An Analysis of the Curling Phenomenon in Viscoelastic Bimaterial Strips

A mathematical analysis is performed to obtain relations for the radius of curvature and flexural moments for initially stretched bimaterial strips in which at least one of the materials exhibits viscoelastic behavior. One practical application of this analysis is for pressure sensitive tapes. Consequently, the radius of curvature and flexural moment relations are obtained as functions of backing and adhesive thicknesses and moduli for typical pressure sensitive tapes. The analysis shows that the flexural moment decreases as the backing thickness and/or backing modulus increase. Furthermore, the flexural moment decreases as the adhesive thickness and/or adhesive modulus decreases.     

Adhesive failure peak in peel spectra

Peel force spectra for pressure‐sensitive adhesive tapes provide a peel peak in the adhesive failure region. The observed peak behavior is coincident with calculation based on a viscoelastic peel model. It turns out that the origin of the peak is significantly associated with viscoelasticity or short relaxation time of the adhesive. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 264–266, 1999     

配方优选程序设计及在SIS压敏胶配方优选中的应用

SIS压敏胶的配方设计性较强，其性能随配方中各组份用量的变化可在较大范围内变化。该胶可作为装配用接触型胶粘剂至压敏胶粘剂，压敏胶的三大性能指标即剥离强度、持粘时间和快粘性能（也称初粘力）随应用场合变化有不同要求，而这三大性能又与增粘剂和增塑剂的使用量极为密切，因此掌握配方与性能之间的定量规律对于开发SIS压敏胶的应用非常重要。本文提出了胶粘剂性能与组成之间关系的数式化模型，并编制了一套可在微机上运行的配方优选程序，该程序具有数据存贮，数据处理，图形输出的功能，利用这些图形可以根据实际需要进行配方优…     

中国压敏胶粘带标准的现状

介绍了中国压敏胶粘带标准的制定情况 ,并将中国压敏胶粘带测试方法的标准 (厚度、剥离粘合力、持粘性、初粘性以及拉伸性能的测试方法 )与ASTM、PSTC、AFERA、JIS和UL等标准组织的相应标准进行了比较 ,指出了它们之间存在的差异。对中国压敏胶粘带标准中存在的问题提出了改进建议     

高固含乳液压敏胶的粒径分析

运用多阶段乳液聚合法可以有效合成高固含乳液乳液粒径无论是单元分散还是多元分散均能实现高固含化在保持乳液稳定的条件下，如果乳液粒径是单元分散，当粒径足够大或者粒径分布足够宽时，乳液实现高固含的同时，可以达到低黏度目的如果是多元分散，粒径分布一般较宽，非常有利于实现乳液低黏度下的高固含化，当乳液的大粒子质量分数在80％左右时最容易达到目的.     

国产SIS及其在胶粘剂中的应用

本文结合岳阳石化总厂橡胶厂生产的1105和1209两种新牌号的SIS的性能和结构特点,论述了SIS配制溶剂型胶剂、热熔型压敏胶、妇女卫生巾用胶粘剂的配方特点及应用情况。     

The Influence of Surfactants on the Peel Strength of Water-based Pressure Sensitive Adhesives

In order to study the effect of surfactants on the adhesive properties, peel measurements were performed with two series of model polymers of ethylhexylmethacrylate (PEHMA), the first prepared by emulsion polymerization with four anionic surfactants, and the second by post-adding the same surfactants to a surfactant-free latex. Cohesive fracture is observed at low peel rates; the peel strength depends on the bulk mechanical properties and is independent of the emulsifier. A transition to another type of separation occurs at higher peel rates, which seems to be an interfacial failure by visual inspection. Surface analytical studies, however, give evidence that this “interfacial” failure is, in fact, a mixed failure, leaving traces of the polymer on the substrate surface. The peel rate at this transition as well as the peel strength at mixed fracture are influenced by the surfactants. Large differences were observed between the four surfactants as well as between both series of polymers, leading to the conclusion that the surfactants have a different mobility within the film. This is also reflected by a different aging behaviour of the films.     

聚丙烯酸酯压敏胶的研制及在反光膜中的应用

以丙烯酸异辛酯(EHA)和丙烯酸丁酯(BA)为软单体,甲基丙烯酸甲酯(MMA)为硬单体,丙烯酸(AA)和丙烯酸羟丙酯(HPA)为交联单体,过氧化苯甲酰(BPO)为引发剂,乙酸乙酯为溶剂,采用溶液聚合法制备了一种溶剂型聚丙烯酸酯压敏胶。考查了各单体用量对压敏胶综合性能的影响。结果表明,当软单体质量分数为85%、MMA质量分数为5%、AA质量分数为6%和HPA质量分数为4%时,PSA综合性能优异,可满足反光膜的使用要求。     

氢化丙烯酸松香/丙烯酸酯复合乳液的制备及其压敏胶的性能

以氢化丙烯酸松香为增黏树脂,将其溶解在丙烯酸酯单体中,预乳化后采用半连续乳液聚合工艺制备了氢化丙烯酸松香/丙烯酸酯复合乳液。研究了氢化丙烯酸松香的用量对单体转化率、凝胶率、溶胶相对分子质量及其分布、乳胶膜的玻璃化温度(Tg)和压敏胶粘接性能等的影响。结果表明,氢化丙烯酸松香对单体聚合具有一定的阻聚作用,随着氢化丙烯酸松香用量的增加,单体转化率、凝胶率及相对分子质量下降,相对分子质量分布变窄。氢化丙烯酸松香的合适用量为8.0%wt,此时压敏胶的初黏力为15#,180°剥离强度为10.6N.25mm-1,持黏力大于120h。     

Effect of trifunctional cross-linker triallyl isocyanurate (TAIC) on the surface morphology and viscoelasticity of the acrylic emulsion pressure-sensitive adhesives

Acrylic pressure sensitive adhesive (PSA) latexes were synthesized via a starved monomer-seeded semi-continuous emulsion polymerization process with butyl acrylate (BA), methyl methacrylate, acrylic acid (AA), 2-hydroxyethyl acrylate and trifunctional cross-linker, triallyl isocyanurate (TAIC). Influences of TAIC on the resultant latex and PSA properties were comprehensively investigated. The results indicated that latex particle size was independent of the amount of TAIC in the pre-emulsion feed, while the viscosity of the latex increased remarkably with TAIC content increased. Thermal gravimetric analysis result showed that the thermal stability of the polymers was improved significantly with the addition of TAIC. Besides, with the increase in TAIC content, gel content of the polymer increased significantly, while molecular weight between cross link points (M_c) and sol molecular weight (M_w, M_n) of the polymer decreased remarkably. Moreover, for the cross-linked adhesive film, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength, when compared with the uncrosslinked counterparts. Finally, dynamic mechanical analysis and atomic force microscopy were also used to evaluate the viscoelastic properties and surface morphology of the acrylic emulsion PSA film, respectively.     

浅析水性压敏胶保护膜"塔形"现象

对水性压敏胶应用于表面保护膜过程中出现的“塔形”现象进行了探讨,具体分析了水性压敏胶、基材、固化剂、环境温度,以及保护膜生产工艺对“塔形”现象的影响,并提出了相应的解决办法。     

苯乙烯-异戊二烯嵌段聚合物热熔压敏胶性能影响因素探讨

用不同种类增粘树脂、不同牌号苯乙烯-异戊二烯嵌段聚合物(简称SIS)制备SIS热熔压敏胶,考察不同种类增粘树脂、不同牌号SIS及萜烯树脂含量对SIS热熔压敏胶性能的影响,结果表明:萜烯树脂是改性SIS热熔压敏胶适宜的增粘树脂,当萜烯树脂在SIS热熔压敏胶中含量达50%时,SIS热熔压敏胶性能较佳,随不同牌号SIS中两嵌段SI含量的增加,SIS热熔压敏胶的剥离强度有所增加,持粘力有所下降。     

耐高温丙烯酸酯乳液压敏胶的固化及性能研究

将环氧有机硅固化剂9301以及异氰酸固化剂2102加入到增黏丙烯酸酯乳液中,成功制备出耐高温丙烯酸酯压敏胶。研究压敏胶的固化行为,探讨固化剂的种类和用量对压敏胶粘接性能及耐温性的影响。结果表明:固化剂与复合物发生了交联反应,9301和2102固化体系的适宜固化条件分别为150℃/5min和110℃/3min。随着固化剂用量增加,压敏胶的凝胶率和玻璃化转变温度提高,剥离时由内聚破坏转变为界面破坏,初黏力与剥离强度降低,耐高温性能得到改善。当9301与2102用量为2wt%时,压敏胶的剥离强度分别为11.6N/25mm与10.2N/25mm,可耐180℃高温。     

反应型乳化剂对保护膜用丙烯酸酯乳液型压敏胶性能的影响

采用预乳化法制备了丙烯酸酯压敏胶乳液,探讨了不同乳化剂体系对压敏胶物理性能的影响。FTIR测试表明,反应型乳化剂参与了反应;TEM测试显示,反应型乳化剂体系所得乳液粒径小,分布均匀。实验结果表明:当w(复合乳化剂)=3%,m(ANPEO10)∶m(DNS-458)∶m(DNS-501)=1.5∶1.1∶0.4时,所得乳液的固体分质量分数为48.03%,单体转化率达到97.66%,乳液黏度为38.8 s,平均粒径为238 nm,压敏胶的初粘力能吸住8号钢球,持黏性大于24 h,180°剥离强度达到0.304 N/mm。贴在不锈钢表面的保护膜经80℃烘烤24 h后,不锈钢表面无残胶和雾影。     

Improvement in wettability of pressure‐sensitive adhesive on silicon wafer using crosslinking agent with siloxane groups

Acrylic copolymers are prepared by radical polymerization of 2‐ethylhexyl acrylate, ethyl acrylate, and acrylic acid followed by crosslinking to manufacture the pressure‐sensitive adhesives (PSAs) for silicon wafer protection. Both higher reliability and wettability are required for the protective acrylic PSAs in the semiconductor processing applications. The siloxane linkages are introduced in the acrylic PSAs via crosslinking with siloxane‐containing crosslinking agent to modify the thermal and wetting properties of PSAs efficiently. The more efficient formation of crosslinked network structure was achieved with higher content of tetra‐functional crosslinking agent, and the surface energy of PSAs decreased significantly with increasing the content of siloxane linkage resulting in the improved areal wetting rate. The thermal stability of PSAs was also improved significantly by incorporation of siloxane linkages. The adhesion properties such as peel strength and probe tack of acrylic PSAs decreased significantly by increasing the content of either crosslinking agent or siloxane linkage. The acrylic PSA with siloxane group showed both satisfactory wetting and clean debonding properties for the optimal protection of thin silicon wafers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

硅树脂改性丙烯酸酯压敏胶的耐老化性能及耐温性能研究

将含有乙烯基的硅树脂利用溶液聚合法将其引入到丙烯酸酯分子链中,合成了有机硅树脂改性丙烯酸酯压敏胶。利用红外光谱对改性后的压敏胶进行了结构表征。对改性前后压敏胶的耐高低温冲击等性能、耐热老化性能及耐湿热老化性能进行比较,得出改性后的压敏胶性能优越。60℃下湿热老化1000h后改性压敏胶180°室温剥离强度为5.68N/25mm。对丙烯酸酯压敏胶、有机硅压敏胶、有机硅改性丙烯酸酯压敏胶的室温、高温性能及高低温冲击性能进行了比较,经高低温冲击后,丙烯酸酯压敏胶失去压敏性能,而硅树脂改性的丙烯酸酯压敏胶还具有一定的剥离强度,为10.32 N/25mm。     

The effects of graphene on the properties of acrylic pressure-sensitive adhesive

Graphene was examined as a conductive filler to reduce the surface resistivity of an acrylic pressure-sensitive adhesive (PSA). The graphene effectively reduced the surface resistivity; however it also reduced the peel strength of the PSA. This peel strength reduction could be minimized when the graphene was not mixed homogeneously but embedded in the PSA as a separate layer. In addition, the surface resistivity was reduced much more effectively. Typically, the surface resistivity reduced to one-millionth, when 1 part of graphene was imbedded as a separate layer in 100 parts of PSA, compared to that of homogeneously dispersed composite.     

电子元件定位用耐高温压敏胶带研制

本文介绍了以具有双官能团的氯化基胶ＣⅡＲ为主要原料,研制耐１７０℃高温压敏胶的合成工艺和涂胶制带工艺。     

汽油组分罐罐体提升分析计算及建议

低压储罐由于储罐基础设计不当,导致储罐底板外缘与罐基础分离。通过对储罐原设计文件调研、分析总结出事故原因,根据实际运行的内部和外部条件,重新对储罐的内压、风压、倾覆力矩等参数进行计算。通过试算的方式得出储罐底板与基础分离的临界值,并给出解决方案和措施。     

Effect of the stress relaxation property of acrylic pressure‐sensitive adhesive on light‐leakage phenomenon of polarizer in liquid crystal display

The acrylic pressure‐sensitive adhesive systems with the different stress relaxation abilities are prepared by varying the curing agent from 0.3% to 3.0% and the effect of the stress relaxation ability of pressure‐sensitive adhesive system on the durability of LCD polarizer was investigated. The stress relaxation ability of the crosslinked pressure‐sensitive adhesive systems was measured by transient tensile test and dynamic viscoelastic test. And the durability was evaluated by the light‐leakage test of polarizer coated with the pressure‐sensitive adhesive after it was aged under the condition of 60°C and the relative humidity of 95% for 72 h. It was observed that the stress relaxation ability of pressure‐sensitive system is decreased with the crosslinking density, as intended. And the pressure‐sensitive adhesive with the lower stress relaxation ability exhibited the lower light‐leakage and consequently the higher durability than the other PSA systems. This observation is obviously contradictory to the previous design strategy of PSA system and the reason for this observation was discussed briefly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007