保护膜用高初粘低剥离力丙烯酸酯压敏胶的研制

采用丙烯酸异辛酯、特殊丙烯酸酯单体A、丙烯酸、丙烯酸羟乙酯和甲基丙烯酸甲酯为单体,乙酸乙酯、甲苯为溶剂,偶氮二异丁腈为引发剂,制备了保护膜用高初粘、低剥离力溶剂型丙烯酸酯压敏胶。采用单因素试验法探讨了溶剂的类型与配比、引发剂用量、软硬单体配比、功能单体用量、特殊丙烯酸酯单体A的用量、固化剂种类和用量对压敏胶黏度、180°剥离强度及应用性能的影响。研究结果表明:对于保护膜用溶剂型丙烯酸酯压敏胶,通过引入外交联剂,能够显著增大其内聚力。外交联剂类型和用量对压敏胶的剥离强度、初粘性及排气性能均有很大的影响;氨基树脂固化剂在初粘性、排气性能、降低剥离强度方面表现更佳。     

外交联型丙烯酸酯乳液压敏胶的制备与性能研究

以丙烯酸丁酯(BA)、醋酸乙烯酯(VAc)、丙烯酸(AA)单体为基础,采用双丙酮丙烯酰胺(DAAM)/己二酸二酰肼(ADH)外交联体系,通过预乳化和半连续加料工艺制备了外交联型丙烯酸酯乳液压敏胶.采用红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等手段对其进行了表征和分析.并研究了软硬单体配比[m(BA)∶m(VAc)]、官能单体(AA)用量及外交联体系(DAAM/ADH)用量对压敏胶性能的影响.结果表明,通过调节软硬单体配比和官能单体用量可以使压敏胶性能达到一个较优的水平.当m(BA)∶m(VAc)=85∶15,w(AA)=3％时,压敏胶初粘力为17号球,180°剥离强度为504 N/m,室温持粘力＞30 d,高温(100℃)持粘力为140 min.外交联体系DAAM/ADH的引入可以在对初粘力和180°剥离强度影响较小的情况下显著提高压敏胶的高温持粘力到540 min,从而得到高温持粘力优异的外交联型丙烯酸酯乳液压敏胶.     

外交联型丙烯酸酯乳液压敏胶的制备与性能

以丙烯酸丁酯(BA)、醋酸乙烯酯(VAc)、丙烯酸(AA)单体为基础,采用双丙酮丙烯酰胺(DAAM)/己二酸二酰肼(ADH)外交联体系,通过预乳化和半连续加料工艺制备了外交联型丙烯酸酯乳液压敏胶。采用红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等手段对其进行了表征和分析。并研究了软硬单体配比〔m(BA)∶m(VAc)〕、官能单体(AA)用量及外交联体系(DAAM/ADH)用量对压敏胶性能的影响。结果表明,通过调节软硬单体配比和官能单体用量可以使压敏胶性能达到一个较优的水平。当m(BA)∶m(VAc)=85∶15,w(AA)=3%时,压敏胶初粘力为17号球,180°剥离强度为504 N/m,室温持粘力>30 d,高温(100℃)持粘力为140 min。外交联体系DAAM/ADH的引入可以在对初粘力和180°剥离强度影响较小的情况下显著提高压敏胶的高温持粘力到540 min,从而得到高温持粘力优异的外交联型丙烯酸酯乳液压敏胶。     

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。     

无溶剂辐射固化丙烯酸压敏胶的性能和制备

本文以聚氨酯丙烯酸酷(UV-7605)和环氧树脂(EP815)作为预聚体,丙烯酸作为增粘树脂,二甲基丙烯酸酯作为稀释剂,羟基环己基苯酮作为光引发剂,制备了性能优异的无溶剂辐射固化型丙烯酸压敏胶.通过对丙烯酸压敏胶的成膜性、固化时间、初粘力、粘结强度、附着力和耐老化性能测试,研究讨论了预聚体、增粘树脂、单体稀释剂、光引发...     

热熔压敏胶粘接性能的流变学研究

研究了苯乙烯嵌段共聚物系热熔压敏胶的动态流变学行为和持粘力之间的联系,主要研究了决定持粘力的流变学参数.研究证明,持粘力受到体系的蠕变过程的控制,可以通过较高温度下得到的持粘力数据来预测室温持粘力的大小.研究了液体树脂含量对持粘力的影响,提出损耗角正切(tan δ)最小值及其对应的温度是决定热熔压敏胶持粘力的关键流变学参数.     

溶剂型高性能丙烯酸酯压敏胶的制备

通过调节加料配比、引入功能单体的方式,制备了一种单组分自交联型丙烯酸酯压敏胶.该丙烯酸酯压敏胶具有较高的分子量和较窄的分子量分布,呈现出很好的初粘性和持粘性.详细地探讨了加料配比、单体种类、固化剂和增黏树脂用量对压敏胶性能的影响,为制备溶剂型高性能丙烯酸酯压敏胶提供新的研究思路.     

耐热性乳液型丙烯酸酯压敏胶的合成

采用种子乳液聚合法合成丙烯酸酯压敏胶，利用自交联单体N-羟甲基丙烯酰胺（NMA）提高其耐热性能，并采用反应型乳化剂DNS-86进一步提高压敏胶综合性能。研究了不同软硬单体用量比和功能单体配比对压敏胶性能的影响，探讨了自交联功能单体用量压敏胶耐热性能的影响，讨论了反应性乳化剂用量对压敏胶性能的贡献。结果表明：以最佳配方所制备出的乳液型压敏胶，其180°耐热剥离强度达到220N／m，耐热初粘力为11号钢球，耐热持粘力大于36h，固体质量分数为50％，粘度为460mPa·s。     

可移除耐高温丙烯酸酯压敏胶的制备及性能研究

以过氧化苯甲酰为引发剂,丙烯酸（AA）、甲基丙烯酸羟乙酯（HEMA）为功能单体,丙烯酸丁酯、丙烯酸异辛酯为软单体,醋酸乙烯为硬单体,采用溶液聚合法制备了一种可移除耐高温丙烯酸酯压敏胶。着重探讨了功能单体用量、软硬单体比例、交联剂种类及用量对压敏胶性能的影响。研究结果表明：功能单体HEMA和AA用量都在2.0%时,压敏胶的耐温性优异,同时剥离力、初粘力符合要求;当软硬单体质量比为90∶10时,压敏胶的剥离力、初粘力、耐温性均符合要求,效果较佳;引入交联剂可显著提高压敏胶的内聚能,赋予压敏胶可移性,当选用异氰酸酯交联剂L-75为1.5%时,压敏胶特性相对最佳。     

丙烯酸酯乳液压敏胶的改性研究

在丙烯酸酯乳液共聚中引入改性单体 ,通过交联等方法来调节水乳型压敏胶的内聚力和粘接力。并研究了增粘树脂、表面活性剂对压敏胶性能的影响。     

丙烯酸酯PSA环形初粘力影响因素研究

以反应型乳化剂(DNS-86)/阴离子型乳化剂(2A1)为复合乳化剂、甲基丙烯酸(MAA)与甲基丙烯酸羟乙酯(HEMA)为极性单体和正十二硫醇为链转移剂时,采用单体预乳化法和半连续乳液聚合法制备丙烯酸酯PSA(压敏胶)乳液。考察了PSA胶带的基材、干胶厚度、烘干条件、复合乳化剂、极性单体和链转移剂等对环形初粘力的影响。结果表明:当基材为白色BOPP(双向拉伸聚丙烯)薄膜、干胶厚度为50μm、烘干时间为3 min、烘干温度为110~115℃、w(正十二硫醇)=0.09%、同时引入MAA和HEMA极性单体、w(复合乳化剂)=1.5%和m(2A1)∶m(DNS-86)=2∶1时,相应丙烯酸酯PSA乳液的环形初粘力相对最大(14.73 N/25 mm)。     

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.     

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.     

Hot tack of metallocene catalyzed polyethylene and low-density polyethylene blend

Films made of metallocene catalyzed polyethylene (mPE), low-density polyethylene (LDPE), and their blend were prepared to investigate how LDPE influences the hot tack of film. Experimental results showed hot tack is independent of film thickness. The addition of 30 wt % of LDPE can increase the hot tack of mPE film. The thermograms of differential scanning calorimetry (DSC) suggest the respective partial melting and recrystallization of those smaller size crystals at the bond forming and joint fracture stages play very important roles. The large amount of partial melting and high flow may induce a higher degree of molecular diffusion. Higher residual crystallinity and recrystallization at the hot tack testing process may induce higher resistant to bond fracture. Those two positive influences show that the mPE/LDPE film has the higher hot tack. The evidence from optical (higher optical transmission and lower haze) as well as viscoelastic (higher storage modulus and lower melt viscosity) properties further support this hypothesis. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1769–1773, 1999     

Effect of molecular weight of epoxidized‐natural rubber on viscosity and tack of pressure‐sensitive adhesives

The effect of molecular weight of rubber on viscosity and loop tack of rubber‐adhesives were studied using two grades of epoxidized‐natural rubber, i.e., ENR 25 and ENR 50. Coumarone–indene resin, gum rosin, and petro resin were used as tackifiers. Toluene was used as the solvent throughout the experiment. The adhesive was coated on polyethylene terephthalate (PET) substrate using a SHEEN hand coater. Viscosity was determined by a HAAKE Rotary Viscometer, whereas loop tack was measured by a Llyod Adhesion Tester operating at 10 cm/min. Results show that viscosity increases gradually upto a critical molecular weight of 6.8 × 10⁴ and 3.9 × 10⁴ for ENR 25 and ENR 50, respectively, before a rapid increase in viscosity is observed. Loop tack indicates maximum value at the respective critical molecular weights for the three tackifiers investigated suggesting the culmination of wettability. For both rubbers, loop tack increases with coating thickness due to the concentration effect of adhesive. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of Synthesis Variables on Tack in Urea-Formaldehyde Resin

The degree of tack-the ability of resin to adhere to another surface under light pressure and over short time-in urea-formaldehyde resin varies throughout the particleboard manufacturing process and affects mill maintenance and board quality. A three-part study was conducted to evaluate the effects of certain synthesis variables-molar formaldehyde:urea ratio, ingredient concentration, reaction pH, and reaction catalyst-on tack of urea-formaldehyde resin in particleboard manufacturing. Southern pine particleboard mats were formed and prepressed in the laboratory, and tack was evaluated with the push-off method. Reaction pH significantly affected tack and viscosity, which were highly related. On the average, reducing formaldehyde:urea ratio and ingredient concentration increased tack; these two variables may be significant to tack development and resin morphology. Reaction catalyst did not affect tack or other resin morphology. Reaction catalyst did not affect tack or other resin characteristics, but resin surface tension contributed significantly to tack development. Further study should better define optimum manufacturing time and make tack development in particleboard manufacturing more predictable.     

单组分湿固化聚氨酯密封胶的表干时间研究

单组分湿固化密封胶由于使用方便,性能优良而被广泛应用.对其合成工艺进行了说明,并就其表干时间进行了分析研究.通过实验发现催化剂、脱水剂、增塑剂以及游离的异氰酸酯含量对密封胶的表干时间有很大的影响.实验结果表明,当催化剂的比例在0.1%,脱水剂适量,增塑剂的添加量在13%～15%、游离的异氰酸酯含量为2.5%～3.5%时,所制得的密封胶的表干时间最佳.     

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.     

苯乙烯系热塑性弹性体类压敏粘合剂的失粘──Ⅱ

研究了以热塑性弹性体为基料的压敏粘合剂失粘的原因。试验了基料中苯乙烯含量、固态增粘剂用量、物理形态、贮存期、液态增粘剂用量和芳香系石油树脂用量和形态,增塑剂用量和胶层厚度等对压敏粘合剂的抗失粘性能的影响。