Adhesive for amorphous strip and preparation method thereof

Abstract

The invention discloses an adhesive for an amorphous strip and a preparation method of the adhesive, and relates to the field of adhesives. The invention discloses an adhesive for an amorphous strip. The adhesive comprises the following raw materials in parts by weight: 55-65 parts of epoxy resin; 15-23 parts of an episulfide epoxy resin; 8 to 15 parts of alkyl glycidyl ether with 12 to 14 carbon atoms; 3-7 parts of calcium carbonate powder; 0.8 to 1.5 parts of a titanate coupling agent; 2-5 parts of a thermal curing agent; the epoxy resin is prepared from bisphenol F type epoxy resin and episulfide epoxy resin through a reaction of bisphenol A type epoxy resin and potassium thiocyanate. The adhesive provided by the invention has good bonding strength, thermal stability and excellent water resistance to the amorphous strip, can meet the high-temperature and high-humidity environment requirements of the amorphous strip, and does not affect the soft magnetic performance of the amorphous strip.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and more particularly to an adhesive for amorphous strips and a method for preparing the same. Background Technology

[0002] Amorphous ribbons are metallic materials with a non-static structure, typically prepared by rapid solidification techniques using metals such as iron, nickel, and cobalt, and non-metallic elements such as silicon and boron. Amorphous ribbons possess a unique atomic arrangement structure, exhibiting a microstructure characterized by short-range order and long-range disorder, thus possessing excellent soft magnetic properties and showing broad application prospects in fields such as power electronics, magnetic materials, and sensors.

[0003] Amorphous ribbons are typically used in two ways: one is to wind the amorphous ribbon into a ring, vacuum impregnate it with adhesive, and then cure it; the other is to stack multiple layers of polycrystalline ribbons to the required thickness and then fix them together with adhesive. Both methods require adhesives, which not only need to provide good bonding strength to the amorphous ribbon to meet the performance requirements of the amorphous ribbon in harsh environments such as high temperature, high frequency, and high humidity, but also need to have excellent thermal stability and thermal conductivity, with a coefficient of linear expansion close to that of the amorphous ribbon to meet the application requirements of electrical equipment.

[0004] The adhesives used for bonding amorphous strips are generally acrylic adhesives, silicone adhesives or epoxy resin adhesives. Because the surface of amorphous strips is smoother, existing adhesives have poor adhesion to amorphous strips, resulting in insufficient bonding strength. In addition, existing adhesives cannot meet the high temperature and high humidity requirements of amorphous strips. Summary of the Invention

[0005] In order to develop an adhesive with good bonding strength, excellent thermal stability and water resistance for amorphous strips, this application provides an adhesive for amorphous strips and a method for preparing the same.

[0006] This application provides an adhesive for amorphous ribbons and a method for preparing the same, using the following technical solution: In a first aspect, this application provides an adhesive for amorphous ribbons, comprising the following raw materials in parts by weight: 55-65 parts epoxy resin; 15-23 parts of cyclosulfide epoxy resin; 8-15 parts of C12-14 alkyl glycidyl ether; 3-7 parts calcium carbonate powder; 0.8-1.5 parts of titanate coupling agent; 2-5 parts of thermosetting agent; The epoxy resin is selected from bisphenol F type epoxy resin, and the epoxy-cured epoxy resin is prepared by reacting bisphenol A type epoxy resin with potassium thiocyanate.

[0007] By adopting the above technical solution, epoxy resin and cyclic vulcanized epoxy resin are selected as the main components of the adhesive. Epoxy resin itself has excellent bonding and electrical insulation properties, but it suffers from high internal stress, brittleness, and poor resistance to damp heat. Cyclic vulcanized epoxy resin, by converting the oxygen in the three-membered ring into sulfur, has lower viscosity and higher bonding strength. At the same time, it has a faster curing speed, better water resistance, and is suitable for high humidity environments. The combination of the two makes the adhesive have strong adhesion to amorphous materials without introducing excessive stress, which would affect the soft magnetic properties of the amorphous strips.

[0008] The introduction of C12-14 alkyl glycidyl ether can reduce viscosity, provide flexibility to epoxy resin, and improve the wetting ability of calcium carbonate filler and the adhesion of amorphous ribbons due to its low surface tension. Titanate coupling agent improves the compatibility between filler and resin system, making the adhesive molding more stable. The addition of calcium carbonate powder can reduce the stress introduced by the adhesive, which is beneficial to improve the bonding strength of amorphous ribbons, while maintaining the soft magnetic properties of amorphous materials.

[0009] Optionally, the cyclic vulcanized epoxy resin is prepared by the following steps: Potassium thiocyanate and epoxy resin E-51 were dissolved in a certain amount of methanol solution to obtain solution A and solution B, respectively. Two-thirds of solution A was placed in a flask and heated to 35-40°C. Solution B was added dropwise to the flask while stirring, and the addition time was controlled at 25-30 minutes. After the addition was completed, the reaction was carried out for 1 hour, and then the remaining solution A was added to the flask. The reaction was carried out with stirring for 2-2.5 hours. After the reaction was completed, the reaction solution was poured into distilled water, extracted with chloroform, the organic phase was dried with anhydrous magnesium sulfate and the solvent was removed under reduced pressure, and then recrystallized with butanone / methanol to obtain cyclic sulfurized epoxy resin.

[0010] By adopting the above technical solution, epoxy resin and potassium thiocyanate are reacted to generate cyclic sulfurized epoxy resin containing cyclic sulfur groups, which has a faster curing speed and better water resistance.

[0011] Optionally, the weight ratio of potassium thiocyanate to epoxy resin is (1.2-1.4):1.

[0012] Optionally, the thermosetting agent is selected from one or more of 2-ethyl-4-methylimidazolium, diaminodiphenylmethane, polyamide 650 curing agent, and modified diamine.

[0013] By adopting the above technical solution, the diamine curing agent can form a cross-linking system with the epoxy resin, thereby promoting the curing of the resin.

[0014] Optionally, the thermosetting agent is a modified diamine, prepared through the following steps: Diphenylmethane bismaleimide and diaminodiphenylmethane were mixed evenly in a weight ratio of (0.8-1):1, heated to 160-180℃, and stirred at a constant temperature to achieve prepolymerization in the molten state, thus obtaining a modified diamine curing agent.

[0015] By adopting the above technical solution, diaminodiphenylmethane is chain-extended and modified with diphenylmethane maleimide, and benzene rings and imide rings with good heat resistance are introduced into the curing agent. This also improves the rigidity and water resistance of the molecular structure. After curing the epoxy resin system, the high temperature resistance and moisture resistance of the resulting adhesive are improved.

[0016] Optionally, the epoxy resin is a silicone-modified epoxy resin, prepared through the following steps: Weigh the epoxy resin and add it to a flask. Heat the flask until it is completely dissolved. Add the silicone resin, silane coupling agent KH-560 and dibutyltin dilaurate. Stir and heat the flask to 80-90℃ and react for 4-6 hours to generate silicone-modified epoxy resin.

[0017] By adopting the above technical solution, the epoxy resin is modified by adding organosilicon resin. The organosilicon improves the flexibility of the epoxy resin, while its high temperature resistance and water resistance are also enhanced, which is beneficial to improving the performance of the adhesive.

[0018] Optionally, the weight ratio of the epoxy resin, silicone resin, silane coupling agent and dibutyltin dilaurate is 10:(7-10):(0.5-0.7):(0.08-0.1).

[0019] Optionally, the titanate coupling agent is selected from one or more of NDZ-201, HY-109, and KR-41B.

[0020] Secondly, this application provides a method for preparing an adhesive for amorphous ribbons, comprising the following steps: The epoxy resin, epoxidized epoxy resin, C12-14 alkyl glycidyl ether, calcium carbonate powder and titanate coupling agent are mixed and stirred evenly to obtain a mixture. The thermosetting agent is heated to 70-80℃, added to the mixture and stirred evenly. Vacuum degassing is then performed to obtain an adhesive for amorphous strips.

[0021] By adopting the above technical solution, an adhesive with strong adhesion to amorphous strips and resistance to high temperature and moisture was prepared.

[0022] In summary, this application has at least one of the following beneficial effects: Epoxy resin and cyclic vulcanized epoxy resin are selected as the main components of the adhesive. Epoxy resin itself has excellent bonding and electrical insulation properties, but it has problems such as high internal stress, brittleness, and poor resistance to damp heat. Cyclic vulcanized epoxy resin, by converting the oxygen in the three-membered ring into sulfur, has lower viscosity and higher adhesion. At the same time, it has a faster curing speed, better water resistance, and is suitable for high humidity environments. The combination of the two makes the adhesive have strong adhesion to amorphous materials without introducing excessive stress, which would affect the soft magnetic properties of the amorphous strips.

[0023] The introduction of C12-14 alkyl glycidyl ether can reduce viscosity, provide flexibility to epoxy resin, and improve the wetting ability of calcium carbonate filler and the adhesion of amorphous ribbons due to its low surface tension. Titanate coupling agent improves the compatibility between filler and resin system, making the adhesive molding more stable. The addition of calcium carbonate powder can reduce the stress introduced by the adhesive, which is beneficial to improve the bonding strength of amorphous ribbons, while maintaining the soft magnetic properties of amorphous materials. Detailed Implementation

[0024] The present application will be further described in detail below with reference to Examples 1-8 and Comparative Examples 1-3.

[0025] Raw material source: Bisphenol F type epoxy resin, Nan Ya NPEF 170, purchased from Shanghai Huiyi Materials Technology Co., Ltd. Bisphenol A type epoxy resin, E-51 epoxy resin, purchased from Wuhan Kanos Technology Co., Ltd. Potassium thiocyanate, CAS No. 333-20-0, was purchased from Jiangsu Bost Chemical Technology Co., Ltd. C12-14 alkyl glycidyl ether, CAS No. 68609-97-2, was purchased from Wuhan Smike Biotechnology Co., Ltd. Calcium carbonate powder, made of 1000-mesh heavy calcium carbonate powder, was purchased from Lingshou County Baixin New Material Technology Co., Ltd. The silicone resin used was FJN-9802 self-drying silicone resin, purchased from Changzhou Jianuo Silicone Co., Ltd. Example

[0026] Example 1 An adhesive for amorphous ribbons, comprising the following raw materials: 55 parts of epoxy resin, bisphenol F type epoxy resin is selected; 15 parts of cyclic sulfide epoxy resin were prepared by the following steps: 60g of potassium thiocyanate and 50g of epoxy resin E-51 were dissolved in 250ml and 200nl of methanol solution, respectively, to obtain solution A and solution B. 2 / 3 of solution A was put into a flask and heated to 35℃. Solution B was added dropwise to the flask while stirring, and the addition time was controlled at 25min. After the addition was completed, the reaction was carried out for 1h. Then the remaining solution A was added to the flask and the reaction was carried out by stirring for 2h. After the reaction was completed, the reaction solution was poured into 150 ml of distilled water, extracted with 300 ml of chloroform, the organic phase was dried with anhydrous magnesium sulfate and the solvent was removed under reduced pressure, and then recrystallized with butanone / methanol to obtain cyclic sulfurized epoxy resin. 8 parts of C12-14 alkyl glycidyl ether; 3 parts calcium carbonate powder; 0.8 parts of titanate coupling agent, using NDZ-201 titanate coupling agent, purchased from Nanjing Quanxi New Materials Co., Ltd. Two parts of thermosetting agent, 2-ethyl-4-methylimidazole, were purchased from Shandong Shouhua Chemical Co., Ltd.

[0027] A method for preparing an adhesive for amorphous ribbons includes the following steps: The epoxy resin, epoxidized epoxy resin, C12-14 alkyl glycidyl ether, calcium carbonate powder and titanate coupling agent are mixed and stirred evenly to obtain a mixture. The thermosetting agent is heated to 70°C, added to the mixture and stirred evenly. Vacuum degassing is then performed to obtain an adhesive for amorphous strips.

[0028] Example 2 An adhesive for amorphous ribbons, comprising the following raw materials: 65 parts of epoxy resin, bisphenol F type epoxy resin is selected; 23 parts of cyclic sulfide epoxy resin were prepared by the following steps: 70g of potassium thiocyanate and 50g of epoxy resin E-51 were dissolved in 350ml and 200nl of methanol solution, respectively, to obtain solution A and solution B. 2 / 3 of solution A was put into a flask and heated to 40℃. Solution B was added dropwise to the flask while stirring, and the addition time was controlled at 30min. After the addition was completed, the reaction was carried out for 1h. Then the remaining solution A was added to the flask and the reaction was carried out by stirring for 2.5h. After the reaction was completed, the reaction solution was poured into 200 ml of distilled water, extracted with 400 ml of chloroform, the organic phase was dried with anhydrous magnesium sulfate and the solvent was removed under reduced pressure, and then recrystallized with butanone / methanol to obtain cyclic sulfurized epoxy resin. 15 parts of C12-14 alkyl glycidyl ether; 7 parts calcium carbonate powder; 1.5 parts of titanate coupling agent, using HY-109 titanate coupling agent, purchased from Wuhan Kanos Technology Co., Ltd.; Five parts of thermosetting agent, using diaminodiphenylmethane, purchased from Shandong Xuchen Chemical Technology Co., Ltd.

[0029] A method for preparing an adhesive for amorphous ribbons includes the following steps: The epoxy resin, epoxidized epoxy resin, C12-14 alkyl glycidyl ether, calcium carbonate powder and titanate coupling agent are mixed and stirred evenly to obtain a mixture. The thermosetting agent is heated to 80°C, added to the mixture and stirred evenly. Vacuum degassing is then performed to obtain an adhesive for amorphous ribbons.

[0030] Example 3 An adhesive for amorphous ribbons, comprising the following raw materials: 59 parts of epoxy resin, bisphenol F type epoxy resin was selected; 21 parts of cyclic sulfide epoxy resin were prepared by the following steps: 66g of potassium thiocyanate and 50g of epoxy resin E-51 were dissolved in 300ml and 200nl of methanol solution, respectively, to obtain solution A and solution B. 2 / 3 of solution A was placed in a flask and heated to 38°C. Solution B was added dropwise to the flask while stirring, and the addition time was controlled at 25min. After the addition was completed, the reaction was carried out for 1h. Then the remaining solution A was added to the flask and the reaction was carried out by stirring for 2.5h. After the reaction was completed, the reaction solution was poured into 180 ml of distilled water and extracted with 300 ml of chloroform. The organic phase was dried with anhydrous magnesium sulfate and the solvent was removed under reduced pressure. Then, it was recrystallized with butanone / methanol to obtain cyclic sulfurized epoxy resin. 12 parts of C12-14 alkyl glycidyl ether; 5 parts calcium carbonate powder; 1.3 parts of titanate coupling agent, KR-41B titanate coupling agent, purchased from Jinan Jiushang New Material Technology Co., Ltd.; Four parts of thermosetting agent, using polyamide 650 curing agent, purchased from Jinan Qingtian Chemical Technology Co., Ltd.

[0031] The adhesive was prepared using the same method as in Example 1.

[0032] Example 4 The difference between this embodiment and Embodiment 1 is that an equal amount of silicone-modified epoxy resin is used instead of epoxy resin in the adhesive raw materials.

[0033] Organosilicon-modified epoxy resin is prepared through the following steps: Weigh 10g of bisphenol F epoxy resin and add it to a flask. Heat the flask to 40°C until the epoxy resin is completely dissolved. Add 7g of silicone resin, 0.5g of silane coupling agent KH-560 and 0.08g of dibutyltin dilaurate. Stir and heat the flask to 80°C. React for 4 hours to generate silicone-modified epoxy resin.

[0034] Example 5 The difference between this embodiment and Embodiment 1 is that an equal amount of silicone-modified epoxy resin is used instead of epoxy resin in the adhesive raw materials.

[0035] Organosilicon-modified epoxy resin is prepared through the following steps: Weigh 10g of bisphenol F epoxy resin and add it to a flask. Heat the flask to 45°C until the epoxy resin is completely dissolved. Add 10g of silicone resin, 0.7g of silane coupling agent KH-560 and 0.1g of dibutyltin dilaurate. Stir and heat the flask to 90°C. React for 6 hours to generate silicone-modified epoxy resin.

[0036] Example 6 The difference between this embodiment and Embodiment 1 is that, in the adhesive raw materials, an equal amount of modified diamine is used instead of 2-ethyl-4-methylimidazole as a thermosetting agent.

[0037] Modified diamines are prepared through the following steps: Mix 8g of diphenylmethane bismaleimide and 10g of diaminodiphenylmethane evenly, heat to 160℃, and stir at a constant temperature to achieve prepolymerization in the molten state, thus obtaining a modified diamine curing agent.

[0038] Example 7 The difference between this embodiment and Embodiment 1 is that, in the adhesive raw materials, an equal amount of modified diamine is used instead of 2-ethyl-4-methylimidazole as a thermosetting agent.

[0039] Modified diamines are prepared through the following steps: Mix 10g of diphenylmethane bismaleimide and 10g of diaminodiphenylmethane evenly, heat to 180℃, and stir at a constant temperature to achieve prepolymerization in the molten state, thus obtaining a modified diamine curing agent.

[0040] Example 8 The difference between this embodiment and Embodiment 1 is that: in the adhesive raw materials, an equal amount of silicone-modified epoxy resin is used instead of epoxy resin; and an equal amount of modified diamine is used instead of 2-ethyl-4-methylimidazole as the thermosetting agent.

[0041] Organosilicon-modified epoxy resin is prepared through the following steps: Weigh 10g of bisphenol F epoxy resin and add it to a flask. Heat the flask to 40°C until the epoxy resin is completely dissolved. Add 7g of silicone resin, 0.5g of silane coupling agent KH-560 and 0.08g of dibutyltin dilaurate. Stir and heat the flask to 80°C. React for 4 hours to generate silicone-modified epoxy resin.

[0042] Modified diamines are prepared through the following steps: Mix 10g of diphenylmethane bismaleimide and 10g of diaminodiphenylmethane evenly, heat to 180℃, and stir at a constant temperature to achieve prepolymerization in the molten state, thus obtaining a modified diamine curing agent. Comparative Example

[0043] Comparative Example 1 The difference between this comparative example and Example 1 is that an equal amount of bisphenol A type epoxy resin E-51 is used instead of epoxidized epoxy resin in the raw materials of the adhesive.

[0044] Comparative Example 2 The difference between this comparative example and Example 1 is that no C12-14 alkyl glycidyl ether was added to the raw materials of the adhesive.

[0045] Comparative Example 3 The difference between this comparative example and Example 1 is that no calcium carbonate powder was added to the raw materials of the adhesive. Performance testing

[0046] The adhesives for amorphous ribbons prepared in Examples 1-8 and Comparative Examples 1-3 were tested to achieve the following properties.

[0047] When bonding amorphous strips, the adhesive is used to treat the amorphous strip stacks using vacuum impregnation technology, allowing the adhesive to fully penetrate the gaps between the strips. Under the pressure of a hot press, it is pre-cured at 100°C for 2 hours, then heated to 140°C for 1 hour, and then cooled to room temperature under the pressure of the hot press. This controls the curing reaction rate and avoids the formation of bubbles and voids in the cured amorphous blocks due to excessive heat release during the curing reaction.

[0048] Adhesion: Peel strength was tested using a universal tensile testing machine according to the T-peel method in GB / T2791—1995 "Adhesives - Test Method for T-Peel Strength". A better peel strength indicates stronger adhesion between the adhesive and the amorphous strip.

[0049] High-temperature resistance: The adhesive was poured into a flat mold cavity, placed in an oven, and cured at 120℃ for 2 hours. The temperature was then increased to 150℃ for 2 hours, followed by another 2 hours of curing at 180℃. After cooling to room temperature and standing for 24 hours, the sample was demolded. The glass transition temperature (Tg) of the sample was tested using a differential scanning calorimeter (DSC). A higher Tg value indicates better high-temperature resistance of the adhesive.

[0050] Water resistance: Using a precision electronic balance, weigh the sample to be tested and record the weight as W1. Then, immerse it in deionized water (25℃) for 7 days, remove it, wipe the surface moisture with filter paper, weigh it again and record the weight as W2. Calculate the water absorption rate = (W2-W1) / W1×100%. The lower the water absorption rate, the better the water resistance of the adhesive, and the more suitable it is for use in high humidity environments.

[0051] Tensile strength: Tested according to GB / T 2568-1995 "Test Method for Tensile Properties of Resin Castings".

[0052] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An adhesive for amorphous ribbons, characterized by, The raw materials include the following weight parts: epoxy resin 55-65 parts; ring sulfurization epoxy resin 15-23 parts; carbon 12-14 alkyl glycidyl ether 8-15 parts; calcium carbonate powder 3-7 parts; titanate coupling agent 0.8-1.5 parts; thermal curing agent 2-5 parts; The epoxy resin is selected from bisphenol F type epoxy resin, and the ring sulfurization epoxy resin is prepared by reacting bisphenol A type epoxy resin with potassium thiocyanate.

2. An adhesive for amorphous ribbons according to claim 1, characterized in that, The ring sulfurization epoxy resin is prepared by the following steps: Potassium thiocyanate and epoxy resin E-51 are respectively dissolved in a certain amount of methanol solution to obtain A solution and B solution, 2 / 3 of the A solution is put into a flask and heated to 35-40℃, while stirring, the B solution is added dropwise into the flask, the dropwise adding time is controlled in 25-30min, after the dropwise adding is completed, the remaining A solution is added into the flask after 1h reaction, and the reaction is stirred for 2-2.5h; After the end, the reaction liquid is poured into distilled water, extracted with chloroform, the organic phase is dried with anhydrous magnesium sulfate and the solvent is removed under reduced pressure, and then recrystallized with butanone / methanol to obtain the ring sulfurization epoxy resin.

3. An adhesive for amorphous ribbons according to claim 2, characterized in that: The weight ratio of the potassium thiocyanate and the epoxy resin is (1.2-1.4):

1.

4. An adhesive for amorphous ribbons according to claim 1, characterized by: The thermal curing agent is selected from one or more of 2-ethyl 4-methyl imidazole, diaminodiphenylmethane, polyamide 650 curing agent, and modified diamine.

5. An adhesive for amorphous ribbons according to claim 1, characterized by: The thermal curing agent is selected from modified diamine, which is prepared by the following steps: The diphenylmethane bismaleimide and diaminodiphenylmethane with a weight ratio of (0.8-1):1 are mixed uniformly, heated to 160-180℃, and pre-polymerized in the molten state to obtain the modified diamine curing agent.

6. An adhesive for amorphous ribbons according to claim 1, characterized by: The epoxy resin is selected from silicone modified epoxy resin, which is prepared by the following steps: The epoxy resin is weighed and added into a flask, heated to completely dissolve, and then the silicone resin, silane coupling agent KH-560 and dibutyltin dilaurate are added, stirred and heated to 80-90℃, and reacted for 4-6h to generate the silicone modified epoxy resin.

7. An adhesive for amorphous ribbons according to claim 6, characterized in that: The weight ratio of the epoxy resin, silicone resin, silane coupling agent and dibutyltin dilaurate is 10:(7-10):(0.5-0.7):(0.08-0.1).

8. An adhesive for amorphous ribbons according to claim 1, characterized by: The titanate coupling agent is selected from one or more of NDZ-201, HY-109 and KR-41B.

9. A method of making an adhesive for amorphous ribbons as claimed in any one of claims 1 to 8, characterised in that, The following steps are included: The epoxy resin, ring sulfurization epoxy resin, carbon 12-14 alkyl glycidyl ether, calcium carbonate powder and titanate coupling agent are mixed and stirred uniformly to obtain a mixture; The thermal curing agent is heated to 70-80℃, added into the mixture and stirred uniformly, and vacuum degassed to obtain an adhesive for amorphous strips.