A water-based release agent, its preparation method and use

Abstract

The present application relates to meteorological balloon production technology field, especially to a kind of water-based release agent and its preparation method and application.The water-based release agent of the present application includes the following mass fraction of raw material composition: nanoparticle 8~32 parts, modified vegetable oil polyester 40~52 parts, plasticizer 4.8~14 parts, microcapsule 3~6 parts and pH regulator 8~39.2 parts.The water-based release agent of the present application significantly improves the demolding efficiency, so that the production cycle of rubber products or silicone products is greatly shortened, and the production efficiency is improved;VOC emission is greatly reduced, in line with the trend of modern industrial green production, helps to protect the environment and worker health;The surface quality of rubber products or silicone thin products is improved, the rate of defective products due to improper demolding is reduced, and the stability of product quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of weather balloon manufacturing technology, and in particular to a water-based release agent, its preparation method, and its application. Background Technology

[0002] Currently, most rubber product release agents on the market are solvent-based. Although they offer good release effects, they contain large amounts of volatile organic compounds (VOCs), causing serious environmental pollution and failing to meet increasingly stringent environmental regulations. Furthermore, traditional release agents often struggle to form a uniform film during use, resulting in low release efficiency, surface defects, and increased scrap rates. In recent years, while some new water-based release agents have entered the market, they still exhibit significant shortcomings in lubrication, non-adhesion, and environmental performance.

[0003] Currently, several solutions have been proposed by the industry to address these issues. One approach is to adjust the formulation of traditional release agents by adding a certain amount of surfactant to improve their flowability. However, this only slightly improves the release effect and does not fundamentally solve the problem. Another approach is to develop novel release agents based on silicone oil or fluorides. While these release agents can significantly improve release performance, their high cost and poor environmental performance have prevented widespread acceptance. A third approach is to try using bio-based raw materials to replace traditional petroleum-based raw materials in the preparation of release agents. This method can reduce VOC emissions to some extent, but it still faces problems such as poor film quality and stability.

[0004] In summary, existing mold release agent technologies have significant limitations, particularly in terms of environmental performance, release efficiency, and product surface quality. Furthermore, current technologies struggle to achieve efficient and economical production of high-quality rubber or silicone products, limiting their application in high-end markets. Summary of the Invention

[0005] The purpose of this invention is to provide an aqueous release agent, its preparation method, and its application, so as to improve the demolding efficiency of rubber or silicone products, enhance environmental performance, and improve the surface quality of thin rubber or silicone products.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: One of the technical solutions of this invention provides an aqueous isolation agent comprising the following raw materials in parts by weight: 8-32 parts nanoparticles, 40-52 parts modified vegetable oil polyester, 4.8-14 parts plasticizer, 3-6 parts microcapsules, and 8-39.2 parts pH adjuster.

[0007] The second technical solution of the present invention provides a method for preparing an aqueous isolation coating, comprising the following steps: (1) Weigh the raw materials according to the specified mass fractions; (2) Mix nanoparticles, modified vegetable oil polyester and water to obtain component A; mix plasticizer and microcapsules to obtain component B; (3) Spray component A onto the mold to form an isolation layer; (4) Spray component B onto the surface of the isolation layer to form a functional layer and obtain a water-based isolation coating.

[0008] The third technical solution of this invention provides the application of the above-mentioned water-based release agent in the preparation of rubber products or silicone products, wherein the rubber products include tires, weather balloons or industrial sealing rings; and the silicone products include medical silicone or food-grade silicone.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1) Significantly improved demolding efficiency, which greatly shortens the production cycle of rubber or silicone products and improves production efficiency.

[0010] 2) It significantly reduces VOC emissions, which aligns with the trend of green production in modern industry and helps protect the environment and workers' health.

[0011] 3) It improves the surface quality of thin rubber or silicone products, reduces the defect rate caused by improper demolding, and ensures the stability of product quality. Attached Figure Description

[0012] Figure 1 The image shows a weather balloon that has been released using the release agent prepared according to the present invention. Detailed Implementation

[0013] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0014] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0015] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0016] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0017] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0018] The room temperature described in this invention is 25±2℃.

[0019] All raw materials used in this invention can be obtained commercially or prepared using existing technologies.

[0020] This invention provides an aqueous isolation agent comprising the following raw materials in parts by weight: 8-32 parts nanoparticles, 40-52 parts modified vegetable oil polyester, 4.8-14 parts plasticizer, 3-6 parts microcapsules, and 8-39.2 parts pH adjuster.

[0021] In this invention, the aqueous isolation agent comprises 8 to 32 parts of nanoparticles, for example, 8 parts, 10 parts, 12 parts, 15 parts, 20 parts, 25 parts, or 32 parts, etc.

[0022] In this invention, the nanoparticles include one or more of nano-silica, nano-alumina, nano-titanium dioxide, and nano-zinc oxide. Different particle sizes of nanoparticles can be replaced according to actual needs to adapt to different application scenarios.

[0023] In this invention, the nanoparticles are a mixture of nano-silica and nano-alumina; the mass ratio of the nano-silica to the nano-alumina particles is 1.5 to 3:1, for example, it can be 1.5:1, 1.8:1, 2:1, 2.2:1 or 3:1, etc.; the particle size of the nano-silica is 15 to 25 nm; the average particle size of the nano-silica is 20 nm; the particle size of the nano-alumina is 20 to 35 nm; the average particle size of the nano-alumina is 30 nm.

[0024] In some embodiments of the present invention, nano-silica and nano-alumina, when mixed in a specific ratio, can form a uniformly dispersed suspension in an aqueous medium.

[0025] Understandably, this invention utilizes nanotechnology to improve the basic formulation of water-based release agents. By adding specific proportions of nano-silica and nano-alumina particles, these particles can be uniformly dispersed in the aqueous medium, forming an ultra-thin and highly stable release film. This significantly enhances the lubricity and non-adhesiveness of the release agent, thereby greatly improving demolding efficiency. Precisely controlling the particle size of the nanoparticles and their suspension stability in the aqueous medium ensures that the release agent forms a uniform film during application. This not only improves demolding speed but also greatly enhances the surface finish of the product, reducing surface defects caused by poor demolding.

[0026] In this invention, the water-based separating agent comprises 40 to 52 parts of modified vegetable oil polyester, for example, 40 parts, 45 parts, 48 ​​parts, or 52 parts.

[0027] In this invention, the modified vegetable oil polyester is self-emulsifying and includes modified castor oil polyester, modified soybean oil polyester, modified palm oil polyester, or modified sunflower seed oil polyester; the molecular weight of the modified vegetable oil polyester is 8000~12000, for example, it can be 8000, 8500, 9000, 10000, 11000, or 12000; The modified vegetable oil polyester can also be replaced with modified polyoxyethylene sorbitan monostearate polyester; the molecular weight of the modified polyoxyethylene sorbitan monostearate polyester is 622.9.

[0028] The modification method of the modified polyoxyethylene sorbitan monostearate polyester is to introduce polar groups such as hydroxyl and carboxyl groups into the molecular chain through an oxidation reaction, thereby improving its hydrophilicity and its ability to interact with other polar substances.

[0029] Understandably, the use of modified polyester derived from vegetable oil as the main film-forming material, combined with biodegradable plasticizers, ensures that the entire formula meets both high-performance requirements and green environmental protection standards, significantly reducing VOC emissions and protecting the environment and workers' health.

[0030] In this invention, the water-based separating agent includes 4.8 to 14 parts of plasticizer, for example, 4.8 parts, 5 parts, 7 parts, 10 parts, 12 parts or 14 parts, etc.

[0031] In this invention, the plasticizer includes triethyl citrate, acetylated tributyl citrate, trioctyl citrate, glyceryl triacetate, polymethylhydrosiloxane, clay powder, or kaolin; the biodegradable plasticizer is used to adjust the flexibility of the polymer chain; the flexibility and processing performance of the formulation are adjusted by selecting different types of biodegradable plasticizers. In this invention, the aqueous isolation agent includes 8 to 39.2 parts of a pH adjuster, for example, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, or 39.2 parts; the pH adjuster includes ammonia, potassium hydroxide solution, or sodium hydroxide solution; the solvent of the potassium hydroxide solution is water; the solvent of the sodium hydroxide solution is water; the pH value of the pH adjuster is 11.

[0032] In this invention, the aqueous barrier agent comprises 3 to 6 parts of microcapsules, for example, 3 parts, 4 parts, 5 parts or 6 parts, etc.

[0033] In this invention, the microcapsules have a particle size ≤10μm, preferably 4~8μm; the wall material of the microcapsules is a natural rubber polymer compound, and the core material includes amino silicone oil, fluorosilane, epoxy silicone oil or sodium methylsiloxane; the type and concentration of the filling material inside the microcapsules can be adjusted for specific application environments to achieve the best effect.

[0034] Understandably, this invention introduces microcapsule sustained-release technology, which encapsulates the active ingredients in tiny capsules. As friction occurs during production and use, the active ingredients are gradually released, extending the effective action time of the release agent and further enhancing the stability and reliability of long-term use.

[0035] This invention also provides a method for preparing an aqueous isolation coating, comprising the following steps: (1) Weigh the raw materials according to the specified mass fractions; (2) Mix nanoparticles, modified vegetable oil polyester and water to obtain component A; mix plasticizer and microcapsules to obtain component B; (3) Spray component A onto the mold to form an isolation layer; (4) Spray component B onto the surface of the isolation layer to form a functional layer and obtain a water-based isolation coating.

[0036] In this invention, before spraying, it is also necessary to check whether the spray gun is unobstructed and to confirm that the water is clear and free of impurities; preheat the mold to a suitable temperature, usually room temperature or slightly above room temperature; and use compressed air to thoroughly blow the surface of the mold to remove dust and particles.

[0037] In step (3) of this invention, when spraying, start the spray gun, adjust the appropriate pressure, and uniformly spray component A from the edge of the mold to form the first basic isolation layer; Step (4) of the present invention is to wait for the first layer to air dry naturally for 3 to 5 minutes; then restart the spray gun to spray component B to form the second functional layer containing specific additives.

[0038] In this invention, after both layers have fully cured, normal weather balloon product molding operations can be carried out; after use, the spray gun and related equipment should be cleaned in time to avoid residue clogging the pipes.

[0039] Working principle: When the water-based release agent is sprayed onto the mold surface, the water evaporates rapidly, leaving a dry coating composed of nanoparticles, modified polyester, and biodegradable plasticizers. Due to the presence of nanoparticles, the coating exhibits excellent lubricity and non-adhesion, effectively preventing the weather balloon product from sticking to the mold. Simultaneously, the active ingredients within the microcapsules are gradually released during use due to friction, continuing to exert their effect and extending the effective lifespan of the release agent. It is particularly noteworthy that in the double-coating process, the bottom layer provides the necessary release function, while the top layer enhances overall durability and ease of cleaning.

[0040] In this invention, the spraying includes electrostatic spraying or pneumatic spraying; in step (3), the voltage for electrostatic spraying is 50~55kV, and the pressure for pneumatic spraying is 0.25~0.4MPa; in step (4), the voltage for electrostatic spraying is 45~48kV, and the pressure for pneumatic spraying is 0.28~0.4MPa.

[0041] In this invention, the thickness of the isolation layer is 6~25μm, and the thickness of the functional layer is 4~25μm.

[0042] Understandably, this invention designs a special double-layer coating process, first laying a base isolation film, and then covering it with a functional layer containing special additives. The base isolation layer is composed of nanoparticles and modified polyester, which is responsible for providing the initial isolation effect; the functional layer contains biodegradable plasticizers and other auxiliary components, which not only enhance the isolation effect, but also help to facilitate the operation of subsequent processes, such as improving the mold's anti-fouling ability and cleaning efficiency.

[0043] Furthermore, to further optimize this technology, additional additives, such as antioxidants and UV absorbers, can be introduced into the base formulation to give the finished product better weather resistance and a longer service life. Additionally, the use of more efficient spraying equipment, such as electrostatic sprayers, can be explored. This would not only improve spraying efficiency but also reduce material waste and lower production costs.

[0044] The present invention also provides the application of the above-mentioned aqueous release agent in the preparation of rubber products or silicone products, wherein the rubber products include tires, weather balloons or industrial sealing rings; and the silicone products include medical silicone or food-grade silicone.

[0045] This technology is mainly applicable to the demolding process of weather balloon products, and is especially suitable for the high-end market of thin products with high requirements for environmental protection and product surface quality.

[0046] In summary, through the aforementioned technological innovations, this invention achieves a comprehensive improvement in the water-based release agent in terms of demolding efficiency, environmental performance, and surface quality. It not only accelerates the production process of weather balloon products and reduces production costs, but also makes a positive contribution to environmental protection, while ensuring high-quality product output and meeting the high standards of modern industrial production.

[0047] In some embodiments of the present invention, both the nano-silica and nano-alumina are surface-modified by reacting with amines (Si-OH+NH2R-H2O-Si-O-HNR) to enhance their dispersibility in the aqueous system; the tributyl citrate is purchased from Anpu New Materials (Guangzhou) Co., Ltd.; and the modified polyester derived from vegetable oil is purchased from Dongguan Ruian Polymer Resin Co., Ltd.

[0048] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0049] Example 1 The separating agent for weather balloon products is prepared by weighing the raw materials according to the following mass fractions: 32% nanoparticles, 40% modified polyoxyethylene sorbitan monostearate, 14% polymethylhydrosiloxane plasticizer, 6% microcapsules, and 8% pH adjuster; The nanoparticles consist of nano-silica (35nm in diameter) and nano-alumina (20nm in diameter), with a mass ratio of 3:1. The modified polyoxyethylene sorbitan monostearate polyester has a molecular weight of 622.9. The microcapsules have a particle size of 5μm and contain fluorosilane. The pH adjuster is ammonia water with a pH value of 11.

[0050] Preparation method of a special insulating coating for the production of weather balloon products (tires): (1) The nanoparticles, modified polyoxyethylene sorbitan monostearate polyester and pH adjuster were mixed by mass fraction as component A; the polymethylhydrosiloxane plasticizer and microcapsules were mixed by high-speed stirring (RPM450) as component B; (2) Check whether the spray gun is unobstructed and confirm that the water is clear and free of impurities; (3) Preheat the mold to 80°C; (4) Use compressed air to thoroughly blow away dust and particles from the mold surface; (5) Start the spray gun, adjust the spraying pressure to 0.4MPa, and spray component A evenly from the edge of the mold. Wait for component A to air dry for 10 minutes to form a 25μm thick isolation film. Start the spray gun again, adjust the spraying pressure to 0.4MPa, and spray component B on the isolation film. Wait for component B to air dry and cure for 10 minutes to form a 25μm thick functional layer, thus completing the preparation of the isolation coating.

[0051] When weather balloon products were molded using molds coated with this insulating coating, tests showed that under vulcanization conditions at 80℃, demolding efficiency increased by 30%, the number of demolding cycles increased to 5, the surface Ra value of the product was less than 1.6μm, and VOC emissions were less than 20 mg / m³. 3 This improved the surface quality of weather balloon products. Figure 1 ).

[0052] Example 2 A special release agent for rubber product manufacturing, made from the following raw materials by mass fraction: 12% nanoparticles, 45% modified castor oil polyester, 6% triethyl citrate, 5% microcapsules, and 32% pH adjuster; The nanoparticles consist of nano-silica (25 nm in diameter) and nano-alumina (35 nm in diameter), with a mass ratio of 1.5:1. The modified castor oil polyester has a molecular weight of 10,000, the microcapsules have a particle size of 8 μm, the microcapsules contain amino silicone oil, and the pH adjuster is sodium hydroxide solution with a pH value of 11.

[0053] Preparation method of a special isolation coating for rubber product (tire) production: (1) The nanoparticles, modified castor oil polyester and pH adjuster were mixed by mass fraction as component A; the triethyl citrate and microcapsules were mixed by high-speed stirring (RPM450) as component B. (2) Check whether the spray gun is unobstructed and confirm that the water is clear and free of impurities; (3) Preheat the mold to 40°C; (4) Use compressed air to thoroughly blow away dust and particles from the mold surface; (5) Using a dual-station automatic spraying system, adjust the spraying pressure to 0.3MPa, spray component A evenly from the edge of the mold, wait for component A to air dry for 4 minutes to form a 15μm thick isolation film; adjust the spraying pressure to 0.25MPa again, spray component B on the isolation film, wait for component B to air dry and cure for 4 minutes to form a 10μm thick functional layer, and complete the preparation of the isolation coating.

[0054] Tire molding using molds coated with this insulating coating showed that, under vulcanization conditions at 185°C, the number of demolding cycles increased to 300 per coating application, the tire surface bubble rate decreased by 92%, and VOC emissions were below 50 mg / m³. 3 The mold cleaning cycle is extended by 3 times.

[0055] Example 3 The release agent for medical silicone products is prepared by weighing the following raw materials in the following mass fractions: nanoparticles 8%, modified soybean oil polyester 50%, acetylated tributyl citrate 5%, microcapsules 3%, and pH adjuster 34%. The nanoparticles consist of nano-silica (18 nm in diameter) and nano-alumina (25 nm in diameter), with a mass ratio of 2:1. The modified soybean oil polyester has a molecular weight of 9000, the microcapsules have a particle size of 5 μm, the microcapsules contain fluorosilane, and the pH adjuster is ammonia water with a pH value of 11.

[0056] Preparation method of a special protective coating for medical silicone products: (1) The nanoparticles, modified soybean oil polyester and pH adjuster were mixed by mass fraction as component A; the acetylated tributyl citrate and microcapsules were mixed by high-speed stirring (RPM450) as component B. (2) Preheat the mold to 25°C; (3) Use compressed air to thoroughly blow away dust and particles from the mold surface; (4) Using a precision electrostatic spraying device, adjust the voltage to 50 kV, spray component A, wait for component A to air dry for 2 min, and form an isolation film with a thickness of 8 μm; then, with the voltage at 45 kV, spray component B on the isolation film, wait for component B to air dry and cure for 2 min, and form a functional layer with a film thickness of 5 μm, thus completing the preparation of the isolation coating.

[0057] Medical silicone was molded using a mold coated with this isolation coating. After testing, zero-defect demolding was achieved in a 120℃ vulcanization environment. The product surface Ra value is ≤0.2μm, VOC emission is <10g / L, and it has passed ISO 10993 biocompatibility certification.

[0058] Example 4 The release agent for industrial sealing ring rubber products is prepared by weighing the raw materials according to the following mass fractions: 10% nanoparticles, 48% modified palm oil polyester, 5.5% trioctyl citrate, 4% microcapsules, and 32.5% pH adjuster; The nanoparticles consist of nano-silica (20 nm in diameter) and nano-alumina (25 nm in diameter), with a mass ratio of 1.8:1. The modified palm oil polyester has a molecular weight of 11,000, the microcapsules have a particle size of 7 μm, the microcapsules contain epoxy silicone oil, and the pH adjuster is potassium hydroxide solution with a pH value of 11.

[0059] Preparation method of special isolation coating for industrial sealing ring rubber products: (1) The nanoparticles, modified palm oil and pH adjuster were mixed by mass fraction as component A; the trioctyl citrate and microcapsules were mixed by high-speed stirring (RPM450) as component B; (2) Preheat the mold to 35°C; (3) Use compressed air to thoroughly blow away dust and particles from the mold surface; (4) Using a pneumatic spraying system, adjust the spraying pressure to 0.28 MPa, spray component A, wait for component A to air dry for 3 minutes to form a 12 μm thick isolation film; adjust the spraying pressure to 0.28 MPa again, spray component B on the isolation film, wait for component B to air dry and cure for 3 minutes to form a functional layer with a film thickness of 8 μm, and complete the preparation of the isolation coating.

[0060] The sealing rings were formed using a mold coated with this insulating coating. Testing showed that after 250 consecutive demoldings at a vulcanization temperature of 150℃, no sticking occurred. The dimensional tolerance of the sealing rings was controlled within ±0.05mm, mold residue was reduced by 78%, the time required for a single cleaning cycle was shortened to 1 / 3 of the original process, and VOC emissions were below 50 mg / m³. 3 .

[0061] Example 5 The release agent for food-grade silicone products is prepared by weighing the raw materials according to the following mass fractions: nanoparticles 9%, modified sunflower seed oil polyester 52%, glyceryl triacetate 4.8%, microcapsules 3.5%, and pH adjuster 30.7%. The nanoparticles consist of nano-silica (15 nm in diameter) and nano-alumina (20 nm in diameter), with a mass ratio of 2.2:1. The modified sunflower seed oil polyester has a molecular weight of 8500, the microcapsules have a particle size of 4 μm, the microcapsules contain sodium methylsilanolate, and the pH adjuster is ammonia water with a pH value of 11.

[0062] Preparation method of a release coating for food-grade silicone products: (1) The nanoparticles, modified sunflower seed oil and pH adjuster were mixed by mass fraction as component A; the triglyceride and microcapsules were mixed by high-speed stirring (RPM450) as component B; (2) Preheat the mold to 30°C; (3) Use compressed air to thoroughly blow away dust and particles from the mold surface; (4) Use electrostatic spraying, adjust the spraying voltage to 55kV, spray component A, wait for component A to air dry for 90s to form a 6μm thick isolation film; adjust the spraying voltage to 48kV again, spray component B on the isolation film, wait for component B to air dry and cure for 90s to form a 4μm thick functional layer, and complete the preparation of the isolation coating.

[0063] Using molds coated with this isolation coating to mold food-grade silicone, tests showed that under a 100°C vulcanization environment, it achieved zero migration demolding as required by FDA standards, the surface gloss of the product reached over 85 GU, the mold lifespan was extended to 4 times that of traditional processes, and the VOC detection value was only 1 / 8 of that of conventional products.

[0064] Comparative Example 1 Traditional solvent-based release agents are made by weighing raw materials according to the following mass fractions: 60% mineral oil-based solvent, 30% paraffin-based release agent, and 10% organosilicon additive.

[0065] Preparation method of tire-specific isolation coating: (1) Mix mineral oil-based solvent, paraffin-based release agent and organosilicon additive according to mass fraction to obtain release agent; (2) Preheat the mold to above 60°C; (3) Use compressed air to thoroughly blow away dust and particles from the mold surface; (4) Using a single-layer spraying process, the spraying pressure is adjusted to 0.4MPa, and the release agent is sprayed evenly from the edge of the mold to form a release coating with a film thickness of 25μm, thus completing the preparation of the release coating.

[0066] Tire molding using molds coated with this isolation coating resulted in VOC emissions exceeding 500g / L, failing to meet environmental regulations. The demolding process was limited to only 50 times per coating application, and the tire surface bubble rate reached as high as 15%. The molds required manual cleaning every 20 production cycles, increasing labor intensity and costs.

[0067] Comparative Example 2 Ordinary water-based release agent, the raw materials are weighed according to the following mass fractions: 15% micron-sized talc powder (particle size 5μm), 40% polyvinyl alcohol film-forming agent, 5% glycerol plasticizer, and 40% ammonia water with a pH value of 11.

[0068] Preparation method of medical-grade silicone protective coating: A water-based release agent is obtained by mixing micron-sized talc powder, polyvinyl alcohol film-forming agent, glycerol plasticizer and water. The isolation coating is prepared by applying a single-layer roller coating to the mold at a coating speed of 2 m / min and a wet film thickness of 50 μm, followed by hot air drying at 80℃ for 10 minutes.

[0069] Tests showed that the maximum number of demolding cycles is 100, the surface Ra value of medical silicone products is ≥1.0μm, the mold cleaning cycle does not exceed 50 production cycles, and although VOC emissions are <50g / L, the isolation coating is prone to cracking.

[0070] Comparative Example 3 The common water-based release agent formulation consists of: 50% clay powder (425 mesh), 20% kaolin (800 mesh), 29.8% calcium chloride aqueous solution coagulant, and 0.2% n-butanol defoamer. Process parameters: direct immersion impregnation process, immersion time 15 seconds, followed by 3 minutes in latex before observing the balloon surface. Performance defects: After balloon formation, obvious powdery residue is visible on the surface (visible white spots), uneven thickness leads to localized defects, the inner layer and appearance of the product are irregular, and the coagulant tends to slide down when lifted, severely affecting the product's appearance quality.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water-based release agent, characterized in that, It includes component A and component B; component A includes the following raw materials in parts by weight: 8-32 parts nanoparticles, 40-52 parts modified vegetable oil polyester and 8-39.2 parts pH adjuster; component B includes the following raw materials in parts by weight: 4.8-14 parts plasticizer and 3-6 parts microcapsules; The plasticizers include triethyl citrate, acetylated tributyl citrate, trioctyl citrate, glyceryl triacetate, and polymethylhydrosiloxane; The wall material of the microcapsules is natural rubber, and the core material includes amino silicone oil, fluorosilane, epoxy silicone oil or sodium methylsiloxane. The modified vegetable oil polyester includes modified castor oil polyester, modified soybean oil polyester, modified palm oil polyester, or modified sunflower seed oil polyester; the molecular weight of the modified vegetable oil polyester is 8000~12000.

2. The aqueous release agent according to claim 1, characterized in that, The nanoparticles include one or more of nano-silica, nano-alumina, nano-titanium dioxide, and nano-zinc oxide.

3. The aqueous release agent according to claim 1, characterized in that, The nanoparticles are a mixture of nano-silica and nano-alumina; the mass ratio of the nano-silica to the nano-alumina particles is 1.5~3:1; the particle size of the nano-silica is 15~25nm; and the particle size of the nano-alumina is 20~35nm.

4. The aqueous release agent according to claim 1, characterized in that, The pH adjuster includes ammonia, potassium hydroxide solution, or sodium hydroxide solution; the pH value of the pH adjuster is 11.

5. The aqueous release agent according to claim 1, characterized in that, The microcapsules have a particle size ≤10μm.

6. A method for preparing a water-based isolation coating, characterized in that, Includes the following steps: (1) Weigh the raw materials according to the mass fractions specified in any one of claims 1 to 5; (2) Mix nanoparticles, modified vegetable oil polyester and pH adjuster to obtain component A; mix plasticizer and microcapsules to obtain component B; (3) Spray component A onto the mold to form an isolation layer; (4) Spray component B onto the surface of the isolation layer to form a functional layer and obtain a water-based isolation coating.

7. The preparation method according to claim 6, characterized in that, The spraying includes electrostatic spraying or pneumatic spraying; in step (3), the voltage for electrostatic spraying is 50~55kV, and the pressure for pneumatic spraying is 0.25~0.4MPa; in step (4), the voltage for electrostatic spraying is 45~48kV, and the pressure for pneumatic spraying is 0.28~0.4MPa.

8. The preparation method according to claim 6, characterized in that, The thickness of the isolation layer is 6~25μm, and the thickness of the functional layer is 4~25μm.

9. The use of the aqueous release agent according to any one of claims 1 to 5 in the preparation of rubber or silicone products, characterized in that, The rubber products include tires, weather balloons, or industrial sealing rings; the silicone products include medical-grade silicone or food-grade silicone.

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