在软质聚醚型聚氨酯块状泡沫中具有最广适用性的

在软质聚醚型聚氨酯块状泡沫中具有最广适用性的 2003中国聚氨酯行业整体淘汰ODS国际论坛 论文 政研论文下载论文大学下载论文大学下载关于长拳的论文浙大论文封面下载 集 吴卫东 T. Boinowitz O. Eyrisch （德固赛化学(上海)有限公司 上海201108） 介绍了德固赛化学公司新开发的新型有机硅表面活性剂Tegostab BF 2470的一些特性。这种表面活性剂用于软质聚醚型聚氨酯块状泡沫的生产，具有较宽的加工宽容度和较高的活性，满足生产 传统的和新型液体CO发泡聚氨酯泡沫的工艺需求。 2 表面活性剂；有机硅；泡沫稳定剂；聚氨酯；软质泡沫塑料 在近10年里，采用液体CO生产软质聚氨酯泡沫的技术已经从实验室阶段发展成为一种大规模生2 产的加工方法。在这个过程中，设备制造商和泡沫生产厂家通过不断技术改进，成功地使用液体CO生2 产出低密度和超柔软高密度泡沫。与此同时添加剂生产商为支持这项技术作出努力，努力开发新型有机 硅表面活性剂(泡沫稳定剂，俗称“硅油”)。由于这项技术仍然有一些不足之处，如在大块泡沫中泡沫 孔径结构的均匀性和泡沫物理性能分布梯度仍需进一步的改良。以此为目的，Degussa公司开发了一种新型的有机硅表面活性剂Tegostab BF 2470。 这种新产品的性能较软泡用有机硅表面活性剂B8110和B8123有了较大的提高。它的特点在于具有极宽的加工宽容度和较高的活性，满足正在开发之中的软质聚氨酯泡沫塑料产品生产的需求，无论是传 统的还是新型的液体CO生产工艺。 2 泡沫生产厂家不得不使用不同的表面活性剂来满足不同的配方需求。众所周知，表面活性剂的活性 和加工宽容度是密不可分的。总的说来，高稳定性的硅表面活性剂在生产高密度产品时，它的加工宽容 度小，但新产品BF2470的适应性非常好。因为它集生产低密度产品需要的高活性和生产高密度产品需 要的高加工宽容度于一身。 这种产品已经完成了实验室和工业化生产设备上的检验。本文将在以该产品与现有的产品对比的基 础上阐述它对泡沫生产商的实际意义。 1 为了有效地稳定较宽范围的配方体系，泡沫生产商使用不同的表面活性剂，具体参数有三个：配方， 泡沫加工条件，最终的产品的性能。后者需最佳的表面活性剂支持。 通常，表面活性剂在软质聚氨酯泡沫中具有以下功效：(1) 对各种原料的乳化作用；(2) 提供有效的成核作用；(3) 泡沫膨胀过程中稳定作用；(4) 溶解生成的聚脲；(5) 引发适当的开孔时机。 某一种泡沫稳定剂产品并不能具备以上所有的功能的最佳值。因此Degussa为软质泡沫工业生产开发了许多有特点的硅油表面活性剂。 图1描述了在生产聚氨酯软泡过程中，中等活性和高活性的泡沫稳定剂(“硅油”)的加工宽容度和活性的相互关系。在发泡过程中，很低的高活性(高效)表面活性剂B8110用量，会导致在发泡过程中首先出现塌陷，用量增加，出现开裂现象。在一个相对较低的硅油用量区域里，生成的泡沫是稳定而开孔 的。当在较高的硅油用量下，由于开孔率的下降，导致泡沫体的收缩。生产合格泡沫，助剂的最大用量 与最小用量之间的范围，我们称之为加工宽容度。图1中B8110陡峭的曲线表明，这种高活性的表面活性剂的加工宽容度比较窄。而其高用量时，较低活性的BF2370的曲线是较平坦的斜线，这意味它具有较高的加工宽容度。 图2中坡度较小的虚线表示了泡沫稳定剂的开发目标。在获得稳定泡沫的前提下，这种产品的用量 比BF2370更低；同时在更高的浓度也不会产生泡沫收缩现象。 204 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 1 B8110 2 BF2370 ( BF2370) 2 2.1 所有的泡沫都采用一般的手工发泡工艺制备。所有的配方均称量300 g聚醚多元醇，相应计算助剂和TDI的用量。辛酸亚锡、多元醇、水、胺和表面活性剂以1000 r/min的搅拌转速混合55 s。如果二氯甲烷作为配方组分，它在开始搅拌45 s后加入。加入TDI 80后以2500 r/min的搅拌转速混合7 s。混合完毕后立即倒入一个27cm，27cm，27cm的发泡箱。 上升时间是从搅拌结束后开始计时直到跳泡完成。泡沫回落高度是指跳泡时的高度与跳泡后3 min的高度之差。 泡沫的开孔性通过测量同一平面上5个不同位置的通气性能来表征，即可以通过测量泡沫对气流通 过时的阻力(背压)来确定，以毫米水柱为计量单位。空气背压数值越高，表示泡沫闭孔率越，越易收缩。 背压超过60mm水柱的临界点时泡沫闭孔率而收缩。 2.2 我们从17到55 kg/m 3的密度范围选取5个不同配方来测试新产品BF 2470的活性和加工宽容度。其中海藻海绵的生产是个有趣的试验，它能说明表面活性剂是如何抵消由消泡剂颗粒造成的使发泡体系 不稳定的负面影响。配方6是一个用来专门说明BF2470独特之处的配方。 3配方1：密度17 kg/m，水5.0份，二氯甲烷5.0份，表面活性剂用量是变量，用于评测其活性。 3配方2：密度25 kg/m，水4.0份，TDI指数和锡用量是变量；表面活性剂用量在低硅油水平时（对 于中等活性的表面活性剂）,0.7份；在高硅油水平时,1.2份，适合评定加工宽容度。 3配方3：密度31 kg/m，水3.0份，表面活性剂用量可变。 3配方4：密度55 kg/m，水1.5份，能评判泡沫的开孔性。 配方5：使用RTV 11作为消泡剂的海藻绵配方。 100 1.0, 1.5, 2.0 多元醇 匀泡剂Tegostab 4.5 1.2 水 消泡剂多元醇溶液 0.15 叔胺Tegoamin PTA (1% RTV 11, 99%多元醇) 0.3 105 有机锡Kosmos 29 TDI-80指数 配方6：用于聚脲沉淀的测定。 多元醇 100 消泡剂多元醇溶液 0.05 水 4.0 (10% T5, 90% 多元醇) Tegoamin DMEA 2.0 TDI 80 48.6 Kosmos 29 0.2 匀泡剂Tegostab 0.0, 0.5, 1.0 205 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 3 试验结果按试验产品密度从低到高的配方顺序排列。BF 2370和B 4900被选择作为对照品。这两种 产品是中等活性的表面活性剂，具有较宽的加工宽容度，能得到满意的泡沫体。 表1为配方1中不同匀泡剂及其用量对泡沫上升时间、回落高度、密度和开孔性的影响。3种表面活性剂用量分别为0.6、0.7和1.0。 1 1 －3表面活性剂 用量/份 上升时间/s 回落高度/cm 密度/kg?m 开孔性/mmHO 2 BF 2370 0.6 82 3.1 20.0 3 B 4900 0.6 80 3.7 20.2 3 BF 2470 0.6 84 1.1 19.3 4 BF 2370 0.7 87 1.7 19.6 7 B 4900 0.7 81 2.7 19.5 5 BF 2470 0.7 86 0.8 18.9 6 BF 2370 1.0 89 0.4 18.5 12 B 4900 1.0 83 1.5 18.9 7 BF 2470 1.0 90 0.2 18.3 11 表1清楚地表征了与发泡体系稳定性相关的有机硅表面活性剂的差异。从回落高度数据可以看到： 尽管B 4900的加入量为1.0份，泡沫回落程度较大，说明稳定性差；BF 2370用量在0.7份时回落也较大；然而BF 2470却能在加入量为0.6份时提供极好的稳定性。BF 2370和B 4900不能在这些除用CO发泡2的泡沫之外的低密度配方中使用。(试验中所有的表面活性剂的用量都比正常的工业化生产低，因为实验 室的小盒子的边缘能对泡沫提供一定的支持。) 3在密度为25 kg/m的需要较少的稳定作用配方2中，可以看到这种趋势。BF 2370和B 4900在0.6份的添加量下回落高度低于1 cm，仅在添加量0.3份时才出现泡沫塌陷。但是BF 2470不会出现这种情况。图3为不同的表面活性剂、在不同的使用量下的泡沫回落高度。 BF 2470较高的用量也可以得到很好开孔性，表明表面活性剂的高活性并不总是与缩泡密切相关。图 34为配方2 (泡沫密度25kg/m)中不同的表面活性剂及加入量的情况下的泡沫开孔性(通气性)。 3 4 高TDI指数不但会使泡沫变稳定、变硬，而且也会使泡沫趋于收缩。但是在TDI指数为125和135的情况下，在配方2中使用BF 2470也能制得开孔很好的泡沫，见图5。 图6 总结 初级经济法重点总结下载党员个人总结TXt高中句型全总结.doc高中句型全总结.doc理论力学知识点总结pdf 了表面活性剂与辛酸亚锡宽容度的相互关系，表面活性剂和锡催化剂用量的增加都会导致 泡沫体稳定性增加和通气性下降。在高锡量(0.28份)的情况下，由于BF2470对闭孔的低敏感性，可得到不开裂的泡沫；而B4900和BF2370对闭孔的敏感性强，泡沫开裂。在另一端，BF2470在辛酸亚锡0.12 206 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 以下时，才会引起开裂。 5 TDI 6 (密度25kg/m33) (配方2，密度25kg/m) 3图7到9都是从配方3 (水3.0份，泡沫密度30 kg/m)中得出，观察了不同浓度的BF2370和BF2470对泡沫密度、空气背压和上升时间的影响。我们已经从配方1和配方2中得出，BF2470具有较多的有效CO气体发生量（也就是能使泡沫密度变低）同时使泡沫开孔更好。上升时间变得更长。 2 7 8 9 BF2370BF2470 在泡沫密度很高时开孔性显得很重要。表2是在配方4中三种硅油的用量在0.8和1.1时的上升 207 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 时间、回落高度和开孔性变化。表2表明使用BF 2470要比使用加工宽容度很宽的B 4900制得的泡沫开孔性更好。 2 4 －3表面活性剂 用量/份 上升时间/s 回落高度/cm 密度/kg?m 开孔性/mmHO 2 BF 2370 0.8 186 0.4 54.9 95 B 4900 0.8 175 0.3 56.8 40 BF 2470 0.8 178 0.4 54.4 22 BF 2370 1.1 183 0.3 54.0 144 B 4900 1.1 175 0.3 56.9 70 BF 2470 1.1 176 0.3 53.9 45 出于选择最佳的有机硅表面活性剂，我们一直在寻找一些对表面活性剂的稳定性要求非常高的配方。 一种使发泡体系不稳定非常有效的方法是使用消泡剂。消泡剂通常是用于海藻泡绵的生产。在这种情况 下不得不需要表面活性剂提供更好的稳定作用来抵销由消泡剂粒子产生的不稳定。 图10为在配方5（海藻泡绵）中使用不同浓度的BF 2370和BF 2470产生的不同泡孔结构。 10 图10表明体系中表面活性剂浓度越高，开孔剂对泡沫的破坏越小。使用BF 2470制得的泡沫的气孔很小，使用1.0份BF 2470即比使用2.0份的BF2370更加有效。 我们采用由Rossmy、Kollmeier和Schator [1]发明的确定表面活性剂对聚脲沉淀的影响的经典理论来 解释这种高稳定性和高宽容度的神奇结合。 配方6 中含非常有效的消泡剂，它能使泡核不能稳定地存在，从而使所有的气泡离开聚醚/异氰酸酯混合物。这样的结果是在一段反应时间之内，得到一个清澈的混合物。但在水与异氰酸酯反应生成的并 且溶解的聚脲沉淀出来时，澄清的混合物立刻变得混浊。这个实验是在一个透明的塑料容器中进行，精 确测量出现沉淀的时间。表3为在配方6中采用不同的泡沫稳定剂时聚脲溶解的时间。 3 6 0 0.5 1.0 匀泡剂用量/份 BF 2370 80 s 93/91* s > 120 s B 8228 80 s 95/91* s － BF 2470 80 s 98/96* s － 注：*试验中所用的某些配方是为了对比不同硅油而采用的较临界的配方，与实际生产中应用之配方有所不同，因而实际 208 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 生产中这些硅油显示的差别可能没那么大。 表3表明了表面活性剂延长聚脲沉淀时间的能力。表面活性剂浓度越高，开始出现聚脲沉淀的时间 越长。表面活性剂的活性越高，产生聚脲沉淀时间越长，它是对聚脲有效溶解的结果。因此使用高活性 的B 8228的聚脲沉淀时间要比使用中等活性的BF 2370的要长。使用BF 2470的聚脲沉淀时间最长。 4 最新开发的表面活性剂 BF2470具有集高活性与极宽加工宽容度于一身的不寻常特性。这一点从涵 3盖了密度低于10到55 kg/m的一系列泡沫配方中可以看出。同时我们可以从图11中直观地得出BF2470具有广泛的适应性。在过去使用的如B 8123或者B 8110那样的高活性表面活性剂，在其高密度配方中使 用有所限制，这是因为它们的加工宽容度比较窄，也就是说容易造成泡沫闭孔。因此，它们在液体CO2 加工工艺中适应性有限。而像B 4900和B 8002这样的中低活性表面活性剂不适合在低密度配方中使用， 因为它们的稳定作用不够。 Density1040508020303[kg/m] 11 对泡沫生产者来说，表面活性剂品种的减少，有利于降低生产的复杂性和仓储成本。 1 Rossmy G, Kollmeier H J, Lidy W, et al. J. Cell. Plastics Nov./Dec. 1981 1963年生，毕业于南京大学化学系。1984年起从事聚氨酯泡沫塑料的生产 和开发工作，1995年加入德国高施米特太平洋有限公司，现负责中国聚氨酯泡沫用 户的技术服务工作。 Tammo Boinowitz博士 1966年生，毕业于Hamburg大学，获Duisburg大学物理 化学博士学位，1995年加入Goldschmidt AG，从事聚醚的研制 和开发工作。现负责软质块泡和模塑泡沫的开发和技术服务。 Oliver Eyrisch博士 1966年出生，毕业于 Freiburg大学，并获生物有机化学博士。 1994年加入Hoechst AG，后又加入Clariant AG，从事清洁剂与 化妆品的阳离子表面活性剂研究；1998年加入Th. Goldschmidt AG，负责欧洲聚氨酯助剂的开发和研制工作；2003年起为公司 聚氨酯助剂部门亚洲区技术经理。 (英文题目：New Silicone Surfactant with Widest Applicability for Flexible Ether Slabstock Foams) 209 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 New Silicone Surfactant with Widest Applicability for Flexible Ether Slabstock Foams J. Wu, T. Boinowitz, O. Eyrisch Degussa Chemicals (Shanghai) Ltd. Polyurethane Additives, Shanghai, 201108 ABSTRACT In the last decade, the Liquid COTechnology for manufacturing Flexible Polyurethane Foam (FPF) has 2 evolved from a novel experimental technique to an established widely used process. During this development, both the equipment manufacturers and foam producers refined their knowledge to successfully implement liquid CO blowing in low density and soft high-density foam grades. In parallel, additive manufacturers also met the 2 specific challenges required of silicone surfactants in support of this technology. Regardless of this progress, some drawbacks still remain. Achieving an optimal cell structure and minimizing the distribution of physical properties within the block are still areas that need some improvement. In response to these targets, Degussa has ,developed a new silicone surfactant, namely TEGOSTAB BF 2470 that exhibits enhanced properties as ,,compared to established products like TEGOSTAB B 8110 and TEGOSTAB B 8123. This development addresses the full latitude of processing and efficiency characteristics that are needed to cover the growing variety of foam grades made with standard processes and the Liquid COProcess. 2 Today foamers have to use typically different silicone surfactants to stabilise most efficiently their extended range of formulations. It is well known that surfactant potency and its processing latitude are not independent from each other. Generally high active stabilisers have the disadvantage of a narrow processing window in higher foam densities. ,The new product TEGOSTAB BF 2470 is suitable for the widest range of formulations because it combines high activity, essential for low densities, with a broad processing needed for high densities. The product has been tested in the laboratory as well as in commercial machine trials. This paper will benchmark the new product in comparison to the established ones and will point out the practical benefits for the foamer. INTRODUCTION Today foamers have to use different silicone surfactants to stabilise their extended range of formulations efficiently. The reason for this is that the parameters a) formulation, b) foam processing conditions and c) final foam properties determine the profile of the optimal surfactant. Generally the surfactant has the following functions in flexible foam: 1. Emulsification of the raw materials 2. Provide sufficient nucleation 3. Stabilise the foam expansion 4. Solubilisation the generated polyurea 5. Trigger the timing of cell opening Not all functions can be maximised within one product. Therefore Degussa has developed an extensive range of surfactants for the flexible foam industry with most beneficial profiles. Figure 1 demonstrates the processing latitude and potency of a medium and high active surfactant. If the surfactant dosage of the high active surfactant B 8110 is increased the result of the foaming experiment will be first a collapse, then splits and at a relative low surfactant concentration a stable, open foam. At a higher 210 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 stabiliser dosage the airflow will not be sufficient anymore and the foam will shrink. The difference between maximum and minimum surfactant dosage which results in acceptable foam is called processing latitude. The steep curve indicates that the processing latitude of B 8110 is narrow. The BF 2370 curve is shifted to higher concentrations, which reflects the lower potency and has a lower slope, which means a higher processing latitude. Foam Quality Foam Quality ShrinkageShrinkage B 8110BF 2370BF 2370 Stable FoamStable FoamDesired Profile SplitsSplitsCollapseCollapse broadSurfactant Dosagebroadestnarrowbroad Surfactant DosageProcessing latitudeProcessing latitudeFigure 1. Scheme of potency and processing latitude Figure 2. Scheme of potency and processing latitude of high (B 8110) and medium active (BF 2370) of medium active surfactant (BF 2370) and desired surfactants. Simplified as linear correlation. product. Simplified as linear correlation. The red curve in figure 2 characterises the objective of the product development, which will be discussed in this paper. The target molecule should stabilise a foam at lower concentrations than BF 2370 and should be applicable in higher concentrations, without resulting in shrinking foam. EXPERIMENTAL Foam Preparation and Measurement of Settling, Rise Time and Porosity All the foams were produced according to our standardised handpour procedure. All recipes were calculated for 300 g of polyol. Stannous octoate, polyol and a blend of water, amine and surfactant were mixed at 1000 rpm for 55 s. If methylene chloride was part of the formulation it was added after 45s. After dosage of TDI 80 the whole mixture was stirred for additional 7s at 2500 rpm. Immediately after finishing mixing the blend was poured into a 27x27x27cm box. The rise time was measured from finishing stirring until blow-off was observed. The settling was defined as difference between full foam height at time of blow-off and foam height in the same position three minutes later. The porosity of the foams was measured at five different positions of a horizontal layer. The tightness was measured by the “resistance” of the foam to a defined air stream. This “resistance”correlates to a pressure of the air stream, which was measured in mm water column (= air backpressure). The higher the values of air backpressure the tighter the foam. Values higher than 60 mm indicate a foam with critical tightness close to shrinkage. Formulations For the testing of the new TEGOSTAB , BF 2470 5 different formulations were selected. The density range was from 17 to 55 kg/m? to stress potency (activity) as well as processing latitude. The sponge foam formulation is a particular interesting test, which demonstrates how the surfactant compensates the destabilising effect of the solid defoamer particles. Formulation 6 was chosen to find an explanation for the unique character of BF 2470. 211 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 , Formulation 1: Density: 17 kg/m?, 5,0 pphp water, 5,0 pphp methylene chloride. Surfactant concentration variable. Critical for Potency. , Formulation 2: Density: 25 kg/m?, 4,0 water. Surfactant concentration, index, tin level was varied. At lower surfactant levels (for medium active surfactants: < 0,7 pphp) critical for potency, at higher levels (< 1,2 pphp) suitable to evaluate processing latitude. , Formulation 3: Density: 31 kg/m?, 3,0 pphp water. Surfactant concentration variable. , Formulation 4: Density: 55 kg/m?, 1,5 pphp water. Very critical concerning tight foams. , Formulation 5: Sponge foam with RTV 11(From Altropol Kunststoff GmbH. D-23617 Stockelsdorf) as defoamer. Polyol 100 pphp Water 4.5 pphp ?TEGOAMIN PTA 0.15 pphp ?KOSMOS 29 0.3 pphp ?TEGOSTAB 1.0, 1.5, 2.0 pphp Defoamer mixture 1.2 pphp (1% RTV 11, 99% Polyol) TDI 80 105 Index , Formulation 6: Detection of Polyurea Precipitation. Polyol 100 pphp Water 4.0 pphp ?TEGOAMIN DMEA 2.0 pphp ?KOSMOS 29 0.2 pphp ?TEGOSTAB 0.0, 0.5, 1.0 pphp Defoamer mixture 0.05 pphp (10% T5, 90% Polyol) TDI 80 48.6 RESULTS AND DISCUSSION The results are arranged from testing in formulation of lowest to highest density. In most cases TEGOSTAB BF 2370 and B 4900 were selected as control. Both products are classified as medium active surfactants which provide a broad processing latitude, i.e. contribute to a robust foam production. Table 1. Rise Time, Settling, Density and Porosity in Formulation 1, Variation of 3 surfactants with 0,6, 0,7 and 1,0 pphp. Surfactant Conc. [pphp] Rise Settling [cm] Density [kg/m?] Porosity [mm HO] 2time [s] BF 2370 0.6 82 3.1 20.0 3 B 4900 0.6 80 3.7 20.2 3 BF 2470 0.6 84 1.1 19.3 4 BF 2370 0.7 87 1.7 19.6 7 B 4900 0.7 81 2.7 19.5 5 BF 2470 0.7 86 0.8 18.9 6 BF 2370 1.0 89 0.4 18.5 12 B 4900 1.0 83 1.5 18.9 7 BF 2470 1.0 90 0.2 18.3 11 Formulation 1 clearly exhibits any deficiencies of the silicone surfactant concerning stabilisation. From the settling you might conclude that B 4900 is not able to stabilise the foam with acceptable settling even at a dosage of 1,0 pphp. BF 2370 leads to severe settling at 0,7 pphp level, whereas the new BF 2470 provides excellent stabilisation even at levels of 0,6 pphp. All surfactant levels are lower than in full scale foam production because 212 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 in small laboratory boxes the side walls give overproportional support. BF 2370 and B 4900 are normally not used for these low densities with the exception of CO-blown foams. 2 0,8 3000,6O] 2TEGOSTAB B 49002500,4TEGOSTAB BF 2370 Surfactant [pphp]TEGOSTAB BF 24700,2200 00,30,61,22,4150-0,2 TEGOSTAB B 4900Settling [cm]-0,4TEGOSTAB BF 2370100 TEGOSTAB BF 2470-0,6BF 2370: collapse50B 4900: collapseAir Backpressure [mm H BF 2370: collapse-0,8B 4900: collapse0 -10,30,61,22,4 Surfactant Concentration [pphp] Figure 3. Settling with different surfactants at Figure 4. Foam Porosity with different surfactants at variable level. Formulation 2: Density 25 kg/m?. variable level. Formulation 2: Density 25 kg/m?. This trend is also visible in Formulation 2, which needs less stabilisation. BF 2370 and B 4900 result at 0,6 pphp level in less than 1 cm settling but both foams collapse at 0,3 pphp. BF 2470 leads to a stable foam. The highest foam porosities (Figure 4) at higher concentrations of BF 2470 demonstrate that high surfactant potency must not be correlated to tight foams. A high isocyanate index leads generally to more stable and harder but also tighter foams. Also at index levels of 125 and 135 in formulation 2 BF 2470 gave the most open foams (Figure 5). 350 300 250 O]2002 TEGOSTAB B 4900150TEGOSTAB BF 2370 TEGOSTAB BF 2470100 50 0 Air Backpressure [mm H <85><95><105><115><125><135>IndexFigure 5. Foam porosity with different surfactants FIGURE 6. Foam porosity with different surfactants with variable isocyanate index. with variable stannous octoate level. Formulation 2: Density 25 kg/m?. Formulation 2: Density 25 kg/m?. Figure 6 summarises the interaction of surfactant with stannous octoate (“tin latitude”). Both the catalyst and the surfactant contribute to stabilisation and low airflow of the foam. At high stannous octoate levels above 0,28 pphp BF 2470 result in foams free of splits due to its low contribution to tightness. High tin levels in combinations with BF 2370 and B 4900 led to splits. At the other end of the spectrum BF 2470 results in splits at tin level 0,12 pphp and lower. Figures 7 to 9 confirm also in formulation 3, which has a density of 30 kg/m? what we already learned in formulation 1 and 2: BF 2470 leads to a better gas yield (i.e. lower densities) in combination with more open foams. The rise time is significantly longer. 213 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 Density[kg/m 30 31 32 33 34 TEGOSTAB B 2370TEGOSTAB B 247035 36 0,3 0,4 0,6 0,8 1,0 1,2Surfactant Concentration [pphp] Figure 7. Foam density with different concentrations of BF 2370 and BF 2470. Formulation 3: 3,0 pphp water. Air Backpressure [mm HO]Rise Time [s]2 100160 80150TEGOSTAB BF 2370TEGOSTAB BF 2470 60140 40130 20 120TEGOSTAB B 2370TEGOSTAB B 2470 01100,3 0,4 0,6 0,8 1,0 1,2 0,3 0,4 0,6 0,8 1,0 1,2Surfactant Concentration [pphp]Surfactant Concentration [pphp] Figure 8. Foam porosity with different concentrations Figure 9. Rise time with different concentrations of BF 2370 and BF 2470. of BF 2370 and BF 2470. Formulation 3: Density 30 kg/m?. Formulation 3: Density 30 kg/m?. At high foam densities tightness is always crucial. Table 2 demonstrates that BF 2470 provides even more open foams than B 4900 a product with a very broad processing latitude. Table 2. Rise Time, Settling, Density and Porosity in Formulation 4 Variation of 3 surfactants with 0,8 and 1,1 pphp Surfactant Conc. [pphp] Rise time [s] Settling [cm] Density [kg/m?] Porosity [mm H O] 2 BF 2370 0.8 186 0.4 54.9 95 B 4900 0.8 175 0.3 56.8 40 BF 2470 0.8 178 0.4 54.4 22 BF 2370 1.1 183 0.3 54.0 144 B 4900 1.1 175 0.3 56.9 70 BF 2470 1.1 176 0.3 53.9 45 For the optimisation of silicone surfactants we are always looking for formulations which need highest contribution to stability from the surfactant. A very efficient tool to destabilise cells are defoamers which are typically used for sponge foams. The surfactant has to provide a high amount of stability to compensate the locally acting defoamer particle. Photo 1 shows that the higher the surfactant concentration the less severe is the defoaming effect. The pore size is much more smaller with BF 2470. Even 2,0 pphp BF 2370 have not the same activity than 1,0 pphp BF 2470. 214 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 BF 2370BF 2470 Photo 1. Pore structures with different concentrations of BF 2370 and BF 2470 in formulation 5 – sponge foam. 1,0 pphp1,0 pphp To find an explanation for the unusual and very beneficial 1 combination of high stabilisation and broadest processing latitude we to determine the impact of the surfactant on the time of polyurea 1,5 pphp1,5 pphpused an old technique developed from Rossmy, Kollmeier and Schatorprecipitation. Formulation 6 contains a very efficient defoamer, which avoids the formation of stable cells. All gas bubbles leave the liquid 2,0 pphp2,0 pphpisocyanate/polyol blend. The consequence is a transparent reaction mixture. At a certain well defined time the solubilised polyurea, which was generated by the water isocyanate reaction, precipitates. The clear mixture became immediately white and intransparent. The experiment was performed in a transparent plastic bag to measure the time accurately. Table 3. Time of polyurea precipitation with different surfactants in formulation 6. Surfactant 0 pphp 0.5 pphp 1.0 pphp BF 2370 80 s 93/91* s > 120 s B 8228 80 s 95/91* s - BF 2470 80 s 98/96* s - Table 3 indicates that surfactants have the ability to extend the time till polyurea precipitation takes place. The higher the surfactant concentration the later the polyurea forms a second phase. The later the polyurea precipitation, which is a result of very efficient polyurea solubilisation, the more active is the surfactant. Therefore the high active B 8228 leads to longer times than the medium active BF 2370. Anyway BF 2470 result in latest polyurea precipitation. CONCLUSION This paper demonstrates the unusual combination of high potency and broadest processing latitude of the newly developed surfactant B 2470. This is valid in formulations covering densities from below 10 up to 55 kg/m?. The result is a broad applicability of BF 2470 as shown in Figure 10. In the past high active surfactants like B 8123 or B 8110 had their limitations in high density formulations due to their narrow processing latitude, i.e. high contribution to foam tightness. Furthermore they showed limited applicability in the Liquid CO Process. Medium and low potent 2 surfactants like BF 2370, B 4900 and B 8002 were not applicable in low density formulations due to unsufficient stabilisation activity. The benefit for the foamer is that in future the number of silicone surfactants can be reduced, Density1040508020303[kg/m]which has the advantage of less machine complexity and lower warehouse costs. Figure 10. Applicability of different silicone surfactants 1 Rossmy, G., Kollmeier, H.J., Lidy, W. Schator, H., Wiemann, M., J. Cell. Plastics Nov./Dec. 1981 215 2003中国聚氨酯行业整体淘汰ODS国际论坛论文集 BIOGRAPHIES J. Wu Mr. Jason Wu born in 1963. He began to involve in the production and development of polyurethane foam since 1984, after he graduated from Chemistry Department of Nanjing University. He joined TH. Goldschmidt AG Pacific Co. Ltd in 1995, Now he is technical service manager for Chinese foam customers. Tammo Boinowitz Dr. Tammo Boinowitz, born in 1966, studied Chemistry at the University of Hamburg. He received his Ph.D. in Physical Chemistry from the University of Duisburg. He joined Goldschmidt AG in 1995, being involved first in R&D of Polyethers. Today he is responsible for development and technical service of additives for flexible slabstock and molded foams. Oliver Eyrisch Dr. Oliver Eyrisch, born in 1966, studied Chemistry at the University of Freiburg. After receiving his Ph.D. in Bioorganic Chemistry he joined the Hoechst AG in 1994, later Clariant AG, working as a R&D-manager in the field of cationic surfactants for detergent and cosmetic applications. In 1998 he joined the PU-labs of Th. Goldschmidt AG, being responsible for the development and technical service of polyurethane additives to the flexible slabstock and molded foam industry in Europe. Since 2003 he is Technical Director PU-Additives Asia and located in the new Technical Centre Shanghai. 216