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.     

带有压敏性的环氧胶带的研制

研制带有压敏性的环氧胶带,可以使用表面涂或内部加压敏胶的方法,两种方法有各自的优缺点。表面涂压敏胶,压敏性好,但固化的粘接强度较低;内加压敏胶则相反。全面衡量,内加压敏胶的方法较好。     

双组分溶剂型丙烯酸酯压敏胶的制备及应用

制备了一种双组分溶剂型丙烯酸酯压敏胶SPS01,它具有优良的初粘性和180°剥离强度,适中的黏度和较高的固含量、讨论了交联剂用量对其性能的影响．测试了用SPS01制备的双面胶粘带在钢板、玻璃、塑料和胶合板4种不同被粘表面的上180°剥离强度比较了SPS01与单组分压敏胶粘剂的应用特性及生产中的优缺点.     

Characterizing acrylic foam pressure sensitive adhesive tapes for structural glazing applications-Part II: Creep rupture results

The objective of this study was to determine relevant, primary mechanical characteristics of high-performance acrylic foam pressure sensitive adhesive (PSA) tapes, an alternate fastening method for structural glazing applications. Traditional fastening methods for structural glazing typically employ structural silicones and, consequently, relevant ASTM test standards and specifications appear to be more appropriate for silicones and similar products that exhibit limited time dependence. This study was aimed at characterizing and evaluating acrylic foam PSA tapes for structural glazing applications, and because of their time dependence, viscoelastic characterization was included. Since there may be significant differences in the viscoelastic responses of acrylic foam PSA tapes and silicones, the study may account for important differences between acrylics and silicones in structural glazing applications. The acrylic foam PSA used in the study was 3M™ VHB™ Tape G23F. For comparison, parallel ramp-to-fail tests were also conducted on 3 silicones: two one-part and one two-part compositions. Mechanical characteristics determined for the VHB™ Tape included the viscoelastic properties over a range of temperatures and test rates. Mechanical characteristics available in the literature were assumed for the silicones and confirm their limited time dependence. Ramp-to-fail strength data (Part I paper) and creep rupture (accompanying paper, Part II paper) data was collected for the VHB™ Tape and the silicones. Using the time–temperature superposition principle, master curves of VHB™ Tape storage and loss moduli in shear and tension were developed with data from a dynamic mechanical analyzer (DMA). The thermal shift factors obtained from these constitutive tests were successfully applied to the VHB™ Tape creep rupture and ramp-to-fail data collected at 23, 40, and 60 °C, resulting in master curves of ramp-to-fail strength (in Part I of paper) and creep rupture durability (Part II paper) in shear and tension.     

法庭科学中胶带的检验现状与发展

在法庭科学领域,包装胶带和透明办公胶带作为物证出现的频率越来越高.对这两种胶带的构成以及目前国内外胶带的检验现状进行了比较详细的介绍.有国外报道利用包装胶带和透明办公胶带一系列的物理特征、物理方法和化学方法对带基和胶黏剂进行检验,区分率可以达到99%以上,并且建立了胶带数据库,还建立了推荐使用的胶带系统检验程序.国内在这方面的工作也开展了一些,但是还不够系统,需要进一步大量的工作.     

国产1^#粘纸的研制与应用

本文研究采用天然橡胶，合成橡胶与丙烯酸酯类三元共聚的配方、工艺。并分析了合成胶粘剂的一些成分对胶卷感光活性的影响，通过试验和应用结果表明，制得的胶粘带产品可以替代１＾＃粘纸。     

Synthesis of removable and repositionable water‐borne pressure‐sensitive adhesive acrylics

This publication shows the synthesis of the water‐borne removable pressure‐sensitive adhesive (PSA) based on acrylates and the influence of parameters such as internal emulsifiers on peel adhesion on steel and also the influence of N‐methylol acrylamide and plasticizers on peel adhesion on glass, poly(vinyl chloride), and polypropylene during aging time. Removable and repositionable pressure‐sensitive adhesives based on acrylic polymers are used for the production of removable memo notes, paper and foil labels, double‐sided tapes, carrier‐free tapes to protective films, and manufacturing aids. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 886–892, 2005     

Synthesis of isocyanate microcapsules as functional crosslinking agent for wood adhesive

ABSTRACT

In this study, controlled-release isocyanate microcapsules were synthesized as functional crosslinking to slowdown the rate of cross-linking reactions. The isocyanate microcapsules were prepared by In-situ polymerization with polymethylene polyphenyl polyisocyanates (PAPI) as core and Urea formaldehyde resin as shell in oil-in-water emulsions. The particle size distribution, chemical structure, morphology, activity, and stability of the microcapsules were comprehensively characterized. Finally, the microcapsules were applied in a wood adhesive to prepare water-resistant plywood. The results showed that the size of the microcapsules was around 100 μm, the active content of NCO was about 23.5%, and the core content was approximately 80%. Compared with the stability of the bulk isocyanate, the stability of the isocyanate in microcapsules was significantly improved in the wood adhesive system. Furthermore, the isocyanate microcapsules showed highly efficient in plywood at different time, which indicated that isocyanate microcapsules could be controllable released in plywood applications.     

UV curable pressure‐sensitive adhesives for fabricating semiconductors. I. Development of easily peelable dicing tapes

In order to develop easily peelable dicing tapes from diced wafers, UV curing of various pressure‐sensitive adhesives (PSAs) was studied. After UV irradiation, the adhesive strength of a PSA composition including a diacrylourethane oligomer (UDA) decreased drastically compared with other compositions. Because of network formation via UV irradiation, this composition had a greater volume contraction that might yield microvoids at the interface between the adhesive and the wafer, resulting in the loose adhesion. Its storage modulus increased up to about 1000 times that before UV curing, which was due to the crosslinking of the UDA component. It was suggested that the increased crosslinking density and the high internal coagulant energy of the UDA backbone structure caused a remarkable decrease of the adhesive strength. Furthermore, it was ascertained that the UV‐irradiated UDA adhesives left few residual deposits on the wafer released from the tape. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 436–441, 2003     

压敏胶(带)的可剥离性能的研究进展

综述了压敏胶(带)的可剥离性能的研究进展,介绍了压敏胶高聚物的弹性模量、交联、分子极性、接枝改性、与被保护表面的界面接触面积和使用条件等对剥离性能的影响。     

Carboxymethylated polysaccharide-based films as carriers for acrylic pressure-sensitive adhesives

A novel application of a biodegradable polysaccharide-based film as a pressure-sensitive acrylic adhesive carrier has been reported. For film preparation carboxymethyl derivatives of starch (CMS) and cellulose (CMC) have been used. Based on physicochemical tests results (solubility in water, moisture absorption, mechanical properties) the most promising CMS/CMC 50/50 wt% film was selected as a carrier for an acrylic pressure-sensitive adhesive tape. Prepared double-sided self-adhesive tapes were characterized by good tack 5 N/2.5 cm, peel adhesion 12 N/2.5 cm and shear strength 90 N/6.25 cm² at 20 °C. Such acrylic self-adhesive tapes could find application in the paper industry.     

微胶囊促进剂在环氧树脂胶带固化中的应用

把环氧树脂固化促进剂制成了以脲醛树脂为外壁的微胶囊 ,并将其应用于环氧树脂胶带中 ,结果表明 ,微胶囊促进剂的使用可以显著提高胶带的使用期 ,尤其是使用部分反应的EMI微胶囊 ,且微胶囊的加入对胶带的粘结强度和耐热性基本没有不利影响     

乳液型压敏胶用色浆的制备

叙述了制造有色压敏胶带时，所需色浆的制备方法，按色浆配方，色浆调色和色浆的研磨分别进行了介绍，给出了一个黄青色色浆的配方实例，并且从涂布后胶带的色泽和遮盖力两方面讨论了色浆质量的判别，介绍了判断胶带遮盖力的简易迭层法。     

医用自交联聚丙烯酸酯压敏胶的性能研究

研究了一种皮肤用聚丙烯酸酯压敏胶,讨论了自交联剂和干燥时间等因素对压敏胶性能的影响,介绍了医用胶带的制备和测试方法。     

FPC保护膜用耐高温PSA胶带的研制

以丙烯酸-2-乙基己酯(2-EHA)、丙烯酸-2-羟乙酯(HEA)、丙烯酸(AA)和醋酸乙烯酯(VAc)为共聚单体,以环氧系列交联剂(E-5C)和苯二亚甲基二异氰酸酯交联剂(XDI)为复合交联剂,以偏苯三酸三辛酯(TOTM)为增塑剂,采用溶液共聚法制备溶剂型丙烯酸酯压敏胶(PSA);然后通过后期交联和增塑改性,制成柔性印刷电路板(FPC)保护膜用耐高温耐酸碱型PSA胶带。研究结果表明:当m(丙烯酸酯共聚溶液)∶m(E-5C)∶m(XDI)∶m(TOTM)=100∶15∶1.5∶3和干胶厚度为8～10μm时,相应PSA胶带的综合性能良好,其初始黏合力适中、耐高温性能和耐酸碱性能优异,并且其中试产品完全满足FPC加工过程的应用要求。     

双组份保护压敏胶带的研制

本文讨论了一种溶液型丙烯酸类双组份保护压敏胶带的基材种类、胶层厚度、干燥温度及涂胶时间等因素对胶带性能的影响。     

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.     

Elastic Analysis of the Loop Tack Test for Pressure Sensitive Adhesives

The behavior of pressure sensitive adhesive (PSA) tapes is sometimes examined via the loop tack test, in which a loop of the tape is brought into contact with a flat surface and then pulled away. A numerical analysis of the test is presented here. The loop is treated as an elastica, but with a nonlinear moment-curvature relation, so that the material is assumed to be elastic and inextensible. Debonding at the edge of the contact region is assumed to occur when the adhesive reaches a critical elongation. This elongation is assumed to depend on the maximum contact pressure and, in part of the results, on the length of time of contact. Shapes of the loop and values of the corresponding forces are obtained using a shooting method, and the effects of the stiffness and thickness of the adhesive and backing are examined.     

Surface and Interfacial Structure of Release Coatings for Pressure Sensitive Adhesives I. Polyvinyl N-Alkyl Carbamates

Polyvinyl N-alkyl carbamates belong to the general class of long alkyl side chain polymers. Such polymers are commonly used as release coatings for pressure sensitive adhesive tapes. In this paper the bulk, surface, and interfacial structures of polyvinyl N-alkyl carbamates having either decyl or octadecyl side chains are examined. The bulk structures and thermal transitions were characterized using X-ray scattering and differential scanning calorimetry. Dynamic mechanical thermal analysis was used to investigate thermal transitions and rheology (i.e., segmental mobility) of the polyvinyl N-alkyl carbamates. The surface energies of polyvinyl N-alkyl carbamate coatings were determined using contact angle methods, while X-ray photoelectron spectroscopy and static secondary ion mass spectrometry were employed to characterize the near-surface compositional profiles of the coatings. The peel force provided by the polyvinyl N-alkyl carbamate coatings, as a function of aging time and temperature, was measured for a tape having an acrylic acid containing alkyl acrylate based pressure sensitive adhesive. The changes in peel force with aging time and temperature were related to the ability to maintain a stable interfacial structure between the PSA and polyvinyl N-alkyl carbamate coatings. Changes in the interfacial composition upon aging were characterized by comparing the surface compositions of the PSA and polyvinyl N-alkyl carbamate coatings initially, prior to contact, as well as after aging and peeling them apart. The increase in peel force upon aging can be attributed, in large part, to a restructuring at the PSA/polyvinyl alkyl carbamate interface. Energetically favorable acid-base interactions between the basic urethane and acetate groups in the polyvinyl alkyl carbamates and the acrylic acid groups in the PSA provide a driving force for the restructuring. If the segmental mobility within the polyvinyl alkyl carbamate is sufficient, restructuring can occur, leading to increased concentrations of these groups at the PSA/polyvinyl alkyl carbamate interface, resulting in higher attractive forces and greater adhesion. The propensity for the polyvinyl N-alkyl carbamate coatings to restructure upon contact with a polar medium was also characterized by monitoring the receding contact angle of water, as a function of water contact time and temperature. A good correlation is seen between the ability of the polyvinyl alkyl carbamate coatings to provide a low peel force for the acrylate PSA tape and the ability of the coatings to maintain a high water receding contact angle.     

点焊密封胶带的研制

以丙烯酸酯类为主要单体经乳液种子聚合所得胶乳为基料，通过加入导电填料制成具有双面粘性的点焊密封胶带，以解决点焊件不易密封之难题，这不仅使生产工艺简化，节约工时，而且使密封效果得以保证。