High-temperature release agent and preparation method thereof

Abstract

The invention 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 prepared from purified water, nanoscale aluminum sol powder, boron nitride powder, zirconium oxide powder, water-soluble silicone oil and special auxiliaries (a dispersing agent, a wetting agent and a suspending agent) through a specific process. Brookfield viscosity is 900-1100 cps, pH is 2-5, the total proportion of boron nitride and zirconium oxide after combustion is greater than or equal to 82%, and boron nitride and zirconium oxide are nanoscale ultrafine powder. The release agent is stable at the high temperature of 1300 DEG C or above, does not produce toxic byproducts, is easy to wash with water, adapts to full atmosphere, solves the problem of high-temperature forming and demolding of metal, improves the production efficiency and quality, has environment-friendly and economic values, and is suitable for forming of complex metal parts such as engine pistons.

Description

Technical Field

[0001] This invention belongs to the field of metal forming auxiliary materials technology, specifically relating to a high-temperature release agent and its preparation method. Background Technology

[0002] In the field of metal forming processes, some complex processes, such as the forming of large engine piston cylinder blocks, are quite cumbersome. Specifically, the two cylinder blocks must first be formed separately, then welded together, followed by water rinsing and cooling. During the welding process, the cylinder block temperature reaches as high as 1300℃, which places stringent requirements on the mold release agent in several aspects.

[0003] First, high temperature resistance: The release agent must be able to meet high temperature operating conditions above 1300℃, and maintain stable performance at such high temperatures without decomposition or failure.

[0004] Second, it should not affect welding: it should not have an adverse effect on high-temperature welding operations, such as leaving impurities at the welding site, so as not to affect the welding quality and strength.

[0005] Third, ease of demolding: It should be easy to demold to ensure that the molded cylinder can be smoothly separated from the mold, improve production efficiency, and avoid or reduce mold damage.

[0006] Fourth, easy to rinse: It is easy to rinse with water at the end of the mold forming process, which facilitates subsequent cleaning work and ensures the smooth production process.

[0007] Fifth, environmental friendliness: It produces virtually no toxic gases or residues, and there is no environmental pollution during the entire use process, which meets the environmental protection requirements of modern industrial production.

[0008] However, the core components of common mold release agents, such as boron nitride and zirconium oxide, are mostly micron-sized, making them prone to agglomeration and difficult to form a uniform and stable high-temperature lubricating film. At temperatures above 1300℃, the film is prone to cracking and peeling, failing to provide sustained and effective demolding. This leads to adhesion between the mold and the molded part, affecting product quality and production efficiency. Some mold release agents produce toxic gases and residues when burned or used, polluting the environment and affecting metal welding performance. Furthermore, they have narrow adaptability to working atmospheres, failing to meet the full-atmosphere requirements of complex processes and limiting their application scenarios. Summary of the Invention

[0009] Therefore, this invention provides a high-temperature release agent and its preparation method, which solves the problem that existing release agents have unstable film layers at high temperatures, cannot continuously and effectively release molds, and affect product quality and production efficiency.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature release agent, wherein the release agent is composed of purified water and functional additives; wherein 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;

[0011] According to the weight ratio, the content of each raw material in 100 parts of high temperature release agent is as follows: 43.5-61.0 parts of purified water; 39.0-56.5 parts of functional additives.

[0012] As a preferred embodiment of a high-temperature release agent, the functional additive is formulated in the following weight proportions:

[0013] 5.0–8.0 parts of nano-sized aluminum sol powder;

[0014] 15.0–20.0 parts of nano-sized boron nitride powder;

[0015] 15.0–20.0 parts of nano-sized zirconium oxide powder;

[0016] Thickener 2.5–4.5 parts;

[0017] Dispersant 0.5–1.5 parts;

[0018] Wetting agent 0.25-0.5 parts;

[0019] Suspension agent 0.75-2.0 parts.

[0020] As a preferred option for high-temperature release agents, the purified water is purified water free of metal ions or cation exchange resin water.

[0021] As a preferred high-temperature release agent, the nano-sized aluminum sol powder is produced by Hangzhou Hengge Nanotechnology Co., Ltd. The nano-sized aluminum sol powder has a particle size of 10-60 nm, is a transparent or semi-transparent colloid, has a pH of 2-5, and is conducive to system stability in acidic environments. It possesses adhesive properties, film-forming properties, and high-temperature resistance (does not decompose or melt at 1300℃), forming a feather-like nanostructure to enhance film adhesion.

[0022] The nano-grade boron nitride powder is an ultrafine nano-grade boron nitride powder produced by Hebei Wenlun Metal Materials Co., Ltd. The nano-grade boron nitride powder has a layered structure similar to graphite, a friction coefficient <0.1, maintains lubricity at high temperatures (3000℃), is chemically inert, and does not react with molten metal. Simultaneously, the ultrafine powder has a large specific surface area, forming a continuous lubricating film, preventing coarse particles from scratching the mold, reducing friction between the metal and the mold (especially during welding at 1300℃), and is resistant to high-temperature decomposition, without producing impurities that affect welding.

[0023] The nano-sized zirconia powder is OE-006-3 nano-sized ultrafine zirconia powder produced by Haotian Nanotechnology (Shanghai) Co., Ltd. The nano-sized zirconia powder has a particle size of 50-100 nm, a monoclinic crystal phase, a hardness second only to diamond (Mohs hardness 8.5), a melting point of 2700℃, and low thermal conductivity. It undergoes a crystal transformation at high temperatures, absorbs stress, prevents film cracking, and can form a composite structure of "boron nitride lubricating layer + zirconia supporting skeleton," ensuring that the film does not shatter during welding at 1300℃.

[0024] The thickener is 8116 water-soluble silicone oil / polyether-modified silicone oil produced by Shandong Luderui New Material Co., Ltd.; the thickener is polyether-modified silicone oil, which can form a stable aqueous solution with water, appropriately increasing the viscosity of the carrier, which is beneficial to improving the overall stability of the release agent and preventing the sedimentation of nanoparticles (with the assistance of suspending agent).

[0025] The dispersant is 5027W dispersant produced by Huayue Fine Chemicals Kunshan Co., Ltd. 5027W dispersant has a non-ionic structure and disperses nanoparticles (aluminum sol, boron nitride, etc.) through steric hindrance, preventing agglomeration, similar to a dispersant specifically for aluminum sol, ensuring the powder remains uniformly stable in the aqueous phase for more than 6 months. It effectively disperses high-content powders such as boron nitride and zirconium oxide, preventing precipitation.

[0026] The wetting agent is 1020 wetting agent produced by Huayue Fine Chemical Kunshan Co., Ltd.; 1020 wetting agent can reduce the surface tension of water to below 25mN / m (ordinary water 72mN / m), improve the wettability of nanopowder and mold, and improve the stability of the release agent; nano-sized droplets penetrate the micropores of the mold to form a dense film, ensuring that the release agent spreads and forms a film quickly, avoiding "tears" or "missing coating", especially in the corners of complex molds (such as the 8 molding processes of engine cylinder block), uniformly adhering to 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 interactions, suspending nanoparticles (boron nitride density 2.25 g / cm³). 3 Zirconium oxide 6.0 g / cm³ 3 It is easy to settle, which solves the problem of high-density powder settling and ensures that no stirring is required before use (adapting to rapid material handling in production lines). At the same time, it maintains stable solid content during spraying, ensuring film thickness and demolding effect.

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

[0029] As a preferred embodiment of a high-temperature release agent, the high-temperature release agent has a Brinell viscosity of 900–1100 cps at 3 / 60.

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

[0031] This invention also provides a method for preparing a high-temperature release agent, the method comprising the following steps:

[0032] According to the weight ratio, add all the measured pure water into the product vessel and preheat it to 40±3℃;

[0033] 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.

[0034] 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.

[0035] 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 1000±50 RPM for 120 to 180 minutes to obtain a stable high-temperature release agent.

[0036] This invention also provides an application of a high-temperature release agent for demolding in high-temperature environments above 1300°C.

[0037] The present invention has the following advantages:

[0038] First, it can maintain stable performance in high-temperature environments above 1300℃, with the Brinell viscosity @3 / 60 remaining stable at 900-1100cps and the pH value between 2 and 5, effectively meeting the stringent requirements of high-temperature metal forming processes.

[0039] Secondly, the core components such as nano-sized boron nitride and zirconium oxide make the film layer formed by the mold release agent have good lubricity and high strength, which makes it easy to demold and reduces friction and adhesion between the mold and the molded part, thereby reducing mold wear and improving production efficiency and product quality.

[0040] Third, the release agent does not affect the mold welding process, and it is easy to wash with water after molding, which is convenient and quick. It meets the multi-step requirements of complex processes such as engine block molding, and ensures the smooth progress of the production process.

[0041] Fourth, it produces virtually no toxic gases or residues, and its use causes no environmental pollution, meeting the requirements of modern industry for green production.

[0042] Fifth, through specific preparation methods and optimized raw materials, it is ensured that all components in the release agent are uniformly dispersed and stably suspended, resulting in high performance consistency between product batches and a long storage period. 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 the present invention has the following raw material details as shown in Table 2:

[0052] Table 2. Formulation of the high-temperature release agent in 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 purified water to balance fluidity and solid content. The functional additives total 45.0 kg: 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 bring the viscosity close to 1000 cps; 0.8 kg of dispersant to accommodate increased 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 overall performance and is suitable for conventional high-temperature molding processes. The preparation method is the same as in Example 1.

[0055] Example 3

[0056] The high-temperature release agent provided in Example 3 of this invention has the following raw material details as shown in Table 3:

[0057] Table 3. Formulation of the high-temperature release agent in Example 3

[0058]

[0059] Referring to Table 3, in the high-temperature release agent of Example 3, the liquid carrier was 52.4 kg of purified water, and the functional additives were 47.6 kg. 6.5 kg of aluminum sol powder increased film density, 18.0 kg of boron nitride powder reduced the coefficient of friction to below 0.08, 18.0 kg of zirconia powder improved fracture toughness, 3.0 kg of water-soluble silicone oil resulted in a viscosity of 983.7 cps, 0.8 kg of dispersant maintained dispersion due to the advantages of nanoparticles, 0.3 kg of wetting agent ensured uniform film formation under high solids content, and 1.0 kg of suspending agent inhibited powder sedimentation. All indicators in this example met the standards, making it a preferred embodiment. The preparation method was the same as in Example 1.

[0060] Example 4

[0061] The high-temperature release agent provided in Example 4 of this invention has the following raw material details as shown in Table 4:

[0062] Table 4. Formulation of the high-temperature release agent in 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 purified 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 scratch resistance, 4.0 kg of water-soluble silicone oil brings the viscosity close to 1050 cps, 1.0 kg of dispersant ensures monodispersity of the powder, 0.4 kg of wetting agent overcomes the coating resistance of high viscosity, and 1.5 kg of suspending agent suspends the high-density zirconia powder. It is suitable for extreme high-temperature scenarios requiring thick film protection. The preparation method is the same as in Example 1.

[0065] Example 5

[0066] The high-temperature release agent provided in Embodiment 5 of this invention has the following raw material details as shown in Table 5:

[0067] Table 5. Formulation of the high-temperature release agent in 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 purified water, and the functional additives reach the upper limit of 56.5 kg. 8.0 kg of aluminum sol powder sinters the film into a ceramic state, 20.0 kg of boron nitride powder forms an ultra-low friction lubricating layer, 20.0 kg of zirconia powder imparts excellent thermal shock resistance, 4.5 kg of water-soluble silicone oil brings the viscosity close to 1100 cps, 1.5 kg of dispersant forcibly disperses the high-concentration powder, 0.5 kg of wetting agent ensures the adhesion of the paste system, and 2.0 kg of suspending agent completely inhibits zirconia sedimentation. It is suitable for extreme high-temperature and high-wear conditions such as those in aero-engines. The preparation method is the same as in Example 1.

[0070] See Table 6 for a detailed comparison of Examples 1 to 5:

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

[0072]

[0073] Referring to Table 6, Example 1 contains 61.0% pure water, has low viscosity and is easy to coat, and is used for simple molds; Example 2 is well-balanced and suitable for conventional cylinder molding; Example 3 has the best cost performance and is suitable for welding at 1300℃; Example 4 has high hardness lubrication and is used for high-wear die casting; Example 5 has extreme high temperature resistance and is suitable for aerospace applications.

[0074] See Table 7 for performance data of Examples 1 to 5, with Example 3 being the optimal example. During the performance testing, the Brookfield viscosity was determined according to standard GB / T11145; the boron nitride + zirconium oxide content was determined using the solid content determination method (combustion method), with the following steps: 1) Accurately weigh the crucible; 2) Slowly add the sample (100g) to the weighed crucible; 3) Heat the crucible to and maintain the temperature at approximately 500℃ for 3 hours until the non-solid substances are completely burned; 4) After the crucible has cooled naturally in a ventilated area, accurately weigh it, subtract the crucible weight, and then subtract the weight of the aluminum sol powder from the difference to obtain the weight of boron nitride + zirconium oxide. pH was determined using the pH test paper method.

[0075] Table 7 Performance data of the high-temperature release agent in the best example 3

[0076]

[0077]

[0078] See Table 8 for the required specifications of high-temperature release agents:

[0079] Table 8 Main Requirements for High-Temperature Release Agents

[0080] project index Remark main components Boron nitride & Zirconium oxide Nanoscale ultrafine powder Suitable work atmosphere all Combustion composition, boron nitride & zirconium oxide, % ≥ 82.0 liquid carrier purified water binder phase <![CDATA[AI2O3]]> Nanoscale ultrafine powder Brinell viscosity @ 3 / 60, cps 900～1100 Appearance White It can be dyed in other colors as needed. pH value 2～5

[0081] Referring to Tables 7 and 8, the main components of the optimal embodiment 3, boron nitride and zirconium oxide, reach 85.4%, exceeding the target (≥82.0%). Furthermore, these are nano-scale ultrafine powders, ensuring the formation of a stable and lubricated effective film layer at high temperatures, meeting the core requirements for demolding. The Brinell viscosity is 983.7 cps, within the target range (900-1100 cps), guaranteeing both fluidity during spraying / brushing and the formation of a uniform film layer, suitable for coating complex molds at high temperatures. The pH value is 4.3, within the acidic range of 2-5, ensuring system stability and preventing stratification and precipitation due to pH fluctuations during storage and use, guaranteeing consistent performance. The base is white, but can be dyed as needed, such as by adding blue pigment in Example 3, to meet the identification and visualization requirements of different production lines, flexibly adapting to production scenarios. In summary, this invention, through formula design, fully meets the required indicators in terms of component ratio, physical properties (viscosity, pH), and process adaptability (appearance, coating). It can stably perform demolding and protective functions at high temperatures, is easy to wash with water, effectively improves the efficiency and quality of metal forming processes, and is both environmentally friendly and economical.

[0082] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

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, the content of each raw material in 100 parts of high temperature release agent is as follows: 43.5-61.0 parts of purified water; 39.0-56.5 parts of functional additives.

2. The high-temperature release agent according to claim 1, characterized in that, 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.

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

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

5. 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.

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

7. A method for preparing a high-temperature release agent according to any one of claims 1-6, 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 to 180 minutes to obtain a stable high-temperature release agent.

8. The application of the high-temperature release agent as described in any one of claims 1-6 in releasing molds in high-temperature environments above 1300°C.

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