Method of preparing fibrils having properties for making improved paper sheets
    4.
    发明授权
    Method of preparing fibrils having properties for making improved paper sheets 失效
    制备具有改良纸张性质的原纤维的方法

    公开(公告)号:US3904728A

    公开(公告)日:1975-09-09

    申请号:US29808572

    申请日:1972-10-16

    CPC classification number: D21H5/202 D21B1/063 D21H13/14

    Abstract: An improvement in the fibril formation process which includes dissolving at an elevated temperature an olefin polymer having an inherent viscosity of at least 3.5 in a hot hydrocarbon solvent, shearing the hot polyolefin solution to thereby orient the polymer molecules therein, passing the sheared solution through a cooling zone maintained below the precipitation temperature of the solution while maintaining the orientation of the polymer molecules within the solution to thereby precipitate by thermal means the polymer in the form of a solvent swollen fibrous mass, separating a substantial portion of the polymer solvent from the fibrous mass, beating the fibrous mass in a liquid which is a non-solvent for the polymer and which is soluble in the polymer solvent for a time sufficient to break down the fibrous mass into a plurality of fibrils, and separating the fibrils from the nonsolvent liquid. The improvement consists of incorporating from about 5 up to about 15 weight percent based on the weight of the polyolefin of a surfactant selected from the group consisting of those nonionic surfactants having an HLB value from 7 to 12 and those anionic surfactants having an HLB value greater than 13 into the hot polyolefin/hydrocarbon solvent solution prior to the fibril formation steps of the process whereby the resultant fibrils containing the surfactant possess improved hydrophilic properties and paper sheets fabricated from these fibrils possess improved physical properties, particularly increased tensile strength.

    Abstract translation: 原纤维形成方法的改进,其包括在高温下将热固性烃溶剂中特性粘度至少为3.5的烯烃聚合物溶解,剪切热聚烯烃溶液,从而使聚合物分子在其中定向,使剪切溶液通过 冷却区保持低于溶液的沉淀温度,同时保持聚合物分子在溶液中的取向,从而通过热法沉淀出溶剂溶胀纤维团形式的聚合物,将大部分聚合物溶剂与纤维 将纤维质量在作为聚合物的非溶剂的液体中打浆,并且其可溶于聚合物溶剂中足以将纤维物质分解成多个原纤维的时间,并将原纤与非溶剂液体分离 。 改进之处在于从基于聚烯烃重量的约5至约15重量%的表面活性剂,该表面活性剂选自HLB值为7至12的那些非离子表面活性剂和HLB值较大的那些阴离子表面活性剂 在进行原纤维形成步骤之前,将其加热到热的聚烯烃/烃溶剂溶液中,由此所得到的含有表面活性剂的原纤维具有改善的亲水性,并且由这些原纤维制成的纸张具有改善的物理性能,特别是增加的拉伸强度。

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