Toda Kogyo Corporation

Torayuki Honmyo

Naoya Kobayashi

Tsutomu Katamoto

Akinori Yamamoto

Kanae Honmyo

Kanae Yuasa

The present invention relates to a heat retaining agent for agricultural films comprising hydrotalcite-type particles which can satisfy all of a transparency required for heat retaining agents for agricultural films, dispersibility in resins, and handling property at a high level. According to the present invention, there are provided hydrotalcite-type particles having an oil absorption of not more than 35 mL/100 g and a ratio of an oil absorption to a plate surface diameter (oil absorption/plate surface diameter) of 140 to 190; a heat retaining agent for agricultural films comprising the hydrotalcite-type particles; and an agricultural film comprising the heat retaining agent for agricultural films.

Hydrotalcite-type particles, heat retaining agent for agriculture films, master batch for agricultural films, and agricultural film

According to the present invention, there are provided hydrotalcite-based compound particles surface-treated with an organic compound having not less than 3 carbon atoms, have a specific surface area of 5 to 150 m/g, wherein a conceptual value x corresponding to micropores and ultramicropores, and a conceptual value y corresponding to volumes of macropores and micropores, both calculated from a water vapor adsorption curve thereof when exposed to a temperature of 25&#xb0; C. and a humidity of 50% for 250 hours, are respectively within specific ranges. The hydrotalcite-based compound particles of the present invention are capable of capturing even a very small amount of halogens contained in various resins, and exhibiting an excellent effect of preventing deterioration of the resins. Further, the hydrotalcite-based compound particles of the present invention are used in the form of particles or a molded product and are capable of exhibiting a function for capturing an anionic organic or inorganic compound from a solution to a maximum extent without being dissolved, by themselves, in the solution.

Hydrotalcite-based compound particles, resin stabilizer using the same, halogen-containing resin composition and anion scavenger using the same

A chlorine-containing resin composition for covering an electric wire of the present invention, has a heat stability of not less than 240 minutes and a volume resistivity of 5.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm when measured according to JIS K6723, and comprises:

Mg-Al-based hydrotalcite-type particles, chlorine-containing resin composition and process for producing the particles

The Mg&mdash;Al-based hydrotalcite-type particles according to the present invention have a plate surface diameter as large as from 0.1 to less than 1.0 &mgr;m, an adequate thickness ranging from 0.02 to 0.08 &mgr;m and a heat-resisting time of not less than 160 minutes when measured by a specific method, and are, therefore, suitable as a stabilizer for chlorine-containing resins.

Mg-Al based hydrotalcite-type particles, chlorine-containing resin stabilizer and process for producing the particles

Disclosed herein are a process for producing poreless plate-like magnetite particles which have as large a plate ratio (average particle diameter/thickness) as possible and which are discrete each other, the process comprising the step of: obtained by oxidizing a suspension containing FeCO.sub.3 obtained by reacting an aqueous ferrous salt solution and an aqueous alkali carbonate solution by passing an oxygen-containing gas therethrough, wherein the suspension is obtained by reacting a ferrous salt solution containing 0.2 to 5.0 mol % of a ferric salt, calculated as Fe(III), based on Fe(II) and an aqueous alkali carbonate the amount of which is so controlled that the equivalent ratio of an alkali carbonate to the Fe(II) and Fe(III) in the aqueous ferrous salt solution is not less than 1 and the following general formula is satisfied: ##EQU1## and if necessary, 0.01 to 8.0 ml % of a water-soluble organic compound having a --COONa or --COOK group based on the Fe(II) and Fe(III) are added to any of the aqueous ferrous salt solution, the aqueous alkali carbonate solution and the suspension containing FeCO.sub.3 before the oxidation, and poreless plate-like magnetite particle which has as large a plate ratio and are discrete each other.

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Otake, Japan

Torayuki Honmyo