有机硅压敏胶的合成与性能

以硅橡胶和MQ硅树脂为原料,通过羟基缩合反应制备了有机硅压敏胶。用FT—IR和GPC表征了其结构。讨论了硅橡胶和MO硅树脂的原料配比、硅橡胶的黏度、MQ硅树脂的分子质量等因素对压敏胶力学性能的影响：测定了压敏胶的初粘性、1800剥离强度和持粘性等性能。结果表明,用MQ硅树脂与运动黏度为100×10^-4m^2／s的硅橡胶在质量比为2：3时,可得到具有良好粘接性能的有机硅压敏胶。     

MQ硅树脂的制备、改性及其应用研究进展

概述了MQ硅树脂的结构和性能特点,综述了近年来MQ硅树脂的制备及其改性的研究进展,介绍了MQ硅树脂在加成型液体硅橡胶和硅氧烷压敏胶中的应用概况,指出了MQ硅树脂的发展趋势。     

MQ硅树脂改性丙烯酸酯压敏胶的研究

采用溶液聚合法将含有乙烯基的MQ硅树脂共聚到丙烯酸酯链节之中,合成了硅树脂改性丙烯酸酯压敏胶。利用FT-IR对改性后的压敏胶进行结构表征,确定了硅树脂的加入时间和最佳用量。结果表明,在聚合反应先期或中期加入10%的硅树脂,制得的压敏胶性能优异。改性丙烯酸酯压敏胶在150℃下持粘性为2200s,室温180°剥离强度为14.5N/25mm,100℃的180°剥离强度为6.3N/25mm,在200℃热老化10h后,剥离强度仍达6.2N/25mm。     

MQ硅树脂及其在医用压敏胶领域的应用

概述了MQ硅树脂的结构性能特点、医用压敏胶的性能要求以及有机硅压敏胶在医用领域的优势。研究了MQ硅树脂的M/Q值和用量对医用有机硅压敏胶性能的影响,结果表明:MQ硅树脂用于医用压敏胶时,较佳的M/Q值为0.78,较佳用量为55%,此时可制得具有优异性能的医用有机硅压敏胶。     

有机硅压敏胶的研制

采用价格低廉的水玻璃制备MQ硅树脂,通过对硅树脂体系引入苯基、乙烯基提高压敏胶的综合性能,研究MQ硅树脂的合成与压敏胶的制造工艺,制备出高性能的有机硅压敏胶。     

电气胶带用有机硅压敏胶的研制

通过MQ硅树脂和端羟基聚二甲基硅氧烷(PDMS)的硅醇缩合反应制备有机硅压敏胶溶液,将合成的有机硅PSA压敏胶溶液涂布在基材上干燥后得到有机硅压敏胶胶带(PSA),研究了PSA的合成配料、工艺以及胶带生产工艺对压敏胶带性能的影响。结果表明,硅树脂/硅橡胶比例在1.2~1.4之间具有良好的初粘、持粘和剥离力,硅树脂含量增加胶带耐热性增强;此外,反应真空度低于0.07MPa,反应温度高于140℃,且添加2%~3%左右的BPO时所制备的PSA胶带具有良好的综合性能。     

耐高温聚丙烯酸酯压敏胶的合成与研究

采用溶液聚合的方法制备了具有良好粘接性能的溶剂型聚丙烯酸酯压敏胶,并探讨了聚合工艺、聚合单体配方等对聚丙烯酸酯压敏胶的物理性能和粘接性能的影响。在此基础上,引入交联剂乙酰丙酮铝、异氰酸酯、耐高温材料硅树脂对压敏胶基胶进行耐高温改性,制得了耐高温性能优异的聚丙烯酸酯压敏胶。研究结果表明:相对较优的聚合条件是软单体丙烯酸异辛酯(2-EHA)与丙烯酸丁酯(BA)的比例为2∶1,硬单体苯乙烯(St)的含量为7%,官能单体丙烯酸(AA)的含量为3.5%,丙烯酸羟丙酯(HPA)的含量为0.6%,引发剂过氧化二苯甲酰(BPO)的用量占单体总量的0.3%。交联剂的引入可影响聚丙烯酸酯压敏胶体系的粘接性能,其中,乙酰丙酮铝(ALAA)交联得到的压敏胶的综合性能要优于甲苯二异氰酸酯(TDI)交联得到的压敏胶。甲基乙烯基MQ硅树脂的引入,可以大幅度提高聚丙烯酸酯压敏胶的耐高温性能,并且对压敏胶的黏性和内聚强度有一定的提升;当VMQ硅树脂的含量为单体总量0.8%时,压敏胶的黏性和耐高温性能较佳,经过260℃/5 min高温测试后,依然保持良好的黏性,且压敏胶未出现黄变现象。     

溶剂型有机硅压敏胶的制备及性能研究

以正硅酸乙酯和六甲基二硅氧烷为原料制得MQ硅树脂,MQ硅树脂再与107硅橡胶进行缩合反应,制备了107-MQ;再加入过氧化苯甲酰（BPO）及辅料配成有机硅压敏胶。考察了MQ硅树脂与107硅橡胶的质量比、BPO用量、外加辅料对压敏胶性能的影响。较佳工艺为：MQ与107硅橡胶的质量比为0．75：1．1．75：1、BPO用量2份、丙烯酸羟乙酯用量0．5份（MQ与107硅橡胶总用量100份）,此时有机硅压敏胶液稳定,可长时间放置,初粘32#钢球,剥离强度12N／25mm。     

MQ硅树脂的制备与应用研究进展

介绍了MQ硅树脂的结构和性能,综述了MQ硅树脂的制备研究进展及其在硅橡胶、有机硅压敏胶以及消泡剂,封装材料,UV光固化涂料等领域的应用技术进展。     

ABS塑料粘接胶的制备与性能研究

以改性聚氨酯树脂、增塑剂、粘接促进剂、乙烯基MQ硅树脂、碳酸钙等为原料,制备了一种对ABS塑料粘接良好的改性聚氨酯胶。研究结果表明:改性聚氨酯树脂按照n(-NCO)∶n(-OH)=1.6∶1.0,w(γ-甲基丙烯酰氧基丙基三甲氧基硅烷)=1.5%、w(乙烯基MQ硅树脂)=8%(相对于密封胶总质量而言)时,密封胶对ABS塑料的粘接性能较好。     

Multifunctional propyleneimines-new generation of crosslinkers for solvent-based pressure-sensitive adhesives

This article describes work with the goal of crosslinking pressure sensitive acrylic adhesives (PSA) and a new generation of crosslinkers based on multifunctional propyleneimine derivates. Crosslinking of PSA is an established technology used in many industrial manufacturing processes. New applications and technical specifications stimulate the continuous development of new crosslinking agents with very interesting properties. These new crosslinkers influence physico-mechanical properties of acrylic PSA such as tack, peel resistance (adhesion) and shear strength (cohesion). The weak point of propyleneimine crosslinkers is their very short potlife.     

Pressure Sensitive Adhesives Based on Oleic Acid

Existing pressure sensitive adhesives (PSA) are mostly based on petrochemical‐based polymers. This study reveals a new class of bio‐based polymers that can be used as PSA. The polymers are hydroxyl‐containing polyesters from the step‐growth polymerization of epoxidized oleic acid (EOA), an AB‐type monomer containing both a carboxylic acid group (A) and an epoxy group (B). The monomer is derived from epoxidation of renewable methyl oleate followed by selective hydrolysis of the ester group. The polymers (PEOA) of EOA were characterized for their chemical structure and molecular weight. The PEOA after being cured with a very small amount of a crosslinking agent could serve as a PSA with high peel strength, high tack force, superior shear resistance, excellent aging resistance, and excellent thermal stability. The PSA contains 99 wt% of green renewable materials. The PSA were also characterized for their viscoelastic properties and thermal properties.     

Secondary dispersion‐based reactive pressure‐sensitive adhesives with improved tack

Reactive pressure‐sensitive adhesives (PSA) have to meet the requirements for sufficient tack prior to crosslinking but also high shear after crosslinking. This article examines the use of secondary acrylic dispersions with reactive groups and epoxy resin dispersions for such PSA. Long‐term stable secondary PSA dispersions with high tack after film formation were obtained. Tack was dependent on the amount of carboxylic acid groups in the polymer as well as the base used for partial neutralization of the solvent‐borne copolymers. Reactive PSA were prepared by mixing a secondary dispersion with high amounts of carboxylic acid groups with an epoxy resin dispersion providing no tack. Variation of mixing ratio gave reactive PSA with sufficient tack, peel, and shear prior to crosslinking. Crosslinking of these reactive PSA at elevated temperatures led to high shear which was limited by incomplete molecular mixing of both phases. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46315.     

Microsphere pressure sensitive adhesives—acrylic polymer/montmorillonite clay nanocomposite materials

In this study, the synthesis and characterization of acrylic polymer/montmorillonite (MMT) clay nanocomposite pressure sensitive adhesives (PSA) are presented. Different types and amounts of modified and unmodified montmorillonite clays were dispersed in ethyl acrylate (EA)/2-ethylhexyl acrylate (2-EHA) monomer mixture, which was then polymerized using a suspension polymerization technique. Polymerization was monitored in-line using attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy. The adhesion properties of the synthesized nanocomposite materials were determined using standard measurements of tack, peel and shear strength. Viscoelastic properties of dried adhesive films were analyzed using dynamic mechanical analysis (DMA). The results showed that the kinetics of suspension polymerization was independent of the addition of MMT clays. On the other hand, adhesive properties were strongly influenced by the type and the amount of MMT clay added. While peel strength and tack gradually decreased with higher amount of modified MMT clay, a substantial increase in shear strength was determined with a maximal value at 1 wt% of added MMT clay. Moderate influence on tack, peel and shear strength was observed when the unmodified type of MMT clay was used. DMA analysis showed an increase in storage modulus (G′) for adhesives synthesized with MMT clay addition, but no significant differences were determined between particular types of MMT clays. A decrease in tan δ value for adhesives with 1 wt% of added MMT clay was observed, which also concurs with higher shear strength and implies to the improved cohesion of adhesive.     

Mechanism for the action of tackifying resins in pressure-sensitive adhesives

In a study of pressure-sensitive adhesives prepared from mixtures of natural rubber and three different tackifying resins, it was shown that a tackifying resin may form either one- or two-phase systems with natural rubber. Measurements of the viscoelastic properties of the adhesives show that the effect of tackifying resins is to modify the viscoelastic properties so that the adhesive performance in bonding and unbonding is improved. It is suggested that a two-phase system is not necessary for good tack, and a theory based on a two-phase system cannot adequately explain the rate dependence of tack tests. Tack measured by the probe test is shown to be dependent upon a balance between the viscoelastic properties and the transition temperature of the adhesives. This theory is used to explain the effect of contact time, withdrawal speed, and resin softening point on the tack of adhesives.     

Preparation and adhesion performance of transparent acrylic pressure sensitive adhesives for touch screen panel

Transparent acrylic pressure sensitive adhesives (PSAs) comprised semi-interpenetrated structured polymer networks were prepared with different co-monomer compositions. Emphasis was placed on the effect of functional groups in the co-monomer including morpholine and tetrahydrofurane moieties in the typical acrylic PSA formulation. The synthesized acrylic PSA syrups were characterized and the optical properties of the acrylic PSA film were also examined by ultraviolet–visible spectroscopy, haze meter, and prism coupler. Acrylic PSAs exhibit high transparency in the visible wavelength region. Adhesion performance was measured by the peel strength, cohesion strength, and probe tack tests. With increasing 4-acryloyl morpholine monomer concentration in the acrylic PSAs, the peel strength, cohesion strength, and probe tack increased.     

Biodegradable self-adhesive tapes with starch carrier

The disposed pressure-sensitive adhesive (PSA) tape widely used in daily life has been contaminating the environment and producing the vastly non-degradable trash. In this pioneering work, the advanced biodegradable pressure-sensitive double-coated tape containing starch carrier and water-soluble partially degradable modified pressure sensitive adhesive is architecturally designed and fabricated. The results have illustrated the excellent tack and peel adhesion of these newly constructed biodegradable self-adhesive tapes, and high thermal shear strength. Most importantly, the complete biodegradability of starch carrier and partially biodegradability of modified acrylic pressure-sensitive adhesives (PSA) have been confirmed experimentally. This environmentally friendly technology based on the starch resource utilization and novel water-soluble PSA will have great potentials for diverse applications such as the paper industry for manufacturing of ecological biodegradable product, the production of water-soluble biodegradable labels, medical tapes and biomedical electrodes.     

Fundamental Understanding in Rolling Ball Tack of Tackified Block Copolymer Adhesives

In the pressure sensitive adhesive (PSA) industry, rolling ball tack is a very common tack test, which is simple, inexpensive and easy to operate. This work attempts to search for key parameter(s), which will affect the rolling ball tack of a PSA based on a blend of styrene-isoprene-styrene triblock copolymer(SIS) and hydrocarbon tackifier(s). We want to better understand whether this particular PSA performance is controlled by the surface or bulk properties of the adhesive.

Firstly, to test the contribution from the surface properties, we employ a model system of SIS/aliphatic tackifier in 1/1 wt. ratio as the control. Part of the tackifier in this PSA is then replaced by various amounts of low molecular weight diluents with different surface tensions. The idea is to vary the surface properties of the PSA because these low surface tension and low molecular weight diluents tend to migrate to the PSA surface. It is observed that the incorporation of a lower surface tension and a lower molecular weight diluent in the PSA tends to produce a larger increase in rolling ball tack compared with the unmodified PSA. On the other hand, the incorporation of a higher surface tension and a more compatible diluent tends to produce a larger increase in loop, peel and quick stick. Each diluent lowers the shear adhesion failure temperature (SAFT) of the diluent-modified PSA. These observations are explained in terms of tackifier molecular weight, and surface tension and compatibility of the various components (polyisoprene, tackifier, diluent and oil) in the adhesive formulation.

Secondly, to test the contribution from the bulk properties, we derive an equation for rolling ball tack in terms of the bulk viscoelastic behavior of the block copolymer PSA. However, experimental values of rolling ball tack do not follow this equation. Also, with increasing tackifier concentration in SIS, rolling ball tack has very different behavior compared with loop, peel, quick stick and probe tack. The latter set of performance criteria is known to be related to PSA bulk viscoelastic behavior. Therefore, these suggest that rolling ball tack is related more to the surface properties than to the bulk properties of the adhesive based on these results and those of the diluent-modified PSA systems.     

Fundamental Understanding in Rolling Ball Tack of Tackified Block Copolymer Adhesives

In the pressure sensitive adhesive (PSA) industry, rolling ball tack is a very common tack test, which is simple, inexpensive and easy to operate. This work attempts to search for key parameter(s), which will affect the rolling ball tack of a PSA based on a blend of styrene-isoprene-styrene triblock copolymer(SIS) and hydrocarbon tackifier(s). We want to better understand whether this particular PSA performance is controlled by the surface or bulk properties of the adhesive.

Firstly, to test the contribution from the surface properties, we employ a model system of SIS/aliphatic tackifier in 1/1 wt. ratio as the control. Part of the tackifier in this PSA is then replaced by various amounts of low molecular weight diluents with different surface tensions. The idea is to vary the surface properties of the PSA because these low surface tension and low molecular weight diluents tend to migrate to the PSA surface. It is observed that the incorporation of a lower surface tension and a lower molecular weight diluent in the PSA tends to produce a larger increase in rolling ball tack compared with the unmodified PSA. On the other hand, the incorporation of a higher surface tension and a more compatible diluent tends to produce a larger increase in loop, peel and quick stick. Each diluent lowers the shear adhesion failure temperature (SAFT) of the diluent-modified PSA. These observations are explained in terms of tackifier molecular weight, and surface tension and compatibility of the various components (polyisoprene, tackifier, diluent and oil) in the adhesive formulation.

Secondly, to test the contribution from the bulk properties, we derive an equation for rolling ball tack in terms of the bulk viscoelastic behavior of the block copolymer PSA. However, experimental values of rolling ball tack do not follow this equation. Also, with increasing tackifier concentration in SIS, rolling ball tack has very different behavior compared with loop, peel, quick stick and probe tack. The latter set of performance criteria is known to be related to PSA bulk viscoelastic behavior. Therefore, these suggest that rolling ball tack is related more to the surface properties than to the bulk properties of the adhesive based on these results and those of the diluent-modified PSA systems.