An adhesive for electronic precision devices and a method for preparing the same

Abstract

This invention discloses an adhesive for precision electronic devices, comprising the following components in parts by weight: 80-100 parts naphthyl epoxy resin, 5-30 parts siloxane, 5-25 parts diluent, 10-50 parts insulating and thermally conductive material, and 3-20 parts composite curing agent; the insulating and thermally conductive material is an OH-BN / AlN / PLGA-PEG-NH2 composite material; the composite curing agent comprises modified polythiol curing agent A and modified polythiol curing agent B, which are mixed at a mass ratio of (1-2.5):(1-2.5), and 0.05-1% silane coupling agent is added and stirred to obtain the final product. The adhesive prepared by this invention exhibits excellent bonding performance and good thermal conductivity, and cures rapidly at room temperature, showing promising application prospects in the field of electronics and electrical appliances.

Description

[0001] The present application claims priority to the Chinese patent application No. 202411195425.2, filed on August 28, 2024, entitled "An adhesive for electronic precision devices and a preparation method thereof", the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of adhesives, in particular to an adhesive for electronic precision devices and a preparation method thereof. BACKGROUND

[0003] With the development of technology, the use of heat-conducting adhesives is becoming more and more widespread, such as in the fields of aerospace, mobile communication, new energy vehicles, medical devices, electronics and electrical appliances, etc. Polymer composites combine the advantages of polymer matrix and heat-conducting fillers, and play a crucial role in the use of today's electronic devices. The development trend of electronic products is miniaturization and functional integration, so higher and higher requirements are put forward for the heat dissipation system.

[0004] Currently, the heat-conducting function of heat-conducting adhesives is mainly achieved by filling heat-conducting powder. Heat-conducting powder mainly includes aluminum oxide, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, silicon nitride, silicon carbide, carbon fiber and graphene, etc., which form a random dispersion state in the adhesive, causing problems such as low strength of the adhesive. Epoxy resin is widely used in semiconductor and electronic packaging materials due to its excellent mechanical, electrical and heat-resistant properties. Single-component epoxy adhesives are convenient to use and can be directly extruded for use. However, the single-component epoxy resin adhesives circulating in the market use latent curing agents, which have poor storage stability, are prone to viscosity increase, and the adhesive liquid is cured, and generally require high-temperature curing.

[0005] Therefore, there is still a need to develop a single-component adhesive with good heat-conducting performance that can be cured at room temperature. SUMMARY

[0006] The purpose of the present application is to provide an adhesive for electronic precision devices and a preparation method thereof, which has rapid curing at room temperature, good adhesion, storage stability, good heat-conducting performance, and better meets the use requirements of electronic appliances.

[0007] To this end, the present application adopts the following technical solutions:

[0008] The present application provides an adhesive for electronic precision devices, which comprises the following components by weight:

[0009] Naphthyl epoxy resin 80-100 parts, siloxane 5-30 parts, diluent 5-25 parts, insulating heat-conducting material 10-50 parts and composite curing agent 3-20 parts;

[0010] The insulating and heat-conducting material is an OH-BN / AlN / PLGA-PEG-NH2 composite material.

[0011] The composite curing agent comprises a modified polythiol curing agent A and a modified polythiol curing agent B, and the two are mixed at a mass ratio of (1-2.5):(1-2.5).

[0012] The mass ratio (1-2.5):(1-2.5) is mixed, 0.05-1% of a silane coupling agent is added, and stirring is performed, and the mixture is obtained.

[0013] The naphthyl epoxy resin is endowed with a series of excellent properties due to the rigid planar conjugated structure of the naphthalene ring, such as low moisture absorption, high chemical stability, low CTE, and excellent mechanical and thermal mechanical properties.

[0014] Further, the preparation method of the insulating and heat-conducting material comprises the following steps:

[0015] The preparation method of the OH-BN / AlN / PLGA-PEG-NH2 composite material comprises the following steps:

[0016] (1) Boron nitride is added in isopropyl alcohol and ultrasonically shaken in a water bath for 10-24 h, NaOH solution is added and heated and stirred, the heating temperature is 110-150 DEG C, the reaction time is 12-72 h, suction filtration is performed, washed with pure water for 3-5 times, dried, and ground to obtain hydroxyl-modified ON-BN powder;

[0017] (2) The OH-BN powder is mixed with aluminum nitride at a mass ratio of (0.5-1):(1-3), added into a mixed solution of a tris-hydroxymethyl aminomethane buffer and ethanol, ultrasonically dispersed for 20-30 min, stirred and reacted for 12-24 h, suction filtered, washed with ethanol for 2-3 times, dried, and ground to obtain OH-BN / AlN powder;

[0018] (3) The OH-BN / AlN powder is added into chloroform, ultrasonically shaken for 24-48 h, and then the solvent is removed and dried to obtain OH-BN / AlN lamella;

[0019] (4) Poly (lactic-co-glycolic acid) -polyethylene glycol amino is dissolved in dichloromethane, the OH-BN / AlN lamella obtained in step (3) is added, stirred and dispersed for 15-40 min, then poured into a mold, the solvent is removed, and the OH-BN / AlN / PLGA-PEG-NH2 composite material is demolded.

[0020] Preferably, the concentration of the sodium hydroxide solution in step (1) is 50-150 g / L.

[0021] Preferably, the mass percentage of OH-BN / AlN in the OH-BN / AlN / PLGA-PEG-NH2 composite material in step (3) is 10-50%.

[0022] Furthermore, the preparation method of the modified polythiol curing agent A includes: heating and stirring a mixture of glycerol triglycidyl ether and pentaerythritol tetrakis(3-mercaptopropionic acid) in a molar ratio of (1-3):1 under the action of a catalyst.

[0023] Preferably, the catalyst is triethylamine; and / or, the heating reaction temperature is 60-80°C; and / or, the reaction time is 6-24 h.

[0024] Furthermore, the preparation method of the modified polythiol curing agent B includes: heating and stirring hexamethylene diisocyanate and pentaerythritol tetrakis(3-mercaptopropionic acid) in a molar ratio of (0.5-4):1 under the action of a catalyst.

[0025] Preferably, the catalyst is an organotin catalyst, more preferably dibutyltin dilaurate; and / or, the heating reaction temperature is 60-80℃; and / or, the reaction time is 6-24h.

[0026] Preferably, the siloxane is selected from one or more of vinylsilane, aminosilane, epoxysilane, mercaptosilane, and methacryloxysilane.

[0027] Preferably, the diluent is selected from one or more of alkylene glycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, benzyl glycidyl ether, and butyl glycidyl ether.

[0028] Preferably, the adhesive further includes one or more of the following: toughening agent, plasticizer, defoamer, anti-aging agent, and antioxidant.

[0029] This invention also provides a method for preparing an adhesive for precision electronic devices, comprising the following steps:

[0030] 1) After blending and melting naphthyl epoxy resin and siloxane, add diluent and stir to mix evenly;

[0031] 2) Add insulating and thermally conductive materials and composite curing agents and blend them together. The curing temperature is 25-150℃ and the heating rate is 5-20℃ / min to obtain the adhesive for electronic precision devices.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The adhesive for precision electronic devices of the present invention is a composite curing agent obtained by mixing naphthyl epoxy resin, siloxane, diluent and OH-BN / AlN / polylactic acid-hydroxyacetic acid copolymer polyethylene glycol amino complex thermally conductive and insulating material, modified polythiol curing agent A and modified polythiol curing agent B. It has excellent adhesion properties, thermal conductivity and fast curing speed at room temperature.

[0034] The insulating and thermally conductive OH-BN / AlN / PLGA-PEG-NH2 composite material provided by this invention uses edge-hydroxylated boron nitride and aluminum nitride composite nanosheets to react with PLGA-PEG-NH2, uniformly dispersing and binding the nanosheets on the long molecular chain of PLGA-PEG-NH2, which greatly increases the specific surface area of ​​the nanomaterial, and also significantly improves the dispersibility of boron nitride and aluminum nitride and the compatibility of the system. Adding it can effectively improve the performance of the material.

[0035] The composite curing agent provided by this invention is a composite of modified polythiol curing agent A and modified polythiol curing agent B. After modification, more diverse functional groups are introduced, and it also possesses a better cross-linking structure, enabling the adhesive system to obtain a better network structure and enhancing its bonding performance. The composite curing agent of this invention achieves instant curing and exhibits good storage stability.

[0036] This invention uses naphthyl epoxy resin as the matrix resin. By melting and mixing it with siloxane, the resin matrix has better reactivity and heat resistance. Combined with the thermally conductive material and curing agent of the system, it achieves good adhesion and thermal conductivity.

[0037] The adhesive provided by this invention has excellent overall performance and has good application prospects in electronic devices. Detailed Implementation

[0038] The following specific embodiments further describe the detailed implementation of the technical solution described herein. These embodiments are for the purpose of detailed description of the technical solution and not for limiting the technical solution. Based on the embodiments in this description, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this description. Unless otherwise specified, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in this technical field, and the reagents and materials used in the following embodiments are all commercially available.

[0039] Naphthalene-type epoxy resin EBA-65 was purchased from Hubei Langbowan Biomedical Co., Ltd.

[0040] Hexagonal boron nitride was purchased from Shenzhen Advanced New Materials Manufacturing Co., Ltd.

[0041] Aluminum nitride, CAS No. 24304-00-5, purchased from Hebei Teng Shuang Metal Materials Co., Ltd.

[0042] Polylactic acid-glycolic acid copolymer-polyethylene glycol-amino (PLGA-PEG-NH2) (trade code: R-PL1005-5KD), with a molecular weight of 2000, was purchased from Xi'an Ruixi Biotechnology Co., Ltd.

[0043] Preparation Example 1

[0044] This preparation example provides a modified thiol curing agent A, which is prepared by weighing 49g of pentaerythritol tetrakis(3-mercaptopropionic acid) and 1g of triethylamine into a three-necked flask, mechanically stirring, adding 13g of glycerol triglycidyl ether dropwise into the three-necked flask, heating to 70 ℃, stirring and reacting for 18h, and collecting the product.

[0045] Preparation Example 2

[0046] This preparation example provides a modified thiol curing agent B, which is prepared by weighing 85g of pentaerythritol tetrakis(3-mercaptopropionic acid) and dibutyltin dilaurate into a three-necked flask and mechanically stirring. Then, 16.8g of toluene diisocyanate is added dropwise into the three-necked flask, and the mixture is stirred at 65 °C for 12 h. The product is then collected.

[0047] Preparation Example 3

[0048] Preparation of composite curing agent: The modified thiol curing agent A of Preparation Example 1 and the modified thiol curing agent B of Preparation Example 2 were mixed at a mass ratio of 1:1, and 0.3% of silane coupling agent Z-6040 was added. The mixture was stirred for 20 minutes to obtain the final product.

[0049] The composite curing agent is used in the following examples and comparative examples.

[0050] Preparation Example 4

[0051] This preparation example provides an insulating and thermally conductive OH-BN / AlN / PLGA-PEG-NH2 composite material, the preparation method of which includes the following steps:

[0052] (1) Add 20g of boron nitride (BN) to 100mL of isopropanol and sonicate in a water bath for 10-24h. Add 50mL of NaOH solution with a mass concentration of 120 g / L and heat and stir at 140℃ for 24h. Filter, wash with pure water 5 times, dry, and grind to obtain hydroxyl-modified ON-BN powder.

[0053] (2) OH-BN and aluminum nitride (AlN) were mixed at a mass ratio of 1:3 and added to a mixture of buffer solution of tris(hydroxymethyl)aminomethane and ethanol. The mixture was ultrasonically dispersed for 30 min, stirred and reacted for 20 h, filtered, washed three times with ethanol, dried, and ground to obtain OH-BN / AlN powder.

[0054] (3) The OH-BN / AlN powder prepared above was added to 150 mL of chloroform, sonicated for 48 h, then the solvent was removed, dried, and ground to obtain OH-BN / AlN sheets.

[0055] (4) Dissolve polylactic acid-hydroxyacetic acid copolymer polyethylene glycol amino (PLGA-PEG-NH2) in dichloromethane, add the OH-BN / AlN sheet prepared in step (3) at a mass ratio of 50%, stir and disperse for 40 min, then pour into a mold, remove the solvent, and demold to obtain the OH-BN / AlN / PLGA-PEG-NH2 composite material.

[0056] Example 1

[0057] This embodiment provides an adhesive for use in precision electronic devices, comprising the following components in parts by weight:

[0058] 80 parts of naphthyl epoxy resin, 20 parts of siloxane KH560, 15 parts of 1,4-butanediol diglycidyl ether, 40 parts of insulating and thermally conductive material, and 10 parts of composite curing agent;

[0059] The insulating and thermally conductive material is the OH-BN / AlN / PLGA-PEG-NH2 composite material prepared in Preparation Example 4;

[0060] The composite curing agent is the composite curing agent prepared in Preparation Example 3, which is prepared by composite preparation before the preparation of adhesive.

[0061] The method for preparing adhesives for precision electronic devices provided in this embodiment includes the following steps:

[0062] 1) After blending and melting naphthyl epoxy resin and siloxane, add diluent and stir to mix evenly;

[0063] 2) Add insulating and thermally conductive materials and composite curing agents, mix, ultrasonically disperse, and cure at 25°C to obtain the adhesive for electronic precision devices.

[0064] Example 2

[0065] This embodiment provides an adhesive for use in precision electronic devices, comprising the following components in parts by weight:

[0066] 100 parts of naphthyl epoxy resin, 10 parts of siloxane KH560, 15 parts of 1,4-butanediol diglycidyl ether, 40 parts of insulating and thermally conductive material, and 5 parts of composite curing agent;

[0067] The insulating and thermally conductive material is the OH-BN / AlN / PLGA-PEG-NH2 composite material prepared in Preparation Example 4;

[0068] The composite curing agent is the composite curing agent prepared in Preparation Example 3, which is prepared by composite preparation before the preparation of adhesive.

[0069] The method for preparing adhesives for precision electronic devices provided in this embodiment includes the following steps:

[0070] 1) After blending and melting naphthyl epoxy resin and siloxane, add diluent and stir to mix evenly;

[0071] 2) Add insulating and thermally conductive materials and composite curing agents, mix, ultrasonically disperse, and cure at 25°C to obtain the adhesive for electronic precision devices.

[0072] Example 3

[0073] This embodiment provides an adhesive for use in precision electronic devices, comprising the following components in parts by weight:

[0074] 90 parts of naphthyl epoxy resin, 20 parts of siloxane KH560, 20 parts of benzyl glycidyl ether, 50 parts of insulating and thermally conductive material, and 15 parts of composite curing agent;

[0075] The insulating and thermally conductive material is the OH-BN / AlN / PLGA-PEG-NH2 composite material prepared in Preparation Example 4;

[0076] The composite curing agent is the composite curing agent prepared in Preparation Example 3, which is prepared by composite preparation before the preparation of adhesive.

[0077] The method for preparing adhesives for precision electronic devices provided in this embodiment includes the following steps:

[0078] 1) After blending and melting naphthyl epoxy resin and siloxane, add diluent and stir to mix evenly;

[0079] 2) Add insulating and thermally conductive materials and composite curing agents, mix, ultrasonically disperse, and cure at 25°C to obtain the adhesive for electronic precision devices.

[0080] Comparative Example 1

[0081] Compared with Example 1, the difference is that the hydroxyl-modified BN / AlN / polyPLGA-PEG-NH2 composite material for insulation and thermal conductivity is replaced with an equal weight of BN, while all other aspects are the same.

[0082] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0083] Comparative Example 2

[0084] Compared with Example 1, the difference is that the insulating and thermally conductive hydroxyl-modified BN / AlN / PLGA-PEG-NH2 composite material is replaced with an equal weight of AlN, while all other aspects are the same.

[0085] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0086] Comparative Example 3

[0087] Compared with Example 1, the difference is that the insulating and thermally conductive hydroxyl-modified BN / AlN / PLGA-PEG-NH2 composite material is replaced with an equal weight proportion of BN and AlN mixed filler, and the molar ratio of BN and AlN is kept the same as the ratio of the two in the hydroxyl-modified BN / AlN / polylactic acid-glycolic acid copolymer polyethylene glycol amino composite, and all other aspects are the same.

[0088] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0089] Comparative Example 4

[0090] Compared with Example 1, the difference is that the hydroxyl-modified BN / AlN / PLGA-PEG-NH2 composite material with insulating and thermally conductive material was not added; all other aspects are the same.

[0091] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0092] Comparative Example 5

[0093] Compared with Example 1, the difference is that the composite curing agent is replaced with the conventional curing agent polyetheramine D400, and everything else is the same.

[0094] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0095] Comparative Example 6

[0096] Compared with Example 1, the difference is that the composite curing agent contains only an equal weight proportion of modified thiol curing agent A, while everything else is the same.

[0097] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0098] Comparative Example 7

[0099] Compared with Example 1, the difference is that the composite curing agent contains only an equal weight proportion of modified thiol curing agent B, while everything else is the same.

[0100] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0101] Comparative Example 8

[0102] Compared with Example 1, the difference is that no siloxane was added, but everything else is the same.

[0103] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0104] Comparative Example 9

[0105] Compared with Example 1, the difference is that the composite curing agent is replaced with 5 parts of modified thiol curing agent A and 5 parts of modified thiol curing agent B. The two are only physically mixed, and everything else is the same.

[0106] The adhesive in this comparative example was prepared using the same method as in Example 1.

[0107] Performance testing: The adhesives prepared in Examples 1-3 and Comparative Examples 1-8 were subjected to the following performance tests.

[0108] 1. Thermal conductivity: Measured according to ASTM-5470 standard.

[0109] 2. Volume resistivity: 1) Volume resistivity was tested under high humidity conditions in accordance with GB / T 31838.2-2019, with a humidity of 85% in the test environment; 2) Volume resistivity was tested after aging for 500 hours in accordance with JESD22-A101-C, with a humidity of 85% and a temperature of 85℃ in the test environment.

[0110] 3. Shear strength: The shear strength of the adhesives prepared according to Examples 1-3 and Comparative Examples 1-8 in 3003Al-3003Al, PET-PET substrates in accordance with GB / T 7124-2008.

[0111] 4. Curing time: Record the time required for curing at room temperature (25℃).

[0112] The test results are shown in Tables 1 and 2.

[0113] Table 1. Test results of adhesive curing performance

[0114]

[0115] Table 2 Test Results of Insulation and Thermal Conductivity

[0116]

[0117] As can be seen from the test data of Examples 1-3 and Comparative Examples 1-9 given in Tables 1 and 2, the adhesive provided by the present invention has excellent bonding ability to both aluminum and PET plastic materials. The thermal conductivity of the adhesive provided by the present invention can reach 9.05 W / m·K, which is significantly higher than that of ordinary epoxy adhesives. Moreover, it still maintains excellent insulation ability under humid heat aging environment. The adhesive provided by the present invention has a fast curing speed and can be cured at room temperature in 18-25 minutes.

[0118] The test data from Example 1 and Comparative Examples 1-9 show that:

[0119] The addition of the insulating and thermally conductive material provided by this invention can significantly and effectively improve the thermal conductivity of adhesives, and has a superior effect on enhancing thermal conductivity compared to conventional thermally conductive fillers such as BN and AlN. The insulating and thermally conductive material provided by this invention can also enhance the shear strength of adhesives and improve their bonding performance to aluminum and plastic materials.

[0120] The composite curing agent provided by this invention can significantly improve the curing speed of adhesives and exhibits better curing enhancement performance than conventional amine curing agents. Furthermore, the composite curing agent provided by this invention is more effective at improving the curing speed of adhesives than any single-component curing agent, indicating that the mixture can synergistically enhance the curing speed and improve adhesive properties.

[0121] The adhesive provided by this invention uses a scientific combination of naphthyl epoxy resin, siloxane, thermally conductive materials, etc., and under the action of a composite curing agent, forms a system structure with both good rigidity and good network crosslinking degree. The thermally conductive materials are uniformly dispersed and bonded to the molecular chains in the system, enabling the adhesive to obtain good thermal conductivity and mechanical properties.

[0122] The adhesive provided by this invention has excellent thermal conductivity and bonding properties, and a fast curing speed, which helps to achieve better application results in the field of electronic packaging and has good application prospects.

[0123] Although embodiments of the present description have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present description, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adhesive for use in precision electronic devices, characterized in that, The composition includes the following components in parts by weight: 80-100 parts of naphthyl epoxy resin, 5-30 parts of siloxane, 5-25 parts of diluent, 10-50 parts of insulating and thermally conductive material, and 3-20 parts of composite curing agent; the insulating and thermally conductive material is an OH-BN / AlN / PLGA-PEG-NH2 composite material; the composite curing agent includes modified polythiol curing agent A and modified polythiol curing agent B, which are mixed in a mass ratio of (1-2.5):(1-2.5), and 0.05-1% of silane coupling agent is added and stirred to obtain the final product; the preparation method of the OH-BN / AlN / PLGA-PEG-NH2 composite material includes the following steps: (1) adding boron nitride to isopropanol and ultrasonically vibrating in a water bath for 10-24h, adding NaOH and heating and stirring at a temperature of 110-150℃ for a reaction time of 12-72h, filtering, and washing with pure water 3-5 times. (1) Dry and grind to obtain OH-BN powder; (2) Mix hydroxyl-modified OH-BN powder with aluminum nitride at a mass ratio of (0.5-1):(1-3), add to a mixture of buffer solution of tris(hydroxymethyl)aminomethane and ethanol, sonicate for 20-30 min, stir for 12-24 h, filter, wash with ethanol 2-3 times, dry, grind to obtain OH-BN / AlN powder; (3) Add OH-BN / AlN powder to chloroform, sonicate for 24-48 h, then remove the solvent, dry to obtain OH-BN / AlN sheets; (4) Dissolve polylactic acid-hydroxyacetic acid copolymer polyethylene glycol amino in dichloromethane, add to the OH-BN / AlN sheets obtained in step (3), stir and disperse for 15-40 min, then pour into a mold, remove the solvent, demold to obtain OH-BN / AlN / PLGA-PEG-NH2 composite material; The mass percentage of OH-BN / AlN in the OH-BN / AlN / PLGA-PEG-NH2 composite material in step (4) is 10-50%; the preparation method of the modified polythiol curing agent A includes: heating and stirring glycerol triglycidyl ether and pentaerythritol tetrakis(3-mercaptopropionic acid) in a molar ratio of (1-3):1 under the action of a catalyst; the preparation method of the modified polythiol curing agent B includes: heating and stirring hexamethylene diisocyanate and pentaerythritol tetrakis(3-mercaptopropionic acid) in a molar ratio of (0.5-4):1 under the action of a catalyst.

2. The adhesive for precision electronic devices according to claim 1, characterized in that, The siloxane is selected from one or more of vinylsilane, aminosilane, epoxysilane, mercaptosilane, and methacryloxysilane.

3. The adhesive for precision electronic devices according to claim 1, characterized in that, The diluent also includes one or more of the following: alkylene glycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, benzyl glycidyl ether, and butyl glycidyl ether.

4. The adhesive for precision electronic devices according to any one of claims 1-3, characterized in that, It also includes one or more of the following: toughening agents, plasticizers, defoamers, anti-aging agents, and antioxidants.

5. A method for preparing an adhesive for precision electronic devices as described in any one of claims 1-4, characterized in that, The process includes the following steps: 1) After blending and melting naphthyl epoxy resin and siloxane, add diluent and stir to mix evenly; 2) Add insulating and thermally conductive material and composite curing agent and blend, with a curing temperature of 25-150℃ and a heating rate of 5-20℃ / min to obtain the adhesive for electronic precision devices.

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