Fluoroelastomer toughened crystalline fluoropolymers and seal applications thereof

Abstract

The application belongs to the technical field of sealing elements, and particularly relates to a fluorine-containing elastomer toughened crystalline fluorine-containing polymer and sealing element application thereof. Raw materials of the fluorine-containing elastomer toughened crystalline fluorine-containing polymer include uncrosslinked fluorine-containing elastomer, crystalline fluorine-containing polymer and crosslinking agent, the mass ratio of the uncrosslinked fluorine-containing elastomer, the crystalline fluorine-containing polymer and the crosslinking agent is 100:30-400:(1-3), and the fluorine content of the fluorine-containing elastomer is greater than 50%. The fluorine-containing elastomer toughened crystalline fluorine-containing polymer of the application, and the ESC sealing element formed on the basis of the fluorine-containing elastomer toughened crystalline fluorine-containing polymer, have both the elasticity of rubber and the etching gas resistance of fluorine-containing plastic, and are convenient to operate on site.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealing elements, and specifically relates to a fluorine-containing elastomer toughened crystalline fluorine-containing polymer and sealing element application thereof. BACKGROUND

[0002] Electrostatic chuck (ESC) is a very important component in the semiconductor manufacturing process, which provides support for the back of the wafer during wafer processing and ensures the fixation of the wafer by electrostatic adsorption, and also provides dynamic constant temperature for the wafer. ESC uses the coulomb force of the two electrode plates of the capacitor to fix the wafer, avoids the damage to the wafer caused by mechanical clamping, and can adjust the temperature of the wafer to improve the uniformity in the processing process.

[0003] In the application of ESC, several layers of different materials (such as PTFE sealing strip ring and rubber sealing strip) are often combined to achieve the effect of combined sealing. This combination can damage the sealing ring or PTFE sealing strip due to human operation error during installation, and the deviation of this combination can also limit the use of the overall product. In the traditional sealing element formula system, crystalline fluorine-containing polymer powder is added as a filler into the system, and rubber is the continuous phase while crystalline fluorine-containing polymer powder is the discontinuous phase, and the addition ratio is less than 30 parts (23 wt%). When the addition amount of crystalline fluorine-containing polymer powder exceeds 30 parts, the discontinuous phase crystalline polymer will precipitate at high temperature, and the elasticity of the sealing element will decrease greatly.

[0004] The applicant explored several ways to protect the gap of the electrostatic chuck, such as the two invention patents, CN115873359B Fluorine rubber extremely fine sealing element for protecting the gap of electrostatic chuck; CN117777941B Sealing glue for the gap of electrostatic chuck, its preparation method and application. These two ways can partially solve the application scene problem of electrostatic chuck sealing.

[0005] Pure PTFE sealing strip lacks the elasticity of elastomer, and the probability of etching gas entering the electrostatic chuck is very large. The combination of the inner ring of PTFE sealing strip and a layer of rubber ring can block the entry of etching gas, but this operation will increase the probability of operation error on site. Therefore, there is an urgent need for a sealing element that has the elasticity of rubber and the etching gas resistance of fluoroplastic, and is convenient to operate on site. SUMMARY

[0006] In view of the blank in the prior art, the purpose of the present application is to provide a fluorine-containing elastomer toughened crystalline fluoropolymer and its sealing application, especially integrated circuit sealing application, and an ESC seal formed on the basis, which has both the elasticity of rubber and the etching gas resistance of fluoroplastic, and has the convenience of on-site operation, thereby solving the problems in the prior art.

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

[0008] The second aspect of the present application provides a preparation method of a fluorine-containing elastomer toughened crystalline fluoropolymer, which includes reacting uncrosslinked fluorine-containing elastomer, crosslinking agent and crystalline fluoropolymer above the melting point of the crystalline fluoropolymer to obtain the fluorine-containing elastomer toughened crystalline fluoropolymer.

[0009] For the meltable crystalline fluoropolymer: one of a twin-screw extruder blending system, a double-tapered extruder or a high-temperature internal mixer is used to melt the meltable crystalline fluoropolymer uniformly, so that the meltable crystalline fluoropolymer forms a continuous phase; the uncrosslinked fluorine-containing elastomer is added with the crosslinking agent on an open mill, and then the elastomer micro-powder with a D50 less than 50um is prepared by a freeze-pulverization technology, and the elastomer micro-powder is mixed with the meltable crystalline fluoropolymer forming the continuous phase to obtain the fluorine-containing elastomer toughened crystalline fluoropolymer.

[0010] For the non-melt-processable crystalline fluoropolymer: the uncrosslinked fluorine-containing elastomer is added with the crosslinking agent on an open mill, and then the elastomer micro-powder with a D50 less than 50um is prepared by a freeze-pulverization technology, and the high-speed mixer is used to mix the elastomer micro-powder and the non-melt-processable crystalline fluoropolymer uniformly at room temperature, and then cold-pressed at high pressure, and then heated; and then cooled to room temperature to obtain the fluorine-containing elastomer toughened crystalline fluoropolymer.

[0011] The third aspect of the present application provides the use of the fluorine-containing elastomer toughened crystalline fluoropolymer according to the present application and / or the fluorine-containing elastomer toughened crystalline fluoropolymer obtained by the preparation method according to the present application in integrated circuit seals.

[0012] The fourth aspect of the present application provides an integrated circuit seal, which includes the fluorine-containing elastomer toughened crystalline fluoropolymer according to the present application and / or the fluorine-containing elastomer toughened crystalline fluoropolymer obtained by the preparation method according to the present application.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] The present application creatively completes a fluorine-containing elastomer toughened crystalline fluorine-containing polymer, and the ESC seal formed on the basis has the elasticity of rubber, the etching gas resistance of fluorine-containing plastic, and the convenience in on-site operation. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is shown that the optimum processing temperature of the molten resin PFA is between 330°C, as judged by the rotary rheometer in Example 1. DETAILED DESCRIPTION

[0016] Hereinafter, a fluorine-containing elastomer toughened crystalline fluorine-containing polymer and its sealant application are specifically disclosed.

[0017] The ranges disclosed herein are defined by the lower and upper limits in the form of a range, and the given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The ranges defined in this way can include or not include the end values, and can be arbitrarily combined, i.e. any lower limit can be combined with any upper limit to form a range. For example, if the ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise stated, the numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is only a shorthand notation for these numerical combinations. In addition, when a parameter is stated to be ≥2 integers, it is equivalent to disclose that the parameter is, for example, integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0018] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0019] In the traditional sealing formula system, the crystalline fluoropolymer micro powder is added into the system as a filler, the rubber is the continuous phase and the crystalline fluoropolymer micro powder is the discontinuous phase, and the addition ratio is less than 24 wt%, and the crystalline fluoropolymer micro powder is not well applied in the market when the addition amount exceeds 30 parts. The application creatively completes a fluorine-containing elastomer toughened crystalline fluoropolymer, and the ESC seal formed on the basis has the elasticity of rubber, the etching gas resistance of fluoroplastic, and the convenience in on-site operation.

[0020] The inventor finds through a large number of experimental researches that by selecting a suitable crystalline fluoropolymer and matching a special fluorine-containing elastomer, high etching gas resistance can be achieved without affecting the basic properties of the elastomer. The elastomer of the application has the basic properties of rubber and the basic properties of crystalline polymer, and the on-site equipment is simpler and more efficient. On this basis, the application is completed.

[0021]

Fluorine-containing elastomer toughened crystalline fluoropolymer

[0022] The application provides a fluorine-containing elastomer toughened crystalline fluoropolymer, and the raw materials of the fluorine-containing elastomer toughened crystalline fluoropolymer include uncrosslinked fluorine-containing elastomer, crystalline fluoropolymer and crosslinking agent.

[0023] In the fluorine-containing elastomer toughened crystalline fluoropolymer provided by the application, the mass ratio of the uncrosslinked fluorine-containing elastomer, the crystalline fluoropolymer and the crosslinking agent is 100:(30-400):(1-3). Optionally, the mass ratio of the fluorine-containing elastomer and 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) and the like.

[0024] In the fluorine-containing elastomer toughened crystalline fluoropolymer provided by the application, the fluorine content (weight) of the fluorine-containing elastomer is greater than 50%. The fluorine content can be measured by F spectrum NMR nuclear magnetic resonance. When the fluorine content is less than 50%, the compatibility of the elastomer system is affected, and a very low fluorine content shows poor resistance to fluorine-containing etching gas. Optionally, the fluorine-containing 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] The crosslinking agent in the fluoroelastomer toughened crystalline fluoropolymer provided by the present application is selected from one or a mixture of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, dibenzoyl peroxide, di-tert-butyl perbenzoate, di[1,3-dimethyl-3-(tert-butylperoxy)butyl]carbonate, 2,5-dimethylbenzenethiol, bisphenol A, perfluorobisphenol A, triallyl isocyanurate, tris(methylallyl) isocyanurate, tris(diallylamine)-s-triazine, triallyl phosphite, N,N-diallyl acrylamide, tris(5-norbornene-2-ylmethylene) cyanurate, trivinyl isocyanurate, hexaallyl phosphoramide, N,N,N-2,4,6-trivinylmethyltrisiloxane, tetraphenyl tin, N,N-dicinnamylidene, trimethylenediamine, cinnamylidene ethylene diamine, cinnamylidene hexamethylene diamine, hexamethylene diamine carbamate, bis(4-aminocyclohexyl)methane carbamate, 2,2-bis-(3-amino-4-hydroxyphenyl)-hexafluoropropane (BOAP), 1,3-diaminopropane monocarbamate, ethylene diamine carbamate, or trimethylenediamine dicarbamate, etc.

[0026] The crystalline fluoropolymer in the fluoroelastomer toughened crystalline fluoropolymer provided by the present application is selected from one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyfluoroethylene-propylene (FEP), tetrafluoroethylene-perfluoro-n-propyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), polytrifluorochloroethylene (PCTFE). Among them, polytetrafluoroethylene (PTFE) is a non-melt processable crystalline fluoropolymer. Polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyfluoroethylene-propylene (FEP), tetrafluoroethylene-perfluoro-n-propyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), polytrifluorochloroethylene (PCTFE) are melt processable crystalline fluoropolymers.

[0027] The difference between the fluorine content of the crystalline fluoropolymer and the fluorine content of the fluoroelastomer in the fluoroelastomer toughened crystalline fluoropolymer provided by the present application is DeltaF%, and 0<DeltaF<25. Alternatively, 0<DeltaF<10, 10<DeltaF<25, 10<DeltaF<15, 15<DeltaF<20, 20<DeltaF<25, etc.

[0028]

Method for preparing the fluoroelastomer toughened crystalline fluoropolymer

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

[0030] For a meltable crystalline fluoropolymer: one of a twin-screw extruder blending system, a twin-tapered extruder, or a high-temperature internal mixer is used to melt the meltable crystalline fluoropolymer uniformly, so that the meltable crystalline fluoropolymer forms a continuous phase; the uncrosslinked fluoroelastomer is added with a crosslinking agent on an open mill, and then an elastomer micro-powder with a D50 of less than 50 um is prepared by a freeze-pulverization technology, and the elastomer micro-powder is mixed with the meltable crystalline fluoropolymer forming a continuous phase to obtain a fluoroelastomer toughened crystalline fluoropolymer.

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

[0032] For a non-meltable fluoropolymer (such as PTFE): the uncrosslinked fluoroelastomer is added with a crosslinking agent on an open mill, and then an elastomer micro-powder with a D50 of less than 50 um is prepared by a freeze-pulverization technology, and a high-speed mixer is used to uniformly mix the elastomer micro-powder and the non-meltable crystalline fluoropolymer at room temperature, and then cold-pressing is performed under high pressure, and then heating is performed; and then the temperature is lowered to room temperature to obtain a fluoroelastomer toughened crystalline fluoropolymer, and subsequent turning is used to obtain a desired part type.

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

[0034] The elastomer micro-powder used in the present application has a D50 of less than 50 um, and the sample is obtained by a freeze-pulverization technology. For details, refer to patent CN115847665A A pulverization process for recycling perfluoroether rubber and preparation thereof, and CN118834485B A fluororubber composition containing crosslinked perfluoroether rubber and a preparation method thereof. If the particle size of the elastomer micro-powder is too large, a longer thermal history and shear force are required to form a uniform melt phase with the crystalline resin, and a longer thermal history will make the elastomer more unstable, ultimately leading to product yellowing, decreased elasticity, and other defects.

[0035]

Use

[0036] The present application also provides the use of the fluoroelastomer toughened crystalline fluoropolymer as described in the present application and / or the fluoroelastomer toughened crystalline fluoropolymer obtained by the preparation method as described in the present application in integrated circuit sealants.

[0037]

Sealant for integrated circuit

[0038] The present application also provides a sealant for integrated circuit comprising the fluoroelastomer toughened crystalline fluoropolymer as described in the present application and / or the fluoroelastomer toughened crystalline fluoropolymer obtained by the preparation method as described in the present application.

[0039] The beneficial effects of the present application are further illustrated in the following examples.

[0040] In the following examples, the reagents, materials and instruments used are commercially available unless otherwise specified.

[0041] Silicone representative, purchased from Shin-Etsu SR3250U (fluorine content 0%);

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

[0043] Tetrafluoroethylene-propylene copolymer purchased from AGC manufacturer Aflas 600S model 600X (fluorine content 53%);

[0044] Vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer purchased from Chemours manufacturer model GBL600S (fluorine content 68%);

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

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

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

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

[0049] Elasticity test method of breakback retraction experiment: the obtained thermoplastic elastomer granules are molded into A214 O-rings, the O-rubber rings are stretched on a tensile testing machine at a stretching speed of 80 mm / min, the O-rings are broken to see the straight-line distance between the two sections, the greater the distance, the worse the resilience.

[0050] Molding surface evaluation: no burr, no pit, no uneven part, etc.

[0051] Example 1

[0052] 1. Preparation of elastomer fine powder:

[0053] 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane bis 25 was purchased from NOREL

[0054] TAIC triallyl isocyanurate was purchased from TCI

[0055] 100 parts of uncrosslinked fluorine-containing elastomer 600X was added with 3 parts of crosslinking agent (2 parts of bis 25 and 1 part of TAIC) through an open mill, and then the elastomer fine powder with a D50 of 25 um was prepared through a freeze crushing technique (frozen in liquid nitrogen for 20-40 min, and then the sample was crushed and sieved).

[0056] 2. Preparation of fluorine-containing elastomer toughened crystalline fluoropolymer:

[0057] Figure 1 The best melt processing temperature of PFA was shown to be about 330°C.

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

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

[0060] C1 section was the feeding section of PFA, and PFA completed uniform melting in the stages of C1-C5, while C5 section started to add the above-mentioned elastomer fine powder with a D50 of 25 um, and under the action of screw thread shear force, it formed melt blending with PFA for 2-6 min, while the elastomer self-crosslinked and crosslinked, forming dynamic crosslinking. After the blend came out of the head, it was dried and granulated by water cooling, forming a thermoplastic elastomer.

[0061] Example 2

[0062] 1. Preparation of elastomer fine powder:

[0063] 100 parts of uncrosslinked fluorine-containing elastomer GBL600S was added with 3 parts of crosslinking agent (2 parts of bis 25 and 1 part of TAIC) through an open mill, and then the elastomer fine powder with a D50 of 25 um was prepared through a freeze crushing technique (frozen in liquid nitrogen for 20-40 min, and then the sample was crushed and sieved).

[0064] 2. Preparation of fluorine-containing elastomer toughened crystalline fluoropolymer was the same as in Example 1.

[0065] Example 3

[0066] 1. Preparation of elastomer micropowder:

[0067] 100 parts of uncrosslinked fluoroelastomer 95HT was added with 2 parts of crosslinking agent (bis 25) by open mill and then prepared into elastomer micropowder with D50 of 25 um by freeze-crushing technique (put into liquid nitrogen for 20-40 min, then crush and sieve the sample).

[0068] 2. Preparation of fluoroelastomer toughened crystalline fluropolymer was the same as Example 1.

[0069] Comparative Example 1

[0070] 1. Preparation of elastomer micropowder:

[0071] 100 parts of SR3250U was added with 1.2 parts of crosslinking agent (bis 25) by open mill and then prepared into elastomer micropowder with D50 of 25 um by freeze-crushing technique (put into liquid nitrogen for 20-40 min, then crush and sieve the sample).

[0072] 2. Preparation of elastomer toughened crystalline fluropolymer was the same as Example 1.

[0073] Comparative Example 2

[0074] 1. Preparation of elastomer micropowder:

[0075] 100 parts of FSE 7360 was added with 2 parts of crosslinking agent (bis 25) by open mill and then prepared into elastomer micropowder with D50 of 25 um by freeze-crushing technique (put into liquid nitrogen for 20-40 min, then crush and sieve the sample).

[0076] 2. Preparation of fluoroelastomer toughened crystalline fluropolymer was the same as Example 1.

[0077] Comparative Example 3

[0078] 1. Preparation of elastomer micropowder:

[0079] 100 parts of 95HT was added with 2 parts of crosslinking agent (bis 25) by open mill and then prepared into elastomer micropowder with D50 of 25 um by freeze-crushing technique (put into liquid nitrogen for 20-40 min, then crush and sieve the sample).

[0080] 2. The elastomer micropowder with D50 of 25 um was mixed with PFA in an internal mixer at 180℃ for 40 min to obtain the product.

[0081] The test results of each example and comparative example are shown in Table 1.

[0082] Table 1

[0083]

[0084]

[0085] The present invention compares the appearance of the product caused by the difference of the fluorine content of the elastomer crystalline polymer in Examples 1-3 and Comparative Examples 1-3. As can be seen from Table 1, when the difference of the fluorine content is greater than 25, there is a significant difference in the heat resistance of the elastomer and the crystalline polymer, resulting in yellowing of the product, which cannot be used as an end product.

[0086] Example 4

[0087] The difference compared with Example 3 is that the elastomer micro powder with a D50 of 46 um is prepared in Step 1. The rest of the conditions are the same.

[0088] Comparative Example 4

[0089] The difference compared with Example 3 is that the elastomer micro powder with a D50 of 65 um is prepared in Step 1. The rest of the conditions are the same.

[0090] Table 2

[0091]

[0092] Examples 3, 4 and Comparative Example 4 in Table 2 study the effect of different elastomer D50 sizes on the performance of the granular elastomer. When the D50 is greater than 50 um, the particles are coarse and the molded samples have burrs.

[0093] Example 5

[0094] The difference compared with Example 3 is that PFA is 40 parts in Step 1. The rest of the conditions are the same.

[0095] Example 6

[0096] The difference compared with Example 3 is that PFA is 250 parts in Step 1. The rest of the conditions are the same.

[0097] Example 7

[0098] The difference compared with Example 3 is that PFA is 380 parts in Step 1. The rest of the conditions are the same.

[0099] Comparative Example 5

[0100] The difference compared with Example 3 is that PFA is 20 parts in Step 1. The rest of the conditions are the same.

[0101] Comparative Example 6

[0102] The difference compared to Example 3 is that in Step 1 the PFA is 450 parts. The rest of the conditions are the same.

[0103] Table 3

[0104]

[0105] As can be seen from Table 3, Examples 5-7 and Comparative Examples 5-6 study the effect of the mass ratio of fluoroelastomer and crystalline fluoropolymer of 100:30-400 on the product performance. Within the above range, the granules are transparent and the molded products have good resilience. When the amount of PFA is too large, the molded products have poor resilience. When the amount of PFA is too small, the granules are coarse and the screw torque is extremely large.

[0106] Example 8

[0107] For non-melt processable crystalline fluoropolymer: the uncrosslinked fluoroelastomer is added with crosslinking agent on an open mill, and then the elastomer micro powder with D50 less than 50 um is prepared by a freeze crushing technique, the high-speed mixer is used to mix the elastomer micro powder and the non-melt processable crystalline fluoropolymer uniformly at room temperature, and then cold pressing is performed under high pressure, and then the temperature is increased; and then the temperature is decreased to room temperature to obtain the fluoroelastomer toughened crystalline fluoropolymer. Specifically:

[0108] PTFE (2) (fluorine content 76%) is purchased from Kumo model Teflon PTFE 7C X, melting point 327°C, D50 = 31 um

[0109] 100 parts of 95HT are added with 2 parts of crosslinking agent (double 25) on an open mill, and then the elastomer micro powder with D50 of 25 um is prepared by a freeze crushing technique (put into liquid nitrogen for 20-40 min, and then the sample is crushed and sieved). The PTFE micro powder and the elastomer micro powder are mixed uniformly by a high-speed mixer, and then filled into a mold, molded under a pressure of 20 MPa at room temperature, and then subjected to the following heat treatment: 180 degrees for 20 minutes, 250 degrees for 18 hours, 370 degrees for 4 hours, and then decreased to room temperature for 24 hours. According to specific requirements, the desired product is turned.

[0110] Example 9

[0111] Compared with Example 8, the difference is that in Step 1 the elastomer micro powder with D50 of 46 um is prepared. The rest of the conditions are the same.

[0112] Comparative Example 7

[0113] Compared with Example 8, the difference is that in Step 1 the elastomer micro powder with D50 of 65 um is prepared. The rest of the conditions are the same.

[0114] Comparative Example 8

[0115] Compared with Example 8, the difference is that the processing procedure is as follows: the first vulcanization temperature is 180℃, the vulcanization time is 7min, the second vulcanization temperature is 250℃, and the vulcanization time is 16h.

[0116] Table 4

[0117]

[0118]

[0119] As can be seen from Table 4, PTFE cannot form a uniform phase below the melting point, i.e. cannot form an interpenetrating network structure with the crosslinked elastomer, so the overall elasticity is much poorer.

[0120] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application in any form or in essence. It should be noted that those skilled in the art can make some improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be considered as the protection scope of the present application. Any equivalent changes, modifications and evolutions made by those skilled in the art based on the disclosed technical content without departing from the spirit and scope of the present application are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolutions made by those skilled in the art based on the disclosed technical content without departing from the spirit and scope of the present application are equivalent embodiments of the present application.

Claims

1. A fluoroelastomer toughened crystalline fluoropolymer for ESC seals, characterized in that, The raw material for the fluoroelastomer toughened crystalline fluoropolymer includes uncrosslinked fluoroelastomer, crystalline fluoropolymer and crosslinking agent, the mass ratio of the uncrosslinked fluoroelastomer, the crystalline fluoropolymer and the crosslinking agent is 100: (250-400): (1-3), the fluorine content of the uncrosslinked fluoroelastomer is greater than 50wt%; A1) for the melt processable crystalline fluoropolymer: melt homogenize the melt processable crystalline fluoropolymer to form a continuous phase using one of a twin screw extruder blending system, a twin cone extruder or a high temperature internal mixer; add the uncrosslinked fluoroelastomer to the crosslinking agent in an open mill, then prepare the elastomer micro powder with D50 less than 50um by freeze crushing technology, mix and react the elastomer micro powder with the melt processable crystalline fluoropolymer to form a fluoroelastomer toughened crystalline fluoropolymer; A2) for the non-melt processable crystalline fluoropolymer: add the uncrosslinked fluoroelastomer to the crosslinking agent in an open mill, then prepare the elastomer micro powder with D50 less than 50um by freeze crushing technology, mix and homogenize the elastomer micro powder and the non-melt processable crystalline fluoropolymer at room temperature using a high speed mixer, cold press into shape under high pressure, then heat up; then cool down to room temperature to obtain a fluoroelastomer toughened crystalline fluoropolymer.

2. The fluoroelastomer toughened crystalline fluoropolymer for ESC seals of claim 1, wherein, The uncrosslinked fluoroelastomer is selected from one or more of vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-trifluorochloroethylene copolymer, tetrafluoroethylene-propylene copolymer, ethylene-tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

3. The fluoroelastomer toughened crystalline fluropolymer for ESC seals of claim 1, wherein, The crosslinking agent is selected from one or more of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, dibenzoyl peroxide, di[1,3-dimethyl-3-(tert-butylperoxy)butyl]carbonate, bisphenol A, perfluorobisphenol A, triallyl isocyanurate, tris(methylallyl) isocyanurate, tris(diallylamine)-s-triazine, triallyl phosphite, N,N-diallyl acrylamide, tris(5-norbornene-2-ylmethylene) cyanurate, trivinyl isocyanurate, hexaallyl phosphoramide, trimethylenediamine, hexamethylenediamine carbamate, bis(4-aminocyclohexyl)methane carbamate, 2,2-bis-(3-amino-4-hydroxyphenyl)-hexafluoropropane (BOAP), 1,3-diaminopropane monocarbamate, ethylenediamine carbamate or trimethylenediamine dicarbamate.

4. The fluoroelastomer toughened crystalline fluropolymer for ESC seals of claim 1 wherein, The crystalline fluoropolymer is selected from one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyperfluoroethylpropylene (FEP), tetrafluoroethylene-perfluoro-n-propyl vinyl ether copolymer (PFA), polyvinyl fluoride (PVF), polytrifluorochloroethylene (PCTFE).

5. The fluoroelastomer toughened crystalline fluropolymer for ESC seals of claim 1 wherein, 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 fluoroelastomer toughened crystalline fluropolymer for ESC seals of claim 1 wherein, Also included are any one or more of the following conditions: A11) in feature A1), the reaction time is 2 to 5 min; A21) in feature A2), the high pressure is 15 to 40 MPa; A22) in feature A2), the temperature ramp is: 15 to 30 minutes at 180°C, 16 to 20 hours at 250°C, and 4 to 6 hours at 360 to 380°C.

7. Use of the fluoroelastomer-toughened crystalline fluoropolymer according to any one of claims 1 to 6 in integrated circuit encapsulation.

8. A seal for an integrated circuit, characterized by A crystalline fluoropolymer toughened with a fluoroelastomer according to any one of claims 1 to 6.

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