Nissan Chemical Industries Limited

Toyota Jidosha Kabushiki Kaisha

Akira Kitajima

Yoshitane Watanabe

Keiko Tasaki

Isamu Yuuki

Kiyomi Ema

Akitoshi Yoshida

Yoshiro Hayashi

Masaharu Kosaka

Hisayuki Sato

Ken-ichi Okubi

Disclosed is an inorganic adhesive composition comprising (a) an aqueous silica sol and (b) an inorganic refractory powder along with one or more materials selected from (c) a fine powdery silica, (d) an aqueous alkali silicate solution and (e) a silane coupling agent. After hardening, the hardened product of the composition displays noticeably improved adhesion strength and electric insulating property.

Inorganic adhesive composition

A binder for manufacture of a precision casting mold comprising a transparent solution containing an alkyl orthosilicate or an alkyl polysilicate having a polymerization degree of 2 to 10, and an amino-alkoxide of a metal selected from a group consisting of titanium, zirconium, tin and aluminum or a mixture thereof in the mol ratio (Si/N) of 0.01 to 1.0 calculated in terms of the silicon atom contained in the silicate and the basic nitrogen atom contained in the amino-alkoxide. This binder is excellent in preservation stability and workability and does not dissolve the surface of a water-soluble pattern.

Binder for manufacture of precision casting mold

Binders for manufacture of precision casting molds are provided, which are highly stable and are advantageous in that these may impart a high strength to the green molds as obtained by forming an accumulative refractory coat layer on a water-soluble pattern and then taking off the pattern from the coat layer, that no interlayer cleavage occurs in the accumulative coat layer when the pattern is taken off in the formation of the green mold, that the binders may impart a high strength to fired molds, that the castings as obtained by the use of the present fired molds are free from the surface roughness and other surface faults and that the dimension accuracy of the castings is not deteriorated at all by the use of the present binders. The binders of the present invention are characterized by containing the following components (a), (b) and (c) and optionally (d):

Binders for manufacture of precision casting molds

A process for preparing a mold by preparing a slurry of refractory powder in a binder solution comprising silica sol and monomethyl triethanol ammonium silicate or tetraethanol ammonium silicate at a mole ratio of SiO.sub.2 /M.sub.2 O of 10 to 22 and a mole ratio of SiO.sub.2 /NR of 9 to 28 wherein M represents Li or Na and NR represents monoethyl triethanol ammonium hydroxide or tetraethanol ammonium hydroxide, and repeating an overcoating of said slurry and a refractory powder by coating said slurry on a pattern, sanding said refractory powder on the coated pattern and drying it to form a green mold, separating said green mold from said pattern and calcining said green mold.

Process for preparing mold

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Funabashi, Japan

Akira Kitajima