High-toughness glass intermediate film and preparation method thereof

Abstract

The invention relates to the technical field of glass intermediate films, in particular to a high-toughness glass intermediate film and a preparation method thereof. The problems of poor toughness and high temperature resistance of the glass intermediate film are solved. The preparation method comprises the following steps: preparing a plasticizer, a hybrid filler, a borate dynamic cross-linking agent and a self-repairing microcapsule, and mixing and calendering the materials to obtain a PVB functional layer; grafting amino through plasma treatment to obtain a surface grafted polyester layer; the PVB functional layer and the surface grafted polyester layer are added into a three-channel co-extruder to be extruded, the glass intermediate film of a layered structure is obtained through electron beam irradiation and gradient cooling, and the intermediate film sequentially comprises the surface grafted polyester layer, the PVB functional layer and the surface grafted polyester layer from inside to outside; by controlling the component dosage and process parameters in the preparation process, the toughness and high temperature resistance of the prepared glass intermediate film are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of glass interlayer films, and particularly to a high-toughness glass interlayer film and a preparation method thereof. Background Art

[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. As the core component of laminated glass, the performance of the glass interlayer film directly affects the overall performance of laminated glass. Currently, most glass interlayer films are PVB films. Due to many defects in the performance of single PVB films, laminated interlayer films composed of polyester are widely used. Although traditional laminated glass interlayer films have the ability to bond glass to a certain extent, they have significant defects in terms of toughness and high-temperature resistance.

[0003] From the perspective of toughness, when laminated glass is accidentally impacted or affected by strong winds in extreme weather, due to the limitations of its own molecular structure and performance, the laminated interlayer film is difficult to effectively disperse and absorb the impact force, resulting in the glass being prone to cracking or even falling off, and unable to provide reliable safety protection for users; in terms of high-temperature resistance, with the continuous improvement of the energy-saving and heat-insulation requirements of modern buildings and automobiles, the glass needs to be in a high-temperature environment for a long time, such as the exterior wall glass of a building under direct sunlight in summer or the front windshield of a car. At this time, the laminated interlayer film will have a decrease in the interlayer adhesion force due to high temperature, causing the interlayer film to delaminate from the glass, and then damaging the integrity and functionality of the laminated glass, seriously affecting its service life and safety performance.

[0004] Therefore, a high-toughness glass interlayer film and a preparation method thereof are proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-toughness glass interlayer film and a preparation method thereof. By preparing a plasticizer, a hybrid filler, a borate dynamic crosslinking agent, and self-healing microcapsules, and mixing and calendering the above materials to obtain a PVB functional layer; grafting amino groups through plasma treatment to obtain a surface-grafted polyester layer; adding the PVB functional layer and the surface-grafted polyester layer into a three-channel co-extrusion machine for extrusion, and obtaining a laminated glass interlayer film through electron beam irradiation and gradient cooling. The interlayer film is composed of a surface-grafted polyester layer, a PVB functional layer, and a surface-grafted polyester layer from the inside out; by controlling the component dosage and process parameters in the preparation process, the toughness and high-temperature resistance of the prepared glass interlayer film are improved.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] It should be noted that all parts in the present invention are parts by mass.

[0008] On the one hand, the present invention provides a method for preparing a high-toughness glass interlayer film, and the preparation method is as follows: subject a polyester film to plasma treatment to graft amino groups to obtain a surface-grafted polyester layer (0.1 mm); mix PVB resin, a plasticizer, a hybrid filler, and a borate dynamic crosslinking agent and then calender to obtain a PVB functional layer (0.5 mm); add the surface-grafted polyester layer and the PVB functional layer into a three-channel co-extrusion machine for extrusion; then use an electron beam irradiation device for irradiation, and subsequently perform gradient cooling to obtain the interlayer film;

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

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

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

[0012] Preferably, the preparation method of the surface-grafted polyester layer is as follows: place the polyester film in a plasma treatment device, evacuate to 10 -3 Pa, adjust the power to 150 - 200 W, introduce oxygen, with an oxygen flow rate of 30 sccm, and treat for 5 min to obtain a pretreated polyester film; dissolve 2 - 6 parts of allylamine monomer and 0.2 part of potassium persulfate in 20 parts of deionized water to obtain a grafting solution; inject the grafting solution into the plasma treatment device and react for 30 min to obtain the surface-grafted polyester layer.

[0013] Preferably, the preparation method of the PVB functional layer is as follows: premix 30 parts of PVB resin and 4 - 8 parts of plasticizer in a kneader at 50 °C for 20 min, add 1 - 3 parts of hybrid filler, 1 part of nano-ceria, and 1 part of antioxidant 1010, and melt and disperse through a twin-screw extruder at a temperature of 190 °C; cool down to 140 °C, add 1 - 5 parts of borate dynamic crosslinking agent, react in a static mixer for 20 min, cool down to 50 °C, add 8 - 12 parts of self-healing microcapsules, stir and then calender to obtain the PVB functional layer.

[0014] Preferably, the preparation method of the plasticizer is as follows: add 10 parts of hydroxyethyl acrylate and 20 parts of toluene into a three-necked flask, stir for 15 min, add 0.3 - 1 part of divinylbenzene and continue to stir for 20 min to obtain a mixed solution; dissolve 0.12 part of benzoyl peroxide in 5 parts of toluene, dropwise add it to the mixed solution, with a dropping time of 30 min, heat up to 80 °C, and stir at a speed of 150 rpm for 6 h to obtain the plasticizer.

[0015] Preferably, the preparation method of the hybrid filler is as follows: Dispersing 10 parts of boron nitride powder in 20 parts of isopropanol, and ultrasonically treating for 4 h at 40 kHz to obtain a suspension; Reacting the suspension and the silane coupling agent KH550 at a mass ratio of 100:1 in a water bath at 60 °C for 2 h, centrifuging and drying to obtain modified boron nitride; Ball-milling and mixing the modified boron nitride and multi-walled carbon nanotubes at a mass ratio of 5-10:3 to obtain the hybrid filler.

[0016] Preferably, the preparation method of the borate dynamic crosslinking agent is as follows: Mixing phenylboronic acid and epichlorohydrin at a mass ratio of 1:2-6, adding 1 wt% of tetraethylammonium hydroxide for catalytic reaction, and reacting at 80 °C for 6 h. The obtained product is precipitated with acetone and dried in vacuum to obtain the borate dynamic crosslinking agent.

[0017] Preferably, the preparation method of the self-healing microcapsules is as follows: Mixing bisphenol A epoxy resin (E51) and isophorone diisocyanate at a mass ratio of 2-6:1 to form a core material; Emulsifying the core material in deionized water containing 5 wt% polyvinyl alcohol (rotation speed 8000 rpm, 10 min), heating to 50 °C and reacting for 3 h to form a polyurea shell layer, followed by centrifugal washing and freeze-drying to obtain the self-healing microcapsules.

[0018] Preferably, the electron beam energy of the electron beam irradiation device is 3-7 MeV, the absorption dose is 6-12 kGy, the beam current intensity is 10 mA, the scanning width is 300 mm, and the single-sided irradiation time is 40 s; Gradient cooling is to cool down at a speed of 3-7 °C / min to 40-70 °C first, and then naturally cool to room temperature.

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

[0020] On the other hand, the present invention provides a high-toughness glass interlayer. The interlayer is, from the inside out, a surface-grafted polyester layer, a PVB functional layer, and a surface-grafted polyester layer; The interlayer is prepared by the preparation method of any one of the above.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. In the present invention, the polyester film is treated by oxygen plasma activation to form surface free radicals, and allylamine is further grafted to introduce amino functional groups, significantly enhancing the interfacial bonding force between the polyester layer and the PVB functional layer. During this process, the amino polar groups form hydrogen bond networks 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 temperatures, dynamically regulating the molecular chain segment movement ability. Under the synergistic effect of both, the interfacial adhesion strength and the flexibility of the internal molecular chains of the material are enhanced simultaneously, avoiding the interlayer peeling phenomenon and being able to absorb impact energy through the dynamic bond breakage-re-crosslinking mechanism, effectively improving the anti-crack propagation ability and long-term deformation recovery of the interlayer film under extreme temperature changes, thereby enhancing its toughness.

[0023] 2. In the hybrid filler of the present invention, the modified boron nitride is uniformly dispersed with the PVB resin through grafting with a silane coupling agent. Its lamellar structure can block the heat flow transfer path and reduce the thermal conductivity of the material; while the multi-walled carbon nanotubes form a three-dimensional conductive network, locally dissipating heat through the Joule heat effect and delaying the relaxation of molecular chains in a high-temperature environment. The modified boron nitride blocks the external heat source from entering, while the multi-walled carbon nanotubes actively conduct out the excess internal heat, forming an "external prevention and internal drainage" thermal management mechanism; at the same time, the gradient cooling process controls the temperature drop rate in stages, enabling the thermal expansion coefficient differences between the PVB functional layer and the grafted polyester layer to be gradually adapted during the cooling process, avoiding microcracks and interfacial thermal stress concentration caused by rapid cooling, and improving the high-temperature resistance of the interlayer film.

[0024] 3. In the present invention, the self-healing microcapsules use isophorone diisocyanate as the shell material to encapsulate the epoxy resin core material. When the interlayer film is damaged by external force, the microcapsules rupture to release the core material, which reacts with the hydroxyl groups in PVB to generate polyurethane repair bodies, achieving crack self-sealing; while electron beam irradiation initiates a free radical crosslinking reaction in the PVB layer, forming a high-density network structure, and at the same time, generating nano-scale crack-sensitive regions in the microcapsule shell layer through high-energy particle bombardment, reducing its rupture threshold; this synergistic strategy of process and material, on the one hand, enhances the rigidity and anti-penetrability of the base material through irradiation, and on the other hand, the microcapsules sensitively respond to damage and release the repair agent, and the dual mechanisms dynamically repair internal defects and restore the material continuity, thereby enhancing the toughness of the interlayer film.

[0025] 4. The hydroxyethyl acrylate-based plasticizer of the present invention forms stable hydrogen bonds with the PVB resin through polar hydroxyl groups, and at the same time forms a moderately flexible three-dimensional network under the regulation of a cross-linking agent, endowing the PVB functional layer with the characteristic of a rigid-flexible balance. In the three-channel co-extrusion process, the differential temperature extrusion of the grafted polyester layer and the PVB functional layer enables partial embedding of the molten polyester molecular chains into the PVB interface region, forming an interpenetrating interface transition layer; and the plasticizer optimizes the compatibility of the two phases through polar matching during this process, reducing the molecular chain rejection phenomenon at the interface. The synergistic effect of the two enables the interface region to have both the temperature resistance of high-toughness polyester and the dynamic energy dissipation ability of PVB, and still maintain the interface bonding strength under high-temperature impact or long-term heat exposure, suppressing the risks of delamination and brittle fracture. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a graph showing the test results of the high-temperature resistance performance of Example 2, Examples 5-6 and Comparative Examples 4-9 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Please refer to Figure 1 , the present invention 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 invention are as follows:

[0030] The polyester film is purchased from Hangzhou Dahua Plastics Industry Co., Ltd.; the allylamine monomer is purchased from Shandong Luyue Chemical Group; the boron nitride powder (1μm) is purchased from Shanghai Dipai Biotechnology Co., Ltd.; the multi-walled carbon nanotubes are purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0031] Example 1

[0032] Place the polyester film in a plasma treatment device and evacuate to 10 -3Pa, adjust the power to 150 W, introduce oxygen, with an oxygen flow rate of 30 sccm, and treat for 5 min to obtain a pretreated polyester film; dissolve 2 parts of allylamine monomer and 0.2 part of potassium persulfate in 20 parts of deionized water to obtain a grafting solution; pressurize the plasma treatment equipment to atmospheric pressure under nitrogen protection, inject the grafting solution, and react for 30 min to obtain a surface-grafted polyester layer (0.1 mm); premix 30 parts of PVB resin and 4 parts of plasticizer in a kneader at 50 °C for 20 min, add 1 part of hybrid filler, 1 part of nano-ceria, and 1 part of antioxidant 1010, and melt and disperse through a twin-screw extruder at a temperature of 190 °C; cool down to 140 °C, add 1 part of borate dynamic crosslinking agent, react in a static mixer for 20 min, cool down to 50 °C, add 8 parts of self-healing microcapsules, stir at a speed of 500 rpm for 10 min, and calender to obtain a PVB functional layer (0.5 mm); add the surface-grafted polyester layer and the PVB functional layer to a three-channel co-extruder, with channel 1 and channel 3 being the surface-grafted polyester layer and channel 2 being the PVB functional layer. The extrusion temperature of the surface-grafted polyester layer is 230 °C, and the extrusion temperature of the PVB functional layer is 180 °C; then irradiate with an electron beam irradiation device, with an electron beam energy of 3 MeV, an absorption dose of 6 kGy, a beam current intensity of 10 mA, a scanning width of 300 mm, and a single-sided irradiation time of 40 s; subsequently, cool down gradiently, first cool down to 40 °C at a rate of 3 °C / min, and then cool naturally to room temperature to obtain an intermediate film.

[0033] The preparation method of the plasticizer is as follows: Add 10 parts of hydroxyethyl acrylate and 20 parts of toluene to a three-necked flask, stir for 15 min, add 0.3 part of divinylbenzene and continue to stir for 20 min to obtain a mixed solution; dissolve 0.12 part of benzoyl peroxide in 5 parts of toluene, dropwise add it to the mixed solution, with a dropping time of 30 min, heat up to 80 °C, stir at a speed of 150 rpm for 6 h, cool down, and extract with deionized water, and then perform rotary evaporation at a temperature of 50 °C and a vacuum degree of 0.09 MPa to obtain the plasticizer.

[0034] The preparation method of the hybrid filler is as follows: Disperse 10 parts of boron nitride powder in 20 parts of isopropanol, and ultrasonically treat for 4 h at 40 kHz to obtain a suspension; react the suspension and silane coupling agent KH550 at a mass ratio of 100:1 in a water bath at 60 °C for 2 h, centrifuge and dry to obtain modified boron nitride; ball-mill and mix the modified boron nitride and multi-walled carbon nanotubes at a mass ratio of 5:3 (200 rpm, 6 h) to obtain the hybrid filler.

[0035] The preparation method of the borate dynamic crosslinking agent is as follows: Mix benzeneboronic acid and epichlorohydrin at a mass ratio of 1:2, add 1 wt% of tetraethylammonium hydroxide for catalytic reaction, react at 80 °C for 6 h, and the obtained product is precipitated with acetone and dried in vacuum to obtain the borate dynamic crosslinking agent.

[0036] The preparation method of the self-healing microcapsules is as follows: Bisphenol A epoxy resin (E51) and isophorone diisocyanate are mixed in a mass ratio of 2:1 to form the 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 °C and reacted for 3 h to form a polyurea shell layer. After centrifugal washing and freeze-drying, self-healing microcapsules (particle size 5-10 μm) are obtained.

[0037] Examples 2-4

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

[0039] Comparative Example 1

[0040] Referring to the preparation method and parameter conditions of Example 1, the difference is that the surface of the polyester film is not grafted.

[0041] Comparative Example 2

[0042] Referring to the preparation method and parameter conditions of Example 1, the difference is that the borate dynamic crosslinking agent is not added when preparing the PVB functional layer.

[0043] Comparative Example 3

[0044] Referring to the preparation method and parameter conditions of Example 1, the difference is that the borate dynamic crosslinking agent is replaced by tributyl borate when preparing the PVB functional layer.

[0045] Experimental Example 1 Toughness Test

[0046] The elongation at break of the 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 Tests 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 forms surface free radicals through oxygen plasma activation treatment, and further grafts allylamine to introduce amino functional groups, significantly enhancing 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 dynamic crosslinking agent in the PVB functional layer undergoes reversible dissociation and recombination at high temperatures, dynamically regulating the molecular chain segment movement ability; under the synergistic action of the two, the interfacial adhesion strength and the flexibility of the internal molecular chains of the material are enhanced simultaneously, avoiding the interlayer peeling phenomenon and being able to absorb impact energy through the dynamic bond breakage-re-crosslinking mechanism, effectively improving the anti-crack propagation ability and long-term deformation recovery of the interlayer film under extreme temperature changes, thereby enhancing the toughness. In Example 2, when the mass ratio of the two is 1:4, the amount of the crosslinking agent is 3 parts, the amount of the allylamine monomer is 4 parts, and the plasma treatment power is 170 W, the toughness of the prepared interlayer film is the best, and the elongation at break is 320%. In Comparative Example 1, the polyester film was not surface-grafted. Due to the large polarity difference between the polyester layer and the PVB layer, they are only combined by physical adsorption, and the shear strength is greatly reduced, and interlayer peeling is likely to occur under external impact or thermal stress; moreover, the surface of the ungrafted film has a high smoothness, and the interface becomes a weak link for stress transfer, and cracks tend to rapidly expand along the interface rather than dissipate into the PVB interior, resulting in an obvious loss of overall toughness. In Comparative Example 2, the borate dynamic crosslinking agent was not added when preparing the PVB functional layer. The original dynamic crosslinking bonds could break and absorb energy in the micro-region at the crack tip, delaying crack propagation. After the dynamic bonds were missing, the crack propagation rate increased and the fracture toughness decreased significantly. In Comparative Example 3, when preparing the PVB functional layer, the borate dynamic crosslinking agent was replaced with tributyl borate. The covalent bond could not respond to stress to adjust the network structure, and the molecular chain segments could not disperse energy through dynamic recombination under the action of external force, and the material showed the phenomenon of "stiff-brittle fracture"; in addition, the static crosslinking network was more likely to undergo chain segment thermal degradation at high temperatures.

[0050] Examples 5-6

[0051] Referring to the preparation method and parameter conditions of Example 2, the specific differences are shown in Table 2; in Table 2, the mass ratio of the two is the mass ratio of the modified boron nitride and the multi-walled carbon nanotubes; the cooling rate and the cooling temperature are both parameters during gradient cooling.

[0052] Comparative Example 4

[0053] Referring to the preparation method and parameter conditions of Example 2, the difference is that the hybrid filler was not added when preparing the PVB functional layer.

[0054] Comparative Example 5

[0055] Referring to the preparation method and parameter conditions of Example 2, the difference is that only 1 part of the modified boron nitride was used as the filler.

[0056] Comparative Example 6

[0057] Referring to the preparation method and parameter conditions of Example 2, except that only 1 part of multi-walled carbon nanotubes is used as the filler.

[0058] Comparative Example 7

[0059] Referring to the preparation method and parameter conditions of Example 2, except that only 1 part of boron nitride powder is used as the filler.

[0060] Comparative Example 8

[0061] Referring to the preparation method and parameter conditions of Example 2, except that gradient cooling is not carried out, but directly cooled to room temperature naturally.

[0062] Comparative Example 9

[0063] Referring to the preparation method and parameter conditions of Example 2, except that gradient cooling is not carried out, but directly cooled to room temperature at a rate of 5 °C / min.

[0064] Experimental Example 2 High Temperature Resistance Test

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

[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 1It can be seen that in Examples 2 and 5-6, in the hybrid filler, the modified boron nitride is grafted through a silane coupling agent to achieve uniform dispersion with the PVB resin. Its lamellar structure can block the heat flow transfer path and reduce the thermal conductivity of the material. The multi-walled carbon nanotubes form a three-dimensional conductive network, and the heat is locally dissipated through the Joule heat effect, delaying the relaxation of molecular chains in a high-temperature environment. At the same time, the gradient cooling process controls the temperature drop rate in stages, enabling the thermal expansion coefficient differences between the PVB functional layer and the grafted polyester layer to be gradually adapted during the cooling process, avoiding microcracks and interfacial thermal stress concentration caused by rapid 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 was added when preparing the PVB functional layer. The PVB resin itself is a low-thermal-conductivity material and cannot effectively transfer heat, and local temperature is likely to accumulate in a high-temperature environment, triggering thermal degradation of molecular chains. In Comparative Example 5, only 1 part of modified boron nitride was used as the filler. The lamellar structure of boron nitride forms parallel heat conduction paths, and the transverse thermal conductivity is limitedly improved, and heat is not easily diffused to both sides. Moreover, due to the lack of the cross-linking and strengthening effect of carbon nanotubes, the crack propagation resistance of the PVB matrix at high temperature decreases, and local brittle fracture is likely to occur. In Comparative Example 6, only 1 part of multi-walled carbon nanotubes was used as the filler. It has high thermal conductivity along the axial direction of the carbon tube, 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 was used as the filler. The unmodified boron nitride particles are difficult to be uniformly dispersed, forming micropores or stress concentration points, which become the starting points of high-temperature cracking. In Comparative Examples 8-9, gradient cooling was not carried out, lacking the stress release and microstructure optimization ability of gradient cooling, and it is easy for the material to undergo chain segment relaxation and deformation at high temperature.

[0069] Examples 7-9

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

[0071] Comparative Example 10

[0072] Referring to the preparation method and parameter conditions of Example 5, the difference is that no self-healing microcapsules were added.

[0073] Comparative Example 11

[0074] Referring to the preparation method and parameter conditions of Example 5, the difference is that no irradiation was carried out using an electron beam irradiation device.

[0075] Experimental Example 3 Toughness Test

[0076] Referring to the test method of Experimental Example 1; the obtained 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 and Examples 7-9, the self-healing microcapsules use isophorone diisocyanate as the shell material to encapsulate the epoxy resin core material. When the middle film is damaged by external force, the microcapsules rupture and release the core material to react with the hydroxyl groups in PVB to generate polyurethane repair bodies, realizing crack self-sealing; while electron beam irradiation initiates 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 nano-scale crack-sensitive area in the microcapsule shell layer, reducing its rupture threshold; this synergistic strategy of process and material, on the one hand, enhances the rigidity and anti-penetration of the base material through irradiation, and on the other hand, the microcapsules sensitively respond to damage and release the repair agent, and the dual mechanisms dynamically repair internal defects and restore material continuity, thereby improving the toughness of the middle film. In Example 7, when the mass ratio of the two is 4:1, the dosage of the self-healing microcapsules is 10 parts, the electron beam energy is 5 MeV, and the absorbed dose is 8 kGy, the toughness of the prepared middle film is the best, and the elongation at break is 323%. In Comparative Example 10, no self-healing microcapsules were added, and the microcracks generated by external force could not be filled and repaired by the flow of the core material. The stress concentration continued to occur at the crack tip, and it rapidly expanded into a macroscopic fracture channel, resulting in a decrease in toughness. In Comparative Example 11, no electron beam irradiation device was used for irradiation, and no irradiation-induced covalent cross-linking network was formed in the PVB matrix. The interfacial bonding and the cross-linking degree of the matrix were insufficient, and the molecular chains were prone to slip or interfacial debonding when the material was stressed.

[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 was 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 was used as the plasticizer.

[0086] Experimental Example 4 High-temperature toughness test

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

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

[0089]

[0090] As can be seen from Table 4, in Example 7 and Examples 10 - 12, the hydroxyethyl acrylate-based plasticizer forms stable hydrogen bonds with the PVB resin through polar hydroxyl groups, and at the same time forms a moderately flexible three-dimensional network under the regulation of the cross-linking agent, endowing the PVB functional layer with the characteristics of a rigid-flexible balance. In the three-channel co-extrusion process, the differential temperature extrusion of the grafted polyester layer and the PVB functional layer forces some of the molten polyester molecular chains to embed in the PVB interface region, forming an interpenetrating interface transition layer; and the plasticizer optimizes the compatibility of the two phases through polar matching during this process, reducing the molecular chain rejection phenomenon at the interface. The synergistic effect of the two enables the interface region to have both the temperature resistance of high-toughness polyester and the dynamic energy dissipation ability of PVB, and can still maintain the interface bonding strength under high-temperature impact or long-term heat exposure, inhibiting the risks of delamination and brittle fracture. In Example 10, when the dosage of divinylbenzene is 0.5 part, the dosage of the 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 intermediate film has the best toughness at high temperature, and the retention rate of the elongation at break is 95.6%. In Comparative Example 12, no plasticizer was added when preparing the PVB functional layer, the rigidity of the PVB molecular chain increased, and it was still in the glassy state or weak high-elastic state at high temperature, and the chain segments were difficult to extend. When an external force was applied, the lack of the lubrication effect of the plasticizer caused the molecular chains to directly bear the stress, and cracks quickly initiated and propagated. In Comparative Example 13, dibutyl phthalate was used as the plasticizer, and its low molecular weight and high volatility led to insufficient high-temperature stability, and it was 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 the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a high-toughness glass interlayer film, characterized in that: The preparation method is as follows: subject the polyester film to plasma treatment to graft amino groups to obtain a surface-grafted polyester layer; mix PVB resin, a plasticizer, a hybrid filler, and a borate-based dynamic crosslinking agent and then calender to obtain a PVB functional layer; add the surface-grafted polyester layer and the PVB functional layer into a three-channel co-extrusion machine for extrusion; then irradiate with an electron beam irradiation device, and subsequently cool at a gradient to obtain the intermediate film; The plasticizer is obtained by the reaction of 2-hydroxyethyl acrylate and divinylbenzene; The hybrid filler is prepared from boron nitride powder, a silane coupling agent, and multi-walled carbon nanotubes; The borate-based dynamic crosslinking agent is obtained by the reaction of benzeneboronic acid and epichlorohydrin.

2. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: The preparation method of the surface-grafted polyester layer is as follows: place the polyester film in a plasma treatment device, adjust the power to 150 - 200 W, introduce oxygen, and treat to obtain a pretreated polyester film; dissolve 2 - 6 parts of allylamine monomer and potassium persulfate in deionized water to obtain a grafting solution; inject the grafting solution into the plasma treatment device to react to obtain the surface-grafted polyester layer.

3. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: The preparation method of the PVB functional layer is as follows: premix the PVB resin and 4 - 8 parts of the plasticizer in a kneader, add 1 - 3 parts of the hybrid filler, nano-ceria, and an antioxidant, and melt and disperse through a twin-screw extruder; add 1 - 5 parts of the borate-based dynamic crosslinking agent, react in a static mixer, then add 8 - 12 parts of self-healing microcapsules, stir, and calender to obtain the PVB functional layer.

4. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: The preparation method of the plasticizer is as follows: add the 2-hydroxyethyl acrylate and toluene into a three-necked flask, stir, then add 0.3 - 1 part of the divinylbenzene and continue stirring to obtain a mixed solution; dissolve benzoyl peroxide in toluene, dropwise add it to the mixed solution, and stir to obtain the plasticizer.

5. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: The preparation method of the hybrid filler is as follows: disperse the boron nitride powder in isopropanol and ultrasonically obtain a suspension; react the suspension and the silane coupling agent in a water bath, centrifuge and dry to obtain modified boron nitride; ball-mill and mix the modified boron nitride and the multi-walled carbon nanotubes in a mass ratio of 5 - 10:3 to obtain the hybrid filler.

6. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: The preparation method of the borate-based dynamic crosslinking agent is as follows: mix the benzeneboronic acid and the epichlorohydrin in a mass ratio of 1:2 - 6, add tetraethylammonium hydroxide for catalytic reaction, and the obtained product is precipitated with acetone and dried under vacuum to obtain the borate-based dynamic crosslinking agent.

7. The preparation method of a high-toughness glass interlayer film according to claim 3, characterized in that: The preparation method of the self-healing microcapsules is as follows: mix bisphenol A epoxy resin and isophorone diisocyanate in a mass ratio of 2 - 6:1 to form a core material; emulsify the core material in deionized water containing polyvinyl alcohol, react to form a polyurea shell layer, and after centrifugal washing and freeze-drying, obtain the self-healing microcapsules.

8. The preparation method of a high-toughness glass interlayer film 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 at a rate of 3 - 7 °C / min to 40 - 70 °C, and then naturally cool to room temperature.

9. The preparation method of a high-toughness glass interlayer film according to claim 1, characterized in that: In the three-channel co-extrusion machine, Channel 1 and Channel 3 are the surface-grafted polyester layers, and Channel 2 is the PVB functional layer; the extrusion temperature of the surface-grafted polyester layer is 230-250°C, and the extrusion temperature of the PVB functional layer is 180-200°C.

10. A high-toughness glass interlayer, characterized in that: The intermediate film is, 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 described in any one of claims 1-9.

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