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1、SC formulations 水悬浮剂,Suspension Concentrates 海利尔农药论坛（第十届山东省农药信息交流会） 英国禾大公司 www.C,SC 水悬浮剂,描述：固体颗粒悬浮于水中 Description: Solid particles suspended in water 常见问题Issues 悬浮物质与水之间存在密度差 Density difference between suspended matter and water 如果原药密度大于1克/毫升将形成沉淀 Will form sediment if density is 1 如果原药密度大于1克/毫升将漂浮
2、Will float if density is 1 根据斯托克斯定律：较小的粒径是必须的 Stokes law: small particles are required 怎样获得较小的粒径 How to obtain small particles? 怎样保持粒子的悬浮稳定性 How to keep the particles suspended? 结晶增长Crystal growth,Formulation breakdown processes制剂被破坏的过程,Reversible可逆的,Irreversible不可逆的,膏化,沉淀,絮凝,相转化,聚结,奥氏熟化,Ca.i. small
3、 小粒径,Oswald ripening奥氏熟化,A.I. has limited water solubility 原药在水中有一定的溶解度 Solubility of small particle is higher than solubility of large particle 较小粒经的溶解度大于较大粒经的溶解度,Ca.i. large 大粒径,Ca.i. small小粒经 Ca.i. large大粒径,How to prevent Oswald ripening怎样预防奥氏熟化的发生,较窄的粒径分布范围 Narrow particle size distribution 还有其他
4、的诀窍 There are other tricks: Very limited amount of diluted oil in aqueous phase 将一定量的油稀释到水相中,To make an SC 水悬浮剂制备,Preparation of small particles 小粒子的制备 Preventing flocculation Preventing sedimentation,To make an SC 水悬浮剂制备,Preparation of small particles 小粒子的制备 Small suspended particles are prepared b
5、y milling process 通过砂磨设备获得较小粒径 Processing conditions are important 生产工艺条件很重要,To make an SC 水悬浮剂制备,Preparation of small particles 小粒子的制备,Wetting - Dispersion - stabilization润湿 分散 稳定性,Issue during milling process砂磨过程中出现的问题,During milling process fresh surface is generated 砂磨过程中新的粒子表面产生 Fresh surface i
6、s generally of non-polar nature en will cluster together rapidly 新产生的非极性的表面通常是的自然对开很容易迅速聚集 This could lead to increased viscosity and even mill blockage 这可能导致粘度增加甚至阻碍砂磨进程 To overcome mill blockage a wetting agent is needed 为了克服这一问题所以润湿剂的加入是非常必要的,To make an SC 水悬浮剂制备,Preparation of small particles Pr
7、eventing flocculation 絮凝的预防 Preventing sedimentation,How to prevent flocculation? 怎样预防絮凝的产生,Use of dispersants 分散剂的使用 Dispersant should be firmly locked on substrate Anchoring 锚固作用 Dispersant types: 分散剂种类 Anionic阴离子 Electrostatic stabilisation静电稳定作用 CaDDBS / NaDDBS（十二烷基苯磺酸钙/钠） Fosfate esters （磷酸酯类）
8、Non ionic非离子 Steric stabilisation 空间位阻稳定作用 Alcohol etoxylates（乙氧基醇醚类） Polymeric dispersants（高分子表面活性剂） Mix of the two Electrosteric stabilisation混合静电/空间位阻 Naphtalene condensate sulfonates (萘磺酸盐甲醛缩合物) Lignin sulfonates （木质素磺酸盐类）,Electrostatic Stabilization静电排斥作用,Electrostatic静电学,2dM h,G,2dp,Monomer单体-
9、Polymer高分子,Steric Stabilization空间位阻作用,空间位阻是由于非离子表里面活性剂和/或高分子表面活性剂提供的Steric barriers are produced by adsorption of nonionic surfactants and/or polymeric surfactant 由于链的不利交叉排斥和熵值作用对重大交叠的影响Repulsion is due to unfavourable mixing of the chains and entropic effects on significant overlap,Functions of sur
10、factants表面活性剂的功能,Wet 润湿 Disperse 分散,Functions of surfactants表面活性剂的功能,Wet 润湿作用 Dynamic molecules to wet surface during milling stage在砂磨期间动态分子润湿新鲜的表面 Smaller molecules 分子量较小 Negative regarding stability 对稳定性有负面影响 Disperse 分散作用 Larger molecules to stabilise suspended particles大分子对粒子提供稳定的悬浮支撑作用 Act slow
11、 作用进程缓慢,Size does matter 分子大小关系,2dM h,G,2dp,Monomer单体-Polymer高分子,Steric Stabilization空间位阻作用,空间位阻是由于非离子表里面活性剂和/或高分子表面活性剂提供的Steric barriers are produced by adsorption of nonionic surfactants and/or polymeric surfactant 由于链的不利混合排斥和熵值作用对重大交叠的影响Repulsion is due to unfavourable mixing of the chains and en
12、tropic effects on significant overlap,Rheology profile wetting agent vs. polymeric dispersant 润湿剂与高分子分散剂流变性特征对比,Wetting agent 润湿剂,Polymeric dispersant 高分子分散剂,No shear effect polymeric dispersant flow curve: suspension is properly stabilized高分子分散剂在剪切作用下的流变曲线无影响：悬浮液相对稳定 Wetting agent flow curve increa
13、ses hugely at low shear: insufficient stabilisation润湿剂在低剪切作用下的流变曲线明显增大：不够稳定 If wetting agent is required, use at low possible concentration! 如果润湿剂是必须添加的，尽可能在最低添加量下使用,To make an SC 水悬浮剂制备,Preparation of oil droplets in water Preventing coalescence Preventing sedimentation 沉淀的预防,Stokes law 斯托克斯定律,Vs =
14、 velocity of settling /creaming粒子沉降速度，cm/s; = viscosity 水悬浮剂粘度，Pa.S; g = gravity 重力加速度， cm/s; r = radius of sphere 分散介质粒子直径，cm; = density difference sphere part II结晶增长,Polymeric Dispersant高分子分散剂,Polymeric plus monomeric Dispersant 高分子/单体分散剂,Crystal growth; part II结晶增长,Effect of surfactant micelles 表面活性剂胶体束的作用,油滴oil droplets,固体颗粒solid particles,Crystal growth; part II结晶增长,Avoid micelle forming surfactants 避免使用产生胶体束的表面活性剂 Monomeric surfactants form relatively easy micelles 单体表面活性剂相对容易形成胶体束 Polymeric surfactants do not form micelles 高分子表面活性剂不会形成胶体束,
