UV固化聚丙烯酸酯压敏胶的制备及其性能研究

采用本体聚合方法将丙烯酸酯单体的混合物实施热聚合制备预聚体,采用核-壳聚合法的单体投料方式同时加入链转移剂十二烷基硫酵来控制反应进程。在常温下涂布后直接紫外光交联固化,考察了光引发剂、交联剂、光固化时间等因素对UV固化压敏胶综合性能的影响。     

UV固化丙烯酸酯压敏胶的制备及性能研究

以线性丙烯酸酯共聚物及聚合单体丙烯酸酯为原料,采用光聚合技术,制备了UV固化丙烯酸酯压敏胶。通过红外光谱(FT-IR)分析了产物的结构;对压敏胶的粘接性能进行了研究。结果表明:光引发剂含量为0.4~0.8phr,官能单体含量为1~3phr,软/硬单体配比为8:2时,压敏胶的综合性能最佳。     

UV固化环氧丙烯酸酯涂料研究进展

综述了UV固化环氧丙烯酸酯的合成与改性,介绍了反应温度、原料配比、催化剂及阻聚剂的影响;改性主要是针对降低黏度,增加柔韧性,提高耐热、阻燃等性能。介绍了光引发剂及活性单体的研究进展,最后对光固化技术的发展趋势进行了展望。     

UV固化无溶剂型耐高温丙烯酸酯压敏胶的研制及性能研究

以2-乙基己基丙烯酸酯(2-EHA)、丙烯酸(AA)、丙烯酸丁酯(BA)为原料,2′-羟基-4′,5′-二甲基乙酰苯(HP-8)为光引发剂,通过紫外光引发聚合的方法制备出一系列丙烯酸酯预聚物,并通过UV-DSC和RT-FTIR,探究较佳光聚合体系。以上述丙烯酸酯预聚物为基体,通过加入不同含量的交联剂,制备出一系列半互穿网络结构的UV固化丙烯酸酯压敏胶(PSA),系统地研究了UV辐射能和乙氧基化三羟甲基丙烷三丙烯酸酯(ETPTA)含量对UV固化丙烯酸酯PSA的凝胶含量、粘接性能和黏弹性性能影响规律。研究结果表明:较佳光引发剂含量为0.5%,较佳UV辐射能为600 mJ/cm2,且当以PI-0.50为预聚物体系时,UV固化丙烯酸酯PSA的综合性能优异。此外,当ETPTA添加量为6%时,UV固化丙烯酸酯PSA的剪切破坏温度高达200℃。     

UV固化压敏胶工程

压敏胶及其制品工业需要向节能、减排、绿色方面发展。其中以UV固化压敏胶制品的工业化最为先进。UV固化压敏胶工业化,即UV固化压敏胶工程分为4部分予以实现:1)UV固化压敏胶制备;2)UV固化辐照设备设计;3)UV固化压敏胶涂布生产线的建造和改造;4)工厂管理和成本测算。     

UV固化丙烯酸酯胶粘剂的合成及性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酸缩水甘油酯(GMA)和丙烯酸羟乙酯(HEA)为共聚单体,并以二缩三丙二醇二丙烯酸酯(TPGDA)为交联剂、十二烷基硫醇(NDM)为链转移剂和乙酸乙酯为极性溶剂,采用核/壳溶液聚合法合成了侧链含C=C的丙烯酸酯预聚体;然后以此为基体树脂、丙烯酸异冰片酯(IBOA)和三羟甲基丙烷二丙烯酸酯(TMPTA)为活性稀释剂、651为自由基光引发剂和碘鎓盐为阳离子光引发剂,制备了UV固化胶粘剂。研究结果表明:合成丙烯酸酯预聚体的最佳工艺条件是m(BA)∶m(MMA)∶m(GMA)∶m(TPGDA)∶m(HEA)=20∶60∶10∶4∶6、n(TPGDA)∶n(NDM)=2∶2、w(热引发剂)=3%和w(乙酸乙酯)≥70%(均相对于共聚单体总质量而言);自由基/阳离子混杂双重UV固化胶粘剂比单一自由基UV固化胶粘剂具有更大的附着力和耐酸碱性,此时前者的最佳配方中w(预聚体)=55%、w(651或碘鎓盐)=5%、w(IBOA)=15%、w(TMPTA)=12%和w(GMA)=8%(均相对于胶粘剂总物料质量而言)。     

聚氨酯丙烯酸酯UV固化涂料的制备及性能研究

以甲苯二异氰酸酯(TDI)、聚氧化丙烯三醇和甲基丙烯酸羟乙酯(HEMA)为主要单体,1,6-己二醇二丙烯酸酯(HDDA)为活性稀释剂,二月桂酸二丁基锡(DBTDL)为催化剂,合成了UV固化涂料制备用聚氨酯丙烯酸酯(PUA)低聚物。研究结果表明:当n(TDI)∶n(聚氧化丙烯三醇)∶n(HEMA)=3.08∶1∶3时,PUA低聚物的Mr(相对分子质量)比较理想;当固化时间为4 min、w(PUA低聚物)=87%、w(光引发剂Irgacure184)=5%、w(HDDA)=4%和w(其他助剂)=3%(均相对于总物料质量而言)时,UV固化涂料的综合性能相对最好,其胶膜硬度为2H、附着力为1级、耐酸碱性大于72 h和Tg(玻璃化转变温度)为38.9℃。     

活性稀释单体对 UV固化压敏胶性能的影响

作为 UV固化压敏胶的重要组成部分,活性稀释单体对压敏胶性能有重要影响。选用 7种具有代表性的单官能度活性稀释单体,通过研究其对压敏胶固化过程、玻璃化转变温度、流变性能和黏合强度的影响,系统探究了单体结构对压敏胶性能的影响。结果表明：丙烯酸羟乙酯（ HEA）、丙烯酸异冰片酯（ IBOA）可以提高压敏胶玻璃化转变温度和内聚强度,适量添加时可提高压敏胶的黏合强度;丙烯酸 -2-乙基己酯（ 2-EHA）、丙烯酸月桂酯（ LA）、丙烯酸苄酯（ BZA）、四氢化糠基丙烯酸酯（THFA）、乙氧基乙氧基乙基丙烯酸酯（EOEOEA）等单体的添加会降低压敏胶玻璃化转变温度和内聚强度,从而导致压敏胶黏合强度出现不同程度的下降。此外, HEA有助于 UV固化压敏胶耐热性的提高,添加 HEA的 UV固化压敏胶可将对照组的耐高温温度从 100 ℃提高至 120 ℃。     

有机硅丙烯酸酯预聚体的合成及其在UV固化丙烯酸酯压敏胶中的应用

利用单端羟基硅油、异佛尔酮二异氰酸酯、丙烯酸羟乙酯制备了含有氨基甲酸酯基的有机硅丙烯酸酯预聚体。以此预聚体作为硬单体,丙烯酸异辛酯为软单体,低生物毒性2,4,6-三甲基苯甲酰基苯基膦酸乙酯（TPO-L）为光引发剂,采用紫外光（UV）固化聚合制备了吸水性、透水气性、耐水性和粘接性能优异的丙烯酸酯压敏胶。通过二正丁胺反滴定法探究了预聚体合成最佳温度、时间、催化剂用量等工艺参数。研究了光照时间、光引发剂种类及用量对压敏胶固化程度的影响,以及预聚体含量对压敏胶粘接性能、吸水性和湿气透过性的影响。研究结果表明：在有机硅丙烯酸酯预聚体合成中,第一步反应温度为40℃,第二步反应温度为50℃,反应时间都为60 min,催化剂最佳用量为0.10%（质量分数）;在改性压敏胶制备中,光照120 s,光引发剂TPO-L用量为3%（质量分数）,预聚体含量为20%时制备的压敏胶光固化程度较高,初粘力为21号球,180°剥离强度为5.7 N/（25 mm）,持粘力超过360 h,对非极性表面PP板180°剥离强度为3.2 N/（25 mm）;改性后的压敏胶吸水性、湿气透过性良好。     

Novel pyridinium derivatives as very efficient photoinitiators for UV-activated synthesis of acrylic pressure-sensitive adhesives

During the development of synthesis of acrylic pressure-sensitive adhesives, newly synthesized pyridinium derivatives were used by the UV-initiated polymerization quarantines of new polymer design for the synthesized self-adhesive acrylics with excellent performance, for which tack, peel adhesion, shear strength and shrinkage were measured. For example, the best tack and peel adhesion performances were achieved after 30 and 60 s UV radiation for 3.0 wt% pyridinium photoinitiator PPP, after 60 and 90 s UV exposure for 4.0 wt% pyridinium photoinitiator HPP and after 90 s UV-crosslinking in the case of 5.0 wt% pyridinium photoinitiator OPP. An increase of novel pyridinium photoinitiators concentration causes in an increase of the monomers conversion. For high photoinitiator content, characterized for each investigated photoinitiator, ranging from about 3.0 (PPP) to 5.0 wt% (OPP), the degree of monomer conversion reaches a maximum value of about 99.6 wt%.Preliminary results are reported illustrating the effectiveness of the acrylic PSA development.     

Adhesion properties of polyurethane pressure-sensitive adhesive

In this study, the adhesion properties of polyurethane (PUR) pressure-sensitive adhesive (PSA) were investigated. The PUR-PSA was prepared by the cross-linking reaction of a urethane polymer consisting of toluene-2,4-diisocyanate and poly(propylene glycol) components using polyisocyanate as a cross-linking agent. The peel strength increased with the cross-linking agent content and exhibited cohesive failure until the maximum value, after which it decreased with interfacial failure. The PUR-PSA exhibited frequency dependence of the storage modulus obtained from dynamic viscoelastic measurements, but did not show dependence of the tack on the rolling rate measured using a rolling cylinder tack test under the experimental conditions used, which is quite different from the acrylic block copolymer/tackifier system. The PUR-PSA showed strong contact time dependence of tack measured by a probe tack test. The tendency was significantly larger than for the acrylic block copolymer/tackifier system. Therefore, the storage modulus increased, whereas the interfacial adhesion seems to be decreased with increase in the rolling rate for this PUR-PSA system. It was estimated that the influence of rolling rate on the interfacial adhesion and the storage modulus was offset, and, as a result, the rolling cylinder tack did not exhibit rate dependency.     

Molecular dynamics study of the mechanical properties of polydisperse pressure-sensitive adhesives

Amorphous polymers are one of the primary materials used in pressure sensitive adhesives (PSAs). Their design can be aided by a better understanding of the mechanisms governing the molecular and mesoscopic scale behavior. This work presents a molecular dynamics study of the toughness and failure modes of a coarse-grained polydisperse PSA model in probe peel tests, achieved by varying the crosslinking density and locations. Generally, the toughness of polydisperse PSAs increases at a crosslinking density of 0.5%, compared to the non-crosslinked structure, and declines at higher crosslinking densities, which also changes the failure mode from cohesive to adhesive. The performance is affected by the length of the polymer chains that form crosslinks, although high crosslinking densities make the system less sensitive to effects related to its polydispersity. The results herewith presented display an optimal performance when 35–45% of the particles in the system belong to the giant component of the PSA network. This is achieved at crosslinking densities of 0.5–1.0%, depending on the length of the chains that are allowed to crosslink.     

反应性乳化剂应用于丙烯酸酯类乳液压敏胶的研制

使用正交试验法设计压敏胶配方,得到用反应性乳化剂参与的AA、HEA、BA和EA、M AA等多元共聚物乳液,研究该聚合物应用于压敏胶的初粘、持粘、剥离强度等力学性能。结果表明,在该体系下引发剂用量、反应温度、AA、反应性乳化剂用量对压敏胶乳液综合性能关系密切,其它各因素影响不明显。得到的优化配方为BA(83%)、AA(1%)、HEA(1%)、MM A和EA的混合单体(15%)。     

水性聚氨酯压敏胶的合成及其性能表征

以异佛尔酮二异氰酸酯(IPDI)、聚醚多元醇(N220、N210)、二羟甲基丙酸(DMPA)和三羟甲基丙烷(TMP)为主要原料制得了环保交联型水性聚氨酯(WPU)压敏胶,讨论了n(-NCO)/n(-OH)比值、交联剂用量以及聚醚相对分子质量大小对该压敏胶性能的影响。研究结果表明,由N220合成的WPU压敏胶的初粘力优于由N210合成的WPU压敏胶;随着n(-NCO)/n(聚醚中-OH)比值的减小,压敏胶的初粘力提高,持粘力呈先降后增再降的趋势;适度的交联可以提高压敏胶的粘接强度;当n(-NCO)∶n(聚醚中-OH)为2.5∶1、n(TMP中-OH)∶n(聚醚中-OH)为1∶3.0时,压敏胶的综合性能优异,初粘力达到13号钢球,持粘力达到23.1h,180°剥离强度达到20.14N/(20mm)。     

Optical properties and adhesion performance of optically clear acrylic pressure sensitive adhesives using chelate metal acetylacetonate

Optically clear acrylic pressure-sensitive adhesives (PSAs) with different co-monomers were synthesized. This study employed metal chelate aluminum acetylacetonate and zirconium acetylacetonate as curing agents. The optical properties of the acrylic PSAs were examined by UV–visible spectroscopy and a prism coupler. In addition, the adhesion performance was obtained by assessing the peel strength, the tack, and the shear adhesion failure temperature. The decrease in the adhesion performance may be related to a higher crosslinking density, which also resulted in a higher gel content.     

Miscibility and fracture energy of probe tack for acrylic pressure-sensitive adhesives: acrylic copolymer/tackifier resin systems

The relationship between the miscibility of acrylic pressure-sensitive adhesive (PSA) and the fracture energy (W) (Jm⁻²) of the probe tack was investigated, wherein the master curve of W was compared with that of the maximum force (σ_max) (gf) of the probe tack. It was ascertained that W of acrylic PSA was closely related to the miscibility between the components (acrylic copolymer and tackifier resin). In the case of the miscible blend system, the master curve of W shifted toward the lower rate side and, at the same time, the magnitude decreased as the tackifier resin content increased. The degree of the shift of W was extremely smaller than that of σ_max. In the case of the immiscible blend system, the master curve of W remarkably decreased as the tackifier resin content increased, which suggests the fact that W of the PSA depended on the dynamic mechanical properties of the matrix phase and that the resin-rich phase acted as a kind of filler, thus reducing the practical performance. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 581–587, 1998     

链转移剂与极性单体对丙烯酸酯乳液压敏胶性能的影响

研究了链转移剂硫醇及极性单体丙烯酸(AA)、丙烯酸-β-羟丙酯(β-HPA)对丙烯酸酯乳液压敏胶性能的影响。同时还探讨了极性单体不同加入方式对压敏胶性能的影响。结果表明:适量分批加入硫醇、丙烯酸和丙烯酸-β-羟丙酯可显著提高压敏胶的初粘性、持粘性和剥离强度。     

Effect of model fillers on the adhesive strength of pressure-sensitive tapes

—The effect of various model fillers, namely glass beads, 'Spheriglass', and PTFE powder, on the adhesive strength of natural rubber (NR) and poly(n-butyl acrylate) (PBA) tapes has been investigated. Glass fillers treated with alkyl chlorosilane were also used. The adhesive strength was measured over a range of rates and temperatures, and corrections for the thickness of the adhesive and volume fraction of the polymer were introduced into the rate term. It was observed that the adhesive strength of PBA tapes filled with 20% PTFE is comparable to that of the control sample without filler. The strength measured over a range of strain rates increased for both untreated and treated Spheriglass-filled adhesives. Filled NR adhesives showed an enhanced strength only at very high strain rates. With 40% PTFE, this increase was quite apparent. The mechanism of improvement of the strength of adhesion due to the incorporation of a filler is explained. The addition of a filler introduces an additional mechanism of energy dissipation during deformation of the adhesive and a higher energy will be expended due to debonding of the filler and hysteresis.     

Novel versatile pressure-sensitive adhesives for polarizing film of TFT-LCDs: Viscoelastic characteristics and light leakage performance

One of the main problems in thin film transistor liquid crystal displays (TFT-LCD) is a phenomenon called “light leakage”, seriously affecting black–white contrast and color brightness. It occurs due to a thermal shrinkage of the polarizing film in TFT-LCDs, caused by a heat from the backlight unit. A pressure-sensitive adhesive (PSA) used for assembling of the polarizing film to the TFT-LCD panel can relieve the stress and minimize the light leakage. PSAs are designed specifically for a certain size LCDs, and cannot be used for another size LCD because of poorer light leakage. Obviously, there is a certain necessity to develop a universal PSA applicable simultaneously for LCDs with different sizes, such as mobile phones, digital cameras, navigation systems, computer monitors, HDTVs, etc.In this paper, we introduced N-vinyl pyrrolidone as a comonomer to a conventional copolymer of butyl acrylate, acrylic acid, and 2-hydroxy ethyl methacrylate. It resulted in a higher elasticity modulus and a higher shrinkage resistance of the PSA. A significant reduction of the light leakage to some extend was observed at increase of the hardener content for 2.5 and 7 in samples. However, it was accompanied by deterioration of the peel strength below spec requirements. Lowering molecular weight of the polymers from 626,000 to 205,000 Da resulted in excellent light leakage of both small and large specimens. Dynamic mechanical analysis confirmed that zero light leakage was achieved through a synergy of two mechanisms: high modulus, i.e. resistance to thermo-induced shrinkage, and high stress relaxation of lower molecular weight polymers. The results of this work are perspective for creation of a universal PSA for polarizing film in TFT-LCDs of different sizes.