Low-strain low-modulus damping rubber and preparation method thereof

Abstract

The invention provides a low-strain low-modulus vibration damping rubber and a preparation method thereof, and the low-strain low-modulus vibration damping rubber is prepared by mixing the following components: epoxy resin, PVC resin, synthetic rubber, a diluent, an adhesion promoter, a curing agent, a foaming agent, a flame retardant and a filler; wherein the synthetic rubber is selected from styrene butadiene rubber with the styrene content of 22.5-24.5% and the organic acid content of 4.0-6.0%. According to the low-strain low-modulus damping rubber and the preparation method thereof, specific types of resin, rubber, the diluent, the adhesion promoter and other components are preferably selected, and are compounded and reacted according to a specific proportion, so that the modulus, the strength and the shrinkage stress are reduced, the elongation and the adhesion of a product are improved, and the technical requirements of low strain and low modulus are met.

Description

Technical Field

[0001] The invention relates to the technical field of vibration-damping adhesives, and in particular to a low-strain and low-modulus vibration-damping adhesive and a preparation method thereof. Background Art

[0002] With the need to reduce the weight of automobiles, the steel plates of vehicle bodies are thinned or lightweight aluminum plates are used, and the strength of the outer sheet metal decreases. This problem often occurs during the manufacturing process: the existing vibration-damping glue causes sheet metal pitting problems and cannot meet the requirements of the OEM for vehicle body performance and appearance. The vibration-damping glue's anti-pitting performance needs to be improved.

[0003] In the prior art, CN201510571821.5 discloses a high-strength, low-hardness shock-absorbing rubber and a preparation method thereof. The shock-absorbing rubber has a relatively high rubber occupancy ratio to ensure that the shear strength of the shock-absorbing rubber is above 0.7 MPa, and the hardness of the shock-absorbing rubber is reduced to 12A by adding liquid rubber to ensure product elasticity. However, when used on a lightweight and thinned steel plate body, pitting is prone to occur, affecting the performance and appearance of the body.

[0004] Therefore, the art needs to explore a vibration-damping adhesive that can reduce the dent deformation of the steel plate and maintain the beauty of the vehicle body. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a low-strain and low-modulus vibration-damping adhesive and a preparation method thereof. By optimizing components such as resin, rubber, diluent and adhesion promoter, the modulus, strength, and shrinkage stress are reduced, and the elongation and adhesion of the product are improved to meet the technical requirements of low strain and low modulus, reduce the tensile deformation of the steel plate caused by the vibration-damping adhesive, maintain the beauty of the vehicle body, and at the same time meet the process requirements of flame retardancy and automated construction of the vibration-damping adhesive.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: The present invention provides a low-strain and low-modulus vibration-damping adhesive, which is prepared by mixing the following components, wherein the components include: epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler; Wherein, the synthetic rubber is selected from styrene-butadiene rubber with a styrene mass content of 22.5%-24.5% and an organic acid mass content of 4.0%-6.0%.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the low-strain and low-modulus vibration-damping adhesive component includes the following raw materials in percentage by weight: Epoxy resin 1%-4%; PVC resin 1%-4%; Synthetic rubber 10%-14%; Diluent 30%-50%; Adhesion promoter 0.5%-4%; Curing agent 0.5%-2%; Foaming agent 0%-0.05%; Flame retardant 2%-8%; Filling 30%-50%.

[0009] Furthermore, the epoxy resin is selected from at least one of alkyl or alkoxy glycol mono / diglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

[0010] Furthermore, the PVC resin is selected from at least one of polyvinyl chloride homopolymer resin and vinyl chloride-vinyl acetate copolymer resin.

[0011] Furthermore, the diluent is at least one of diisononyl phthalate, dipropylheptyl phthalate, and dioctyl sebacate.

[0012] Furthermore, the adhesion promoter is selected from at least one of acrylic resin, rosin resin, phenolic resin, terpene resin and petroleum resin.

[0013] Furthermore, the curing agent is a mixture of dicyandiamide, 4,4'-methylenebis(phenyldimethylurea), and di-(tert-butylperoxyisopropyl)benzene.

[0014] Further, the foaming agent is one of a chemical foaming agent and expandable microspheres; The flame retardant is microencapsulated red phosphorus.

[0015] Furthermore, the filler is selected from at least one of calcium carbonate, mica powder, quartz powder, diatomaceous earth, kaolin, silicon powder, silicon dioxide, calcium oxide and carbon black.

[0016] In a second aspect, the present invention further provides a method for preparing the low-strain and low-modulus vibration damping adhesive as described in the first aspect, comprising the following steps: S1: Weigh epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler in a preset mass ratio; S2: Stirring and mixing the weighed synthetic rubber and diluent at 60°C-70°C until they are completely dissolved to obtain a liquid mixture; S3: adding the liquid mixture obtained in step S2 and the epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent, flame retardant and filler weighed in step S1 into a dynamic mixer respectively, stirring at 30° C.-40° C. until uniformly dispersed, to obtain an intermediate mixture; S4: vacuum stirring and degassing the intermediate mixture obtained in step S3 to obtain a low-strain and low-modulus vibration-damping adhesive; Among them, the process parameters of vacuum stirring degassing are: vacuum pressure is not less than -0.09MPa, and degassing stirring time is 30min-40min.

[0017] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The low-strain and low-modulus vibration-damping adhesive and its preparation method achieve the technical requirements of low strain and low modulus by selectively selecting specific types of resin, rubber, diluent, adhesion promoter and other components, compounding and reacting them in specific proportions, thereby reducing the modulus, strength, and shrinkage stress, and improving the elongation and adhesion of the product.

[0018] Specifically, based on previous vibration-damping glue products, the vibration-damping glue product provided by the present invention reduces the 30% compression modulus from 0.42MPa to 0.06MPa, the shear strength from 0.40MPa to 0.26MPa, the panel strain to 5.8um, and the elongation at break to 460%, thereby reducing the tensile deformation of the steel plate caused by the vibration-damping glue, maintaining the beauty of the vehicle body, and meeting the process requirements of flame retardancy and automated construction of the vibration-damping glue. DETAILED DESCRIPTION

[0019] The specific implementation of the present invention is described in detail below. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the protection scope of the present invention.

[0020] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0022] In the present invention, the sources of raw materials are described as follows: Epoxy resin: BE-188EL purchased from Changchun Chemical, YDF-170 was purchased from Guodu Chemical.

[0023] PVC resin: polyvinyl chloride homopolymer resin PSM-31 purchased from Shenyang Chemical, Vinyl chloride-vinyl acetate copolymer resin PCMA-12 was purchased from Shenyang Chemical.

[0024] Synthetic rubber: Styrene butadiene rubber SBR1009 was purchased from Nanjing Guochen Chemical.

[0025] Diluent: Diisononyl phthalate DINP purchased from Liancheng Chemical, Dipropylheptyl phthalate (DPHP) was purchased from Shanghai Kunrui Chemical. Dioctyl sebacate (DOS) was purchased from Guangzhou Fufei Chemical.

[0026] Adhesion promoter: Acrylic resin purchased from Mitsubishi Chemical, Rosin resin was purchased from Shaxian Licheng Chemical. Phenolic resin was purchased from Qingdao Huiming.

[0027] Curing agent: dicyandiamide purchased from OMICURE, Organic urea 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.

[0028] Foaming agent: Azodicarbonamide was purchased from Jiangsu Sopo, Dinitrosopentamethylenetetramine was purchased from Jiangsu Yake Chemical. Sulfonylhydrazide diphenyl ether was purchased from Dongda Chemical.

[0029] The microsphere foaming agent was purchased from Akzo Nobel.

[0030] Flame retardant: Microencapsulated red phosphorus was purchased from Hongtaiji Industrial.

[0031] Filler: Calcium carbonate SP200 purchased from Shanxi Lanhua, Calcium carbonate CC905 was purchased from Guangxi Kelong. Silica TS720 was purchased from CABOT, Calcium oxide was purchased from Zibo Hainuo. Carbon black M570 was purchased from CABOT.

[0032] The remaining reagents are commercially available.

[0033] The low-strain and low-modulus vibration-damping adhesive provided by the present invention is prepared by mixing the following components, wherein the components include: epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler.

[0034] Wherein, the synthetic rubber is selected from styrene-butadiene rubber with a styrene mass content of 22.5%-24.5% and an organic acid mass content of 4.0%-6.0%.

[0035] Preferably, the low-strain and low-modulus vibration-damping adhesive component comprises the following raw materials in weight percentage: Epoxy resin 1%-4%; PVC resin 1%-4%; Synthetic rubber 10%-14%; Diluent 30%-50%; Adhesion promoter 0.5%-4%; Curing agent 0.5%-2%; Foaming agent 0%-0.05%; Flame retardant 2%-8%; Filling 30%-50%.

[0036] The epoxy resin is selected from at least one of alkyl or alkoxy glycol mono / diglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

[0037] The PVC resin is selected from at least one of polyvinyl chloride homopolymer resin and vinyl chloride-vinyl acetate copolymer resin.

[0038] The diluent is at least one of diisononyl phthalate, dipropylheptyl phthalate and dioctyl sebacate.

[0039] The adhesion promoter is selected from at least one of acrylic resin, rosin resin, phenolic resin, terpene resin and petroleum resin.

[0040] The curing agent is a mixture of dicyandiamide, 4,4'-methylenebis(phenyldimethylurea) and di-(tert-butylperoxyisopropyl)benzene.

[0041] The foaming agent is one of a chemical foaming agent and expandable microspheres.

[0042] The flame retardant is microencapsulated red phosphorus.

[0043] The filler is selected from at least one of calcium carbonate, mica powder, quartz powder, diatomaceous earth, kaolin, silica powder, silicon dioxide, calcium oxide and carbon black.

[0044] The preparation method of the low-strain and low-modulus vibration-damping adhesive comprises the following steps: S1: Weigh epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler in a preset mass ratio; S2: Stirring and mixing the weighed synthetic rubber and diluent at 60°C-70°C until they are completely dissolved to obtain a liquid mixture; S3: adding the liquid mixture obtained in step S2 and the epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent, flame retardant and filler weighed in step S1 into a dynamic mixer respectively, stirring at 30° C.-40° C. until the mixture is uniformly dispersed, to obtain an intermediate mixture; S4: vacuum stirring and degassing the intermediate mixture obtained in step S3 to obtain a low-strain and low-modulus vibration-damping adhesive; Among them, the process parameters of vacuum stirring degassing are: vacuum pressure is not less than -0.09MPa, and degassing stirring time is 30min-40min.

[0045] The following is further introduced in conjunction with specific embodiments: Example 1 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 1 below: Table 1 Composition of the vibration damping adhesive provided in Example 1

[0046] The preparation method of the vibration damping adhesive of this embodiment comprises the following steps: S1, weigh each raw material according to the component ratio provided in Table 1.

[0047] S2, stirring and mixing the synthetic rubber and the diluent at 60° C. until they are completely dissolved to obtain a liquid mixture.

[0048] S3, respectively add the liquid mixture, epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent, flame retardant and filler into a dynamic mixer, stir for 30 minutes at 35°C, revolution 15 Hz and rotation 30 Hz until the mixture is evenly dispersed, to obtain an intermediate mixture.

[0049] S4, degassing for 30 minutes in vacuum (vacuum pressure above -0.09MPa) under the conditions of 35℃, revolution 15Hz and rotation 10Hz.

[0050] Example 2 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 2 below: Table 2 Composition of the vibration damping adhesive provided in Example 2

[0051] The preparation method of the vibration damping adhesive of this embodiment comprises the following steps: S1, weigh each raw material according to the component ratio provided in Table 2.

[0052] S2, stirring and mixing the synthetic rubber and the diluent at 70° C. until they are completely dissolved to obtain a liquid mixture.

[0053] S3, respectively add the liquid mixture, epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent, flame retardant and filler into a dynamic mixer, stir for 30 minutes at 40°C, revolution 15 Hz and rotation 30 Hz until the mixture is evenly dispersed, to obtain an intermediate mixture.

[0054] S4, degassing for 40 minutes in vacuum (vacuum pressure above -0.09MPa) under the conditions of 40℃, revolution 15Hz and rotation 10Hz.

[0055] Example 3 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 3 below: Table 3 Composition of the vibration damping adhesive provided in Example 3

[0056] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0057] Example 4 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 4 below: Table 4 Composition of the vibration damping adhesive provided in Example 4

[0058] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0059] Example 5 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 5 below: Table 5 Composition of the vibration damping adhesive provided in Example 5

[0060] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0061] Example 6 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 6 below: Table 6 Composition of the vibration damping adhesive provided in Example 6

[0062] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0063] Example 7 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 7 below: Table 7 Composition of vibration damping adhesive provided in Example 7

[0064] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0065] Example 8 This embodiment provides a vibration-damping adhesive, which is prepared from the raw materials shown in Table 8 below: Table 8 Composition of vibration damping adhesive provided in Example 8

[0066] The preparation method of the vibration-damping adhesive of this embodiment is basically the same as that of Embodiment 1, and will not be described in detail here.

[0067] Comparative Example 1 This comparative example provides a vibration-damping rubber, which is prepared from the raw materials shown in Table 9 below: Table 9 Composition of vibration damping rubber provided in Comparative Example 1

[0068] The preparation method of the vibration-damping rubber in this comparative example is basically the same as that in Example 1, and will not be described in detail here.

[0069] Comparative Example 2 This comparative example provides a vibration-damping rubber, which is prepared from the raw materials shown in Table 10 below: Table 10 Composition of vibration damping rubber provided in Comparative Example 2

[0070] The preparation method of the vibration-damping rubber in this comparative example is basically the same as that in Example 1, and will not be described in detail here.

[0071] Comparative Example 3 This comparative example provides a vibration-damping rubber, which is prepared from the raw materials shown in Table 11 below: Table 11 Composition of vibration damping rubber provided in Comparative Example 3

[0072] The preparation method of the vibration-damping rubber in this comparative example is basically the same as that in Example 1, and will not be described in detail here.

[0073] Comparative Example 4 This comparative example provides a vibration-damping rubber, which is prepared from the raw materials shown in Table 12 below: Table 12 Composition of vibration damping rubber provided in Comparative Example 4

[0074] The preparation method of the vibration-damping rubber in this comparative example is basically the same as that in Example 1, and will not be described in detail here.

[0075] Comparative Example 5 This comparative example provides a vibration-damping rubber, which is prepared from the raw materials shown in Table 13 below: Table 13 Composition of vibration damping rubber provided in Comparative Example 5

[0076] The preparation method of the vibration-damping rubber in this comparative example is basically the same as that in Example 1, and will not be described in detail here.

[0077] The performance of the vibration damping rubber obtained in the above examples and comparative examples was tested, and the testing method is as follows: 1. Shear strength: All the test pieces used were cold-rolled steel test pieces (100mm*25mm*0.8mm). The test pieces were cleaned with acetone (or butanone), and then evenly coated with anti-rust oil (QUAKER 6130N) on the surface after drying. The amount of oil applied was about 2.5g / m 2 .

[0078] According to GB / T 7124 standard, the vibration damping adhesive was adhered between the two test pieces, with an overlap area of ​​25mm*25mm and an adhesive layer thickness of 3.0mm. The fixed test pieces were cured at 170℃×20min, taken out, placed at room temperature for 1h, and the clamps were removed.

[0079] The shear strength test is carried out at 23±1℃ and the unit is expressed in MPa.

[0080] 2. 30% compression modulus: Prepare a cylindrical rubber cake of vibration damping rubber with the following dimensions: 30 mm in diameter and 10 mm in height; Testing machine fixture travel speed: 50 mm / min; Measure the compressive strength of the vibration damping rubber when the compression reaches 30%, expressed in MPa.

[0081] 3. Panel strain: (1) Sample preparation A. Material preparation: 100mm×100mm×0.65mm cold-rolled steel plate; 100mm×100mm×2mm galvanized sheet; 5mm thick metal gasket; B. Make a rubber sample with a diameter of 10mm and a height of 5mm in the center of the thin steel plate, and assemble the samples so that the thin steel plate faces.

[0082] (2) Sample testing: A. Scan the thin steel plate surface of the sample with a 3D profile scanner to obtain the initial surface profile of the thin steel plate; B. Sample curing: Keep at 170℃ for 20 minutes, take out the sample and let it cool naturally to room temperature; C. Scan the thin steel plate surface of the sample again with a 3D profile scanner to obtain the surface profile of the thin steel plate after baking; D. Subtract the contour before baking from the contour after baking to get the difference in surface contour change of the thin steel plate.

[0083] 4. Elongation at break The test method is detailed in JIS K 6301, 3.2 Test piece: No. 1 dumbbell bar, thickness: 2 mm.

[0084] Performance Test Results Table 13 Performance test results statistics

[0085] Combined with the performance test result table, it can be seen that compared with comparative examples 1 to 5, the low-strain and low-modulus vibration damping adhesives of embodiments 1 to 8 achieve the technical requirements of low strain and low modulus by preferably selecting specific types of resins, rubbers, diluents, adhesion promoters and other components, and compounding them in specific proportions.

[0086] Specifically, based on the previous vibration damping rubber products, the 30% compression modulus of the vibration damping rubber product of the present invention is reduced from 0.42MPa to 0.06MPa, the shear strength is reduced from 0.40MPa to 0.26MPa, the panel strain is reduced to 5.8um, and the elongation at break is increased to 460%, thereby reducing the tensile deformation of the steel plate caused by the vibration damping rubber, maintaining the beauty of the car body, and at the same time meeting the process requirements of flame retardancy and automated construction of the vibration damping rubber.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-strain and low-modulus vibration damping rubber, characterized in that: The composition is prepared by mixing the following components, wherein the components include: epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler; Wherein, the synthetic rubber is selected from styrene-butadiene rubber with a styrene mass content of 22.5%-24.5% and an organic acid mass content of 4.0%-6.0%.

2. The low-strain and low-modulus vibration damping adhesive according to claim 1, characterized in that: The low-strain and low-modulus vibration-damping rubber component includes the following raw materials in percentage by weight: Epoxy resin 1%-4%; PVC resin 1%-4%; Synthetic rubber 10%-14%; Diluent 30%-50%; Adhesion promoter 0.5%-4%; Curing agent 0.5%-2%; Foaming agent 0%-0.05%; Flame retardant 2%-8%; Filling 30%-50%.

3. The low-strain and low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The epoxy resin is selected from at least one of alkyl or alkoxy glycol mono / diglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

4. The low-strain, low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The PVC resin is selected from at least one of polyvinyl chloride homopolymer resin and vinyl chloride-vinyl acetate copolymer resin.

5. The low-strain and low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The diluent is at least one of diisononyl phthalate, dipropylheptyl phthalate and dioctyl sebacate.

6. The low-strain, low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The adhesion promoter is selected from at least one of acrylic resin, rosin resin, phenolic resin, terpene resin and petroleum resin.

7. The low-strain, low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The curing agent is a mixture of dicyandiamide, 4,4'-methylenebis(phenyldimethylurea) and di-(tert-butylperoxyisopropyl)benzene.

8. The low-strain, low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The foaming agent is one of a chemical foaming agent and expandable microspheres; The flame retardant is microencapsulated red phosphorus.

9. The low-strain, low-modulus vibration damping adhesive according to claim 1 or 2, characterized in that: The filler is selected from at least one of calcium carbonate, mica powder, quartz powder, diatomaceous earth, kaolin, silicon powder, silicon dioxide, calcium oxide and carbon black.

10. A method for preparing the low-strain and low-modulus vibration-damping adhesive according to any one of claims 1 to 9, characterized in that: The steps include: S1: Weigh epoxy resin, PVC resin, synthetic rubber, diluent, adhesion promoter, curing agent, foaming agent, flame retardant and filler in a preset mass ratio; S2: Stirring and mixing the weighed synthetic rubber and diluent at 60°C-70°C until they are completely dissolved to obtain a liquid mixture; S3: adding the liquid mixture obtained in step S2 and the epoxy resin, PVC resin, adhesion promoter, curing agent, foaming agent, flame retardant and filler weighed in step S1 into a dynamic mixer respectively, stirring at 30° C.-40° C. until uniformly dispersed, to obtain an intermediate mixture; S4: vacuum stirring and degassing the intermediate mixture obtained in step S3 to obtain a low-strain and low-modulus vibration-damping adhesive; Among them, the process parameters of vacuum stirring degassing are: vacuum pressure is not less than -0.09MPa, and degassing stirring time is 30 min-40min.

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