Sealing material and preparation method and application thereof
By preparing a sealing material with the synergistic effect of carbon black of a specific particle size and plasticizer, the problem of poor permeability resistance of low-temperature heat pump seals was solved, and the excellent permeability resistance and mechanical properties of the sealing material were maintained at low temperatures.
Patent Information
- Application Number
- CN202510940495.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-11-07
AI Technical Summary
Existing low-temperature heat pump seals have poor resistance to penetration by low-temperature refrigerants, which leads to an increase in the distance between molecular chain segments of the sealing material, resulting in bulges or delamination and a decrease in mechanical properties.
By preparing a sealing material, the synergistic effect of first carbon black, second carbon black and plasticizer with specific particle sizes is utilized. The preparation method includes mixing raw rubber, carbon black, plasticizer, antioxidant and zinc oxide, controlling the particle size and mass ratio, and improving the compatibility of the sealing material with refrigerant.
The prepared sealing material exhibits excellent resistance to low-temperature refrigerant permeability at low temperatures, avoiding bulging and delamination while maintaining good mechanical properties.
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Figure CN120904582A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of sealing, in particular to a sealing material and a preparation method and application thereof. BACKGROUND
[0002] As a kind of high-efficiency energy-saving device that makes full use of low-grade heat energy, heat pump is one of new energy technologies that are concerned in the world at present. At present, with the continuous development and progress of science and technology, the demand for high-temperature heating and large temperature difference heating is increasing day by day in the aspects of automobile low-temperature heating, building heating, industrial heating, etc., especially in the cold northern region, developing low-temperature heat pump technology suitable for large temperature difference is one of the main development directions of heat pump industry at present.
[0003] Low-temperature heat pump technology uses ultra-low temperature compressor and low-temperature refrigerant for heating, and the energy efficiency ratio of heating at low temperature (above-45℃) is 50%~80% higher than that of conventional heat pump. Low-temperature heat pump sealing element is a necessary component of low-temperature heat pump, and when the existing low-temperature heat pump sealing element contacts with low-temperature refrigerant, the low-temperature refrigerant is easy to penetrate into the inside of the sealing element, which leads to the increase of the distance between molecular chains of the sealing material, and causes the uniform or non-uniform expansion and bulging of the whole contact area or local area, forming a bulge or stratification, and the mechanical properties are also greatly reduced. Therefore, it is necessary to improve the penetration resistance of the sealing element to low-temperature refrigerant to ensure the normal operation of the low-temperature heat pump. Therefore, it is a technical problem that needs to be solved by those skilled in the art to provide a sealing material with good penetration resistance to low-temperature refrigerant. SUMMARY
[0004] In view of the deficiencies of the prior art, the present application provides a sealing material and a preparation method and application thereof, which solves the technical problem of poor penetration resistance of the existing sealing element to low-temperature refrigerant.
[0005] To achieve the above object, the present application is implemented by the following technical solutions:
[0006] In a first aspect, the present application provides a preparation method of a sealing material, comprising the following steps:
[0007] S1, mixing 100 parts by mass of raw rubber and 30-60 parts by mass of first carbon black with an average particle size of 40-50 nm for 60-130 seconds;
[0008] S2, adding 70-90 parts by mass of second carbon black with an average particle size of 200-500 nm, 5-30 parts by mass of plasticizer, 1-3 parts by mass of antioxidant and 2-5 parts by mass of zinc oxide, and fully mixing until it is bonded into a lump;
[0009] S3, adding 3-8 parts by mass of vulcanizing agent, mixing the temperature to 100-120℃ to remove the gum and preparing the sealing material.
[0010] The preparation method comprises a first carbon black with an average particle size of 40-50 nm, a second carbon black with an average particle size of 200-500 nm, and a plasticizer, wherein the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 30-60:70-90:5-30, and under the process conditions, the first carbon black, the second carbon black, and the plasticizer have a synergistic effect in improving the compatibility between the sealing material and the refrigerant, and the prepared sealing material has excellent low-temperature refrigerant permeation resistance.
[0011] Preferably, the raw rubber is selected from ethylene propylene diene rubber (EPDM).
[0012] Preferably, the first carbon black has an average particle size of 40 nm, the second carbon black has an average particle size of 200 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 6:7:3.
[0013] Preferably, the first carbon black has an average particle size of 45 nm, the second carbon black has an average particle size of 300 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 6:18:1.
[0014] Preferably, the first carbon black has an average particle size of 50 nm, the second carbon black has an average particle size of 500 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 10:16:3.
[0015] The particle size of the first carbon black, the particle size of the second carbon black, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer are controlled to make the prepared sealing material have excellent low-temperature refrigerant permeation resistance.
[0016] Preferably, the preparation method of the sealing material satisfies at least one of the following conditions:
[0017] The plasticizer is selected from hydrogenated paraffin oil;
[0018] The antioxidant is selected from 4,4'-bis(alpha,alpha-dimethylbenzyl) diphenylamine or 4,4'-di(phenylisopropyl) diphenylamine;
[0019] The zinc oxide is an indirect zinc oxide, which improves the reactivity;
[0020] The vulcanizing agent is selected from 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane and triallyl isocyanurate. The vulcanizing agent vulcanizes the raw rubber.
[0021] In a second aspect, the present application provides a sealing material prepared by the preparation method of the first aspect.
[0022] In a third aspect, the present application provides a use of the sealing material prepared by the preparation method of any one of the first aspect or the sealing material of the second aspect in the preparation of a low-temperature heat pump seal, the low-temperature heat pump seal including a sealing sheet, a sealing strip, an O-ring, or a composite gasket. BRIEF DESCRIPTION OF DRAWINGS
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.
[0024] Figure 1 is a flow chart of the preparation method of the sealing material in embodiment 1. DETAILED DESCRIPTION
[0025] In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0026] In order to better understand the above technical solutions, the above technical solutions will be described in detail in combination with the drawings in the specification and specific embodiments.
[0027] I. Preparation method
[0028] Embodiment 1
[0029] The present embodiment provides a preparation method of a sealing material, which comprises the following steps: Figure 1 , comprising the following steps:
[0030] S1, put 100 parts by mass of raw rubber EPDM into a mixing mill to break the rubber, then add 60 parts by mass of first carbon black with an average particle size of 40 nm, and mix for about 60 seconds;
[0031] S2, add 70 parts by mass of second carbon black with an average particle size of 200 nm, 30 parts by mass of paraffin oil plasticizer, 3 parts by mass of antioxidant 445, and 5 parts by mass of indirect zinc oxide, and mix sufficiently until the mixture is coagulated into a lump;
[0032] S3, add 8 parts by mass of vulcanizing agent double 25, and mix until the temperature reaches 120℃, and then discharge the rubber.
[0033] The uniformly mixed rubber is taken, preformed by open mill, and then added into a mold for vulcanization to form a sealing material test piece.
[0034] Example 2
[0035] The present example provides a sealing material preparation method, comprising the following steps:
[0036] S1, 100 parts by mass of raw rubber EPDM is put into a banbury mixer for breaking, then 30 parts by mass of first carbon black with an average particle size of 45 nm is added, and mixed for about 100 seconds;
[0037] S2, 90 parts by mass of second carbon black with an average particle size of 300 nm, 5 parts by mass of paraffin oil plasticizer, 1 part by mass of antioxidant KY405, and 2 parts by mass of indirect zinc oxide are added, and mixed until coagulation;
[0038] S3, 3 parts by mass of curing agent D25 is added, and the mixing temperature is raised to 120°C for discharging.
[0039] The uniformly mixed rubber is taken, preformed by open mill, and then added into a mold for vulcanization to form a sealing material test piece.
[0040] Example 3
[0041] The present example provides a sealing material preparation method, comprising the following steps:
[0042] S1, 100 parts by mass of raw rubber EPDM is put into a banbury mixer for breaking, then 30 parts by mass of first carbon black with an average particle size of 45 nm is added, and mixed for about 100 seconds;
[0043] S2, 80 parts by mass of second carbon black with an average particle size of 500 nm, 15 parts by mass of paraffin oil plasticizer, 2 parts by mass of antioxidant KY405, and 3 parts by mass of indirect zinc oxide are added, and mixed until coagulation;
[0044] S3, 5 parts by mass of curing agent D25 is added, and the mixing temperature is raised to 120°C for discharging.
[0045] The uniformly mixed rubber is taken, preformed by open mill, and then added into a mold for vulcanization to form a sealing material test piece.
[0046] Comparative Example 1
[0047] The difference between the present comparative example and Example 1 is that the first carbon black is not added, and 116 parts by mass of second carbon black and 44 parts by mass of plasticizer are added, and the rest is the same as Example 1.
[0048] Comparative Example 2
[0049] The present comparative example differs from Example 1 in that no second carbon black is added, 100 parts by mass of the first carbon black, and 60 parts by mass of the plasticizer are added, and the rest is the same as Example 1.
[0050] Comparative Example 3
[0051] The present comparative example differs from Example 1 in that no paraffin oil plasticizer is added, 61.5 parts by mass of the first carbon black, and 98.5 parts by mass of the second carbon black are added, and the rest is the same as Example 1.
[0052] II. Test Methods
[0053] 1. Hardness: tested according to GB / T 531.1.
[0054] 2. Tensile strength and elongation at break: tested according to GB / T 528.
[0055] 3. Compression set: tested according to GB / T 7759.1.
[0056] 4. Glass transition temperature: tested using DSC.
[0057] 5. Resistance to penetration of refrigerant and refrigeration oil mixture: tested according to GB / T 1690.
[0058] 5.1. Change in hardness: tested according to GB / T 531.1.
[0059] 5.2. Change rate of tensile strength: tested according to GB / T 528.
[0060] 5.3. Change rate of elongation at break: tested according to GB / T 528.
[0061] 5.4. Change rate of volume: tested according to GB / T 1690.
[0062] 5.5. Surface morphology of test piece: visually observed.
[0063] III. Test Results
[0064] The test results of the test pieces of the sealing material prepared in the examples and comparative examples are shown in Table 1.
[0065] Table 1. Test results of properties of sealing material prepared in examples and comparative examples
[0066]
[0067] As shown in Table 1, the sealing materials prepared in Examples 1-3 have no blistering and delamination on the surface of the test pieces, and the hardness, tensile strength and elongation at break are less reduced, and the volume is slightly increased after the test pieces are treated at 150℃ for 168 hours in the refrigerant and refrigerant oil mixed liquid atmosphere. Therefore, the sealing materials prepared in the present application have excellent resistance to low-temperature refrigerant permeation. The sealing materials prepared in Comparative Examples 1-3 have not only blistering or delamination on the surface of the test pieces, but also the hardness, tensile strength and elongation at break are greatly reduced, and the volume is greatly expanded after the test pieces are treated at 150℃ for 168 hours in the refrigerant and refrigerant oil mixed liquid atmosphere. It can be seen that the first carbon black with an average particle size of 40 nm, the second carbon black with an average particle size of 200 nm and the plasticizer have a synergistic effect in improving the resistance of the sealing material to refrigerant permeation. Under the synergistic effect, the sealing material prepared in the present application has excellent resistance to low-temperature refrigerant permeation, and the sealing material has good compatibility with the refrigerant.
[0068] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... " does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.
[0069] The above examples are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
[0070] The present application is described by the above examples to illustrate the detailed process flow of the present application, but the present application is not limited to the above detailed process flow, i.e. it does not mean that the present application must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.
Claims
1. A method for producing a sealing material, characterized by, The method comprises the following steps: S1, mixing 100 parts by mass of raw rubber and 30-60 parts by mass of first carbon black with an average particle size of 40-50 nm for 60-130 seconds; S2, adding 70-90 parts by mass of second carbon black with an average particle size of 200-500 nm, 5-30 parts by mass of plasticizer, 1-3 parts by mass of antioxidant, and 2-5 parts by mass of zinc oxide, and fully mixing until the mixture is coagulated into a lump; S3, adding 3-8 parts by mass of vulcanizing agent, and mixing at a temperature of 100-120 °C to remove the gum to obtain a sealing material.
2. The method for producing a sealing material according to claim 1, wherein The raw rubber is selected from ethylene-propylene-diene rubber.
3. The method of producing a sealing material according to claim 1, wherein The first carbon black has an average particle size of 40 nm, the second carbon black has an average particle size of 200 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 6:7:
3.
4. The method of producing a sealing material according to claim 1, wherein The first carbon black has an average particle size of 45 nm, the second carbon black has an average particle size of 300 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 6:18:
1.
5. The method of producing a sealing material according to claim 1, wherein The first carbon black has an average particle size of 50 nm, the second carbon black has an average particle size of 500 nm, and the mass ratio of the first carbon black, the second carbon black, and the plasticizer is 10:16:
3.
6. The method of producing a sealing material according to claim 1, wherein At least one of the following conditions is met: The plasticizer is selected from hydrogenated paraffin oil. The antioxidant is selected from 4,4'-bis(α,α-dimethylbenzyl) diphenylamine or 4,4'-di(phenylisopropyl) diphenylamine. The zinc oxide is indirect zinc oxide. The vulcanizing agent is selected from 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane and triallyl isocyanurate.
7. A sealing material, characterized by, Prepared by the method of claim 1.
8. Use of a sealing material prepared by the process according to any one of claims 1 to 6 or according to claim 7 for the production of a seal for a low-temperature heat pump, characterized in that The low temperature includes -50 °C-0 °C, and the sealing member includes a sealing sheet, a sealing strip, an O-ring, and a composite gasket.