环保型低剥离力压敏胶的研制

采用半连续乳液聚合法制备了一种丙烯酸类水基型低剥离力压敏胶。主要考察了甲基丙烯酸(MAA)等功能单体和外加交联剂对产物性能的影响。实验表明,随MAA等亲水单体用量的增多,乳液粘度会增大,而引入交联单体在实验范围内可显著降低剥离强度。功能单体用量有一合适范围。选用较高反应活性的氨基树脂作交联剂,可改善耐温性,保持初粘力,得到综合性能较好的低剥离力压敏胶。     

Atomic force microscopy investigation of phase morphology correlated with adhesive properties for modified telechelic natural rubber based-pressure sensitive adhesive

Atomic force microscopy (AFM) is a powerful technique to determine phase morphology and surface mechanical properties of materials. In this research natural rubber was degraded and grafted by malelic anhydride before modification with 3-amino-1,2,4-triazole to obtain modified telechelic natural rubber or modified TNR. It was then blended with cumarone-indene resin at 10, 30, and 50 phr, acting as tackifier. Phase morphology and surface topography were investigated by intermitted AFM. The results showed that tackifier enriched domains were clearly observed in modified TNR matrix after added 30 and 50 phr and the domain sizes were approximately to be the order of micrometer (5–10 µm) which it increased with increasing tackifier content. The intermolecular hydrogen bonding interaction between tackifier and modified TNR was observed by attenuated total reflectance Fourier transform infrared spectroscopy. The adhesive properties (loop tack, peel, and shear strength) were governed by the size of tackifier enriched domains, surface mean roughness and compatibility or interaction between modified TNR rubber and cumarone-indene tackifier resin.     

交联型聚丙烯酸酯压敏胶乳液的合成及其粘接性能的研究

利用功能单体的自交联作用,采用种子半连续乳液聚合的方法进行多元共聚,合成了兼具较高剪切强度和剥离强度的交联型聚丙烯酸酯压敏胶乳液。运用DSC、DMA及粘接性能测试分别考察了聚合物的玻璃化转变温度、动态力学性能和压敏胶粘性能,并分析讨论了三者之间的相互关系。结果表明:功能单体所产生适度交联作用能较好地协调聚合物的内聚力和粘合力之间的平衡,使其具有较好的粘接及力学性能。聚合物的Tg、粘弹性等物理参数可用于评估其内聚力及粘接强度。     

一种新型可生物降解聚酯压敏胶的制备与性能

以丁二酸、己二酸、1,3丙-二醇、1,4丁-二醇为单体,C-94为催化剂,丙三醇为交联剂,制备了一种新型的、可生物降解的四元无规共聚酯压敏胶,使用核磁共振波谱仪测定了共聚酯中各单元的组成比例,并对其黏弹性、初黏性、持黏性、180°剥离强度等进行了表征,考察了交联剂用量对压敏胶性能的影响。实验结果表明,丙三醇质量分数为0.6%时,压敏胶性能较佳。     

松香基丙烯酸酯核-壳共聚压敏胶的研制

根据“分子设计”的原理,采用种子乳液聚合的方法研制出一种具有复合核／壳结构的改性松香型丙烯酸酯压敏胶聚合物乳液,讨论了核壳乳液比例、引发剂、乳化剂、相比等因素对乳液性能的影响,确定了最佳的松香酯乳液用量。结果表明,所得产物是一种性能优良的压敏胶粘剂。     

Adhesion behavior of natural rubber‐based adhesives crosslinked by benzoyl peroxide

The loop tack, peel, and shear strength of crosslinked natural rubber adhesive were studied using coumarone‐indene and toluene as the tackifying resin and solvent, respectively. The concentration of benzoyl peroxide‐the crosslinking agent—was varied from 1 to 4 parts per hundred parts of rubber (phr). A SHEEN hand coater was used to coat the adhesive on the polyethylene terephthalate substrate at various coating thickness. Loop tack, peel, and shear strength were measured by a Llyod adhesion tester operating at 30 cm min^?1. Result shows that loop tack and peel strength of the adhesive increases up to 2 phr of benzoyl peroxide concentration after which it decreases with further benzoyl peroxide content. This observation is attributed to the optimum crosslinking of natural rubber where optimum cohesive and adhesive strength occurs at 2 phr peroxide loading. However, for the shear strength, it increases with increasing benzoyl peroxide concentration where higher rate of increase is observed after 2 phr of peroxide content, an observation which is associated to the steady increase in cohesive strength of crosslinked rubber. In all cases, the adhesion properties of adhesives increase with increase in coating thickness. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

PS-3698苯丙型压敏胶粘剂的研制

论述了以苯乙烯、丙烯酸 2 -乙基己酯和特种单体经乳液聚合反应合成的苯丙型压敏胶乳液的研制。讨论了各种单体配比、引发剂、聚合温度、时间等因素对压敏胶粘剂性能的影响。     

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.     

Photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) by the use of selected photoinitiators type I

This study investigated the photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) containing selected photoinitiators type I, known as α-cleavage photoinitiators. Photocrosslinking of PSA, especially of acrylic PSA, is well established crosslinking process using the UV radiation technology. UV-initiated crosslinking of acrylic PSA allows the synthesis of the wide range of UV-crosslinkable PSA with the interesting features. Especially, the important balances of properties such as adhesive and cohesive strength which are typically critical for the application performance can be achieved by this technology. The selection of suitable photoinitiator plays an important role to obtain the optimum properties of acrylic PSA including tack, peel adhesion, and shear strength. In this study, the investigations on different saturated conventional photoinitiators of type I for solvent-based PSA were carried out. The effects of photoinitiator concentration, UV crosslinking time and UV dose on the tack, peel strength, and shear strength were explored in detail for guiding the choice of photoinitiators to fabricate advanced PSA for industrial usage.     

广告、交通标志用压敏胶的研制

叙述了广告、交通标志用丙烯酸酯类压敏胶共聚的单体组成、合成及其性能,研究了官能单体、交联剂及协同剂等因素对压敏胶性能的影响。     

Influence of crosslinking and peeling rate on tack properties of polyacrylic pressure-sensitive adhesives

Tack properties and peeling behavior of crosslinked polyacrylic pressure-sensitive adhesives were investigated. The model adhesive was a crosslinked poly(n-butyl acrylate-acrylic acid) random copolymer with an acrylic acid content of 5?mol% with various crosslinking degrees. Tack was measured using a probe tack test with probe rates of 1 and 10?mm/s and various contact time. The tack increased with contact time. The degree of tack rising with contact time decreased with an increase in crosslinking degree for 10?mm/s, while the tendency was opposite for 1?mm/s. The temperature dependency of tack was measured with a contact time of 30?s. The tack peak shifted to higher temperatures with an increase in crosslinking degree and probe rate. Peeling behavior was observed using high-speed microscopy. The peeling behavior changed from A to C with the decrease of peeling rate and crosslinking degree. A: Cavitation and peeling progressed simultaneously at maximum stress at 10?mm/s independent on the crosslinking degree. B: Cavitation occurred at the edge of the probe at low stress and spread to the center of the probe at maximum stress at 1?mm/s and high crosslinking degree, then peeled out. C: After B, fibrillation occurred at 1?mm/s with low crosslinking degree. The change of peeling behavior was caused by the following: the interfacial adhesion increased, while the cohesive strength decreased as crosslinking degree and probe rate decreased.     

水性聚氨酯压敏胶的制备与性能研究

以聚丙二醇(N-220)和异佛尔酮二异氰酸酯(IPDI)为主要原料、二羟甲基丙酸(DMPA)和聚乙二醇(PEG)为亲水性物质、三乙胺为中和剂,制备出一种具有压敏特性的水性聚氨酯(WPU)胶粘剂。通过红外光谱(FT-IR)法、粒度分析法等检测手段,研究了DMPA、PEG、中和剂、增黏树脂和交联剂等对WPU的结构和性能的影响。结果表明:亲水性基团含量越少,产物粒径越大,耐水性越好;中和度越低,WPU胶膜的耐水性越好,同时可供交联的羧基含量越多;当中和度为33.3%、w(固化剂)=1.5%时,WPU压敏胶带的内聚强度较大且不脱胶,其吸水率为31.2%,180°剥离强度为2.2N/25mm,可望在保护膜胶带等领域中得到应用。     

Adhesion properties of pressure-sensitive adhesives prepared from SMR 10/ENR 25, SMR 10/ENR 50, and ENR 25/ENR 50 blends

The adhesion properties, i.e. viscosity, tack, and peel strength of pressure-sensitive adhesives prepared from natural rubber/epoxidized natural rubber blends were investigated using coumarone-indene resin and toluene as the tackifier and solvent respectively. One grade of natural rubber (SMR 10) and two grades of epoxidized natural rubbers (ENR 25 and ENR 50) were used to prepare the rubber blends with blend ratio ranging from 0 to 100%. Coumarone-indene resin content was fixed at 40 parts per hundred parts of rubber (phr) in the adhesive formulation. The viscosity of adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength was determined using a Lloyd Adhesion Tester operating at 30 cm/min. Results show that the viscosity of the adhesive passes through a minimum value at 20% blend ratio. For loop tack and peel strength, it indicates a maximum at 60% blend ratio for SMR 10/ENR 25 and SMR 10/ENR 50 systems. However, for ENR 25/ENR 50 blend, maximum value is observed at 80% blend ratio. SMR 10/ENR 25 blend consistently exhibits the best adhesion property in this study, an observation which is attributed to the optimum compatibility between rubbers and wettability of adhesive on the substrate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mapping the tack of the pressure-sensitive adhesive joint vs. applied stress and age

A tacky elastomer, the pressure-sensitive adhesive spontaneously bonds with a solid on contact to form a load-bearing pressure-sensitive adhesive joint (PSAJ) that makes many manufactured goods. While the property called the tack of the PSAJ, measured by the green strength of the joint at low applied stress, is vigilantly monitored for quality assurance, it harbors considerable indefinitude because it increases with applied stress and age to span a continuous spectrum that no finite number of discrete empirical readings can fully cover. Assuming the joint strength to be proportional to adhesive/substrate contact area on the atomic level, and treating the contact process as atomic-scale creep, this work determines from first principles the measured tack of a given PSAJ as a function of applied stress and age. The quantitative structure of the function and its implications are explored. The result is tested with published empirical data and used as a basis for mapping the tack spectrum from discrete readings. It brings settlement of long-standing issues such as ranking PSAJs by their non-corresponding tack readings, explaining the disconcertingly high noise : signal ratios plaguing tack data, buffering the uncertainty and extending the domain of tack measurement. It also shows that the tack and the mature joint strength constitute one smooth continuous spectrum.     

保护胶带用高剥离强度乳液压敏胶的研究

以丙烯酸丁酯(BA)、丙烯酸异辛酯(2-EHA)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯酸(AA)、丙烯酸羟丙酯(HPA)为原料进行乳液共聚,合成了保护膜用丙烯酸酯乳液压敏胶。讨论了乳化剂种类及用量、引发剂及缓冲剂用量、聚合温度、聚合时间、种子乳液用量对压敏胶性能的影响。结果表明,合成的压敏胶具有较高的剥离强度和初粘性,同时具有较好的耐高温高湿老化性能。     

环氧-聚砜结构胶粘剂耐环境性能的研究

报导了SY-14环氧-聚砜胶粘剂体系的耐环境性能研究结果。在北京、南昌、广州和海口四个不同气候条件下的10年大气曝晒试验表明,各项胶接强度均末发生明显变化。含有抑制腐蚀底胶的胶接试板进行的10年室温盐水浸泡试验也取得了优良的试验结果。     

马来酸酐改性氯化聚乙烯的合成及粘接性能研究

研究了马来酸酐改性ＣＰＥ的合成反应条件,比较了纯ＣＰＥ和改性ＣＰＥ的粘接强度,用ＩＲ对 产物进行了表征。实验表明：马来酸酐能改善ＣＰＥ表面的粘接性;并探讨了己内酰胺作为电子给体添加剂对 接枝反应的影响。     

聚氨酯-丙烯酸酯细乳液聚合及其压敏胶应用

以十八烷基丙烯酸酯为助稳定剂（ODA）,Dowfax2A1（80%）为乳化剂,十二烷基硫醇为链转移剂,采用细乳液聚合的方法制备了聚氨酯-丙烯酸酯杂化乳液。系统的研究了聚合温度、链转移剂的量、2-羟乙基甲基丙烯酸酯（HEMA）和羟乙基化双酚A的比例、PU含量以及丙烯酸丁酯（BA）与甲基丙烯酸甲酯（MMA）的质量比等因素对乳液聚合及其膜的机械性、粘合性的影响。结果表明,当n（HEMA）/n（NCO）=1∶5,链转移剂对单体的量为0.2%,PU含量为20%,m（BA）/m（MMA）=3∶1时,在70℃下制备的乳胶膜的机械性能和粘合性能最佳。     

Effect of Coumarone-Indene Resin on Adhesion Property of SMR 20-Based Pressure-Sensitive Adhesives

The viscosity, tack, and peel strength of a natural rubber (SMR 20)–based pressure-sensitive adhesive (PSA) was studied using coumarone-indene resin as the tackifier. The resin loading was varied from 0–80 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment. The viscosity of PSA was measured using a Haake Rotary Viscometer whereas loop tack and peel strength were determined using a Lloyd Adhesion Tester. PSA was coated onto the substrates using a SHEEN hand coater to give a coating thickness of 60 μm and 120 μm. Results show that the viscosity and tack of the adhesive increases with resin content due to the concentration effect of tackifier resin. However, for the peel strength, it increases up to 40 phr of resin for both coating thickness, an observation that is attributed to the wettability of substrates.     

Fracture mechanism and oil absorption of an oil-accommodating adhesive

We have studied the fracture mechanism and oil absorption in an oil-accommodating adhesive. Shear and T-peel tests were carried out for test pieces prepared from two steel plates bonded with the adhesive, which is mainly composed of epoxy resin, modified NBR, and inorganic powders. When the modified NBR content was varied from 3 to 25 wt%, both the shear and the T-peel strengths increased with the modified NBR content and levelled off at around 10 wt% modified NBR content. This behavior was coincident with that in the tear test by the samples prepared from cured adhesive. Therefore, fracture in the shear and T-peel tests is attributed to the tearing of cured adhesive. The oil absorbed in the non-cured adhesive bleeds out during curing. However, this oil can be stored in the grooves of steel plates.