A low-density adhesive for bonding buoyancy materials and its preparation method

Abstract

The present invention relates to a low-density adhesive for bonding buoyancy materials and a preparation method thereof. The raw material components thereof are composed of epoxy resin, diluent, light filler, aliphatic amine curing agent, polyetheramine curing agent, crosslinking agent and catalyst. Taking epoxy resin as the matrix, the mass percentages of other raw materials relative to epoxy resin are as follows: diluent 5-8%, aliphatic amine curing agent 5-10%, polyetheramine curing agent 10-15%, light filler 20-25%, crosslinking agent 2-2.5%, catalyst 2-2.5%; the aliphatic amine curing agent contains 5-8% of C56 and 5-8% of C59; the polyetheramine curing agent contains 5-8% of C56 and 5-8% of C59. The adhesive provided by the present invention has excellent properties such as low density, high bonding strength and heat insulation. After curing, the density is 600-800 kg / m 3 , the flat tensile strength is 10-20 MPa, and it is suitable for bonding buoyancy materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and relates to a low-density adhesive for bonding buoyancy materials and a preparation method thereof. Background Art

[0002] An adhesive refers to a natural or synthetic, organic or inorganic substance that can connect two or more workpieces or materials together through actions such as interfacial adhesion and cohesion. There are many classification methods for adhesives. According to the application method, they can be divided into thermosetting type, hot-melt type, room-temperature curing type, etc.; according to the application object, they are divided into structural type, non-structural type or special adhesives; according to the form, they can be divided into water-soluble type, water emulsion type, solvent type, etc.

[0003] Solid buoyancy materials and structural support materials (including various composite materials and metal materials) are increasingly frequently used in combination. However, the difference in thermal expansion between the two is relatively large, and a flexible adhesive is required to connect the material interfaces, ensuring both the bonding strength and heat resistance, and also ensuring that the deformation difference between components of different materials can be eliminated through elastic deformation. The adhesives in the prior art are difficult to simultaneously meet the requirements of solid buoyancy materials for low density, high bonding strength, good toughness, heat resistance and heat insulation, etc., and it is difficult to simultaneously achieve the bonding effect on multiple bonding substrates. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a low-density adhesive for bonding buoyancy materials and a preparation method thereof in view of the above deficiencies in the prior art. The adhesive can effectively bond the structure of solid buoyancy materials (mainly obtained by compounding organic polymer materials and inorganic light fillers) without increasing the overall density, or be used for bonding composite materials and metal skeletons, and has high bonding strength and low density, and can meet the requirements of equipment for heat resistance and heat insulation performance.

[0005] To solve the above technical problems, the technical solution provided by the present invention is:

[0006] Provide a low-density adhesive for bonding buoyancy materials, the raw material components of which are composed of epoxy resin, diluent, light filler, aliphatic amine curing agent, polyetheramine curing agent, crosslinking agent and catalyst. Based on the epoxy resin as the matrix, the mass percentages of other raw materials relative to the epoxy resin are as follows: diluent 5-8%, aliphatic amine curing agent 5-10%, polyetheramine curing agent 10-15%, light filler 20-25%, crosslinking agent 2-2.5%, catalyst 2-2.5%;

[0007] The aliphatic amine curing agent is obtained by mixing triethylenetetramine, C56 and C59;

[0008] The polyetheramine curing agent is obtained by mixing terminal amino polyoxypropylene ether, C56 and C59;

[0009] The C56 is obtained by mixing KH-550 and KH-560 at a molar ratio of 1:2 and stirring for 1-1.5 h at 60-80 °C;

[0010] The C59 is obtained by mixing KH-792 and KH-560 at a molar ratio of 1:3 and stirring for 1-1.5 h at 60-80 °C.

[0011] According to the above scheme, the epoxy resin is epoxy resin E51.

[0012] According to the above scheme, the diluent is an epoxy diluent, preferably butyl glycidyl ether.

[0013] According to the above scheme, the aliphatic amine curing agent contains 5-8% of C56 and 5-8% of C59.

[0014] According to the above scheme, the polyetheramine curing agent contains 5-8% of C56 and 5-8% of C59.

[0015] According to the above scheme, the light filler is a mixture of hollow glass microspheres and fumed silica. The particle size of the hollow glass microspheres is 20-40 μm, and the particle size of the fumed silica is 10-20 nm. The addition amount of fumed silica is 20-50 wt% of the hollow glass microspheres. The addition of an appropriate amount of fumed silica can adjust the fluidity of the adhesive.

[0016] According to the above scheme, the crosslinking agent is tetraethyl orthosilicate.

[0017] According to the above scheme, the catalyst is dibutyltin dilaurate.

[0018] The present invention also includes a preparation method of the low-density adhesive applied to the bonding of buoyancy materials as described above. The specific steps are as follows:

[0019] 1) Weigh the raw materials according to the ratio and set aside;

[0020] 2) Pour the epoxy resin into a vacuum kneader. After it is mixed evenly, gradually add the light filler into the kneader. After adding, mix until the light filler is evenly dispersed in the epoxy resin. Then add the diluent, crosslinking agent and catalyst, mix evenly, and then add the aliphatic amine curing agent and polyetheramine curing agent into the vacuum kneader, mix evenly, and discharge after vacuum vibration defoaming to obtain a low-density adhesive applied to the bonding of buoyancy materials.

[0021] The present invention also includes the application of the above-mentioned low-density adhesive used for bonding buoyancy materials in the bonding of buoyancy materials. It is mainly applied in the manufacture of ocean exploration equipment. For example, it is used to bond single-piece buoyancy material cores to form a fixed structure, or to bond buoyancy materials to composite materials or metals, effectively improving the overall mechanical properties of the product without significantly increasing the overall density.

[0022] The specific usage method is as follows: Place the low-density adhesive used for bonding buoyancy materials at the bonding position required for the buoyancy materials, evenly brush the bonding interface, and subsequently supplement the adhesive at the bonding position as needed. Use a specific tooling to extrude the bonded buoyancy materials so that the adhesive can be evenly filled in the bonding gap, and then cure according to the following process conditions: First, cure at 40 - 45 °C for 1 - 1.5 h, then cure at 60 - 70 °C for 2 h, and finally cure at 80 - 85 °C for 5 - 8 h. Adopting the curing system of the present invention can improve the degree of curing.

[0023] In order to reduce the density of the adhesive, the present invention adds lightweight fillers (such as hollow glass microspheres) to the adhesive system. However, the compatibility of these lightweight fillers with the adhesive is poor, significantly reducing the bonding strength of the adhesive. Through the adjustment of the compound curing agent and the preparation process, the present invention obtains a good overall effect, increasing the bonding strength and overall toughness of the adhesive and reducing internal stress.

[0024] The beneficial effects of the present invention are as follows: 1. The adhesive provided by the present invention has excellent properties such as low density, high bonding strength, and heat insulation. After curing, the density is 600 - 800 kg / m 3 , the flat tensile strength is 10 - 20 MPa, which is suitable for bonding buoyancy materials; 2. The preparation process of the present invention is simple and suitable for industrial production. Specific Embodiments

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to embodiments.

[0026] Example 1

[0027] An adhesive used for bonding solid buoyancy materials to the main body and other similar media to reduce the overall density of the finished product and meet the bonding strength and toughness, and its preparation method is as follows:

[0028] 1) Weigh the following raw materials by mass: 100 parts of epoxy resin E51 (CYD128 epoxy resin from Baling Petrochemical), 5 parts of butyl glycidyl ether, 10 parts of aliphatic amine curing agent, 15 parts of polyetheramine curing agent, 24 parts of lightweight filler (obtained by mixing 20 parts of hollow glass microspheres with a particle size of 20 - 40 μm and 4 parts of fumed silica with a particle size of 10 - 20 μm), 2 parts of tetraethyl orthosilicate, and 2.5 parts of dibutyltin dilaurate;

[0029] The above-mentioned aliphatic amine curing agent is obtained by mixing triethylenetetramine, C56 and C59, wherein the content of C56 is 5% and the content of C59 is 5%.

[0030] The above-mentioned polyetheramine curing agent is obtained by mixing terminal amino polyoxypropylene ether (commercially available), C56 and C59.

[0031] Wherein the content of C56 is 5% and the content of C59 is 5%.

[0032] The C56 is obtained by mixing KH-550 and KH-560 in a molar ratio of 1:2 and then stirring and mixing for 1 h in an 80°C oil bath. The C59 is obtained by mixing KH-792 and KH-560 in a molar ratio of 1:3 and then stirring and mixing for 1 h in an 80°C oil bath.

[0033] 2) Pour the epoxy resin into a vacuum kneader. After it is mixed evenly, gradually add light filler into the kneader. After adding, mix until the light filler is evenly dispersed in the epoxy resin. Then add diluent, crosslinking agent and catalyst. After mixing evenly, add the aliphatic amine curing agent and polyetheramine curing agent into the vacuum kneader, mix evenly, and then discharge after vacuum vibration and defoaming to obtain a low-density adhesive applied to the bonding of buoyancy materials.

[0034] The curing conditions of the low-density adhesive prepared in this example are: 40°C for 1 h + 60°C for 2 h + 80°C for 5 h.

[0035] Samples of the adhesive prepared in this example were taken and tested according to the standard of "GB / T 6343-2009 Determination of Apparent Density of Foamed Plastics and Rubbers", and the measured density was 623 kg / m 3 .

[0036] According to the standard of "GB / T1452-2018 Test Method for Flat Tensile Strength of Sandwich Structures", the buoyancy material samples were bonded with the adhesive prepared in this example, and the flat tensile strength was tested after curing. The average value of the flat tensile strength was measured to be 12.8 MPa.

[0037] Samples of the low-density adhesive prepared in this example were made according to the standard of "GB / T1451-2005 Test Method for Simple Beam Impact Toughness of Fiber Reinforced Plastics", and the average value of the impact toughness after curing was measured to be 7.43 kJ / m 2 .

[0038] Comparative Example 1

[0039] An adhesive, the difference in its preparation method from Example 1 is that no light filler is added, and the remaining preparation conditions and curing conditions are the same as those in Example 1.

[0040] The curing process conditions of the adhesive prepared in this comparative example: 40°C for 1 h + 60°C for 2 h + 80°C for 5 h.

[0041] Using the test method of Example 1 to test the cured adhesive of this comparative example, the density of the cured adhesive was measured to be 1286 kg / m 3 , the average flat tensile strength was 16.98 MPa, and the average impact toughness was 8.37 kJ / m 2 .

[0042] Comparative Example 2

[0043] An adhesive, the difference in its preparation method from Example 1 is that: C56 and C59 are not added, and the remaining preparation conditions and curing conditions are the same as those in Comparative Example 1.

[0044] Using the test method of Example 1 to test the cured adhesive of this comparative example, the density of the cured adhesive was measured to be 653 kg / m 3 , the average flat tensile strength was 9.13 MPa, and the average impact toughness was 5.16 kJ / m 2 . The bonding strength of this adhesive is low and the toughness is also poor.

[0045] Comparative Example 3

[0046] An adhesive, the difference in its preparation method from Example 1 is that: light fillers, C56 and C59 are not added, and the remaining preparation conditions and curing conditions are the same as those in Example 1.

[0047] Using the test method of Example 1 to test the cured adhesive of this comparative example, the density of the cured adhesive was measured to be 1296 kg / m 3 , the average flat tensile strength was 15.13 MPa, and the average impact toughness was 6.69 kJ / m 2 . This adhesive has a relatively high density, high bonding strength but poor toughness.

[0048] The test results of the performance of the adhesive samples prepared in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3 of the present invention after curing are shown in Table 1.

[0049] Table 1

[0050]

[0051] Remarks: √ indicates addition, and × indicates non-addition.

[0052] It can be seen from the comparison in Table 1 that the present invention reduces the density by adding light fillers, and by appropriately incorporating C56 and C59 into the aliphatic amine curing agent and polyetheramine curing agent, the flat tensile strength and impact toughness of the cured adhesive only decrease slightly, meeting the actual use requirements.

Claims

1. A low-density adhesive for bonding solid buoyancy materials, characterized in that: The raw material components are composed of epoxy resin, diluent, light filler, fatty amine curing agent, polyether amine curing agent, crosslinking agent and catalyst. The epoxy resin is used as the matrix, and the mass percentage of other raw materials in the epoxy resin is as follows: diluent 5-8%, fatty amine curing agent 5-10%, polyether amine curing agent 10-15%, light filler 20-25%, crosslinking agent 2-2.5%, catalyst 2-2.5%; The lightweight filler is a mixture of hollow glass microspheres and fumed silica, and the amount of fumed silica added is 20-50wt% of the hollow glass microspheres; The fatty amine curing agent is obtained by mixing triethylenetetramine, C56 and C59, and the fatty amine curing agent contains 5-8% of C56 and 5-8% of C59; The polyetheramine curing agent is obtained by mixing amino-terminated polyoxypropylene ether, C56 and C59, wherein the polyetheramine curing agent contains 5-8% of C56 and 5-8% of C59; The C56 is obtained by mixing KH-550 and KH-560 in a molar ratio of 1:2 and stirring at 60-80°C for 1-1.5h; The C59 is obtained by mixing KH-792 and KH-560 in a molar ratio of 1:3 and stirring at 60-80° C. for 1-1.5 hours; The specific steps of its preparation method are as follows: 1) Weigh the raw materials according to the proportion and set aside; 2) Pour the epoxy resin into a vacuum kneader, and after mixing evenly, gradually add the lightweight filler into the kneader, and mix until the lightweight filler is evenly dispersed in the epoxy resin. Then add the diluent, cross-linking agent and catalyst, and after mixing evenly, add the fatty amine curing agent and the polyether amine curing agent into the vacuum kneader, mix evenly, and after vacuum vibration degassing, obtain a low-density adhesive used for bonding solid buoyancy materials.

2. The low-density adhesive for bonding solid buoyancy materials according to claim 1, characterized in that: The epoxy resin is epoxy resin E51.

3. The low-density adhesive for bonding solid buoyancy materials according to claim 1, characterized in that: The diluent is an epoxy diluent.

4. The low-density adhesive for bonding solid buoyancy materials according to claim 1, characterized in that: The particle size of the hollow glass microspheres is 20-40 μm, and the particle size of the fumed silica is 10-20 nm.

5. The low-density adhesive for bonding solid buoyancy materials according to claim 1, characterized in that: The cross-linking agent is tetraethyl orthosilicate; and the catalyst is dibutyltin dilaurate.

6. The method for preparing the low-density adhesive for bonding solid buoyancy materials according to any one of claims 1 to 5, characterized in that: The specific steps are as follows: 1) Weigh the raw materials according to the proportion and set aside; 2) Pour the epoxy resin into a vacuum kneader, and after mixing evenly, gradually add the lightweight filler into the kneader, and mix until the lightweight filler is evenly dispersed in the epoxy resin. Then add the diluent, cross-linking agent and catalyst, and after mixing evenly, add the fatty amine curing agent and the polyether amine curing agent into the vacuum kneader, mix evenly, and after vacuum vibration degassing, obtain a low-density adhesive used for bonding solid buoyancy materials.

7. Use of the low-density adhesive for bonding solid buoyancy materials as claimed in claim 1 in bonding solid buoyancy materials.

8. The use of the low-density adhesive for bonding solid buoyancy materials according to claim 7 in bonding solid buoyancy materials, characterized in that: The specific method of use is: place the low-density adhesive used for bonding solid buoyancy materials at the required bonding position of the solid buoyancy materials, brush the bonding interface evenly, and then supplement the adhesive at the bonding position as needed, use specific tooling to extrude the bonded solid buoyancy materials so that the adhesive can be evenly filled in the bonding gap, and then cure according to the following process conditions: first cure at 40~45℃ for 1~1.5h, then cure at 60~70℃ for 2h, and finally cure at 80~85℃ for 5~8h.

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