Multifunctional pvc interlayer for laminated glass and its preparation method and application

Abstract

The present application relates to the technical field of functional materials for laminated glass, and particularly relates to a multifunctional PVB interlayer for laminated glass, a preparation method and application thereof. In the interlayer, the first skin layer and the second skin layer respectively comprise PVB resin, modified LaB6, synergistic stabilizer (epoxy resin, organic titanium chelating agent and ultraviolet stabilizer), plasticizer, adhesion regulator and antioxidant; the core layer comprises PVB elastomer mixture and plasticizer, and the PVB elastomer mixture comprises PVB elastomer prepared from first PVA (polymerization degree 1700-1800, alcoholysis degree 86-90%) and PVB elastomer prepared from second PVA (polymerization degree 2000-2100, alcoholysis degree 86-90%); the thickness of the skin layer is greater than that of the core layer, and the content of the plasticizer in the skin layer is less than that in the core layer. Through synergistic design of the three-layer composite structure, the present application realizes high integration of infrared blocking, anti-aging, strong adhesion and high-efficiency sound insulation functions.

Description

Technical Field

[0001] This invention relates to the field of functional materials for laminated glass, and in particular to a multifunctional PVB interlayer for laminated glass, its preparation method, and its application. Background Technology

[0002] Laminated glass is widely used in the automotive, construction, and rail transportation industries due to its excellent explosion-proof safety performance. Among them, polyvinyl butyral (PVB) interlayer, as a key functional layer of laminated glass, not only plays the role of bonding the glass, but can also achieve various performance enhancements such as infrared blocking and ultraviolet protection through functional modification.

[0003] Lanthanum hexaboride (LaB6), as a highly efficient near-infrared absorbing material, shows promising application potential in PVB interlayer films. However, it is prone to hydrolysis and photodegradation in the polymer matrix, affecting its long-term stability. While existing technologies attempt to improve this through stabilizers such as epoxy resins, the problem of limited functionality remains. Particularly in terms of sound insulation performance, traditional PVB interlayer films rely primarily on the damping properties of the substrate itself, making it difficult to meet the effective blocking requirements for mid-to-high frequency noise in applications such as automobiles and high-speed rail.

[0004] Currently, most sound-insulating PVB interlayer films on the market adopt a single elastomer structure or a simple composite structure, which has the following technical shortcomings: First, elastomer modification easily interferes with the dispersion and stability of infrared absorbers, leading to a decrease in heat insulation performance; Second, the structural design lacks systematicity, and the thickness ratio of the skin layer and the core layer, as well as the plasticizer content, have not been synergistically optimized, making it difficult to balance sound insulation effect and structural strength; Third, the effective integration of infrared blocking, anti-aging, strong adhesion, and sound insulation functions has not yet been achieved, limiting its adaptability in different application scenarios; Fourth, the preparation process of the core layer PVB elastomer lacks a standardized process, affecting the consistency of product performance.

[0005] Therefore, it is of great significance to develop a PVB interlayer with optimized structure, integrated functions, and standardized process to significantly improve sound insulation while ensuring high stability, excellent optical performance, and strong adhesion. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a multifunctional PVB interlayer for laminated glass, its preparation method, and its application. Through the synergistic design of the "skin / core / skin" three-layer composite structure, a high degree of integration of infrared blocking, anti-aging, strong adhesion, and efficient sound insulation functions is achieved.

[0007] To achieve the above objectives, the present invention provides a multifunctional PVB interlayer for laminated glass, wherein the interlayer has a three-layer composite structure, including a first skin layer, a core layer, and a second skin layer; The first and second skin layers respectively contain PVB resin, modified LaB6, synergistic stabilizers, plasticizers, adhesion modifiers, and antioxidants; the synergistic stabilizers include epoxy resin, organotitanium chelators, and UV stabilizers; The core layer comprises a PVB elastomer mixture and a plasticizer; the PVB elastomer mixture comprises a PVB elastomer prepared from a first PVA and a PVB elastomer prepared from a second PVA; the first PVA has a degree of polymerization of 1700-1800 and a degree of hydrolysis of 86-90%; the second PVA has a degree of polymerization of 2000-2100 and a degree of hydrolysis of 86-90%. The thickness of both the first and second skin layers is greater than the thickness of the core layer, and the plasticizer content in both the first and second skin layers is less than the plasticizer content in the core layer.

[0008] In the technical solution of this invention, by setting the thickness of the skin layer to be greater than that of the core layer and controlling the plasticizer content of the skin layer to be lower than that of the core layer, the skin layer possesses higher hardness and structural strength, thereby ensuring good adhesion to glass and stability of infrared blocking function. Simultaneously, when sound waves penetrate the interlayer, the core layer, under the influence of a higher plasticizer content, can effectively induce reciprocating deformation of polymer chain segments. Through internal friction between molecular chains and the deformation hysteresis effect of the cross-linked network, sound energy is converted into heat energy dissipation, thus achieving efficient sound insulation. This design creates a "hard-soft-hard" gradient structure between the skin layer and the core layer, which not only ensures the overall mechanical strength of the membrane layer but also fully utilizes the damping sound insulation function of the core layer, achieving synergistic optimization of structural strength and acoustic performance.

[0009] In an optional embodiment, the first and second skin layers, by weight, respectively comprise 100 parts of PVB resin, 0.005-0.1 parts of modified LaB6, 0.65-5 parts of synergistic stabilizer, 20-30 parts of plasticizer, 0.05-0.3 parts of adhesion modifier, and 0.1-0.3 parts of antioxidant.

[0010] In an optional embodiment, the mass ratio of the epoxy resin, organotitanium chelating agent, and UV stabilizer in the synergistic stabilizer is (10-80):(1-10):(2-10). This synergistic stabilization system forms a triple protection mechanism of "physical encapsulation-chemical coordination-photoprotection" through the physical encapsulation of epoxy resin, the chemical coordination of organotitanium chelating agent, and the photoprotective effect of UV stabilizer, significantly improving the dispersion stability and aging resistance of LaB6 in the PVB matrix.

[0011] In an optional embodiment, the epoxy resin is selected from bisphenol A type epoxy resin. The organic titanium chelating agent is selected from one or more of tetrabutyl titanate, tetraisopropyl titanate, and di(acetylacetonyl)titanium diisopropylate, more preferably di(acetylacetonyl)titanium diisopropylate. The ultraviolet stabilizer is selected from one or more of benzotriazole ultraviolet stabilizers and benzoxazinone ultraviolet stabilizers, more preferably 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (CAS No.: 2440-22-4), 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole (CAS No.: 3147-75-9), and 2,2'-methylenebis(4-tert-butyl-6-benzoxazinone) (CAS No.: 13878-58-5).

[0012] In one optional embodiment, the adhesion modifier is selected from one or more of magnesium carboxylate salts and potassium carboxylate salts with 2-16 carbon atoms; the magnesium carboxylate salt with 2-16 carbon atoms is selected from one or more of magnesium acetate, magnesium propionate, magnesium 2-ethylbutyrate, and magnesium 2-ethylhexanoate; the potassium carboxylate salt with 2-16 carbon atoms includes one or more of potassium acetate, potassium propionate, potassium 2-ethylbutyrate (CAS No.: 53496-15-4), and potassium 2-ethylhexanoate.

[0013] In one optional embodiment, the antioxidant is selected from one or more of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants; the hindered phenolic antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, and antioxidant 1098; the phosphite antioxidant is selected from one or more of antioxidant 168, antioxidant 626, and antioxidant 618; and the thioester antioxidant is selected from one or more of antioxidant DLTP and antioxidant DSTP.

[0014] In one optional embodiment, the core layer comprises, by weight, 100 parts of a PVB elastomer mixture and 24-60 parts of a plasticizer.

[0015] In an optional embodiment, the plasticizers used in the first skin layer, the second skin layer, and the core layer are selected from one or more of the following: triethylene glycol di-2-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol dioctanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propanediol di-2-ethylbutyrate, and 1,4-butanediol di-2-ethylbutyrate.

[0016] In an optional embodiment, the mass ratio of the PVB elastomer prepared from the first PVA to the PVB elastomer prepared from the second PVA in the PVB elastomer mixture is (30-70):(30-70). By mixing PVB elastomers prepared from two PVAs with different degrees of polymerization in a specific ratio, the core layer can exhibit excellent damping characteristics over a wide audio range (200-3000Hz), thereby achieving effective blocking of mid-to-high frequency noise.

[0017] In an optional embodiment, the first PVA is preferably PVA 1788 (degree of polymerization 1700, degree of hydrolysis 88%), and the second PVA is preferably PVA 2088 (degree of polymerization 2000, degree of hydrolysis 88%).

[0018] In an optional embodiment, the method for preparing the PVB elastomer from the first PVA includes the following steps: (1) The first PVA is crushed to obtain first PVA powder with a particle size of 80-120 mesh; 95-105 parts by weight of the first PVA powder are added to a glass container equipped with a reflux condenser, thermometer and anchor-type stirring paddle, and 450-550 parts by weight of ion-exchange water are added. The system temperature is raised to 80-95℃ to completely dissolve the first PVA powder and obtain the first PVA aqueous solution. (2) Slowly cool the first PVA aqueous solution to 5-20℃ (cooling time is 35-45min), and add 95-105 parts by weight of hydrochloric acid solution with a mass fraction of 18-22% and 45.3-55.7 parts by weight of aldehyde compound in sequence, and carry out acetalization reaction for 100-120min; the aldehyde compound includes butyraldehyde and glutaraldehyde; (3) After the acetalization reaction is completed, the system is heated to 50-70℃ within 50-60 min and kept at that temperature for 130-150 min. Then, a sodium hydroxide solution with a mass fraction of 31-33% is added dropwise to adjust the pH of the solution to 7.0-9.0. (4) The resin precipitated in the system is washed with ion-exchanged water, centrifuged and dried to obtain the PVB elastomer prepared from the first PVA.

[0019] In an optional embodiment, the preparation process of the PVB elastomer prepared from the second PVA is the same as that of the PVB elastomer prepared from the first PVA, except that the first PVA is replaced with the second PVA.

[0020] In one optional embodiment, the total thickness of the intermediate film is 0.3-1.5 mm; the thickness ratio of the first skin layer, the second skin layer, and the core layer is (1.2-3):(1.2-3):1.

[0021] In an optional embodiment, the modified LaB6 is nano-LaB6 modified with a silane coupling agent. The preparation method includes the following steps: dispersing nano-LaB6 with a particle size of 50-100 nm in ethanol, adding 1-5% (by mass) of silane coupling agent KH550 of the nano-LaB6, stirring the mixture at 60-80°C and 500-700 r / min for 2-4 h, centrifuging, and drying at 85-95°C for 2.5-3.5 h to obtain the modified LaB6. The surface-modified LaB6 exhibits significantly improved dispersibility in the PVB matrix, which is beneficial for achieving a uniform and stable infrared blocking effect.

[0022] In an optional embodiment, the PVB resin in the first and second skin layers has a hydroxyl content of 15-25 mol%, a degree of acetylation of 1-5 mol%, a degree of acetalization of 70-84 mol%, and a weight-average molecular weight of 250,000-400,000 g / mol. This specific range of PVB resin ensures both good adhesion to glass and good compatibility with modified LaB6 and the synergistic stabilizing system, ensuring stable performance of the infrared blocking function.

[0023] The present invention also provides a method for preparing the aforementioned multifunctional laminated glass PVB interlayer, comprising the following steps: S1. Prepare the skin layer material and the core layer material separately; S2. The skin material and the core material are extruded through a three-layer co-extruder to form a three-layer composite structure including a first skin layer, a core layer and a second skin layer. After molding, a multifunctional PVB interlayer film for laminated glass is obtained.

[0024] In an optional embodiment, in step S1, the process of preparing the skin material includes the following steps: PVB resin, plasticizer, adhesion modifier, and antioxidant are stirred and mixed at 80-90°C and 800-1000 r / min for 30-60 min to obtain a premix; a synergistic stabilizer is added to the premix, and stirring is continued at 550-650 r / min for 20-30 min; subsequently, modified LaB6 is added, and the mixture is dispersed at 1000-1500 r / min for 40-60 min to obtain the skin material. This stepwise mixing process ensures the uniform dispersion of each functional additive in the PVB resin, especially the sufficient contact between the synergistic stabilizer and modified LaB6, which is beneficial for forming a stable protective system.

[0025] In an optional embodiment, in S1, the process of preparing the core layer material includes the following steps: melting and mixing the components contained in the core layer at 140-160°C for 30-60 minutes to obtain the core layer material.

[0026] In an optional embodiment, in step S2, the skin layer material and the core layer material are respectively added to the corresponding barrels of a three-layer co-extruder and extruded through a composite die. During the extrusion process, the barrel temperature of the skin layer material is 160-180℃, the barrel temperature of the core layer material is 140-160℃, the die temperature is 165-175℃, and the screw speed is 30-50 r / min. By controlling the processing temperature of each layer material, good melt flowability is ensured, potential degradation of the core layer elastomer at high temperatures is avoided, and the interfacial bonding strength between the skin layer and the core layer is ensured.

[0027] In an optional embodiment, in S2, the forming method is calendering; after forming, it is naturally cooled to room temperature; then it is cured for 24-48 hours at a temperature of 40-50°C and a humidity of 40-60% to eliminate internal stress and obtain a PVB interlayer for multifunctional laminated glass.

[0028] The present invention also provides a laminated glass comprising the aforementioned PVB interlayer for multifunctional laminated glass.

[0029] The present invention also provides the application of the aforementioned multifunctional laminated glass PVB interlayer film or the aforementioned laminated glass in automobile windshields, building curtain walls, high-speed rail windows or aircraft windows.

[0030] The present invention has achieved the following beneficial effects: (1) This invention achieves a high degree of integration of infrared blocking, anti-aging, strong adhesion and efficient sound insulation functions through the synergistic design of a three-layer composite structure of "skin layer / core layer / skin layer". Among them, the first skin layer and the second skin layer are loaded with modified LaB6 and a synergistic stabilizing system, which endows the intermediate film with excellent infrared blocking performance and long-term stability; the core layer adopts a mixture of PVB elastomers prepared by the first PVA and the second PVA with specific degrees of polymerization and hydrolysis, and utilizes the high damping characteristics formed by the synergy of the two to achieve effective absorption of mid-to-high frequency noise. More importantly, this invention forms a "hard-soft-hard" gradient structure by controlling the thickness of the first skin layer and the second skin layer to be greater than the thickness of the core layer, and the plasticizer content in the skin layer to be less than the plasticizer content in the core layer: the skin layer maintains high hardness and structural strength, ensuring good adhesion to glass and stability of infrared blocking function; the core layer has excellent damping characteristics due to the high plasticizer content, which can efficiently absorb sound wave energy. This synergistic combination of structural and component design enables the interlayer membrane to simultaneously possess comprehensive performance characteristics such as infrared blocking rate ≥85%, visible light transmittance ≥90%, yellowing index ≤1.0, and sound transmission loss (STL) ≥35dB in the 200-3000Hz frequency band.

[0031] (2) This invention significantly improves the dispersion stability and aging resistance of modified LaB6 in a PVB matrix through a triple synergistic stabilization mechanism of "physical encapsulation-chemical coordination-photoprotection". In the synergistic stabilizers, epoxy resin isolates LaB6 particles from the external environment through physical encapsulation, slowing down hydrolysis and oxidation; the organotitanium chelating agent forms stable coordination bonds with the LaB6 surface through chemical coordination, further enhancing its structural stability; and the ultraviolet stabilizer prevents photodegradation of LaB6 by absorbing and dissipating ultraviolet energy. The three work synergistically to form multiple layers of protection for LaB6. Experimental data show that the intermediate film prepared in this embodiment of the invention exhibits good performance under conditions of 80℃ temperature, 95% relative humidity, and ultraviolet irradiation (300-400nm, irradiation intensity 0.5W / m²). 2 After aging for 1000 hours under the specified conditions, the change rate of infrared transmittance is ≤2.1%.

[0032] (3) This invention ensures excellent and stable sound insulation performance through standardized preparation process and specific ratio design of core PVB elastomer. The first PVA and the second PVA are respectively prepared into PVB elastomer through standardized steps such as crushing, dissolving, cooling, acetalization reaction, heating and heat preservation, pH adjustment, washing and drying. The process parameters are clear and the process is standardized, ensuring the consistency of performance of different batches of products.

[0033] (4) This invention ensures compatibility between various functions through the synergistic adaptation of the skin and core material systems, avoiding the problem of sound insulation modification affecting the dispersion stability of infrared absorbers in traditional technologies. Experimental data show that the optical, interfacial, and mechanical properties of the intermediate film of this invention remain at an excellent level.

[0034] (5) The preparation process of the present invention has a high degree of standardization and strong adaptability, and is easy to industrialize and promote. The preparation process is compatible with existing PVB interlayer film production lines, requiring only the addition of a core layer preparation unit and a three-layer co-extrusion die, with low modification costs and good industrialization prospects. Detailed Implementation

[0035] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0036] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0037] In the following embodiments and comparative examples of the present invention, "parts" refers to "parts by weight"; the bisphenol A type epoxy resin is bisphenol A type epoxy resin E-51, with an epoxy value of 0.51-0.54 eq / 100g, an epoxy equivalent of 185-196g / eq, and a rotational viscosity of 11000-15000mPa・s at 25°C.

[0038] Example 1 This embodiment provides a multifunctional PVB interlayer for laminated glass (total thickness 0.76 mm), which is a three-layer composite structure including a first skin layer, a core layer, and a second skin layer, with a thickness ratio of 1.4:1.4:1.

[0039] The first and second skin layers each comprise: 100 parts of PVB resin (hydroxyl content 18 mol%, acetylation degree 2 mol%, acetalization degree 80 mol%, weight average molecular weight 300,000 g / mol), 0.02 parts of modified LaB6, 2.5 parts of synergistic stabilizer, 25 parts of plasticizer (triethylene glycol di-2-ethylhexanoate), 0.1 parts of adhesion modifier (magnesium 2-ethylbutyrate), and 0.2 parts of antioxidant. The synergistic stabilizer includes bisphenol A epoxy resin, diisopropyl di(acetylacetonate) titanate, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, in a mass ratio of 20:2:3; the antioxidant includes antioxidant 1010 and antioxidant 168, in a mass ratio of 1:1.

[0040] The core layer comprises: 100 parts of a PVB elastomer mixture and 35 parts of triethylene glycol di-2-ethylhexanoate. The PVB elastomer mixture includes PVB elastomer prepared from PVA 1788 and PVB elastomer prepared from PVA 2088, in a mass ratio of 50:50.

[0041] This embodiment also provides a method for preparing the above-mentioned multifunctional PVB interlayer for laminated glass, including the following steps: Preparation of modified LaB6: 0.02 parts of nano-LaB6 with a particle size of 80 nm were dispersed in 50 parts of ethanol, and 5% of the mass of nano-LaB6 was added as silane coupling agent KH550. The mixture was stirred at 70 °C and 600 r / min for 3 h. After centrifugation, the mixture was dried at 90 °C for 3 h to obtain modified LaB6.

[0042] Preparation of PVB elastomer from PVA 1788: PVA 1788 was pulverized to obtain PVA 1788 powder with a particle size of 80-120 mesh. 100 parts of PVA 1788 powder were added to a glass container equipped with a reflux condenser, thermometer, and anchor-type stirrer. 500 parts of deionized water were added, and the system temperature was raised to 85℃ to completely dissolve the PVA 1788 powder, obtaining a PVA 1788 aqueous solution. The PVA 1788 aqueous solution was slowly cooled to 10℃ (cooling time 40 min), and 100 parts of 20% hydrochloric acid solution, 50 parts of butyraldehyde, and 0.5 parts of glutaraldehyde were added sequentially to carry out an acetalization reaction for 120 min. After the acetalization reaction was completed, the system temperature was raised to 60℃ within 55 min and held for 130 min. Subsequently, a 32% sodium hydroxide solution was added dropwise to adjust the pH of the solution to 9.0. The resin precipitated in the system was washed with ion-exchanged water and dried by centrifugation to obtain PVB elastomer prepared from PVA 1788.

[0043] Preparation of PVB elastomers from PVA 2088: The preparation process is the same as that for PVB elastomers from PVA 1788, except that the raw material PVA 1788 is replaced with PVA 2088.

[0044] Preparation of the skin material: PVB resin, plasticizer, adhesion modifier and antioxidant were stirred and mixed at 85℃ and 900r / min for 45min to obtain a premix; a synergistic stabilizer was added to the premix and stirred and mixed at 600r / min for 25min; then modified LaB6 was added and dispersed at 1200r / min for 50min to obtain the skin material.

[0045] Preparation of core material: The components contained in the core layer are melt-mixed at 150°C for 45 minutes to obtain the core material.

[0046] Extrusion and molding: The skin material and the core material are respectively added to the corresponding barrels of the three-layer co-extruder. The barrel temperature of the skin material is 170℃, the barrel temperature of the core material is 150℃, the die temperature is 170℃, and the screw speed is 40r / min. After extrusion, the material is calendered and naturally cooled to room temperature. It is then cured for 36 hours at a temperature of 45℃ and a humidity of 50% to obtain a multifunctional PVB interlayer for laminated glass.

[0047] Example 2 This embodiment provides a multifunctional PVB interlayer for laminated glass (total thickness 0.76 mm), which is a three-layer composite structure including a first skin layer, a core layer, and a second skin layer, with a thickness ratio of 1.875:1.875:1.

[0048] The first and second skin layers each comprise: 100 parts of PVB resin (22 mol% hydroxyl content, 3 mol% acetylation, 75 mol% acetalization, and 350,000 g / mol weight average molecular weight), 0.03 parts of modified LaB6, 3.7 parts of synergistic stabilizer, 28 parts of plasticizer (tetraethylene glycol di-2-ethylhexanoate), 0.15 parts of adhesion modifier (potassium 2-ethylhexanoate), and 0.2 parts of antioxidant (antioxidant 1076). The synergistic stabilizer includes bisphenol A epoxy resin, tetrabutyl titanate, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, in a mass ratio of 30:3:4.

[0049] The core layer comprises: 100 parts of a PVB elastomer mixture and 45 parts of tetraethylene glycol di-2-ethylhexanoate. The PVB elastomer mixture includes PVB elastomer prepared from PVA 1788 and PVB elastomer prepared from PVA 2088, with a mass ratio of 30:70.

[0050] This embodiment also provides a method for preparing the above-mentioned multifunctional PVB interlayer for laminated glass, including the following steps: Preparation of modified LaB6: 0.03 parts of nano-LaB6 with a particle size of 60 nm were dispersed in 60 parts of ethanol, and 5% of the mass of nano-LaB6 was added as silane coupling agent KH550. The mixture was stirred at 75 °C and 700 r / min for 2.5 h. After centrifugation, it was dried at 90 °C for 3 h to obtain modified LaB6.

[0051] Preparation of PVB elastomer from PVA 1788: PVA 1788 was pulverized to obtain PVA 1788 powder with a particle size of 80-120 mesh. 100 parts of PVA 1788 powder were added to a glass container equipped with a reflux condenser, thermometer, and anchor-type stirrer. 500 parts of deionized water were added, and the system temperature was raised to 90℃ to completely dissolve the PVA 1788 powder, obtaining a PVA 1788 aqueous solution. The PVA 1788 aqueous solution was slowly cooled to 15℃ (cooling time 40 min), and 100 parts of 20% hydrochloric acid solution and 50 parts of glutaraldehyde were added sequentially to carry out an acetalization reaction for 110 min. After the acetalization reaction was completed, the system temperature was raised to 70℃ within 60 min and held for 130 min. Subsequently, a 32% sodium hydroxide solution was added dropwise to adjust the pH of the solution to 8.0. The resin precipitated in the system was washed with ion-exchanged water and dried by centrifugation to obtain PVB elastomer prepared from PVA 1788.

[0052] Preparation of PVB elastomers from PVA 2088: The preparation process is the same as that for PVB elastomers from PVA 1788, except that the raw material PVA 1788 is replaced with PVA 2088.

[0053] Preparation of the skin material: PVB resin, plasticizer, adhesion modifier and antioxidant were stirred and mixed at 90℃ and 1000r / min for 30min to obtain a premix; a synergistic stabilizer was added to the premix and stirred and mixed at 600r / min for 25min; then modified LaB6 was added and dispersed at 1200r / min for 50min to obtain the skin material.

[0054] Preparation of core material: The components contained in the core layer are melt-mixed at 155°C for 40 min to obtain the core material.

[0055] Extrusion and molding: The skin material and the core material are respectively added to the corresponding barrels of the three-layer co-extruder. The barrel temperature of the skin material is 175℃, the barrel temperature of the core material is 155℃, the die temperature is 170℃, and the screw speed is 40r / min. After extrusion, the material is calendered and naturally cooled to room temperature. It is then cured for 24 hours at a temperature of 50℃ and a humidity of 45% to obtain a multifunctional PVB interlayer for laminated glass.

[0056] Example 3 This embodiment provides a multifunctional PVB interlayer for laminated glass (total thickness 0.76 mm), which is a three-layer composite structure including a first skin layer, a core layer, and a second skin layer, with a thickness ratio of 1.23:1.23:1.

[0057] The first and second skin layers each comprise: 100 parts of PVB resin (20 mol% hydroxyl content, 4 mol% acetylation, 76 mol% acetalization, and 320,000 g / mol weight average molecular weight), 0.04 parts of modified LaB6, 3.1 parts of synergistic stabilizer, 22 parts of plasticizer (dioctyl azelate), 0.2 parts of adhesion modifier (magnesium acetate), and 0.3 parts of antioxidant. The synergistic stabilizer includes bisphenol A epoxy resin, tetraisopropyl titanate, and 2,2'-methylenebis(4-tert-butyl-6-benzoxazinone) in a mass ratio of 25:2.5:3.5; the antioxidant includes antioxidant 626 and antioxidant DLTP in a mass ratio of 1:1.

[0058] The core layer comprises: 100 parts of a PVB elastomer mixture and 40 parts of dioctyl azelate. The PVB elastomer mixture includes PVB elastomer prepared from PVA 1788 and PVB elastomer prepared from PVA 2088, with a mass ratio of 70:30.

[0059] This embodiment also provides a method for preparing the above-mentioned multifunctional PVB interlayer for laminated glass, including the following steps: Preparation of modified LaB6: 0.04 parts of nano-LaB6 with a particle size of 70 nm were dispersed in 55 parts of ethanol, and 5% of the mass of nano-LaB6 was added as silane coupling agent KH550. The mixture was stirred at 65 °C and 550 r / min for 3.5 h. After centrifugation, it was dried at 90 °C for 3 h to obtain modified LaB6.

[0060] Preparation of PVB elastomer from PVA 1788: PVA 1788 was pulverized to obtain PVA 1788 powder with a particle size of 80-120 mesh. 100 parts of PVA 1788 powder were added to a glass container equipped with a reflux condenser, thermometer, and anchor-type stirrer. 500 parts of deionized water were added, and the system temperature was raised to 80℃ to completely dissolve the PVA 1788 powder, obtaining a PVA 1788 aqueous solution. The PVA 1788 aqueous solution was slowly cooled to 8℃ (cooling time 40 min), and 100 parts of 20% hydrochloric acid solution and 50 parts of glutaraldehyde were added sequentially to carry out an acetalization reaction for 120 min. After the acetalization reaction was completed, the system temperature was raised to 65℃ within 60 min and held for 140 min. Subsequently, a 32% sodium hydroxide solution was added dropwise to adjust the pH of the solution to 7.0. The resin precipitated in the system was washed with ion-exchanged water and dried by centrifugation to obtain PVB elastomer prepared from PVA 1788.

[0061] Preparation of PVB elastomers from PVA 2088: The preparation process is the same as that for PVB elastomers from PVA 1788, except that the raw material PVA 1788 is replaced with PVA 2088.

[0062] Preparation of the skin material: PVB resin, plasticizer, adhesion modifier and antioxidant were stirred and mixed at 82℃ and 850r / min for 50min to obtain a premix; a synergistic stabilizer was added to the premix and stirred and mixed at 600r / min for 25min; then modified LaB6 was added and dispersed at 1200r / min for 50min to obtain the skin material.

[0063] Preparation of core material: The components contained in the core layer are melt-mixed at 145°C for 50 min to obtain the core material.

[0064] Extrusion and molding: The skin material and the core material are respectively added to the corresponding barrels of the three-layer co-extruder. The barrel temperature of the skin material is 172℃, the barrel temperature of the core material is 145℃, the die temperature is 170℃, and the screw speed is 40r / min. After extrusion, the material is calendered and naturally cooled to room temperature. It is then cured for 40 hours at a temperature of 42℃ and a humidity of 55% to obtain a multifunctional PVB interlayer film for laminated glass.

[0065] Comparative Example 1 This comparative example provides a PVB interlayer film (0.76 mm thick) for laminated glass, which is a single-layer structure and comprises: 100 parts of PVB resin (hydroxyl content 18 mol%, degree of acetylation 2 mol%, degree of acetalization 80 mol%, weight average molecular weight 300,000 g / mol), 0.02 parts of LaB6 (unmodified), 2.5 parts of synergistic stabilizer (bisphenol A type epoxy resin), 25 parts of plasticizer (triethylene glycol di-2-ethylhexanoate), 0.1 parts of adhesion modifier (magnesium 2-ethylbutyrate), and 0.2 parts of antioxidant. The antioxidant includes antioxidant 1010 and antioxidant 168, with a mass ratio of 1:1.

[0066] This comparative example also provides a method for preparing the above-mentioned PVB interlayer for laminated glass. The same skin material preparation method as in Example 1 was used to prepare the interlayer material. The barrel temperature was set to 170°C, the die temperature to 170°C, and the screw speed to 40 r / min. After extrusion, the material was calendered, naturally cooled to room temperature, and then cured for 36 hours at 45°C and 50% humidity to obtain the PVB interlayer for laminated glass.

[0067] Comparative Example 2 This comparative example provides a PVB interlayer film (thickness 0.76 mm) for laminated glass, which is a single-layer structure and comprises: 100 parts of PVB resin (hydroxyl content 22 mol%, degree of acetylation 3 mol%, degree of acetalization 75 mol%, weight average molecular weight 350000 g / mol), 0.03 parts of modified LaB6, 28 parts of plasticizer (tetraethylene glycol di-2-ethylhexanoate), 0.15 parts of adhesion modifier (potassium 2-ethylhexanoate), and 0.2 parts of antioxidant (antioxidant 1076).

[0068] This comparative example also provides a method for preparing the above-mentioned PVB interlayer for laminated glass. The same skin material preparation method as in Example 2 was used to prepare the interlayer material. The barrel temperature was set to 175°C, the die temperature to 170°C, and the screw speed to 40 r / min. After extrusion, the material was calendered, naturally cooled to room temperature, and then cured for 24 hours at 50°C and 45% humidity to obtain the PVB interlayer for laminated glass.

[0069] Comparative Example 3 The difference between this comparative example and Example 1 is that the "synergistic stabilizer" in the first and second dermal layers of Example 1 is omitted, while the remaining composition and preparation process are the same as in Example 1.

[0070] Experimental Example 1 The PVB interlayer films prepared in Examples 1-3 and Comparative Examples 1-3 were used to prepare laminated glass. The specific preparation methods are as follows: A PVB interlayer film was placed between two pieces of transparent glass (300mm long × 300mm wide × 2mm thick) to obtain a laminate. The laminate was placed in a rubber bag and degassed under a vacuum of 2.6 kPa for 20 min. After degassed, the rubber bag containing the laminate was transferred to an oven and vacuum pre-pressed at 90°C for 30 min. After pre-pressing, it was transferred to an autoclave and pressed at 135°C and 1.2 MPa for 20 min to obtain laminated glass.

[0071] The performance of the laminated glass and its interlayer prepared above was tested. The specific test items, test standards and test conditions are as follows: (1) Visible light transmittance: According to ASTM D1003-61, the transmittance at a wavelength of 550nm was tested; (2) Infrared blocking efficiency: The infrared blocking efficiency in the 700-2000nm band was tested; (3) Haze: Tested according to ASTM D1003-61; (4) Yellowing Index (YI): Tested according to ASTM D1925; (5) Change rate of infrared transmittance after aging: at a temperature of 80℃, relative humidity of 95%, and ultraviolet irradiation (300-400nm, irradiation intensity of 0.5W / m²), the infrared transmittance was measured. 2 The infrared transmittance at 1000nm was measured after aging for 1000 hours under the specified conditions. (6) Drop ball impact glass residue rate: In an environment of -17℃, a 1kg steel ball is dropped freely from a height of 1m to impact the laminated glass, and the proportion of glass remaining on the PVB interlayer after impact is tested. (7) Interfacial adhesion: The 180° peel test was used to test the peel strength between the glass and the PVB interlayer. (8) Tensile strength: Tested according to ASTM D638; (9) Sound transmission loss (STL): According to ISO 140-3, the sound transmission loss in the 200-3000Hz frequency band is tested.

[0072] The performance test results are recorded in Table 1.

[0073] Table 1 Performance Test Results

[0074] As shown in Table 1, in terms of optical performance, the visible light transmittance of Examples 1-3 is ≥91.8%, the infrared blocking rate is ≥87.6%, the haze is ≤0.9%, and the yellowing index is ≤0.9, indicating that the intermediate film of the present invention has excellent optical transparency and infrared blocking performance. Regarding aging stability, after 1000 hours of rigorous aging, the infrared transmittance change rate of Examples 1-3 is ≤2.1%, far superior to that of Comparative Examples 1-3 (15.6-28.3%), proving that the excellent aging stability of the present invention is the result of the synergistic effect of the "three-layer structure" and the "synergistic stabilization system". In terms of mechanical and interfacial properties, the glass residue rate after falling ball impact of Examples 1-3 is ≥93%, the interfacial adhesion is ≥4.8 N / cm, and the tensile strength is ≥32.5 MPa, all of which are superior to or significantly superior to the comparative examples. Regarding sound insulation performance, Examples 1-3 all exhibited a sound transmission loss (STL) ≥36.8dB in the 200-3000Hz frequency band, significantly higher than Comparative Examples 1-2 (28.5-29.1dB) without sound insulation structure. This demonstrates that the three-layer composite structure design of the present invention significantly improves the sound insulation effect. Comparative Example 3, although possessing a sound insulation structure, suffers from poor aging stability due to the lack of a synergistic stabilizing system.

[0075] Therefore, this invention, through a three-layer composite structure design of "skin / core / skin", multiple protection mechanisms of a synergistic stabilization system, standardized preparation and specific ratio of PVB elastomer in the core layer, and synergistic optimization of the thickness and plasticizer content of the skin and core layers, successfully achieves a high degree of integration of infrared blocking, anti-aging, strong adhesion and efficient sound insulation functions. It has excellent comprehensive performance and fully meets the stringent requirements of stability, safety and sound insulation in application scenarios such as automotive windshields, building curtain walls, high-speed rail windows and aviation windows.

[0076] Finally, it should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A multifunctional PVB interlayer for laminated glass, characterized in that, The intermediate membrane has a three-layer composite structure, including a first skin layer, a core layer, and a second skin layer; The first and second skin layers respectively contain PVB resin, modified LaB6, synergistic stabilizers, plasticizers, adhesion modifiers, and antioxidants; the synergistic stabilizers include epoxy resin, organotitanium chelators, and UV stabilizers; The core layer comprises a PVB elastomer mixture and a plasticizer; the PVB elastomer mixture comprises a PVB elastomer prepared from a first PVA and a PVB elastomer prepared from a second PVA; the first PVA has a degree of polymerization of 1700-1800 and a degree of hydrolysis of 86-90%; the second PVA has a degree of polymerization of 2000-2100 and a degree of hydrolysis of 86-90%. The thickness of both the first and second skin layers is greater than the thickness of the core layer, and the plasticizer content in both the first and second skin layers is less than the plasticizer content in the core layer.

2. The PVB interlayer for multifunctional laminated glass according to claim 1, characterized in that, The first and second skin layers, by weight, respectively contain 100 parts of PVB resin, 0.005-0.1 parts of modified LaB6, 0.65-5 parts of synergistic stabilizer, 20-30 parts of plasticizer, 0.05-0.3 parts of adhesion modifier and 0.1-0.3 parts of antioxidant; In the synergistic stabilizer, the mass ratio of the epoxy resin, the organic titanium chelating agent and the ultraviolet stabilizer is (10-80):(1-10):(2-10).

3. The PVB interlayer for multifunctional laminated glass according to claim 1, characterized in that, The core layer, by weight, comprises 100 parts of a PVB elastomer mixture and 24-60 parts of a plasticizer; In the PVB elastomer mixture, the mass ratio of the PVB elastomer prepared from the first PVA to the PVB elastomer prepared from the second PVA is (30-70):(30-70).

4. The PVB interlayer for multifunctional laminated glass according to claim 1, characterized in that, The total thickness of the intermediate membrane is 0.3-1.5 mm; the thickness ratio of the first skin layer, the second skin layer, and the core layer is (1.2-3):(1.2-3):

1.

5. The PVB interlayer for multifunctional laminated glass according to claim 1, characterized in that, The modified LaB6 is nano-LaB6 modified with a silane coupling agent.

6. The PVB interlayer for multifunctional laminated glass according to claim 1, characterized in that, The hydroxyl content of the PVB resin in the first and second skin layers is 15-25 mol%, the degree of acetylation is 1-5 mol%, the degree of acetalization is 70-84 mol%, and the weight-average molecular weight is 250,000-400,000 g / mol.

7. A method for preparing a PVB interlayer for multifunctional laminated glass as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Prepare the skin layer material and the core layer material separately; S2. The skin material and the core material are extruded through a three-layer co-extruder to form a three-layer composite structure including a first skin layer, a core layer and a second skin layer. After molding, a multifunctional PVB interlayer film for laminated glass is obtained.

8. The method according to claim 7, characterized in that, In S2, during the extrusion process, the barrel temperature of the outer layer material is 160-180℃, the barrel temperature of the core layer material is 140-160℃, the die temperature is 165-175℃, and the screw speed is 30-50 r / min.

9. A laminated glass, characterized in that, The laminated glass includes a PVB interlayer for multifunctional laminated glass as described in any one of claims 1 to 6.

10. The application of the PVB interlayer film for multifunctional laminated glass according to any one of claims 1 to 6 or the laminated glass according to claim 9 in automobile windshields, building curtain walls, high-speed rail windows or aircraft windows.

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