A fluororubber composition containing cross-linked perfluoroether rubber and a preparation method thereof

Abstract

The present invention relates to the technical field of sealing materials, and in particular to a fluororubber composition containing cross-linked perfluoroether rubber powder and a preparation method thereof. The raw materials of the fluororubber composition include cross-linked perfluoroether rubber powder, fluororubber, a cross-linking agent and a vulcanizing agent, and the fluororubber is not cross-linked; the fluororubber composition satisfies the formula: ΔF*C*D50<350um; wherein ΔF=cross-linked perfluoroether rubber fluorine content-fluororubber fluorine mass percentage; C=(weight parts of cross-linked perfluoroether rubber powder / weight parts of fluororubber)*100; D50 is the average particle size of the cross-linked perfluoroether rubber powder, in um. The product obtained by the present invention has good high-temperature compression performance.

Description

Technical Field

[0001] The invention relates to the technical field of sealing materials, in particular to a fluororubber composition containing cross-linked perfluoroether rubber powder and a preparation method thereof. Background Art

[0002] Perfluoroether rubber (FFKM) is a high-performance sealing material. Its excellent performance makes it widely used in semiconductors.

[0003] In the entire manufacturing system of the product, perfluoroether sealing ring is one of the main consumables required for integrated circuit production. Perfluoroether rubber is mainly composed of tetrafluoroethylene and perfluoroalkyl vinyl ether as the main monomers, and is copolymerized with a small amount of cross-linkable third monomer. There are no hydrogen atoms on the macromolecular chain of perfluoroether rubber, and the CC bond is basically surrounded by a shell composed of F atoms, which makes the polymer have significant chemical resistance, high and low temperature resistance, high temperature steam resistance, low release and precipitation, and plasma resistance.

[0004] In semiconductor manufacturing, the reliability of elastic seals is very critical. It is very costly to stop production and replace seals. In order to avoid potential risks, the cleanliness and purity of seals are very strict. At the same time, seals must be able to work for a long time in high vacuum, corrosive chemical gases and high temperature environments. Therefore, the synthesis technology of perfluoroether rubber is very complicated and the cost is very expensive.

[0005] The relevant content has been patented in CN 115847665A. The idea is to cut the recycled perfluoroether rubber into granules, put the granular perfluoroether rubber into a liquid nitrogen freezing pulverizer and crush it for 20-40 minutes to obtain cross-linked perfluoroether rubber powder. The invention uses a specific pulverization process to perform multi-stage freezing and pulverization of semiconductor-grade seals to obtain perfluoroether rubber powder, and then re-enters the new formula system through a mixing process, and obtains semiconductor-grade perfluoroether seals again through molding and vulcanization processes. This invention not only alleviates the supply problem of semiconductor-grade perfluoroether rubber and reduces the cost of raw materials for enterprises, but also improves the resource recycling rate of perfluoroether seals in the industrial chain, alleviates the suppression and supply problems of foreign companies on China's semiconductor industry chain, and is of great significance to the development and security of China's semiconductor industry chain.

[0006] However, the polymerization monomers of perfluoroether rubber are all perfluoromonomers (mainly tetrafluoroethylene, perfluoroalkyl vinyl ether and fluorine-containing cross-linking monomers), and the high price of perfluoroalkyl vinyl ether monomers leads to the high price of perfluoroether rubber. Non-perfluoroether rubber is also called fluororubber. In addition to tetrafluoroethylene monomer, its polymerization monomers also include non-perfluoromonomers such as vinylidene fluoride or propylene. These monomers are cheap, so the price of fluororubber is relatively cheap. However, it is precisely the existence of carbon-hydrogen bonds on these non-perfluoromonomers that leads to the obvious disadvantages of fluororubber compared with perfluoroether rubber in terms of high temperature resistance (above 250 degrees), chemical resistance and etching gas resistance.

[0007] The fluorine content of fluororubber ranges from 55% to 70% by mass, while the fluorine content of perfluoroether rubber ranges from 72% to 74%. The case of mixing uncrosslinked fluororubber and uncrosslinked perfluoroether rubber to develop products is an obvious technology in the rubber field. Because both have uncrosslinked crosslinking monomers, these crosslinking monomers can make the entire system more compatible. The present invention is a further invention based on patent application CN115847665A. The crosslinked perfluoroether rubber powder loses the functional groups that can react again after a certain period of thermal history (i.e., vulcanization reaction), and the changes in the reactive crosslinking functional groups can be judged by FT-IR. Therefore, when the crosslinked perfluoroether rubber powder is used as a formulation additive in fluororubber, it is inevitable to involve the problem of improving the interface compatibility between the two.

[0008] Preliminary experiments have shown that the introduction of inappropriate cross-linked micropowder will reduce the yield rate of fluororubber products, which will in turn lead to a decrease in the product's high-temperature compression set performance and chemical resistance. Summary of the invention

[0009] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a fluororubber composition containing cross-linked perfluoroether rubber powder and a preparation method thereof, so as to solve the problems in the prior art.

[0010] To achieve the above-mentioned purpose and other related purposes, one aspect of the present invention provides a fluororubber composition, wherein the raw materials of the fluororubber composition include cross-linked perfluoroether rubber powder, fluororubber, a cross-linking agent and a vulcanizing agent, and the fluororubber is not cross-linked; the fluororubber composition satisfies the formula: ΔF*C*D50<350um; wherein ΔF=the mass percentage of fluorine in the cross-linked perfluoroether rubber powder-the mass percentage of fluorine in the fluororubber; C=(the weight of the cross-linked perfluoroether rubber powder / the weight of the fluororubber)*100; and D50 is the average particle size of the cross-linked perfluoroether rubber powder.

[0011] The second aspect of the present invention provides a method for preparing the fluororubber composition described in the first aspect of the present invention, the preparation method comprising: first kneading the raw rubber of the fluororubber, then adding cross-linked perfluoroether rubber powder and a cross-linking agent to mix, continuing to knead and then discharging the rubber, and calendering a sheet, cooling to obtain a film; softening the film and wrapping it with a roller, adding a vulcanizing agent for vulcanization, and cooling to room temperature to obtain the fluororubber composition.

[0012] The third aspect of the present invention provides the use of the fluororubber composition in semiconductor sealing materials and petroleum extraction.

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

[0014] The fluororubber composition and preparation method thereof of the present invention use recycled cross-linked perfluoroether rubber powder as a formulation additive in low-cost fluororubber, and by adjusting ΔF*C*D50<350um, the compatibility of the interface between the two is improved, the yield of the product is improved, and then the high-temperature compression deformation performance and chemical resistance of the product are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown is a normal distribution diagram of the particle size of cross-linked perfluoroether rubber powder.

[0016] Figure 2 Shown is the morphology of cross-linked perfluoroether rubber powder packed in a PE bag.

[0017] Figure 3 Shown are the FTIR graphs of cross-linked perfluoroether rubber powder and perfluoroether rubber raw rubber.

[0018] Figure 4 It shows the particle size diagram of the micropowder obtained by the pulverization process of the cross-linked perfluoroether rubber micropowder 1.

[0019] Figure 5 This is a product image showing the addition of cross-linked perfluoroether rubber powder 3 to 600S. DETAILED DESCRIPTION

[0020] The inventor has conducted a lot of exploratory experiments and optimized the formula. Specifically, when recycled cross-linked perfluoroether rubber powder is used as a formula additive in low-cost fluororubber, the compatibility of the interface between the two is improved by adjusting ΔF*C*D50<350um, and the product has good high-temperature voltage-transformation performance. On this basis, the present invention was completed.

[0021] Hereinafter, a fluororubber composition containing cross-linked perfluoroether rubber powder and a method for preparing the same are specifically disclosed in detail.

[0022] "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.

[0023] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0024] Fluororubber composition

[0025] One aspect of the present invention provides a fluororubber composition, the raw materials of which include cross-linked perfluoroether rubber powder, fluororubber, a cross-linking agent and a vulcanizing agent, wherein the fluororubber is uncross-linked raw rubber.

[0026] The fluororubber composition provided by the present invention satisfies the formula: ΔF*C*D50<350um. Optionally, 0<ΔF*C*D50<350um, 0<ΔF*C*D50<340um, 0<ΔF*C*D50<330um, 0<ΔF*C*D50<320um, 0<ΔF*C*D50<310um, 0<ΔF*C*D50<300um, 0<ΔF*C*D50<290um, 0<ΔF*C*D50<280um, 0<ΔF*C*D50<340um, 0<ΔF*C*D50<350um, 0<ΔF*C*D50<360um, 0<ΔF*C*D50<370um, 0<ΔF*C*D50<380um, 0<ΔF*C*D50<390um, 0<ΔF*C*D50<310um, 0<ΔF*C*D50<320um, 0<ΔF*C*D50<330um, 0<ΔF*C*D50<350um, 0<ΔF*C*D50<360um, 0<ΔF*C*D50<380um, 0<ΔF*C*D50<39 ... D50<270um, 0<ΔF*C*D50<260um, 0<ΔF*C*D50<250um, 0<ΔF*C*D50<240um, 0<ΔF*C*D50<23 0um, 0<ΔF*C*D50<220um, 0<ΔF*C*D50<210um, 0<ΔF*C*D50<200um, 0<ΔF*C*D50<190um, 0< ΔF*C*D50<180um, 0<ΔF*C*D50<170um, 0<ΔF*C*D50<160um, 0<ΔF*C*D50<150um, 0<ΔF*C*D 50<140um, 0<ΔF*C*D50<130um, 0<ΔF*C*D50<120um, 0<ΔF*C*D50<110um, 0<ΔF*C*D50<100 um, 0<ΔF*C*D50<90um, 0<ΔF*C*D50<80um, 0<ΔF*C*D50<70um, 0<ΔF*C*D50<60um, 0<ΔF*C*D50<50um, 0<ΔF*C*D50<40um, 0<ΔF*C*D50<30um, 0<ΔF*C*D50<20um or 0<ΔF*C*D50<10um, etc. When D50, C and ΔF meet the above formula, the product has good high temperature compression performance.

[0027] In the formula, ΔF = fluorine content of cross-linked perfluoroether rubber powder - fluorine content of fluororubber. Optionally, the fluorine content of the cross-linked perfluoroether rubber powder is 72%-74%; the fluorine content of the fluororubber is 55%-70%. Optionally, the fluorine content of the cross-linked perfluoroether rubber powder is 72%-73%, 73%-74%, 72%-73.6% or 73.6%-74%, etc. The fluorine content of the fluororubber can be, for example, 55%-60%, 60%-65% or 65%-70%, etc.

[0028] Preferably, the ΔF is 2% to 19%. Optionally, ΔF can be, for example, 2% to 5%, 5% to 10%, 10% to 15%, or 15% to 19%. Within the above range of values, the advantage is that fluororubber and cross-linked perfluoroether rubber powder have better similar compatibility in different temperature ranges (20°C-280°C). Good compatibility is the guarantee of good yield, and also guarantees chemical resistance and high temperature performance. When ΔF is less than 2%, fluororubber becomes perfluoroether rubber. This idea has been described in CN115847665A. When ΔF is greater than 19%, the polarity of fluororubber and cross-linked perfluoroether rubber powder is too different, which is not conducive to the construction of a uniform system.

[0029] In a specific embodiment of the present invention, ΔF=73.6%-the mass percentage of fluorine in the fluororubber.

[0030] In the formula, C = (weight parts of cross-linked perfluoroether rubber powder / weight parts of fluororubber) * 100, optionally, C is less than or equal to 80. Optionally, C is 5-80, 10-80, 20-80, 20-28, 28-80, 20-50, 20-40, 40-50 or 60-80, etc., preferably 20-80. When C is too small, the amount of cross-linked perfluoroether rubber added is too small, and the improvement in high temperature compression and chemical resistance is not significant. When C is greater than 80, it is not conducive to the construction of a uniform system. Among them, C units are dimensionless. For example: when the fluororubber raw rubber is 100 parts and the cross-linked perfluoroether rubber powder is added as 20 parts, C = 20.

[0031] In the formula, D50 is the average particle size of the cross-linked perfluoroether rubber powder. The unit is um. Optionally, D50≤140um. Further optionally, 0<D50≤140um, 0<D50≤130um, 0<D50≤120um, 0<D50≤110um, 0<D50≤100um, 0<D50≤90um, 0<D50≤80um, 0<D50≤70um, 0<D50≤60um, 0<D50≤50um, 0<D50≤40um, 0<D50≤30um, 0<D50≤20um or 0<D50≤10um, etc. When D50 is greater than 140um, the specific surface area of ​​the cross-linked perfluoroether rubber becomes smaller, and the effective contact area with the fluororubber becomes smaller. The yield rate of the prepared product decreases, and the granularity in the product is obvious. For example, D50≤130um means that 50% of the cross-linked perfluoroether rubber powder obtained by crushing has a particle size of less than or equal to 130um. The normal distribution diagram of its particle size is as follows: Figure 1 .

[0032] The fluororubber composition provided by the present invention has no cross-linkable cross-linking monomer in the cross-linked perfluoroether rubber powder, wherein the cross-linking monomer is, for example, cyano or carbon-halogen or double bond.

[0033] The fluororubber composition provided by the present invention, the preparation method of the cross-linked perfluoroether rubber powder comprises: cutting the recycled cross-linked perfluoroether rubber into granules, putting the granular cross-linked perfluoroether rubber into a liquid nitrogen freezing pulverizer and pulverizing it for 20-40 minutes, and sieving to obtain the cross-linked perfluoroether rubber powder. The cross-linked perfluoroether rubber powder is packed in a PE bag in the form of Figure 2 .

[0034] In the preparation method of cross-linked perfluoroether rubber powder, the cross-linked perfluoroether rubber powder is in granular form with a length of 0.3-1.0 cm. Optionally, the length can be, for example, 0.3-0.5 cm, 0.5-0.8 cm, 0.8-1.0 cm, 0.3-0.6 cm or 0.6-1.0 cm.

[0035] In the method for preparing cross-linked perfluoroether rubber powder, the temperature of the liquid nitrogen freezing mill is -196 to -150°C; more preferably, -196 to -170°C; further preferably, -196°C.

[0036] The particle size of the cross-linked perfluoroether rubber can be controlled by controlling the pulverization process. The specific size is described by D50 and D90. For example, D50≤130um, D90≤230um means that 50% of the cross-linked perfluoroether rubber powder obtained by pulverization has a particle size less than or equal to 130um, and 90% of the particles have a particle size less than or equal to 230um.

[0037] After a certain period of thermal history (i.e., vulcanization reaction), the cross-linked perfluoroether rubber powder loses the functional groups that can react again. The changes of the cross-linking functional groups can be judged by FT-IR. For perfluoroether rubber raw rubber, the functional groups that can react are at 1036cm in FTIR. -1 There is a peak on the top, which corresponds to the cross-linkable cyano group (-CN). The cross-linked perfluoroether rubber powder has a peak at 1036cm -1 There is no peak, indicating that the cross-linkable cyano group has reacted completely. Figure 3 .

[0038] The crushing process for recovering perfluoroether rubber described in the present invention is applicable to all perfluoroether rubbers on the market.

[0039] The fluororubber composition provided by the present invention has a Mooney viscosity ML (1+10min) of 20-90 at 121°C, which can be selected from 20-50, 50-90, 20-30, 30-40, 40-90, 50-60, 60-70, 70-80 or 80-90.

[0040] In the fluororubber composition provided by the present invention, the crosslinking agent is selected from one or more of olefins, halides and nitrile compounds.

[0041] Preferably, the cross-linking agent is triallyl isocyanurate (CAS No.: 1025-15-6).

[0042] Further, the weight portion of the cross-linking agent is 0.2-4 parts. Optionally, the weight portion of the cross-linking agent can be, for example, 0.2-0.5 parts, 0.5-2 parts, 2-3.5 parts, 3.5-4 parts, etc.

[0043] In the fluororubber composition provided by the present invention, the vulcanizing agent is selected from one or more of peroxides and amine compounds. Further, the peroxide is selected from one or more of dialkyl peroxides, diacyl peroxides, ketal peroxides, and peroxyesters.

[0044] Preferably, the dialkyl peroxides include one or more of diisopropyl benzene peroxide (CAS No.: 80-43-3), di(tert-butylperoxyisopropyl)benzene (CAS No.: 2212-81-9), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (CAS No.: 78-63-7), and 1,1-di(tert-butylperoxy)3,3,5-trimethylcyclohexane (CAS No.: 6731-36-8); further preferably, it is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

[0045] Preferably, the diacyl peroxides include di(2,4-dichlorobenzoyl) peroxide (CAS No.: 133-14-2).

[0046] Preferably, the ketal peroxide includes 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No.: 6731-36-8).

[0047] Preferably, the peroxyesters include one or more of tert-butyl perbenzoate (CAS No.: 614-45-9), tert-amyl perbenzoate (CAS No.: 4511-39-1), di(hexadecyl) peroxide dicarbonate (CAS No.: 26322-14-5), tert-butyl isopropyl peroxide (CAS No.: 3457-61-2), and tert-butyl peroxyisopropyl carbonate (CAS No.: 2372-21-6).

[0048] Preferably, the amine compound contains at least two amino groups.

[0049] Preferably, the amine compounds include m-phenylenediamine (CAS No.: 108-45-2), hexamethylenediamine carbamate (CAS No.: 143-06-6), 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (CAS No.: 83558-87-6), hexamethylenediamine (CAS No.: 124-09-4), tert-butylbis(2-aminoethyl)carbamate (CAS No.: 556082-02-1), 2,2-bis[4(4-aminophenoxy)phenyl] One or more of propane (CAS No. 13080-86-9), 4,4'-methylenedianiline (CAS No. 101-77-9), 4,4'-diaminodicyclohexylmethane (CAS No. 1761-71-3), 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (CAS No. 83558-87-6), isophoronediamine (CAS No. 2855-13-2), and 2,2-bis(4-aminophenyl)propane (CAS No. 2479-47-2).

[0050] In the fluororubber composition provided by the present invention, the weight portion of the vulcanizing agent is 0.2-1.5 parts. Optionally, the weight portion of the vulcanizing agent can be, for example, 0.2-0.5 parts, 0.5-1 parts, 0.2-1 parts or 1-1.5 parts.

[0051] In some preferred embodiments, the selection of the crosslinking agent is related to the performance of the perfluoroether rubber powder. The inventors of the present application have creatively discovered that different perfluoroether rubber powders and different crosslinking agents can constitute different crosslinking systems, thereby enabling the preparation of perfluoroether seals with excellent performance.

[0052] Preparation method of fluororubber composition

[0053] The second aspect of the present invention provides a method for preparing the fluororubber composition described in the first aspect of the present invention, the preparation method comprising: first kneading the raw rubber of the fluororubber, then adding cross-linked perfluoroether rubber powder and a cross-linking agent to mix, continuing to knead and then discharging the rubber, and calendering a sheet, cooling to obtain a film; softening the film and wrapping it with a roller, adding a vulcanizing agent for vulcanization, and cooling to room temperature to obtain the fluororubber composition.

[0054] In the preparation method of the fluororubber composition of the present invention, the fluororubber raw rubber banburying temperature is 110°C-130°C; the fluororubber raw rubber banburying time is 60 seconds-120 seconds. Optionally, the fluororubber raw rubber banburying temperature is 110°C-120°C or 120°C-130°C, etc. The fluororubber raw rubber banburying time can be, for example, 60 seconds-80 seconds, 80 seconds-100 seconds, 100 seconds-120 seconds, etc.

[0055] In the preparation method of the fluororubber composition of the present invention, the raw rubber of the fluororubber is kneaded in an internal mixer, and the kneading time is continued for 60-120 seconds. The kneading time can be, for example, 60 seconds to 80 seconds, 80 seconds to 100 seconds, 100 seconds to 120 seconds, etc.

[0056] In the preparation method of the fluororubber composition of the present invention, the debonding temperature is controlled below 150°C.

[0057] In the preparation method of the fluororubber composition of the present invention, sheets are calendered on an open mixing mill.

[0058] In the preparation method of the fluororubber composition of the present invention, the sheet is calendered and cooled and placed for at least 4 hours for use.

[0059] In the preparation method of the fluororubber composition of the present invention, the film is softened and rolled, and in the step of adding a vulcanizing agent for vulcanization, the open mill is adjusted to a suitable roller distance, the film that has been parked and cooled is put into the open mill to soften and roll, the vulcanizing agent is slowly added, and the knife is cut left and right for multiple times to mix; after complete mixing, the roller distance is adjusted to 0.1-0.2mm, the triangle package is made multiple times, the thin pass is made multiple times, the open mill is adjusted to a suitable roller distance of 1-5mm, the film is produced, and the film is parked and cooled for more than 12 hours for standby use; the above-produced fluoroelastomer is vulcanized at a pressure of 7-15MPa and a temperature of 160-180°C for 5-20min.

[0060] Specifically, the preparation method of the fluororubber composition includes the following steps: the temperature of the internal mixer is raised to 110-130°C, the raw rubber is put into the internal mixer for internal mixing for 60-120 seconds, and then the weighed cross-linked perfluoroether rubber powder and the cross-linking agent are added and slowly added into the internal mixer in batches. After the raw materials are completely mixed, the internal mixing is continued for 60-120 seconds, and then the rubber is discharged (the discharge temperature is controlled below 150°C) and the sheet is calendered on the open mixer, and the sheet is cooled and parked for at least 4 hours for standby use; the open mixer is adjusted to a suitable roller distance, the rubber sheet after being parked and cooled is put into the open mixer to soften and roll it, and the vulcanizer is slowly added, and the left and right cutters are used 10 times each to mix it. After complete mixing, adjust the roller distance to 0.1-0.2mm, make triangle packages 10 times, thin pass 10 times, adjust the open mill to an appropriate roller distance of 1-5mm, produce sheets, and stop to cool for more than 12 hours for use; vulcanize the above-produced fluorine-containing elastomer at a pressure of 7-15MPa and a temperature of 160-180°C for 5-20min, and cool to room temperature to obtain fluororubber.

[0061] In the preparation method of the fluororubber composition of the present invention, chemical and physical methods are combined by adjusting the temperature and time of banburying and increasing the number of triangle packing.

[0062] application

[0063] The third aspect of the present invention provides use of the fluororubber composition as described in the first aspect of the present invention in semiconductor sealing materials and petroleum extraction.

[0064] The beneficial effects of the present invention are further illustrated below in conjunction with embodiments.

[0065] 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.

[0066] 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.

[0067] In the following examples, the reagents, materials and instruments used are all commercially available unless otherwise specified.

[0068] Preparation of cross-linked perfluoroether rubber powder 1, cross-linked perfluoroether rubber powder 2 and cross-linked perfluoroether rubber powder 3:

[0069] The cross-linked perfluoroether rubber is cross-linked PFR 5910M, and its preparation method comprises: 100 parts of PFR 5910M and 1.3 parts of TX101 are mixed evenly on an open mill, and then vulcanized under one sulfur condition at a pressure of 5-10MPa, 165-175C*10min, and two sulfur conditions at 220C*8h to form cross-linked PFR 5910M.

[0070] The cross-linked PFR 5910M is cut into 0.3 cm-1 cm particles, the particles of the cross-linked perfluoroether rubber are put into a liquid nitrogen freezing mill and crushed for 20-40 minutes, and the cross-linked perfluoroether rubber powder is obtained by sieving.

[0071] The mass percentage of fluorine in the cross-linked perfluoroether rubber is 73.6%.

[0072] In this experiment, micropowders of different particle sizes were obtained by adjusting different crushing processes (by selecting a rotation speed adjustment of 3000-10000rpm and a 0.1-1mm screen). Among them, the rotation speed was selected to be 8000-10000rpm, and the screen was passed through 0.1-0.2mm to obtain cross-linked perfluoroether rubber micropowder 1. The rotation speed was selected to be 5000-8000rpm, and the screen was passed through 0.3-0.4mm to obtain cross-linked perfluoroether rubber micropowder 2. The rotation speed was selected to be 3000-10000rpm, and the screen was passed through 0.5-0.7mm to obtain cross-linked perfluoroether rubber micropowder 3.

[0073] For specific dimensions, see Table 1 and Figure 4 (Test results)

[0074] Table 1

[0075] Cross-linked perfluoroether rubber powder 1 Cross-linked perfluoroether rubber powder 2 Cross-linked perfluoroether rubber powder 3 D50 / um 72 131 333

[0076] in, Figure 4 The particle size shown in is D50 = 72 um.

[0077]

ΔF

[0078] Table 2

[0079]

[0080] The mass percentage of fluorine in fluorosilicone DS412 is 35wt / %, and the mass percentage of fluorine in cross-linked perfluoroether rubber powder 1, cross-linked perfluoroether rubber powder 2 and cross-linked perfluoroether rubber powder 3 is 73.6%. The difference in fluorine content between fluorosilicone DS412 and cross-linked perfluoroether rubber powder 1, cross-linked perfluoroether rubber powder 2 and cross-linked perfluoroether rubber powder 3 is 38.6%, that is, ΔF is greater than the upper limit value of 19% required by the present invention. The present invention selects the finest cross-linked perfluoroether rubber powder 1 (72um) for comparative experiments with DS412, and finds that even if the addition amount of cross-linked perfluoroether rubber powder 1 is only 1 part, the finished ring of fluorosilicone also shows a very serious granular feeling that does not meet the product requirements. As shown in Table 3:

[0081] Table 3

[0082] Comparative Example 1 Comparative Example 2 Comparative Example 3 DS412 100 copies 100 copies 100 copies TX101 1 serving 1 serving 1 serving Micro powder 1 72um 0 copies 1 serving 2 servings ΔF<19% 38.6％ 38.6％ 38.6％ Sample surface No graininess Obvious graininess Obvious graininess

[0083] Comparative Example 4

[0084] When cross-linked perfluoroether rubber powder 3 is added to 600S, even if 5 parts are added, because the powder size D50 = 333um> 140um, the compatibility of the whole system is poor and the yield rate is low. Figure 5, the product will show serious cracking after the compression test.

[0085] Comparative Example 5

[0086] The temperature of the internal mixer was raised to 120°C, and the raw fluororubber 600S was put into the internal mixer for internal mixing for 100 seconds. Then, the crosslinking agent TAIC was added, and the mixture was divided into two equal parts and slowly added into the internal mixer respectively and stirred evenly. Then, the internal mixing was continued for 100 seconds, and the rubber was discharged at a temperature of 100°C, and sheets were calendered on the mixing mill, and then cooled for 8 hours. The sheets after cooling were put into the mixing mill, and after rolling the rollers for 3 circles at room temperature, the vulcanizing agent TX101 was slowly added. After the left and right cutters were used for 10 times each to mix evenly, the roller spacing was adjusted to 0.1mm, and the triangle package was made 10 times, and the thin pass was made 10 times. Then, the roller spacing of the mixing mill was adjusted to 3mm, and the sheets were produced. The sheets were cooled for 15 hours for use. The fluoroelastomer produced was vulcanized at a pressure of 10MPa and a temperature of 170°C for 15 minutes, and the fluororubber composition seal was obtained by cooling to 25°C.

[0087] Example 1

[0088] The temperature of the internal mixer was raised to 120°C, and the raw fluororubber 600S was put into the internal mixer for internal mixing for 100s. Then, the cross-linked perfluoroether rubber powder 1 and the cross-linking agent TAIC were added, and they were divided into two equal parts and slowly added into the internal mixer respectively and stirred evenly. Then, the internal mixing was continued for 100s, and the rubber was discharged at a temperature of 100°C, and the sheets were rolled out on the open mixer, and then stopped to cool for 8h; the sheets after being stopped and cooled were put into the open mixer, and after rolling 3 times at room temperature, the vulcanizing agent TX101 was slowly added, and the left and right cutters were used 10 times each to mix them evenly, and then the roller distance was adjusted to 0.1mm, and the triangle package was made 10 times, and the thin pass was made 10 times. The roller distance of the open mixer was adjusted to 3mm, and the sheets were taken out, and stopped to cool for 15h for use; the fluoroelastomer taken out was vulcanized at a pressure of 10MPa and a temperature of 170°C for 15min, and cooled to 25°C to obtain a fluororubber composition seal.

[0089] Examples 2 to 4 and Comparative Example 6 refer to Example 1, and the specific parameter formula adjustment is shown in Table 4.

[0090] Table 4

[0091]

[0092]

[0093] Table 4 takes AGC 600S rubber as an example to study the differences in the added content of cross-linked perfluoroether rubber powder 1; specifically taking powder 1 as an example, ΔF of 600S and powder 1 is 16.6%, powder 1 is 72um, ΔF*C*D50<350um, when this value is greater than 350um, a granular feel will appear, although the high temperature compression deformation performance is acceptable, but the appearance is not acceptable for the product.

[0094] Examples 5 to 8 and Comparative Examples 7 and 8 refer to Example 1, and the specific parameter formula adjustment is shown in Table 5.

[0095] Table 5

[0096]

[0097] Table 5 takes GB206W rubber as an example to study the difference in the added content of cross-linked perfluoroether rubber powder 1; specifically taking powder 1 as an example, ΔF of GB206W and powder 1 is 8.6%, powder 1 is 72um, ΔF*C*D50<350um, when this value is greater than 350um, a granular feel will appear, although the high temperature compression deformation performance is acceptable, but the appearance is not acceptable for the product.

[0098] 270C*30h compression deformation test method: 2GB / T 7759.1-2015 Determination of compression deformation of vulcanized rubber or thermoplastic rubber Part 1: At room temperature and elevated temperature. It should be noted that the sample size does not use the size in this standard, but the O-ring sample of AS568-214 is used. The specific test conditions are: under 25% strain, the permanent compression deformation of the O-ring sample is tested after being placed in an oven at 270℃ for 30 hours. Generally speaking, the compression deformation value measured using a cylindrical sample is much smaller than the value measured by the O-ring of AS568-214, that is, the compression deformation value of the O-ring test is too large, so all formulations must be compared under the same test conditions and sample conditions of the same size.

[0099] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0100] 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 fluororubber composition, characterized in that: The raw materials of the fluororubber composition include cross-linked perfluoroether rubber powder, fluororubber, a cross-linking agent and a vulcanizing agent, and the fluororubber is not cross-linked; the fluororubber composition satisfies the formula: ΔF*C*D50<350um; Wherein, ΔF=the mass percentage of fluorine in the cross-linked perfluoroether rubber powder-the mass percentage of fluorine in the fluororubber; the ΔF is 2% to 19%; C = (weight parts of cross-linked perfluoroether rubber powder / weight parts of fluororubber)*100; C is 5 to 80; D50 is the average particle size of the cross-linked perfluoroether rubber powder, in um; the D50 is ≤140um.

2. The fluororubber composition according to claim 1, characterized in that The preparation method of the cross-linked perfluoroether rubber powder comprises: cutting the recycled cross-linked perfluoroether rubber into granules, putting the granular cross-linked perfluoroether rubber into a liquid nitrogen freezing pulverizer for 20-40 minutes, and sieving to obtain the cross-linked perfluoroether rubber powder.

3. The fluororubber composition according to claim 2, characterized in that: The cross-linked perfluoroether rubber powder is in granular form and has a length of 0.3 cm to 1.0 cm.

4. The fluororubber composition according to claim 1, characterized in that: The mass percentage of fluorine contained in the cross-linked perfluoroether rubber micropowder is 72%-74%; the mass percentage of fluorine contained in the fluororubber is 55%-70%.

5. The fluororubber composition according to claim 1, characterized in that: Also includes any one or more of the following features: A1) there is no cross-linkable cross-linking monomer in the cross-linked perfluoroether rubber powder; A2) the fluororubber Mooney viscosity ML (1+10min) at 121°C is 20-90; A3) the cross-linking agent is selected from one or more of olefins, halides, and nitrile compounds; A4) the vulcanizing agent is selected from one or more of peroxides and amine compounds; A5) the weight portion of the cross-linking agent is 0.2-4 parts; A6) The weight portion of the vulcanizing agent is 0.2-1.5 parts.

6. The fluororubber composition according to claim 5, characterized in that: The peroxide includes one or more of dialkyl peroxides, diacyl peroxides, ketal peroxides, and peroxyesters.

7. The fluororubber composition according to claim 1, characterized in that: The C is 20-80.

8. A method for preparing a fluororubber composition according to any one of claims 1 to 7, characterized in that: The process comprises first kneading raw fluororubber, then adding cross-linked perfluoroether rubber powder and a cross-linking agent, mixing, continuing kneading, discharging the rubber, rolling out sheets, and cooling to obtain a film; softening the film, wrapping it with a roller, adding a vulcanizing agent for vulcanization, and cooling it to room temperature to obtain a fluororubber composition.

9. The method for preparing a fluororubber composition according to claim 8, characterized in that: Also includes any one or more of the following features: B1) The mixing temperature of the raw rubber of the fluororubber is 110-130°C; B2) the fluororubber raw rubber mixing time is 60-120 seconds; B3) the raw rubber of the fluororubber is kneaded in an internal mixer; B4) continue kneading for 60-120 seconds; B5) The debinding temperature is controlled below 150℃; B6) rolling out sheets on an open mixing mill; B7) rolling out sheets, cooling and keeping for at least 4 hours for use; B8) Soften the film and wrap it with a roll. Add the vulcanizing agent to vulcanize. In the step of vulcanization, adjust the open mill to a suitable roll distance, put the cooled film into the open mill to soften and wrap it with a roll, slowly add the vulcanizing agent, and cut it left and right several times to mix it; after it is completely mixed, adjust the roll distance to 0.1-0.2mm, make a triangle wrap several times, and make a thin pass several times, adjust the open mill to a suitable roll distance of 1-5mm, and produce a sheet, and leave it to cool for more than 12 hours for use; vulcanize the fluorine-containing elastomer produced above at a pressure of 7-15MPa and a temperature of 160-180°C for 5-20min.

10. Use of the fluororubber composition according to any one of claims 1 to 7 or the fluororubber composition prepared by the method for preparing the fluororubber composition according to any one of claims 8 to 9 in semiconductor sealing materials and petroleum extraction.

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