Fluorine-containing elastomer toughened crystalline fluorine-containing polymer and application of fluorine-containing elastomer toughened crystalline fluorine-containing polymer in sealing element

Abstract

The invention belongs to the technical field of sealing elements, and particularly relates to a fluorine-containing elastomer toughened crystalline fluorine-containing polymer and a sealing element application thereof. The fluorine-containing elastomer toughened crystalline fluorine-containing polymer comprises the following raw materials: an uncrosslinked fluorine-containing elastomer, a crystalline fluorine-containing polymer and a cross-linking agent, the mass ratio of the uncrosslinked fluorine-containing elastomer to the crystalline fluorine-containing polymer to the cross-linking agent is 100: (30-400): (1-3), and the fluorine content of the fluorine-containing elastomer is greater than 50%. According to the fluorine-containing elastomer toughening crystal type fluorine-containing polymer, the ESC sealing element formed on the basis of the fluorine-containing elastomer toughening crystal type fluorine-containing polymer not only has the elasticity of rubber, but also has the etching gas resistance of fluorine-containing plastic, and meanwhile, the ESC sealing element is convenient to operate on site.

Description

Technical Field

[0001] This invention belongs to the field of sealing technology, specifically relating to a fluorinated elastomer-toughened crystalline fluorinated polymer and its sealing applications. Background Technology

[0002] Electrostatic chucks (ESCs) are crucial components in semiconductor manufacturing. Their function is to provide support for the back of the wafer during processing, securing it via electrostatic adsorption, and maintaining a dynamically constant temperature. ESCs utilize the Coulomb attraction between the two electrode plates of a capacitor to hold the wafer in place, avoiding potential damage from mechanical clamping and allowing for temperature regulation, thus improving processing uniformity.

[0003] In ESC applications, several layers of different materials (such as PTFE sealing strips and rubber sealing strips) are often combined to achieve a combined seal. This combination is susceptible to damage to the sealing rings or PTFE sealing strips due to human error during installation, and deviations in this combination can also limit the overall product's usability. In traditional sealing formulations, crystalline fluoropolymer micropowders are added as fillers, with rubber as the continuous phase and the crystalline fluoropolymer micropowder as the discontinuous phase, and the addition ratio is less than 30 parts (23 wt%). When the addition amount of crystalline fluoropolymer micropowder exceeds 30 parts, the discontinuous crystalline polymer phase will precipitate at high temperatures, and the elasticity of the seal will decrease significantly.

[0004] The applicant explored several methods for protecting the gaps in electrostatic chucks, specifically as described in these two invention patents: CN115873359B, a fluororubber ultrafine sealant for protecting the gaps in electrostatic chucks; and CN117777941B, a sealant for the gaps in electrostatic chucks and its preparation method and application. These two methods can partially solve the application scenario problems of sealing electrostatic chucks.

[0005] Pure PTFE sealing strips lack the elasticity of elastomers, making it highly susceptible to the entry of etching gases into the electrostatic chuck. While adding an inner rubber ring to the PTFE sealing strip can prevent the entry of etching gases, this increases the probability of operational errors in the field. Therefore, there is an urgent need for a sealing component that combines the elasticity of rubber with the etching gas resistance of fluoroplastics, while also offering ease of operation in the field. Summary of the Invention

[0006] In view of the gaps in the prior art, the purpose of this invention is to provide a fluoropolymer toughened crystalline fluoropolymer and its sealing application, especially the sealing application of integrated circuits. The ESC seal formed based on this has both the elasticity of rubber and the corrosion gas resistance of fluoroplastics, while also being convenient for field operation, thereby solving the problems in the prior art.

[0007] The first aspect of this invention provides a fluorinated elastomer-toughened crystalline fluorinated polymer, wherein the raw materials for the fluorinated elastomer-toughened crystalline fluorinated polymer include an uncrosslinked fluorinated elastomer, a crystalline fluorinated polymer, and a crosslinking agent, wherein the mass ratio of the uncrosslinked fluorinated elastomer, the crystalline fluorinated polymer, and the crosslinking agent is 100:(30-400):(1-3), and the fluorine content of the fluorinated elastomer is greater than 50 wt%.

[0008] A second aspect of the present invention provides a method for preparing a fluorinated elastomer-toughened crystalline fluorinated polymer, the method comprising reacting an uncrosslinked fluorinated elastomer, a crosslinking agent and a crystalline fluorinated polymer above the melting point of the crystalline fluorinated polymer to obtain a fluorinated elastomer-toughened crystalline fluorinated polymer.

[0009] For fusible crystalline fluoropolymers: A twin-screw extruder blending system, a twin-cone extruder, or a high-temperature internal mixer is used to uniformly melt the fusible crystalline fluoropolymer, forming a continuous phase. Uncrosslinked fluorinated elastomers are mixed with a crosslinking agent in an open mill, and then elastomer micropowders with a D50 less than 50 μm are prepared using cryogenic pulverization technology. These elastomer micropowders are then mixed and reacted with the fusible crystalline fluoropolymer forming the continuous phase to obtain a fluorinated elastomer-toughened crystalline fluoropolymer.

[0010] For non-melt-processable crystalline fluoropolymers: Uncrosslinked fluoroelastomers are mixed with crosslinking agents in an open mill, and then elastomer micropowders with a D50 of less than 50 μm are prepared by cryogenic pulverization. The elastomer micropowders and non-melt-processable crystalline fluoropolymers are mixed evenly at room temperature using a high-speed mixer, cold-pressed under high pressure, and then heated; then cooled to room temperature to obtain fluoroelastomer-toughened crystalline fluoropolymers.

[0011] A third aspect of the present invention provides the use of the fluorinated elastomer-toughened crystalline fluorinated polymer described in the present invention and / or the fluorinated elastomer-toughened crystalline fluorinated polymer obtained by the preparation method described in the present invention in integrated circuit seals.

[0012] A fourth aspect of the present invention provides a sealing component for integrated circuits, comprising a fluorinated elastomer-toughened crystalline fluorinated polymer as described in the present invention and / or a fluorinated elastomer-toughened crystalline fluorinated polymer obtained by the preparation method described in the present invention.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0014] This invention creatively completes a fluorinated elastomer-toughened crystalline fluoropolymer. Based on this, the ESC seal has both the elasticity of rubber and the corrosion resistance of fluoroplastics, while also being convenient for on-site operation. Attached Figure Description

[0015] Figure 1 As shown in Example 1, the optimal processing temperature for molten PFA resin, determined by a rotational rheometer, is between 330°C and 40°C. Detailed Implementation

[0016] The following details the specific disclosure of a fluorinated elastomer-toughened crystalline fluorinated polymer and its application as a sealant.

[0017] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0018] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0019] In traditional sealing component formulations, crystalline fluoropolymer micropowders are added as fillers, with rubber as the continuous phase and the crystalline fluoropolymer micropowder as the discontinuous phase. Furthermore, the addition ratio is less than 24 wt%, and formulations with an addition exceeding 30 parts of crystalline fluoropolymer micropowder have not seen good market applications. This invention creatively develops a fluoroelastomer-toughened crystalline fluoropolymer. ESC seals molded based on this material possess both the elasticity of rubber and the corrosion gas resistance of fluoroplastics, while also offering convenience in field operation.

[0020] Through extensive experimental research, the inventors discovered that by selecting a suitable crystalline fluoropolymer and combining it with a special fluoroelastomer, high resistance to etching gases can be achieved without compromising the basic properties of the elastomer. This allows the elastomer of this invention to possess both the basic properties of rubber and the basic properties of crystalline polymers, making field equipment simpler and more efficient. Based on this, this application was completed.

[0021] Toughened crystalline fluoropolymers with fluorinated elastomers

[0022] This invention provides a fluorinated elastomer-toughened crystalline fluorinated polymer, wherein the raw materials for the fluorinated elastomer-toughened crystalline fluorinated polymer include an uncrosslinked fluorinated elastomer, a crystalline fluorinated polymer, and a crosslinking agent.

[0023] In the fluorinated elastomer-toughened crystalline fluoropolymer provided by the present invention, the mass ratio of the uncrosslinked fluorinated elastomer to the crystalline fluoropolymer to the crosslinking agent is 100:(30-400):(1-3). Optionally, the mass ratio of the fluorinated elastomer to the crystalline fluoropolymer can be, for example, 100:(30-100):(1-3), 100:(100-400):(1-3), 100:(100-200):(1-3), 100:(200-300):(1-3), 100:(300-400):(1-3), etc.

[0024] In the fluorinated elastomer-toughened crystalline fluorinated polymer provided by this invention, the fluorine content (by weight) of the fluorinated elastomer is greater than 50%. This can be measured by F-spectrum NMR nuclear magnetic resonance. When the fluorine content is less than 50%, it will affect the compatibility of the elastic system, and particularly low fluorine content will exhibit poor resistance to fluorinated etching gases. Optionally, the fluorinated elastomer is selected from one or more of the following: vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-trifluorochloroethylene, tetrafluoroethylene-propylene copolymer, ethylene-tetrafluoroethylene-perfluoroalkyl vinyl ether, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

[0025] In the fluorine-containing elastomer toughened crystalline fluorine-containing polymer provided by the present invention, the crosslinking agent is selected from one or a mixture of several of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl perbenzoate, bis[1,3-dimethyl-3-(tert-butylperoxy)butyl] carbonate, 2,5-dimethylbenzenethiol, bisphenol A, perfluorobisphenol A, triallyl isocyanurate, tris(methallyl) isocyanurate, tris(diallylamine)-s-triazine, triallyl phosphite, N,N-diallyl acrylamide, tris(5-norbornene-2-methylene) cyanurate, trivinyl isocyanurate, hexallyl phosphoramide, N,N,N-2,4,6-trivinylmethyltrisiloxane, tetraphenyltin, N,N-dicinnamylidene, trimethylenediamine, cinnamylethylideneethylenediamine, cinnamylidenehexamethylenediamine, hexamethylenediamine carbamate, bis(4-aminocyclohexyl)methane carbamate, 2,2-bis-(3-amino-4-hydroxyphenyl)-hexafluoropropane (BOAP), 1,3-diaminopropane monocarbonate, ethylenediamine carbamate or trimethylenediamine dicarbamate, etc.

[0026] In the fluorine-containing elastomer toughened crystalline fluorine-containing polymer provided by the present invention, the crystalline fluorine-containing polymer is selected from one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroethylene-propylene copolymer (FEP), tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), and polychlorotrifluoroethylene (PCTFE). Among them, polytetrafluoroethylene (PTFE) is a non-melt-processable crystalline fluorine-containing polymer. Polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroethylene-propylene copolymer (FEP), tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), and polychlorotrifluoroethylene (PCTFE) are meltable crystalline fluorine-containing polymers.

[0027] In the fluorine-containing elastomer toughened crystalline fluorine-containing polymer provided by the present invention, the absolute value of the difference between the fluorine content of the crystalline fluorine-containing polymer and the fluorine content of the fluorine-containing elastomer is ΔF%, and 0 < ΔF < 25. Optionally, 0 < ΔF < 10, 10 < ΔF < 25, 10 < ΔF < 15, 15 < ΔF < 20, 20 < ΔF < 25, etc.

[0028]

Preparation Method of Fluorine-containing Elastomer Toughened Crystalline Fluorine-containing Polymer

[0029] This invention also provides a method for preparing a fluorinated elastomer-toughened crystalline fluoropolymer, the method comprising: subjecting a fluorinated elastomer and a crystalline fluoropolymer to a temperature process above the melting point of the crystalline fluoropolymer for a period of time to obtain a fluorinated elastomer-toughened crystalline fluoropolymer. The reaction time can be, for example, 2-6 min, 2-3 min, 3-4 min, 4-5 min, or 3-6 min.

[0030] For fusible crystalline fluoropolymers: A twin-screw extruder blending system, a twin-cone extruder, or a high-temperature internal mixer is used to uniformly melt the fusible crystalline fluoropolymer, forming a continuous phase. Uncrosslinked fluorinated elastomers are mixed with a crosslinking agent in an open mill, and then elastomer micropowders with a D50 less than 50 μm are prepared using cryogenic pulverization technology. These elastomer micropowders are then mixed and reacted with the fusible crystalline fluoropolymer forming the continuous phase to obtain a fluorinated elastomer-toughened crystalline fluoropolymer.

[0031] The reaction time can be, for example, 2-6 min, 2-3 min, 3-4 min, 4-5 min, or 3-6 min.

[0032] For non-melt-processable fluoropolymers (such as PTFE): Uncrosslinked fluoroelastomers are mixed with a crosslinking agent in an open mill, and then elastomer micropowders with a D50 of less than 50 μm are prepared by cryogenic pulverization. The elastomer micropowders and non-melt-processable crystalline fluoropolymers are mixed evenly at room temperature using a high-speed mixer, and then cold-pressed under high pressure, followed by heating; then cooled to room temperature to obtain fluoroelastomer-toughened crystalline fluoropolymers, which are then machined to obtain the desired part type.

[0033] The high pressure can be selected from 15-40MPa, 15-20MPa, 20-40MPa, 15-18MPa, 18-20MPa, etc. The heating process is as follows: 15-30 minutes below 180℃, 16-20 hours at 250℃, and 4-6 hours at 360-380℃.

[0034] The elastomer micropowder used in this invention has a D50 of less than 50 μm, achieved through cryogenic pulverization. For details, please refer to patents CN115847665A (a pulverization process and preparation method for recycled perfluoroether rubber) and CN118834485B (a fluororubber composition containing cross-linked perfluoroether rubber and its preparation method). When the particle size of the elastomer micropowder is too large, a longer thermal history and shear force are required to form a uniform molten phase with the crystalline resin. However, a longer thermal history makes the elastomer less stable, ultimately leading to defects such as yellowing and decreased elasticity in the product.

[0035]

use

[0036] The present invention also provides the use of fluorinated elastomer-toughened crystalline fluoropolymers as described in the present invention and / or fluorinated elastomer-toughened crystalline fluoropolymers obtained by the preparation method described in the present invention in integrated circuit seals.

[0037] Seals for integrated circuits

[0038] The present invention also provides a sealing component for integrated circuits, comprising the fluorinated elastomer-toughened crystalline fluorinated polymer described in the present invention and / or the fluorinated elastomer-toughened crystalline fluorinated polymer obtained by the preparation method described in the present invention.

[0039] The beneficial effects of the present invention will be further illustrated below with reference to the embodiments.

[0040] Unless otherwise specified, all reagents, materials and instruments used in the following embodiments are commercially available.

[0041] Silicone, purchased from Shanxin SR3250U (fluorine content 0%);

[0042] Fluorosilicone, purchased from Momentive FSE 7360 (fluorine content 28%);

[0043] The tetrafluoroethylene-propylene copolymer was purchased from AGC manufacturer Aflas 600S model 600X (fluorine content 53%).

[0044] The vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer was purchased from Chemours, model GBL600S (fluorine content 68%).

[0045] Tetrafluoroethylene-perfluoroalkyl vinyl ether was purchased from Solvay, model PFR, model 95HT (fluorine content 73%).

[0046] PFA (fluorine content 73.6%) was purchased from Daikin, model AP-231SH, melting point 308℃;

[0047] PTFE(1) (fluorine content 76%) was purchased from Daikin M-111, melting point 326℃;

[0048] PTFE(2) (fluorine content 76%) was purchased from Chemours, model Teflon PTFE 7C X, melting point 327℃;

[0049] Tensile recovery test elasticity test method: The obtained thermoplastic elastomer granules are molded into A214 O-rings. The O-rings are subjected to tensile tests on a tensile testing machine at a tensile speed of 80 mm / min. The straight distance between the two cross-sections is observed when the O-ring is broken. The greater the distance, the worse the rebound.

[0050] Surface finish evaluation: No burrs, no pits, no uneven areas, etc.

[0051] Example 1

[0052] 1. Preparation of elastomer micro powder:

[0053] 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane di25 was purchased from Norinon.

[0054] TAIC triallyl isocyanurate was purchased from TCI

[0055] 100 parts of uncrosslinked fluorinated elastomer 600X were mixed with 3 parts of crosslinking agent (2 parts of double 25 and 1 part of TAIC) through an open mill, and then elastomer micro powder with a D50 of 25 μm was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 min, and then pulverizing and sieving the sample).

[0056] 2. Preparation of toughened crystalline fluoropolymers using fluorinated elastomers:

[0057] Figure 1 The optimal melt processing temperature for PFA is shown to be around 330°C.

[0058] A twin-screw extruder with a length-to-diameter ratio (L / D) greater than or equal to 40 (manufacturer: JSW twin-screw compounding extruder, model TEX25 series) was selected, with at least 8 barrels (referred to as C), and C5 having one side-feeding system. The temperature settings for each barrel are as follows:

[0059] C1 C2 C3 C4 C5 C6 C7 C8 C9 machine head 30℃ 120℃ 250℃ 300℃ 330℃ 320℃ 300℃ 300℃ 300℃ 300℃

[0060] Section C1 is the PFA feeding section. During stages C1-C5, the PFA undergoes uniform melting. Simultaneously, in section C5, the aforementioned elastomer powder with a D50 of 25µm is added. Under the action of thread shear force, it melt-blends with the PFA for 2-6 minutes. At the same time, the elastomer undergoes a self-crosslinking reaction, forming dynamic crosslinks. After exiting the die head, the blend is water-cooled, dried, and granulated to form a thermoplastic elastomer.

[0061] Example 2

[0062] 1. Preparation of elastomer micro powder:

[0063] 100 parts of uncrosslinked fluorinated elastomer GBL600S were mixed with 3 parts of crosslinking agent (2 parts of double 25 and 1 part of TAIC) through an open mill, and then the elastomer powder with a D50 of 25 μm was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 min, and then pulverizing and sieving the sample).

[0064] 2. The preparation of toughened crystalline fluoropolymers with fluorinated elastomers is the same as in Example 1.

[0065] Example 3

[0066] 1. Preparation of elastomer micro powder:

[0067] 100 parts of uncrosslinked fluorinated elastomer 95HT were mixed with 2 parts of crosslinking agent (double 25) through an open mill, and then elastomer micro powder with a D50 of 25um was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 minutes, and then pulverizing and sieving the sample).

[0068] 2. The preparation of toughened crystalline fluoropolymers with fluorinated elastomers is the same as in Example 1.

[0069] Comparative Example 1

[0070] 1. Preparation of elastomer micro powder:

[0071] 100 parts of SR3250U were mixed with 1.2 parts of crosslinking agent (double 25) through an open mill, and then the elastomer powder with a D50 of 25um was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 minutes, and then pulverizing and sieving the sample).

[0072] 2. The preparation of the elastomer-toughened crystalline fluoropolymer is the same as in Example 1.

[0073] Comparative Example 2

[0074] 1. Preparation of elastomer micro powder:

[0075] 100 parts of FSE 7360 were mixed with 2 parts of crosslinking agent (double 25) through an open mill, and then the elastomer powder with a D50 of 25um was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 minutes, and then pulverizing and sieving the sample).

[0076] 2. The preparation of toughened crystalline fluoropolymers with fluorinated elastomers is the same as in Example 1.

[0077] Comparative Example 3

[0078] 1. Preparation of elastomer micro powder:

[0079] 100 parts of 95HT were mixed with 2 parts of crosslinking agent (double 25) through an open mill, and then the elastomer powder with a D50 of 25um was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 minutes, and then pulverizing and sieving the sample).

[0080] 2. Elastomer powder with a D50 of 25 μm and PFA were mixed in an internal mixer at 180°C for 40 min to obtain the product.

[0081] The test results for each embodiment and comparative example are detailed in Table 1.

[0082] Table 1

[0083]

[0084]

[0085] This invention compares the effects of differences in fluorine content in the elastomeric crystalline polymer on the appearance of the products with those in Examples 1-3 and Comparative Examples 1-3. Table 1 shows that when the difference in fluorine content is greater than 25%, there is a significant difference in heat resistance between the elastomer and the crystalline polymer, leading to yellowing of the product and rendering it unusable as a final product.

[0086] Example 4

[0087] The difference between Example 3 and Example 4 is that in step 1, elastomer powder with a D50 of 46 μm is prepared. All other conditions are the same.

[0088] Comparative Example 4

[0089] The difference between Example 3 and Example 4 is that in step 1, elastomer powder with a D50 of 65 μm is prepared. All other conditions are the same.

[0090] Table 2

[0091]

[0092] Table 2 shows the effects of different elastomer D50 sizes on the properties of granular elastomers in Examples 3, 4, and Comparative Example 4. When D50 is greater than 50 μm, the particles are coarse and the molded samples have burrs.

[0093] Example 5

[0094] The difference from Example 3 is that the amount of PFA in step 1 is 40 parts. All other conditions are the same.

[0095] Example 6

[0096] The difference from Example 3 is that the amount of PFA in step 1 is 250. All other conditions are the same.

[0097] Example 7

[0098] The difference from Example 3 is that the number of PFAs in step 1 is 380. All other conditions are the same.

[0099] Comparative Example 5

[0100] The difference from Example 3 is that in step 1, the amount of PFA is 20 parts. All other conditions are the same.

[0101] Comparative Example 6

[0102] The difference from Example 3 is that the number of PFAs in step 1 is 450. All other conditions are the same.

[0103] Table 3

[0104]

[0105] Table 3 shows that Examples 5-7 and Comparative Examples 5-6 investigated the effect of a mass ratio of fluorinated elastomer to crystalline fluorinated polymer of 100:30-400 on product performance. Within this range, the granules are transparent and the molded products have good resilience. When the PFA content is too high, the molded products have poor resilience. When the PFA content is too low, the granules are coarse and the screw torque is extremely high.

[0106] Example 8

[0107] For non-melt-processable crystalline fluoropolymers: Uncrosslinked fluoroelastomers are mixed with a crosslinking agent in an open mill, and then elastomer micropowders with a D50 of less than 50 μm are prepared using cryogenic pulverization technology. The elastomer micropowders and the non-melt-processable crystalline fluoropolymers are then uniformly mixed at room temperature using a high-speed mixer. The mixture is then cold-pressed under high pressure, followed by heating; and finally cooled to room temperature to obtain a fluoroelastomer-toughened crystalline fluoropolymer. Specifically:

[0108] PTFE(2) (fluorine content 76%) was purchased from Chemours, model Teflon PTFE 7C X, melting point 327℃, D50 = 31µm.

[0109] 100 parts of 95HT were mixed with 2 parts of crosslinking agent (double 25) using an open mill, and then elastomer micropowder with a D50 of 25µm was prepared by cryogenic pulverization (freezing in liquid nitrogen for 20-40 minutes, followed by sample pulverization and sieving). The PTFE micropowder and elastomer micropowder were then mixed evenly using a high-speed mixer, filled into a mold, and molded at 20MPa pressure at room temperature. The mixture was then subjected to the following heat treatments: below 180°C for 20 minutes, at 250°C for 18 hours, at 370°C for 4 hours, and then cooled to room temperature for 24 hours. The product was then machined to the desired specifications.

[0110] Example 9

[0111] The difference between Example 8 and Example 9 is that the elastomer powder with a D50 of 46 μm was prepared in step 1. All other conditions were the same.

[0112] Comparative Example 7

[0113] The difference between Example 8 and Example 9 is that in step 1, elastomer powder with a D50 of 65 μm is prepared. All other conditions are the same.

[0114] Comparative Example 8

[0115] Compared with Example 8, the difference lies in the processing procedure: the first vulcanization temperature is 180°C and the vulcanization time is 7 min, and the second vulcanization temperature is 250°C and the vulcanization time is 16 h.

[0116] Table 4

[0117]

[0118]

[0119] As can be seen from Table 4, PTFE cannot form a homogeneous phase below its melting point, meaning it cannot form an interpenetrating network structure with the cross-linked elastomer, resulting in a significantly poorer overall elasticity.

[0120] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A fluorinated elastomer-toughened crystalline fluorinated polymer, characterized in that, The raw materials for the fluorinated elastomer toughening crystalline fluorinated polymer include uncrosslinked fluorinated elastomer, crystalline fluorinated polymer and crosslinking agent, wherein the mass ratio of the uncrosslinked fluorinated elastomer, crystalline fluorinated polymer and crosslinking agent is 100:(30-400):(1-3), and the fluorine content of the uncrosslinked fluorinated elastomer is greater than 50wt%.

2. The fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 1, characterized in that, The uncrosslinked fluorinated elastomer is selected from one or more of the following: vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-trifluorochloroethylene, tetrafluoroethylene-propylene copolymer, ethylene-tetrafluoroethylene-perfluoroalkyl vinyl ether, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

3. The fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 1, characterized in that, The crosslinking agent is selected from 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl perbenzoate, di[1,3-dimethyl-3-(tert-butylperoxy)butyl]carbonate, 2,5-dimethylbenzylthiophenol, bisphenol A, perfluorobisphenol A, triallyl isocyanurate, tris(methylallyl) isocyanurate, tris(diallylamine)-s-triazine, triallyl phosphite, N,N-diallylacrylamide, tris(5-norbornene-2-methylene)cyanurate, and trivinyl isocyanurate. Hexamethylenephosphoramide, N,N,N-2,4,6-trivinylmethyltrisiloxane, tetraphenyltin, N,N-dicinnamyl subunit, trimethylenediamine, cinnamethylenediamine, cinnamyl hexamethylenediamine, hexamethylenediamine carbamate, bis(4-aminocyclohexyl)methane carbamate, 2,2-bis-(3-amino-4-hydroxyphenyl)-hexafluoropropane (BOAP), 1,3-diaminopropane carbamate, ethylenediamine carbamate, or trimethylenediaminodicarbamate, or one or more of these.

4. The fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 1, characterized in that, The crystalline fluoropolymer is selected from one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroethylene propylene (FEP), tetrafluoroethylene-perfluoropropyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), and polychlorotrifluoroethylene (PCTFE).

5. The fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 1, characterized in that, The absolute value of the difference between the fluorine content of the crystalline fluoropolymer and the fluorine content of the uncrosslinked fluoroelastomer is DeltaF%, 0. <DeltaF<25。 6. The method for preparing the fluorinated elastomer-toughened crystalline fluorinated polymer according to any one of claims 1 to 5, characterized in that, The preparation method includes reacting an uncrosslinked fluorinated elastomer, a crosslinking agent, and a crystalline fluorinated polymer above the melting point of the crystalline fluorinated polymer to obtain a fluorinated elastomer-toughened crystalline fluorinated polymer.

7. The method for preparing the fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 6, characterized in that, It also includes one or more of the following conditions: A1) For fusible crystalline fluoropolymers: Use one of the following: a twin-screw extruder blending system, a twin-cone extruder, or a high-temperature internal mixer to melt the fusible crystalline fluoropolymer uniformly, so that the fusible crystalline fluoropolymer forms a continuous phase; add a crosslinking agent to the uncrosslinked fluorinated elastomer in a two-roll mill, and then prepare elastomer micropowder with a D50 of less than 50 μm by cryogenic pulverization technology; mix and react the elastomer micropowder with the fusible crystalline fluoropolymer that forms the continuous phase to obtain a fluorinated elastomer-toughened crystalline fluoropolymer. A2) For non-melt-processable crystalline fluoropolymers: Uncrosslinked fluoroelastomers are added to a two-roll mill with a crosslinking agent, and then elastomer micropowders with a D50 of less than 50 μm are prepared by cryogenic pulverization. The elastomer micropowders and non-melt-processable crystalline fluoropolymers are mixed evenly at room temperature using a high-speed mixer, and then cold-pressed under high pressure and then heated. Then, the temperature is lowered to room temperature to obtain a fluorinated elastomer-toughened crystalline fluorinated polymer.

8. The method for preparing the fluorinated elastomer-toughened crystalline fluorinated polymer according to claim 7, characterized in that, It also includes one or more of the following conditions: In characteristic A1), the reaction time is 2–5 min; A21) In characteristic A2), the high pressure is 15-40 MPa; In feature A2), the heating process is as follows: 15-30 minutes below 180℃, 16-20 hours at 250℃, and 4-6 hours at 360-380℃.

9. The use of the fluorinated elastomer-toughened crystalline fluoropolymer according to any one of claims 1 to 5 and / or the fluorinated elastomer-toughened crystalline fluoropolymer obtained by the preparation method according to any one of claims 6 to 8 in integrated circuit seals.

10. A sealing element for integrated circuits, characterized in that, This includes the fluorinated elastomer-toughened crystalline fluorinated polymer as described in any one of claims 1 to 5 and / or the fluorinated elastomer-toughened crystalline fluorinated polymer obtained by the preparation method according to any one of claims 6 to 8.

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