Ceramic mica flexible antioxidant graphite material and preparation method thereof

Abstract

The invention relates to the technical field of gasket materials, in particular to a ceramic mica flexible antioxidant graphite material and a preparation method thereof. The ceramic mica flexible antioxidant graphite material is prepared from the following raw materials in parts by weight: 35-45 parts of a framework material, 25-30 parts of mica, 20-30 parts of a flexible matrix, 3-5 parts of a catalyst, 1-2 parts of antioxidant graphite, 2-3 parts of boron nitride powder and 5-7 parts of an additive, the framework material comprises aluminum oxide nano powder and zirconium oxide powder, the mica is fluorophlogopite powder, the flexible matrix comprises phenyl siloxane rubber and polytetrafluoroethylene emulsion, the additive comprises a silane coupling agent and fumed silica, and the catalyst is a vulcanization system catalyst. The ceramic mica flexible antioxidant graphite material disclosed by the invention realizes the balance of high temperature resistance and compression resilience, and is suitable for high-end sealing scenes such as aerospace and high-temperature petrochemical equipment.

Description

Technical Field

[0001] The present application relates to the technical field of gasket materials, and more specifically, to a ceramic mica flexible anti-oxidation graphite material and a preparation method thereof. Background Art

[0002] Sealing of components is involved in various fields such as aerospace, rail transportation, petrochemical equipment, and electronic components, and sealing materials are required to have functions such as simple construction, long service life, and reliable sealing performance. If the sealing is improper, it will cause damage to the structure and system, thereby significantly reducing the service life of the components.

[0003] Sealing gaskets are commonly used for sealing in various technical fields, especially in aerospace and high-temperature petrochemical equipment. Gaskets are subjected to rigorous multi-dimensional operating conditions. Their high-temperature resistance and compression rebound properties directly affect the gasket's sealing performance, and thus, occupant safety. Currently, most gasket materials on the domestic market struggle to balance high-temperature resistance with compression rebound performance, significantly limiting their use. Summary of the Invention

[0004] The purpose of this application is to overcome the defect that most existing gasket materials are difficult to optimize high temperature resistance while taking into account compression rebound performance.

[0005] To this end, the present application provides a ceramic mica flexible anti-oxidation graphite material, the raw materials for its preparation include, by weight: 35-45 parts of skeleton material, 25-30 parts of mica, 20-30 parts of flexible matrix, 3-5 parts of catalyst, 1-2 parts of anti-oxidation graphite, 2-3 parts of boron nitride powder and 5-7 parts of additives; the skeleton material includes aluminum oxide nanopowder and zirconium oxide powder, the mica is fluorphlogopite powder, the flexible matrix includes phenyl silicone rubber and polytetrafluoroethylene emulsion, the additives include silane coupling agent and fumed silica, and the catalyst is a vulcanization system catalyst.

[0006] Furthermore, the catalyst is a mixture of dicumyl peroxide and a platinum catalyst.

[0007] Furthermore, the mass ratio of dicumyl peroxide to platinum catalyst in the catalyst is (2-3):(1-2).

[0008] Furthermore, the mass ratio of alumina nanopowder to zirconium oxide powder in the skeleton material is (4-5):(3-4).

[0009] Furthermore, the fluorphlogopite powder is a fluorphlogopite powder with a particle size of 400-1250 meshes.

[0010] Preferably, the fluorphlogopite powder is fluorphlogopite powder with a particle size of 800 meshes.

[0011] Furthermore, the mass ratio of phenyl silicone rubber to polytetrafluoroethylene emulsion in the flexible matrix is (2-5):1.

[0012] Furthermore, the mass ratio of the silane coupling agent to the fumed silica in the additive is (2-3):(3-4).

[0013] Furthermore, the silane coupling agent is selected from at least one of KH550 silane coupling agent, KH570 silane coupling agent, and KH560 silane coupling agent.

[0014] Preferably, the silane coupling agent is a mixture of KH550 silane coupling agent and KH560 silane coupling agent.

[0015] The present application also provides a method for preparing the aforementioned ceramic mica flexible anti-oxidation graphite material, which comprises the following preparation steps:

[0016] Mixing mica and additives uniformly to obtain a premixed base;

[0017] The flexible matrix and the catalyst are kneaded in an internal mixer to form a colloid, and then the skeleton material, the premixed base material, the antioxidant graphite and the boron nitride powder are added in sequence and kneaded to obtain a mixture;

[0018] The mixed material is pressed into shape and then vulcanized in sections.

[0019] In summary, this application has the following beneficial effects:

[0020] 1. In the preparation raw materials of the ceramic mica flexible anti-oxidation graphite material of the present application, the skeleton material can cooperate with fluorophlogopite to enable the ceramic mica flexible anti-oxidation graphite material to maintain the structural stability of the ceramic mica flexible anti-oxidation graphite material at high temperature. The silane coupling agent and gas-phase silica in the additives improve the interface strength between mica and the skeleton material, and the performance of the ceramic mica flexible anti-oxidation graphite material is balanced by the cooperation of anti-oxidation graphite, boron nitride powder, phenyl silicone rubber and polytetrafluoroethylene emulsion in the flexible matrix, and catalyst with the other raw materials, thereby achieving a balance between high temperature resistance and compression rebound performance, and is suitable for high-end sealing scenarios such as aerospace, high-temperature petrochemical equipment, etc.

[0021] 2. When the particle size of the fluorphlogopite mica powder of the ceramic mica flexible anti-oxidation graphite material of the present application is 800 mesh, the high temperature resistance of the ceramic mica flexible anti-oxidation graphite material is further improved; when the silane coupling agent is a mixture of KH550 silane coupling agent and KH560 silane coupling agent, the compression rebound rate of the ceramic mica flexible anti-oxidation graphite material is further improved.

[0022] 3. The ceramic mica flexible anti-oxidation graphite material of this application not only achieves a balance between high-temperature performance and compression rebound performance, but also has excellent electrical insulation and flame retardant properties, and is suitable for high-end sealing scenarios such as aerospace, high-temperature petrochemical equipment, etc. DETAILED DESCRIPTION

[0023] The following examples are provided to further better understand the present application, but are not limited to the best implementation mode described herein, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the scope of protection of the present application.

[0024] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0025] Preparation Example

[0026] Preparation Example 1

[0027] Preparation Example 1 provides an oxidation-resistant graphite, the preparation method of which comprises the following steps:

[0028] Slowly adding ethyl silicate to anhydrous ethanol under stirring to prepare a first mixed solution, wherein the volume ratio of ethyl silicate in the first mixed solution is 15%;

[0029] Add expanded graphite powder to the mixed solution and stir magnetically for 30 minutes to obtain a second mixed solution, wherein 5 g of expanded silicon powder is added to every 100 mL of the first mixed solution in the second mixed solution;

[0030] Ammonia water was added to the mixed solution under stirring until the pH value of the second mixed solution reached 10, and the second mixed solution was heated to 50° C. and stirred for 3 hours. After stirring, the mixture was centrifuged to obtain a precipitate, and the precipitate was washed 3-4 times with deionized water and then dried at 12° C. for 10 hours to obtain antioxidant graphite;

[0031] The CAS number of ethyl silicate is 78-10-4; the expansion degree of expanded graphite is 80 Ml / g, and it is purchased from Qingdao Ouer Graphite Co., Ltd.

[0032] Example

[0033] Example 1

[0034] Example 1 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which includes the following preparation steps:

[0035] S1. Mix 280 g of 800-mesh fluorphlogopite powder and 65 g of an additive at room temperature to obtain a premixed base, wherein the additive is a KH550 silane coupling agent and fumed silica in a mass ratio of 3:4;

[0036] S2. 250 g of the flexible matrix and 40 g of the catalyst were kneaded in an internal mixer at 60° C. to form a colloid, and then 400 g of the skeleton material, the premixed base material obtained in step S1, 15 g of the antioxidant graphite prepared in Preparation Example 1, and 25 g of boron nitride powder were added in sequence and kneaded for 2 h to obtain a mixture; the flexible matrix was phenyl silicone rubber and polytetrafluoroethylene emulsion with a solid content of 60% in a mass ratio of 3:1, the catalyst was dicumyl peroxide and platinum catalyst in a mass ratio of 2:1, and the aggregate was alumina nanopowder and zirconium oxide powder in a mass ratio of 4:3;

[0037] S3. Pour the mixture into a ceramic mica flexible antioxidant graphite material mold and press it into a 3 mm thin sheet. Then sinter the thin sheet at 0.5 MPa and 120°C for 30 min, 1.2 MPa and 180°C for 2 h, and normal pressure and 160°C for 1 h. Finally, cool it naturally to obtain the ceramic mica flexible antioxidant graphite material.

[0038] Fluorphlogopite powder with a particle size of 800 mesh and a silica content of 58 wt% was purchased from Shijiazhuang Runze Gold Mining Products Co., Ltd.; fumed silica was of the model CAB-O-SIL and was purchased from Shanghai Zhenlishi Network Technology Co., Ltd.; phenyl silicone rubber was a phenyl compound rubber with the brand MY3840 and was purchased from Anhui Mingyi Silicon Industry Co., Ltd.; polytetrafluoroethylene emulsion with a solid content of 60% was of the brand DISP30 and was purchased from DuPont, USA; dicumyl peroxide was of the CAS number 80-43- 3. The platinum catalyst was selected from Custer Catalyst, with a CAS number of 68478-92-2, purchased from Wuhan Kemik Biomedical Technology Co., Ltd.; the nano-alumina powder was of model ZTL-WAO, purchased from Yangzhou Zhongtianli New Materials Co., Ltd.; the zirconium oxide powder had a CAS number of 1314-23-4 and a product number of XD-R800, purchased from Wuhu Xinda New Materials Technology Co., Ltd.; the boron nitride powder had a particle size of 100 nm, purchased from Shanghai Naio Nanotechnology Co., Ltd.

[0039] Example 2-3

[0040] Example 2-3 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material. The preparation steps are the same as those in Example 1, with the only difference being the different proportions of the raw materials. See Table 1 for details.

[0041] Table 1 Ratios of raw materials in Examples 1-3

[0042]

[0043]

[0044] Example 4

[0045] Example 4 provides a preparation method of a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the fluorophlogopite mica powder has a particle size of 1250 mesh and a silicon dioxide content of 58 wt %, which is purchased from Shijiazhuang Runze Gold Mining Products Co., Ltd.

[0046] Example 5

[0047] Example 5 provides a preparation method of a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the fluorophlogopite mica powder has a particle size of 400 mesh and a silicon dioxide content of 58 wt %, which is purchased from Shijiazhuang Runze Gold Mining Products Co., Ltd.

[0048] Example 6

[0049] Example 6 provides a preparation method of a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the silane coupling agent is KH570 silane coupling agent.

[0050] Example 7

[0051] Example 7 provides a preparation method of a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the silane coupling agent is KH560 silane coupling agent.

[0052] Example 8

[0053] Example 8 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the mixing temperature in step S2 is 70°C.

[0054] Example 9

[0055] Example 9 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of platinum catalyst is used instead of diisopropylbenzene oxide.

[0056] Example 10

[0057] Example 10 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material. The only difference from Example 1 is that the silane coupling agent is a mixture of KH550 silane coupling agent and KH560 silane coupling agent, and the mass ratio of KH550 silane coupling agent to KH560 silane coupling agent is 1:1.

[0058] Example 11

[0059] Example 11 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the mass ratio of dicumyl peroxide to platinum catalyst in the catalyst is 1:2.

[0060] Example 12

[0061] Example 12 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the mass ratio of aluminum oxide nanopowder and zirconium oxide powder in the skeleton material is 2:1.

[0062] Example 13

[0063] Example 13 provides a preparation method of a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the mass ratio of phenyl silicone rubber and polytetrafluoroethylene emulsion with a solid content of 60% in the flexible matrix is 1:1.

[0064] Example 14

[0065] Example 14 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that the mass ratio of the silane coupling agent to the fumed silica in the additive is 2.5:2.

[0066] Comparative Example

[0067] Comparative Example 1

[0068] Comparative Example 1 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of aluminum oxide nanopowder is used instead of zirconium oxide powder.

[0069] Comparative Example 2

[0070] Comparative Example 2 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of phenyl silicone rubber is used instead of polytetrafluoroethylene emulsion.

[0071] Comparative Example 3

[0072] Comparative Example 3 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of fumed silica is used instead of the silane coupling agent.

[0073] Comparative Example 4

[0074] Comparative Example 4 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of mica is used to replace the skeleton material.

[0075] Comparative Example 5

[0076] Comparative Example 5 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of skeleton material is used instead of mica.

[0077] Comparative Example 6

[0078] Comparative Example 6 provides a method for preparing a ceramic mica flexible anti-oxidation graphite material, which differs from Example 1 only in that an equal amount of anti-oxidation graphite is used instead of boron nitride powder.

[0079] Performance testing

[0080] Test 1

[0081] The ceramic mica flexible anti-oxidation graphite material was prepared according to the preparation method of each embodiment and comparative example, and then the compression rebound rate of the ceramic mica flexible anti-oxidation graphite material prepared in each embodiment and comparative example was tested according to the ASTM D395 test standard. The test results are shown in Table 2.

[0082] Test 2

[0083] According to the preparation methods of the embodiments and comparative examples, ceramic mica flexible anti-oxidation graphite materials were prepared and the temperature resistance of each ceramic mica flexible anti-oxidation graphite material was tested. The test method is:

[0084] Cut the ceramic mica flexible anti-oxidation graphite material into 1000×60mm 2 The samples were dried in an oven at 105°C for 2 hours, and the mass of each cut sample was weighed as m1. The dried samples were then placed in a high-temperature furnace and heated to 850°C at a heating rate of 5°C / min and kept at that temperature for 24 hours. After the temperature was kept at that temperature, the samples were cooled to room temperature in the furnace and the mass of each sample was weighed as m2. The mass loss rate was calculated. The test results are shown in Table 2.

[0085] Test 3

[0086] Ceramic mica flexible anti-oxidation graphite materials were prepared according to the preparation methods of the embodiments and comparative examples, and then the tensile strength of the ceramic mica flexible anti-oxidation graphite materials prepared according to the preparation methods of the embodiments and comparative examples was tested according to the standard GB / T 528-2009. The test results are shown in Table 2.

[0087] Test 4

[0088] Ceramic mica flexible oxidation-resistant graphite materials were prepared according to the preparation methods of the embodiments and comparative examples, and then the volume resistivity of the ceramic mica flexible oxidation-resistant graphite materials prepared according to the preparation methods of the embodiments and comparative examples was tested according to the standard GB / T 1410-2006. The test results are shown in Table 2.

[0089] Test 5

[0090] Ceramic mica flexible oxidation-resistant graphite materials were prepared according to the preparation methods of the embodiments and comparative examples, and then the flame retardant properties of the ceramic mica flexible oxidation-resistant graphite materials prepared according to the preparation methods of the embodiments and comparative examples were tested according to the UL 94 standard. The test results are shown in Table 2.

[0091] Table 2 Test results of various embodiments and comparative examples

[0092]

[0093]

[0094] In the preparation raw materials of the ceramic mica flexible anti-oxidation graphite material of the present application, the skeleton material can cooperate with fluorophlogopite to enable the ceramic mica flexible anti-oxidation graphite material to maintain the structural stability of the ceramic mica flexible anti-oxidation graphite material at high temperature. The silane coupling agent and gas-phase silica in the additives improve the interface strength between mica and the skeleton material, and the performance of the ceramic mica flexible anti-oxidation graphite material is balanced by the cooperation of anti-oxidation graphite, boron nitride powder, phenyl silicone rubber and polytetrafluoroethylene emulsion in the flexible matrix, and catalyst with the other raw materials, thereby achieving a balance between high-temperature resistance and compression rebound performance, and is suitable for high-end sealing scenarios such as aerospace, high-temperature petrochemical equipment, etc.

[0095] When the particle size of the fluorphlogopite mica powder of the ceramic mica flexible anti-oxidation graphite material of the present application is 800 mesh, the high temperature resistance of the ceramic mica flexible anti-oxidation graphite material is further improved; when the silane coupling agent is a mixture of KH550 silane coupling agent and KH560 silane coupling agent, the compression rebound rate of the ceramic mica flexible anti-oxidation graphite material is further improved.

[0096] The ceramic mica flexible anti-oxidation graphite material of this application not only achieves a balance between high-temperature performance and compression rebound performance, but also has excellent electrical insulation and flame retardant properties, and is suitable for high-end sealing scenarios such as aerospace, high-temperature petrochemical equipment, etc.

[0097] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A ceramic mica flexible anti-oxidation graphite material, characterized in that: The preparation raw materials include, by weight, 35-45 parts of skeleton material, 25-30 parts of mica, 20-30 parts of flexible matrix, 3-5 parts of catalyst, 1-2 parts of antioxidant graphite, 2-3 parts of boron nitride powder and 5-7 parts of additives; the skeleton material includes aluminum oxide nanopowder and zirconium oxide powder, the mica is fluorphlogopite powder, the flexible matrix includes phenyl silicone rubber and polytetrafluoroethylene emulsion, the additives include silane coupling agent and fumed silica, and the catalyst is a vulcanization system catalyst.

2. The ceramic mica flexible anti-oxidation graphite material according to claim 1, characterized in that: The catalyst is a mixture of dicumyl peroxide and a platinum catalyst.

3. The ceramic mica flexible anti-oxidation graphite material according to claim 2, characterized in that: The mass ratio of dicumyl peroxide to platinum catalyst in the catalyst is (2-3):(1-2).

4. The ceramic mica flexible anti-oxidation graphite material according to claim 1, characterized in that: The mass ratio of the aluminum oxide nanopowder to the zirconium oxide powder in the skeleton material is (4-5):(3-4).

5. The ceramic mica flexible anti-oxidation graphite material according to claim 1, characterized in that: The fluorphlogopite powder is a fluorphlogopite powder with a particle size of 400-1250 meshes.

6. The ceramic mica flexible anti-oxidation graphite material according to claim 1, characterized in that: The mass ratio of phenyl silicone rubber to polytetrafluoroethylene emulsion in the flexible matrix is (2-5):

1.

7. The ceramic mica flexible anti-oxidation graphite material according to claim 1, characterized in that: The mass ratio of the silane coupling agent to the fumed silica in the additive is (2-3):(3-4).

8. The ceramic mica flexible anti-oxidation graphite material according to claim 7, characterized in that: The silane coupling agent is selected from at least one of KH550 silane coupling agent, KH570 silane coupling agent, and KH560 silane coupling agent.

9. The method for preparing the ceramic mica flexible anti-oxidation graphite material according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: Mixing mica and additives uniformly to obtain a premixed base; The flexible matrix and the catalyst are kneaded in an internal mixer to form a colloid, and then the skeleton material, the premixed base material, the antioxidant graphite and the boron nitride powder are added in sequence and kneaded to obtain a mixture; The mixed material is pressed into shape and then vulcanized in sections.

Images