A kind of organic silicon fire retardant coating and its preparation method and application

Abstract

The present invention provides a kind of organic silicon fire retardant coating and its preparation method and application, the organic silicon fire retardant coating comprises component A and component B, the component A comprises: 50 parts of vinyl silicone oil; 5-15 parts of flame retardant filler; 20-40 parts of refractory filler; 2-6 parts of water remover; 2.8-6.8 parts of adhesion promoter; 0.1-0.3 parts of catalyst; the component B comprises: 50 parts of vinyl silicone oil; 11-13 parts of hydrogen-containing silicone oil; 0.001-0.004 parts of inhibitor; 10-20 parts of flame retardant filler; 15-25 parts of refractory filler; 2-4 parts of water remover; the refractory filler in the component A comprises talcum powder and glass powder; the refractory filler in the component B comprises kaolin. The organic silicon fire retardant coating provided by the present invention has good insulation, fire resistance, crack resistance and good adhesion, and is used for the housing of the power battery box of new energy vehicles to ensure the safety of battery use.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire retardant coatings, and relates to an organosilicon fire retardant coating and a preparation method and application thereof, and in particular to a high-insulation organosilicon fire retardant coating for a power battery box shell of a new energy vehicle and a preparation method thereof. Background Art

[0002] High temperature, collision, overcharging, etc. are all potential safety hazards that may cause thermal runaway of power batteries. With the rapid development of the power battery industry, battery safety and thermal management have become the primary issues to be addressed in its transformation.

[0003] Traditional fireproof felts and fireproof mats can hardly withstand high temperatures above 1000°C. At present, new flame-retardant fireproof coatings have been developed on the market, mainly epoxy resin fireproof coatings and silicone-modified epoxy fireproof coatings, which can maintain good fire resistance at 1000-1400°C. Applying these coatings on the inner and outer shells of batteries can help control and delay the spread of fire and protect passengers from evacuating vehicles.

[0004] However, these new fire retardant coatings are also accompanied by new problems during their application: for example, epoxy fire retardant coatings are not environmentally friendly, the carbon layer is conductive after burning, the carbon layer is not strong, and the viscosity is high and difficult to spray. New silicone fire retardant coatings are rarely reported, and have problems such as complex preparation process, cracking, difficult to control curing time, and poor adhesion.

[0005] CN105238222A discloses an environmentally friendly intumescent fire-retardant coating and a preparation method thereof, which consists of two components, A and B. Component A uses epoxy resin as the main film-forming material, and adds active diluent, catalyst, carbon forming agent, foaming agent, flame retardant, auxiliary agent, and solvent; component B consists of curing agent, curing accelerator, pigment filler, auxiliary agent, refractory fiber, and solvent. In the preparation process of this method, refractory fiber is added, resulting in a complicated production process or coarse particles and poor sprayability. At the same time, organic solvents are added, which are toxic and harmful, and are not suitable for large-scale industrial use.

[0006] CN113136140A discloses an organic silicon fireproof heat-insulating coating and a preparation method thereof, which is prepared from raw materials including component A and component B, wherein component A includes vinyl polysiloxane, silicone resin, hydrogen-containing silicone oil, expanded graphite, mica powder and reaction inhibitor; component B includes vinyl polysiloxane, silicone resin, expanded graphite, mica powder, adhesion promoter and catalyst. The fireproof coating prepared by the method has good fire resistance, but the addition of silicone resin may cause the coating to have a high crosslinking density, thereby causing cracking; and the addition of expanded graphite may cause electrical conductivity after burning.

[0007] Therefore, in the art, it is desired to develop an organosilicon fire retardant coating which simultaneously has good insulation, fire resistance, crack resistance and good adhesion. Summary of the invention

[0008] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a silicone fire retardant coating and a preparation method and application thereof, and specifically to provide a high-insulation silicone fire retardant coating for a power battery box housing of a new energy vehicle and a preparation method thereof. The silicone fire retardant coating provided by the present invention has good insulation, fire resistance, crack resistance and good adhesion, and the preparation process is simple. It is used in the power battery box housing of a new energy vehicle to ensure the safety of the use of new energy vehicle batteries.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an organic silicon fire retardant coating, wherein the organic silicon fire retardant coating comprises component A and component B, which are calculated by weight.

[0011] The A component comprises:

[0012]

[0013]

[0014] The B component includes:

[0015]

[0016] The refractory filler in the A component includes talcum powder and glass powder; the refractory filler in the A component includes talcum powder with a higher melting point and softer and glass powder with a melting point of 800-900°C, which mainly play the role of extending the refractory time and preventing cracking;

[0017] The refractory filler in the B component includes flaky calcined kaolin with a relatively high melting point, which mainly plays the role of extending the refractory time and reducing the back plate temperature.

[0018] The organosilicon fire retardant coating provided by the present invention overcomes the problems of epoxy fire retardant coatings in terms of conductivity and weak carbon layer during fire. The present invention does not add any easily conductive fillers and has excellent insulation properties before and after fire. The present invention adds glass powder and talcum powder soft refractory materials to component A, and adds kaolin hard refractory filler to component B. The two work synergistically to ensure that the coating has good fire resistance while ensuring that its surface does not crack. The present invention improves the adhesion of the coating to a variety of substrates by adding an adhesion promoter. The curing speed of the organosilicon fire retardant coating provided by the present invention can be stably controlled, and has good insulation, fire resistance, crack resistance and good adhesion.

[0019] In the present invention, based on the amount of the vinyl silicone oil in component A (50 parts), the amounts of other components in component A are as follows:

[0020] The amount of flame retardant filler can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc.;

[0021] The amount of refractory filler can be 20 parts, 23 parts, 25 parts, 28 parts, 30 parts, 33 parts, 35 parts, 38 parts, 40 parts, etc.;

[0022] The dosage of the dewatering agent can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, etc.;

[0023] The amount of adhesion promoter can be 2.8 parts, 3 parts, 4 parts, 5 parts, 6 parts, 6.8 parts, etc.;

[0024] The amount of catalyst used can be 0.1 part, 0.2 part, 0.3 part, etc.;

[0025] Based on the amount of the vinyl silicone oil in component B (50 parts), the amounts of other components in component B are as follows:

[0026] The amount of hydrogen-containing silicone oil can be 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, etc.;

[0027] The dosage of the inhibitor can be 0.001 part, 0.0015 part, 0.002 part, 0.0025 part, 0.003 part, 0.0035 part, 0.004 part, etc.;

[0028] The amount of flame retardant filler can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc.;

[0029] The amount of refractory filler can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, etc.;

[0030] The dosage of the dewatering agent can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0031] Preferably, the melting point of the glass powder is 800-900°C, for example, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, etc.

[0032] Preferably, the particle size of the glass powder is ≤50 μm, for example, 45 μm, 40 μm, 35 μm, 30 μm, etc.

[0033] Preferably, the particle size of the kaolin is ≤50 μm, for example, 45 μm, 40 μm, 35 μm, 30 μm, etc.

[0034] Preferably, the vinyl silicone oils in the A component and the B component are both vinyl-terminated silicone oils, and the viscosity is independently 500-3000 mPa·s, such as 500 mPa·s, 1000 mPa·s, 1500 mPa·s, 2000 mPa·s, 3000 mPa·s, etc., and the vinyl content is independently 0.19-0.4%, such as 0.19%, 0.22%, 0.28%, 0.32%, 0.4%, etc. If the viscosity of the vinyl silicone oil is too low, the coating strength will be low and the wear resistance will be poor; if the viscosity of the vinyl silicone oil is too high, the coating strength will be too high and it will be easy to crack after burning, and too high viscosity will lead to difficulty in spraying.

[0035] Preferably, the flame retardant filler in the A component includes 3.5-hydrate zinc borate, which mainly plays the role of flame retardancy and lowering the temperature of the backplane.

[0036] Preferably, the particle size of the 3.5-hydrate zinc borate is ≤50 μm, such as 50 μm, 40 μm, 30 μm, etc.

[0037] Preferably, the dehydrating agents in the component A and the component B each independently include any one of molecular sieve, calcium oxide or isocyanate or a combination of at least two thereof, preferably molecular sieve.

[0038] Preferably, the adhesion promoter includes any one of an acryloxy type tackifier, a "vinyl" reactive tackifier or a silane coupling agent, or a combination of at least two thereof, preferably a combination of an acryloxy type tackifier and a silane coupling agent.

[0039] Preferably, the silane coupling agent includes epoxy silane series, preferably KH560.

[0040] Preferably, the catalyst comprises a Karlsruhe catalyst, wherein the platinum concentration is 3000-8000 ppm, for example 3000 ppm, 4000 ppm, 5000 ppm, 6000 ppm, 7000 ppm, 8000 ppm, etc., preferably 5000 ppm.

[0041] Preferably, the hydrogen content of the hydrogen-containing silicone oil is 0.1-0.3%, for example, 0.1%, 0.13%, 0.2%, 0.25%, 0.3%, etc.

[0042] Preferably, the inhibitor includes an amide compound type inhibitor and an acetylenic alcohol and acrylate combined type inhibitor, and the amide compound type inhibitor is preferred.

[0043] Preferably, the amide compound type inhibitor includes N,N-diallylformamide. This type of inhibitor does not produce wrinkles on the surface during vulcanization, and the interior and the surface can be vulcanized uniformly at the same time.

[0044] Preferably, the flame retardant filler in the B component includes calcium borate, which mainly plays the role of flame retardancy and lowering the temperature of the back plate.

[0045] Preferably, the particle size of the calcium borate is ≤50 μm, such as 50 μm, 40 μm, 30 μm, etc.

[0046] Preferably, the mass ratio of component A to component B is (0.9-1.1):1, for example, 0.9:1, 1:1, 1.1:1, etc.

[0047] In a second aspect, the present invention provides a method for preparing the organic silicon fire retardant coating as described in the first aspect, the preparation method comprising the following steps:

[0048] (1) mixing a formulated amount of vinyl silicone oil, a flame retardant filler, a fire resistant filler, a water scavenger, an adhesion promoter, and a catalyst to obtain a component A;

[0049] (2) mixing the formulated amounts of vinyl silicone oil, hydrogen-containing silicone oil, inhibitor, flame retardant filler, refractory filler and dehydrating agent to obtain component B;

[0050] (3) Mixing component A and component B to obtain the organic silicon fire retardant coating.

[0051] In the present invention, when preparing component B, the hydrogen-containing silicone oil and the inhibitor can be directly mixed with other components; or the inhibitor and the hydrogen-containing silicone oil can be first prepared into a concentrated solution, and the concentrated solution is diluted into the formula by weighing during the formula metering process, which can avoid the problem of unstable curing time caused by inaccurate weighing of a very small amount of inhibitor.

[0052] In a third aspect, the present invention provides an application of the organic silicon fire retardant coating as described in the first aspect in a power battery box housing.

[0053] Preferably, the power battery box housing comprises a new energy vehicle power battery box housing.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) The organosilicon fire retardant coating provided by the present invention overcomes the problems of epoxy fire retardant coatings in terms of conductivity and weak carbon layer during fire. The present invention does not add any conductive fillers and has excellent insulation properties before and after fire. The present invention adds glass powder and talcum powder soft refractory materials to component A and adds kaolin hard refractory filler to component B. The two work synergistically to ensure that the coating has good fire resistance while ensuring that its surface does not crack. The present invention improves the adhesion of the coating on various substrates by adding an adhesion promoter.

[0056] (2) The performance of the organic silicon fire retardant coating provided by the present invention can reach:

[0057] 1) Insulation

[0058] Leakage current: 1Kv, 60s, 0mA.

[0059] 2) Fire resistance

[0060] Fire resistance: 1300~1400℃, back plate temperature ≤300℃, and the surface does not crack.

[0061] 3) Anti-cracking

[0062] The surface does not crack after burning.

[0063] 4) Adhesion

[0064] Adhesion: Grade 0.

[0065] 5) Good parallelism of curing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is the appearance of the coating after the organic silicon fire retardant coating provided in Example 1 has been subjected to a cracking test.

[0067] Figure 2 The appearance of the silicone fire retardant coating provided for Comparative Example 4 after cracking test.

[0068] Figure 3 This is a graph showing the insulation test results of the silicone fire retardant coating provided in Example 1.

[0069] Figure 4 This is a graph showing the adhesion test results of the silicone fire retardant coating provided in Example 2. DETAILED DESCRIPTION

[0070] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0071] The following raw materials used in the following examples and comparative examples of the present invention are as follows:

[0072] (1) Vinyl silicone oil

[0073] Vinyl silicone oil a: viscosity 500mPa·s, vinyl content 0.4%;

[0074] Vinyl silicone oil b: viscosity 1000 mPa·s, vinyl content 0.32%;

[0075] (2) Silicone resin: vinyl content: 0.0558 mol / 100 g, viscosity: 13538 cP (25°C);

[0076] (3) Flame retardant filler

[0077] 3.5 Zinc borate hydrate: particle size 3-5um, solid content ≥99%, water content ≤0.1%;

[0078] Calcium borate: particle size 30-40um, solid content ≥99%, water content ≤0.1%;

[0079] (4) Refractory filler

[0080] Talc: melting point is 1300℃, particle size is 20-30um, oil absorption value is 28-38g / 100g, solid content is ≥99%, water content is ≤0.1%;

[0081] Glass powder: melting point 810℃, particle size 5-10um, solid content ≥99.5%, water content ≤0.1%;

[0082] Calcined kaolin: melting point 1700℃, particle size 5-10um, solid content ≥99%, water content ≤0.1%;

[0083] (5) Dewatering agent

[0084] Molecular sieve: particle size 2-4um, water content ≤0.5%;

[0085] (6) Adhesion promoter

[0086] Tackifier: UM-TBT2 model from Wuhan Enric Materials Co., Ltd.;

[0087] Silane coupling agent: KH560;

[0088] (7) Catalyst

[0089] Platinum catalyst, the concentration of platinum is 5000ppm;

[0090] (8) Hydrogen-containing silicone oil: The hydrogen content is 0.13%.

[0091] Example 1

[0092] In this embodiment, a silicone fire retardant coating is provided. The silicone fire retardant coating includes component A and component B. The specific formula is shown in Table 1.

[0093] The preparation method comprises the following steps:

[0094] (1) According to the formula in Table 1, vinyl silicone oil, flame retardant filler, refractory filler, dehumidifier, adhesion promoter and catalyst are added into a metal barrel respectively, dispersed evenly under a high-speed stirrer to obtain component A, and sealed and covered;

[0095] (2) Add 0.02 g of inhibitor (N,N-diallylformamide) to a glass bottle containing 130 g of hydrogen-containing silicone oil, stir evenly to obtain a concentrated solution of hydrogen-containing silicone oil and inhibitor, and seal for later use;

[0096] According to the formula in Table 1, vinyl silicone oil, hydrogen silicone oil, concentrate of inhibitor, flame retardant filler, fire resistant filler and dehydrating agent are added into metal barrels respectively, dispersed evenly under a high-speed stirrer to obtain component B, and sealed and covered;

[0097] (3) When in use, component A and component B are mixed to obtain the organic silicon fire retardant coating.

[0098] Examples 2-3, Comparative Examples 1-5

[0099] In Examples 2-3 and Comparative Examples 1-5, respectively, a silicone fire retardant coating is provided, which differs from Example 1 only in that the formula is different, as shown in Table 1. The components not shown in Table 1 are the same as those in Example 1, and the preparation method refers to Example 1.

[0100] The performance of the organic silicon fire retardant coating provided in the embodiment and the comparative example was tested, and the test method was as follows:

[0101] Sample preparation: The silicone fire retardant coating was evenly coated on an aluminum plate (150mm*150mm*2.5mm) using a coater (1000um) to a coating thickness of 1mm, and then cured in an oven at 80°C for 1h for performance evaluation.

[0102] (1) Fire resistance: Place the sample firmly on the test stand with the coated side facing the fire source, connect the thermocouple to the uncoated side, and press it with insulation cotton to prevent heat loss and maintain test accuracy; open the "thermocouple" software on the computer, click to start the test, and record the back temperature curve; open the butane gas, ignite the flame, turn off the gas source after testing for 30 minutes, and save the computer software data.

[0103] (2) Insulation: Connect the sample after the fire resistance test to the positive and negative poles of the TH9120D withstand voltage insulation tester through the red and black wires, set the test voltage to 1Kv, the test time to 60s, and the leakage current to ≤0.1mA; click Text to start the test. During the test, the Danger light will light up. If the test fails, the device will sound an alarm, turn on automatic protection and stop the test, and the screen will display "Short Circuit Protection". If the test passes, the screen will display "Pass" after the test ends.

[0104] (3) Cracking: After the fire resistance test, observe the surface condition of the coating.

[0105] (4) Adhesion: Test in accordance with the national standard "GB / T 9286-2021": Draw a cross grid on the coating surface at 3 mm intervals, adhere with tape and then tear it off; if the coating surface is smooth and there is no coating shedding in the grid, it is rated as "0"; if there is coating shedding and the size of the shedding area is large, it is evaluated according to levels 1, 2, 3, 4, and 5, respectively.

[0106] The performance test results are shown in Table 1.

[0107] Table 1

[0108]

[0109]

[0110] It can be seen from Table 1 that the organic silicon fire retardant coatings provided in the embodiments of the present invention have excellent insulation, weather resistance, crack resistance and good adhesion.

[0111] Compared with Example 2, the insulation and crack resistance of the silicone fire retardant coating provided in Comparative Example 1 are both deteriorated; the insulation and crack resistance of the silicone fire retardant coating provided in Comparative Example 2 are both deteriorated; the fire resistance of the silicone fire retardant coating provided in Comparative Example 3 is deteriorated; the insulation and crack resistance of the silicone fire retardant coating provided in Comparative Example 4 are both deteriorated; the fire resistance and adhesion of the silicone fire retardant coating provided in Comparative Example 5 are both deteriorated.

[0112] After the cracking test of the organic silicon fire retardant coatings provided in Example 1 of the present invention and Comparative Example 4, the appearance of the coatings are as follows: Figure 1 and Figure 2 As shown, it can be seen that the coating in Example 1 did not crack, while the coating in Comparative Example 4 cracked.

[0113] The insulation test results of the organic silicon fire retardant coating provided in Example 1 of the present invention are shown in FIG. Figure 3 As shown in the figure, it can be seen that the organic silicon fire retardant coating of the present invention has excellent insulation properties. After burning, under a voltage of 1Kv, the leakage current is "0" mA.

[0114] The adhesion test results of the organic silicon fire retardant coating provided in Example 2 of the present invention are shown in FIG. Figure 4 As shown, it can be seen that the test sample shows that the coating has basically no shedding phenomenon, indicating good adhesion.

[0115] The applicant declares that the present invention illustrates the organic silicon fire retardant coating and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organosilicon fire retardant coating, characterized in that: The organic silicon fire retardant coating comprises component A and component B, which are calculated by weight. The A component comprises: 50 parts of vinyl silicone oil; 5-15 parts of flame retardant filler; 20-40 parts of refractory filler; 2-6 parts of dewatering agent; Adhesion promoter 2.8-6.8 parts; Catalyst 0.1-0.3 parts; The B component includes: 50 parts of vinyl silicone oil; 11-13 parts of hydrogen silicone oil; Inhibitor 0.001-0.004 parts; 10-20 parts of flame retardant filler; 15-25 parts of refractory filler; 2-4 parts of dewatering agent; The refractory filler in the A component includes talc and glass powder; The refractory filler in the B component includes kaolin; The melting point of the glass powder is 800-900°C; The vinyl silicone oils in the A component and the B component are both vinyl-terminated silicone oils, and the viscosity is independently 500-1000 mPa•s, and the vinyl content is independently 0.19-0.4%; The flame retardant filler in the A component includes 3.5 hydrated zinc borate; The adhesion promoter is a combination of an acryloxy-type tackifier and a silane coupling agent; The flame retardant filler in the B component includes calcium borate.

2. The organic silicon fire retardant coating according to claim 1, characterized in that: The particle size of the glass powder is ≤50 μm.

3. The organic silicon fire retardant coating according to claim 1, characterized in that: The particle size of the kaolin is ≤50 μm.

4. The organic silicon fire retardant coating according to claim 1, characterized in that: The particle size of the 3.5-hydrate zinc borate is ≤50 μm.

5. The organic silicon fire retardant coating according to claim 1, characterized in that: The dehydrating agents in the A component and the B component each independently include any one of molecular sieves, calcium oxide or isocyanate or a combination of at least two of them.

6. The organic silicon fire retardant coating according to claim 5, characterized in that: The dehydrating agent in the A component and the B component is a molecular sieve.

7. The organic silicon fire retardant coating according to claim 1, characterized in that: The catalyst comprises a Kaarst catalyst, wherein the platinum concentration is 3000-8000 ppm.

8. The organic silicon fire retardant coating according to claim 1, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is 0.1-0.3%.

9. The organic silicon fire retardant coating according to claim 1, characterized in that: The inhibitors include amide compound type inhibitors and acetylenic alcohol and acrylate combined type inhibitors.

10. The organic silicon fire retardant coating according to claim 9, characterized in that: The inhibitor is an amide compound type inhibitor.

11. The organic silicon fire retardant coating according to claim 10, characterized in that: The amide compound type inhibitor includes N,N-diallylformamide.

12. The organic silicon fire retardant coating according to claim 1, characterized in that: The particle size of the calcium borate is ≤50 μm.

13. The organic silicon fire retardant coating according to claim 1, characterized in that: The mass ratio of component A to component B is (0.9-1.1):

1.

14. A method for preparing the organic silicon fire retardant coating according to any one of claims 1 to 13, characterized in that: The preparation method comprises the following steps: (1) Mixing a formulated amount of vinyl silicone oil, a flame retardant filler, a fire resistant filler, a water scavenger, an adhesion promoter, and a catalyst to obtain a component A; (2) Mixing the formulated amounts of vinyl silicone oil, hydrogen-containing silicone oil, inhibitor, flame retardant filler, refractory filler and dehydrating agent to obtain component B; (3) Component A and component B are mixed to obtain the organic silicon fire retardant coating.

15. Use of the organic silicon fire retardant coating according to any one of claims 1 to 13 in a power battery box housing.

16. The use of the organic silicon fire retardant coating in a power battery box housing according to claim 15, characterized in that: The power battery box housing includes a new energy vehicle power battery box housing.

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