A preparation process of perfluoroether rubber compound

Abstract

The invention discloses a preparation process of a perfluoroether rubber compound, relates to the technical field of polymer materials, and aims to improve the low temperature resistance, medium resistance and process stability of the perfluoroether rubber compound by optimizing the formula composition and the preparation process. Specifically, the present invention introduces specific additives such as 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, and adopts ultrasonic assisted mixing and optimized vulcanization process. Through comparative experiments, the present invention reveals the specific effects of different ingredients and preparation conditions on the performance of perfluoroether rubber compound, and optimizes the formula and preparation process accordingly. Experimental results show that the optimized perfluoroether rubber compound shows significant improvement in low temperature resistance, medium resistance and process stability.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a preparation process of a perfluoroether rubber compound. Background Art

[0002] As a high-performance elastomer, perfluoroether rubber has been widely used in aerospace, petrochemical, automotive industry, medical equipment and other fields due to its excellent chemical corrosion resistance, high temperature resistance, low temperature resistance and excellent mechanical properties. However, the preparation process of perfluoroether rubber is complicated, and its performance is easily affected by the formulation ingredients and preparation conditions. Traditional preparation processes often make it difficult to ensure production efficiency while taking into account the low temperature resistance, medium resistance and process stability of the compounded rubber.

[0003] In terms of formulation, the low temperature resistance and medium resistance of perfluoroether rubber often rely on specific additives, such as plasticizers, crosslinking agents, etc. However, the addition of these additives may affect the processing performance of the compound and the physical properties of the final product. Therefore, how to optimize the formulation ingredients while ensuring the performance of the compound has become an urgent problem to be solved.

[0004] In terms of preparation technology, traditional mixing and vulcanization processes often have problems such as high energy consumption, low production efficiency, and unstable product quality. In particular, how to ensure the uniform dispersion of various components in the rubber matrix during the mixing process and how to achieve a good cross-linking structure during the vulcanization process are key factors affecting the performance of perfluoroether rubber. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a process for preparing a perfluoroether rubber compound, which solves the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention is implemented by the following technical scheme: A preparation process of perfluoroether rubber compound comprises the following steps:

[0007] S1. Weigh the perfluoroether rubber, liquid fluoroelastomer, special type crosslinking agent, accelerator, nano-scale inorganic filler and processing aid according to mass fraction;

[0008] S2, putting the perfluoroether rubber and liquid fluoroelastomer into an internal mixer for plasticization;

[0009] S3, pre-mix the special type cross-linking agent, accelerator, nano-scale inorganic filler and processing aid, and gradually add them into the internal mixer to mix them evenly with the rubber;

[0010] S4. During the mixing process, an ultrasonic generator is used to emit ultrasonic waves into the internal mixer, and the energy of ultrasonic waves can make the mixing more uniform;

[0011] S5, aging the mixed rubber for a period of time, and then repeatedly re-refining it for standby use;

[0012] S6, adding the re-refined rubber compound to a vulcanization device for vulcanization treatment;

[0013] S7. After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

[0014] Furthermore, in step S1, the mass proportions of the components are 50-100 parts of perfluoroether rubber, 10-50 parts of liquid fluoroelastomer, 0.5-3 parts of special type cross-linking agent, 0.5-4 parts of accelerator, 1-30 parts of nano-scale inorganic filler and 1-3 parts of processing aid.

[0015] Furthermore, the special type of cross-linking agent is a fluorinated cross-linking agent containing multiple functional groups.

[0016] Furthermore, the multifunctional fluorinated crosslinking agent is 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane.

[0017] Furthermore, the accelerator is any one of sulfur, dibenzothiazole disulfide and sodium N,N-dimethyldithiocarbamate or a mixture thereof.

[0018] Furthermore, the nano-scale inorganic filler is any one of nano-silicon dioxide and nano-aluminum oxide or a mixture thereof.

[0019] Furthermore, the processing aid is an antioxidant, and any one or a mixture of diaryl secondary amines, p-phenylenediamine derivatives, and condensates of aldehyde amines and ketone amines is used.

[0020] Furthermore, in step S2, the mixing time of the internal mixer is 10-12 minutes and the temperature is 120-140°C.

[0021] Furthermore, in step S5, the aging time is not less than 5 days, and the refining is repeated 3-5 times.

[0022] Furthermore, in step S6, the vulcanization equipment is divided into a first-stage vulcanization and a second-stage vulcanization, the temperature of the first-stage vulcanization is 120-150°C, and the temperature of the second-stage vulcanization is 200-230°C.

[0023] The present invention provides a preparation process of a perfluoroether rubber compound. Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Improve low temperature resistance: By introducing specific additives such as 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, the low temperature resistance of perfluoroether rubber compound is significantly improved, so that it can still maintain good toughness in extremely low temperature environment.

[0025] 2. Enhanced media resistance: By optimizing the formula ingredients, especially selecting additives and fillers with excellent chemical stability, the media resistance of perfluoroether rubber compound is significantly improved, so that it can remain stable in various corrosive media.

[0026] 3. Improve process stability: By improving the preparation process, such as using an ultrasonic generator to enhance mixing uniformity and optimizing vulcanization conditions, the process stability of perfluoroether rubber compound has been significantly improved, and the energy consumption and scrap rate in the production process have been reduced.

[0027] 4. Optimize the formula and preparation process: Through comparative experiments, the specific effects of different ingredients and preparation conditions on the performance of perfluoroether rubber compounds are revealed, providing a scientific basis for further optimizing the formula and preparation process. DETAILED DESCRIPTION

[0028] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0029] Example 1

[0030] A preparation process of a perfluoroether rubber compound comprises the following steps:

[0031] S1. Weigh 50 parts of perfluoroether rubber, 10 parts of liquid fluoroelastomer, 0.5 parts of 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 0.5 parts of accelerator, 1 part of nano-scale inorganic filler and 1 part of processing aid by mass;

[0032] S2, putting the perfluoroether rubber and liquid fluoroelastomer into an internal mixer for plasticization for 10 minutes at a temperature of 120°C;

[0033] S3, pre-mix 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, accelerator, nano-scale inorganic filler and processing aid, and gradually add them into an internal mixer to mix them evenly with the rubber;

[0034] S4. During the mixing process, an ultrasonic generator is used to emit ultrasonic waves into the internal mixer, and the energy of ultrasonic waves can make the mixing more uniform;

[0035] S5, after the mixed rubber is aged for more than 5 days, it is repeatedly re-refined 3-5 times and then set aside;

[0036] S6, adding the re-refined rubber compound to a vulcanization device for vulcanization treatment, the vulcanization device is divided into a first-stage vulcanization and a second-stage vulcanization, the first-stage vulcanization temperature is 120°C, and the second-stage vulcanization temperature is 200°C;

[0037] S7. After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

[0038] The accelerator is sulfur.

[0039] The nano-scale inorganic filler adopts nano-silicon dioxide.

[0040] The processing aid is an antioxidant, and a diaryl secondary amine is used.

[0041] Example 2

[0042] A preparation process of a perfluoroether rubber compound comprises the following steps:

[0043] S1. Weigh 80 parts of perfluoroether rubber, 40 parts of liquid fluoroelastomer, 2.5 parts of 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 3 parts of accelerator, 25 parts of nano-scale inorganic filler and 2 parts of processing aid by mass;

[0044] S2, putting the perfluoroether rubber and liquid fluoroelastomer into an internal mixer for plasticization for 11 minutes at a temperature of 130°C;

[0045] S3, pre-mix 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, accelerator, nano-scale inorganic filler and processing aid, and gradually add them into an internal mixer to mix them evenly with the rubber;

[0046] S4. During the mixing process, an ultrasonic generator is used to emit ultrasonic waves into the internal mixer, and the energy of ultrasonic waves can make the mixing more uniform;

[0047] S5, after the mixed rubber is aged for more than 5 days, it is repeatedly re-refined 3-5 times and then set aside;

[0048] S6, adding the re-refined rubber compound to a vulcanization device for vulcanization treatment, the vulcanization device is divided into a first-stage vulcanization and a second-stage vulcanization, the first-stage vulcanization temperature is 140°C, and the second-stage vulcanization temperature is 220°C;

[0049] S7. After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

[0050] The accelerator is dibenzothiazole disulfide.

[0051] The nano-scale inorganic filler adopts nano-alumina.

[0052] The processing aid is an antioxidant, and a p-phenylenediamine derivative is used.

[0053] Example 3

[0054] A preparation process of a perfluoroether rubber compound comprises the following steps:

[0055] S1. Weigh 100 parts of perfluoroether rubber, 50 parts of liquid fluoroelastomer, 3 parts of 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 4 parts of accelerator, 30 parts of nano-scale inorganic filler and 3 parts of processing aid by mass;

[0056] S2, putting the perfluoroether rubber and liquid fluoroelastomer into an internal mixer for plasticization for 12 minutes at a temperature of 140°C;

[0057] S3, pre-mix 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, accelerator, nano-scale inorganic filler and processing aid, and gradually add them into an internal mixer to mix them evenly with the rubber;

[0058] S4. During the mixing process, an ultrasonic generator is used to emit ultrasonic waves into the internal mixer, and the energy of ultrasonic waves can make the mixing more uniform;

[0059] S5, after the mixed rubber is aged for more than 5 days, it is repeatedly re-refined 3-5 times and then set aside;

[0060] S6, adding the re-refined rubber compound to a vulcanization device for vulcanization treatment, the vulcanization device is divided into a first-stage vulcanization and a second-stage vulcanization, the first-stage vulcanization temperature is 150° C., and the second-stage vulcanization temperature is 230° C.;

[0061] S7. After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

[0062] The accelerator is a mixture of sulfur, dibenzothiazole disulfide and sodium N,N-dimethyldithiocarbamate, with a mixing ratio of 1:1:2.

[0063] The nano-scale inorganic filler is a mixture of nano-silicon dioxide and nano-alumina, with a mixing ratio of 1:1.

[0064] The processing aid is an antioxidant, which is a mixture of diaryl secondary amine, p-phenylenediamine derivative, and aldehyde amine and ketone amine condensate, and the mixing ratio is 1:1:1.

[0065] Experimental design

[0066] 1. Purpose of the experiment

[0067] The purpose of this experiment is to compare different preparation processes and formulas, and comprehensively evaluate their effects on the low temperature resistance, medium resistance and process stability of perfluoroether rubber compounds, so as to optimize the preparation process and formula and improve the comprehensive performance of perfluoroether rubber compounds.

[0068] 2. Experimental Materials and Equipment

[0069] Materials: perfluoroether rubber, liquid fluoroelastomer, 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, accelerators (sulfur, dibenzothiazole disulfide, sodium N,N-dimethyldithiocarbamate, etc.), nano-scale inorganic fillers (nano-silica, nano-alumina, etc.), processing aids (diaryl secondary amines, para-phenylenediamine derivatives, aldehyde amine and ketoamine condensates, etc.), and common inorganic fillers (such as calcium carbonate).

[0070] Equipment: internal mixer, ultrasonic generator, vulcanization equipment, low temperature brittleness tester, immersion test device, rheological properties tester, etc.

[0071] 3. Experimental groups and formulations

[0072] A. Example group:

[0073] Example 1: Weigh 50 parts of perfluoroether rubber, 10 parts of liquid fluoroelastomer, 0.5 parts of 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 0.5 parts of sulfur accelerator, 1 part of nano-silica filler and 1 part of diaryl secondary amine processing aid by mass.

[0074] Example 2: Weigh 80 parts of perfluoroether rubber, 40 parts of liquid fluoroelastomer, 2.5 parts of 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 3 parts of dibenzothiazole disulfide accelerator, 25 parts of nano-alumina filler and 2 parts of p-phenylenediamine derivative processing aid by mass.

[0075] Example 3: Weigh 100 parts of perfluoroether rubber, 50 parts of liquid fluoroelastomer, 3 parts of 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, 4 parts of sulfur / dibenzothiazole disulfide / sodium N,N-dimethyldithiocarbamate mixed accelerator (1:1:2 ratio), 30 parts of nano-silica / nano-alumina mixed filler (1:1 ratio) and 3 parts of diaryl secondary amine / p-phenylenediamine derivative / aldehyde amine and ketoamine condensate mixed processing aid (1:1:1 ratio) by mass.

[0076] B. Comparative Example Group:

[0077] Comparative Example 1: A similar formulation to that of Example 1 was used, but 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane was omitted.

[0078] Comparative Example 2: A similar formulation to that of Example 2 was used, but ordinary inorganic filler (calcium carbonate) was used instead of the nano-scale inorganic filler.

[0079] Comparative Example 3: A similar formulation to that of Example 3 was used, but the accelerator was changed to sulfur alone.

[0080] 4. Preparation process

[0081] The perfluoroether rubber and liquid fluoroelastomer are put into an internal mixer for plasticization. The time and temperature are adjusted according to the specific requirements of the examples and comparative examples.

[0082] The other ingredients (1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, accelerator, nano-scale inorganic filler, processing aid) are mixed uniformly in advance, and gradually added into the internal mixer to be uniformly mixed with the rubber.

[0083] During the mixing process, an ultrasonic generator was used to emit ultrasonic waves into the internal mixer to enhance the mixing uniformity.

[0084] After the mixed rubber is aged for more than 5 days, it is repeatedly re-mixed 3-5 times before use.

[0085] The re-milled rubber mix is ​​added to a vulcanization device for vulcanization treatment. The vulcanization device is divided into a first-stage vulcanization and a second-stage vulcanization. The temperature is adjusted according to the specific requirements of the embodiment and the comparative example.

[0086] After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

[0087] V. Experimental Results

[0088]

[0089]

[0090] VI. Conclusion

[0091] 1. Low temperature resistance:

[0092] After omitting 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane in Comparative Example 1, the low temperature resistance decreased significantly, indicating that this component plays an important role in improving the low temperature toughness of the rubber compound.

[0093] After ordinary inorganic fillers were used instead of nano-scale inorganic fillers in Comparative Example 2, the low-temperature resistance was also reduced, but the reduction was less than that in Comparative Example 1, indicating that the nano-scale inorganic fillers have a certain contribution to the low-temperature resistance, but not as significant as 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane.

[0094] After the type of accelerator was changed in Comparative Example 3, the low temperature resistance decreased slightly, but was still better than Comparative Examples 1 and 2, indicating that the type of accelerator also has a certain effect on the low temperature resistance, but not as significant as other ingredients.

[0095] 2. Medium resistance performance:

[0096] After omitting 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane in Comparative Example 1, the media resistance performance was significantly reduced, indicating that this component helps to enhance the chemical stability of the rubber compound.

[0097] After using common inorganic fillers in Comparative Example 2, the medium resistance performance is also reduced, but the reduction is less than that in Comparative Example 1, indicating that the nano-scale inorganic fillers have a certain contribution to the medium resistance performance.

[0098] After the type of accelerator was changed in Comparative Example 3, the medium resistance performance was slightly improved, but still lower than that of Example 3, indicating that the effect of the accelerator type on the medium resistance performance was relatively small.

[0099] 3. Process stability:

[0100] The process stability of the three comparative examples is slightly lower than that of the corresponding embodiments, which shows that the formula and preparation process in the embodiments have more advantages in improving process stability.

[0101] Among them, the process stability of Comparative Example 1 decreased most significantly, which may be due to the omission of the key component 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane.

Claims

1. A process for preparing a perfluoroether rubber compound, characterized in that: The steps include: S1. Weigh the perfluoroether rubber, liquid fluoroelastomer, special type crosslinking agent, accelerator, nano-scale inorganic filler and processing aid according to mass fraction; S2, putting the perfluoroether rubber and liquid fluoroelastomer into an internal mixer for plasticization; S3, pre-mix the special type cross-linking agent, accelerator, nano-scale inorganic filler and processing aid, and gradually add them into the internal mixer to mix them evenly with the rubber; S4. During the mixing process, an ultrasonic generator is used to emit ultrasonic waves into the internal mixer, and the energy of ultrasonic waves can make the mixing more uniform; S5, aging the mixed rubber for a period of time, and then repeatedly re-refining it for standby use; S6, adding the re-refined rubber compound to a vulcanization device for vulcanization treatment; S7. After vulcanization, the mixture is allowed to stand at room temperature to obtain a perfluoroether rubber compound.

2. A process for preparing a perfluoroether rubber compound according to claim 1, characterized in that: In step S1, the mass proportions of the components are 50-100 parts of perfluoroether rubber, 10-50 parts of liquid fluoroelastomer, 0.5-3 parts of special type crosslinking agent, 0.5-4 parts of accelerator, 1-30 parts of nano-scale inorganic filler and 1-3 parts of processing aid.

3. A process for preparing a perfluoroether rubber compound according to claim 1 or 2, characterized in that: The special type of cross-linking agent is a fluorinated cross-linking agent containing multiple functional groups.

4. A process for preparing a perfluoroether rubber compound according to claim 3, characterized in that: The multifunctional fluorinated crosslinking agent is 1,6-di(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane.

5. A process for preparing a perfluoroether rubber compound according to claim 1 or 2, characterized in that: The accelerator is any one of sulfur, dibenzothiazole disulfide and sodium N,N-dimethyldithiocarbamate or a mixture thereof.

6. A process for preparing a perfluoroether rubber compound according to claim 1 or 2, characterized in that: The nano-scale inorganic filler is any one of nano-silicon dioxide and nano-aluminum oxide or a mixture thereof.

7. A process for preparing a perfluoroether rubber compound according to claim 1 or 2, characterized in that: The processing aid is an antioxidant, and is any one or a mixture of diaryl secondary amines, p-phenylenediamine derivatives, and aldehyde amine and ketone amine condensates.

8. The process for preparing a perfluoroether rubber compound according to claim 1, characterized in that: In step S2, the mixing time of the internal mixer is 10-12 minutes and the temperature is 120-140°C.

9. A process for preparing a perfluoroether rubber compound according to claim 1, characterized in that: In step S5, the aging time is not less than 5 days, and the refining is repeated 3-5 times.

10. The process for preparing a perfluoroether rubber compound according to claim 1, characterized in that: In step S6, the vulcanization equipment is divided into one-stage vulcanization and two-stage vulcanization, the temperature of the one-stage vulcanization is 120-150°C, and the temperature of the two-stage vulcanization is 200-230°C.

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