A low-temperature-resistant wear-resistant thermoplastic sealing material, a preparation method and application thereof

Abstract

The application belongs to the technical field of sealing materials, and particularly relates to a low-temperature-resistant and wear-resistant thermoplastic sealing material, a preparation method and application thereof, and the preparation method comprises the following steps: mixing polyolefin elastomer, long carbon chain nylon elastomer, a compatibilizer, an optional auxiliary crosslinking agent, a lubricant and optional other auxiliaries to obtain a blend; then, the obtained blend is extruded and granulated by a double-screw extruder to obtain a blend master batch; the blend master batch is mixed with an optional crosslinking agent, and then dynamic vulcanization is performed on the blend master batch by the double-screw extruder to obtain thermoplastic sealing material particles. The obtained sealing material has excellent mechanical properties, low-temperature resistance and wear resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealing materials, and particularly relates to a low-temperature-resistant and wear-resistant thermoplastic sealing material and a preparation method and application thereof. BACKGROUND

[0002] Generally, the thermoplastic sealing material takes PP / EPDM (ethylene propylene diene rubber) as a base material; however, the thermoplastic sealing material taking PP / EPDM as the base material has poor wear resistance of the sealing strip due to a large friction coefficient and small cohesion of the material. Especially when it is used as a sealing strip for a guide groove of a vehicle window glass, the sealing strip surface needs to have very good wear resistance due to the long-term up-and-down movement of the vehicle window glass to repeatedly rub the surface of the sealing strip.

[0003] The conventional vulcanized rubber sealing strip usually solves the problem of poor wear resistance by spraying a wear-resistant coating on the surface of the rubber sealing strip after the rubber sealing strip is formed, but inevitably increases the production process.

[0004] In addition, the thermoplastic sealing material taking PP / EPDM as the base material has poor low-temperature resistance, and the material becomes hard and brittle in a low-temperature environment, which causes sealing failure and even product damage.

[0005] Therefore, how to develop a sealing material with excellent low-temperature resistance and wear resistance is a subject to be further studied. SUMMARY

[0006] In order to solve the above problems existing in the prior art, the purpose of the present application is to provide a low-temperature-resistant and wear-resistant thermoplastic sealing material and a preparation method and application thereof, and the obtained sealing material has excellent mechanical properties, low-temperature resistance and wear resistance.

[0007] In order to achieve the above purpose, the present application provides the following technical scheme:

[0008] In a first aspect, a low-temperature-resistant and wear-resistant thermoplastic sealing material is provided, which is a product prepared by processing a blend and a crosslinking agent; wherein,

[0009] The blend comprises the following components in parts by weight:

[0010] Polyolefin elastomer, 10-40 parts, for example, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts;

[0011] Long-chain carbon nylon elastomer, 60-90 parts; for example, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts;

[0012] The blend further comprises the following components in parts by weight, based on the sum of the parts by weight of the polyolefin elastomer and the long carbon chain nylon elastomer being 100 parts:

[0013] compatibilizing agent, 1-10 parts, for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 8 parts;

[0014] co-agent, 0-3 parts, for example, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts;

[0015] lubricant, 2-6 parts, for example, 2.5 parts, 4 parts, 5 parts, 5.5 parts, preferably 3-5 parts,

[0016] other auxiliary agent, 0-10 parts, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 8 parts;

[0017] The amount of the crosslinking agent is 1-5 parts, for example, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 4 parts, 4.5 parts, based on the sum of the parts by weight of the polyolefin elastomer and the long carbon chain nylon elastomer in the blend being 100 parts.

[0018] In some embodiments of the thermoplastic sealing material provided herein, the polyolefin elastomer is selected from one or more of ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer.

[0019] The long carbon chain nylon elastomer, as one of high-end PA products, has outstanding dimensional stability, low-temperature flexibility, and chemical corrosion resistance, and also has excellent physical and mechanical properties, thermal stability, and wear resistance; however, it has the problem of poor resilience when used to prepare a sealing material. The present inventors have found that, by compounding the long carbon chain nylon elastomer with a polyolefin elastomer as a base resin of a sealing material, the resilience, mechanical properties, thermal stability, and wear resistance can be achieved.

[0020] In some embodiments, the long carbon chain nylon elastomer is selected from one or more of nylon 11, nylon 1012, nylon 1212, and nylon 12.

[0021] In some embodiments, the lubricant is selected from one or more of vinyltrimethylsilane, vinyltriethylsilane, vinylphenyldimethylsilane, and (1-fluorovinyl)methyldiphenylsilane. The siloxane with vinyl group is added to the base resin as a lubricant, and the purpose of its introduction is mainly to provide the material with durable wear resistance; the siloxane with vinyl group interacts with the crosslinking agent and the co-agent, and through the crosslinking action of peroxide, the siloxane group can be fixed on the polyolefin resin molecular chain, which can avoid the problem of loss of wear resistance caused by precipitation of the lubricant during processing and use of the product.

[0022] In some embodiments, the compatibilizer is a maleic anhydride grafted polymer.

[0023] In some embodiments, the maleic anhydride grafted polymer is selected from one or more of PE-G-MAH, PP-G-MAH, POE-G-MAH and SEBS-G-MAH.

[0024] In some embodiments, the crosslinking agent is selected from one or more of dicumyl peroxide, di-tert-butyl peroxide isopropyl benzene, 2,5-dimethyl-2,5 di-tert-butyl peroxide hexane and tert-butyl peroxy-2-ethylhexyl carbonate.

[0025] In some embodiments, the co-crosslinking agent is selected from one or more of trimethylolpropane trimethacrylate, triallyl isocyanurate and diallyl phthalate.

[0026] In some embodiments, the other auxiliary agent can be an additive commonly used in the art, such as an antioxidant, a colorant, a release agent, etc. which will not be described here.

[0027] According to the thermoplastic sealing material provided by the present application, in some embodiments, the brittle temperature of the thermoplastic sealing material is in the range of -41℃ to -65℃; for example, -42℃, -43℃, -44℃, -45℃, -46℃, -48℃, -50℃, -52℃, -54℃, -55℃, -58℃, -60℃, -62℃-64℃.

[0028] According to the thermoplastic sealing material provided by the present application, in some embodiments, the compression permanent deformation of the thermoplastic sealing material can be in the range of 15-25%, for example, 16%, 18%, 20%, 22%, 24%.

[0029] In a second aspect, a method for preparing the thermoplastic sealing material as described above is provided, which comprises the following steps:

[0030] S1, mixing the polyolefin elastomer, the long carbon chain nylon elastomer, the compatibilizer, the optional co-crosslinking agent, the lubricant and the optional other auxiliary agent to obtain a blend; and then extruding and granulating the obtained blend by a twin-screw extruder to obtain a blend master batch;

[0031] S2, mixing the blend master batch with the crosslinking agent, and then dynamically vulcanizing it by a twin-screw extruder to obtain the thermoplastic sealing material particles.

[0032] According to the preparation method provided by the present application, in some embodiments, the blending and extruding and granulating process of each component in step S1 can be a conventional operation in the art, which will not be described here.

[0033] In some embodiments, in the step S1, the operating temperature of the extruder can range from 160℃ to 200℃, and the main motor speed can range from 300 rpm to 600 rpm.

[0034] In a third aspect, the application provides the use of the thermoplastic sealing material as described above or the thermoplastic sealing material prepared by the preparation method as described above.

[0035] According to the use provided by the application, in some embodiments, the thermoplastic sealing material is processed into a sealing strip. For example, the thermoplastic sealing material particles are extruded to form a sealing strip with high wear resistance and low temperature resistance. The processing step of the thermoplastic sealing material and the process conditions can be conventional choices in the art, which will not be described here.

[0036] According to the use provided by the application, in some embodiments, the thermoplastic sealing material is applied in the fields of automobiles, ships, electricity, doors and windows.

[0037] Compared with the prior art, the technical scheme of the application has at least the following beneficial effects:

[0038] (1) The application selects polyolefin elastomer and long carbon chain nylon elastomer as the base resin of the sealing material, and adds a specific lubricant to the base resin, so that the sealing material produced by dynamic vulcanization has thermoplasticity, resilience, low temperature resistance, wear resistance and excellent aging resistance. By selecting long carbon chain nylon elastomer in the base resin of the sealing material, the wear resistance and low temperature resistance of the material can be effectively improved.

[0039] (2) The application uses siloxane substances with vinyl groups as lubricants, which can bridge with the base resin under the synergistic effect of crosslinking agents and co-crosslinking agents, thereby increasing the connection stability between the base resin and the siloxane, avoiding the loss of wear resistance caused by the precipitation of the lubricant during processing and product use. This not only effectively improves the long-term wear resistance of the material and prolongs the service life of the wear-resistant material, but also has little effect on the mechanical properties of the material, ensuring the high mechanical properties of the wear-resistant material. DETAILED DESCRIPTION

[0040] In order to enable a detailed understanding of the technical features and content of the application, the preferred embodiments of the application will be described in more detail below. Although the preferred embodiments of the application are described in the examples, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments described herein. If no specific conditions are indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used.

[0041] The sources of the reagents or raw materials used in the following examples and comparative examples are as follows, if the manufacturer of the reagents or raw materials is not specified, they are conventional products that can be purchased on the market.

[0042] Sources of raw materials:

[0043] Polyolefin elastomer, ethylene-octene copolymer (POE) Wansuper 5017 and Wansuper 5057, melt flow rate ≤5 g / min at 190℃, 2.16 kg;

[0044] Long carbon chain nylon elastomer, WANELITE 7211 and WANELITE 6011, nylon 12 elastomer with a melting point ≥160℃;

[0045] Compatibilizer, POE-G-MAH;

[0046] Lubricant, vinyltrimethylsilane, vinylphenyldimethylsilane;

[0047] Crosslinking agent, dicumyl peroxide;

[0048] Co-crosslinking agent, triallyl isocyanurate;

[0049] Other additives include: antioxidant 1010, black masterbatch (colorant);

[0050] The above raw materials are all conventional products on the market, unless otherwise specified.

[0051] Example 1:

[0052] The preparation method of the low-temperature resistant and wear-resistant thermoplastic sealing material comprises the following steps:

[0053] S1, preparing a mixed masterbatch by one-time blending: according to the formula shown in Table 1, the polyolefin elastomer, long carbon chain nylon elastomer, POE-G-MAH compatibilizer, co-crosslinking agent, lubricant and other additives are weighed and added to a high-speed mixer with a rotation speed of 40 rpm for stirring and mixing to obtain a blend; then the blend is added to a twin-screw extruder for extrusion granulation, the operating temperature of the extruder is 140℃-190℃, the main machine rotation speed is 300 rpm, and the extrusion granulation obtains a blended masterbatch;

[0054] S2, mixing the obtained blended masterbatch with the peroxide crosslinking agent weighed according to the formula shown in Table 1, and then adding the mixture to a twin-screw extruder with a temperature range of 160℃-200℃ and a main machine rotation speed of 600 rpm for dynamic vulcanization granulation to obtain thermoplastic sealing material particles.

[0055] Examples 2-6:

[0056] The thermoplastic sealing material of Examples 2 to 6 was prepared according to the procedure of Example 1, except that the types of components and their proportions were different, as shown in Table 1.

[0057] Table 1: Components and their amounts in the sealing material of each example

[0058]

[0059]

[0060] Note: In Table 1, the amount of each component is in parts by weight.

[0061] Comparative Example 1:

[0062] A commercially available ordinary sealing strip product was purchased, which was a sealing product processed by blending a formulation composition comprising the following components and their amounts:

[0063] The composition comprises the following components and their amounts:

[0064] EPDM, 30 parts,

[0065] paraffin oil, 30 parts,

[0066] PP, 40 parts;

[0067] Based on the sum of the weight parts of EPDM, paraffin oil and PP being 100 parts, the above formulation further comprises the following components in the following weight parts: phenolic resin crosslinking agent 2 parts, co-crosslinking agent 1 part, talc 5 parts, 1 part of antioxidant 1010, color master batch 2 parts.

[0068] Comparative Example 2:

[0069] The thermoplastic sealing material was prepared according to the procedure of Example 1, except that the long-chain carbon nylon elastomer in the formulation was replaced by PP with a similar melting point.

[0070] Comparative Example 3:

[0071] The thermoplastic sealing material was prepared according to the procedure of Example 1, except that no lubricant was added to the formulation.

[0072] Comparative Example 4:

[0073] The thermoplastic sealing material was prepared according to the procedure of Example 1, except that the amount of lubricant in the formulation was 1 part.

[0074] Comparative Example 5:

[0075] The thermoplastic sealing material was prepared according to the procedure of Example 1, except that the amount of lubricant in the formulation was 8 parts.

[0076] The sealing materials prepared in the above Examples 1-6 and Comparative Examples 1-5 were subjected to performance tests according to the test methods in Table 2 below. The test results are shown in Table 3 below.

[0077] Table 2 Test methods

[0078] Test item Test standard Hardness D GB / T 531.1 Tensile strength (MPa) GB / T 528 Elongation at break (%) GB / T 528 Tear strength (kN / m) GB / T 529 Abrasion grade (dry grinding) GB / T 21282 Brittleness temperature (℃) GB / T 15256 Compression set (%; test conditions: 23℃*72h*25%) GB / T 7759

[0079] Table 3

[0080]

[0081]

[0082] Comparing the test results of Examples 1-6 with those of Comparative Example 1, it can be seen that the sealing material prepared in the present application not only has more excellent comprehensive mechanical properties, wear resistance and low temperature resistance, but also has stronger compression deformation resistance.

[0083] In addition, comparing the test results of Example 1 with those of Comparative Examples 2-3, it can be seen that in the present application, the long carbon chain nylon elastomer and the vinyl siloxane are added at the same time, and under the synergistic effect of the two components, the comprehensive mechanical properties, long-lasting wear resistance and low temperature resistance of the material can be effectively improved, so that the obtained product has excellent comprehensive performance as a sealing material.

[0084] Comparing the test results of Example 1 with those of Comparative Examples 4-5, it can be seen that by selecting a suitable amount range of the lubricant, the present application can effectively improve the comprehensive mechanical properties, long-lasting wear resistance and low temperature resistance of the material, so that the obtained product has excellent comprehensive performance as a sealing material.

[0085] The above has described various embodiments of the present application, and the above description is exemplary and is not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the spirit of the present application.

Claims

1. A low-temperature resistant and wear-resistant thermoplastic sealing material, characterized in that, This sealing material is a product obtained by processing blends and crosslinking agents; wherein, The blend comprises the following components in parts by weight: Polyolefin elastomer, 10-40 parts Long-chain carbon nylon elastomer, 60-90 parts; The long-chain nylon elastomer is selected from one or more of nylon 11, nylon 1012, nylon 1212 and nylon 12; Based on a weight ratio of 100 parts for the polyolefin elastomer and the long-chain nylon elastomer, the blend further includes the following components in parts by weight: Compatibilizer, 1-10 parts Crosslinking agent, 0-3 parts Lubricant, 2-6 parts Other adjuvants, 0-10 parts; Based on the premise that the sum of the weight parts of polyolefin elastomer and long-chain nylon elastomer in the blend is 100 parts, the amount of the crosslinking agent is 1-5 parts; The lubricant is selected from one or more of vinyltrimethylsilane, vinyltriethylsilane, vinylphenyldimethylsilane, and (1-fluorovinyl)methyldiphenylsilane.

2. The thermoplastic sealing material according to claim 1, characterized in that, The polyolefin elastomer is selected from one or more of ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer.

3. The thermoplastic sealing material according to claim 1, characterized in that, The lubricant is present in 3-5 parts by weight.

4. The thermoplastic sealing material according to claim 1, characterized in that, The compatibilizer is a maleic anhydride graft polymer.

5. The thermoplastic sealing material according to claim 4, characterized in that, The maleic anhydride graft polymer is selected from one or more of PE-G-MAH, PP-G-MAH, POE-G-MAH and SEBS-G-MAH.

6. The thermoplastic sealing material according to any one of claims 1-5, characterized in that, The crosslinking agent is selected from one or more of dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide, and tert-butyl peroxide-2-ethylhexyl carbonate.

7. The thermoplastic sealing material according to any one of claims 1-5, characterized in that, The crosslinking agent is selected from one or more of trimethylolpropane trimethacrylate, triallyl isocyanurate, and diallyl phthalate.

8. The thermoplastic sealing material according to any one of claims 1-5, characterized in that, The brittle temperature of the thermoplastic sealing material is between -41°C and -65°C.

9. The method for preparing the thermoplastic sealing material according to any one of claims 1-8, characterized in that, The method includes the following steps: S1. Mix polyolefin elastomer, long-chain nylon elastomer, compatibilizer, optional crosslinking agent, lubricant and optional other additives to obtain a blend; then extrude and granulate the obtained blend using a twin-screw extruder to obtain blend masterbatch; S2. The blended masterbatch is mixed with a crosslinking agent and then dynamically vulcanized using a twin-screw extruder to obtain thermoplastic sealing material particles.

10. The application of the thermoplastic sealing material according to any one of claims 1-8 or the thermoplastic sealing material prepared by the preparation method according to claim 9, characterized in that, The thermoplastic sealing material is processed into sealing strips.

11. The application according to claim 10, characterized in that, The thermoplastic sealing material is applied in the automotive, shipbuilding, electrical, and door and window industries.

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