A glass interlayer prepared by copolymerization of a polyurethane prepolymer with (meth)acrylate monomers and a method for preparing the same

Abstract

This invention relates to the field of glass material preparation, specifically to a method for preparing a glass interlayer using polyurethane prepolymer and (meth)acrylate monomer through co-condensation. The invention involves heating and stirring an excess of polyol and isocyanate to prepare an incompletely reacted polyurethane prepolymer retaining unreacted hydroxyl groups. Subsequently, (meth)acrylate monomer is added, causing it to co-condense with the unreacted hydroxyl groups in the prepolymer. During the reaction, low-boiling-point substances are extracted under vacuum and combined with low-temperature heating to promote complete reaction, ultimately achieving melt co-condensation of the incompletely reacted polyurethane prepolymer and (meth)acrylate monomer. This method is simple, easy to industrialize, and the prepared copolymer possesses high adhesion, high strength, high water resistance, and excellent optical properties, making it widely applicable in the preparation of novel glass interlayers and the production of various types of safety glass.

Description

Technical Field

[0001] This invention relates to the field of glass material preparation, specifically to a method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer. Background Technology

[0002] The interlayer is the core functional material of laminated safety glass, playing a crucial role in bonding the glass substrate, absorbing impact energy, and preventing glass shattering and fragmentation. Its overall performance directly determines the safety, durability, and optical performance of the safety glass. Currently, the most widely used interlayer materials in industry mainly include thermoplastic polyurethane (TPU) and ionomers (such as SGP). However, existing TPU interlayers have significant performance defects: on the one hand, their interfacial adhesion to the glass substrate is relatively low, making them prone to delamination under harsh environments such as temperature cycling and humid aging, leading to a significant decrease in the overall mechanical properties of the safety glass; on the other hand, the tensile strength of TPU itself is insufficient, making it difficult to meet the high safety requirements of applications such as high-rise buildings and automotive windshields. While SGP ionic polymer interlayers outperform TPU in tensile strength and impact resistance, they have a fatal flaw: poor water resistance. The ionic bonds in their molecular chains are easily hydrolyzed and broken by water molecules. In humid environments or under long-term immersion conditions, a large number of bubbles will be generated, which not only seriously reduces the light transmittance and aesthetics of the glass, but also further weakens the adhesion between the interlayer and the glass, ultimately leading to the failure of the safety glass.

[0003] Therefore, inventing a novel glass interlayer material that combines high adhesion, high strength, high water resistance, and excellent optical properties remains a pressing technical challenge in this field. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention aims to develop a method for preparing a glass interlayer using polyurethane prepolymer and (meth)acrylate monomer through co-condensation. The method involves heating and stirring an excess of polyol and isocyanate to prepare an incompletely reacted polyurethane prepolymer retaining unreacted hydroxyl groups. Subsequently, (meth)acrylate monomer is added, causing it to co-condense with the unreacted hydroxyl groups in the prepolymer. During the reaction, low-boiling-point substances are extracted under vacuum and combined with low-temperature heating to promote complete reaction, ultimately achieving melt co-condensation of the incompletely reacted polyurethane prepolymer and (meth)acrylate monomer. This invention offers a simple process, is easy to industrialize, and produces a copolymer with high adhesion, high strength, high water resistance, and excellent optical properties, making it widely applicable in the preparation of novel glass interlayers and the production of various types of safety glass.

[0005] This invention discloses a method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, comprising the following steps:

[0006] Preparation of S1 incompletely reacted polyurethane prepolymer: Isocyanate and polyether polyol are mixed, heated to 90~150℃ and stirred for 1.5~2.5h to produce an incompletely reacted polyurethane prepolymer; Preparation of S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 is cooled to 70°C and then (meth)acrylate monomer is added dropwise. The mixture is stirred and heated to 60~110°C. Then, low-boiling substances are distilled off under vacuum until the reaction is complete and there is no distillate. The remaining reaction liquid is then collected to obtain the glass interlayer.

[0007] Preferably, in step S1, the mass ratio of the isocyanate to the polyether polyol is 1:6.

[0008] Preferably, in step S1, the isocyanate is toluene diisocyanate, isoflurane diisocyanate, or hexamethylene diisocyanate.

[0009] Preferably, in step S1, the polyether polyol has an average molecular weight of 300-5000 and a hydroxyl value of 30-650 mgKOH / g.

[0010] Preferably, in step S2, the mass ratio of the (meth)acrylate monomer to the polyether polyol in step S1 is 1:3.

[0011] Preferably, in step S2, the vacuum level of the vacuum pump is 0.9~1.0 atm.

[0012] Preferably, in step S2, the low-boiling material is water, methanol, ethanol, and unreacted monomer residue generated by the co-condensation reaction.

[0013] Preferably, in step S2, the (meth)acrylate monomer is methyl acrylate, ethyl acrylate, methyl methacrylate, or ethyl methacrylate.

[0014] Preferably, in step S2, the dropping rate of the (meth)acrylate monomer is 1-3 mL / min.

[0015] A glass interlayer prepared by any of the above-described methods for preparing a glass interlayer by co-condensation of a polyurethane prepolymer and a (meth)acrylate monomer.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a method for preparing a glass interlayer by co-condensation of a polyurethane prepolymer and a (meth)acrylate monomer, which has the following characteristics: (1) This invention first synthesizes the polyurethane prepolymer through incomplete reaction, so that an appropriate amount of unreacted hydroxyl groups are retained in the prepolymer. During the subsequent co-condensation with (meth)acrylate monomers, a large number of polar ester groups and hydroxyl groups are introduced into the polymer molecular chain. These polar groups can form strong hydrogen bonds and chemical bonds with the silanol groups on the glass surface, which greatly enhances the interfacial bonding force between the interlayer and the glass, and fundamentally solves the problem of easy delamination and separation of traditional TPU interlayers.

[0017] (2) The present invention effectively seals the hydrophilic groups and pores inside the material through the dense cross-linked structure formed by melt co-condensation, significantly reducing the permeation rate of water molecules, so that the material is not prone to bubbling even after long-term use in a humid environment.

[0018] (3) This invention effectively removes residual monomers and small molecule impurities from the reaction system through a vacuum extraction process for low-boiling substances, avoiding light scattering caused by impurities, and resulting in a cocondensate with extremely high transparency and extremely low haze. The light transmittance of the prepared glass interlayer material is greater than 89%, and the haze is less than 0.3%, meeting the optical performance requirements of high-end safety glass.

[0019] (4) The tensile strength of the glass interlayer prepared by the present invention can reach more than 30 kPa, which can effectively resist external impact and prevent glass from breaking and splashing. At the same time, the acrylate structural units introduced into the molecular chain increase the material’s resistance to yellowing. After long-term outdoor use, it can still maintain stable mechanical and optical properties, significantly extending its service life. Detailed Implementation

[0020] 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.

[0021] 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.

[0022] Example 1: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: 40g of isocyanate and 300g of polyether glycol are mixed, heated to 90℃ and stirred for 2.5h to generate an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is toluene diisocyanate, the average molecular weight of the polyether glycol is 300, and the hydroxyl value is 30mg KOH / g.

[0023] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 1mL / min. The mixture was stirred and heated to 60°C, followed by vacuum distillation to remove low-boiling components at a vacuum level of 0.9 atm. The remaining reaction solution was collected after the reaction was complete and no distillate was obtained to obtain the glass interlayer. The mass ratio of (meth)acrylate monomer to the polyether polyol in step S1 was 1:3; the (meth)acrylate monomer was methyl acrylate; and the low-boiling components were water, methanol, ethanol, and unreacted monomer residue generated from the co-condensation reaction. The obtained glass interlayer was then tested.

[0024] Example 2: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: 50g of isocyanate and 300g of polyether diol were heated to 100℃ and stirred for 2.3h to generate an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is isoflurane diisocyanate, the average molecular weight of the polyether polyol is 1500, and the hydroxyl value is 200mg KOH / g.

[0025] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 1.5mL / min. The mixture was stirred and heated to 75°C, and then vacuum distilled off low-boiling components at a vacuum level of 0.92atm. The reaction proceeded until no distillate remained, and the remaining reaction liquid was collected to obtain the glass interlayer. The (meth)acrylate monomer was ethyl acrylate, and the low-boiling components were water, methanol, ethanol, and unreacted monomer residues generated from the copolymerization reaction. The obtained glass interlayer was then tested.

[0026] Example 3: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: Isocyanate 50 and polyether triol 300g were mixed, heated to 120℃ and stirred for 2.1h to generate an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is hexamethylene diisocyanate; the polyether polyol has an average molecular weight of 2500 and a hydroxyl value of 300mg KOH / g.

[0027] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 2mL / min. The mixture was stirred and heated to 85°C, followed by vacuum distillation to remove low-boiling components at a vacuum level of 0.94 atm. The reaction proceeded until no distillate remained, and the remaining reaction liquid was collected to obtain the glass interlayer. The (meth)acrylate monomer was methyl methacrylate, and the low-boiling components were water, methanol, ethanol, and unreacted monomer residues generated during the copolymerization reaction. The obtained glass interlayer was then tested.

[0028] Example 4: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: 50g of isocyanate and 300g of polyether triol were mixed, heated to 120℃ and stirred for 1.9h to generate an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is isoflurane diisocyanate; the average molecular weight of the polyether polyol is 1500 and the hydroxyl value is 112mg KOH / g.

[0029] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 2.5mL / min. The mixture was stirred and heated to 75°C, and then vacuum distilled off the low-boiling components at a vacuum degree of 0.96atm. The reaction proceeded until no distillate remained, and the remaining reaction liquid was collected to obtain the glass interlayer. The (meth)acrylate monomer was ethyl acrylate; the low-boiling components were water, methanol, ethanol, and unreacted monomer residues generated from the copolymerization reaction. The obtained glass interlayer was then tested.

[0030] Example 5: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: Isocyanate 40 and polyether diol 300g were mixed, heated to 120℃ and stirred for 1.7h to produce an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is toluene diisocyanate, the polyether polyol has an average molecular weight of 1000 and a hydroxyl value of 112mg KOH / g.

[0031] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 2.0mL / min. The mixture was stirred and heated to 75°C, and then vacuum distilled off the low-boiling components at a vacuum degree of 0.98atm. The reaction proceeded until no distillate was obtained, and the remaining reaction liquid was collected to obtain the glass interlayer. The (meth)acrylate monomer was methyl acrylate; the low-boiling components were water, methanol, ethanol, and unreacted monomer residues generated from the copolymerization reaction. The obtained glass interlayer was then tested.

[0032] Example 6: A method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer, characterized by comprising the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: Isocyanate 50 and polyether triol 300g were mixed, heated to 150℃ and stirred for 1.5h to generate an incompletely reacted polyurethane prepolymer; wherein, the isocyanate is hexamethylene diisocyanate; the polyether polyol has an average molecular weight of 5000 and a hydroxyl value of 650mg KOH / g.

[0033] Preparation of the S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 was cooled to 70°C, and then 100g of (meth)acrylate monomer was added dropwise at a rate of 3mL / min. The mixture was stirred and heated to 110°C, and then vacuum distilled off the low-boiling components at a vacuum level of 1.0 atm. The reaction proceeded until no distillate was obtained, and the remaining reaction liquid was collected to obtain the glass interlayer. The (meth)acrylate monomer was ethyl methacrylate; the low-boiling components were water, methanol, ethanol, and unreacted monomer residues generated from the copolymerization reaction. The obtained glass interlayer was then tested.

[0034] Example 7: Weigh 300g of polyether glycol with an average molecular weight of 1000 and a hydroxyl value of 112mg KOH / g, and 70g of toluene diisocyanate (TDI). While stirring, slowly add the two raw materials to a 500ml three-necked round-bottom flask. Set the heating temperature to 120℃ to start the reaction. Observe the reaction carefully until the apparent viscosity of the system increases significantly, then stop heating and cool to 70℃. Weigh 50g of methyl methacrylate monomer and slowly add it to the system. Set the heating temperature to 75℃ to start heating, stirring and applying a vacuum (0.9~1.0 atm) to extract low-boiling-point substances until the raw materials react completely and no low-boiling-point substances distill off (the distillate components include water, methanol, and unreacted low-boiling-point monomer residues generated from the co-condensation reaction). After the reaction is complete, discharge and test.

[0035] Example 8: Weigh 300g of polyether triol with an average molecular weight of 1500 and a hydroxyl value of 112mg KOH / g, and 80g of isophorone diisocyanate (IPDI). While stirring, slowly add the two raw materials to a 500ml three-necked round-bottom flask. Set the heating temperature to 120℃ to start the reaction. Observe the reaction carefully until the apparent viscosity of the system increases significantly, then stop heating and cool to 70℃. Weigh 50g of ethyl acrylate monomer and slowly add it to the system. Set the heating temperature to 75℃ to start heating, stirring and applying a vacuum (0.9~1.0 atm) to extract low-boiling-point substances until the raw materials react completely and no low-boiling-point substances distill off (the distillate components include water, ethanol, and unreacted low-boiling-point monomer residues generated from the co-condensation reaction). After the reaction is complete, discharge and test.

[0036] Example 9: Weigh 300g of polyether glycol with an average molecular weight of 1000 and a hydroxyl value of 112mg KOH / g and 70g of toluene diisocyanate (TDI). While stirring, slowly add the two raw materials to a 500ml three-necked round-bottom flask. Set the heating temperature to 120℃ to start the reaction. Observe the reaction carefully until the apparent viscosity of the system increases significantly, then stop heating and cool to 70℃. Weigh 50g of ethyl acrylate monomer and slowly add it to the system. Set the heating temperature to 75℃ to start heating, stirring and applying a vacuum (0.9~1.0 atm) to extract low-boiling substances until the raw materials react completely and no low-boiling substances distill off (the distillate components include water, ethanol, and unreacted low-boiling monomer residues generated from the cocondensation reaction). After the reaction is complete, discharge and test.

[0037] The glass interlayers prepared in Examples 1-9 were tested using the following methods: 1. Collect the reaction products of the above examples and comparative examples and observe and test the relevant physicochemical properties.

[0038] 2. Take an appropriate amount of the above reaction product and place it between heat-resistant polyester films coated with release agent. Heat press at 80-120℃ for 30-120 minutes. Take out the film and test its tensile strength, light transmittance, and haze performance.

[0039] 3. Take a 10cm sample that has been cleaned and dried. 10cm Several glass slides, each 0.1 cm in size, are coated with the reaction product synthesized above and hot-pressed at 80-120℃ for 30-120 minutes. Then, the transmittance, haze, and other properties are tested.

[0040] The detection results obtained by the above detection methods in Examples 1-9 are shown in the table below:

[0041] The data from the above table shows that: (1) Examples 1-6 are glass interlayers prepared according to the preparation method provided by the present invention. The finished products of Examples 1-6 have excellent and stable comprehensive performance. In terms of adhesion, since the prepolymerization reaction is controlled at the incomplete stage, 20-40% of unreacted hydroxyl groups are retained in the system. These hydroxyl groups undergo co-condensation reaction with the subsequently added (meth)acrylate monomers, directly introducing a large number of polar ester groups and hydroxyl groups into the polyurethane molecular backbone. They can form strong hydrogen bonds and partial chemical bonds with the silanol groups on the glass surface. Therefore, the adhesion of all experimental group samples reaches the highest level 0 of the cross-cut adhesion test, effectively solving the problem of easy delamination of traditional TPU interlayers. In terms of water resistance and mechanical properties, the melt co-condensation process forms a uniform and dense interpenetrating network structure between polyurethane and acrylate segments. This effectively seals the hydrophilic groups and pores within the material, significantly reducing the permeation rate of water molecules. As a result, no bubbling or debonding occurred after 1000 hours of damp heat aging at 85℃ and 85% RH. Furthermore, the combination of the high elasticity of polyurethane and the high strength of acrylate resulted in tensile strengths exceeding 30 kPa for all samples, significantly higher than that of traditional TPU interlayers. Regarding optical properties, the simultaneous vacuum extraction process effectively removed residual monomers, small molecule byproducts, and moisture—the main impurities causing light scattering—resulting in a light transmittance greater than 89% and a haze less than 0.3% for all experimental samples, meeting the optical performance requirements of high-end safety glass. Among them, Example 4 and Example 5 exhibited the best overall performance. Example 4 used isoflurane diisocyanate (IPDI) and polyether triol to form a moderately cross-linked network structure, and added highly reactive ethyl acrylate to make the co-condensation reaction more complete. Example 5 used toluene diisocyanate (TDI) and polyether diol, which reduced the raw material cost while ensuring performance. The vacuum degrees of the two examples reached 0.96 atm and 0.98 atm, respectively, and the removal effect of low-boiling impurities was the best, so the optical performance was particularly outstanding.

[0042] (2) Examples 7-9 served as the control group. The process route of reacting polyether polyol with isocyanate until complete and then adding the same amount of (meth)acrylate monomer was adopted. All properties showed a significant decline, and the copolymerization modification effect was not significant. Specifically, the tensile strength was only 26.9-28.1 kPa, all below 30 kPa; the light transmittance was only 88.1-88.5%; the haze was 0.36-0.41%, all above 0.3%; the adhesion was only grade 1 in the cross-cut adhesion test; slight blistering occurred after 1000 hours of humid heat aging at 85°C and 85% RH; and the yellowing resistance ΔE value was also higher than that of Examples 1-6. This is because after the prepolymerization reaction is complete, there are almost no remaining hydroxyl groups in the system available for the cocondensation reaction. At this point, the added (meth)acrylate monomers mainly undergo self-polymerization to generate polyacrylate homopolymers, which cannot be effectively grafted onto the polyurethane molecular chains, resulting in low polar group content and weak interfacial bonding. At the same time, significant phase separation occurs between the polyurethane phase and the polyacrylate phase, which destroys the dense structure of the material and reduces mechanical properties and water resistance. In addition, the generated low molecular weight polyacrylate homopolymers are difficult to completely remove by vacuum extraction, which exacerbates light scattering and leads to a decrease in optical properties.

[0043] In summary, this invention successfully achieved efficient co-condensation of polyurethane prepolymer and (meth)acrylate monomer through an innovative incomplete reaction synthesis process. The resulting glass interlayer material possesses high adhesion, high strength, high water resistance, and excellent optical properties. Examples 1-6 all exhibit tensile strengths exceeding 30 kPa, light transmittance greater than 89%, and haze below 0.3%, while also demonstrating good resistance to yellowing, fully meeting the beneficial effects proposed in this invention. Examples 4 and 5 show the best overall performance and are the preferred embodiments of this invention. The method of this invention is simple and easy to industrialize. The prepared glass interlayer material can be widely used in the production of high-end safety glass in high-rise buildings, automobiles, and rail transportation, demonstrating excellent application prospects.

[0044] Obviously, 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 method for preparing a glass interlayer by co-condensation of a polyurethane prepolymer and a (meth)acrylate monomer, characterized in that, Includes the following steps: Preparation of S1 incompletely reacted polyurethane prepolymer: Isocyanate and polyether polyol are mixed, heated to 90~150℃ and stirred for 1.5~2.5h to produce an incompletely reacted polyurethane prepolymer; Preparation of S2 glass interlayer: The incompletely reacted polyurethane prepolymer obtained in step S1 is cooled to 70°C and then (meth)acrylate monomer is added dropwise. The mixture is stirred and heated to 60~110°C. Then, low-boiling substances are distilled off under vacuum until the reaction is complete and there is no distillate. The remaining reaction liquid is then collected to obtain the glass interlayer.

2. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S1, the mass ratio of isocyanate to polyether polyol is 1:

6.

3. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S1, the isocyanate is toluene diisocyanate, isoflurane diisocyanate, or hexamethylene diisocyanate.

4. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S1, the polyether polyol has an average molecular weight of 300-5000 and a hydroxyl value of 30-650 mg KOH / g.

5. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S2, the mass ratio of the (meth)acrylate monomer to the polyether polyol in step S1 is 1:

3.

6. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S2, the vacuum level of the vacuum pump is 0.9~1.0 atm.

7. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S2, the low-boiling material is water, methanol, ethanol and unreacted monomer residue generated by the co-condensation reaction.

8. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S2, the (meth)acrylate monomer is methyl acrylate, ethyl acrylate, methyl methacrylate, or ethyl methacrylate.

9. The method for preparing a glass interlayer by co-condensation of polyurethane prepolymer and (meth)acrylate monomer according to claim 1, characterized in that, In step S2, the (meth)acrylate monomer is added at a rate of 1-3 mL / min.

10. A glass interlayer prepared by a method for preparing a glass interlayer by co-condensation of a polyurethane prepolymer and a (meth)acrylate monomer as described in any one of claims 1 to 9.

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