Preparation method of carbon intercalation modified potassium magnesium titanate and friction material

Abstract

The present invention discloses a method for preparing carbon-intercalated potassium magnesium titanate, comprising the following steps: immersing flaky potassium magnesium titanate in an acid solution containing copper ions with a pH of 3 to 5 for 1 to 24 hours; washing the solution until neutral to obtain a neutral solution; adding polyethanolamine to an alkaline potassium permanganate solution to obtain an alkaline solution of polyethanolamine; gradually adding the alkaline solution of polyethanolamine dropwise to the neutral solution, reacting at 60 to 80°C for 1 to 12 hours; washing the solution until neutral, and calcining it at 800 to 1000°C for 2 to 12 hours to obtain the carbon-intercalated potassium magnesium titanate. The present invention finds that when the carbon-intercalated potassium magnesium titanate is used as a friction material, the brake noise caused by friction between the carbon-intercalated potassium magnesium titanate and the brake disc is significantly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of friction materials, and in particular to a preparation method of carbon intercalation-modified potassium magnesium titanate and a friction material. Background Art

[0002] The increasing popularity of new energy vehicles (NEVs) has placed new demands on brake pads, a key automotive component. Since NEVs lack engines and instead utilize electric motors, this creates even higher demands for brake noise. Metal, the primary friction material in traditional brake pads, provides high braking force but also significant wear and noise. Summary of the Invention

[0003] The object of the present invention is to provide a preparation method of carbon intercalation modified potassium magnesium titanate, a preparation method thereof, and a friction material, so as to solve one or more of the above-mentioned problems in the prior art.

[0004] In one aspect, the present invention provides a method for preparing carbon intercalation-modified potassium magnesium titanate, comprising the following steps:

[0005] Soaking the flake potassium magnesium titanate in an acid solution containing copper ions for 1 to 24 hours, wherein the pH value of the acid solution is 3 to 5;

[0006] Washing the above solution until it becomes neutral to obtain a neutral solution;

[0007] adding polyethanolamine to an alkaline potassium permanganate solution to obtain an alkaline solution of polyethanolamine;

[0008] Gradually adding the alkaline solution of polyethanolamine to the neutral solution, and reacting at 60-80° C. for 1-12 hours;

[0009] The solution is washed to neutrality, and calcined at 800-1000° C. for 2-12 hours to obtain the carbon intercalation modified potassium magnesium titanate.

[0010] In some embodiments, the dimensions of the plate-like potassium magnesium titanate are 5 to 20 μm in length, 1 to 20 μm in width, and 0.3 to 1 μm in thickness.

[0011] In some embodiments, the acid solution containing copper ions is a nitric acid solution, a hydrochloric acid solution, or a sulfuric acid solution containing copper ions.

[0012] In some embodiments, the molar ratio of the sheet-like potassium magnesium titanate to the copper ions is 1:(1.2-2).

[0013] In some embodiments, the concentration of the acid solution containing copper ions is 0.05-2 g / L.

[0014] In some embodiments, the pH value of alkaline potassium permanganate is 8-10, and the concentration of potassium permanganate is 0.001-0.5 g / L.

[0015] In some embodiments, the molar ratio of polyethanolamine to the sheet-like potassium magnesium titanate is (2-8):1.

[0016] On the other hand, the present invention provides a method for preparing carbon intercalation modified potassium magnesium titanate prepared by the above preparation method.

[0017] In another aspect, the present invention provides a method for preparing a friction material comprising carbon intercalation-modified potassium magnesium titanate prepared by the above preparation method.

[0018] In another aspect, the present invention provides a method for preparing a friction material comprising the carbon intercalation-modified potassium magnesium titanate.

[0019] Beneficial effects of the present invention:

[0020] 1. The creative point of the present invention is that when the pH value is 3-5, the potassium ions in the middle of the layered structure of potassium magnesium titanate are completely ion-exchanged with hydrogen ions or copper ions because the surface of potassium magnesium titanate is negatively charged and exhibits charge attraction with copper ions; when the pH is too low, the surface of potassium magnesium titanate is positively charged, which repel copper ions, resulting in poor adsorption effect; when the pH is too high, hydroxide in the solution easily reacts with copper ions for precipitation.

[0021] 2. Another creative point of the present invention is that it is found that under the action of alkaline potassium permanganate, polyvinyl alcohol dissociates, which then promotes the coordination reaction with copper ions. Therefore, the copper ions between the titanate layers after ion exchange react with polyvinyl alcohol at a certain temperature.

[0022] 3. Another creative point of the present invention is that the potassium magnesium titanate after the coordination reaction is calcined at a high temperature, and the carbon obtained after the polyvinyl alcohol coordination compound between the titanate layers is calcined, thereby obtaining carbon-intercalated potassium magnesium titanate.

[0023] 4. The last creative point of the present invention is that when the carbon-intercalated potassium magnesium titanate is used as a friction material, the braking noise caused by the friction between it and the brake disc is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of a method for preparing carbon intercalation-modified potassium magnesium titanate prepared in one embodiment of the present invention;

[0025] Figure 2 This is an XRD pattern of the preparation method of carbon intercalation modified potassium magnesium titanate prepared in one embodiment of the present invention;

[0026] Figure 3This is a noise performance table of a brake disc made of carbon intercalation modified potassium magnesium titanate prepared in one embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the following examples. The following examples are only used to more clearly illustrate the performance of the present invention and are not intended to be limiting.

[0028] Example 1:

[0029] A method for preparing carbon intercalation-modified potassium magnesium titanate comprises the following steps:

[0030] 1 mol of sheet potassium magnesium titanate was immersed in an acid solution containing 1.2 mol of copper ions for 12 hours. The concentration of the acid solution containing copper ions was -2 g / L and the pH value of the acid solution was 3.

[0031] Washing the above solution until it is neutral to obtain a neutral solution;

[0032] 2 mol of polyethanolamine was added to an alkaline potassium permanganate solution with a pH of 8 and a concentration of 0.5 g / L to obtain an alkaline solution of polyethanolamine;

[0033] The alkaline solution of polyethanolamine was gradually added dropwise to the neutral solution, and the mixture was reacted at 60° C. for 6 h;

[0034] The solution was washed to neutrality, and calcined at 800° C. for 2 h to obtain the carbon intercalation-modified potassium magnesium titanate.

[0035] like Figure 1 As shown:

[0036] When an acid solution containing copper ions is added to potassium magnesium titanate with potassium ions between layers, when the pH value is 3 to 5, the potassium ions in the middle of the layered structure of potassium magnesium titanate undergo complete ion exchange with hydrogen ions or copper ions due to the negative charge on the surface of potassium magnesium titanate and the charge attraction with copper ions. When the pH is too low, the surface of potassium magnesium titanate carries a positive charge, which repel copper ions, resulting in poor adsorption effect. When the pH is too high, the hydroxide in the solution easily reacts with copper ions for precipitation.

[0037] At the same time, under the action of alkaline potassium permanganate, polyvinyl alcohol dissociates, which then promotes the coordination reaction with copper ions. Therefore, the copper ions between the titanate layers after ion exchange react with polyvinyl alcohol at a certain temperature.

[0038] Finally, the potassium magnesium titanate after the coordination reaction is calcined at a high temperature, and the carbon obtained after the polyvinyl alcohol coordination compound between the titanate layers is calcined, thereby obtaining carbon-intercalated potassium magnesium titanate.

[0039] Performance testing:

[0040] XRD analysis was performed on a Rigaku DMAX-RB X-ray diffractometer with a Cu target, a current of 30 mA, and a voltage of 40 kV. A graphite monochromator was used. The goniometer had a scanning rate of 4° / min, a scanning range of 2θ = 10°-60°, and a θ / 2θ linked scanning mode. The scanning step was 0.02° / step. The optical path divergence slit was 1°, the anti-scattering slit was 10 mm, the variable slit was automatically adjusted by the instrument, and the receiving slit was 0.3 mm.

[0041] like Figure 2 As shown, the characteristic peak of 2θ of 11.306° corresponds to the (0 2 0) plane of potassium magnesium titanate, the characteristic peak of 2θ of 28.956° corresponds to the (1 3 0) plane of potassium magnesium titanate, and the characteristic peak of 2θ of about 26° corresponds to carbon. It can be seen that the preparation method of carbon intercalation modified potassium magnesium titanate is successfully prepared. Due to the addition of carbon, the intensity of the characteristic peak of 2θ of 11.306° is stronger than that of conventionally synthesized potassium magnesium titanate. This is because carbon wraps the active surface (0 2 0) plane, so that the (1 3 0) plane of the finally synthesized potassium magnesium titanate is more than the (1 3 0) plane of conventionally synthesized potassium magnesium titanate.

[0042] Performance testing:

[0043] The following examples and comparative examples are used to further illustrate the technical solution of the present invention. To verify the effect of the present invention, the friction material of Example 1 was prepared and subjected to noise testing.

[0044] The friction formula prepared in Example 1 is as shown in Table 1 below:

[0045]

[0046] Table 1: Friction material formulation

[0047] According to the SAE J2521 test standard, the friction material prepared in Example 1 of the present invention was bench tested on the LINK3900 in the United States, and the noise generation tests at different frequencies were compared and scored. The J2521 noise test results of the brake pad prepared with the friction material prepared in Example 1 are as follows: Figure 3 .

[0048] from Figure 3It can be seen that for formula A, within the range of 2 kHz to 17 kHz, noise greater than 70 decibels occurred 31 times, of which, within the range of 2 kHz to 4 kHz, noise greater than 70 decibels occurred 2 times, within the range of 4 kHz to 6 kHz, noise greater than 70 decibels occurred 21 times, within the range of 6 kHz to 10 kHz, noise greater than 70 decibels occurred 8 times, within the range of 10 kHz to 14 kHz, noise greater than 70 decibels occurred 0 times, and within the range of 14 kHz to 17 kHz, noise greater than 70 decibels occurred 0 times. The scoring system of the J2521 system gives formula A a score of 9.2 points. It can be seen that the brake pad made of potassium magnesium titanate in Example 1 exhibits very excellent noise performance.

[0049] In summary:

[0050] 1. The creative point of the embodiments of the present invention is that when the pH value is 3 to 5, the potassium ions in the middle of the layered structure of potassium magnesium titanate are completely ion-exchanged with hydrogen ions or copper ions because the surface of potassium magnesium titanate is negatively charged and exhibits charge attraction with copper ions; when the pH is too low, the surface of potassium magnesium titanate is positively charged, which repel copper ions, resulting in poor adsorption effect; when the pH is too high, hydroxide in the solution easily undergoes precipitation reaction with copper ions.

[0051] 2. Another creative point of the embodiment of the present invention is that it is found that under the action of alkaline potassium permanganate, polyvinyl alcohol dissociates, which then promotes the coordination reaction with copper ions. Therefore, the copper ions between the titanate layers after ion exchange react with polyvinyl alcohol at a certain temperature.

[0052] 3. Another creative point of the embodiment of the present invention is that the potassium magnesium titanate after the coordination reaction is calcined at a high temperature, and the carbon obtained after the polyvinyl alcohol coordination compound between the titanate layers is calcined, thereby obtaining carbon-intercalated potassium magnesium titanate.

[0053] 4. The last creative point of the embodiment of the present invention is that when the carbon-intercalated potassium magnesium titanate is used as a friction material, the braking noise caused by the friction between it and the brake disc is significantly reduced.

[0054] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these should also be considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing carbon intercalation-modified potassium magnesium titanate, characterized in that: The following steps are involved: Soaking the flake potassium magnesium titanate in an acid solution containing copper ions for 1 to 24 hours, wherein the pH value of the acid solution is 3 to 5; Washing the above solution until it is neutral to obtain a neutral solution; adding polyethanolamine to an alkaline potassium permanganate solution to obtain an alkaline solution of polyethanolamine; Gradually adding the alkaline solution of polyethanolamine to the neutral solution, and reacting at 60-80° C. for 1-12 hours; The solution is washed to neutrality, and calcined at 800-1000° C. for 2-12 hours to obtain the carbon intercalation modified potassium magnesium titanate.

2. The preparation method according to claim 1, characterized in that The dimensions of the sheet-like potassium magnesium titanate are 5 to 20 μm in length, 1 to 20 μm in width, and 0.3 to 1 μm in thickness.

3. The preparation method according to claim 1, characterized in that The acid solution containing copper ions is a nitric acid solution, a hydrochloric acid solution or a sulfuric acid solution containing copper ions.

4. The preparation method according to claim 1, characterized in that The molar ratio of the flaky potassium magnesium titanate to the copper ions is 1:(1.2-2).

5. The preparation method according to claim 1, characterized in that The concentration of the acid solution containing copper ions is 0.05-2 g / L.

6. The preparation method according to claim 1, characterized in that The pH value of the alkaline potassium permanganate is 8-10, and the concentration of the potassium permanganate is 0.001-0.5 g / L.

7. The preparation method according to claim 1, characterized in that The molar ratio of the polyethanolamine to the sheet-like potassium magnesium titanate is (2-8):

1.

8. Carbon intercalation-modified potassium magnesium titanate obtained according to the preparation method according to any one of claims 1 to 7.

9. A friction material comprising carbon intercalation-modified potassium magnesium titanate prepared by the preparation method according to any one of claims 1 to 7.

10. A friction material comprising the carbon intercalation modified potassium magnesium titanate according to claim 8.

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