A new soft segment, polyurethane acrylate oligomer, acrylate UV-curable damping adhesive and a preparation method thereof

Abstract

This invention relates to a novel soft segment, a polyurethane acrylate oligomer, an acrylate UV-curable damping adhesive, and their preparation method, belonging to the field of adhesive technology. The novel soft segment contains dynamic oxime ester bonds with hydroxyl groups at both ends. By self-producing a novel soft segment containing dynamic oxime ester bonds and constructing a "hard segment-soft segment-hard segment" type polyurethane acrylate oligomer, placing the dynamic oxime ester bonds in the soft segment instead of the traditional hard segment, the glass transition region is fundamentally broadened and the damping performance is improved. The resulting UV-curable adhesive is suitable for bonding precision components such as motors, and can be rapidly cured by UV irradiation for 8-15 seconds, providing high adhesive strength. Through the synergy of the polyurethane acrylate oligomer, acrylate monomer, and filler, high damping characteristics with tanδ≥0.45 are maintained in a wide temperature range of -30℃ to 80℃. The chain transfer agent can adjust the crosslinking density and optimize the glass transition temperature, jointly endowing the adhesive with rapid curing, strong adhesion, and superior overall damping performance.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to a novel soft segment, polyurethane acrylate oligomer, acrylate UV-curable damping adhesive and its preparation method. Background Technology

[0002] As smartphones and other mobile devices rapidly evolve towards higher performance, thinner designs, and immersive user experiences, haptic feedback has become a key technology for enhancing human-computer interaction. Linear Resonant Actuators (LRAs) and Voice Coil Motors (VCMs), due to their advantages such as fast response, precise control, and rich tactile feedback, are widely used in high-end smartphones, providing users with diverse haptic experiences such as button feedback, notification alerts, and game interactions.

[0003] However, existing mobile phone vibration motors suffer from ringing issues in practical applications: after the drive signal stops, the motor generates unnecessary continuous vibrations (i.e., ringing) due to its mechanical inertia and elastic system. This ringing severely affects the "clean and crisp" feel of haptic feedback, causing a "trailing" phenomenon, blurring the tactile distinction between different vibration modes (such as single click, double click, and long press), and reducing the realism and immersion of the user experience.

[0004] In existing technologies, motor components in mobile phones are typically bonded and fixed using adhesives. Therefore, to reduce the negative impact of residual vibrations generated by the mobile phone motor on the user experience, the adhesive used needs to have good adhesion to materials and excellent damping properties. Damping refers to a material's ability to absorb mechanical energy (such as vibration or sound energy) in contact with it, suppressing or slowing down the energy transfer from the vibration source.

[0005] In practical applications, it has been found that while silicone-based UV-curable damping adhesives have good damping performance, they also have other limitations, such as incomplete curing, slow curing speed, and weak adhesion. Acrylic-based UV-curable damping adhesives, while having fast curing speed and strong adhesion, suffer from a lower damping coefficient and poor damping effect, resulting in noticeable residual vibration in the mobile phone.

[0006] CN121182188A discloses a photothermal dual-curing resin composition, its preparation method and application, and a damping elastomer. The damping elastomer provided by this invention has a curing time of 7.5~10.5 hours, and when the ambient temperature is -20℃~85℃, the damping coefficient tanδ≥0.35 and the tensile strength ≥13MPa. However, due to its long curing time and insufficient damping performance, further improvement is needed.

[0007] Therefore, there is an urgent need for a UV-curable damping adhesive that has fast curing speed, strong adhesion, and excellent damping performance over a wide temperature range. Summary of the Invention

[0008] To address the issue of existing UV-curable damping adhesives having varying curing speeds, adhesion strengths, and damping properties, this invention provides a novel soft segment. This soft segment reacts with diisocyanate and acrylate monomers to form a polyurethane acrylate oligomer with a "hard segment-soft segment-hard segment" structure and acrylate groups at both ends. An acrylate-based UV-curable damping adhesive is then prepared from this polyurethane acrylate oligomer. This adhesive exhibits a curing time ≤13s, an adhesion strength ≥13.5MPa, and excellent damping properties, with a damping coefficient tanδ ≥0.45 at ambient temperatures ranging from -30°C to 80°C. Within the confined space of a mobile phone, this adhesive can withstand the impacts, drops, and temperature changes experienced during daily use of motor components, providing strong support for the stability and long-term reliability of its internal structure.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a novel polyester soft segment with hydroxyl groups at both ends and a main chain containing dynamic oxime ester bonds.

[0011] The dynamic oxime ester bonds in this soft segment, along with their neighboring carbonyl oxygen atoms, can form a strong hydrogen bond network with hydrogen atoms in the system. Under external vibrational stress, the hydrogen bonds undergo reversible breakage and recombination first, rapidly dissipating energy. As the stress increases or continues, the dynamic oxime ester bonds undergo further reversible breakage and topological rearrangement, thus deeply dissipating mechanical energy and avoiding permanent damage. After the vibration disappears, the dynamic oxime ester bond network is reconstructed, and the hydrogen bonds spontaneously recover, allowing the internal structure of the material to reorganize and return to an equilibrium state. This hierarchical and synergistic energy dissipation mechanism makes this soft segment an ideal core unit for constructing high-performance damping materials.

[0012] This novel soft segment can precisely construct a "hard segment-soft segment-hard segment" block structure by reacting its hydroxyl groups with diisocyanate. Because the soft segment itself has a glass transition temperature below -40°C, when used as a soft phase matrix, it ensures at the molecular level that the resulting polyurethane acrylate oligomers and their UV-cured adhesives both possess low glass transition onset temperatures. This characteristic fundamentally meets the requirement that damping adhesives maintain high elasticity and energy dissipation capacity even at low temperatures.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0014] As a preferred technical solution of the present invention, the structural formula of the novel soft segment is as follows: where n is an integer from 3 to 5.

[0015]

[0016] Precisely controlling the degree of polymerization (n) of the novel soft segments within the range of 3 to 5 is based on a comprehensive balance requirement of dynamics, mechanical properties, and processability. This range ensures that each polymer chain contains 3 to 5 dynamic oxime ester bonds, providing a sufficient density of reversible crosslinking points for efficient stress dissipation and network recombination, while maintaining a suitable glass transition temperature. Simultaneously, this chain length facilitates the formation of effective chain entanglement, imparting the material with the necessary strength and elasticity, and promoting appropriate microphase separation from the hard segments. Furthermore, the corresponding molecular weight range (approximately 1500 to 2500) provides the soft segments with moderate viscosity, ensuring the feasibility of subsequent synthesis and processing. Deviations from this range will lead to insufficient dynamic properties, decreased mechanical strength, or processing difficulties, thereby significantly deteriorating the overall performance of the final material.

[0017] As a preferred embodiment of the present invention, the degree of polymerization n of the novel soft segment is 4. Each polymer chain contains 4 dynamic oxime ester bonds, which ensures sufficient reversible crosslinking points to maintain efficient network recombination ability while avoiding excessive restriction of chain segment movement due to excessively dense dynamic bonds, thereby balancing dynamism and chain segment flexibility at the molecular scale.

[0018] Preferably, the glass transition temperature (Tg) of the novel soft segment is below -45°C. This characteristic directly reflects the excellent low-temperature compliance of the soft segment, which helps to broaden the effective damping temperature range of the final adhesive, ensuring that the chain segments can still move freely in low-temperature environments, thereby activating a significant viscoelastic energy dissipation mechanism and obtaining excellent damping performance.

[0019] Secondly, the present invention provides a method for preparing a novel soft segment, the method comprising the following steps:

[0020] S1: Under nitrogen protection, dimethylglyoxime was dissolved in anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of triethylamine and chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0021] S2: The white crystalline intermediate was mixed with excess anhydrous ethylene glycol and anhydrous K2CO3 and reacted at 80-85℃ for 24-36 hours; after cooling, it was extracted and the organic phase was purified by column chromatography to obtain the bis(hydroxyethyl)glyoxime diester monomer.

[0022] S3: Under nitrogen protection, the bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and adipic acid chloride solution was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 20-24 hours.

[0023] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and salt water, then dried and concentrated. The concentrate is added dropwise with anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated and then dried under high vacuum to obtain a white new soft segment.

[0024] Preferably, during step S1, when adding the mixture of triethylamine and chloroacetyl chloride, the internal reaction temperature should be controlled below 10°C. This operation aims to suppress the exothermic reaction by using low temperature and slow dropwise addition, avoiding side reactions such as hydrolysis or excessive acylation of chloroacetyl chloride due to local overheating, thereby ensuring reaction selectivity and obtaining a high-purity white crystalline intermediate in high yield.

[0025] Preferably, when adding the adipic acid chloride solution in step S3, the internal temperature must be strictly controlled between 0 and 5°C. Low temperature conditions can suppress side reactions between the acyl chloride groups and impurities such as water, ensuring that its polycondensation with the hydroxyl groups proceeds in a predetermined sequence. This is crucial for achieving controllable chain growth and obtaining the target molecular weight and a narrow molecular weight distribution.

[0026] As a preferred embodiment of the present invention, the molar ratio of dimethylglyoxime, chloroacetyl chloride and anhydrous ethylene glycol is 1:(2.0~2.2):(10~20).

[0027] Chloroacetyl chloride is highly volatile and extremely sensitive to moisture, and trace amounts may be lost or hydrolyzed during operation and reaction. A slight excess of chloroacetyl chloride ensures that both oxime hydroxyl groups in each dimethylglyoxime molecule are completely acylated, preventing incomplete reaction due to insufficient chloroacetyl chloride, avoiding the formation of one-sided reaction byproducts, and improving the yield of the target intermediate.

[0028] Increasing the concentration of the nucleophile (ethylene glycol) can significantly promote the forward reaction, making it more complete and faster. The terminal chloroacetyl group of the intermediate remains highly reactive. If the ethylene glycol concentration is insufficient, the generated monomer molecule with a terminal hydroxyl group may react with the chlorine of another intermediate molecule, leading to dimerization or polymerization and generating byproducts of varying molecular weights. Using a large excess of ethylene glycol ensures that each intermediate molecule is surrounded and attacked by sufficient ethylene glycol, thereby inhibiting intermolecular coupling and ensuring that the product is a well-defined small molecule monomer, rather than an oligomer. Furthermore, excess ethylene glycol can be relatively easily removed through subsequent extraction, washing with water, and column chromatography.

[0029] Preferably, the molar ratio of bis(hydroxyethyl)glyoxime diester monomer to adipic acid chloride is (1.03~1.07):1, so that the bis(hydroxyethyl)glyoxime diester monomer is slightly in excess, which can ensure that the novel soft segment chain is capped with hydroxyl groups and better control the number average molecular weight of the polymer between 3000 and 4000.

[0030] Preferably, the molar ratio of bis(hydroxyethyl)glyoxime diester monomer to adipicoyl chloride is 1.05:1, which ensures hydroxyl end-capping while also providing a suitable safety margin.

[0031] Thirdly, the present invention provides a polyurethane acrylate oligomer prepared from the novel soft segment described in the first aspect, which has a distinct "hard segment-soft segment-hard segment" triblock linear structure, with hard segments at both ends and long-chain flexible soft segments in the middle, and a glass transition temperature range of -30~90℃.

[0032] To broaden the damping temperature range, this invention prepares this block oligomer by precisely controlling the structure and ratio of soft and hard segments. The soft segment is a novel soft segment containing dynamic oxime urethane bonds. Its long-chain flexibility provides an extremely low glass transition temperature (Tg < -40℃), forming the basis for low-temperature elasticity and damping. The dynamic oxime urethane bonds embedded in the main chain can reversibly break and recombine under stress, becoming highly efficient energy dissipation units. The hard segment is formed by the reaction of diisocyanate with the soft segment and a capping agent. Its polyurethane segments are rich in urethane bonds, which can form a physical cross-linked network through strong hydrogen bonding, not only imparting strength and heat resistance to the material but also participating in viscous energy dissipation at high temperatures. Acrylic monomers are used as capping agents to introduce UV-curable end groups.

[0033] Due to the thermodynamic incompatibility of the soft and hard segments, microphase separation occurs within the material, forming a soft-segment-rich phase (Tg approximately -40℃) and a hard-segment-rich phase (Tg extending to above 90℃). The glass transition regions of the two phases connect and overlap, giving the oligomer a wide transition range of -30℃ to 90℃, thus achieving high damping performance over a wide temperature range on a macroscopic scale. The abundant hydrogen bonds in the hard segments and the dynamic covalent bonds in the soft segments work synergistically to construct a multi-level, efficient energy dissipation mechanism, which is key to the material's excellent overall performance.

[0034] Fourthly, the present invention provides a method for preparing a polyurethane acrylate oligomer, comprising the following steps:

[0035] T1: Under dry nitrogen protection, the novel soft segment is dissolved in anhydrous butanone; a catalyst is added, and the mixture is heated to 70°C. Then, the diisocyanate solution is slowly added dropwise to the system.

[0036] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculation value, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0037] T3: Cool the prepolymer solution to 50°C, and premix the end-capping agent hydroxyethyl acrylate with a small amount of polymerization inhibitor and catalyst until homogeneous;

[0038] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0039] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain a viscous polyurethane acrylate oligomer.

[0040] T6: Store polyurethane acrylate oligomers in a sealed container under low temperature, dry, and light-protected conditions.

[0041] As a preferred embodiment of the present invention, the molar ratio of the novel soft segment, diisocyanate and hydroxyethyl acrylate is 1:(2.0~2.2):(2.2~2.4).

[0042] The reaction between isocyanate groups (-NCO) and hydroxyl groups (-OH) is reversible. Using an excess of -NCO ensures that the -OH groups at both ends of the novel soft segment are completely reacted. A slight excess of the -OH groups in hydroxyethyl acrylate ensures that the -NCO groups at both ends of the prepolymer are completely consumed, generating the target acrylate-terminated product. Residual -NCO groups can trigger side reactions during subsequent UV curing or storage, affecting stability.

[0043] Preferably, when the molar ratio of the novel soft segment, diisocyanate, and hydroxyethyl acrylate is 1:2.1:2.2, a moderate excess of diisocyanate can effectively inhibit cross-linking between the novel soft segments via diisocyanate, ensuring the acquisition of a linear, soluble prepolymer. In addition, a slight excess of hydroxyethyl acrylate (-OH) can both promote the complete completion of the end-capping reaction and significantly reduce the risk of unreacted small molecule hydroxyethyl acrylate residues, thereby protecting the purity, glass transition temperature, and mechanical properties of the final prepolymer.

[0044] Preferably, the diisocyanate is one or a combination of at least two of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates.

[0045] Preferably, the diisocyanate is isophorone diisocyanate. Since isophorone diisocyanate belongs to the alicyclic diisocyanate group and has an asymmetric structure, the polyurethane acrylate oligomers prepared using it exhibit excellent UV resistance to yellowing and good toughness.

[0046] Fifthly, the present invention provides an acrylate UV-curable damping adhesive made from the polyurethane acrylate oligomer of the fourth aspect, comprising, by weight, the following components: 25-60 parts of polyurethane acrylate oligomer, 20-70 parts of acrylate monomer, 1-6 parts of photoinitiator, and 1-10 parts of filler.

[0047] The adhesive provided by this invention incorporates polyurethane acrylate oligomers and acrylate monomers. The polyurethane acrylate oligomers primarily function as a functional framework; their "hard-segment-soft-segment-hard-segment" structure provides a broad glass transition region through microphase separation. Furthermore, the dynamic bonds in the soft segments and the hydrogen bonds in the hard segments together constitute an efficient energy dissipation mechanism, which is crucial for achieving intrinsic high-damping performance over a wide temperature range. The acrylate monomers primarily function as network modifiers and process media, ensuring processability by adjusting the system viscosity and precisely controlling the crosslinking density, curing speed, and mechanical properties of the final network through their functionality and reactivity. Through their synergistic effect, a gradient network structure required for wide-temperature-range damping is constructed at the molecular level, while rapid curing and high-strength adhesion are achieved in the process. Adding only polyurethane acrylate oligomers results in excessively high system viscosity, making processing difficult and preventing fine-tuning of the network for performance optimization. Adding only acrylate monomers, while achieving rapid curing, lacks the intrinsic structure necessary for generating high-damping performance over a wide temperature range, failing to meet high-performance requirements.

[0048] In this invention, the weight parts of the polyurethane acrylate oligomer are 25 to 60 parts, for example, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, or 60 parts, etc.

[0049] In this invention, the weight parts of the acrylate monomer are 20 to 70 parts, for example, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts, 68 parts, or 70 parts, etc.

[0050] In this invention, the content of polyurethane acrylate oligomer and acrylate monomer within the aforementioned range can balance the rapid curing and high-strength adhesion of the adhesive, and optimize its micro-network structure, thereby achieving excellent damping performance over a wide temperature range. If the ratio of polyurethane acrylate oligomer to acrylate monomer is too high, it will lead to excessive system viscosity, making construction difficult, insufficient flexibility of the cured network, and a decrease in low-temperature damping performance; if the ratio is too low, it will weaken the wide-temperature-range damping characteristics provided by microphase separation, and may lead to poor high-temperature mechanical properties and durability due to insufficient crosslinking density and cohesive strength.

[0051] In this invention, the photoinitiator is in the form of 1 to 6 parts by weight, for example, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3.0 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4.0 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5.0 parts, 5.2 parts, 5.5 parts, 5.8 parts, or 6.0 parts, etc.

[0052] In this invention, the filler is in the form of 1-10 parts by weight, for example, 1.0 parts, 1.5 parts, 2.0 parts, 2.5 parts, 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts, or 10.0 parts, etc.

[0053] As a preferred embodiment of the present invention, the acrylate monomer is one or a combination of at least two of the following: ethyl acrylate, n-butyl acrylate, isooctyl acrylate, lauryl acrylate, dodecyl acrylate, octadecyl acrylate, n-octyl acrylate, n-nonyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, tetrahydrofuran acrylate, isobornyl acrylate, and N,N-dimethylacrylamide.

[0054] Hydroxyethyl acrylate is a preferred acrylate monomer. It has three functions: reactivity, process regulation, and performance enhancement. As a reactive diluent, it can effectively regulate the viscosity of the system, giving it good coating and application properties. At the same time, its terminal acryloyloxy group can participate in free radical copolymerization under UV irradiation, becoming a covalently cross-linked structural unit of the cured network.

[0055] Crucially, the hydroxyl groups (-OH) in the acrylate monomer molecules can form a strong hydrogen bond network with multiple sites in the polyurethane acrylate oligomer:

[0056] (1) With the carbonyl oxygen (C=O) and amide hydrogen (NH) in the hard segment of urethane;

[0057] (2) The nitrogen or oxygen atom of the oxime ester bond in the dynamic soft segment.

[0058] These hydrogen bonds can undergo reversible breakage and recombination when the material is subjected to dynamic stress, becoming another efficient energy dissipation pathway besides dynamic covalent bonds, and directly contributing to the improvement of damping performance (tanδ). At the same time, the hydrogen bond network can enhance the physical crosslinking density and cohesive strength of the system, which helps to maintain the structural stability and mechanical equilibrium of the material over a wide temperature range, thereby synergistically achieving the performance target of high damping (tanδ≥0.45) in the range of -30℃ to 80℃.

[0059] Preferably, the photoinitiator is one or a combination of at least two of the following: 1-hydroxycyclohexylphenyl ketone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, methyl benzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-isopropylthioxanthrone, benzoin dimethyl ether, dimethylbenzoyl ketal, and benzophenone.

[0060] Preferably, the filler is one or a combination of at least two of the following: fumed silica, spherical silica powder, aluminum hydroxide, calcium oxide, and talc. The filler and the polymer matrix form a dynamically interacting interface, and through interfacial friction and slippage, mechanical vibration energy is efficiently converted into heat energy.

[0061] Preferably, the acrylate UV-curable damping adhesive of the present invention further includes 0-1 parts by weight of chain transfer agent.

[0062] In this invention, the chain transfer agent is in the form of 0 to 1 part by weight, for example, 0 parts, 0.05 parts, 0.10 parts, 0.15 parts, 0.20 parts, 0.25 parts, 0.30 parts, 0.35 parts, 0.40 parts, 0.45 parts, 0.50 parts, 0.55 parts, 0.60 parts, 0.65 parts, 0.70 parts, 0.75 parts, 0.80 parts, 0.85 parts, 0.90 parts, 0.95 parts, or 1.00 parts, etc.

[0063] Preferably, the chain transfer agent is any one or a combination of at least two of pentaerythritol tetra(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), and pentaerythritol tetra(3-mercaptobutyric acid).

[0064] The present invention also provides a method for preparing an acrylate UV-curable damping adhesive, comprising the following steps: in a dry environment, polyurethane acrylate oligomer, acrylate monomer, photoinitiator, filler and chain transfer agent are placed in a small beaker in the above proportions, and mechanically stirred at 500 rpm / min for 5 to 10 minutes to obtain the acrylate UV-curable damping adhesive.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] (1) By making a novel soft segment containing dynamic oxime ester bonds and constructing a "hard segment-soft segment-hard segment" type polyurethane acrylate oligomer, the dynamic oxime ester bonds are placed in the soft segment instead of the traditional hard segment, which fundamentally broadens the glass transition region and improves the damping performance.

[0067] (2) The obtained UV-curable adhesive is suitable for bonding precision parts such as motors. It can be cured quickly by UV irradiation for 8 to 15 seconds, providing high bonding strength. Through the synergy of polyurethane acrylate oligomers, acrylate monomers and fillers, it maintains high damping characteristics of tanδ≥0.45 in a wide temperature range of -30℃ to 80℃.

[0068] (3) The chain transfer agent in the system can adjust the crosslinking density and further optimize the glass transition temperature. The components work together to give the adhesive rapid curing, strong adhesion and better overall damping performance. Detailed Implementation

[0069] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments and comparative examples. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0070] To fully and clearly explain the implementation process, some raw material parameters and sources are disclosed as follows:

[0071] Dimethylglyoxime: Sigma-Aldrich 40390, provided by Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0072] Chloroacetyl chloride: Millipore 802411, provided by Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0073] Adipic acid chloride: Aldrich 165212, provided by Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0074] Isophorone diisocyanate: Aldrich 317624, provided by Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0075] Acrylate monomer: Hydroxyethyl acrylate, provided by Changzhou Qiangli Electronic New Materials Co., Ltd.;

[0076] Photoinitiator: 1-hydroxycyclohexylphenyl ketone, provided by Changzhou Qiangli Electronic New Materials Co., Ltd.

[0077] Filler: Fumed silica, provided by Changzhou Qiangli Electronic New Materials Co., Ltd.

[0078] Chain transfer agent: Pentaerythritol tetra(3-mercaptopropionate), provided by Changzhou Qiangli Electronic New Materials Co., Ltd.

[0079] Preparation of novel soft segment A1

[0080] S1: Under nitrogen protection, 11.81 g of dimethylglyoxime was dissolved in 80 ml of anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of 44.6 ml of triethylamine and 16.8 ml of chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0081] S2: 14.91 g of white crystalline intermediate was mixed with 41.7 ml of anhydrous ethylene glycol and 1.38 g of anhydrous K2CO3 and reacted at 80-85 °C for 24-36 hours; after cooling, the mixture was extracted and the organic phase was purified by column chromatography to obtain bis(hydroxyethyl)glyoxime diester monomer;

[0082] S3: Under nitrogen protection, 2.943 g of bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and 1.098 g of adipic acid chloride solution was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 20-24 hours.

[0083] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and brine, then dried and concentrated. The concentrate is added dropwise to 40 ml of anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated, then dried under high vacuum to obtain a white novel soft segment with a degree of polymerization n of 2.

[0084] Preparation of novel soft segment A2

[0085] S1: Under nitrogen protection, 11.81 g of dimethylglyoxime was dissolved in 80 ml of anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of 44.6 ml of triethylamine and 16.8 ml of chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0086] S2: 14.91 g of white crystalline intermediate was mixed with 41.7 ml of anhydrous ethylene glycol and 1.38 g of anhydrous K2CO3 and reacted at 80-85 °C for 24-36 hours; after cooling, the mixture was extracted and the organic phase was purified by column chromatography to obtain bis(hydroxyethyl)glyoxime diester monomer;

[0087] S3: Under nitrogen protection, 2.943 g of bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and 1.220 g of adipic acid chloride solution was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 20-24 hours.

[0088] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and brine, then dried and concentrated. The concentrate is added dropwise to 40 ml of anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated, then dried under high vacuum to obtain a white novel soft segment with a degree of polymerization n of 3.

[0089] Preparation of novel soft segment A3

[0090] S1: Under nitrogen protection, 11.81 g of dimethylglyoxime was dissolved in 80 ml of anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of 44.6 ml of triethylamine and 16.8 ml of chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0091] S2: 14.91 g of white crystalline intermediate was mixed with 41.7 ml of anhydrous ethylene glycol and 1.38 g of anhydrous K2CO3 and reacted at 80-85 °C for 24-36 hours; after cooling, the mixture was extracted and the organic phase was purified by column chromatography to obtain bis(hydroxyethyl)glyoxime diester monomer;

[0092] S3: Under nitrogen protection, 2.943g of bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and 1.423g of adipic acid chloride solution was added dropwise. After the addition was completed, the reaction was carried out at room temperature for 20-24 hours.

[0093] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and salt water, then dried and concentrated. The concentrate is added dropwise to 40 ml of anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated, then dried under high vacuum to obtain a white novel soft segment with a degree of polymerization n of 4.

[0094] Preparation of novel soft segment A4

[0095] S1: Under nitrogen protection, 11.81 g of dimethylglyoxime was dissolved in 80 ml of anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of 44.6 ml of triethylamine and 16.8 ml of chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0096] S2: 14.91 g of white crystalline intermediate was mixed with 41.7 ml of anhydrous ethylene glycol and 1.38 g of anhydrous K2CO3 and reacted at 80-85 °C for 24-36 hours; after cooling, the mixture was extracted and the organic phase was purified by column chromatography to obtain bis(hydroxyethyl)glyoxime diester monomer;

[0097] S3: Under nitrogen protection, 2.943 g of bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and 1.497 g of adipic acid chloride solution was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 20-24 hours.

[0098] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and salt water, then dried and concentrated. The concentrate is added dropwise to 40 ml of anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated, then dried under high vacuum to obtain a white novel soft segment with a degree of polymerization n of 5.

[0099] Preparation of novel soft segment A5

[0100] S1: Under nitrogen protection, 11.81 g of dimethylglyoxime was dissolved in 80 ml of anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of 44.6 ml of triethylamine and 16.8 ml of chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate.

[0101] S2: 14.91 g of white crystalline intermediate was mixed with 41.7 ml of anhydrous ethylene glycol and 1.38 g of anhydrous K2CO3 and reacted at 80-85 °C for 24-36 hours; after cooling, the mixture was extracted and the organic phase was purified by column chromatography to obtain bis(hydroxyethyl)glyoxime diester monomer;

[0102] S3: Under nitrogen protection, 2.943 g of bis(hydroxyethyl) ethylenedioxime diester monomer solution was cooled to 0°C in an ice-salt bath, and 1.525 g of adipic acid chloride solution was added dropwise. After the addition was completed, the reaction was carried out at room temperature for 20-24 hours.

[0103] S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and brine, then dried and concentrated. The concentrate is added dropwise to 40 ml of anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated, then dried under high vacuum to obtain a white novel soft segment with a degree of polymerization n of 6.

[0104] Preparation of polyurethane acrylate oligomer B1

[0105] T1: Under dry nitrogen protection, 1.617 g of the novel soft segment A1 was dissolved in 3.0 mL of anhydrous butanone; 1.6 mg of organotin laurate catalyst was added, and the mixture was heated to 70 °C. Then, 0.467 g of isophorone diisocyanate solution was slowly added dropwise to the system.

[0106] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculated value of 2.9%, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0107] T3: Cool the prepolymer solution to 50°C, and premix 0.255 g of end-capping agent hydroxyethyl acrylate, 2.3 mg of hydroquinone monomethyl ether polymerization inhibitor, and 0.8 mg of lauric acid organotin catalyst evenly.

[0108] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0109] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain viscous polyurethane acrylate oligomer B1.

[0110] T6: Store polyurethane acrylate oligomer B1 in a sealed container under low temperature, dry, and light-protected conditions.

[0111] Preparation of polyurethane acrylate oligomer B2

[0112] T1: Under dry nitrogen protection, 2.022 g of the novel soft segment A2 was dissolved in 3.9 mL of anhydrous butanone; 2.0 mg of organotin laurate catalyst was added, and the mixture was heated to 70 °C. Then, 0.467 g of isophorone diisocyanate solution was slowly added dropwise to the system.

[0113] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculated value of 2.6%, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0114] T3: Cool the prepolymer solution to 50°C, and premix 0.255 g of end-capping agent hydroxyethyl acrylate, 2.7 mg of hydroquinone monomethyl ether polymerization inhibitor, and 1 mg of lauric acid organotin catalyst evenly.

[0115] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0116] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain viscous polyurethane acrylate oligomer B2.

[0117] T6: Store polyurethane acrylate oligomer B2 in a sealed container under low temperature, dry, and light-protected conditions.

[0118] Preparation of polyurethane acrylate oligomer B3

[0119] T1: Under dry nitrogen protection, 3.235 g of the novel soft segment A3 was dissolved in 4.6 mL of anhydrous butanone; 3.2 mg of organotin laurate catalyst was added, and the mixture was heated to 70 °C. Then, 0.467 g of isophorone diisocyanate solution was slowly added dropwise to the system.

[0120] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculated value of 2.4%, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0121] T3: Cool the prepolymer solution to 50°C, and premix 0.255 g of end-capping agent hydroxyethyl acrylate, 4.0 mg of hydroquinone monomethyl ether polymerization inhibitor, and 1.6 mg of lauric acid organotin catalyst evenly.

[0122] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0123] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain viscous polyurethane acrylate oligomer B3.

[0124] T6: Store polyurethane acrylate oligomer B3 in a sealed container under low temperature, dry, and light-protected conditions.

[0125] Preparation of polyurethane acrylate oligomer B4

[0126] T1: Under dry nitrogen protection, 4.044 g of the novel soft segment A4 was dissolved in 5.3 mL of anhydrous butanone; 4.0 mg of organotin laurate catalyst was added, and the mixture was heated to 70 °C. Then, 0.467 g of isophorone diisocyanate solution was slowly added dropwise to the system.

[0127] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculated value of 2.2%, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0128] T3: Cool the prepolymer solution to 50°C, and premix 0.255 g of end-capping agent hydroxyethyl acrylate, 4.8 mg of hydroquinone monomethyl ether polymerization inhibitor, and 2.0 mg of lauric acid organotin catalyst evenly.

[0129] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0130] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain viscous polyurethane acrylate oligomer B4.

[0131] T6: Store polyurethane acrylate oligomer B4 in a sealed container under low temperature, dry, and light-protected conditions.

[0132] Preparation of polyurethane acrylate oligomer B5

[0133] T1: Under dry nitrogen protection, 4.448 g of the novel soft segment A5 was dissolved in 5.7 mL of anhydrous butanone; 4.4 mg of organotin laurate catalyst was added, and the mixture was heated to 70 °C. Then, 0.467 g of isophorone diisocyanate solution was slowly added dropwise to the system.

[0134] T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculated value of 2.1%, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends;

[0135] T3: Cool the prepolymer solution to 50°C, and premix 0.255 g of end-capping agent hydroxyethyl acrylate, 5.2 mg of hydroquinone monomethyl ether polymerization inhibitor, and 2.2 mg of lauric acid organotin catalyst evenly.

[0136] T4: Slowly add the hydroxyethyl acrylate end-capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted;

[0137] T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain viscous polyurethane acrylate oligomer B5.

[0138] T6: Store polyurethane acrylate oligomer B5 in a sealed container under low temperature, dry, and light-protected conditions.

[0139] Example 1

[0140] In a dry environment, 40 parts by weight of polyurethane acrylate oligomer B2, 40 parts by weight of hydroxyethyl acrylate, 3 parts by weight of 1-hydroxycyclohexylphenyl ketone, 5 parts by weight of fumed silica and 0.5 parts by weight of pentaerythritol tetra(3-mercaptopropionate) are placed in a small beaker and mechanically stirred at 500 rpm / min for 5 to 10 minutes to obtain acrylate UV-curable damping adhesive C2.

[0141] Examples 2-5, Comparative Examples 1-5

[0142] An acrylate UV-curable damping adhesive differs from Example 1 only in the type and / or amount (parts by weight) of each component, as shown in Table 1. The preparation method of the acrylate UV-curable damping adhesive is the same as that of Example 1.

[0143] Table 1 - Types and amounts (parts by weight) of each component in the adhesives of Examples 2-5 and Comparative Examples 1-5

[0144]

[0145] Test 1: Determination of Adhesive Strength

[0146] A1: Take two chips and determine the bonding area and bonding region size as 5mm×10mm;

[0147] A2: Take a small amount of adhesive, apply it and cover the bonding area, and then make the bonding area completely adhered;

[0148] A3: Allow to cure fully according to the adhesive curing conditions;

[0149] A4: After curing, allow the bonded workpieces to cool fully to room temperature before loading them into a tensile testing machine (model SY-500, manufactured by Dongguan Jinton Testing Equipment Co., Ltd.).

[0150] A5: Set the speed of the tensile testing machine to "10mm / min", move the tensile testing machine upward until the two chips are pulled apart, and record the maximum tensile force value during this process;

[0151] A6: Calculate the shear strength of the adhesive based on the average tensile force.

[0152] Note: Shear strength (MPa) = Average tensile force (N) / Bond area (mm²) 2 )

[0153] Test 2: DSC Measurement

[0154] B1: Turn on the power to the DSC (Differential Scanning Calorimeter, model DSC25, manufactured by Waters Instruments, Inc., USA), connect the protective gas nitrogen, and adjust the pressure to 10~20 PSI;

[0155] B2: Start the control computer, run the Trios software, and click the "Connect" button to establish communication with the instrument;

[0156] B3: Weigh 5-10 mg of adhesive sample, place it in an aluminum crucible and seal it;

[0157] B4: Set the temperature range to 25℃~250℃ and the heating rate to 10℃ / min;

[0158] B5: Click the "Start" button to begin the experiment;

[0159] B6: After the experiment, switch the page to the "Results" interface and analyze the DSC curve.

[0160] Test 3: Curing Time

[0161] LED curing. The adhesive thickness is 0.15mm, and curing is performed using an LED UV lamp, such as the IGE XC210 (wavelength 365nm). Its light intensity is 800mw / cm². 2 ~1200mw / cm 2 Record the curing time.

[0162] Test 4: Determination of Damping Coefficient

[0163] Dynamic mechanical analysis (DMA) is a core method for measuring the damping coefficient of materials, assessing their viscoelasticity and energy dissipation capacity through periodic loading. The specific test procedures are as follows:

[0164] (1) Sample preparation

[0165] Cut the material to standard dimensions (e.g., a 100mm × 100mm × 2mm rubber sample), ensuring a smooth and defect-free surface.

[0166] (2) Instrument settings

[0167] ① Select a dynamic mechanical analyzer (such as the German Netzsch DMA242E) and set the test parameters:

[0168] ② Temperature range: -50℃ to 100℃ (adjustable);

[0169] ③ Frequency range: typically 0.1~100Hz (adjusted according to material properties);

[0170] ④ Strain amplitude: Controlled within the material's elastic limit.

[0171] (3) Dynamic mechanical testing

[0172] Mount the sample onto the DMA instrument fixture and start the testing program. The instrument records the material's stress-strain curve by measuring periodic strain (such as tension, compression, or shear).

[0173] (4) Data processing

[0174] ① Calculate the loss factor (damping coefficient) according to the formula tanδ = G" / G′, where:

[0175] "aG" represents the loss modulus;

[0176] bG′ is the energy storage modulus.

[0177] ② Generate temperature or frequency spectra to analyze the frequency and temperature dependence of material properties.

[0178] Precautions

[0179] (1) The test must be conducted in a vacuum or inert gas environment to avoid the effects of oxidation or moisture.

[0180] (2) The frequency and temperature scanning range need to be optimized for different materials. For example, compression or tensile vibration methods are usually preferred for rubber.

[0181] The results of the above performance tests are shown in Table 2 below:

[0182] Table 2

[0183]

[0184] As can be seen from the test results in Table 2, the adhesives of Examples 1 to 5 included in this invention have a wide glass transition region, covering the ambient temperature fluctuation range of -30℃ to 80℃, and the lowest damping coefficient is ≥0.45N·s / m; in addition, the bonding strength is ≥13.5MPa and the curing time is ≤13s.

[0185] Compared with Example 4, Comparative Example 1 had poorer bond strength, narrower glass transition zone, and significantly reduced high-temperature damping performance due to the addition of less than 25 parts by weight of polyurethane acrylate oligomer.

[0186] Compared with Example 5, Comparative Example 2 showed enhanced bonding strength and prolonged curing time due to the addition of polyurethane acrylate oligomers (>60 parts by weight); the glass transition region was narrowed, and the low-temperature damping performance was reduced to some extent.

[0187] Compared with Examples 1-3, Comparative Example 3 has a poorer bonding strength, a significantly higher glass transition temperature Tg, and significantly reduced low-temperature damping performance because the degree of polymerization n of the novel soft segment A1 is less than 3.

[0188] Compared with Examples 1-3, Comparative Example 4 has a lower bonding strength and longer curing time due to the degree of polymerization n>5 ​​of the novel soft segment A5; the glass transition region is narrower and moves to a lower temperature, and the high temperature damping performance is significantly reduced.

Claims

1. A novel soft segment, characterized in that, The novel soft segment contains a dynamic oxime ester bond and has hydroxyl groups at both ends.

2. The novel soft segment according to claim 1, characterized in that, The structural formula of the novel soft segment is as follows: Where n is an integer from 3 to 5.

3. The novel soft segment according to claim 2, characterized in that, The value of n is 4.

4. A method for preparing the novel soft segment according to any one of claims 1 to 3, characterized in that, The preparation method includes the following steps: S1: Under nitrogen protection, dimethylglyoxime was dissolved in anhydrous dichloromethane and cooled to 0-5°C in an ice bath. A mixture of triethylamine and chloroacetyl chloride was added dropwise, and the mixture was brought to room temperature and stirred for 12 hours. The reaction solution was washed, dried, concentrated, and recrystallized to obtain a white crystalline intermediate. S2: The white crystalline intermediate was mixed with excess anhydrous ethylene glycol and anhydrous K2CO3 and reacted at 80-85°C for 24-36 hours; after cooling, it was extracted and the organic phase was purified by column chromatography to obtain the bis(hydroxyethyl)glyoxime diester monomer. S3: Under nitrogen protection, cool the excess bis(hydroxyethyl) ethylenedioxime diester monomer solution to 0°C in an ice-salt bath, add adipic acid chloride solution dropwise, and react at room temperature for 20-24 hours after the addition is complete. S4: After the reaction solution is quenched with ice water, it is extracted. The organic phase is washed with acid, alkali and salt water, then dried and concentrated. The concentrate is added dropwise with anhydrous diethyl ether to precipitate. The solid is repeatedly dissolved and precipitated and then dried under high vacuum to obtain the white novel soft segment. Preferably, in step S1, the internal temperature of the triethylamine and chloroacetyl chloride mixture should be below 10°C, and in step S3, when the adipic acid chloride solution is added dropwise, the internal temperature should be controlled between 0°C and 5°C.

5. The preparation method according to claim 4, characterized in that, The molar ratio of dimethylglyoxime, chloroacetyl chloride and anhydrous ethylene glycol is 1:(2.0~2.2):(10~20), and the molar ratio of bis(hydroxyethyl)glyoxime diester monomer and adipicoyl chloride is (1.03~1.07):

1.

6. A polyurethane acrylate oligomer prepared from the novel soft segment according to any one of claims 1 to 5, wherein the polyurethane acrylate oligomer has a structure with hard segments at both ends and a long-chain flexible soft segment in the middle, and a glass transition temperature range of -30 to 90°C.

7. A method for preparing the polyurethane acrylate oligomer of claim 6, characterized in that, The preparation method includes the following steps: T1: Under dry nitrogen protection, the novel soft segment is dissolved in anhydrous butanone; a catalyst is added, and the mixture is heated to 70°C, followed by the slow dropwise addition of a diisocyanate solution to the system; T2: Maintain the reaction at 70℃ and monitor the content of -NCO groups in the reaction system; when the measured value is stable and close to the theoretical calculation value, stop the reaction to obtain a prepolymer solution with -NCO end caps at both ends; T3: Cool the prepolymer solution to 50°C, and premix the end-capping agent hydroxyethyl acrylate with a small amount of polymerization inhibitor and catalyst until uniform; T4: Slowly add the hydroxyethyl acrylate capping agent mixture to the prepolymer solution and maintain the reaction at 50°C until the -NCO groups have completely reacted; T5: After the reaction is complete, remove the solvent by vacuum distillation below 40°C to obtain a viscous polyurethane acrylate oligomer. T6: The polyurethane acrylate oligomer is sealed and stored under low temperature, dry and light-protected conditions.

8. The method for preparing the polyurethane acrylate oligomer according to claim 7, characterized in that, The molar ratio of the novel soft segment, diisocyanate, and hydroxyethyl acrylate is 1:(2.0~2.2):(2.2~2.4). Preferably, the diisocyanate is one or a combination of at least two of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates.

9. An acrylic UV-curable damping adhesive made from the polyurethane acrylate oligomer according to any one of claims 6 to 8, characterized in that, Based on parts by weight, it includes the following components: 25-60 parts of polyurethane acrylate oligomer; 20-70 parts of acrylate monomer; 1-6 parts of photoinitiator; 1-10 parts of filler; Preferably, the glass transition region of the acrylate UV-curable damping adhesive is -30℃ to 80℃, and tanδ ≥ 0.

45.

10. The acrylate UV-curable damping adhesive according to claim 9, characterized in that, The acrylate monomer is one or a combination of at least two of the following: ethyl acrylate, n-butyl acrylate, isooctyl acrylate, lauryl acrylate, dodecyl acrylate, octadecyl acrylate, n-octyl acrylate, n-nonyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, tetrahydrofuran acrylate, isobornyl acrylate, and N,N-dimethylacrylamide. Preferably, the acrylate monomer is hydroxyethyl acrylate; Preferably, the photoinitiator is one or a combination of at least two of the following: 1-hydroxycyclohexylphenyl ketone, 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, methyl benzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-isopropylthioxanthrone, benzoin dimethyl ether, dimethylbenzoyl ketal, or benzophenone. Preferably, the filler is one or a combination of at least two of the following: fumed silica, spherical silica powder, aluminum hydroxide, calcium oxide, and talc.

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