medium excellent in ink absorptivity and process for its production, and process for producing silica-alumina composite sol

An alumina sol having an alumina solid content of at least 10 wt % and a viscosity of not higher than 5 Pa.s measured by a Brookfield viscometer and containing a cation other than a hydrogen ion in a total ion equivalent concentration in the range of from 2.0.times.10.sup.-4 to 1.0.times.10.sup.-1 N and a method of preparing the same.

High concentration alumina sol of low viscosity

A process for producing zinc oxide-containing spherical silica, which comprises emulsifying, in an organic solvent containing a surfactant, a dispersion having zinc oxide with a particle size of from 0.005 to 0.5 .mu.m dispersed in an aqueous alkali metal silicate solution in an amount of from 10 to 70 wt % based on the total amount of zinc oxide and SiO.sub.2 in the aqueous alkali metal silicate solution, followed by gelation of the resulting emulsion with carbon dioxide gas.

Zinc oxide-containing spherical silica and process for its production

Growing community of inventors

Ichihara, Japan

Hachirou Hirano