Low-tension pit expansion type damping glue and preparation method thereof
By designing a low-pitching expansion type damping adhesive, and utilizing the cell wall materials of synthetic rubber, epoxy resin, and PVC resin, along with foaming agents and vacuum mixing technology, the problem of pitting on the sheet metal during the cooling process of the damping adhesive is solved, achieving a balance between high adhesion performance and expansion rate, while maintaining the aesthetic appearance of the vehicle body.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUBEI HUITIAN NEW MATERIALS STOCK CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-19
AI Technical Summary
Existing damping adhesives are prone to causing dents in the sheet metal during the cooling process, which cannot meet the requirements for vehicle body performance and appearance.
Low-tillage expansion type vibration damping adhesive is used, which forms the cell wall material by combining appropriate synthetic rubber with epoxy resin and PVC resin, and is combined with a specific foaming agent to achieve delayed expansion effect to offset cooling shrinkage, combined with vacuum stirring degassing technology.
It reduces cooling shrinkage during the cooling process, maintains adhesion and expansion rate, and meets the low dent requirement for a pleasing car body appearance.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of vibration damping adhesive technology, specifically relating to a low-indentation expansion type vibration damping adhesive and its preparation method. Background Technology
[0002] With the need for lightweight vehicles, the steel body panels are thinned or lightweight aluminum panels are used, resulting in a decrease in the strength of the outer sheet metal. The following problems often occur during the manufacturing process: When existing damping adhesives are applied between the panels and reinforcing ribs of the four doors, two hoods, and roof to buffer vibration and reduce noise, in order to better adapt to the changes in the spacing between the panels under different working conditions, the damping adhesives are usually designed as foaming expansion products, expanding during the heating and curing process; however, shrinkage during the cooling process can easily lead to dents in the sheet metal, which cannot well meet the requirements of OEMs for vehicle body performance and appearance. Summary of the Invention
[0003] In view of this, the present invention provides a low-cratering expansion type vibration damping adhesive and its preparation method, which can reduce cooling shrinkage and ensure bonding performance and expansion rate, and has low cratering and expansion damping properties.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a low-pitting-expansion type vibration damping adhesive, comprising the following raw materials: epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, and filler; The synthetic rubber includes at least one of styrene-butadiene rubber and NBR-PVC rubber-plastic alloy, and the foaming agent includes DPT.
[0005] Preferably, the styrene content in the styrene-butadiene rubber is 22.5%~24.5% by mass; and / or, The NBR-PVC rubber-plastic alloy contains 19.0% to 25.0% acrylonitrile by mass.
[0006] Preferably, the low-pitting-expansion vibration damping adhesive comprises the following raw materials in weight percentages: 3.0%~7.0% epoxy resin, 3.0%~7.0% PVC resin, 5.0%~10.0% synthetic rubber, 25.0%~35.0% diluent, 1.0%~2.0% adhesion promoter, 0.5%~1.5% curing agent, 0.1%~0.6% foaming agent, and 40.0%~60.0% filler.
[0007] Preferably, the low-pitting-expansion vibration damping adhesive comprises the following raw materials in weight percentages: 4.0%~6.0% epoxy resin, 4.0%~6.0% PVC resin, 6.0%~8.0% synthetic rubber, 25.0%~35.0% diluent, 1.0%~2.0% adhesion promoter, 0.8%~1.2% curing agent, 0.2%~0.5% foaming agent, and 43.0%~58.0% filler.
[0008] Preferably, the epoxy resin comprises at least one of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether; and / or, The PVC resin includes polyvinyl chloride homopolymer resin.
[0009] Preferably, the diluent includes at least one of diisononyl phthalate, dipropylheptyl phthalate, and dioctyl sebacate.
[0010] Preferably, the adhesion promoter comprises at least one selected from acrylic resin, rosin resin, phenolic resin, terpene resin, and petroleum resin; and / or, The curing agent is composed of a first curing agent and a second curing agent. The first curing agent includes dicyandiamide and 4,4'-methylenebis(phenyl dimethylurea), and the second curing agent includes at least one of di-(tert-butylperoxyisopropyl)benzene and butyl 4-bis(tert-butylperoxy)valerate.
[0011] Preferably, the filler includes at least one of calcium carbonate, mica powder, quartz powder, diatomaceous earth, kaolin, silica powder, silicon dioxide, calcium oxide, and carbon black.
[0012] Secondly, the present invention also provides a method for preparing the aforementioned low-crater expansion type vibration damping adhesive, comprising the following steps: S1. Dissolve synthetic rubber in a diluent to obtain a liquid mixture; S2. Mix the liquid mixture, epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent and filler to obtain an intermediate mixture; S3. Vacuum stir and degas the intermediate mixture to obtain a low-trap expansion type vibration damping adhesive.
[0013] Preferably, in step S1, the dissolution temperature is 60 ℃~70 ℃; and / or, In step S2, mixing is performed using a dynamic mixer; and / or, In step S2, the mixing temperature is 20 ℃~40 ℃; and / or, In step S3, the vacuum pressure for vacuum stirring and degassing is greater than or equal to -0.09 MPa, and the time is 30 min to 40 min.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The low-tear expansion type vibration damping adhesive provided by the present invention forms a cell wall material by using suitable synthetic rubber, epoxy resin and PVC resin, and with a specific foaming agent, it has a delayed expansion effect of continuous micro-expansion for a period of time after heating, which can offset the cooling shrinkage during the subsequent cooling process, reduce the tearing deformation of the vibration damping adhesive on the external sheet metal, and at the same time ensure the bonding performance and expansion rate.
[0015] (2) The low-pitting expansion type vibration damping adhesive provided by the present invention has a shear strength greater than 0.20 MPa, a panel cooling shrinkage amount less than 0.2 mm, and a volume expansion rate greater than 30%, which can meet the technical requirements of low pitting of expansion type vibration damping adhesive and maintain the appearance of the car body. Detailed Implementation
[0016] The present invention will be further described in detail below with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art, and all reagents and consumables are commercially available products.
[0017] The sources of raw materials in the embodiments and comparative examples of this invention are explained as follows: Epoxy resins: BE-188EL was purchased from Changchun Chemical; YDF-170 was purchased from Guodu Chemical.
[0018] PVC resin: Polyvinyl chloride homopolymer resin PSM-31 was purchased from Shenyang Chemical.
[0019] Synthetic rubbers: Styrene-butadiene rubber SBR1009 was purchased from Nanjing Guochen Chemical Co., Ltd.; NBR-PVC rubber-plastic alloy NBR1016 was purchased from Hengshui Chitu Ma New Materials Co., Ltd.
[0020] Diluents: Diisononyl phthalate (DINP) was purchased from Liancheng Chemical; Dipropylheptaphthalate (DPHP) was purchased from Shanghai Kunrui Chemical; Dioctyl sebacate (DOS) was purchased from Guangzhou Fufeng Chemical.
[0021] Adhesion promoters: Acrylic resin was purchased from Mitsubishi Chemical; rosin resin was purchased from Shaxian Licheng Chemical; phenolic resin was purchased from Hangmo New Materials.
[0022] Curing agents: Dicyandiamide was purchased from OMICURE; 4,4'-methylenebis(phenyl dimethylurea) was purchased from CVC; di-(tert-butylperoxyisopropyl)benzene was purchased from ARKEMA; butyl 4-bis(tert-butylperoxy)valerate was purchased from Jinan Guochen Taifu Chemical Co., Ltd.
[0023] Foaming agents: DPT (dinitrospentamethylenetetramine) was purchased from Jiangsu Yake Chemical; OBSH foaming agent (4,4'-oxobisbenzenesulfonylhydrazine) was purchased from Lanxess; AC foaming agent (azodicarbonamide) was purchased from Jiangsu Suopu; microsphere foaming agent (DU 120) was purchased from Norinon.
[0024] Fillers: Nano calcium carbonate SP200 was purchased from Shanxi Lanhua; calcium carbonate CC905 was purchased from Guangxi Kelong; calcium oxide was purchased from Zibo Hainuo.
[0025] Example 1 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 1 below: Table 1 Composition of the damping adhesive provided in Example 1
[0026] The preparation method of low-indentation expansion type vibration damping adhesive includes the following steps: S1. Weigh each raw material according to the component ratio provided in Table 1; S2. Stir and mix the synthetic rubber and diluent at 60 ℃~70 ℃ until completely dissolved to obtain a liquid mixture; S3. Add the liquid mixture, epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent and filler into the dynamic mixer respectively, and stir for 30 min at 20 ℃~40 ℃, 15 Hz revolution and 30 Hz rotation until uniformly dispersed to obtain the intermediate mixture. S4. Degas under vacuum (vacuum pressure above -0.09 MPa) for 30 min at 20 ℃~40 ℃, 15 Hz revolution and 10 Hz rotation to obtain the product.
[0027] Example 2 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 2 below: Table 2 Composition of the damping adhesive provided in Example 2
[0028] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0029] Example 3 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 3 below: Table 3 Composition of the damping adhesive provided in Example 3
[0030] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0031] Example 4 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 3 below: Table 4 Composition of the damping adhesive provided in Example 4
[0032] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0033] Example 5 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 5 below: Table 5 Composition of the damping adhesive provided in Example 5
[0034] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0035] Example 6 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 6 below: Table 6 Composition of the damping adhesive provided in Example 6
[0036] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0037] Example 7 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 7 below: Table 7 Composition of the damping adhesive provided in Example 7
[0038] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0039] Example 8 This embodiment provides a low-indentation-expansion type vibration damping adhesive, which is prepared from the raw materials shown in Table 8 below: Table 8 Composition of the damping adhesive provided in Example 8
[0040] The preparation method of the low-trap expansion type vibration damping adhesive is the same as that in Example 1.
[0041] Comparative Example 1 This comparative example provides an intumescent damping adhesive, which is prepared from the raw materials shown in Table 9 below: Table 9 Composition of the damping adhesive provided in Comparative Example 1
[0042] The preparation method of the expanding damping adhesive is the same as that in Example 1.
[0043] Comparative Example 2 This comparative example provides an intumescent damping adhesive, which is prepared from the raw materials shown in Table 10 below: Table 10 Composition of the damping adhesive provided in Comparative Example 2
[0044] The preparation method of the expanding damping adhesive is the same as that in Example 1.
[0045] Comparative Example 3 This comparative example provides an intumescent damping adhesive, which is prepared from the raw materials shown in Table 11 below: Table 11 Composition of the damping adhesive provided in Comparative Example 3
[0046] The preparation method of the expanding damping adhesive is the same as that in Example 1.
[0047] Comparative Example 4 This comparative example provides an intumescent damping adhesive, which is prepared from the raw materials shown in Table 12 below: Table 12 Composition of the damping adhesive provided in Comparative Example 4
[0048] The preparation method of the expanding damping adhesive is the same as that in Example 1.
[0049] Performance Tests and Results The performance of the expanding damping adhesives of Examples 1-8 and Comparative Examples 1-4 were tested respectively, and the test methods are as follows: 1. Shear strength: All test pieces used were cold-rolled steel pieces (100 mm * 25 mm * 0.8 mm). The test pieces were cleaned with acetone (or methyl ethyl ketone), dried, and then evenly coated with rust-preventive oil (QUAKER 6130N), with an oil application rate of approximately 2.5 g / m². 2 ; According to GB / T 7124 standard, the vibration damping adhesive is adhered between the two test pieces with an overlap area of 25 mm*25 mm and an adhesive layer thickness of 2.0 mm. After the fixed test pieces are cured at 170 ℃ for 20 min, they are removed and placed at room temperature for 1 h before the clamps are removed. Shear strength was tested at 23±1 ℃, and the unit is expressed in MPa.
[0050] 2. Cooling shrinkage: (1) Sample preparation A. Material preparation: Cold-rolled steel sheet: 200 mm × 50 mm × 2.0 mm, 2 pieces, each end with a 10 mm diameter hole; Bolts and nuts: 8 mm in diameter * 20 mm in length, 2 pairs; Metal gasket: 20 mm × 20 mm × 6.0 mm, with a 10 mm diameter hole drilled in the center; Metal sheets: 30 mm × 30 mm × 1.0 mm, 3 pieces; B. Sample preparation: 1) Pass bolts through the holes at both ends of a cold-rolled steel plate, place it horizontally, place metal washers on the bolts, and evenly place 3 metal sheets on the cold-rolled steel plate. 2) Make a cone-shaped gel sample with a diameter of 20 mm and a height of 10 mm at the center of each metal sheet; 3) Pass another cold-rolled steel plate through the bolt, tighten the nut, with the cold-rolled plates spaced 6 mm apart, and assemble the sample; (2) Sample testing: A. Sample curing: Keep at 170 ℃ for 20 min, remove the sample and let it cool naturally to room temperature, then let it stand for 2 h; B. Use a gap gauge to measure the distance between the three metal sheets in the sample and the cold-rolled steel plate below, take the average value, and retain two decimal places. The unit is mm.
[0051] 3. Volume expansion rate: 1) Determine the mass m1 of a (100×25) mm aluminum plate in air and the mass m2 in water; 2) Coat a semi-circular sample with a length of 80 mm and a diameter of 10 mm onto a dry aluminum plate, and weigh the aluminum plate and the sample in air (m3) and in water (m4) using a balance. 3) Place the sample in a 170 ℃ oven and bake for 20 min. After cooling, measure the mass m5 of the aluminum plate and the sample in air and the mass m6 in water. 4) Calculate the volumetric expansion rate using the following formula. Test three samples in parallel for each group and take the average value:
[0052] The performance test results of each vibration damping adhesive are shown in Table 13.
[0053] Table 13 Performance test results of various vibration damping adhesives
[0054] As can be seen from Table 13, the low-pitting expansion type vibration damping adhesives of Examples 1 to 8 have a shear strength greater than 0.20 MPa, a panel cooling shrinkage of less than 0.2 mm, and a volume expansion rate greater than 30%, which can meet the technical requirements for low pitting and maintain the appearance of the vehicle body.
[0055] Unless otherwise specified, all raw materials used in this invention are existing substances that can be purchased directly from the market.
[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A low draw pit expansion type damping rubber, characterized by, The raw materials include: epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, and filler; The synthetic rubber includes at least one of styrene-butadiene rubber and NBR-PVC rubber-plastic alloy, and the foaming agent includes DPT.
2. The low draw pit expansion damping gel of claim 1, wherein, The styrene-butadiene rubber contains 22.5% to 24.5% styrene by mass; and / or, The NBR-PVC rubber-plastic alloy contains 19.0% to 25.0% acrylonitrile by mass.
3. The low draw pit expansion damping gel of claim 1, wherein, The low-pit expansion type vibration damping adhesive comprises the following raw materials by weight percentage: 3.0%~7.0% epoxy resin, 3.0%~7.0% PVC resin, 5.0%~10.0% synthetic rubber, 25.0%~35.0% diluent, 1.0%~2.0% adhesion promoter, 0.5%~1.5% curing agent, 0.1%~0.6% foaming agent, and 40.0%~60.0% filler.
4. The low draw pit expansion damping gel of claim 3, wherein, The low-pit expansion type vibration damping adhesive comprises the following raw materials in weight percentages: 4.0%~6.0% epoxy resin, 4.0%~6.0% PVC resin, 6.0%~8.0% synthetic rubber, 25.0%~35.0% diluent, 1.0%~2.0% adhesion promoter, 0.8%~1.2% curing agent, 0.2%~0.5% foaming agent, and 43.0%~58.0% filler.
5. The low draw pit expansion damping gel of claim 1, wherein, The epoxy resin includes at least one of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether; and / or The PVC resin includes polyvinyl chloride homopolymer resin.
6. The low draw pit expansion damping gel of claim 1, wherein, The diluent includes at least one of diisononyl phthalate, dipropylheptyl phthalate, and dioctyl sebacate.
7. The low draw pit expansion damping gel of claim 1, wherein, The adhesion promoter includes at least one selected from acrylic resin, rosin resin, phenolic resin, terpene resin, and petroleum resin; and / or, The curing agent is composed of a first curing agent and a second curing agent. The first curing agent includes dicyandiamide and 4,4'-methylenebis(phenyl dimethylurea), and the second curing agent includes at least one of di-(tert-butylperoxyisopropyl)benzene and butyl 4-bis(tert-butylperoxy)valerate.
8. The low draw pit expansion damping gel of claim 1, wherein, The filler includes at least one of calcium carbonate, mica powder, quartz powder, diatomaceous earth, kaolin, silica powder, silicon dioxide, calcium oxide, and carbon black.
9. The method of producing a low draw pit expansion damping gel according to any one of claims 1 to 8, characterized by, Includes the following steps: S1. Dissolve synthetic rubber in a diluent to obtain a liquid mixture; S2. Mix the liquid mixture, epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent and filler to obtain an intermediate mixture; S3. Vacuum stir and degas the intermediate mixture to obtain a low-trap expansion type vibration damping adhesive.
10. The method for preparing the low-pitching expansion type vibration damping adhesive according to claim 9, characterized in that, In step S1, the dissolution temperature is 60 ℃~70 ℃; and / or, In step S2, the mixing is performed using a dynamic mixer; and / or, In step S2, the mixing temperature is 20 ℃~40 ℃; and / or, In step S3, the vacuum pressure of the vacuum stirring and degassing is greater than or equal to -0.09 MPa, and the time is 30 min to 40 min.