Waterproof sealing rubber pad and preparation method thereof

Abstract

The invention belongs to the technical field of rubber pads, and particularly discloses a waterproof sealing rubber pad and a preparation method thereof.The waterproof sealing rubber pad comprises an inner high-elasticity rubber layer and an outer waterproof wear-resistant rubber layer, and a reinforced fiber net is arranged between the high-elasticity rubber layer and the waterproof wear-resistant rubber layer; a hexagonal protrusion array structure is arranged on the surface of the waterproof wear-resistant rubber layer, and a porous structure is arranged in the high-elasticity rubber layer. According to the waterproof sealing rubber pad and the preparation method, the preparation method is easy and convenient to operate, the high-quality native material and the bionic structure are combined, the waterproof performance, elasticity, strength and aging resistance of the prepared rubber pad all reach the high level, and the strict requirements of different fields for the waterproof sealing rubber pad can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber pads, and in particular to a waterproof sealing rubber pad and a preparation method thereof. Background Art

[0002] Waterproof sealing rubber pads play a vital role in many industrial and civil fields, such as waterproofing of tunnels and basements in construction projects, sealing of engine compartments and doors in automobile manufacturing, and waterproof protection of electronic equipment. Traditional waterproof sealing rubber pads are made of recycled rubber or a mixture mixed with recycled rubber (such as materials obtained by simple recycling, crushing, and processing of used scrap tires). The performance is unstable and there are large differences between batches. The rubber pads are also less resistant to aging and wear. The cost of using virgin rubber is generally increased by 1-2.5 times. However, in an environment with high humidity and large pressure fluctuations, waterproof sealing rubber pads made of virgin rubber will also age and wear after long-term use, which will lead to reduced elasticity and deterioration of sealing performance. Therefore, it is of great practical significance to develop a waterproof sealing rubber pad that is wear-resistant, aging-resistant, and can adapt to a variety of complex working conditions. Summary of the Invention

[0003] The purpose of the present invention is to provide a waterproof sealing rubber pad and a preparation method. The preparation method is simple to operate and combines high-quality native materials with a bionic structure. The prepared rubber pad achieves a high level of waterproof performance, elasticity, strength and aging resistance, and can meet the strict requirements of different fields for waterproof sealing rubber pads.

[0004] To achieve the above-mentioned objectives, the present invention provides a waterproof sealing rubber pad, comprising an inner high-elasticity rubber layer and an outer waterproof and wear-resistant rubber layer, a reinforcing fiber mesh is arranged between the high-elasticity rubber layer and the waterproof and wear-resistant rubber layer, the surface of the waterproof and wear-resistant rubber layer is provided with a hexagonal protrusion array structure, and the interior of the high-elasticity rubber layer is provided with a porous structure.

[0005] Preferably, the thickness ratio of the high elasticity rubber layer to the waterproof and wear-resistant rubber layer is 10:3-10.

[0006] Preferably, the high elasticity rubber layer comprises the following components in parts by weight: 60-260 parts of natural rubber, 40-60 parts of styrene-butadiene rubber, 30-80 parts of carbon black, 3-15 parts of zinc oxide, 1-10 parts of stearic acid, 2-13 parts of high-efficiency accelerator, 1-7 parts of sulfur, 5-33 parts of environmentally friendly plasticizer, 3-7 parts of foaming agent; The waterproof and wear-resistant rubber layer comprises the following components in parts by weight: 70-90 parts of EPDM rubber, 40-60 parts of white carbon black, 2-4 parts of silane coupling agent, 3-5 parts of antioxidant, 1-3 parts of dicumyl peroxide, 5-10 parts of paraffin oil; The reinforcing fiber mesh is formed by interweaving virgin aramid fibers or virgin glass fibers.

[0007] Preferably, the high-efficiency accelerator is a mixture of 2-mercaptobenzothiazole, dibenzothiazyl disulfide and N-cyclohexyl-2-benzothiazole sulfenamide, and the mass ratio of the 2-mercaptobenzothiazole, the dibenzothiazyl disulfide and the N-cyclohexyl-2-benzothiazole sulfenamide is 1:2:1; High-efficiency accelerators can ensure vulcanization efficiency while avoiding early vulcanization (scorching) of rubber during processing, ensuring the cross-linking effect and mechanical properties of the highly elastic rubber layer.

[0008] The environmentally friendly plasticizer is one or both of epoxy soybean oil and epoxy fatty acid methyl ester; Environmentally friendly plasticizers in the high-elastic rubber layer can interact with the rubber molecular chains, weaken the intermolecular forces, make the rubber easier to shape during processing, and the finished product has good elasticity and low-temperature performance.

[0009] The foaming agent is azodicarbonamide (ADC); The silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, and the mass ratio of the γ-aminopropyltriethoxysilane to the γ-mercaptopropyltrimethoxysilane is 3:1; Silane coupling agent can give full play to the synergistic effect, solve the problem of uneven dispersion of silica in rubber, and improve the reinforcement effect.

[0010] The antioxidant is a mixture of N-isopropyl-N'-phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2,6-di-tert-butyl-p-cresol, and the mass ratio of the N-isopropyl-N'-phenyl-p-phenylenediamine, the 2,2,4-trimethyl-1,2-dihydroquinoline polymer and the 2,6-di-tert-butyl-p-cresol is 2:2:1.

[0011] Antiaging agents can fully resist the aging of rubber caused by factors such as heat, oxygen, and ozone during use, ensuring that the waterproof sealing rubber gasket maintains stable performance during long-term use.

[0012] The present invention also provides a method for preparing a waterproof sealing rubber pad, comprising the following steps: S1. Preparation of high elastic rubber layer: According to the proportion, natural rubber and styrene-butadiene rubber are masticated at 120-140°C for 10-15 minutes, carbon black, zinc oxide, stearic acid, high-efficiency accelerator and environmentally friendly plasticizer are added in sequence, and mastication is continued for 15-20 minutes. The mixture is transferred to an open mill and thinned 5-8 times at 60-80°C. Sulphur is then added and mixed for 8-10 minutes. The mixture is allowed to stand for 12-24 hours to obtain rubber compound A. S2. Preparation of waterproof and wear-resistant rubber layer: According to the proportion, EPDM rubber was masticated at 130-150° C. for 8-12 minutes, white carbon black and silane coupling agent were added in sequence, masticated for 12-18 minutes, antioxidant, paraffin oil and dicumyl peroxide were added, masticated for 10-15 minutes, and allowed to stand for 12-24 hours to obtain rubber compound B; S3, molding: laying the reinforcing fiber mesh in the mold, placing the rubber compound A obtained in S1 into the mold, transferring it to a flat vulcanizer, and vulcanizing it once to obtain a high-elastic rubber layer with a porous structure and preliminarily combining it with the reinforcing fiber mesh, and then covering the rubber compound B obtained in S2 on the high-elastic rubber layer, and vulcanizing it twice to obtain a waterproof sealing rubber pad.

[0013] Preferably, in S3, the mold surface has a texture of a hexagonal protrusion array structure.

[0014] Preferably, in S3, the primary vulcanization temperature is 150-170° C., the pressure is 10-15 MPa, and the vulcanization time is 5-8 min.

[0015] Preferably, in S3, the secondary vulcanization temperature is 160-180° C., the pressure is 12-18 MPa, and the time is 8-12 min.

[0016] Therefore, the present invention adopts the above-mentioned waterproof sealing rubber pad and preparation method, and the beneficial effects are as follows: The preparation method of the present invention is simple and convenient to operate, and is conducive to the industrialized production of waterproof sealing rubber pads.

[0017] The inner layer of the waterproof sealing rubber gasket of the present invention is a high-elasticity rubber layer, which mainly provides good elasticity and buffering performance, ensuring that it can fit tightly to the sealing surface under different pressure conditions; the outer layer is a waterproof and wear-resistant rubber layer, which has excellent waterproof performance and wear resistance, and effectively resists the erosion of external moisture and abrasion media; the reinforced fiber mesh significantly improves the overall strength and tensile strength of the rubber gasket, preventing the rubber gasket from tearing, deformation and other problems during use. The prepared rubber gasket with a porous inner layer and a dense outer layer has achieved a high level in waterproof performance, elasticity, strength and aging resistance, and can meet the strict requirements of different fields for waterproof sealing rubber gaskets.

[0018] The waterproof sealing rubber pad of the present invention adopts a combination of high-quality original materials and bionic structures. The waterproof and wear-resistant rubber layer has a hexagonal protrusion array structure similar to a tortoise shell, which has extremely high structural stability, can evenly disperse external stress, and reduce fatigue damage of the rubber layer under long-term stress and environmental erosion, thereby delaying the aging process. Tiny guide grooves are formed between the hexagonal protrusions, which can guide the surface moisture to be quickly discharged, reduce the residence time of moisture on the rubber surface, and reduce the penetration and aging effect of water on the rubber. The dense structure (hole-free design) has closely arranged molecules to form a continuous waterproof and wear-resistant barrier; the high-elasticity rubber layer has a porous structure similar to a honeycomb, which not only reduces the weight of the rubber pad, but also provides a buffer space when the rubber expands and contracts due to temperature changes, reduces internal stress, and further improves the aging resistance of the rubber pad.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of a waterproof sealing rubber pad of the present invention; Figure 2 It is a top view of a waterproof sealing rubber pad of the present invention.

[0021] Reference numerals

[0022] 1. High elasticity rubber layer; 2. Waterproof and wear-resistant rubber layer; 3. Reinforced fiber mesh; 4. Hexagonal protrusion array structure; 5. Porous structure. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0024] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0025] In the present invention, natural rubber, styrene-butadiene rubber and EPDM rubber are all made of high-quality virgin materials and do not contain any recycled low-end raw materials, so as to ensure that the performance of the rubber pad meets the requirements.

[0026] Example 1

[0027] like Figure 1-2 As shown, a waterproof sealing rubber pad includes an inner high-elasticity rubber layer 1, an outer waterproof and wear-resistant rubber layer 2 and a reinforcing fiber mesh 3, and the thickness ratio of the high-elasticity rubber layer 1 to the waterproof and wear-resistant rubber layer 2 is 1:1.

[0028] The high elastic rubber layer 1 comprises: 60 parts of natural rubber, 40 parts of styrene-butadiene rubber, 30 parts of carbon black, 3 parts of zinc oxide, 1 part of stearic acid, 2 parts of high-efficiency accelerator, 1 part of sulfur, 5 parts of epoxy fatty acid methyl ester and 3 parts of azodicarbonamide.

[0029] The waterproof and wear-resistant rubber layer 2 comprises: 90 parts of EPDM rubber, 60 parts of white carbon black, 4 parts of silane coupling agent, 5 parts of antioxidant, 3 parts of dicumyl peroxide (DCP), and 10 parts of paraffin oil.

[0030] The preparation method is as follows: S1. Preparation of high elastic rubber layer 1: Natural rubber and styrene-butadiene rubber were masticated at 130°C for 10 min according to the proportions, and carbon black, zinc oxide, stearic acid, a high-efficiency accelerator, an environmentally friendly plasticizer, and a foaming agent were added in sequence. The mixture was masticated for 15 min, and then transferred to an open mill and thinned 8 times at 70°C. Sulfur was then added, and the mixture was mixed for 8 min. The mixture was allowed to stand for 12 h to obtain rubber compound A. S2. Preparation of waterproof and wear-resistant rubber layer 2: According to the proportion, EPDM rubber was masticated at 140° C. for 8 minutes, white carbon black and silane coupling agent were added in sequence, and masticated for 12 minutes. Then, antioxidant, paraffin oil and dicumyl peroxide were added, and masticated for 10 minutes. The mixture was allowed to stand for 12 hours to obtain rubber compound B. S3, molding: lay the reinforced fiber mesh 3 in the mold, put the rubber material A obtained in S1 into the mold, transfer it to a flat vulcanizer, and perform primary vulcanization at a vulcanization temperature of 160°C, a pressure of 10 MPa, and a vulcanization time of 5 min to obtain a high elastic rubber layer 1 with a porous structure 5 and preliminarily combine it with the reinforced fiber mesh 3, then cover the rubber material B obtained in S2 on the high elastic rubber layer 1, perform secondary vulcanization at a vulcanization temperature of 170°C, a pressure of 12 MPa, and a time of 8 min to obtain a waterproof sealing rubber pad with a hexagonal protrusion array structure 4.

[0031] Example 2

[0032] A waterproof sealing rubber pad is different from Example 1 in that the thickness ratio of the high elastic rubber layer 1 to the waterproof and wear-resistant rubber layer 2 is 2:1.

[0033] The high elastic rubber layer 1 comprises: 140 parts of natural rubber, 60 parts of styrene-butadiene rubber, 80 parts of carbon black, 8 parts of zinc oxide, 4 parts of stearic acid, 6 parts of high-efficiency accelerator, 3 parts of sulfur, 16 parts of epoxy soybean oil and 5 parts of azodicarbonamide.

[0034] The waterproof and wear-resistant rubber layer 2 comprises: 80 parts of EPDM rubber, 50 parts of white carbon black, 3 parts of silane coupling agent, 4 parts of antioxidant, 2 parts of dicumyl peroxide (DCP), and 8 parts of paraffin oil.

[0035] Example 3

[0036] A waterproof sealing rubber pad is different from Example 1 in that the thickness ratio of the high elastic rubber layer 1 to the waterproof and wear-resistant rubber layer 2 is 10:3.

[0037] The high elastic rubber layer 1 comprises: 260 parts of natural rubber, 60 parts of styrene-butadiene rubber, 80 parts of carbon black, 15 parts of zinc oxide, 10 parts of stearic acid, 13 parts of high-efficiency accelerator, 7 parts of sulfur, 33 parts of epoxy soybean oil and 7 parts of azodicarbonamide.

[0038] The waterproof and wear-resistant rubber layer 2 comprises: 70 parts of EPDM rubber, 40 parts of white carbon black, 2 parts of silane coupling agent, 3 parts of antioxidant, 1 part of dicumyl peroxide (DCP), and 5 parts of paraffin oil.

[0039] Experimental testing

[0040] The waterproof sealing rubber pads obtained in Examples 1-3 were trimmed to remove burrs and burrs on the edges of the rubber pads, and then the sealing performance and aging tests were performed.

[0041] Test results: The waterproof sealing rubber pads obtained in Examples 1-3 all had good waterproof performance and remained leak-free for 24 hours under a water pressure of 1 MPa.

[0042] The elastic recovery rate of the waterproof sealing rubber gasket obtained in Example 3 reaches more than 90%; the tensile strength is 15 MPa; and after the accelerated aging test (100°C×72h), the performance retention rate reaches more than 85%.

[0043] The elastic recovery rate of the waterproof sealing rubber gasket obtained in Example 2 is 92%; the tensile strength is increased to 18 MPa; and after an accelerated aging test (100° C.×72 h), the performance retention rate is over 88%.

[0044] The elastic recovery rate of the waterproof sealing rubber gasket obtained in Example 1 reaches 95%; the tensile strength is 20 MPa; and after an accelerated aging test (100° C.×72 h), the performance retention rate reaches more than 90%.

[0045] Therefore, the present invention adopts the above-mentioned waterproof sealing rubber pad and preparation method. The preparation method is simple to operate, and the combination of high-quality native materials and bionic structures is designed. The prepared rubber pad has achieved a high level in waterproof performance, elasticity, strength and aging resistance, and can meet the strict requirements of different fields for waterproof sealing rubber pads.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A waterproof sealing rubber pad, characterized in that: It includes an inner high-elasticity rubber layer and an outer waterproof and wear-resistant rubber layer, a reinforced fiber mesh is arranged between the high-elasticity rubber layer and the waterproof and wear-resistant rubber layer, the surface of the waterproof and wear-resistant rubber layer is provided with a hexagonal protrusion array structure, and the interior of the high-elasticity rubber layer is provided with a porous structure.

2. A waterproof sealing rubber pad according to claim 1, characterized in that: The thickness ratio of the high elasticity rubber layer to the waterproof and wear-resistant rubber layer is 10:3-10.

3. The waterproof sealing rubber pad according to claim 1, characterized in that: The high elasticity rubber layer comprises the following components in parts by weight: 60-260 parts of natural rubber, 40-60 parts of styrene-butadiene rubber, 30-80 parts of carbon black, 3-15 parts of zinc oxide, 1-10 parts of stearic acid, 2-13 parts of high-efficiency accelerator, 1-7 parts of sulfur, 5-33 parts of environmentally friendly plasticizer, 3-7 parts of foaming agent; The waterproof and wear-resistant rubber layer comprises the following components in parts by weight: 70-90 parts of EPDM rubber, 40-60 parts of white carbon black, 2-4 parts of silane coupling agent, 3-5 parts of antioxidant, 1-3 parts of dicumyl peroxide, 5-10 parts of paraffin oil; The reinforcing fiber mesh is formed by interweaving virgin aramid fibers or virgin glass fibers.

4. A waterproof sealing rubber pad according to claim 3, characterized in that: The high-efficiency accelerator is a mixture of 2-mercaptobenzothiazole, dibenzothiazyl disulfide and N-cyclohexyl-2-benzothiazole sulfenamide, and the mass ratio of the 2-mercaptobenzothiazole, the dibenzothiazyl disulfide and the N-cyclohexyl-2-benzothiazole sulfenamide is 1:2:1; The environmentally friendly plasticizer is one or both of epoxy soybean oil and epoxy fatty acid methyl ester; The foaming agent is azodicarbonamide; The silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, and the mass ratio of the γ-aminopropyltriethoxysilane to the γ-mercaptopropyltrimethoxysilane is 3:1; The antioxidant is a mixture of N-isopropyl-N'-phenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2,6-di-tert-butyl-p-cresol, and the mass ratio of the N-isopropyl-N'-phenyl-p-phenylenediamine, the 2,2,4-trimethyl-1,2-dihydroquinoline polymer and the 2,6-di-tert-butyl-p-cresol is 2:2:

1.

5. A method for preparing the waterproof sealing rubber pad according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Preparation of high elastic rubber layer: According to the proportion, natural rubber and styrene-butadiene rubber are masticated at 120-140°C for 10-15 minutes, carbon black, zinc oxide, stearic acid, high-efficiency accelerator and environmentally friendly plasticizer are added in sequence, and mastication is continued for 15-20 minutes. The mixture is transferred to an open mill and thinned 5-8 times at 60-80°C. Sulphur is then added and mixed for 8-10 minutes. The mixture is allowed to stand for 12-24 hours to obtain rubber compound A. S2. Preparation of waterproof and wear-resistant rubber layer: According to the proportion, EPDM rubber was masticated at 130-150° C. for 8-12 minutes, white carbon black and silane coupling agent were added in sequence, masticated for 12-18 minutes, antioxidant, paraffin oil and dicumyl peroxide were added, masticated for 10-15 minutes, and allowed to stand for 12-24 hours to obtain rubber compound B; S3, molding: laying the reinforcing fiber mesh in the mold, placing the rubber compound A obtained in S1 into the mold, transferring it to a flat vulcanizer, and vulcanizing it once to obtain a high-elastic rubber layer with a porous structure and preliminarily combining it with the reinforcing fiber mesh, and then covering the rubber compound B obtained in S2 on the high-elastic rubber layer, and vulcanizing it twice to obtain a waterproof sealing rubber pad.

6. The method for preparing a waterproof sealing rubber pad according to claim 5, characterized in that: In S3, the mold surface has a texture of a hexagonal protrusion array structure.

7. The method for preparing a waterproof sealing rubber pad according to claim 5, characterized in that: In S3, the primary vulcanization temperature is 150-170° C., the pressure is 10-15 MPa, and the vulcanization time is 5-8 min.

8. The method for preparing a waterproof sealing rubber pad according to claim 5, characterized in that: In S3, the secondary vulcanization temperature is 160-180° C., the pressure is 12-18 MPa, and the time is 8-12 min.

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