环氧类胶粘剂黏度及触变性研究

基考查了硅微粉添量、两种不同型号(104B和145A)的气相二氧化硅对环氧胶粘剂黏度和触变指数的影响.结果表明,硅微粉添量由0％增加到40％时,环氧胶粘剂黏度增加明显,但触变指数未发生变化;两种气相二氧化硅对环氧胶粘剂不仅具有增稠作用,且填加气相二氧化硅的环氧胶粘剂触变性增加,并有随着硅微粉添量增加触变性变化幅度增大的...     

特殊填料在胶粘剂中的应用

<正>1德国瓦克特殊填料在胶粘剂中的应用气相二氧化硅号称"工业味精",分散在胶粘剂中,可以形成氢键桥联作用,产生可逆的三维网状结构,因而赋予胶粘剂最适宜的流变效果。     

专利介绍

自催化交联型有机硅／环氧复合密封胶;耐湿热环氧胶粘剂;光学部件用粘合剂;改性环氧树脂胶粘剂及其制备方法;建筑防水层自粘胶;皮革全转膜用热烫印背胶及其制备方法.     

改性气相二氧化硅作为填料的聚氨酯预聚体的合成与表征

将改性后的气相二氧化硅分散在聚四亚甲基醚二醇(PTMEG)中,制备出均匀分散的混合物,选用液态异氰酸酯(MDI)为实验原料合成聚氨酯弹性体预聚体,通过原液聚合法共混制备气相二氧化硅/聚氨酯复合材料,对复合材料的机械、力学、热性能进行测试,得到最佳的实验原料配方。研究了不同含量气相二氧化硅的加入对聚氨酯内部结构、热力学性质及力学性能的影响,着重探讨了改性后的气相二氧化硅在聚氨酯中的均匀分散以及界面之间的相互作用。     

现代热烫印装饰技术(一)

本文对热烫印技术进行了全面的论述,重点介绍了热烫印箔的组成、结构,品种分类、热烫印技术特征、应用领域和国外发展情况,并对国内市场作了分析,对发展我国热烫印木纹箔的前景进行了科学预测。     

热烫印制品耐温水性失效分析及工艺优化

热烫印工艺是一种常见的表面处理技术，它通过将热敏箔或热熔胶与印刷材料结合，利用热力和压力将图案转移至基材表面。然而，在实际应用中，热烫印产品耐温水性差的问题突出。文章对热烫印耐温水性失效进行原因分析，发现热烫印原材料性能、热烫印硬件和热烫印工艺三个方面可能存在问题，故从这些方面提出了热烫印耐温水性的改善方案，经验证满足了性能要求。     

现代热烫印装饰技术(二)

<正> §5热烫印技术国外发展概况在国外现代装饰工业中出现的新材料、新工艺——热烫印箔及热烫印工艺,已获得较快的发展,广泛应用于各个部门,具有较强的竞争能力和一定的市场。热烫印箔产品的制造技术,是以真空技术,照相制     

卡博特蓝星气相二氧化硅项目试车成功

由美国卡博特公司与中国蓝星（集团）总公司合资兴建的化工（江西）有限公司年产4800t气相二氧化硅项目6月初投料试车一次成功，顺利产出合格产品，并实现连续稳定生产。气相二氧化硅是典型的纳米级粉体材料，具有增强、增稠、防沉、触变、消光等作用，用于环氧胶粘剂、氯丁胶粘剂、水基高分子异氰酸酯系木材用胶粘剂、聚氨酯胶粘剂等能显著提高粘接强度、耐热性、耐水性、耐久性等。     

纳米SiO_2改性金刚石柔性磨轮磨削性能的研究

文章通过依次研究超声分散时间、纳米添加量对丙烯酸树脂力学性能的影响规律,确定当纳米SiO2含量为3%,超声分散时间为15min时树脂胶粘剂具有最佳抗拉伸强度和较高拉伸剪切强度,都较未超声分散时提高近21%;当超声分散15min,纳米SiO2添加量为3%时,具有最佳抗拉强度和拉伸剪切强度,较未添加纳米SiO2时分别提高4%和7%;以胶料比为2:1加入w40金刚石后,经3%纳米SiO2改性胶粘剂抗拉伸强度提高40%,拉伸剪切强度提高36%;采用3%纳米SiO2改性后的丙烯酸树脂胶粘剂配制的金刚石柔性磨轮较未改性金刚石柔性磨轮磨削性能有大大提高,同时证明了胶粘剂力学性能与金刚石柔性磨轮磨削性能的相对应性.     

环氧树脂改性醋-丙乳液胶粘剂的研究

为了提高醋-丙乳液胶粘剂的粘结强度、成膜性能、涂膜硬度和耐玷污性,将环氧树脂加入到聚合体系中,通过乳液聚合的方法制备出环氧树脂改性醋-丙乳液胶粘剂。采用正交实验方法分析讨论了不同的引发剂加入量、乳化剂加入量、丙烯酸丁酯加入量、环氧树脂加入量等因素对环氧树脂改性醋-丙乳液胶粘剂剥离强度的影响。从中优化出最佳聚合配方,采用...     

Preparation of nanosilica reinforced waterborne silylated polyether adhesive with high shear strength

Waterborne adhesives are extremely environment‐friendly but unfortunately deficient in mechanical properties. In this article, nanosilica, stemming from tetraethyl orthosilicate (TEOS), silica sol, and/or fumed silica powder, was employed to reinforce the waterborne silylated polyether adhesives. Effects of TEOS content, silica sol content, and the type and content of fumed silica on the shear strength of the adhesive were investigated using a scanning electronic microscope and an electronic instron tester and the strengthening mechanisms of different silica source were discussed. All the shear strengths of silylated polyether adhesives first increased and then decreased as TEOS content, silica sol content or fumed silica content increased. Colloidal silica particles was less efficient than fumed silica particles for reinforcing the polyether adhesive but can increase the shear strength of hydrophobic fumed silica embedded adhesive. Comparing the adhesives with the hydrophilic fumed silica (HS‐5) or the extremely hydrophobic fumed silica (TS‐720), the adhesive with moderate hydrophobic fumed silica (TS‐610) had the highest shear strength. The maximal shear strength of 2.5 MPa was achieved when TEOS, silica sol, and fumed silica were combined. It seemed that TEOS, silica sol, and fumed silica played crosslinking (with polyether chain), dispersing (for fumed silica), and reinforcing roles on waterborne adhesive, respectively. This reinforcing mechanism opened a new way to fabricate waterborne adhesives (or coatings) with high performances. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of using sepiolite silicate + fumed silica mixtures as fillers on the characteristics of solvent-based polyurethane adhesives

Abstract —Both fumed silica and sepiolite have been used as a filler of polyurethane (PU) adhesives. Although effective, the small particle size and the relative high cost of fumed silica are limitations in some applications. Sepiolite is cheaper than fumed silica, but its relatively large particle size facilitates its settling from the adhesive solutions. In this study, the usefulness of using sepiolite + fumed silica mixtures as a filler in solvent-based PU adhesives is demonstrated. The rheological and adhesion properties of the PU adhesive solutions and the rheological and mechanical properties of the PU films (without solvent) were studied. SEM micrographs of PU films showed the morphology and compatibility of the fillers with the PU matrix. The use of sepiolite + fumed silica mixtures inhibited the settlement of the filler from the PU adhesive solutions, increased both the storage and the loss moduli, and improved the rheological and mechanical properties of the PU. On the other hand, the green (immediate) T-peel strengths of roughened styrene-butadiene rubber/PU adhesive joints and plasticized PVC/PU adhesive joints were greatly improved in filled PU adhesives. The effects produced by using fumed silica alone or sepiolite + fumed silica mixtures were very similar, although in general, somewhat more marked in fumed silica-filled PU.     

Comparison of the Properties of Polyurethane Adhesives Containing Fumed Silica or Sepiolite as Filler

Fumed silica is a well-known mineral filler of epoxy and polyurethane adhesives. Although effective, the small particle size and the relative high cost of fumed silicas suggest the need for an alternative filler. In this study, the usefulness of adding a natural hydrated magnesium silicate (sepiolite) as a new filler in solvent-based polyurethane (PU) adhesive formulations has been demonstrated. The rheological and adhesion performance of the sepiolite-filled PU adhesive was compared with that in PU adhesives containing fumed silicas. The addition of a filler to PU adhesives provided an increase in viscosity, imparted thixotropy and pseudoplasticity to the adhesive solution, produced an increase in storage and loss moduli, and improved the rheology of the PU. The mechanical properties of adhesive films were increased by adding filler, mainly with fumed silica. On the other hand, the immediate T-peel strength of roughened or (roughened + chlorinated) styrene-butadiene rubber/PU adhesive joints was greatly improved in filled PU adhesives. The effects produced by adding sepiolite or fumed silica to the adhesives were very similar, although in general more noticeable in fumed silica filled PU due to the formation of hydrogen bonds between the filler and the solvent and/or the polyurethane (in sepiolite-filled adhesives, van der Waals forces seemed to be responsible for the interactions between the filler and the solvent and/or polyurethane).     

Comparative Properties of Hydrophilic and Hydrophobic Fumed Silica Filled Two-Component Polyurethane Adhesives

Two fumed silicas, one hydrophilic and another hydrophobic, were added to a two-component polyurethane (PU) adhesive and their properties compared. The filled polyurethanes were characterized by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and water and diiodomethane contact angle measurements. The adhesive strength was evaluated from single lap-shear tests of solvent wiped stainless steel/polyurethane adhesive joints. The fumed silicas were well-dispersed in the polyurethane matrix as bundles of nanometric spherical silica particles. However, some micron size agglomerates of fumed silica appeared in the filled polyurethane. The addition of fumed silica favoured the degree of phase separation between the hard and the soft segments in the polyurethane. The polyurethanes were not fully cured under the conditions used in this study and the addition of fumed silica inhibited the curing reaction; the extent of the curing reaction was not affected by the hydrophilic or hydrophobic nature of the fumed silica. The filled polyurethanes were further cured during DSC experiments and this was noticed by the appearance of the melting of the hard segments and the displacement of the second glass transition to a higher temperature. On the other hand, the addition of fumed silica increased the wettability and the surface energy of the polyurethane; this increase was mainly due to an increase in the polar component of the surface energy. The increase in surface energy is somewhat more marked in the case of the hydrophilic silica filled polyurethane, indicating that the polarity of the fumed silica affected the surface properties of the polyurethane. Finally, the addition of the hydrophilic fumed silica increased the adhesion of the filled polyurethane adhesive to stainless steel which was in agreement with the higher surface energy of the hydrophilic fumed silica filled polyurethane.     

Effect of loading chemically and mechanically pre-treated fumed silica as filler on an etch & rinse model dental adhesive

Fumed silica is one of the most commonly used fillers for dental resin adhesives. However, fumed silica produced by flame hydrolysis of chlorosilanes are typically agglomerated aggregates instead of isolated primary particles. The fumed silica aggregates may affect the dispersion of fillers in the resin matrix, thus affect the bonding performance of the dental adhesives. In this study, fumed silica fillers chemically treated with methacrylsilane were loaded into an etch & rinse model dental adhesive. Filler 1 was only chemically pre-treated, while Filler 2 was combined chemically and mechanically pre-treated to break the agglomerated aggregates. The experiment result indicated that Filler 1 has faster rheology control effect than Filler 2 on the handling property of the filled resin adhesive showing as the rapid increased viscosity, which may due to the fast inorganic phase growing in the Filler 1 filled resin matrix. As for the mechanical properties, neither Filler 1 nor Filler 2 has an positive effect on the micro-tensile bond strength in short term and long term, despite of the fact that lower weight percent of Filler 2 loading is favourable to the penetration of the experimental adhesive into dentin substrate. In conclusion, mechanically pre-treatment to break the agglomerated fumed silica is helpful to increase the limit of filler loading percent while maintaining appropriate handling property, but the chemically and mechanically pre-treatment cannot provide positive effect on bonding performance within the range of this study.     

缩合型RTV有机硅胶粘剂的补强及老化研究

烟气道用胶粘剂对耐酸性、耐热性和阻燃性有严格的要求。考查了经酸和热老化后,无机阻燃剂Al(OH)3、气相SiO2和沉淀法SiO2对室温固化(RTV)有机硅胶粘剂力学性能的影响。结果表明,加入这3种填料的胶粘剂的力学性能均有大幅度提高;经10%的硫酸老化5d后,胶粘剂的强度有明显下降,而经180℃老化24h后,胶粘剂的强度有所增大;胶粘剂老化后的断裂伸长率均大幅降低。     

气相法白炭黑的应用技术

介绍了气相法白炭黑的制备方法、特性以及在橡胶、塑料、涂料、胶粘剂、电子方面的应用及其相关作用机理。简述了气相法白炭黑的国内市场情况和发展方向。     

气相法二氧化硅应用机理及特性

主要介绍了气相法二氧化硅在液态体系、干燥体系、固态体系中的作用机理；气相法二氧化硅在应用中的特殊性能；以及比表面积、pH、含水量、添加量、表面处理程度等气相法二氧化硅各项物理性能对应用性能的影响。     

NR/改性气相法白炭黑复合材料的性能研究

在改性气相法自炭黑填充NR胶料中加入粘合剂RH，研究粘合剂RH用量对胶料性能的影响，并与偶联剂Si69／气相法白炭黑胶料进行对比。结果表明，粘合剂RH的加入明显改善了硫化胶的物理性能，拉伸强度提高10％以上；粘合剂RH用量为4份时，硫化胶的综合物理性能最佳；有机改性剂M2改性气相法白炭黑参与了橡胶的共硫化，使硫化胶的交联密度增大；偶联剂Si69对硫化胶物理性能的改善效果不及粘合剂RH。     

气相白炭黑对氟橡胶／硅橡胶共混胶性能的影响

采用气相白炭黑补强氟橡胶／硅橡胶共混胶。研究了气相白炭黑的用量和比表面积对氟橡胶／硅橡胶共混胶的力学性能、耐热老化性能和耐油性能的影响,并采用SEM观察了共混硫化胶的拉伸断面形貌。研究表明,随着气相白炭黑的用量从0份增加到50份,气相白炭黑的比表面积从120m^2·g^-1增大到380m^2·g^-1,共混胶的力学性能和耐油性能提高,而耐热老化性能下降;当气相白炭黑用量为40份,且比表面积为220m^2·g^-1时,共混硫化胶具有较好的综合性能。SEM照片表明,随着气相白炭黑用量增大,其在氟橡胶／硅橡胶共混胶中的分散均匀性下降;当气相白炭黑比表面积为220m^2·g^-1时,气相白炭黑的分散性较好。