Low viscosity, high concentration drag reducing agent and method therefor
    26.
    发明授权
    Low viscosity, high concentration drag reducing agent and method therefor 失效
    低粘度,高浓度减阻剂及其方法

    公开(公告)号:US5733953A

    公开(公告)日:1998-03-31

    申请号:US496489

    申请日:1995-06-29

    Abstract: Low viscosity, high concentration drag reducing agents may be prepared by slowly adding a liquid, non-solvent (e.g. isopropyl alcohol) for a drag reducing polymer (e.g. a polyalphaolefin) to a mixture of the polymer and the solvent (e.g. kerosene) in which the polymer is dissolved. When enough non-solvent is added, the polymer precipitates into fine particles. The supernatant mixture of solvent and non-solvent is then removed from the precipitated polymer slurry concentrate. Further solvent contained in the slurry concentrate may be removed by evaporation or further extraction with the liquid, non-solvent. The resulting slurry concentrate dissolves rapidly in flowing hydrocarbon streams to reduce the drag therein, and gives exceptionally good drag reducing results at low concentrations. Additionally, no injection probes or other special equipment is required to introduce the drag reducing slurry into the hydrocarbon stream, nor is grinding of the polymer necessary to form a suitable DRA slurry.

    Abstract translation: 低粘度,高浓度的减阻剂可以通过向聚合物和溶剂(例如煤油)的混合物中缓慢加入用于减阻聚合物(例如聚α-烯烃)的液体非溶剂(例如异丙醇)来制备,其中 聚合物溶解。 当加入足够的非溶剂时,聚合物沉淀成细颗粒。 然后从沉淀的聚合物淤浆浓缩物中除去溶剂和非溶剂的上清液混合物。 可以通过蒸发或用液体非溶剂进一步萃取来除去浆料浓缩物中所含的其它溶剂。 所得到的浆料浓缩物快速溶解在流动的烃流中以减少其中的阻力,并且在低浓度下给出非常好的减阻结果。 另外,不需要注射探针或其他特殊设备将减阻剂引入烃流中,也不需要研磨形成合适的DRA浆料所需的聚合物。

    Substituted 1,2-dihydropyridines and process for preparing same
    30.
    发明授权
    Substituted 1,2-dihydropyridines and process for preparing same 失效
    取代的1,2-二羟基吡啶及其制备方法

    公开(公告)号:US4013661A

    公开(公告)日:1977-03-22

    申请号:US461685

    申请日:1974-04-17

    Abstract: Substituted 1,2-dihydropyridines of the formula ##SPC1##In which R and R.sup.2 are selected from the group consisting of hydrogen, --NH.sub.2, silyl, silyl linked via oxygen, silyl linked via nitrogen, sulfamyl, organosulfonamido, nitro, organic radical, organic radical linked via oxygen, organic radical linked via sulfur, organic radical linked via nitrogen, organic radical linked via --SO-- and organic radical linked via --SO.sub.2 --; with the proviso that the R.sup.2 groupings when joined together form an ortho condensed cyclic or polycyclic hydrocarbon; R.sup.1 is a member selected from the group consisting of hydrogen, --NH.sub.2, silyl, silyl linked via oxygen, silyl linked via nitrogen, sulfamyl, organosulfonamido, nitro, organic radical, organic radical linked via oxygen, organic radical linked via sulfur, organic radical linked via nitrogen, organic radical linked via --SO-- organic radical linked via --SO.sub.2 --, mercapto, sulfino and sulfo; R.sup.3 is a member selected from the group consisting of hydrogen, halogen, and methyl; and Z is a member selected from the group consisting of halogen and an electron-withdrawing group containing an electronegative atom doubly or triply bonded to a more positive atom which atom is singly bonded to the carbon atom attached to the pyridine ring. Exemplary of such compositions is 1,4-bis(trimethylsilyl)-2-(1-cyanoethyl)-1,2-dihydropyridine. The compounds of the invention are useful as antioxidants for polyphenyl ethers, as stabilizers for halogenated polyhydrocarbons, as curing agents for silicones and epoxide resins, as dyeing improvers for polyesters and as fuel additives for imparting hypergolic properties.

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