摘要:
A polyurethane/urea/thiourea latex having a narrow molecular weight polydispersity and sub-micron particle size can be prepared by first preparing a high solids (between about 65% and 74% solids) latex of a polyurethane/urea/thiourea prepolymer, then contacting the emulsion with a chain-extending reagent under such conditions to form the polymer latex.
摘要:
Claimed is a substrate having a polar surface and, adherent thereto, a polyurethane polymer which was applied as a latex. The latexes of the present invention are chain extended in water with aminoethyl ethanolamine and are prepared and applied in the substantial absence of organic solvents. The prepolymers used to prepare the latexes are substantially free ionic groups on the polymer backbone.
摘要:
Disclosed are stable aqueous polyurethane latexes prepared from prepolymer formulations including a polyisocyanate component and polyol component, wherein from 5 to 40 percent of the weight of the polyol component is ethylene oxide in the form of ethylene oxide applied as an end cap onto a propylene oxide or higher oxyalkylene polyoxyalkylene polyol, and no more than 45 percent of the weight of polyol component is ethylene oxide. These latexes are prepared without the use of organic solvents.
摘要:
A roller assembly for use, for example, in agricultural machines where the roller assembly has an exterior surface portion adapted to contact a conveyor element supporting the agricultural products and a bearing sub-assembly positioned about an axle in the center of the roller assembly. The bearing sub-assembly has at least one bearing, at least one sealing element having an elastomeric sealing portion positioned outboard of the bearing and at least one standoff also positioned outboard of the bearing. There may be a plug in place of one of the sealing elements, the plug being elastomeric and configured to make a compression fit with the hub.
摘要:
A polyurethane/urea/thiourea latex having a narrow molecular weight polydispersity and sub-micron particle size can be prepared by first preparing a high internal phase ratio (HIPR) emulsion of a polyurethane/urea/thiourea prepolymer, then contacting the emulsion with a chain-extending reagent under such conditions to form the polymer latex.
摘要:
The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.
摘要:
A roller assembly for use, for example, in agricultural machines where the roller assembly has an exterior surface portion adapted to contact a conveyor element supporting the agricultural products and a bearing sub-assembly positioned about an axle in the center of the roller assembly. The bearing sub-assembly has at least one bearing, at least one sealing element having an elastomeric sealing portion positioned outboard of the bearing and at least one standoff also positioned outboard of the bearing. The standoffs have grooves in their outer dimension adapted to receive the elastomeric sealing portion. The diameter of the standoffs are about the same as the diameter of the elastomeric sealing portion. The horizontal length of the standoffs may also be chosen so as to offset the exterior surface portion of the assembly a predetermined distance with respect to the conveyor element.
摘要:
A polymer polyol is produced by a process comprising free radical polymerizing an addition polymerizable di-(substituted phenyl)monomer (e.g., methacrylic ester of diglycidylether of tetrabromobisphenol A) component in the presence of a polyol, wherein the monomer has at least one aromatic halogen and at least one aromatic ethylenically unsaturated substituent. The polymer polyol can also be made by copolymerizing said monomer with an additional ethylenically unsaturated monomer component such as styrene and acrylonitrile. Said polymer polyols are reacted with a polyisocyanate compound forming a flame retardant polyurethane foam.
摘要:
An insulated wall panel comprising of two outer layers, an insulating foam core, and a spacer within the foam core which holds the panel spacing and retains the foam during foam introduction and expansion in the cavity and remains as part of the panel. The panel has no thermal bridging between the outer layers and is manufactured with reduced need of rigid mold forms. The final effect after pouring becomes a monolithic foam core of substantially consistent material and provides a superior product to using dissimilar retained spacing materials.
摘要:
The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.