摘要:
There are disclosed a thermal insulating foamed material, which is superior in thermal insulating property and does not cause deterioration of the thermal insulating property with a time lapse, and a method for producing the same. According to a method for producing a thermal insulating foamed material, a foamed polyurethane resin composition having closed cells, in which at least carbon dioxide is filled, is formed by blowing a raw material mixture containing epoxides comprising at least two members of an epoxide compound having high reactivity with carbon dioxide and an epoxide compound having low reactivity with carbon dioxide, a carbon dioxide fixation catalyst, polyisocyanate, a reactive blowing agent which evolves carbon dioxide by reacting with said polyisocyanate, and a polyol composition. Then, the carbon dioxide in the closed cells is allowed to react with the epoxides in the presence of the carbon dioxide fixation catalyst, thereby to fix carbon dioxide as carbonate compounds.
摘要:
This invention relates to improved one part polyepoxide resins which are tough and have enhanced flexible and elastic properties. The polyepoxide resins comprise a polyepoxide resin based on a polyglycidyl ether of a phenol, an oxazolidone toughener and a latent amine curative. The improvement in the polyepoxide resin formulation comprises incorporating an oxazolidone toughener represented by the formula:
wherein R is the residue of an aliphatic glycol or aliphatic ether glycol having from 2 to 20 carbon atoms.
摘要:
Described are anisotropic polymers produced from a diepoxide A of the formula (I) in which: Y is O-CY2, CH2 or a C-C single bond; X is one of structural elements (a), (b), (c), (d), (e) or (f); R1 to R5, independently or each other, are hydrogen, halogen or a methyl, ethyl, propyl or butyl group; or R2, R3, R4 or R5 may be a benzene group, whereby R2 to R5 is hydrogen when R1 is not hydrogen and R1 is hydrogen when R2 to R5 are not hydrogen, and n may be 1 to 3; whereby the central grouping Z may be an aromatic heterocyclic ring containing one or two nitrogen atoms or a cycloaliphatic trans-1,4-cyclohexylene group, and from a diisocyanate B of one of the formulae (II) to (VII) in which: Y is a C-C single bond, CH2 or C2H4; X is one of structural elements (a), (b), (c) or (f), n is 0 or 1 and R1 to R5 are the atoms or groups given in the definition of formula (I); whereby the central grouping Z may also be a cycloaliphatic trans-1,4-cyclohexylene group, and R is (CH2)6-NCO, the molar ratio of diepoxide A to diisocyanate B being about 2:1 to 1:4. Also described is a method for the production of such anisotropic polymers, in which the diepoxide A and the diisocyanate B are reacted at a temperature of about 100 to 300 °C at a molar ratio of about 2:1 to 1:4. These anisotropic polymers have a low coefficient of thermal expansion in the direction of orientation of the molecules and can be used in the manufacture of insulation materials, laminates and coatings.
摘要:
The invention describes a polyurethane having a softening temperature above 65°C and being formed by the reaction, in the presence of a curing agent, of an isocyanate-terminated polymer with an hydroxyl-containing organic compound in proportions to provide a -NCO/-OH ratio of at least 1.5 to yield a crosslinked polyurethane comprising isocyanurate and/or oxazolidone structures. This polyurethane may be used as a binder, e.g. for composite abrasive wheels with improved thermal properties. Such an abrasive wheel is comprised of a fibrous substrate with abrasive particles adhered thereto by a crosslinked polyurethane binder comprising heterocyclic groups. The heterocyclic structures, such as isocyanurate and/or oxazolidone rings, in the binder system improve the thermal properties required for a tough, durable abrasive wheel.
摘要:
A multi-block polymer comprising an oxazolidone prepolymer chain extended with a second compatible prepolymer, the membrane made therefrom and the use of said membrane in aromatics/non-aromatics separations is disclosed. The multi-block polymer comprises an oxazolidone containing prepolymer chain extended with a second compatible prepolymer, said second prepolymer selected from the group of prepolymers produced by combining a) an (A) diisocyanate with a monomer selected from (B) polyester dianhydride or corresponding tetraacid or diacid-diester, and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably 2.0 to 1.1; b) an (A) dianhydride or its corresponding tetraacid or diacid-diester with a monomer selected from (B) epoxy, diisocyanate, polyester and diamine in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, or c) an (A) diamine with a monomer selected from (B) epoxy, diisocyanate, dianhydride, or its corresponding tetraacid or diacid-diester in an A/B mole ratio ranging from about 2.0 to 1.05, preferably about 2.0 to 1.1, and mixtures thereof. The membranes made from these multi-block polymers comprising thin dense films of said polymer deposited on a micro-porous support are also claimed. The membranes are useful for separating aromatic hydrocarbons from mixtures of same with non-aromatic hydrocarbons under perstraction or pervaporation conditions.
摘要:
Significant improvements in the utility of oxazolidone and polyoxazolidone compounds and in their manufacture can be achieved using a novel catalyst in the reaction between a hindered isocyanate and an epoxy, forming oxazolidone ring structures. The novel catalyst of the invention promotes the efficient and rapid formation of oxazolidone and polyoxazolidone compounds. The use of hindered isocyanate in the reaction prevents formation of side reaction products such as isocyanate trimer, allophanate and biuret.