摘要:
PIPA polyols are made in a two-step process. In the first step, a base polyether polyol and a polyisocyanate are reacted to form a mixture that contains unreacted base polyol, unreacted polyisocyanate and adducts of the base polyol and polyisocyanate. A low equivalent weight polyol is then added and reacted in a second step to form the dispersion. The process unexpectedly produces a stable dispersion of the fine PIPA particles in the base polyol, even when the base polyol contains mostly secondary hydroxyl groups. The process also permits the tuning of product viscosity by increasing or decreasing the extent of reaction in the first step.
摘要:
The invention relates to a two-component composition containing a polymer polyol, a diol chain extender, an aldimine of formula (I), optionally additional polyols and diphenylmethandiisocyanates in the two components. The composition is particularly suitable as a manually applicable solvent-free liquid film for coating and/or sealing floors and roofs. It also has a long open time, cures quickly and without complications in a wide temperature and humidity range, has a high level of strength and is weather resistant.
摘要:
A process for forming a conventional flexible polyurethane foam includes providing a polyol component including a PIPA polyol that is a dispersion having a solids content from 10% to 75 wt %, based on a total weight of the PIPA polyol, providing an isocyanate component that includes at least one polyisocyanate, providing an additive component that includes a catalyst, and forming a reaction mixture including the polyol component, the isocyanate component, and the additive component to form a flexible polyurethane foam with a resiliency value below 45%. The reaction mixture has an isocyanate index from 90 to 150. The PIPA polyol is a reaction product of a mixture including at least a low equivalent weight polyol having a number average hydroxyl equivalent weight of less than 80, a polyisocyanate compound having a number average isocyanate equivalent weight that is less than 225, and a liquid base poly ether polyol having a number average hydroxyl equivalent weight from 200 to 1500 and at least 80% of secondary hydroxyl groups based on a total amount of hydroxyl groups in the liquid base polyether polyol.
摘要:
This invention relates to hybrid polymer polyols. These hybrid polymer polyols comprise the free-radical polymerization product of (A) a base polyol comprising (1) a polymer modified polyol selected from (a) dispersions of polyureas and/or polyhydrazodicarbonamides in a hydroxyl group containing compound and (b) polyisocyanate polyaddition polyols, and (2) optionally, a polyol having a functionality of 2 to 6 and an OH number of from 20 to 500; (B) optionally, a preformed stabilizer; and (C) one or more ethylenically unsaturated monomers, in the presence of (D) a free-radical polymerization initiator, and (E) optionally, a polymer control agent. The present invention also relates to a process for the preparation of these hybrid polymer polyols, foams prepared from these hybrid polymer polyols and to a process for the preparation of these foams.
摘要:
Described herein, in the preferred embodiment, is a leonardite-based polyurethane resin binder that may be used, among other applications, as a binder in combination with foundry aggregate, e.g., sand, for molding or casting metal parts. The binders described herein comprise a humic substance, preferably leonardite, combined with a polymerizable polyol, an isocyanate, and a polymerization catalyst to make a polyurethane resin binder in situ in a foundry aggregate, such as sand. The lignite is mixed with the polymerizable polyol and dispersing agents as additives to improve the suspension quality and binder performance of the lignite-containing part of the binder components.
摘要:
A process for making a stable dispersion comprising the steps: (a) contacting, in a single mixer, a preformed polymer resin, a polyether polyol, and if necessary or desired, a stabilizer under conditions of sufficient heat to melt the preformed polymer, thereby forming a polymer melt, and sufficient shear to form an initial dispersion of the polymer resin in the polyol; and (b) while under shear, cooling the initial dispersion sufficiently to form a stable dispersion; wherein the preformed polymer resin is a polyethylene polymer, the process being characterized by the polyether polyol having a weight-averaged molecular weight of between 500 and 8000, a functionality of from 2 to 8, and a hydroxyl number of 70 to 5.61 and the dispersion comprising a stabilizer that is an imide reaction product of a maleic anhydride functionalized polyethylene wax and a monoamine polyol.
摘要:
A polymer polyol composition having dispersed polymer particles in a continuous phase which includes at least one polyether natural oil based polyol comprising at least two natural oil moieties separated by at least one of a molecular structure having an average of at least about 19 ether groups between any 2 of the natural oil moieties and a polyether molecular structure having an equivalent weight of at least about 400. The polymer polyol composition may be used in forming polyurethane foams.
摘要:
A non-aqueous dispersion (NAD) resin from natural oils having solids content of greater than 90%, and more preferably, greater than 95%, fast cure, low VOC, and low bake temperatures, and wherein the inclusion of multifunctional isocyanates provide faster dry times and harder films.