Special resin composition for PVB (polyvinyl butyral) intermediate film based on toughening modification

Abstract

The invention relates to the technical field of high polymer material modification, and discloses a toughening modification-based special resin composition for a PVB (polyvinyl butyral) intermediate film, which is prepared from the following raw materials: PVB resin, a plasticizer, a rheological competition inhibitor, a latent cross-linking agent and a supported toughening master batch, the master batch is prepared from a maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer, pentaerythritol ester of hydrogenated rosin, zinc stearate and an imidazole compound. The preparation method comprises the steps of spraying and premixing of the modified plasticizing liquid, solid-phase diffusion and swelling of the master batch and twin-screw reaction extrusion. According to the invention, hydrogenated rosin pentaerythritol ester is utilized to adjust the refractive index of the elastomer so as to match the matrix and eliminate interface light scattering; latent catalysis is realized by using a zinc-imidazole complex, and scorching during processing is prevented; and the crosslinking degree is controlled by using a rheological competitive inhibition mechanism. The composition has high low-temperature toughness, high light transmittance and excellent melt processing fluidity.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, specifically to a special resin composition for toughened modified PVB interlayer films. Background Technology

[0002] Polyvinyl butyral (PVB) resin is an important thermoplastic polymer material, prepared by the acetalization reaction of polyvinyl alcohol and n-butyral under the action of a catalyst. This resin possesses excellent adhesion to inorganic glass, good film-forming properties, and high optical transparency. In fields such as architectural safety glass, automotive windshields, and photovoltaic cell encapsulation, PVB resin serves as a core base material, primarily used in the preparation of interlayer films to bond glass fragments, resist penetration, and absorb impact energy.

[0003] To overcome the problem of pure PVB resin becoming brittle and losing impact resistance at low temperatures, existing technologies often employ elastomer toughening modification processes. In industrial applications, styrene-based thermoplastic elastomers are commonly introduced into the PVB matrix. Since PVB is a polar material and elastomers are non-polar materials, direct mixing results in poor compatibility. Therefore, the conventional practice is to add a small amount of epoxy resin or acid anhydride as a compatibilizer during the extrusion process.

[0004] However, existing modification technologies face technical bottlenecks in practical applications. The refractive index of conventional elastomers inherently differs from that of PVB resin, causing light scattering at the phase interface after blending, leading to a sharp increase in film haze and making it difficult to meet optical-grade transparency requirements. Traditional chemical compatibilization reactions lack latent control mechanisms, resulting in excessively rapid release of catalytic activity. Furthermore, materials are prone to early cross-linking and scorching in the extruder feeding section due to heating, leading to a sudden increase in melt viscosity, deterioration of flowability, increased processing energy consumption, and the formation of non-meltable gel points within the film. Therefore, this invention provides a toughened modified PVB interlayer film-specific resin composition to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a toughened modified PVB interlayer resin composition, which solves the problems of existing polyvinyl butyral resins, which are difficult to balance low-temperature impact strength, optical transparency and melt processing fluidity when undergoing elastomer toughening modification, and the physical blending system suffers from delamination and stress whitening caused by weak interfacial bonding.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a special resin composition for toughened modified PVB interlayer film, the raw materials of which include polyvinyl butyral resin, plasticizer, rheology competition inhibitor, latent crosslinking agent and supported toughening masterbatch; wherein, the weight ratio of each component is as follows: 100 parts of polyvinyl butyral resin; 18 to 22 parts of plasticizer; 0.2 to 0.5 parts of rheology competition inhibitor; 3.0 to 4.5 parts of latent crosslinking agent; and 18 to 22 parts of supported toughening masterbatch.

[0007] By adopting the above technical solution, the dispersion state, optical properties, and interfacial bonding of the elastomer phase in the polyvinyl butyral matrix are improved through the synergistic effect of multiple components. The specific working principle is as follows: During high-temperature processing, the latent crosslinking agent undergoes a ring-opening reaction, chemically reacting with the hydroxyl groups on the polyvinyl butyral molecular chain and the active groups of the elastomer matrix in the supported toughening masterbatch, respectively, to form a graft copolymer in situ at the interface between the two phases. This chemical bonding improves compatibility, enabling the elastomer dispersion phase to stably transfer and dissipate impact energy.

[0008] The refractive index adjusting carrier contained in the loaded toughening masterbatch preferentially dissolves and penetrates into the elastomer phase, increasing the refractive index of the elastomer phase to a value close to that of the polyvinyl butyral matrix. This matching of refractive indices between the two phases reduces light scattering and reflection at the phase interface, thereby maintaining the transmittance of the modified material and reducing haze.

[0009] As a monofunctional acidic substance, the rheology-competitive inhibitor competes with the hydroxyl groups of polyvinyl butyral to consume the epoxy groups of the latent crosslinking agent. This competitive reaction controls the degree of polymerization of the crosslinking reaction, preventing the over-reaction of the bifunctional crosslinking agent from forming a three-dimensional network gel, and ensuring that the resin composition enhances interfacial bonding while retaining the melt flowability and reprocessing ability of the thermoplastic material.

[0010] Preferably, the polyvinyl butyral resin is a low-viscosity resin; the plasticizer is triethylene glycol diisooctanoate; the rheology competitive inhibitor is stearic acid; and the latent crosslinking agent is an alicyclic epoxy resin selected from 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate.

[0011] By adopting the above technical solutions, the low-viscosity resin as the matrix can offset the increase in system viscosity caused by the addition of elastomers; triethylene glycol diisooctanoate provides cold-resistant plasticizing effect; stearic acid utilizes the reactivity of its carboxyl group to adjust the molecular weight; alicyclic epoxy resin has moderate reactivity and does not contain benzene rings, which is beneficial to maintaining the weather resistance of the material.

[0012] Preferably, the loaded toughening masterbatch is prepared from raw materials comprising an elastomer matrix, a refractive index adjusting carrier, zinc stearate, imidazole compounds, and auxiliary antioxidants; wherein the elastomer matrix is ​​a maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer; and the refractive index adjusting carrier is hydrogenated rosin pentaerythritol ester.

[0013] By employing the above technical solution, the side-chain anhydride groups of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer provide active sites for interfacial reactions. Hydrogenated rosin pentaerythritol ester has a high refractive index and compatibility with styrene blocks, and is used to improve the optical properties of the rubber phase. Zinc stearate and imidazole compounds constitute a latent catalytic system. The zinc ions in zinc stearate form coordination complexes with the nitrogen atoms in imidazole compounds, inhibiting the catalytic activity of imidazoles at low temperatures or during masterbatch preparation, preventing scorching of the material during the premixing stage. When the temperature rises to the extrusion processing temperature, the coordination bonds dissociate, and the released imidazole compounds catalyze the epoxy ring-opening and esterification reactions at the interface.

[0014] Preferably, in the raw materials of the supported toughening masterbatch, the weight ratio of the refractive index adjusting carrier to the elastomer matrix is ​​0.5 to 0.75:1; the imidazole compound is 2-ethyl-4-methylimidazole, and the weight ratio of zinc stearate to 2-ethyl-4-methylimidazole is 2.5:1.

[0015] By adopting the above technical solution, this ratio range ensures that the elastomer particles are fully swollen and do not undergo phase separation, achieving refractive index matching, and the specific ratio of zinc to imidazole ensures that the two form a stable complex.

[0016] Secondly, the present invention provides a method for preparing a toughened modified PVB interlayer resin composition, which adopts the following technical solution: A method for preparing a toughened modified PVB interlayer resin composition includes the following steps: S1. Stearic acid and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate are dissolved in triethylene glycol diisooctanoate to prepare a modified plasticizing liquid, which is then sprayed into polyvinyl butyral resin. After mixing and curing, a matrix premix is ​​obtained. S2. Hydrogenated rosin pentaerythritol ester, zinc stearate and 2-ethyl-4-methylimidazol are melt-mixed to form an active carrier melt. Then, maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles are added to the active carrier melt under low shear conditions for solid-phase diffusion swelling. After cooling, a loaded toughening masterbatch is obtained. S3. The matrix premix obtained in step S1 is added to the main feed port of the twin-screw extruder, and the loaded toughening masterbatch obtained in step S2 is added to the side feed port of the twin-screw extruder. After melt blending, interfacial reaction and devolatilization granulation, a resin composition is obtained.

[0017] By adopting the above technical solution, the resin composition is prepared through stepwise feeding and in-situ reaction control. The specific structural evolution process is as follows: In step S1, epoxy resin and stearic acid are pre-dissolved in plasticizer and penetrate into the interior of polyvinyl butyral resin, so that the reactants are dispersed at the molecular level in the matrix phase, preventing uneven cross-linking caused by excessively high local concentrations.

[0018] In step S2, a solid-phase diffusion swelling process is used to prepare the masterbatch. Hydrogenated pentaerythritol rosin is used as a carrier to carry zinc stearate and imidazole compounds into the amorphous region of the elastomer particles without melting them. This process achieves pre-filling of the refractive index modifier into the rubber phase and physically isolates the catalyst components within the rubber particles, preventing the catalyst from being directly exposed to the thermal-oxidative environment, thus improving the material's anti-aging properties and color stability.

[0019] During the dynamic extrusion process in step S3, the system undergoes the following changes: Melting and dispersion: The matrix premix and the loaded toughening masterbatch are heated and melted in the extruder conveying section. The hydrogenated rosin pentaerythritol ester in the masterbatch softens and assists in the dispersion of the elastomer.

[0020] Activity release: When the material temperature rises to the set temperature of the interface reaction zone, the coordination complex of zinc stearate and imidazole dissociates, releasing free imidazole molecules.

[0021] Interfacial bonding: Free imidazole molecules catalyze the ring-opening of epoxy groups dissolved in the matrix phase, reacting with the hydroxyl groups of polyvinyl alcohol on the matrix side and the carboxyl groups of maleic anhydride hydrolysis products on the dispersed phase side, respectively, to achieve chemical bonding at the phase interface.

[0022] Reaction termination: The pre-placed stearic acid in the system consumes the remaining epoxy groups through a competitive reaction, terminating chain growth and stabilizing the final molecular weight and phase structure.

[0023] Preferably, in step S1, the preparation temperature of the modified plasticizing liquid is 55 to 65 degrees Celsius, the stirring and dissolving time is 15 to 25 minutes, the mixing time is 5 to 10 minutes, and the maturation time is 1.5 to 2.5 hours.

[0024] By adopting the above technical solutions, mild dissolution conditions prevent premature ring-opening of epoxy resin; the curing time ensures that plasticizers and reaction aids completely migrate into the pores of polyvinyl butyral resin particles, thereby improving plasticizing efficiency and reaction uniformity.

[0025] Preferably, step S2 further includes: mixing and melting hydrogenated rosin pentaerythritol ester, zinc stearate, 2-ethyl-4-methylimidazole and auxiliary antioxidant at 115 to 125 degrees Celsius, so that zinc stearate and 2-ethyl-4-methylimidazole are in-situ coordinated complexed; reducing the stirring speed to 50 to 80 rpm, adding maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles, and stirring at a constant temperature of 105 to 120 degrees Celsius for 25 to 60 minutes, so that the active carrier melt penetrates into the particle interior; cooling to 30 to 35 degrees Celsius, adding an anti-sticking agent, mixing and discharging to obtain a loaded toughening masterbatch.

[0026] By employing the above technical solution, zinc ions occupy the active sites on the imidazole ring to form a complex at 115 to 125 degrees Celsius. Subsequent low-temperature, low-shear mixing utilizes the free volume expansion effect of the polymer to allow the carrier mixture to diffuse into the deep layers of the particles, while avoiding strong shear forces that could damage the morphology of the elastomer particles and preventing thermal adhesion of the particles.

[0027] Preferably, in step S3, the temperature distribution of the twin-screw extruder is controlled as follows: 140 to 160 degrees Celsius in the conveying and plasticizing zone, 170 to 180 degrees Celsius in the dispersion and mixing zone, 195 to 215 degrees Celsius in the interface reaction zone, and 175 to 180 degrees Celsius in the devolatilization and granulation zone and the die head.

[0028] By adopting the above technical solution, the temperature of the conveying zone and the dispersion zone is relatively low, and physical mixing and dispersion are mainly carried out. The high temperature of 195 to 215 degrees Celsius in the interface reaction zone is used to stimulate the dissociation of zinc-imidazolium complex and initiate the interface reaction, ensuring that the chemical reaction is concentrated in a specific area after phase dispersion is completed, thereby obtaining a uniform composite structure.

[0029] This invention provides a toughened modified PVB interlayer resin composition. It has the following beneficial effects: 1. This invention introduces hydrogenated rosin pentaerythritol ester as a refractive index adjusting carrier to swell maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, thereby increasing the refractive index of the dispersed phase elastomer to match the refractive index value of the polyvinyl butyral matrix. This consistency in refractive index significantly reduces light scattering and reflection at the two-phase interface, allowing the modified resin composition to maintain excellent light transmittance and extremely low haze while improving low-temperature impact strength.

[0030] 2. This invention utilizes a coordination complex formed by zinc stearate and 2-ethyl-4-methylimidazole to block the catalytic activity of imidazole during the low-temperature premixing and feeding stages, effectively preventing early cross-linking or local scorching of materials in the extruder feeding section. The complex only dissociates and releases the active catalyst when it reaches a specific high-temperature interface reaction zone, thereby ensuring that the chemical reaction is concentrated in the predetermined process section and guaranteeing the uniformity of product quality.

[0031] 3. This invention introduces stearic acid as a monofunctional competitive agent, which competes with the resin hydroxyl groups to consume epoxy groups, thereby limiting the chain growth length and crosslinking density of the interfacial chemical reaction. This effectively avoids the formation of an inmeltable three-dimensional network gel structure due to excessive reaction of the difunctional crosslinking agent, ensuring that the obtained resin composition retains the melt flowability and secondary processing capability expected of thermoplastic materials while possessing chemically bonded and reinforced interfaces. Attached Figure Description

[0032] Figure 1 This is a dynamic rheological curve of the resin composition of the present invention; Figure 2 The figures show a comparison of the optical properties of the various formulation systems of the present invention; wherein, Figure (a) is a comparison of light transmittance and Figure (b) is a comparison of haze. Figure 3 The bar charts show the mechanical properties and interfacial bonding strength of the present invention; wherein, Figure (a) is a comparison chart of tensile strength, Figure (b) is a comparison chart of elongation at break, and Figure (c) is a comparison chart of glass peel strength. Figure 4 This is a graph showing the color change trend during the thermal aging process of this invention. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0035] Polyvinyl butyral resin: CAS No. 63148-65-2, low viscosity type, acetal content of 76% to 80% by mass, polyvinyl alcohol group content of 18% to 24% by mass, vinyl acetate group content of less than 3%, and its 10% ethanol solution viscosity of 20 mPa·s to 50 mPa·s is determined according to GB / T2794-1995 standard.

[0036] Triethylene glycol diisooctanoate: CAS number 94-28-0, purity greater than 98.5%, used as a plasticizer.

[0037] 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate: CAS No. 2386-87-0, epoxy equivalent of 130 g / eq to 140 g / eq, used as a latent crosslinking agent.

[0038] Stearic acid: CAS number 57-11-4, octadecanoic acid, purity greater than 98%, used as a rheology competitive inhibitor.

[0039] Maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer: a commercially available polymeric modified material, wherein the styrene block content is 25% to 30% by mass and the maleic anhydride grafting rate is 1.0% to 1.6% by mass, as a grafted elastomer.

[0040] Hydrogenated rosin pentaerythritol ester: CAS number 64365-17-9, softening point 98℃ to 105℃, refractive index 1.53 to 1.54 at 25℃, used as a refractive index adjusting carrier.

[0041] 2-Ethyl-4-methylimidazole: CAS number 931-36-2, purity greater than 98%, used as an interfacial catalyst.

[0042] Zinc stearate: CAS No. 557-05-1, with a zinc content of 10.5% to 11.5% by mass, used as a complexing stabilizer.

[0043] Co-antioxidant: It is composed of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (CAS No. 6683-19-8) and tris(2,4-di-tert-butylphenyl) phosphite (CAS No. 31570-04-4) in a mass ratio of 1:1.

[0044] Preparation Example 1: This preparation example provides a method for preparing toughening masterbatch, including the following steps: (1) Preparation of active carrier melt: In a high-speed mixer equipped with a heating jacket and a precise temperature control system, 6 parts by weight of hydrogenated rosin pentaerythritol ester, 0.2 parts by weight of zinc stearate, 0.08 parts by weight of 2-ethyl-4-methylimidazole and 0.2 parts by weight of auxiliary antioxidant are added in sequence; the heating system is turned on to raise the material temperature to 115°C and the mixture is stirred at 400 rpm for 10 minutes until the above materials are completely melted and form a homogeneous transparent liquid mixture. At this time, zinc stearate and imidazole complete in-situ coordination complexation in the melt. (2) Solid-phase diffusion swelling: Reduce the stirring speed of the high-speed mixer to 60 rpm to prevent shear force from breaking the subsequently added elastomer particles. Add 12 parts by weight of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles to the above melt. Keep the temperature constant at 115℃ and continue to tumble and stir at low speed for 40 minutes to allow the molten active carrier mixture to penetrate into the interior and surface of the elastomer particles through physical diffusion, thus completing the solid-phase swelling load. (3) Cooling and anti-sticking treatment: Turn on the cooling circulating water of the mixer jacket to quickly reduce the material temperature to 35℃; add 0.05 parts by weight of fumed silica as an anti-sticking isolator, mix at low speed for 1 minute and then discharge to obtain a dry and non-sticky loaded active toughening masterbatch.

[0045] Preparation Example 2: This preparation example provides a method for preparing toughening masterbatch, including the following steps: (1) Preparation of active carrier melt: In a high-speed mixer with a heating jacket, add 9 parts by weight of hydrogenated rosin pentaerythritol ester, 0.3 parts by weight of zinc stearate, 0.12 parts by weight of 2-ethyl-4-methylimidazol and 0.2 parts by weight of auxiliary antioxidant in sequence; turn on the heating and raise the temperature to 118°C, and stir at 450 rpm until completely melted and in a homogeneous state; (2) Solid-phase diffusion swelling: Reduce the rotation speed to 80 rpm and add 12 parts by weight of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles; keep the temperature at 115℃ and stir at a constant temperature and low speed for 45 minutes to ensure that a high proportion of rosin ester carrier can fully penetrate into the elastomer matrix. (3) Cooling and anti-sticking treatment: Cool the mixture with water to below 35°C, add 0.08 parts by weight of 1250 mesh talc powder as an anti-sticking agent, mix evenly and discharge to obtain a high-load toughening masterbatch.

[0046] Preparation Example 3: This preparation example provides a method for preparing toughening masterbatch, including the following steps: (1) Preparation of active carrier melt: In a high-speed mixer, add 6 parts by weight of hydrogenated rosin pentaerythritol ester, 0.2 parts by weight of zinc stearate, 0.08 parts by weight of 2-ethyl-4-methylimidazol and 0.2 parts by weight of auxiliary antioxidant; heat to 115°C, stir and melt evenly, then reduce the temperature and stabilize at 105°C; (2) Solid-phase diffusion swelling: Adjust the speed to 50 rpm and add 12 parts by weight of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles; stir at a constant temperature and low speed at 105℃ for 60 minutes, and use a longer period of mild heat treatment to allow the carrier to slowly and uniformly diffuse into the deep layer of the particles, thereby reducing the viscosity of the particle surface. (3) Cooling and anti-sticking treatment: Cool to 30°C, add 0.05 parts by weight of fumed silica, discharge the material, and obtain toughening masterbatch.

[0047] Preparation Example 4: This preparation example provides a method for preparing toughening masterbatch, including the following steps: (1) Preparation of active carrier melt: In a high-speed mixer, add 6 parts by weight of hydrogenated rosin pentaerythritol ester, 0.2 parts by weight of zinc stearate, 0.08 parts by weight of 2-ethyl-4-methylimidazole and 0.2 parts by weight of auxiliary antioxidant; rapidly heat to 125°C and stir to melt; (2) Solid-phase diffusion swelling: Reduce the speed to 60 rpm and add 12 parts by weight of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles; control the temperature at close to the softening critical point of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer 120℃, and stir at a constant temperature for 25 minutes to accelerate the swelling process by utilizing the characteristic of increased molecular chain movement at high temperature. (3) Cooling and anti-sticking treatment: Since the surface of the particles is sticky at high temperature, the cooling water flow rate needs to be increased to quickly cool down to below 30°C, and 0.1 parts by weight of fumed silica is added. After thorough mixing to prevent sticking, the material is discharged to obtain toughening masterbatch.

[0048] Example 1: This embodiment provides a toughened modified PVB interlayer resin composition, comprising the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 60°C; add 0.3 parts by weight of stearic acid and 3.0 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 20 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are put into a low-speed mixer, the above modified plasticizing liquid is sprayed at room temperature, mixed for 8 minutes, and allowed to stand for 2 hours to mature, so as to obtain a surface-dried matrix premix.

[0049] S20, reactive extrusion: S21. A co-rotating twin-screw extruder with an aspect ratio (L / D) of 44:1 is used. The prepared matrix premix is ​​added to the main feed port; the supported active toughening masterbatch prepared in Preparation Example 1 is added to the side feed port located at screw 12D. The amount of the supported active toughening masterbatch added is 18 parts by weight, which includes 12 parts of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, 6 parts of rosin ester, and corresponding additives.

[0050] S22. The extruder process parameters are set as follows: screw speed 350 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, C9-C12 interface reaction zone 195℃-210℃, C13-End devolatilization and granulation zone 175℃, and die head temperature 175℃.

[0051] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final PVB resin composition.

[0052] Example 2: This embodiment provides a toughened modified PVB interlayer resin composition, comprising the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 60°C; add 0.3 parts by weight of stearic acid and 3.0 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 20 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are put into a low-speed mixer, the above modified plasticizing liquid is sprayed at room temperature, mixed for 8 minutes, and allowed to stand for 2 hours to mature, so as to obtain a surface-dried matrix premix.

[0053] S20, Dynamic Reaction Extrusion: S21. A co-rotating twin-screw extruder with an aspect ratio (L / D) of 44:1 was used. The prepared matrix premix was added to the main feed port; the high-load toughening masterbatch prepared in Preparation Example 2 was added to the side feed port located at screw 12D. The amount of high-load toughening masterbatch added was 21 parts by weight, which included 12 parts of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, 9 parts of rosin ester, and corresponding additives.

[0054] S22. The extruder process parameters are set as follows: screw speed 350 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, C9-C12 interface reaction zone 195℃-210℃, C13-End devolatilization and granulation zone 175℃, and die head temperature 175℃.

[0055] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final granular PVB resin composition.

[0056] Example 3: This embodiment provides a toughened modified PVB interlayer resin composition, comprising the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 55°C; add 0.4 parts by weight of stearic acid and 4.5 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 25 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are added to a low-speed mixer, the modified plasticizing liquid is sprayed at room temperature, mixed for 10 minutes, and allowed to stand for 2.5 hours to mature, so as to obtain a surface-dried matrix premix.

[0057] S20, Dynamic Reaction Extrusion: S21. A co-rotating twin-screw extruder with an aspect ratio (L / D) of 44:1 is used. The prepared matrix premix is ​​added to the main feed port; the supported active toughening masterbatch prepared in Preparation Example 3 is added to the side feed port located at screw 12D, and the amount of the supported active toughening masterbatch added is 18 parts by weight.

[0058] S22. The extruder process parameters are set as follows: screw speed 300 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, C9-C12 interface reaction zone 195℃-210℃, C13-End devolatilization and granulation zone 175℃, and die head temperature 175℃.

[0059] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final granular PVB resin composition.

[0060] Example 4: This embodiment provides a toughened modified PVB interlayer resin composition, which is prepared by the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 65°C; add 0.2 parts by weight of stearic acid and 3.0 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 15 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are put into a low-speed mixer, the modified plasticizing liquid is sprayed at room temperature, mixed for 5 minutes, and allowed to stand for 1.5 hours to mature, so as to obtain a surface-dried matrix premix.

[0061] S20, Dynamic Reaction Extrusion: S21. A co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 44:1 is used. The prepared matrix premix is ​​added to the main feed port; the supported active toughening masterbatch prepared in Preparation Example 4 is added to the side feed port located at screw 12D, and the amount of the supported active toughening masterbatch added is 18 parts by weight.

[0062] S22. The extruder process parameters are set as follows: screw speed 400 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, C9-C12 interface reaction zone 195℃-210℃, C13-End devolatilization and granulation zone 175℃, and die head temperature 175℃.

[0063] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final granular PVB resin composition.

[0064] Example 5: This embodiment provides a toughened modified PVB interlayer resin composition, which is prepared by the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 60°C; add 0.5 parts by weight of stearic acid and 3.0 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 20 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are put into a low-speed mixer, the above modified plasticizing liquid is sprayed at room temperature, mixed for 8 minutes, and allowed to stand for 2 hours to mature, so as to obtain a surface-dried matrix premix.

[0065] S20, Dynamic Reaction Extrusion: S21. A co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 44:1 is used. The obtained matrix premix is ​​added to the main feed port; the supported active toughening masterbatch obtained in Preparation Example 1 is added to the side feed port located at screw 12D, and the amount of the supported active toughening masterbatch added is 18 parts by weight.

[0066] S22. The extruder process parameters are set as follows: screw speed 350 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, C9-C12 interface reaction zone 195℃-210℃, C13-End devolatilization and granulation zone 175℃, and die head temperature 175℃.

[0067] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final granular PVB resin composition.

[0068] Example 6: This embodiment provides a toughened modified PVB interlayer resin composition, which is prepared by the following steps: S10. Preparation of matrix premix: S11. Add 20 parts by weight of triethylene glycol diisooctanoate to a stainless steel mixing vessel and heat to 60°C; add 0.3 parts by weight of stearic acid and 3.0 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate in sequence, and stir at 200 rpm for 20 minutes until the stearic acid is completely dissolved to obtain a clear and transparent modified plasticizer. S12. Then, 100 parts by weight of polyvinyl butyral resin are put into a low-speed mixer, the above modified plasticizing liquid is sprayed at room temperature, mixed for 8 minutes, and allowed to stand for 2 hours to mature, so as to obtain a surface-dried matrix premix.

[0069] S20, Dynamic Reaction Extrusion: S21. A co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 44:1 is used. The obtained matrix premix is ​​added to the main feed port; the supported active toughening masterbatch obtained in Preparation Example 1 is added to the side feed port located at screw 12D, and the amount of the supported active toughening masterbatch added is 18 parts by weight.

[0070] S22. The extruder process parameters are set as follows: screw speed 350 rpm; temperature distribution in each zone: C1-C4 conveying and plasticizing zone 140℃-160℃, C5-C8 dispersion and mixing zone 170℃-180℃, to promote rapid high-temperature reaction at the interface, the temperature of the C9-C12 interface reaction zone is increased to 210℃-215℃, C13-End devolatilization and granulation zone 175℃, and the die head temperature 180℃.

[0071] S23. The extruded strip is granulated underwater, centrifuged, dehydrated, and dried with hot air at 45°C to obtain the final granular PVB resin composition.

[0072] Comparative Example 1: Compared with Example 1, the difference is that stearic acid is not added, while the proportions of other raw materials and the preparation process are the same.

[0073] Comparative Example 2: Compared with Example 1, the difference is that the feeding process was changed and the pre-preparation step of the supported active toughening masterbatch was not used.

[0074] Comparative Example 3: Compared with Example 1, the difference is that 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 2-ethyl-4-methylimidazolium, stearic acid and zinc stearate are not added, and it is only a physical blend system, otherwise the same.

[0075] Comparative Example 4: Compared with Example 1, the difference is that: hydrogenated rosin pentaerythritol ester is not added, and 2-ethyl-4-methylimidazole and zinc stearate are added directly in powder form after premixing with maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, while the rest are the same.

[0076] Comparative Example 5: The difference from Example 1 is that zinc stearate is not added, but the rest are the same.

[0077] Test Example 1: Test Description: This test uses a torque rheometer to simulate the melting, dispersion, and reaction processes of the resin composition under high temperature and high shear conditions. By monitoring the change in torque over time in real time, the processing stability of the system and the controllability of the crosslinking reaction are evaluated.

[0078] Test steps: Experimental preparation: The raw material components corresponding to Example 1, Comparative Example 1, and Comparative Example 5 were weighed according to their respective formulation ratios, with the total mass controlled at 55.0g. To ensure the accuracy of the test, all raw materials were not pre-extruded and granulated before the test, but were directly added in the form of dry mix.

[0079] Parameter settings: Install a rotor mixer to simulate the extreme temperature of the reaction section of a twin-screw extruder. Set the mixing chamber temperature to 200℃, the rotor speed to 60r / min, and the data sampling frequency to 1Hz.

[0080] Feeding and testing: After the equipment temperature stabilizes, start the rotor and quickly add the dry mixture into the mixing chamber. The feeding time should be controlled within 20 seconds, and then press down the feeding plug to seal it.

[0081] Data recording: The system automatically records the torque change curve and melt temperature change curve from the start of feeding to 30 minutes. The experiment termination criteria are set as follows: the torque remains stable and balanced for 10 minutes, or the torque exceeds 50 N·m, which is considered as severe cross-linking and gelation.

[0082] Cleaning: After each set of tests, immediately stop the rotor, clean the residual material in the mixing chamber, and use a copper brush to polish the rotor surface to prevent cross-linking residue from affecting the test data of the next set.

[0083] The test data is shown in Table 1: Table 1: Data on the variation of rheological torque of different formulations at 200℃ over time (unit: N·m)

[0084] According to the appendix Figure 1 As shown in Table 1, the rheological behavior of different systems under high-temperature shear fields varies, as detailed below: The rheological curve of Example 1 exhibited three typical stages: 0-2 minutes was the physical melting zone, where the torque rapidly decreased to 8.21 N·m; 2-10 minutes was the reaction induction and grafting zone, where the torque increased slightly and slowly from 7.95 to 9.12 N·m, indicating that the epoxy ring-opening and grafting reactions at the interface were proceeding in an orderly manner, and the system viscosity increased slightly due to the increase in molecular weight; 10-30 minutes was the rheological equilibrium zone, where the torque stabilized at around 10.0 N·m without divergence. This data indicates that the stearic acid introduced into the system successfully consumed the remaining epoxy groups in the later stages of the reaction, blocking the possibility of forming a three-dimensional network structure between the PVB matrix, ensuring that the material retains the flow characteristics required for thermoplastic processing while exhibiting grafting reinforcement effects.

[0085] Data from Comparative Example 1 showed that the torque began to rise sharply approximately 5 minutes after the material began to melt. At 10 minutes, the torque reached 24.35 N·m, about 2.5 times that of Example 1; by 20 minutes, the torque exceeded 50 N·m, causing a protective shutdown of the equipment. This indicates that in the absence of stearic acid as a competitive inhibitor, the bifunctional epoxy resin underwent an uncontrolled cross-linking reaction with the hydroxyl groups on the PVB molecular chain under the action of a catalyst, leading to rapid gelation of the system and loss of reprocessing capability.

[0086] Data from Comparative Example 5 showed that the torque jumped from 9.43 N·m to 14.56 N·m in the initial melting stage (2-5 minutes), a faster rate of increase than in Example 1. This indicates that the imidazole catalyst exhibits high activity in the early stages of processing due to the lack of zinc ion coordination, leading to premature scorching. Although the final torque stabilized at 17.65 N·m, without complete gelation as in Comparative Example 1, the excessively high base viscosity means a narrower processing window, and the higher torque plateau is usually accompanied by the formation of some micro-crosslinking points, which increases energy consumption and equipment wear risk in subsequent extrusion processing.

[0087] Test Example 2: Test Description: This test is conducted in accordance with GB / T 2410-2008 "Determination of transmittance and haze of transparent plastics". A transmittance and haze meter is used to quantitatively evaluate the optical transmittance performance and internal light scattering degree of different resin compositions in the visible light band, thereby determining the influence of the refractive index adjustment carrier on the optical uniformity of the multiphase system.

[0088] Test instructions: Sample preparation: The resin composition particles prepared in Examples 1 to 6 and Comparative Example 4 were placed in a forced-air drying oven and dried at 45°C for 4 hours to control the particle moisture content to below 0.4% in order to eliminate the interference of microbubbles generated by moisture vaporization on optical testing.

[0089] Hot pressing: Weigh a measured amount of dried resin particles and place them in the mold cavity. The mold thickness is controlled at 0.76mm ± 0.02mm, consistent with the standard thickness of commercial PVB interlayer film. Place the mold in a flat vulcanizing machine and set the upper and lower platen temperatures to 150℃. First, preheat at a low pressure of 0.5MPa for 3 minutes to fully soften the resin and expel air between the particles; then quickly increase the pressure to 10MPa and hold for 2 minutes; finally, while maintaining the pressure, turn on the cooling water circulation. When the mold temperature drops below 40℃, release the pressure and demold to obtain a standard test sample with a smooth surface and no bubbles.

[0090] Sample conditioning and testing: The prepared samples were conditioned for 24 hours at 23℃ and 50% relative humidity. After calibrating the transmittance and haze meter, the transmittance (Tt) and haze (Haze) of each sample were measured. Five parallel samples were prepared for each formulation. During testing, measurements were taken at four points on each sample, including the center and the four sides. The final result was the arithmetic mean of all measurements.

[0091] The test data is shown in Table 2: Table 2: Optical performance test data of PVB resin composition samples for each formulation system

[0092] According to the appendix Figure 2 Based on the test data in Table 4, the influence of each component on the optical properties of the system exhibits clear physical laws, which are analyzed in detail below: The transmittance of samples from Examples 1 to 6 remained above 90%, and the haze was controlled below 1.2%. Despite the introduction of 12% by weight of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer into the system, the material maintained optical transmittance comparable to pure PVB resin. Example 6 exhibited optical properties of 91.85% transmittance and 0.65% haze, indicating that at higher reaction temperatures, the interfacial grafting reaction was more complete, and the resulting interfacial transition layer more effectively suppressed light scattering at the interfacial. Although Example 2 increased the masterbatch loading, leading to a slight increase in impurity content in the rubber phase and a slight increase in haze from 0.82% to 1.15%, the transmittance remained at 90.15%, demonstrating that the refractive index modifier maintained good compatibility and modulating ability even at higher concentrations.

[0093] The data for Comparative Example 4 showed a deterioration, with transmittance dropping to 68.42% and haze surging to 24.37%, resulting in a milky white, semi-transparent appearance. From an optical physics perspective, the refractive index of the pure PVB matrix is ​​approximately 1.485, while the refractive index of the maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer rubber phase inherently deviates from that of the matrix. In the case of a high refractive index adjusting component (RI≈1.54) lacking rosin ester, a significant refractive index difference exists between the dispersed and continuous phases. When light passes through these two refractive index mismatched phase interfaces, intense refraction and reflection occur, leading to enhanced Rayleigh and Mie scattering, macroscopically manifesting as a loss of material transparency.

[0094] Regression analysis of the example data demonstrated the effectiveness of the "refractive index self-balancing mechanism." Hydrogenated rosin pentaerythritol ester diffused into the interior of maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles, increasing the mixed refractive index of the rubber phase to approach that of the PVB matrix (1.485). Simultaneously, the grafted copolymer layer generated by the interfacial reaction constructed a gradient structure with a smooth refractive index transition between the two phases, effectively eliminating optical abrupt changes at the phase interface and thus maintaining high transparency in the multiphase toughened system.

[0095] Test Example 3: Test Description: This test aims to evaluate the macroscopic mechanical properties and interfacial bonding state of the resin compositions of Examples 1, 2, and Comparative Example 3. Tensile testing was used to examine the stress transfer efficiency of the elastomeric phase in the matrix, and glass peel strength testing was used to examine the adhesion stability of the modified material to the inorganic glass surface.

[0096] Test steps: Tensile specimen preparation: A measured amount of dried resin composition particles were pressed into a homogeneous sheet with a thickness of 2.0 mm on a flat vulcanizing machine at 150℃ and 10 MPa. After cooling and demolding, the sheet was cut into dumbbell-shaped specimens conforming to GB / T 1040.2-2006 using a punch press and a standard cutter. Five specimens were prepared for each formulation and placed in a constant temperature and humidity environment at 23℃ for 48 hours to eliminate internal stress.

[0097] Tensile property testing: The test was conducted using a universal testing machine equipped with a large deformation extensometer. The tensile rate was set to 50 mm / min, and the gauge length to 50 mm. The system automatically recorded the stress-strain curves and calculated the tensile strength at break and elongation at break.

[0098] Laminated glass preparation: A 0.76 mm thick resin film was placed between two clean float glass sheets (300 mm × 300 mm × 3 mm). A vacuum bag system was constructed, and the glass was evacuated at room temperature for 15 minutes to remove interlayer air. Subsequently, while maintaining negative pressure, the temperature was raised to 135 °C, and the glass was treated in a high-temperature autoclave at a pressure of 1.2 MPa for 30 minutes. After cooling and depressurization, transparent laminated glass was obtained.

[0099] Glass peel strength test: According to GB / T 5137.1 standard, laminated glass is cut into strips 25mm wide. A 180-degree peel test is performed using a tensile testing machine, with the tensile rate set to 100mm / min. The average load during the peel process is recorded, and the peel strength (N / cm) is calculated.

[0100] The experimental data are shown in Table 3: Table 3: Test data records of mechanical properties and interfacial peel strength of resin compositions

[0101] According to the appendix Figure 3 Based on the test data in Table 3, the differences in interfacial chemical structure play a decisive role in the macroscopic mechanical properties of the material, as detailed below: The tensile strengths of Examples 1 and 3 reached 28.26 MPa and 31.10 MPa, respectively, with elongation at break maintained at 280% to 330%. In contrast, the tensile strength of Comparative Example 3 was only 16.50 MPa, and the elongation at break dropped significantly to 111.00%. In the physical blend system, the maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer rubber phase lacked chemical bonds with the PVB matrix, resulting in weak interfacial bonding. When the material was subjected to external tensile force, the rubber particles could not effectively bear the stress and instead became microcrack initiation points, leading to interfacial debonding at low strain.

[0102] The data from the example systems validated the effectiveness of the in-situ chemical bonding mechanism at the interface. In Example 1, the latent crosslinking agent reacted at the interface between the two phases to generate a graft copolymer, forming stable chemical crosslinking points. This chemical structure can effectively transfer stress and induce shear yielding in the matrix to absorb energy. Example 3, by increasing the amount of interfacial crosslinking agent and buffer, improved the interfacial crosslinking density, resulting in a further increase in tensile strength (approximately 10% higher than in Example 1). Although the elongation at break decreased slightly, it was still significantly higher than that of the physical blend group, indicating that the formulation maintained good toughness while improving strength.

[0103] Glass peel strength data showed that the example group (approximately 18-19 N / cm) was higher than the comparative example (312.42 N / cm). This indicates that the modification technology in this invention not only enhances the cohesive force between the rubber phase and the resin matrix, but also improves the wettability and chemical adsorption capacity of the resin on the inorganic glass surface due to the introduction of epoxy groups, thus solving the problem of decreased glass adhesion caused by traditional physical blending and toughening of rubber.

[0104] Test Example 4: Experimental Description: This test is based on ASTM D1925 and GB / T 2409 standards. Through forced ventilation heat aging test, the antioxidant capacity and color stability of the resin composition under long-term heat environment are investigated.

[0105] Test steps: Sample preparation: Resin particles prepared in Examples 1, 6, 2, and 5 were selected and hot-pressed at 150°C into flat square pieces of 50mm × 50mm × 1.0mm. Before testing, the surface of the sample was gently wiped with anhydrous ethanol to remove fingerprints or oil stains, and conditioned for 24 hours in a standard laboratory environment (23°C, 50%RH).

[0106] Initial colorimetric determination: Using a spectrophotometer in reflective mode with a standard white background, a D65 light source and a 10° viewing angle, the initial yellowing index of each sample was measured. ) and chromaticity value ( , , Each sample group was measured at 3 locations, and the arithmetic mean was taken as the zero point data.

[0107] Thermal aging treatment: The sample with the initial value measured is suspended in a precision forced-air drying oven, the temperature is set to 100℃±1℃, and forced air circulation is turned on to ensure uniform temperature distribution and sufficient oxygen in the oven.

[0108] Stage sampling and retesting: Samples were taken out at 24 hours, 48 ​​hours, 72 hours, 96 hours, and 120 hours of aging. After the samples cooled naturally to room temperature, their yellowing index was immediately retested. ) and chromaticity values. Calculate the total color difference at each time point. The calculation formula is: in, , , These represent the samples at aging times of [time value missing]. The colorimetric value at that time. After the test, observe the appearance of the sample to see if there are any visible discoloration or degradation spots.

[0109] The experimental data are shown in Table 4: Table 4: Yellowing index and total color difference evolution data of different formulation systems during thermal aging at 100℃

[0110] According to the appendix Figure 4 Based on the test data in Table 4, there is a chemical correlation between the state of the catalyst and the color stability of the system, as detailed below: After 120 hours of rigorous thermal aging, the yellowing index (YI) of Examples 1 and 6 only increased to 1.32 and 1.10, respectively, and the total color difference (ΔE) was controlled within 0.7, making the color change almost imperceptible to the naked eye. This indicates that the constructed "two-way locking system" effectively inhibits the oxidative activity of imidazole compounds. At the microscopic level, most of the catalyst is physically encapsulated by hydrogenated rosin ester within the maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer rubber phase, which acts as a physical barrier to isolate oxygen. Simultaneously, the coordination bond formed between zinc ions and imidazole remains stable under aging conditions at 100°C, occupying the active nitrogen sites on the imidazole ring and preventing it from participating in the thermal oxidation reaction as an electron donor to generate colored chromophores.

[0111] Comparative Example 2 data shows that the YI value reached 9.45 after 120 hours, and the sample exhibited a distinct yellow color. In the direct mixing process, the catalyst was indiscriminately dispersed in the PVB matrix, lacking the physical shielding of the rubber phase, resulting in imidazole molecules being directly exposed to the thermo-oxidative environment. Free amines readily induce the degradation or self-oxidation of acetal groups in the PVB molecular chains at high temperatures, forming quinone structures, thus causing the matrix to yellow.

[0112] Comparative Example 5 showed the worst performance, with the YI value rising to 19.85 and the sample turning a deep brownish-yellow. Lacking the coordination protection of zinc ions, the imidazole was in a highly reactive free amine state. This highly reactive Lewis base not only undergoes its own oxidative discoloration but also accelerates the butyraldehyde removal reaction of the PVB resin, initiating the formation of conjugated double bond sequences and leading to catastrophic optical degradation of the material.

[0113] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A resin composition for toughened modified PVB interlayer films, characterized in that, The resin composition is produced by dynamic reactive extrusion of raw materials comprising the following parts by weight: Polyvinyl butyral resin: 100 parts; Plasticizer: 18-22 parts; Rheology-competitive inhibitor: 0.2-0.5 parts; Latent crosslinking agent: 3.0-4.5 parts; Loaded toughening masterbatch: 18-21 parts.

2. The PVB interlayer resin composition based on toughened modification according to claim 1, characterized in that, The polyvinyl butyral resin is a low-viscosity resin; the plasticizer is triethylene glycol diisooctanoate; the rheology competitive inhibitor is stearic acid; and the latent crosslinking agent is an alicyclic epoxy resin selected from 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate.

3. The PVB interlayer resin composition based on toughened modification according to claim 1, characterized in that, The loaded toughening masterbatch is prepared from raw materials including maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, hydrogenated rosin pentaerythritol ester, zinc stearate, 2-ethyl-4-methylimidazole and auxiliary antioxidants.

4. The PVB interlayer resin composition based on toughened modification according to claim 1, characterized in that, In the raw materials of the supported toughening masterbatch, the weight ratio of the hydrogenated rosin pentaerythritol ester to the maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer is 0.5-0.75:1, and the weight ratio of the zinc stearate to the 2-ethyl-4-methylimidazole is 2.5:

1.

5. A method for preparing a toughened modified PVB interlayer resin composition, used to prepare the toughened modified PVB interlayer resin composition according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Stearic acid and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate are dissolved in triethylene glycol diisooctanoate to prepare a modified plasticizing liquid, which is then sprayed into polyvinyl butyral resin. After mixing and curing, a matrix premix is ​​obtained. S2. Hydrogenated rosin pentaerythritol ester, zinc stearate and 2-ethyl-4-methylimidazol are melt-mixed to form an active carrier melt. Then, maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles are added to the active carrier melt under low shear conditions for solid-phase diffusion swelling. After cooling, a loaded toughening masterbatch is obtained. S3. The matrix premix obtained in step S1 is added to the main feed port of the twin-screw extruder, and the loaded toughening masterbatch obtained in step S2 is added to the side feed port of the twin-screw extruder. After melt blending, interfacial reaction and devolatilization granulation, a resin composition is obtained.

6. The method for preparing the toughened modified PVB interlayer resin composition according to claim 5, characterized in that, In step S1, the preparation temperature of the modified plasticizing liquid is 55-65℃, the stirring and dissolving time is 15-25 minutes, the mixing time is 5-10 minutes, and the maturation time is 1.5-2.5 hours.

7. The method for preparing the toughened modified PVB interlayer resin composition according to claim 5, characterized in that, Step S2 further includes: Hydrogenated rosin pentaerythritol ester, zinc stearate, 2-ethyl-4-methylimidazole and auxiliary antioxidant are mixed and melted at 115-125℃ to allow zinc stearate to coordinate and complex with 2-ethyl-4-methylimidazole in situ. Reduce the stirring speed to 50-80 rpm, add maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles, and stir at a constant temperature of 105-120℃ for 25-60 minutes to allow the active carrier melt to penetrate into the particle interior. Cool the mixture to 30-35℃, add an anti-sticking agent, mix and discharge to obtain a loaded toughening masterbatch.

8. The method for preparing the toughened modified PVB interlayer resin composition according to claim 7, characterized in that, The weight ratio of the hydrogenated rosin pentaerythritol ester, zinc stearate, 2-ethyl-4-methylimidazole, auxiliary antioxidant, and maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer particles is 6-9:0.2-0.3:0.08-0.12:0.2:

12.

9. The method for preparing the toughened modified PVB interlayer resin composition according to claim 5, characterized in that, In step S3, the screw speed of the extruder is 300-400 rpm.

10. The method for preparing the toughened modified PVB interlayer resin composition according to claim 5, characterized in that, In step S3, the temperature distribution of the twin-screw extruder is controlled as follows: 140-160℃ in the conveying and plasticizing zone, 170-180℃ in the dispersion and mixing zone, 195-215℃ in the interface reaction zone, and 175-180℃ in the devolatilization and granulation zone and the die head.

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