Rubber waterstop material with low compression set rate and preparation method thereof

Abstract

The invention discloses a preparation method of a rubber waterstop material with a low compression set rate, which comprises the following steps: firstly, carrying out blending reaction on hydroxyl silicone oil and boric acid to obtain liquid polyborosiloxane; the preparation method comprises the following steps: adding liquid polyborosiloxane and natural rubber into an internal mixer according to a ratio, and carrying out internal mixing to obtain a mixture; adding zinc oxide, an anti-aging agent, stearic acid and an anti-tearing agent into the obtained mixture, and continuously mixing; continuously adding kaolin talcum powder, calcium carbonate, calcium oxide, white carbon black, N550, N330 and KH550, and internally mixing again to obtain a preform; adding a vulcanization accelerator and a vulcanizing agent into the preform, and continuously mixing to obtain a rubber material to be vulcanized; and vulcanizing and forming the rubber material to be vulcanized to prepare the rubber water-stop belt material with the low compression set rate. According to the invention, the compression set rate of the rubber material can be reduced while the tensile strength, elongation, tear resistance and other properties of the rubber are not sacrificed, so that the product performance is enhanced.

Description

Technical Field

[0001] This invention relates to the field of waterstop technology, specifically to a rubber waterstop material with low compression set and its preparation method. Background Technology

[0002] Waterstops are key components of waterproofing systems and are widely used in construction, water conservancy, bridge, and tunnel projects. Rubber waterstops primarily utilize the high elasticity, compressibility, and wear resistance of rubber. Through elastic deformation under various loads, they adapt to the displacement and changes in structural joints. This deformation capability allows them to effectively tighten and seal, preventing leakage in building structures. Simultaneously, rubber waterstops also possess a certain degree of shock absorption and cushioning, absorbing vibration and deformation energy of the structure to a certain extent, enhancing the durability and safety of the project.

[0003] However, the durability of traditional rubber waterstops faces severe challenges during service, especially the problem of increased compression set: when the material is subjected to structural loads, temperature stress or compressive forces generated by foundation settlement for a long time, the rubber molecular chains will undergo irreversible slippage or even breakage, resulting in a decrease in resilience and even loss of sealing ability.

[0004] In existing technologies, while ordinary synthetic rubbers (such as chloroprene rubber or EPDM rubber) possess initial high elasticity, they are prone to problems such as plasticizer migration, crosslinking network degradation, and uneven filler dispersion under humid, hot, oxidizing, or dynamic loading environments. This leads to an increase in compression set (ASTM D395 / GB / T 7759 standard) (typically >30%). This defect reduces the resilience of the waterproofing strip, causes sealing failure, reduces durability and lifespan, and consequently leads to engineering risks such as water leakage and even secondary disasters. Among the existing publicly available technologies, Chinese patent CN118667270A discloses an aging-resistant fluororubber material with low compression set and its preparation method. The fluororubber material is prepared from raw materials including fluororubber raw rubber, vulcanizing agent, and reinforcing agent. After treatment at 200℃×70h and 250℃×70h, the fluororubber material still maintains a low compression set. However, this process is relatively complex, and fluororubber is expensive. Chinese patent CN104072891A discloses an aging-resistant and permanent compression set resistant rubber material. This invention uses EPDM rubber and acrylonitrile-grafted EPDM rubber as the main materials, and adds dicumyl peroxide, vulcanizing agent BIBP, crosslinking aid, reinforcing agent, trioctyl trimellitate and paraffin wax. The resulting rubber material has excellent aging resistance, but its tensile strength and elongation at break are low, making it unsuitable for applications requiring high elasticity and high strain capacity.

[0005] The industry currently improves resistance to permanent compression set primarily by optimizing the vulcanization system or adding reinforcing agents (such as carbon black), but this often comes at the cost of sacrificing the material's low-temperature flexibility or processing performance. Therefore, there is an urgent need to develop a rubber waterstop that combines ultra-low compression set (≤15%), high resilience, and environmental resistance to meet the long-term sealing requirements under harsh working conditions. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention proposes a rubber waterstop material with low compression set and its preparation method. By introducing liquid polyborosiloxane to modify natural rubber, a rubber waterstop material with low compression set and aging resistance is obtained.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A rubber waterstop material with low compression set, comprising the following raw materials by weight:

[0009] 100 parts natural rubber

[0010] 0.2-5 parts of liquid polyborosiloxane

[0011] Zinc oxide 5-5.4 parts,

[0012] Anti-aging agent 5.8 parts,

[0013] Stearic acid 1.5~1.9 parts,

[0014] Microcrystalline wax 1.5~1.9 parts,

[0015] 1.8 parts of tear-resistant agent,

[0016] 13 parts of kaolin talc powder

[0017] Calcium oxide 3.8 parts,

[0018] Calcium carbonate 22-24.5 parts,

[0019] 3 parts of white carbon black

[0020] KH550 2 copies,

[0021] N550 25-27 servings,

[0022] N330 4~5.2 portions,

[0023] 2.4 parts of vulcanization accelerator,

[0024] Vulcanizing agent 0.3~0.6 parts.

[0025] A method for preparing a rubber waterstop material with low compression set includes the following steps:

[0026] Step 1: Pour hydroxyl silicone oil into a vacuum kneader and heat it to 90~95℃. Then add boric acid to carry out a blending reaction to obtain liquid polyborosiloxane. The blending reaction time is 30~40 min.

[0027] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds at a temperature of 30-40°C to obtain a mixture.

[0028] Step 3: Add zinc oxide, antioxidant, stearic acid and tear-resistant agent to the mixture obtained in step 2, and then perform intensive mixing for 90 seconds at a temperature range of 40-50°C.

[0029] Step 4: Continue to add kaolin talc powder, calcium carbonate, calcium oxide, fumed silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature range is 50~65℃.

[0030] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in step 4, and perform intensive mixing. The intensive mixing time is 60s, and the intensive mixing temperature range is 65~75℃, to obtain the rubber compound to be vulcanized.

[0031] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0032] Furthermore, in step 1, the molar ratio of silicon atoms to boron atoms in the liquid polyborosiloxane is 11.2:1 to 33.7:1, and the rheological viscosity is 950 to 1000 mPa·s.

[0033] Further, the antioxidant mentioned in step 3 is a mixture of antioxidant RD, antioxidant 4010NA and antioxidant 4020, and the mass ratio of antioxidant RD, antioxidant 4010NA and antioxidant 4020 is 1.9:2:1.9.

[0034] Furthermore, the kaolin talc powder mentioned in step 4 has a particle size of 45 μm.

[0035] Further, the vulcanization accelerator mentioned in step 5 is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, and the mass ratio of the mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide is 0.5:1:0.9.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) This invention uses natural rubber as the matrix and introduces liquid polyborosiloxane material to utilize its strain rate sensitive effect. That is, it exhibits a fluid dynamic at low strain rates and a rapid increase in viscosity and elasticity at high strain rates, which can effectively dissipate impact energy. Under the action of dynamic external force, the BO bonds of polyborosiloxane will undergo reversible breaking and reconnection reactions to improve the resilience of the rubber, thereby achieving the effect of reducing the compression set of the rubber.

[0038] (2) The liquid polyborosiloxane used in this invention exhibits better dispersibility and compatibility during the blending process compared to its traditional solid form, effectively improving the problems of material agglomeration and uneven mixing.

[0039] (3) The present invention can reduce the compression set of rubber materials without sacrificing the tensile strength, elongation and tear resistance of rubber, thereby enhancing the performance of the product. Detailed Implementation

[0040] The technical solution of the present invention will be described in detail below through specific embodiments.

[0041] A rubber waterstop material with low compression set, comprising the following raw materials by weight:

[0042] 100 parts natural rubber

[0043] 0.2-5 parts of liquid polyborosiloxane

[0044] Zinc oxide 5-5.4 parts,

[0045] Anti-aging agent 5.8 parts,

[0046] Stearic acid 1.5~1.9 parts,

[0047] Microcrystalline wax 1.5~1.9 parts,

[0048] 1.8 parts of tear-resistant agent,

[0049] 13 parts of kaolin talc powder

[0050] Calcium oxide 3.8 parts,

[0051] Calcium carbonate 22-24.5 parts,

[0052] 3 parts of white carbon black

[0053] KH550 2 copies,

[0054] N550 25-27 servings,

[0055] N330 4~5.2 portions,

[0056] 2.4 parts of vulcanization accelerator,

[0057] Vulcanizing agent 0.3~0.6 parts.

[0058] A method for preparing a rubber waterstop material with low compression set includes the following steps:

[0059] Step 1: Pour hydroxyl silicone oil into a vacuum kneader and heat to 90-95°C. Then add boric acid for a blending reaction to obtain liquid polyborosiloxane. The blending reaction time is 30-40 min. The molar ratio of silicon atoms to boron atoms in the liquid polyborosiloxane is 11.2:1 to 33.7:1, and the rheological viscosity is 950-1000 mPa·s.

[0060] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds at a temperature of 30-40°C to obtain a mixture.

[0061] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature range of 40-50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0062] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature range is 50~65℃.

[0063] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform intensive mixing for 60 seconds at a temperature range of 65-75°C to obtain the vulcanized rubber compound. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mass ratio of 0.5:1:0.9.

[0064] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0065] Table 1 is a statistical table of the raw material mass fractions for preparing rubber waterstop materials in Examples 1-5 and the comparative examples.

[0066] Table 1. Parts by weight of comparative examples and Examples 1-5

[0067]

[0068] Example 1

[0069] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 0.2 parts of liquid polyborosiloxane, 5 parts of zinc oxide, 5.8 parts of antioxidant, 1.5 parts of stearic acid, 1.5 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 22 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 25 parts of N550, 4 parts of N330, 2.4 parts of vulcanization accelerator, and 0.3 parts of vulcanizing agent;

[0070] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds. The mixing temperature is controlled below 40°C to obtain a mixture.

[0071] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature below 50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0072] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature is controlled below 65℃.

[0073] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform internal mixing for 60 seconds. The mixing temperature is controlled below 75℃ to obtain the rubber compound to be vulcanized. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide. The mass ratio of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide is 0.5:1:0.9.

[0074] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0075] Example 2

[0076] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 0.5 parts of liquid polyborosiloxane, 5.1 parts of zinc oxide, 5.8 parts of antioxidant, 1.6 parts of stearic acid, 1.6 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 23 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 25.5 parts of N550, 4.5 parts of N330, 2.4 parts of vulcanization accelerator, and 0.35 parts of vulcanizing agent;

[0077] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds. The mixing temperature is controlled below 40°C to obtain a mixture.

[0078] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature below 50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0079] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature is controlled below 65℃.

[0080] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform intensive mixing for 60 seconds at a temperature below 75°C to obtain the vulcanized rubber compound. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mass ratio of 0.5:1:0.9.

[0081] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0082] Example 3

[0083] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 1 part of liquid polyborosiloxane, 5.2 parts of zinc oxide, 5.8 parts of antioxidant, 1.7 parts of stearic acid, 1.7 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 23.5 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 26 parts of N550, 4.8 parts of N330, 2.4 parts of vulcanization accelerator, and 0.4 parts of vulcanizing agent;

[0084] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds. The mixing temperature is controlled below 40°C to obtain a mixture.

[0085] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature below 50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0086] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature is controlled below 65℃.

[0087] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform intensive mixing for 60 seconds at a temperature below 75°C to obtain the vulcanized rubber compound. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mass ratio of 0.5:1:0.9.

[0088] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0089] Example 4

[0090] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 3 parts of liquid polyborosiloxane, 5.3 parts of zinc oxide, 5.8 parts of antioxidant, 1.8 parts of stearic acid, 1.8 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 24 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 26.5 parts of N550, 5.0 parts of N330, 2.4 parts of vulcanization accelerator, and 0.5 parts of vulcanizing agent;

[0091] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds. The mixing temperature is controlled below 40°C to obtain a mixture.

[0092] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature below 50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0093] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature is controlled below 65℃.

[0094] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform intensive mixing for 60 seconds at a temperature below 75°C to obtain the vulcanized rubber compound. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mass ratio of 0.5:1:0.9.

[0095] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0096] Example 5

[0097] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 5 parts of liquid polyborosiloxane, 5.4 parts of zinc oxide, 5.8 parts of antioxidant, 1.9 parts of stearic acid, 1.9 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 24.5 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 27 parts of N550, 5.2 parts of N330, 2.4 parts of vulcanization accelerator, and 0.6 parts of vulcanizing agent;

[0098] Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds. The mixing temperature is controlled below 40°C to obtain a mixture.

[0099] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the mixture obtained in Step 2, and perform intensive mixing for 90 seconds at a temperature below 50°C. The antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mass ratio of 1.9:2:1.9.

[0100] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium carbonate, calcium oxide, silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature is controlled below 65℃.

[0101] Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in Step 4, and perform intensive mixing for 60 seconds at a temperature below 75°C to obtain the vulcanized rubber compound. The vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mass ratio of 0.5:1:0.9.

[0102] Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

[0103] Comparative Example

[0104] Step 1: Weigh out 100 parts of natural rubber (by mass, the same below), 0 parts of liquid polyborosiloxane, 5 parts of zinc oxide, 5.8 parts of antioxidant, 1.5 parts of stearic acid, 1.5 parts of microcrystalline wax, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder, 3.8 parts of calcium oxide, 22 parts of calcium carbonate, 3 parts of silica, 2 parts of KH550, 25 parts of N550, 4 parts of N330, 2.4 parts of vulcanization accelerator, and 0.3 parts of vulcanizing agent;

[0105] Step 2: Mix natural rubber in an internal mixer for 90 seconds, controlling the mixing temperature to be below 40°C, to obtain the composite matrix;

[0106] Step 3: Add zinc oxide, antioxidant, stearic acid, and tear-resistant agent to the composite matrix, and perform intensive mixing for 90 seconds, with the mixing temperature controlled below 50°C; the antioxidant is a mixture of antioxidant RD, antioxidant 4010NA, and antioxidant 4020, with a mixing mass ratio of antioxidant RD, antioxidant 4010NA, and antioxidant 4020 of 1.9:2:1.9;

[0107] Step 4: Continue to add kaolin talc powder (kaolin talc powder particle size is 45μm), calcium oxide, calcium carbonate, silica, KH550, N550, and N330, and carry out intensive mixing for 210 seconds, controlling the mixing temperature below 65℃, and mix evenly to obtain a preform.

[0108] Step 5: Control the temperature below 75℃, add vulcanization accelerator and vulcanizing agent to the preform, and perform intensive mixing for 60 seconds to obtain the vulcanized body; the vulcanization accelerator is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, and the mixing mass ratio of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide is 0.5:1:0.9;

[0109] Step 6: Vulcanize and mold the body to be vulcanized obtained in Step 5 at 143°C.

[0110] The comparative examples and Examples 1-5 were subjected to hardness tests according to GB / T 531.1, tensile strength and elongation at break tests according to GB / T 528, tear strength tests according to GB / T 529, hot air aging tests according to GB / T 3512, and compression set tests according to GB / T 7759.1. The test results are shown in Table 2.

[0111] Table 2 Performance Comparison of Comparative Examples and Examples 1-5

[0112]

[0113] As shown in the table above, the compression set of Examples 1-5 is lower than that of the comparative example, indicating that this liquid polyborosiloxane has a good effect on improving the compression set of natural rubber materials. The rubber materials of Examples 1-5 have lower hardness than the rubber materials of the comparative example. With the increase of the liquid polyborosiloxane content, the elongation at break shows an increasing trend, the tensile strength shows a decreasing trend, and the tear strength shows an initial increasing and then decreasing trend. After aging (70℃×168h), the hardness of the rubber is higher than that of the unaged rubber, but it still shows a decreasing trend with the increase of the liquid polyborosiloxane content and is lower than that of the comparative rubber material. The tensile strength and elongation at break of the rubber materials of the Examples after hot air aging are lower than those of the comparative rubber material.

[0114] A comparison between Examples 1-5 and the comparative examples shows that the method involved in this invention, which prepares rubber waterstop material by adding liquid polyborosiloxane, has a low compression set without sacrificing the tensile strength, elongation, and tear resistance of rubber. This indicates that the technical solution of this invention is stable and reliable, and the method is simple and easy to operate.

[0115] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rubber waterstop material with low compression set, characterized in that, Raw materials, by weight, include: 100 parts natural rubber 0.2-5 parts of liquid polyborosiloxane Zinc oxide 5-5.4 parts, Anti-aging agent 5.8 parts, Stearic acid 1.5~1.9 parts, Microcrystalline wax 1.5~1.9 parts, 1.8 parts of tear-resistant agent, 13 parts of kaolin talc powder Calcium oxide 3.8 parts, Calcium carbonate 22-24.5 parts, 3 parts of white carbon black KH550 2 copies, N550 25-27 servings, N330 4~5.2 portions, 2.4 parts of vulcanization accelerator, Vulcanizing agent 0.3~0.6 parts.

2. The method for preparing a rubber waterstop material with low compression set according to claim 1, characterized in that, Specifically, it includes the following steps: Step 1: Pour hydroxyl silicone oil into a vacuum kneader and heat it to 90~95℃. Then add boric acid to carry out a blending reaction to obtain liquid polyborosiloxane. The blending reaction time is 30~40 min. Step 2: Add liquid polyborosiloxane and natural rubber to a mixer in a certain proportion and mix for 60 seconds at a temperature of 30-40°C to obtain a mixture. Step 3: Add zinc oxide, antioxidant, stearic acid and tear-resistant agent to the mixture obtained in step 2, and then perform intensive mixing for 90 seconds at a temperature range of 40-50°C. Step 4: Continue to add kaolin talc powder, calcium carbonate, calcium oxide, fumed silica, N550, N330, and KH550, and carry out intensive mixing to obtain a preform. The intensive mixing time is 210s, and the intensive mixing temperature range is 50~65℃. Step 5: Add vulcanization accelerator and vulcanizing agent to the preform obtained in step 4, and perform intensive mixing. The intensive mixing time is 60s, and the intensive mixing temperature range is 65~75℃, to obtain the rubber compound to be vulcanized. Step 6: The rubber compound to be vulcanized in Step 5 is vulcanized and molded at 143°C to prepare a rubber waterstop material with low compression set.

3. The method for preparing a rubber waterstop material with low compression set according to claim 2, characterized in that, The molar ratio of silicon atoms to boron atoms in the liquid polyborosiloxane described in step 1 is 11.2:1 to 33.7:1, and the rheological viscosity is 950 to 1000 mPa·s.

4. The method for preparing a rubber waterstop material with low compression set according to claim 2, characterized in that, The antioxidant mentioned in step 3 is a mixture of antioxidant RD, antioxidant 4010NA and antioxidant 4020, and the mass ratio of antioxidant RD, antioxidant 4010NA and antioxidant 4020 is 1.9:2:1.

9.

5. The method for preparing a rubber waterstop material with low compression set according to claim 2, characterized in that, The kaolin talc powder mentioned in step 4 has a particle size of 45 μm.

6. The method for preparing a rubber waterstop material with low compression set according to claim 2, characterized in that, The vulcanization accelerator mentioned in step 5 is a mixture of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide, with a mixing mass ratio of benzothiazole disulfide, tetramethylthiuram disulfide, and N-cyclohexyl-2-benzothiazole sulfenamide of 0.5:1:0.9.

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