A plasma-resistant and low-viscosity metal-free perfluoropolymer and a preparation method thereof

Abstract

The present invention relates to the technical field of sealing ring products, and in particular to a plasma-resistant and low-viscosity metal-free perfluoropolymer and a preparation method thereof. The raw materials of the metal-free perfluoropolymer include the following components by weight: 100 parts of perfluoroether rubber of a peroxide vulcanization system; 10-20 parts of an inorganic nitride; 1-3 parts of a peroxide; and 1-6 parts of a cross-linking aid. The prepared O-type rubber sealing ring has excellent plasma resistance, no metal particles escape, a compression permanent deformation of less than 25%, and an adhesion of less than 50N. On semiconductor processing equipment, it not only has a long service life (plasma resistance, mass loss rate less than 5%), good sealing (compression permanent deformation less than 25%), but also has low viscosity and is easy to replace, which improves the efficiency of replacing the O-type rubber ring and ensures the yield of the product (no metal particles escape).

Description

Technical Field

[0001] The invention relates to the technical field of sealing ring products, and in particular to a plasma-resistant and low-viscosity metal-free perfluoropolymer and a preparation method thereof. Background Art

[0002] Perfluoropolymer refers to a ternary copolymer of tetrafluoroethylene, perfluoro(methyl vinyl) ether and a third monomer crosslinking monomer, also known as perfluoroether rubber (FFKM). The density of perfluoroether rubber is 1.9-2.0g / cm 3 There are no hydrogen atoms in the macromolecules, showing strong inertness. The radius of the F atom is much larger than that of the H atom before substitution. The macromolecular chain is arranged in a spiral shape, and the CC bond is basically surrounded by a shell composed of F atoms, which makes the polymer have significant chemical resistance. Perfluoroether rubber also has low permeability to gases and liquids, good combustion resistance and excellent electrical insulation properties. The biggest feature of FFKM is that it can maintain good sealing under harsh conditions and can be used in many fields such as semiconductors, automobile manufacturing, aerospace and chemical industry.

[0003] Semiconductors are indispensable components in our daily lives and are used in almost all electrical and electronic devices. In the field of semiconductor applications, rubber seals need to have excellent plasma resistance when working under plasma conditions for a long time, and metal particles do not want to escape and affect the yield of the product. In addition, O-ring seals are consumables and need to be replaced regularly. Their excessive adhesion to metal will affect the efficiency of replacement and damage semiconductor equipment. Therefore, a metal-free rubber seal that is both plasma-resistant and low-adhesive is necessary.

[0004] At present, the commonly used fillers in perfluororubber seals are carbon black, white carbon black, etc. In order to achieve better compression permanent deformation and plasma resistance, metal salts (CaCO3, BaSO3, etc.) need to be added. Therefore, the sealing products will contain a large amount of metal ions. This type of perfluororubber seal will produce metal particles during use, which is not conducive to maintaining a high product yield. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a plasma-resistant and low-viscosity metal-free perfluoropolymer and a preparation method thereof, so as to solve the problems in the prior art.

[0006] In order to achieve the above-mentioned object and other related objects, one aspect of the present invention provides a metal-free perfluoropolymer, wherein the raw materials of the metal-free perfluoropolymer include the following components in parts by weight:

[0007]

[0008]

[0009] The second aspect of the present invention provides a method for preparing the metal-free perfluoropolymer described in the first aspect of the present invention, the preparation method comprising: uniformly plasticizing the perfluoroether rubber of the peroxide vulcanization system on a double-roll open mill, then adding the inorganic nitride, peroxide, and cross-linking aid into the open mill, adjusting the roller distance of the open mill to the minimum after mixing evenly in a cigar roll, mixing evenly in a triangle bag, and then discharging the sheet; and then performing primary vulcanization and secondary vulcanization.

[0010] The third aspect of the present invention provides the use of the metal-free perfluoropolymer as described in the first aspect of the present invention in the fields of semiconductor, automobile manufacturing, aerospace and chemical industry.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention provides a plasma-resistant and low-viscosity metal-free perfluoro sealing ring composition and a preparation method thereof. The prepared O-type rubber sealing ring has excellent plasma resistance, no metal particles escape, a compression permanent deformation of less than 25%, and an adhesion of less than 50 N. On semiconductor processing equipment, it not only has a long service life (plasma resistance, mass loss rate less than 5%), good sealing performance (compression permanent deformation less than 25%), but also has low viscosity and is easy to replace, thereby improving the efficiency of replacing the O-type rubber ring and ensuring the product yield (no metal particles escape). DETAILED DESCRIPTION

[0013] The present invention optimizes the formula, specifically, by comprehensively selecting specific amounts, especially specific types of perfluoroether rubber, inorganic nitride, peroxide, crosslinking aid, etc., wherein the inorganic nitride, as a covalent bond compound, has a low thermal expansion coefficient, high thermal conductivity, excellent chemical corrosion resistance, and thermal shock resistance. Adding it to the rubber can not only play a reinforcing role, but also make the metal-free perfluoropolymer have a long service life (plasma resistance, mass loss rate less than 5%), good sealing (compression permanent deformation less than 25%), and low viscosity and easy replacement. On this basis, the present invention is completed.

[0014] Hereinafter, a metal-free perfluoropolymer and a method for preparing the same are specifically disclosed in detail.

[0015] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. 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 scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0016] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0017]

Metal-free perfluoropolymer composition

[0018] One aspect of the present invention provides a metal-free perfluoropolymer composition, the raw materials of which include perfluoroether rubber of a peroxide vulcanization system, an inorganic nitride, a peroxide, and a cross-linking aid.

[0019] The raw materials of the metal-free perfluoropolymer composition provided by the present invention may include 100 parts by weight of perfluoroether rubber of a peroxide vulcanization system.

[0020] The perfluoroether rubber of the peroxide vulcanization system is a perfluoroether polymer polymerized from three monomers: tetrafluoroethylene (TFE), perfluoroalkyl vinyl ether (PAVE) and crosslinking point monomer (CSM). Usually, the crosslinking point monomer of the perfluoroether rubber of the peroxide vulcanization system contains a halogen group, such as an I group, a Br group, etc.

[0021] Peroxide-cured perfluoroether rubber can be manufactured by conventional methods.

[0022] The production of perfluoroether rubber is not particularly limited, and known methods such as bulk polymerization, suspension polymerization, emulsion polymerization and solution polymerization can be used. Examples of polymerization initiation reactions include free radical polymerization using an organic peroxide initiator, an azo initiator, etc., redox polymerization using a redox catalyst, radiation polymerization using ionizing radiation, polymerization using heat or light, etc.

[0023] The Mooney viscosity ML1+10, 121°C of the perfluoroether rubber of the peroxide vulcanization system is 20 to 100. In some embodiments, the Mooney viscosity ML1+10, 121°C of the perfluoroether rubber can be, for example, 20 to 60, 60 to 100, 20 to 50, 50 to 100, 20 to 100, 20 to 45, 45 to 100, 20 to 40, 40 to 100, 20 to 30, 30 to 100, 20, 30, 40, 45, 50, 60, etc. In a preferred embodiment of the present invention, the Mooney viscosity ML1+10, 121°C of the perfluoroether rubber of the peroxide vulcanization system is 45.

[0024] The metal-free perfluoropolymer composition provided by the present invention may include 10-20 parts of inorganic nitride in parts by weight of its raw materials. Optionally, the weight of the inorganic nitride may be, for example, 10-15 parts, 15-20 parts, 10-12 parts, 12-15 parts, 15-18 parts, 18-20 parts, etc. The advantages of the above weight parts are small adhesion and good compression permanent deformation. The disadvantages outside the range are that the adhesion becomes larger and the compression permanent deformation becomes worse, which is not conducive to the usability of the product.

[0025] Furthermore, the inorganic nitride is a non-metallic inorganic nitride, such as silicon nitride (Si3N4), boron nitride, etc.

[0026] Optionally, the inorganic nitride is silicon nitride. Silicon nitride (Si3N4) has three crystalline structures, namely α, β and γ phases. α and β phases are the most common forms of Si3N4 and can be prepared at normal pressure. α-Si3N4 is a granular crystal; β-Si3N4 is a needle-shaped crystal, both of which belong to the hexagonal system. The γ phase can only be synthesized under high pressure and high temperature. Its hardness can reach 35GPa, and it is a spinel structure containing octahedral hexacoordinated silicon atoms. In addition, silicon nitride also has an amorphous phase.

[0027] However, the applicant unexpectedly discovered that the inorganic nitride of the present invention is preferably α-Si3N4 and / or nano-scale amorphous Si3N4.

[0028] Further preferably, the particle size of the inorganic nitride is less than 100nm. Specifically, the particle size of the inorganic nitride may be, for example, less than or equal to 100nm, less than or equal to 80nm, less than or equal to 50nm, less than or equal to 30nm, less than or equal to 20nm, etc. For example, the particle size of the inorganic nitride may be, for example, 0-20nm, 20-100nm, 20-50nm, 50-100nm, 20-30nm, 30-40nm, 40-50nm, 50-60nm, 60-70nm, 70-80nm, 80-90nm or 90-100nm, etc. The advantage of the above particle size is that it has a large specific surface area, can be better dispersed in rubber, and has a better improvement on the performance of rubber. The disadvantage outside the range is that the particle size is large, it is difficult to disperse in the rubber matrix, it is easy to agglomerate, and the compatibility with rubber is deteriorated, which ultimately leads to poor product performance.

[0029] Further, the particle size of the α-phase silicon nitride is less than 100nm. Specifically, the particle size of the α-phase silicon nitride can be, for example, less than or equal to 100nm, less than or equal to 80nm, less than or equal to 50nm, less than or equal to 30nm, less than or equal to 20nm, etc. For example, the particle size of the α-phase silicon nitride can be, for example, 0-20nm, 20-100nm, 20-50nm, 50-100nm, 20-30nm, 30-40nm, 40-50nm, 50-60nm, 60-70nm, 70-80nm, 80-90nm or 90-100nm, etc. The advantage of the above particle size is that nano-scale α-phase silicon nitride has a certain aspect ratio due to its needle-like structure. When the particle size is small enough, it can fully fill the gap in the cross-linked network to achieve the best performance improvement. The disadvantage outside the range is that the particle size is too large, the aspect ratio of its needle-like structure is very large, and its filling is insufficient, resulting in poor performance.

[0030] Further, the particle size of the nano-scale amorphous Si3N4 is less than 100nm. Specifically, the particle size of the nano-scale amorphous Si3N4 can be, for example, less than or equal to 100nm, less than or equal to 80nm, less than or equal to 50nm, less than or equal to 30nm, less than or equal to 20nm, etc. For example, the particle size of the nano-scale amorphous Si3N4 can be, for example, 0-20nm, 20-100nm, 20-50nm, 50-100nm, 20-30nm, 30-40nm, 40-50nm, 50-60nm, 60-70nm, 70-80nm, 80-90nm or 90-100nm, etc. The advantage of the above-mentioned particle size is that the internal atoms of nano-amorphous silicon nitride are in a disordered structure, consisting of a large number of small groups with irregular orientations, which are arranged in order. Therefore, they can be fully filled into the cross-linked network, which is beneficial to the improvement of various performances. The disadvantage outside the range is that the disordered groups with too large particle size are not conducive to full dispersion, and thus cannot well improve the performance.

[0031] The metal-free perfluoropolymer composition provided by the present invention may include 1-3 parts of peroxide in terms of weight. Alternatively, the weight of the peroxide may be, for example, 1-1.5 parts, 1.5-3 parts, etc. The advantage of the above weight is that a good cross-linked network can be formed within this range, thereby showing good performance. The disadvantage outside the range is that too much or too little will result in less cross-linked network or too much small molecule substances, which will affect the performance of the final product.

[0032] The metal-free perfluoropolymer provided by the present invention comprises the following peroxides: 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di-tert-butyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3,1,1-di(tert-butylperoxy)-3,3-5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroxyperoxide, benzoyl peroxide, tert-butylbenzene peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butylperoxymaleic acid, tert-butylperoxyisopropyl carbonate, and the like.

[0033] The metal-free perfluoropolymer composition provided by the present invention may include 1-6 parts of a crosslinking aid in terms of weight of its raw materials. Optionally, the weight of the crosslinking aid may be, for example, 1-3 parts, 3-6 parts, 1-2 parts, 2-3 parts, 3-5 parts, 5-6 parts, etc. The advantage of the above weight is that the crosslinking aid within this range can form a good crosslinking network, and the disadvantage outside the range is that too much or too little addition is not conducive to forming an optimal crosslinking network, thereby resulting in the performance not being optimal.

[0034] The metal-free perfluoropolymer composition provided by the present invention, the cross-linking auxiliary agent is triallyl isocyanurate (TAIC).

[0035] The metal-free perfluoropolymer composition provided by the present invention has a permanent deformation of less than 25%. Optionally, for example, the permanent deformation of the metal-free perfluoropolymer can be 0-24%, 0-23%, 0-22%, 0-21%, 0-20%, 0-19%, 0-18%, 0-17%, 0-16%, 0-15%, 0-14%, 0-13%, 0-12%, 0-11%, 0-10%, 0-9%, 0-8%, 0-7%, 0-6%, 0-5%, 0-4%, 0-3%, 0-2% or 0-1%, etc.

[0036] The metal-free perfluoropolymer composition provided by the present invention has an adhesive force lower than 50 N. Optionally, the adhesive force may be, for example, 0-49 N, 0-43 N, 0-40 N, 0-38 N, 0-35 N, 0-30 N, 0-25 N, 0-23 N, 0-20 N, 0-15 N, 0-13 N, 0-10 N, 0-8 N, 0-5 N, 0-3 N, etc.

[0037] The metal-free perfluoropolymer composition provided by the present invention has a plasma-resistant mass loss rate of less than 5%. Optionally, the plasma-resistant mass loss rate is less than 4.5%, less than 4%, less than 3.5%, or less than 3.0%.

[0038] [Method for preparing metal-free perfluoropolymer composition]

[0039] The second aspect of the present invention provides a method for preparing the metal-free perfluoropolymer described in the first aspect of the present invention, the preparation method comprising: plasticizing the perfluoroether rubber of the peroxide vulcanization system on a double-roll mill evenly and wrapping the rolls, then adding inorganic nitrides, peroxides, and cross-linking aids to the mill, cutting the rubber mixture wrapped on the rolls on the left and right, adjusting the roller distance of the mill to the minimum, making triangle wraps, mixing evenly at a certain temperature and then discharging sheets; and then performing primary vulcanization and secondary vulcanization.

[0040] Specifically, the method for preparing the metal-free perfluoropolymer composition comprises the following steps:

[0041] (1) The perfluoroether rubber of the peroxide vulcanization system is plasticized and rolled evenly on a double-roll mill, and then the inorganic nitride, peroxide and cross-linking aid are added to the mill. The rolled rubber mixture is cut 5-10 times from left to right, the roll distance of the mill is adjusted to the minimum, and triangle wrap is made 10-20 times. The temperature of the roll of the mill is controlled within 60°C, and the sheets are produced after mixing evenly.

[0042] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 150-170°C and a vulcanization time of 10-15 minutes. After parking for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 200-250°C and a vulcanization time of 4-16 hours.

[0043] Preferably, in step (2), the primary vulcanization is performed at 160°C for 10 min, and the secondary vulcanization is performed at 230°C for 8 h.

[0044]

application

[0045] The third aspect of the present invention provides the use of the metal-free perfluoropolymer as described in the first aspect of the present invention in the fields of semiconductor, automobile manufacturing, aerospace and chemical industry.

[0046] The beneficial effects of the present invention are further illustrated below in conjunction with embodiments.

[0047] In order to make the invention purpose, technical scheme and beneficial technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with examples. However, it should be understood that the examples of the present invention are only for explaining the present invention, not for limiting the present invention, and the examples of the present invention are not limited to the examples given in the specification. The specific experimental conditions or operating conditions not specified in the examples are made under conventional conditions, or are made under the conditions recommended by the material supplier.

[0048] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0049] In the following examples, the reagents, materials and instruments used are all commercially available unless otherwise specified.

[0050] The manufacturer of peroxide vulcanization system perfluoroether rubber is Zhonghao Chenguang Chemical Research Institute Co., Ltd., brand G806.

[0051] α-Si3N4, 50nm was purchased from Adamas, CAS No. 12033-89-5.

[0052] α-Si3N4, 100nm was purchased from Anhui AVIC Nanotechnology Co., Ltd., CAS No. 12033-89-5.

[0053] α-Si3N4, 0.5-1μm was purchased from Adamas, CAS No. 12033-89-5.

[0054] Amorphous silicon nitride, 20nm, purchased from Ningbo Jinlei Nanomaterials Co., Ltd., CAS No. 12033-89-5.

[0055] β-Si3N4 (20-100nm) was purchased from Adamas, CAS No. 12033-89-5.

[0056] β-Si3N4 (1-3μm) was purchased from Adamas, CAS No. 12033-89-5.

[0057] The test methods or standards involved are as follows

[0058] 1. Compression set: in accordance with ASTM D395-03 Standard test methods for rubber property-Compression Set;

[0059] 2. Adhesion: The O-type rubber ring obtained after vulcanization is cut with a 5mm fixed width knife to eliminate internal stress, and the cut O-type rubber ring is fastened in the test fixture with 25% compression deformation. The material used is 304 stainless steel. Place it in an aging box at 204℃ for 24 hours, take it out and leave it for 3 hours, and then test the adhesion on a tensile machine with a tensile speed of 10mm / min;

[0060] 3. Plasma resistance: At a temperature of 100°C, a time of 60 minutes, a power of 800w, and a gas flow rate of 80sccm, O2 and

[0061] The mass change of CH4 ion etching gas is calculated according to the following formula: mass change (%) = (mass before etching - mass after etching) / mass before etching * 100.

[0062] Example 1

[0063] The method for preparing a metal-free perfluoropolymer composition comprises the following steps:

[0064] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a two-roll mill, and then 10 parts of silicon nitride (α phase, 50nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0065] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0066] Example 2

[0067] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0068] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 10 parts of silicon nitride (α phase, 100 nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrapping is performed 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0069] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0070] Example 3

[0071] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0072] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 10 parts of silicon nitride (amorphous, 20nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0073] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 15 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0074] Example 4

[0075] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0076] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a two-roll mill, and then 15 parts of silicon nitride (α phase, 50nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0077] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0078] Example 5

[0079] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0080] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a two-roll mill, and then 20 parts of silicon nitride (α phase, 50nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0081] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0082] Example 6

[0083] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0084] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 20 parts of silicon nitride (α phase, 100 nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0085] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0086] Example 7

[0087] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0088] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 20 parts of silicon nitride (amorphous, 20nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0089] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0090] Comparative Example 1

[0091] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a two-roll mill, and then 25 parts of silicon nitride (α phase, 50nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0092] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0093] Comparative Example 2

[0094] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0095] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 10 parts of silicon nitride (α phase, 0.5-1 μm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrapping is performed 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0096] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0097] Comparative Example 3

[0098] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0099] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 15 parts of silicon nitride (α phase, 0.5-1 μm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrapping is performed 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0100] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0101] Comparative Example 4

[0102] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0103] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 10 parts of silicon nitride (β phase, 20-100nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle rolls are made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0104] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0105] Comparative Example 5

[0106] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0107] (1) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 10 parts of silicon nitride (β phase, 1-3 μm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrapping is performed 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0108] (2) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0109] Comparative Example 6

[0110] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0111] (3) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 5 parts of silicon nitride (α phase, 50nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0112] (4) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 minutes. After standing for 24 hours, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 hours.

[0113] Comparative Example 7

[0114] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0115] (5) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill, and then 5 parts of silicon nitride (amorphous, 20nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3 parts of triallyl isocyanurate are added to the mill, the rolled rubber mixture is cut 15 times on each side, the mill roll distance is adjusted to the minimum, and triangle wrap is made 15 times. The mill roll temperature is controlled within 60°C, and the sheets are produced after mixing evenly.

[0116] (6) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 min. After standing for 24 h, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 h.

[0117] Comparative Example 8

[0118] The method for preparing a metal-free perfluoropolymer comprises the following steps:

[0119] (7) 100 parts of perfluoroether rubber of peroxide curing system are plasticized and rolled evenly on a double-roll mill. Then, 10 parts of silicon nitride (5 parts of α phase, 50 nm and 5 parts of amorphous, 20 nm), 1.5 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 3 parts of triallyl isocyanurate are added to the mill. The rolled rubber mixture is cut 15 times on each side. The roller distance of the mill is adjusted to the minimum. The rolls are triangularly rolled 15 times. The temperature of the mill rollers is controlled within 60°C. After mixing evenly, the sheets are produced.

[0120] (8) Carry out primary vulcanization on a flat vulcanizer at a vulcanization temperature of 160°C and a vulcanization time of 10 min. After standing for 24 h, place the product in an oven for secondary vulcanization at a vulcanization temperature of 230°C and a vulcanization time of 8 h.

[0121] The embodiments and test results are shown in Table 1.

[0122] Table 1

[0123]

[0124] The experimental results show that after adding 10 to 20 parts of 20 to 100 nm α-Si3N4 or nano-scale amorphous Si3N4 inorganic nitride, the prepared sealing ring has very small adhesion, small pressure change, and good plasma resistance. Although the plasma resistance tends to improve with the increase of the number of parts, the compression permanent deformation and adhesion are significantly improved, so the recommended number of parts is 10 to 20 parts, and 10 parts is more preferred.

[0125] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0126] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A metal-free perfluoropolymer composition, characterized in that: The raw materials of the metal-free perfluoropolymer composition include the following components by weight: The inorganic nitride is α-Si3N4 or nano-scale amorphous Si3N4, and the particle size of the inorganic nitride is less than 100nm; The metal-free perfluoropolymer composition has a compression permanent deformation of less than 25%, an adhesion of less than 50N, and a plasma-resistant mass loss rate of less than 5%; the test method or standard is as follows: Compression set: According to ASTM D395-03; Adhesion: Prepare O-type rubber rings, cut samples with a 5mm fixed width knife to eliminate internal stress, and fasten the cut O-type rubber rings in the test fixture with 25% compression deformation. The material used is 304 stainless steel, and place them in an aging box at 204℃ for 24 hours. After taking them out and leaving them for 3 hours, test the adhesion on a tensile machine at a tensile speed of 10mm / min. Plasma resistance: At a temperature of 100°C, a time of 60min, a power of 800w, and a gas flow rate of 80sccm, O2 and CH4 ion etching gases are used to calculate the mass change. The mass change is based on the following formula: mass change (%) = (mass before etching - mass after etching) / mass before etching * 100.

2. The metal-free perfluoropolymer composition according to claim 1, characterized in that The perfluoroether rubber of the peroxide vulcanization system is a perfluoroether polymer formed by polymerization of three monomers: tetrafluoroethylene, perfluoroalkyl vinyl ether and crosslinking point monomer, and the crosslinking point monomer of the perfluoroether rubber of the peroxide vulcanization system contains a halogen group; And / or, the Mooney viscosity of the perfluoroether rubber of the peroxide vulcanization system is ML1+10 at 121°C of 20 to 100.

3. The metal-free perfluoropolymer composition according to claim 1, characterized in that The particle size of the inorganic nitride is 20 to 100 nm.

4. The metal-free perfluoropolymer composition according to claim 1, characterized in that The peroxide is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)-p-diisopropylbenzene, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroxyperoxide, benzoyl peroxide, tert-butyl peroxide benzene, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butyl peroxy maleic acid, and tert-butyl peroxy isopropyl carbonate.

5. The metal-free perfluoropolymer composition according to claim 1, characterized in that The cross-linking auxiliary agent is triallyl isocyanurate.

6. The method for preparing the metal-free perfluoropolymer composition according to any one of claims 1 to 5, characterized in that: The preparation method comprises: uniformly plasticizing the perfluoroether rubber of the peroxide vulcanization system on a double-roll open mill, then adding the inorganic nitride, peroxide and cross-linking auxiliary agent into the open mill, mixing uniformly by rolling into cigar rolls, adjusting the roller distance of the open mill to the minimum, mixing uniformly by rolling into triangle packages, and then producing sheets; and then performing primary vulcanization and secondary vulcanization.

7. Use of the metal-free perfluoropolymer prepared by the metal-free perfluoropolymer composition according to any one of claims 1 to 5 or the method for preparing the metal-free perfluoropolymer composition according to claim 6 in the fields of semiconductors, automobile manufacturing, aerospace and chemical industry.

Images