Modified perfluoroether rubber as well as preparation method and application thereof

Abstract

The invention relates to the field of perfluoroether rubber, and provides modified perfluoroether rubber as well as a preparation method and application thereof. The modified perfluoroether rubber comprises the following components in parts by weight: 100 parts of raw perfluoroether rubber, 20-30 parts of a modified filler and 1-2 parts of a cross-linking agent, the modified filler is a filler modified by a silane coupling agent, and the silane coupling agent is a silane coupling agent containing a perfluorinated chain segment. The silane coupling agent modified filler containing a perfluoro chain segment is adopted, and the molecular structure of the silane coupling agent contains the perfluoro chain segment and is similar to the perfluoro main chain structure of raw perfluoroether rubber, so that the modified filler has good compatibility with a rubber matrix, and further interface defects are reduced. After the filler is modified by the silane coupling agent containing the perfluoro chain segment, the binding force between the rubber matrix and the filler is remarkably improved, the mechanical property and high temperature resistance of the sealing element are enhanced, the sealing element is particularly suitable for the sealing element in the semiconductor production process, the reliability of a product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of perfluoroether rubber, and in particular to a modified perfluoroether rubber and a preparation method and application thereof. Background Art

[0002] Perfluoroelastomer (FFKM) is widely used in high-tech fields such as semiconductor manufacturing due to its excellent high-temperature resistance, chemical corrosion resistance, and low outgassing. To optimize its mechanical properties, the addition of fillers is commonly used as a modification method. However, the interfacial bonding between the filler and the perfluoroelastomer matrix is insufficient, resulting in problems such as decreased mechanical properties and sealing failure during use of the composite material. Some studies have attempted to improve the dispersion of fillers through mechanical blending, but physical modification can only achieve weak van der Waals bonding between the filler and the matrix, with limited effectiveness and unable to fundamentally solve the problem of insufficient interfacial bonding. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect of insufficient interface bonding between filler and perfluoroether rubber matrix in the prior art, thereby providing a modified perfluoroether rubber and its preparation method and application.

[0004] To this end, the present invention provides the following technical solutions:

[0005] The present invention provides a modified perfluoroether rubber, comprising the following components in parts by weight:

[0006] 100 parts of perfluoroether rubber, 20-30 parts of modified filler and 1-2 parts of cross-linking agent;

[0007] The modified filler is a filler modified by a silane coupling agent, and the silane coupling agent is a silane coupling agent containing a perfluorinated segment.

[0008] Perfluoroether rubber raw rubber refers to the perfluoroether rubber base material that has not been vulcanized.

[0009] In an optional embodiment, the perfluoroether rubber raw rubber is a perfluoroether rubber containing cyanide vulcanization sites, which is purchased from SOLVAY Group.

[0010] A perfluorinated chain segment refers to a carbon chain structure in which all hydrogen atoms in an organic molecule are completely replaced by fluorine atoms.

[0011] In an optional embodiment, the silane coupling agent includes perfluorooctyltriethoxysilane.

[0012] The CAS number of perfluorooctyltriethoxysilane is 51851-37-7.

[0013] In an optional embodiment, the filler includes one or more of silicon dioxide, carbon black, graphene and carbon nanotubes; and the particle size of the filler is 20 nm-50 nm.

[0014] In an optional embodiment, the preparation method of the modified filler comprises the following steps:

[0015] The silane coupling agent and the filler are mixed and reacted to obtain a modified filler.

[0016] In an optional embodiment, the mass ratio of the silane coupling agent to the filler is (2-4):100.

[0017] In an optional embodiment, the reaction temperature is 60° C.-80° C.; the reaction time is 2 h-4 h; the reaction is carried out under a protective atmosphere; and the protective atmosphere includes nitrogen or argon.

[0018] In an optional embodiment, after the reaction is completed, the obtained sample is washed and dried in sequence to obtain a modified filler.

[0019] In an optional embodiment, washing and drying can be accomplished by conventional techniques in the art; the washing reagent is ethanol, and the drying method is vacuum drying.

[0020] In an alternative embodiment, the cross-linking agent comprises triallyl isocyanurate.

[0021] The schematic diagram of the working principle of the modified filler in the present invention is as follows: Figure 1 shown. Figure 1 In the formula, X is a perfluorinated chain segment, Y is a functional group on the surface of the organic matrix (rubber), and Z is a hydroxyl group on the surface of the filler. Figure 1 It can be seen that the silane coupling agent containing a perfluorinated segment generates a silanol group through its bifunctional structure (one end contains a hydrolyzable alkoxy group, and the other end contains an active functional group (perfluorinated segment) compatible with the organic matrix (rubber)). After hydrolysis (hydrolysis occurs after encountering moisture in the air), it condenses with the hydroxyl group on the filler surface to form a stable Si-O-Si covalent bond. At the same time, it is tightly combined with the organic matrix (rubber) on the other side through chemical bonding or physical action (forming hydrogen bonds), thereby constructing a "chemical bridge" between the modified filler and the rubber matrix.

[0022] The present invention also provides a method for preparing the modified perfluoroether rubber, comprising the following steps:

[0023] (1) mixing the raw perfluoroether rubber and the modified filler to obtain a masterbatch;

[0024] (2) Mixing the masterbatch and the cross-linking agent to obtain the modified perfluoroether rubber.

[0025] In an optional embodiment, perfluoroether rubber raw rubber and modified filler are subjected to internal mixing to obtain a masterbatch, which includes: setting the temperature of the internal mixer to 105-115°C, and after the temperature stabilizes, adding the perfluoroether rubber raw rubber to the internal mixing chamber and mixing for 140-160s until the torque stabilizes, and then adding the modified filler to the internal mixing chamber through the feeding port, lowering the upper plug and mixing for 2min-10min to obtain the masterbatch.

[0026] In an optional embodiment, the masterbatch obtained in step (1) is post-processed before step (2), and the post-processing includes: degumming the masterbatch, setting the degumming temperature to 130°C-150°C, placing it on a mixing mill with a roller spacing of 0.1mm-0.5mm after degumming, making triangular packages 6 times, and finally adjusting the roller spacing of the mixing mill to 1.5mm, rolling out sheets, and parking for more than 12 hours for standby use.

[0027] In an optional embodiment, the masterbatch and the cross-linking agent are mixed to obtain the modified perfluoroether rubber, which includes: passing cooling water through the open mill, adjusting the roller spacing of the open mill to 1.0mm-1.5mm, putting the post-treated masterbatch into the open mill, softening it and mixing it evenly through the shearing action of the rollers, then adding the cross-linking agent for mixing, cutting the rubber left and right and turning it over, after uniform mixing, adjusting the roller spacing of the open mill to 0.08mm-0.12mm, thinning it 5-10 times, continuing to adjust the roller spacing of the open mill to 1.5mm, and rolling out sheets to obtain the modified perfluoroether rubber, which is parked for more than 12 hours for standby use.

[0028] The present invention also provides application of the modified perfluoroether rubber in semiconductor equipment sealing components.

[0029] In an optional embodiment, the semiconductor device seal includes an O-ring seal, a valve seat seal, or a reaction chamber seal.

[0030] In an optional embodiment, the application method includes: placing the modified perfluoroether rubber into a mold, then placing the mold into a flat vulcanizer for one-stage compression vulcanization to obtain a one-stage vulcanized product, leaving the one-stage vulcanized product for 12 hours, and then placing it in an oven for two-stage vulcanization to obtain a sealing product.

[0031] In an optional embodiment, the vulcanization temperature of the one-stage compression vulcanization is 160° C.-180° C., the vulcanization time is 15 min-25 min, and the vulcanization pressure is 10 MPa-20 MPa.

[0032] In an optional embodiment, the temperature rising process of the second-stage vulcanization includes: raising the oven temperature from 20°C-30°C to 190°C-210°C at a heating rate of 1°C / min-5°C / min, maintaining at this temperature for 7h-9h, and then raising the temperature to 280°C-300°C at a heating rate of 8°C / h-12°C / h, and maintaining at this temperature for 23h-25h.

[0033] In an optional embodiment, after the second stage vulcanization is completed, the temperature is naturally cooled to 20° C.-30° C. to obtain a sealed product.

[0034] The technical solution of the present invention has the following advantages:

[0035] The present invention provides a modified perfluoroether rubber, comprising the following components in parts by weight: 100 parts of perfluoroether rubber raw rubber, 20-30 parts of a modified filler, and 1-2 parts of a crosslinking agent; wherein the modified filler is a filler modified by a silane coupling agent, and the silane coupling agent is a silane coupling agent containing a perfluoro chain segment.

[0036] The present invention utilizes a filler modified with a silane coupling agent containing perfluorinated segments. The molecular structure of the silane coupling agent contains perfluorinated segments, similar to the perfluorinated backbone structure of perfluoroether rubber (PFEE), resulting in good compatibility between the modified filler and the rubber matrix, thereby reducing interfacial defects. The filler modified with the silane coupling agent containing perfluorinated segments significantly enhances the bonding strength between the rubber matrix and the filler, enhancing the mechanical properties and high-temperature resistance of the seal, making it particularly suitable for use as a seal in semiconductor production processes and improving product reliability and service life.

[0037] The silane coupling agent containing a perfluorinated chain segment generates a silanol group through its bifunctional structure (one end contains a hydrolyzable alkoxy group, and the other end contains an active functional group (perfluorinated chain segment) compatible with the organic matrix (rubber)). After hydrolysis, it condenses with the hydroxyl group on the filler surface to form a stable Si-O-Si covalent bond. At the same time, it is tightly bonded to the organic matrix (rubber) on the other side through chemical bonding or physical action (forming hydrogen bonds), thereby constructing a "chemical bridge" between the modified filler and the rubber matrix, effectively enhancing the interfacial bonding force, improving the filler dispersion, and enhancing the mechanical properties of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1Schematic diagram of the working principle of the modified filler in the present invention. DETAILED DESCRIPTION

[0040] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0041] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0042] Example 1

[0043] This embodiment provides a modified perfluoroether rubber, comprising the following components in parts by weight:

[0044] 100 parts of perfluoroether rubber (purchased from SOLVAY Group), 20 parts of modified filler, and 1.5 parts of cross-linking agent (triallyl isocyanurate).

[0045] Among them, the modified filler is silica modified with perfluorooctyltriethoxysilane, and the preparation method includes: mixing perfluorooctyltriethoxysilane and silica with a particle size of 35 nm (the mass ratio of perfluorooctyltriethoxysilane to silica is 3:100), reacting at 70°C for 3 hours under a nitrogen atmosphere, and after the reaction, washing the obtained sample with ethanol, and vacuum drying to obtain the modified filler.

[0046] This embodiment also provides a method for preparing the modified perfluoroether rubber, comprising the following steps:

[0047] Set the temperature of the internal mixer to 110℃. After the temperature stabilizes, add the perfluoroether rubber raw rubber into the internal mixing chamber and mix for 150s until the torque stabilizes. Then add the modified filler into the internal mixing chamber through the feeding port, lower the upper plug and mix for 5 minutes to obtain the masterbatch. Degumming the masterbatch, set the degumming temperature to 140℃, and place it on an open mill with a roller gap of 0.1mm after degumming. Make triangular packages 6 times with a thin pass, and finally adjust the roller gap of the open mill to 1.5mm. Roll out the sheet and park it for more than 12 hours for standby use.

[0048] Pass cooling water through the open mill, adjust the roller distance of the open mill to 1.5mm, put the above-mentioned spare masterbatch into the open mill, soften it and mix it evenly through the shearing action of the rollers, then add the cross-linking agent for mixing, cut the rubber left and right and turn it over. After mixing evenly, adjust the roller distance of the open mill to 0.1mm, pass it through 6 times, continue to adjust the roller distance of the open mill to 1.5mm, and calender out sheets to obtain modified perfluoroether rubber. Park it for more than 12 hours and set aside.

[0049] Example 2

[0050] This embodiment provides a modified perfluoroether rubber, wherein the other conditions in Example 1 remain unchanged, and the weight fraction of the modified filler is changed to 25 parts.

[0051] This embodiment also provides a preparation method of the modified perfluoroether rubber, which is the same as that of Example 1.

[0052] Example 3

[0053] This embodiment provides a modified perfluoroether rubber, wherein other conditions in Example 1 remain unchanged, and the weight fraction of the modified filler is changed to 30 parts.

[0054] This embodiment also provides a preparation method of the modified perfluoroether rubber, which is the same as that of Example 1.

[0055] Comparative Example 1

[0056] This comparative example provides a perfluoroether rubber composition, in which the other conditions in Example 1 remain unchanged, and the modified filler is replaced by an unmodified filler, namely, silicon dioxide with a particle size of 35 nm.

[0057] This comparative example also provides a method for preparing the perfluoroether rubber composition, wherein the other conditions in Example 1 remain unchanged, and the modified filler is changed to a filler.

[0058] Comparative Example 2

[0059] This comparative example provides a perfluoroether rubber composition, in which the other conditions in Example 2 remain unchanged, and the modified filler is replaced by an unmodified filler, namely, silicon dioxide with a particle size of 35 nm.

[0060] This comparative example also provides a method for preparing the perfluoroether rubber composition, wherein the other conditions in Example 2 remain unchanged, and the modified filler is changed to a filler.

[0061] Comparative Example 3

[0062] This comparative example provides a perfluoroether rubber composition, in which the other conditions in Example 3 remain unchanged, and the modified filler is replaced by an unmodified filler, namely, silicon dioxide with a particle size of 35 nm.

[0063] This comparative example also provides a method for preparing the perfluoroether rubber composition, wherein the other conditions in Example 3 remain unchanged, and the modified filler is changed to a filler.

[0064] The modified perfluoroether rubber prepared in Examples 1-3 and the perfluoroether rubber compositions prepared in Comparative Examples 1-3 were prepared into O-rings. Taking the modified perfluoroether rubber prepared in Example 1 as an example, the preparation method was as follows: the modified perfluoroether rubber was placed in a mold, and the mold was then placed in a flat vulcanizer for a stage of compression vulcanization (vulcanization temperature of 170°C, vulcanization time of 20min, and vulcanization pressure of 15MPa) to obtain a first-stage vulcanized product. After the first-stage vulcanized product was parked for 12h, it was placed in an oven for a second-stage vulcanization (the oven temperature was raised from 25°C to 200°C at a heating rate of 3°C / min, maintained at 200°C for 8h, and then heated to 290°C at a heating rate of 10°C / h, and maintained at 290°C for 24h), and naturally cooled to 25°C to obtain an O-ring.

[0065] The above O-type sealing rings were subjected to performance tests, and the performance test results of different O-type sealing rings were obtained, as shown in Table 1.

[0066] Table 1 Performance test results of different O-rings

[0067]

[0068] Table 1 shows a plasma resistance test method that includes subjecting the O-rings prepared in Examples 1-3 and Comparative Examples 1-3 to plasma treatment for 60 minutes in an O2 plasma atmosphere at a temperature of 150°C, a power of 500W, a vacuum of 1 Torr, and a gas flow rate of 500 sccm. The mass loss rate is then measured. Table 1 shows that the modified perfluoroether rubber prepared in the present invention exhibits significantly improved bonding between the modified filler and the perfluoroether rubber matrix, thereby enhancing the mechanical properties, high-temperature resistance, and plasma resistance of the O-ring. The O-ring is particularly suitable for use as a seal in semiconductor production processes, improving product reliability and service life.

[0069] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A modified perfluoroether rubber, characterized in that: The composition comprises the following components in parts by weight: 100 parts of perfluoroether rubber, 20-30 parts of modified filler and 1-2 parts of cross-linking agent; The modified filler is a filler modified by a silane coupling agent, and the silane coupling agent is a silane coupling agent containing a perfluorinated segment.

2. The modified perfluoroether rubber according to claim 1, characterized in that The silane coupling agent includes perfluorooctyltriethoxysilane.

3. The modified perfluoroether rubber according to claim 1 or 2, characterized in that The filler includes one or more of silicon dioxide, carbon black, graphene and carbon nanotubes; Optionally, the particle size of the filler is 20nm-50nm.

4. The modified perfluoroether rubber according to claim 1 or 2, characterized in that The preparation method of the modified filler comprises the following steps: The silane coupling agent and the filler are mixed and reacted to obtain a modified filler.

5. The modified perfluoroether rubber according to claim 4, characterized in that The mass ratio of the silane coupling agent to the filler is (2-4):

100.

6. The modified perfluoroether rubber according to claim 4, characterized in that At least one of the following conditions is met: (1) The reaction temperature is 60°C-80°C; (2) The reaction time is 2h-4h; (3) the reaction is carried out under a protective atmosphere; Optionally, the protective atmosphere includes nitrogen or argon.

7. The modified perfluoroether rubber according to claim 1, characterized in that The cross-linking agent includes triallyl isocyanurate.

8. The method for preparing the modified perfluoroether rubber according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing the raw perfluoroether rubber and the modified filler to obtain a masterbatch; (2) Mixing the masterbatch and the cross-linking agent to obtain the modified perfluoroether rubber.

9. Use of the modified perfluoroether rubber according to any one of claims 1 to 7 in semiconductor equipment seals.

10. The use according to claim 9, characterized in that The semiconductor equipment seal includes an O-ring seal, a valve seat seal or a reaction chamber seal.

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