A composite film containing a glass layer and a method for preparing and using the same

Abstract

The application relates to a composite film containing a glass layer and a preparation method and application thereof, and relates to the technical field of composite film preparation. The composite film containing the glass layer comprises a base film and a glass layer, the glass layer is obtained by coating a glass melt on the surface of the base film, and the base film comprises a polymer film or a surface-modified polymer film. The glass layer in the composite film is obtained by coating a continuous and homogeneous melt, and gaps or bubbles are fully removed in advance, so that the composite film containing the dense, continuous and well-adhesive glass layer can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite film preparation, in particular to a composite film containing a glass layer and a preparation method and application thereof. BACKGROUND

[0002] High-barrier films are mainly used for food packaging, medicine packaging, electronic device packaging, to protect food, medicine or electronic device from water vapor, oxygen and other external environmental erosion. Materials that can achieve high barrier capability generally have a dense atomic structure, and at present high-barrier films generally rely on dense inorganic layers. For metal materials, although the atomic arrangement in the metal crystal is tight, which makes it have excellent barrier performance, but because it is conductive and opaque, its application occasions are greatly limited.

[0003] With the development of material science, the heat resistance temperature of some organic polymer materials has exceeded the processing temperature of inorganic glass, which provides the possibility for processing glass layers on organic polymer substrates.

[0004] Glass is an important high-barrier packaging material. Glass with a thickness of less than 1 mm is generally called ultra-thin glass, and some enterprises have already produced ultra-thin glass products with a thickness of only a few tens of microns. Ultra-thin glass is generally manufactured by processes such as float method, overflow down-draw method, and slot draw method, and its production equipment is more expensive, the process is more complex, and the technical difficulty is higher than that of ordinary flat glass. Taking float glass as an example, it needs to be drawn by a draw edge machine on a molten tin bath to gradually thin the glass melt, and currently the industry can produce ultra-thin float glass with a thickness of 120 μm. On this basis, it still needs to go through subsequent processing steps such as cutting, thinning, ion implantation, and crystal growth, before obtaining the final ultra-thin glass product. This method has problems such as high energy consumption, low production efficiency, high cost, and chemical pollution. Ultra-thin glass has improved brittle resistance compared to ordinary thick glass, but it is still more fragile than polymer materials. Once the ultra-thin glass cracks, it will rapidly expand under stress, leading to glass breakage and failure, and a sharp decrease in its barrier packaging performance. Therefore, how to overcome the fragility of ultra-thin glass is a key problem that needs to be solved for its use as a high-barrier packaging material.

[0005] Currently, the dense inorganic barrier layer is mainly prepared by chemical vapor deposition method. Among them, plasma enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD) are two representative deposition techniques. The conventional CVD deposition temperature is 700-900℃, which is difficult to be used for heat-sensitive polymer substrates. PECVD uses plasma to ionize the reactants into active particles, so that the deposition can be realized at a lower temperature (usually 300-400℃). ALD technology realizes precise atomic level thickness control through surface self-limiting reaction, and can prepare ultra-thin inorganic layer with high density, high purity and high uniformity. However, PECVD and ALD equipment are expensive, the deposition rate is low, and the cost is high, which is not conducive to large-scale application. SUMMARY

[0006] In view of the above problems, the present application provides a composite film containing a glass layer, wherein the glass layer in the composite film is obtained by coating a continuous homogeneous melt, and by pre-removing voids or bubbles, a composite film containing a dense, continuous and well-adhered glass layer is obtained.

[0007] In order to achieve the above purpose, the present application provides a composite film containing a glass layer, comprising a substrate film and a glass layer, wherein the glass layer is obtained by coating a glass melt on the surface of the substrate film, and the substrate film comprises a polymer film or a surface-modified polymer film.

[0008] In the present technology, the inventors hope to utilize the excellent flexibility, film-forming property and relatively high heat resistance of some high-temperature-resistant polymer materials, and to prepare a dense inorganic glass layer on the surface thereof by coating a glass melt, so as to obtain a composite film with both flexibility and high barrier properties. Common high-temperature-resistant polymer materials include polyimide (PI), polybenzoxazole (PBO), polybenzimidazole (PBI), polybenzothiazole (PBT), polyoxadiazole (POXA), polyquinazolinedione (PQZO), polyquinoxaline (PQ), polyphenylquinoxaline (PPQ), etc. Unlike the traditional process of sintering enamel or glass enamel at high temperature (usually > 800℃) on a metal substrate, the heat-resistant temperature of an organic polymer substrate is usually not more than 600℃. Therefore, in order to prepare a glass coating on a polymer film, a glass formula with easy melting characteristics and a high-heat-resistant polymer are required to match the forming temperature of the glass with the heat-resistant temperature of the polymer substrate. Meanwhile, a reasonable coating structure and forming process need to be designed to obtain a dense, continuous and well-adhered glass coating under the premise of not damaging the polymer substrate at high temperature.

[0009] In the previous research, the inventors prepared a composite film by coating a glass slurry or glass powder on a polymer substrate and then high-temperature treatment, but this method has some problems:

[0010] (1) Glass slurry (suspension) itself is an unstable system, glass particles cannot form uniform dispersion in it, which leads to the difficulty in preparing a powder layer with uniform thickness.

[0011] (2) The powder particles in the glass slurry adsorb solvent molecules during preparation and storage due to their large specific surface area. The organic solvent cannot be completely removed during high-temperature treatment, which may cause carbonization and blackening, thereby damaging the optical properties of the film and the formation of a dense structure. Some solvents, such as water, may react with some components in the glass, and the powder cannot be fully glassified when heated again, resulting in the formation of crystals inside the glass, which makes the glass appear frosted and reduces the optical transparency.

[0012] (3) High-temperature-resistant polymers are generally insulators, and it is difficult for them to spread uniformly and densely on the surface of the substrate after being electrified, like metal plates, which makes it difficult to prepare a powder layer with uniform thickness.

[0013] (4) Glass powder undergoes volume shrinkage during high-temperature melting, which makes it difficult to obtain a completely dense glass layer and leads to poor barrier properties of the composite film.

[0014] (5) In order to obtain a continuous glass coating, the thickness of the powder layer needs to be increased, but thick powder layers are prone to cracking and peeling during drying, which requires multiple cycles of coating and sintering to repair and fill gaps, significantly prolonging the preparation time and causing additional thermal damage to the substrate.

[0015] (6) The self-leveling of glass melt is used to achieve uniform spreading, which has high requirements for the flowability of the glass melt. The glass components that can meet the requirements are very limited. Improving the flowability of the melt requires the introduction of alkali metal ions or the breaking of some glass network connections, which generally makes the glass less resistant to water and less chemically stable.

[0016] Therefore, the present inventors propose the following technical solutions:

[0017] (1) The glass is prepared into a continuous and homogeneous melt in advance, and a suspension (slurry) is not used, which avoids the instability of the glass slurry in the prior art and the difficulty in manufacturing a powder layer with uniform thickness. At the same time, since no solvent is used, there is no problem of adsorbing organic solvent molecules, carbonization and blackening, and solvent-induced crystallization.

[0018] (2) The gas and voids in the glass melt are removed before coating, which avoids the problem of voids between the powder or particles during high-temperature treatment in the prior art.

[0019] (3) The coating process by mechanical action makes the melt into a thin layer. In the coating process, the mechanical force of the die, scraper and other mechanical devices is used to realize the uniform spreading of the glass layer, and the thin layer forming process is worked, not only relying on the self-leveling of the melt to obtain a flat surface, reducing the dependence on low viscosity glass melt, so that higher viscosity, better stability and water resistance of glass components can be used.

[0020] (4) The glass needs a long time high temperature heat treatment to fully remove the void and obtain good fluidity, while the polymer only needs to meet the stress in the composite film after coating to room temperature to meet the use requirements, and the polymer does not need to accompany the glass to withstand the harsh high temperature environment, and the heat of the two should be distinguished. By making the glass melt and the polymer substrate heat respectively and at different temperatures, the manufacturing strategy of shortening the time of heating the glass and the substrate at the same time can greatly reduce the thermal damage of the polymer substrate during the forming process;

[0021] (5) The interface effect of the surface of the polymer substrate is used to make the glass layer forming follow the interface film forming mechanism, which is more conducive to obtaining a uniform thickness ultra-thin glass layer compared with the independent film forming mechanism.

[0022] In one embodiment, the surface modified polymer film includes a polymer film and a modified layer covering the surface of the polymer film, and the modified layer includes at least one of an infiltration layer with a surface energy close to that of the glass melt, a corrosion-resistant layer with strong bond energy, an adhesion layer with strong adhesion to the substrate, and a thermal insulation layer.

[0023] The above-mentioned modified layer can further improve the wettability and bonding force between the glass layer and the polymer film, and improve the corrosion resistance and heat resistance of the polymer film.

[0024] In one embodiment, the difference between the surface energy of the infiltration layer in the polymer film or the surface modified polymer film and the glass melt is ≤200 mJ m -2 .

[0025] In one embodiment, the strong bond energy is ≥300 kJ mol -1 .

[0026] In one embodiment, the strong adhesion force is ≥2 MPa.

[0027] In one embodiment, the thermal conductivity of the thermal insulation layer is less than 10 W m -1 K -1 .

[0028] In one embodiment, the raw material of the glass melt includes a fusible glass, and the maximum heat resistance temperature of the substrate film is ≥ the coating temperature of the glass melt.

[0029] By controlling the maximum heat resistance temperature, the excellent heat resistance of certain high-performance polymers is fully utilized to realize the direct forming of a glass layer on the surface thereof.

[0030] In one embodiment, the softening temperature of the fusible glass is ≤ 550℃, and the softening temperature corresponds to a fusible glass viscosity of 10 6.6 Pa s.

[0031] The application also provides a preparation method of the composite film, comprising the following steps: making the base film linear in the width direction at a predetermined temperature; heating the raw material of the glass melt to a temperature above the void removal temperature to remove the voids in the glass melt; coating the glass melt on the surface of the base film at a coating temperature; and performing heat treatment to obtain a composite film containing a glass layer.

[0032] The above preparation method can produce flexible high-barrier composite films at low cost, high efficiency, continuously and on a large scale, can promote the industrialization development of the polymer base glass lining technology, and can prepare new functional film materials with practical value. The above linear shape is the geometric shape of the polymer film or the surface-modified polymer film in the coating area relying on the mechanical structure, which is beneficial to realize the uniform thickness coating of the glass melt. It can be understood that in the actual production process, the step of making the base film linear in the width direction may not obtain a perfect linear shape due to factors such as temperature rise or insufficient mechanical processing precision, therefore, slight deformation caused by temperature change or mechanical processing is allowed, but the deformation should not significantly affect the uniformity of the coating layer thickness. The coating area includes but is not limited to a linear or approximately linear area.

[0033] In one embodiment, the normal temperature ≤ the predetermined temperature ≤ the process temperature, the process temperature is higher than the coating temperature, and the coating temperature is any temperature corresponding to the viscosity of the glass melt between 0.01 and 10 6.6 Pa s. 5 Pa s.

[0034] The above predetermined temperature refers to the temperature of each component in the coating system obtained after theoretical derivation and experimental optimization, including but not limited to the temperature of multiple components in the coating system, such as the temperature of the extruder (front, middle, and rear), the die head, the support roller, the flow guide plate, the doctor blade, the scraper, the annealing zone, and the like. That is, the temperature preset for the system to allow the equipment in the coating system to operate normally.

[0035] The process temperature refers to the highest working temperature of the heating element itself in the coating system, which is the higher temperature existing in the coating system compared with the predetermined temperature. There are usually multiple heating elements distributed in different components in the coating system, each heating element has its working temperature, and the process temperature specifically refers to the highest temperature value among all these heating elements. For example, a certain heating element provides heat as a heat source for a system component, and the temperature of the component surface is one of the predetermined temperatures, while the temperature of the heating element is the process temperature of the component. Since there are multiple heating elements in the system, and each heating element is usually not uniformly heated, the process temperature specifically refers to the highest temperature point of all heating elements in the entire system. This distinction between predetermined temperature and process temperature enables the temperature state of the system to be completely summarized, which helps to accurately describe the coating process.

[0036] In one embodiment, the method for preparing the composite film comprises the following steps:

[0037] Step (1) substrate film treatment:

[0038] The high-temperature-resistant polymer film or the high-temperature-resistant polymer film after surface modification treatment is tensioned and fixed using a film tensioning device or a roller, so that the surface profile of the film in the coating area is linear at least at a certain temperature between room temperature and process temperature in the width direction. The highest heat-resistant temperature of the high-temperature-resistant polymer film or the high-temperature-resistant polymer film after surface modification treatment is higher than the coating temperature of the glass melt.

[0039] To ensure that the linear surface profile during coating can be maintained, a support roller, a support plate or a support line can be used for support on the other side of the film. When a support roller or a support plate is used, a pre-designed deformation can be used to ensure the linear shape of the mechanical structure during operation.

[0040] The surface modification polymer film includes: modification to improve the wettability of the glass melt to the high-molecular polymer film, so that the film surface is covered with an inorganic layer with a surface energy similar to that of the glass melt; modification to improve the bonding force of the glass layer to the polymer film, so that the film surface is connected to an inorganic layer with strong bonding force to the glass; modification to prevent the polymer film from being corroded by the glass melt, covering a strong bond energy corrosion protection layer on the film surface; modification to prevent the polymer film from being damaged by high temperature of the glass melt, covering a heat insulation layer on the film surface.

[0041] Step (2) preparation of glass melt:

[0042] The fusible glass powder or particles are heated in a container to a temperature above the void temperature, and the voids and bubbles are fully removed to obtain a homogeneous and dense glass melt. The void temperature is the temperature at which the viscosity of the glass melt is 10 5Pa s) to the temperature corresponding to the glass viscosity of 10

[0043] Another alternative is to use the batch of the fusible glass directly instead of the fusible glass powder or particles; the batch is heated to the melting temperature and above, and the interstices in the powder or particles and the small molecules generated during the melting process are removed under the mechanical extrusion or stirring to directly obtain the glass melt without bubbles and pores. The melting temperature refers to the temperature required for the batch to complete the physical and chemical changes such as dehydration, decomposition, and combination, which is usually higher than the temperature used for coating.

[0044] The container includes an extruder or other device capable of providing a high-temperature function for holding the melt, such as a hot melt adhesive machine, a high-temperature metering pump, a crucible (with heating device), etc.

[0045] Step (3) glass melt coating:

[0046] The glass melt is coated on the linear or approximately linear surface area of the polymer film after tensioning and fixing; in order to ensure that the coating area can still maintain linear shape when subjected to the extrusion force or the gravity of the melt during coating, support can be provided on the other side of the film; during the coating process, the optimization design (pre-deformation, etc.) of the structure of the support roller, the coating die, the doctor blade, etc. is beneficial to obtaining a glass coating layer with uniform thickness.

[0047] Step (4) heat treatment:

[0048] The polymer film coated with the glass melt is subjected to heat treatment to obtain a composite film containing a glass layer. The heat treatment includes annealing, cooling, quenching, and laser treatment. The purpose of the annealing treatment is to eliminate the stress in the glass layer and / or the flexible base film, which is generally carried out in the temperature range between the strain point temperature (corresponding to the glass viscosity of 10 13.5 Pa s) to the glass transition temperature (corresponding to the glass viscosity of 10 12 Pa s). The heat treatment can also include quenching treatment to make the glass layer develop in the direction of tempered glass, thereby improving the surface hardness and scratch resistance of the glass layer. In addition, the heat treatment method of laser irradiation can be used to extend the flow time of the glass melt by irradiation, thereby obtaining a glass layer with lower surface roughness; the short-wavelength laser only acts on the surface of the glass, which can reduce the thermal damage to the polymer film at high temperature.

[0049] In one embodiment, the coating includes at least one of the following: engraving wheel coating, reverse coating, slot die coating, lip coating, doctor blade coating, blade coating, plate coating, liquid cavity doctor blade coating, rod coating, air doctor blade coating, micro-recess coating.

[0050] The heat treatment includes at least one of the following: annealing, cooling, quenching, and laser irradiation.

[0051] In one embodiment, the annealing temperature is the strain point temperature of the glass (10). 13.5 Pa s) to glass transition temperature (10 12 Any temperature between Pa and s.

[0052] The present invention also provides the application of the composite film in the preparation of functional films, wherein the functional film is a high-barrier film, an impact-resistant film, and / or a hardened film, and the functional film is used in packaging or encapsulation.

[0053] In one embodiment, the functional film includes at least one of food packaging film and pharmaceutical packaging film, and the encapsulation film includes at least one of flexible electronic device encapsulation film and integrated circuit encapsulation film.

[0054] The present invention also provides a film for packaging or encapsulation, including the composite film described above.

[0055] The present invention also provides a device packaging method, comprising the following steps: covering the upper surface and / or lower surface of the device with the thin film, providing a packaging wall around the device, connecting the packaging wall with the thin film on the upper surface and / or lower surface to form a sealed cavity, and encapsulating the device within the sealed cavity.

[0056] In one embodiment, the material of the encapsulation wall includes low-temperature sintered ceramic, and the connection between the encapsulation wall and the thin film on the upper and / or lower surfaces is achieved by sintering.

[0057] In one embodiment, the low-temperature sintered ceramic is sintered below 600°C.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] This invention discloses a composite film containing a glass layer, its preparation method, and its application. The glass layer in the composite film is obtained by continuous and homogeneous melt coating, with voids or bubbles being thoroughly eliminated beforehand, thereby obtaining a composite film containing a dense, continuous, and well-adhesive glass layer. This preparation method enables low-cost, high-efficiency, continuous, and large-scale manufacturing of flexible high-barrier composite films, promotes the industrialization of polymer-based glass-lined technology, and enables the preparation of novel functional thin film materials with practical value. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the forming part of the equipment in Example 1, wherein 1 is the die head, 2 is the glass layer, 3 is the support roller, 4 is the polyimide film, 5 is the polyimide film, 6 is the glass melt, and 7 is the die head lip.

[0061] Figure 2 Schematic representation of the structure of the forming part of the apparatus in Example 2, wherein 8 is the glass layer, 9 is the support roller, 10 is the (modified) polyimide film, 11 is the glass melt, 12 is the lip die;

[0062] Figure 3 Schematic representation of the structure of the forming part of the apparatus in Example 3, wherein 13 is the glass melt, 14 is the comma blade, 15 is the laser irradiation, 16 is the glass layer, 17 is the support roller, 18 is the (modified) polyimide film;

[0063] Figure 4 Schematic representation of the line blade coating in Example 4, wherein 19 is the glass melt, 20 is the support arm, 21 is the line blade, 22 is the glass layer, 23 is the (modified) polyimide film, 24 is the base;

[0064] Figure 5 Schematic representation of the doctor blade coating in Example 5, wherein 25 is the (modified) polyimide film, 26 is the tension control roller, 27 is the doctor blade, 28 is the glass layer, 29 is the support plate, 30 is the clamp, 31 is the grating ruler, 32 is the base;

[0065] Figure 6 Schematic representation of the liquid chamber blade (microgravure printing) coating in Example 6, wherein 33 is the melt chamber, 34 is the (modified) polyimide film, 35 is the drive roller, 36 is the glass layer, 37 is the coating roller. DETAILED DESCRIPTION

[0066] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. There is shown in the drawings, by way of illustration, a preferred embodiment of the application. It should be noted, however, that the application can be practiced in a variety of forms other than that which is specifically described. Rather, the embodiments are provided as illustrative of the disclosure of the application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0068] Source:

[0069] The reagents, materials, and apparatuses used in the present embodiments are commercially available unless otherwise specified; the test methods are conventional test methods in the art unless otherwise specified.

[0070] Example 1

[0071] The structure of the forming part of the apparatus is as followsFigure 1 as shown.

[0072] Step (1) Substrate film treatment: Take a colored polyimide film Upilex-S (25 μm thick) with a width of 125 mm. Tension the film with a take-up and pay-off roll, and set a support roll that can be heated on the back of the film to ensure that the extrusion coating pressure and the weight of the melt do not damage the straightness of the film coating area and enable the film to be preheated. The support roll and the lip portion of the slot die are pre-deformed to ensure that the lip portion of the die and the area adjacent thereto are straight at a predetermined temperature that is lower than the process temperature (the predetermined temperature is a set of temperatures between the normal temperature and the process temperature, and a person skilled in the art can select a temperature that enables normal operation of each device and component in the coating system). In particular, the film attached to the support roll is straight in the width direction to ensure that the glass melt can rely on this straight structure to form a glass layer with uniform thickness. The heat-resistant temperature of Upilex-S is higher than 500°C, which is the coating temperature.

[0073] Step (2) Preparation of glass melt: After the colored lead-free fusible glass (softening temperature 380°C, viscosity of the fusible glass at the softening temperature 10 6.6 Pa s) is made into a powder, it is added to a single-screw extruder, the end of the extruder is connected to a slot die, the width of the slot die discharge opening is 110 mm, and the temperature of the extruder is gradually increased in sections to reach 500°C at the end (which is higher than the devitrification temperature of the glass, which is the temperature at which the viscosity of the glass melt is 10 5 Pa s). As the screw of the single-screw extruder rotates, the material is automatically discharged backward to expel the gas in the gap, and a dense glass melt is obtained. At the position opposite the support roll and the lip portion of the slot die, both mechanical structures are straight.

[0074] Step (3) Glass melt coating: The obtained glass melt is extruded through the slot die to produce a melt film with uniform thickness, and the melt film is brought into contact with the substrate to perform coating (the coating temperature is a certain temperature in the temperature range corresponding to the viscosity of the glass melt between 0.01 and 10 6.6 Pa s, and in this embodiment, the coating temperature is 500°C), and the substrate film moves at a certain speed. The entire device is placed in a glass isolation cover and protected by nitrogen gas to prevent the influence of dust, water vapor, oxygen, and the like on the process during operation.

[0075] Step (4) Heat treatment: After coating, the composite film is annealed at the glass transition temperature of the glass (330°C) to eliminate the thermal stress in the glass, which corresponds to a glass viscosity of 10 12 Pa s. After annealing, the composite film is cooled to room temperature, wound, and packaged.

[0076] The water vapor permeability of the composite film is less than 10 -3 g m-2 day -1 , no heavy metal lead, can be used for food, drug packaging needs to be saved from light.

[0077] Example Two

[0078] The device forming site structure is shown in Figure 2 .

[0079] Step (1) substrate film treatment: select a polyimide film Upilex-S with a width of 125 mm, deposit a layer of SiO2 on the film surface by PECVD as a glass melt infiltration performance improvement layer for the substrate. The surface energy difference between the surface modified polymer and the glass melt is less than 200 mJ m -2 . Tension the film with a film tensioning device, and ensure the geometry of the support roller and the lip die at the coating temperature under the predetermined temperature conditions (a set of temperatures between the normal temperature and the process temperature, which can be selected by a person skilled in the art according to the conditions of each device and component in the coating system to ensure normal operation) below 600 ℃ process temperature to ensure that the forming area is linear.

[0080] Step (2) preparation of glass melt: after the lead-containing colorless fusible glass (softening temperature ≤ 550 ℃, the viscosity of the fusible glass at the softening temperature is 10 6.6 Pa s, the temperature at which the glass melt has a viscosity of 10 5 Pa s) is made into particles, it is added to a single screw extruder, the extruder is heated in sections, and the temperature at the middle section reaches 550 ℃ (much higher than the temperature at which the glass melt has a viscosity of 10 6.6 Pa s), the end of the extruder is connected to a lip die, and the width of the die outlet is 110 mm. As the screw in the extruder rotates, the gas between the gaps of the particles is discharged, and a dense glass melt is obtained. The melt is preformed after passing through the lip die.

[0081] Step (3) glass melt coating: on the linear surface area of the film tensioned and fixed in step (1), the glass melt obtained in step (2) is coated (the coating temperature is a certain temperature in the corresponding temperature range when the viscosity of the glass melt is between 0.01 and 10 6.6 Pa s), the film moves relative to the material area, and the coating is completed.

[0082] Step (4) heat treatment: quenching treatment is performed on the composite film coated with the glass melt, and a composite film with excellent surface hardness (> 4H) is obtained.

[0083] Example Three

[0084] The device forming site structure is shown in Figure 3 .

[0085] Step (1) Base film treatment: Select a 125mm wide polyimide film. Treat the film surface with alkali to open some of the imide rings. After washing with deionized water, prepare an Al2O3 layer on the film surface using the sol-gel method. The Al2O3 layer has strong bonding ability with polyimide, with an adhesion strength ≥3MPa, which can improve the adhesion of the glass layer to the substrate. Tension the film with a film tensioning device. Pre-deformation ensures that the support roller and comma doctor blade maintain a straight geometric shape during operation at a predetermined temperature below 550℃ (the predetermined temperature is a set of temperatures between room temperature and process temperature; those skilled in the art can select the temperature that allows the equipment and components in the coating system to operate normally). The melt pump feeds the material into the melt tank, and the heat resistance temperature of the film is higher than the coating temperature. To ensure the stable performance of the polyimide film under high temperature conditions, the equipment is enclosed in a glass cover to provide a water-free, oxygen-free, and dust-free working environment for the manufacturing process.

[0086] Step (2) Preparation of glass melt: Lead-free, colorless, fusible glass particles (softening temperature ≤ 450℃, viscosity of fusible glass at softening temperature is 10) are prepared. 6.6 Pa s) is added to the melt pump and heated to the operating point (10). 3 The gas in the gaps is completely removed at a temperature above the Pa s temperature (above the gap-removal temperature) to obtain a homogeneous and dense glass melt. The melt is pumped onto an inclined heating plate at a 45-degree angle to the vertical direction. The heating plate, support rollers, and comma-shaped scraper together form a melt tank with an opening width of 110 mm. The comma-shaped scraper is used to ensure that the melt is uniformly distributed in the width direction.

[0087] Step (3) Glass melt coating: On the straight surface area of ​​the film that was tensioned and fixed in step (1), the glass melt from step (2) is coated (the coating temperature is when the viscosity of the glass melt is between 0.01 and 10). 6.6 The film moves relative to the material area, achieving roll-to-roll continuous coating, where the temperature is between Pa and s (corresponding to a certain temperature).

[0088] Step (4) Heat treatment: The coated composite film is heat treated by ultraviolet laser irradiation. The short-wave laser acts on the surface of the glass layer, and the heat has little damage to the base polyimide. This treatment can prolong the self-leveling time of the glass melt and obtain a composite film with lower surface roughness.

[0089] The water vapor permeability of the composite membrane is less than 10%. -3 gm -2 day -1 It is free of heavy metal lead, colorless and transparent, and can be used for encapsulation of flexible electronic devices (thin-film solar cells) that require light transmission.

[0090] Example 4

[0091] Step (1) substrate film treatment: select a polyimide film with a width of 125 mm, deposit a layer of Si3N4 on the film surface by PECVD, the bond energy of Si-N bond in Si3N4 is greater than 300 kJ mol -1 The layer can prevent the glass melt from corroding the polyimide substrate. The film is tensioned by a film tensioning device, and the geometry of the support roller and the linear doctor blade during operation is ensured by pre-deformation at a predetermined temperature condition (a group of temperatures between room temperature and the process temperature) lower than 550 ℃, to ensure that the film is linear in the width direction at the forming position.

[0092] Step (2) preparation of glass melt: the glass-ceramic (mainly amorphous glass, crystalline phase as auxiliary, containing a small amount of unremoved voids, softening temperature ≤ 550 ℃, viscosity at softening temperature is 10 6.6 Pa s) is made into particles, and a metering pump with heating and stirring device is used to obtain a glass-ceramic melt and precisely control the output flow rate of the melt. The glass-ceramic contains a small amount of refractory (nanoscale) ceramic particles or crystalline particles. The glass-ceramic melt is pumped to the surface of the polyimide film adjacent to the linear doctor blade area for coating. The discharge width of the linear doctor blade is 110 mm. The schematic diagram of linear doctor blade coating is shown in Figure 4 .

[0093] Step (3) glass melt coating: the linear surface area of the film is tensioned and fixed in step (1), and the metered glass-ceramic melt in step (2) is coated by a linear doctor blade (the coating temperature is a certain temperature in the corresponding temperature range when the melt viscosity is between 0.01 and 10 6.6 Pa s), the film moves relative to the doctor blade to achieve continuous coating.

[0094] Step (4) heat treatment: the coated composite film is slowly cooled to room temperature to obtain a composite film with excellent barrier properties and impact resistance, which can be used for integrated circuit packaging.

[0095] Compared with other dies or blades and doctor blades, the deformation of the linear doctor blade after heating mainly occurs in the length direction, and the thermal expansion deformation in the diameter direction is small, so the thermal deformation of the mechanical structure does not easily interfere with the control of the thickness of the glass melt layer. The composition of polyimide and glass is diverse, and in order to meet various needs, a series of composite films need to be developed, and the equipment needs to work at different temperature conditions. The price of a single meter-long slot die is more than 1 million yuan, and the pre-deformation design can only adapt to one material system. The linear doctor blade in the embodiment can adapt to a variety of different material systems.

[0096] Example Five

[0097] Step (1) substrate film treatment: select a colorless polyimide film with width of 125 mm, deposit a TiO2 layer on the film surface by magnetron sputtering technology, the thermal conductivity of the layer is 0.5 W m -1 K -1 It can play a role of thermal insulation, prevent the glass melt thermal damage to the polyimide substrate. The film is pulled tight by a winding and unwinding device, a support plate is arranged on the back of the film, and the straightness of the coating area is ensured under the condition of a predetermined temperature (a group of temperatures between normal temperature and process temperature, which can be selected by those skilled in the art according to the condition of each equipment and component in the coating system to ensure normal operation) lower than 550℃ process temperature.

[0098] Step (2) preparation of glass melt: put the colorless lead-containing fusible glass (softening temperature 380℃, the viscosity of the fusible glass at the softening temperature is 10 6.6 Pa s) into the crucible in the resistance heating furnace, heat to above the working temperature (higher than the de-void temperature, the de-void temperature is the temperature when the viscosity of the glass melt is 10 5 Pa s), and remove the air in the voids to obtain a homogeneous glass melt. Pour the glass melt into a graphite tank while hot to form a long strip, and obtain a glass strip with a length of 110 mm after cooling.

[0099] Step (3) glass melt coating: place the glass strip on the heating plate, cover it with a cover, and maintain a temperature of 500℃ in the chamber, the glass strip melts, and under the action of gravity, it contacts with the moving modified polyimide film, and the glass melt is uniformly coated on the surface of the polyimide film (the coating temperature is a certain temperature in the corresponding temperature when the viscosity of the glass melt is between 0.01-10 6.6 Pa s). The schematic diagram of doctor blade coating is shown in Figure 5 .

[0100] Step (4) heat treatment: the composite film after coating is annealed at 350℃ for 30 min to eliminate residual stress. After annealing, it is cooled to room temperature to obtain a colorless transparent composite film.

[0101] Example six

[0102] Step (1) substrate film treatment: select a colorless polyimide film with a width of 125 mm, treat the surface of the polyimide film with an alkali solution to open some of the imide rings, and then wash with deionized water. An Al2O3 layer is then prepared on the surface of the film by sol-gel method. The Al2O3 layer has strong bonding ability and adhesion strength of ≥3 MPa to the polyimide, and can improve the adhesion of the glass melt to the substrate. The film is tensioned by a take-up and pay-off roll, and a drive roll is provided on the back of the film to ensure that the pressure during coating at a predetermined temperature (which is a set of temperatures between room temperature and the process temperature, and can be selected by a person skilled in the art according to the conditions of each device and component in the coating system to ensure normal operation) does not damage the straightness of the film in the width direction.

[0103] Step (2) preparation of glass melt: lead-free colorless fusible glass batch (the resulting glass has a softening temperature of ≤550°C, and the viscosity of the fusible glass at the softening temperature is 10 6.6 Pa s) is directly added to an extruder, where the glass melting and de-slotting are completed (the melting temperature refers to the temperature required for the batch to complete dehydration, decomposition, combination and other physical and chemical changes, which is usually much higher than the temperature used for coating). The end of the extruder is connected to a melt chamber, and the micro-concave roll is in contact with the liquid surface in the melt chamber, and the glass melt fills the micro-concave pits on the surface of the roll. Because the melt does not cool to room temperature, nor is it broken into powder or particles, this step reduces energy consumption compared to the previous scheme and avoids dust pollution.

[0104] Step (3) glass melt coating: the straight surface area of the film is tensioned and fixed in step (1), and the glass melt prepared in step (2) is coated on the colorless polyimide film by micro-concave printing (the coating temperature is a certain temperature in the temperature corresponding to the viscosity of the glass melt between 0.1 and 1 Pa s). The micro-concave roll rotates, and the film moves relative to the micro-concave roll to achieve continuous printing and coating. The liquid chamber doctor blade (micro-concave printing) coating schematic is shown in Figure 6 .

[0105] Step (4) heat treatment: the coated composite film is annealed at 350°C for 30 min to eliminate residual stress. After annealing, it is cooled to room temperature to obtain a colorless transparent composite film, which can be used for packaging of flexible electronic devices (flexible display or flexible solar devices).

[0106] Example Seven

[0107] A low-temperature sintering ceramic, which is a borate ceramic, is used as a side seal material for electronic devices. The specific formulation is: 60 wt.% B2O3, 25 wt.% SiO2, 10 wt.% Al2O3, and 5 wt.% ZnO.

[0108] The above raw materials are mixed according to the ratio, and dry ball milling in a ball mill for 4h to ensure uniformity. The milled powder is mixed with an organic binder system (total content not more than 3wt.%) to make a slurry, wherein the organic component is selected from a low-temperature decomposition type binder, and the balance is solvent.

[0109] The composite film prepared by example 4 or example 6 is covered on the upper surface and lower surface of the electronic device, and a low-temperature sintering ceramic raw material slurry is coated on the sealing area of the electronic device (including the periphery of the electronic device, between the composite films on the upper / lower surfaces) by screen printing technology, and the thickness of the slurry green body is controlled at 100-150μm.

[0110] The sample is placed in a glove box with high-purity nitrogen (purity 99.999%) atmosphere. The sample is pre-dried on a hot stage at 80℃ for 30min, and then treated at 150℃ in a vacuum environment for 20min to remove the organic components. At this temperature, the organic matter can be slowly decomposed and volatilized, while the electronic device is not damaged. The ultrasonic packaging device is turned on, and the ultrasonic frequency and power are adjusted so that the green body is sintered and densified under ultrasonic vibration. By optimizing the ultrasonic parameters, the sintering temperature is maintained below 550℃ to avoid high-temperature damage to the polymer film. At the same time, ultrasonic vibration helps to improve the density of the ceramic and improve the packaging airtightness.

[0111] The borate ceramic is sintered under ultrasonic action, and a dense edge sealing structure is formed after sintering.

[0112] The technical features of the above-described embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0113] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A composite film containing a glass layer, characterized by, The composite film comprises a base film and a glass layer, the glass layer is obtained by coating a glass melt on the surface of the base film, the base film comprises a polymer film or a surface-modified polymer film; The method for preparing the composite film comprising a glass layer comprises the following steps: making the base film linear in the width direction at a predetermined temperature; heating the raw material of the glass melt to above the void-removing temperature to remove the voids in the glass melt; coating the glass melt on the surface of the base film at a coating temperature; and performing heat treatment to obtain the composite film comprising a glass layer. room temperature ≤ the predetermined temperature ≤ process temperature, the process temperature being higher than the coating temperature, the process temperature referring to the highest working temperature of the heating element itself in the coating system, the coating temperature being any temperature in the range of 0.01 to 10 6.6 Pa·s 5 Pa·s.

2. The composite film according to claim 1, characterized by, The surface-modified polymer film comprises a polymer film and a modified layer, the modified layer covers the surface of the polymer film, and the modified layer comprises an inorganic layer, the inorganic layer comprises at least one of a wetting layer with surface energy close to the glass melt, an anti-corrosion layer with strong bond energy, an adhesive layer with strong adhesion to the base, and a heat insulation layer.

3. The composite film of claim 1, wherein The raw material of the glass melt comprises a fusible glass, and the maximum heat resistance temperature of the base film is greater than the coating temperature of the glass melt.

4. The composite film of claim 3, wherein, The softening temperature of the fusible glass is ≤ 550℃, and the viscosity of the fusible glass corresponding to the softening temperature is 10 6.6 Pa·s.

5. The method of producing the composite film according to any one of claims 1 to 4, characterized by, The method comprises the following steps: The method comprises the following steps: making the base film linear in the width direction at a predetermined temperature; heating the raw material of the glass melt to above the void-removing temperature to remove the voids in the glass melt; coating the glass melt on the surface of the base film at a coating temperature; and performing heat treatment to obtain the composite film comprising a glass layer. room temperature < the predetermined temperature < process temperature, the process temperature being higher than the coating temperature, the coating temperature being a temperature at which the viscosity of the glass melt is between 0.01 and 10 Pa-s 6.6 the de-voiding temperature being a temperature at which the viscosity of the glass melt is 10 5 Pa-s.

6. The production method according to claim 5, wherein The coating comprises at least one of engraving wheel coating, reverse coating, slot die coating, lip coating, doctor blade coating, blade coating, plate coating, liquid cavity doctor blade coating, rod coating, air doctor blade coating, and micro-recess coating. The heat treatment comprises at least one of annealing, cooling, quenching, and laser irradiation treatment.

7. Use of the composite film according to any one of claims 1-4 in the preparation of a functional film, the functional film being a high-barrier film, an impact-resistant film, and / or a hardened film, the functional film being applied to packaging or encapsulation.

8. A film for packaging or encapsulation, characterized in that, The composite film according to any one of claims 1-4.

9. A method of packaging a device, characterized by, The method comprises the following steps: covering the film according to claim 8 on the upper surface and / or the lower surface of a device, arranging an encapsulation wall around the device, connecting the encapsulation wall with the film on the upper surface and / or the lower surface, forming a sealed cavity, and wrapping the device in the sealed cavity. The method comprises the following steps: covering the film according to claim 8 on the upper surface and / or the lower surface of a device, arranging an encapsulation wall around the device, connecting the encapsulation wall with the film on the upper surface and / or the lower surface, forming a sealed cavity, and wrapping the device in the sealed cavity.

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