High-solid-content aluminum alloy die-casting release agent and preparation method thereof

Abstract

The invention relates to a release agent, in particular to a high-solid-content aluminum alloy die-casting release agent and a preparation method thereof. The stability of the emulsion is improved through compounding of the nonionic surfactant and the anionic surfactant, meanwhile, a water-in-oil (W / O) emulsion is firstly formed by a system through step-by-step stirring and temperature control, and then an oil-in-water (O / W) emulsion is gradually formed by controlling the adding speed of water, so that uniform dispersion of the system is ensured. The highest solid content of the product can reach 62.86%, the product has good storage stability and can be diluted by common tap water, a casting can be completely and smoothly separated from a mold only by applying extremely small external force during demolding operation, and the product is simple in preparation method, low in cost, easy for industrial production, environment-friendly and non-toxic, and meets the modern environmental protection requirement.

Description

Technical Field

[0001] The present invention relates to a release agent, in particular to a high-solid-content aluminum alloy die-casting release agent and a preparation method thereof. Background Art

[0002] With the continuous progress of industry, aluminum alloy die-casting has been widely used in fields such as automotive, aerospace, electronics, and communication. The release agent can form a uniform protective film on the surface of the mold, reduce the adhesion between the aluminum alloy liquid and the mold, and enable the casting to smoothly fall off from the mold. In addition, the release agent can effectively protect the mold, extend the service life of the mold, and reduce production costs. Generally speaking, a good release agent can improve the surface quality of the casting, increase the gloss, reduce surface defects, and increase the added value of the product.

[0003] In many industrial manufacturing fields, there are obvious differences between high-solid-content release agents and low-solid-content release agents in practical applications. For example, in the production process of plastic injection molding, a toy factory using a low-solid-content release agent needs to spray frequently, and each molding cycle is about 1 minute. After demolding, the product will have mucosal marks, and the scrap rate is as high as 5%. Later, the enterprise used a high-solid-content release agent. Because the effective ingredient content of the release agent is high, only a small amount of spraying on the surface of the mold will form a uniform and tough protective layer. The molding time is shortened to 45 seconds, and the scrap rate is reduced to less than 1%. Similarly, in the field of composite material manufacturing, a wind power generation blade manufacturer originally had a product qualification rate of 80% when using a low-solid-content release agent. When using a high-solid-content release agent, the product qualification rate increased to 95%. The same is true in the aluminum alloy die-casting industry. Taking a professional manufacturer of automotive engine cylinder block die-castings as an example, due to the use of a high-solid-content release agent, the direct contact between the molten metal and the mold is effectively blocked. Even in the face of complex molds and high temperature and high pressure conditions, it can ensure smooth demolding of the casting, the surface quality of the casting is good, and defects such as scratches and strains are greatly reduced. The scrap rate can even be guaranteed to be below 3%.

[0004] At present, the solid content of many release agents on the domestic market is generally low, with a solid content of 15-25%. To ensure the stability of the release agent, producing high-solid-content release agents often requires more complex processes and higher production costs. Compared with low-solid-content release agents, high-solid-content release agents can often improve the surface quality of the mold, reduce production accidents, lower costs, and increase production efficiency. In addition, high-solid-content release agents can often select different dilution ratios according to different production requirements, have a wider dilution multiple range, and can even be diluted 300 times, effectively solving production quality problems caused by insufficient ingredient content in low-solid-content release agents.

[0005] A mold release agent with a high solid content means an increase in the active ingredients. It is extremely difficult to ensure that numerous raw materials are evenly and stably dispersed in the system during the production process. For example, in a mold release agent with a low solid content, the distribution of silicone oil droplets in the aqueous phase is relatively stable. However, in a silicone oil emulsion with a high solid content, due to the large proportion of silicone oil, the free energy of the emulsion system is high, and the emulsion is prone to phase separation. The silicone oil droplets are prone to aggregation and fusion, resulting in emulsion stratification. Moreover, due to changes in some environmental conditions, the silicone oil will float to the surface and the emulsion will break. In addition, compared with the high-solid-content mold release agent, since the low-solid-content mold release agent contains less silicone oil, conventional emulsifiers can better encapsulate the silicone oil droplets and maintain the stability of the mold release agent. For the high-solid-content mold release agent, special emulsifiers or compound emulsifiers are required to effectively reduce the surface tension between oil and water and prevent the aggregation of silicone oil liquids.

[0006] Therefore, how to provide an aluminum alloy die-casting mold release agent with excellent mold release effect and high solid content is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] In view of this, in order to overcome the defects of the prior art, the purpose of the present invention is to provide an aluminum alloy die-casting mold release agent with a high solid content and excellent mold release effect and a preparation method thereof. The mold release agent can be diluted up to 300 times with tap water according to the complexity of the mold. Due to the addition of oxidized polyethylene wax, the sample can form a surface layer with a low friction coefficient on the mold, the lubrication effect is improved, and the adhesion coefficient between the formed surface layer and the molding material is low. In addition, the higher silicone oil content composition means a high solid content, enabling the mold release agent to be more widely applied under high temperature and high pressure. Therefore, during the mold release operation, only a very small external force needs to be applied, and the casting can be completely and smoothly separated from the mold.

[0008] It should be noted that the present invention improves the stability of the emulsion by compounding non-ionic surfactants and anionic surfactants. At the same time, through stepwise stirring and temperature control, the system first forms a water-in-oil (W / O) emulsion, and then gradually forms an oil-in-water (O / W) emulsion by controlling the water addition rate to ensure uniform dispersion of the system.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The first object of the present invention is to provide an aluminum alloy die-casting mold release agent with a high solid content. The components and mass percentage contents of the aluminum alloy die-casting mold release agent are as follows:

[0011]

[0012] Optionally, the silicone oil is dimethyl silicone oil or long-chain alkyl silicone oil, the viscosity of the silicone oil is 350-12500 cs, purchased from Shenzhen Jipeng Industrial Group Co., Ltd. or Slok New Materials Co., Ltd., and preferably the viscosity is 1000-3000 cs.

[0013] Optionally, the non-ionic surfactant is one or a mixture of two of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and sorbitan fatty acid ester.

[0014] Optionally, the anionic surfactant is one of sodium dodecyl sulfate, sodium polycarboxylate, and sodium hexadecylbenzenesulfonate.

[0015] Optionally, the melting point of the oxidized polyethylene wax is one or any combination of two or more of 36°C, 60°C, 89°C, and 98°C, purchased from Zibo Heyi Fine Chemical Co., Ltd., the acid value is 26-30 mgKOH / g, and the product shape is all microbead-shaped.

[0016] Optionally, the thickener is hydroxyethyl cellulose or polyurethane, the defoamer is a silicone defoamer, the extreme pressure agent is one of triethanolamine, tributyl phosphate, and glycerol, and the preservative is a Kathon compound preservative or a BIT preservative.

[0017] The second object of the present invention is to provide a preparation method of a high-solid-content aluminum alloy die-casting release agent as described above.

[0018] In order to achieve the above object, the present invention adopts the following technical solutions:

[0019] A preparation method of a high-solid-content aluminum alloy die-casting release agent, and the specific operation is as follows:

[0020] (1) Weigh silicone oil, non-ionic surfactant, anionic surfactant, and oxidized polyethylene wax respectively according to the mass percentage content of the release agent as described above, mix the above components and heat to a suitable temperature until the wax presents a molten state;

[0021] (2) After the stirring in step (1) is uniform, cool down to 70°C;

[0022] (3) Add water containing a thickener in batches until the sample presents a white gel state. After the temperature drops to room temperature, add the remaining water, and then add a defoamer, a preservative, and an extreme pressure agent, and stir at a constant temperature for 1-2 h to obtain an aqueous release agent, that is, the high-solid-content aluminum alloy die-casting release agent as described above.

[0023] It should be noted that the amount of water added is determined according to the state of the mixture. First, it becomes a transparent crystalline state, and then it becomes a white gel state. Seeing the white gel state proves that the amount of water is sufficient.

[0024] It should be noted that compared with general low-solid-content die-casting release agents, the present invention adopts a staged heating and stirring process to further improve the emulsion stability. In addition, it has significant advantages in terms of the content of active ingredients, dilution ratio, demoulding performance, and the ability to adapt to complex moulds, and is more suitable for high-efficiency and high-quality production requirements.

[0025] Optionally, in step (2), the stirring rate is 700 - 1500 revolutions per minute, and the stirring time is 30 minutes.

[0026] Optionally, the operation of adding water in batches in step (3) is as follows:

[0027] Slowly add tap water to disperse the silicone oil and polyethylene oxide wax in the system by the surfactant to form a W / O emulsion system; then increase the rotation speed to 2000 - 3000 revolutions per minute, and continue to slowly add tap water. The viscosity of the mixed system increases. When it gradually turns into a liquid crystal phase, further increase the rotation speed to 3000 - 5000 revolutions per minute to ensure that the oil phase is evenly dispersed; adjust the rotation speed to 4000 - 6000 revolutions per minute, increase the speed of adding tap water to make the liquid crystal phase turn into a white gel, and then add the remaining water to make the mixed system turn into a milky O / W emulsion. Add defoamers, bactericides, and extreme pressure agents, and continue stirring.

[0028] It should be noted that the purpose of slowly adding tap water is to avoid incomplete emulsification of the sample due to too fast addition rate.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] (1) This product is a milky and delicate emulsion, and the highest solid content can reach 62.86%. It has good storage stability. The emulsion shows no obvious change after being stored for three months under normal conditions, and it does not break emulsion after being diluted and dispersed by high-speed centrifugation.

[0031] (2) This product can be diluted with ordinary tap water. According to the complexity and fineness of the mould, the dilution ratio can be between (80 - 300):1. For simple moulds, the highest dilution multiple with water can reach 300 times.

[0032] (3) The preparation method of this product is simple, the cost is low, it is easy to be industrially produced, environmentally friendly and non-toxic, meeting the modern environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0034] Figure 1 It is the external view of the high-solid-content mold release agent.

[0035] Figure 2 It is the test result diagram of the laser particle size analyzer.

[0036] Figure 3 It is the surface effect diagram after the casting is demolded.

[0037] Figure 4 It is the cleaning effect diagram inside the mold. Specific Embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The special term "embodiment" here, any embodiment described as "exemplary" does not have to be interpreted as superior or better than other embodiments. For the performance index tests in the embodiments of this application, unless otherwise specified, the conventional test methods in the art are adopted. It should be understood that the terms described in this application are only for describing specific embodiments and are not used to limit the content disclosed in this application.

[0040] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the technical field to which this application belongs; the test methods and technical means not specifically noted in other parts of this application refer to the experimental methods and technical means commonly adopted by those of ordinary skill in the art.

[0041] To better illustrate the content of this application, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that this application can still be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well-known to those skilled in the art are not described in detail to highlight the gist of this application.

[0042] On the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the obtained technical solutions belong to the content disclosed in the embodiments of this application.

[0043] The present invention discloses a high-solid-content aluminum alloy die-casting mold release agent and a preparation method thereof.

[0044] To better understand the present invention, the following embodiments are used to further elaborate on the present invention specifically. However, it should not be construed as a limitation of the present invention. For those skilled in the art, some non-essential improvements and adjustments made based on the above-mentioned invention content are also considered to fall within the protection scope of the present invention.

[0045] Example 1

[0046] A high-solid-content aluminum alloy die-casting release agent is composed of the following raw materials in parts by weight:

[0047]

[0048] Among them, the silicone oil is long-chain alkyl silicone oil, purchased from Shenzhen Jipeng Industrial Group Co., Ltd., with a viscosity of 12000 cs; the melting point of oxidized polyethylene wax is 89 °C, purchased from Zibo Heyi Fine Chemical Co., Ltd., and the acid value is 26 - 30 mgKOH / g; the non-ionic surfactant is a mixture of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether, both of industrial grade; the thickener is hydroxyethyl cellulose, of industrial grade; the preservative is Microsave KB608, purchased from Guangdong Micro Control Biotechnology Co., Ltd.

[0049] The preparation method is as follows:

[0050] Mix silicone oil, oxidized polyethylene wax, non-ionic surfactant and anionic surfactant according to the above ratio, heat them to make them melt, and stir at 700 - 1500 revolutions per minute for 30 minutes. After cooling to 70 °C, slowly add tap water so that the silicone oil and oxidized polyethylene wax in the system are dispersed by the surfactant, forming a W / O emulsion system.

[0051] Increase the rotation speed to 2000 - 3000 revolutions per minute, continue to slowly add tap water, the viscosity of the mixed system increases. When it gradually turns into a liquid crystal phase, then increase the rotation speed to 3000 - 5000 revolutions per minute to ensure that the oil phase is evenly dispersed.

[0052] Adjust the rotation speed to 4000 - 6000 revolutions per minute, increase the speed of adding tap water to make the liquid crystal phase turn into a white gel-like state, then add the remaining water to make the mixed system turn into a milky white O / W emulsion, add defoamer, bactericide and extreme pressure agent, and continue to stir for 90 minutes to obtain a high-efficiency aluminum alloy die-casting release agent.

[0053] Example 2

[0054] A high-solid-content aluminum alloy die-casting release agent is composed of the following raw materials in parts by weight:

[0055]

[0056] Among them, the silicone oil is long-chain alkyl silicone oil, purchased from Shenzhen Jipeng Industrial Group Co., Ltd., with a viscosity of 5000 cs; the melting point of polyethylene wax oxide is 80 °C, purchased from Zibo Heyi Fine Chemical Co., Ltd., with an acid value of 26 - 30 mgKOH / g; the non-ionic surfactant is alkylphenol polyoxyethylene ether, industrial grade; the preservative is Microsave MBS, purchased from Guangdong Micro Control Biotechnology Co., Ltd.

[0057] The preparation method is the same as that of Example 1.

[0058] Example 3

[0059] A high-solid-content aluminum alloy die-casting release agent is composed of the following raw materials in parts by weight:

[0060]

[0061]

[0062] Among them, the silicone oil is dimethyl silicone oil, purchased from Slok New Materials Co., Ltd., with a viscosity of 1000 cs; the melting point of polyethylene wax oxide is 80 °C, purchased from Zibo Heyi Fine Chemical Co., Ltd., with an acid value of 26 - 30 mgKOH / g; the non-ionic surfactant is a mixture of alkylphenol polyoxyethylene ether and sorbitan fatty acid ester, both of industrial grade; the thickener is water-soluble polyurethane, with a solid content of 30%, purchased from Anhui Yuanchen New Materials Co., Ltd.; the preservative is TC-20, purchased from Guangdong Micro Control Biotechnology Co., Ltd.

[0063] The preparation method is the same as that of Example 1.

[0064] In order to highlight the superiority of the technical improvement of the present invention, the following comparative examples are designed:

[0065] Comparative Example 1

[0066] Taking the formula of Example 1 without adding an anionic surfactant as Comparative Example 1, and only using a non-ionic surfactant to prepare an emulsion.

[0067] Result: The emulsion has poor stability, is prone to layering and demulsification, and the emulsification rate is significantly reduced.

[0068] Comparative Example 2

[0069] Taking the formula of Example 2 as the formula of Comparative Example 2, changing the staged stirring at different temperatures to one-time stirring, that is, all components are added and stirred simultaneously.

[0070] Result: The emulsion is not evenly dispersed, the oil and water are separated, and the droplet size is large.

[0071] Comparative Example 3

[0072] Taking the formulation of Example 3 as the formulation of Comparative Example 3, the silicone oil content was reduced to 10%, and other components remained unchanged.

[0073] Result: The active ingredient decreased, the demoulding performance declined, the surface of the casting was prone to sticking to the film, and foams were easily generated after dilution with water.

[0074] Taking the high-solid-content aluminum alloy die-casting demoulding agent sample prepared in Example 2 as an example, the appearance of this sample is a milky white liquid. As Figure 1 shown, the particle size of this sample is small and evenly distributed. After being tested by a laser particle size analyzer, the particle size is 1.01 μm. A sample with a small and evenly distributed particle size helps to improve the emulsion stability.

[0075] Figure 3 , Figure 4 This is the demoulding effect of the casting after the sample is diluted 300 times and sprayed on the mold. The surface of the demoulded casting is smooth and flawless, the edge is regular and intact, and there is no residue of the demoulding agent inside the mold. This demoulding agent can not only solve the problems of difficult demoulding of traditional molds, easy damage to castings, and inconvenient mold cleaning, but also increase the content of active ingredients. It can be diluted in different proportions according to the difficulty of the casting, greatly improving the production efficiency and product quality, and having good innovation and practicality. tool The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0076] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high solid content aluminum alloy die casting release agent, characterized in that: The components and mass percentages of the aluminum alloy die-casting release agent are:

2. The high solid content aluminum alloy die casting release agent according to claim 1, characterized in that: The silicone oil is dimethyl silicone oil or long-chain alkyl silicone oil, and the viscosity of the silicone oil is 350-12500cs.

3. The high solid content aluminum alloy die casting release agent according to claim 1, characterized in that: The nonionic surfactant is one or a mixture of two of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether and sorbitan fatty acid ester.

4. The high solid content aluminum alloy die casting release agent according to claim 1, characterized in that: The anionic surfactant is one of sodium dodecyl sulfate, sodium polycarboxylate and sodium hexadecylbenzene sulfonate.

5. The high solid content aluminum alloy die casting release agent according to claim 1, characterized in that: The melting point of the oxidized polyethylene wax is one of 36° C., 60° C., 89° C., and 98° C., or any combination of two or more thereof, the acid value is 26-30 mgKOH / g, and the product shape is microbeads.

6. The high solid content aluminum alloy die casting release agent according to claim 1, characterized in that: The thickener is hydroxyethylene cellulose or polyurethane, the defoamer is a silicone defoamer, the extreme pressure agent is one of triethanolamine, tributyl phosphate and glycerol, and the preservative is a Kathon compound preservative or a BIT preservative.

7. A method for preparing a high solid content aluminum alloy die casting release agent as claimed in claim 1, characterized in that: The specific operations are as follows: (1) Weighing silicone oil, nonionic surfactant, anionic surfactant, and oxidized polyethylene wax according to the mass percentage as described in claim 1, mixing the above components and heating them to a suitable temperature until the wax is in a molten state; (2) After the mixture in step (1) is stirred evenly, the temperature is lowered to 70° C.; (3) Add water containing a thickener in batches until the sample becomes a white gel. When the temperature drops to room temperature, add the remaining water, then add a defoamer, a preservative and an extreme pressure agent. After stirring at a constant temperature for 1-2 hours, a water-based release agent is obtained, i.e., the high solid content aluminum alloy die casting release agent.

8. The preparation method according to claim 7, characterized in that: In step (2), the stirring rate is 700-1500 rpm and the stirring time is 30 min.

9. The preparation method according to claim 7, characterized in that: The batch addition of water in step (3) is performed as follows: Slowly add tap water to disperse the silicone oil and oxidized polyethylene wax in the system by the surfactant to form a W / O emulsion system; then increase the speed to 2000-3000 rpm, continue to slowly add tap water, the viscosity of the mixed system increases, and when it gradually turns into a liquid crystal phase, increase the speed to 3000-5000 rpm to ensure that the oil phase is evenly dispersed; adjust the speed to 4000-6000 rpm, increase the speed of adding tap water, and turn the liquid crystal phase into a white gel, then add the remaining water to turn the mixed system into a milky white O / W emulsion, add defoaming agent, bactericide and extreme pressure agent, and continue stirring.

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