摘要:
Process for the production of foam boards having a minimum thickness of 20 mm and a cross-sectional area of at least 50 cm.sup.2 by extruding a mixture of the styrene polymer, from 1 to 10% by weight, based on the styrene polymer, of a blowing agent, wherein the blowing agent contains at least one ether from the group consisting of dimethyl ether, methyl ethyl ether and methyl vinyl ether.
摘要:
Extruded foam boards produced using halogen-free blowing agents from a styrene polymer thermoplastic matrix having a Vicat softening temperature VST B 50 of at most 100.degree. and a melt index MVI 200/5 of at least 5 ml/10 min are at least 20 mm, preferably more than 50 mm and in particular from 80 to 200 mm, thick. Preferred blowing agents for producing the foam boards are carbon dioxide alone, as well as mixtures of carbon dioxide and ethanol and/or dimethyl ether.
摘要:
A composite foam of low thermal conductivity comprisesa) 20-80% by volume of silica aerogel particles having a mean diameter of from 0.1 to 20 mm and a density of from 0.08 to 0.40 g/cm.sup.3,b) 20-80% by volume of a styrene polymer foam which surrounds the particles of component a) and binds them to one another and has a density of from 0.01 to 0.15 g/cm.sup.3, and, if desired,c) conventional additives in effective amounts.
摘要翻译:低热导率的复合泡沫体包括a)20-80体积%的平均直径为0.1-20mm,密度为0.08-0.40g / cm3的二氧化硅气凝胶颗粒,b)20-80体积% 的苯乙烯聚合物泡沫体,其围绕组分a)的颗粒并将它们彼此结合并具有0.01至0.15g / cm 3的密度,以及如果需要,c)有效量的常规添加剂。
摘要:
A composite foam of low thermal conductivity comprisesa) 20-80% by volume of silica aerogel particles having a mean diameter of from 0.1 to 20 mm and a density of from 0.08 to 0.40 g/cm.sup.3,b) 20-80% by volume of styrene polymer foam which surrounds the particles of component a) and binds them to one another and has a density of from 0.01 to 0.15 g/cm.sup.3, and, if desired,c) conventional additives in effective amounts.
摘要翻译:低热导率的复合泡沫体包括a)20-80体积%的平均直径为0.1-20mm,密度为0.08-0.40g / cm3的二氧化硅气凝胶颗粒,b)20-80体积% 的苯乙烯聚合物泡沫塑料,其围绕组分a)的颗粒并将它们彼此结合并具有0.01至0.15g / cm 3的密度,并且如果需要,c)有效量的常规添加剂。
摘要:
A thermal insulating material based on a pigment-containing silica aerogel is obtainable bya) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogen, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 .mu.m,b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water,c) displacing the water in the hydrogen by a low-boiling liquid which is inert toward the pigment-containing silica gel,d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, ande) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.