A cooking range oil separation membrane and a preparation method thereof

Abstract

The present application relates to the technical field of high-temperature-resistant protective materials for kitchens, in particular to a cooking range oil separation film and a preparation method thereof; in view of the problem that the existing cooking range oil separation film is prone to yellowing, embrittlement and loss of elasticity under long-term high temperature; the present application adopts a four-layer gradient heat management design: the first layer is a working surface layer, polyetherimide (PEI) is used as the base resin, and dispersed modified nano boron nitride and nano cerium oxide fillers are used; the second layer is a main heat insulation layer, organic silicone resin is used as the base, hollow glass microbeads and silica powder are added to improve the heat insulation strength; the third layer is a flexible buffer layer, an organic silicone elastomer containing a foaming agent is used to form a microporous structure; the fourth layer is an intelligent adhesion layer, organic silicone pressure-sensitive adhesive is used and modified thermal expansion microspheres are added to automatically reduce adhesion under high temperature; each layer is first formed separately, and then low-temperature laminated and co-cured to prepare; the oil separation film has excellent anti-aging and stability under long-term high temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-temperature-resistant protective materials for kitchen, in particular to a cooking range oil separation film and a preparation method thereof. BACKGROUND

[0002] Household kitchen cooking ranges are often splashed with oil stains and scalded by high temperature in daily cooking. In order to protect the surface of the cooking range from being clean and prevent oil stains from accumulating, an oil separation film or a protective pad is usually used to cover the surface of the cooking range. However, the existing cooking range oil separation film material is prone to aging problems after being used in a high temperature environment for a period of time, which is specifically manifested in yellowing, brittle material, and decrease in elasticity and adhesion, etc. This is mainly due to thermal oxidative aging of the commonly used high molecular materials in long-term high temperature and oil fume environment.

[0003] At present, the common cooking range oil-proof films on the market mainly include the following types:

[0004] First, Teflon-coated glass fiber cloth gasket, which has the characteristics of not sticking to oil stains and being resistant to a certain high temperature. When the gasket is close to an open flame or exceeds its temperature resistance range, the polytetrafluoroethylene (PTFE) coating will gradually degrade, resulting in discoloration, hardening, and even releasing harmful smoke. The glass fiber substrate may also be brittle or delaminated due to high temperature after long-term use.

[0005] Second, silica gel pad or silicone rubber-coated protective film. Silicone rubber material has excellent heat resistance and elasticity, and can withstand higher temperatures for a short time. However, ordinary silica gel pads may still exhibit aging phenomena such as surface yellowing, poor elasticity, and even hardening and cracking after long-term use in high temperature areas of the cooking range. This is due to further cross-linking or oxidation of the silica gel at high temperatures. In addition, the silica gel pad has low thermal conductivity but limited heat insulation effect. Increasing the thickness will affect the soft and comfortable nature, and the adhesion performance of the bottom will decrease after a period of use, which is prone to edge curling or displacement.

[0006] Third, aluminum foil gasket and other metal films, which are resistant to high temperature but have high thermal conductivity and cannot provide thermal insulation buffer. They are mainly used once and have poor environmental protection and aesthetics.

[0007] In summary, the existing cooking range oil separation film materials have some deficiencies in terms of long-term use stability and heat insulation performance in high temperature environments, and it is difficult to simultaneously consider high heat resistance, non-aging, good heat insulation, and necessary flexibility and adhesion. Therefore, there is an urgent need for a new oil separation protective film material that does not yellow and does not crack when used in a high temperature environment for a long time, and has excellent heat insulation and anti-scald performance and sustained adhesion and flexibility. SUMMARY

[0008] The application provides a cooking bench oil separation film and a preparation method thereof, and aims to significantly improve the stability of the oil separation film in a long-term high-temperature environment, so that the oil separation film remains yellow-free and brittle-free after experiencing high-temperature oil fume impact, and maintains good elasticity and adhesion performance; meanwhile, the heat insulation and protection effect is improved, and the surface of the cooking bench is protected from high-temperature scalding.

[0009] The specific technical scheme is as follows:

[0010] A cooking bench oil separation film and a preparation method thereof are as follows:

[0011] S1: raw material preparation and pretreatment.

[0012] S11: nanometer boron nitride and nanometer cerium oxide are dispersed in an ethanol aqueous solution, ultrasonic dispersion is performed to obtain a suspension; the silane coupling agent KH-550 is added to the suspension, mechanical stirring is performed, cooling to room temperature is performed, centrifugal separation is performed, washing is performed, vacuum drying is performed, grinding is performed, and surface-modified nanometer composite fillers are obtained; the thermal expansion microspheres are added to the ethanol aqueous solution, stirring is performed, and a suspension is obtained; the silane coupling agent KH-901 is added to the suspension, then heating to 55 DEG C and mechanical stirring are performed, centrifugal separation is performed, washing is performed, vacuum drying is performed, and modified thermal expansion microspheres are obtained.

[0013] S12: the PEI powder is added to N-methyl pyrrolidone (NMP) and stirring is performed at 65 DEG C until complete dissolution, and a PEI solution is obtained; the surface-modified nanometer composite fillers prepared in S11, the antioxidant 1010 and the dispersant BYK-163 are premixed with N-methyl pyrrolidone to obtain a premixed slurry; the premixed slurry is added to the PEI solution, stirring is performed, grinding is performed, and defoaming is performed, and a working surface layer slurry is obtained.

[0014] S13: the silicone resin is uniformly mixed with the solvent N-methyl pyrrolidone, the rheological aid BYK-410 is added, stirring is performed, and then the hollow glass microspheres and the silicon dioxide powder are added, and vacuum defoaming is performed, and a main heat insulation layer slurry is obtained.

[0015] S14: the two-component liquid silicone rubber is mixed with the foaming agent azodicarbonamide, and stirring is performed, and a flexible buffer layer rubber material is obtained.

[0016] S15: the modified thermal expansion microspheres are added to the high-temperature-resistant silicone pressure-sensitive adhesive, and stirring is performed, and a smart adhesion layer glue is obtained.

[0017] S2: preliminary preparation and curing.

[0018] S21: the working surface layer slurry prepared in S12 is coated on the PET release film, and then drying is performed, and a semi-dry working surface layer is obtained; the microstructure is imprinted on the semi-dry working surface layer, and then UV irradiation is performed, and then heat curing is performed, and cooling to room temperature is performed, and winding is performed, and a working surface layer film is obtained.

[0019] S22: The main heat insulation layer slurry prepared in S13 is coated on the polyimide film, then stepwise temperature curing is performed, cooling is performed, and winding is performed, to obtain a main heat insulation layer film.

[0020] S23: The flexible buffer layer rubber prepared in S14 is coated on the PET release film, then stepwise temperature curing is performed, cooling is performed, and winding is performed, to obtain a flexible buffer layer film.

[0021] S24: The smart adhesion layer glue prepared in S15 is coated in the PET release film treated by the corona, then curing is performed, cooling is performed, winding is performed, and aging is performed, to obtain a smart adhesion layer film.

[0022] S3: Processing and preparation.

[0023] S31: The PET release film of the flexible buffer layer film prepared in S22 is peeled off, and the main heat insulation layer film prepared in S21 is plasma treated on the surface to be bonded.

[0024] S32: The PET release film of the working surface layer film prepared in S21 is peeled off, and the main heat insulation layer film and the flexible buffer layer film that are plasma treated in S31 are laminated through alignment laminating rollers, and then UV irradiation is performed, to obtain a pre-cured composite film; the pre-cured composite film is subjected to stepwise temperature curing through a hot press, and finally cooling roll cooling is performed, to obtain a semi-finished composite film.

[0025] S33: The flexible buffer layer of the semi-finished composite film prepared in S32 is laminated with the smart adhesion layer film at room temperature, to obtain an oil barrier film.

[0026] Further, the ethanol aqueous solution in S11, wherein the volume ratio of ethanol to water is 4:1.

[0027] The nano boron nitride and the nano cerium oxide in S11, and the volume ratio of the mass of the two to the volume of the ethanol aqueous solution is 1:20-1:50.

[0028] The ultrasonic dispersion in S11, and the parameters are set as follows: power 600-800 W, on 2 s / off 1 s, and time length 30-60 min.

[0029] The KH-550 in S11, and the mass of the KH-550 is 1.5-3.0% of the total weight of the nano fillers.

[0030] The mechanical stirring in S11, and the parameters are set as follows: 300-500 rpm, temperature 65-75℃, and time length 4-6 h.

[0031] The washing in S11, and the anhydrous ethanol and the deionized water are alternately washed for 3 times each.

[0032] The vacuum drying of S11 has the following parameter settings: vacuum degree -0.085 MPa, temperature 80 DEG C, and time length 24 h.

[0033] Further, the premixing of S12 has the following parameter settings: rotation speed 10000 rpm, and time length 15 min.

[0034] The defoaming of S12 has the following parameter settings: vacuum degree -0.095 MPa, and time length 25 min.

[0035] The working surface layer slurry of S12 has the following material proportions based on 100 parts of PEI resin: N-methyl pyrrolidone 350-450 parts, surface-modified nano-composite filler 15-25 parts, antioxidant 1010 0.5-3 parts, and BYK-163 1-3 parts.

[0036] Further, the main thermal insulation layer slurry of S13 has the following material proportions based on 100 parts of silicone resin: solvent N-methyl pyrrolidone 150-250 parts, hollow glass microbeads 30-50 parts, silica powder 10-20 parts, and BYK-410 0.5-2 parts.

[0037] Further, the flexible buffer layer rubber of S14 has the following material proportions based on 100 parts of two-component liquid silicone rubber: foaming agent azodicarbonamide 2-5 parts.

[0038] Further, the intelligent adhesive layer rubber of S15 has the following material proportions based on 100 parts of high-temperature-resistant silicone pressure-sensitive adhesive: modified thermal expansion microspheres 5-15 parts.

[0039] Further, the drying of S21 has the following parameter settings: temperature 80-90 DEG C, and time length 1-2 min.

[0040] The microstructure of S21 is a reverse micro-lip array structure.

[0041] The UV irradiation of S21 has the following parameter settings: wavelength 365 nm, intensity 1500 mW / cm 2 , and exposure time 1 s.

[0042] The heat curing of S21 has the following parameter settings: temperature 200-220 DEG C, and time length 10-20 min.

[0043] Further, the stepwise temperature rising of S22 has the following parameter settings: first zone temperature 80-100 DEG C, time length 5-10 min, second zone temperature 130-150 DEG C, time length 5-10 min, and third zone temperature 180-200 DEG C, time length 15-30 min.

[0044] Further, the parameters of the step S23 of the stepwise temperature increase are as follows: the first zone temperature is 80-100 DEG C, the time length is 5-10 min, the second zone temperature is 150-170 DEG C, the time length is 3-5 min, and the third zone temperature is 180-200 DEG C, and the time length is 5-10 min.

[0045] Further, the parameters of the step S24 of the solidification are as follows: the temperature is 60-80 DEG C, the time length is 5-10 min, and the curing parameters are as follows: the temperature is 25 DEG C, and the time length is 24 h.

[0046] Further, the parameters of the step S31 of the plasma treatment are as follows: the power is 500-1500 W, the processing gas is air, and the processing speed is 1-5 m / min.

[0047] Further, the pressure of the step S32 of the lamination is 1 N / cm 2 .

[0048] The parameters of the step S32 of the UV irradiation are as follows: the wavelength is 395 nm, the intensity is 500-1000 mW / cm 2 , and the exposure time length is 3-10 s.

[0049] The parameters of the step S32 of the hot press are as follows: the roll gap 1 temperature is 80-100 DEG C, the linear pressure is 10-20 N / cm, and the residence time is 10-20 s; the roll gap 2 temperature is 120-140 DEG C, the linear pressure is 30-50 N / cm, and the residence time is 20-40 s; and the roll gap 3 temperature is 160-180 DEG C, the linear pressure is 20-30 N / cm, and the residence time is 10-20 s.

[0050] Further, the pressure parameter of the step S33 of the light pressing is 3 N / cm.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] 1. The present application uses PEI and modified nano fillers on the working surface layer, delays the thermal oxidation process of the material in a high-temperature environment, and significantly improves the anti-yellowing and anti-brittle ability.

[0053] 2. The present application realizes smooth thermal transition from the high-temperature working surface to the low-temperature adhesion surface through four-layer functional design, and the synergistic effect of the composite filler system of the main heat insulation layer ensures that the glue layer temperature is always lower than the tolerance limit.

[0054] 3. The present application effectively resolves stress through a flexible buffer layer, and the laminating co-curing process ensures the interlayer bonding strength, so that the whole film does not crack and delaminate in the cold and hot cycle.

[0055] 4. The present application realizes firm pasting, easy tearing and no residue through the intelligent adhesion layer, and improves the use experience. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 is a preparation process flow chart of a stove oil separation film.

[0057] Figure 2 is a schematic diagram of the oil separation film of Example 1.

[0058] Figure 3 is a thermal imaging diagram of the back surface equilibrium temperature of the oil separation film finally prepared in Examples 1-4 and Comparative Examples 1-3 under a 250°C heat source.

[0059] Figure 4 is a comparison diagram of the elongation at break retention rate and tensile strength retention rate of the oil separation film finally prepared in Examples 1-4 and Comparative Examples 1-3.

[0060] Figure 5 is a comparison diagram of the thermal conductivity and back surface equilibrium temperature data of the oil separation film finally prepared in Examples 1-4 and Comparative Examples 1-3 under a 250°C heat source. DETAILED DESCRIPTION

[0061] The following examples further explain and illustrate the technical solutions of the present application. It is particularly pointed out that each specific embodiment is a specific embodiment and explanation of the technical solutions, and should not be regarded as a limitation on the protection scope of the present application. Those skilled in the art still have the right to modify the technical solutions of these examples, to equivalently replace part or all of the technical features, and these modifications or replacements do not change the essence of the corresponding technical solutions, and do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions described in the present application.

[0062] The present application proposes a stove oil separation film and a preparation method thereof, which adopts a four-layer gradient heat management design: the first layer is a working surface layer, PEI is used as the base resin, modified nano-boron nitride and nano-cerium oxide fillers are dispersed, and antioxidants are added to enhance the high-temperature resistance and anti-aging performance; the second layer is a main heat insulation layer, which uses silicone resin as the base, and hollow glass microbeads and silica powder are added to improve the heat insulation strength; the third layer is a flexible buffer layer, which uses a silicone elastomer containing a foaming agent to form a microporous structure; the fourth layer is a smart adhesion layer, which uses silicone pressure-sensitive adhesive and incorporates modified thermal expansion microspheres to automatically reduce adhesion at high temperatures; each layer is first formed separately, and then laminated and co-cured at low temperature to be integrated. As shown in the accompanying drawings, a preparation method of a stove oil separation film is provided, and the detailed technical solutions are as follows: Figure 1

[0063] 1. Raw material preparation and pretreatment

[0064] ​Surface modification: nano boron nitride and nano cerium oxide are modified. The reason is that the specific surface area of nanoparticles is large, the surface energy is high, and the nanoparticles are easy to agglomerate. The untreated nano filler cannot be uniformly dispersed in the organic polymer matrix, which will form stress defects and damage the material performance. Silane coupling agent can build a solid bridge between inorganic filler and organic resin through grafting, and improve the compatibility and interfacial bonding force. The thermal expansion microspheres are selected to have an initial expansion temperature above 90°C and an optimal expansion temperature around 120°C. This is because the temperature of the surrounding countertop is usually between 50°C and 80°C, which is much lower than the trigger temperature of the microspheres. Therefore, the heat of normal cooking is completely insufficient to activate the microspheres, and the adhesion remains stable, and the film will never fall off by itself. The thermal expansion microspheres are modified with KH901 to improve their heat resistance and solvent resistance in the organic silicone adhesive.

[0065] Work surface layer preparation: PEI is used as the base resin, and modified nano boron nitride and nano cerium oxide fillers are dispersed, and antioxidants are added to enhance the high temperature resistance and aging resistance. PEI resin can form a continuous phase with high temperature resistance. N-methyl pyrrolidone dissolves PEI to adjust the viscosity. The modified composite filler plays a role in enhancing heat conduction and anti-aging. Antioxidants play a synergistic antioxidant role. BYK-163 prevents nanoparticles from re-agglomerating and settling through steric hindrance or electrostatic repulsion. The work surface layer is prepared and imprinted simultaneously with UV irradiation. The surface resin is rapidly and preliminarily cured at the same time as imprinting, accurately replicating and fixing the micro-nano structure, and forming a work surface layer with super oil-repellent potential.

[0066] Main heat insulation layer preparation: organic silicone resin is used as the base, and hollow glass microspheres, silica powder, and BYK-410 are added. The hollow glass microspheres and silica powder play a synergistic heat insulation role. BYK-410 forms a three-dimensional network structure in the slurry, greatly increasing the viscosity at low shear rates, effectively preventing the settling of fillers with high density such as hollow glass microspheres, and ensuring uniformity during coating. The main heat insulation layer is prepared. This step aims to prepare an intermediate layer with excellent heat insulation performance and certain mechanical strength. The decomposition of the foaming agent occurs at 130-150°C, forming a uniform and closed microcellular foam structure. The silicone resin is completely cross-linked and cured at 180-200°C, forming a final stable foam.

[0067] Flexible cushion layer preparation: silicone elastomer containing a foaming agent is used to form a microcellular structure. Its main role is to absorb the stress between the countertop and the film caused by thermal expansion and contraction, prevent the film layer from warping or falling off, and improve the comfort of the touch. At 150-170°C, azodicarbonamide rapidly decomposes to produce nitrogen. Since the silicone rubber has been preliminarily cross-linked, the gas is encapsulated to form a uniform closed-cell foam structure. At 180-200°C, the silicone rubber completes the cross-linking reaction, and the foam structure is completely set.

[0068] Smart Adhesion Layer Preparation: Silicone pressure sensitive adhesive is used and modified thermal expansion microspheres are incorporated. Temperature resistant silicone pressure sensitive adhesive is used, which can still maintain adhesion and subsequent tearability at high temperature. Modified thermal expansion microspheres provide sufficient adhesion at room temperature.

[0069] Plasma Treatment: The surfaces of the main insulation layer film and the flexible buffer layer film prepared above that need to be bonded are subjected to plasma treatment. This step is to ensure that the interfaces of the layers are clean, in preparation for high-quality lamination. High-energy particles in the plasma bombard the surface of the material, etching away the weak boundary layer and introducing active groups such as hydroxyl and carboxyl groups on the surface, greatly improving the wettability and reactivity of the surface and enhancing the interlayer bonding force, without the need for additional adhesives.

[0070] 2. Oil Barrier Film Preparation

[0071] Multi-layer Lamination and Curing: The working surface layer film prepared above, the main insulation layer film and the flexible buffer layer film subjected to plasma treatment are laminated by aligning and passing through the lamination rollers, followed by UV irradiation and then heat curing, to obtain a semi-finished composite film. The purpose of this step is to integrate the three functional layers, achieve firm interfacial bonding of the three functional layers, and ensure that the functions of the layers are not impaired, so that the performance is in the best state.

[0072] UV irradiation before heat curing is used because after plasma treatment, the interfaces of the layers are rich in active free radicals and polar groups. The irradiation of UV light can quickly initiate the crosslinking reaction of the polymers at the interface, forming a very thin but firm crosslinked network at the interlayer interface within a few seconds. This network, like countless tiny "anchor points", preliminarily but firmly fixes the three functional layers together, preventing their relative displacement during subsequent heat pressing. Radiation curing occurs at the very surface of the interface and does not significantly heat or soften the entire material bulk. The micro-nano structure of the working surface layer and the porous structure of the insulation layer are well preserved and will not be damaged by heat and pressure. Moreover, the air remaining between the layers can be left in the limited un-cured area. When subsequent gradient heat pressing is performed, these air has more sufficient paths and time to be slowly squeezed out, reducing the risk of air bubbles and delamination.

[0073] Preparation of Oil Barrier Film: The flexible buffer layer of the semi-finished composite film prepared above is laminated with the smart adhesion layer film at room temperature by light pressing, winding, and aging to obtain an oil barrier film. This step combines the smart adhesion layer with the functional film body prepared above and completes the preparation of the oil barrier film.

[0074] Example 1

[0075] A method for preparing a cooktop oil barrier film is as follows:

[0076] Table 1: Main Raw Materials

[0077]

[0078] S1: raw material preparation and pretreatment.

[0079] S11: disperse nano-boron nitride and nano-cerium oxide in ethanol aqueous solution, ultrasonic dispersion, to obtain a suspension; add silane coupling agent KH-550 to the suspension, mechanical stirring, cooling to room temperature, centrifugal separation, washing, vacuum drying, grinding, to obtain surface modified nano-composite filler; add thermal expansion microspheres to ethanol aqueous solution, stirring, to obtain a suspension; add silane coupling agent KH-901 to the suspension, then heat to 55℃ and mechanical stirring, centrifugal separation, washing, vacuum drying, to obtain modified thermal expansion microspheres. Wherein, the volume ratio of ethanol to water is 4:1; the mass ratio of nano-boron nitride and nano-cerium oxide to the volume of ethanol aqueous solution is 1:35; the ultrasonic dispersion parameter setting is: power 700W, open 2s / close 1s, time length 45min; the mass of KH-550 is 2.3% of the total weight of nano-filler; the mechanical stirring parameter setting is: 400rpm, temperature 70℃, time length 5h; the washing uses anhydrous ethanol and deionized water alternately; the vacuum drying parameter setting is: vacuum degree-0.085MPa, temperature 80℃, time length 24h.

[0080] S12: add PEI powder to N-methyl pyrrolidone, stirring at 65℃ until completely dissolved, to obtain a PEI solution; mix the surface modified nano-composite filler prepared in S11, antioxidant 1010, dispersant BYK-163 and N-methyl pyrrolidone, to obtain a premix slurry; add the premix slurry to the PEI solution, stirring, grinding, defoaming, to obtain a working surface layer slurry. Wherein, the premix parameter setting is: rotation speed 10000rpm, time length 15min; the defoaming parameter setting is: vacuum degree-0.095MPa, time length 25min; based on 100 parts of PEI resin, the proportion of each component is: N-methyl pyrrolidone 400 parts, surface modified nano-composite filler 20 parts, antioxidant 1010 1.8 parts, BYK-163 2 parts.

[0081] S13: mix silicone resin and solvent N-methyl pyrrolidone uniformly, add rheological aid BYK-410, low speed stirring and add hollow glass microspheres and silica powder, until uniform then vacuum defoaming, to obtain a main heat insulation layer slurry. Wherein, based on 100 parts of silicone resin, solvent N-methyl pyrrolidone 200 parts, hollow glass microspheres 40 parts, silica powder 15 parts, BYK-410 1.3 parts.

[0082] S14: Mix the two-component liquid silicone rubber with the foaming agent azodicarbonamide, stir until uniform, to obtain the flexible buffer layer compound. Among them, take 100 parts of two-component liquid silicone rubber as the base, and 3.5 parts of foaming agent azodicarbonamide.

[0083] S15: Add the modified thermal expansion microspheres to the high-temperature-resistant silicone pressure-sensitive adhesive, stir until uniform, to obtain the smart adhesion layer glue. Among them, take 100 parts of high-temperature-resistant silicone pressure-sensitive adhesive as the base, and 10 parts of modified thermal expansion microspheres.

[0084] S2: Preliminary preparation and curing.

[0085] S21: Apply the working surface layer paste prepared in S12 to the PET release film, then dry to obtain a semi-dry working surface layer; imprint the microstructure on the semi-dry working surface layer, and then irradiate with UV, followed by heat curing, cooling to room temperature, and winding to obtain a working surface layer film. Among them, the drying parameters are set as follows: temperature 85°C, time 1.5 min; the microstructure is a reverse micro-papilla array structure; the UV irradiation parameters are set as follows: wavelength 365 nm, intensity 1500 mW / cm 2 , exposure time 1 s; the heat curing parameters are set as follows: temperature 210°C, time 15 min.

[0086] S22: Apply the main heat insulation layer paste prepared in S13 to the polyimide film, then perform stepwise temperature rising curing, cool, and wind to obtain a main heat insulation layer film. The first zone temperature is 90°C, the time is 8 min, the second zone temperature is 140°C, the time is 8 min, and the third zone temperature is 190°C, the time is 23 min.

[0087] S23: Apply the flexible buffer layer compound prepared in S14 to the PET release film, then perform stepwise temperature rising curing, cool, and wind to obtain a flexible buffer layer film. Among them, the stepwise temperature rising parameters are set as follows: the first zone temperature is 90°C, the time is 8 min, the second zone temperature is 160°C, the time is 4 min, and the third zone temperature is 190°C, the time is 8 min.

[0088] S24: Apply the smart adhesion layer glue prepared in S15 to the PET release film treated by corona, then perform low-temperature curing, cool, wind, and aging to obtain a smart adhesion layer film. Among them, the low-temperature curing parameters are set as follows: temperature 70°C, time 8 min, and the aging parameters are set as follows: temperature 25°C, time 24 h.

[0089] S3: Processing and preparation.

[0090] S31: The flexible buffer layer film prepared in S22 is peeled off from the PET release film, and the surface to be bonded of the main thermal barrier layer film prepared in S21 is subjected to plasma treatment. The plasma treatment parameters are set as follows: power, 1000 W; treatment gas, air; and treatment speed, 3 m / min.

[0091] S32: The working surface layer film prepared in S21 is peeled off from the PET release film, and the main thermal barrier layer film and the flexible buffer layer film subjected to plasma treatment in S31 are laminated by alignment and lamination rollers, and then subjected to UV irradiation to obtain a pre-cured composite film. The pre-cured composite film is subjected to stepwise heating by a hot press and then cooled by a cooling roller to obtain a semi-finished composite film. The lamination pressure is set as follows: 1 N / cm 2 ; the UV irradiation parameters are set as follows: wavelength, 395 nm; intensity, 750 mW / cm 2 ; and exposure time, 7 s; and the hot press parameters are set as follows: roll gap 1 temperature, 90°C; linear pressure, 15 N / cm; residence time, 15 s; roll gap 2 temperature, 130°C; linear pressure, 40 N / cm; residence time, 30 s; and roll gap 3 temperature, 170°C; linear pressure, 25 N / cm; residence time, 15 s.

[0092] S33: The flexible buffer layer of the semi-finished composite film prepared in S32 is lightly pressed and laminated with the smart adhesive layer film at room temperature, wound, and aged to obtain an oil barrier film. The light pressing pressure parameter is set as follows: 3 N / cm. Figure 2 The schematic diagram of Example 1.

[0093] Example 2

[0094] Referring to the composition and preparation process of Example 1, the difference lies in that:

[0095] In S11 of the preparation process, the mass ratio of the nano boron nitride and the nano cerium oxide to the volume of the ethanol aqueous solution is 1:20, and the mass of KH-550 is 1.5% of the total weight of the nano filler. Other components are the same.

[0096] In S11 of the preparation process, the ultrasonic dispersion parameters are set as follows: power, 600 W; on 2 s / off 1 s; time, 30 min; and the mechanical stirring parameters are set as follows: speed, 300 rpm; temperature, 65°C; and time, 4 h. Other steps are the same.

[0097] In S12 of the preparation process, N-methyl pyrrolidone is 350-450 parts, the surface-modified nano composite filler is 15 parts, the antioxidant 1010 is 0.5 parts, and the BYK-163 is 1 part. Other components are the same.

[0098] In S13 of the preparation process, the solvent N-methyl pyrrolidone is 150 parts, the hollow glass microbeads are 30 parts, the silica powder is 10 parts, and the BYK-410 is 0.5 parts. Other components are the same.

[0099] The foaming agent azodicarbonamide in S14 of the preparation process is 2 parts, and the other components are the same.

[0100] The modified thermal expansion microspheres in S15 of the preparation process are 5 parts, and the other components are the same.

[0101] In S21 of the preparation process, the drying parameters are temperature 80℃ and time length 1min; the heat curing parameters are set as temperature 200℃ and time length 10min, and the other steps are the same.

[0102] In S22 of the preparation process, the stepwise temperature rising parameters are set as temperature 80℃ for 5min in the first zone, temperature 130℃ for 5min in the second zone, and temperature 180℃ for 15min in the third zone, and the other steps are the same.

[0103] In S23 of the preparation process, the stepwise temperature rising parameters are set as temperature 80℃ for 5min in the first zone, temperature 150℃ for 3min in the second zone, and temperature 180℃ for 5min in the third zone, and the other steps are the same.

[0104] In S24 of the preparation process, the low-temperature curing parameters are set as temperature 60℃ and time length 5min.

[0105] In S31 of the preparation process, the plasma treatment power is 500W, and the treatment speed is 1m / min, and the other steps are the same.

[0106] In S32 of the preparation process, the UV irradiation intensity is 500mW / cm 2 , the exposure time is 3s; the hot press parameters are set as roll gap 1 temperature 80℃, linear pressure 10N / cm, residence time 10s, roll gap 2 temperature 120℃, linear pressure 30N / cm, residence time 20s, roll gap 3 temperature 160℃, linear pressure 20N / cm, residence time 10s, and the other steps are the same.

[0107] Example 3

[0108] Referring to the composition and preparation process of Example 1, the difference is that:

[0109] In S11 of the preparation process, the mass ratio of nano boron nitride and nano cerium oxide to the volume of ethanol aqueous solution is 1:50, the mass of KH-550 is 3.0% of the total weight of nano filler, and the other components are the same.

[0110] In S11 of the preparation process, the ultrasonic dispersion parameters are set as power 800W, on 2s / off 1s, time length 60min, and the mechanical stirring parameters are set as 500rpm, temperature 75℃, and time length 6h, and the other steps are the same.

[0111] The preparation process of S12 is as follows: 450 parts of N-methyl pyrrolidone, 25 parts of surface modified nanocomposite filler, 3 parts of antioxidant 1010, 3 parts of BYK-163, and the same as other components.

[0112] The preparation process of S13 is as follows: 250 parts of N-methyl pyrrolidone as solvent, 30-50 parts of hollow glass microbeads, 20 parts of silica powder, 2 parts of BYK-410, and the same as other components.

[0113] The preparation process of S14 is as follows: 5 parts of azodicarbonamide as foaming agent, and the same as other components.

[0114] The preparation process of S15 is as follows: 15 parts of modified thermal expansion microspheres, and the same as other components.

[0115] The preparation process of S21 is as follows: drying parameters: temperature 90℃, time 2min; heat curing parameters: temperature 220℃, time 20min, and the same as other steps.

[0116] The preparation process of S22 is as follows: stepwise temperature rising parameters: first zone temperature 100℃, time 10min; second zone temperature 150℃, time 10min; third zone temperature 200℃, time 30min, and the same as other steps.

[0117] The preparation process of S23 is as follows: stepwise temperature rising parameters: first zone temperature 100℃, time 10min; second zone temperature 170℃, time 5min; third zone temperature 200℃, time 10min, and the same as other steps.

[0118] The preparation process of S24 is as follows: low temperature curing parameters: temperature 80℃, time 10min.

[0119] The preparation process of S31 is as follows: plasma treatment power 1500W, treatment speed 5m / min, and the same as other steps.

[0120] The preparation process of S32 is as follows: UV irradiation intensity 1000mW / cm 2 , exposure time 10s; hot press parameters: roll gap 1 temperature 100℃, linear pressure 20N / cm, residence time 20s; roll gap 2 temperature 140℃, linear pressure 50N / cm, residence time 40s; roll gap 3 temperature 180℃, linear pressure 30N / cm, residence time 20s, and the same as other steps.

[0121] Example 4

[0122] Referring to the composition and preparation process of Example 1, the difference is that:

[0123] The mass ratio of nano-boron nitride and nano-cerium oxide to the volume of ethanol aqueous solution in S11 of the preparation process is 1:40, the mass of KH-550 is 1.9% of the total weight of the nano-filler, and the other components are the same.

[0124] In S11 of the preparation process, the ultrasonic dispersion parameters are set as follows: power 650W, on 2s / off 1s, time length 50min, and the mechanical stirring parameters are set as follows: 450rpm, temperature 68℃, time length 5.5h, and the other steps are the same.

[0125] In S12 of the preparation process, N-methyl pyrrolidone is 420 parts, surface-modified nano-composite filler is 23 parts, antioxidant 1010 is 2.5 parts, BYK-163 is 1.2 parts, and the other components are the same.

[0126] In S13 of the preparation process, the solvent N-methyl pyrrolidone is 170 parts, hollow glass microbeads are 35 parts, silicon dioxide powder is 18 parts, and BYK-410 is 0.9 parts, and the other components are the same.

[0127] In S14 of the preparation process, the foaming agent azodicarbonamide is 4 parts, and the other components are the same.

[0128] In S15 of the preparation process, the modified thermal expansion microspheres are 13 parts, and the other components are the same.

[0129] In S21 of the preparation process, the drying parameters are set as follows: temperature 88℃, time length 1.8min, and the heat curing parameters are set as follows: temperature 215℃, time length 13min, and the other steps are the same.

[0130] In S22 of the preparation process, the stepwise temperature rising parameters are set as follows: first zone temperature 82℃, time length 6min, second zone temperature 133℃, time length 9min, third zone temperature 197℃, time length 25min, and the other steps are the same.

[0131] In S23 of the preparation process, the stepwise temperature rising parameters are set as follows: first zone temperature 87℃, time length 9min, second zone temperature 152℃, time length 4.5min, third zone temperature 196℃, time length 6min, and the other steps are the same.

[0132] In S24 of the preparation process, the low-temperature curing parameters are set as follows: temperature 62℃, time length 9min.

[0133] In S31 of the preparation process, the plasma treatment power is 1300W, and the treatment speed is 1.5m / min, and the other steps are the same.

[0134] In S32 of the preparation process, the UV irradiation intensity is 600mW / cm 2Exposure time 4s; hot press parameters: gap 1 temperature 85℃, linear pressure 12N / cm, residence time 13s, gap 2 temperature 122℃, linear pressure 33N / cm, residence time 24s, gap 3 temperature 165℃, linear pressure 28N / cm, residence time 18s, other steps are the same.

[0135] Comparative Example 1

[0136] Referring to the composition and preparation process of Example 1, the difference is that:

[0137] In S3 of the preparation process, a single-layer structure is used: 100 parts of polyimide film, single-sided coating of conventional organic silicon pressure-sensitive adhesive, and other steps are the same.

[0138] Comparative Example 2

[0139] Referring to the composition and preparation process of Example 1, the difference is that:

[0140] In S2 of the preparation process, PTFE is used for working surface coating, and other steps are the same.

[0141] Comparative Example 3

[0142] Referring to the composition and preparation process of Example 1, the difference is that:

[0143] In S2 of the preparation process, the preparation of the four films is deleted, and the slurry of the working surface layer, the main thermal insulation layer, the flexible buffer layer, and the intelligent adhesion layer is coated in turn, and all processes are completed at one time in a high-temperature oven, and the temperature is raised in steps: the first zone temperature is 90℃, the time is 8min; the second zone temperature is 180℃, the time is 20min, the third zone temperature is 210℃, the time is 5min; other steps are the same.

[0144] In combination with Examples 1-4 and Comparative Examples 1-3, the final prepared oil separation film is sampled, and the initial state and high-temperature yellowing index of the sample after aging are tested. The aging condition is placed in a 230℃ hot air aging oven for 168h, and the reference standard is ASTM E313 "Standard Practice for Computing the Colors-Some Colors Indices from Instrumentally Measured Color Coordinates".

[0145] In combination with Examples 1-4 and Comparative Examples 1-3, the final prepared oil separation film is sampled, and the tensile strength and elongation at break of the sample before and after aging are tested, and the reference standard is GB / T 1040.3-2022 "Plastics-Determination of tensile properties-Part 3: Test conditions for films and sheets".

[0146] In combination with Examples 1-4 and Comparative Examples 1-3, the final prepared oil separation film is sampled, and the thermal conductivity is tested, and the reference standard is ASTM D5470 "Test Method for Thermal Transmission Properties of Thin Thermally Insulating Materials".

[0147] In summary, Examples 1-4 and Comparative Examples 1-3, the final prepared oil barrier films were sampled and tested for backside equilibrium temperature under a heat source of 250°C by covering the sample on a hot plate set at 250°C and measuring the surface temperature of the other side of the sample when it reached equilibrium using a thermal imager.

[0148] In summary, Examples 1-4 and Comparative Examples 1-3, the final prepared oil barrier films were sampled and tested for adhesion by reference to the standard ASTM D3654 “Test Method for Pressure-Sensitive Tape Council Adhesion”.

[0149] In summary, Examples 1-4 and Comparative Examples 1-3, the final prepared oil barrier films were sampled and tested for peel strength by reference to the standard ASTM D903 “Test Method for Resistance of Adhesive Bonds to Shear or Peel”.

[0150] The specific test results are shown in Tables 2, 3, 4, Figure 3 , Figure 4 , Figure 5

[0151] Table 2 Comparison of mechanical properties and yellowing resistance after high temperature aging of Examples 1-4 and Comparative Examples 1-3:

[0152]

[0153] Table 3 Comparison of thermal insulation and adhesion properties of Examples 1-4 and Comparative Examples 1-3:

[0154]

[0155] Table 4 Process and structural integrity evaluation table of Examples 1-4 and Comparative Examples 1-3:

[0156]

[0157] ​From the above comparison results, the comprehensive performance of Example 1 is the best, and the best performance balance is achieved through high-performance material selection, four-layer functional gradient design, KH-550 modification, plasma treatment, and precise process control, which indicates that Example 1 successfully solves the problems of the cooking table oil separation film material in high-temperature long-term use stability and heat insulation protection performance; the comprehensive performance of Example 2 to Example 4 is slightly lower than that of Example 1 but still maintains a high level, which indicates that excellent extraction effect is achieved within a large range of parameter variation; the single polyimide film of Comparative Example 1 is heat-resistant, but has poor heat insulation, high hardness, poor flexibility, and cannot be attached to the table surface, and the durability and anti-aging of the conventional silicone pressure-sensitive adhesive under long-term high temperature are far inferior to the "intelligent adhesion layer" designed in the present application; the flexible buffer layer of Comparative Example 2 is directly pasted with the cooking table, and the surface is not designed for adhesion, so the initial adhesion and durability will be poor, and it will be easily softened and failed under high temperature; Comparative Example 3 puts four materials, functions, and curing conditions together for one-time high-temperature forming, which results in poor mechanical properties, heat insulation performance, and adhesion performance.

[0158] In summary, through the above examples and comparative examples, it can be clearly seen that the cooking table oil separation film provided by the present application is significantly better than the traditional scheme in terms of anti-yellowing, heat insulation performance, and adhesion performance, which is due to the four-layer gradient heat management design, thereby solving the problem of yellowing, embrittlement, or loss of elasticity of the polymer material of the oil separation film in a high-temperature environment.

Claims

1. A cooking stove oil isolation film, characterized in that: the cooking stove oil isolation film is a multi-layer composite structure, sequentially comprising from top to bottom: a working surface layer for contacting oil stains, a main heat insulation layer for insulating heat, a flexible buffer layer for absorbing stress, and a smart adhesion layer for adhering to the cooking stove; the working surface layer is based on polyetherimide as a matrix resin, and disperses modified nano boron nitride and nano cerium oxide fillers; the main heat insulation layer uses silicone resin as a matrix and adds hollow glass microbeads and silica powder; the flexible buffer layer forms a microporous structure using a silicone elastomer containing a blowing agent; the smart adhesion layer uses silicone pressure-sensitive adhesive and incorporates modified thermal expansion microspheres; each layer is first formed separately, and then laminated and co-cured at low temperature to be integrated; the working surface layer is prepared by coating the working surface layer slurry on a PET release film; the composition of the working surface layer slurry is as follows: based on 100 parts of PEI resin, the proportions of other materials are: N-methyl pyrrolidone 350-450 parts, surface modified nano composite filler 15-25 parts, antioxidant 1010 0.5-3 parts, and BYK-163 1-3 parts; the surface modified nano composite filler is composed of modified nano boron nitride and modified nano cerium oxide at a mass ratio of 1:1; the main heat insulation layer is prepared by coating the main heat insulation layer slurry on a polyimide film; the composition of the main heat insulation layer slurry is as follows: based on 100 parts of silicone resin as a matrix, the proportions of other materials are: solvent N-methyl pyrrolidone 150-250 parts, hollow glass microbeads 30-50 parts, silica powder 10-20 parts, and BYK-410 0.5-2 parts; the flexible buffer layer is prepared by coating the flexible buffer layer compound on a PET release film, and the composition of the flexible buffer layer compound is as follows: based on 100 parts of two-component liquid silicone rubber as a base, a blowing agent azodicarbonamide is 2-5 parts; the two-component liquid silicone rubber comprises A component and B component, which are mixed at a mass ratio of 1:1; the A component comprises base glue, platinum catalyst, and filler, and the B component comprises base glue, crosslinking agent, inhibitor, and filler; the smart adhesion layer is prepared by coating the smart adhesion layer glue on a PET release film treated by corona discharge; the composition of the smart adhesion layer glue is as follows: based on 100 parts of high-temperature-resistant silicone pressure-sensitive adhesive, modified thermal expansion microspheres are 5-15 parts. comprising the following steps:

2. The method for preparing a stovetop grease barrier according to claim 1, characterized in that, S1: raw material preparation and pretreatment; S11: dispersing nano boron nitride and nano cerium oxide in an ethanol aqueous solution, ultrasonic dispersion to obtain a suspension; adding silane coupling agent KH-550 to the suspension, mechanical stirring, cooling to room temperature, centrifugal separation, washing, vacuum drying, and grinding to obtain surface modified nano composite filler; adding thermal expansion microspheres to an ethanol aqueous solution, stirring to obtain a suspension; adding silane coupling agent KH-901 to the suspension, then heating to 55℃ and mechanical stirring, centrifugal separation, washing, and vacuum drying to obtain modified thermal expansion microspheres; ​ S12: PEI powder is added into N-methyl pyrrolidone and stirred at 65℃ until completely dissolved to obtain a PEI solution; surface modified nano-composite filler prepared in S11, antioxidant 1010 and dispersant BYK-163 are pre-mixed with N-methyl pyrrolidone to obtain a pre-mixed slurry; the pre-mixed slurry is added into the PEI solution, stirred, ground and defoamed to obtain a working surface layer slurry; S13: silicone resin is uniformly mixed with solvent N-methyl pyrrolidone, rheological additive BYK-410 is added, stirred, and hollow glass microspheres and silica powder are then added, followed by vacuum defoaming to obtain a main thermal insulation layer slurry; S14: two-component liquid silicone rubber is mixed with foaming agent azodicarbonamide and stirred to obtain a flexible buffer layer compound; S15: modified thermal expansion microspheres are added into high-temperature-resistant silicone pressure-sensitive adhesive and stirred to obtain an intelligent adhesion layer glue; S2: preliminary preparation and curing; S21: the working surface layer slurry prepared in S12 is coated onto a PET release film, then dried to obtain a semi-dry working surface layer; a microstructure is imprinted on the semi-dry working surface layer, and then UV irradiation is performed, followed by thermal curing, cooling to room temperature and winding to obtain a working surface layer film; S22: the main thermal insulation layer slurry prepared in S13 is coated onto a polyimide film, then subjected to stepwise temperature rising curing, cooled and wound to obtain a main thermal insulation layer film; S23: the flexible buffer layer compound prepared in S14 is coated onto a PET release film, then subjected to stepwise temperature rising curing, cooled and wound to obtain a flexible buffer layer film; S24: the intelligent adhesion layer glue prepared in S15 is coated onto a PET release film subjected to corona treatment, then cured, cooled, wound and aged to obtain an intelligent adhesion layer film; S3: processing and preparation; S31: the flexible buffer layer film prepared in S22 is peeled off from the PET release film, and the main thermal insulation layer film prepared in S21 is subjected to plasma treatment on the surface to be bonded; S32: the working surface layer film prepared in S21 is peeled off from the PET release film, and the main thermal insulation layer film and the flexible buffer layer film subjected to plasma treatment in S31 are superimposed by a register superimposition roller, and then subjected to UV irradiation to obtain a pre-cured composite film; the pre-cured composite film is subjected to stepwise temperature rising by a heat press, and finally cooled by a cooling roller, aged to obtain a semi-finished product composite film; S33: the flexible buffer layer of the semi-finished product composite film prepared in S32 is lightly pressed with the intelligent adhesion layer film at room temperature, wound and aged to obtain an oil barrier film.

3. The preparation method of the cooktop oil barrier film according to claim 2, characterized in that: the ethanol aqueous solution in S11, wherein the volume ratio of ethanol to water is 4:1; the nano boron nitride and nano cerium oxide in S11, wherein the mass ratio of the two to the volume of the ethanol aqueous solution is 1:20-1:50; the ultrasonic dispersion in S11, wherein the parameters are set as follows: power 600-800 W, on 2 s / off 1 s, time length 30-60 min; the KH-550 in S11, wherein the mass of KH-550 is 1.5-3.0% of the total weight of the nano filler; The mechanical stirring of S11 is set as 300-500 rpm, 65-75℃, and 4-6 h; The washing of S11 is set as 3 times of anhydrous ethanol and 3 times of deionized water; The vacuum drying of S11 is set as-0.085 MPa, 80℃, and 24 h.

4. The method of claim 2, wherein: The premixing of S12 is set as 10000 rpm and 15 min; The defoaming of S12 is set as-0.095 MPa and 25 min.

5. The method of claim 2, wherein: The drying of S21 is set as 80-90℃ and 1-2 min; The microstructure of S21 is reverse micro-lip array structure; UV irradiation as described in S21 with the following parameters: wavelength 365 nm, intensity 1500 mW / cm 2 , exposure time 1 s; The thermal curing of S21 is set as 200-220℃ and 10-20 min; The temperature-ladder of S22 is set as 80-100℃ for 5-10 min, 130-150℃ for 5-10 min, and 180-200℃ for 15-30 min; The temperature-ladder of S23 is set as 80-100℃ for 5-10 min, 150-170℃ for 3-5 min, and 180-200℃ for 5-10 min; The curing of S24 is set as 60-80℃ for 5-10 min, and the curing parameter is set as 25℃ for 24 h.

6. The method of claim 2, wherein: The plasma treatment of S31 is set as 500-1500 W, air as the treatment gas, and 1-5 m / min; S32 said superposition, whose pressure setting: 1 N / cm 2 ; S32 said UV irradiation, parameter setting: wavelength 395 nm, intensity 500-1000 mW / cm 2 , exposure time 3-10 s; The hot press of S32 is set as 80-100℃ for 10-20 s, 120-140℃ for 20-40 s, and 160-180℃ for 10-20 s.

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