摘要:
A degradable article comprising a polyurethane polymer gel or foam whose polymer structure contains hydrolytically unstable ester linkages and various additives. The article can be constructed so that some of the additives are released from the article at a sustained rate. In a preferred embodiment the additives are sensory stimulants for marine or aquatic organisms and the article is used as bait for those organisms. Such sensory stimulants can include high molecular weight thickeners, to impart a slippery texture.
摘要:
A water absorbent, relatively dimensionally stable foam is formed from a prepolymer prepared from a polyoxyethylene containing diol, a crosslinking agent and a polyisocyanate. The preferred polyisocyanate is methylene bis(cyclohexyl isocyanate). The foam also demonstrates the ability to hold substantial amounts of water, even under pressure, and can be used in various personal and medical care products such as diapers and surgical sponges.
摘要:
This invention relates to a storage stable, heat reactive, adhesive dispersion composition comprising a solid epoxy resin containing more than one epoxy group and a solid, sterically unhindered, tertiary amine catalyst in a liquid vehicle which is a non-solvent for the solids but in which said solids are at least partially soluble in the melt. Heating said dispersion to a temperature at or above which the solids melt results in a thermoset product usable as an adhesive, sealant or coating.
摘要:
This invention relates to hydrophilic, urethane-forming compositions and a method of forming polyurethanes having low residual, potentially carcinogenic, aromatic amines by adding scavengers comprising polyols end-capped with aliphatic polyisocyanates.
摘要:
A flexible, hydrophobic polyurethane foam is produced by mixing together an aqueous phase which can optionally contain reinforcing fibers and surfactants and a resin phase comprising a prepolymer derived from a poly (oxy C.sub.2-4 alkylene) diol having a molecular weight of at least about 1100, an MDI containing isocyanate product having a functionality greater than 2.0 made of a mixture of MDI and isocyanate containing derivatives of MDI, and a monomeric polyol crosslinking agent having 3 or 4 hydroxyl equivalents per mole. The preferred polyol is trimethylolpropane and the diol is an equimolar mixture of Carbowax 1000 and Carbowax 1450. The diol and the polyol, such as trimethylolpropane, are present in a mole ratio in the range of 4:1 to 8:1 while the ratio of the isocyanate equivalents to the total hydroxyl equivalents is in the range of 2.5:1 to 3.5:1. The isocyanate containing product comprises less than 50% by weight of the prepolymer and Isonate 143L is the preferred isocyanate product. Flexible foams are obtained which are water-absorbing for medical or personal care applications.
摘要:
This invention relates to urethane forming compositions and a method of forming polyurethanes having low residual potentially carcinogenic aromatic amines by adding scavengers from the group comprising cyclohexyl monoisothiocyanate and hindered aliphatic monoisocyanates of the general formula: ##STR1## wherein R.sub.1 - R.sub.7 are H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof and x is 1 to 7.
摘要:
The invention disclosed is for new improved hydrophilic crosslinked polyurethane foams which simulate natural sponges and prepared by reacting an isocyanate capped polyoxyethylene polyol reactant with an aqueous reactant and a carefully balanced combination of a nonionic surface-active agent and a liquid defoaming agent. The resultant foams are characterized by a majority of large size cells and membranes which themselves are foamed with small cells.
摘要:
A degradable article comprising a polyurethane polymer gel or foam whose polymer structure contains hydrolytically unstable ester linkages and various additives. The article can be constructed so that some of the additives are released from the article at a sustained rate. In a preferred embodiment the additives are sensory stimulants for marine or aquatic organisms and the article is used as bait for those organisms.
摘要:
A weldable sealant composition is made by adding ferrous metal particles to a sealant having a viscosity of at least 6 million centipoises. The sealant composition is placed between two metal plates and permits resistance welding, i.e. spot welding, to take place.
摘要:
A weldable sealant composition is made by adding ferrous metal particles to a sealant having a viscosity of at least 6 million centipoises. The sealant composition is placed between two metal plates and permits resistance welding, i.e. spot welding, to take place.