High-flame-retardant pouring sealant and preparation method thereof

Abstract

The invention discloses a high-flame-retardant pouring sealant and a preparation method thereof, and belongs to the field of flame-retardant materials. The pouring sealant comprises a component A and a component B, wherein the component A comprises the following raw materials: a base adhesive, an inorganic filler, titanium dioxide, a flame retardant and a deep curing agent; the component B comprises the following raw materials: a diluent, a waterproof agent, a cross-linking agent, a coupling agent and a catalyst, the inorganic filler comprises at least one of aluminum hydroxide or magnesium hydroxide, and the flame retardant comprises at least one of UN-333, melamine phosphate, melamine cyanurate or melamine polyphosphate. According to the high-flame-retardance pouring sealant, the flame retardance of a product can be improved by adding a small amount of flame retardant, the flame retardance of the pouring sealant can also be enhanced by adding a proper amount of magnesium hydroxide filler, and the flame retardant grade is UL94V0 grade. The pouring sealant can quickly realize deep curing, has a synchronous curing effect on the surface and the interior of the sealant, and also has excellent tensile strength and elongation at break, low sealant viscosity, good flowability and excellent aging resistance.

Description

Technical Field

[0001] The invention relates to the field of flame retardant materials, in particular to a highly flame retardant potting glue and a preparation method thereof. Background Art

[0002] Potting refers to the process of mechanically or manually pouring liquid composite materials into devices equipped with electronic components and circuits, and solidifying them at room temperature or under heating conditions to become thermosetting polymer insulating materials with excellent performance. It can enhance the integrity of electronic devices and improve the resistance of devices to external impacts and vibrations. It is conducive to the miniaturization and lightweight of devices. It can avoid direct exposure of components and circuits, and at the same time improve the waterproof and moisture-proof properties of devices, and improve their performance and stability parameters.

[0003] The potting glue for the junction box of photovoltaic modules can seal and bond the cells, circuit boards and other equipment inside the module, which plays an important role in improving the quality of the junction box and protecting the internal components from the external environment. Photovoltaic modules are exposed to the external environment for a long time, and are inevitably affected by various factors such as high temperature, rain, dust, etc. When the internal electronic components are overloaded or short-circuited, it is very important to use highly flame-retardant potting glue to ensure the long-term stable operation of the electronic modules in order to prevent the spread of fire or even the occurrence of fire.

[0004] Patent CN107474789A discloses a masterbatch A for two-component potting glue, a two-component potting glue and a preparation method thereof. The masterbatch is mainly prepared from the following components in parts by weight: 1 to 2 parts by weight of base glue, 4 to 5 parts by weight of aluminum hydroxide, 0.05 to 0.06 parts by weight of titanium dioxide and 0.04 to 0.05 parts by weight of stearic acid. The B agent is mainly composed of the following components in parts by weight: 0.5 to 1.5 parts by weight of tetraethyl orthosilicate, 1 to 2 parts by weight of polyether, 0.7 to 0.8 parts by weight of methyltrimethoxysilane, N-(β-aminoethyl)-γ-amino 0.2-0.3 parts by weight of propyl triethoxysilane, 0.05-0.1 parts by weight of glycidyloxypropyl trimethoxysilane, and 0.005-0.006 parts by weight of dibutyltin dilaurate; Agent A has low viscosity and better stability, and when mixed with Agent B, the mixed viscosity is low, the leveling property is better, and the bubbles are easy to discharge, and the mechanical properties of the two-component potting glue prepared thereby are improved, and the wrinkle cracking of the two-component potting glue after curing is improved, so that the potting glue has better performance in storage, use, and protection, and the comprehensive performance is greatly improved. However, it does not indicate changes in the tensile strength, elongation at break, bonding properties, aging properties, etc. of the potting glue. Summary of the invention

[0005] In order to solve the technical problems of the prior art, the main purpose of the present invention is to provide a highly flame-retardant potting glue and a preparation method thereof. The potting glue of the present invention has excellent tensile strength, elongation at break, bonding properties, aging properties and flame retardant properties, and has moderate viscosity and good fluidity.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: A highly flame retardant potting glue, the potting glue comprising component A and component B, The component A comprises the following raw materials in parts by weight: 300-320 parts of base rubber, 230-250 parts of inorganic filler, 10-20 parts of titanium dioxide, 30-0 parts of flame retardant, and 1-5 parts of deep curing agent; The B component comprises the following raw materials in parts by weight: 50-60 parts of diluent, 25-35 parts of waterproofing agent, 5-10 parts of cross-linking agent, 5-10 parts of coupling agent, and 0.1-1 part of catalyst.

[0007] Preferably, the mass ratio of component A to component B is 3-8:1.

[0008] More preferably, the mass ratio of component A to component B is 6:1.

[0009] Preferably, the base rubber is 107 silicone rubber with a viscosity of 1000-2000 mPa·s.

[0010] More preferably, the viscosity of the base glue is 1500 mPa·s.

[0011] Preferably, the inorganic filler is selected from at least one of aluminum hydroxide and magnesium hydroxide.

[0012] Preferably, the flame retardant is selected from at least one of UN-333, melamine phosphate, melamine cyanurate or melamine polyphosphate.

[0013] Preferably, the diluent is dimethyl silicone oil with a viscosity of 100 mPa·s.

[0014] Preferably, the waterproofing agent is polymethyltriethoxysilane; The crosslinking agent is selected from at least one of ethyl orthosilicate, polyethyl silicate or dimethyldiethoxysilane; More preferably, the crosslinking agent is tetraethyl orthosilicate.

[0015] The coupling agent is selected from at least one of γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; The catalyst is selected from at least one of di-n-butyltin dilaurate, stannous octoate or triethyltindiamine.

[0016] More preferably, the catalyst is di-n-butyltin dilaurate.

[0017] The present invention also provides a method for preparing the highly flame-retardant potting glue, comprising the following steps: S1. Mix the base rubber, inorganic filler, titanium dioxide and flame retardant by mechanical stirring under normal pressure, and then stir and mix them evenly by planetary mixer under vacuum conditions; S2. Add a deep curing agent to the above mixture, stir and mix evenly with a planetary machine under normal pressure, stir and mix under vacuum conditions, and discharge to obtain component A; S3. Preparation of component B: shake and mix the diluent, waterproofing agent, coupling agent, cross-linking agent and catalyst in a fluorination bottle to obtain component B; S4, mixing and curing: mixing components A and B to obtain the flame retardant potting glue.

[0018] Preferably, in step S1, the vacuum degree of the vacuum condition is -0.1 to -0.09 MPa; The mechanical stirring speed is 2000~2200r / min, and the stirring time is 30~40min; The stirring speed of the planetary machine is 150~170r / min, and the stirring time is 5~10min.

[0019] Preferably, in step S2, the planetary machine stirring speed is 150-170 r / min, and the stirring time is 30-40 min; The vacuum degree of the vacuum condition is -0.1~-0.09MPa; the stirring time is 5~10min.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses low-viscosity 107 glue as the main cross-linking raw material, adds inorganic fillers and flame retardants to improve the flame retardant effect, dilutes component B to different viscosities with a diluent, cross-links component A with a cross-linking agent to form a network structure, couples the system to form a bond, catalysts catalyze the entire cross-linking system, and waterproofing agents make the cross-linking system waterproof. At the same time, the low viscosity of 107 glue enables component A and component B to have excellent outflow, leveling and low mixing viscosity during the mixing process, greatly improving the operability time, and ensuring the timely discharge of bubbles and smooth appearance during stirring.

[0021] 2. The flame retardancy of the potting glue is improved by adding a small amount of flame retardant, and its flame retardancy grade reaches UL94V0; the tensile strength and elongation at break after DH1000 aging can be maintained above 75%; and it can quickly achieve deep curing and achieve synchronous curing effect on the surface and inside of the colloid.

[0022] 3. The combination of the raw materials of each component of the present invention makes the flame retardant potting adhesive have good comprehensive properties, and the preparation method thereof is simple and easy to implement, and is suitable for industrial production. DETAILED DESCRIPTION

[0023] In the following examples, the deep layer curing agent is M-1320 deep layer curing agent, and UN-333 is purchased from Shanghai Unai Silicone Materials Co., Ltd.

[0024] Embodiment 1: A highly flame retardant potting adhesive, comprising component A and component B: The component A comprises the following raw materials in parts by weight: 300 parts of 107 glue (viscosity 1500 mPa·s), 240 parts of aluminum hydroxide, 15 parts of titanium dioxide (vanadium titanium), 30 parts of UN-333, 15 parts of melamine phosphate, and 3 parts of deep curing agent; The B component includes the following raw materials in parts by weight: 55 parts of dimethyl silicone oil (viscosity 100 mPa·s), 29 parts of polymethyltriethoxysilane, 8 parts of ethyl orthosilicate, 3.9 parts of γ-aminopropyltriethoxysilane, 3.5 parts of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 0.6 parts of dibutyltin dilaurate; The method for preparing the highly flame-retardant potting glue comprises the following steps: S1. Mix 107 glue, aluminum hydroxide, titanium dioxide, UN-333 and melamine phosphate at a mechanical stirring speed of 2100r / min under normal pressure for 30min. After being evenly dispersed, stir and mix them with a planetary machine under a vacuum condition of -0.095MPa for 5min. S2. Add a deep curing agent to the mixture obtained in step S1, mix for 30 minutes at a stirring speed of 160 r / min on a planetary machine under normal pressure, and then continue to stir and mix for 5 minutes under a vacuum condition with a vacuum degree of -0.095 MPa to obtain component A; S3, shaking and mixing dimethyl silicone oil, polymethyltriethoxysilane, ethyl orthosilicate, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and dibutyltin dilaurate in a fluoride bottle to obtain component B; S4. Component A and component B are mixed evenly at a mass ratio of 6:1 to obtain a highly flame-retardant potting adhesive with low viscosity and synchronous curing inside the colloid.

[0025] Embodiment 2: A highly flame retardant potting adhesive, comprising component A and component B: The component A comprises the following raw materials in parts by weight: 300 parts of 107 glue (viscosity 1500 mPa·s), 180 parts of aluminum hydroxide, 60 parts of magnesium hydroxide, 15 parts of titanium dioxide (vanadium titanium), 30 parts of UN-333, 15 parts of melamine phosphate, and 3 parts of deep curing agent; The B component includes the following raw materials in parts by weight: 55 parts of dimethyl silicone oil (viscosity 100 mPa·s), 29 parts of polymethyltriethoxysilane, 8 parts of ethyl orthosilicate, 3.9 parts of γ-aminopropyltriethoxysilane, 3.5 parts of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 0.6 parts of dibutyltin dilaurate; The method for preparing the highly flame-retardant potting glue comprises the following steps: S1. Mix 107 glue, aluminum hydroxide, titanium dioxide, 30 parts of UN-333 and 15 parts of melamine phosphate at a mechanical stirring speed of 2100r / min under normal pressure for 30 minutes. After being evenly dispersed, stir and mix with a planetary machine at a vacuum degree of -0.095MPa for 5 minutes. S2. Add a deep curing agent to the mixture obtained in step S1, mix for 30 minutes at a stirring speed of 160 r / min on a planetary machine under normal pressure, and then continue to stir and mix for 5 minutes under a vacuum condition with a vacuum degree of -0.095 MPa to obtain component A; S3, shaking and mixing dimethyl silicone oil, polymethyltriethoxysilane, ethyl orthosilicate, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and dibutyltin dilaurate in a fluoride bottle to obtain component B; S4. Component A and component B are mixed evenly at a mass ratio of 6:1 to obtain a highly flame-retardant potting adhesive with low viscosity and synchronous curing inside the colloid.

[0026] Embodiment 3: A highly flame retardant potting adhesive, comprising component A and component B: The A component includes the following raw materials in parts by weight: 315 parts of 107 glue (viscosity 1500mPa·s), 192 parts of aluminum hydroxide, 48 parts of magnesium hydroxide, 15 parts of titanium dioxide (vanadium titanium), 20 parts of UN-333, 10 parts of melamine phosphate, and 3 parts of deep curing agent; The B component includes the following raw materials in parts by weight: 55 parts of dimethyl silicone oil (viscosity 100 mPa·s), 29 parts of polymethyltriethoxysilane, 8 parts of ethyl orthosilicate, 3.9 parts of γ-aminopropyltriethoxysilane, 3.5 parts of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 0.6 parts of dibutyltin dilaurate; The method for preparing the highly flame-retardant potting glue comprises the following steps: S1. Mix 107 glue, aluminum hydroxide and titanium dioxide at a mechanical stirring speed of 2100r / min under normal pressure for 30 minutes. After being evenly dispersed, stir and mix them with a planetary machine under a vacuum condition of -0.095MPa for 5 minutes. S2, adding a deep curing agent to the mixture obtained in step S1, mixing for 30 minutes at a stirring speed of 160r / min on a planetary machine under normal pressure, and then continuing to stir and mix for 5 minutes under a vacuum condition with a vacuum degree of -0.095MPa, i.e. component A; S3, shaking and mixing dimethyl silicone oil, polymethyltriethoxysilane, ethyl orthosilicate, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and dibutyltin dilaurate in a fluoride bottle, i.e. component B; S4. Component A and component B are mixed evenly at a mass ratio of 6:1 to obtain a highly flame-retardant potting adhesive with low viscosity and synchronous curing inside the colloid.

[0027] Embodiment 4: A highly flame retardant potting adhesive, comprising component A and component B: The component A comprises the following raw materials in parts by weight: 315 parts of 107 glue (viscosity 1500 mPa·s), 160 parts of aluminum hydroxide, 80 parts of magnesium hydroxide, 15 parts of titanium dioxide (vanadium titanium), 20 parts of UN-333, 10 parts of melamine phosphate, and 3 parts of deep curing agent; The B component includes the following raw materials in parts by weight: 55 parts of dimethyl silicone oil (viscosity 100 mPa·s), 29 parts of polymethyltriethoxysilane, 8 parts of ethyl orthosilicate, 3.9 parts of γ-aminopropyltriethoxysilane, 3.5 parts of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 0.6 parts of dibutyltin dilaurate; The method for preparing the highly flame-retardant potting glue comprises the following steps: S1. Mix 107 glue, aluminum hydroxide and titanium dioxide at a mechanical stirring speed of 2100r / min under normal pressure for 30 minutes. After being evenly dispersed, stir and mix them with a planetary machine under a vacuum condition of -0.095MPa for 5 minutes. S2, add deep curing agent to the mixture obtained in S1, mix at a planetary mixer at a stirring speed of 160r / min for 30min under normal pressure, and then continue to stir and mix at a vacuum condition of -0.095MPa for 5min, i.e. component A; S3, shaking and mixing dimethyl silicone oil, polymethyltriethoxysilane, ethyl orthosilicate, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and dibutyltin dilaurate in a fluoride bottle, i.e. component B; S4. Component A and component B are mixed evenly at a mass ratio of 6:1 to obtain a highly flame-retardant potting adhesive with low viscosity and synchronous curing inside the colloid.

[0028] Comparative Example 1: The same as Example 1, the only difference is that melamine phosphate is replaced by melamine polyphosphate.

[0029] Comparative Example 2: The same as Example 1, the only difference is that melamine phosphate is replaced by melamine cyanurate.

[0030] Comparative Example 3: The same as Example 1, the only difference is: 275 parts of aluminum hydroxide, no UN-333 and melamine phosphate.

[0031] Comparative Example 4: The same as Example 3, the only difference is that melamine phosphate is replaced by melamine cyanurate.

[0032] Comparative Example 5: The same as Example 3, the only difference is that the flame retardant is 10 parts of UN-333 and 5 parts of melamine phosphate.

[0033] The mixed viscosity, tensile strength, elongation at break, flame retardancy (characterized by its burning time) and mechanical properties after aging of DH1000 of the potting glue prepared in Examples 1-4 and Comparative Examples 1-5 were measured, and the measured results are shown in Table 1.

[0034] Table 1

[0035] According to Table 1, it can be seen from Examples 1-4 and Comparative Examples 1-5 that the addition of flame retardants will reduce the viscosity and tensile strength of the potting glue. The use of flame retardant UN-333 and melamine phosphate or melamine cyanurate has a significant effect on improving the flame retardant properties of the potting glue. The flame retardant effect of melamine polyphosphate is relatively general. It can be seen from Examples 2-3 that increasing the content of flame retardants can improve the flame retardant properties of the potting glue.

[0036] It can be seen from Examples 1-4 that magnesium hydroxide can increase the viscosity and tensile strength of the potting glue, and can greatly improve the flame retardant properties of the potting glue. The potting glue has good mechanical properties after DH1000 aging, and the aging resistance of magnesium hydroxide is better than that of aluminum hydroxide.

[0037] The potting adhesive prepared by the invention has excellent tensile strength, elongation at break, low adhesive viscosity, good fluidity and excellent aging resistance, and the flame retardant grade can easily reach UL94V0 grade.

[0038] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A highly flame retardant potting glue, characterized in that: The potting compound comprises component A and component B. The component A comprises the following raw materials in parts by weight: 300-320 parts of base rubber, 230-250 parts of inorganic filler, 10-20 parts of titanium dioxide, 30-50 parts of flame retardant, and 1-5 parts of deep curing agent; The B component comprises the following raw materials in parts by weight: 50-60 parts of diluent, 25-35 parts of waterproofing agent, 5-10 parts of cross-linking agent, 5-10 parts of coupling agent, and 0.1-1 part of catalyst.

2. The highly flame retardant potting compound according to claim 1, characterized in that: The mass ratio of component A to component B is 3-8:

1.

3. The highly flame retardant potting compound according to claim 1, characterized in that: The base rubber is 107 silicone rubber with a viscosity of 1000-2000 mPa·s.

4. The highly flame retardant potting adhesive according to claim 1, characterized in that: The inorganic filler is selected from at least one of aluminum hydroxide and magnesium hydroxide.

5. The highly flame retardant potting adhesive according to claim 1, characterized in that: The flame retardant is selected from at least one of UN-333, melamine phosphate, melamine cyanurate or melamine polyphosphate.

6. The highly flame retardant potting adhesive according to claim 1, characterized in that: The diluent is dimethyl silicone oil with a viscosity of 100 mPa·s.

7. The highly flame retardant potting adhesive according to claim 1, characterized in that: The waterproofing agent is polymethyltriethoxysilane; The crosslinking agent is selected from at least one of ethyl orthosilicate, polyethyl silicate or dimethyldiethoxysilane; The coupling agent is selected from at least one of γ-aminopropyltriethoxysilane or N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; The catalyst is selected from at least one of di-n-butyltin dilaurate, stannous octoate or triethyltindiamine.

8. The method for preparing the highly flame retardant potting compound according to any one of claims 1 to 6, characterized in that: S1. Mix the base rubber, inorganic filler, titanium dioxide and flame retardant by mechanical stirring under normal pressure, and then stir and mix them evenly by planetary mixer under vacuum conditions; S2. Add a deep curing agent to the above mixture, stir and mix evenly with a planetary machine under normal pressure, stir and mix under vacuum conditions, and discharge to obtain component A; S3. Preparation of component B: shake and mix the diluent, waterproofing agent, coupling agent, cross-linking agent and catalyst in a fluorination bottle to obtain component B; S4, mixing and curing: mixing components A and B to obtain the flame retardant potting glue.

9. The method for preparing the highly flame-retardant potting compound according to claim 7, characterized in that: In step S1, the vacuum degree of the vacuum condition is -0.1 to -0.09 MPa; The mechanical stirring speed is 2000~2200r / min, and the stirring time is 30~40min; The planetary machine stirring speed is 150~170r / min, and the stirring time is 5~10min.

10. The method for preparing the highly flame-retardant potting compound according to claim 7, characterized in that: In step S2, the planetary machine stirring speed is 150-170 r / min, and the stirring time is 30-40 min; The vacuum degree of the vacuum condition is -0.1~-0.09MPa; the stirring time is 5~10min.

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