单组分紫外光交联丙烯酸压敏胶粘剂的研究

本文通过将交联单体甲基丙烯酸环氧丙酯共聚引入到丙烯酯酯主链结构中,用二芳基碘六氟锑酯盐在紫外光激发下引发环氧基交联,从而制得一种综合性能优良的此外光交联型压敏胶粘剂,资助系统研究了该压敏胶作为单组分胶粘剂的使用期及性能与时间的关系。紫外光剂量、紫外光引发剂用量、交联单体用量等因素对压敏胶综合性能的影响。结果表明该体系是一种稳定性能好,综合性能尤其是持粘及耐温性能高的单一组分溶剂型压敏胶。     

紫外光本体聚合制备丙烯酸酯压敏胶

采用紫外光(UV)本体聚合的方法,将光引发剂在UV LED光源激发分解下引发多种丙烯酸酯类单体聚合制备压敏胶。考察了光照强度与距离的关系以及不同单体的聚合反应速率,进而确定了软硬单体最佳配比以及压敏胶最佳反应时间,表征了压敏胶交联前后的热稳定性,并且将UV本体聚合制备的压敏胶与加热本体聚合的压敏胶进行了对比。结果显示,当丙烯酸(AA)作为硬单体、软硬单体配比为90∶10(质量比)、单体质量为30g、反应时间为20s时,压敏胶有最佳的综合性能。与加热本体聚合相比,UV本体聚合制备的压敏胶无论在性能还是生产方式上都占有很大优势。     

乳液型丙烯酸酯压敏胶的研制

采用乳液聚合制备了乳液型聚丙烯酸酯压敏胶,讨论了软单体的用量、硬单体用量、交联单体的种类及用量、引发剂的用量、交联剂的用量和乳化剂的配比对压敏胶性能的影响。实验表明,在相同的条件下,丙烯酸的改性效果比丙烯酸羟乙酯好,当m（EHA）∶m（VAc）=82∶10时,压敏胶的综合性能最佳。交联剂的加入明显提高了剥离强度,当其质量分数为0.3%时,剥离强度达到357.33 N/m。     

聚丙烯酸酯压敏胶的研制及在反光膜中的应用

以丙烯酸异辛酯(EHA)和丙烯酸丁酯(BA)为软单体,甲基丙烯酸甲酯(MMA)为硬单体,丙烯酸(AA)和丙烯酸羟丙酯(HPA)为交联单体,过氧化苯甲酰(BPO)为引发剂,乙酸乙酯为溶剂,采用溶液聚合法制备了一种溶剂型聚丙烯酸酯压敏胶。考查了各单体用量对压敏胶综合性能的影响。结果表明,当软单体质量分数为85%、MMA质量分数为5%、AA质量分数为6%和HPA质量分数为4%时,PSA综合性能优异,可满足反光膜的使用要求。     

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。     

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。     

偏光片用丙烯酸酯压敏胶粘接性能和老化性能研究

针对偏光片用压敏胶对耐老化性能的特殊要求,采用丙烯酸丁酯、丙烯酸异辛酯、甲基丙烯酸甲酯、甲基丙烯酸羟丙酯、丙烯酸等单体通过溶液聚合的方法,制得了不同的丙烯酸酯压敏胶（PSA）。讨论了引发剂、丙烯酸、交联方法等因素对PSA光学性能、粘接性能、热老化及湿热老化性能的影响。当BPO用量为单体总量的为0.6%,AA用量为0.5%,IPDI用量为固含量的3%时,制备的压敏胶具有适宜的粘接性能。湿热老化前后,PET基材压敏胶的剥离强度分别为7.76N/25mm、6.36N/25mm,具有较高剥离强度保持率。该压敏胶用于偏光片和玻璃板贴附时,显示出优良的湿热老化性能。     

UV本体聚合制备压敏胶的性能研究

以丙烯酸酯类单体为原料,采用UV本体聚合的方法制备丙烯酸酯预聚物,然后补加引发剂和光敏树脂后制备得到压敏胶。选择丙烯酸(AA)作为硬单体,考察了单体的选择及配比、预聚物中单体转化率、固化光照强度、光敏树脂交联剂以及引发剂用量对压敏胶性能的影响,并通过TG表征了固化前后的热稳定性,DSC表征了玻璃化温度,最后将光聚合与热聚合生产的压敏胶进行了对比。结果表明:当AA含量为10%,BA与2-EHA质量比为4:1,光敏树脂用量为3%~3.5%时,压敏胶的综合性能最佳;而较低的固化光照强度可以赋予压敏胶更好的力学性能,适宜的引发剂用量可以提高固化速率。与加热溶液聚合相比,UV本体聚合制备的压敏胶无论在性能还是生产方式上都具有很大的优势。     

单组分常温交联型环氧——苯丙乳液研究

采用核壳乳液聚合，并在核中加入供交联环氧树脂，合成单组分常温交联环氧－苯丙乳液。讨论了引发剂品种对单体转化率的影响，以及单体和树脂的用量对涂料性能的影响。     

胶粘剂新专利

压敏胶粘剂组成物及其应用方法和制备方法 US20100190918A1 2010-07—29 介绍了一种压敏胶组成物,其包括含有可交联的环氧基团的共聚物以及溶剂。此共聚物由一种或多种的第1、第27FD第3单体聚合而成,其中第1单体具有环氧基团,第3单体含有庞大的侧链。特别是,第3单体具有稳定性不会影响共聚物的交联性能。此发明同样述及制备和使用此压敏胶粘剂组成物的方法。     

UV crosslinkable microsphere pressure sensitive adhesives—influence on adhesive properties

In the following study, a synthesis and characterization of UV crosslinkable acrylic pressure sensitive adhesives are presented. Different amounts of unsaturated photoinitiator 4-acryloyloxy benzophenone (4-ABF) were added in t-butyl acrylate/2-ethylhexyl acrylate monomer mixture and then polymerized using a suspension polymerization technique. The adhesive suspension was coated on a pilot coating machine, dried by application of IR and subsequently crosslinked under UV light. The copolymerized 4-ABF photoinitiator will produce reactive radicals upon absorption of UV light, which are capable of initiating a rapid chain reaction with neighboring C-H positions of polymer side chains, what leads to formation of crosslinked polymer structures. UV crosslinking process was monitored by ATR-FTIR spectroscopic technique. Adhesion properties of the synthesized materials were determined using standard measurements of tack, peel and shear strength. Results have shown that all adhesive properties are strongly influenced by the degree of crosslinking of the microspheres, which increased with higher amounts of added 4-ABF photoinitiator. All the three measured adhesive properties showed a substantial decrease even at small amounts of added 4-ABF. The decrease in adhesion may be correlated with higher crosslinking density, what also resulted in higher gel phase amounts. Determination of glass transition temperature showed minor difference between adhesive coatings.     

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.     

Solventless UV crosslinkable acrylic pressure sensitive adhesives

The synthesis and characterization of solventless acrylic UV crosslinkable pressure sensitive adhesives are presented. Different prepolymers were synthesized using bulk polymerization procedure. The reaction mixture consisted of acrylic monomers (2-ethylhexyl acrylate, acrylic acid and t-butyl acrylate), azobisisobutyronitrile initiator, chain transfer agent n-dodecylmercaptan and unsaturated UV photoinitiator 4-acryloyloxybezophenone, which was copolymerized into polymer backbone. Different formulations were tested and the prepolymer was characterized by viscosity measurements and final monomer conversions. The prepolymers were coated onto PET foil and crosslinked by application of UV light source. Peel adhesion at 180° on glass plate was measured. Gel phase was determined using the Soxhlet extraction and copolymer glass transition temperatures (T_g) were analyzed by differential scanning calorimetry (DSC). Results showed that the final monomer conversions in highly exothermic bulk polymerization reached a level between 75% and 90%. Prepolymer viscosity was highly influenced by change in polymer molecular weight and by addition of acrylic acid as a comonomer. On the other hand, the viscosity remained at the low level when t-butyl acrylate was used. The amount of gel phase for all adhesives was above 60 wt.%. Peel strength measurements showed decrease in peel strength with decreasing polymer molecular weight and increase of peel, when acrylic acid was used as a comonomer. All adhesive coatings with t-butyl acrylate comonomer showed cohesive failure.     

Synthesis and dynamic mechanical analysis of nanocomposite UV crosslinkable 100% solid acrylic pressure sensitive adhesives

A synthesis and characterization of nanocomposite solventless acrylic UV crosslinkable pressure sensitive adhesives is presented. Different prepolymers were synthesized using bulk polymerization procedure. The reaction mixture consisted of acrylic monomers (2-ethylhexyl acrylate, acrylic acid and t-butyl acrylate), azobisisobutyronitrile initiator, chain transfer agent n-dodecylmercaptan and unsaturated UV photoinitiator 4-acryloyloxybezophenone. Different formulations with different amounts of modified and unmodified montmorillonite (MMT) clays were tested and the prepolymer was characterized by viscosity measurements. UV crosslinking process was monitored using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Gel phase amount in crosslinked samples was determined by Soxhlet extraction. Clay dispersion in polymer matrix was investigated by X-ray diffraction analysis (XRD). Three basic adhesive properties, the tack, peel and shear strength were measured and the viscoelastic properties of crosslinked adhesive films were characterized using dynamic mechanical analysis (DMA). Results of the study showed high increase in prepolymer viscosity, when hydrophobic types of MMT clays were added in the reaction mixture. The addition of clay had a negative effect on UV crosslinking process. XRD analysis confirmed complete exfoliation and/or intercalation of modified clays in polymer matrix, depending on modifier amount and type. Results of adhesive properties testing showed a major influence of clay addition on adhesive properties, especially on shear strength. DMA analysis showed an increase in storage modulus (G′) and a decrease of tan δ values for adhesives synthesized with clay what also concurs with higher shear strength and implies an improved cohesion of adhesive.     

UV油墨的制备与性能优化

探讨了预聚物、单体、光引发剂、颜料等组分对UV油墨固化速度、附着力、耐抗性等性能的影响,应用正交实验设计方法对UV油墨各组分种类进行选择,对正交试验结果做极差分析及方差分析,结果表明：根据预先设计的组分比例,采用预聚物PQ611,单体A,光引发剂B,活性氨为加速剂,获得性能较好的UV油墨。     

环氧丙烯酸酯的光固化动力学研究

采用光差扫描量热法考察了环氧丙烯酸酯的光固化动力学行为。实验结果表明，增加光引发剂和活性单体的浓度的都可以使反应的转化率有明显的提升，当光引发剂的质量分数从2％增加到5％，转化率由76．2％上升至88.3％；当活性单体质量分数从15％增加到25％，转化率由73．8％上升至95．3％，但单体质量分数的提高对反应速率的变化不是很明显。此外，光固化反应速率对光强非常敏感，而氧气对丙烯酸酯光固化体系的阻聚作用较弱。     

Novel pyridinium photoinitiators and their applications for the ultraviolet crosslinking of acrylic pressure‐sensitive adhesives

The demand for ultraviolet (UV)‐crosslinkable pressure‐sensitive adhesives (PSAs) has rapidly been increasing. A variety of different PSAs containing new photoreactive pyridinium derivatives have been evaluated for their effectiveness in improving adhesion and cohesion in UV‐crosslinkable PSAs. PSAs have been evaluated with respect to the tack, peel adhesion, and shear strength. This article summarizes the breakthrough technology used to achieve better performances in UV‐crosslinkable acrylic PSAs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

LCD用UV固化胶黏剂的研制

以聚酯多元醇、二异氰酸酯和丙烯酸羟乙酯为原料,合成聚氨酯丙烯酸预聚体,并在此基础上通过添加活性稀释单体、光引发剂等配制成UV固化胶黏剂。通过分析不同组分在LCD液晶灌注口密封及金属管脚固定的粘接性能影响,确定合成预聚体所需的聚酯多元醇种类及丙烯酸羟乙酯的合适用量,同时确定配胶所需活性稀释单体与光引发剂的合适用量。最后制得粘接性能好、耐候性能佳,可满足LCD产品生产工艺的性能要求的UV固化胶黏剂。     

Viscoelastic Windows of Pressure-Sensitive Adhesives

A viscoelastic window (VW) concept has been proposed to identify different types of pressure-sensitive adhesives (PSA's). Such viscoelastic windows are constructed from the values of dynamic storage modulus: G' and dynamic loss modulus G' at frequencies of 10^-2 and 10² rad/sec. These frequencies are chosen because the range covers most of the time scales corresponding to the uses of PSA's at different application rates in performance tests. A four quadrant concept has also been recommended to categorize different types of PSA's based on the location of their VW's on the log-log cross plot of G' and G'. It was found that for most PSA's, the range of G' and G' at room temperature within these selected frequencies falls between 10³ and 10⁶ Pascals. The proposed four-quadrants (top-left hand quadrant of high G' and low G', top-right hand quadrant of high G' and high G', lower left hand quadrant of low G' and low G', and lower right-hand quadrant of low G' and high G') correspond respectively to (1) non-PSA or release coatings (2) high shear PSA's, (3) removable PSA's and medical PSA's and (4) quick and cold stick PSA's. It was also observed that the VW's of general purpose permanent PSA's occupy the central region which straddles part of the four quadrants.     

Kinetic study of photoinitiated frontal polymerization

The frontal polymerization of a monomer exposed continuously to UV radiation in the presence of a photobleachable initiator has been studied on the basis of the rate equations. The time dependence of photoinitiator concentration profile and that of monomer conversion within the irradiated sample have been calculated, assuming steady‐state conditions. It is thus possible to visualize how fast the polymerization profile is moving within the sample and how effectively the polymerization of a monomer layer located at a given distance from the surface proceeds upon exposure to UV radiation. © 2001 Society of Chemical Industry