Integrated aluminum alloy die casting release agent cleaned by a cleaning agent and polymer molecules thereof

Abstract

This application discloses an integrated aluminum alloy die-casting release agent that requires no cleaning agent and its polymer molecules. The structural formula of the polymer molecules is as follows: where n=10~15, m=5~10.

Description

Technical Field

[0001] This invention relates to the technical field of die-casting aluminum alloy release machines, and more particularly to an integrated aluminum alloy die-casting release agent that requires no cleaning agent and its polymer molecules. Background Technology

[0002] Die casting is a casting process used for efficient, mass production of high-precision metal parts. This process involves injecting molten metal into a metal mold cavity at high pressure and speed, allowing it to cool and solidify rapidly under pressure, thus obtaining precisely sized metal parts. Water-based release agents, using water as a carrier, are currently the most widely used die casting release agents, suitable for the die casting of most aluminum, magnesium, and zinc alloys. They feature stable release performance, high cost-effectiveness, and low VOC emissions, meeting green environmental protection requirements. In metal die casting, release agents play a crucial role, primarily including: (1) forming an isolation film on the mold cavity surface to prevent high-temperature molten metal from directly impacting the mold; (2) providing lubrication, making it easier for the molten metal to fill the cavity, assisting in casting formation and reducing losses; (3) during spraying, the evaporation of water can remove heat from the mold surface, playing a role in cooling and temperature control.

[0003] Traditional water-based release agents typically contain one or more of silicone oil emulsions, wax emulsions, and ester emulsions. These components work together to form a film and lubricate the film: silicone oil can form a high-temperature insulating layer to prevent sticking and provide lubrication; wax can spread at high temperatures, enhance silicone oil adhesion, and promote film formation; esters assist silicone oil in film formation and have better film-forming performance than wax at medium and low temperatures.

[0004] With the development of die casting technology, a new integrated die casting process has emerged in the automotive field. Unlike the traditional method of casting and welding multiple parts separately, integrated die casting uses a super-large die casting machine with a clamping force of over 6,000 tons to die cast multiple parts that were originally die-cast separately into a complete part at one time, thus simplifying the traditional process from stamping to welding. The integrated die casting mold has a complex structure and a deeper cavity, making subsequent cleaning of the casting difficult. This has led more factories to favor no-clean release agents and has also raised higher requirements for environmental protection. This has also brought at least the following new challenges to traditional release agents: (1) Silicone oil is prone to carbon buildup on the mold surface, making it difficult to clean; (2) Wax is not easy to clean after high-temperature film formation, and may clog the nozzle when spraying a small amount; (3) Synthetic esters leave a lot of residue at high temperatures, requiring subsequent cleaning. To address these issues, die casting release agents are constantly developing towards the direction of no-clean.

[0005] Chinese patent CN108339930A discloses a water-based release agent made by compounding silicone oil, silicone wax, and polyethylene wax emulsion. This release agent emulsion exhibits outstanding stability, is not prone to delamination during long-term storage and at high temperatures, and can significantly improve release performance and casting surface quality, facilitating subsequent processes such as spraying and electroplating. However, the silicone wax in this solution has poor high-temperature resistance, and residual silicone oil may lead to problems such as carbon buildup and blackening of castings. The presence of wax also increases the difficulty of degreasing, resulting in challenging post-processing and higher costs. Its applicability is mainly limited to traditional die-casting processes; improvements may still be needed for more demanding no-clean integrated die-casting applications.

[0006] Chinese patent CN109175224A discloses a water-based release agent for zinc alloys, with mineral oil and paraffin wax as the main components. This solution is free of silicone oil, fundamentally avoiding the problem of silicone oil carbon buildup, reducing the burden of mold cleaning, and its composition is environmentally friendly, with relatively controllable costs. It also shows stability in traditional zinc alloy die casting. However, this formula is mainly for zinc alloys, while the mainstream integrated die casting is aluminum alloys. The two have significant differences in process temperature and mold requirements. The insufficient stability and lubrication performance of release agents based on paraffin wax and mineral oil at high temperatures make it difficult to fully meet the needs of large-tonnage integrated die casting that requires no cleaning agent.

[0007] Chinese patent CN107377868A discloses a water-based release agent with talc as the main component, free of silicone oil and grease. It uses nano-talc to form a high-temperature resistant isolation film, solving the problem of silicone carbon buildup and residue. Castings can be rinsed with tap water, greatly simplifying subsequent cleaning processes. The raw material cost is low and meets environmental protection requirements. However, the suspension stability of talc in the emulsion depends on the dispersing effect of surfactants. Uneven dispersion can lead to uneven coverage in complex deep cavities, affecting release consistency. Furthermore, its lubrication performance is inferior to traditional silicone oil solutions, and it may cause wear to the spraying equipment during high-pressure, high-speed filling.

[0008] Chinese patent CN116493540A discloses a silicone-free release agent for aluminum alloy die casting. Its core formulation uses a styrene-acrylic acid copolymer as the main film-forming substance, compounded with organophosphates (such as dodecyl polyoxyethylene phosphate) and modified cellulose, prepared through separate emulsification. This solution is completely silicone-free, solving the carbon buildup problem and ensuring uniform subsequent oxidation and coloring of the castings, aligning with the trend towards no-cleaning processes. The styrene-acrylic acid copolymer and organophosphate compound exhibit excellent thermal stability and film-forming properties, with a high measured yield (>93%), good emulsion stability, suitability for automated spraying, and low raw material costs. However, organophosphates decompose at high temperatures, producing VOCs that are toxic to humans, failing to meet environmental protection requirements; the carboxyl groups in the acrylic units of the styrene-acrylic acid copolymer may undergo decarboxylation or decomposition at high temperatures, posing a risk of carbon buildup.

[0009] In summary, traditional water-based release agents offer excellent release performance, uniform film formation, and superior lubrication. However, they suffer from significant carbon buildup and difficulty in cleaning, requiring further degreasing processes and failing to meet the requirements of clean-free and environmentally friendly integrated die casting. Furthermore, most existing silicone-free solutions utilize talc suspension systems or paraffin / mineral oil systems, which suffer from poor suspension stability at high temperatures, easy decomposition and failure of the lubricating film, and poor film uniformity and durability. Another study uses styrene-acrylic acid copolymers for film formation. This polymer exhibits excellent high-temperature resistance and self-crosslinks to form a film at high temperatures, preventing adhesion to the deep cavity of the die casting mold. However, this polymer has the potential for decarboxylation decomposition at high temperatures. Summary of the Invention

[0010] This application aims to develop a new type of aluminum alloy release agent suitable for integrated die casting, replacing traditional silicone oil, wax and synthetic ester formulations. It fundamentally solves the problem of mold carbon buildup caused by high-temperature decomposition of organic matter, enabling die castings to meet the requirements of subsequent processes such as spraying and bonding without the need for subsequent degreasing and cleaning. At the same time, it does not produce VOCs that are toxic to the human body in high-temperature environments.

[0011] Furthermore, the technical solution of this application uses styrene copolymers as the core film-forming material to ensure that it forms a stable, firm, and non-adhesive isolation film at around 700°C. At the same time, it is combined with auxiliary lubricating components that can be completely volatilized or decomposed at high temperatures without leaving any residue, achieving a balance between excellent lubricity and zero residue. This ensures that the new formula can still achieve uniform and complete film coverage in deep-cavity, complex integrated die-casting molds, and provide continuous and effective lubrication to meet the challenges brought by high pressure and high-speed filling, and to meet the stringent process requirements of ultra-large and complex molds.

[0012] To achieve at least one of the above objectives, this application provides a polymer molecule for integral aluminum alloy die casting demolding for cleaning without cleaning agents, the polymer molecule having the following structural formula:

[0013]

[0014] And where n = 10~15, m = 5~10.

[0015] According to one embodiment of this application, n = 10 to 12.

[0016] According to one embodiment of this application, m = 8 to 10.

[0017] According to one embodiment of this application, the integrated aluminum alloy die-casting release agent that requires no cleaning comprises:

[0018] The polymer molecules are 20-35;

[0019] Mineral oil 10-15;

[0020] Self-emulsifying esters 7-10;

[0021] Nonionic emulsifier 5-7;

[0022] Organic alcohol amines 0.5–2;

[0023] Defoamer 0.5-1.0; and

[0024] Deionized water 30-57.

[0025] According to one embodiment of this application, the mineral oil is implemented as a cycloalkyl mineral oil.

[0026] According to one embodiment of this application, the self-emulsifying ester is implemented as a dimer acid polyoxyethylene ether monoester.

[0027] According to one embodiment of this application, the nonionic emulsifier is implemented as at least one selected from fatty alcohol polyoxyethylene ether, sodium petroleum sulfonate, or span.

[0028] According to one embodiment of this application, the organic alcohol amine is implemented as at least one selected from triethanolamine, triisopropanolamine, or carbon dioxide-modified ethanolamine.

[0029] According to one embodiment of this application, the defoamer is implemented as a silicone-free polyol polyether defoamer. Detailed Implementation

[0030] The preferred embodiments described below are merely examples, and other obvious variations will be apparent to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0031] A preferred embodiment of this application of an integrated aluminum alloy die-casting release agent that requires no cleaning will be described in detail below, wherein the integrated aluminum alloy die-casting release agent that requires no cleaning comprises a polymer molecule with the following molecular formula:

[0032] Furthermore, n = 10–15, and m = 5–10. It is worth noting that in the above molecular formula, the benzene ring structure provides excellent thermal stability, and by limiting n to 10–15, the number of C atoms is restricted, thus maintaining structural integrity under high-temperature and high-pressure die casting, especially under aluminum alloy high-temperature and high-pressure die casting, thereby providing excellent thermal stability. If n is below the lower limit, the emulsion's high-temperature resistance (around 700℃) is poor, and it is easily decomposed; if it exceeds the upper limit, the emulsion's stability deteriorates, and VOC volatilization increases, leading to carbon buildup. Simultaneously, by limiting the value of m, the number of hydroxyl functional groups is restricted, thereby controlling hydrophilicity. If m is below the lower limit, the emulsion's stability deteriorates, and the number of adhesion sites at high temperatures decreases, resulting in lower effective adhesion; if m is above the upper limit, the emulsion's adhesion ability at high temperatures also deteriorates, making it easily washed away. The increase in hydroxyl functional groups enhances hydrophilicity, promotes the emulsification and dispersion stability of the polymer in the aqueous phase, and allows for cross-linking reactions at high temperatures, forming a continuous and dense protective film. The film adheres firmly to the mold surface, effectively isolating the molten metal. It can be rinsed clean directly with tap water without migration residue, avoiding the burden of cleaning and eliminating the need for special cleaning agents.

[0033] In one embodiment, the cleaning-free integrated aluminum alloy die-casting release agent comprises 20 to 35 parts by weight of polymer molecules.

[0034] According to another aspect of this application, the integrated aluminum alloy die-casting release agent that requires no cleaning further includes the following percentages by weight:

[0035] Mineral oil 10-15;

[0036] Self-emulsifying esters 7-10;

[0037] Nonionic emulsifier 5-7;

[0038] Organic alcohol amines 0.5–2;

[0039] Defoamer 0.5-1.0; and

[0040] Deionized water 30-57.

[0041] In one embodiment, the mineral oil may be implemented as a cycloalkyl mineral oil.

[0042] In one embodiment, the self-emulsifying ester may be implemented as a dimer acid polyoxyethylene ether monoester.

[0043] In one embodiment, the nonionic emulsifier may be implemented as at least one selected from fatty alcohol polyoxyethylene ether, sodium petroleum sulfonate, or span.

[0044] In one embodiment, the organic alcohol amine may be implemented as at least one selected from triethanolamine, triisopropanolamine, or carbon dioxide-modified ethanolamine.

[0045] Preferably, the polyol polyether defoamer is a silicone-free defoamer. More preferably, the defoamer can be implemented as a polyol polyether defoamer.

[0046] Example 1

[0047] In the polymer molecule, n=10, m=5, the polymer content is 30 parts and mineral oil 20 parts; self-emulsifying ester 15 parts, nonionic emulsifier 5 parts; organic alcohol amine 2 parts; defoamer 1 part, the remainder is deionized water, thereby forming the integrated aluminum alloy die casting release agent that does not require cleaning.

[0048] Example 2

[0049] In the polymer molecule, n=12, m=8, the polymer content is 30 parts and mineral oil 20 parts; self-emulsifying ester 15 parts, nonionic emulsifier 5 parts; organic alcohol amine 2 parts; defoamer 1 part, the remainder is deionized water, thereby forming the integrated aluminum alloy die casting release agent that does not require cleaning.

[0050] Example 3

[0051] In the polymer molecule, n=15, m=10, the polymer content is 30 parts and mineral oil 20 parts; self-emulsifying ester 15 parts, nonionic emulsifier 5 parts; organic alcohol amine 2 parts; defoamer 1 part, the remainder is deionized water, thereby forming the integrated aluminum alloy die casting release agent that does not require cleaning.

[0052] Comparative Example 1

[0053] In the polymer molecule, n=9, m=10, the polymer content is 30 parts and mineral oil 20 parts; self-emulsifying ester 15 parts, nonionic emulsifier 5 parts; organic alcohol amine 2 parts; defoamer 1 part, the remainder is deionized water, thereby forming the integrated aluminum alloy die casting release agent that does not require cleaning.

[0054] Comparative Example 2

[0055] In the polymer molecule, n=16, m=10, the polymer content is 30 parts and mineral oil 20 parts; self-emulsifying ester 15 parts, nonionic emulsifier 5 parts; organic alcohol amine 2 parts; defoamer 1 part, the remainder is deionized water, thereby forming the integrated aluminum alloy die casting release agent that does not require cleaning.

[0056] Comparative Example 3

[0057] In the polymer molecule, n = 10, m = 4, 30 parts of polymer content and 20 parts of mineral oil; 15 parts of self-emulsifying ester, 5 parts of non-ionic emulsifier; 2 parts of organic alkanolamine; 1 part of defoamer, and the rest is deionized water, thereby forming the integrated aluminum alloy die-casting release agent cleaned by the cleaning-free agent.

[0058] Comparative Example 4

[0059] In the polymer molecule, n = 10, m = 11, 30 parts of polymer content and 20 parts of mineral oil; 15 parts of self-emulsifying ester, 5 parts of non-ionic emulsifier; 2 parts of organic alkanolamine; 1 part of defoamer, and the rest is deionized water, thereby forming the integrated aluminum alloy die-casting release agent cleaned by the cleaning-free agent.

[0060] Determination of the VOC evaporation amount at the mold cavity temperature: The high-temperature VOC evaporation amount of the release agent was determined by gas chromatography - hydrogen flame ionization detector. The release agent samples prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were taken respectively, the inlet temperature was set at 300 °C, high-purity nitrogen was used as the carrier gas, the high-temperature volatile organic compounds were trapped, separated by gas chromatography and then detected by FID. Samples with a VOC content less than 15 g / L were considered environmentally friendly products.

[0061] Thermogravimetric analysis experiment: 20 mg of the sample was placed in a TGA sample pan, and the temperature was raised from room temperature to 700 °C at a heating rate of 20 °C / min under a nitrogen atmosphere, and the percentage of the residual mass of the sample at 700 °C in the initial mass was recorded. A residue amount higher than 20% was judged to have excellent high-temperature resistance performance.

[0062] Centrifugal stability experiment: The release agent samples of the examples and comparative examples were diluted with tap water to 1:100 respectively, placed in a centrifuge and centrifuged at 3000 r / min for 15 min. After taking out and observing, the emulsion was considered to be stable if it did not stratify, break, or precipitate.

[0063] High-temperature spraying experiment: The sample was diluted with tap water to 1:100, the spraying pressure was adjusted to 5 kg, and the spraying amount of 2 g was evenly sprayed on the surface of the ADC12 aluminum plate preheated to 300 °C. After cooling, the mass of the residue on the aluminum plate surface was measured, and the residue amount per unit area was calculated. Samples with a residue amount greater than 750 mg / m² were judged to have excellent high-temperature film-forming performance.

[0064] Coke deposition simulation experiment: The samples of the examples and comparative examples were diluted with tap water to 1:100, evenly sprayed on the surface of the ADC12 aluminum plate, placed in a muffle furnace at 700 °C and heated for 30 seconds, taken out and cooled naturally, and the surface of the aluminum plate was observed. If obvious black spots appeared, it was judged that the coke deposition was serious.

[0065]

[0066] Those skilled in the art should understand that the embodiments of the present invention described above are merely examples and do not limit the invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations of the implementation of the present invention may be made without departing from the stated principles.

Claims

1. A polymer molecule for integral aluminum alloy die casting demolding with no cleaning agent, characterized in that, The The structural formula of the polymer molecule is as follows: And where n = 10~15, m = 5~10.

2. The polymer molecules for integrated aluminum alloy die casting demolding using cleaning agents-free cleaning as described in claim 1, characterized in that, n= 10～12。 3. The polymer molecules for integrated aluminum alloy die-casting demolding using cleaning agents-free cleaning as described in claim 1, characterized in that, m=8～10。 4. An integrated aluminum alloy die-casting release agent that requires no cleaning agent, characterized in that: The cleaning-free, integrated aluminum alloy die-casting release agent include: The polymer molecules as described in claim 1 are 20-35; Mineral oil 10-15; Self-emulsifying esters 7-10; Nonionic emulsifier 5-7; Organic alcohol amines 0.5–2; Defoamer 0.5-1.0; and Deionized water 30-57.

5. The integrated aluminum alloy die-casting release agent that requires no cleaning agent as described in claim 4, characterized in that, The mineral oil is implemented as a cycloalkyl mineral oil.

6. The integrated aluminum alloy die-casting release agent that requires no cleaning agent as described in claim 4, characterized in that, The self-emulsifying ester is implemented as a dimer acid polyoxyethylene ether monoester.

7. The integrated aluminum alloy die-casting release agent for cleaning without cleaning agent according to claim 4, characterized in that, The nonionic emulsifier is implemented as at least one selected from fatty alcohol polyoxyethylene ether, sodium petroleum sulfonate, or span.

8. The integrated aluminum alloy die-casting release agent that requires no cleaning agent as described in claim 4, characterized in that, The organic alcohol amine is implemented as at least one selected from triethanolamine, triisopropanolamine, or carbon dioxide-modified ethanolamine.

9. The integrated aluminum alloy die-casting release agent for cleaning without cleaning agent according to claim 4, characterized in that, The defoamer is implemented as a silicone-free polyol polyether defoamer.

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