A drawing effect ink and a preparation method thereof

Abstract

The present application relates to the technical field of ink, and discloses a wire drawing effect ink and a preparation method thereof, which comprises the following steps: preparing a molten core phase, wherein the molten core phase comprises a high-molecular-weight wire drawing component, a low-melting-point solid carrier and a latent compatibilizer, and the wire drawing component and a film-forming resin have different polymer properties; preparing an ink matrix phase comprising the film-forming resin, dispersing the molten core phase in the ink matrix phase to form a thermotropic emulsion; and rapidly cooling and solidifying the thermotropic emulsion to form solid core phase microparticles, wherein the wire drawing component and the latent compatibilizer are physically coated in the solid microparticles through rapid cooling and solidification, physical isolation of the wire drawing component is realized in the storage stage, and the rheological stability of the ink is ensured; meanwhile, the latent compatibilizer solves the problem of wire drawing failure caused by incompatibility of the wire drawing component and the matrix resin after high-temperature melting triggering, and ensures stable realization of the wire drawing effect.

Description

Technical Field

[0001] This invention relates to a brushed effect ink and its preparation method, belonging to the field of ink technology. Background Technology

[0002] Currently, in high-end manufacturing fields such as automotive interior parts and consumer electronics casings, in order to enhance the aesthetic value of products, it is necessary to form unique brushed or spider web textures on their surfaces. In existing ink technologies, high molecular weight polymers are usually added as brushing components to achieve this effect.

[0003] However, there are defects in practical applications. The reason is that the production of the stringing effect depends on the entanglement and orientation of polymer chains in the fluid stretching state. It is this entanglement characteristic of the polymer chains that causes the polymer chains to undergo spontaneous slow creep, aggregation, or even phase separation during the static storage of ink. This will directly cause an irreversible increase in the viscosity of the ink system, which in turn leads to the phenomenon of layering or gelation.

[0004] In existing single systems, there is an inherent technical contradiction between the drawing functionality and storage stability of drawing inks, making it difficult to achieve both simultaneously;

[0005] With the popularization of automated and long-cycle production processes such as robotic automatic spraying and high-speed roll-to-roll printing, production lines have high requirements for the uniformity of the rheological properties of inks between batches or before and after storage. The short shelf life and uncontrollable rheological properties of existing inks have become the main obstacles restricting the large-scale application of this special effect.

[0006] Although those skilled in the art have attempted to find a balance between the two by adjusting the formulation or using conventional encapsulation techniques, these conventional methods often fail to suppress the molecular chain creep of functional components during storage. For example, Chinese invention patent CN107200481A provides a process for preparing a metal wire drawing effect film on a glass surface. This process essentially employs a multi-step transfer technology, first curing the wire drawing texture on a PET film, then using it as a mold to transfer it to a glass substrate, and finally spraying metallic ink and sealing ink in sequence. This method has a lengthy process flow, highly relies on multi-step curing and precise registration, and does not solve the technical problem of simultaneously achieving wire drawing function and storage stability in a single ink system.

[0007] Therefore, how to provide a drawing effect ink and its preparation method, and how to achieve physical isolation of the drawing components in the ink storage state to ensure long-term rheological stability, is the technical problem to be solved by this invention. Summary of the Invention

[0008] This invention provides a stringing effect ink and its preparation method, with the main objective of solving the problem of how to achieve the controllable release of the stringing function during the application curing stage while ensuring the storage stability of the ink.

[0009] To achieve the above objectives, the present invention provides a method for preparing a brushed effect ink, comprising the following steps:

[0010] Step 101: Prepare a molten core phase. The molten core phase contains a high molecular weight drawing component, a low melting point solid carrier, and a latent compatibilizer. The high molecular weight drawing component has a second polymer property. The low melting point solid carrier is solid at room temperature and liquid at a preset trigger temperature.

[0011] Step 102: Prepare the ink matrix phase, which includes a film-forming resin having first polymer properties, pigments, and a main solvent;

[0012] Step 103: Under shear conditions, the molten nucleus phase is dispersed in the ink matrix phase to form a thermotropic emulsion;

[0013] Step 104: The thermotropic emulsion is subjected to rapid cooling to solidify the molten nucleus phase, forming solid nucleus microparticles that are dispersed in the ink matrix phase to obtain a stringing effect ink; wherein, the properties of the first polymer are different from those of the second polymer, the molecular structure of the latent compatibilizer includes a first segment compatible with the properties of the second polymer and a second segment compatible with the properties of the first polymer, and the latent compatibilizer is encapsulated in the solid nucleus microparticles.

[0014] Preferably, the high molecular weight fiber-forming component is polyisobutylene, the film-forming resin is acrylic resin, and the latent compatibilizer is polyisobutylene-b-polymethyl methacrylate block copolymer, wherein the first segment is a polyisobutylene segment and the second segment is a polymethyl methacrylate segment.

[0015] Preferably, in step 101, the low-melting-point solid support comprises at least two different solid support components, which are miscible in the molten state and have different independent melting points. The preset triggering temperature of the solid nucleus particles is determined by adjusting the mass ratio between the at least two solid support components.

[0016] Preferably, in step 104, the thermotropic emulsion is subjected to rapid cooling using a flash evaporation method. The flash evaporation includes introducing the thermotropic emulsion obtained in step 103 into a flash evaporation container in a low-pressure environment, causing partial vaporization of the main solvent in the thermotropic emulsion, thereby causing the molten nucleus phase to solidify instantaneously.

[0017] Preferably, in step 103, a shell-forming precursor polymer is also added to the ink matrix phase; the method further includes a shell curing step performed after step 104, the shell curing step including: adding a shell curing trigger to the drawing effect ink, so that the shell-forming precursor polymer is cured at the interface of solid core phase particles to form a non-thermal solid shell.

[0018] Preferably, the shell-forming precursor polymer is sodium alginate; and the shell-curing trigger is a soluble calcium salt.

[0019] Preferably, the low-melting-point solid carrier is selected from one of crystalline polyester wax, Fischer-Tropsch wax, carnauba wax, erucamide, and solid polyethylene glycol.

[0020] Preferably, the preset trigger temperature is in the range of 60°C to 90°C, the shearing condition in step 103 is achieved by a high-speed homogenizer, and the quenching treatment in step 104 is achieved by a plate heat exchanger.

[0021] A brushed effect ink, prepared by a brushed effect ink preparation method.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This invention physically encapsulates the fiber-drawing component in solid carrier particles through melt emulsification and rapid cooling curing. In the storage state, physical isolation effectively blocks the entanglement path of the fiber-drawing component, ensuring the long-term rheological stability of the ink. During heating and curing, the solid carrier melts and releases the fiber-drawing component, realizing the on-demand and controllable activation of the fiber-drawing function.

[0024] 2. By pre-implanting a latent compatibilizer into the molten core phase and encapsulating it together with the solid microparticles during the rapid cooling step, the technical bottleneck of incompatibility between the drawing component and the ink matrix resin due to polarity differences after high-temperature melting is solved. When the microparticles are heated and melted, the compatibilizer and the drawing component are released simultaneously and in situ to the interface, actively reducing the interfacial tension between the two phases, guiding the originally incompatible polymer chains to effectively entangle, avoiding the dew-like failure of the drawing function, and ensuring the stable realization of the drawing effect.

[0025] 3. When preparing the molten nucleus phase, at least two solid carrier components with different melting points are used and melt-blended according to a preset mass ratio. This method utilizes the physicochemical principle of the eutectic system so that the melting point of the final solid nucleus phase particles, i.e. the trigger threshold, is no longer locked by the physical properties of a single material, but is transformed into a process parameter that can be precisely controlled by the preparation ratio. This allows the ink product to flexibly adapt to the diverse downstream drying tunnel temperature requirements, and obtains the necessary process safety window between ensuring storage stability and reliable triggering. Attached Figure Description

[0026] Figure 1 This is a flow chart of the melt emulsification and rapid cooling preparation process of the fiber-drawing effect ink of the present invention;

[0027] Figure 2 This is a process optimization curve showing the effect of shear rate on particle size and coating efficiency in this invention.

[0028] Figure 3 This is a schematic diagram illustrating the thermal triggering mechanism for the storage application of the drawing ink in this invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] This invention provides a fiber-drawing effect ink and its preparation method. Through a melt-emulsification-rapid curing process, a special core-shell microstructure is constructed, physically encapsulating a high-molecular-weight fiber-drawing component and a latent compatibilizer within carrier particles that are solid at room temperature. The rheological properties of the ink are precisely controlled temporally during preparation, storage, and application. In the storage state, the fiber-drawing component is physically isolated, resulting in a low viscosity and high stability. During application and heating curing, the solid particles melt, and the fiber-drawing component and latent compatibilizer are released simultaneously, ensuring compatibility. The agent immediately bridges the fiber-drawing component and the ink matrix resin, ensuring the effective occurrence of the fiber-drawing effect. The preparation method of the fiber-drawing effect ink of this invention includes the following steps: Step 101, preparing a molten core phase; this step aims to prepare a functional core for subsequent emulsification and dispersion, pre-containing two key components to achieve the fiber-drawing function and ensure the effectiveness of fiber drawing. This molten core phase contains a high molecular weight fiber-drawing component, a low-melting-point solid carrier, and a latent compatibilizer; the high molecular weight fiber-drawing component is the functional source for producing the fiber-drawing or cobweb effect, and it has secondary polymer properties. In the specific technical solution, the fiber-drawing... The filament component can be polyisobutylene (PIB), with a molecular weight typically between 1 million and 5 million Daltons. PIB exhibits typical non-polar polymer properties, which is the second polymer property. A low-melting-point solid carrier is used to construct the physical isolation structure and thermal triggering mechanism. It is solid at room temperature but transforms into a liquid state at a preset triggering temperature. The selection of this preset triggering temperature is a key technical balance point to ensure the reliable industrial implementation of this solution. On the one hand, the temperature needs to be higher than the highest ambient temperature the ink may experience during storage or transportation to ensure the microstructure of the solid core phase. The granules must not melt during storage, typically requiring a temperature not lower than 60°C. On the other hand, this temperature must also be within the standard process temperature window of the curing oven for downstream applications, such as automotive interior coating or roll-to-roll printing, to ensure that the drawing function can be activated by conventional heating processes. The upper limit of this temperature is typically no higher than 90°C to ensure compatibility with heat-sensitive plastic substrates. Therefore, the preset trigger temperature is preferably in the range of 60°C to 90°C. To achieve this goal, the low-melting-point solid carrier can be one or more of crystalline polyester wax, Fischer-Tropsch wax, carnauba wax, erucamide, and solid polyethylene glycol.

[0031] A latent compatibilizer, at the moment the solid core phase particles are thermally triggered and melted, resolves the thermodynamic incompatibility problem between the high molecular weight drawing component and the film-forming resin in the ink matrix phase due to significant differences in polymer properties such as polarity. The latent compatibilizer is encapsulated within the solid core phase particles. The molecular structure of the latent compatibilizer includes a first segment compatible with the second polymer properties and a second segment compatible with the film-forming resin (possessing the first polymer properties) in the ink matrix phase in subsequent steps. In a specific example, when the high molecular weight drawing component is thermally triggered and melted, the latent compatibilizer... When the fiber component (second polymer property) is nonpolar polyisobutylene, and the film-forming resin (first polymer property) in the ink matrix phase is a moderately polar acrylic resin, the latent compatibilizer is preferably a polyisobutylene-b-polymethyl methacrylate block copolymer; in this structure, the polyisobutylene segment is the first segment, which is physically compatible with the high molecular weight fiber drawing component PIB, and the polymethyl methacrylate segment is the second segment, which is physically compatible with the acrylic resin in the matrix phase; the specific process for preparing the molten core phase... The process includes: placing a low-melting-point solid carrier in a reaction vessel and heating it above its melting point, for example, to 95°C to 105°C, until it is completely melted into a liquid carrier; adding a high-molecular-weight fiber-drawing component and a latent compatibilizer, and fully dissolving and mixing them under stirring conditions to obtain a molten nucleus phase; in a preferred technical solution, to achieve flexible control of the preset trigger temperature to adapt to the diverse drying tunnel process requirements of downstream customers, in step 101, the low-melting-point solid carrier contains at least two different solid carrier components; at least two solid carrier components can dissolve in each other in the molten state and have different independent melting points to form a eutectic system or solid solution. For example, crystalline polyester wax with a melting point of 65°C and erucamide with a melting point of 85°C can be selected as the two carrier components. By controlling the mass ratio between the two solid carrier components in the melting process of step 101, the overall melting point of the final solid nucleus phase particles can exhibit a predictable change between 65°C and 85°C, so that the trigger threshold of the ink product can be accurately calibrated.

[0032] Step 102: Preparation of the ink matrix phase; this step aims to prepare the continuous phase of the ink product, whose rheological properties determine the stability of the ink in the storage state; the ink matrix phase comprises a film-forming resin with a first polymer property, a pigment, and a main solvent; the first polymer property differs from the second polymer property, creating thermodynamic incompatibility within the ink system required to achieve subsequent functions; in specific examples, the film-forming resin can be acrylic resin or polyurethane resin, with moderate or strong polarity, representing the first polymer property; the pigment can be a conventional organic or inorganic pigment, such as phthalocyanine blue, carbon black, etc.; the main solvent can be a conventional ester, ketone, or aromatic solvent, such as butyl acetate, cyclohexanone, etc. During preparation, following conventional ink processing, the above components are mixed with necessary additives (such as dispersants and leveling agents), and then ground and dispersed using a sand mill or three-roll mill until the preset fineness requirement is met, thus obtaining the ink matrix phase. In step 103, under shear conditions, the molten nucleus phase is dispersed in the ink matrix phase to form a thermotropic emulsion. The purpose of this step is to shear and disperse the high-temperature liquid functional core into micron- or submicron-sized droplets, ensuring their uniform distribution within the continuous ink matrix phase. Specifically, the ink matrix phase obtained in step 102 is preheated to an intermediate temperature, such as 70°C to 80°C, which is lower than the boiling point of the main solvent but higher than the melting point of the solid carrier. Under rapid shear conditions, the high-temperature molten nucleus phase (e.g., 95°C) obtained in step 101 is slowly injected into the ink matrix phase. The shear conditions can be provided by a high-speed homogenizer or colloid mill, with the shear rate typically controlled between 3000 rpm and 10000 rpm to ensure the molten nucleus phase is sufficiently broken into fine, non-aggregated droplets, forming a thermotropic emulsion. In step 104, the thermotropic emulsion is rapidly cooled to solidify the molten nucleus phase, forming solid nucleus particles that disperse in the ink matrix phase, resulting in a stringy ink. This step is crucial for achieving physical isolation of the stringy components; its core lies in ensuring a sufficiently fast cooling rate so that the tiny droplets in the thermotropic emulsion do not have enough time to dissolve. Before aggregation or curing occurs due to interfacial energy, the temperature is lowered below the solidification point of the solid carrier, thereby achieving in-situ solidification and structural locking. In a specific embodiment, the quenching treatment can be achieved by immediately pumping the thermotropic emulsion obtained in step 103 into a plate heat exchanger or jacketed cooling vessel, and rapidly lowering its temperature to room temperature within minutes using an external cooling medium (such as circulating cooling water). After quenching and solidification, the original liquid molten nucleus phase is transformed into dispersed and independent solid nucleus phase particles. Inside these particles, the high molecular weight drawing component and the latent compatibilizer are jointly and physically encapsulated and frozen in the lattice or amorphous network of the solid carrier, thereby completely isolating them from the ink matrix phase.

[0033] In another preferred technical solution, to avoid the inherent problem of uneven cooling rate in conventional conductive cooling (such as plate heat exchangers) and to obtain solid nucleus phase microparticles with narrower and more uniform particle size distribution, the quenching treatment in step 104 is achieved through flash quenching, including: directly pumping or spraying the high-temperature (e.g., 80°C) thermotropic emulsion obtained in step 103 into a flash container in a low-pressure environment; under low pressure, the main solvent or the compounded low-boiling-point co-solvent in the emulsion undergoes violent and instantaneous boiling or vaporization; the solvent vaporization uniformly and instantaneously carries away a large amount of latent heat of vaporization from the entire volume of the system, causing a sudden drop in system temperature, causing the molten nucleus phase droplets to instantaneously solidify within a sub-second time, resulting in solid nucleus phase microparticles with highly uniform particle size; in yet another preferred technical solution, to improve the physical stability of solid nucleus phase microparticles under harsh storage conditions (such as high-temperature cycling) and prevent slow soft agglomeration or cold sintering between microparticles, this method also aims to improve the physical stability of the solid nucleus phase microparticles under harsh storage conditions (such as high-temperature cycling) and prevent slow soft agglomeration or cold sintering between microparticles. An external non-thermal protective shell is constructed. Specifically, in step 103, during melt emulsification, a shell-forming precursor polymer is added to the ink matrix phase. The method also includes a shell curing step performed after step 104. This shell curing step includes adding a shell curing trigger to the quenched, stringy ink. The trigger reacts with the shell-forming precursor polymer enriched at the particle interface, causing the shell-forming precursor polymer to cure at the interface of the solid core phase particles, forming a non-thermal solid shell. In a specific example, the shell-forming precursor polymer can be sodium alginate, which acts as a protective colloid to stabilize the emulsion in step 103. The shell curing trigger can be a soluble calcium salt, such as an aqueous solution of calcium chloride. After quenching in step 104, the calcium salt solution is added dropwise to the ink. Sodium alginate undergoes an ionic crosslinking reaction with calcium ions, forming a tough, non-thermal calcium alginate gel shell on the surface of the solid core phase particles.

[0034] When the ink matrix phase (B) is a solvent-based system, the shell-forming precursor polymer mentioned in step 103 can be a polymer that is soluble in the ink matrix phase and contains active hydrogen functional groups, specifically a hydroxyl acrylic resin with a hydroxyl value in the range of 30 to 80 mg KOH / g (solids). Correspondingly, in the shell curing step performed after step 104, the added shell curing trigger can be a polyisocyanate curing agent, such as a trimer of hexamethylene diisocyanate (HDI), wherein the molar ratio (NCO:OH) of the added polyisocyanate curing agent to the hydroxyl acrylic resin is controlled within the range of 0.8 to 1.2. The present invention also provides a product prepared by any of the above methods. The ink for creating a stringy effect comprises: an ink matrix phase, which includes a film-forming resin, pigment, and main solvent having a first polymer property; and solid nucleus particles dispersed in the ink matrix phase; the solid nucleus particles include: a low-melting-point solid carrier, which is solid at room temperature and liquid at a preset trigger temperature; a high-molecular-weight stringy component having a second polymer property, which is different from the first polymer property; and a latent compatibilizer; wherein the high-molecular-weight stringy component and the latent compatibilizer are physically encapsulated in the low-melting-point solid carrier; the molecular structure of the latent compatibilizer includes a first segment compatible with the second polymer property and a second segment compatible with the first polymer property.

[0035] Example 1: In a large-scale automated spraying production line for automotive interior parts, such as dashboard components, a 200L central storage tank is used to continuously supply ink to a robotic spraying arm. The circulation cycle of the ink in the tank and pipeline may last for several weeks. Under such conditions, existing fiber-drawing inks will slowly aggregate and entangle, causing the ink viscosity to rise irreversibly over time, eventually leading to nozzle clogging, uneven atomization, and production line shutdown. The fiber-drawing ink prepared by the method of this invention is used in this scenario. The high molecular weight fiber-drawing component (with the second polymer property) is non-polar polyisobutylene, the film-forming resin (with the first polymer property) is a moderately polar acrylic resin, the latent compatibilizer is polyisobutylene-b-polymethyl methacrylate block copolymer, and the low-melting-point solid carrier is a crystalline polyester wax with a melting point of 70°C. During the preparation of the ink, through a rapid cooling curing step, polyisobutylene and polyisobutylene-b-polymethyl methacrylate block copolymer are physically coated together in solid core phase particles with a melting point of 70°C.

[0036] The ink was injected into a 200L central storage tank and circulation was initiated, running continuously for 14 days. During this period, because the high molecular weight fiber-drawing component was physically isolated within the solid core phase particles, it could not interact with the ink matrix phase. The rheological properties of the ink system were determined solely by the low viscosity ink matrix phase. Periodic sampling and testing showed that the ink viscosity remained within the initial value (45±2 mPa·s) fluctuation range throughout the 14 days, without any viscosity increase, stratification, or gelation. The nozzle pressure and atomization pattern of the robotic spraying arm remained consistent. When the ABS dashboard substrate coated with this ink entered the downstream 85°C industrial drying tunnel, the ink system temperature rapidly exceeded the preset trigger temperature of 70°C, and the solid core phase particles melted instantaneously. At this time, the non-polar polyisobutylene fiber-drawing component and the latent compatibilizer were simultaneously and isotropically released into the central storage tank. In an isopolar acrylic resin matrix, if a latent compatibilizer is not present, the two polymers will separate due to incompatibility, resulting in failure of the stringing function. In this embodiment, the polyisobutylene segments of the latent compatibilizer immediately anchor the released polyisobutylene molecular chains, while the polymethyl methacrylate segments interpenetrate and anchor in the acrylic resin matrix. The compatibilizer acts as a molecular bridge at the interface between the two phases, actively reducing the interfacial tension. This in-situ compatibility mechanism at the moment of thermal triggering allows the polyisobutylene molecular chains to extend and physically entangle in the acrylic resin matrix, rather than condensing into oil droplets. As the solvent evaporates and the paint film cures in the drying tunnel, this controlled molecular chain entanglement forms a uniform and repeatable stringing texture under the action of external force, and the texture effect is consistent on the parts produced on day 1 and day 14.

[0037] Example 2: This example uses a set of controlled experiments to verify the synergistic effect of the preparation method of the present invention in solving the problems of ink storage stability and ensuring the drawing function of the latent compatibilizer after thermal triggering. The experiment set up included three sample groups: the sample group of the present invention (T-1), control group 1 (C-1), and control group 2 (C-2). All sample groups used the same ink matrix phase (B), which was composed of 40% (solid content) acrylic resin (weight average molecular weight of about 50,000, soluble in butyl acetate). The film-forming resin, carbon black pigment, and butyl acetate / cyclohexanone (1:1 mass ratio) as the main solvent were ground and dispersed to a fineness of less than 10µm using conventional processes. The high molecular weight fiber-drawing component (PIB) was polyisobutylene with a weight average molecular weight of 3.2 million g / mol. The low melting point solid carrier (W) was a crystalline polyester wax with a measured melting point of 70.5℃. The latent compatibilizer (C) was a PIB-b-PMMA block copolymer (block molecular weight 55,000-b-50,000 g / mol).

[0038] Preparation of the sample group (T-1) of this invention: Step 101: Heat 10 parts by mass of carrier (W) and 5 parts by mass of compatibilizer (C) to 100°C, stir and mix evenly, add 15 parts by mass of fiber-drawing component (PIB), and continue stirring until completely dissolved to obtain a molten core phase; Step 102: Take 70 parts by mass of ink matrix phase (B); Step 103: Preheat ink matrix phase (B) to 75°C, inject the molten core phase at 100°C under the shearing condition of 5000 rpm in a high-speed homogenizer, and continue emulsifying for 10 minutes to form a thermotropic emulsion; Step 104: Immediately pass the thermotropic emulsion through... The sample group (T-1) of this invention was obtained by quenching the sample through a plate heat exchanger with 10℃ cooling water circulation and controlling the outlet temperature at 25℃. Preparation of control group 1 (C-1): This sample group simulates existing technology, i.e., direct mixing of the drawing component and the matrix. 70 parts by mass of ink matrix phase (B), 15 parts by mass of the drawing component (PIB), 5 parts by mass of compatibilizer (C), and 10 parts by mass of butyl acetate solvent were used to make up the total mass. The mixture was then sheared and mixed for 20 minutes at 5000 rpm using a high-speed homogenizer at room temperature (25℃). Preparation of control group 2 (C-2): This sample group was used to verify the latent compatibilizer. The synergistic effect of (C) is the same as that of the sample group (T-1) of the present invention, with the only difference being that: in step 101, 5 parts by mass of compatibilizer (C) are not added, and the molten core phase consists only of 10 parts by mass of carrier (W) and 15 parts by mass of drawing component (PIB); Experimental testing process: 1. Accelerated aging test for storage stability: 100 mL samples were taken from each of the three sample groups (T-1, C-1, C-2), sealed, and placed in a constant temperature oven at 50°C for accelerated aging. This temperature is lower than the melting point of the carrier (W) of 70.5°C; using Brinell rotational adhesive The apparent viscosity of each sample group was measured on day 0 (initial) and day 14 of aging using a viscosity meter (RVT type, rotor No. 4, 20 rpm, 25℃). Thermal triggering functional test: The three sample groups aged at 50℃ for 14 days were taken out, allowed to return to room temperature, and coated onto a black ABS plastic substrate using a 100µm coating rod. They were then immediately placed in an 85℃ forced-air oven for 30 minutes to cure (this temperature is higher than the melting point of the carrier (W) at 70.5℃). After cooling, the surface morphology of the cured ink film was visually observed to evaluate the formation of the stringing texture. The test results are shown in Table 1.

[0039] Table 1: Comparative Test Results of Accelerated Aging Stability and Thermally Triggered Functionality

[0040] Sample group Description of test conditions Initial viscosity (T=0 days, mPa·s) Viscosity after 14 days (T=14 days, 50℃) Appearance after 14 days of aging and heat triggering (85°C) T-1 The present invention sample (W+PIB+C, quenched) 48.5 51.2 The surface is smooth, forming a uniform and clear brushed texture. C-1 Control group (direct mixing) 850.4 >20000 (already gelled) The sample has gelled and cannot be leveled, therefore it cannot be applied. C-2 Control group (W+PIB, sudden cooling, no C) 47.9 50.5 The surface is uneven, with numerous "dewdrop" pores and no brushed texture.

[0041] The viscosity data in Table 1 show that the initial viscosity of control group 1 (C-1) was relatively high because the high molecular weight fiber-drawing component (PIB) was directly exposed to the matrix. After 14 days of accelerated aging at 50°C, it gelled and completely lost its fluidity. In contrast, the sample group (T-1) and control group 2 (C-2) of this invention both adopted a melt-quench curing process. Their initial viscosity was similar to that of conventional ink matrix. After undergoing the same accelerated aging, the viscosity remained stable without increase. This confirms that the method of physically encapsulating the fiber-drawing component (PIB) in solid core phase particles through a low melting point solid carrier (W) effectively solves the problem of storage stability of fiber-drawing ink. The appearance results of the functional test show that the gelled control group 1 (C-1) is unusable. Although control group 2 (C-2) is stable in storage, after thermal triggering at 85°C, due to the lack of latent compatibilizer (C) in its core phase, the released non-polar PIB is incompatible with the polar acrylic resin matrix, resulting in phase separation and dew formation failure, which prevents the formation of fiber-drawing texture.

[0042] Example 3: This example combines Figures 1 to 3 This describes a type of brushed ink and its preparation method, such as... Figure 1 As shown, the process begins with two parallel preparation steps: step 101, preparing a molten nucleus phase, comprising a high molecular weight drawing component, a low melting point solid carrier, and a latent compatibilizer; and step 102, preparing an ink matrix phase, comprising a film-forming resin, pigment, and main solvent. Then, step 103, dispersing to form a thermotropic emulsion, involves dispersing the molten nucleus phase into the ink matrix phase under shear conditions. This is followed by step 104, a rapid cooling treatment, which solidifies the molten nucleus phase to form solid nucleus microparticles. The preferred method for this rapid cooling treatment is flash cooling, which utilizes the latent heat of vaporization of the main solvent to instantaneously solidify the molten nucleus phase. After the rapid cooling treatment, there is an optional step: a shell-curing step, which involves adding a shell-curing trigger to form a non-thermally sensitive solid shell at the microparticle interface, ultimately obtaining an ink with a drawing effect.

[0043] like Figure 2 As shown, the left ordinate represents the average particle size D[4,3] in µm, represented by a solid line, while the right ordinate represents the coating percentage in %, represented by a dashed line. The curve shows that as the shear rate increases from 2000 rpm to 5000 rpm, the average particle size D[4,3] decreases, while the coating percentage increases accordingly and reaches a peak. When the shear rate further increases to 10000 rpm, the change in average particle size D[4,3] slows down, but the coating percentage decreases. Figure 3As shown in the figure, the core mechanism of the brushed effect ink of the present invention in industrial applications is illustrated. Specifically, the ink stored in the central storage tank is in a storage state, where its rheological properties are stable. Because the brushed components are physically isolated, the ink is applied to the surface of the automotive interior component substrate by a robot sprayer and then enters an industrial drying tunnel for heating and curing, for example, heating to 85°C. This heating process triggers the core mechanism: thermal trigger activation. That is, when the temperature of the drying tunnel is higher than the preset trigger temperature, for example, 70°C, the low melting point solid carrier melts and releases the brushed components and latent compatibilizer, ultimately forming a finished product on the substrate, namely a uniform and clear brushed texture.

[0044] Example 4: This example provides a standardized engineering calibration procedure for determining the melting point of a low-melting-point solid carrier, i.e., the preset trigger temperature, to adapt to diverse industrial curing temperature windows. In specific application scenarios, such as coating consumer electronics casings, the oven curing temperature is set within a lower window, requiring the preset trigger temperature to be precisely controlled within the range of 80℃ (±2℃). This calibration procedure selects two solid carrier components with different melting points mentioned in the specific embodiments: solid carrier component 1 (C1), i.e., the crystalline polyester wax used in Example 2, with a peak melting point of 70.5℃ determined by differential scanning calorimetry (DSC); and solid carrier component 2 (C2), i.e., erucamide, with a peak melting point of 85.0℃ determined by DSC; a series of molten nucleus phases with different ratios are prepared: according to the mass ratio of C1:C2, 100:0, 80:20, 60:40, and 40... Two solid carrier components were weighed at ratios of 60:60, 20:80, and 0:100. For each mass ratio, the two components were mixed and heated to 100°C, and stirred until completely melted and blended. While maintaining the temperature, a high molecular weight fiber-drawing component (PIB) and a latent compatibilizer (C) were added to the melt-blended carrier. The types and addition ratios of the two components (relative to the total mass of the carrier) were consistent with the present invention sample group (T-1) in Example 2. Stirring was continued until completely dissolved to obtain six groups of molten nucleus phase samples to be tested. Differential scanning calorimetry (DSC) was used to perform thermal analysis on the above six groups of molten nucleus phase samples. The test conditions were: under a nitrogen atmosphere, the temperature was increased from 25°C to 120°C at a heating rate of 10°C / min. The peak temperature of the endothermic peak in the second heating curve of each sample was taken as the preset trigger temperature under this ratio. The correspondence between the mass ratio and the preset trigger temperature obtained by the experiment is shown in Table 2.

[0045] Table 2: Correspondence between the mass ratio of solid carrier components and the preset trigger temperature of the molten nucleus phase

[0046] Sample group number C1:C2 mass ratio Preset trigger temperature (DSC peak, °C) P-1 100:0 70.5 P-2 80:20 74.2 P-3 60:40 77.8 P-4 40:60 80.1 P-5 20:80 82.9 P-6 0:100 85.0

[0047] According to the data in Table 2, the preset trigger temperature of sample P-4 is 80.1℃, which meets the requirement of the target process window of 80℃ (±2℃). Therefore, the mass ratio of solid carrier component 1 (C1) to solid carrier component 2 (C2) is selected as 40:60. Using the molten nucleus phase with a ratio of 40:60, and strictly following steps 102 to 104 of sample T-1 in Example 2, a stringing effect ink suitable for curing at 80℃ is prepared. This ink is stable when stored at 50℃ and exhibits the expected stringing texture in the 80℃ drying tunnel.

[0048] Example 5: This example provides a standardized engineering procedure for calibrating the synergistic effect of the shear conditions in step 103 and the quenching treatment in step 104; using the formulation of the sample group (T-1) of the present invention in Example 2, under the condition of quenching treatment at 10°C with a plate heat exchanger in step 104, three groups of samples were prepared in step 103 with shear rates of 2000 rpm, 5000 rpm, and 10000 rpm respectively using a high-speed homogenizer; the average particle size (D[4,3]) of the solid nucleus phase particles of each group of samples was measured by a laser particle size analyzer, and the particles were separated by centrifugation. The encapsulation rate of the high molecular weight fiber-forming component (PIB) by microparticles was determined by separation, extraction, and thermogravimetric analysis (TGA). The results showed that at 2000 rpm, the average particle size was 12.8 µm and the encapsulation rate was only 71.6%. At 10000 rpm, although the average particle size decreased to 4.5 µm, the encapsulation rate also decreased to 78.3%, presumably due to excessive shearing damaging the stability of the nascent microparticles. At a shear rate of 5000 rpm, an average particle size of 5.2 µm and an encapsulation rate of 94.5% were obtained. This 5000 rpm was determined to be the optimal shear rate for this formulation system. Process parameters; This embodiment further provides a procedure for calibrating the mass ratio of latent compatibilizer (C) to high molecular weight fiber drawing component (PIB) in the molten nucleus phase; the ink matrix phase (B) is fixed at 70 parts by mass, the total mass of the molten nucleus phase is 30 parts by mass, of which the low melting point solid carrier (W) is fixed at 10 parts by mass; the remaining 20 parts by mass are composed of PIB and C, and four groups of samples are prepared with PIB:C mass ratios of 20:0 (i.e., control group C-2), 18:2, 15:5 (i.e., sample group T-1 of this invention) and 10:10, respectively; all samples are collected using... Using the preparation method of T-1 in Example 2, namely 5000rpm shearing and 10°C rapid cooling treatment with a plate heat exchanger; after thermally triggered curing at 85°C, the appearance of the four groups of samples was observed. The 20:0 sample group showed severe dew-like shrinkage cavities, the 18:2 sample group still had a small number of shrinkage cavities, while the 15:5 and 10:10 sample groups formed uniform and smooth stringy textures. This indicates that under this system, the mass ratio of compatibilizer (C) to stringy component (PIB) needs to be no less than 15:5, that is, the mass of C should be no less than one-third of the mass of PIB, to ensure effective compatibility after thermal triggering.

[0049] To determine the mass ratio of the low-melting-point solid carrier (W) to the total mass of the high molecular weight fiber-drawing component (PIB) and latent compatibilizer (C), the following calibration steps can be performed: Fix the mass fraction of the ink matrix phase (B), for example, 70 parts by mass; fix the mass ratio between the high molecular weight fiber-drawing component (PIB) and latent compatibilizer (C) at 3:1; prepare a series of samples with a total mass of 30 parts by mass of molten core phase, wherein the mass of the low-melting-point solid carrier (W) is set to 5 parts, 10 parts, and 20 parts, respectively, and the total mass of (PIB+C) is correspondingly 25 parts, 20 parts, and 10 parts; use the same steps 103... The ink was prepared using the rapid cooling process in step 104, and then subjected to accelerated aging and thermal triggering functional tests. The test results showed that when the mass of the carrier (W) was 5 parts, the viscosity of the sample increased after aging at 50°C for 14 days, indicating incomplete physical coating. When the mass of the carrier (W) was 20 parts, the sample was stable during storage, but the stringing texture was weak after thermal triggering at 85°C, indicating that the functional components were over-diluted. When the mass of the carrier (W) was 10 parts, the sample had both storage stability and thermal triggering functionality. Therefore, the preferred mass ratio of the carrier (W) to the total mass of (PIB+C) was determined to be 10:20, or 1:2.

[0050] Example 6: Preparation of the present invention sample group (T-3) with a non-thermally sensitive solid shell, used to compare with the present invention sample group (T-1) in Example 2, to evaluate the physical stability of the shell under freeze-thaw cycle conditions; The preparation of sample group T-3, steps 101, 102 and 104 are completely the same as T-1, but an adjustment is made in step 103. After preheating 70 parts by mass of ink matrix phase (B) to 75°C, 0.5 parts by mass of sodium alginate as shell formation precursor polymer is added to matrix phase (B) and stirred to dissolve it. Then, the molten core phase is injected under shear at 5000 rpm according to the method of T-1 and emulsified for 10 minutes; After the plate heat exchanger is quenched in step 104, the shell solidification step is performed at a low speed of 100 rpm. Under stirring, 1.0 part by weight of a 5% calcium chloride aqueous solution was slowly added dropwise to the rapidly cooled ink as a shell curing trigger. After the addition was complete, stirring was continued for 5 minutes to allow sodium alginate and calcium ions to undergo ionic cross-linking and curing at the interface of solid nucleus particles, forming a non-thermal-sensitive solid shell. Sample groups T-1 and T-3 were subjected to 10 freeze-thaw cycles simultaneously. Each cycle included freezing at -15°C for 12 hours and immediately transferring to 45°C for 12 hours of thawing. The apparent viscosity of the samples was tested using a Brookfield rotational viscometer (under the same conditions as in Example 2) before the initial cycle and after the completion of 10 cycles. The volume average particle size of the solid nucleus particles was tested using a laser particle size analyzer (under the same conditions as in Example 3). The test results are shown in Table 3.

[0051] Table 3: Results of the freeze-thaw cycle stability comparison test

[0052] Sample group Loop count Apparent viscosity (mPa·s) Average particle size D[4,3](µm) T-1 0 (Initial) 48.5 5.2 T-1 10 times 82.4 9.7 T-3 0 (Initial) 49.1 5.3 T-3 10 times 50.8 5.5

[0053] The test results in Table 3 show that after 10 freeze-thaw cycles, the apparent viscosity of sample T-1 increased by about 70% and the average particle size increased by about 87%, indicating that its solid nucleus particles agglomerated under temperature fluctuations. Sample T-3, due to the formation of a non-thermal-sensitive solid shell on the surface of its particles, did not change its viscosity and average particle size after the same freeze-thaw cycles.

[0054] 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.

[0055] 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 method for preparing a drawing effect ink, characterized by, The method comprises the following steps: Step 101, preparing a molten core phase, the molten core phase comprising a high-molecular-weight stringing component, a low-melting-point solid carrier and a latent compatibilizer, the high-molecular-weight stringing component having a second polymer attribute, the low-melting-point solid carrier being solid at room temperature and liquid at a preset trigger temperature; Step 102, preparing an ink matrix phase, the ink matrix phase comprising a film-forming resin having a first polymer attribute, a pigment and a primary solvent; Step 103, dispersing the molten core phase in the ink matrix phase under shearing conditions to form a thermotropic emulsion; Step 104, quenching the thermotropic emulsion to solidify the molten core phase, form solid core phase microparticles and disperse them in the ink matrix phase, thereby obtaining a stringing effect ink; wherein the first polymer attribute is different from the second polymer attribute, the molecular structure of the latent compatibilizer comprises a first segment compatible with the second polymer attribute and a second segment compatible with the first polymer attribute, and the latent compatibilizer is coated in the solid core phase microparticles.

2. A method of preparing a drawing effect ink according to claim 1, characterized in that, The high-molecular-weight stringing component is polyisobutylene, the film-forming resin is an acrylic resin, the latent compatibilizer is a polyisobutylene-b-poly(methyl methacrylate) block copolymer, the first segment is a polyisobutylene segment, and the second segment is a poly(methyl methacrylate) segment.

3. A method of preparing a drawing effect ink according to claim 1, characterized in that, In step 101, the low-melting-point solid carrier comprises at least two different solid carrier components, the at least two solid carrier components are mutually soluble in a molten state and have different independent melting points, and the preset trigger temperature of the solid core phase microparticles is determined by adjusting the mass ratio between the at least two solid carrier components.

4. The method of claim 1, wherein the drawing effect ink is prepared by adding 0.1 to 1% of the drawing effect agent to 100 parts of the base ink. In step 104, the quenching of the thermotropic emulsion is performed by flash quenching, which comprises: The thermotropic emulsion obtained in step 103 is introduced into a flash vessel in a low-pressure environment, so that the primary solvent in the thermotropic emulsion is partially vaporized, thereby instantaneously solidifying the molten core phase.

5. The method of claim 1, wherein the drawing effect ink is prepared by adding 0.1 to 1.0 parts by weight of the drawing effect pigment to 100 parts by weight of the base ink. In step 103, a shell-forming precursor polymer is also added to the ink matrix phase; The method further comprises a shell solidification step performed after step 104, which comprises: A shell solidification trigger is added to the stringing effect ink, so that the shell-forming precursor polymer is solidified at the interface of the solid core phase microparticles to form a non-heat-sensitive solid shell.

6. A method of preparing a drawing effect ink according to claim 5, characterized in that, The shell-forming precursor polymer is sodium alginate, and the shell solidification trigger is a soluble calcium salt.

7. The method for preparing a brushed effect ink according to claim 1, characterized in that, The low-melting-point solid carrier is selected from one of crystalline polyester wax, Fischer-Tropsch wax, carnauba wax, erucamide and solid polyethylene glycol.

8. The method for preparing a brushed effect ink according to claim 1, characterized in that, The preset trigger temperature is in the range of 60-90°C, the shearing conditions in step 103 are achieved by a high-speed homogenizer, and the quenching in step 104 is achieved by a plate heat exchanger.

9. A pull-up effect ink, characterized in that The stringing effect ink is prepared by the method of claim 1.

Images