High temperature release agent and method of making same

Abstract

The application discloses a high-temperature release agent and a preparation method thereof, and relates to the field of metal forming auxiliary materials. The release agent is composed of pure water, nano aluminum sol powder, boron nitride powder, zirconium oxide powder, water-soluble silicone oil and special additives (dispersants, wetting agents and suspending agents) and is prepared through a specific process. The release agent has a Brookfield viscosity of 900-1100 cps, a pH of 2-5, and a total proportion of boron nitride and zirconium oxide of greater than or equal to 82% after combustion, and the boron nitride and the zirconium oxide are nano-level superfine powder. The release agent is stable at a high temperature of 1300 DEG C or above, does not produce toxic by-products, is easy to wash with water, is suitable for full atmosphere, solves the problem of metal high-temperature forming demolding, improves production efficiency and quality, has environmental protection and economic value, and is suitable for forming of complex metal parts such as engine pistons.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal forming auxiliary materials, and particularly relates to a high-temperature release agent and a preparation method thereof. BACKGROUND

[0002] In the field of metal forming processes, some complex processes such as the forming process of large engine piston cylinder bodies are quite cumbersome. Specifically, two parts of the cylinder body need to be formed first, then welded, and then water-washed and cooled. Among them, the cylinder body temperature in the welding step is as high as 1300℃, which puts forward many strict requirements on the release agent:

[0003] First, high temperature resistance: the release agent should be able to meet the high temperature operation condition of 1300℃ or above, and still maintain stable performance at such high temperature without decomposition, failure, etc.

[0004] Second, no influence on welding: it cannot have adverse effects on high-temperature welding operations, such as leaving impurities at the welding site, which can affect the welding quality and strength.

[0005] Third, release convenience: it should be easy to release, ensuring that the formed cylinder body can be smoothly separated from the mold, improving production efficiency and avoiding or reducing mold damage.

[0006] Fourth, easy to wash: it is easy to wash with water at the end of the mold forming process, facilitating subsequent cleaning work and ensuring smooth production flow.

[0007] Fifth, environmental protection: it basically does not produce toxic gas and toxic residue, and there is no environmental pollution during the entire use process, meeting the environmental protection requirements of modern industrial production.

[0008] However, the core components such as boron nitride and zirconium oxide in ordinary release agents are micron-sized, easy to agglomerate, and difficult to form a uniform and stable high-temperature lubricating film layer. At a temperature of 1300℃ or above, the film layer is easy to crack and fall off, which cannot continuously and effectively release the mold, resulting in adhesion between the mold and the formed part, affecting product quality and production efficiency. Some release agents produce toxic gases and residues when burned or used, polluting the environment and affecting the metal welding performance; at the same time, they have narrow working atmosphere adaptability and cannot meet the full atmosphere demand of complex processes, limiting the application scenarios. SUMMARY

[0009] Therefore, the present application provides a high-temperature release agent and a preparation method thereof, which solves the problem that the film layer of the existing release agent is unstable at high temperature, cannot continuously and effectively release the mold, and affects product quality and production efficiency.

[0010] In order to achieve the above object, the present application provides the following technical scheme: a high-temperature release agent, which is composed of pure water and functional additives; the functional additives are composed of nano aluminum sol powder, nano boron nitride powder, nano zirconium oxide powder, thickening agent, dispersant, wetting agent and suspending agent;

[0011] In 100 parts of the high-temperature release agent, the content of each raw material is: 43.5-61.0 parts of pure water; 39.0-56.5 parts of functional additives.

[0012] As a preferred scheme of the high-temperature release agent, the functional additives are proportioned by weight parts as follows:

[0013] The nano aluminum sol powder is 5.0-8.0 parts;

[0014] The nano boron nitride powder is 15.0-20.0 parts;

[0015] The nano zirconium oxide powder is 15.0-20.0 parts;

[0016] The thickening agent is 2.5-4.5 parts;

[0017] The dispersant is 0.5-1.5 parts;

[0018] The wetting agent is 0.25-0.5 parts;

[0019] The suspending agent is 0.75-2.0 parts.

[0020] As a preferred scheme of the high-temperature release agent, the pure water is pure water without metal ions or cation resin exchange water.

[0021] As a preferred scheme of the high-temperature release agent, the nano aluminum sol powder is produced by Hangzhou Hengge Nano Technology Co., Ltd.; the nano aluminum sol powder has a particle size of 10-60 nm, is transparent and translucent colloid, has a pH of 2-5, is beneficial to system stability in an acidic environment, has adhesion, film forming property, high-temperature resistance (not decomposed and not melted at 1300℃), forms a feather-like nano structure and enhances film layer adhesion;

[0022] The nano boron nitride powder is produced by Hebei Wenlun Metal Material Co., Ltd.; the nano boron nitride powder has a layered structure similar to graphite, a friction coefficient of <0.1, lubricity at high temperature (3000℃), chemical inertness, no reaction with metal melt, a large specific surface area of superfine powder, formation of a continuous lubricating film, avoidance of rough particles scratching the mold, reduction of friction between the metal and the mold (especially when welding at 1300℃), high-temperature decomposition resistance and no impurities affecting welding;

[0023] The nanoscale zirconium oxide powder is OE-006-3 nanoscale ultra-fine zirconium oxide powder produced by Haotian Nanometer Science and Technology (Shanghai) Co., Ltd.; the nanoscale zirconium oxide powder has a particle size of 50-100 nm, a monoclinic crystal phase, a hardness only inferior to diamond (Mohs hardness 8.5), a melting point of 2700 DEG C, and low thermal conductivity. The nanoscale zirconium oxide powder can occur crystal transformation at high temperature, absorb stress, prevent film layer cracking, form a composite structure of "boron nitride lubricating layer+zirconium oxide support skeleton", and ensure that the film layer does not break when welding at 1300 DEG C.

[0024] The thickening agent is 8116 water-soluble silicone oil / polyether modified silicone oil produced by Shandong Luduerui New Material Co., Ltd.; the thickening agent is polyether modified silicone oil, can form a stable aqueous solution with water, appropriately improve the consistency of the carrier, and is conducive to improving the overall stability of the release agent and preventing the nanoscale powder from settling (with the aid of a suspending agent).

[0025] The dispersant is 5027W dispersant produced by Huayue Fine Chemicals Kunshan Co., Ltd.; the 5027W dispersant is a non-ionic structure, disperses nanometer particles (aluminum sol, boron nitride, etc.) through steric hindrance effect, prevents agglomeration, is similar to an aluminum sol special dispersant, ensures that the powder is uniformly and stably in the aqueous phase for more than 6 months, effectively disperses high-content powders such as boron nitride and zirconium oxide, and avoids precipitation.

[0026] The wetting agent is 1020 wetting agent produced by Huayue Fine Chemicals Kunshan Co., Ltd.; the 1020 wetting agent can reduce the surface tension of water to below 25 mN / m (ordinary water 72 mN / m), improve the wettability of the nanoscale powder and the mold, and improve the stability of the release agent; nanoscale liquid droplets penetrate the micro-pores of the mold, form a dense film, ensure that the release agent quickly spreads into a film, avoid "tear marks" or "leakage", and especially uniformly adhere to the corners of complex molds (such as 8 forming processes of engine cylinder blocks), improve the consistency of the release effect.

[0027] The suspending agent is 707 suspending agent produced by Huayue Fine Chemicals Kunshan Co., Ltd. The 707 suspending agent forms a three-dimensional network through hydrogen bonding / electrostatic interaction, suspends nanoscale powder (boron nitride density 2.25 g / cm 3 , zirconium oxide 6.0 g / cm 3 , easy to settle), solves the problem of high-density powder settling, ensures that there is no need to stir before use (adapt to the rapid material taking of the production line), and at the same time maintains the stability of the solid content during spraying, ensures the film thickness and release effect.

[0028] As a preferred scheme of the high-temperature release agent, the total content of boron nitride and zirconium oxide after combustion accounts for ≥82.0% in the high-temperature release agent.

[0029] As a preferred scheme of the high-temperature release agent, the Brookfield viscosity @3 / 60 of the high-temperature release agent is 900-1100 cps.

[0030] As a preferred solution of the high-temperature release agent, the pH value of the high-temperature release agent is 2-5.

[0031] The application also provides a preparation method of the high-temperature release agent, comprising the following steps:

[0032] According to the proportion by weight, the metered pure water is all added into the product kettle and preheated to 40±3℃;

[0033] The thickening agent, dispersant, wetting agent and suspending agent are metered and added into the product kettle, and the thickening agent, dispersant, wetting agent and suspending agent are completely dissolved / dispersed uniformly under stirring;

[0034] The stirring speed is increased to 650±50 RPM, the nanoscale aluminum sol powder is slowly added into the product kettle, and constant temperature stirring is carried out for 60±5 minutes to make the nanoscale aluminum sol powder completely dispersed;

[0035] The temperature and stirring speed are kept, the nanoscale boron nitride powder and nanoscale zirconia powder are metered and slowly added into the product kettle, and the stirring speed is increased to 1000±50 RPM, and the stirring is continuously carried out at 1000±50 RPM for 120-180 minutes to obtain the stable high-temperature release agent.

[0036] The application also provides an application of the high-temperature release agent in releasing at a high-temperature environment above 1300℃.

[0037] The application has the following advantages:

[0038] Firstly, in a high-temperature environment above 1300℃, the stable performance can still be maintained, the Brookfield viscosity @3 / 60 is stably kept at 900-1100 cps, the pH value is between 2-5, and the strict requirements of the high-temperature metal forming process can be effectively met;

[0039] Secondly, the core components such as nanoscale boron nitride and zirconia make the film layer formed by the release agent have good lubricity and high strength, the release is easy, the friction and adhesion between the mold and the formed piece are reduced, the mold loss is reduced, and the production efficiency and product quality are improved;

[0040] Thirdly, the release agent does not affect the mold welding process, is easy to wash with water after forming, is convenient and fast, meets the multi-step requirements of complex processes such as engine cylinder body forming, and ensures the smooth progress of the production process.

[0041] Fourthly, basically no toxic gas and toxic residue are generated, no environmental pollution occurs in the use process, and the modern industrial requirements for green production are met.

[0042] Fifthly, through the specific preparation method and the preferred raw materials, it is ensured that the components in the release agent are uniformly dispersed and stably suspended, the performance consistency between batches of products is high, and the storage period is long. Detailed Implementation

[0043] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] The high-temperature release agent provided in Example 1 of this invention has the following raw material details as shown in Table 1:

[0046] Table 1. Formulation of the high-temperature release agent in Example 1

[0047]

[0048]

[0049] Referring to Table 1, in the high-temperature release agent of Example 1, the liquid carrier is 61.0 kg of purified water, which serves as a solvent to adjust the system's fluidity. The total amount of functional additives is 39.0 kg, including 5.0 kg of nano-sized aluminum sol powder to form the basic binder phase, 15.0 kg of nano-sized boron nitride powder to provide basic lubrication, 15.0 kg of nano-sized zirconia powder to assist in enhancing film strength, 2.5 kg of water-soluble silicone oil to adjust viscosity to a minimum, 0.5 kg of 5027W dispersant to maintain low-concentration powder dispersion, 0.25 kg of 1020 wetting agent to improve wettability, and 0.75 kg of 707 suspending agent to prevent powder sedimentation. This formulation has the highest proportion of purified water, making it suitable for rapid coating applications with lower viscosity requirements. During the preparation process, according to the weight ratio, all the measured pure water is added to a stainless steel or plastic product vessel with a feeding port and preheated to 40±3℃. Thickener, dispersant, wetting agent, and suspending agent are measured and added to the product vessel, and stirred to ensure that the thickener, dispersant, wetting agent, and suspending agent are completely dissolved / uniformly dispersed. The stirring speed is increased to 650±50 RPM, and nano-sized aluminum sol powder is slowly added to the product vessel. The mixture is stirred at a constant temperature for 60±5 minutes to ensure that the nano-sized aluminum sol powder is completely dispersed. While maintaining the temperature and stirring speed, nano-sized boron nitride powder and nano-sized zirconium oxide powder are measured and slowly added to the product vessel, and the stirring speed is increased to 1000±50 RPM. The mixture is stirred at 1000±50 RPM for 120 to 180 minutes to obtain a stable high-temperature release agent.

[0050] Example 2

[0051] The high-temperature release agent provided in Embodiment 2 of this invention has the following raw material details as shown in Table 2:

[0052] Table 2: High temperature release agent ratio of Example 2

[0053]

[0054] Referring to Table 2, in the high temperature release agent of Example 2, the liquid carrier is 55.0 kg of pure water to balance the flowability and solid content. The functional additives are 45.0 kg in total, 6.0 kg of aluminum sol powder to improve adhesion, 16.0 kg of boron nitride powder and 16.0 kg of zirconium oxide powder to enhance lubrication and thermal shock resistance respectively, 3.0 kg of water-soluble silicone oil to make the viscosity close to 1000 cps, 0.8 kg of dispersant to adapt to the increase of powder concentration, 0.3 kg of wetting agent to ensure uniform coating at medium viscosity, and 0.9 kg of suspending agent to prevent slight sedimentation. The high temperature release agent of Example 2 has balanced comprehensive performance and is suitable for conventional high temperature molding process. The preparation method is the same as Example 1.

[0055] Example 3

[0056] The high temperature release agent provided in Example 3 of the present application has the specific raw material conditions as shown in Table 3:

[0057] Table 3: High temperature release agent ratio of Example 3

[0058]

[0059] Referring to Table 3, in the high temperature release agent of Example 3, the liquid carrier is 52.4 kg of pure water, and the functional additives are 47.6 kg. 6.5 kg of aluminum sol powder increases the density of the film layer, 18.0 kg of boron nitride powder reduces the friction coefficient to below 0.08, 18.0 kg of zirconium oxide powder improves the fracture toughness, 3.0 kg of water-soluble silicone oil cooperates to form a viscosity of 983.7 cps, 0.8 kg of dispersant relies on the advantages of nano-powder to maintain dispersion, 0.3 kg of wetting agent ensures uniform film formation under high solid content, and 1.0 kg of suspending agent inhibits powder sedimentation. This example meets all the indicators and is an optimal example. The preparation method is the same as Example 1.

[0060] Example 4

[0061] The high temperature release agent provided in Example 4 of the present application has the specific raw material conditions as shown in Table 4:

[0062] Table 4: High temperature release agent ratio of Example 4

[0063]

[0064] Referring to Table 4, in the high-temperature release agent of Example 4, the liquid carrier is 48.1 kg of pure water, and the functional additives are 51.9 kg. 7.0 kg of aluminum sol powder enhances adhesion, 19.0 kg of boron nitride powder and 19.0 kg of zirconia powder improve release efficiency and anti-scratching ability, 4.0 kg of water-soluble silicone oil makes the viscosity close to 1050 cps, 1.0 kg of dispersant ensures single dispersion of the powder, 0.4 kg of wetting agent overcomes the resistance of high-viscosity coating, and 1.5 kg of suspending agent suspends high-density zirconia powder. It is suitable for extreme high-temperature scenes that require thick film layer protection. The preparation method is the same as Example 1.

[0065] Example 5

[0066] The high-temperature release agent provided by Example 5 of the present application has the specific raw material conditions as shown in Table 5:

[0067] Table 5: High-temperature release agent ratio of Example 5

[0068]

[0069] Referring to Table 5, in the high-temperature release agent of Example 5, the liquid carrier is 43.5 kg of pure water, and the functional additives are 56.5 kg to reach the upper limit. 8.0 kg of aluminum sol powder makes the film layer sintered into a ceramic state, 20.0 kg of boron nitride powder forms an ultra-low friction lubricating layer, 20.0 kg of zirconia powder gives excellent thermal shock resistance, 4.5 kg of water-soluble silicone oil makes the viscosity close to 1100 cps, 1.5 kg of dispersant forcibly disperses high-concentration powder, 0.5 kg of wetting agent ensures the adhesion of the paste system, and 2.0 kg of suspending agent completely suppresses the settlement of zirconia. It is suitable for extreme high-temperature and high-wear working conditions of aircraft engines. The preparation method is the same as Example 1.

[0070] Referring to Table 6, the specific comparison of Examples 1 to 5 is as follows:

[0071] Table 6: Comparison of high-temperature release agents of Examples 1-5

[0072]

[0073] Referring to Table 6, Example 1 is 61.0% pure water, low viscosity and easy to coat, used for simple molds; Example 2 is balanced and suitable for conventional cylinder forming; Example 3 is the most cost-effective, suitable for 1300°C welding; Example 4 is high-hardness lubrication, used for high-wear die casting; and Example 5 is extremely high-temperature resistant, suitable for aerospace scenes.

[0074] Referring to Table 7, the performance data of Examples 1 to 5, wherein Example 3 is the optimal example, during the testing process of the performance data, the Brookfield viscosity is measured according to the standard GB / T11145; the content of boron nitride + zirconium oxide is measured by the solid content determination method (combustion method), and the steps are as follows: 1) accurately weigh the weight of the crucible; 2) slowly add the sample into the weighed crucible, and the sample is 100 g; 3) heat the crucible to and control at about 500 DEG C, keep the combustion temperature for 3 hours, until the non-solid substance is completely combusted; 4) accurately weigh the crucible after being naturally cooled in the ventilated place, subtract the weight of the crucible, and then subtract the weight of the aluminum sol powder, and the difference is the weight of boron nitride + zirconium oxide. The pH value is measured by the pH test paper method.

[0075] Table 7 Performance data of high-temperature release agent of optimal example 3

[0076]

[0077]

[0078] Referring to Table 8, the required index of the high-temperature release agent is as follows:

[0079] Table 8 Main required index of high-temperature release agent

[0080] Item Index Remark Main component Boron nitride & zirconium oxide Nanoscale ultrafine powder Suitable working atmosphere All Combustion residue, boron nitride & zirconium oxide, %, ≥ 82.0 Liquid carrier Pure water Binder phase AI2O3 Nanoscale ultrafine powder Brookfield viscosity @ 3 / 60, cps 900～1100 Appearance White Can be dyed to other colors as needed pH value 2～5

[0081] Referring to Table 7 and Table 8, the main component boron nitride + zirconium oxide of the optimal example 3 reaches 85.4%, which exceeds the index (≥82.0%), and is a nano-level superfine powder, which ensures the formation of a stable and lubricating effective film layer at high temperature, and meets the core requirement of release. The Brookfield viscosity is 983.7 cps, which is in the index interval (900-1100 cps), which not only ensures the flowability during spraying / brushing, but also can form a uniform film layer, which is suitable for coating of high-temperature complex mold. The pH value is 4.3, which meets the acidic range of 2-5, the system is stable, and is not easy to produce stratification and precipitation due to pH fluctuation during storage and use, which ensures the performance consistency. The base is white, and can be dyed as needed, such as adding blue pigment in Example 3, which meets the needs of different production lines for identification and visualization, and flexibly adapts to the production scene. In summary, the present application fully meets the required index in composition ratio, physical performance (viscosity, pH) and process adaptability (appearance, coating), and can stably play the release and protection role at high temperature, and is convenient for water washing, effectively improves the efficiency and quality of metal forming process, and has environmental protection and economy.

[0082] Although the present application has been described in detail with general description and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present application. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection claimed by the present application.

Claims

1. A high-temperature release agent, characterized in that, The release agent is composed of purified water and functional additives; the functional additives are composed of nano-sized aluminum sol powder, nano-sized boron nitride powder, nano-sized zirconium oxide powder, thickener, dispersant, wetting agent and suspending agent; According to the weight ratio, in 100 parts of high-temperature release agent, the content of each raw material is as follows: purified water 43.5~61.0 parts; functional additives 39.0~56.5 parts; The functional additives are formulated in the following weight proportions: 5.0–8.0 parts of nano-sized aluminum sol powder; 15.0–20.0 parts of nano-sized boron nitride powder; 15.0–20.0 parts of nano-sized zirconium oxide powder; Thickener 2.5–4.5 parts; Dispersant 0.5–1.5 parts; Wetting agent 0.25~0.5 parts; Suspension agent 0.75–2.0 parts; The thickener is 8116 water-soluble silicone oil / polyether modified silicone oil; The dispersant is 5027W dispersant; The wetting agent is 1020 wetting agent; The suspending agent is 707 suspending agent.

2. The high-temperature release agent according to claim 1, characterized in that, The purified water is purified water or cation exchange water that does not contain metal ions.

3. The high-temperature release agent according to claim 1, characterized in that, The total content of boron nitride powder and zirconium oxide powder in the high-temperature release agent after combustion is ≥82.0%.

4. The high-temperature release agent according to claim 1, characterized in that, The high-temperature release agent has a Brinell viscosity of 900~1100 cps at 3 / 60.

5. The high-temperature release agent according to claim 1, characterized in that, The pH value of the high-temperature release agent is 2~5.

6. A method for preparing a high-temperature release agent according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: According to the weight ratio, add all the measured pure water into the product vessel and preheat it to 40±3℃; The thickener, dispersant, wetting agent, and suspending agent are metered and added to the product vessel, and the thickener, dispersant, wetting agent, and suspending agent are completely dissolved / dispersed uniformly under stirring. Increase the stirring speed to 650±50 RPM, slowly add the nano-aluminum sol powder into the product vessel, and stir at a constant temperature for 60±5 minutes to completely disperse the nano-aluminum sol powder. While maintaining the temperature and stirring speed, meter and slowly add nano-sized boron nitride powder and nano-sized zirconium oxide powder into the product vessel, and increase the stirring speed to 1000±50 RPM. Continue stirring at this speed for 120~180 minutes to obtain a stable high-temperature release agent.

7. The application of the high-temperature release agent as described in any one of claims 1-5 in releasing molds in high-temperature environments above 1300°C.

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