A flame-retardant two-component silicone potting adhesive with high fluidity and anti-settling properties and a preparation method thereof
By modifying the combination of flame retardant filler and specific components, the contradiction between flame retardant performance and fluidity of aluminum hydroxide under high filling is solved, and a two-component silicone potting glue with high flame retardant grade and good fluidity is achieved , suitable for flame retardant filling of power supply appliances and junction boxes.
Patent Information
- Application Number
- CN202211701019.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-26
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2042-12-26
AI Technical Summary
As a flame retardant, aluminum hydroxide is difficult to take into account both flame retardant and fluidity under high filling, and its compatibility with silicone rubber is poor, affecting the processing performance of the material.
A modified flame retardant filler is used to treat aluminum hydroxide through a surface treatment agent, and combined with components such as α, ω-dihydroxypolydimethylsiloxane and dimethylsiloxane to prepare flame retardant with high fluidity resistance. Two-component silicone potting glue ensures uniform and stable components through specific stirring and mixing processes.
In the case of high filling, high flame retardant grade V-0 is maintained, and the mixing viscosity is significantly reduced, ensuring fluidity and avoiding settlement, and is suitable for flame retardant filling of power supply appliances and junction boxes.
Smart Images
Figure BDA0004017425070000041
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of adhesives, and particularly relates to a flame-retardant two-component organic silicon potting adhesive with high fluidity and anti-settling properties and a preparation method thereof. Background Art
[0002] As a commonly used flame retardant, aluminum hydroxide has received more and more attention in all walks of life due to its excellent low smoke and environmental protection characteristics. Aluminum hydroxide begins to decompose to form aluminum oxide and water at a temperature above 200°C, and the reaction is an endothermic process, so the material has flame retardancy. But at the same time, a large number of studies have also found that aluminum hydroxide needs a larger filling amount (accounting for more than 60% of the total mass of the material) to show a better flame retardant effect, and when applied to polymer materials, including silicone rubber, the compatibility of the two is poor, which ultimately has a greater impact on the processing performance and physical properties of the material. In addition, high filling also means poor processing performance and flow properties. How to solve these contradictions in a unified way has become a major technical difficulty at present. Summary of the invention
[0003] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a flame retardant two-component silicone potting adhesive which has good flame retardant and smoke suppression effects, good fluidity under high filling, and uniform and stable components for a long time, and can realize flame retardant potting of power supply electrical appliances and junction boxes, and has anti-sedimentation and high fluidity.
[0004] The technical solution adopted to achieve the above invention object is:
[0005] A flame-retardant two-component silicone potting adhesive with high fluidity and anti-settling properties, characterized in that the silicone potting adhesive is composed of the following components A and B in a weight ratio of 10:1, wherein
[0006] The component A comprises: 100 parts of α, ω-dihydroxy polydimethylsiloxane and 200-230 parts of modified flame retardant filler, wherein the modified flame retardant filler is made of aluminum hydroxide, a first surface treatment agent, a polycarboxylic acid water reducer, and a second surface treatment agent, dimethyldichlorosilane;
[0007] Component B includes: 100 parts of dimethyl silicone oil, 60-80 parts of a cross-linking agent, 10-30 parts of a silane coupling agent, and 0.6-2.0 parts of an organic tin catalyst.
[0008] The amount of each component in the modified flame retardant filler is calculated by weight:
[0009] 100 parts of aluminum hydroxide,
[0010] The first surface treatment agent is 2-4 parts of polycarboxylic acid water reducer,
[0011] The second surface treatment agent is 0.5-1 part of dimethyldichlorosilane.
[0012] The modified flame retardant filler is prepared by the following method: adding a first surface treatment agent, a polycarboxylic acid-based water reducer, to aluminum hydroxide powder, stirring for 60-120 minutes at a temperature of 60-80° C., then adding a second surface treatment agent, dimethyldichlorosilane, continuing to stir for 120-240 minutes at a temperature of 60-80° C., and then filtering to obtain the modified aluminum hydroxide.
[0013] The crosslinking agent is at least one of tetrapropoxysilane, polymethyltriethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane and ethyl orthosilicate.
[0014] The silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-glycidyloxypropyltrimethoxysilane.
[0015] The organic tin catalyst is at least one of dibutyltin dilaurate, di-n-butyltin diacetate, and dibutyltin dioctoate.
[0016] The method for preparing the above-mentioned flame-retardant two-component silicone potting adhesive with high fluidity and anti-settling properties is characterized in that the process steps include:
[0017] 1) Preparation of component A: Add α, ω-dihydroxy polydimethylsiloxane into a planetary mixer, add modified aluminum hydroxide in batches, and stir for 60-90 minutes under the conditions of water cooling temperature 25-35° C., vacuum degree -0.090 to -0.100 MPa, and rotation speed 15-20 Hz to obtain component A;
[0018] 2) Preparation of component B: Add dimethyl silicone oil into a planetary mixer, and add a crosslinking agent, a silane coupling agent and a catalyst in sequence, and stir for 15-30 minutes under the conditions of a water-cooled temperature of 25-35° C., a vacuum degree of -0.090 to -0.100 MPa, and a rotation speed of 15-20 Hz to obtain component B.
[0019] The above component A and component B are uniformly mixed in a weight ratio of 10:1 to obtain a two-component potting adhesive.
[0020] The two-component silicone potting adhesive of the present invention not only maintains a high flame retardant grade V-0, but also has good fluidity under high filling (accounting for more than 60% of the total mass of the material), and the mixed viscosity is reduced by about 50-60%. In addition, component A is uniform and stable for a long time without sedimentation, and can realize flame retardant potting of power supply electrical appliances and junction boxes. DETAILED DESCRIPTION
[0021] The modified flame retardant filler used in the following examples was prepared by the following method:
[0022] By weight, 3 parts (water reducing agent, from Jiangsu Subote New Materials Co., Ltd.) and 100 parts of aluminum hydroxide powder were stirred at high speed for 60 minutes in a reactor at 65°C, and then 0.8 parts of dimethyldichlorosilane were added. The temperature was controlled at 65°C and stirred at high speed for 180 minutes. Modified aluminum hydroxide was obtained by filter pressing.
[0023] Example 1
[0024] 100 parts by weight of α, ω-dihydroxypolydimethylsiloxane with a viscosity of 400 mPa.s at 25°C was put into a planetary mixer, and 200 parts by weight of modified aluminum hydroxide was added in batches. The mixture was stirred for 60 minutes under the conditions of a water-cooled temperature of 30°C, a vacuum degree of -0.090 MPa, and a rotation speed of 20 Hz to obtain component A.
[0025] 100 parts by weight of dimethyl silicone oil with a viscosity of 100 mPa.s at 25°C were put into a planetary mixer, and then 80 parts by weight of tetrapropoxysilane, 18 parts by weight of γ-aminopropyltriethoxysilane, and 1.2 parts by weight of dibutyltin dilaurate were added in sequence. The mixture was stirred for 20 minutes under the conditions of water cooling temperature of 30°C, vacuum degree of -0.090 MPa, and rotation speed of 20 Hz to obtain component B.
[0026] Example 2
[0027] 100 parts by weight of α, ω-dihydroxypolydimethylsiloxane with a viscosity of 400 mPa.s at 25°C was put into a planetary mixer, and 230 parts by weight of modified aluminum hydroxide was added in batches. The mixture was stirred for 60 minutes under the conditions of a water-cooled temperature of 30°C, a vacuum degree of -0.100 MPa, and a rotation speed of 20 Hz to obtain component A.
[0028] 100 parts by weight of dimethyl silicone oil with a viscosity of 100 mPa.s at 25°C were put into a planetary mixer, and then 40 parts by weight of tetrapropoxysilane, 30 parts by weight of polymethyltriethoxysilane, 18 parts by weight of γ-aminopropyltriethoxysilane, and 1.0 part by weight of dibutyltin dilaurate were added in sequence, and stirred for 20 minutes at a water-cooled temperature of 30°C, a vacuum degree of -0.100 MPa, and a rotation speed of 20 Hz to obtain component B.
[0029] Comparative Example 1
[0030] 100 parts by weight of α, ω-dihydroxypolydimethylsiloxane with a viscosity of 400 mPa.s at 25°C was put into a planetary mixer, and 200 parts by weight of unmodified aluminum hydroxide was added in batches. The mixture was stirred for 60 minutes under the conditions of a water-cooled temperature of 30°C, a vacuum degree of -0.090 MPa, and a rotation speed of 20 Hz to obtain component A.
[0031] 100 parts by weight of dimethyl silicone oil with a viscosity of 100 mPa.s at 25°C were put into a planetary mixer, and then 80 parts by weight of tetrapropoxysilane, 18 parts by weight of γ-aminopropyltriethoxysilane, and 1.2 parts by weight of dibutyltin dilaurate were added in sequence. The mixture was stirred for 20 minutes under the conditions of water cooling temperature of 30°C, vacuum degree of -0.090 MPa, and rotation speed of 20 Hz to obtain component B.
[0032] Comparative Example 2
[0033] 100 parts by weight of α, ω-dihydroxypolydimethylsiloxane with a viscosity of 400 mPa.s at 25°C was put into a planetary mixer, and 230 parts by weight of unmodified aluminum hydroxide was added in batches. The mixture was stirred for 60 minutes under the conditions of a water-cooled temperature of 30°C, a vacuum degree of -0.100 MPa, and a rotation speed of 20 Hz to obtain component A.
[0034] 100 parts by weight of dimethyl silicone oil with a viscosity of 100 mPa.s at 25°C were put into a planetary mixer, and then 40 parts by weight of tetrapropoxysilane, 30 parts by weight of polymethyltriethoxysilane, 18 parts by weight of γ-aminopropyltriethoxysilane, and 1.0 part by weight of dibutyltin dilaurate were added in sequence, and stirred for 20 minutes at a water-cooled temperature of 30°C, a vacuum degree of -0.100 MPa, and a rotation speed of 20 Hz to obtain component B.
[0035] The A and B components of the above-mentioned Example 1-2 and Comparative Example 1-2 were mixed evenly at a weight ratio of 10:1 to obtain a two-component potting adhesive. The specific properties of the two-component potting adhesive are shown in Table 1.
[0036] Table 1:
[0037]
[0038]
[0039] From the above results, it can be seen that compared with unmodified aluminum hydroxide, the highly filled (accounting for more than 60% of the total mass of the material) two-component potting adhesive prepared from modified aluminum hydroxide not only maintains a high flame retardant grade V-0, but also has good fluidity under high filling, and the mixed viscosity is reduced by about 50-60%. In addition, component A is uniform and stable for a long time without sedimentation.
Claims
1. A flame-retardant two-component silicone potting adhesive with high fluidity and anti-settling properties, characterized in that The organic silicone potting glue is composed of the following components A and B in a weight ratio of 10:1, wherein The component A comprises: 100 parts of α,ω-dihydroxy polydimethylsiloxane and 200-230 parts of modified flame retardant filler. The modified flame retardant filler is made of aluminum hydroxide, a first surface treatment agent, a polycarboxylic acid water reducer, and a second surface treatment agent, dimethyldichlorosilane. The amount of each component in the modified flame retardant filler is calculated by weight as follows: 100 parts of aluminum hydroxide, The first surface treatment agent is 2-4 parts of polycarboxylic acid water reducer, The second surface treatment agent is dimethyldichlorosilane 0.5-1 part; Component B includes: 100 parts of dimethyl silicone oil, 60-80 parts of a cross-linking agent, 10-30 parts of a silane coupling agent, and 0.6-2.0 parts of an organic tin catalyst.
2. The flame-retardant two-component silicone potting adhesive with high fluidity and anti-settling properties as claimed in claim 1, characterized in that The modified flame retardant filler is prepared by the following method: adding a first surface treatment agent, a polycarboxylic acid-based water reducer, to aluminum hydroxide powder, stirring for 60-120 minutes at a temperature of 60-80° C., then adding a second surface treatment agent, dimethyldichlorosilane, continuing to stir for 120-240 minutes at a temperature of 60-80° C., and then filtering to obtain the modified aluminum hydroxide.
3. The anti-settling and high-fluidity flame-retardant two-component silicone potting adhesive according to claim 1, characterized in that The crosslinking agent is at least one of tetrapropoxysilane, polymethyltriethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane and ethyl orthosilicate.
4. The anti-settling and high-flow flame-retardant two-component silicone potting adhesive according to claim 1, characterized in that The silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-glycidyloxypropyltrimethoxysilane.
5. The anti-settling high-flow flame-retardant two-component silicone potting adhesive according to claim 1, characterized in that The organic tin catalyst is at least one of dibutyltin dilaurate, di-n-butyltin diacetate, and dibutyltin dioctoate.
6. The method for preparing the anti-settling high-fluidity flame-retardant two-component silicone potting adhesive according to any one of claims 1 to 5, characterized in that The process steps include: 1) Preparation of component A: Add α,ω-dihydroxypolydimethylsiloxane into a planetary mixer, add modified aluminum hydroxide in batches, and stir for 60-90 minutes under the conditions of water cooling temperature 25-35°C, vacuum degree -0.090 to -0.100MPa, and rotation speed 15-20HZ to obtain component A; 2) Preparation of component B: Add dimethyl silicone oil into a planetary mixer, and add a crosslinking agent, a silane coupling agent and a catalyst in sequence. Stir for 15-30 minutes under the conditions of a water-cooled temperature of 25-35°C, a vacuum degree of -0.090 to -0.100 MPa, and a rotation speed of 15-20 Hz to obtain component B.