Anti-aging rubber waterstop and preparation method thereof

Abstract

The invention relates to the technical field of waterstops, and provides an anti-aging rubber waterstop and a preparation method thereof.The anti-aging rubber waterstop is prepared from, by weight, 60-80 parts of ethylene propylene diene monomer, 40-60 parts of filler, 6-10 parts of flame retardant, 1-3 parts of antioxidant, 2-3 parts of vulcanizing agent and 6-8 parts of plasticizer; the ethylene propylene diene monomer is ethylidene norbornene type ethylene propylene diene monomer, and the ethylidene norbornene type ethylene propylene diene monomer consists of first ethylidene norbornene type ethylene propylene diene monomer and second ethylidene norbornene type ethylene propylene diene monomer; the ENB content of the first ethylidene norbornene type ethylene propylene diene monomer is different from that of the second ethylidene norbornene type ethylene propylene diene monomer. By means of the technical scheme, the problem that in the related technology, a rubber water stop belt is not resistant to aging is solved.

Description

Technical Field

[0001] The invention relates to the technical field of waterstop strips, and in particular to an aging-resistant rubber waterstop strip and a preparation method thereof. Background Art

[0002] Rubber waterstop is an elastic waterstop material made of rubber as the main raw material and various additives. It is usually in the shape of a long strip with waterstop ribs of different shapes in the middle, such as center hole type, dumbbell type and other forms. Its appearance can be designed with different widths and thicknesses, and the color is generally black or other dark colors. It is widely used in water conservancy projects, construction projects, transportation projects and other fields.

[0003] During use, rubber waterstops are exposed to the natural environment for a long time. Under the influence of ultraviolet radiation, temperature changes, oxygen and water, the rubber molecular chain is easy to break, causing the rubber to become hard and brittle, and cracking. This will make the waterstop lose its elasticity and unable to fit tightly to the waterstop part, thus creating a leakage channel. In an environment with frequent temperature changes, the aged rubber waterstop may crack due to thermal expansion and contraction, further exacerbating the leakage problem.

[0004] For water conservancy projects and underground buildings, leakage may cause water accumulation inside the structure, accelerate steel corrosion and concrete deterioration, and in severe cases even threaten the safety of the entire structure and cause engineering accidents. Therefore, it is necessary to develop a rubber waterstop with good aging resistance. Summary of the invention

[0005] The invention provides an aging-resistant rubber waterstop and a preparation method thereof, which solves the problem that the rubber waterstop in the related art is not aging-resistant.

[0006] The technical solution of the present invention is as follows: The present invention provides an anti-aging rubber waterstop, comprising the following component raw materials in parts by weight: 60-80 parts of EPDM rubber, 40-60 parts of filler, 6-10 parts of flame retardant, 1-3 parts of antioxidant, 2-3 parts of vulcanizer, and 6-8 parts of plasticizer; The EPDM rubber is an ethylidene norbornene type EPDM rubber, which is composed of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber, and the first ethylidene norbornene type EPDM rubber and the second ethylidene norbornene type EPDM rubber have different ENB contents.

[0007] As a further technical solution, the ENB content is the content of ethylidene norbornene in the ethylidene norbornene type EPDM rubber.

[0008] As a further technical solution, the mass ratio of the first ethylidene norbornene type EPDM rubber to the second ethylidene norbornene type EPDM rubber is 1-6:1.

[0009] As a further technical solution, the ENB content of the first ethylidene norbornene type EPDM rubber is 2.7wt%, and the ENB content of the second ethylidene norbornene type EPDM rubber is 5.5wt%.

[0010] As a further technical solution, the mass ratio of the first ethylidene norbornene type EPDM rubber to the second ethylidene norbornene type EPDM rubber is 4-5:1.

[0011] As a further technical solution, the filler includes carbon black and metal oxide, and the mass ratio of the carbon black to the metal oxide is 2~3:1.

[0012] In the present invention, carbon black and metal oxides are added as fillers in an EPDM rubber matrix to prepare a rubber waterstop. By exerting the synergistic effect between the carbon black and the metal oxides, a uniform heat conduction channel is formed in the rubber matrix, heat is effectively dispersed, thermal aging of the rubber caused by excessive local heat accumulation is avoided, and thermal degradation of the rubber molecular chain is inhibited, thereby further improving the aging resistance of the rubber waterstop.

[0013] As a further technical solution, the metal oxide includes one or both of magnesium oxide and tungsten trioxide.

[0014] As a further technical solution, when the metal oxide consists of tungsten trioxide and magnesium oxide, the mass ratio of the tungsten trioxide to the magnesium oxide is 1-2:1.

[0015] In the present invention, tungsten trioxide and magnesium oxide are added as metal oxides at the same time, and the synergistic effect of the two is exerted to further improve the aging resistance of the rubber waterstop.

[0016] As a further technical solution, the preparation method of the filler comprises the following steps: carbon black, metal oxide, propylene sulfonic acid and solvent are uniformly mixed, ball milled, dried and sieved to obtain the filler.

[0017] As a further technical solution, the mass ratio of the carbon black and the metal oxide to the propylene sulfonic acid is 18:1, the solvent is ethanol, and the mass ratio of the carbon black and the metal oxide to the solvent is 2:1.

[0018] As a further technical solution, the mesh size of the sieving sieve is 400 meshes.

[0019] As a further technical solution, the flame retardant includes one or both of ammonium polyphosphate and triphenyl phosphate.

[0020] As a further technical solution, the antioxidant includes one or more of antioxidant 1076, antioxidant 264, and antioxidant 168.

[0021] As a further technical solution, the vulcanizing agent includes one or both of dicumyl peroxide and benzoyl peroxide.

[0022] As a further technical solution, the plasticizer includes one or both of dioctyl adipate and dioctyl sebacate.

[0023] The present invention also provides a method for preparing an aging-resistant rubber waterstop, comprising the following steps: S1, weighing EPDM rubber, filler, flame retardant, antioxidant, plasticizer, mixing, adding vulcanizing agent and continuing mixing to obtain a mixed rubber material; S2. The mixed rubber material is subjected to injection molding to obtain an aging-resistant rubber waterstop.

[0024] As a further technical solution, the mixing temperature is 130-140° C., and the mixing time is 5-10 min.

[0025] The working principle and beneficial effects of the present invention are: In the present invention, two ethylidene norbornene-type ethylene propylene diene monomer rubbers with different ENB contents are used as raw materials to prepare an aging-resistant rubber waterstop. By adjusting the cross-linking structure of the rubber molecular chain, the resistance of the waterstop to aging factors such as ultraviolet rays, oxygen and heat is improved, thereby improving the aging resistance of the rubber waterstop. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the following examples and comparative examples: The first ethylene norbornene type EPDM rubber: model EPDM 763P, ENB content is 2.7wt%, ethylene content is 69.0wt%, propylene content is 32.0wt%, specific gravity is 0.87 g / cm 3 ; Second ethylene norbornene type EPDM rubber: Model: EPDM S5890F, ENB content: 5.5wt%, ethylene content: 68.0wt%, specific gravity: 0.86 g / cm 3 ; Carbon black: model N220; Magnesium oxide: median particle size is 3 μm; Tungsten trioxide: median particle size is 1μm.

[0028] Example 1 A method for preparing an aging-resistant rubber waterstop comprises the following steps: S1. Weigh 60 parts of EPDM rubber, 40 parts of filler, 6 parts of ammonium polyphosphate, 1 part of antioxidant 1076, and 6 parts of dioctyl adipate, mix at 130° C. for 10 min, add 2 parts of dicumyl peroxide and stir evenly to obtain a mixed rubber material, wherein the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 1:1, and the filler is carbon black; S2. The mixed rubber material is subjected to injection molding to obtain an aging-resistant rubber waterstop.

[0029] Example 2 A method for preparing an aging-resistant rubber waterstop comprises the following steps: S1. Weigh 70 parts of EPDM rubber, 50 parts of filler, 8 parts of ammonium polyphosphate, 2 parts of antioxidant 264, and 7 parts of dioctyl adipate, mix at 135° C. for 8 min, add 2.5 parts of dicumyl peroxide and stir evenly to obtain a mixed rubber material, wherein the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 1:1, and the filler is carbon black; S2. The mixed rubber material is subjected to injection molding to obtain an aging-resistant rubber waterstop.

[0030] Example 3 A method for preparing an aging-resistant rubber waterstop comprises the following steps: S1. Weigh 80 parts of EPDM rubber, 60 parts of filler, 10 parts of triphenyl phosphate, 3 parts of antioxidant 168, and 8 parts of dioctyl sebacate, mix at 140° C. for 5 min, add 3 parts of benzoyl peroxide and stir evenly to obtain a mixed rubber material, wherein the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 1:1, and the filler is carbon black; S2. The mixed rubber material is subjected to injection molding to obtain an aging-resistant rubber waterstop.

[0031] Example 4 Compared with Example 1, Example 4 is different in that the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 4:1.

[0032] Example 5 Compared with Example 1, Example 5 is different in that the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 5:1.

[0033] Example 6 Compared with Example 1, Example 6 is different in that the EPDM rubber consists of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber in a mass ratio of 6:1.

[0034] Example 7 Compared with Example 5, the difference of Example 7 is that the filler is magnesium oxide.

[0035] Example 8 Compared with Example 7, the difference of Example 8 is that the filler is tungsten trioxide.

[0036] Example 9 The preparation method of the filler comprises the following steps: weighing 60 parts of carbon black, 30 parts of magnesium oxide, 5 parts of propylene sulfonic acid and 45 parts of ethanol, mixing them evenly and then ball milling them, drying them and passing them through a 400-mesh sieve to obtain the filler; Compared with Example 8, the difference of Example 9 is that the filler is a filler obtained by the above-mentioned preparation method.

[0037] Example 10 Compared with Example 9, the difference in Example 10 is that magnesium oxide is replaced by an equal amount of tungsten trioxide.

[0038] Embodiment 11 Compared with Example 10, the difference in Example 11 is that when preparing the filler, the amount of carbon black added is 67.5 parts, and the amount of tungsten trioxide added is 22.5 parts.

[0039] Example 12 Compared with Example 11, Example 12 is different in that carbon black is replaced by an equal amount of magnesium oxide.

[0040] Example 13 Compared with Example 11, the difference of Example 13 is that tungsten trioxide is replaced by tungsten trioxide and magnesium oxide in a mass ratio of 1:1.

[0041] Embodiment 14 Compared with Example 11, the difference of Example 14 is that tungsten trioxide is replaced by tungsten trioxide and magnesium oxide in a mass ratio of 2:1.

[0042] Embodiment 15 Compared with Example 11, the difference in Example 15 is that the carbon black and tungsten trioxide are not ball-milled.

[0043] Example 16 Compared with Example 14, the difference of Example 16 is that in the preparation process of the filler, propylene sulfonic acid is replaced by an equal amount of sodium dodecylbenzene sulfonate.

[0044] Comparative Example 1 Compared with Example 1, the difference of Comparative Example 1 is that the EPDM rubber is a first ethylidene norbornene type EPDM rubber.

[0045] Comparative Example 2 Compared with Example 1, the difference of Comparative Example 2 is that the EPDM rubber is a second ethylidene norbornene type EPDM rubber.

[0046] The rubber waterstops prepared in Examples 1 to 16 and Comparative Examples 1 to 2 were prepared into Type 2 dumbbell specimens with a thickness of 6.3 mm according to the sample preparation method specified in Q / CR 562.2-2017 and tested according to the following method: 1. Tensile strength: According to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop", the tensile strength of the sample before and after hot air aging treatment is tested. The conditions of hot air aging treatment are: 80°C, 168h, and the change rate of tensile strength after aging = (tensile strength after aging - tensile strength before aging) / tensile strength before aging × 100%.

[0047] 2. Elongation at break: According to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop", the elongation at break of the test sample before and after hot air aging treatment is tested. The conditions for hot air aging treatment are: 80°C, 168h. The change rate of elongation at break after aging = (elongation at break after aging - elongation at break before aging) / elongation at break before aging × 100%.

[0048] The test results are shown in Table 1 below: Table 1 Performance test results of rubber waterstops prepared in Examples 1 to 16 and Comparative Examples 1 to 2

[0049] Compared with Comparative Examples 1 and 2, Example 1 simultaneously adds the first ethylidene norbornene type EPDM rubber and the second ethylidene norbornene type EPDM rubber. As a result, the tensile strength and elongation at break of the rubber waterstop obtained in Example 1 before aging are better than those of Comparative Examples 1 and 2, and the change rate of tensile strength and the change rate of elongation at break after aging are lower than those of Comparative Examples 1 and 2, indicating that the first ethylidene norbornene type EPDM rubber and the second ethylidene norbornene type EPDM rubber play a synergistic role in improving the tensile strength, elongation at break and aging resistance of the rubber waterstop.

[0050] In Example 1 and Examples 4 to 6, different mass ratios of the first ethylidene norbornene type EPDM rubber and the second ethylidene norbornene type EPDM rubber were added. As a result, the tensile strength and elongation at break of the rubber waterstop obtained in Examples 4 and 5 before aging were better than those in Example 1 and Example 6, and the change rates of tensile strength and elongation at break after aging were lower than those in Example 1 and Example 6, indicating that when the mass ratio of the first ethylidene norbornene type EPDM rubber to the second ethylidene norbornene type EPDM rubber is 4 to 5:1, the obtained rubber waterstop has better tensile strength, elongation at break and aging resistance.

[0051] Compared with Examples 5, 7 and 8, Examples 9 to 11 add fillers prepared by ball milling carbon black and metal oxides. As a result, the tensile strength and elongation at break of the rubber waterstop obtained in Examples 9 to 11 before and after aging are better than those in Examples 5, 7 and 8, and the change rate of tensile strength and elongation at break after aging are lower than those in Examples 5, 7 and 8, indicating that carbon black and metal oxides have a synergistic effect, which further improves the tensile strength, elongation at break and aging resistance of the rubber waterstop.

[0052] Compared with Example 11, Examples 13 and 14 simultaneously added magnesium oxide and tungsten trioxide as metal oxides. As a result, the tensile strength and elongation at break of the rubber waterstop obtained in Examples 13 and 14 before aging were better than those in Example 11, and the change rates of tensile strength and elongation at break after aging were lower than those in Example 11, indicating that magnesium oxide and tungsten trioxide play a synergistic role in improving the tensile strength, elongation at break and aging resistance of the rubber waterstop.

[0053] Compared with Example 15, Example 11 adds fillers prepared by ball milling. Results The tensile strength and elongation at break of the rubber waterstop obtained in Example 11 before aging are better than those in Example 15, and the change rate of tensile strength and the change rate of elongation at break after aging are lower than those in Example 15, indicating that the filler is prepared by ball milling, which further improves the tensile strength, elongation at break and aging resistance of the rubber waterstop.

[0054] Compared with Example 16, Example 14 adds propylene sulfonic acid when preparing the filler. As a result, the tensile strength and elongation at break of the rubber waterstop obtained in Example 14 before aging are better than those in Example 16, and the change rate of tensile strength and elongation at break after aging are lower than those in Example 16, indicating that when propylene sulfonic acid is added during the preparation of the filler, the rubber waterstop has better tensile strength, elongation at break and aging resistance.

[0055] The rubber waterstop prepared in Example 1 was also tested as follows: 3. Alkali resistance: Place the sample in a saturated calcium hydroxide solution and let it stand at 23°C for 168 hours, then test the tensile strength and elongation at break of the sample.

[0056] 4. Ozone aging: According to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop", the ozone aging performance of the sample was tested. The aging condition was 50×10 -8 , humidity is 20%, 40℃×48h.

[0057] 5. Compression permanent deformation: According to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop", the compression permanent deformation of the test sample is tested.

[0058] 6. Tear strength: Test the tear strength of the sample according to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop".

[0059] 7. Brittle temperature: Test the brittle temperature of the sample according to the test method specified in Q / CR 562.2-2017 "Railway Tunnel Drainage Materials Part 2: Waterstop".

[0060] The test results are shown in Table 2 below: Table 2 Performance test results of the rubber waterstop prepared in Example 1

[0061] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An aging-resistant rubber waterstop, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of EPDM rubber, 40-60 parts of filler, 6-10 parts of flame retardant, 1-3 parts of antioxidant, 2-3 parts of vulcanizer and 6-8 parts of plasticizer; the EPDM rubber is ethylidene norbornene type EPDM rubber, the ethylidene norbornene type EPDM rubber is composed of a first ethylidene norbornene type EPDM rubber and a second ethylidene norbornene type EPDM rubber, and the first ethylidene norbornene type EPDM rubber and the second ethylidene norbornene type EPDM rubber have different ENB contents.

2. The aging-resistant rubber waterstop according to claim 1, characterized in that: The mass ratio of the first ethylidene norbornene type EPDM rubber to the second ethylidene norbornene type EPDM rubber is 1-6:

1.

3. The aging-resistant rubber waterstop according to claim 1, characterized in that: The ENB content of the first ethylidene norbornene type EPDM rubber is 2.7 wt %, and the ENB content of the second ethylidene norbornene type EPDM rubber is 5.5 wt %.

4. The aging-resistant rubber waterstop according to claim 1, characterized in that: The filler includes carbon black and metal oxide, and the mass ratio of the carbon black to the metal oxide is 2-3:

1.

5. The anti-aging rubber waterstop according to claim 4, characterized in that: The metal oxide includes one or both of magnesium oxide and tungsten trioxide.

6. The anti-aging rubber waterstop according to claim 5, characterized in that: When the metal oxide consists of tungsten trioxide and magnesium oxide, the mass ratio of the tungsten trioxide to the magnesium oxide is 1-2:

1.

7. The anti-aging rubber waterstop according to claim 4, characterized in that: The preparation method of the filler comprises the following steps: carbon black, metal oxide, propylene sulfonic acid and solvent are uniformly mixed, and the filler is obtained after ball milling, drying and sieving.

8. The anti-aging rubber waterstop according to claim 1, characterized in that: The flame retardant includes one or both of ammonium polyphosphate and triphenyl phosphate.

9. The anti-aging rubber waterstop according to claim 1, characterized in that: It also includes at least one of the following technical features: The antioxidant includes one or more of antioxidant 1076, antioxidant 264, and antioxidant 168; The vulcanizing agent includes one or both of dicumyl peroxide and benzoyl peroxide; The plasticizer includes one or both of dioctyl adipate and dioctyl sebacate.

10. A method for preparing an aging-resistant rubber waterstop according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, weighing EPDM rubber, filler, flame retardant, antioxidant, plasticizer, mixing, adding vulcanizing agent and continuing mixing to obtain a mixed rubber material; S2. The mixed rubber material is subjected to injection molding to obtain an aging-resistant rubber waterstop.

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