Preparation method of synthetic leather with light and temperature dual-response effect of see-through superposition type

Abstract

The application discloses a kind of synthetic leather preparation methods with perspective superimposed type light temperature double response effect, comprising the following steps: high transparent ultraviolet light variable surface material slurry is scraped on release paper, and transparent light variable surface layer is formed by drying;Color temperature change medium slurry is scraped on transparent light variable surface layer, and color temperature change layer is formed by drying;Adhesive bottom layer slurry is scraped on color temperature change layer, bottom layer is formed in semi-dry state, and is adhered with microfiber base material, after drying and curing, release paper is stripped, and synthetic leather is obtained;Transparent light variable surface layer allows most visible light to pass through and discolor under ultraviolet light irradiation, color temperature change layer has initial undertone and discolors when temperature changes, and the two superimposed realize light temperature double response dynamic visual effect.By constructing the optical coupling structure of high transparent light variable surface layer and color temperature change layer, four kinds of certainty, designable visual state of synthetic leather under different light and temperature environment are realized, thereby creating unprecedented dynamic interactive experience and decoration function of synthetic leather.

Description

Technical Field

[0001] This invention relates to the field of synthetic leather technology, specifically to a method for preparing synthetic leather with a perspective-superimposed light and temperature dual-response effect. Background Technology

[0002] Synthetic leather, a widely used material in footwear, apparel, bags, home furnishings, and automotive interiors, has always been a focus of industry innovation due to its surface decoration effects and functional properties. With increasing consumer demand for personalized, interactive, and technologically advanced products, smart color-changing synthetic leather with environmentally responsive characteristics has become a research hotspot. Among these, photochromism and thermochromism are two of the most common smart color-changing technologies. However, existing technologies still have significant limitations:

[0003] First, color interference and turbidity. Single-response products (only light-changing or only temperature-changing) have a monotonous visual effect; if light-changing and temperature-changing materials are mixed in the same coating, their color-changing mechanisms may interfere with each other, and color superposition is difficult to control, which can easily lead to turbid, dull, and unattractive colors.

[0004] Second, the structural design is unreasonable. If multiple layers are used, and the top layer does not have high transparency, it will completely cover the color of the lower layer, making it impossible to achieve the superposition effect, and only the color of the outermost layer can be displayed; if each layer is transparent or semi-transparent but lacks a color-developing base, the product color will be pale and weak under natural light, and the superposition of colors will be poor. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing synthetic leather with a perspective-overlay type light and temperature dual-response effect. By constructing an optical coupling structure between a highly transparent light-changing surface layer and a color-changing temperature layer, four deterministic and designable visual states of synthetic leather under different light and temperature environments are achieved, thereby creating an unprecedented dynamic interactive experience and decorative function for synthetic leather.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing synthetic leather with a perspective-overlay type light-temperature dual-response effect, comprising the following steps: S1: applying a highly transparent ultraviolet photochromic fabric slurry to release paper and drying it to form a transparent photochromic surface layer; S2: applying a color-developing temperature-changing intermediate slurry to the transparent photochromic surface layer and drying it to form a color-developing temperature-changing layer; S3: applying an adhesive underlayer slurry to the color-developing temperature-changing layer, forming an underlayer in a semi-dry state, bonding it with a microfiber substrate, drying and curing it, and then peeling off the release paper to obtain synthetic leather; wherein, the transparent photochromic surface layer allows most visible light to pass through and changes color under ultraviolet light irradiation, and the color-developing temperature-changing layer has an initial base color and changes color when the temperature changes, and the two are superimposed to achieve a dynamic visual effect of light-temperature dual response.

[0007] Furthermore, the high-transparency UV-sensitive fabric slurry mentioned in step S1 comprises, by weight: 100 parts of high-transparency hydrolysis-resistant polyurethane resin; 50-70 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 5-12 parts of nano-sized UV-sensitive powder; and 0.5-1.5 parts of high-transparency dispersant.

[0008] Furthermore, the highly transparent, hydrolysis-resistant polyurethane resin is Hexin Chemical HX-6048 resin.

[0009] Furthermore, the nano-scale ultraviolet photochromic powder has a particle size D50 of less than 200nm and is selected from the MC-24 series transparent ultraviolet photochromic powder of Dongguan Qiansebian New Materials Co., Ltd.

[0010] Furthermore, the color-changing thermochromic slurry mentioned in step S2 includes, by weight: 100 parts of hydrolysis-resistant resin; 40-60 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 10-20 parts of thermochromic material; and 3-10 parts of base color paste.

[0011] Furthermore, the hydrolysis-resistant resin is Hexin Chemical HX-6048 resin.

[0012] Furthermore, the thermochromic material is a thermochromic powder selected from the QDR-22-SP series transparent thermochromic powder of Dongguan Qiansebian New Material Co., Ltd., and its color-changing temperature is any one of 5℃, 10℃, 15℃, 18℃, 22℃, 25℃, 28℃, 31℃, 33℃ or 38℃.

[0013] Furthermore, the adhesive underlayer slurry in step S3 comprises, by weight: 100 parts of hydrolysis-resistant resin; 40-50 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 10-15 parts of colorant; the modulus of the adhesive underlayer slurry is 10-25 kg / cm², the solid content is 45%, and the viscosity is 8000-10000 cps.

[0014] Furthermore, when applying the adhesive base layer to the color-changing thermochromic layer, the coating amount is 190-210 g / m². After drying to semi-dry at 120°C, it is immediately bonded to the pretreated microfiber substrate and then dried and cured under a gradient temperature increase of 120-145°C.

[0015] Furthermore, the dry film thickness of the transparent optically variable surface layer is 10-20 micrometers; the dry film thickness of the color-changing thermochromic layer is 20-40 micrometers.

[0016] This invention provides a method for preparing synthetic leather with a perspective-superimposed light-temperature dual-response effect. By constructing an optical coupling structure between a highly transparent ultraviolet-chromatic surface layer and a color-changing temperature-sensitive layer, four deterministic and designable visual states of the synthetic leather under different light and temperature environments are achieved, thereby creating an unprecedented dynamic interactive experience and decorative function for synthetic leather. Specifically, it manifests as follows:

[0017] 1. Precise visual control through single-factor triggering and two-factor coupling is achieved. The synthetic leather's response logic to the external environment (light, temperature) is clear and predictable: in the absence of ultraviolet light, the visual effect is controlled solely by temperature; in the presence of ultraviolet light, the visual effect is synthesized by superimposing a fixed light-changing color with a dynamic temperature-changing color. Four states (normal temperature without light, heated without light, normal temperature with ultraviolet light, heated with ultraviolet light) cover the vast majority of product usage scenarios. Each state presents a unique and stable color, making the product not just a simple color changer, but possessing intelligent attributes of scene-adaptive color display.

[0018] 2. Creates a rich color hierarchy. State 1 (normal temperature, no light, only the color-changing layer displays the initial base color) provides the product's basic aesthetic style in everyday environments. State 2 (heating, no light, color-changing layer changes color) visually reflects temperature changes through color variations, suitable for scenarios requiring temperature indication or enhanced user experience. State 3 (light, no temperature increase, transparent color-changing layer changes color) triggers hidden colors under specific lighting conditions (such as outdoors or in entertainment venues), bringing a sense of surprise. State 4 (light and temperature increase, contrasting colors superimposed) under the combined effect of light and temperature, produces a fourth type of composite contrasting color that cannot be achieved in the first three states, achieving a visual breakthrough with the most dazzling dynamic effect. This color evolution from static to single dynamic, and then to dual dynamic coupling, gives the product a strong sense of visual hierarchy.

[0019] 3. The structural design ensures the realism and clarity of the optical effects. The high transparency of the transparent color-changing surface layer is the basis for the transparency of the middle layer colors and the prerequisite for the superposition rather than the masking effect of states three and four. The preset initial base color of the color-changing temperature-changing layer is the visual basis of states one and three, and also the starting point for the color evolution of states two and four. This design ensures that even under complex responses, the color changes remain orderly and predictable.

[0020] 4. It broadens the application dimensions and added value of functional synthetic leather. This synthetic leather product integrates normal decoration, temperature indication, ultraviolet light recognition, and dynamic color enhancement, allowing a single material to meet various marketing, functional, and experiential needs. It can be widely used in high-end fashion products (such as color-changing shoes, clothing, and bags), interactive interiors (such as automobiles and home furnishings), environmental sensing devices, and new anti-counterfeiting packaging, significantly enhancing its technological appeal and added value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the synthetic leather with a perspective superimposed light and temperature dual response effect in this invention.

[0022] Figure labels: 1. Transparent optically variable surface layer; 2. Color-changing thermochromic layer; 3. Base layer; 4. Microfiber substrate; 5. Release paper. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see the appendix Figure 1 This invention provides a method for preparing synthetic leather with a perspective-superimposed photothermal dual-response effect. By placing photochromic and thermochromic materials in two independent physical layers and optically coupling them through a highly transparent surface layer, color superimposition is achieved while effectively avoiding interference between the two functional materials at the molecular level, ensuring the independence and stability of their respective color-changing responses. The synthetic leather preparation method specifically includes the following steps:

[0025] S1: Apply a highly transparent UV-sensitive material paste to release paper 5 and dry it to form a transparent optically variable surface layer 1.

[0026] S2: Apply a color-changing thermochromic slurry to the transparent optical variable surface layer 1 and dry it to form a color-changing thermochromic layer 2.

[0027] S3: Apply adhesive base layer paste to color-changing thermochromic layer 2, form base layer 3 in semi-dry state, and bond it with microfiber substrate 4. After drying and curing, peel off release paper 5 to obtain synthetic leather.

[0028] The transparent light-changing surface layer 1 allows most visible light to pass through and changes color under ultraviolet light irradiation, while the color-changing thermochromic layer 2 has an initial base color and changes color when the temperature changes. The two layers are superimposed to achieve a dynamic visual effect with dual light and temperature response.

[0029] The synthetic leather preparation method of the present invention achieves dual light and temperature response through the stacked structure design of transparent light-changing surface layer 1 + color-changing temperature layer 2, presenting a variety of dynamic color effects on a single material, and enhancing the visual hierarchy and interactivity of the product.

[0030] Preferably, the high-transparency UV-sensitive fabric slurry in step S1 comprises, by weight: 100 parts of high-transparency hydrolysis-resistant polyurethane resin; 50-70 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 5-12 parts of nano-sized UV-sensitive powder; and 0.5-1.5 parts of high-transparency dispersant. This fabric slurry formulation ensures that the coating maintains high transparency while exhibiting color-changing properties under UV light, without affecting the color development of the temperature-sensitive color-changing slurry.

[0031] Preferably, the highly transparent, hydrolysis-resistant polyurethane resin is Hexin Chemical HX-6048 resin. Selecting a specific type of highly transparent resin ensures the surface layer's hydrolysis resistance and optical transparency, improving product durability and appearance stability.

[0032] Preferably, the nano-scale ultraviolet photochromic powder has a particle size D50 of less than 200 nm and is selected from the MC-24 series transparent ultraviolet photochromic powder of Dongguan Qiansebian New Materials Co., Ltd. Using nano-scale ultraviolet photochromic powder reduces light scattering, improves light transmittance and color-changing uniformity, and enhances visual clarity and color purity.

[0033] Preferably, the highly transparent dispersant is BYK-163.

[0034] Preferably, to achieve temperature-responsive color change and superimpose it with the light-changing effect of the transparent light-changing surface layer 1 to form a composite color change, the color-developing thermochromic slurry comprises, by weight: 100 parts of hydrolytically resistant resin; 40-60 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 10-20 parts of thermochromic material; and 3-10 parts of base color paste. The base color paste is light gray, off-white, or khaki. The base color paste imparts an initial base color to the thermochromic layer, providing a color foundation for the subsequent light-temperature superposition effect and enhancing the controllability of the visual design. Dark-colored base color pastes should not be used, as this would result in an overly dark base color, preventing color change.

[0035] Preferably, the hydrolysis-resistant resin is Hexin Chemical HX-6048 resin.

[0036] Preferably, the thermochromic material is a thermochromic powder, selected from the QDR-22-SP series transparent thermochromic powder of Dongguan Qiansebian New Material Co., Ltd., with a color-changing temperature of any one of 5℃, 10℃, 15℃, 18℃, 22℃, 25℃, 28℃, 31℃, 33℃, or 38℃. By selecting a specific thermochromic powder, the color-changing temperature is adjustable, adapting to different application scenarios and enhancing the product's environmental responsiveness and practicality.

[0037] Preferably, the adhesive underlayer 3 slurry in step S3 comprises, by weight: 100 parts of hydrolysis-resistant resin; 40-50 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; and 10-15 parts of colorant. The adhesive underlayer 3 slurry has a modulus of 10-25 kg / cm², a solid content of 45%, and a viscosity of 8000-10000 cps. The underlayer 3 slurry possesses suitable modulus and viscosity, enhancing the adhesion strength to the microfiber substrate 4 and improving the peel strength and durability of the finished product.

[0038] Preferably, when applying the adhesive base layer 3 slurry to the color-changing thermochromic layer 2, the coating amount is 190-210 g / m². After drying to semi-dry at 120°C, it is immediately bonded to the pretreated microfiber substrate 4, and then dried and cured under a gradient temperature increase of 120-145°C. The bonding process parameters are optimized to ensure a strong bond between the layers, avoid delamination or bubbles, and improve the yield and consistency.

[0039] Preferably, the dry film thickness of the transparent optically variable surface layer 1 is 10-20 micrometers; controlling the dry film thickness of the surface layer to 10-20 micrometers balances light transmittance, flexibility, and mechanical strength, avoiding weakening functionality due to excessive thinness or affecting transparency due to excessive thickness. The dry film thickness of the color-changing thermochromic layer 2 is 20-40 micrometers, ensuring color rendering effect and feel, while not affecting overall softness and adhesion. The dry film thickness of the bottom layer 3 is 20-40 micrometers.

[0040] This invention provides a method for preparing synthetic leather with a perspective-superimposed light-temperature dual-response effect. By constructing an optical coupling structure between a highly transparent ultraviolet light-changing surface layer and a color-changing temperature-changing layer 2, four deterministic and designable visual states of the synthetic leather under different light and temperature environments are achieved, thereby creating an unprecedented dynamic interactive experience and decorative function for the synthetic leather. Specifically, it manifests as follows:

[0041] 1. Precise visual control through single-factor triggering and two-factor coupling is achieved. The synthetic leather's response logic to the external environment (light, temperature) is clear and predictable: in the absence of ultraviolet light, the visual effect is controlled solely by temperature; in the presence of ultraviolet light, the visual effect is synthesized by superimposing a fixed light-changing color with a dynamic temperature-changing color. Four states (normal temperature without light, heated without light, normal temperature with ultraviolet light, heated with ultraviolet light) cover the vast majority of product usage scenarios. Each state presents a unique and stable color, making the product not just a simple color changer, but possessing intelligent attributes of scene-adaptive color display.

[0042] 2. It created a rich variety of color layers.

[0043] State 1 (at room temperature and without light, only the color-changing layer 2 shows the initial base color) provides the basic aesthetic style of synthetic leather in everyday environments.

[0044] State 2 (heating without light, color-changing layer 2 changes color) intuitively reflects temperature changes through color changes, suitable for scenarios that need to indicate temperature or enhance the user experience.

[0045] State 3 (no temperature rise under light, transparent light-changing surface 1 changes color) triggers hidden colors under specific lighting conditions (such as outdoors, entertainment venues), bringing a sense of surprise.

[0046] State 4 (with illumination and heating, color blocking): Under the combined effect of light and temperature, a fourth type of composite color blocking is produced, which cannot be achieved in the first three states, achieving a visual breakthrough and the most dazzling dynamic effect. This color evolution from static to single dynamic, and then to dual dynamic coupling, gives the product a strong sense of visual hierarchy.

[0047] 3. The structural design ensures the realism and clarity of the optical effects. The high transparency of the transparent optical variable layer 1 is the basis for the transparency of the middle layer colors and the prerequisite for the superposition rather than the covering effect of states three and four. The preset initial base color of the color temperature variable layer 2 is the visual basis of states one and three, and also the starting point for the color evolution of states two and four. This design ensures that even under complex responses, the color changes remain orderly and predictable.

[0048] 4. It broadens the application dimensions and added value of functional synthetic leather. This synthetic leather product integrates normal decoration, temperature indication, ultraviolet light recognition, and dynamic color enhancement, allowing a single material to meet various marketing, functional, and experiential needs. It can be widely used in high-end fashion products (such as color-changing shoes, clothing, and bags), interactive interiors (such as automobiles and home furnishings), environmental sensing devices, and new anti-counterfeiting packaging, significantly enhancing its technological appeal and added value.

[0049] The beneficial technical effects of the preparation method of the present invention will be explained below through several examples and comparative examples.

[0050] Example 1

[0051] This example provides a method for preparing synthetic leather with a perspective-superimposed light and temperature dual-response effect, including the following steps:

[0052] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0053] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0054] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0055] The synthetic leather prepared in Example 1 was observed under four different environmental conditions, and its color showed a regular change as shown in the table below:

[0056] Table 1. Performance parameters of the synthetic leather obtained in Example 1 in four states

[0057] Environmental conditions Observed synthetic leather surface color Color formation State 1 25°C, no ultraviolet light Light gray Only the initial base color of the color temperature change layer is visible. State 2 35°C, no ultraviolet light pink Only the color temperature change layer responds to the temperature, changing from light gray to red. State 3 25°C, 365nm ultraviolet light irradiation blue-gray The transparent, light-changing surface turns blue, overlapping with the underlying light gray layer. State 4 35°C, 365nm ultraviolet light irradiation Purple / Violet The transparent, light-changing surface layer turns blue, which overlaps with the underlying, red-colored thermochromic layer.

[0058] Example 2

[0059] This example provides a method for preparing synthetic leather with a perspective-superimposed light and temperature dual-response effect, including the following steps:

[0060] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 12 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0061] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0062] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0063] Example 3

[0064] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0065] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 20 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 12 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 4 parts of base color paste (light gray).

[0066] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0067] Example 4

[0068] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0069] S2: Apply a color-developing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-developing thermochromic layer with a dry film thickness of 30 micrometers; the color-developing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 18 parts of thermochromic powder (QDR-22-SP transparent to red, color change temperature 38℃), and 6 parts of base color paste (off-white).

[0070] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0071] Example 5

[0072] This example provides a method for preparing synthetic leather with a perspective-superimposed light and temperature dual-response effect, including the following steps:

[0073] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0074] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (khaki).

[0075] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0076] Comparative Example 1

[0077] This example provides a method for preparing synthetic leather, including the following steps:

[0078] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, and 1 part of high-transparency dispersant (BYK-163).

[0079] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0080] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0081] Comparative Example 2

[0082] This example provides a method for preparing synthetic leather, including the following steps:

[0083] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0084] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, and 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃).

[0085] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0086] Comparative Example 3

[0087] This example provides a method for preparing synthetic leather, including the following steps:

[0088] S1: Apply a high-transparency UV-sensitive fabric slurry to release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of ordinary micron-sized UV-sensitive powder (transparent to blue, D50>500nm); and 1 part of high-transparency dispersant (BYK-163).

[0089] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0090] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0091] Comparative Example 4

[0092] This example provides a method for preparing synthetic leather, including the following steps:

[0093] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0094] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0095] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure at a constant temperature of 110℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0096] Comparative Example 5

[0097] This example provides a method for preparing synthetic leather, including the following steps:

[0098] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 25 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of high-transparency hydrolysis-resistant polyurethane resin (Hexin Chemical HX-6048 resin), 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0099] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of hydrolysis-resistant resin (Hexin Chemical HX-6048 resin), 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0100] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of hydrolysis-resistant resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18 kg / cm², the solid content is 45%, and the viscosity is 9000 cps.

[0101] Comparative Example 6

[0102] This example provides a method for preparing synthetic leather, including the following steps:

[0103] S1: Apply a high-transparency UV-sensitive fabric slurry to the release paper and dry it (90℃, 3 minutes) to form a transparent photochromic surface layer with a dry film thickness of 15 micrometers. The high-transparency UV-sensitive fabric slurry includes 100 parts of ordinary polyurethane resin, 40 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 8 parts of nano-grade UV-sensitive powder (MC-24 transparent blue); and 1 part of high-transparency dispersant (BYK-163).

[0104] S2: Apply a color-changing thermochromic slurry to the transparent optically variable surface layer and dry it (100℃, 4 minutes) to form a color-changing thermochromic layer with a dry film thickness of 30 micrometers; the color-changing thermochromic slurry includes 100 parts of ordinary polyurethane resin, 30 parts of dimethylformamide, 20 parts of methyl ethyl ketone, 15 parts of thermochromic powder (QDR-22-SP transparent to red, color-changing temperature 22℃), and 5 parts of base color paste (light gray).

[0105] S3: Apply an adhesive underlayer slurry (coating amount 200g / ㎡) to the color-changing thermochromic layer, bake at 120℃ until semi-dry to obtain an underlayer with a dry film thickness of 30 micrometers, and then bond it to a pretreated microfiber substrate. Subsequently, dry and cure under a gradient temperature of 120-145℃ to obtain synthetic leather. The adhesive underlayer slurry includes 100 parts of ordinary polyurethane resin; 30 parts of dimethylformamide; 10 parts of methyl ethyl ketone; and 12 parts of black pigment. The modulus of the adhesive underlayer slurry is 18Kg / cm², the solid content is 45%, and the viscosity is 9000cps.

[0106] Table 2 Performance test parameters of synthetic leather samples obtained in Examples 1-5 and Comparative Examples 1-6

[0107] Light transmittance UV color change response time Temperature response Peel strength Implementation status and effect evaluation of the four states Example 1 85.2 2.1 yes 4.8 All achieved, with excellent results. The color overlay in states three and four is clear and has a strong sense of depth. Example 2 80.5 1.8 yes 4.7 All features are now implemented, resulting in enhanced effects. The dominant colors in states three and four are more vibrant and saturated. Example 3 87.6 2.0 yes 4.5 All conditions were met with good results. The colors in states one and two were slightly paler, but states three and four had higher transparency. Example 4 84.8 2.2 yes 4.9 All are achieved, with unique effects. States two and four are triggered at high temperatures and are suitable for specific scenarios. Example 5 84.0 2.3 yes 4.8 All features are implemented, resulting in diverse effects. The designability of colors in states one, three, and four is demonstrated under different base colors. Comparative Example 1 86.0 none yes 4.6 Only states one and two are implemented. States three and four are missing. There is no ultraviolet light response and no color overlay effect. Comparative Example 2 88.5 2.5 weak 4.0 The effects of states one and three are lost, while the effects of states two and four are extremely poor. It appears white under natural light, and the sense of layering is hollow. Comparative Example 3 58.3 4.5 yes 4.2 Conditions three and four result in severely degraded effects. Due to extremely low light transmittance, the underlying colors cannot show through, causing the layering to become opaque and the colors to become muddy. Comparative Example 4 84.5 2.2 no 2.5 States two and four cannot be achieved. The thermochromic material is not fully activated, resulting in poor interlayer bonding and product failure. Comparative Example 5 78.1 2.8 yes 4.6 In states three and four, the effect decreases. Light transmittance and response speed decrease, and the superimposed colors become darker and less vivid. Comparative Example 6 79.8 2.3 It is (initial). 4.3 It can be achieved in the short term, but due to poor hydrolysis resistance, all states and effects will be severely degraded or fail after long-term use.

[0108] 1. Transmittance (%): The transmittance at a visible light wavelength of 550nm was measured using a haze meter.

[0109] 2. UV color change response time (s): The time required for the surface color to reach a stable change after irradiation with a 365nm ultraviolet lamp.

[0110] 3. Temperature change response range (ΔE>5): Measured using a spectrophotometer under light-protected conditions, the sample temperature was increased from 15℃ to 30℃, and the color difference ΔE was calculated. Judgment criterion: ΔE≥5 indicates a significant response.

[0111] 4. Peel strength (KG / cm): The peel strength between the surface layer and the substrate is determined according to the QB / T 2710 standard.

[0112] Based on the experimental data in Table 2, the following conclusions can be drawn:

[0113] 1. The synthetic leathers prepared in all embodiments exhibited excellent basic properties: light transmittance (80.5%-87.6%) and peel strength (4.5-4.9 kg / cm) were both at excellent levels, with rapid ultraviolet light response (1.8-2.3 s) and significant temperature response (ΔE≥5). Most importantly, all products in the embodiments could fully realize the four visual states from state one to state four, and the superimposed effect was clear and had a strong sense of layering, fully demonstrating that the preparation method of the present invention can stably prepare photothermal dual-response synthetic leather with excellent comprehensive performance.

[0114] 2. Comparative Example 1 (without photochromic powder) directly caused the synthetic leather to lose its UV response function and could not achieve states three and four, which confirmed the necessity of the transparent photochromic surface layer and its components.

[0115] Comparative Example 2 (without base color in the thermochromic layer) caused the product to appear white under natural light and had a hollow sense of color overlay. The visual effect of State 1 and State 3 was lost, which confirmed the necessity of adding base color pigment to the color-changing thermochromic layer.

[0116] Comparative Example 3 (using micron-sized photochromic powder) suffered a severe decrease in light transmittance (58.3%), causing the overlay function to fail. The effects of states three and four were cloudy, demonstrating the crucial role of nano-sized ultraviolet photochromic powder in ensuring high light transmittance.

[0117] Comparative Example 4 (low-temperature curing) resulted in thermal response failure and a sharp drop in peel strength (2.5 kg / cm), indicating that specific drying and curing process parameters (120-145℃) are key to ensuring the activation of functional materials and strong interlayer bonding.

[0118] Comparative Example 5 (excessive surface layer thickness) caused a decrease in light transmittance and response speed, resulting in darker superimposed colors, illustrating the necessity of a certain range of dry film thickness for transparent photochromic surface layers.

[0119] Although Comparative Example 6 (using ordinary resin) can initially achieve some of the desired state, its poor hydrolysis resistance will cause all visual effects to be unable to be maintained for a long time, indicating that the selection of a specific high-transparency hydrolysis-resistant resin plays an important role in the long-term durability of synthetic leather.

[0120] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing synthetic leather with a perspective-superimposed photothermal dual-response effect, characterized in that: Includes the following steps: S1: Apply a highly transparent UV-sensitive material paste to the release paper and dry it to form a transparent optically variable surface layer; S2: Apply color-changing thermochromic slurry onto the transparent optically variable surface layer and dry to form a color-changing thermochromic layer; S3: Apply adhesive base layer paste to the color-changing thermochromic layer, form the base layer in a semi-dry state, and bond it with the microfiber substrate. After drying and curing, peel off the release paper to obtain synthetic leather. The transparent light-changing surface layer allows most visible light to pass through and changes color under ultraviolet light irradiation, while the color-changing thermochromic layer has an initial base color and changes color when the temperature changes. The two layers are superimposed to achieve a dynamic visual effect with dual light and temperature response.

2. The method for preparing synthetic leather according to claim 1, characterized in that: The high-transparency UV-sensitive fabric sizing agent mentioned in step S1 includes, by weight: 100 parts of highly transparent, hydrolysis-resistant polyurethane resin; 50-70 parts of solvent, wherein the solvent is a combination of dimethylformamide and butanone; 5-12 parts of nano-sized ultraviolet photochromic powder; 0.5-1.5 parts of high-transparency dispersant.

3. The method for preparing synthetic leather according to claim 2, characterized in that: The highly transparent, hydrolysis-resistant polyurethane resin is Hexin Chemical HX-6048 resin.

4. The method for preparing synthetic leather according to claim 2, characterized in that: The nano-scale ultraviolet photochromic powder has a particle size D50 of less than 200nm and is selected from the MC-24 series transparent ultraviolet photochromic powder of Dongguan Qiansebian New Materials Co., Ltd.

5. The method for preparing synthetic leather according to claim 1, characterized in that: The color-changing temperature-sensitive slurry mentioned in step S2 includes, by mass parts: 100 parts of hydrolysis-resistant resin; 40-60 parts of solvent, wherein the solvent is a combination of dimethylformamide and methyl ethyl ketone; 10-20 parts of thermochromic material; 3-10 parts of base color pigment.

6. The method for preparing synthetic leather according to claim 5, characterized in that: The hydrolysis-resistant resin is Hexin Chemical HX-6048 resin.

7. The method for preparing synthetic leather according to claim 5, characterized in that: The thermochromic material is a thermochromic powder, selected from the QDR-22-SP series transparent thermochromic powder of Dongguan Qiansebian New Material Co., Ltd., with a color-changing temperature of any one of 5℃, 10℃, 15℃, 18℃, 22℃, 25℃, 28℃, 31℃, 33℃ or 38℃.

8. The method for preparing synthetic leather according to claim 1, characterized in that: The adhesive underlayer slurry mentioned in step S3 includes, by weight: 100 parts of hydrolysis-resistant resin; 40-50 parts of solvent, wherein the solvent is a combination of dimethylformamide and butanone; 10-15 parts of color powder; The adhesive underlayer slurry has a modulus of 10-25 kg / cm², a solid content of 45%, and a viscosity of 8000-10000 cps.

9. The method for preparing synthetic leather according to claim 8, characterized in that: When applying the adhesive base layer to the color-changing thermochromic layer, the coating amount is 190-210g / ㎡. After drying to semi-dry at 120℃, it is immediately bonded to the pretreated microfiber substrate and then dried and cured under a gradient temperature of 120-145℃.

10. The method for preparing synthetic leather according to claim 1, characterized in that: The dry film thickness of the transparent optically variable surface layer is 10-20 micrometers; the dry film thickness of the color-changing thermochromic layer is 20-40 micrometers.

Images