Two-component foaming organic silicon sealant composition and preparation method thereof

Abstract

The invention discloses a two-component foaming organic silicon sealant composition which comprises a component A, a component B and a component C, the component A comprises vinyl polysiloxane, a crystal water compound, a hydroxyl compound, a platinum catalyst, fumed silica, CaCO3 coated polymer microspheres and a reaction inhibitor; a component B; and the component B comprises vinyl polysiloxane, hydrogen-containing silicone oil, ATH coated polymer microspheres and a flame-retardant filler. According to the invention, crystalline hydrates (such as Al2 (SO4) 3.18 H2O and Na2SO4. 10H2O) are used for replacing graphite, so that the water release temperature is accurately controlled; a hydroxyl compound (alcohol / alcohol ether) is added as a synergistic foaming agent and reacts with hydrogen-containing silicone oil to produce hydrogen; the two-component design isolates the active components, and improves the storage stability.

Description

Technical Field

[0001] This invention relates to the field of organosilicon materials technology, and in particular to a two-component foamed organosilicon sealant composition and its preparation method. Background Technology

[0002] Silicone foam materials, especially automatically dispensing silicone foam, are a new trend in battery pack casing sealing solutions. They are automatically dispensed by a dispensing machine, then cured into foam at room temperature or high temperature, and achieve a sealing effect through compression.

[0003] Existing technology uses the reaction of moisture in expandable graphite with hydrogen-containing silicone oil to produce hydrogen foam, but it has the following drawbacks:

[0004] 1. The release of ink from graphite is uncontrollable, and the uniformity of the bubbles is poor;

[0005] 2. High graphite addition (>8wt%) affects mechanical properties;

[0006] 3. Flame retardancy relies on graphite, resulting in low formulation flexibility. Summary of the Invention

[0007] The purpose of this invention is to provide a two-component foamed silicone sealant composition and its preparation method, thereby solving one or more of the problems in the prior art.

[0008] On one hand, the two-component foamed silicone sealant composition provided by the present invention includes the following components:

[0009] Component A; Component A includes vinyl polysiloxane, a hydrated compound, a hydroxyl compound, a platinum catalyst, fumed silica, CaCO3-coated polymer microspheres, and a reaction inhibitor;

[0010] Component B; Component B includes vinyl polysiloxane, hydrogen-containing silicone oil, ATH-coated polymer microspheres, and flame-retardant filler.

[0011] In some embodiments, the polymer microspheres are acrylonitrile / acrylate copolymers or vinylidene chloride copolymers, with a diameter of 20-150 μm, and contain a foaming agent.

[0012] In some implementations, the blowing agent is isobutane / pentane.

[0013] In some implementations, the coating layer is CaCO3.

[0014] In some implementations, the covering layer is ATH.

[0015] In some embodiments, CaCO3 is physically adsorbed or chemically bonded to the surface of microspheres by a binder to obtain CaCO3-coated polymer microspheres.

[0016] In some embodiments, ATH is physically adsorbed or chemically bonded to the surface of microspheres by an adhesive to obtain ATH-coated polymer microspheres.

[0017] In some implementations, the binder is a silane coupling agent.

[0018] In some implementations, the coating thickness is 1-5 μm.

[0019] In some embodiments, component A comprises the following raw materials by weight percentage:

[0020]

[0021] In some embodiments, the hydroxyl compound is selected from propylene glycol / ethylene glycol ether.

[0022] Component B comprises the following raw materials by weight percentage:

[0023]

[0024] In some embodiments, the flame-retardant filler is selected from Al(OH)3.

[0025] On the other hand, the method for preparing the two-component foamed silicone sealant composition provided by the present invention includes the following steps:

[0026] Step S1, Preparation of component A:

[0027] Vinyl polysiloxane, fumed silica, crystalline water, hydroxyl compound, platinum catalyst, coated polymer microspheres and reaction inhibitor are mixed and dispersed at high speed;

[0028] Step S2, Preparation of component B:

[0029] Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed.

[0030] Step S3, Curing:

[0031] Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

[0032] In some implementations, the dispersion speed in step S1 is 2000 rpm and the dispersion time is 5 min.

[0033] In some embodiments, the Si-H / vinyl molar ratio in step S2 is 1.2-1.5.

[0034] The innovative aspects of this invention are as follows:

[0035] 1. Collaborative foaming mechanism

[0036] Crystallization water compounds dehydrate at room temperature to 120°C. Providing a controlled water source, i.e., room temperature curing, also allows the crystallization water to achieve the desired effect.

[0037] Al2(SO4)3.18H2O→Al2(SO4)3+18H2O

[0038] Hydroxyl compounds (such as propylene glycol methyl ether) react with Si-H bonds to produce hydrogen:

[0039] Si-H+ROH→Si-OR+H2

[0040] Dual-source foaming results in a cell diameter distribution D 90 / D 10 ≤3 (better than the comparative example of ≥5);

[0041] 2. Component isolation design

[0042] Component A contains platinum catalyst, water of crystallization, and hydroxyl compounds; Component B contains hydrogen-containing silicone oil and flame-retardant microspheres.

[0043] Avoid pre-reaction;

[0044] 3. Flame retardant synergistic effect

[0045] Crystallization hydrates (such as borax Na2B4O7·10H2O) absorb heat during dehydration, thus improving flame retardancy;

[0046] ATH-coated microspheres (component B) provide UL94 V0 flame retardancy.

[0047] Beneficial effects: This invention uses hydrated compounds (such as Al2(SO4)3·18H2O, Na2SO4·10H2O) to replace graphite, precisely controlling the water release temperature; it adds hydroxyl compounds (alcohols / alcohol ethers) as synergistic foaming agents, which react with hydrogen-containing silicone oil to produce hydrogen; the two-component design isolates active ingredients and improves storage stability. Detailed Implementation

[0048] The present invention will be further described in detail below through embodiments.

[0049] Example 1

[0050] This two-component foamed silicone sealant composition comprises the following components:

[0051] Component A comprises the following raw materials by weight percentage:

[0052]

[0053]

[0054] Preparation method:

[0055] Step S1, Preparation of component A:

[0056] Vinyl polysiloxane, fumed silica, crystalline hydrate, hydroxyl compound, platinum catalyst, coated polymer microspheres and reaction inhibitor were mixed and dispersed at high speed at a speed of 2000 rpm for 5 min.

[0057] Step S2, Preparation of component B:

[0058] Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed.

[0059] Step S3, Curing:

[0060] Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

[0061] The Si-H / vinyl group molar ratio is 1.2-1.5.

[0062] Inhibitors can be acetylenol.

[0063] Example 2

[0064] This two-component foamed silicone sealant composition comprises the following components:

[0065] Component A comprises the following raw materials by weight percentage:

[0066]

[0067] Component B comprises the following raw materials by weight percentage:

[0068]

[0069]

[0070] Preparation method:

[0071] Step S1, Preparation of component A:

[0072] Vinyl polysiloxane, fumed silica, crystalline hydrate, hydroxyl compound, platinum catalyst, coated polymer microspheres and reaction inhibitor were mixed and dispersed at high speed at a speed of 2000 rpm for 5 min.

[0073] Step S2, Preparation of component B:

[0074] Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed.

[0075] Step S3, Curing:

[0076] Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

[0077] The Si-H / vinyl group molar ratio is 1.2-1.5.

[0078] Example 3

[0079] This two-component foamed silicone sealant composition comprises the following components:

[0080] Component A comprises the following raw materials by weight percentage:

[0081]

[0082] Component B comprises the following raw materials by weight percentage:

[0083]

[0084] Preparation method:

[0085] Step S1, Preparation of component A:

[0086] Vinyl polysiloxane, fumed silica, crystalline hydrate, hydroxyl compound, platinum catalyst, coated polymer microspheres and reaction inhibitor were mixed and dispersed at high speed at a speed of 2000 rpm for 5 min.

[0087] Step S2, Preparation of component B:

[0088] Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed.

[0089] Step S3, Curing:

[0090] Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

[0091] The Si-H / vinyl group molar ratio is 1.2-1.5.

[0092] Comparative Example 1:

[0093]

[0094] Component B comprises the following raw materials by weight percentage:

[0095]

[0096] Preparation method: Preparation of component A:

[0097] Vinyl polysiloxane, platinum catalyst, fumed silica, CaCO3-coated polymer microspheres and reaction inhibitors were mixed and dispersed at high speed at a speed of 2000 rpm for 5 min.

[0098] Step S2, Preparation of component B:

[0099] Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed.

[0100] Step S3, Curing:

[0101] Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

[0102] Of these, only hydrogen-containing silicone oil is responsible for releasing hydrogen-blowing agent;

[0103] The Si-H / vinyl molar ratio is 1.2-1.5.

[0104] Performance testing

[0105] Performance tests were conducted on Examples 1-3 and the comparative example. The test results are shown in the table below:

[0106] Test Items Example 1 Example 2 Example 3 Comparative Example <![CDATA[Density (g / cm 3 )]]> 0.35 0.50 0.55 0.60 Compression deformation (85℃×24h) 15％ 5％ 10％ 30％ <![CDATA[Cell uniformity (D 90 / D 10 )]]> 2.1 2.0 2.2 5.8 UL94 flame retardant V0 V0 V0 V1

[0107] The sealing compositions prepared in Examples 1-3 were coated onto the edge of the battery casing, and cured after the casing was closed to form a sealing layer with uniform pores.

[0108] Result: Passed the IPX7 waterproof test, and showed no leakage after testing at 85℃ and 85% humidity.

[0109] In summary: This invention uses hydrated compounds (such as Al2(SO4)3·18H2O, Na2SO4·10H2O) to replace graphite, precisely controlling the water release temperature; it adds hydroxyl compounds (alcohols / alcohol ethers) as synergistic foaming agents, which react with hydrogen-containing silicone oil to produce hydrogen; the two-component design isolates the active ingredients and improves storage stability.

[0110] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these should also be considered within the scope of protection of the invention.

Claims

1. A two-component foamed silicone sealant composition, characterized in that, Includes the following components: Component A; Component A includes vinyl polysiloxane, a hydrated compound, a hydroxyl compound, a platinum catalyst, fumed silica, CaCO3-coated polymer microspheres, and a reaction inhibitor; Component B; Component B includes vinyl polysiloxane, hydrogen-containing silicone oil, ATH-coated polymer microspheres, and flame-retardant filler.

2. The two-component foamed silicone sealant composition according to claim 1, characterized in that, Component A comprises the following raw materials by weight percentage:

3. The two-component foamed silicone sealant composition according to claim 2, characterized in that, The hydroxyl compound is selected from propylene glycol / ethylene glycol ether.

4. The two-component foamed silicone sealant composition according to claim 1, characterized in that, Component B comprises the following raw materials by weight percentage:

5. The two-component foamed silicone sealant composition according to claim 4, characterized in that, The flame-retardant filler is selected from Al(OH)3.

6. A method for preparing the two-component foamed silicone sealant composition according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step S1, Preparation of component A: Vinyl polysiloxane, fumed silica, crystalline water, hydroxyl compound, platinum catalyst, coated polymer microspheres and reaction inhibitor are mixed and dispersed at high speed; Step S2, Preparation of component B: Vinyl polysiloxane, hydrogen-containing silicone oil, flame-retardant filler, and ATH-coated microspheres were mixed. Step S3, Curing: Mix component A and component B and cure at room temperature for 96 hours or dry at 60°C for 12 hours.

7. The method for preparing the two-component foamed silicone sealant composition according to claim 6, characterized in that, In step S1, the dispersion speed is 2000 rpm and the dispersion time is 5 min.

8. The method for preparing the two-component foamed silicone sealant composition according to claim 6, characterized in that, In step S2, the Si-H / vinyl molar ratio is 1.2-1.

5.

9. The method for preparing the two-component foamed silicone sealant composition according to claim 6, characterized in that, In step S3, the volume ratio of component A to component B is 1:1.

Images