An environmentally friendly preparation process for a rubber seal

Abstract

The present invention belongs to the technical field of rubber materials, and particularly relates to an environment-friendly preparation process for rubber seals, including: putting a metal substrate into a mixed alkaline solution for microwave treatment for 20 - 50 minutes, taking it out and drying to obtain a degreased metal substrate; performing abrasive treatment on the metal substrate, using ethanol as a coolant, then putting it into ethanol for ultrasonic cleaning for 1 - 2 hours, and filtering to obtain a metal substrate with a rough surface; putting the metal substrate into a reaction kettle, introducing trichloromethylsilane vapor to deposit a liquid film, and then spraying methyltriethoxysilane on the surface to form a secondary liquid film; putting the metal substrate with the secondary liquid film into the reaction kettle and standing for 5 - 10 minutes, then bonding the metal substrate with rubber, and vulcanizing to obtain a rubber seal. The present invention uses silane as a binder and a surface modifier to achieve a tight structure between the rubber and the metal substrate, reducing the formation of voids and bubbles.

Description

Technical Field

[0001] The present invention belongs to the technical field of rubber materials, and particularly relates to an environment-friendly preparation process for rubber seals. Background Art

[0002] Currently, in the rubber industry with metal substrates, the following two surface treatment methods are mostly adopted: one is the phosphate-based surface treatment technology; the other is the mechanical surface treatment technology, such as shot peening, sandblasting, etc., among which the phosphate surface treatment technology is the main one. The phosphate surface treatment technology uses phosphating solution as the main raw material. The phosphating solution mainly contains phosphates and phosphoric acid. A crystalline film is formed on the metal surface through a chemical reaction to achieve the purpose of rust prevention and convenient painting for the metal substrate in the later stage. The phosphating surface treatment technology causes relatively serious corrosion to the equipment, and the chemical reaction is complex, which brings troubles to problem-solving. At the same time, with the improvement of environmental protection requirements, the sewage treatment cost is becoming increasingly high, and even in some areas, zero phosphorus discharge of industrial wastewater is required. The phosphating solution in this technology has relatively high toxicity. To reduce the treatment time and obtain a better phosphating film, a large amount of wastewater that does not meet environmental protection requirements is generated during the phosphating treatment process. The mechanical surface treatment technology only improves through surface friction, but there is still a problem of poor compatibility and connection. Summary of the Invention

[0003] Aiming at the problems in the prior art, the present invention provides an environment-friendly preparation process for rubber seals, solves the pollution problem of existing rubber seals, and uses silane as a binder and a surface modifier to achieve a tight structure between the rubber and the metal substrate and reduce the formation of cavities and bubbles.

[0004] To achieve the above technical purposes, the technical solution of the present invention is as follows:

[0005] An environment-friendly preparation process for rubber seals includes the following steps:

[0006] Step 1: Put the metal substrate into a mixed alkaline solution and perform microwave treatment for 20 - 50 min, take it out and dry it to obtain a degreased metal substrate. The solutes of the mixed alkaline solution are sodium hydroxide and sodium carbonate, and the mass ratio of the two is 2:2 - 3. The concentration of sodium hydroxide is 5 - 10 g / L. The microwave power of the microwave treatment is 300 - 500 W, and the temperature is 20 - 50 °C. The drying temperature is 100 - 120 °C. This step uses the alkaline solution to remove cottonseed oil and impurities to achieve the purpose of alkaline degreasing.

[0007] Step 2: The metal substrate is subjected to sanding treatment, with ethanol as the coolant, and then ultrasonic cleaning is carried out in ethanol for 1-2 h. After filtration, a metal substrate with a rough surface is obtained. The sanding treatment uses fine sandpaper, the temperature of ethanol is 10-15 °C, the flow rate is 1-5 mL / min, the ultrasonic frequency of the ultrasonic cleaning is 40-70 kHz, and the temperature is 20-30 °C. In this step, the surface of the metal substrate is refined by sanding, and at the same time, ethanol is used as the mobile phase to play the role of cooling and removing impurities, reducing the influence of impurities for subsequent continuous sanding, so as to form a stable and uniform fine concave-convex structure.

[0008] Step 3: The metal substrate is placed in a reaction kettle, and trichloromethylsilane vapor is introduced to deposit a liquid film, and then methyltriethoxysilane is sprayed on the surface to form a secondary liquid film. The trichloromethylsilane vapor is a mixed gas of ether and trichloromethylsilane, and the volume ratio of ether to trichloromethylsilane is 2:2-3, and the temperature is 70-75 °C. The deposition temperature is 50-60 °C. The spraying amount of methyltriethoxysilane is 0.1-0.3 mL / cm2, and the temperature is 20-30 °C. In this step, ether and trichloromethylsilane are used as vapors to directly act on the surface of the metal substrate, and the concave-convex structure on the surface of the metal substrate is used in combination with low-temperature deposition to realize the homogenization of the liquid film on the surface. At the same time, with the residual dissolution amount of ether as the solvent, it can bring a certain fluidity to trichloromethylsilane, improving the surface adhesion uniformity, that is, reducing the exposed surface. Methyltriethoxysilane is used as a secondary adherent, which can cover trichloromethylsilane to ensure its fixation in the inner layer.

[0009] Step 4: The metal substrate with the secondary liquid film is placed in the reaction kettle and left standing for 5-10 min, and then the metal substrate is bonded to the rubber and vulcanized to obtain a rubber seal. The atmosphere in the reaction kettle is a water vapor and nitrogen atmosphere, and the volume ratio of water vapor is 5-8%, and the standing temperature is 20-30 °C. In this process, water vapor comes into contact with the secondary liquid film, hydrolyzing trichloromethylsilane and methyltriethoxysilane. And based on the hydrolysis of trichloromethylsilane inside to form hydrogen chloride, combined with the viscous state formed after the self-transformation of methyltriethoxysilane, it promotes part of the hydrogen chloride to act on the surface of the metal substrate preferentially, achieving good surface acidification treatment, which is helpful for the adhesion between the hydrolysis product of trichloromethylsilane and the metal substrate. The bonding uses a bonding system with temperature and pressure, the pressure is 0.3-0.5 MPa, and the temperature is the softening temperature of the rubber. This mechanism uses the active groups in the rubber such as hydroxyl groups, double bonds, free radicals, epoxy groups, etc. to form a bonding reaction with the hydroxyl groups in the silicon system, and combines with the pressure effect to increase the contact area between the rubber and the silicon material, achieving an excellent connection effect.

[0010] From the above description, it can be seen that the present invention has the following advantages:

[0011] 1. The present invention solves the problem of pollution of existing rubber seals. By using silane as a binder and a surface modifier, a tight structure between the rubber and the metal substrate is achieved, reducing the formation of voids and bubbles.

[0012] 2. The present invention uses silane as a transfer agent to form stable chemical bond connections with both the metal substrate and the rubber, increasing the surface adhesion force. At the same time, silane itself forms a stable three-dimensional silicon-oxygen structure, improving its own structural stability and not forming displacement under stress.

[0013] 3. The present invention uses a system combining trichloromethylsilane and triethoxymethylsilane to form a composite deposition effect in a wrapped state, enhancing the stability of silane as a binder and reducing the construction difficulty. Detailed implementation mode

[0014] A specific embodiment of the present invention is described in detail, but no limitation is made to the claims of the present invention. Example 1

[0015] An environmentally friendly preparation process for a rubber seal includes the following steps:

[0016] Step 1: Place the metal substrate in a mixed alkaline solution and microwave it for 20 - 50 minutes, then take it out and dry it to obtain a degreased metal substrate. The solutes of the mixed alkaline solution are sodium hydroxide and sodium carbonate, and the mass ratio of the two is 2:2 - 3. The concentration of sodium hydroxide is 5 - 10 g / L. The microwave power of the microwave treatment is 300 - 500 W, the temperature is 20 - 50 °C, and the drying temperature is 100 - 120 °C.

[0017] Step 2: Grind the metal substrate, use ethanol as a coolant, and then put it into ethanol for ultrasonic cleaning for 1 - 2 hours, and filter to obtain a metal substrate with a rough surface. The grinding treatment uses fine sandpaper. The temperature of ethanol is 10 - 15 °C, the flow rate is 1 - 5 mL / min, the ultrasonic frequency of the ultrasonic cleaning is 40 - 70 kHz, and the temperature is 20 - 30 °C.

[0018] Step 3: Place the metal substrate in a reaction kettle, introduce trichloromethylsilane vapor to deposit a liquid film, and then spray methyltriethoxysilane on the surface to form a secondary liquid film. The trichloromethylsilane vapor is a mixed gas of ether and trichloromethylsilane, and the volume ratio of ether to trichloromethylsilane is 2:2 - 3, the temperature is 70 - 75 °C, and the deposition temperature is 50 - 60 °C. The spraying amount of methyltriethoxysilane is 0.1 - 0.3 mL / cm2, and the temperature is 20 - 30 °C.

[0019] Step 4: Place the metal substrate with the secondary liquid film into the reaction kettle and let it stand for 5 - 10 minutes. Then bond the metal substrate to the rubber and obtain the rubber seal through vulcanization. The atmosphere in the reaction kettle is a steam and nitrogen atmosphere, and the volume ratio of steam is 5 - 8%. The standing temperature is 20 - 30°C. The bonding uses a bonding system with temperature and pressure. The pressure is 0.3 - 0.5 MPa, and the temperature is the softening temperature of the rubber.

[0020] The rubber coverage rate of this example is 98%, the shear breaking force is 32.6 kN, the number of small - amplitude impacts at a frequency of 3 Hz is 400,000 times, and it also has good wear resistance and weather resistance. Example 2

[0021] An environmentally friendly preparation process for rubber seals includes the following steps:

[0022] Step 1: Place the metal substrate into the mixed alkaline solution and perform microwave treatment for 20 - 50 minutes. After taking it out and drying, obtain the degreased metal substrate. The solutes of the mixed alkaline solution are sodium hydroxide and sodium carbonate, and the mass ratio of the two is 2:2 - 3. The concentration of sodium hydroxide is 5 - 10 g / L. The microwave power of the microwave treatment is 300 - 500 W, the temperature is 20 - 50°C, and the drying temperature is 100 - 120°C.

[0023] Step 2: Perform frosting treatment on the metal substrate, use ethanol as the coolant, and then put it into ethanol for ultrasonic cleaning for 1 - 2 hours. After filtration, obtain the metal substrate with a rough surface. The frosting treatment uses fine sandpaper. The temperature of ethanol is 10 - 15°C, the flow rate is 1 - 5 mL / min, the ultrasonic frequency of the ultrasonic cleaning is 40 - 70 kHz, and the temperature is 20 - 30°C.

[0024] Step 3: Place the metal substrate into the reaction kettle, and introduce trichloromethylsilane vapor to deposit a liquid film, and then spray methyltriethoxysilane on the surface to form a secondary liquid film. The trichloromethylsilane vapor is a mixed gas of ether and trichloromethylsilane, and the volume ratio of ether to trichloromethylsilane is 2:2 - 3, the temperature is 70 - 75°C, and the deposition temperature is 50 - 60°C. The spraying amount of methyltriethoxysilane is 0.1 - 0.3 mL / cm2, and the temperature is 20 - 30°C.

[0025] Step 4: Place the metal substrate with the secondary liquid film into the reaction kettle and let it stand for 5 - 10 minutes. Then bond the metal substrate to the rubber and obtain the rubber seal through vulcanization. The atmosphere in the reaction kettle is a steam and nitrogen atmosphere, and the volume ratio of steam is 5 - 8%. The standing temperature is 20 - 30°C. The bonding uses a bonding system with temperature and pressure. The pressure is 0.3 - 0.5 MPa, and the temperature is the softening temperature of the rubber.

[0026] The rubber coverage rate of this embodiment is 99%, the shear destructive force is 33.2 kN, the number of small - amplitude impacts at a frequency of 3 Hz is 420,000 times, and it also has good wear resistance and weather resistance. Example 3

[0027] An environmentally friendly preparation process for a rubber seal, comprising the following steps:

[0028] Step 1, put the metal substrate into a mixed alkaline solution for microwave treatment for 20 - 50 min, take it out and dry it to obtain a degreased metal substrate. The solutes of the mixed alkaline solution are sodium hydroxide and sodium carbonate, and the mass ratio of the two is 2:2 - 3. The concentration of sodium hydroxide is 5 - 10 g / L. The microwave power of the microwave treatment is 300 - 500 W, the temperature is 20 - 50 °C, and the drying temperature is 100 - 120 °C;

[0029] Step 2, perform sanding treatment on the metal substrate, use ethanol as a coolant, and then put it into ethanol for ultrasonic cleaning for 1 - 2 h, filter to obtain a metal substrate with a rough surface. The sanding treatment uses fine sandpaper, the temperature of ethanol is 10 - 15 °C, the flow rate is 1 - 5 mL / min, the ultrasonic frequency of the ultrasonic cleaning is 40 - 70 kHz, and the temperature is 20 - 30 °C;

[0030] Step 3, put the metal substrate into a reaction kettle, and introduce trichloromethylsilane vapor to deposit a liquid film, and then spray methyltriethoxysilane on the surface to form a secondary liquid film; the trichloromethylsilane vapor is a mixed gas of diethyl ether and trichloromethylsilane, and the volume ratio of diethyl ether to trichloromethylsilane is 2:2 - 3, the temperature is 70 - 75 °C, the deposition temperature is 50 - 60 °C; the spraying amount of methyltriethoxysilane is 0.1 - 0.3 mL / cm², and the temperature is 20 - 30 °C;

[0031] Step 4, put the metal substrate with the secondary liquid film into the reaction kettle and let it stand for 5 - 10 min, then bond the metal substrate with rubber and vulcanize to obtain a rubber seal. The atmosphere in the reaction kettle is a water vapor and nitrogen atmosphere, and the volume fraction of water vapor is 5 - 8%, the standing temperature is 20 - 30 °C; the bonding uses a bonding system with temperature and pressure, the pressure is 0.3 - 0.5 MPa, and the temperature is the softening temperature of the rubber.

[0032] The rubber coverage rate of this embodiment is 98%, the shear destructive force is 32.9 kN, the number of small - amplitude impacts at a frequency of 3 Hz is 410,000 times, and it also has good wear resistance and weather resistance.

[0033] It can be understood that the above specific description of the present invention is only for the purpose of illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effects; as long as the use requirements are met, they are all within the protection scope of the present invention.

Claims

1. An environment-friendly preparation process for a rubber seal, characterized in that: It includes the following steps: Step 1: Put the metal substrate into a mixed alkaline solution and microwave it for 20 - 50 min, take it out and dry it to obtain a degreased metal substrate; Step 2: Conduct a grinding treatment on the metal substrate, use ethanol as a coolant, then put it into ethanol and ultrasonically clean it for 1 - 2 h, and filter to obtain a metal substrate with a rough surface; Step 3: Put the metal substrate into a reaction kettle, introduce trichloromethylsilane vapor to deposit a liquid film, and then spray methyltriethoxysilane on the surface to form a secondary liquid film; Step 4: Put the metal substrate with the secondary liquid film into the reaction kettle and let it stand for 5 - 10 min, then bond the metal substrate with rubber and vulcanize to obtain a rubber seal; 2. The environment-friendly preparation process of the rubber seal according to claim 1, characterized in that: In Step 1, the solutes of the mixed alkaline solution are sodium hydroxide and sodium carbonate, and the mass ratio of the two is 2:2 - 3, and the concentration of sodium hydroxide is 5 - 10 g / L.

3. The environment-friendly preparation process of the rubber seal according to claim 1, characterized in that: In Step 1, the microwave power of the microwave treatment is 300 - 500 W, the temperature is 20 - 50 °C, and the drying temperature is 100 - 120 °C.

4. The environmentally friendly preparation process of the rubber seal according to claim 1, characterized in that: In Step 2, the grinding treatment uses fine sandpaper, the temperature of ethanol is 10 - 15 °C, the flow rate is 1 - 5 mL / min, the ultrasonic frequency of the ultrasonic cleaning is 40 - 70 kHz, and the temperature is 20 - 30 °C.

5. The environmentally friendly preparation process of the rubber seal according to claim 1, characterized in that: In Step 3, the trichloromethylsilane vapor is a mixed gas of diethyl ether and trichloromethylsilane, and the volume ratio of diethyl ether to trichloromethylsilane is 2:2 - 3, the temperature is 70 - 75 °C, and the deposition temperature is 50 - 60 °C.

6. The environmentally friendly preparation process of the rubber seal according to claim 1, characterized in that: The spraying amount of methyltriethoxysilane in the step 3 is 0.1-0.3 mL / cm 2 , and the temperature is 20-30 °C.

7. The environmentally friendly preparation process of the rubber seal according to claim 1, characterized in that: The atmosphere in the reaction kettle in Step 4 is a water vapor and nitrogen atmosphere, and the volume ratio of water vapor is 5 - 8%, and the standing temperature is 20 - 30 °C.

8. The environmentally friendly preparation process of the rubber seal according to claim 1, characterized in that: In Step 4, the bonding uses a bonding system with temperature and pressure, the pressure is 0.3 - 0.5 MPa, and the temperature is the softening temperature of the rubber.