摘要:
Rigid isocyanurate foams having a substantially open cell structure are prepared by foaming a mixture of an organic polyisocyanate and a polyol having a NCO/OH equivalent ratio of 3.5 to 13.
摘要:
There is disclosed a polyurethane/unsaturated polyester hybrid foam of the rigid type prepared from novel components including not only polyol and polyisocyanate but also a unique hydroxy-containing vinyl ester and vinyl monomer, optionally together with an additional polar vinyl monomer, all together providing the necessary components for a hybrid polyurethane-polyvinyl ester matrix, which mixture of components before foaming is capable of having suspended therein fillers and reinforcing fibers to produce a foam or reinforced foam composite having a density between about 20 and 100 pounds per cubic foot. The reinforced foam can be made into baords and the like and advantageously has continuous fiberglass strands or yarn disposed longitudinally in or adjacent the surface skin of the foam. The strands or yarn are preferably parallel and close together and are preferably flattened out in the foam-forming process so that the surfaces have a continuous fiberglass implant longitudinally and substantially so transversely. One preferred structural composite is illustrated in the drawings.
摘要:
This invention generally relates to a high resilience urethane foam (HR foam) having low compression set at a wide range of isocyanate index for use in small void filling in integrated foam parts.The small voids formed in the molding process of integrated foam parts can be filled without penetration of foaming liquids into existing foam cells. In addition, resulting foams have very low compression set values at a wide range of isocyanate index.The foaming system of the present invention is composed of two components, i.e., thixotropic polyisocyanate component and thixotropic polyol component. Their thixotropicity is obtained by adding benzal sorbitol into respective components. The polyisocyanate is selected from organic polyisocyanates and the polyol component is prepared by mixing a polyol blend composed of a polyolefinic polyol and a polyoxyalkylene polyol in a weight ratio between 95/5 to 50/50, a blowing agent, a surfactant and a catalyst.
摘要:
There is disclosed a polyurethane foam of the rigid type having three different types of polyol components capable of having suspended therein fillers and reinforcing fibers. The foam is made into boards and the like and has continuous fiber glass strands or yarn disposed longitudinally in or adjacent the surface skin of the foam. The strands or yarn are parallel and close together and are flattened out in the foam-forming process so that the surfaces have a continuous fiber glass implant longitudinally and substantially so transversely.
摘要:
A halogen-free blowing agent is used to produce isocyanate-based polymeric foams. The blowing agent is an organic liquid which is free from halogens and contains a positive binary azeotrope having a minimum boiling temperature in the range of about 15.degree. C. to about 80.degree. C. at normal atmospheric pressure. Particularly preferred is a binary azeotrope of an alicyclic hydrocarbon such as cyclopentane or cyclohexane and methyl formate.The halogen-free blowing agents contemplated herein provide the following advantages: no ozone depletion potential, no global warming potential, direct replacement in foam formulations for trichloromonofluoromethane (CFC-11), relatively higher blowing action, relatively lower foam density, relatively lower thermal conductivity, better compatibility, and relatively lower materials cost.
摘要:
Oxazolidones are produced by reacting an organic isocyanate with an epoxide in the presence of a catalyst selected from the group consisting of dialkyl zinc, zinc carboxylate, organozinc chelate compound and trialkyl aluminum. Polyoxazolidones produced according to the present invention are useful starting materials for the manufacture of a wide variety of product including foams, coatings, adhesives, elastomers and the like.
摘要:
In a process for preparing a smoke-retardant polyisocyanurate foam by reacting an organic polyisocyanate in the presence of a blowing agent and an isocyanate-trimerization catalyst, the improvement comprising conducting the reaction by adding 0.5 to 6 wt. % as Si to the total components of the foam of an organosilicone surfactant having a Si content of 4-22%, and selected from an organopolysiloxane-poly-oxyalkylene copolymer, polyvinylsilane having polyoxyalkylene side chain or modified products thereof wherein the mole % of the ethylene oxide units of the polyoxyalkylene moiety of the organosilicone surfactant is greater than 40 mole % based on the total number of ethylene oxide and propylene oxide units in said polyoxyalkylene moiety.
摘要:
In a process for preparing a smoke-retardant polyisocyanurate foam by reacting an organic polyisocyanate in the presence of a blowing agent and an isocyanate-trimerization catalyst, an improvement is characterized in that the reaction is conducted in the presence of an organosilicate having the formula Si(OR).sub.4 or R.sub.n Si(OR').sub.4-n wherein R and R' are the same or different and represent aliphatic, alicyclic and aromatic hydrocarbon groups having 1-12 carbon atoms or substituted derivatives thereof and n is an integer of 1 to 3.
摘要:
There is disclosed a process for producing an isocyanate-based polymer by catalytically reacting a polyisocyanate alone or in combination with a polyhydroxy compound, the improvement in which an aromatic aldehyde having aldehyde group and no functional group capable of reacting with the isocyanate group, as a smoke suppressing agent is added to the reaction system.
摘要:
A cryogenic heat insulating structure comprises: a wall coated with a plurality of superposed rigid foam layers each of the layers having a skin and each layer containing fibers oriented parallel to the wall.