A damping composite plate and a preparation method thereof

Abstract

The present invention belongs to the technical field of damping and vibration reduction materials, and particularly relates to a damping composite plate and a preparation method thereof, which includes a damping layer and constraint layers located on both sides of the damping layer. The damping layer includes alternately laminated rubber layers and resin layers. The resin layer includes the following components in weight percentages: 35-45% of a high damping resin, 35-45% of barium sulfate, 8-12% of phenolic resin, and 8-12% of petroleum resin. The high damping resin is a styrene-isobutylene-styrene triblock copolymer or foamed polyvinyl chloride. The present invention has high flexural strength, damping, vibration reduction and sound insulation effects under the condition of low thickness.

Description

Technical Field

[0001] The present invention belongs to the technical field of damping and vibration reduction materials, and particularly relates to a damping composite plate and a preparation method thereof. Background Art

[0002] Damping and vibration reduction technology is to add high-damping materials to a structure in a certain way to increase the modal damping ratio of the structure and suppress the dynamic response near the resonance region. The traditional damping and vibration reduction technology is the constrained damping and vibration reduction technology. Its implementation method is to paste a high-damping additional layer at the place where the surface strain of the structure is large, and then bond a constraint layer on the damping layer. The visco-elastic effect of the damping layer material is used to dissipate the vibration energy of the structure and achieve the effect of damping and vibration reduction.

[0003] For example, Invention CN201610782986.1 discloses a high-damping composite plate, which uses resin to replace rubber and adopts a technical solution of bonding multiple damping layers to improve the effective damping frequency domain and temperature domain. However, the application of multiple damping layers reduces the strength of the composite plate, and the use of a large amount of adhesives will also seriously affect the damping performance of the composite plate.

[0004] Invention Application CN202010614702.4 discloses a vibration reduction plate applicable to a wide temperature range and a preparation method thereof, which adopts a technical solution of superimposing multiple damping adhesives and constraint layers to achieve the damping and vibration reduction effect in a wide temperature range. However, this technical solution has complex processing procedures, and the large number of bonding points between the constraint layer and the damping layer will also seriously affect the strength of the composite plate and the stability of its damping performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a damping composite plate and a preparation method thereof, which have high bending strength, damping, vibration reduction and sound insulation effects under the condition of low thickness.

[0006] The content of the present invention is a damping composite plate, which includes a damping layer and constraint layers on both sides of the damping layer. The damping layer includes alternately laminated rubber layers and resin layers. The resin layer includes the following components in weight percentage: 35-45% of high-damping resin, 35-45% of barium sulfate, 8-12% of phenolic resin, and 8-12% of petroleum resin. The high-damping resin is styrene-isobutylene-styrene triblock copolymer or foamed polyvinyl chloride.

[0007] Generally, the rubber layer and the resin layer are laminated together, with the same thickness and a fixed weight ratio between them.

[0008] Preferably, the resin layer includes the following components in weight percentage: 40% of high-damping resin, 40% of barium sulfate, 10% of phenolic resin, and 10% of petroleum resin.

[0009] Preferably, the rubber layer comprises the following components by weight percentage: 60 - 80% of high-damping rubber, 10 - 30% of carbon black, and 5 - 10% of a mixture of vulcanizing agent and vulcanization accelerator.

[0010] Preferably, the rubber layer comprises the following components by weight percentage: 70% of high-damping rubber, 20% of carbon black, and 10% of a mixture of vulcanizing agent and vulcanization accelerator.

[0011] Preferably, the high-damping rubber is butyl rubber or chloroprene rubber.

[0012] Preferably, the thickness of the damping layer is 30 - 60 μm. In the damping layer, the number of alternating laminations of rubber layers and resin layers is 8, 16, or 32 times. The performance is mainly controlled by controlling the total thickness. If the number of alternating layers is more, the thickness of a single layer is thinner. When a single layer is too thin, it is easy to damage the multi-layer structure.

[0013] Preferably, the thickness of the constraint layer is 0.6 - 1 mm.

[0014] Preferably, the constraint layer is a metal material or a non-metal material. The metal material is steel or aluminum plate, and the non-metal material is carbon fiber composite board and glass fiber composite board.

[0015] The present invention provides a method for preparing the damping composite board as described above. The steps are as follows: melt the rubber layer material and the damping layer material respectively, and alternately laminate them to obtain the damping layer; then sandwich the damping layer between two constraint layers, apply pressure and raise the temperature to perform co-curing to obtain the damping composite board.

[0016] The beneficial effect of the present invention is that for the currently common damping composite boards, the damping materials used are generally single rubber or resin. Among them, the glass transition temperature (Tg) of the rubber material is below 0 °C, and the effective damping temperature range is in the low-temperature range; while the Tg of the resin material is above room temperature, and the effective damping temperature range is in the relatively high-temperature range. However, no matter whether rubber or resin material is used, problems such as narrow effective temperature range of the damping material and low damping efficiency cannot be solved. The rubber / resin composite material with an alternating multi-layer structure prepared by the co-extrusion technology of the present invention has a wide temperature range and an extremely high loss factor, and can endow the structural damping composite board with excellent damping performance.

[0017] For the damping composite board of the present application, the damping material is integrated into the structural design and integrally formed, so that the structural member has both high stiffness and strength, and high structural damping, load-bearing, and vibration reduction functions.

[0018] The damping composite board of the present invention is different from traditional composite boards in dealing with the bonding problem between the damping layer and the constraint layer. It abandons the use of bonding and adopts a co-curing process, which improves the structural strength and damping characteristics of the composite board while optimizing the forming process and reducing processing costs. The integrated vulcanization forming process makes the structural damping composite board provided by the present invention a truly structure-function integrated structural member, which not only has excellent damping performance, but also has strong vibration reduction, sound insulation and load-bearing performance, and is a multi-functional high-damping composite board.

[0019] The damping composite board of the present invention uses foamed PVC filled with barium sulfate to replace traditional resin materials, and utilizes the microporous structure of the foamed material to improve the sound absorption coefficient of the composite material. The micro-nano laminated rubber / resin composite material prepared by an improved formula is used as the damping layer, which greatly improves the vibration reduction and sound insulation performance of the composite damping board. The amount of barium sulfate used in the present invention is equivalent to the amount of foamed PVC, and it has better vibration reduction and sound insulation performance compared with using other fillers or other amounts of fillers.

[0020] During the forming process of the damping composite board of the present invention, the thickness of the damping layer is controlled at the micron level, which reduces the shear slip between the constraint plates and improves the load-bearing performance of the structural damping composite board at low thickness. Brief Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the present invention.

[0022] Figure 2 It is a process flow diagram of the present invention.

[0023] In the figure, 1 is the upper constraint layer, 2 is the damping layer, 3 is the lower constraint layer, 21 is the resin layer, and 22 is the rubber layer. Detailed Description of the Invention

[0024] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0025] Embodiment 1

[0026] A structural damping composite board includes a damping layer and constraint layers on both sides of the damping layer; the damping layer includes alternately laminated and stacked rubber layer 22 and resin layer 21.

[0027] The rubber layer is made of 70wt% chloroprene rubber, 20wt% carbon black, 5wt% vulcanizing agent (sulfur), and 5wt% vulcanization accelerator (2.5wt% zinc oxide and 2.5wt% stearic acid).

[0028] The resin layer is made of 40wt% foamed PVC, 40wt% barium sulfate, 10wt% phenolic resin, and 10wt% petroleum resin.

[0029] Put the above-mentioned formulated amounts of chloroprene rubber, carbon black, vulcanizing agent, and vulcanization accelerator into a kneader in proportion, heat to 180°C and knead to prepare the rubber layer material, and control the kneader speed at 40 revolutions per minute.

[0030] Put the above-mentioned formulated amounts of foamed PVC, barium sulfate, phenolic resin, and petroleum resin into a kneader in proportion, heat to 180°C and knead to prepare the resin layer material, and control the kneader speed at 40 revolutions per minute.

[0031] Add the prepared rubber layer material and resin layer material into two extruders of a micro-layer co-extrusion device respectively. After the two materials are melted and plasticized in their respective channels, they are stacked into two layers of melt at the confluence, and then passed through a lamination unit, and then led out by a traction device to obtain a micro-nano laminated rubber / plastic composite material.

[0032] The structure of the structural damping composite plate of Example 1 is as Figure 1 shown, consisting of two constraint layers and one damping layer 2, where the two constraint layers are the upper constraint layer 1 and the lower constraint layer 3 respectively. The material of the damping layer 2 is the above-prepared micro-nano laminated rubber / plastic composite material, the material of the constraint layer 2 is a soft steel plate with the grade of DC06, and the thickness of the constraint layer 2 is 1mm.

[0033] Form an upper constraint layer-damping layer-lower constraint layer sandwich structure with the upper constraint layer 1, the damping layer 2, and the lower constraint layer 3, and carry out co-curing molding by heating under pressure. The co-curing temperature is 160°C, the pressure is 10MPa, and the co-curing time is 15 - 18min. Control the pressure during the molding process so that the thickness of the damping layer is 30um to obtain the structural damping composite plate.

[0034] After testing, the bending strength of the composite plate is 249MPa, the maximum damping factor is 0.33, the relative vibration reduction amount is 16dB, and the weighted sound insulation amount is 36dB.

[0035] Comparative Example 1

[0036] The difference between this Comparative Example 1 and Example 1 is that the resin layer in the damping layer is made of 80% unfoamed PVC resin, 10% phenolic resin, and 10% petroleum resin. The rubber layer material is the same as that in Example 1.

[0037] The prepared resin layer material and rubber layer material are directly mixed and extruded to obtain a damping layer.

[0038] Other conditions are the same as in Example 1.

[0039] After testing, the bending strength of the composite board is 246 MPa, the maximum damping factor is 0.12, the relative vibration reduction is 3.5 dB, and the weighted sound insulation is 6.4 dB.

[0040] Analysis of the performance of Example 1 and Comparative Example 1 shows that the structural damping composite board prepared with the micro-nano laminated rubber / plastic composite as the damping layer has more excellent damping performance compared with the structural damping composite board prepared with the traditional blended material as the damping layer. There is no alternating layered structure in the damping layer of Comparative Example 1, and it hardly has the functions of vibration reduction and sound insulation.

[0041] Comparative Example 2

[0042] The difference between Comparative Example 2 and Example 1 is that the rubber layer in the damping layer is made of 60 wt% chloroprene rubber and 40 wt% carbon black, that is, the vulcanizing agent and vulcanization accelerator that play a cross-linking role are replaced by carbon black; the resin layer in the damping layer is made of 80% foamed PVC and 20% petroleum resin, that is, barium sulfate is replaced by foamed PVC, and the phenolic resin that plays a cross-linking role is replaced by petroleum resin. The micro-nano laminated rubber / plastic composite is prepared according to the method of Example 1.

[0043] Then, an adhesive is coated between the constraint layer and the damping layer, and co-curing molding is carried out by the method of Example 1 to obtain a structural damping composite board.

[0044] Other conditions are the same as in Example 1.

[0045] After testing, the bending strength of the composite board is 122 MPa, the maximum damping factor is 0.22, the relative vibration reduction is 9.49 dB, and the weighted sound insulation is 21.4 dB.

[0046] Analysis of the performance of Example 1 and Comparative Example 2 shows that the structural damping composite board prepared by the co-curing process has more excellent bending strength and damping performance compared with the structural damping composite board prepared by the traditional bonding process. In addition, the vibration reduction and sound insulation performance of Example 1 are also better than those of Comparative Example 2.

[0047] Comparative Example 3

[0048] The difference between Comparative Example 3 and Example 1 is that the resin layer in the damping layer is made of 80% unfoamed PVC resin, 10% phenolic resin and 10% petroleum resin. Other conditions are the same as in Example 1.

[0049] The bending strength of the composite board is 238 MPa, the maximum damping factor is 0.31, the relative vibration reduction is 11.52 dB, and the weighted sound insulation is 24.4 dB.

[0050] Analysis of the performance of Example 1 and Comparative Example 3 shows that the structural damping composite board prepared by using foamed PVC and adding barium sulfate has more excellent vibration reduction and sound insulation performance compared with the composite board prepared by using unfoamed PVC resin. In addition, there is also a certain improvement in damping performance.

[0051] Comparative Example 4

[0052] The difference between Comparative Example 4 and Example 1 is that the resin layer in the damping layer is made of 70 wt% foamed PVC resin, 10 wt% barium sulfate, 10% phenolic resin, and 10% petroleum resin. Others are the same as Example 1.

[0053] After testing, the bending strength of the composite board is 254 MPa, the maximum damping factor is 0.31, the relative vibration reduction is 11.77, and the weighted sound insulation is 25.6 dB.

[0054] Analysis of the performance of Example 1 and Comparative Example 4 shows that the structural damping composite board prepared by using high-filled barium sulfate reinforced resin composite has more excellent vibration reduction and sound insulation performance compared with the structural damping composite board prepared by using low-filled fillers. In addition, there is also a certain improvement in damping performance.

[0055] Comparative Example 5

[0056] The difference between Comparative Example 5 and Example 1 is that the resin layer in the damping layer is made of 25 wt% foamed PVC resin, 55 wt% barium sulfate, 10% phenolic resin, and 10% petroleum resin. Others are the same as Example 1.

[0057] After testing, the bending strength of the composite board is 252 MPa, the maximum damping factor is 0.33, the relative vibration reduction is 14.2 dB, and the weighted sound insulation is 26.8 dB.

[0058] Comparative Example 6

[0059] The difference between Comparative Example 6 and Example 1 is that the resin layer in the damping layer is made of 40 wt% foamed PVC, 20 wt% carbon black, 10 wt% barium sulfate, 10 wt% heavy calcium carbonate, 10% phenolic resin, and 10% petroleum resin. Others are the same as Example 1.

[0060] After testing, the bending strength of the composite board is 251 MPa, the maximum damping factor is 0.31, the relative vibration reduction is 13.47, and the weighted sound insulation is 28 dB.

[0061] Those of ordinary skill in the art should understand that any discussion of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; under the concept of this application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of one or more embodiments of this application as described above, and for the sake of brevity, they are not provided in detail.

[0062] One or more embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application shall be included within the scope of protection of this application.

Claims

1. A damping composite plate, characterized in that, It includes a damping layer and constraint layers located on both sides of the damping layer. The damping layer includes alternately laminated rubber layers and resin layers. The resin layer includes the following components in weight percentages: 40% of high damping resin, 40% of barium sulfate, 10% of phenolic resin, and 10% of petroleum resin. The high damping resin is styrene-isobutylene-styrene triblock copolymer or foamed polyvinyl chloride; The rubber layer includes the following components in weight percentages: 70% of high damping rubber, 20% of carbon black, and 10% of a mixture of vulcanizing agent and vulcanization accelerator; The high damping rubber is butyl rubber or chloroprene rubber; The thickness of the damping layer is 30 - 60 μm; In the damping layer, the number of alternations of the alternately laminated rubber layers and resin layers is 8, 16, or 32 times.

2. The damping composite plate according to claim 1, characterized in that, The thickness of the constraint layer is 0.6 - 1 mm.

3. The damping composite plate according to claim 1, characterized in that, The constraint layer is a metal material or a non-metal material. The metal material is steel or aluminum plate, and the non-metal material is carbon fiber composite board and glass fiber composite board.

4. A preparation method of the damping composite plate according to any one of claims 1-3, characterized in that, The steps are as follows: melt the rubber layer material and the damping layer material respectively, alternately laminate them to obtain the damping layer; then sandwich the damping layer between two constraint layers, apply pressure and raise the temperature for co-curing to obtain the damping composite board.

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