Waterborne skin-touch solvent-free polyurethane synthetic leather for sofa home furnishing and preparation method thereof

Abstract

The invention discloses waterborne skin-touch solvent-free polyurethane synthetic leather for sofa home furnishing and a preparation method of the waterborne skin-touch solvent-free polyurethane synthetic leather. The polyurethane synthetic leather comprises a waterborne skin-touch surface layer, an environment-friendly solvent-free surface layer and a base cloth layer which are sequentially arranged from top to bottom. The reactive solvent-free color paste, the solvent-free dry method veneering process and the water-based surface ultraviolet light curing process are combined, a solvent-free surface layer is used in a prepared dry method layer to serve as a surface layer, the low-energy-consumption and low-material-consumption process route of a water-based solvent-free product is achieved, and by selecting the modulus of solvent-free raw materials, the water-based solvent-free surface layer is obtained. The defects of poor wear resistance and hydrolysis resistance are overcome, the reactive solvent-free color paste is used, the problem that a solvent-free surface layer is single in color and not gorgeous is solved, the cost is effectively reduced, and the technological process is shortened. An ultraviolet light curing process is adopted in the surface treatment process, and compared with traditional oven drying and curing, the problems that long-time high-temperature curing is needed for water-based surface treatment, and the vehicle speed can only be reduced due to the length problem of an oven are solved, and the production efficiency is improved; the problem of stiff hand feeling of water-based solvent-free synthetic leather is improved in the aspect of hand feeling of finished leather, and the water-based solvent-free synthetic leather has the advantages of environmental protection and green.

Description

Technical Field

[0001] This invention relates to the field of synthetic leather technology, and in particular to a water-based, solvent-free, skin-feeling polyurethane synthetic leather for sofas and home furnishings, and its preparation method. Background Technology

[0002] Water-based solvent-free coatings are widely used in modern coatings, synthetic leather, inks, and other fields due to their environmental friendliness, safety, and performance characteristics. Their advantages include being green, safe, healthy, and easy to apply; they contain no organic solvents, reducing the release of volatile organic compounds at the source and complying with stringent global environmental regulations.

[0003] The current production process of water-based solvent-free synthetic leather mainly follows the traditional oil-based solvent-free synthetic leather production process, using a water-based top layer + water-based intermediate layer + solvent-free method. This has several limitations and drawbacks, including slow drying speed, high latent heat of vaporization, high energy requirements, and drying speed significantly affected by temperature and humidity. Initial costs are higher, as water-based resins and environmentally friendly additives are more expensive than traditional solvent-based raw materials, leading to increased production costs. Process control is demanding, as the high surface tension of water results in poor penetration of release paper, limiting the range of release paper options. The solvent-free reaction has specific requirements for moisture content and pH value; the complete drying of the water-based resin coating and the pH value of the water-based resin itself significantly affect the solvent-free reaction, potentially causing abnormal interfacial bonding. The high hardness of the water-based resin system and its film-forming mechanism result in a stiffer feel in the finished leather, with poor abrasion and hydrolysis resistance. Furthermore, in existing solvent-free synthetic leathers, the pigment components in the color paste cannot effectively participate in the reaction, affecting light transmission and refraction, reducing the purity and vibrancy of the product's color.

[0004] Therefore, how to solve the problems of high energy consumption, high material consumption, stiff feel, poor wear resistance, and poor hydrolysis resistance of water-based solvent-free synthetic leather, and further improve the production efficiency of synthetic leather and improve its appearance and color to give it a three-dimensional and vibrant color, are the technical problems that need to be solved at present, so as to meet consumers' demand for water-based skin-feel solvent-free sofa and furniture products and create economic and social value. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a water-based skin-feel polyurethane synthetic leather for sofas and furniture and its preparation method, so as to solve the problems in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a water-based, skin-feeling, solvent-free polyurethane synthetic leather for sofas and furniture, comprising, from top to bottom, a water-based, skin-feeling surface layer, an environmentally friendly, solvent-free top layer, and a base fabric layer, wherein: The environmentally friendly solvent-free topcoat is prepared from an environmentally friendly solvent-free topcoat slurry. By weight, the environmentally friendly solvent-free topcoat slurry comprises the following raw materials: 40-60 parts of polyether polycarbonate copolymer oligomer diol, 60-80 parts of polycarbonate copolymer oligomer diol, 45-55 parts of isocyanate, 0.5-2 parts of reactive solvent-free color paste, 0.1-0.2 parts of amine catalyst, 0.03-0.05 parts of metal catalyst, and 0.3-1.2 parts of wetting and leveling agent. Preferably, the polyether polycarbonate copolymer oligomer diol has a modulus of 60-70 MPa, which is considered a medium-high modulus, providing good abrasion resistance and hydrolysis resistance; the polycarbonate copolymer oligomer diol has a modulus of 30-40 MPa, which is considered a medium-low modulus, providing good hydrolysis resistance and giving the synthetic leather a soft feel.

[0007] As a preferred technical solution, the reactive solvent-free pigment is the NS series solvent-free pigment. It belongs to the reactive pigment category and is a colored polyurethane prepolymer containing reactive functional groups (-NCO isocyanate groups). (This can be understood as pigments being chemically bonded to polyurethane molecular chains, with -NCO groups at the ends of these chains.) After the addition of substances such as polyether polycarbonate copolymer oligomer diols and polycarbonate copolymer oligomer diols, it participates in a solvent-free reaction, forming a three-dimensional network structure. This enhances the crosslinking density between molecular chains, improving the mechanical strength and abrasion resistance of synthetic leather. Furthermore, it allows the resulting synthetic leather products to exhibit vibrant colors with high saturation, high transparency, and high three-dimensionality. The NS series in the name of the NS series solvent-free pigment is a prefix for the pigment designation. This series includes various specific colors, and the various color pigments belonging to this series have similar properties and can all achieve the objectives of this invention. Those skilled in the art can select the appropriate color pigment according to actual needs.

[0008] The water-based skin-feel surface treatment layer is prepared from a water-based skin-feel surface treatment layer slurry. By weight, the water-based skin-feel surface treatment layer slurry comprises the following raw materials: 100 parts of water-based oil-wax polyurethane emulsion, 0.5-1 parts of leveling agent, 1-2 parts of isocyanate curing agent, 0.5-1 parts of aziridine curing agent, 1-3 parts of abrasion-resistant additive, 2-4 parts of photoinitiator, and 0.5-3 parts of water-based colorant. Preferably, the water-based oil-wax polyurethane emulsion includes at least one of LXW-1301A (matte) and LXW-1144 (glossy). These two emulsions have an oil-wax feel and, after cross-linking and curing, provide excellent abrasion resistance, imparting a skin-feel to water-based solvent-free synthetic leather and improving abrasion resistance. Specifically, the water-based oil-wax polyurethane emulsion can be either LXW-1301A (matte) or LXW-1144 (gloss), or a mixture of LXW-1301A (matte) and LXW-1144 (gloss) in any proportion, the specific proportion of which can be determined according to the product gloss requirements.

[0009] The base fabric layer uses a bio-based material, which is environmentally friendly and recyclable. Specifically, it is made of renewable polylactic acid fiber, with a thickness of 1.4±0.1mm and a basis weight of 360±30g / cm². 2 .

[0010] This invention also provides a method for preparing the water-based, solvent-free, skin-feeling polyurethane synthetic leather for sofas and furniture as described above, comprising the following steps: An environmentally friendly solvent-free topcoat slurry is prepared, coated onto the front side of release paper, and preheated to a semi-dry state. Then, a base fabric layer is laminated onto the preheated paper, and finally dried to form a dry layer. Preferably, the coating thickness of the environmentally friendly solvent-free topcoat slurry is 0.30-0.40 mm; the preheating temperature is 85-105℃; the drying temperature is 130-140℃, and the drying time is 4-6 min; the lamination gap between the laminated base fabric layer and the base fabric layer is 60-70% of the thickness of the base fabric layer. A water-based skin-feel surface treatment slurry is prepared, and the water-based skin-feel surface treatment slurry is coated on the surface of the dry layer. After curing and drying with ultraviolet light, the finished synthetic leather product is obtained.

[0011] As a preferred technical solution, the coating amount of the water-based skin-feeling surface treatment slurry is 10-15 g / m². 2 The light intensity parameters for UV curing are 150-200 mW / cm². 2 The curing time is 3-5 seconds; the energy for UV curing is 300-600 mJ / cm². 2 .

[0012] The wear-resistant additives, wetting agents, heat stabilizers, pigment pastes, leveling agents, curing crosslinking agents, etc. used in this application are all commonly used additives in the field, and this application does not impose any special restrictions.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The preparation method provided by this invention combines reactive solvent-free color paste, solvent-free dry lamination process, and water-based surface treatment UV curing process. In terms of process path, the dry layer, through the selection of solvent-free resin modulus and the use of reactive color paste, solves the defects of solvent-free surface layers, such as dull color, poor wear resistance, and poor hydrolysis resistance. This achieves a low-energy, low-material consumption process for water-based solvent-free products, effectively reducing costs and shortening the process flow. The surface treatment process uses UV curing, which, compared to traditional oven drying and curing, avoids the problem of prolonged high-temperature curing required for water-based surface treatment and the limitation of reduced machine speed due to oven length constraints, thus improving production efficiency. In terms of leather feel, it improves the stiff feel of water-based solvent-free synthetic leather and has environmentally friendly advantages.

[0014] The present invention provides an environmentally friendly solvent-free surface layer for polyurethane synthetic leather, which improves the mechanical strength and abrasion resistance of the synthetic leather by using reactive solvent-free color pastes. It also gives the synthetic leather product a vibrant color with high saturation, high transparency, and high three-dimensionality, solving the problem of limited color options for solvent-free layers used in dry-process surface layers. The principle is that ordinary solvent-free color pastes are physical mixtures of resin and pigments. Because the pigments cannot effectively participate in the reaction, they adversely affect the mechanical properties of the product. Furthermore, ordinary color pastes contain a large amount of solvent and resin, which affect light transmission and refraction, reducing the purity and vibrancy of the color. This application utilizes a reactive solvent-free pigment, which is 100% effective. The reactive pigment, through its reactive functional groups, reacts with alcohols and other raw materials in the system to form a three-dimensional network structure, enhancing the cross-linking density between molecular chains and improving the mechanical properties of the synthetic leather. Furthermore, after the pigment reacts, the color is uniformly fixed on the walls of the microporous framework. Light, after multiple refractions and reflections within the micropores, appears to emanate from within, resulting in a highly saturated, highly transparent, and vividly three-dimensional color. This solves the problem of monotonous color in solvent-free layers used as dry-process surface layers. By coating the pigment onto release paper and drying it in an oven at a specific temperature, then bonding it to a fabric base in a semi-dry state, a solvent-free polyurethane synthetic leather dry-process layer with stable hue and good color vibrancy can be obtained.

[0015] The environmentally friendly solvent-free topcoat used in this application contains two types of polyols: polyether polycarbonate copolymer oligomer diol and polycarbonate copolymer oligomer diol. The polyether polycarbonate copolymer oligomer diol has a modulus of 60-70 MPa, which is considered a medium-to-high modulus. This high modulus polyol enhances the support of the finished leather, thereby improving its abrasion resistance and hydrolysis resistance. The polycarbonate copolymer oligomer diol has a modulus of 30-40 MPa, which is considered a medium-to-low modulus. This low modulus polyol contributes to high flexibility, giving the finished leather better softness and flexural properties. This process reduces the use of waterborne polyurethane resin as a topcoat, lowering product costs, increasing production efficiency, improving the feel of the finished leather, and solving problems such as high energy consumption, low production speed, high material costs, and stiff leather feel associated with waterborne solvent-free products.

[0016] The water-based skin-feel surface treatment layer used in this invention contains two types of curing agents: isocyanate curing agents and aziridine curing agents. These two curing agents react with different active groups to cure the coating, allowing the components in the surface treatment layer to fully cross-link, resulting in a dense film. This invention adds a photoinitiator to the raw materials of the water-based skin-feel surface treatment layer and uses an ultraviolet light curing process to achieve ultra-fast curing of the coating. This results in a short cross-linking time and a fast cross-linking speed. Compared to traditional oven drying curing processes, this avoids the problems of prolonged high-temperature curing required for water-based surface treatments and the need to reduce machine speed due to oven length limitations, effectively improving production efficiency. The synthetic leather prepared by this invention has a lasting skin feel, good durability and abrasion resistance, achieving hydrolysis resistance for 10 years, Valspar abrasion resistance ≥200,000 times, and color fastness to rubbing: dry rubbing (9N*500 times) ≥4 grade, wet rubbing (9N*200 times) ≥3.5 grade. It also exhibits no surface cracking after 100,000 flexing cycles at room temperature. Detailed Implementation

[0017] The present invention will be further described below with reference to embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention. In addition, unless otherwise specified, the preparation processes in the following embodiments are conventional methods in the prior art, and therefore will not be described in detail. All parts in the following embodiments refer to parts by mass.

[0018] The specific information of the raw materials used in the following examples and comparative examples is as follows: The water-based oil-wax polyurethane emulsions LXW-1301A and LXW-1144 are supplied by Zhejiang Luoxing Chemical Co., Ltd.

[0019] The photoinitiator used is lrgacure-184, supplied by BASF China Ltd.

[0020] The polyether polycarbonate copolymer oligomer diol is AL-3015A, and the polycarbonate copolymer oligomer diol is AL-2020A. The supplier is Hefei Anli Polyurethane New Materials Co., Ltd. The isocyanate is AL-5040B, and the supplier is Hefei Anli Polyurethane New Materials Co., Ltd. The metal catalyst is DY-20 and the amine catalyst is DY-155, both supplied by Shanghai Deyin Chemical Co., Ltd.

[0021] The wear-resistant additive is wear-resistant additive 3238, and the supplier is Shanghai Heshuo Chemical Co., Ltd.

[0022] The leveling agent is model LA-1610, and the supplier is Stahl Company.

[0023] The reactive solvent-free color paste is the NS series solvent-free color paste, and the supplier is World Name Technology Co., Ltd.

[0024] The isocyanate curing agent is model FB-12, and the supplier is Leling Sisheng Polymer Materials Co., Ltd.

[0025] The aziridine curing agent is model KT-100, and the supplier is Shanghai Ketian New Material Technology Co., Ltd.

[0026] The wetting and leveling agent is model LT-7110, and the supplier is Hefei Anli Polyurethane New Materials Co., Ltd.

[0027] The water-based pigment is the S19-LR series water-based pigment, and the supplier is Shanghai Maicai New Materials Co., Ltd.

[0028] The standard solvent-free color paste is the 9055 series, supplied by Zhejiang Luoxing Chemical Co., Ltd.

[0029] It should be noted that the above raw materials and additives are merely examples to make the technical solution of the present invention clearer, and do not mean that the present invention can only use the above raw materials and additives. The specific scope is subject to the claims. In addition, unless otherwise specified, "parts" and "number of parts" mentioned in the following embodiments refer to parts by weight.

[0030] Example 1 This embodiment proposes a water-based, skin-feeling, solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based, skin-feeling surface layer, an environmentally friendly solvent-free top layer, and a base fabric layer arranged sequentially from top to bottom. Its preparation method includes the following two steps, S1-S2.

[0031] S1. Apply an environmentally friendly solvent-free slurry to the front side of the release paper. The coating thickness of the environmentally friendly solvent-free slurry is 0.30 mm. The preheating temperature is 85℃, and the paper is preheated to a semi-dry state. Then, a 1.40 mm single-sided fleece base fabric is laminated to form a base fabric layer, with a lamination thickness of 0.85 mm. After curing and drying at 130℃ for 6 minutes, the release paper is peeled off and the paper is rolled up to obtain a semi-finished polyurethane synthetic leather product.

[0032] The preparation process of the environmentally friendly solvent-free surface coating slurry is as follows: 40 parts of polyether polycarbonate copolymer oligomer diol AL-3015A, 80 parts of polycarbonate copolymer oligomer diol AL-2020A, 45 parts of isocyanate AL-5040B, 0.15 parts of amine catalyst DY-155, 0.03 parts of metal catalyst DY-20, 2 parts of reactive solvent-free color paste, and 0.3 parts of wetting and leveling agent LT-7110 are mixed and stirred evenly, and then vacuumed to obtain the environmentally friendly solvent-free surface coating slurry.

[0033] The single-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.4±0.1 mm and a weight of 360±30 g / cm³. 2 . S2. The dry layer is treated with water-based matte skin-feel surface treatment material LXW-1301A by roller coating, and then cured and dried by ultraviolet light to obtain the finished synthetic leather product.

[0034] The preparation process of the water-based skin-feel surface treatment slurry is as follows: 100 parts of water-based oil-wax polyurethane emulsion LXW-1301A, 1 part of isocyanate curing agent FB-12, 0.5 parts of pyridine curing agent KT-100, 1 part of wear-resistant additive 3238, 2 parts of photoinitiator lrgacure-184, and 1 part of water-based color paste are added to obtain the water-based skin-feel surface treatment slurry.

[0035] The ultraviolet curing parameters are as follows: light intensity is 150 mW / cm². 2 The curing time is 3 seconds, and the energy is 300 mJ / cm². 2 The coating amount of the water-based surface treatment slurry is 10 g / m². 2 .

[0036] Tests showed that the synthetic leather prepared in this embodiment has a lasting skin feel, good abrasion resistance, and can withstand hydrolysis for 10 years, a Valspar abrasion resistance of 200,000 times, a dry rubbing (9N*500 times) rating of 4, a wet rubbing (9N*200 times) rating of 3.5, and no surface cracking after 100,000 bending cycles at room temperature.

[0037] Example 2 This embodiment proposes a water-based, skin-feeling, solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based, skin-feeling surface layer, an environmentally friendly solvent-free top layer, and a base fabric layer arranged sequentially from top to bottom. Its preparation method includes the following two steps, S1-S2.

[0038] S1. Apply an environmentally friendly solvent-free slurry to the front side of the release paper. The coating thickness of the environmentally friendly solvent-free slurry is 0.40 mm. The preheating temperature is 105℃, and the paper is preheated to a semi-dry state. Then, a 1.40 mm single-sided fleece base fabric is laminated to form a base fabric layer, and the lamination thickness is 1.0 mm. After curing and drying at 140℃ for 4 minutes, the release paper is peeled off and the paper is rolled up to obtain a semi-finished polyurethane synthetic leather product.

[0039] The preparation process of the environmentally friendly solvent-free surface coating slurry is as follows: 60 parts of polyether polycarbonate copolymer oligomer diol AL-3015A, 60 parts of polycarbonate copolymer oligomer diol AL-2020A, 55 parts of isocyanate AL-5040B, 0.2 parts of amine catalyst DY-155, 0.05 parts of metal catalyst DY-20, 2 parts of reactive solvent-free color paste, and 0.3 parts of wetting and leveling agent LT-7110 are mixed and stirred evenly, and then vacuumed to obtain the environmentally friendly solvent-free surface coating slurry.

[0040] The single-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.4±0.1 mm and a weight of 360±30 g / cm³. 2 .

[0041] S2. The dry layer is treated with water-based glossy skin-feel surface treatment material LXW-1144 by roller coating, and then cured and dried by ultraviolet light to obtain the finished synthetic leather product.

[0042] The preparation process of the water-based skin-feel surface treatment slurry is as follows: 100 parts of water-based oil-wax polyurethane emulsion LXW-1144, 1 part of isocyanate curing agent FB-12, 0.5 parts of pyridine curing agent KT-100, 1 part of wear-resistant additive 3238, 2 parts of photoinitiator lrgacure-184, and 1 part of water-based color paste are added to obtain the water-based skin-feel surface treatment slurry.

[0043] The ultraviolet curing parameters are as follows: light intensity is 150 mW / cm². 2 The curing time is 5 seconds, and the energy is 300 mJ / cm². 2 The coating amount of the water-based surface treatment slurry is 15 g / m². 2 .

[0044] Tests showed that the synthetic leather prepared in this embodiment has a lasting skin feel, good abrasion resistance, and can withstand hydrolysis for 12 years, Valspar abrasion for 300,000 cycles, dry rubbing (9N*500 times) is rated as level 4, wet rubbing (9N*200 times) is rated as level 4, and the surface does not crack after 100,000 cycles of bending at room temperature.

[0045] Example 3 This embodiment proposes a water-based, skin-feeling, solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based, skin-feeling surface layer, an environmentally friendly solvent-free top layer, and a base fabric layer arranged sequentially from top to bottom. Its preparation method includes the following two steps, S1-S2.

[0046] S1. Apply an environmentally friendly solvent-free slurry to the front side of the release paper. The coating thickness of the environmentally friendly solvent-free slurry is 0.40 mm. The preheating temperature is 105℃, and the paper is preheated to a semi-dry state. Then, a 1.40 mm single-sided fleece base fabric is laminated to form a base fabric layer, and the lamination thickness is 1.0 mm. After curing and drying at 140℃ for 4 minutes, the release paper is peeled off and the paper is rolled up to obtain a semi-finished polyurethane synthetic leather product.

[0047] The preparation process of the environmentally friendly solvent-free surface coating slurry is as follows: 60 parts of polyether polycarbonate copolymer oligomer diol AL-3015A, 60 parts of polycarbonate copolymer oligomer diol AL-2020A, 55 parts of isocyanate AL-5040B, 0.2 parts of amine catalyst DY-155, 0.05 parts of metal catalyst DY-20, 0.5 parts of reactive solvent-free color paste, and 0.3 parts of wetting and leveling agent LT-7110 are mixed and stirred evenly, and then vacuumed to obtain the environmentally friendly solvent-free surface coating slurry.

[0048] The single-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.4±0.1 mm and a weight of 360±30 g / cm³. 2 .

[0049] S2. The dry layer is treated with water-based glossy skin-feel surface treatment material LXW-1144 by roller coating, and then cured and dried by ultraviolet light to obtain the finished synthetic leather product.

[0050] The preparation process of the water-based skin-feel surface treatment slurry is as follows: 100 parts of water-based oil-wax polyurethane emulsion LXW-1144, 2 parts of isocyanate curing agent FB-12, 1 part of pyridine curing agent KT-100, 3 parts of wear-resistant additive 3238, 4 parts of photoinitiator lrgacure-184, and 1 part of water-based color paste are added to obtain the water-based skin-feel surface treatment slurry.

[0051] The ultraviolet curing parameters are as follows: light intensity is 200 mW / cm². 2 The curing time is 5 seconds, and the energy is 600 mJ / cm². 2 The coating amount of the water-based surface treatment slurry is 15 g / m². 2 .

[0052] Tests showed that the synthetic leather prepared in this embodiment has a lasting skin feel, good abrasion resistance, and can withstand hydrolysis for 15 years, Valspar abrasion resistance for 400,000 cycles, dry rubbing (9N*500 times) is rated as level 4, wet rubbing (9N*200 times) is rated as level 4, and the surface does not crack after 100,000 cycles of bending at room temperature.

[0053] Comparative Example 1 Compared with Example 1, the difference in this comparative example is that in step S1, the amount of polyether polycarbonate copolymer oligomer diol AL-3015A is 0, and the amount of polycarbonate copolymer oligomer diol AL-2020A is 120 parts; all other processes are the same as in Example 1.

[0054] The polyurethane synthetic leather prepared in this comparative example did not have the medium-to-high modulus polyether polycarbonate copolymer oligomer diol AL-3015A added, resulting in poor support performance after leather formation, and thus could not meet Valspar's requirement of 200,000 abrasion resistance cycles.

[0055] Comparative Example 2 Compared with Example 1, the difference in this comparative example is that in step S1, the amount of polyether polycarbonate copolymer oligomer diol AL-3015A is 120 parts and the amount of polycarbonate copolymer oligomer diol AL-2020A is 0 parts; all other processes are the same as in Example 1.

[0056] The polyurethane synthetic leather prepared in this comparative example did not contain the low-modulus polycarbonate copolymer oligomer diol AL-2020A, resulting in a stiff feel, reduced bending performance, and surface cracking after 100,000 bending cycles at room temperature.

[0057] Comparative Example 3 Compared with Example 1, the difference in this comparative example is that in step S1, the reactive solvent-free pigment is replaced with an equal amount of ordinary solvent-free pigment; all other processes are the same as in Example 1.

[0058] The polyurethane synthetic leather prepared in this comparative example has poor color development performance of ordinary solvent-free pigments, resulting in poor color saturation and transparency after leather production.

[0059] Comparative Example 4 Compared with Example 1, the difference in this comparative example is that in step S2, the water-based oil-wax polyurethane emulsion LXW-1301A is replaced with SF-6201M (Zhejiang Jiande Shunfa Chemical Co., Ltd.), and all other processes are the same as in Example 1.

[0060] The polyurethane synthetic leather prepared in this comparative example did not meet the skin feel performance requirements because the SF-6201M water-based surface treatment agent has a dry and slippery feel and does not have a skin-friendly effect.

[0061] Comparative Example 5 Compared with Example 1, the difference in this comparative example is that in step S2, the amount of isocyanate curing agent FB-12 is 1.5 parts and the amount of pyridine curing agent KT-100 is 0 parts; all other processes are the same as in Example 1.

[0062] The polyurethane synthetic leather prepared in this comparative example has poor surface layer density because the isocyanate curing agent mainly reacts with hydroxyl and amino groups, and cannot react with the carboxyl groups in the water-based oil-wax polyurethane emulsion. As a result, Valspar's abrasion resistance cannot meet the requirement of 200,000 cycles.

[0063] Comparative Example 6 Compared with Example 1, the difference in this comparative example is that in step S2, the amount of isocyanate curing agent FB-12 is 0 parts, and the amount of pyridine curing agent KT-100 is 1.5 parts; all other processes are the same as in Example 1.

[0064] The polyurethane synthetic leather prepared in this comparative example has poor surface layer film density because the pyridine curing agent mainly reacts with carboxyl groups and cannot react with hydroxyl and amino groups in water-based oil-wax polyurethane emulsions. As a result, Valspar's abrasion resistance cannot meet the requirement of 200,000 cycles.

[0065] In summary, this invention achieves a dry-process layer by applying an environmentally friendly, solvent-free coating onto a release paper texture and then bonding it to a fabric base. The addition of macromolecular reactive colorant to this solvent-free layer results in a surface layer with good color vibrancy, softness, and abrasion resistance. Using a water-based, abrasion-resistant surface treatment as the top layer, and then curing it using ultraviolet light, a high-performance, skin-feeling, solvent-free polyurethane synthetic leather for sofas and furniture can be obtained.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture, characterized in that, The material comprises, from top to bottom, a water-based skin-feel surface layer, an environmentally friendly solvent-free top layer, and a base fabric layer, wherein: the environmentally friendly solvent-free top layer is prepared from an environmentally friendly solvent-free top layer slurry; by weight, the environmentally friendly solvent-free top layer slurry comprises the following raw materials: 40-60 parts of polyether polycarbonate copolymer oligomer diol, 60-80 parts of polycarbonate copolymer oligomer diol, 45-55 parts of isocyanate, 0.5-2 parts of reactive solvent-free color paste, 0.1-0.2 parts of amine catalyst, 0.03-0.05 parts of metal catalyst, and 0.3-1.2 parts of wetting and leveling agent.

2. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that, The modulus of the polyether polycarbonate copolymer oligomer diol is 60-70 MPa.

3. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that, The modulus of the polycarbonate copolymer oligomer diol is 30-40 MPa.

4. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that, The reactive solvent-free color paste is an NS series solvent-free color paste.

5. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that, The aqueous skin-feel surface treatment layer is prepared from an aqueous skin-feel surface treatment layer slurry; by weight, the aqueous skin-feel surface treatment layer slurry comprises the following raw materials: 100 parts of water-based oil-wax polyurethane emulsion, 0.5-1 part of leveling agent, 1-2 parts of isocyanate curing agent, 0.5-1 part of aziridine curing agent, 1-3 parts of wear-resistant additive, 2-4 parts of photoinitiator, and 0.5-3 parts of water-based color paste.

6. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 5, characterized in that, The water-based oil-wax polyurethane emulsion includes at least one of LXW-1301A and LXW-1144.

7. The water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that, The base fabric layer is a bio-based material base fabric.

8. The method for preparing water-based, solvent-free, skin-feel polyurethane synthetic leather for sofas and furniture as described in any one of claims 1 to 7, characterized in that: Includes the following steps: An environmentally friendly solvent-free surface layer slurry is prepared, which is then coated on the front side of the release paper and preheated to a semi-dry state. The base fabric layer is then laminated, and after drying, a dry layer is formed. A water-based skin-feel surface treatment slurry is prepared, and the water-based skin-feel surface treatment slurry is coated on the surface of the dry layer. After curing and drying with ultraviolet light, a synthetic leather product is obtained.

9. The preparation method according to claim 8, characterized in that: The coating thickness of the environmentally friendly solvent-free topcoat slurry is 0.30-0.40 mm; the preheating temperature is 85-105℃. And / or, the drying temperature is 130-140℃ and the drying time is 4-6 min.

10. The preparation method according to claim 8, characterized in that: The coating amount of the water-based skin-feeling surface treatment slurry is 10-15 g / m². 2 ; And / or, the light intensity parameter of the ultraviolet curing is 150-200 mW / cm². 2 ; And / or, the curing time of the ultraviolet light curing is 3-5 seconds; And / or, the energy of the ultraviolet light curing is 300-600 mJ / cm². 2 .