Organic silicon adhesive and preparation method thereof

Abstract

The invention provides an organic silicon adhesive and a preparation method thereof. The organic silicon adhesive comprises a component A and a component B, the component A comprises first vinyl silicone resin, first vinyl-terminated silicone oil, a silicone oil-gas silicon premix, end-side hydrogen-containing silicone oil, iron oxide red, a heat-resistant agent, a coupling agent and an inhibitor; wherein the coupling agent comprises a first coupling agent and a second coupling agent, the first coupling agent comprises a silane polymer, and the second coupling agent comprises at least one of 3-glycidyl ether oxypropyl trimethoxy silane and 3-(methylacryloyloxy) propyl trimethoxy silane; the component B comprises second vinyl silicone resin, second vinyl-terminated silicone oil and a catalyst. The material has the advantages of high temperature resistance, high shear strength and high toughness.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to an organosilicon adhesive and its preparation method. Background Technology

[0002] Silicon-oxygen bonds endow silicone materials with excellent resistance to high and low temperatures and aging. Therefore, silicone adhesives based on silicone materials are widely used in industrial fields with high reliability requirements, especially in high-precision fields such as military industry, aerospace, nuclear technology and integrated circuits.

[0003] However, with continuous technological advancements, industrial sectors requiring high-temperature resistance are placing increasingly higher demands on silicone adhesives. Currently, most high-temperature resistant silicone adhesives on the market suffer from low shear strength and poor toughness after high-temperature aging. Summary of the Invention

[0004] In view of this, the present invention provides an organosilicon adhesive and its preparation method, which has high temperature resistance, high shear strength and high toughness.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an organosilicon adhesive, comprising component A and component B; Component A comprises a first vinyl silicone resin, a first end-vinyl silicone oil, a silicone oil-vapor silicone premix, an end-hydrogen-containing silicone oil, iron oxide red, a heat resistant agent, a coupling agent, and an inhibitor; wherein the coupling agent comprises a first coupling agent and a second coupling agent, the first coupling agent comprising a silane polymer, and the second coupling agent comprising at least one of 3-glycidyl etheroxypropyltrimethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane; Component B includes a second vinyl silicone resin, a second end vinyl silicone oil, and a catalyst.

[0006] It should be noted that the silicone oil-gas-silicone premix is ​​prepared by fully mixing vinyl-terminated silicone oil and fumed silica through a physical method, wherein the mass ratio of vinyl-terminated silicone oil to fumed silica can be 3:1, and the ethylene content of the silicone oil-gas-silicone premix is ​​equal to the vinyl content of the vinyl-terminated silicone oil used × 0.75; the iron oxide red can be at least one of Oxerra Materials' RO2097, RO3097, and RO4097; the coupling agent includes at least two of 3-glycidyl etheroxypropyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and silane polymers, and one of them must be a silane polymer; the silicone adhesive is used by mixing the A component and the B component and then curing them, wherein the A component and the B component can be mixed at a mass ratio of 10:1, and the curing can be performed at 100°C for 6 hours; the application of the silicone adhesive in material bonding includes, but is not limited to, the bonding of steel, aluminum alloys, anodized aluminum, and ceramics.

[0007] Preferably, the mass percentage of component A, calculated as 100%, comprises: 10% to 40% of the first vinyl silicone resin, 10% to 20% of the first terminal vinyl silicone oil, 20% to 50% of the silicone oil-vapor silicone premix, 1% to 10% of the terminal hydrogen-containing silicone oil, 10% to 30% of the iron oxide red, 1% to 5% of the heat resistant agent, 1% to 5% of the coupling agent, and 0.05% to 0.2% of the inhibitor.

[0008] Preferably, the B component, by mass percentage (100%), comprises: 40% to 60% of the second vinyl silicone resin, 40% to 60% of the second end vinyl silicone oil, and 0.1% to 1% of the catalyst.

[0009] Preferably, the first vinyl silicone resin has a vinyl content of 0.9wt%~1.4wt%, a viscosity of 10000mPa·s~100000mPa·s, and a resin content greater than or equal to 50wt%; and / or, The first-terminal vinyl silicone oil has a vinyl content of 0.06wt%~0.3wt% and a viscosity of 1000mPa·s~100000mPa·s; and / or, The vinyl content of the silicone oil-gas silicone premix is ​​0.04wt%~0.24wt%; and / or, The end-side hydrogen-containing silicone oil has a silicon-hydrogen (Si-H) content of 0.5wt%~0.9wt% and a viscosity of 15mPa·s~80mPa·s.

[0010] Preferably, the heat-resistant agent is cerium oxide; and / or, The inhibitors include at least one of polyvinyl polymers, ethynylcyclohexanol, and trimethyldodecylynol.

[0011] Preferably, the silane polymer comprises at least one of epoxy silane coupling agent oligomers and acyl silane coupling agent oligomers.

[0012] Preferably, the second vinyl silicone resin has a vinyl content of 0.9wt%~1.4wt%, a viscosity of 10000mPa·s~100000mPa·s, and a resin content greater than or equal to 50wt%; and / or, The second-terminated vinyl silicone oil has a vinyl content of 0.06wt%~0.3wt% and a viscosity of 1000mPa·s~100000mPa·s; and / or, The catalyst is a platinum catalyst.

[0013] It should be noted that the platinum catalyst can be a Karstedt platinum catalyst with a platinum content of 3000 ppm.

[0014] Secondly, the present invention also provides a method for preparing the aforementioned silicone adhesive, comprising the following steps: S1. Mix the first vinyl silicone resin, the first end vinyl silicone oil, the silicone oil-vapor silicone premix, the iron oxide red and the heat resistant agent, and then add the end hydrogen-containing silicone oil, the inhibitor and the coupling agent to obtain component A; S2. Mix the second vinyl silicone resin and the second terminal vinyl silicone oil, then add the catalyst and mix to obtain component B.

[0015] It should be noted that the order of steps S1 and S2 is not restricted. Step S1 can be performed first, step S2 can be performed first, or steps S1 and S2 can be performed simultaneously. The mixing device in steps S1 and S2 can be a dual planetary mixer.

[0016] Preferably, in step S1, the first vinyl silicone resin, the first end-vinyl silicone oil, the silicone oil-vapor silicone premix, the iron oxide red, and the heat resistant agent are mixed and vacuum dehydrated at 105°C to 120°C for 1 to 2 hours. After cooling to 30°C to 40°C, the end-side hydrogen-containing silicone oil, the inhibitor, and the coupling agent are added and vacuum mixed for 20 to 30 minutes to obtain component A.

[0017] Preferably, in step S2, the second vinyl silicone resin and the second end vinyl silicone oil are vacuum mixed for 20 min to 60 min, and then the catalyst is added and vacuum mixed for 20 min to 30 min to obtain component B.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The vinyl silicone resin used in this invention has a high crosslinking density after curing and crosslinking with end-side hydrogen-containing silicone oil, forming a dense and stable crosslinking network. Unlike the linear structure of end-vinyl silicone oil, the structure of the silicone resin after curing greatly inhibits the cycle degradation reaction, ensuring that the silicone adhesive has high tensile strength after curing and good high-temperature aging resistance. End-vinyl silicone oil is used to ensure that the silicone adhesive has sufficient elongation at break after curing. Silicone oil-vaporized silicone premix is ​​used to ensure the processability of the silicone adhesive during use.

[0019] (2) This invention uses a compound of iron oxide red and a heat resistant agent (cerium oxide). Iron oxide red (Fe2O3) is inexpensive, and its stable α-type crystal structure can effectively absorb and reflect thermal radiation, thus delaying the thermal oxidation of silica gel at the physical level. The Fe on the surface of iron oxide red... 3+ It can combine with free radicals generated after thermal oxidation, terminating the chain reaction of molecular chain breakage initiated by free radicals. The extensive use of iron oxide red can reduce the amount of heat-resistant agent (cerium oxide), thereby improving the high-temperature aging resistance of silicone adhesives while taking cost into account.

[0020] (3) The complex crosslinking agent used in this invention enables the silicone adhesive to have a better shear failure mode when bonding steel, aluminum, anodized aluminum and ceramics. Under the premise of excellent adhesion, the high crosslinking density also enables the silicone adhesive to have high tensile shear strength after curing and high temperature aging when bonding the above materials. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.

[0022] Example 1 This embodiment provides an organosilicon adhesive, the composition of which is as follows: The material allocation for Group A is shown in the table below:

[0023] The material allocation for Group B is shown in the table below:

[0024] The preparation method of silicone adhesive is as follows: Preparation of Component A: According to the composition in the table, vinyl silicone resin, terminal vinyl silicone oil, silicone oil-gas silicone premix, iron oxide red and heat resistant agent are added to a double planetary mixer and mixed. Vacuum dehydration is carried out at 110°C for 2 hours. After cooling to 40°C, terminal hydrogen-containing silicone oil, inhibitor and coupling agent are added and vacuum mixed for 20 minutes to obtain the final product.

[0025] Preparation of component B: According to the composition in the table, the vinyl silicone resin and the terminal vinyl silicone oil are vacuum mixed in a dual planetary mixer for 20 min, and then the catalyst is added and vacuum mixed for 20 min to obtain the final product.

[0026] When using silicone adhesive, mix component A and component B at a mass ratio of 10:1 and cure at 100°C for 6 hours.

[0027] Example 2 This embodiment provides an organosilicon adhesive, the composition of which is as follows: The material allocation for Group A is shown in the table below:

[0028] The material allocation for Group B is shown in the table below:

[0029] The preparation method is the same as in Example 1.

[0030] Example 3 This embodiment provides an organosilicon adhesive, the composition of which is as follows: The material allocation for Group A is shown in the table below:

[0031] The material allocation for Group B is shown in the table below:

[0032] The preparation method is the same as in Example 1.

[0033] Example 4 This embodiment provides an organosilicon adhesive, the composition of which is as follows: The material allocation for Group A is shown in the table below:

[0034] The material allocation for Group B is shown in the table below:

[0035] The preparation method is the same as in Example 1.

[0036] Example 5 This embodiment provides an organosilicon adhesive, the composition of which is as follows: The material allocation for Group A is shown in the table below:

[0037] The material allocation for Group B is shown in the table below:

[0038] The preparation method is the same as in Example 1.

[0039] Comparative Example 1 This comparative example provides an organosilicon adhesive, which differs from Example 1 in that the iron oxide red in component A is replaced by an equal amount of Haiyang powder crystalline silica micro powder HY-G10, while the remaining materials and preparation methods are the same as in Example 1.

[0040] Comparative Example 2 This comparative example provides an organosilicon adhesive, which differs from Example 1 in that the heat-resistant agent in component A is replaced by an equal amount of iron oxide red RO3097, while the remaining materials and preparation method are the same as in Example 1.

[0041] Comparative Example 3 This comparative example provides an organosilicon adhesive, which differs from Example 1 in that the vinyl silicone resin in component A is replaced by an equal amount of a mixture of vinyl-terminated silicone oil A and vinyl-terminated silicone oil B in a mass ratio of 16.3:11.1. The vinyl-terminated silicone oil A has a viscosity of 105000 mPa·s and a vinyl content of 0.06 wt%, while the vinyl-terminated silicone oil B has a viscosity of 25 mPa·s and a vinyl content of 3 wt%. The remaining materials and preparation methods are the same as in Example 1.

[0042] Comparative Example 4 This comparative example provides an organosilicon adhesive, which differs from Example 1 in that the coupling agent in component A is replaced by an equal amount of a mixture of 3-glycidyl etheroxypropyltrimethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane in a mass ratio of 2:1. The remaining materials and preparation methods are the same as in Example 1.

[0043] Performance Tests and Results The tensile strength at break, elongation at break, and tensile shear strength of the silicone adhesives prepared in Examples 1-5 and Comparative Examples 1-4 were tested respectively. The tensile strength at break, elongation at break, and tensile shear strength of the silicone adhesives prepared in Examples 1-5 and Comparative Examples 1-4 after high-temperature aging were also tested. The results are shown in Table 1. The storage stability of the silicone adhesives prepared in Examples 1-5 and Comparative Examples 1-4 was also tested. The specific test methods are as follows: Tensile strength at break: Refer to GB / T 528-2009; Elongation at break: Refer to GB / T 528-2009; Tensile shear strength: Refer to GB / T 7124-2008, the adhesive layer thickness is 0.5mm, and the substrate is polished 6-series aluminum; High-temperature aging conditions: 300℃ for 30 minutes; Storage stability: Observe whether gelling and normal curing occur after storing at 70℃ for 7 days.

[0044] Table 1 Performance test results of silicone adhesives in each embodiment and comparative example

[0045] The silicone adhesives of Examples 1-5 and Comparative Examples 1-4 did not gel and cured normally after the storage stability test.

[0046] As can be seen from Table 1, the silicone adhesive provided by the present invention still has high tensile strength, elongation at break and tensile shear strength after curing and aging at 300℃ for 30 min. The tensile strength at break after high temperature aging is ≥3MPa, the elongation at break after high temperature aging is ≥80%, and the tensile shear strength after high temperature aging is ≥3MPa.

[0047] As can be seen from the examples and comparative examples, the iron oxide red and vinyl silicone resin used in this invention, with the assistance of the heat-resistant agent, ensure that the silicone adhesive still has high tensile strength, elongation at break and tensile shear strength after high-temperature aging after curing. The compounded coupling agent also takes into account the tensile shear strength of the silicone adhesive after curing and high-temperature aging, so that the silicone adhesive provided by this invention has the characteristics of high temperature resistance, high shear strength and high toughness.

[0048] Unless otherwise specified, all raw materials used in this invention are existing substances that can be purchased directly from the market.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An organosilicon adhesive, characterized in that, Includes component A and component B; Component A comprises a first vinyl silicone resin, a first end-vinyl silicone oil, a silicone oil-vapor silicone premix, an end-hydrogen-containing silicone oil, iron oxide red, a heat resistant agent, a coupling agent, and an inhibitor; wherein the coupling agent comprises a first coupling agent and a second coupling agent, the first coupling agent comprising a silane polymer, and the second coupling agent comprising at least one of 3-glycidyl etheroxypropyltrimethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane; Component B includes a second vinyl silicone resin, a second end vinyl silicone oil, and a catalyst.

2. The silicone adhesive according to claim 1, characterized in that, The mass percentage of component A, calculated as 100%, includes: 10% to 40% of the first vinyl silicone resin, 10% to 20% of the first end-vinyl silicone oil, 20% to 50% of the silicone oil-vapor silicone premix, 1% to 10% of the end-side hydrogen-containing silicone oil, 10% to 30% of the iron oxide red, 1% to 5% of the heat resistant agent, 1% to 5% of the coupling agent, and 0.05% to 0.2% of the inhibitor.

3. The silicone adhesive according to claim 1, characterized in that, The B component, by mass percentage (100%), comprises: 40% to 60% of the second vinyl silicone resin, 40% to 60% of the second end vinyl silicone oil, and 0.1% to 1% of the catalyst.

4. The silicone adhesive according to claim 1, characterized in that, The first vinyl silicone resin has a vinyl content of 0.9wt%~1.4wt%, a viscosity of 10000mPa·s~100000mPa·s, and a resin content greater than or equal to 50wt%; and / or, The first-terminal vinyl silicone oil has a vinyl content of 0.06wt%~0.3wt% and a viscosity of 1000mPa·s~100000mPa·s; and / or, The vinyl content of the silicone oil-gas silicone premix is ​​0.04wt%~0.24wt%; and / or, The hydrogen-containing silicone oil on the end side has a silane content of 0.5wt%~0.9wt% and a viscosity of 15mPa·s~80mPa·s.

5. The silicone adhesive according to claim 1, characterized in that, The heat-resistant agent is cerium oxide; and / or, The inhibitors include at least one of polyvinyl polymers, ethynylcyclohexanol, and trimethyldodecylynol.

6. The silicone adhesive according to claim 1, characterized in that, The silane polymer includes at least one of epoxy silane coupling agent oligomers and acyl silane coupling agent oligomers.

7. The silicone adhesive according to claim 1, characterized in that, The second vinyl silicone resin has a vinyl content of 0.9wt%~1.4wt%, a viscosity of 10000mPa·s~100000mPa·s, and a resin content greater than or equal to 50wt%; and / or, The second-terminated vinyl silicone oil has a vinyl content of 0.06wt%~0.3wt% and a viscosity of 1000mPa·s~100000mPa·s; and / or, The catalyst is a platinum catalyst.

8. A method for preparing the silicone adhesive according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix the first vinyl silicone resin, the first end vinyl silicone oil, the silicone oil-vapor silicone premix, the iron oxide red and the heat resistant agent, and then add the end hydrogen-containing silicone oil, the inhibitor and the coupling agent to obtain component A; S2. Mix the second vinyl silicone resin and the second terminal vinyl silicone oil, then add the catalyst and mix to obtain component B.

9. The method for preparing the silicone adhesive according to claim 8, characterized in that, In step S1, the first vinyl silicone resin, the first end-vinyl silicone oil, the silicone oil-gas silicone premix, the iron oxide red, and the heat resistant agent are mixed and vacuum dehydrated at 105℃~120℃ for 1h~2h. After cooling to 30℃~40℃, the end-side hydrogen-containing silicone oil, the inhibitor, and the coupling agent are added and vacuum dehydrated for 20min~30min to obtain component A.

10. The method for preparing the silicone adhesive according to claim 8, characterized in that, In step S2, the second vinyl silicone resin and the second end vinyl silicone oil are vacuum mixed for 20 min to 60 min, and then the catalyst is added and vacuum mixed for 20 min to 30 min to obtain component B.

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