Abstract: There is disclosed a method for purifying a polymer by extracting volatile materials contained in the molten polymer. According to the disclosure, a polymer having a very high degree of extraction of volatile materials can be obtained. The polymer obtained by the method of disclosure can meet the severe demands of the market that restricts the concentration of remaining volatile material impurities.

Abstract: There is disclosed a method for producing a foamed resin which incolves the steps of removing volatile substances from a polymer by contacting the polymer with an extractant and foaming the purified polymer by using the same extractant dissolved in the polymer as a foaming agent. According to the disclosure the purification and blowing of a polymer can be carried out efficiently and economically with a purification sufficient to meet market demand and with a desired blowing expansion rate.

Abstract: A reactor tube for thermally cracking or reforming hydrocarbons comprising a tube member made of Fe-Cr-Ni heat resisting material and a covering layer of self-fluxing alloy fusing to the inner surface of the tube member, the covering layer made of heat resisting material free from Ni or with a low Ni content. The tube member is manufactured by centrifugal casting, and the covering layer is formed by applying the self-fluxing alloy powder by scattering with or without thermit agent or spraying the alloy to the inner surface of the tube member.

Abstract: Corrosion of a combustion furnace is prevented by a coating of an alkali metal carbonate or an alkaline earth metal carbonate formed on metal surfaces of the furnace before it has started operation.

Abstract: A reactor tube for thermally cracking or reforming of hydrocarbons wherein a reacting layer contacting hydrocarbons is made of heat resisting steel comprising, in terms of % by weight, 0.3 to 1.5% C, up to 3% Si, 6 to 15% Mn, 20 to 30% Cr, up to 3% Nb, up to 0.15% N, the balance being substantially Fe and a covering layer which covers the said reacting layer is made of Fe-Cr-Ni heat resisting steel and is fused to the reacting layer at their boundary.

Abstract: A reactor tube for thermally cracking or reforming hydrocarbons comprising an outer tube member made of Ni-containing heat resisting material and having enhanced mechanical strength with a large wall thickness, and an inner tube member of small wall thickness fitted in the outer tube member and made of heat resisting material free from Ni or with a low Ni content. The inner and outer tube members have been subjected to a diffusion treatment with a thin coating of Ni-P solid solution provided at the junction therebetween and thereby bonded together.