Dry-wet combined patching method for metal plate and rubber layer

Abstract

The invention belongs to the technical field of rubber-metal composite plates, and particularly relates to a dry-wet combined patching method for a metal plate and a rubber layer. The composite patching method comprises the following steps: coating a pretreated steel plate with an adhesive, calendering and patching, and carrying out dry-type adhesive layer patching; carrying out surface cleaning after secondary vulcanization, and then coating a liquid glue layer to carry out wet-type surface mounting; the rubber-metal composite plate finally obtained by the composite patching method is firm in interlayer bonding, the thickness of the adhesive layer is accurately regulated and controlled, and the rubber-metal composite plate has the characteristics of high adhesive force of the adhesive layer, easiness in thickness regulation, low process processing cost and good production economic benefit.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber-metal composite plates, and in particular relates to a dry-wet combination pasting method of a metal plate and a rubber layer. Background Art

[0002] Rubber / metal composite panels are the core material of automotive brake pads, reducing brake noise by damping vibration and sound wave transmission. Their typical structure is a sandwich of a rubber functional layer, a metal substrate, and a rubber functional layer. They are typically 0.4–0.8 mm thick and are installed on the back of the brake pad to block frictional vibration transmission.

[0003] Among them, the composite of rubber layer and metal plate (rubber layer patch) is the key to processing and forming. The traditional patch process is to composite the calendered rubber sheet and the metal plate with adhesive roller pressing, which is a dry patch and the thickness of the film is not easy to control. Some manufacturers use adhesive roller coating or scraping, which is a wet patch. The thickness of the adhesive layer can be precisely controlled, but there are the following problems: first, the wet method is directly coated on the surface of the metal plate, the bonding is not strong, the adhesion is poor, and the adhesive layer is prone to fall off after the composite plate is formed; second, when the adhesive layer is thick, simply using wet coating will result in high equipment cost, low resource utilization, and poor economic benefits. Summary of the Invention

[0004] The purpose of the present invention is to provide a dry-wet combined patch method with firm composite bonding between the rubber layer and the metal plate and precise control of the thickness of the adhesive layer. The method has the characteristics of high adhesive layer adhesion, easy thickness adjustment, low process processing cost and good production economic benefits.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A dry-wet combination patching method for a metal plate and a rubber layer, characterized by comprising: Step 1: After the steel plate is pretreated, its surface is coated with adhesive; Step 2: bonding the steel plate treated in step 1 to the calendered rubber sheet to form a rubber layer on the surface of the steel plate; Step 3: The composite plate formed by the steel plate and the rubber layer after the treatment in step 2 is subjected to primary vulcanization at a temperature of 100°C-150°C for a vulcanization time of 5-8 minutes, and secondary vulcanization at a temperature of 60°C-80°C for a vulcanization time of 5-8 minutes; Step 4: Clean the surface of the rubber layer to remove impurities; Step 5: A liquid rubber layer is coated on the surface of the rubber layer. The liquid rubber layer is obtained by foaming a rubber matrix accounting for 20%-25% with an organic solvent.

[0006] Additional technical features of the above-mentioned dry-wet combined lamination method of the metal plate and the rubber layer include: The steel plate pretreatment process in step 1 includes step 6, wherein the uncoiled steel plate is subjected to hot bath cleaning with an alkaline cleaning agent, and a chemical conversion film is formed on the surface of the steel plate; The step 1 includes several drying processes, wherein the steel plate after hot bath cleaning is dried with hot air; the chemical conversion film is dried with hot air followed by cold air curing; and the adhesive is dried with hot air, maintaining the steel plate temperature between 50°C and 60°C. In step 6, the alkaline cleaning agent is a sodium hydroxide solution with a concentration of 2%-5%, and the heating bath temperature is between 50°C and 60°C; In step 6, the chemical conversion film is a passivation film formed by a chromium-free passivation solution; In step 4, the cleaning process includes using an ethyl acetate solution with a concentration of 30%-80% for pre-washing, followed by purging and air-drying; using anhydrous ethanol for post-washing, followed by purging and air-drying; - Add step 7 after step 4, performing corona shock treatment on the surface of the air-dried rubber layer to improve the activity of the rubber surface; In step 2, the calendered rubber sheet is made of nitrile rubber, fluororubber or silicone rubber, and the thickness of the rubber layer formed on the surface of the steel plate is between 40 μm and 150 μm. In step 5, the thickness of the liquid rubber layer is between 5% and 25% of the rubber layer. - Adding step eight after step five, drying and then vulcanizing the liquid adhesive layer at a temperature of 160°C-190°C and a vulcanization time of 8-12 minutes; - Adding step 9 after step 8, coating the surface of the liquid adhesive layer with a functional coating for improving appearance and heat insulation, wherein the functional coating is a fluorocarbon coating; Compared with the prior art, the dry-wet combined patching method of a metal plate and a rubber layer provided by the present invention has the following advantages: the dry-wet combined patching method is used for compounding a metal plate and a rubber layer, the dry patching method is to compound the calendered rubber sheet and the metal plate by roller pressing with an adhesive, and the wet patching method is to coat the surface of the dry adhesive layer with liquid rubber to accurately adjust the thickness of the entire rubber layer, thereby ensuring the processing accuracy and use quality of the composite plate, avoiding the disadvantages of the traditional dry adhesive layer thickness control, the poor adhesion of the wet adhesive layer, and the high processing cost, and the dry-wet combination achieves the precise thickness of the rubber layer. Control to ensure the production quality of rubber-metal composite panels; secondly, the key to the dry-wet combined patch method lies in the cleaning process between the dry adhesive layer and the wet adhesive layer. The impurities on the surface of the dry adhesive layer can be completely removed by pre-washing with ethyl acetate and post-washing with anhydrous ethanol. In addition, the corona impact treatment process is added to improve the surface activity of the adhesive layer, laying the foundation for wet coating, significantly enhancing its adhesion and making the bonding between the two layers stronger. The rubber-metal composite panel manufactured by this method has the advantages of high adhesive layer adhesion, easy thickness adjustment, low process processing cost and good production economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a flow chart of a dry-wet combination pasting method of a metal plate and a rubber layer according to the present invention; Figure 2 It is a performance comparison index of the rubber-metal composite obtained by applying the method of the present invention. DETAILED DESCRIPTION

[0008] The following is combined with Figure 1 The process and operating principle of the wet-dry bonding method for bonding a metal plate to a rubber layer provided by the present invention will be further described in detail. It is apparent that the embodiments described herein are merely a portion of the embodiments of the present invention, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention. Example

[0009] Steel plate pretreatment: Cold rolled steel plate (SPCC, 0.8 mm) was cleaned with 3% sodium hydroxide solution in a 55°C hot bath → hot air drying → coating with chromium-free passivation solution (thickness 0.3 μm) → hot air drying + cold air curing; Adhesive coating: Roller-coat chloroprene rubber adhesive → hot air drying (steel plate temperature 55°C); Dry patch, calendered film composite: calendered nitrile film (thickness 100μm) is bonded to the steel plate; Step vulcanization: primary vulcanization--130℃×6 minutes, secondary vulcanization--70℃×6 minutes; Surface cleaning of adhesive layer: Pre-washing - spraying with 50% ethyl acetate solution → high-pressure air drying; Post-washing - ultrasonic cleaning with anhydrous ethanol → infrared drying; Corona shock treatment: corona power 5kW (electrode spacing 2mm, speed 8m / min); Wet patch, liquid glue coating: nitrile rubber / toluene foaming liquid (rubber accounts for 22%), scraping thickness 15μm (accounting for 15% of the rubber layer of the calendered film); Re-vulcanization: 170℃×10min; Functional coating: spraying fluorocarbon coating (solid content 45%), wet film thickness 30μm; Post-processing: Dry and cure at 80℃ → air cool to room temperature; apply 0.1mm PE protective film on the front and acrylic double-sided tape on the back; slitting and reeling. Example

[0010] Pretreatment: Galvanized steel sheet (SECC, 1.0 mm) was cleaned with a pH = 12 alkaline detergent (containing sodium silicate) at 60°C → phosphate conversion coating (0.8 μm); Adhesive coating: epoxy modified adhesive, drying temperature 58°C; Dry patch, calendered film composite: fluororubber calendered sheet (thickness 80μm); Step vulcanization: primary vulcanization--140℃×6 minutes, secondary vulcanization--75℃×6 minutes; Surface cleaning of adhesive layer: pre-wash - spray with 65% ethyl acetate solution → high-pressure air drying; post-wash - spray with anhydrous ethanol (containing 0.5% surfactant) → hot air drying; Corona shock treatment: corona power 7kW (electrode spacing 2mm, speed 10m / min); Wet patch, liquid adhesive coating: fluororubber / acetone system (rubber 24%), thickness 20μm (accounting for 25% of the rubber layer of the calendered film); Re-vulcanization: 180℃×11 minutes; Functional coating: thermal insulation fluorocarbon coating containing glass beads (thickness 10μm); Post-processing: same as Example 1 Example

[0011] Pretreatment: Aluminum alloy plate (5052, 1.2 mm) was cleaned with 4.5% NaOH solution at 60°C → nano-ceramic passivation film (containing SiO2, 1.2 μm); Adhesive coating: After silane coupling agent treatment, apply general resin adhesive with a roller → hot air drying (steel plate temperature 55°C); Dry patch, calendered film composite: silicone rubber calendered sheet (thickness 150μm); Step vulcanization: primary vulcanization--150℃×5 minutes, secondary vulcanization--80℃×7 minutes; Surface cleaning of adhesive layer: pre-wash - spray with 80% ethyl acetate solution → high-pressure air drying; post-wash - spray with anhydrous ethanol → hot air drying; Corona shock treatment: corona power 8kW (electrode spacing 1.5mm, speed 10m / min, nitrogen protection); Wet patch, liquid adhesive coating: silicone rubber / xylene system (rubber 25%), thickness 20μm (accounting for 13% of the rubber layer of the calendered film); Re-vulcanization: 190℃×9 minutes; Functional coating: nano-alumina reinforced fluorocarbon coating (thickness 20μm); Post-treatment: Compared with Example 1-2, a UV curing process is added; Comparative Example: In the existing technology (traditional wet patch process), the metal plate is only mechanically polished. Single vulcanization (160℃×15 minutes), no liquid adhesive layer and corona treatment, the rubber layer is directly compounded with non-functional coating; like Figure 2 As shown, the performance indicators of the comparative example and Examples 1-3, wherein the test basis is: peel strength ASTMD429-14; noise test SAE J2521; heat aging ISO 188. Compared with the comparative example, the technical effects of the present invention are reflected in the following: the interface between the metal plate and the rubber layer is strengthened, the thickness of the rubber layer is controllable, and the adhesion between the layers is enhanced; step vulcanization eliminates internal stress; dry-wet combined patch, the liquid adhesive layer fills the rubber micropores (SEM shows that the porosity is reduced from 12% in the comparative example to 3.5%); weather resistance is improved, the passivation film + corona treatment extends the salt spray resistance time from 240h (comparative example) by at least 1 times; noise reduction performance is improved, the liquid adhesive layer forms a damping structure, the functional coating absorbs high-frequency vibrations, and the 2000Hz noise attenuation rate increases by 40%; production efficiency is improved, and the dry-wet combined process reduces the vulcanization waiting time.

[0012] The above-described embodiments are only used to illustrate the technical solution of the present invention and are not limiting conditions for the implementation of the present invention. Therefore, any other modifications or equivalent replacements of configuration dimensions and internal structures made to the technical solution of the present invention should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A dry-wet combination lamination method for a metal plate and a rubber layer, characterized by: include Step 1: After the steel plate is pretreated, its surface is coated with adhesive; Step 2: bonding the steel plate treated in step 1 to the calendered rubber sheet to form a rubber layer on the surface of the steel plate; Step 3: The composite plate formed by the steel plate and the rubber layer after the treatment in step 2 is subjected to primary vulcanization at a temperature of 100°C-150°C for a vulcanization time of 5-8 minutes, and secondary vulcanization at a temperature of 60°C-80°C for a vulcanization time of 5-8 minutes; Step 4: Clean the surface of the rubber layer to remove impurities; Step 5: A liquid rubber layer is coated on the surface of the rubber layer. The liquid rubber layer is obtained by foaming a rubber matrix accounting for 20%-25% with an organic solvent.

2. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 1, characterized in that: The steel plate pretreatment process in step one includes step six, wherein the uncoiled steel plate is cleaned in a hot bath with an alkaline cleaning agent, and a chemical conversion film is formed on the surface of the steel plate.

3. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 2, characterized in that: The step 1 includes several drying processes, among which the steel plate after hot bath cleaning is dried with hot air; the chemical conversion film is dried with hot air and then solidified with cold air; the adhesive is dried with hot air, and the temperature of the steel plate is maintained between 50°C and 60°C.

4. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 2, characterized in that: In step six, the alkaline cleaning agent is a sodium hydroxide solution with a concentration of 2%-5%, and the hot bath temperature is between 50°C and 60°C.

5. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 2, characterized in that: In the step six, the chemical conversion film is a passivation film formed by a chromium-free passivation solution.

6. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 1, characterized in that: In the step 4, the cleaning process includes using an ethyl acetate solution with a concentration of 30%-80% for pre-washing, followed by purging and air-drying; using anhydrous ethanol for post-washing, followed by purging and air-drying.

7. A dry-wet combined lamination method of a metal plate and a rubber layer according to claim 1 or 6, characterized in that: Step 7 is added after step 4, wherein the surface of the air-dried rubber layer is subjected to corona impact treatment to improve the activity of the rubber surface.

8. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 1, characterized in that: In the step 2, the calendered film is made of nitrile rubber, fluororubber or silicone rubber, and the thickness of the rubber layer formed on the surface of the steel plate is between 40μm and 150μm. In the step 5, the thickness of the liquid rubber layer accounts for between 5% and 25% of the rubber layer.

9. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 1, characterized in that: Add step eight after step five, drying and then vulcanizing the liquid adhesive layer at a temperature of 160° C. to 190° C. for a vulcanization time of 8 to 12 minutes.

10. The dry-wet combined lamination method of a metal plate and a rubber layer according to claim 9, characterized in that: Add step nine after step eight, coating the surface of the liquid adhesive layer with a functional coating for improving appearance and heat insulation, wherein the functional coating is a fluorocarbon coating.

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