胶粘剂在微型扬声器中的应用及发展

程真真，王海荣，谈彩花，张增辉

王梦媚，刘春利，周厚强，李 春

（歌尔股份有限公司，山东潍坊  261000）

【摘 要】微型扬声器在电子产品中，特别是在日常应用中非常广泛，比如手机、手表、耳机和VR等。微型扬声器最重要的组装方式之一就是粘接，胶粘剂的作用举足轻重。本文综述性地介绍了微型扬声器常用的胶粘剂，比如紫外线固化胶、瞬干胶、改性硅胶、厌氧胶以及反应型热熔胶等，以及常见的粘接应用，包括球顶和振膜的粘接、球顶和音圈的粘接、振膜和边框的粘接、磁铁和盆架的粘接、盆架和边框的粘接、单体与模组的粘接以及上下壳粘接等，并对微型扬声器用胶粘剂的发展趋势进行了展望。

【关键词】微型扬声器；胶粘剂；组装；应用

虫胶片类型与粘接基底表面状态对粘接强度及其波动性的影响研究

谢钰洁^1,2，潘晓磊¹，吴冶平¹，李高明¹

古云松²，赵秀丽¹，张  平²，张银宇¹

（1.中国工程物理研究院化工材料研究所，四川绵阳  621900；2.西南科技大学材料与化学学院，四川绵阳  621010）

【摘  要】虫胶片作为一种天然胶粘剂，因其施工便捷、力学性能较好而受到广泛关注。然而，虫胶原胶的性能易受气候、品种的影响，且目前缺乏针对塑料和金属基底的粘接工艺研究，导致其粘接强度波动性较大，进而影响粘接连接的可靠性。本文通过改变虫胶片类型、虫胶-乙醇溶液（虫胶漆）配制有效期、晾置时间以及粘接基底的种类等变量，发现虫胶片的粘接强度与其理化性质密切相关。酸值达标且溶液黏度较高的虫胶片表现出更优的粘接性能，同时具有较高的熔点（T_m）和熔化热焓（ΔH_m）、较低熔程（ΔT_m）的虫胶片通常具有更高的粘接强度。粘接工艺方面，基底表面均匀涂覆单层虫胶漆，并于涂胶后立即完成叠合，可获得最佳粘接性能。此外，粘接材质对虫胶片的固化过程和粘接性能存在显著影响，其中聚甲基丙烯酸甲酯（PMMA）的粘接强度最高（约2.8 MPa），铝片次之（约1.0 MPa），聚醚醚酮（PEEK）最低（约0.5 MPa）。基底经过打磨处理虽能提升粘接强度，但需延长固化时间以达到最佳性能。本文为优化虫胶片粘接工艺和提高其在不同基底上的粘接性能提供了理论依据和实践指导。

【关键词】虫胶片；虫胶片类型；粘接工艺；粘接基底表面状态；粘接性能

汽车内饰用乳液型丙烯酸酯压敏胶的研制

李铭杰，李健雄

（皇冠新材料科技股份有限公司，广东中山  528478）

【摘  要】采用丙烯酸丁酯(BA)、丙烯酸异辛酯（2-EHA)、丙烯酸(AA)、马来酸二丁酯(DBM)和甲基丙烯酸甲酯（MMA)为单体，烯丙基醚磺酸盐为乳化剂，过硫酸钾(KPS)-亚硫酸氢钠氧化还原体系为引发剂，碳酸氢钠为pH调节剂，同时添加复合型润湿剂、缔合型增稠剂、中和剂和松香树脂增黏乳液等，制备了一款高剥离力、抗反弹、低气味和低挥发性有机物（VOC）汽车内饰用乳液型丙烯酸酯压敏胶。采用单因素试验法探讨了反应型乳化剂的用量、引发剂的用量、功能单体的用量、DBM单体的用量和水性松香增黏乳液的用量对乳液型压敏胶180°剥离力和应用性能的影响。研究结果表明：乳化剂用量为单体总质量的2.0%，引发剂用量为单体总质量的0.7%，功能单体用量为单体总质量的2.5%，DBM的用量为单体总质量的2.0%，水性松香增黏乳液加入量为丙烯酸酯乳液质量的10%，乳液型压敏胶的性能相对最优。反应型乳化剂的用量影响乳液聚合过程以及丙烯酸酯聚合物的分子量和分布，功能单体用量影响压敏胶的180°剥离力和乳液聚合的稳定性，适量的DBM单体可以提升乳液型压敏胶的初粘力和抗反弹性能，水性松香增黏乳液可以显著提升乳液型压敏胶的180°剥离力但影响抗反弹性能。制备的胶带产品气味在2.5~3.5级之间，抗反弹性能为A+，乳液型压敏胶满足汽车内饰要求的低气味、低VOC、低释放性气味物质（FOG）的行业标准及应用性能要求。

【关键词】乳液型压敏胶；丙烯酸酯；抗反弹；低气味；低VOC

CTBN/PPE改性环氧胶粘剂的制备及力学性能研究

侯 燕¹，王金朝¹，杨 扬²，陈 涛¹

林新志¹，张红元¹，曾 飞¹

（1.洛阳双瑞橡塑科技有限公司，河南洛阳 471003；2.中铁十七局集团深圳建设有限公司，广东深圳 518000）

【摘 要】针对乙烯-醋酸乙烯共聚物（EVA）泡沫板大厚度和耐海洋环境使用的需求，对环氧胶粘剂进行改性。本文采用端羧基丁腈橡胶（CTBN）和端羟基聚苯醚（PPE）对环氧树脂（EP）进行增韧改性，聚酰胺和聚醚胺为固化剂，研究了CTBN/PPE不同添加量对改性环氧胶粘剂的力学性能和粘接性能的影响，并对其力学性能和凝胶时间进行测定。研究结果表明：CTBN/PPE改性环氧胶粘剂能够明显促进EP的固化。当CTBN/PPE的质量添加量为15%时，改性EP体系的弯曲强度达到最大值62.5 MPa，冲击强度达到最大值19.1 kJ/m²，比未改性的EP体系分别提高了66.4%和65.3%。改性环氧胶粘剂对EVA-EVA板材进行粘接时，均表现出较好的剥离强度和拉剪强度，经过70 ℃人工海水浸泡后仍保持较好的剥离强度；对玻纤-玻纤复合板进行粘接，当CTBN/PPE添加量为15%时，拉剪强度达到了最大值17.2 MPa，比未改性EP的拉剪强度提高了81.2%。

【关键词】环氧胶粘剂；人工海水；粘接性能；力学性能

油箱防护胶低温固化性影响因素的研究

秦  丽，任  飞，李守锋，骆志超

（沈阳帕卡濑精有限总公司，辽宁沈阳 110122）

 【摘  要】油箱防护胶用于汽车油箱表面的防护，起到防腐、减震、降噪的作用。为满足汽车主机厂降低烘烤温度、缩短烘烤时间的要求，本研究通过对油箱防护胶的低温固化性影响因素及有效调整方法进行研究。采用增塑剂（DINP、Mesamoll）复配使用，PVC掺混树脂和氯醋树脂协同作用，制备了油箱防护胶，并进行了涂膜附着性、力学性能及操作性的研究，以期达到低温固化性的要求。研究结果表明：⑴PVC树脂低温塑化性筛选中，氯醋树脂表现最优，其次是PVC糊树脂，最后为PVC掺混树脂。当w(氯醋树脂)=15%时，最终选择w（PVC掺混树脂）=3%，喷涂施工性、涂膜性能相对最优。⑵通过对增塑剂种类和配比的研究，最终选用DINP作为增塑剂、Mesamoll为辅助增塑剂联合使用。初步确定增塑剂复配使用占比30%，其中Mesamoll配比3%~7%。⑶聚酰胺增黏剂在低温固化性方面贡献不明显，当增黏剂配比为1.3%时可以达到很好的附着作用。⑷从经济利益、产品性能综合考虑，选择增塑剂w(Mesamoll)=3%，w(DINP)=27%为最佳配比。

【关键词】油箱防护胶；低温固化性；PVC树脂；增塑剂

高芯片剪切强度的单组分环氧导电银胶的制备及性能研究

杨晓杨^1,2，林泽锋^1,2，伦英慧³

王冬雪^1,2，王  通¹，周迎春^1,2

[1.深圳市计量质量检测研究院技术研发中心，广东深圳 518055；2.国家市场监督管理总局技术创新中心（智能光电传感），广东深圳  518000；3.湖南工学院材料科学与工程学院，湖南衡阳  421002]

【摘  要】本文研究并分析了银粉种类、固化剂种类和添加量以及促进剂种类等重要因素对导电银胶电学和力学性能的影响，评估并分析了导电银胶粘接不同界面的力学性能。最终确定以银粉负载量为80%，双氰胺类固化剂在树脂中添加量为8.3%，促进剂选用复合促进剂，制备了具有较长的室温适用期的单组分导电银胶。研究结果表明：导电银胶具有优异的电学和力学性能，体积电阻率低至1.11×10^-4Ω·cm，粘接Si-Ag、Ni-Ni、Au-Au、Cu-Cu和Ag-Ag界面的芯片剪切强度分别为36.17、33.38、30.22、18.01和11.07 kgf，可与市售进口导电银胶性能相媲美。此外，研究发现可以通过微调导电银胶配方的方法，来改善不同材料界面粘接的力学性能。

【关键词】环氧树脂；导电银胶；芯片剪切强度；体积电阻率；各向同性

轨道车辆挡风玻璃胶粘剂选型研究

赵 辉¹，侯敏俏¹，孙玉英¹

谢静思¹，李 唯¹，耿树江²

(1.中车唐山机车车辆有限公司，河北唐山 063035；2.东北大学，辽宁沈阳 110819）

【摘 要】为解决轨道车辆挡风玻璃胶粘剂选型问题，本研究采用有限元分析方法，对轨道车辆挡风玻璃粘接接头受力进行分析。通过试验测得胶粘剂的力学性能参数，将部分参数用于有限元计算，并对其进行接头分析。研究结果表明：⑴在不同的温湿度条件下，胶粘剂的力学性能随温湿度的提高而呈现减小的趋势。⑵经过43 d的湿热老化后，胶粘剂的剪切强度、拉伸强度均有损失，但是，湿热老化和疲劳老化后剩余的强度均大于80%。在复杂环境下，胶粘剂具有良好的抗湿热、抗疲劳性能。但是，在经过10⁷次疲劳老化后，胶粘剂的剪切强度下降到原有强度的6.4%，强度明显下降。⑶随着UV老化时间的增加，拉伸强度、断裂拉伸强度、断裂伸长率的总体变化趋势不明显，证明胶粘剂抗紫外性能优良。⑷综合有限元计算，在12种静强度工况和2种疲劳强度工况下，胶粘剂均满足使用要求。

【关键词】挡风玻璃；胶粘剂；有限元；试验

高压电缆平滑铝粘接护层用热熔胶的材料选型与关键性能研究

周  宏¹，陈嘉威¹，李垠阅²，王  涌²，刘  英²

（1.国网上海市电力公司电缆分公司，上海  200072；2.西安交通大学电气工程学院，陕西西安  710049）

【摘  要】平滑铝套高压交联聚乙烯（XLPE）电缆是国内近期发展热点，其机械性能在很大程度上取决于铝护套与外护套是否牢固粘接，因此，针对粘接护层中的实际应用需求开展热熔胶的关键性能及选型策略研究是当下的一项重要工作。首先通过测试并比较多种不同化学体系的热熔胶在粘接铝片和聚乙烯试片时的强度大小，筛选出适用于平滑铝粘接护层的热熔胶体系，即聚乙烯（PE）基热熔胶。之后，针对两种粘接强度较高的PE基热熔胶，分析了基本成分，测试了结晶度、熔融温度及老化性能，讨论了两种热熔胶的性能差异及主要原因。在此基础上，建立了四点弯曲仿真模型，研究了电缆弯曲条件下热熔胶层的损伤特性，分析了弹性模量的影响以及粘接强度的要求，提出了平滑铝粘接护层用热熔胶的基本选型策略。研究结果表明：PE热熔胶在粘接平滑铝与聚乙烯外护套时表现出良好的基本性能；PE热熔胶经90 ℃老化后粘接强度提高，但130 ℃老化后性能劣化明显；相同条件下，对于弹性模量较大的热熔胶，要求其剪切强度更高，以弹性模量200 MPa为界，剪切强度应分别不低于2.0和4.0 MPa；剥离强度对于热熔胶层的累积损伤影响较小，建议取值为不低于0.5 N/mm。

【关键词】平滑铝护套；热熔胶；粘接强度；老化性能

纤维素醚和乳胶粉对水泥基材料的改性及对性能的影响试验

刘浩研¹，刘  聪²

（1.九州职业技术学院建筑工程与设计学院，江苏徐州  221116；2.徐州市非物质文化遗产展示馆，户部山明清建筑保护中心，江苏徐州  221018）

【摘  要】为提高水泥基修补材料的耐久性能，提出用纤维素醚和乳胶粉对水泥基材料进行改性。添加粉煤灰、矿渣、硝酸盐早强剂等，优化配比，以期得到一种耐久性更好的水泥基建筑修补加固材料。对其流动性、凝结时间、力学性能等进行表征。研究结果表明：当羟丙基甲基纤维素醚用量为0.3%，可再分散乳胶粉用量为5%，粉煤灰用量为10%，矿渣用量为3%，硝酸盐早强剂用量为1.5%时，制备的水泥基材料性能最佳。此时水泥砂浆的流动度为165 mm，坍落度为170 mm，凝结时间为30 min，粘接强度为4.7 MPa，28 d干收缩率为3.71×10^-2%，满足建筑材料修补要求，可以作为建筑加固修补材料使用。

【关键词】水泥基材料；修补材料；力学性能；粘接强度；耐久性

香草醛衍生含硅烯类单体合成及改性环氧树脂研究

魏  莉，索军营，陈心怡，周勋

[成都飞机工业（集团）有限责任公司，四川成都  610091]

【摘要】为了克服环氧树脂固化后因交联密度过大而导致的脆性问题，本文设计合成了一种香草醛衍生的含硅烯丙基生物基改性剂，来提升环氧树脂的韧性。以KH-550和香草醛衍生的烯类化合物（AM）为反应原料，合成了含硅烯丙基化合物（AMTPM）。分别采用傅里叶红外光谱仪（FT-IR）和核磁共振氢谱仪（¹H-NMR）对AMTPM的化学结构进行了表征，同时研究了AMTPM不同添加量对环氧树脂性能的影响。研究结果表明：通过AMTPM与环氧树脂进行熔融共混，制备了不同AMTPM含量的改性E-AMTPM树脂，AMTPM树脂可以降低环氧树脂的固化温度；AMTPM的添加，提高了E-AMTPM树脂的残碳率，使固化后树脂的交联密度降低，从而改善了树脂的韧性；E-AMTPM树脂具有更大的延展性，因此拉伸剪切强度得到较大提升。

【关键词】环氧树脂共聚改性；固化行为；热机械性能；剪切强度

Application and development of adhesive in micro speaker

Cheng Zhenzhen, Wang Hairong, Tan Caihua, Zhang Zenghui,

Wang Mengmei, Liu Chunli, Zhou Houqiang, Li Chun

(Goertek Inc., Weifang 261000, Shandong, China)

【Abstract】Micro speaker is widely used in electronic products, especially in daily applications such as mobile phones, watches, headphones, and VR.One of the most important assembly methods for micro speaker is bonding, and the role of adhesive is crucial. A comprehensive overview of commonly used adhesive for micro speaker was provided in this article, such as UV cured adhesive, instant adhesive, modified silicone adhesive, anaerobic adhesive, and reactive hot melt adhesive, as well as common bonding applications, including bonding between the dome and diaphragm, the dome and voice coil, the diaphragm and frame, the magnet and basin holder, the basin holder and frame, the individual unit and module, and the upper and lower shells. The development trend of adhesive for micro speaker was also discussed.

【Keywords】micro speaker; adhesive; assembly; application

Research on the influence of shellac flake type and surface state of bonding substrate on bonding strength and its fluctuation

Xie Yujie^1,2, Pan Xiaolei¹,Wu Yeping¹, Li Gaoming¹, Gu Yunsong²,Zhao Xiuli¹, Zhang Ping², Zhang Yinyu¹

（1.Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang  621900, Sichuan, China; 2.School of Materials and Chemistry, Southwest University of Science and Technology, Mianyang  621010, Sichuan, China）

【Abstract】Shellac flakes, as natural adhesive, have received significant attention due to their ease of application and favorable mechanical properties. However, the performance of raw shellac is easily affected by climate and variety, and there is currently a lack of research on bonding processes for plastic and metal substrates, resulting in significant fluctuations in bonding strength and affecting the reliability of bonding connections. It was found in this article that the bonding strength of shellac flakes was closely related to their physical and chemical properties by changing variables such as the type of shellac flakes, the effective period of shellac-ethanol solution (shellac paint) preparation, the drying time, and the type of bonding substrate. Shellac flakes that met the acid value standard and had higher solution viscosity exhibited better bonding performance, while shellac flakes with higher melting points (T_m) and melting enthalpy (ΔH_m), as well as lower melting ranges (ΔT_m) typically had higher bonding strength. In terms of bonding process, the substrate surface was uniformly coated with a single layer of shellac paint, and the lamination was completed immediately after bonding to achieve the best bonding performance. In addition, the bonding material had a significant impact on the curing process and bonding performance of shellac flakes, with polymethyl methacrylate (PMMA) having the highest bonding strength (about 2.8 MPa), followed by aluminum sheet (about 1.0 MPa), and polyether ether ketone (PEEK) having the lowest (about 0.5 MPa). Although polishing the substrate could improve the bonding strength, it was necessary to extend the curing time to achieve optimal performance. This article provided theoretical basis and practical guidance for optimizing the bonding process of shellac flakes and improving their bonding performance on different substrates.

【Keywords】shellac flake; shellac flake type; bonding process; surface state of bonding substrate; bonding performance

Development of emulsion-type acrylate pressure sensitive adhesive for automotive interior trim

Li Mingjie, Li Jianxiong

（Crown New Materials Technology Co., Ltd., Zhongshan  528478, Guangdong, China）

【Abstract】Using butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA), dibutyl maleate (DBM), and methyl methacrylate (MMA) as monomers, allyl ether sulfonate as emulsifier, potassium persulfate (KPS)-sodium bisulfite redox system as initiator, and sodium bicarbonate as pH regulator, and adding composite wetting agent, associative thickener, neutralizer and rosin resin tackifying emulsion, a kind of emulsion-type acrylate pressure sensitive adhesive with high peel strength, anti-rebound, low odor and low volatile organic compound (VOC) for automotive interior trim was prepared. The effects of the amount of reactive emulsifier, initiator, functional monomer, DBM monomer and waterborne rosin tackifying emulsion on the 180° peel strength and application performance of emulsion-type pressure sensitive adhesive were investigated by single factor test. The research results showed that, the amount of emulsifier was 2.0% of the total mass of monomer, the amount of initiator was 0.7% of the total mass of monomer, the amount of functional monomer was 2.5% of the total mass of monomer, the amount of DBM was 2.0% of the total mass of monomer, the amount of water-borne rosin tackifying emulsion was 10% of the mass of acrylate emulsion, the performance of emulsion-type pressure sensitive adhesive was relatively optimal. The amount of reactive emulsifier affected the emulsion polymerization process as well as the molecular weight and distribution of acrylate polymer. The amount of functional monomer affected the 180° peel force of pressure sensitive adhesive and the stability of emulsion polymerization. An appropriate amount of DBM monomer could improve the initial tack and anti rebound performance of emulsion-type pressure sensitive adhesive. The waterborne rosin tackifying emulsion could significantly improve the 180° peel force of emulsion-type pressure sensitive adhesive, but affected the anti rebound performance.The smell of the prepared tape product was between 2.5 and 3.5 levels, and the anti rebound performance was A+. The emulsion-type pressure sensitive adhesive met the industry standard and application performance requirements of low odor, low VOC, and low release odor substance (FOG) required for automotive interior trim.

【Keywords】emulsion-type pressure sensitive adhesive; acrylate; anti rebound; low odor; low VOC

Preparation and mechanical properties of epoxy adhesive modified by CTBN/PPE

Hou Yan¹,Wang Jinzhao¹, Yang Yang²,Chen Tao¹, Lin Xinzhi¹, Zhang Hongyuan¹, Zeng Fei¹

（1.Luoyang Sunrui Rubber & Plastic Science and Technology Co., Ltd., Luoyang 471003, Henan, China; 2.China Railway 17th Bureau Group Shenzhen Construction Co., Ltd., Shenzhen  518000, Guangdong, China)

【Abstract】The epoxy adhesive was modified to meet the requirements of ethylene-vinyl acetate copolymer (EVA) foam board for large thickness and marine environment resistance.In this paper, carboxyl terminated nitrile rubber (CTBN) and hydroxyl terminated polyphenylene ether (PPE) were used to toughen epoxy resin (EP). Polyamide and polyether amine were used as curing agents. The effects of different addition amounts of CTBN/PPE on the mechanical properties and bonding properties of modified epoxy adhesive were studied, and its mechanical properties and gel time were measured. The research results showed that CTBN/PPE modified epoxy adhesive could significantly promote the curing of EP. When the mass addition of CTBN/PPE was 15%, the flexural strength of modified EP system reached its maximum value of 62.5 MPa, and the impact strength reached its maximum value of 19.1 kJ/m², which was 66.4% and 65.3% higher than the unmodified EP system, respectively. When modified epoxy adhesive was used to bond EVA-EVA boards, it exhibited good peel strength and tensile shear strength, and maintained good peel strength even after immersion in artificial seawater at 70 ℃. When bonding the fiberglass-fiberglass composite panels, the tensile shear strength reached its maximum value of 17.2 MPa when the CTBN/PPE addition amount was 15%, which was 81.2% higher than the tensile shear strength of unmodified EP.

【Keywords】epoxy adhesive;artificial seawater; bonding property; mechanical property

Study on influencing factors of low temperature curing of fuel tank protective adhesive

Qin Li, Ren Fei, Li Shoufeng, Luo Zhichao

(Shenyang Parkerizing Co., Ltd., Shenyang 110122, Liaoning, China)

【Abstract】Fuel tank protective adhesive is used to protect the surface of car fuel tanks, playing a role in corrosion prevention, shock absorption, and noise reduction. In order to meet the requirements of automobile manufacturers to reduce baking temperature and shorten baking time, the factors affecting the low temperature curing of fuel tank protective adhesive and effective adjustment methods were investigated in this study. A fuel tank protective adhesive was prepared by compounding plasticizers (DINP, Mesamoll) and synergistically mixing PVC blended resin with vinyl chloride-acetate copolymer. The adhesion, mechanical properties, and operability of the coating film were studied to meet the requirements of low temperature curing. The research results showed that, ⑴In the low temperature plasticization screening of PVC resin, vinyl chloride-acetate copolymer performed the best, followed by PVC paste resin, and finally PVC blended resin. When w(vinyl chloride-acetate copolymer)=15%, the final choice of w(PVC blended resin)=3% resulted in relatively optimal spraying application and coating performance. ⑵ After studying the types and ratios of plasticizers, DINP was ultimately selected as the plasticizer and Mesamoll was used in combination as the auxiliary plasticizer. It has been preliminarily determined that the proportion of plasticizer compound used was 30%, with Mesamoll ratio ranging from 3% to 7%. ⑶ The contribution of polyamide tackifier in low temperature curing was not significant, but good adhesion could be achieved when the proportion of tackifier was 1.3%. ⑷ Considering both economic benefits and product performance, the optimal ratio for plasticizer w(Mesamoll) was 3% and w(DINP) was 27%.

【Keywords】fuel tank protective adhesive; low temperature curing; PVC resin; plasticizer

Preparation and performance study of one-component epoxy conductive silver adhesive with high chip shear strength

Yang Xiaoyang^1,2, Lin Zefeng^1,2,Lun Yinghui³, Wang Dongxue^1,2, Wang Tong¹,Zhou Yingchun^1,2

(1. Technology Research and Development Centre, Shenzhen Academy of Metrology & Quality Inspection, Shenzhen 518055, Guangdong, China; 2. Technology Innovation Center of Intelligent Opto-Electronic Sensing, State Administration for Market Regulation, Shenzhen  518000, Guangdong, China; 3. School of Materials Science and Engineering, Hunan Institute of Technology, Hengyang  421002, Hunan, China)

【Abstract】The influence of important factors such as silver powder type, curing agent type and dosage, and accelerator type on the electrical and mechanical properties of conductive silver adhesive was studied and analyzed in this article, and the mechanical properties of conductive silver adhesive bonding at different interfaces were evaluated and analyzed. Finally, the one-component conductive silver adhesive with the long room temperature applicability period was prepared with the silver powder loading of 80%, the melamine curing agent added to the resin of 8.3%, and the composite promoter selected. The research results showed that, the conductive silver adhesive had excellent electrical and mechanical properties, with the volume resistivity as low as 1.11×10^-4 Ω•cm. The chip shear strength for bonding Si-Ag, Ni-Ni, Au-Au, Cu-Cu, and Ag-Ag interfaces was 36.17, 33.38, 30.22, 18.01, and 11.07 kgf, respectively, which was comparable to the performance of commercially available imported conductive silver adhesive. In addition, it has found that the mechanical properties of interface bonding between different materials could be improved by fine-tuning the conductive silver adhesive formula.

【Keywords】epoxy resin; conductive silver adhesive; chip shear strength; volume resistivity; isotropic

Adhesive selection for windscreen of railway vehicle

Zhao Hui¹, Hou Minqiao¹, Sun Yuying¹, Xie Jingsi¹, Li Wei¹, Geng Shujiang²

（1.CRRC Tangshan Co., Ltd., Tangshan  063035, Hebei, China;

2.Northeastern University, Shenyang 110819, Liaoning, China）

【Abstract】To solve the problem of selecting adhesive for the windscreen of railway vehicle, finite element analysis method was adopted in this study to analyze the force on the adhesive joint of the windscreen of rail vehicle. The mechanical performance parameters of the adhesive were measured through experiments, and some of the parameters were used for finite element calculations, which were subjected to joint analysis. The research results showed that, ⑴Under different temperature and humidity conditions, the mechanical properties of adhesive showed a decreasing trend with the increase of temperature and humidity. ⑵ After 43 days of hydrothermal aging, both the shear strength and tensile strength of the adhesive were lost, but the remaining strength after hydrothermal aging and fatigue aging was greater than 80%. In complex environments, adhesive had good resistance to moisture and fatigue. However, after 10⁷ cycles of fatigue aging, the shear strength of the adhesive decreased to 6.4% of its original strength, indicating a significant decrease in strength. ⑶ With the increase of UV aging time, the overall trend of changes in tensile strength, tensile strength at break, and elongation at break was not significant, indicating that the adhesive had excellent UV resistance. ⑷ Based on comprehensive finite element calculations, the adhesive met the application requirements under 12 static strength working conditions and 2 fatigue strength working conditions.

【Keywords】windscreen; adhesive; finite element; test

Study on material selection and key properties of hot melt adhesive for smooth aluminum bonding protective layer of high-voltage cable

Zhou Hong¹, Chen Jiawei¹, Li Yinyue², Wang Yong²,Liu Ying²

(1. State Grid Shanghai Electric Power Company Cable Branch, Shanghai200072, China;

2. School of Electrical Engineering, Xi’an Jiaotong University, Xi’an710049, Shaanxi, China))

【Abstract】High-voltage cross-linked polyethylene (XLPE) cable with smooth aluminum sheath is a recent development hotspot in China, and its mechanical properties largely depend on whether the aluminum sheath and the outer sheath are firmly bonded. Therefore, conducting research on the key properties and selection strategies of hot melt adhesive for practical application needs in adhesive protective layer is an important task at present. Firstly, by testing and comparing the strength of various hot melt adhesive with different chemical systems when bonding aluminum sheets and polyethylene test pieces, a hot melt adhesive system suitable for smooth aluminum bonding sheath, namely polyethylene (PE) based hot melt adhesive, was selected. Afterwards, the basic components of two kinds of PE based hot melt adhesive with high bonding strength were analyzed, and crystallinity, melting temperature, and aging properties were tested. The performance differences and main reasons of two kinds of hot melt adhesive were discussed. On this basis, a four point bending simulation model was established to study the damage characteristics of hot melt adhesive layer under cable bending conditions. The influence of elastic modulus and the requirements for bonding strength were analyzed, and a basic selection strategy for hot melt adhesive for smooth aluminum bonding sheath was proposed. The research results showed that PE based hot melt adhesive exhibited good basic performance in bonding smooth aluminum and polyethylene outer sheath. After aging at 90 ℃, the bonding strength of PE hot melt adhesive increased, but the performance deteriorated significantly after aging at 130 ℃. Under the same conditions, for hot melt adhesive with higher elastic modulus, higher shear strength was required. With an elastic modulus of 200 MPa as the boundary, the shear strength should not be lower than 2.0 MPa and 4.0 MPa, respectively. The peel strength had a relatively small impact on the cumulative damage of hot melt adhesive layer, and it was recommended to take a value of not less than 0.5 N/mm.

【Keywords】smooth aluminum sheath; hot melt adhesive; bonding strength; aging property

Experimental study on the modification of cement-based materials by cellulose ether and latex powder and their effects on properties

Liu Haoyan¹, Liu Cong²

（1.College of Architecture and Design, Jiuzhou Polytechnic, Xuzhou 221116, Jiangsu, China; 2. Xuzhou Intangible Cultural Heritage Museum, Hubushan Ming and Qing Architecture Protection Center, Xuzhou  221018, Jiangsu, China)

【Abstract】In order to improve the durability of cement-based repair materials, it was proposed to modify cement-based materials with cellulose ether and latex powder. Adding fly ash, slag, nitrate-based early strength admixture, and optimizing the ratio, in order to obtain a more durable cement-based building repair and reinforcement material. Its fluidity, setting time, mechanical properties, etc. were characterized. The research results showed that, when the dosage of hydroxypropyl methyl cellulose ether was 0.3%, the dosage of redispersible latex powder was 5%, the dosage of fly ash was 10%, the dosage of slag was 3%, and the dosage of nitrate-based early strength admixture was 1.5%, the performance of the prepared cement-based material was optimal. At this time, the fluidity of cement mortar was 165 mm, the slump was 170 mm, the setting time was 30 minutes, the bonding strength was 4.7 MPa, and the 28-days dry shrinkage rate was 3.71×10^-2%, which met the requirements of building material repair and could be used as building reinforcement and repair materials.

【Keywords】cement-based material; repair material; mechanical property; bonding strength; durability

Synthesis of vanillin-derived silicone-containing allyl monomer and its modification on epoxy resin

Wei Li, Suo Junying, Chen Xinyi, Zhou Xun

[Chengdu Aircraft Industrial (Group) Co., Ltd., Chengdu 610091, Sichuan, China]

【Abstract】In order to overcome the brittleness problem caused by excessive cross-linking density after curing of epoxy resin, a silicone-containing allyl biobased modifier derived from vanillin was designed and synthesized in this paper, to enhance the toughness of epoxy resin. Silicone-containing allyl compounds (AMTPM) were synthesized by using KH-550 and vanillin-derived alkene compounds (AM) as reaction materials. The chemical structure of AMTPM was characterized by using Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectroscopy (¹H-NMR), and the effects of different amounts of AMTPM on the properties of epoxy resin were studied. The research results showed that modified E-AMTPM resins with different AMTPM contents were prepared by melt blending AMTPM with epoxy resin. AMTPM resins could lower the curing temperature of epoxy resin. The addition of AMTPM increased the residual carbon rate of E-AMTPM resin, reduced the crosslinking density of the cured resin, and thus improved the toughness of the resin. E-AMTPM resin had greater ductility, resulting in a significant improvement in tensile shear strength.

【Keywords】epoxy resin copolymerization modification; solidification behavior; thermal mechanical property; shear strength