High ductility 3D texture water transfer printing ink for automobile trim and preparation process thereof

Abstract

The application relates to the technical field of automobile ornament coating, and discloses a high-ductility 3D texture water transfer printing ink for automobile ornaments and a preparation process thereof, which comprises a polyurethane matrix resin, amino-poly-silsesquioxane, rheological modification fillers and an organic solvent; the amino-poly-silsesquioxane is distributed in the polyurethane matrix resin in the form of a uniform dispersed phase; amino groups on the surface of the amino-poly-silsesquioxane are associated with urethane groups in the polyurethane matrix resin through hydrogen bonds to form a hydrogen bond connection network; the hydrogen bond connection network is used to realize conversion of deformation energy into heat energy, to eliminate local stress concentration and to prevent molecular chain rupture when the film layer is deformed under stress, by dissociation of hydrogen bond sites; the amino-poly-silsesquioxane acts as a discrete rigid support unit, and a thixotropic skeleton constructed by the amino-poly-silsesquioxane and the rheological modification fillers restricts resin flow, so that the film layer can keep the texture micro-depth and inhibit whitening in a stretched state.

Description

Technical Field

[0001] This invention relates to a high-ductility 3D texture water transfer ink for automotive trim parts and its preparation process, belonging to the field of automotive trim part coating technology. Background Technology

[0002] Currently, water transfer printing technology is often used to achieve carbon fiber or geometric textures on the surface of automotive trim parts. To obtain a certain 3D tactile feel and visual depth on the surface of the trim parts, the ink film layer needs to have a certain thickness and cross-linking density to maintain the shape stability of the texture edges in the water tank. During the transfer process of automotive trim parts, the ink film layer undergoes non-uniform stretching with the substrate. The local stretching rate of deep drawing areas usually exceeds 200%. Existing water transfer printing inks use a single thermoplastic resin system or thermosetting resin system, which causes mechanical conflict in the film layer under extreme deformation. That is, the high cross-linking degree of thick film generates stress accumulation during deformation, which easily produces microcracks or visual whitening at the deformation site. On the other hand, adding plasticizers or reducing the degree of cross-linking to improve ductility will lead to a decrease in the modulus of the ink film layer, causing the texture to collapse or lose clarity during the heating stage before transfer.

[0003] Therefore, the technical problem to be solved by this invention is how to construct a composition that can respond to deformation intensity and generate stress relaxation, thereby eliminating brittle failure caused by extreme stretching while maintaining the thickness of the film texture. Summary of the Invention

[0004] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A high-ductility 3D texture water transfer ink for automotive trim parts, composed of the following components:

[0005] The polyurethane matrix resin has a content of 45 to 55 parts by weight and a hydroxyl value of 25. Up to 35 ;

[0006] Aminated polysilsesquioxane, in an amount of 8 to 12 parts by weight, wherein the amino functionality of the aminated polysilsesquioxane molecule is 6 to 8.

[0007] The rheology-modified filler has a content of 3 to 6 parts by weight and the balance is an organic solvent. The aminated polysilsesquioxane is uniformly dispersed in the polyurethane matrix resin, and the amino groups on the surface of the aminated polysilsesquioxane and the urethane groups in the polyurethane matrix resin segments form a hydrogen bond crosslinking network through hydrogen bonding.

[0008] Hydrogen bond crosslinking networks perform stress dissociation and displacement reconstruction of hydrogen bond sites during the stress deformation process of high-ductility 3D texture water transfer ink film layers used in automotive trim parts, so as to convert mechanical deformation energy into heat energy dissipation of molecular chain segments and resolve micro-stress concentration caused by local deformation.

[0009] Aminated polysilsesquioxane, as a discrete rigid support unit, is nested with a thixotropic spatial skeleton composed of rheology-modified fillers. Under the condition of a stretch ratio of not less than 200%, it constrains the flow of polyurethane matrix resin in the vertical plane of 3D texture, thereby enabling the film layer formed by curing high-ductility 3D texture water transfer ink for automotive trim parts to maintain more than 90% of the microscopic depth of the texture after stretching.

[0010] Preferably, the aminated polysilsesquioxane is an octaminophenyl cage-type silsesquioxane, and its dispersion particle size in the polyurethane matrix resin is 30. Up to 80 The molar ratio between the amino groups on the surface of the aminated polysilsesquioxane and the urethane groups in the polyurethane matrix resin is 1.2:1 to 2.5:1. When the stretching ratio of the high-ductility 3D texture water transfer ink film used for automotive trim is in the range of 150% to 250%, the proportion of hydrogen bond sites that break in the hydrogen bond crosslinking network is linearly positively correlated with the energy dissipation per unit volume of the film, so as to establish a stress self-relaxation mechanism inside the film.

[0011] Preferably, the high-ductility 3D texture water transfer ink for automotive trim parts has shear thickening response characteristics, and its corresponding viscosity jump coefficient satisfies the following formula: ,in, It is the viscosity jump coefficient, and It ranges from 1.5 to 1.8; For high-ductility 3D texture water transfer inks used in automotive trim parts, at 25 After passing 4500 Shearing process 30 The final kinetic viscosity; For high-ductility 3D texture water transfer inks used in automotive trim parts, at 25 Initial kinetic viscosity under initial mixing conditions; viscosity jump coefficient The positive offset characterizes the building density of the hydrogen bond crosslinking network.

[0012] Preferably, the polyurethane matrix resin is at 25 The kinetic viscosity is 1500. Up to 2500 The polyurethane matrix resin is composed of polyester polyol segments and isocyanate segments, and the number average molecular weight of the polyester polyol segments is 2000 to 3000.

[0013] Preferably, the rheology-modified filler is fumed silica modified with a silane coupling agent, and its primary particle size is 10. Up to 20 The thixotropic network constructed within the highly ductile 3D texture water transfer ink for automotive trim by the rheology-modified filler can synergistically counteract the gravitational rheological tendency of the polyurethane matrix resin under tension by working together with the rigid anchoring force generated by the aminated polysilsesquioxane.

[0014] Preferably, the organic solvent includes ethyl acetate, butyl acetate and propylene glycol methyl ether acetate; based on the total weight of the organic solvents as 100%, ethyl acetate accounts for 30% to 35% by weight, butyl acetate accounts for 45% to 50% by weight, and the balance is propylene glycol methyl ether acetate.

[0015] Preferred initial kinetic viscosity 1180 up to 1220 And the endpoint kinetic viscosity For 1850 up to 2100 .

[0016] Preferably, the dissociation energy level of the hydrogen bond crosslinking network is lower than the covalent bond energy level of the polyurethane matrix resin molecular chain, so that during the stress stretching process of the high-ductility 3D texture water transfer ink film layer used for automotive trim parts, the physical breakage of hydrogen bond sites takes precedence over the chemical breakage of the polymer skeleton.

[0017] Preferably, the film layer formed by curing high-ductility 3D texture water transfer ink for automotive trim parts exhibits a surface 3D texture depth attenuation rate of no more than 10% when stretched to 2.5 times its initial length, and shows no whitening areas under microscopic observation. The high-ductility 3D texture water transfer ink for automotive trim parts also exhibits a depth attenuation rate of 25°C. The change in kinetic viscosity after 180 days of storage in the environment is within 5% of its initial kinetic viscosity before storage.

[0018] A method for preparing a high-ductility 3D texture water transfer ink for automotive trim parts includes the following steps:

[0019] Step 1101: Add the polyurethane matrix resin to a stirring container equipped with a heating function, and heat to 45°C. Up to 50 and with 500 Up to 600 The rotation speed is used for initial stirring;

[0020] Step 1102: The aminated polysilsesquioxane is added dropwise to the stirring container at a uniform rate according to a mass ratio of 1:8.5 to 1:7.0 between the aminated polysilsesquioxane and the polyurethane matrix resin, with the addition time set to 3 minutes. Up to 5 Simultaneously, rheology-modified fillers and organic solvents are added;

[0021] Step 1103: Increase the speed of the mixing container to 3500. Up to 4500 To perform high-shear anchoring treatment, under this high-shear field for 25 seconds Up to 30 ;

[0022] Step 1104, online monitoring of the kinetic viscosity of the system, when used as a high-ductility 3D texture water transfer ink for automotive trim parts, at 25 The kinetic viscosity is reduced from the initial kinetic viscosity. It jumped suddenly and stabilized at 1850. up to 2100 endpoint kinetic viscosity Stop shearing and allow to cool.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. In high-ductility 3D texture water transfer ink, by introducing octaaminophenyl polysilsesquioxane with a specific ammonia density into the film-forming matrix, the high shear field during the preparation process induces the formation of a spatially ordered array of hydrogen bonds between the surface amino groups and polyurethane segments. When the ink film is subjected to extreme tensile energy impact, these lattice hydrogen bonds, as sacrificial bonds, undergo orderly zipper-like dissociation to absorb mechanical energy. This achieves stress self-dissipation without destroying the integrity of the polymer backbone, thus solving the problem of brittle failure caused by internal stress accumulation in the deep drawing part of the 3D texture ink.

[0025] 2. The ink composition utilizes the high bulk modulus of polysilsesquioxane microregions to establish discrete rigid anchor points within the polyurethane matrix, and forms a non-affine deformation structure in conjunction with specific rheology-modified fillers. During the overall deformation process, the polyurethane matrix undergoes a large-scale displacement around the aforementioned anchor points to provide extensibility, while the local film thickness supported by the anchor points remains stable. This allows the ink to achieve ultra-high stretch ratios while maintaining the original visual depth of the surface texture, eliminating the physical constraint of thinning due to stretching in traditional solutions.

[0026] 3. The established stress-grading relaxation mechanism, through the dynamic disassembly and instantaneous reconstruction of the hydrogen bond network, converts and balances the deformation energy inside the film layer in real time. This energy dissipation path effectively prevents the evolution of microcracks in the film layer caused by micro-stress concentration, and avoids the micro-whitening phenomenon caused by the forced breakage of polymer chain segments from a physical perspective. This ensures that automotive interior parts with complex curved surface structures still have excellent visual consistency and color saturation in extreme tensile regions. Attached Figure Description

[0027] Figure 1 This is a diagram illustrating the hydrogen bonding crosslinking and thixotropic support microstructure of the high-ductility 3D texture ink of this invention.

[0028] Figure 2 This is the dynamic response curve of hydrogen bond dissociation and stress evolution during the stress deformation process of the film layer of the present invention;

[0029] Figure 3 This is a flowchart illustrating the high-shear anchoring ink preparation process and its application in vacuum transfer printing according to the present invention. Detailed Implementation

[0030] The present invention will be described below with reference to embodiments. It should be understood that the following embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0031] This invention provides a high-ductility 3D texture water transfer printing ink for automotive interior parts and its preparation process. The ink is composed of a polyurethane matrix resin, aminated polysilsesquioxane, rheology-modified fillers, and organic solvents. By constructing a lattice-like hydrogen bond network within the polyurethane matrix resin, a stress self-relaxation mechanism is generated in the film layer to maintain the 3D texture depth under extreme deformation. This ink exhibits shear thickening characteristics, with its viscosity increasing with shear strength. Since automotive interior parts involve localized non-uniform stretching exceeding 200% during water transfer printing, this invention uses a polyurethane matrix resin as the continuous phase to address the internal stress accumulation during deformation. The hydroxyl value of the polyurethane matrix resin is 25. Up to 35 The number average molecular weight is 2000 to 3000, and it is at 25 The kinetic viscosity is 1500. Up to 2500 The polyurethane matrix resin provides the basic flexibility of the film layer and participates in the construction of the hydrogen-bonded crosslinking network through urethane groups. The ink film layer is prone to microcracks or whitening under extreme deformation. This invention adds 8 to 12 parts by weight of an aminated polysilsesquioxane to the polyurethane matrix resin. The aminated polysilsesquioxane is an octaminophenyl cage-type silsesquioxane with an amino functionality of 6 to 8. The amino groups on the surface of the aminated polysilsesquioxane associate with the urethane groups in the polyurethane matrix resin segments through hydrogen bonding, forming a hydrogen-bonded crosslinking network. The density of the hydrogen-bonded crosslinking network is determined by the viscosity jump coefficient. Characterized, specifically, the viscosity jump coefficient The calculation formula is as follows: ,in, This is the viscosity jump coefficient, with values ​​ranging from 1.5 to 1.8; For ink at 25 After passing 4500 Shearing process 30 The final kinetic viscosity was 1850. up to 2100 ; For ink at 25 The initial kinetic viscosity under the initial mixing state is 1180. up to 1220 The kinetic viscosity was measured using a coaxial cylindrical rotational rheometer. The sample was placed in a constant temperature unit at 25±0.1℃ for 120 seconds to defoam. The steady-state viscosity at a shear rate of 10s⁻¹ was selected. The initial kinetic viscosity μi was the value measured when the components were premixed uniformly and high-shear dispersion was not activated. The final kinetic viscosity μf was the value measured after high-shear dispersion was stopped and the sample was cooled to 25℃. When the film is subjected to stress deformation, the hydrogen bond crosslinking network performs stress dissociation and displacement reconstruction of hydrogen bond sites, converting mechanical deformation energy into heat dissipation of molecular chain segments. This sacrificial bond mechanism eliminates local micro-stress concentration and prevents polymer molecular chain breakage.

[0032] During the ink spreading process, the film layer tends to thin, leading to a decrease in texture clarity. This invention uses 3 to 6 parts by weight of a rheology-modified filler, which is fumed silica modified with a silane coupling agent, and its original particle size is 10 mm. Up to 20 Aminated polysilsesquioxane serves as a discrete rigid support unit, with a dispersion particle size of 30 μm in the polyurethane matrix resin. Up to 80 The thixotropic spatial framework, composed of aminated polysilsesquioxane and rheology-modified filler, is nested within each other, constraining the flow of polyurethane matrix resin in the vertical plane of the 3D texture under a stretch ratio of not less than 200%. Thus, the cured film retains more than 90% of the initial texture micro-depth after stretching. Organic solvents are used to adjust the coating rheology of the ink, including ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate. Based on the total weight of the organic solvents (100%), ethyl acetate accounts for 30% to 35%, butyl acetate accounts for 45% to 50%, and the balance is propylene glycol methyl ether acetate. The preparation method of the above-mentioned high-ductility 3D texture water transfer ink for automotive trim includes the following steps: adding polyurethane matrix resin to a stirring container equipped with a heating function, and heating to 45°C. Up to 50 , with 500 Up to 600 Stirring at a certain speed; before feeding, determine the actual hydroxyl value of the polyurethane matrix resin and correct the amount of aminated polysilsesquioxane added. The correction formula is that the actual amount of aminated polysilsesquioxane added is equal to the base formula amount multiplied by the ratio of the actual hydroxyl value to 30, so that the molar ratio of amino to urethane groups in the system is maintained in the range of 1.2:1 to 2.5:1 to ensure consistent hydrogen bond crosslinking network density. According to the mass ratio of aminated polysilsesquioxane to polyurethane matrix resin of 1:8.5 to 1:7.0, at 3 Up to 5 Aminated polysilsesquioxane was added dropwise, along with rheology-modified filler and organic solvent, while simultaneously increasing the stirring speed of the vessel to 3500 rpm. Up to 4500 .

[0033] Continuous action under high shear field for 25 Up to 30 The high-shear anchoring process generates mechanical heat, requiring the system temperature to be maintained at 45°C to 50°C. When the shear speed is increased to above 3500 rpm, the cooling circulation of the mixing vessel jacket is activated. The cooling medium temperature is set at 5°C to 10°C. The cooling medium flow rate is adjusted according to the real-time monitoring of the material temperature to counteract the volumetric heat generated by shear friction and maintain a constant temperature. The kinetic viscosity of the system is monitored online. When the ink is at 25°C... The kinetic viscosity is lower than the initial kinetic viscosity. It jumped and stabilized at 1850. up to 2100 endpoint kinetic viscosity At that time, shearing is stopped and cooling is performed; in the finished product process of high-ductility 3D texture water transfer ink for automotive trim parts, after the high-shear anchoring process is completed, a graded cooling and physical degassing treatment is performed, and the flow rate of the jacket cooling water is controlled to keep the material at 2 / min to 3 Cool at a constant rate of / min to 28 Simultaneously, the vacuum device is activated to adjust the pressure inside the stirring container to -0.08. to -0.09 And maintain 15 Pitting defects after film curing are eliminated by removing microbubbles entrained during the dispersion stage. The resulting material is then filtered through a 300-mesh stainless steel screen and stored at 25°C. The fineness of the finished ink measured below is no greater than 10. .

[0034] Example 1: In a specific automotive trim production process, 3D texture water transfer printing was performed on dashboard trim parts with complex curved surfaces and deep-drawn structures. When the dashboard trim parts entered the vacuum adsorption molding stage along with the water transfer film, the ink film layer in the corner areas of the dashboard trim parts was in a non-uniform strain state with a local tensile rate exceeding 200%. To verify the technical performance under this condition, the ink composition determined in the aforementioned specific implementation method was used, wherein a hydroxyl value of 30 was selected. 50 parts by weight of a polyurethane matrix resin with a number average molecular weight of 2800, 10 parts by weight of an octaaminophenyl cage-type silsesquioxane with 8 amino functional sites, and 4.5 parts by weight of fumed silica modified with a silane coupling agent, along with an organic solvent composed of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate, are added. Following the preparation method described in steps one to four above, the mixture is heated at 4000... 30 under high shear field This makes the system at 25 Initial kinetic viscosity From 1200 A transition occurs, and the resulting endpoint kinetic viscosity Stable in 1956 The viscosity jump coefficient was calculated. It is 1.63.

[0035] During the aforementioned strain process, the amino groups on the surface of the aminated polysilsesquioxane associate with the urethane groups in the polyurethane segments through hydrogen bonding. The hydrogen bond sites formed preferentially undergo stress dissociation as sacrificial bonds, converting mechanical deformation energy into heat energy during molecular segment slippage. This establishes a stress self-relaxation mechanism within the film layer, dissolving the stress accumulation generated during deformation of the highly cross-linked film layer. Simultaneously, the thixotropic framework formed by the aminated polysilsesquioxane as a discrete rigid support unit and the rheology-modified filler maintains its spatial occupancy during hydrogen bond dissociation, constraining the flow of the polyurethane matrix resin in the vertical plane of the texture. Actual measurements show that at the 250% stretch ratio of the dashboard trim, the ink film surface is smooth and no whitening areas appear under a 50x microscope, with an initial texture depth of 48. The extended texture depth is 44. The resulting depth retention rate was 91.6%, and the film layer was at 80°C. Placed in a constant temperature environment for 24 hours Afterwards, no blurring of texture outlines was observed.

[0036] Example 2: This experiment was used to verify the stress relaxation performance and 3D texture retention rate of the ink composition under gradient variables. The experiment was conducted under simulated conditions of vacuum adsorption molding of automotive interior parts, using a displacement control accuracy of 0.01. The universal testing machine was used as a tensile force application platform, utilizing a spatial resolution of 0.1. Texture morphology was characterized using confocal microscopy, and the temperature fluctuation of the experimental environment was controlled within... The sampling period for key parameters in the data acquisition system is set to 10. The value of the sampling period depends on the real-time requirement for capturing stress jump signals. When the strain rate generated by the film under stress reaches 50... To ensure complete recording of the modulus evolution at the instant of hydrogen bond site dissociation, the sampling period was set to the lower limit of its predetermined range. A multi-dimensional control system was designed, with the experimental group (the sample group of this invention) containing 10 parts by weight of aminated polysilsesquioxane, as defined in the aforementioned specific embodiments. Control group A had the aminated polysilsesquioxane removed to evaluate the physical response when the dynamic stress dissipation network was missing. Control group B adjusted the content of aminated polysilsesquioxane to 5 parts by weight to verify the failure critical point of the low-density hydrogen bond network under extreme tension. Control group C adjusted the content of aminated polysilsesquioxane to 15 parts by weight to verify the negative constraints of high filling amount on the system's rheology. Each sample group was prepared according to the aforementioned steps one to four.

[0037] During the experiment, the inks of each sample group were coated onto the surface of the carrier film and dried until the film thickness was 20 mm. It was fixed in the testing machine fixture and subjected to uniaxial constant speed tensile testing, with the tensile rate kept constant at 50. The experiment simultaneously monitored the membrane layer at 25°C. The kinetic viscosity evolution under different conditions was analyzed, and the viscosity jump coefficient was utilized. Characterizing the construction density of hydrogen bond networks; the specific formula is as follows: ,in, This is the viscosity jump coefficient; The final kinetic viscosity of the system after being subjected to a high shear field, in units of... ; The initial kinetic viscosity of the system during the initial mixing phase is expressed in units of... The obtained data are shown in Table 1, which is an example table of measured performance data for each sample group. The tensile ratio of 4.0 corresponds to 300% tensile strain, which is used to simulate the ultimate deformation of the deep drawing part.

[0038] Table 1: Example Table of Actual Performance Data for Each Sample Group

[0039]

[0040] Analysis of the data in Table 1 shows that the experimental group had a viscosity jump coefficient At a strength of 1.63, the texture depth retention rate remained at 89.1% even under a 4.0-fold extreme stretching without whitening, confirming that the hydrogen bond network constructed between the aminated polysilsesquioxane and polyurethane segments played a sacrificial bond energy dissipation role during deformation. Control group A, lacking aminated polysilsesquioxane, could not form dynamic crosslinks between molecular chains, and its… The value was close to 1.0, and the depth retention rate was only 68.4% at 2.5 times stretching, accompanied by whitening caused by film fragmentation; Control group B, due to the addition of less than 8 parts by weight of stress regulator, had insufficient hydrogen bond site density to dissipate local stress concentration, resulting in rapid performance degradation with increasing stretching ratio; Control group C, although showing good texture retention after stretching, due to... Values ​​exceeding 1.8 result in an excessively strong shear thickening effect in the ink system, which manifests as decreased leveling properties and visible orange peel defects on the film surface during actual coating processes.

[0041] Example 3: This example combines Figures 1 to 2 This document describes a high-ductility 3D texture water transfer ink for automotive trim parts and its preparation process. Figure 1 As shown, the polyurethane matrix resin, as a component containing urethane groups, undergoes hydrogen bonding association with the amino-containing polysilsesquioxane, which is uniformly dispersed and has surface amino groups. That is, the amino groups combine with the urethane groups to construct a hydrogen bond network as a dynamic physical crosslinking lattice. During the deformation process, the hydrogen bond sites dissociate under stress, converting deformation energy into heat energy, relieving local stress concentration, preventing molecular chain breakage, and inhibiting whitening. At the same time, the rheology-modified filler, which serves as the basis for the thixotropic framework, works synergistically with the amino-containing polysilsesquioxane to construct the framework. Through the nesting of discrete rigid supports and thixotropic networks, a thixotropic spatial framework is formed, which constrains the resin to flow in the vertical plane and maintains spatial occupancy, thereby maintaining the microscopic depth of the texture. After the organic solvent, which serves as the medium carrier, evaporates and forms a film, the above mechanisms work together to form a highly ductile 3D textured film, so that the texture depth retention rate of the film is greater than 90% under tension.

[0042] like Figure 2As shown, the left vertical axis represents stress and stress concentration factor, the right vertical axis represents the hydrogen bond dissociation rate (%), the solid line represents the trajectory of the applied stress (MPa), the dashed line represents the trajectory of the hydrogen bond dissociation rate (%), and the dotted line represents the trajectory of the local stress concentration factor. On the time axis, these three show a dynamic relationship: as the applied stress increases, the hydrogen bond dissociation rate increases accordingly, while the local stress concentration factor initially increases and then decreases with the dissociation of hydrogen bonds. Figure 3 As shown, at the raw material mixing and pre-preparation stage, the polyurethane matrix resin, which serves as the continuous phase carrier, is mixed with functional components, namely aminated polysilsesquioxane and fillers, in a constant-temperature heating and stirring device. The premixed material is then conveyed to the next stage. Next, at the high-shear structure construction stage, a high-shear disperser is used to perform hydrogen bond network construction, namely the association of amino and urethane, and the generation of rigid support units from the thixotropic skeleton, which are then dispersed and transferred to the post-processing stage. Then, at the finished product refining and quality control stage, a vacuum degassing and filtration system is used to physically remove bubbles to eliminate pitting defects, and kinetic viscosity monitoring is performed to confirm viscosity jump characteristics and complete the delivery of the finished ink. Finally, at the end-of-life transfer application stage, in a vacuum adsorption molding station, the ink film is stretched for automotive dashboard trim parts with deep-drawing structures and high elongation, and the stress self-relaxation mechanism is activated.

[0043] Example 4: In the research and development of automotive air conditioning vent trim for ultra-deep drawing ratios, the surface curvature radius of the trim is less than 2. The ink film layer is 0.5 It is subjected to transient stress impact with a tensile rate of 280%; to determine the physical mapping relationship between high shear field strength and hydrogen bond network saturation, a parameter calibration method based on kinetic energy input is adopted, providing data at 48... Using a polyurethane matrix resin in a isothermal activated state as a continuous phase carrier, the ordered anchoring of aminated polysilsesquioxane at the phase interface was induced by controlling the shear rate gradient in the stirred vessel. The experimental settings included shear rates of 3200... 3800 4200 With 4500 The sample group was analyzed, and an online viscometer monitoring system was used to monitor the viscosity at 25°C. The kinetic viscosity change was used to calculate the viscosity jump coefficient. When the shear rate is 3200 At that time, because the mechanical energy input density was lower than the activation energy required for the amino-modified polysilsesquioxane molecule to overcome steric hindrance, the system at 30 Viscosity jump coefficient within The value remained below 1.25, indicating insufficient abundance of hydrogen bond network construction. When the simulated stretching was increased to 2.5 times the length, microcracks appeared locally in the film due to stress accumulation; when the shear rate was increased to 4200... Afterwards, the system was at 26 The kinetic viscosity transition occurs at a certain moment, and the final kinetic viscosity is measured. For 2015 Initial kinetic viscosity 1210 The viscosity jump coefficient was calculated. The value was 1.67; transmission electron microscopy revealed that the aminated polysilsesquioxane formed within the polyurethane matrix with a spacing of 60 mm. The lattice-like distribution of the topology, when subjected to 280% non-uniform strain, converts mechanical energy into thermal energy through the ordered dissociation and reconstruction of hydrogen bond sites, reducing the local stress concentration factor inside the film from 4.5 to 1.2.

[0044] In the calibration process used to confirm the spatial continuity of the hydrogen bond network, the array density of aminated polysilsesquioxane in the polyurethane matrix resin was calculated. When the content of aminated polysilsesquioxane was set in the range of 8 parts by weight to 12 parts by weight, the average centroid distance between individual POSS molecules was calculated. Determined by the following formula: ;in, The average centroid distance is expressed in units of 1. ; The equivalent diameter of a single POSS molecule is 3. Up to 5 ; It is the volume fraction; Pi; the calculated average distance between the centroids. At 15 Up to 25 Within this range, the value matches the statistical bending radius of the polyurethane chain segment, enabling each POSS unit to associate with multiple polymer chain segments at multiple points. Thus, under non-uniform stretching of more than 200%, the integrity of the film's physical structure is maintained through the stepwise dissociation of sacrificial bonds. It has been determined that the ink product prepared under this calibration process has a 3D texture depth retention rate of 93.8%, and the micro whitening index after surface stretching remains stable below 0.05.

[0045] Example 5: In material compatibility scenarios involving different production batches of polyurethane matrix resin, the hydroxyl value of the polyurethane matrix resin is 25. Up to 35 Within the range, to establish the viscosity jump coefficient For baseline consistency calculations, an initial viscosity calibration method was used, where the material after adding the aminated polysilsesquioxane and organic solvent was placed at 25°C. In the constant temperature jacket, at 500 Stirring speed 5 Using an online rotational viscometer at a shear rate of 10 Under the condition of reading 1 consecutive The median viscosity data within the range is defined as the initial kinetic viscosity. The obtained values ​​are used as the starting characteristic for subsequent evaluation of the hydrogen bond network construction density, thereby eliminating the differences in thixotropy between different batches of raw materials under static conditions.

[0046] To address the varying requirements for film ductility in decorative elements with different surface curvatures, a dynamic calibration method for process parameters was adopted at 3500. Up to 4500 During the high shear field process, the system collects data on the system in real time at 25°C. The kinetic viscosity at the following levels With shearing time The trajectory of change is determined, and the characteristic slope of the viscosity change rate is calculated. Among them, the characteristic slope The calculation formula is as follows: ,in, This is the viscosity change rate, in units of... ; This represents the change in viscosity, in units of... ; For time increments, the unit is 1. When the feature slope is detected The viscosity drift rate exceeded 5 times the initial state for three consecutive sampling periods, and the instantaneous viscosity jump coefficient When the ink enters the range of 1.5 to 1.8, the system determines that the spatial association between the aminated polysilsesquioxane and the polyurethane chain segment has reached an equilibrium state and outputs a stop shearing signal. The inks produced in this way have a 3D texture depth retention rate of no less than 90% when stretched to 2.5 times the initial length.

[0047] Example 6: In a volume of 500 The ink is dispersed in a stirring container, the impeller diameter of which is [missing information]. By adjusting the stirring speed The linear velocity at the edge of the impeller Set at 22 Up to 28 Within the range, the impeller edge linear velocity The calculation formula is as follows: ;in, The impeller edge linear velocity, in units of ; Pi; The impeller diameter is expressed in units of 1000 mm. ; The stirring speed is expressed in units of 1000 rpm. Impeller edge linear velocity As a kinetic input reference for inducing the formation of a multi-point array anchored by aminated polysilsesquioxane in polyurethane matrix resin, it is used to establish consistent hydrogen bond building strength across dispersion devices of different geometries.

[0048] When the humidity of the production environment When the concentration is above 65%, before adding the aminated polysilsesquioxane, add 0.5% to 1.2% by weight of an isocyanate capping agent to the organic solvent composed of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate to eliminate residual moisture in the system; the stirring vessel is at 500... The system was stirred at a certain speed, and the viscosity was monitored using an online viscometer. The viscosity was considered reduced when the measured viscosity drift rate dropped to 0.2%. When the process of adding aminated polysilsesquioxane is initiated, the resulting ink film retains 91.2% to 94.5% of the 3D texture depth when stretched to 2.5 times the initial length.

[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-ductility 3D texture water transfer ink for automotive trim parts, characterized in that, It consists of the following components: The polyurethane matrix resin has a content of 45 to 55 parts by weight and a hydroxyl value of 25. Up to 35 ; Aminated polysilsesquioxane, in an amount of 8 to 12 parts by weight, wherein the amino functionality of the aminated polysilsesquioxane molecule is 6 to 8. Rheology-modified filler, which is fumed silica modified with a silane coupling agent, has a native particle size of 10. Up to 20 Its content is 3 to 6 parts by weight; the balance is organic solvent; the film layer formed by curing high-ductility 3D texture water transfer ink for automotive trim has a surface 3D texture depth attenuation rate of no more than 10% when stretched to 2.5 times the initial length, and no whitening area under microscopic observation. High-ductility 3D texture water transfer inks for automotive trim parts exhibit shear-thickening response characteristics, and their corresponding viscosity jump coefficients satisfy the following formula: ,in, It is the viscosity jump coefficient, and It ranges from 1.5 to 1.8; The endpoint kinetic viscosity; The initial kinetic viscosity was used. The kinetic viscosity value was measured using a coaxial cylindrical rotational rheometer. The sample was placed in a constant temperature unit at 25±0.1℃ for 120 seconds to defoam, and a shear rate of 10s was selected. -1 The steady-state viscosity value; where the initial kinetic viscosity is... 1180 up to 1220 endpoint kinetic viscosity For 1850 up to 2100 .

2. The high-ductility 3D texture water transfer ink for automotive trim parts according to claim 1, characterized in that, Aminated polysilsesquioxanes are octaminophenyl cage-type silsesquioxanes, with a dispersion particle size of 30 in polyurethane matrix resins. Up to 80 .

3. The high-ductility 3D texture water transfer ink for automotive trim parts according to claim 1, characterized in that, Polyurethane matrix resin at 25 The kinetic viscosity is 1500. Up to 2500 The polyurethane matrix resin is composed of polyester polyol segments and isocyanate segments, and the number average molecular weight of the polyurethane matrix resin is 2000 to 3500.

4. The high-ductility 3D texture water transfer ink for automotive trim parts according to claim 1, characterized in that, The organic solvents include ethyl acetate, butyl acetate and propylene glycol methyl ether acetate; based on the total weight of the organic solvents as 100%, ethyl acetate accounts for 30% to 35% by weight, butyl acetate accounts for 45% to 50% by weight, and the balance is propylene glycol methyl ether acetate.

5. A method for preparing a high-ductility 3D texture water transfer ink for automotive trim parts as described in claim 1, characterized in that, Includes the following steps: Step 1101: Add the polyurethane matrix resin to a stirring container equipped with a heating function, and heat to 45°C. Up to 50 and with 500 Up to 600 The rotation speed is used for initial stirring; Step 1102: Add the aminated polysilsesquioxane dropwise to the stirring container at a uniform rate, with the dropwise addition time set to 3 minutes. Up to 5 Simultaneously, rheology-modified fillers and organic solvents are added; Step 1103: Increase the speed of the mixing container to 3500. Up to 4500 To perform high-shear anchoring treatment, under this high-shear field for 25 seconds Up to 30 ; Step 1104, online monitoring of the kinetic viscosity of the system, when used as a high-ductility 3D texture water transfer ink for automotive trim parts, at 25 The kinetic viscosity is lower than the initial kinetic viscosity. It jumped suddenly and stabilized at 1850. up to 2100 endpoint kinetic viscosity Stop shearing and allow to cool.

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