A dense bead sealant and a preparation method thereof

Abstract

The application relates to the technical field of high polymer materials, and particularly discloses a dense-hole sealing adhesive tape and a preparation method thereof. The dense-hole sealing adhesive tape comprises the following raw materials in parts by mass: 90-110 parts of a ternary ethylene-propylene rubber, 60-90 parts of carbon black, 10-20 parts of white carbon black, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 40-60 parts of paraffin oil, 0.5-1 part of polyethylene glycol, 2-3 parts of magnesium oxide, 3-5 parts of a vulcanization system, 1-1.5 parts of a mildew-proof agent and 3-6 parts of a microporous foaming agent. The dense-hole sealing adhesive tape has the advantages that the mechanical properties of the sealing adhesive tape can be improved without affecting the sealing property.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high polymer materials, in particular to a dense hole sealing adhesive strip and a preparation method thereof. BACKGROUND

[0002] The light-weight sealing adhesive strip microcellular foaming material is a new type of sealing material and is widely used in indoor wooden doors. Compared with traditional sealing materials, the microcellular foaming material has a lower density and can effectively reduce the overall weight and improve the energy efficiency and performance of the product. Generally, the microcellular foaming material is prepared from ethylene propylene diene rubber (EPDM) as a rubber material with good weather resistance, insulation and flexibility, and is widely used in the field of sealing adhesive rings.

[0003] In order to obtain a light-weight sealing adhesive strip, the filler is usually reduced, foaming or low-density materials are replaced, but this may damage the microstructure and composition ratio of the material, thereby possibly reducing the crosslinking density, weakening the elasticity and resilience, causing the material to be difficult to restore to its original state after being pressed, and thus deforming, thereby affecting the sealing property of the sealing adhesive strip. SUMMARY

[0004] In order to improve the mechanical properties of the sealing adhesive strip without affecting the sealing property, the application provides a dense hole sealing adhesive strip and a preparation method thereof.

[0005] The application provides a dense hole sealing adhesive strip and a preparation method thereof, which adopt the following technical scheme:

[0006] In a first aspect, the application provides a dense hole sealing adhesive strip, which comprises the following mass parts of raw materials: 90-110 parts of ethylene propylene diene rubber, 60-90 parts of carbon black, 10-20 parts of white carbon black, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 40-60 parts of paraffin oil, 0.5-1 part of polyethylene glycol, 2-3 parts of magnesium oxide, 3-5 parts of a vulcanization system, 1-1.5 parts of a mildew-proof agent, and 3-6 parts of a microcellular foaming agent.

[0007] The synergistic reinforcement of ethylene propylene diene rubber and carbon black forms a rigid-flexible composite structure to ensure high elasticity and tensile strength of the sealing strip. The introduction of white carbon black can reduce the density of the sealing strip. The two-way filler reduces stress concentration and improves tear resistance. Zinc oxide and stearic acid synergistically optimize the vulcanization efficiency to form a uniform crosslinking network, thereby improving the heat resistance and mechanical properties of the sealing strip. Paraffin oil can reduce hardness without excessively sacrificing strength. Polyethylene glycol ensures uniform distribution of fillers and prevents the formation of local weaknesses. The vulcanization system forms uniform crosslinking bonds, which can improve the crosslinking density of the sealing strip and enhance its resistance to deformation and resilience. The microcellular foaming agent forms a uniform closed-cell structure that effectively blocks the penetration of water vapor and dust, which is beneficial for long-term sealing. The mildew-resistant agent provides antibacterial function for the sealing strip, which can enhance the durability of the sealing strip.

[0008] Preferably, the vulcanization system is a peroxide vulcanizing agent, and the peroxide vulcanizing agent is one of an alkyl peroxide and a diacyl peroxide.

[0009] The peroxide vulcanizing agent can decompose at high temperatures to generate free radicals, which can initiate the formation of carbon-carbon crosslinking bonds between the molecular chains of ethylene propylene diene rubber. Compared with the polysulfide bonds formed by traditional sulfur vulcanization systems, carbon-carbon bonds have higher bond energy and stronger thermal stability, which can improve the heat resistance and aging resistance of the sealing strip. The crosslinking network is not easily broken under high temperature or long-term use, which can prevent performance degradation. In addition, the peroxide vulcanizing agent has high reactivity and can form a uniform and dense crosslinking network in ethylene propylene diene rubber.

[0010] Preferably, the peroxide vulcanizing agent is one of 2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane and dilauroyl peroxide.

[0011] 2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane and dilauroyl peroxide can generate carbon-carbon crosslinking bonds through free radical reaction, which has significantly higher bond energy than the polysulfide bonds formed by traditional sulfur vulcanization. The uniform crosslinking rate of 2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane and dilauroyl peroxide prevents the microcellular foaming agent from excessive expansion, resulting in a dense and uniform microcellular structure that maintains the sealing performance.

[0012] Preferably, the paraffin oil is a paraffin oil with a flash point of 280℃ or higher and an aromatic hydrocarbon content of 0%.

[0013] The paraffin oil with flash point of 280℃ or above is almost not volatile during high temperature mixing and vulcanization, so the formula proportion imbalance caused by oil loss is not easy to occur, the density and performance of the rubber strip are uniform, the volatile residue characteristics make the oil after vulcanization not easy to migrate to the surface of the pore wall, the microporous structure is not easy to collapse due to oil seepage, the closed pore integrity is maintained, the long-term sealing effect is ensured, and the paraffin oil with 0% aromatic content makes the rubber strip not easy to release harmful substances after being used or discarded.

[0014] Preferably, the mildew-proof agent comprises the following raw materials: 1-5g modified nano zinc oxide, 15-25g 3-iodo-2-propynyl butyl carbamate, 25-25.7ml anhydrous ethanol, 55-65ml deionized water.

[0015] The modified nano zinc oxide can destroy the microbial cell membrane and inhibit enzyme activity by releasing zinc ions, achieving high-efficiency mildew prevention, while the 3-iodo-2-propynyl butyl carbamate has a rapid killing effect on fungi and bacteria by penetrating the microbial cell membrane and oxidizing proteins and nucleic acids, and forms a double-antibacterial mechanism with the modified nano zinc oxide, expanding the antibacterial spectrum and delaying the development of drug resistance.

[0016] Preferably, the preparation method of the mildew-proof agent is as follows: 15-25g 3-iodo-2-propynyl butyl carbamate is weighed in a beaker, 25-25.7ml anhydrous ethanol and 55-65ml deionized water are added, stirring is performed until the 3-iodo-2-propynyl butyl carbamate is completely dissolved to obtain a mixed solution, 1-5g modified nano zinc oxide is weighed in 10-50ml of the mixed solution for ultrasonic dispersion treatment, then it is placed in a vacuum drying box, the vacuum dryer is vacuumized to-0.06 to-0.12MPa, blending is performed for 0.5-1.5h, it is left to stand for 25-35min, then centrifugation is performed at a speed of 2500-3500r / min, and finally drying is performed in an oven at 25-35℃ for 10-14h to obtain the mildew-proof agent.

[0017] Preferably, the modified nano zinc oxide comprises the following raw materials: 3-7g nano zinc oxide, 490-710ml N,N-dimethylformamide, 3-9mL 3-aminopropyl triethoxysilane, 5-7g β-cyclodextrin, 5-7mL 1,1-carbonyldiimidazole.

[0018] The nano-oxidized surface has strong polarity, and the compatibility between the nano-oxidized surface and the non-polar EPDM rubber is poor. The hydrolysis and condensation reaction occurs between the 3-aminopropyl triethoxysilane and the hydroxyl group on the surface of the nano-zinc oxide, forming a stable Si-O-Zn covalent bond, and a layer of amino functional layer is constructed on the surface of the nano-particles, which can be combined with the polar region of the EPDM rubber, reducing the interface repulsion, thereby improving the compatibility between the nano-zinc oxide and the EPDM rubber. The hydrophobic cavity of the β-cyclodextrin wraps the nano-zinc oxide modified by the 3-aminopropyl triethoxysilane through the host-guest interaction, forming a physical barrier, so that the particles are not easy to directly contact and agglomerate. The 1,1-carbonyl diimidazole activates the hydroxyl group of the β-cyclodextrin to generate an active imidazole ester intermediate, which reacts with the amino group of the 3-aminopropyl triethoxysilane to form an amide, and the nano-particles are anchored in the hydrophobic cavity of the cyclodextrin, further reducing the interfacial tension with the non-polar segment of the EPDM rubber.

[0019] Preferably, the preparation method of the modified nano-zinc oxide comprises the following steps: 3-7 g of nano-zinc oxide is dispersed in 150-250 ml of N,N-dimethylformamide, stirred for 10-20 min and ultrasonically oscillated for 0.5-1.5 h, then 3-9 ml of 3-aminopropyl triethoxysilane is added dropwise, stirred at 85-95°C for 5-7 h, cooled to 20-30°C, centrifuged at a speed of 3500-4500 r / min for 8-12 min, and the separated solid particles are washed with N,N-dimethylformamide and deionized water, then placed in a vacuum drying box and dried at 35-45°C for 2-4 days for grinding to obtain an intermediate product; 5-7 g of β-cyclodextrin is dissolved in 180-220 ml of N,N-dimethylformamide, then 5-7 ml of 1,1-carbonyl diimidazole is added dropwise, and the activated β-cyclodextrin solution is obtained by magnetic stirring at 20-30°C for 1-3 h; the intermediate product is dispersed in 160-240 ml of N,N-dimethylformamide, the activated β-cyclodextrin solution is slowly added dropwise, and stirring is performed at 20-30°C for 15-25 h, and then washed with N,N-dimethylformamide and deionized water, placed in a drying box and dried at 55-65°C for 1-3 days for grinding to obtain the modified nano-zinc oxide.

[0020] In a second aspect, the present application provides a preparation method of a dense hole sealing adhesive strip, which adopts the following technical scheme:

[0021] A preparation method of a dense hole sealing adhesive strip comprises the following steps:

[0022] S1: first press-mix 90-110 parts of ethylene-propylene-diene rubber, then sequentially add 60-90 parts of carbon black, 10-20 parts of white carbon black, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 0.5-1 part of polyethylene glycol, 20-30 parts of paraffin oil, mix uniformly, then discharge, the discharge temperature is 145-155 DEG C, sheeting, cooling, storage, to obtain an intermediate;

[0023] S2: after the intermediate obtained in S1 is stored for 22-26 hours, first mixing, then add 2-3 parts of magnesium oxide, 3-5 parts of vulcanization system, 1-1.5 parts of mildew inhibitor, 3-6 parts of microcellular foaming agent, the discharge temperature is controlled at 80-100 DEG C, the roll gap is 1-1.5 mm during thin passing, to obtain a mixed rubber;

[0024] S3: extrude the mixed rubber from a special mold in a rubber extruder, into a molten salt at 250-280 DEG C, and vulcanize in an air-tight environment;

[0025] S4: after the reaction is completed, the product is cooled, shaped, and welded into a frame.

[0026] In summary, the present application has the following beneficial effects:

[0027] 1. Through the synergistic reinforcement of ethylene-propylene-diene rubber and carbon black, a rigid-flexible composite structure is formed, ensuring the high elasticity and tensile strength of the sealing strip. The introduction of white carbon black can reduce the density of the sealing strip. The two-way filler reduces stress concentration and improves tear resistance. Zinc oxide and stearic acid synergistically optimize the vulcanization efficiency, forming a uniform crosslinking network, thereby improving the heat resistance and mechanical properties of the strip. Paraffin oil can reduce hardness without excessively sacrificing strength. Polyethylene glycol ensures uniform distribution of fillers and prevents the formation of local weak points. The vulcanization system forms uniform crosslinking bonds, giving the strip higher crosslinking density, which helps to improve the strip's resistance to deformation and resilience. The microcellular foaming agent forms a uniform closed-cell structure, effectively blocking the penetration of water vapor and dust, which is beneficial to long-term sealing. The mildew inhibitor provides antibacterial function to the strip, which helps to enhance the long-lasting mildew resistance of the strip.

[0028] 2. Peroxide vulcanizing agent can decompose to generate free radicals at high temperature, which can induce the formation of carbon-carbon crosslinking bonds between ethylene-propylene-diene rubber molecular chains. Compared with the polysulfide bonds formed by traditional sulfur vulcanization system, carbon-carbon bonds have higher bond energy and stronger thermal stability, which helps to improve the heat resistance and aging resistance of the strip. The crosslinking network is not easily broken under high temperature or long-term use, which helps to prevent performance degradation. In addition, peroxide vulcanizing agent has high reactivity and can form a uniform and dense crosslinking network in ethylene-propylene-diene rubber.

[0029] 3. Because 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and dilauroyl peroxide can generate carbon-carbon crosslinks through free radical reactions, the bond energy is significantly higher than that of polysulfide bonds in traditional sulfur sulfidation. Furthermore, the uniform crosslinking rate of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and dilauroyl peroxide makes it difficult for the microporous foaming agent to over-expand, thus resulting in a dense and uniform microporous structure that maintains sealing performance. Detailed Implementation

[0030] The present application will be further described in detail below with reference to Examples 1-7 and Comparative Examples 1-2.

[0031] raw material

[0032] Ethylene propylene diene monomer (EPDM) rubber; Carbon black CAS: 1333-86-4; Silica CAS: 14464-46-1; Zinc oxide CAS: 1314-13-2; Stearic acid CAS: 57-11-4; Paraffin oil (Hebei Oujia Lubricating Oil Co., Ltd.); Polyethylene glycol CAS: 25322-68-3; Magnesium oxide CAS: 1309-48-4; 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane CAS: 78-63-7; Microporous foaming agent (Zhejiang Shuntai Technology Co., Ltd.) ; 3-Iodo-2-propynylcarbamate butyl ester Maclean Reagent Co., Ltd.; Anhydrous ethanol CAS: 64-17-5; Deionized water CAS: 7732-18-5; Nano zinc oxide Beijing Deco Island Gold Technology Co., Ltd.; N,N-Dimethylformamide Shanghai Aladdin Biochemical Technology Co., Ltd.; 3-Aminopropyltriethoxysilane Shanghai Aladdin Biochemical Technology Co., Ltd.; β-Cyclodextrin CAS: 7585-39-9; 1,1-Carbonyldiimidazole Shanghai Aladdin Biochemical Technology Co., Ltd.

[0033] Example 1

[0034] A dense, porous sealing strip comprises the following raw materials in parts by weight: 100 parts EPDM rubber, 75 parts carbon black, 15 parts silica, 6.5 parts zinc oxide, 2 parts stearic acid, 50 parts paraffin oil, 0.75 parts polyethylene glycol, 2.5 parts magnesium oxide, 4 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1.25 parts mildew inhibitor, and 4.5 parts microporous foaming agent.

[0035] Specifically, the preparation method of the dense pore sealing strip includes the following steps:

[0036] S1: 5 g of nano zinc oxide was weighed and dispersed in 200 ml of N, N-dimethylformamide, stirred for 15 min and ultrasonically oscillated for 1 h, then 6 mL of 3-aminopropyl triethoxysilane was added dropwise, stirred at 90°C for 6 h, cooled to 25°C, centrifuged at a speed of 4000 r / min for 10 min, and the separated solid particles were washed with N, N-dimethylformamide and deionized water, then placed in a vacuum drying oven at 40°C for 3 days for grinding to obtain an intermediate product;

[0037] S2: 6 g of β-cyclodextrin was dissolved in 200 mL of N, N-dimethylformamide, then 6 mL of 1,1-carbonyldiimidazole was added dropwise, and magnetic stirring was carried out at 25°C for 2 h to obtain an activated β-cyclodextrin solution;

[0038] S3: The intermediate product was dispersed in 200 mL of N, N-dimethylformamide, and the activated β-cyclodextrin solution was slowly added dropwise, and stirred at 25°C for 20 h, and washed with N, N-dimethylformamide and deionized water, and placed in a drying oven at 60°C for 2 days for grinding to obtain modified nano zinc oxide;

[0039] S4: 20 g of 3-iodo-2-propynyl butyl carbamate was weighed into a beaker, 25.35 ml of anhydrous ethanol and 60 ml of deionized water were added, and stirring was carried out until the 3-iodo-2-propynyl butyl carbamate was completely dissolved to obtain a mixed solution, 3 g of modified nano zinc oxide was weighed into 30 ml of the mixed solution and ultrasonically dispersed, then placed in a vacuum drying oven, and the vacuum dryer was evacuated to -0.09 MPa, and blended for 1 h, and after standing for 30 min, it was taken out, then centrifuged at a speed of 3000 r / min, and finally dried in an oven at 30°C for 12 h to obtain a mildew-proof agent;

[0040] S5: 100 parts of ethylene propylene diene rubber was first pressure-mixed, then 75 parts of carbon black, 15 parts of white carbon black, 6.5 parts of zinc oxide, 2 parts of stearic acid, 0.75 parts of polyethylene glycol, 25 parts of paraffin oil were added and mixed uniformly, then discharged, the discharge temperature was 150°C, and the sheet was cooled and stored;

[0041] S6: The intermediate obtained in S5 was stored for 24 h, then mixed, and then 2.5 parts of magnesium oxide, 4 parts of 2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane, 1.25 parts of mildew-proof agent, and 4.5 parts of microporous foaming agent were mixed, and the discharge temperature was controlled at 90°C, and the roll gap was 1.25 mm during thin passing to obtain a mixed rubber;

[0042] S7: The mixed rubber was extruded from a special mold in a rubber extruder and immersed in molten salt at 265°C to vulcanize in an air-tight manner;

[0043] S8: After the reaction is completed, the generated product is cooled, shaped, and welded into a frame.

[0044] Examples 2-3

[0045] The difference from Example 1 is that the mass fractions of the components of the dense hole sealing strip are different, as shown in Table 1.

[0046] Table 1: Table of mass fractions of components of the dense hole sealing strip in Examples 1-3 (parts)

[0047] Example 1 Example 2 Example 3 Ethylene propylene diene rubber 100 90 110 Carbon black 75 90 60 White carbon black 15 10 20 Zinc oxide 6.5 5 8 Stearic acid 2 3 1 Paraffin oil 50 60 40 Polyethylene glycol 0.75 0.5 1 Magnesium oxide 2.5 2 3 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane 4 5 3 Mold inhibitor 1.25 1 1.5 Microcellular blowing agent 4.5 6 3

[0048] Examples 4-5

[0049] The difference from Example 1 is that the mass fractions of the components of the mold inhibitor are different, as shown in Table 2.

[0050] Table 2: Table of mass fractions of components of the mold inhibitor in Examples 1 and 4-5

[0051] Example 1 Example 4 Example 5 Modified nano-zinc oxide 3g 1g 5g 3-Iodo-2-propynyl butylcarbamate 20g 25g 15g Anhydrous ethanol 25.35ml 25ml 25.7ml Deionized water 60ml 65ml 55ml

[0052] Examples 6-7

[0053] The difference from Example 1 is that the mass fractions of the components of the modified nano zinc oxide are different, as shown in Table 3.

[0054] Table 3: Table of mass fractions of components of the modified nano zinc oxide in Examples 1 and 6-7

[0055] Example 1 Example 6 Example 7 Nano-zinc oxide 5g 3g 7g N,N-Dimethylformamide 600ml 490ml 710ml 3-Aminopropyl triethoxysilane 6ml 9ml 3ml Beta-cyclodextrin 6g 7g 5g 1,1-Carbonyldiimidazole 6ml 5ml 7ml

[0056] Comparative Example 1

[0057] The difference from Example 1 is that 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is replaced with the same amount of sulfur vulcanizing system.

[0058] The vulcanizing system is composed of sulfur powder and accelerator NR.

[0059] Comparative Example 2

[0060] The difference from Example 1 is that the mold inhibitor is no longer added.

[0061] Performance test

[0062] I. Sealing performance

[0063] Three samples were taken from each of Examples 1-7 and Comparative Examples 1-2, 27 identical glass bottles with a diameter of 3 cm and a height of 5 cm were taken, and each sample was made into a sealing ring shape matched with the glass bottle cap, and 27 sealing ring samples were installed in the bottle cap, keeping the inside of the glass bottle dry, 27 glass bottles were filled with white copper sulfate powder, and then the 27 bottle caps were tightly capped on the glass bottles. After 1 h of water immersion, the glass bottles were taken out, the color of the copper sulfate powder in the glass bottles was observed, and the results were recorded.

[0064] The test data are shown in Table 4.

[0065] Table 4 Sealing performance test results of Examples 1-7 and Comparative Examples 1-2

[0066] Powder color before detection Powder color after detection Example 1 White White Example 2 White White Example 3 White White Example 4 White White Example 5 White White Example 6 White White Example 7 White White Comparative Example 1 White The powder at the bottle mouth was darker blue, and the powder inside was light blue Comparative Example 2 White White

[0067] II. Mechanical properties

[0068] Three samples were taken from each of Examples 1-7 and Comparative Examples 1-2, and the tensile strength and elongation at break of the samples were tested according to GB / T 528-2009 “Determination of Tensile Stress-Strain Properties of Vulcanized or Thermoplastic Rubber”.

[0069] The test data are shown in Table 5.

[0070] Table 5 Mechanical property test results of Examples 1-7 and Comparative Examples 1-2

[0071] Tensile strength (MPa) Elongation at break (%) Example 1 4.44 197 Example 2 4.12 185 Example 3 4.08 190 Example 4 4.20 192 Example 5 4.15 188 Example 6 4.25 195 Example 7 4.18 193 Comparative Example 1 3.25 142 Comparative Example 2 4.31 187

[0072] III. Mildew resistance

[0073] Three samples were taken from each of Examples 1-7 and Comparative Examples 1-2, and the mildew resistance of the samples was tested according to JC / T 885-2001 “Mildew-Resistant Sealant for Buildings”.

[0074] Mildew resistance grade description:

[0075] 0 grade: no obvious mildew under 50 times magnification;

[0076] 1 grade: no or difficult to see mildew with the naked eye, but obvious mildew under magnification;

[0077] 2 grade: obvious mildew with the naked eye, with a coverage rate of 10%-30% on the surface of the sample;

[0078] 3 grade: obvious mildew with the naked eye, with a coverage rate of 30%-60% on the surface of the sample;

[0079] Grade 4: Long mold is obviously observed by naked eyes, and the coverage on the surface of the sample is more than 60%;

[0080] The test data is shown in Table 6.

[0081] Table 6 Test results of the mildew resistance of Example 1-Example 7 and Comparative Example 1-Comparative Example 2

[0082] Mold resistance (grade) Example 1 0 Example 2 0 Example 3 0 Example 4 0 Example 5 0 Example 6 0 Example 7 0 Comparative Example 1 0 Comparative Example 2 3

[0083] It can be seen from the combination of Example 1 and Comparative Example 1 and the combination of Tables 4-6 that the mildew resistance of Comparative Example 1 is still at Grade 0 relative to Example 1, but the powder at the bottle opening after testing of Comparative Example 1 is darker blue, the internal powder is light blue, and the tensile strength and elongation at break of Comparative Example 1 are both obviously decreased, which indicates that compared with adding a conventional vulcanization system, adding 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane can effectively improve the mechanical properties of the sealant strip, and does not easily affect the sealing performance and mildew resistance of the sealant strip.

[0084] It can be seen from the combination of Example 1 and Comparative Example 2 and the combination of Tables 4-6 that the color of the powder after testing of Comparative Example 2 is still white, the tensile strength and elongation at break of Comparative Example 2 are decreased, and the mildew resistance of Comparative Example 2 is at Grade 3, which indicates that compared with not adding a mildew resistance agent, adding a mildew resistance agent can effectively improve the mildew resistance of the sealant strip, and the mildew resistance agent does not easily affect the sealing performance and mechanical properties of the sealant strip.

[0085] It can be seen from the combination of Example 1 and Example 2-Example 3 and the combination of Tables 4-6 that the color of the powder after testing of Example 2 and Example 3 is still white, and the mildew resistance of Example 2 and Example 3 is still at Grade 0, and the tensile strength and elongation at break of Example 2 and Example 3 are decreased, which indicates that the mass fraction of the components added to the dense and porous sealant strip affects the mechanical properties of the sealant strip, and therefore, the mass fraction of the components added to the dense and porous sealant strip in Example 1 can effectively improve the mechanical properties of the sealant strip without affecting the sealing performance and mildew resistance of the sealant strip.

[0086] It can be seen from the combination of the embodiment 1 and the embodiment 4 to the embodiment 5 and the combination of the table 4 to the table 6 that, compared with the embodiment 1, the color of the powder after detection of the embodiment 4 and the embodiment 5 is still white, the mildew resistance of the embodiment 4 and the embodiment 5 is still at the level 0, and the tensile strength and the elongation at break of the embodiment 4 and the embodiment 5 decrease, thus it is illustrated that the adding amount of the components of the mildew resistance agent influences the mechanical properties of the sealing strip, therefore, the adding amount of the components of the mildew resistance agent in the embodiment 1 can effectively improve the mechanical properties of the sealing strip without influencing the sealing performance and the mildew resistance of the sealing strip.

[0087] It can be seen from the combination of the embodiment 1 and the embodiment 6 to the embodiment 7 and the combination of the table 4 to the table 6 that, compared with the embodiment 1, the color of the powder after detection of the embodiment 6 and the embodiment 7 is still white, the mildew resistance of the embodiment 6 and the embodiment 7 is still at the level 0, and the tensile strength and the elongation at break of the embodiment 6 and the embodiment 7 decrease, thus it is illustrated that the adding amount of the components of the modified nano zinc oxide influences the mechanical properties of the sealing strip, therefore, the adding amount of the components of the modified nano zinc oxide in the embodiment 1 can effectively improve the mechanical properties of the sealing strip without influencing the sealing performance and the mildew resistance of the sealing strip.

[0088] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and the person skilled in the art can make a modification without a creative contribution according to the need after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A dense bead of sealant, characterized in that, The raw materials include the following quality parts: 90-110 parts of ethylene-propylene-diene rubber, 60-90 parts of carbon black, 10-20 parts of white carbon black, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 40-60 parts of paraffin oil, 0.5-1 part of polyethylene glycol, 2-3 parts of magnesium oxide, 3-5 parts of a vulcanization system, 1-1.5 parts of a mildew-proof agent, and 3-6 parts of a microporous foaming agent; The vulcanization system is a peroxide vulcanizing agent, and the peroxide vulcanizing agent is one of an alkyl peroxide and a diacyl peroxide; The peroxide vulcanizing agent is one of 2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane and dilauryl peroxide. The preparation method of the mildew-proof agent is as follows: 15-25 g of 3-iodo-2-propynyl butylcarbamate is weighed into a beaker, 25-25.7 ml of anhydrous ethanol and 55-65 ml of deionized water are added, and stirring is performed until the 3-iodo-2-propynyl butylcarbamate is completely dissolved to obtain a mixed solution, 1-5 g of modified nano zinc oxide is weighed into 10-50 ml of the mixed solution for ultrasonic dispersion treatment, then it is placed in a vacuum drying box, the vacuum drier is vacuumized to -0.06 to -0.12 MPa, and blending is performed for 0.5-1.5 h, and after standing for 25-35 min, it is taken out, then centrifugation is performed at a speed of 2500-3500 r / min, and finally drying is performed in an oven at 25-35℃ for 10-14 h to obtain the mildew-proof agent. The preparation method of the modified nano zinc oxide is as follows: 3-7 g of nano zinc oxide is dispersed in 150-250 ml of N,N-dimethylformamide, stirring is performed for 10-20 min and ultrasonic oscillation is performed for 0.5-1.5 h, then 3-9 ml of 3-aminopropyl triethoxysilane is added dropwise, stirring is performed at 85-95℃ for 5-7 h, after cooling to 20-30℃, centrifugation is performed at a speed of 3500-4500 r / min for 8-12 min, and the separated solid particles are washed with N,N-dimethylformamide and deionized water, then they are placed in a vacuum drying box and dried at 35-45℃ for 2-4 days for grinding to obtain an intermediate product; 5-7 g of β-cyclodextrin is dissolved in 180-220 ml of N,N-dimethylformamide, then 5-7 ml of 1,1-carbonyldiimidazole is added dropwise, and magnetic stirring is performed at 20-30℃ for 1-3 h to obtain an activated β-cyclodextrin solution; the intermediate product is dispersed in 160-240 ml of N,N-dimethylformamide, the activated β-cyclodextrin solution is slowly added dropwise thereto, and stirring is performed at 20-30℃ for 15-25 h, and then the product is washed with N,N-dimethylformamide and deionized water, placed in a drying box and dried at 55-65℃ for 1-3 days for grinding to obtain the modified nano zinc oxide.

2. A dense bead sealant strip according to claim 1, wherein: The paraffin oil is a paraffin oil with a flash point of more than 280℃ and an aromatic hydrocarbon content of 0%.

3. A method of producing a dense bead sealant strip according to any one of claims 1-2, characterized in that, The method comprises the following steps: S1: first 90-110 parts of ethylene propylene rubber pressure mixing, then add 60-90 parts of carbon black, 10-20 parts of white carbon black, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 0.5-1 parts of polyethylene glycol, 20-30 parts of paraffin oil mixing uniformly after extrusion, the extrusion temperature is 145-155 ℃, sheet, cooling, parking, get intermediate; S2: the intermediate obtained in S1 is parked for 22-26 h, then mixed, then 2-3 parts of magnesium oxide, 3-5 parts of vulcanization system, 1-1.5 parts of mildew resistant agent, 3-6 parts of microcellular foaming agent are mixed, the extrusion temperature is controlled at 80-100 ℃, the roll gap is 1-1.5 mm when thin passing, to get the rubber compound; S3: the rubber compound is extruded from a special mold in a rubber extruder, enters into 250-280 ℃ molten salt, and is vulcanized in the absence of air; S4: after the reaction is completed, the product is cooled, shaped, and welded into a frame.