Wear-resistant and weather-resistant film-coated sealing rubber strip and preparation process thereof

Abstract

The invention discloses a wear-resistant and weather-resistant film-coated sealing rubber strip. The sealing rubber strip comprises a hard part, a soft part and a weather-resistant part, the hard part serves as a framework of the sealing rubber strip and is integrally connected to one side of the soft part, and the weather-proof part evenly covers the surface of the soft part. The hard part is prepared from the following raw material components: high-polymerization PVC, a first plasticizer, a stabilizer and other auxiliaries; the soft part is prepared from the following raw material components: low-polymerization PVC, a second plasticizer, an elastic modifier and other auxiliaries; the weather-proof part is prepared from the following raw material components: low-polymerization PVC, a third plasticizer, modified graphene oxide and other auxiliaries; the hard part, the soft part and the weather-proof part are extruded and integrally formed through a co-extrusion mold. The wear-resistant and weather-resistant laminated sealing rubber strip provided by the invention has good weather resistance and wear resistance, and the preparation process of the wear-resistant and weather-resistant laminated sealing rubber strip can improve the weather resistance and wear resistance of the PVC sealing rubber strip.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation process of sealing strips, and particularly to a film-coated sealing strip with wear resistance and weather resistance and its preparation process. Background Art

[0002] In industrial fields such as automobiles, buildings, and electronics, as a key functional material, the performance of sealing strips directly affects the waterproof, sound insulation, heat insulation, and durability of equipment. A good sealing strip must have excellent anti-degradation properties such as resistance to sunlight ultraviolet aging, ozone aging, and heat-oxygen aging. At the same time, it should also have low compression set and creep properties, resistance to high and low temperatures, and rainwater resistance. In the processing technology, the rubber compound should also have characteristics such as easy extrusion, small shrinkage deformation, and good flexibility.

[0003] Currently, in the prior art, there are PVC sealing strips mainly composed of polyvinyl chloride (PVC) resin, added with plasticizers (such as DINP, DOP), stabilizers, lubricants, etc., and manufactured by an extrusion molding process. The existing PVC sealing strips are widely used in the sealing of doors and windows, etc. due to their low cost and high processing efficiency, which are suitable for large-scale production. However, the current PVC sealing strips have disadvantages such as insufficient mechanical strength, and their application in doors and windows is relatively limited. Summary of the Invention

[0004] The present application provides a film-coated sealing strip with wear resistance and weather resistance and its preparation process, which are used to improve the weather resistance and wear resistance of PVC sealing strips.

[0005] A film-coated sealing strip with wear resistance and weather resistance provided by the present application, the sealing strip includes a hard part, a soft part, and a weather-resistant part; the hard part is integrally connected to one side of the soft part as the framework of the sealing strip, and the weather-resistant part is uniformly coated on the surface of the soft part; the raw material components of the hard part include high-polymerization PVC, a first plasticizer, a stabilizer, and other additives; the raw material components of the soft part include low-polymerization PVC, a second plasticizer, an elastic modifier, and other additives; the raw material components of the weather-resistant part include low-polymerization PVC, a third plasticizer, modified graphene oxide, and other additives; the hard part, the soft part, and the weather-resistant part are integrally formed by extrusion through a co-extrusion die.

[0006] By adopting the above technical solution, the present application is obtained by co-extruding a hard part, a soft part and a weather-resistant part through a co-extrusion die. The hard part provides structural support and strength and is used for clamping on a fixed port in a door frame structure or a window frame structure. The soft part endows flexibility and sealing function and is used for abutting against the edge of a door or a window to achieve a sealing effect. The weather-resistant part has weather resistance and wear resistance effects. During the process of the soft part abutting against the door and window, the weather resistance and wear resistance of the soft part are improved. The present application adopts the same die to extrude the hard part, the soft part and the weather-resistant part and synchronously cool and shape them, so that the interfaces of the three are closely combined.

[0007] Preferably, the modified graphene oxide is functionalized with polyacrylic acid.

[0008] By adopting the above technical solution, the material of the weather-resistant part in the present application includes modified graphene oxide. After graphene oxide is treated with polyacrylic acid, the carboxyl groups (-COOH) on its surface form hydrogen bonds and mechanical cross-linking effects with polar groups (such as C-Cl) in the PVC molecular chain, restricting the molecular chain slippage, thereby improving the tensile strength and toughness. The structure of graphene oxide can act as a physical barrier to inhibit the chain segment decomposition of PVC at high temperatures, and further block the penetration of corrosion media such as water vapor and salt spray, and then improve the weather resistance and wear resistance of the sealing strip through the treatment of the weather-resistant part.

[0009] Preferably, in the raw materials of the hard part, the first plasticizer includes dioctyl terephthalate and chlorinated polyethylene; the stabilizer includes a calcium-zinc composite stabilizer and a β-diketone heat stabilizer; in the raw materials of the soft part, the second plasticizer includes cyclohexanedicarboxylate; the elastic modifier includes polyurethane and ethylene propylene diene monomer; in the raw materials of the weather-resistant part, the third plasticizer includes epoxidized soybean oil and dioctyl phthalate.

[0010] On the other hand, the present application discloses a preparation method of a wear-resistant and weather-resistant coated sealing strip. The preparation method includes the following operation steps: pretreatment of the raw materials of the hard part, pretreatment of the raw materials of the soft part, pretreatment of the raw materials of the weather-resistant part, co-extrusion molding of the sealing strip, and surface treatment of the sealing strip.

[0011] Preferably, the pretreatment of the raw materials of the hard part includes the following operation steps: mixing high-polymerization PVC, the first plasticizer, the stabilizer and other additives in a heated PVC mixer, controlling the temperature at 100-120°C for 5-15 minutes, and mixing them, and then cooling the mixed material to below 40°C to obtain the pretreated raw materials of the hard part.

[0012] Preferably, the pretreatment of the soft part raw material includes the following operating steps: mixing low-polymerization PVC, a second plasticizer, an elastic modifier, and other additives in a heating PVC mixer and premixing at 60°C for 5-10 minutes, then controlling the temperature at 80-100°C for 10-15 minutes and performing heating and mixing, and then cooling the mixed material to below 50°C to obtain the pretreated soft part raw material.

[0013] Preferably, the pretreatment of the weather-resistant part raw material includes the following operating steps: pretreatment of modified graphene oxide, premixing and pretreatment of the weather-resistant part raw material; the pretreatment of the modified graphene oxide includes the following operating steps: dispersing graphene oxide in a 65% ethanol solution, performing ultrasonic treatment for a certain time to remove surface impurities; filtering the graphene oxide and adding a silane coupling agent to introduce active groups on the surface of the graphene oxide, transferring it to a reaction kettle, adding acrylic monomers, initiators, and crosslinking agents for mixing, and reacting the reaction kettle at a certain temperature for a certain time, then adding a hydrochloric acid ethanol solution to terminate the polymerization to obtain a mixed solution with modified graphene oxide, and finally performing post-treatment on the mixed solution to obtain a product with modified graphene oxide.

[0014] Preferably, the premixing and pretreatment of the weather-resistant part raw material include the following operating steps: mixing low-polymerization PVC with a third plasticizer, controlling the temperature at 50-60°C and premixing for 10 minutes, then adding modified graphene oxide, a calcium-zinc composite stabilizer, and nano-calcium carbonate, and continuing to mix for 10-50 minutes to ensure uniform coating of the filler, and then cooling the mixed material to below 50°C to obtain the pretreated weather-resistant part raw material.

[0015] Preferably, the co-extrusion molding of the sealing strip includes the following operating steps: transferring the hard part raw material, soft part raw material, and weather-resistant part raw material to a co-extrusion die, using a three-head co-extrusion die head, independently controlling the temperature of each layer of flow channel (temperature difference ±1°C), shear rate ≥6000 s-1, the temperature of the hard part raw material flow channel is 190-210°C, the temperature of the soft part raw material channel is 170-180°C, the temperature of the weather-resistant part raw material channel is 160-170°C, controlling the overall temperature gradient difference of the die head within 5°C, and the melts of each layer converge 5 cm in front of the die lip to obtain a three-layer composite sealing strip.

[0016] Preferably, the surface treatment of the sealing strip includes the following operating steps: performing a coating treatment on the surface of the three-layer composite sealing strip, and the coating material mainly includes polyurethane resin.

[0017] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0018] 1. The rigid part in this application provides structural support and strength, and is used to be clamped on the fixed port in the door frame structure or window frame structure; the soft part endows flexibility and sealing function, and is used to abut against the edge of the door or window to achieve the sealing effect; the weather-resistant part has the effects of weather resistance and abrasion resistance, and during the process of the soft part abutting against the door and window, it improves its weather resistance and abrasion resistance.

[0019] 2. This application extrudes the rigid part, the soft part and the weather-resistant part with the same mold and synchronously cools and shapes them, so that the interfaces of the three are closely combined.

[0020] 3. In this application, the material of the weather-resistant part is modified graphene oxide. After being treated with polyacrylic acid, hydrogen bonds and mechanical cross-linking effects are formed between the carboxyl groups on its surface and the polar groups in the PVC molecular chain, restricting the slippage of the molecular chain, thereby improving the tensile strength and toughness; and the graphene oxide structure can serve as a physical barrier to inhibit the chain segment decomposition of PVC at high temperatures, and further block the penetration of corrosion media such as water vapor and salt spray. Furthermore, through the treatment of the weather-resistant part, the weather resistance and abrasion resistance of the sealing strip are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of the overall structure of the wear-resistant and weather-resistant coated sealing strip in Embodiment 1;

[0023] Figure 2 It is a schematic cross-sectional view of the wear-resistant and weather-resistant coated sealing strip in Embodiment 1.

[0024] Description of the reference numerals: 1. Rigid part; 2. Soft part; 3. Weather-resistant part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] This application provides a wear-resistant and weather-resistant coated sealing strip and its preparation process, which are used to improve the weather resistance and abrasion resistance of the PVC sealing strip.

[0026] Next, the technical solutions in the embodiments of this application will be clearly and completely described with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0027] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or modules that are not clearly listed or are inherent to these processes, methods, products or devices.

[0028] Raw materials

[0029] High-polymerization PVC: The high-polymerization-degree PVC resin currently commercially available used in this application has an average molecular weight in the range of 50,000 to 100,000;

[0030] Low-polymerization PVC: The low-polymerization-degree PVC resin currently commercially available used in this application has an average molecular weight in the range of 1,000 to 10,000;

[0031] Graphene oxide: The graphene oxide currently commercially available used in this application has a CAS number of 2640657-49-2.

[0032] Examples

[0033] Example 1

[0034] S1. Pretreatment of raw materials for the hard part:

[0035] Add 20 phr dioctyl terephthalate, 18 phr chlorinated polyethylene, 4 phr calcium-zinc composite stabilizer, 0.3 phr β-diketone heat stabilizer, 0.3 phr stearic acid and 0.5 phr polyethylene wax to high-polymerization PVC and mix. In a heated PVC mixer, control the temperature at 100 °C for 10 minutes and mix, then cool the mixed material to 40 °C to obtain the pretreated raw materials for the hard part.

[0036] S2. Pretreatment of raw materials for the soft part:

[0037] Add 25 phr cyclohexanedicarboxylate, 15 phr polyurethane, 2 phr ethylene-propylene-diene monomer, 0.8 phr paraffin wax and 0.5 phr stearic acid to low-polymerization PVC and mix; premix at 60 °C for 8 min in a heated PVC mixer, then control the temperature at 90 °C for 12 minutes and heat-mix, then cool the mixed material to below 50 °C to obtain the pretreated raw materials for the soft part.

[0038] S3. Pretreatment of weather-resistant part raw materials:

[0039] Pretreatment of modified graphene oxide:

[0040] Disperse graphene oxide in a 65% ethanol solution, ultrasonically treat for 1 h to remove surface impurities; filter the graphene oxide and then add a silane coupling agent (KH560) with a ratio of 1:0.3 to graphene oxide, thereby introducing active groups on the surface of graphene oxide, and transfer it to a reaction kettle. Add acrylic acid monomer, ammonium persulfate initiator, and N,N-methylenebisacrylamide crosslinking agent and mix. The mass ratio of graphene oxide to acrylic acid monomer is 1:2; the mass ratio of acrylic acid monomer, ammonium persulfate initiator, and N,N-methylenebisacrylamide crosslinking agent is 10:1:0.1. Then control the reaction kettle to react at 70 °C for 4 h, then add hydrochloric acid ethanol solution to terminate the polymerization to obtain a mixed solution with modified graphene oxide. Secondly, perform suction filtration on the mixed solution, wash it 3 times with ethanol and acetone in turn to remove unreacted monomers and impurities, and finally dry it under vacuum at 60 °C for 12 hours to obtain a product with modified graphene oxide.

[0041] Premixing and pretreatment of weather-resistant part raw materials:

[0042] Add 5 phr of epoxidized soybean oil and 8 phr of dioctyl phthalate to low-polymerization PVC and mix, control the temperature at 60 °C, and premix for 10 min. Then add 5 phr of modified graphene oxide, 4 phr of calcium-zinc composite stabilizer, and 1 phr of nano-calcium carbonate, and continue to mix for 30 min to ensure uniform coating of the filler. Then cool the mixed material to below 50 °C to obtain pretreated weather-resistant part raw materials.

[0043] S4. Co-extrusion molding of the sealing strip:

[0044] Transfer the hard part raw materials, soft part raw materials, and weather-resistant part raw materials to a co-extrusion die. Use a three-head co-extrusion die head, with independent temperature control for each layer of flow channel (temperature difference ±1 °C), shear rate ≥6000 s-1. The temperature of the hard part raw material flow channel is 190 °C, the temperature of the soft part raw material channel is 170 °C, the temperature of the weather-resistant part raw material channel is 160 °C, and the overall temperature gradient difference of the die head is controlled within 5 °C. The melts of each layer converge 5 cm in front of the die lip to obtain a three-layer composite sealing strip.

[0045] S5. Surface treatment of the sealing strip:

[0046] The surface of the three-layer composite sealing strip is coated. Wipe the surface of the strip with ethanol to remove grease, dust and moisture; then heat the polyurethane resin glue to 160 °C, scrape the glue through a rubber head, and the thickness of the glue layer is 0.1 - 0.3 mm. Finally, perform a curing treatment using a vulcanization process at a temperature of 90 °C to form a wear-resistant and weather-resistant film-covered sealing strip.

[0047] Among them, the overall structural schematic diagram of the film-covered sealing strip prepared in Example 1 is as Figure 1 shown, where the sealing strip includes a rigid part 1, a soft part 2 and a weather-resistant part 3 that are integrally formed. Combining Figure 2 shown, the rigid part 1 is integrally connected to one side of the soft part 2 as the framework of the sealing strip, and the weather-resistant part 3 is evenly covered on the surface of the soft part 2.

[0048] Among them, the rigid part 1 provides structural support and strength, and the shape of the rigid part 1 is integrally formed during the extrusion process for clamping in the fixed port in the door frame structure or the window frame structure. The rigid part 1 in this application forms an arrow-end shape as Figure 2 shown for fixing in the door frame structure or the window frame structure. The soft part 2 gives flexibility and a sealing function for abutting against the edge of the door or window. Among them, the soft part 2 adopts a hollow shape, thereby giving the soft part 2 a certain deformation effect and further improving its sealing effect. The weather-resistant part 3 has the effects of weather resistance and wear resistance, which lies in improving the weather resistance and wear resistance of the surface of the soft part 2 during the process of the soft part 2 abutting against the door and window. And this application uses the same mold to extrude the rigid part 1, the soft part 2 and the weather-resistant part 3 and synchronously cool and shape them, so that the interfaces of the three are closely combined. Examples 2 - 6

[0049] The differences between Examples 2 - 6 and Example 1 are that the parameters in the pre-treatment steps of the rigid part raw material, the pre-treatment steps of the soft part raw material, and the pre-treatment steps of the weather-resistant part raw material are different, and the following Table 1 is obtained after sorting.

[0050] Table 1. Parameter table of the pre-treatment steps in Examples 2 - 6 and Example 1

[0051]

[0052]

[0053] Examples 7 - 10

[0054] The differences between Examples 7 - 10 and Example 1 are that the parameters in the co-extrusion molding operation steps of the sealing strip are different, and the following Table 2 is obtained after sorting.

[0055] Table 2. Co-extrusion parameter table of the sealing strip in Examples 7 - 10 and Example 1

[0056]

[0057] Comparative example

[0058] Comparative example 1

[0059] The difference between Comparative Example 1 and Example 1 is that the wear-resistant and weather-resistant film-sealed rubber strip includes a hard part and a soft part; instead of covering the weather-resistant part on the surface of the soft part, a co-extrusion technical solution of rigid PVC and soft PVC is adopted.

[0060] Comparative example 2

[0061] The difference between Comparative Example 2 and Example 1 is that the raw material components of the weather-resistant part are low-polymerization PVC, a third plasticizer, and other additives, and modified graphene oxide is not used in the pretreatment of the raw materials of the weather-resistant part.

[0062] Comparative example 3

[0063] The difference between Comparative Example 3 and Example 1 is that the raw material components of the weather-resistant part are low-polymerization PVC, graphene oxide, a third plasticizer, and other additives, and the graphene oxide is not treated with polyacrylic acid.

[0064] Data detection and result analysis

[0065] In this application, the rubber strips prepared in Examples 1-10 and Comparative Examples 1-3 were tested, and the test standard was detected according to the latest national standard GB / T 24498-2025 "Sealing Rubber Strips for Building Doors and Windows and Curtain Walls".

[0066] Among them, the material of the rubber strip used in this application is mainly polyvinyl chloride (PVC), so its standard adopts the standard of the performance of thermoplastic elastomer materials according to the requirements of the national standard GB / T 24498-2025. The weather resistance detection of the rubber strip includes high and low temperature resistance detection, fatigue resistance detection, light aging resistance detection, and wear resistance detection.

[0067] 1. High and low temperature resistance detection: Cut 6 specimens from the rubber strip products. Before the test, measure the compression force and rebound recovery grade of 3 specimens. Place the other 3 specimens in the air at 23°C ± 2°C for 18 h, then put the specimens into a low-temperature box at -20°C ± 2°C and freeze for 3 h, and then immediately take the specimens out of the low-temperature box and put them into a constant temperature box at 50°C ± 2°C for 3 h. This is 1 cycle, and the test time deviation is ±0.25 h. After repeating 4 cycles, measure the rebound recovery and compression force, and calculate the change rate.

[0068] 2. Fatigue resistance performance testing: Cut 6 specimens from the sealant strip products. Measure the compression force and the resilience recovery grade of the products before testing on 3 specimens. Install the other 3 specimens on the fatigue testing machine and adjust the amplitude of the fatigue testing machine to the working range of the specimens. Conduct repeated tests with a specimen frequency of (600 ± 30) times per hour. After the test, remove the specimens and place them in a standard temperature and humidity environment in a state where the horizontal direction is not under pressure and the working surface is facing up for 24 h, then measure the resilience recovery and compression force, and calculate the change rate.

[0069] 3. Photo-aging performance testing: Cut 4 specimens from the sealant strip products. Seal 1 specimen away from light, and put 2 specimens into the aging chamber for testing simultaneously. Observe the appearance of the specimens after the test, compare the color with the sealed specimen, and evaluate the color change grade. Place the aged specimens in a standard temperature and humidity state for 24 h ± 0.5 h. Draw two markings with a spacing of 50 mm ± 1 mm in the middle part of the 2 specimens. One marking of the specimen is in the length direction of the sealant strip, and the other is in the width direction. The test speed is 500 mm / min ± 50 mm / min. Stretch the distance between the markings to 75 mm ± 5 mm and hold for 3 min, then observe the fracture situation of the specimens.

[0070] 4. Abrasion resistance performance testing: Cut 4 specimens from the sealant strip products and transfer them to the friction testing machine. Use a glass grinding head as the friction tool, with a friction speed of 60 times / min, a friction distance of 100 mm, and a friction number of 20,000 times. Evaluate the result grade according to the test. The grade division is as follows: Grade 1, all the fluff falls off, and all the base materials or all the adhesives / coatings and the base materials are broken and worn; Grade 2, part of the fluff falls off, more than 50% of the base materials or adhesives / coatings are worn, and part of the fluff on the base materials is seen to fall off; Grade 3, less than 50% of the base materials or adhesives / coatings are slightly worn; Grade 4, the fluff becomes shorter but does not fall off, the base materials or adhesives are not shown, and there is no obvious change in appearance / slight wear of the coating; Grade 5, there is no change in appearance.

[0071] Organize the test data as shown in Table 3 below.

[0072] Table 3. Test result table

[0073]

[0074]

[0075] The data of Example 1 and Comparative Example 1 were compared. The difference between Comparative Example 1 and Example 1 is that the film-coated sealing strip includes a hard part and a soft part. Instead of covering the weather-resistant part on the surface of the soft part, a co-extrusion technology of rigid PVC and soft PVC was adopted. Among the data of high and low temperature performance testing, fatigue resistance testing, light aging performance testing, and wear resistance testing, the data of Comparative Example 1 are all smaller than those of Example 1. This is because the weather-resistant part has the effects of weather resistance and wear resistance, and during the process of the soft part abutting against the doors and windows, it improves its weather resistance and wear resistance. And the physical properties of the sealing strip can be improved by the process of extruding the hard part, soft part, and weather-resistant part in the same mold and synchronously cooling and shaping.

[0076] In addition, Comparative Example 2 was compared with Example 1. The difference between Comparative Example 2 and Example 1 is that the raw material components of the weather-resistant part are low-polymerized PVC, a third plasticizer, and other additives, and modified graphene oxide was not used in the pretreatment of the raw materials of the weather-resistant part. Among the data of high and low temperature performance testing, fatigue resistance testing, light aging performance testing, and wear resistance testing, the data of Comparative Example 2 are inferior to those of Example 1 in terms of both weather resistance and wear resistance. This is because modified graphene oxide was not used in the material of the weather-resistant part, and the main material of the weather-resistant part is almost the same as that of the soft part.

[0077] Comparative Example 3 was compared with Example 1. The raw material components of the weather-resistant part in Comparative Example 3 are low-polymerized PVC, graphene oxide, a third plasticizer, and other additives. Among the data of high and low temperature performance testing, fatigue resistance testing, light aging performance testing, and wear resistance testing, the data of Comparative Example 3 are inferior to those of Example 1 in terms of both weather resistance and wear resistance. This is because in Comparative Example 3, the graphene oxide was not treated with polyacrylic acid. Because after the modified graphene oxide in the material of the weather-resistant part is treated with polyacrylic acid, the carboxyl groups on its surface form hydrogen bonds and mechanical cross-linking effects with the polar groups in the PVC molecular chain, restricting the molecular chain slip, thereby improving the tensile strength and toughness; and the graphene oxide structure can act as a physical barrier to inhibit the chain segment decomposition of PVC at high temperatures, and further block the penetration of corrosion media such as water vapor and salt spray, and then improve the weather resistance and wear resistance of the sealing strip through the treatment of the weather-resistant part.

[0078] Finally, an analysis was carried out among Examples 1-6. The parameters in the pretreatment steps of the raw materials of the hard part, soft part, and weather-resistant part among Examples 1-6 are different. This is because in this application, a process of extruding the hard part 1, soft part 2, and weather-resistant part 3 in the same mold and synchronously cooling and shaping is adopted. Therefore, different parameters in the raw material treatment process will cause changes in their interfacial compatibility. Therefore, from the overall analysis of the data, Example 1 is the optimal example.

[0079] Example 1 is analyzed in combination with Examples 7 - 10. Among them, the parameters in the co - extrusion molding operation steps of the sealing strip are different. When transferring the raw materials of the hard part, soft part, and weather - resistant part to the co - extrusion die, a three - head co - extrusion die head is used, and the temperature of each layer of the runner will also affect the interfacial compatibility of the three to improve the weather resistance and wear resistance of the sealing strip. When the temperature of the hard - part raw material runner is 190 °C, the temperature of the soft - part raw material channel is 170 °C, and the temperature of the weather - resistant part raw material channel is 160 °C, a three - layer composite sealing strip is obtained, which has good experimental results. In addition, regarding the detection of the photo - aging performance, in the analysis of the fracture situation of the sealing strip, taking the length direction as the standard, there are no fracture lines in Examples 1 - 10, while there are fine fracture lines at the interface between the weather - resistant part and the hard part in the width direction. This is because there are certain drawbacks in the interfacial bonding tightness in the photo - aging test, but it already meets the test standards. In Comparative Example 1 and Comparative Example 2, cracks in the width direction not only exist at the interface between the hard part and the soft part, but also appear in the soft part.

[0080] Based on the above - mentioned analysis, Application Example 1 is the optimal example.

[0081] It should be noted that the above - mentioned order of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above - mentioned specific embodiments of this specification are described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be executed in a different order from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multi - tasking and parallel processing are also possible or may be advantageous.

[0082] The above - mentioned are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0083] This specification and the drawings are only exemplary descriptions of the present application and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalent technologies, the present application is intended to include these changes and modifications.

Claims

1. A film-coated sealing strip with wear resistance and weather resistance, characterized in that, The seal strip includes a hard part, a soft part and a weather-resistant part; the hard part is integrally connected to one side of the soft part as the skeleton of the seal strip, and the weather-resistant part is uniformly covered on the surface of the soft part; The raw material components of the hard part include high-polymerization PVC, a first plasticizer, a stabilizer and other additives; the raw material components of the soft part include low-polymerization PVC, a second plasticizer, an elastic modifier and other additives; the raw material components of the weather-resistant part include low-polymerization PVC, a third plasticizer, modified graphene oxide and other additives; The hard part, the soft part and the weather-resistant part are integrally formed by extrusion through a co-extrusion die.

2. The preparation process of the wear-resistant and weather-resistant film-coated sealing strip according to claim 1, characterized in that, The modified graphene oxide is functionalized with polyacrylic acid.

3. The preparation process of the wear-resistant and weather-resistant coated seal strip according to claim 2, characterized in that In the raw materials of the hard part, the first plasticizer includes dioctyl terephthalate and chlorinated polyethylene; the stabilizer includes a calcium-zinc composite stabilizer and a β-diketone heat stabilizer; In the raw materials of the soft part, the second plasticizer includes cyclohexanedicarboxylate; the elastic modifier includes polyurethane and ethylene propylene diene monomer; In the raw materials of the weather-resistant part, the third plasticizer includes epoxidized soybean oil and dioctyl phthalate.

4. A preparation method of a wear-resistant and weather-resistant film-coated sealing strip as described in any one of claims 1 to 3, characterized in that, The preparation method includes the following operation steps: pretreatment of the raw materials of the hard part, pretreatment of the raw materials of the soft part, pretreatment of the raw materials of the weather-resistant part, co-extrusion molding of the seal strip, and surface treatment of the seal strip.

5. The preparation process of the wear-resistant and weather-resistant film-coated sealing strip according to claim 4, characterized in that, The pretreatment of the raw materials of the hard part includes the following operation steps: Mix high-polymerization PVC, a first plasticizer, a stabilizer and other additives in a heated PVC mixer, control the temperature at 100-120 °C for 5-15 minutes, and mix, then cool the mixed material to below 40 °C to obtain the pretreated raw materials of the hard part.

6. The preparation process of the wear-resistant and weather-resistant film-coated sealing strip as described in claim 5, characterized in that, The pretreatment of the raw materials of the soft part includes the following operation steps: Mix low-polymerization PVC, a second plasticizer, an elastic modifier and other additives in a heated PVC mixer and premix at 60 °C for 5-10 min, then control the temperature at 80-100 °C for 10-15 minutes, and heat and mix, then cool the mixed material to below 50 °C to obtain the pretreated raw materials of the soft part.

7. The preparation process of the wear-resistant and weather-resistant film-coated sealing strip according to claim 6, characterized in that, The pretreatment of the raw materials of the weather-resistant part includes the following operation steps: pretreatment of modified graphene oxide and premixing and pretreatment of the raw materials of the weather-resistant part; The pretreatment of the modified graphene oxide includes the following operation steps: Disperse graphene oxide in a 65% ethanol solution, ultrasonically treat for a certain time to remove surface impurities; filter the graphene oxide and add a silane coupling agent to introduce active groups on the surface of the graphene oxide, and transfer it to a reaction kettle, add acrylic acid monomer, initiator and crosslinking agent and mix, and control the reaction kettle at a certain temperature for a certain time, then add hydrochloric acid ethanol solution to terminate the polymerization to obtain a mixed solution with modified graphene oxide, and finally post-treat the mixed solution to obtain a product with modified graphene oxide.

8. The preparation process of the wear-resistant and weather-resistant film-coated sealing strip according to claim 7, characterized in that, The premixing and pretreatment of the raw materials of the weather-resistant part includes the following operation steps: Mix low-polymerized PVC with a third plasticizer, control the temperature at 50 - 60 °C, and premix for 10 min. Then add modified graphene oxide, calcium-zinc composite stabilizer, and nano-calcium carbonate, and continue mixing for 10 - 50 min to ensure uniform coating of the fillers. Then cool the mixed material to below 50 °C to obtain the raw material for the pretreated weather-resistant part.

9. The wear-resistant and weather-resistant film-coated sealing strip according to claim 8, characterized in that, The co-extrusion molding of the sealing strip includes the following operating steps: Transfer the raw material for the hard part, the raw material for the soft part, and the raw material for the weather-resistant part to a co-extrusion die. Use a three-head co-extrusion die head, with independent temperature control for each layer of flow channel (temperature difference ±1 °C), shear rate ≥6000 s-1. The temperature of the flow channel for the raw material of the hard part is 190 - 210 °C, the temperature of the channel for the raw material of the soft part is 170 - 180 °C, and the temperature of the channel for the raw material of the weather-resistant part is 160 - 170 °C. The overall temperature gradient difference of the die head is controlled within 5 °C. The melts of each layer converge 5 cm in front of the die lip to obtain a three-layer composite sealing strip.

10. The wear-resistant and weather-resistant film-coated sealing strip according to claim 9, characterized in that, The surface treatment of the sealing strip includes the following operating steps: Perform a coating treatment on the surface of the three-layer composite sealing strip. The coating material mainly includes polyurethane resin.

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