膠粘劑在微型揚聲器中的應用及發展

程真真，王海榮，談彩花，張增輝

王夢媚，劉春利，周厚強，李 春

（歌爾股份有限公司，山東濰坊  261000）

【摘 要】微型揚聲器在電子產品中，特別是在日常應用中非常廣泛，比如手機、手表、耳機和VR等。微型揚聲器最重要的組裝方式之一就是粘接，膠粘劑的作用舉足輕重。本文綜述性地介紹了微型揚聲器常用的膠粘劑，比如紫外線固化膠、瞬干膠、改性硅膠、厭氧膠以及反應型熱熔膠等，以及常見的粘接應用，包括球頂和振膜的粘接、球頂和音圈的粘接、振膜和邊框的粘接、磁鐵和盆架的粘接、盆架和邊框的粘接、單體與模組的粘接以及上下殼粘接等，并對微型揚聲器用膠粘劑的發展趨勢進行了展望。

【關鍵詞】微型揚聲器；膠粘劑；組裝；應用

蟲膠片類型與粘接基底表面狀態對粘接強度及其波動性的影響研究

謝鈺潔^1,2，潘曉磊¹，吳冶平¹，李高明¹

古云松²，趙秀麗¹，張  平²，張銀宇¹

（1.中國工程物理研究院化工材料研究所，四川綿陽  621900；2.西南科技大學材料與化學學院，四川綿陽  621010）

【摘  要】蟲膠片作為一種天然膠粘劑，因其施工便捷、力學性能較好而受到廣泛關注。然而，蟲膠原膠的性能易受氣候、品種的影響，且目前缺乏針對塑料和金屬基底的粘接工藝研究，導致其粘接強度波動性較大，進而影響粘接連接的可靠性。本文通過改變蟲膠片類型、蟲膠-乙醇溶液（蟲膠漆）配制有效期、晾置時間以及粘接基底的種類等變量，發現蟲膠片的粘接強度與其理化性質密切相關。酸值達標且溶液黏度較高的蟲膠片表現出更優的粘接性能，同時具有較高的熔點（T_m）和熔化熱焓（ΔH_m）、較低熔程（ΔT_m）的蟲膠片通常具有更高的粘接強度。粘接工藝方面，基底表面均勻涂覆單層蟲膠漆，并于涂膠后立即完成疊合，可獲得最佳粘接性能。此外，粘接材質對蟲膠片的固化過程和粘接性能存在顯著影響，其中聚甲基丙烯酸甲酯（PMMA）的粘接強度最高（約2.8 MPa），鋁片次之（約1.0 MPa），聚醚醚酮（PEEK）最低（約0.5 MPa）。基底經過打磨處理雖能提升粘接強度，但需延長固化時間以達到最佳性能。本文為優化蟲膠片粘接工藝和提高其在不同基底上的粘接性能提供了理論依據和實踐指導。

【關鍵詞】蟲膠片；蟲膠片類型；粘接工藝；粘接基底表面狀態；粘接性能

汽車內飾用乳液型丙烯酸酯壓敏膠的研制

李銘杰，李健雄

（皇冠新材料科技股份有限公司，廣東中山  528478）

【摘  要】采用丙烯酸丁酯(BA)、丙烯酸異辛酯（2-EHA)、丙烯酸(AA)、馬來酸二丁酯(DBM)和甲基丙烯酸甲酯（MMA)為單體，烯丙基醚磺酸鹽為乳化劑，過硫酸鉀(KPS)-亞硫酸氫鈉氧化還原體系為引發劑，碳酸氫鈉為pH調節劑，同時添加復合型潤濕劑、締合型增稠劑、中和劑和松香樹脂增黏乳液等，制備了一款高剝離力、抗反彈、低氣味和低揮發性有機物（VOC）汽車內飾用乳液型丙烯酸酯壓敏膠。采用單因素試驗法探討了反應型乳化劑的用量、引發劑的用量、功能單體的用量、DBM單體的用量和水性松香增黏乳液的用量對乳液型壓敏膠180°剝離力和應用性能的影響。研究結果表明：乳化劑用量為單體總質量的2.0%，引發劑用量為單體總質量的0.7%，功能單體用量為單體總質量的2.5%，DBM的用量為單體總質量的2.0%，水性松香增黏乳液加入量為丙烯酸酯乳液質量的10%，乳液型壓敏膠的性能相對最優。反應型乳化劑的用量影響乳液聚合過程以及丙烯酸酯聚合物的分子量和分布，功能單體用量影響壓敏膠的180°剝離力和乳液聚合的穩定性，適量的DBM單體可以提升乳液型壓敏膠的初粘力和抗反彈性能，水性松香增黏乳液可以顯著提升乳液型壓敏膠的180°剝離力但影響抗反彈性能。制備的膠帶產品氣味在2.5~3.5級之間，抗反彈性能為A+，乳液型壓敏膠滿足汽車內飾要求的低氣味、低VOC、低釋放性氣味物質（FOG）的行業標準及應用性能要求。

【關鍵詞】乳液型壓敏膠；丙烯酸酯；抗反彈；低氣味；低VOC

CTBN/PPE改性環氧膠粘劑的制備及力學性能研究

侯 燕¹，王金朝¹，楊 揚²，陳 濤¹

林新志¹，張紅元¹，曾 飛¹

（1.洛陽雙瑞橡塑科技有限公司，河南洛陽 471003；2.中鐵十七局集團深圳建設有限公司，廣東深圳 518000）

【摘 要】針對乙烯-醋酸乙烯共聚物（EVA）泡沫板大厚度和耐海洋環境使用的需求，對環氧膠粘劑進行改性。本文采用端羧基丁腈橡膠（CTBN）和端羥基聚苯醚（PPE）對環氧樹脂（EP）進行增韌改性，聚酰胺和聚醚胺為固化劑，研究了CTBN/PPE不同添加量對改性環氧膠粘劑的力學性能和粘接性能的影響，并對其力學性能和凝膠時間進行測定。研究結果表明：CTBN/PPE改性環氧膠粘劑能夠明顯促進EP的固化。當CTBN/PPE的質量添加量為15%時，改性EP體系的彎曲強度達到最大值62.5 MPa，沖擊強度達到最大值19.1 kJ/m²，比未改性的EP體系分別提高了66.4%和65.3%。改性環氧膠粘劑對EVA-EVA板材進行粘接時，均表現出較好的剝離強度和拉剪強度，經過70 ℃人工海水浸泡后仍保持較好的剝離強度；對玻纖-玻纖復合板進行粘接，當CTBN/PPE添加量為15%時，拉剪強度達到了最大值17.2 MPa，比未改性EP的拉剪強度提高了81.2%。

【關鍵詞】環氧膠粘劑；人工海水；粘接性能；力學性能

油箱防護膠低溫固化性影響因素的研究

秦  麗，任  飛，李守鋒，駱志超

（沈陽帕卡瀨精有限總公司，遼寧沈陽 110122）

 【摘  要】油箱防護膠用于汽車油箱表面的防護，起到防腐、減震、降噪的作用。為滿足汽車主機廠降低烘烤溫度、縮短烘烤時間的要求，本研究通過對油箱防護膠的低溫固化性影響因素及有效調整方法進行研究。采用增塑劑（DINP、Mesamoll）復配使用，PVC摻混樹脂和氯醋樹脂協同作用，制備了油箱防護膠，并進行了涂膜附著性、力學性能及操作性的研究，以期達到低溫固化性的要求。研究結果表明：⑴PVC樹脂低溫塑化性篩選中，氯醋樹脂表現最優，其次是PVC糊樹脂，最后為PVC摻混樹脂。當w(氯醋樹脂)=15%時，最終選擇w（PVC摻混樹脂）=3%，噴涂施工性、涂膜性能相對最優。⑵通過對增塑劑種類和配比的研究，最終選用DINP作為增塑劑、Mesamoll為輔助增塑劑聯合使用。初步確定增塑劑復配使用占比30%，其中Mesamoll配比3%~7%。⑶聚酰胺增黏劑在低溫固化性方面貢獻不明顯，當增黏劑配比為1.3%時可以達到很好的附著作用。⑷從經濟利益、產品性能綜合考慮，選擇增塑劑w(Mesamoll)=3%，w(DINP)=27%為最佳配比。

【關鍵詞】油箱防護膠；低溫固化性；PVC樹脂；增塑劑

高芯片剪切強度的單組分環氧導電銀膠的制備及性能研究

楊曉楊^1,2，林澤鋒^1,2，倫英慧³

王冬雪^1,2，王  通¹，周迎春^1,2

[1.深圳市計量質量檢測研究院技術研發中心，廣東深圳 518055；2.國家市場監督管理總局技術創新中心（智能光電傳感），廣東深圳  518000；3.湖南工學院材料科學與工程學院，湖南衡陽  421002]

【摘  要】本文研究并分析了銀粉種類、固化劑種類和添加量以及促進劑種類等重要因素對導電銀膠電學和力學性能的影響，評估并分析了導電銀膠粘接不同界面的力學性能。最終確定以銀粉負載量為80%，雙氰胺類固化劑在樹脂中添加量為8.3%，促進劑選用復合促進劑，制備了具有較長的室溫適用期的單組分導電銀膠。研究結果表明：導電銀膠具有優異的電學和力學性能，體積電阻率低至1.11×10^-4Ω·cm，粘接Si-Ag、Ni-Ni、Au-Au、Cu-Cu和Ag-Ag界面的芯片剪切強度分別為36.17、33.38、30.22、18.01和11.07 kgf，可與市售進口導電銀膠性能相媲美。此外，研究發現可以通過微調導電銀膠配方的方法，來改善不同材料界面粘接的力學性能。

【關鍵詞】環氧樹脂；導電銀膠；芯片剪切強度；體積電阻率；各向同性

軌道車輛擋風玻璃膠粘劑選型研究

趙 輝¹，侯敏俏¹，孫玉英¹

謝靜思¹，李 唯¹，耿樹江²

(1.中車唐山機車車輛有限公司，河北唐山 063035；2.東北大學，遼寧沈陽 110819）

【摘 要】為解決軌道車輛擋風玻璃膠粘劑選型問題，本研究采用有限元分析方法，對軌道車輛擋風玻璃粘接接頭受力進行分析。通過試驗測得膠粘劑的力學性能參數，將部分參數用于有限元計算，并對其進行接頭分析。研究結果表明：⑴在不同的溫濕度條件下，膠粘劑的力學性能隨溫濕度的提高而呈現減小的趨勢。⑵經過43 d的濕熱老化后，膠粘劑的剪切強度、拉伸強度均有損失，但是，濕熱老化和疲勞老化后剩余的強度均大于80%。在復雜環境下，膠粘劑具有良好的抗濕熱、抗疲勞性能。但是，在經過10⁷次疲勞老化后，膠粘劑的剪切強度下降到原有強度的6.4%，強度明顯下降。⑶隨著UV老化時間的增加，拉伸強度、斷裂拉伸強度、斷裂伸長率的總體變化趨勢不明顯，證明膠粘劑抗紫外性能優良。⑷綜合有限元計算，在12種靜強度工況和2種疲勞強度工況下，膠粘劑均滿足使用要求。

【關鍵詞】擋風玻璃；膠粘劑；有限元；試驗

高壓電纜平滑鋁粘接護層用熱熔膠的材料選型與關鍵性能研究

周  宏¹，陳嘉威¹，李垠閱²，王  涌²，劉  英²

（1.國網上海市電力公司電纜分公司，上海  200072；2.西安交通大學電氣工程學院，陜西西安  710049）

【摘  要】平滑鋁套高壓交聯聚乙烯（XLPE）電纜是國內近期發展熱點，其機械性能在很大程度上取決于鋁護套與外護套是否牢固粘接，因此，針對粘接護層中的實際應用需求開展熱熔膠的關鍵性能及選型策略研究是當下的一項重要工作。首先通過測試并比較多種不同化學體系的熱熔膠在粘接鋁片和聚乙烯試片時的強度大小，篩選出適用于平滑鋁粘接護層的熱熔膠體系，即聚乙烯（PE）基熱熔膠。之后，針對兩種粘接強度較高的PE基熱熔膠，分析了基本成分，測試了結晶度、熔融溫度及老化性能，討論了兩種熱熔膠的性能差異及主要原因。在此基礎上，建立了四點彎曲仿真模型，研究了電纜彎曲條件下熱熔膠層的損傷特性，分析了彈性模量的影響以及粘接強度的要求，提出了平滑鋁粘接護層用熱熔膠的基本選型策略。研究結果表明：PE熱熔膠在粘接平滑鋁與聚乙烯外護套時表現出良好的基本性能；PE熱熔膠經90 ℃老化后粘接強度提高，但130 ℃老化后性能劣化明顯；相同條件下，對于彈性模量較大的熱熔膠，要求其剪切強度更高，以彈性模量200 MPa為界，剪切強度應分別不低于2.0和4.0 MPa；剝離強度對于熱熔膠層的累積損傷影響較小，建議取值為不低于0.5 N/mm。

【關鍵詞】平滑鋁護套；熱熔膠；粘接強度；老化性能

纖維素醚和乳膠粉對水泥基材料的改性及對性能的影響試驗

劉浩研¹，劉  聰²

（1.九州職業技術學院建筑工程與設計學院，江蘇徐州  221116；2.徐州市非物質文化遺產展示館，戶部山明清建筑保護中心，江蘇徐州  221018）

【摘  要】為提高水泥基修補材料的耐久性能，提出用纖維素醚和乳膠粉對水泥基材料進行改性。添加粉煤灰、礦渣、硝酸鹽早強劑等，優化配比，以期得到一種耐久性更好的水泥基建筑修補加固材料。對其流動性、凝結時間、力學性能等進行表征。研究結果表明：當羥丙基甲基纖維素醚用量為0.3%，可再分散乳膠粉用量為5%，粉煤灰用量為10%，礦渣用量為3%，硝酸鹽早強劑用量為1.5%時，制備的水泥基材料性能最佳。此時水泥砂漿的流動度為165 mm，坍落度為170 mm，凝結時間為30 min，粘接強度為4.7 MPa，28 d干收縮率為3.71×10^-2%，滿足建筑材料修補要求，可以作為建筑加固修補材料使用。

【關鍵詞】水泥基材料；修補材料；力學性能；粘接強度；耐久性

香草醛衍生含硅烯類單體合成及改性環氧樹脂研究

魏  莉，索軍營，陳心怡，周勛

[成都飛機工業（集團）有限責任公司，四川成都  610091]

【摘要】為了克服環氧樹脂固化后因交聯密度過大而導致的脆性問題，本文設計合成了一種香草醛衍生的含硅烯丙基生物基改性劑，來提升環氧樹脂的韌性。以KH-550和香草醛衍生的烯類化合物（AM）為反應原料，合成了含硅烯丙基化合物（AMTPM）。分別采用傅里葉紅外光譜儀（FT-IR）和核磁共振氫譜儀（¹H-NMR）對AMTPM的化學結構進行了表征，同時研究了AMTPM不同添加量對環氧樹脂性能的影響。研究結果表明：通過AMTPM與環氧樹脂進行熔融共混，制備了不同AMTPM含量的改性E-AMTPM樹脂，AMTPM樹脂可以降低環氧樹脂的固化溫度；AMTPM的添加，提高了E-AMTPM樹脂的殘碳率，使固化后樹脂的交聯密度降低，從而改善了樹脂的韌性；E-AMTPM樹脂具有更大的延展性，因此拉伸剪切強度得到較大提升。

【關鍵詞】環氧樹脂共聚改性；固化行為；熱機械性能；剪切強度

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