High toughness glass interlayer and method of making the same

Abstract

The present application relates to the technical field of glass interlayer, in particular to a high-toughness glass interlayer and a preparation method thereof.The present application overcomes the problem of poor toughness and high-temperature resistance of the glass interlayer.The present application prepares a plasticizer, a hybrid filler, a boric acid ester dynamic crosslinking agent and a self-repairing microcapsule, and obtains a PVB functional layer by mixing and calendering the above materials;obtains a surface grafted polyester layer by grafting amino groups through plasma treatment;extrudes the PVB functional layer and the surface grafted polyester layer into a three-channel co-extruder, and obtains a layered glass interlayer through electron beam irradiation and gradient cooling, wherein the glass interlayer sequentially comprises a surface grafted polyester layer, a PVB functional layer and a surface grafted polyester layer from inside to outside;and the toughness and high-temperature resistance of the prepared glass interlayer are improved by controlling the component dosage and process parameters in the preparation process.

Description

Technical Field

[0001] This invention relates to the field of glass interlayer technology, specifically to a high-toughness glass interlayer and its preparation method. Background Technology

[0002] In the field of glass deep processing, laminated glass is widely used in industries such as construction and automobiles due to its excellent safety performance. The interlayer, as the core component of laminated glass, directly affects its overall performance. Currently, most interlayers are PVB films. However, due to the numerous performance defects of single PVB films, layered interlayers composed of polyester are widely used. While traditional layered interlayers possess some ability to bond glass, they have significant deficiencies in toughness and high-temperature resistance.

[0003] From a toughness perspective, when laminated glass is subjected to accidental impact or strong winds in extreme weather, the interlayer film, due to its molecular structure and performance limitations, is unable to effectively disperse and absorb the impact force, making the glass prone to cracking or even shattering, thus failing to provide reliable safety protection for users. In terms of high-temperature resistance, with the increasing demands for energy conservation and heat insulation in modern buildings and automobiles, glass needs to be exposed to high-temperature environments for extended periods, such as building exterior glass or car windshields under direct sunlight in summer. In such cases, the interlayer film will experience a decrease in interlayer adhesion due to high temperatures, causing the interlayer film to debond from the glass, thereby damaging the integrity and functionality of the laminated glass and seriously affecting its service life and safety performance.

[0004] To address this, a high-toughness glass interlayer and its preparation method are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-toughness glass interlayer and its preparation method. The method involves preparing a plasticizer, hybrid filler, borate ester dynamic crosslinking agent, and self-healing microcapsules, and then mixing and calendering these materials to obtain a PVB functional layer. An amino-grafted layer is obtained through plasma treatment. The PVB functional layer and the surface-grafted polyester layer are then extruded in a three-channel co-extruder, and subjected to electron beam irradiation and gradient cooling to obtain a layered glass interlayer. The interlayer consists of a surface-grafted polyester layer, a PVB functional layer, and another surface-grafted polyester layer, arranged sequentially from the inside out. By controlling the component dosages and process parameters during preparation, the toughness and high-temperature resistance of the resulting glass interlayer are improved.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] It should be noted that all parts in this invention are parts by weight.

[0008] The application provides a preparation method of a high-toughness glass interlayer film.

[0009] The plasticizer is obtained by reacting hydroxyethyl acrylate and divinylbenzene;

[0010] The hybrid filler is prepared from boron nitride powder, silane coupling agent and multi-walled carbon nanotube.

[0011] The borate dynamic crosslinking agent is obtained by reacting phenylboronic acid and epichlorohydrin.

[0012] Preferably, the preparation method of the surface-grafted polyester layer is as follows: the polyester film is placed in a plasma treatment device, vacuumized to 10 Pa, the power is adjusted to 150-200 W, oxygen is introduced, the oxygen flow is 30 sccm, and the pretreated polyester film is obtained after 5 min of treatment; 2-6 parts of allylamine monomer and 0.2 parts of potassium persulfate are dissolved in 20 parts of deionized water to obtain a grafting solution; the grafting solution is injected into the plasma treatment device, and the surface-grafted polyester layer is obtained after 30 min of reaction. -3 Pa, the power is adjusted to 150-200 W, oxygen is introduced, the oxygen flow is 30 sccm, and the pretreated polyester film is obtained after 5 min of treatment; 2-6 parts of allylamine monomer and 0.2 parts of potassium persulfate are dissolved in 20 parts of deionized water to obtain a grafting solution; the grafting solution is injected into the plasma treatment device, and the surface-grafted polyester layer is obtained after 30 min of reaction.

[0013] Preferably, the preparation method of the PVB functional layer is as follows: 30 parts of PVB resin and 4-8 parts of plasticizer are premixed in a mixing mill at 50 DEG C for 20 min, 1-3 parts of hybrid filler, 1 part of nano cerium dioxide and 1 part of antioxidant 1010 are added, and the mixture is melt-dispersed through a double-screw extruder at a temperature of 190 DEG C; the temperature is lowered to 140 DEG C, 1-5 parts of borate dynamic crosslinking agent are added, and the mixture is reacted in a static mixer for 20 min; the temperature is lowered to 50 DEG C, 8-12 parts of self-repairing microcapsules are added, and the PVB functional layer is obtained after stirring and calendering.

[0014] Preferably, the preparation method of the plasticizer is as follows: 10 parts of hydroxyethyl acrylate and 20 parts of toluene are added into a three-necked flask, stirred for 15 min, 0.3-1 parts of divinylbenzene is added and stirred for 20 min to obtain a mixed solution; 0.12 parts of benzoyl peroxide is dissolved in 5 parts of toluene, and the mixed solution is added dropwise, the dropwise adding time is 30 min, the temperature is raised to 80 DEG C, and the stirring speed is 150 rpm; and the plasticizer is obtained after 6 h of stirring.

[0015] Preferably, the hybrid filler is prepared as follows: 10 boron nitride powder is dispersed in 20 parts of isopropanol to obtain a suspension by ultrasonic treatment at 40 kHz for 4 h; the suspension and silane coupling agent KH550 are mixed at a mass ratio of 100:1 and reacted at 60 DEG C in a water bath for 2 h, centrifuged and dried to obtain modified boron nitride; and the modified boron nitride and multi-walled carbon nanotubes are mixed by ball milling at a mass ratio of 5-10:3 to obtain the hybrid filler.

[0016] Preferably, the borate dynamic crosslinking agent is prepared as follows: phenylboronic acid and epichlorohydrin are mixed at a mass ratio of 1:2-6, 1 wt% of tetraethylammonium hydroxide is added to catalyze the reaction, and the product obtained by reacting at 80 DEG C for 6 h is precipitated by acetone and vacuum dried to obtain the borate dynamic crosslinking agent.

[0017] Preferably, the self-repairing microcapsule is prepared as follows: bisphenol A type epoxy resin (E51) and isophorone diisocyanate are mixed at a mass ratio of 2-6:1 to form a core material; the core material is emulsified in deionized water containing 5 wt% polyvinyl alcohol (rotation speed 8000 rpm, 10 min), and the temperature is raised to 50 DEG C to react for 3 h to form a polyurea shell layer, and the self-repairing microcapsule is obtained by centrifugal washing and freeze-drying.

[0018] Preferably, the electron beam irradiation device has an electron beam energy of 3-7 MeV, an absorbed dose of 6-12 kGy, a beam intensity of 10 mA, a scanning width of 300 mm, and a single-side irradiation time of 40 s; and the gradient cooling is first cooled at a speed of 3-7 DEG C / min to 40-70 DEG C, and then naturally cooled to room temperature.

[0019] Preferably, the three-channel co-extruder has a surface grafted polyester layer in channel one and channel three, and a PVB functional layer in channel two; the surface grafted polyester layer has an extrusion temperature of 230-250 DEG C, and the PVB functional layer has an extrusion temperature of 180-200 DEG C.

[0020] Another aspect of the present application provides a high-toughness glass interlayer, which comprises, from inside to outside, a surface grafted polyester layer, a PVB functional layer and a surface grafted polyester layer; and is prepared by any of the above preparation methods.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] 1. In this invention, the polyester film is activated by oxygen plasma to form surface free radicals, and then allyl amine is grafted to introduce amino functional groups, which significantly improves the interfacial bonding force between the polyester layer and the PVB functional layer. During this process, the amino polar groups form a hydrogen bond network with the hydroxyl groups in PVB, while the borate ester dynamic crosslinking agent in the PVB functional layer undergoes reversible dissociation and recombination at high temperature, dynamically regulating the movement ability of molecular chain segments. Under the synergistic effect of the two, the interfacial adhesion strength and the flexibility of the internal molecular chains of the material are enhanced simultaneously, which not only avoids interlayer delamination, but also absorbs impact energy through the dynamic bond breaking-re-crosslinking mechanism, effectively improving the crack propagation resistance and long-term deformation recovery of the interlayer under extreme temperature changes, thereby improving its toughness.

[0023] 2. In this invention, the modified boron nitride in the hybrid filler is grafted with a silane coupling agent to achieve uniform dispersion with PVB resin. Its layered structure can block the heat transfer path and reduce the thermal conductivity of the material. Meanwhile, the multi-walled carbon nanotubes form a three-dimensional conductive network, which locally dissipates heat through the Joule heating effect, delaying the relaxation of molecular chains under high temperature conditions. The modified boron nitride blocks the introduction of external heat sources, while the multi-walled carbon nanotubes actively dissipate excess internal heat, forming a "defense against external heat and heat dissipation within internal heat" thermal management mechanism. At the same time, the gradient cooling process controls the temperature drop rate in stages, so that the difference in thermal expansion coefficients between the PVB functional layer and the grafted polyester layer gradually matches during the cooling process, avoiding microcracks and interfacial thermal stress concentration caused by sudden cooling, and improving the high temperature resistance of the interlayer film.

[0024] 3. In this invention, the self-healing microcapsules use isophorone diisocyanate as the shell material to encapsulate an epoxy resin core material. When the interlayer is damaged by external force, the microcapsules rupture and release the core material, which reacts with the hydroxyl groups in PVB to generate a polyurethane repair, thus achieving self-sealing of cracks. Meanwhile, electron beam irradiation induces a free radical cross-linking reaction in the PVB layer, forming a high-density network structure. At the same time, high-energy particle bombardment creates a nanoscale crack-sensitive area in the microcapsule shell, reducing its rupture threshold. This synergistic strategy of process and materials enhances the rigidity and penetration resistance of the substrate material through irradiation and releases the repair agent through the sensitive response of the microcapsules to damage. This dual mechanism dynamically repairs internal defects and restores the continuity of the material, thereby improving the toughness of the interlayer.

[0025] 4、The hydroxyethyl acrylate-based plasticizer forms stable hydrogen bonds with the PVB resin through the polar hydroxyl groups, and forms a three-dimensional network with moderate flexibility under the regulation of the crosslinking agent, giving the PVB functional layer the characteristics of rigid-flexible balance. In the three-channel co-extrusion process, the differential temperature extrusion of the grafted polyester layer and the PVB functional layer makes the partially embedded polyester molecular chains in the PVB interfacial region, forming an interpenetrating interfacial transition layer; and the plasticizer optimizes the compatibility of the two phases through polarity matching in this process, reducing the molecular chain repulsion phenomenon at the interface, and the synergistic effect of the two makes the interface region have the temperature resistance of high-toughness polyester and the dynamic energy dissipation capacity of PVB, and can still maintain the interfacial bonding strength under high-temperature impact or long-term heat exposure, and inhibit the risk of delamination and brittle fracture. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Figure for the high temperature resistance test results of example 2, examples 5-6 and comparative examples 4-9 of the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Please refer to Figure 1 The present application provides a high-toughness glass interlayer and a preparation method thereof, and the technical solutions are as follows:

[0029] The substances involved in the present application are as follows:

[0030] The polyester film is purchased from Hangzhou Dahua Plastic Industry Co., Ltd.; the allyl amine monomer is purchased from Shandong Luyu Chemical Group Co., Ltd.; the boron nitride powder (1 μm) is purchased from Shanghai Dibo Biological Technology Co., Ltd.; and the multi-walled carbon nanotube is purchased from Shanghai Yenn Chemical Technology Co., Ltd.

[0031] Example 1

[0032] The polyester film is placed in a plasma treatment device, and vacuumed to 10 -3Pa, the adjusting power is 150 W, oxygen is input, the oxygen flow is 30 sccm, and the pretreatment polyester film is obtained by processing for 5 min; 2 parts of allyl amine monomer and 0.2 parts of potassium persulfate are dissolved in 20 parts of deionized water to obtain a grafting solution; the plasma treatment equipment is pressurized to normal pressure under nitrogen protection, the grafting solution is injected, and a surface grafted polyester layer (0.1 mm) is obtained by reacting for 30 min; 30 parts of PVB resin and 4 parts of plasticizer are premixed in a banbury mixer at 50 ℃ for 20 min, 1 part of hybrid filler, 1 part of nano cerium dioxide and 1 part of antioxidant 1010 are added, and the mixture is melt dispersed through a twin-screw extruder at a temperature of 190 ℃; the temperature is lowered to 140 ℃, 1 part of a borate dynamic crosslinking agent is added, and the mixture is reacted in a static mixer for 20 min; the temperature is lowered to 50 ℃, 8 parts of self-repairing microcapsules are added, and the mixture is stirred at a speed of 500 rpm for 10 min; and a PVB functional layer (0.5 mm) is obtained by calendering; the surface grafted polyester layer and the PVB functional layer are added to a three-channel co-extruder, channel one and channel three are the surface grafted polyester layer, and channel two is the PVB functional layer; the extrusion temperature of the surface grafted polyester layer is 230 ℃, and the extrusion temperature of the PVB functional layer is 180 ℃; then an electron beam irradiation device is used for irradiation, the electron beam energy is 3 MeV, the absorbed dose is 6 kGy, the beam current intensity is 10 mA, the scanning width is 300 mm, and the single-side irradiation time is 40 s; and then gradient cooling is performed, the temperature is lowered to 40 ℃ at a speed of 3 ℃ / min, and then the temperature is naturally cooled to room temperature to obtain an intermediate film.

[0033] The plasticizer is prepared in the following manner: 10 parts of hydroxyethyl acrylate and 20 parts of toluene are added to a three-necked flask, stirred for 15 min, 0.3 parts of divinylbenzene is added and stirred for 20 min to obtain a mixed solution; 0.12 parts of benzoyl peroxide is dissolved in 5 parts of toluene, and the solution is added dropwise to the mixed solution, the dropwise adding time is 30 min, the temperature is raised to 80 ℃, and the mixture is stirred at a speed of 150 rpm for 6 h; after cooling, deionized water is used for extraction, and then rotary evaporation is performed under the conditions of a temperature of 50 ℃ and a vacuum degree of 0.09 MPa to obtain the plasticizer.

[0034] The hybrid filler is prepared in the following manner: 10 parts of boron nitride powder is dispersed in 20 parts of isopropanol, and ultrasonic treatment is performed at 40 kHz for 4 h to obtain a suspension; the suspension and silane coupling agent KH550 are reacted at a mass ratio of 100:1 in a 60 ℃ water bath for 2 h, and then centrifugal drying is performed to obtain modified boron nitride; the modified boron nitride and multi-walled carbon nanotubes are ball-mixed (200 rpm, 6 h) at a mass ratio of 5:3 to obtain the hybrid filler.

[0035] The borate dynamic crosslinking agent is prepared in the following manner: phenylboronic acid and epichlorohydrin are mixed at a mass ratio of 1:2, 1 wt% of tetraethylammonium hydroxide is added for catalytic reaction, and the reaction is performed at 80 ℃ for 6 h; the product is subjected to acetone precipitation and vacuum drying to obtain the borate dynamic crosslinking agent.

[0036] The self-repairing microcapsule is prepared as follows: Bisphenol A type epoxy resin (E51) and isophorone diisocyanate are mixed in a mass ratio of 2:1 to form a core material; the core material is emulsified in deionized water containing 5wt% polyvinyl alcohol (rotating speed 8000 rpm, 10 min), and the temperature is raised to 50°C for 3h to form a polyurea shell layer. After centrifugal washing and freeze-drying, the self-repairing microcapsule (particle size 5-10 μm) is obtained.

[0037] Examples 2-4

[0038] The preparation method and parameter conditions of Reference Example 1 are referred to, and the specific differences are shown in Table 1; the mass ratio in Table 1 is the mass ratio of phenylboric acid and epichlorohydrin; the crosslinking agent is a borate dynamic crosslinking agent; and the power is the plasma treatment power when the surface grafted polyester layer is prepared.

[0039] Comparative Example 1

[0040] The preparation method and parameter conditions of Reference Example 1 are referred to, except that the polyester film is not surface grafted.

[0041] Comparative Example 2

[0042] The preparation method and parameter conditions of Reference Example 1 are referred to, except that the borate dynamic crosslinking agent is not added when the PVB functional layer is prepared.

[0043] Comparative Example 3

[0044] The preparation method and parameter conditions of Reference Example 1 are referred to, except that the borate dynamic crosslinking agent is replaced by tributyl borate when the PVB functional layer is prepared.

[0045] Experimental Example 1 Toughness Test

[0046] The elongation at break of the test material is tested according to the standard of ISO 527, and the test speed is 50 mm / min; the obtained results are shown in Table 1.

[0047] Table 1 Toughness Test of Examples 1-4 and Comparative Examples 1-3

[0048]

[0049] As can be seen from Table 1, in Examples 1-4, the polyester film is treated by oxygen plasma activation to form surface radicals, and then grafted with allyl amine to introduce amino functional groups, thereby significantly improving the interfacial bonding force between the polyester layer and the PVB functional layer. In this process, the amino polar groups form a hydrogen bond network with the hydroxyl groups in the PVB, and the borate dynamic crosslinking agent in the PVB functional layer reversibly dissociates and recombines at high temperatures, dynamically adjusting the molecular chain segment movement ability. Under the synergistic action of the two, the interfacial adhesion strength and the material internal molecular chain flexibility are simultaneously enhanced, avoiding interlayer peeling and absorbing impact energy through the dynamic bond breakage-recombination mechanism, effectively improving the anti-crack propagation ability and long-term deformation recovery of the interlayer under extreme temperature changes, thereby improving the toughness. In Example 2, when the mass ratio of the two is 1:4, the crosslinking agent is 3 parts, the allyl amine monomer is 4 parts, and the plasma treatment power is 170 W, the interlayer prepared has the best toughness, with an elongation at break of 320%. In Comparative Example 1, the polyester film is not surface grafted, and the polyester layer and the PVB layer have a large polarity difference, relying only on physical adsorption to combine, resulting in a significant reduction in shear strength and easy interlayer peeling under external impact or thermal stress. Moreover, the ungrafted surface has high smoothness, and the interface becomes a weak link for stress transmission, with cracks tending to rapidly expand along the interface rather than dissipating into the PVB, resulting in a significant loss of overall toughness. In Comparative Example 2, the borate dynamic crosslinking agent is not added when preparing the PVB functional layer. The dynamic crosslinking bond can break and absorb energy in the crack tip micro area, delaying crack propagation. After the dynamic bond is missing, the crack propagation rate increases, and the fracture toughness significantly decreases. In Comparative Example 3, the borate dynamic crosslinking agent is replaced with tributyl borate when preparing the PVB functional layer. The covalent bond cannot adjust the network structure in response to stress, and the molecular chain segments cannot disperse energy through dynamic recombination under external force, resulting in a "stiff- brittle fracture" phenomenon. In addition, the static crosslinking network is more prone to chain degradation at high temperatures.

[0050] Examples 5-6

[0051] The preparation method and parameters of Example 2 were used as reference, with the specific differences shown in Table 2. In Table 2, the mass ratio of the two refers to the mass ratio of the modified boron nitride and the multi-walled carbon nanotube; the cooling rate and cooling temperature are parameters when gradient cooling is performed.

[0052] Comparative Example 4

[0053] The preparation method and parameters of Example 2 were used as reference, except that no hybrid filler was added when preparing the PVB functional layer.

[0054] Comparative Example 5

[0055] The preparation method and parameters of Example 2 were used as reference, except that only 1 part of modified boron nitride was used as the filler.

[0056] Comparative Example 6

[0057] The preparation method and parameters of Example 2 were followed, except that only 1 part of multi-walled carbon nanotubes was used as filler.

[0058] Comparative Example 7

[0059] The preparation method and parameters of Example 2 were followed, except that only 1 part of boron nitride powder was used as filler.

[0060] Comparative Example 8

[0061] The preparation method and parameters of Example 2 were followed, except that no gradient cooling was performed, but rather a direct natural cooling to room temperature.

[0062] Comparative Example 9

[0063] The preparation method and parameters of Example 2 were followed, except that no gradient cooling was performed, but rather a direct cooling to room temperature at a rate of 5 °C / min.

[0064] Example 2 High temperature resistance test

[0065] The heat distortion temperature was tested according to ISO 75 standard; the results obtained are shown in Table 2 and Figure 1

[0066] Table 2 High temperature resistance test of Example 2, Examples 5-6 and Comparative Examples 4-9

[0067]

[0068] From Table 2 and Figure 1 ​It can be seen that in Examples 2, 5-6, the modified boron nitride in the hybrid filler is grafted by the silane coupling agent to achieve uniform dispersion with the PVB resin, and the lamellar structure thereof can block the heat flow transmission path to reduce the thermal conductivity of the material; while the multi-walled carbon nanotubes form a three-dimensional conductive network to locally dissipate heat through the Joule heating effect, delaying the relaxation of molecular chains at high temperature; at the same time, the gradient cooling process gradually adapts the difference in the thermal expansion coefficients of the PVB functional layer and the grafted polyester layer during the cooling process by controlling the temperature reduction rate in stages, avoiding micro-cracks and interfacial thermal stress concentration caused by sudden cooling. In Example 5, when the mass ratio of the two is 7:3, the amount of the hybrid filler is 2 parts, the cooling rate is 5°C / min, and the cooling temperature is 60°C, the intermediate film prepared has the best high-temperature resistance, and the heat distortion temperature is 125°C. In Comparative Example 4, no hybrid filler is added when preparing the PVB functional layer, and the PVB resin itself is a low thermal conductive material, which cannot effectively transfer heat, and the local temperature is easy to accumulate at high temperature, causing thermal degradation of the molecular chain. In Comparative Example 5, only 1 part of modified boron nitride is used as a filler, and the lamellar structure of boron nitride forms parallel heat conduction paths, and the transverse thermal conductivity is limitedly improved, and heat is not easy to diffuse to both sides; and lacking the cross-linking enhancement effect of carbon nanotubes, the crack propagation resistance of the PVB matrix decreases at high temperature, and local brittle fracture is easy to form. In Comparative Example 6, only 1 part of multi-walled carbon nanotubes is used as a filler, which efficiently conducts heat along the carbon tube axis, but the radial heat transfer is blocked, and the local heat diffusion efficiency is lower than that of the hybrid system. In Comparative Example 7, only 1 part of boron nitride powder is used as a filler, and the unmodified boron nitride particles are difficult to uniformly disperse, forming micropores or stress concentration points, which become the starting point of high-temperature cracking. In Comparative Examples 8-9, no gradient cooling is performed, and the stress release and microstructure optimization ability of the gradient cooling is lacking, which is easy to cause chain segment relaxation and deformation at high temperature.

[0069] Examples 7-9

[0070] The preparation method and parameter conditions of Example 5 were referred to, and the specific differences are shown in Table 3; in Table 3, the mass ratio of the two is the mass ratio of bisphenol A type epoxy resin (E51) and isophorone diisocyanate.

[0071] Comparative Example 10

[0072] The preparation method and parameter conditions of Example 5 were referred to, except that no self-repairing microcapsules were added.

[0073] Comparative Example 11

[0074] The preparation method and parameter conditions of Example 5 were referred to, except that no electron beam irradiation device was used for irradiation.

[0075] Experimental Example 3: Toughness Test

[0076] The test method of Experimental Example 1 was referred to; the results are shown in Table 3.

[0077] Table 3 Toughness test of Example 5, Examples 7-9 and Comparative Examples 10-11

[0078]

[0079] As can be seen from Table 3, in Example 5, Examples 7-9, the self-repairing microcapsules encapsulate the epoxy resin core material with isophorone diisocyanate as the shell material. When the interlayer is damaged by external force, the microcapsules rupture to release the core material to react with the hydroxyl groups in the PVB to form a polyurethane repair body, achieving self-sealing of the crack. The electron beam irradiation initiates free radical crosslinking reaction in the PVB layer, forming a high-density network structure at the same time, and through high-energy particle bombardment, a nanoscale crack sensitive zone is generated in the shell layer of the microcapsule, reducing its rupture threshold. This synergistic strategy of process and material, on the one hand, enhances the rigidity and penetration resistance of the base material through irradiation, and on the other hand, releases the repair agent through the sensitive response of the microcapsules to damage, dynamically repairing internal defects and restoring material continuity, thereby improving the toughness of the interlayer. In Example 7, when the mass ratio of the two is 4:1, the amount of self-repairing microcapsules is 10 parts, the electron beam energy is 5 MeV, and the absorbed dose is 8 kGy, the interlayer prepared has the best toughness, with an elongation at break of 323%. In Comparative Example 10, no self-repairing microcapsules are added, and the microcracks generated by external force cannot be filled and repaired by the core material flow, and the crack tip continuously suffers stress concentration, rapidly expanding into a macroscopic fracture channel, reducing the toughness. In Comparative Example 11, no electron beam irradiation device is used for irradiation, and no irradiation-induced covalent crosslinking network is formed in the PVB matrix, and the interface bonding and matrix crosslinking degree are insufficient, and the molecular chain is easy to slip or the interface is easy to debond when the material bears stress.

[0080] Examples 10-12

[0081] Referring to the preparation method and parameter conditions of Example 7, the specific differences are shown in Table 4.

[0082] Comparative Example 12

[0083] Referring to the preparation method and parameter conditions of Example 7, the difference is that no plasticizer is added when preparing the PVB functional layer.

[0084] Comparative Example 13

[0085] Referring to the preparation method and parameter conditions of Example 7, the difference is that dibutyl phthalate is used as a plasticizer.

[0086] Experimental Example 4 High-temperature toughness test

[0087] The prepared interlayer is placed at a temperature of 80°C for 20 days, and its elongation at break is tested according to the standard of ISO 527 and the retention rate is calculated; the results obtained are shown in Table 4.

[0088] Table 4 High temperature toughness test of Example 7, Examples 10-12 and Comparative Examples 12-13

[0089]

[0090] As can be seen from Table 4, in Example 7, Examples 10-12, the hydroxyethyl acrylate-based plasticizer forms stable hydrogen bonds with the PVB resin through the polar hydroxyl group, and at the same time forms a moderately flexible three-dimensional network under the regulation of the crosslinking agent, giving the PVB functional layer the characteristics of rigidity-flexibility balance. In the three-channel co-extrusion process, the differentiated temperature extrusion of the grafted polyester layer and the PVB functional layer forces the partially embedded polyester molecular chains in the PVB interfacial region to form an interpenetrating interfacial transition layer; while the plasticizer optimizes the compatibility of the two phases through polarity matching in this process, reducing the molecular chain repulsion phenomenon at the interface, and the synergistic effect of the two makes the interface region have both the temperature resistance of high toughness polyester and the dynamic energy dissipation capacity of PVB, which can still maintain the interfacial bonding strength under high temperature impact or long-term heat exposure, and suppress the risk of delamination and brittle fracture. In Example 10, when the amount of divinylbenzene is 0.5 parts, the amount of plasticizer is 6 parts, the extrusion temperature of the surface grafted polyester layer is 240°C, and the extrusion temperature of the PVB functional layer is 190°C, the prepared interlayer has the best toughness at high temperature, and the elongation retention rate is 95.6%. In Comparative Example 12, no plasticizer is added when preparing the PVB functional layer, the rigidity of the PVB molecular chain is enhanced, and it is still in a glassy or weakly elastomeric state at high temperature, and the chain segment is difficult to stretch. When an external force acts, the lack of lubricating effect of the plasticizer makes the molecular chain directly bear stress, and cracks quickly develop and expand. In Comparative Example 13, dibutyl phthalate is used as a plasticizer, which has low molecular weight and high volatility, resulting in insufficient high temperature stability, and is easy to migrate from the PVB matrix to the polyester layer interface, forming a weak interface layer and reducing the interlayer bonding strength.

[0091] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-toughness glass interlayer, characterized in that: The preparation method is as follows: a polyester film is subjected to plasma treatment and grafted with amino groups to obtain a surface-grafted polyester layer; PVB resin, plasticizer, hybrid filler and borate ester dynamic crosslinking agent are mixed and calendered to obtain a PVB functional layer; the surface-grafted polyester layer and the PVB functional layer are added to a three-channel co-extruder for extrusion; then irradiated with an electron beam irradiation device, followed by gradient cooling to obtain the intermediate film; The plasticizer is obtained by reacting hydroxyethyl acrylate and divinylbenzene; The hybrid filler was prepared from boron nitride powder, silane coupling agent and multi-walled carbon nanotubes; The borate ester dynamic crosslinking agent is obtained by reacting phenylboronic acid and epichlorohydrin; The PVB functional layer is prepared as follows: the PVB resin and 4-8 parts of the plasticizer are premixed in a mixer, 1-3 parts of the hybrid filler, nano-cerium dioxide and antioxidant are added, and the mixture is melt-dispersed through a twin-screw extruder; 1-5 parts of the borate ester dynamic crosslinking agent are added, and after reacting in a static mixer, 8-12 parts of self-healing microcapsules are added, and the mixture is stirred and then calendered to obtain the PVB functional layer; The self-healing microcapsules are prepared as follows: Bisphenol A type epoxy resin and isophorone diisocyanate are mixed at a mass ratio of 2-6:1 to form a core material; the core material is emulsified in deionized water containing polyvinyl alcohol to form a polyurea shell; after centrifugation, washing and freeze-drying, the self-healing microcapsules are obtained.

2. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: The preparation method of the surface-grafted polyester layer is as follows: the polyester film is placed in a plasma treatment device, the power is adjusted to 150-200W, oxygen is introduced, and the pretreated polyester film is obtained; 2-6 parts of allylamine monomer and potassium persulfate are dissolved in deionized water to obtain a grafting solution; the grafting solution is injected into the plasma treatment device, and the reaction is carried out to obtain the surface-grafted polyester layer.

3. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: The plasticizer is prepared as follows: hydroxyethyl acrylate and toluene are added to a three-necked flask, stirred, and then 0.3-1 parts of divinylbenzene are added and stirred to obtain a mixture; benzoyl peroxide is dissolved in toluene and added dropwise to the mixture, and stirred to obtain the plasticizer.

4. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: The hybrid filler is prepared as follows: the boron nitride powder is dispersed in isopropanol and ultrasonically suspended to obtain a suspension; the suspension and the silane coupling agent are reacted in a water bath and centrifuged and dried to obtain modified boron nitride; the modified boron nitride and the multi-walled carbon nanotubes are ball-milled and mixed at a mass ratio of 5-10:3 to obtain the hybrid filler.

5. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: The preparation method of the borate ester dynamic crosslinking agent is as follows: the phenylboronic acid and the epichlorohydrin are mixed in a mass ratio of 1:2-6, tetraethylammonium hydroxide is added for catalytic reaction, and the product is precipitated with acetone and vacuum dried to obtain the borate ester dynamic crosslinking agent.

6. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: The electron beam energy of the electron beam irradiation device is 3-7 MeV, and the absorbed dose is 6-12 kGy; the gradient cooling is to first cool down to 40-70°C at a rate of 3-7°C / min, and then cool naturally to room temperature.

7. The method for preparing a high-toughness glass interlayer according to claim 1, characterized in that: In the three-channel co-extruder, channels one and three are for the surface-grafted polyester layer, and channel two is for the PVB functional layer; the extrusion temperature of the surface-grafted polyester layer is 230-250℃, and the extrusion temperature of the PVB functional layer is 180-200℃.

8. A high-toughness glass interlayer, characterized in that: The intermediate film consists of, from the inside out, a surface-grafted polyester layer, a PVB functional layer, and the surface-grafted polyester layer; the intermediate film is prepared by the preparation method according to any one of claims 1-7.

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