摘要:
A water-resistant shaped structure of gypsum comprising (A) calcium sulfate dihydrate formed by hardening of calcium sulfate capable of hydration reaction, (B) a calcium type filler for filling up spaces among crystalline particles of said calcium sulfate dihydrate and (C) a water-insoluble or hardly water-soluble salt of a polybasic acid having a second stage dissociation constant of 10.sup.-3 to 10.sup.-10, especially 10.sup.-4 to 10.sup.-9, as measured at 25.degree. C., said calcium type filler (B) being at least one calcium compound selected from the group consisting of calcium hydroxide, calcium carbonate, calcium silicate, calcium aluminosilicate, and non-water-hardenable anhydrous gypsum and partially hydrated products thereof, wherein the amount of the calcium type filler (B) and the water-insoluble or hardly water-soluble calcium salt (C) is 15 to 75% based on the total amount of the components (A), (B) and (C) as calculated as calcium, the amount of the water-insoluble or hardly water-soluble calcium salt (C) is 0.1 to 30% based on the total amount of the components (A), (B) and (C) as calculated as calcium, the water-insoluble or hardly water-soluble calcium salt (C) is distributed predominantly in the surface portion of the shaped structure, and said surface portion has a pore volume smaller than 0.50 ml/g in pores having a radius in the range of 75 to 75000 A and a pore volume smaller than 0.20 ml/g in pores having a radius in the range of 4000 to 10000 A.
摘要:
A method of treating raw materials containing components of metals of the group IVb of the Periodic Table, which comprises heat-treating a raw material of a component of a metal of the group IVb of the Periodic Table containing coloring poisonous metal components such as Mn, V and Cr components in the presence of a flux composed mainly of an alkali metal nitrate or an alkali metal peroxide which is a thermal decomposition product of the alkali metal nitrate in an amount 2 to 5 times the amount of the raw material on the weight basis in a non-reducing atmosphere to thereby effect fluxing reaction, and subjecting the resulting fluxing reaction product to a leaching treatment of at least one stage in an aqueous medium to separate the fluxing reaction product into said coloring metal components and a concentrate of the component of the group IVb of the Periodic Table which is acid-soluble and substantially free of said coloring poisonous metal components. In practising this treating method, if a residue left after the above leaching step is incorporated into a mixture of the raw material and the flux, the composition is granulated and the granulated composition is heat-treated, the fluxing reaction of the raw material can be accomplished while keeping the granulated composition in the substantially non-sticky granular state throughout the fluxing heat treatment.
摘要:
Disclosed is a process for the preparation of lead compounds which comprises reacting lead monoxide according to the wet method with an inorganic acid or organic acid in the presence of hydroxylamine under such conditions that the initial pH value of the reaction system is not higher than 7.Lead monoxide according to the wet method has an excellent reactivity with an inorganic acid or organic acid, but it contains higher oxides such as lead dioxide and minium, which cause coloration in lead compound products. According to this process, this undesirable coloration can effectively prevented.
摘要:
Disclosed is a granular stabilizer for chlorine-containing polymers, which comprises porous spherical particles composed of randomly integrated needle crystals of a polybasic sulfuric acid/fatty acid lead salt having a chemical composition of 1 mole of SO.sub.3, 3.7 to 4.5 moles of PbO and 0.06 to 1.27 moles of a higher fatty acid and also having X-ray diffraction peaks at spacings d of 2.95 A and 3.27 A, wherein the fatty acid component is enrolled in the surfaces of the respective needle crystals without substantial phase separation in the surfaces of the spherical particles.
摘要:
A novel lead monoxide having a true density of 8.3 to 9.2 g/cc, a primary particle size not larger than 0.2 .mu., an infrared absorption peak at a wave number of 1400 to 1410 cm.sup.-1 and a chromic anhydride reactivity of at least 94%.This lead monoxide is of the ultrafine particulate form excellent in light resistance, hue stability and reactivity and is substantially free of metallic lead. Chrome yellow, tribasic lead sulfate, lead silicate, white lead and the like lead salts can be prepared from this lead monoxide without performing a particular washing operation or using a catalyst.
摘要:
When an alkali such as an alkali metal bicarbonate or carbonate is intimately mixed with bauxite or other alumina-containing raw material at an Al.sub.2 O.sub.3 /Na.sub.2 O molar ratio of from 1/1 to 1/3 and the mixture is molded into granules, then calcined and extracted with an aqueous medium, the alumina component can be recovered in a high yield in the form of an aqueous solution of an alkali metal aluminate. The alkali component is not substantially contained in the residue left after recovery of this aqueous solution.
摘要:
A lead battery comprising as an active material a formation product of a novel lead monoxide or a heat treatment product thereof is disclosed. This novel lead monoxide has a true density of 8.3 to 9.2 g/cc, an average particle size not larger than 0.2.mu., an infrared absorption peak at a wave number of 1400 to 1410 cm.sup.-1 and a chromic anhydride reactivity of at least 94%.This lead battery is excellent over lead batterys comprising active materials formed from known starting substances with respect to the active material utilization ratio and it has a very long life and stable capacities. In this lead battery, the active material utilization ratio can be maintained at a very high level over a long period.
摘要:
A stabilizer composition for chlorine-containing polymers having a much reduced tendency to blow at the molding step, which comprises (A) an inorganic stabilizer having a power volume of at least 0.5 cc/g, said stabilizer (A) consisting essentially of at least one member selected from the group consisting of silicates of metals of Groups II and IV of the Periodic Table and composites of silicate acid with oxides, hydroxides and carbonates of said metals, and (B) an organic additive having a boiling point or decomposition point higher than a chlorine-containing polymer-processing temperature, said organic additive (B) being incorporated into the stabilizer (A) at a weight ratio (A) : (B) of 1 : at least 0.1 so that the pore volume ratio defined by the following formula: ##EQU1## WHEREIN PVc denotes the pore volume (cc/g) of the entire composition and PVa denotes the pore volume (cc/g) of said inorganic stabilizer (A),is not higher than 0.8.
摘要:
When titanium phosphate is used as a white pigment to an article of which surface comprises polyolefin composition, the article is remarkably whitened.
摘要:
A process for the preparation of granules of low-melting-point metals which comprises spouting a melt of a low-melting-point metal in the form of fine streams in a gas phase under melt fracture-causing conditions and introducing the fine streams of the molten metal into a collecting liquid phase so that the speed of the molten metal fine streams just above the liquid face is 50 to 300 cm/sec is disclosed. According to this process, granules having a substantially spherical shape and being uniform in the size can be prepared very easily at high efficiency.