本发明提供一种水基嵌段聚氨酯及其制备方法，其特征在于它含有由用于形成软段相的（Ａ）组组分的反应产物与用于形成硬段相的（Ｂ）组组分的反应产物所形成的预聚物在水中继续反应所得的聚合物。（Ａ）：催化剂０．０１－０．２重量份；聚醚或聚酯二元醇３０－１００重量份；芳香族或脂肪族二异氰酸酯５－３０重量份；扩链剂短链脂肪族二元醇２－１０重量份；（Ｂ）：芳香族二异氰酸酯５－２０重量份；交联剂三羟基多元醇０．１－２．０重量份；扩链剂短链脂肪族二元醇２－１０重量份；含羧基的短链脂肪族二元醇２－１０重量份；短链脂肪族有机叔胺类中和剂２－１０重量份。本发明还提供通过施用所述聚氨酯所得的具有防水、保暖、透湿性的材料。
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The utility model relates to an electronic device for helping blind walking and discriminating obstacles, which is worn on a head of a user. The utility model comprises an ultrasonic emission sensor, two ultrasonic receiving sensors, a control circuit which can generate ultrasonic signals, receive u.....
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The present invention provides an optical fiber having the gas laser and the laser optical fiber ring laser gyroscopes. The optical fiber comprises a gas laser excitation gas, the excitation source and the optical cavity, characterized in that the optical cavity by the hollow fiber and single mode f.....
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The present invention relates to a light guide plate and a backlight module having the light guide, the light guide plate on the upper surface of the structure of a plurality of V-shaped grooves, said V-shaped groove structure has a free surface contour of the gradient, the lower surface of the micr.....
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The invention relates to a two-dimension displacement estimation method of elasticity imaging, which comprises the following steps: carrying out two-dimension initial displacement estimation on a first radio frequency frame and a second radio frequency frame of an ultrasonic pattern to be treated by.....
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