摘要:
This invention relates to polyurethane elastomers and to a process for their production. These elastomers comprise the reaction product of a (cyclo)aliphatic isocyanate component having an NCO group content of about 20 to about 45%, with an isocyanate-reactive component comprising one or more polyether polyols which is free of amine groups, and a low molecular weight organic compound containing two hydroxyl groups and which is free of amine groups, in the presence of one or more catalysts.
摘要:
The present invention is directed to a polyisocyanate mixture i) having a monomeric diisocyanate content of less than 3% by weight, ii) having a urethane group content of more than 50 equivalent %, based on the total equivalents of urethane and allophanate groups, and iii) containing siloxane groups (calculated as SiO, MW 44) in an amount of 0.002 to 50% by weight, wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein the siloxane groups are incorporated by reacting a) an isocyanate group from a polyisocyanate adduct containing isocyanurate groups and prepared from a monomeric diisocyanate having at least one cycloaliphatic group with b) a compound containing one or more hydroxyl groups directly attached to a carbon atom and one or more siloxane groups to form urethane groups. The present invention also relates to the use of this polyisocyanate mixture, optionally in blocked form, as an isocyanate component in one- or two-component coating compositions.
摘要:
The present invention is directed to a polyisocyanate mixture i) having an NCO content of 5 to 35% by weight and a monomeric diisocyanate content of less than 3% by weight, and prepared from a polyisocyanate adduct, ii) containing allophanate groups in an amount such that there are more equivalents of allophanate groups than urethane groups and iii) containing fluorine (calculated as F, AW 19) in an amount of 0.001 to 50% by weight, wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein fluorine is incorporated by reacting an isocyanate group with a compound containing two or more carbon atoms, one or more hydroxyl groups and one or more fluorine atoms. The present invention is also directed to a process for the production of this polyisocyanate mixture and to its use, optionally in blocked form, as an isocyanate component in one- or two-component coating compositions.
摘要:
The present invention is directed to P-superfamily conopeptides, to DNA encoding precursors of the P-superfamily conopeptides and to the precursor peptides.
摘要:
Protein disulfide isomerase is a major component of Conus venom ducts. The invention relates to a protein disulfide isomerase (PDI) from Conus snails, a nucleic acid sequence encoding the Conus protein disulfide isomerase, and to methods for folding disulfide-rich peptides using a protein disulfide isomerase. Oxidative folding of conotoxin precursors, catalyzed by a PDI, was more efficient and decreased the number and concentration of transiently accumulated folding species. The PDI-assisted oxidative folding of conotoxins was also influenced by the propeptide relative to the mature peptide.
摘要:
The present invention is directed to conopeptides termed conkunitzins and their use for blocking the flow of potassium ions through voltage-gated potassium channels. In view of the Kunitz domain in the conkunitzins, they are also useful for inhibiting platelet aggregation and as protease inhibitors.
摘要:
A method and apparatus for positioning and supporting the work platform of a mobile workover rig is disclosed. The work platform of the preferred embodiment of the present invention utilizes a unique support structure and automated positioning system for positioning the work platform at the desired height above the wellhead equipment. The preferred embodiment of the present invention utilizes a specialized automated “pinning” system that secures the work platform at the desired height. Additionally, the present invention utilizes one or more support cylinders to position and support the work platform in the horizontal position over the wellhead equipment. The automated positioning and pinning system of the present invention is a unique system that significantly reduces the time required to position the work platform of a mobile workover rig in the operating position, as well as significantly reduces the risk of injury to rig personnel assisting in the positioning operations.
摘要:
The invention relates to alcohol-modified glycidyl carbamate resins wherein at least some of the glycidol groups in the resin have been replaced with an alcohol. The invention also relates to coating compositions containing the resins.
摘要:
One embodiment described herein provides a circuit to approximate the inductor current of a power supply that includes a capacitor; charge/discharge circuitry configured to charge the capacitor with a voltage that is proportional to an input voltage rail of the power supply, and discharge the capacitor with a voltage that is proportional to the output voltage of the power supply; and error correction circuitry is configured to adjust the voltage that is proportional to the input voltage rail and the voltage that is proportional to the output voltage based on an instantaneous current of the inductor; and wherein the voltage on the capacitor is proportional to a current associated with the inductor.