High-temperature-resistant adhesive and preparation method thereof

Abstract

The invention relates to the field of adhesives, in particular to a high-temperature-resistant adhesive and a preparation method thereof, and the high-temperature-resistant adhesive is prepared from the following raw materials in parts by weight: 30-50 parts of organic silicon resin; 10 to 20 parts of epoxy resin; 5-10 parts of a curing agent; 15-30 parts of a high-temperature-resistant filler; 2-5 parts of a coupling agent; 3-8 parts of a toughening agent; and 10-20 parts of a solvent. The adhesive has the beneficial effects that the organic silicon resin and the epoxy resin are compounded as matrix resin, the organic silicon resin has excellent high-temperature resistance, and the epoxy resin has good adhesive property and mechanical property, so that the adhesive not only has higher high-temperature resistance, but also has better adhesive strength and mechanical property through the combination of the organic silicon resin and the epoxy resin.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and in particular to a high-temperature resistant adhesive and its preparation method. Background Technology

[0002] Adhesives, as an important functional material, are widely used in many fields such as aerospace, automobile manufacturing, and electronics. In these applications, adhesives often need to withstand high temperatures. However, most adhesives on the market are prone to softening and peeling under high temperatures, resulting in a significant decrease in bonding performance and failing to meet actual usage requirements.

[0003] To improve the high-temperature resistance of adhesives, researchers have conducted extensive studies. In existing technologies, the high-temperature resistance of adhesives is usually improved by adding high-temperature resistant fillers and modifying the resin matrix, but the effect is not ideal. Either the improvement in high-temperature resistance is limited, or it will affect other properties of the adhesive, such as bonding strength and flexibility. Summary of the Invention

[0004] To overcome the shortcomings mentioned above, the present invention provides a technical solution that can solve the above problems.

[0005] A high-temperature resistant adhesive is prepared from the following raw materials in parts by weight:

[0006] 30-50 parts silicone resin; 10-20 parts epoxy resin; 5-10 parts curing agent; 15-30 parts high-temperature resistant filler; 2-5 parts coupling agent; 3-8 parts toughening agent; 10-20 parts solvent.

[0007] As a further aspect of the present invention: the organosilicon resin is methylphenyl silicone resin, and its phenyl content is 30-50%.

[0008] As a further aspect of the present invention: the epoxy resin is a bisphenol A type epoxy resin with an epoxy value of 0.4-0.6 eq / 100g.

[0009] As a further aspect of the present invention: the curing agent is an aromatic amine curing agent, selected from at least one of 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenyl sulfone.

[0010] As a further aspect of the present invention: the high-temperature resistant filler is at least one of nano-alumina, nano-zirconia, and silicon carbide, with a particle size of 50-100nm.

[0011] As a further aspect of the present invention: the coupling agent is a silane coupling agent, selected from at least one of KH550, KH560, and KH570.

[0012] As a further aspect of the present invention: the toughening agent is carboxyl-terminated butadiene-acrylonitrile rubber.

[0013] As a further aspect of the present invention, the solvent is xylene.

[0014] A method for preparing a high-temperature resistant adhesive includes the following steps:

[0015] (1) Weigh out the organosilicon resin, epoxy resin and solvent by weight, add them to the reaction vessel, and stir and mix for 30-60 minutes at a temperature of 60-80℃ and a stirring speed of 200-300r / min to obtain a mixed resin solution.

[0016] (2) Add high-temperature resistant filler and coupling agent to the mixed resin liquid, and stir and disperse for 60-90 min at a temperature of 80-100℃ and a stirring speed of 400-500r / min to obtain mixed liquid A;

[0017] (3) Add curing agent and toughening agent to mixture A, stir and mix for 40-60 minutes at a temperature of 50-60℃ and a stirring speed of 200-300r / min, and then cool to room temperature to obtain a high temperature resistant adhesive.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. By using a blend of silicone resin and epoxy resin as the base resin, silicone resin has excellent high temperature resistance, while epoxy resin has good adhesion and mechanical properties. The combination of the two makes the adhesive have both high high temperature resistance and good adhesion strength and mechanical properties.

[0020] 2. By adding high-temperature resistant fillers, the high-temperature resistance and mechanical strength of the adhesive can be further improved. Coupling agents can improve the interfacial bonding force between the filler and the resin matrix, thereby improving the overall performance of the adhesive.

[0021] 3. By adding toughening agents, the flexibility of the adhesive can be improved, and the adhesive can be prevented from becoming brittle at high temperatures.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the embodiments of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Example 1

[0027] A high-temperature resistant adhesive is prepared from the following raw materials in parts by weight: 30 parts of methylphenyl silicone resin (phenyl content 30%), 10 parts of bisphenol A type epoxy resin (epoxy value 0.4 eq / 100g), 5 parts of 4,4'-diaminodiphenylmethane, 15 parts of nano alumina, 2 parts of KH550, 3 parts of carboxyl-terminated butadiene nitrile rubber, and 10 parts of xylene.

[0028] Its preparation method includes the following steps:

[0029] Weigh out methylphenyl silicone resin, bisphenol A epoxy resin and xylene according to the weight parts, add them to the reaction vessel, and stir and mix for 30 minutes at a temperature of 60℃ and a stirring speed of 200r / min to obtain a mixed resin solution.

[0030] Nano-alumina and KH550 were added to the mixed resin solution and stirred and dispersed for 60 min at a temperature of 80℃ and a stirring speed of 400 r / min to obtain mixture A.

[0031] Add 4,4'-diaminodiphenylmethane and carboxyl-terminated butadiene-acrylonitrile rubber to mixture A, and stir and mix for 40 minutes at a temperature of 50°C and a stirring speed of 200 r / min. After cooling to room temperature, a high-temperature resistant adhesive is obtained.

[0032] Example 2

[0033] A high-temperature resistant adhesive is prepared from the following raw materials in parts by weight: 40 parts of methyl phenyl silicone resin (phenyl content 40%), 15 parts of bisphenol A type epoxy resin (epoxy value 0.5 eq / 100g), 8 parts of 4,4'-diaminodiphenyl sulfone, 22 parts of nano-zirconia, 3 parts of KH560, 5 parts of carboxyl-terminated butadiene nitrile rubber, and 15 parts of xylene.

[0034] Its preparation method includes the following steps:

[0035] Weigh out methylphenyl silicone resin, bisphenol A epoxy resin and xylene according to the weight parts, add them to the reaction vessel, and stir and mix for 45 minutes at a temperature of 70℃ and a stirring speed of 250r / min to obtain a mixed resin solution.

[0036] Nano-zirconia and KH560 were added to the mixed resin solution and stirred and dispersed for 75 min at a temperature of 90℃ and a stirring speed of 450 r / min to obtain mixed solution A.

[0037] Add 4,4'-diaminodiphenyl sulfone and carboxyl-terminated butadiene-acrylonitrile rubber to mixture A, and stir and mix for 50 minutes at a temperature of 55°C and a stirring speed of 250 r / min. After cooling to room temperature, a high-temperature resistant adhesive is obtained.

[0038] Example 3

[0039] A high-temperature resistant adhesive is prepared from the following raw materials in parts by weight: 50 parts of methylphenyl silicone resin (phenyl content 50%), 20 parts of bisphenol A type epoxy resin (epoxy value 0.6 eq / 100g), 10 parts of a mixture of 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenyl sulfone (weight ratio 1:1), 30 parts of silicon carbide, 5 parts of KH570, 8 parts of carboxyl-terminated butadiene-acrylonitrile rubber, and 20 parts of xylene.

[0040] Its preparation method includes the following steps:

[0041] Weigh out methylphenyl silicone resin, bisphenol A epoxy resin and xylene according to the weight parts, add them to the reaction vessel, and stir and mix for 60 min at a temperature of 80℃ and a stirring speed of 300 r / min to obtain a mixed resin solution.

[0042] Silicon carbide and KH570 were added to the mixed resin solution, and the mixture was stirred and dispersed for 90 min at a temperature of 100℃ and a stirring speed of 500 r / min to obtain mixture A.

[0043] A mixture of 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenyl sulfone, along with carboxyl-terminated butadiene-acrylonitrile rubber, is added to mixture A. The mixture is stirred and mixed for 60 minutes at a temperature of 60°C and a stirring speed of 300 r / min. After cooling to room temperature, a high-temperature resistant adhesive is obtained.

[0044] Comparative Example 1

[0045] An adhesive is prepared from the following raw materials in parts by weight: 55 parts of bisphenol A type epoxy resin (epoxy value 0.5 eq / 100g), 8 parts of 4,4'-diaminodiphenyl sulfone, 22 parts of nano-zirconia, 3 parts of KH560, 5 parts of carboxyl-terminated nitrile rubber, and 15 parts of xylene.

[0046] The preparation method is basically the same as in Example 2, except that methylphenyl silicone resin is not added.

[0047] Comparative Example 2

[0048] An adhesive is prepared from the following raw materials in parts by weight: 55 parts of methylphenyl silicone resin (phenyl content 40%), 8 parts of 4,4'-diaminodiphenyl sulfone, 22 parts of nano-zirconia, 3 parts of KH560, 5 parts of carboxyl-terminated butadiene-acrylonitrile rubber, and 15 parts of xylene.

[0049] The preparation method is basically the same as in Example 2, except that bisphenol A type epoxy resin is not added.

[0050] Comparative Example 3

[0051] An adhesive is prepared from the following raw materials in parts by weight: 40 parts of methylphenyl silicone resin (phenyl content 40%), 15 parts of bisphenol A type epoxy resin (epoxy value 0.5 eq / 100g), 8 parts of 4,4'-diaminodiphenyl sulfone, 3 parts of KH560, 5 parts of carboxyl-terminated butadiene-acrylonitrile rubber, and 15 parts of xylene.

[0052] The preparation method is basically the same as in Example 2, except that nano-zirconia is not added.

[0053] The adhesives prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The test items and methods are as follows:

[0054] High temperature resistance: The adhesive-bonded specimens were placed at 200℃, 250℃ and 300℃ for 24 hours respectively, and then their shear strength was tested. The shear strength test was carried out in accordance with GB / T 7124-2008.

[0055] Shear strength at room temperature: The shear strength of the adhesive-bonded specimens was tested at room temperature in accordance with GB / T 7124-2008.

[0056] The test results are shown in the table below:

[0057]

[0058] The test results above show that the high-temperature resistant adhesives prepared in Examples 1-3 of this invention have high shear strength at room temperature and can still maintain good bonding performance in high-temperature environments, demonstrating excellent high-temperature resistance. In contrast, Comparative Example 1, which did not contain silicone resin, has poor high-temperature resistance. Comparative Example 2, which did not contain epoxy resin, has low shear strength at room temperature. Comparative Example 3, which did not contain high-temperature resistant filler, shows a significant decrease in shear strength at high temperatures.

[0059] In summary, the high-temperature resistant adhesive of the present invention has excellent high-temperature resistance and good room-temperature bonding performance, and has broad application prospects.

[0060] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high temperature resistant adhesive, characterized by: It is prepared from the following raw materials by weight: Silicone resin 30-50 parts; epoxy resin 10-20 parts; curing agent 5-10 parts; high-temperature-resistant filler 15-30 parts; coupling agent 2-5 parts; toughening agent 3-8 parts; solvent 10-20 parts.

2. The high temperature resistant adhesive according to claim 1, characterized in that: The silicone resin is methylphenyl silicone resin with a phenyl content of 30-50%.

3. The high temperature resistant adhesive according to claim 1, wherein: The epoxy resin is bisphenol A type epoxy resin with an epoxy value of 0.4-0.6 eq / 100g.

4. The high temperature resistant adhesive according to claim 1, wherein: The curing agent is an aromatic amine curing agent selected from at least one of 4,4'-diaminodiphenyl methane and 4,4'-diaminodiphenyl sulfone.

5. The high temperature resistant adhesive according to claim 1, wherein: The high-temperature-resistant filler is at least one of nano-alumina, nano-zirconia, and silicon carbide with a particle size of 50-100 nm.

6. The high temperature resistant adhesive according to claim 1, wherein: The coupling agent is a silane coupling agent selected from at least one of KH550, KH560, and KH570.

7. The high temperature resistant adhesive according to claim 1, wherein: The toughening agent is carboxyl-terminated nitrile rubber.

8. The high temperature resistant adhesive as claimed in claim 1, wherein: The solvent is xylene.

9. A process for the preparation of the high temperature resistant adhesive according to any one of claims 1 to 8, characterized by: It includes the following steps: (1) Weigh the silicone resin, epoxy resin, and solvent by weight parts, add them to the reaction kettle, and stir and mix at a temperature of 60-80°C and a stirring speed of 200-300 r / min for 30-60 min to obtain a mixed resin liquid; (2) Add the high-temperature-resistant filler and coupling agent to the mixed resin liquid, stir and disperse at a temperature of 80-100°C and a stirring speed of 400-500 r / min for 60-90 min to obtain a mixed liquid A; (3) Add the curing agent and toughening agent to the mixed liquid A, stir and mix at a temperature of 50-60°C and a stirring speed of 200-300 r / min for 40-60 min, and then cool to room temperature to obtain a high-temperature-resistant adhesive.

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