Building vibration isolation pad and preparation method thereof

Abstract

The invention provides a building vibration isolator which is high in strength, not easy to puncture and high in loss factor and a preparation method of the building vibration isolator. The preparation method comprises the following steps: S1, mixing raw materials at least comprising ethylene propylene diene monomer and filler to obtain first-section rubber; s2, mixing the first-stage rubber, a vulcanizing agent, an accelerant, a scorch retarder, a dehumidizer, a foaming agent and a foaming aid to 90-100 DEG C to prepare second-stage rubber, and standing for 8-16 hours; s3, extruding the second-section rubber to obtain a rubber blank, and then cutting the rubber blank to obtain a preformed rubber blank; s4, putting the preformed rubber blank into a first-section vulcanization mold, and vulcanizing for 10-20 minutes at the temperature of 160-180 DEG C to obtain a first-section vulcanized semi-finished product; and S5, the first-section vulcanized semi-finished product is put into a second-section vulcanization mold to be vulcanized for 10-20 min at the temperature of 160-180 DEG C, a second-section vulcanized product is prepared, and the building vibration isolation pad is obtained after standing.

Description

Technical Field

[0001] The invention belongs to the field of vibration isolation materials, and in particular relates to a building vibration isolation pad and a preparation method thereof. Background Art

[0002] Building vibration isolation pads are usually used to be installed in building structures and mechanical equipment, such as under the floor slab or floor, the bottom surface of electrical equipment, etc., to play a role in vibration isolation and noise reduction.

[0003] Traditional building vibration isolation pads are mainly made of elastic materials such as polyurethane. In recent years, some building vibration isolation pads have also adopted a microporous structure, that is, small micropores are formed through a foaming process during the manufacturing process. These micropores can deform when subjected to force. Therefore, compared with non-porous materials, this type of microporous material can more easily achieve a good vibration reduction effect. At the same time, the presence of micropores can also reduce the overall weight of the material, making it easier to lay. For example, CN114989389A discloses a high closed-cell, low-density polyurethane vibration isolation pad suitable for building floating floors. The size and uniformity of the micropores are controlled by adjusting the rate matching of the foaming reaction and the gel reaction, and a density of 240kg / m 3 ~300kg / m 3 Low-density, high-performance polyurethane vibration isolation pad with a closed-cell rate of 65% and a stiffness change rate of less than 1.35.

[0004] However, polyurethane sheets have low water swelling resistance and are prone to falling apart and breaking. The effect of use in long-term groundwater immersion is difficult to guarantee. Therefore, this type of vibration isolation pad is not suitable for use in harsh environments, such as rainy environments and underground parts of buildings. Polyurethane materials also have problems such as low tensile strength and poor puncture resistance. Once accidentally punctured during construction and installation, the vibration isolation effect will be greatly reduced. Therefore, in actual application, strict attention is usually required and even additional protective measures are added, which leads to construction troubles. In addition, the loss factor of polyurethane pads is low, and the vibration isolation effect is difficult to achieve an ideal state. Summary of the invention

[0005] Based on the above problems, the present invention provides a method for preparing a building vibration isolation pad with high strength, not easy to be punctured and high loss factor, characterized in that it comprises the following steps:

[0006] Step S1, mixing raw materials including at least EPDM rubber and filler to obtain a rubber section;

[0007] Step S2, mixing the first-stage rubber, the vulcanizing agent, the accelerator, the anti-scorching agent, the dehumidifying agent, the foaming agent, and the foaming aid to 90° C.-100° C. to obtain the second-stage rubber, and leaving it for 8-16 hours;

[0008] Step S3, extruding the second-stage rubber to obtain a rubber blank, and then cutting it to obtain a preformed rubber blank;

[0009] Step S4: Place the preformed rubber blank into a first-stage vulcanization mold, vulcanize at 160°C - 180°C for 10 - 20 minutes to obtain a semi-finished product of the first-stage vulcanization.

[0010] Step S5: Place the semi-finished product of the first-stage vulcanization into a second-stage vulcanization mold, vulcanize at 160°C - 180°C for 10 - 20 minutes to obtain a second-stage vulcanized product, and obtain a building vibration isolation pad after standing.

[0011] In the preparation method of the building vibration isolation pad provided by the present invention, step S1 may specifically include:

[0012] Step S1-1: Knead ethylene propylene diene monomer (EPDM), nano-zinc oxide, stearic acid, and antioxidant for 20 - 40 s.

[0013] Step S1-2: Add silica and clay as fillers and a coupling agent, and knead for 40 - 60 s.

[0014] Step S1-3: Add carbon black and paraffin oil as fillers, knead until the discharge temperature reaches 145°C - 150°C, cool and stand for 8 - 16 h to obtain a first-stage rubber.

[0015] In the above preparation method of the building vibration isolation pad provided by the present invention, the ethylene propylene diene monomer (EPDM) may be EPDM 8600.

[0016] In addition, in the above preparation method of the building vibration isolation pad provided by the present invention, the carbon black may be carbon black N774.

[0017] The above preparation method of the building vibration isolation pad provided by the present invention may further have the technical feature that the antioxidant includes at least antioxidant TMQ and antioxidant MB.

[0018] The above preparation method of the building vibration isolation pad provided by the present invention may further have the technical feature that the accelerator is a combination of two or more accelerators, selected from accelerator CBS, accelerator TMTD, accelerator DM, accelerator DTDM-80GE, and accelerator DPTT-70GE.

[0019] The present invention also provides a building vibration isolation pad, which is characterized in that it is prepared by using the preparation method of the building vibration isolation pad as described in any one of the above.

[0020] Function and effect of the invention

[0021] According to the preparation method of the building vibration isolation pad provided by the present invention, since ethylene propylene diene monomer (EPDM) rubber is used as the main material, and the water swelling resistance of EPDM rubber is excellent, and the applicable temperature range is -50°C to 120°C. Compared with polyurethane, it has stronger water swelling resistance and a wider applicable temperature range, and can also achieve good vibration isolation effects in special areas with large temperature differences and a lot of precipitation. In addition, since the vulcanization process adopts two-stage vulcanization and the vulcanization temperature is 160°C - 180°C, on the one hand, by dividing the vulcanization process into two stages, it can avoid the material deformation or cracking caused by the drastic pressure change when the mold is depressurized during the mold opening process; on the other hand, it can reduce the loss of foaming gas caused by the mismatch between the vulcanization speed and the foaming speed during the foaming process, and ensure the overall density. At the same time, the product prepared by the two-stage method has a lower post-shrinkage rate and more stable dimensions.

[0022] The vulcanization temperature is relatively low, the vulcanization speed is slower than the foaming speed, and more foaming gas is lost, resulting in an increase in the overall density. If the temperature continues to decrease, the prepared vibration isolation pad will be difficult to meet the actual application requirements. Therefore, the foaming temperature should not be lower than 160°C.

[0023] In the present invention, the high filling characteristics of EPDM rubber are fully utilized, and clay, silica white, and carbon black are used as fillers in combination. Among them, clay can reduce the adverse effects of fillers on the elasticity of rubber products, and at the same time can be used as a cell nucleus during the cell formation stage to make the cells more uniform and delicate; silica white can provide good dynamic performance for the rubber compound and reduce the ratio of dynamic and static stiffness of the product; carbon black can enhance the strength of the rubber compound and improve the bearing capacity and puncture resistance of the product.

[0024] In the present invention, by selecting EPDM rubber with a high ethylene content, high Mooney viscosity, and high content of the third monomer (such as EPDM rubber 8600), the material strength and vulcanization speed can be improved, so that the vulcanization speed and the foaming speed can be better matched during the vulcanization process of the product, and the foaming quality can be ensured.

[0025] Furthermore, in the present invention, semi-reinforcing carbon black N774 is used. Compared with other types of carbon black, it can avoid the increase in the viscosity of the rubber compound caused by carbon black with high reinforcing properties, so that the finally prepared vibration isolation pad has lower compression set and good elasticity.

[0026] In addition, due to the synergistic cooperation of different anti-aging agents (such as TMQ, MB), the product can still ensure excellent physical and mechanical properties under conditions such as hot air aging and ozone aging.

[0027] In the preparation method of the present invention, since the mixing temperature of the first-stage rubber in steps S1-3 is 145°C - 150°C, it can ensure that the hydroxyl groups on the surface of the silica react with the silanols generated by the hydrolysis of the alkoxy groups on the surface of the coupling agent Si-69 to produce a condensation reaction. At the same time, the sulfur bonds at the other end of the coupling agent Si-69 can react with the rubber molecules, thereby enhancing the binding between the silica and the rubber and improving the tensile strength and dynamic properties.

[0028] The vulcanization system of the present invention adopts a low-sulfur and high-accelerator vulcanization system (i.e., a vulcanization system composed of sulfur and various different accelerators). Therefore, it can improve the vulcanization speed, make the vulcanization speed better match the foaming speed, and it is easy to obtain a product with uniform foaming quality. At the same time, it can make the crosslinking density of the product more uniform, further improving properties such as tensile strength and tear resistance.

[0029] Generally speaking, compared with the polyurethane foam vibration isolation pads in the prior art, the building vibration isolation pads prepared by the present invention have the following advantages:

[0030] 1. Using ethylene propylene diene monomer (EPDM) rubber with better water swelling resistance and a wider applicable temperature range as the main rubber material, so it can be applied to more different scenarios;

[0031] 2. Under the condition that the density and elongation at break are basically the same, compared with the polyurethane vibration isolation pads, it has better tensile strength and better puncture resistance;

[0032] 3. The loss factor is larger and the vibration isolation effect is better.

[0033] 4. The static modulus is high and it has better support performance. Specific Embodiments

[0034] The following examples illustrate the building vibration isolation pads of the present invention and their preparation methods. The specific components and sources of the materials used in the following examples are shown in the table below:

[0035]

[0036]

[0037] In addition, in each example, the reagents and materials whose sources are not specified are all commercially available as usual. The operation methods without specific procedures refer to the conventional operation methods in the prior art, and the parts of each raw material refer to parts by weight.

[0038] The vibration isolation pad preparation methods adopted in each example mainly include the following steps:

[0039] Step S1, mixing raw materials including at least ethylene propylene diene monomer (EPDM) rubber and fillers to obtain the first-stage rubber, specifically including:

[0040] Step S1-1: Mix ethylene propylene diene monomer rubber, nano-zinc oxide, stearic acid, and antioxidant for 20 - 40 s;

[0041] Step S1-2: Add silica white and clay as fillers and a coupling agent, and mix for 40 - 60 s;

[0042] Step S1-3: Add carbon black and paraffin oil as fillers, mix until the discharge temperature reaches 145℃ - 150℃, cool and store for 8 - 16 h to obtain the first-stage rubber;

[0043] Step S2: Mix the first-stage rubber, vulcanizing agent, accelerator, scorch retarder, dehumidifier, foaming agent, and foaming aid until the temperature reaches 90℃ - 100℃, discharge the rubber, then obtain the second-stage rubber through thin pass / triangle wrapping and sheet making, and store for 8 - 16 h;

[0044] Step S3: Extrude the second-stage rubber through a vacuum extruder to obtain a rubber blank, and then cut it to obtain a preformed rubber blank;

[0045] Step S4: Put the preformed rubber blank into a first-stage vulcanization mold, vulcanize at 160℃ - 180℃ for 10 - 20 min, and the vulcanization pressure is 5 Mpa to obtain a first-stage vulcanized semi-finished product;

[0046] Step S5: Put the first-stage vulcanized semi-finished product into a second-stage vulcanization mold, vulcanize at 160℃ - 180℃ for 10 - 20 min, and the vulcanization pressure is 5 Mpa to obtain a second-stage vulcanized product, and obtain a building vibration isolation pad after storing for 7 - 14 days.

[0047] <Example 1>

[0048] This example provides a building vibration isolation pad and its preparation method. The raw materials of the building vibration isolation pad are specifically shown in the following table:

[0049] Serial number Material Quantity 1 EPDM3072EM 140 2 Nano zinc oxide TY-100 5 3 Stearic acid SA1840 2 4 Antioxidant TMQ 1 5 Antioxidant MB 1 6 Carbon black N330 30 7 Carbon black N550 30 8 Kaolin clay 30 9 Silica 165GR 10 10 Coupling agent Si-69 1 11 Paraffin oil 60 12 Sulfur 0.8 13 Accelerator CBS 1 14 Accelerator TMTD 0.5 15 Accelerator DM 1 16 Accelerator DTDM-80GE 1.5 17 Accelerator DPTT-70GE 1.1 18 Scorch retarder CTP 0.1 19 Drying agent ANF-200 5 20 Blowing agent AC 10 21 Blowing aid CK-95B 5

[0050] The specific preparation process includes the following steps:

[0051] Step S1: Mix raw materials including at least ethylene propylene diene monomer rubber and fillers to obtain the first-stage rubber, specifically including:

[0052] Step S1-1: Mix ethylene propylene diene monomer rubber, nano-zinc oxide TY-100, stearic acid SA1840, and antioxidant for 20 - 40 s;

[0053] Step S1-2: Add silica white, clay, and coupling agent Si-69, and mix for 40 s;

[0054] Step S1-3: Add carbon black and paraffin oil, mix until the discharge temperature reaches 145℃, cool and store for 8 h to obtain the first-stage rubber;

[0055] Step S2: Knead a section of glue, vulcanizing agent (i.e., sulfur), accelerator, scorch retarder, dehumidifier, foaming agent, and foaming aid until the temperature reaches 90°C. After discharging the glue, pass it through thin rolling / making a triangle wrap, and then sheet it to obtain the second-stage glue, which is parked for 8 - 16 h;

[0056] Step S3: Extrude the second-stage glue through a vacuum extruder to obtain a rubber blank with a certain thickness, and then use a vibrating cutter for precise cutting to obtain preformed rubber blanks in the shape of sheets with the same size and weight after each cutting;

[0057] Step S4: Place the preformed rubber blank into the first-stage vulcanization mold, vulcanize at 180°C for 10 min, and the vulcanization pressure is 5 Mpa to obtain the first-stage vulcanized semi-finished product;

[0058] Step S5: Place the first-stage vulcanized semi-finished product into the second-stage vulcanization mold, vulcanize at 180°C for 10 min, and the vulcanization pressure is 5 Mpa to obtain the second-stage vulcanized product. After parking for 7 days, a building vibration isolation pad is obtained.

[0059] <Variant Example 1>

[0060] This variant example is a variant of Example 1.

[0061] Compared with Example 1, the difference in this variant example is that the vulcanization condition in Step S4 is vulcanization at 160°C for 10 min, and the vulcanization condition in Step S5 is vulcanization at 160°C for 10 min.

[0062] <Example 2>

[0063] This example provides another building vibration isolation pad and its preparation method. The raw materials of this building vibration isolation pad are shown in the following table:

[0064]

[0065]

[0066] The preparation process of this example is basically the same as that of Example 1, except that in Step S1-1, the kneading time is 20 s.

[0067] <Example 3>

[0068] This example provides yet another building vibration isolation pad and its preparation method. The raw materials of this building vibration isolation pad are shown in the following table:

[0069] Serial number Material Quantity 1 EPDM3072EM 140 2 TY-100 5 3 SA1840 2 4 TMQ 1 5 MB 1 6 Carbon black N774 60 7 Kaolin clay 30 8 165GR 10 9 Si-69 1 10 1968A 60 11 Sulfur 0.8 12 CBS 1 13 TMTD 0.5 14 DM 1 15 DTDM-80GE 1.5 16 DPTT-70GE 1.1 17 CTP 0.1 18 ANF-200 5 19 CK-95A 10 20 CK-95B 5

[0070] The specific preparation process of this example is the same as that of Example 1.

[0071] <Comparative Example 1>

[0072] This comparative example uses the preparation method described in Example 3 of CN114989389A to prepare a polyurethane vibration isolation pad as a comparative example of the building vibration isolation pad of the present invention.

[0073] <Comparative Example 2>

[0074] The preparation process of this comparative example is basically the same as that of Example 1, except that a one-stage vulcanization method is used. That is, after step S3, the preformed rubber embryo is put into a vulcanization mold and vulcanized at 180°C for 20 minutes, and the vulcanization pressure is 5 Mpa.

[0075] <Test Example>

[0076] This test example is for the performance test of the vibration isolation pads of each example and variant. Among them, the density test refers to the standard GB / T1033.1 2008, the tensile strength and elongation at break tests refer to the standard GB / T1040.3 2006, the static elastic modulus test refers to the standard TB / T 3395.1 (insulated at 23±2°C for 24 hours, load 1 kN to 35 kN), the dynamic elastic modulus test refers to the standard TB / T 3395.1, the resilience rate test refers to the standard GB / T 1681 2009, the compression set rate (70°C, 22 hours, 30% compression) test refers to the standard GB / T 10653, the water absorption test refers to the standard GB / T 1690 2010, and the fire performance test refers to the standard GB8624 2006.

[0077] The test results are shown in the following table:

[0078]

[0079] As shown in the above table, compared with Example 1, the vibration isolation pad of Variant 1 has a greater density. The reason may be that the vulcanization temperature is lower, the vulcanization speed is slower than the foaming speed, and more foaming gas is lost, resulting in an increase in the overall density. If the temperature is further reduced, the prepared vibration isolation pad will be difficult to meet the actual application requirements. Therefore, the foaming temperature should not be lower than 160°C.

[0080] The densities and dynamic-to-static ratios of the vibration isolation pads obtained in Examples 1-3 are basically the same as those of Comparative Example 1, but the tensile strengths of each example are significantly higher than those of Comparative Example 1, indicating that the building vibration isolation pad of the present invention has better puncture resistance. At the same time, the static moduli of Examples 1-3 are higher than those of the comparative example, indicating that the building vibration isolation pad of the present invention has better support performance; the loss factor is higher, and the vibration isolation effect is better. In addition, the densities of Examples 1-3 are lower than those of Comparative Example 2, and the elongation at break is higher than that of Comparative Example 2, indicating that compared with the one-stage vulcanization method of Comparative Example 2, the two-stage vulcanization of Examples 1-3 can better ensure the content of foam cells. The reason may be that the two-stage vulcanization makes the vulcanization speed more compatible with the foaming speed, and the loss of foaming gas can be reduced.

[0081] In addition, by comparing Example 1 and Example 2, it can be seen that since Example 2 uses ethylene propylene diene monomer rubber 8600 with a higher content of the third monomer, its vulcanization speed is fast and it can be used together with diene rubber. At the same time, Example 2 also uses natural rubber together, which makes the vulcanization speed faster, the loss of foaming gas less, the sample density lower, the tensile strength and elongation at break higher, and correspondingly has better elasticity.

[0082] In Example 3, since semi-reinforcing carbon black N774 is used instead of carbon black N330 and carbon black N550, the increase in the viscosity of the rubber compound caused by carbon black with high reinforcing properties is avoided, and it has lower compression set and good elasticity.

[0083] Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a building vibration isolation pad, characterized in that, It includes the following steps: Step S1: Knead the raw materials including at least ethylene propylene diene monomer (EPDM) and fillers to obtain the first-stage rubber; Step S2: Knead the first-stage rubber, vulcanizing agent, accelerator, scorch retarder, dehumidifying agent, blowing agent, and blowing agent assistant to 90°C - 100°C to obtain the second-stage rubber, and let it stand for 8 - 16 h; Step S3: Extrude the second-stage rubber to obtain the rubber embryo, and then cut it to obtain the preformed rubber embryo; Step S4: Put the preformed rubber embryo into the first-stage vulcanization mold and vulcanize it at 160°C - 180°C for 10 - 20 min to obtain the first-stage vulcanized semi-finished product; Step S5: Put the first-stage vulcanized semi-finished product into the second-stage vulcanization mold and vulcanize it at 160°C - 180°C for 10 - 20 min to obtain the second-stage vulcanized product, and after standing, obtain the building vibration isolation pad.

2. The preparation method of the building vibration isolation pad according to claim 1, characterized in that: Among them, Step S1 specifically includes: Step S1-1: Knead EPDM, nano zinc oxide, stearic acid, and antioxidant for 20 - 40 s; Step S1-2: Add white carbon black, clay, and coupling agent as fillers and knead for 40 - 60 s; Step S1-3: Add carbon black and paraffin oil as fillers, knead until the discharge temperature is 145°C - 150°C, cool and let it stand for 8 - 16 h to obtain the first-stage rubber.

3. The preparation method of the building vibration isolation pad according to claim 1 or 2, characterized in that: Among them, The EPDM is EPDM 8600.

4. The preparation method of the building vibration isolation pad according to claim 2, characterized in that: Among them, The carbon black is carbon black N774.

5. The preparation method of the building vibration isolation pad according to claim 1, characterized in that: Among them, The antioxidant includes at least antioxidant TMQ and antioxidant MB.

6. The preparation method of the building vibration isolation pad according to claim 1, characterized in that: Among them, The accelerator is a combination of two or more accelerators, selected from accelerator CBS, accelerator TMTD, accelerator DM, accelerator DTDM-80GE, accelerator DPTT-70GE.

7. A building vibration isolation pad, characterized in that, It is prepared by using the preparation method of the building vibration isolation pad according to any one of claims 1 - 6.

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