Perfluoroether rubber composition, perfluoroether rubber and method for producing and use thereof

Abstract

The present application relates to the field of fluoropolymer materials, in particular to a perfluoroether rubber composition, a perfluoroether rubber and a preparation method and application thereof. The perfluoroether rubber composition is characterized in that the perfluoroether rubber composition comprises: 100 parts by weight of perfluoroether rubber, 1-5 parts by weight of vulcanizing agent, 1-10 parts by weight of vulcanization aid, 1-10 parts by weight of antioxidant, 1-5 parts by weight of processing aid and 1-30 parts by weight of filler; wherein the vulcanizing agent is a peroxide vulcanizing agent; the vulcanization aid has a general formula of (RSiO 3 / 2 ) n , n is 6, 8, 10 or 12, R is an alkenyl group of C2-C 10 , R1 is hydrogen or an alkyl group of C1-C4, and R2 is (CH2) m , and m is an integer of 1-10.

Description

Technical Field

[0001] This invention relates to the field of fluorine-containing polymer materials, specifically to a perfluoroether rubber composition, perfluoroether rubber, its preparation method, and its application. Background Technology

[0002] With increasing energy demand and the near depletion of easily exploitable oil and gas resources, hot dry rock has become a hot development area as a new type of geothermal resource. Furthermore, oil and gas exploration and development are moving towards deeper formations, and the extremely high downhole temperature environment places extremely stringent demands on the performance of the materials used. Hot dry rock temperatures generally exceed 230℃, and conventional high-temperature resistant rubber materials are prone to sealing failure under these extreme conditions. The development of high-temperature resistant rubber has become one of the technical bottlenecks restricting effective downhole extraction and development.

[0003] Perfluoroelastomer (PFE) rubber is mainly obtained by copolymerizing tetrafluoroethylene and perfluoroalkyl vinyl ethers as the main monomers with monomers that have a high vulcanization point. In PFE rubber, all hydrogen atoms on the carbon atoms are replaced by fluorine atoms, resulting in excellent high-temperature resistance and chemical corrosion resistance. During the vulcanization process of PFE rubber, the vulcanization system consists of a vulcanizing agent and a co-vulcanizing agent. The co-vulcanizing agent is mainly allyl isocyanurate (TAIC) or triallyl cyanurate (TAC), which causes the cross-linked structure of the vulcanized rubber to contain amide groups. In an acidic environment, these amide groups undergo a decomposition reaction, leading to a decrease in the mechanical properties of the PFE rubber and thus causing sealing failure.

[0004] Currently, there are several commercially available perfluoroelastomer (PFE) products that can operate continuously at temperatures up to 300°C. PFE is widely used in aerospace, chemical, and semiconductor industries. PFEs with bromine or iodine curing points are vulcanized with peroxides. The resulting PFEs exhibits good chemical resistance. An important advantage of iodide curing systems is the absence of metal oxides or other metal catalysts, making the elastomer less susceptible to corrosion in aqueous or acidic environments, but this comes at the cost of some thermal stability. Its maximum continuous operating temperature is 218°C. It is impossible to simultaneously meet the requirements for both high-temperature resistance and chemical resistance. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that existing perfluoroether rubbers cannot simultaneously possess both high-temperature resistance and chemical resistance properties, and to provide a perfluoroether rubber composition, perfluoroether rubber, its preparation method and application. The perfluoroether rubber prepared from this rubber composition not only has high-temperature aging resistance but also excellent chemical resistance properties, enabling it to be used for a long time in harsh environments.

[0006] To achieve the above objectives, the first aspect of the present invention provides a perfluoroether rubber composition, characterized in that the perfluoroether rubber composition comprises: 100 parts by weight of perfluoroether rubber, 1-5 parts by weight of vulcanizing agent, 1-10 parts by weight of co-vulcanizing agent, 1-10 parts by weight of antioxidant, 1-5 parts by weight of processing aid and 1-30 parts by weight of filler.

[0007] The vulcanizing agent is a peroxide-based vulcanizing agent; the co-vulcanizing agent has the general formula (RSiO). 3 / 2 ) n n is 6, 8, 10 or 12, and R is C2-C 10 alkenyl, R1 is hydrogen or a C1-C4 alkyl group, and R2 is (CH2). m m is an integer from 1 to 10.

[0008] A second aspect of the present invention provides a method for preparing perfluoroether rubber, characterized in that the method includes: mixing and vulcanizing the components in the perfluoroether rubber composition provided by the present invention.

[0009] A third aspect of the present invention provides a perfluoroether rubber prepared by the method described in the present invention.

[0010] The fourth aspect of the present invention provides the use of the perfluoroether rubber composition or perfluoroether rubber described herein in the manufacture of rubber sealing components.

[0011] Through the above technical solutions, the perfluoroether rubber composition, perfluoroether rubber, preparation method and application provided by the present invention achieve the following beneficial effects:

[0012] The perfluoroether rubber composition provided by this invention contains specific types and amounts of components, and the components work synergistically and in combination with each other. The resulting vulcanized rubber has excellent resistance to high-temperature aging and chemical resistance.

[0013] Furthermore, the perfluoroether rubber provided by this invention can be used in harsh high-temperature environments, meeting the requirements of rubber sealing components. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] The first aspect of the present invention provides a perfluoroether rubber composition, characterized in that the perfluoroether rubber composition comprises: 100 parts by weight of perfluoroether rubber, 1-5 parts by weight of vulcanizing agent, 1-10 parts by weight of co-vulcanizing agent, 1-10 parts by weight of antioxidant, 1-5 parts by weight of processing aid, and 1-30 parts by weight of filler.

[0016] The vulcanizing agent is a peroxide-based vulcanizing agent; the co-vulcanizing agent has the general formula (RSiO). 3 / 2 ) n Compounds in which n is 6, 8, 10 or 12, and R is C2-C 10 alkenyl, R1 is hydrogen or a C1-C4 alkyl group, and R2 is (CH2). m m is an integer from 1 to 10.

[0017] In this invention, the perfluoroether rubber has a fluorine content of ≥75wt%, which enables it to undergo a free radical reaction with the above-mentioned vulcanizing agent, and then a crosslinking reaction with the vulcanizing agent, thereby obtaining a perfluoroether rubber that simultaneously possesses excellent high-temperature resistance and chemical resistance.

[0018] In this invention, a cage-like silsesquioxane (POSS) structure is introduced into perfluoroether rubber as a crosslinking agent. Utilizing multiple active sites, this chemical structure is relatively stable in water, and its side chains have highly active carbon-carbon double bonds that generate free radicals that can be used to initiate crosslinking reactions. These free radicals can react with free radicals in the perfluoroether rubber and then with the vulcanizing agent to produce a crosslinking reaction. By introducing the POSS cage-like structure into the rubber crosslinking network, the mechanical properties of the perfluoroether rubber are improved.

[0019] Furthermore, by using the aforementioned specific weight proportions of POSS as a vulcanizing agent, vulcanized perfluoroether rubber can exhibit excellent high-temperature aging resistance and chemical resistance. However, when the POSS content is excessive, agglomeration may occur, affecting the aforementioned properties of the rubber.

[0020] In this invention, specific weight parts of perfluoroether rubber, vulcanizing agent, co-vulcanizing agent, antioxidant, processing aid and filler in the perfluoroether rubber composition work synergistically to ensure that the vulcanized perfluoroether rubber meets the requirements of high temperature aging resistance and chemical resistance.

[0021] According to the present invention, the perfluoroether rubber composition comprises: 100 parts by weight of perfluoroether rubber, 1-5 parts by weight of vulcanizing agent, 3-8 parts by weight of co-vulcanizing agent, 1-5 parts by weight of antioxidant, 1-5 parts by weight of processing aid and 10-30 parts by weight of filler.

[0022] The vulcanizing agent is a peroxide-based vulcanizing agent, and the co-vulcanizing agent has the general formula (RSiO). 3 / 2 ) nn is 6, 8, 10 or 12, and R is R1 is hydrogen or a C1-C4 alkyl group, and R2 is (CH2). m m is an integer from 1 to 4.

[0023] According to the present invention, the general formula of the co-vulcanizing agent is (RSiO 3 / 2 ) n n is 8, R is R1 is a C1-C4 alkyl group, and R2 is (CH2). m m is an integer from 1 to 4.

[0024] In this invention, POSS, which contains both carbon-carbon double bonds and acyl groups, is used as a crosslinking agent. In addition to improving mechanical properties, it also enhances the anti-aging properties of rubber.

[0025] Preferably, R1 is methyl or ethyl, and R2 is (CH2). m m is an integer from 1 to 3.

[0026] According to the present invention, the co-vulcanizing agent is selected from methacryloyloxypropyl cage silsesquioxane and / or acryloyloxy cage silsesquioxane.

[0027] According to the present invention, the co-curing agent is methacryloyloxypropyl cage-type silsesquioxane and acryloyloxy cage-type silsesquioxane.

[0028] In this invention, methacryloyloxypropyl cage-type silsesquioxane (MAPOSS) and acryloyloxy cage-type silsesquioxane (AOPOSS) are used in combination. Based on the principle of polarity compatibility, both methacryloyloxypropyl cage-type silsesquioxane and perfluoroether rubber are polar, exhibiting excellent compatibility. The presence of the methyl group activates the acryloyloxypropyl group, enhancing the free radical reactivity of POSS. Furthermore, the combined materials act as a co-crosslinking agent, exhibiting a hybrid cage structure within the molecule. Specifically, the carbon atom attached to the propylene group is sp2 hybridized, the other carbon atom is sp3 hybridized, and the acryloyloxy group is sp2 hybridized. This hybrid cage structure combines the advantages of organic and inorganic groups with a hollow cage structure, thereby improving the mechanical properties of the perfluoroether rubber.

[0029] According to the present invention, the weight ratio of the methacryloyloxypropyl cage-type silsesquioxane to the acryloyloxy cage-type silsesquioxane is 0.25-4:1, preferably 1.5-4:1.

[0030] In this invention, MAPOSS and AOPOSS in a specific weight ratio are used as vulcanizing agents, resulting in better anti-aging properties of perfluoroether rubber.

[0031] According to the present invention, the vulcanizing agent is a peroxide-based vulcanizing agent, preferably one of dicumyl peroxide, di(tert-butylperoxyisopropyl)benzene, dibenzoyl peroxide, di(2,4-dichlorobenzoyl)peroxide, and 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane.

[0032] In this invention, a specific amount of peroxide-based vulcanizing agent is used. If the amount is too small, fewer crosslinking points will be generated, resulting in poor rubber performance. If the amount is too large, the rubber will be over-crosslinked, which will adversely affect the performance of the obtained perfluoroether rubber. Furthermore, the residues from the decomposition of the peroxide will affect the performance of the perfluoroether rubber.

[0033] Furthermore, by using dicumyl peroxide as a vulcanizing agent, no large-area foaming phenomenon was observed on the rubber surface after high-temperature vulcanization.

[0034] According to the present invention, the filler is hard carbon black.

[0035] According to the present invention, the antioxidant is selected from quinoline antioxidants and / or benzimidazole antioxidants.

[0036] According to the present invention, the quinoline antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline, and the benzimidazole antioxidant is 2-mercaptobenzimidazole zinc salt.

[0037] According to the present invention, the antioxidant is 2-mercaptobenzimidazole and 2,2,4-trimethyl-1,2-dihydroquinoline.

[0038] Preferably, the weight ratio of the 2-mercaptobenzimidazole to the 2,2,4-trimethyl-1,2-dihydroquinoline is 1:1-2.

[0039] According to the present invention, the processing aid is a stearate, preferably sodium stearate.

[0040] A second aspect of the present invention provides a method for preparing perfluoroether rubber, characterized in that the method includes: mixing and vulcanizing the components in the perfluoroether rubber composition provided by the present invention.

[0041] According to the present invention, the method includes:

[0042] (1) Mix perfluoroether rubber, vulcanizing agent, filler, antioxidant, vulcanizing agent and processing aid to obtain compound rubber;

[0043] (2) The compound is vulcanized to obtain the perfluoroether rubber.

[0044] According to the present invention, the vulcanization includes: performing a first-stage vulcanization of the compound in a flat vulcanizing machine, followed by a second-stage vulcanization in an oven.

[0045] According to the present invention, the vulcanization temperature is 160-180℃, the vulcanization pressure is 5-20MPa, and the vulcanization time is 10-30min.

[0046] According to the present invention, the conditions for the two-stage vulcanization include: a vulcanization temperature of 200-240°C and a vulcanization time of 6-24 hours.

[0047] A third aspect of the present invention provides a perfluoroether rubber prepared by the preparation method described herein.

[0048] The fourth aspect of the present invention provides the use of the perfluoroether rubber composition or perfluoroether rubber described herein in the manufacture of rubber sealing components.

[0049] The present invention will be described in detail below through embodiments. In the following embodiments,

[0050] The mechanical properties (hardness, tensile strength, elongation at break) of perfluoroether rubber were measured using the method specified in GB / T528-2009.

[0051] The high-temperature aging resistance of perfluoroether rubber was measured in a hydrothermal reactor under aging conditions of 300℃, 15MPa total pressure, and 48h aging time.

[0052] The high-temperature chemical (acid, alkali, oil) resistance of perfluoroether rubber was measured in a hydrothermal reactor under the aging conditions of 300℃, 15MPa total pressure, 48h aging time, 20% NaOH, 20% HCl or hydraulic oil.

[0053] The mass change rate is calculated as follows: (increase in mass of perfluoroether rubber after aging test / mass of perfluoroether rubber before aging) * 100. The smaller the value, the better the aging resistance of the perfluoroether rubber.

[0054] The perfluoroelastomer rubber is Asahi Glass's PM 3000.

[0055] The vulcanizing agents are industrial-grade dicumyl peroxide (DCP) and sulfur powder from Shijiazhuang Fate Chemical Technology Co., Ltd.

[0056] The vulcanizing agent POSS is a combination of methacryloyloxypropyl cage-type silsesquioxane (MAPOSS, n = 8, R1 = methyl, R2 = propylene), acryloyloxy cage-type silsesquioxane (AOPOSS, n = 8, R1 = hydrogen, R2 = propylene), cage-type octavinyl polysilsesquioxane (OVPOSS, n = 8, R = vinyl), and octahydrogen-based cage-type silsesquioxane (Octa H-POSS, n = 8, R = hydrogen) from Xi'an Qiyue Biotechnology Co., Ltd.

[0057] The packing material is N550 from Cabot Chemical (Tianjin) Co., Ltd.

[0058] The antioxidants are 2-mercaptobenzimidazole and 2,2,4-trimethyl-1,2-dihydroquinoline from Shanghai Lanrun Chemical Co., Ltd., and N-phenyl-N from Shanghai Lanrun Chemical Co., Ltd. ’ - Cyclohexyl-p-phenylenediamine (4040NA), N,N-di-n-butyldithiocarbamate (NBC) from Shanghai Lanrun Chemical Co., Ltd.

[0059] The processing aid is sodium stearate from Aladdin Reagent (Shanghai) Co., Ltd.

[0060] The formulations of the perfluoroether rubber compositions A1-A8 and D1-D2 provided in Examples 1-8 and Comparative Examples 1-2 are shown in Table 1.

[0061] Table 1 (parts by weight)

[0062]

[0063] Preparation Example

[0064] According to the formula shown in Table 1, the components were mixed to obtain a compound rubber. The compound rubber was then subjected to a first-stage vulcanization in a vulcanizing machine under the following conditions: temperature 170℃, pressure 10MPa, and vulcanization time 10min. The second-stage vulcanization was carried out in an oven at 220℃ for 12h. Rubber products S1-S8 and DS1-DS2 were obtained. The properties of rubber products S1-S8 and DS1-DS2 were tested, and the test results are shown in Tables 2-5.

[0065] Table 2

[0066]

[0067]

[0068] Table 3

[0069]

[0070] Table 4

[0071]

[0072] Table 5

[0073]

[0074]

[0075] As can be seen from the results in Tables 2-5, the perfluoroether rubber prepared by using the perfluoroether rubber compositions provided in Examples 1-8 of the present invention has excellent high temperature resistance (300°C), chemical resistance, and aging resistance compared with the comparative examples. Furthermore, it can be used in the manufacture of rubber sealing components. In particular, as shown in Table 2, after high temperature aging, the perfluoroether rubber prepared by the perfluoroether rubber compositions provided in Examples 1-8 of the present invention undergoes further cross-linking, and the tensile strength is greater than that before the aging treatment.

[0076] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A perfluoroether rubber composition, characterized in that, The perfluoroether rubber composition comprises: 100 parts by weight of perfluoroether rubber, 1-5 parts by weight of vulcanizing agent, 1-10 parts by weight of co-vulcanizing agent, 1-10 parts by weight of antioxidant, 1-5 parts by weight of processing aid, and 1-30 parts by weight of filler. Wherein, the vulcanizing agent is a peroxide-based vulcanizing agent; the co-vulcanizing agent is methacryloxypropyl cage-type silsesquioxane and acryloxy cage-type silsesquioxane, and the weight ratio of the methacryloxypropyl cage-type silsesquioxane to the acryloxy cage-type silsesquioxane is 0.25-4:

1.

2. The perfluoroether rubber composition according to claim 1, wherein, The weight ratio of the methacryloyloxypropyl cage silsesquioxane to the acryloyloxy cage silsesquioxane is 1.5-4:

1.

3. The perfluoroether rubber composition according to claim 1, wherein, The vulcanizing agent is selected from one of dicumyl peroxide, di(tert-butylperoxyisopropyl)benzene, benzoyl peroxide, di(2,4-dichlorobenzoyl)peroxide, and 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane.

4. The perfluoroether rubber composition according to claim 3, wherein, The filler is carbon black.

5. The perfluoroether rubber composition according to claim 4, wherein, The filler is hard carbon black.

6. The perfluoroether rubber composition according to claim 3, wherein, The processing aid is stearate.

7. The perfluoroether rubber composition according to claim 6, wherein, The processing aid is sodium stearate.

8. The perfluoroether rubber composition according to claim 3, wherein, The antioxidant is selected from quinoline antioxidants and / or benzimidazole antioxidants.

9. The perfluoroether rubber composition according to claim 8, wherein, The quinoline antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline, and the benzimidazole antioxidant is 2-mercaptobenzimidazole zinc salt.

10. The perfluoroether rubber composition according to claim 3, wherein, The antioxidants are 2-mercaptobenzimidazole and 2,2,4-trimethyl-1,2-dihydroquinoline.

11. The perfluoroether rubber composition according to claim 10, wherein, The weight ratio of the 2-mercaptobenzimidazole to the 2,2,4-trimethyl-1,2-dihydroquinoline is 1:1-2.

12. A method for preparing perfluoroether rubber, characterized in that, The method includes: mixing and vulcanizing the components of the perfluoroether rubber composition according to any one of claims 1-11.

13. The preparation method according to claim 12, wherein, The method includes: (1) Mix perfluoroether rubber, vulcanizing agent, filler, antioxidant, vulcanizing agent and processing aid to obtain compound rubber; (2) The compound is vulcanized to obtain the perfluoroether rubber.

14. The method according to claim 12 or 13, wherein, The vulcanization is a two-stage vulcanization process.

15. The method according to claim 14, wherein, The vulcanization process includes: performing a first-stage vulcanization of the compound in a flat vulcanizing machine, followed by a second-stage vulcanization in an oven.

16. The method according to claim 15, wherein, The conditions for the first stage of vulcanization include: vulcanization temperature of 160-180℃, vulcanization pressure of 5-20MPa, and vulcanization time of 10-30 min.

17. The method according to claim 15, wherein, The conditions for the two-stage vulcanization include: a vulcanization temperature of 200-240℃ and a vulcanization time of 6-24 h.

18. A perfluoroether rubber prepared by the method according to any one of claims 12-17.

19. The use of the perfluoroether rubber composition according to any one of claims 1-11 or the perfluoroether rubber according to claim 18 in the manufacture of rubber sealing components.

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