Thermally conductive potting adhesive, preparation method and application thereof

Abstract

The application discloses a heat-conducting pouring sealant and a preparation method and application thereof, and belongs to the field of adhesives. The heat-conducting pouring sealant comprises the following raw materials in mass fractions: 70-130 parts of vinyl silicone oil; 10-35 parts of hydrogen-containing silicone oil mixture; 1-5 parts of filler modifier; 10-30 parts of methyl MQ resin; 150-450 parts of filler; 0.05-0.3 parts of inhibitor; and 0.1-1.5 parts of catalyst. The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil, and the mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is (5-8):1. The heat-conducting pouring sealant has the characteristics of low modulus, high toughness and good surface tackiness, and the pouring sealant can be completely torn off from components, thereby facilitating the rework of a photovoltaic power generation system such as an inverter. In addition, the heat-conducting pouring sealant also has the characteristics of low viscosity, high flow and excellent sedimentation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of adhesives, and particularly relates to a heat-conducting pouring sealant and a preparation method and application thereof. BACKGROUND

[0002] With the development of micro inverters, the demand for pouring sealants in inverters is also increasing. As an important component of photovoltaic power generation systems, micro inverters are often used outdoors and are often affected by various extreme weather conditions. Therefore, the pouring sealant has high requirements for weather resistance, waterproofness, low-temperature resistance and the like to improve the environmental adaptability of the micro inverter. In addition, to cope with the problem of cracking in the later stage, the modulus and hardness of the general inverter pouring sealant are relatively high. However, the components in the micro inverter are relatively small, and they are more likely to crack in an environment with a relatively large modulus or a relatively large modulus change, thereby causing damage. Therefore, it is urgent to develop a pouring sealant with low modulus, good weather resistance, waterproofness and low-temperature resistance to adapt to the micro inverter.

[0003] The main way to improve the waterproofness of the pouring sealant is to improve the adhesion between the pouring sealant and the component. At present, the main methods for improving the adhesion of the pouring sealant include: (1) adding an adhesion enhancer, which can greatly enhance the adhesion of the pouring sealant to the surface of the base material. However, the adhesion of the enhancer is irreversible, and once the inverter is poured, it is difficult to rework, which will greatly affect the manufacturing cost of the micro inverter. (2) greatly excessive terminal hydrogen, the excessive unreacted terminal hydrogen on the surface of the pouring sealant can form good adhesion with the base material. However, this method often requires a relatively low hydrogen / vinyl ratio in the system. In the case of low hydrogen content, the excessive terminal hydrogen will continuously chain extend in the crosslinked network of the pouring sealant, and only a small part of crosslinking points will be formed, thereby reducing the toughness and making it difficult for the pouring sealant to be completely torn off from the surface of the base material.

[0004] In addition, due to the presence of many small components in the micro inverter, the pouring sealant applied in this scenario should also have low viscosity and low thixotropy to ensure that the glue can fully contact the surface of the components. However, low viscosity and low thixotropy often bring the disadvantage of poor sedimentation, which will make the pouring sealant difficult to transport and store, and a series of complicated processes will be required before use. SUMMARY

[0005] In order to overcome the problems existing in the prior art, one of the purposes of the present application is to provide a heat-conducting pouring sealant, which is provided by adding methyl MQ resin and reasonably matching terminal hydrogen-containing silicone oil, and has low modulus, certain adhesion and reworkability.

[0006] The second object of the present application is to provide a preparation method of the heat-conducting pouring sealant, which comprises modifying fillers by a filler modifier to prepare a base material, and then diluting the fillers, thereby providing a heat-conducting pouring sealant with low viscosity, high flow and excellent sedimentation.

[0007] The third object of the present application is to provide an application of the heat-conducting pouring sealant in a photovoltaic power generation system.

[0008] To achieve the above objects, the present application adopts the following technical solutions:

[0009] The first aspect of the present application provides a heat-conducting pouring sealant, which comprises the following raw materials in mass fractions: 70-130 parts of vinyl silicone oil; 10-35 parts of a hydrogen-containing silicone oil mixture; 1-5 parts of a filler modifier; 10-30 parts of a methyl MQ resin; 150-450 parts of fillers; 0.05-0.3 parts of an inhibitor; and 0.1-1.5 parts of a catalyst.

[0010] Preferably, the mass fraction of the vinyl silicone oil in the heat-conducting pouring sealant is 75-125 parts; further preferably, the mass fraction of the vinyl silicone oil in the heat-conducting pouring sealant is 80-120 parts; and more preferably, the mass fraction of the vinyl silicone oil in the heat-conducting pouring sealant is 85-115 parts.

[0011] Preferably, the mass fraction of the hydrogen-containing silicone oil mixture in the heat-conducting pouring sealant is 12-30 parts; further preferably, the mass fraction of the hydrogen-containing silicone oil mixture in the heat-conducting pouring sealant is 15-25 parts; and more preferably, the mass fraction of the hydrogen-containing silicone oil mixture in the heat-conducting pouring sealant is 16-20 parts.

[0012] Preferably, the mass fraction of the filler modifier in the heat-conducting pouring sealant is 1.5-4.5 parts; further preferably, the mass fraction of the filler modifier in the heat-conducting pouring sealant is 2-4 parts; and more preferably, the mass fraction of the filler modifier in the heat-conducting pouring sealant is 2.5-3.5 parts.

[0013] Preferably, the mass fraction of the methyl MQ resin in the heat-conducting pouring sealant is 11-25 parts; further preferably, the mass fraction of the methyl MQ resin in the heat-conducting pouring sealant is 12-20 parts; and more preferably, the mass fraction of the methyl MQ resin in the heat-conducting pouring sealant is 13-18 parts.

[0014] Preferably, the mass fraction of the filler in the heat-conducting pouring sealant is 180-400 parts; further preferably, the mass fraction of the filler in the heat-conducting pouring sealant is 200-350 parts; more preferably, the mass fraction of the filler in the heat-conducting pouring sealant is 220-300 parts.

[0015] Preferably, the mass fraction of the inhibitor in the heat-conducting pouring sealant is 0.06-0.25 parts; further preferably, the mass fraction of the inhibitor in the heat-conducting pouring sealant is 0.07-0.2 parts; more preferably, the mass fraction of the inhibitor in the heat-conducting pouring sealant is 0.08-0.15 parts.

[0016] Preferably, the mass fraction of the catalyst in the heat-conducting pouring sealant is 0.15-1.2 parts; further preferably, the mass fraction of the catalyst in the heat-conducting pouring sealant is 0.2-1 parts; more preferably, the mass fraction of the catalyst in the heat-conducting pouring sealant is 0.3-0.8 parts.

[0017] Preferably, the heat-conducting pouring sealant comprises the following mass fractions of raw materials: 75-125 parts of vinyl silicone oil; 12-30 parts of hydrogen-containing silicone oil mixture; 1.5-4.5 parts of filler modifier; 11-25 parts of methyl MQ resin; 180-400 parts of filler; 0.06-0.25 parts of inhibitor; and 0.15-1.2 parts of catalyst.

[0018] Further preferably, the heat-conducting pouring sealant comprises the following mass fractions of raw materials: 80-120 parts of vinyl silicone oil; 15-25 parts of hydrogen-containing silicone oil mixture; 2-4 parts of filler modifier; 12-20 parts of methyl MQ resin; 200-350 parts of filler; 0.07-0.2 parts of inhibitor; and 0.2-1 parts of catalyst.

[0019] More preferably, the heat-conducting pouring sealant comprises the following mass fractions of raw materials: 85-115 parts of vinyl silicone oil; 16-20 parts of hydrogen-containing silicone oil mixture; 2.5-3.5 parts of filler modifier; 13-18 parts of methyl MQ resin; 220-300 parts of filler; 0.08-0.15 parts of inhibitor; and 0.3-0.8 parts of catalyst.

[0020] Preferably, the mass ratio of the hydrogen content of the end hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil in the heat-conducting pouring sealant is (5.2-7.5):1; further preferably, the mass ratio of the hydrogen content of the end hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil in the heat-conducting pouring sealant is (5.5-7):1; more preferably, the mass ratio of the hydrogen content of the end hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil in the heat-conducting pouring sealant is (5.8-6.5):1.

[0021] Preferably, the hydrogen content of the end-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.05-0.3wt%; further preferably, the hydrogen content of the end-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.06-0.25wt%; more preferably, the hydrogen content of the end-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.08-0.2wt%.

[0022] Preferably, the hydrogen content of the side-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.1-2wt%; further preferably, the hydrogen content of the side-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.3-1.5wt%; more preferably, the hydrogen content of the side-hydrogen-containing silicone oil in the heat-conducting pouring sealant is 0.5-1wt%.

[0023] Preferably, the vinyl content of the vinyl-containing silicone oil in the heat-conducting pouring sealant is 0.1-2wt%; further preferably, the vinyl content of the vinyl-containing silicone oil in the heat-conducting pouring sealant is 0.3-1.8wt%; more preferably, the vinyl content of the vinyl-containing silicone oil in the heat-conducting pouring sealant is 0.35-1wt%.

[0024] Preferably, the filler modifier in the heat-conducting pouring sealant comprises at least one of methyltrimethoxysilane, vinyltrimethoxysilane, trimethoxysilane, 3-aminopropyltriethoxysilane or N-2-aminoethyl-3-aminopropyltrimethoxysilane; further preferably, the filler modifier in the heat-conducting pouring sealant comprises at least one of methyltrimethoxysilane, vinyltrimethoxysilane or trimethoxysilane; more preferably, the filler modifier in the heat-conducting pouring sealant comprises at least one of methyltrimethoxysilane or vinyltrimethoxysilane.

[0025] Preferably, the filler in the heat-conducting pouring sealant comprises at least one of silicon powder, aluminum hydroxide, aluminum oxide or magnesium oxide; further preferably, the filler in the heat-conducting pouring sealant comprises at least one of silicon powder, aluminum hydroxide or aluminum oxide; more preferably, the filler in the heat-conducting pouring sealant comprises silicon powder, aluminum hydroxide or a combination thereof.

[0026] Preferably, the mass ratio of the filler modifier to the filler in the heat-conducting pouring sealant is (0.5-5):100; further preferably, the mass ratio of the filler modifier to the filler in the heat-conducting pouring sealant is (0.8-3):100; more preferably, the mass ratio of the filler modifier to the filler in the heat-conducting pouring sealant is (1-2):100.

[0027] Preferably, the content of the MQ resin in the methyl MQ resin in the heat-conducting pouring sealant is 5-20 wt%; further preferably, the content of the MQ resin in the methyl MQ resin in the heat-conducting pouring sealant is 7-15 wt%; and more preferably, the content of the MQ resin in the methyl MQ resin in the heat-conducting pouring sealant is 9-12 wt%.

[0028] Preferably, the rotary viscosity of the vinyl silicone oil at 25°C in the heat-conducting pouring sealant is 50-400 mPa·s; further preferably, the rotary viscosity of the vinyl silicone oil at 25°C in the heat-conducting pouring sealant is 100-350 mPa·s; and more preferably, the rotary viscosity of the vinyl silicone oil at 25°C in the heat-conducting pouring sealant is 150-300 mPa·s.

[0029] Preferably, the rotary viscosity of the hydrogen-containing silicone oil mixture at 25°C in the heat-conducting pouring sealant is 5-150 mPa·s; further preferably, the rotary viscosity of the hydrogen-containing silicone oil mixture at 25°C in the heat-conducting pouring sealant is 10-100 mPa·s; and more preferably, the rotary viscosity of the hydrogen-containing silicone oil mixture at 25°C in the heat-conducting pouring sealant is 15-80 mPa·s.

[0030] Preferably, the inhibitor in the heat-conducting pouring sealant comprises at least one of an alkyne compound, a phthalimide compound or a maleate compound; further preferably, the inhibitor in the heat-conducting pouring sealant comprises at least one of an alkyne compound or a phthalimide compound; and more preferably, the inhibitor in the heat-conducting pouring sealant is selected from an alkyne compound.

[0031] Preferably, the catalyst in the heat-conducting pouring sealant is selected from a platinum catalyst; further preferably, the catalyst in the heat-conducting pouring sealant comprises at least one of a platinum-vinylsiloxane complex, an alcohol-modified chloroplatinic acid catalyst and a platinum-alkyne-based complex; and more preferably, the catalyst in the heat-conducting pouring sealant is selected from a platinum-vinylsiloxane complex.

[0032] The second aspect of the present application provides a preparation method of the heat-conducting pouring sealant of the first aspect of the present application, comprising the following steps:

[0033] 1) mixing a filler modifier and 35-45% of the formula amount of vinyl silicone oil, then adding 60-80% of the formula amount of filler to mix, and cooling to obtain a base G;

[0034] 2) mixing 40-60% of the formula amount of the base G obtained in step 1), 35-45% of the formula amount of vinyl silicone oil, 10-20% of the formula amount of filler and a catalyst to obtain a mixture A;

[0035] 3) mixing the remaining formulation amount of the base G, the vinyl silicone oil, the filler, and the hydrogen-containing silicone oil, the methyl MQ resin and the inhibitor obtained in step 1) to obtain a mixture B;

[0036] 4) mixing the mixture A obtained in step 2) and the mixture B obtained in step 3) to obtain the heat-conducting pouring sealant.

[0037] Preferably, in the preparation method, the mixing temperature in step 1) is 100-200℃; further preferably, in the preparation method, the mixing temperature in step 1) is 120-180℃; more further preferably, in the preparation method, the mixing temperature in step 1) is 140-160℃.

[0038] Preferably, in the preparation method, after the mixing of the filler in step 1), further mixing is performed under vacuum.

[0039] Preferably, in step 1), the vacuum condition is ≤-0.095 MPa.

[0040] Preferably, in step 1), the mixing temperature under the vacuum condition is 100-200℃; further preferably, in step 1), the mixing temperature under the vacuum condition is 120-180℃; more further preferably, in step 1), the mixing temperature under the vacuum condition is 140-160℃.

[0041] Preferably, in step 1), the mixing time under the vacuum condition is 0.3-3h; further preferably, in step 1), the mixing time under the vacuum condition is 0.5-2h; more further preferably, in step 1), the mixing time under the vacuum condition is 0.8-1.5h.

[0042] Preferably, in the preparation method, the mixing in step 2) is performed under vacuum.

[0043] Preferably, in step 2), the mixing temperature under the vacuum condition is 20-30℃; further preferably, in step 2), the mixing temperature under the vacuum condition is 22-28℃; more further preferably, in step 2), the mixing temperature under the vacuum condition is 24-26℃.

[0044] Preferably, in step 2), the mixing time under the vacuum condition is 0.3-3h; further preferably, in step 2), the mixing time under the vacuum condition is 0.5-2h; more further preferably, in step 2), the mixing time under the vacuum condition is 0.8-1.5h.

[0045] Preferably, in the preparation method, the mixing in step 3) is performed under vacuum.

[0046] Preferably, in step 3), the mixing temperature under the vacuum condition is 20-30℃; further preferably, in step 3), the mixing temperature under the vacuum condition is 22-28℃; more further preferably, in step 3), the mixing temperature under the vacuum condition is 24-26℃.

[0047] Preferably, in step 3), the mixing time under the vacuum condition is 0.3-3h; further preferably, in step 3), the mixing time under the vacuum condition is 0.5-2h; more further preferably, in step 3), the mixing time under the vacuum condition is 0.8-1.5h.

[0048] The third aspect of the present application provides an application of the heat-conducting pouring sealant prepared by the preparation method of the second aspect of the present application or the heat-conducting pouring sealant of the first aspect of the present application in a photovoltaic power generation system.

[0049] Preferably, the photovoltaic power generation system comprises at least one of an inverter, a photovoltaic module and a photovoltaic controller.

[0050] Preferably, the inverter is a micro inverter.

[0051] The present application has the following beneficial effects:

[0052] 1. The present application has the characteristics of low modulus and high toughness by reasonably matching the proportion of hydrogen contained in the end side, in addition, adding methyl MQ resin in the pouring sealant can increase the surface adhesion of the pouring sealant, and does not affect the complete tearing of the pouring sealant from the components, which is convenient for rework of the photovoltaic power generation system such as inverters.

[0053] 2. The present application has the characteristics of low viscosity and high flow by combining filler modification to increase the compatibility of fillers and silicone oil, and the characteristics of thixotropy formed by fillers without modification and silicone oil, preparing a mixture of modified fillers and silicone oil in the early stage, adding part of the silicone oil to dilute the base material in the later stage, and adding part of the unmodified fillers to make the finished product have a certain thixotropy, so that the pouring sealant also has the excellent sedimentation performance.

[0054] 3. The preparation method of the present application is simple and convenient to operate, and the low modulus, surface with certain adhesion but reworkable heat-conducting pouring sealant can be prepared by operating the preparation raw materials of each mass fraction of the present application, which also has the characteristics of low viscosity, high flow and excellent sedimentation. DETAILED DESCRIPTION

[0055] The application will be further described in detail by specific examples. It should also be understood that the following examples are only used to further illustrate the application and cannot be understood as limiting the scope of the application. Some non-essential improvements and adjustments made by those skilled in the art according to the principles set forth in the application are within the scope of the application. The following examples of specific process parameters are only one example in the appropriate range, i.e. those skilled in the art can make appropriate selection within the range according to the description herein, and are not limited to the specific data in the following examples. In addition to the specifically described raw materials, other raw materials can be obtained by market or conventional methods.

[0056] Methyl MQ resin, also known as methyl MQ type silicone resin, is a new type of organic silicon polymer material with a three-dimensional (non-linear) structure formed by Si-O bonds.

[0057] In the specific examples and comparative examples of the application, the hydrogen content of the terminal hydrogen-containing silicone oil is 0.1 wt%; the hydrogen content of the side hydrogen-containing silicone oil is 0.55 wt%; the vinyl content of the vinyl silicone oil is 0.35 wt%; the MQ resin content in the methyl MQ resin is 10 wt%; the filler is silicon powder and aluminum hydroxide; the inhibitor is ethynyl cyclohexanol, and the catalyst is platinum-vinyl siloxane complex; the rotational viscosity of the vinyl silicone oil at 25℃ is 50-400 mPa·s; and the rotational viscosity of the hydrogen-containing silicone oil mixture at 25℃ is 5-150 mPa·s.

[0058] Example 1

[0059] A heat-conducting pouring sealant comprises the following raw materials in mass fraction:

[0060] Vinyl silicone oil: 94 parts;

[0061] Hydrogen-containing silicone oil mixture: 17.5 parts;

[0062] Filler modifier: 3 parts;

[0063] Methyl MQ resin: 15 parts;

[0064] Filler: 250 parts;

[0065] Inhibitor: 0.1 part;

[0066] Catalyst: 0.5 part;

[0067] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0068] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0069] The filler modifier is vinyl trimethoxysilane.

[0070] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0071] (1) In the first stirring pot, 44 parts of vinyl silicone oil and 3.0 parts of vinyl trimethoxysilane are added, and after being heated and stirred to 150°C, 180 parts of silicon powder filler is added, and after being heated and stirred to 150°C again, vacuum extraction is performed at 150°C, and after being stirred for 1 h, it is cooled to 40°C to obtain a base G1 for standby;

[0072] (2) In the second stirring pot, half of the G1 base obtained in (1) is added, 40 parts of vinyl silicone oil, 35 parts of aluminum hydroxide filler, and 0.5 parts of catalyst are added, and vacuum extraction is performed at room temperature for 1 h to form a mixture A1;

[0073] (3) In the third stirring pot, half of the G1 base obtained in (1) is added, 10 parts of vinyl silicone oil, 17 parts of hydrogen-containing silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 parts of inhibitor are added, and vacuum extraction is performed at room temperature for 1 h to form a mixture B1;

[0074] (4) The mixture A1 and the mixture B1 are mixed by stirring at room temperature to obtain the heat-conducting pouring sealant product (C1) of the present embodiment.

[0075] Example 2

[0076] A heat-conducting pouring sealant comprises the following mass parts of preparation raw materials:

[0077] Vinyl silicone oil: 93 parts;

[0078] Hydrogen-containing silicone oil mixture: 18.5 parts;

[0079] Filler modifier: 3 parts;

[0080] Methyl MQ resin: 15 parts;

[0081] Filler: 250 parts;

[0082] Inhibitor: 0.1 parts;

[0083] Catalyst: 0.5 parts;

[0084] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0085] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6.5:1;

[0086] The filler modifier is vinyl trimethoxysilane.

[0087] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0088] (1) In a first stirring pot, 44 parts of vinyl silicone oil and 3.0 parts of vinyl trimethoxysilane were added, and after stirring and heating to 150°C, 180 parts of silicon powder filler were added, and after stirring and heating to 150°C again, vacuum was applied and the temperature was kept at 150°C, and after stirring for 1h, the temperature was cooled to 40°C to obtain base material G’1 ready for use;

[0089] (2) In a second stirring pot, half the amount of G’1 base material obtained in (1) was added, 40 parts of vinyl silicone oil, 35 parts of aluminum hydroxide filler, and 0.5 parts of catalyst were added, and vacuum was applied at room temperature and stirred for 1h to form mixture A’1;

[0090] (3) In a third stirring pot, half the amount of G’1 base material obtained in (1) was added, 9 parts of vinyl silicone oil, 18 parts of hydrogen-terminated silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 parts of inhibitor were added, and vacuum was applied at room temperature and stirred for 1h to form mixture B’1;

[0091] (4) Mixture A’1 and mixture B’1 were mixed at room temperature to obtain the finished product of the heat-conducting pouring sealant (C’1) of the present embodiment.

[0092] Example 3

[0093] A heat-conducting pouring sealant, comprising the following mass fractions of raw materials for preparation:

[0094] vinyl silicone oil: 94 parts;

[0095] hydrogen-containing silicone oil mixture: 17.5 parts;

[0096] filler modifier: 3 parts;

[0097] methyl MQ resin: 15 parts;

[0098] filler: 250 parts;

[0099] inhibitor: 0.1 parts;

[0100] catalyst: 0.5 parts;

[0101] The hydrogen-containing silicone oil mixture is a mixture of hydrogen-terminated silicone oil and side hydrogen-containing silicone oil;

[0102] The mass ratio of the hydrogen content of the hydrogen-terminated silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0103] The filler modifier is vinyl trimethoxysilane.

[0104] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0105] (1) In the first stirring pot, 44 parts of vinyl silicone oil and 3.0 parts of vinyl trimethoxysilane were added, and after being heated and stirred to 150°C, 200 parts of silicon powder filler were added, and after being heated and stirred to 150°C again, vacuum was applied and the temperature was kept at 150°C, and after being stirred for 1h, the temperature was cooled to 40°C to obtain the base G”1 ready for use;

[0106] (2) In the second stirring pot, half the amount of G”1 base obtained in (1) was added, 40 parts of vinyl silicone oil, 25 parts of alumina filler, and 0.5 parts of catalyst were added, and vacuum was applied at room temperature and stirred for 1h to form mixture A”1;

[0107] (3) In the third stirring pot, half the amount of G”1 base obtained in (1) was added, 10 parts of vinyl silicone oil, 17 parts of terminal hydrogen-containing silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, 25 parts of alumina filler, and 0.1 parts of inhibitor were added, and vacuum was applied at room temperature and stirred for 1h to form mixture B”1;

[0108] (4) The mixture A”1 and the mixture B”1 were mixed by stirring at room temperature to obtain the finished product of the heat-conducting pouring sealant (C”1) of the example.

[0109] Comparative Example 1

[0110] A heat-conducting pouring sealant comprising the following mass fractions of raw materials for preparation:

[0111] Vinyl silicone oil: 94 parts;

[0112] Hydrogen-containing silicone oil mixture: 17.5 parts;

[0113] Filler modifier: 3 parts;

[0114] Filler: 250 parts;

[0115] Inhibitor: 0.1 parts;

[0116] Catalyst: 0.5 parts;

[0117] Methyl silicone oil: 15 parts;

[0118] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0119] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0120] The filler modifier is vinyl trimethoxysilane;

[0121] The viscosity of the methyl silicone oil at 25°C is 1000 mPa·s.

[0122] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0123] (1) The base material G2 was obtained by the method of (1) in Example 1 for standby;

[0124] (2) The mixture A2 was obtained by the method of (2) in Example 1;

[0125] (3) In the third stirring pot, half of the G2 base material obtained in (1) was added, 10 parts of vinyl silicone oil, 17 parts of hydrogen-containing silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl silicone oil, 35 parts of aluminum hydroxide filler, and 0.1 parts of inhibitor were added, vacuum stirring at room temperature for 1 h to form mixture B2;

[0126] (4) The mixture A2 and the mixture B2 were mixed by stirring at room temperature to obtain the finished product of the heat-conducting pouring sealant (C2) of the present comparative example.

[0127] Comparative Example 2

[0128] A heat-conducting pouring sealant comprising the following mass fractions of raw materials:

[0129] Vinyl silicone oil: 94 parts;

[0130] Hydrogen-containing silicone oil mixture: 17.5 parts;

[0131] Filler modifier: 3 parts;

[0132] Methyl MQ resin: 5 parts;

[0133] Filler: 250 parts;

[0134] Inhibitor: 0.1 parts;

[0135] Catalyst: 0.5 parts;

[0136] Methyl silicone oil: 10 parts;

[0137] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0138] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0139] The filler modifier is vinyl trimethoxysilane;

[0140] The viscosity of the methyl silicone oil at 25°C is 1000 mPa·s.

[0141] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0142] (1) The base material G3 was obtained by the method of (1) in Example 1 for standby;

[0143] (2) The mixture A3 was obtained by the method of (2) in Example 1;

[0144] (3) In the third stirring pot, add half amount of G3 base obtained in (1), 10 parts of vinyl silicone oil, 17 parts of hydrogen-terminated silicone oil, 0.5 parts of hydrogen-terminated silicone oil, 10 parts of methyl silicone oil, 5 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 part of inhibitor, vacuum stirring at room temperature for 1 h to form mixture B3;

[0145] (4) Mix mixture A3 and mixture B3 at room temperature to obtain the final product of the heat-conducting pouring sealant (C3) of the present comparative example.

[0146] Comparative Example 3

[0147] A heat-conducting pouring sealant comprising the following raw materials in mass parts:

[0148] Vinyl silicone oil: 94 parts;

[0149] Hydrogen-terminated silicone oil mixture: 18.32 parts;

[0150] Filler modifier: 3 parts;

[0151] Methyl MQ resin: 15 parts;

[0152] Filler: 250 parts;

[0153] Inhibitor: 0.1 part;

[0154] Catalyst: 0.5 parts;

[0155] The hydrogen-terminated silicone oil mixture is a mixture of hydrogen-terminated silicone oil and hydrogen-terminated silicone oil;

[0156] The mass ratio of hydrogen content of the hydrogen-terminated silicone oil to that of the hydrogen-terminated silicone oil is 10:1;

[0157] The filler modifier is vinyl trimethoxysilane.

[0158] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0159] (1) Base G4 is prepared according to the method of (1) of Example 1;

[0160] (2) Mixture A4 is prepared according to the method of (2) of Example 1;

[0161] (3) In the third stirring pot, add half amount of G4 base obtained in (1), 10 parts of vinyl silicone oil, 18 parts of hydrogen-terminated silicone oil, 0.32 parts of hydrogen-terminated silicone oil, 15 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 part of inhibitor, vacuum stirring at room temperature for 1 h to form mixture B4;

[0162] (4) The mixture A4 and the mixture B4 are mixed at room temperature to obtain the heat-conducting pouring sealant product (C4) of the present comparative example.

[0163] Comparative Example 4

[0164] A heat-conducting pouring sealant comprises the following raw materials by mass fraction:

[0165] Vinyl silicone oil: 94 parts;

[0166] Hydrogen-containing silicone oil mixture: 15.86 parts;

[0167] Filler modifier: 3 parts;

[0168] Methyl MQ resin: 15 parts;

[0169] Filler: 250 parts;

[0170] Inhibitor: 0.1 part;

[0171] Catalyst: 0.5 part;

[0172] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0173] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 3:1;

[0174] The filler modifier is vinyl trimethoxysilane.

[0175] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0176] (1) The base G5 is prepared according to the method of (1) in Example 1;

[0177] (2) The mixture A5 is prepared according to the method of (2) in Example 1;

[0178] (3) Half of the G5 base obtained in (1) is added to a third stirring pot, 10 parts of vinyl silicone oil, 15 parts of terminal hydrogen-containing silicone oil, 0.86 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 part of inhibitor are added, and vacuum stirring is performed at room temperature for 1 h to form a mixture B5;

[0179] (4) The mixture A5 and the mixture B5 are mixed at room temperature to obtain the heat-conducting pouring sealant product (C5) of the present comparative example.

[0180] Comparative Example 5

[0181] A heat-conducting pouring sealant comprises the following raw materials by mass fraction:

[0182] Vinyl silicone oil: 94 parts;

[0183] hydrogen-containing silicone oil mixture: 17.5 parts;

[0184] filler modifier: 3 parts;

[0185] methyl MQ resin: 15 parts;

[0186] filler: 250 parts;

[0187] inhibitor: 0.1 part;

[0188] catalyst: 0.5 part;

[0189] the hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0190] the mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0191] the filler modifier is vinyl trimethoxysilane.

[0192] the heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0193] (1) in the first stirring pot, 44 parts of vinyl silicone oil and 3 parts of vinyl trimethoxysilane are added, and after stirring and heating to 150°C; 180 parts of silicon powder filler and 70 parts of aluminum hydroxide filler are added and stirred and heated to 150°C again, vacuumized and kept at 150°C, stirred for 1h, and then cooled to 40°C to obtain a base G6 for standby;

[0194] (2) in the second stirring pot, half the amount of G6 base obtained in (1) is added, 40 parts of vinyl silicone oil, 0.5 parts of catalyst, and vacuumized and stirred at room temperature for 1h to form a mixture A6;

[0195] (3) in the third stirring pot, half the amount of G6 base obtained in (1) is added, 10 parts of vinyl silicone oil, 17 parts of terminal hydrogen-containing silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, and 0.1 parts of inhibitor, and vacuumized and stirred at room temperature for 1h to form a mixture B6;

[0196] (4) the mixture A6 and the mixture B6 are stirred at room temperature to obtain the heat-conducting pouring sealant product (C6) of the present comparative example.

[0197] Comparative Example 6

[0198] A heat-conducting pouring sealant comprises the following preparation raw materials in mass parts:

[0199] vinyl silicone oil: 94 parts;

[0200] hydrogen-containing silicone oil mixture: 17.5 parts;

[0201] methyl MQ resin: 15 parts;

[0202] Filler: 250 parts;

[0203] Inhibitor: 0.1 part;

[0204] Catalyst: 0.5 parts;

[0205] Methyl silicone oil: 3 parts;

[0206] The hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil;

[0207] The mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is 6:1;

[0208] The viscosity of the methyl silicone oil at 25°C is 50 mPa·s.

[0209] The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps:

[0210] (1) In the first stirring pot, 44 parts of vinyl silicone oil and 3.0 parts of methyl silicone oil are added, and after stirring and heating to 150°C; 180 parts of silicon powder filler are added, and the temperature is re-raised to 150°C after stirring and heating, vacuum extraction is performed at 150°C, and after stirring for 1 h, the temperature is cooled to 40°C to obtain a base G7 for standby;

[0211] (2) In the second stirring pot, half the amount of G7 base obtained in (1) is added, 40 parts of vinyl silicone oil, 35 parts of aluminum hydroxide filler, and 0.5 parts of catalyst are added, vacuum extraction is performed at room temperature, and stirring is performed for 1 h to form a mixture A7;

[0212] (3) In the third stirring pot, half the amount of G7 base obtained in (1) is added, 10 parts of vinyl silicone oil, 17 parts of terminal hydrogen-containing silicone oil, 0.5 parts of side hydrogen-containing silicone oil, 15 parts of methyl MQ resin, 35 parts of aluminum hydroxide filler, and 0.1 parts of inhibitor are added, vacuum extraction is performed at room temperature, and stirring is performed for 1 h to form a mixture B7;

[0213] (4) The mixture A7 and the mixture B7 are mixed at room temperature to obtain the heat-conducting pouring sealant product (C7) of the present comparative example. Performance characterization:

[0214] (1) Surface tack performance characterization:

[0215] The tackiness is characterized by the peel strength of the sample to aluminum material, and the reference is GB / T 2791-1995.

[0216] (2) Rework performance characterization:

[0217] The pouring sealant is poured onto the PCB with components, and after curing at 80°C for 30 min, the glue is torn off from the PCB, and the integrity of the glue torn off from the PCB is observed.

[0218] (3) Cone-in test characterization:

[0219] Cone-in was measured using the full cone reference GB / T 269-1991.

[0220] (4) Viscosity test characterization:

[0221] Viscosity was tested according to GB / T 2794-2013 with a 6# rotor at 100 rpm.

[0222] (5) Thixotropy test characterization:

[0223] The ratio of the value tested with a 6# rotor at 10 rpm to the value tested at 100 rpm was used as a characterization.

[0224] (6) Flow test characterization:

[0225] According to the patent CN216208371U, after mixing and defoaming the AB component glue, 5g was poured on a flat aluminum foil, and the maximum diameter of the glue flowing in 5min was measured.

[0226] (7) Settling test characterization:

[0227] 300g of the obtained A and B components were placed in a 300ml static state for 14 days, and the thickness of the powder sediment at the bottom of the glue was observed.

[0228] The peel strength of the finished product C1 obtained in Example 1, the finished product C2 obtained in Comparative Example 1, and the finished product C3 obtained in Comparative Example 2 on aluminum material was measured according to the national standard GB / T2791-1995 method, which was 0.14N / mm, 0.05N / mm and 0.07N / mm, respectively. It can be seen that in the C2 formula, there is no methyl MQ resin, and it only has weak peel strength. This weak peel strength may be due to the excessive end hydrogen, which makes the surface of the potting adhesive have partially unhardened end hydrogen, thereby producing partial adhesion. In the C3 formula, there is a small amount of methyl MQ resin, but the content is too low, which leads to weak surface adhesion, while C1 has good adhesion by adding about 4% methyl MQ resin.

[0229] Table 1 Formulation and performance comparison of Examples 1, 2 and Comparative Examples 3, 4

[0230]

[0231]

[0232] The results of Examples 1 and 2 and Comparative Examples 3 and 4 are shown in Table 1. The four products all have a large taper, which indicates that the glue has a low modulus when the hydrogen content is controlled to be low. Examples 1 and 2 both have good peel strength and good rework performance. Because the taper of Example 2 is slightly smaller, the modulus and peel strength are slightly larger. By comparing the results of Comparative Example 1 and Comparative Example 3, it can be found that the peel strength of C1 and C4 is not much different, but the rework performance of C4 is worse. This can be attributed to the high proportion of terminal hydrogen content in C4, which makes the crosslinking point in the crosslinking network system of the glue less, thereby resulting in insufficient toughness, which cannot be completely torn off from the PCB with many components during rework. On the contrary, C5 with a low proportion of terminal hydrogen content can be completely torn off from the PCB, but the peel strength is low, which indicates that the excess terminal hydrogen on the surface of the glue can be beneficial to the surface adhesion of the glue.

[0233] Table 2 Performance comparison of Examples 1, 3 and Comparative Examples 5, 6

[0234]

[0235] The results of Examples 1 and 3 and Comparative Examples 5 and 6 are shown in Table 2. Examples 1 and 2 respectively use a process of first modifying the filler at high temperature to obtain a base material, and then diluting and supplementing powder. Comparative Example 5 uses a process of modifying the filler at high temperature to obtain a base material, and then diluting, without the subsequent step of supplementing powder. Comparative Example 6 does not add a filler modifier, vinyl trimethoxysilane, but the oil-powder ratio has a great influence on the viscosity of the product. In order to maintain the consistency of the oil-powder ratio, methyl silicone oil with a viscosity similar to that of the filler modifier is added, and the remaining steps are consistent with Examples 1 and 3. From the results in Table 2, it can be seen that Comparative Example 6 does not achieve the modification effect of the filler due to the absence of a filler modifier, so it has a high viscosity and thixotropy, and poor flow. After 14 days of storage, the A7 component still has partial sedimentation due to the poor compatibility between the filler and the silicone oil. In Comparative Example 5, all the fillers are modified at high temperature, and the compatibility between the filler and the silicone oil is good, so it has low viscosity and thixotropy, and excellent flow performance. However, it is worth noting that its sedimentation performance is poor, which can be attributed to the fact that although the compatibility between the filler and the silicone oil is improved, it cannot completely overcome the gravity of the filler, thereby causing partial sedimentation. Examples 1 and 3 both use a method of first adding part of the modified filler, and then supplementing part of the unmodified filler, which sacrifices part of the flow performance, but allows the system to retain part of the thixotropy to hinder the sedimentation of the filler, thereby obtaining good sedimentation performance. By modifying the filler with a filler modifier to prepare a base material, and then supplementing the filler for dilution, a heat-conducting potting glue with low viscosity, high flow, and excellent sedimentation performance is obtained.

[0236] The present application has the characteristics of low modulus, high toughness and good surface adhesion by adding methyl MQ resin and reasonably matching the hydrogen content ratio on the end side, and the potting adhesive can be completely torn off from the components, which is convenient for the photovoltaic power generation system such as inverter to rework. In addition, the present application can increase the compatibility of the filler and silicone oil by combining with the modification of the filler, and the filler and silicone oil will form the characteristics of thixotropy without modification, the mixture base of the modified filler and silicone oil is prepared in the early stage, so that the potting adhesive has the characteristics of low viscosity and high flow, and when part of the silicone oil is added to dilute the base, part of the unmodified filler is added, so that the finished product has a certain thixotropy, so that the potting adhesive also has the excellent characteristics of sedimentation. The preparation method of the present application is simple and convenient to operate, and the low modulus, surface with certain adhesion but reworkable heat-conducting potting adhesive can be prepared by operating with the prepared raw materials of each mass fraction, which also has the characteristics of low viscosity, high flow and excellent sedimentation. The heat-conducting potting adhesive prepared by the present application can be used in photovoltaic power generation system components, especially in inverters (such as micro inverters), photovoltaic components and photovoltaic controllers.

Claims

1. A heat conductive potting compound, characterized in that, The preparation raw materials include the following mass fractions: vinyl silicone oil 70-130 parts; hydrogen-containing silicone oil mixture 10-35 parts; filler modifier 1-5 parts; methyl MQ resin 10-30 parts; filler 150-450 parts; inhibitor 0.05-0.3 parts; catalyst 0.1-1.5 parts; the hydrogen-containing silicone oil mixture is a mixture of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil; the mass ratio of the hydrogen content of the terminal hydrogen-containing silicone oil to the hydrogen content of the side hydrogen-containing silicone oil is (5.8-6.5):1; the filler modifier includes at least one of methyltrimethoxysilane, vinyltrimethoxysilane or trimethoxysilane; The heat-conducting pouring sealant is prepared by a preparation method comprising the following steps: 1) mixing the filler modifier and 35-45% of the formula amount of the vinyl silicone oil, then adding 60-80% of the formula amount of the filler and mixing, and cooling to obtain base G; 2) mixing 40-60% of the formula amount of the base G obtained in step 1), 35-45% of the formula amount of the vinyl silicone oil, 10-20% of the formula amount of the filler and the catalyst to obtain mixture A; 3) mixing the remaining formula amount of the base G obtained in step 1), the vinyl silicone oil, the filler, the hydrogen-containing silicone oil mixture, the methyl MQ resin and the inhibitor to obtain mixture B; 4) mixing the mixture A obtained in step 2) and the mixture B obtained in step 3) to obtain the heat-conducting pouring sealant.

2. The heat conductive potting adhesive according to claim 1, wherein The hydrogen content of the terminal hydrogen-containing silicone oil is 0.05-0.3 wt%; And / or, the hydrogen content of the side hydrogen-containing silicone oil is 0.1-2 wt%; And / or, the vinyl content of the vinyl silicone oil is 0.1-2 wt%.

3. The heat conductive potting adhesive of claim 1, wherein The filler includes at least one of silicon powder, aluminum hydroxide, aluminum oxide or magnesium oxide.

4. The heat conductive potting adhesive of claim 1, wherein The MQ resin content in the methyl MQ resin is 5-20 wt%.

5. The heat conductive potting adhesive of claim 1, wherein The rotational viscosity of the vinyl silicone oil at 25°C is 50-400 mPa·s.

6. The heat conductive potting adhesive of claim 1, wherein The rotational viscosities of the hydrogen-containing silicone oil mixtures at 25°C are all 5-150 mPa·s; And / or, the inhibitor includes at least one of acetylenic compound, phthalimide compound or maleate compound; And / or, the catalyst is selected from platinum catalyst.

7. The method for preparing the heat-conducting pouring sealant according to any one of claims 1-6, characterized in that, comprising the following steps: 1) mixing the filler modifier and 35-45% of the formula amount of the vinyl silicone oil, then adding 60-80% of the formula amount of the filler and mixing, and cooling to obtain base G; 2) mixing 40-60% of the formula amount of the base G obtained in step 1), 35-45% of the formula amount of the vinyl silicone oil, 10-20% of the formula amount of the filler and the catalyst to obtain mixture A; 3) mixing the remaining formula amount of the base G obtained in step 1), the vinyl silicone oil, the filler, the hydrogen-containing silicone oil mixture, the methyl MQ resin and the inhibitor to obtain mixture B; 4) mixing the mixture A obtained in step 2) and the mixture B obtained in step 3) to obtain the heat-conducting pouring sealant.

8. The use of the heat-conducting pouring sealant in a photovoltaic power generation system, characterized in that, The heat-conducting pouring sealant is the heat-conducting pouring sealant according to any one of claims 1-6.

9. Use according to claim 8, characterized in that, The photovoltaic power generation system includes at least one of an inverter, a photovoltaic assembly and a photovoltaic controller.

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