Skin-friendly wear-resistant durable water-based solvent-free polyurethane synthetic leather for sofa home furnishing and preparation method thereof

Abstract

The invention discloses skin-friendly wear-resistant durable water-based solvent-free polyurethane synthetic leather for sofa home furnishing and a preparation method thereof. The synthetic leather comprises a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite bonding layer and a base cloth layer which are sequentially arranged from top to bottom. According to the water-based surface layer, water-based anionic polycarbonate polyurethane dispersoid and water-based silicon PUD resin are compounded according to a certain proportion, excellent weather resistance and good skin-friendly touch feeling of a silicon product can be obtained, the problem that the water-based silicon PUD resin is bonded with a water-based polyurethane interface after being coated and scraped to form a film is solved through the compounding formula, and the water-based surface layer is formed. The problems of delamination, powder falling and the like of the silicon water-based solvent-free polyurethane synthetic leather are solved, and the durability of the product is further improved. The water-based mechanical foaming middle layer obtained in a mechanical foaming mode has good rebound resilience and fullness after being dried to form a film. The prepared synthetic leather is high in skin-friendly feeling and excellent in wear resistance and durability.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic leather, in particular to a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings and a preparation method thereof. Background Art

[0002] With the increasing awareness of environmental protection and the strict implementation of environmental regulations by the government, the market demand for water-based solvent-free synthetic leather as an environmentally friendly product is expanding. More and more consumers tend to choose environmentally friendly products, and in the sofa home market, water-based solvent-free synthetic leather just meets this demand.

[0003] Traditional water-based solvent-free synthetic leather on the market is prepared by water-based polyurethane surface layer + water-based polyurethane middle layer + solvent-free layer process. There are common problems such as dry touch, insufficient smoothness and roughness, and stiff leather feel. When water-based silicone material is used as the surface layer, although the silicone material has good wear resistance, it is difficult to combine with the water-based middle layer or solvent-free layer due to its own characteristics. As the use time increases, there are hidden dangers such as peeling.

[0004] With the continuous advancement of technology and the introduction of new synthetic leather materials, the quality and performance of water-based solvent-free synthetic leather products have been significantly improved. Therefore, it has become a market demand to prepare a water-based polyurethane synthetic leather for sofas and home furnishings that is skin-friendly, wear-resistant and durable, meeting consumers' needs for environmentally friendly, skin-feeling sofa and home furnishing products and creating economic and social value. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings and a preparation method thereof, so as to solve the problems in the prior art.

[0006] The present invention provides a skin-friendly, wear-resistant and durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, which comprises a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite adhesive layer and a base fabric layer arranged in sequence from top to bottom;

[0007] Among them, the aqueous surface layer is prepared from an aqueous surface layer slurry, and the aqueous surface layer slurry is prepared from the following components in parts by mass: 30-70 parts of aqueous anionic polyurethane resin, 30-70 parts of aqueous silicone PUD resin, 1-4 parts of curing cross-linking agent, 30-60 parts of water, 1-4 parts of wear-resistant additive, 0.3-1 parts of wetting dispersant, 1-2 parts of thickener, and 3-15 parts of pigment paste.

[0008] The water-based anionic polyurethane resin is composed of water-based anionic polycarbonate polyurethane dispersion KTT728K; the water-based silicone PUD resin is composed of dolphin-1088R.

[0009] The water-based anionic polyurethane resin KTT728K is a medium-low modulus water-based resin, has a skin-friendly touch, and can give synthetic leather a soft feel. The water-based silicone PUD resin has excellent wear resistance.

[0010] The water-based mechanical foaming middle layer is prepared from a water-based mechanical foaming middle layer slurry, and the water-based mechanical foaming middle layer slurry is prepared from the following components in parts by mass: 100-150 parts of water-based aliphatic polyurethane resin, 1-3 parts of curing cross-linking agent, 2-6 parts of wear-resistant additive, 50-100 parts of filler, 0.5-1.5 parts of wetting dispersant, 2-4 parts of thickener, and 3-15 parts of pigment paste.

[0011] As a further improvement of the above solution, the water-based aliphatic polyurethane resin is composed of water-based aliphatic polyurethane resin JF-846HY.

[0012] As a further improvement of the above scheme, the solvent-free composite adhesive layer is prepared from a solvent-free composite adhesive layer slurry, and the solvent-free composite adhesive layer slurry is prepared from the following components by mass: 100-140 parts of polyol, 50-70 parts of isocyanate, and 0.4-1.5 parts of thermal stabilizer. A two-component reactive adhesive layer is adopted, and the cross-linking reaction of polyol and isocyanate does not affect the hand feel and has good hydrolysis resistance. No solvent is added in the system, which has the advantage of being environmentally friendly and green.

[0013] As a further improvement of the above solution, the polyol is a polyether polycarbonate copolymer oligomer diol.

[0014] As a further improvement of the above scheme, the base fabric layer is made of renewable polylactic acid fiber, with a thickness of 1.0±0.05mm and a gram weight of 260±30g / cm 2 .

[0015] The present invention provides a method for preparing the aforementioned skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, comprising the following steps:

[0016] S1. Prepare an aqueous surface slurry, then apply the aqueous surface slurry on the front side of the release paper, and dry it to form an aqueous surface layer;

[0017] S2. Prepare a water-based mechanical foaming middle layer slurry, then apply it on the water-based surface layer, and form a water-based mechanical foaming middle layer on the water-based surface layer after drying; the method for preparing the water-based mechanical foaming middle layer slurry is: weigh 100-150 parts of water-based aliphatic polyurethane resin, 1-3 parts of curing cross-linking agent, 2-6 parts of wear-resistant additive, 50-100 parts of filler, 0.5-1.5 parts of wetting dispersant, 2-4 parts of thickener, 3-15 parts of pigment paste, and then mechanically stir it, and set the stirring speed at 4000-6000r / min to obtain a water-based mechanical foaming middle layer slurry.

[0018] S3. Prepare a solvent-free composite adhesive layer slurry, and then apply it on the water-based mechanical foaming intermediate layer to form an environmentally friendly solvent-free composite adhesive layer on the mechanically foaming water-based intermediate layer, preheat the environmentally friendly solvent-free composite adhesive layer until the environmentally friendly solvent-free composite adhesive layer is in a semi-dry state, and adhere to the base fabric layer; after drying, peel off the release paper and roll it to obtain a finished water-based polyurethane synthetic leather product.

[0019] The preparation method of the present invention combines an aqueous anionic polyurethane resin with an aqueous silicone PUD resin to form an aqueous surface layer, and uses the aqueous polyurethane resin as an intermediate layer after mechanical foaming. In the process path, the finished leather after veneer has the excellent skin-friendly touch and durability of the silicone material, and does not need to be treated in the later stage to improve the surface touch and improve the wear resistance and durability, which effectively shortens the process flow and improves the production efficiency; in terms of durability, the problems of easy delamination and skin breakage when the silicone material is used as the surface layer are improved; in terms of the feel of the finished leather, the intermediate layer has a delicate and uniform pore structure, which improves the fullness of the finished leather.

[0020] As a further improvement of the above scheme, in the step S1, the coating thickness of the aqueous surface layer slurry is 0.10-0.13 mm, and the drying is carried out by forced air drying at a temperature of 80-120° C. for 1.5-2 min;

[0021] And / or, in the step S2, the coating thickness of the aqueous mechanically foamed aqueous intermediate layer slurry is 0.15-0.20 mm, and the drying is performed by forced air drying at a temperature of 90-130° C. for 2-3 min.

[0022] As a further improvement of the above scheme, in the step S3, the coating thickness of the environmentally friendly solvent-free composite adhesive layer slurry is 0.20-0.30 mm, and the preheating temperature is 80-95° C.;

[0023] In the step S3, the coating thickness of the environmentally friendly solvent-free composite adhesive layer slurry is 0.20-0.25 mm, and the preheating temperature is 80-90° C.;

[0024] In the step S3, the lamination gap of the bonding base fabric layer is 70-80% of the thickness of the base fabric layer;

[0025] In step S3, the drying temperature is 130-140° C., and the drying time is 4-6 minutes.

[0026] The wear-resistant additives, wetting and dispersing agents, heat stabilizers, pigment pastes, leveling agents, curing and cross-linking agents, thickeners, etc. used in this application are all commonly used additives in the field, and this application does not impose any special restrictions.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The skin-friendly, wear-resistant and durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings provided by the present invention has a water-based surface layer that is compounded with a water-based anionic polycarbonate polyurethane dispersion and a water-based silicone PUD resin in a certain proportion, so that the silicone product can have excellent weather resistance and good skin-friendly touch. The compound formula improves the problem of the interface bonding between the water-based silicone PUD resin and the water-based polyurethane after film coating, solves the problems of delamination and powder loss of the silicone water-based solvent-free polyurethane synthetic leather, and further improves the durability of the product. The principle is: in terms of physical properties, the lattice constant of silicon is smaller than that of other materials, resulting in a low matching degree between silicon and other materials, and defects and stress are easily generated at the interface, which affects its bonding strength with other materials; in terms of chemical properties, the silicon material has a low surface energy, making it difficult to wet and adhere to its surface, and the silicon material has a high degree of chemical inertness, thereby affecting its bonding strength with other materials. When the water-based silicone PUD resin dolphin-1088R is used as the surface layer alone, it has an abnormal bonding problem with the water-based polyurethane in the middle layer. The aqueous anionic polycarbonate polyurethane KTT728K selected by the present invention is a low modulus dispersion, which has good compatibility with the aqueous silicone PUD resin dolphin-1088R in a certain proportion and meets the production and processing requirements; and the aqueous anionic polycarbonate polyurethane dispersion KTT728K has good bonding performance with the aqueous middle layer resin JF-846HY. Adding a certain amount of additives to the surface layer can improve the bonding performance between the surface layer and the middle layer, thereby obtaining a synthetic leather product with excellent comprehensive performance.

[0029] The skin-friendly, wear-resistant and durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings provided by the present invention has an intermediate layer in which fillers and other additives are added to water-based polyurethane resin, and a mechanical foaming method is used as the intermediate layer to form uniform and stable pores under high-speed mechanical stirring, giving the intermediate layer high resilience, and having a good fullness after leather formation, thereby improving the stiffness of the water-based polyurethane synthetic leather and other problems; when configuring the water-based mechanical foaming intermediate layer slurry, the present invention controls the stirring speed to be 4000-6000r / min, which can fully contact and mix the various components in the raw materials on the one hand, thereby ensuring the uniformity and consistency of the foam; on the other hand, it can improve production efficiency and reduce energy consumption and time costs in the production process. The stirring speed has a significant effect on the pore structure. Insufficient stirring may cause the pore structure to be rough, and the pore wall membrane thickening is not easy to break through to form closed cells. Excessive stirring may make the pores too fine or even cause cracking.

[0030] The synthetic leather prepared by the invention has strong skin-friendly feeling, excellent wear resistance and durability, can resist hydrolysis for 7-10 years, has a wear resistance of ≥100,000 times by Valspar, has a friction color fastness of ≥4 levels for dry rubbing (9N*500 times) and ≥3.5 levels for wet rubbing (9N*200 times), has no surface cracking after 100,000 times of bending at room temperature, and has no surface cracking after 25°C*10% NaOH*48H. DETAILED DESCRIPTION

[0031] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0033] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0034] Water-based anionic polyurethane dispersion KTT728K was purchased from Hefei Ketian Water-based Technology Co., Ltd.

[0035] Water-based silicone PUD resin dolphin-1088R was purchased from Silok Company.

[0036] Water-based anionic polyurethane dispersion JF-846HY was purchased from Zhejiang Huafeng Synthetic Resin Co., Ltd.

[0037] The polyol selected was mixture CC 6945 / 5315A (BASF), and the isocyanate was CC 6945 / 100C-B, both of which were products of BASF Polyurethane Specialties (China) Co., Ltd.

[0038] Heat stabilizer Chisorb 234 and heat stabilizer Chisorb 944 were both purchased from Japan Double Bond Chemical Industry Co., Ltd.

[0039] The wear-resistant additive is 3238 purchased from Shanghai Hersbit Chemical Co., Ltd.

[0040] The model of curing crosslinking agent is 166, purchased from Wanhua Chemical Group Co., Ltd.

[0041] The model of the wetting and leveling agent is SY-8009, which was purchased from Mitsukoshi New Materials Co., Ltd.

[0042] It should be noted that the above raw material additives are only examples made to make the technical solution of the present invention clearer, and do not mean that the present invention can only use the above raw material additives. The specific scope is subject to the claims. In addition, the "parts", "number of parts", etc. mentioned in the following embodiments, unless otherwise specified, all refer to mass parts.

[0043] Example 1

[0044] This embodiment proposes a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite adhesive layer and a base fabric layer arranged in sequence from top to bottom, and its preparation method includes the following three steps S1-S3.

[0045] S1. The aqueous surface layer slurry is evenly coated on the front side of the release paper. The coating thickness of the aqueous surface layer slurry is 0.10 mm. After air drying at 90° C. for 3 minutes, an aqueous surface layer is formed.

[0046] The preparation process of the water-based surface slurry is as follows: 70 parts of water-based polyurethane resin KTT728K, 30 parts of water-based silicone PUD resin dolphin-1088R, 6 parts of pigment paste, 1 part of wear-resistant additive 3238, 1 part of curing cross-linking agent 166. Dissolve 0.5 parts of leveling dispersant SY-8009 and 1 part of thickener U-605 in 60 parts of water, stir thoroughly and evacuate to obtain a water-based surface slurry.

[0047] S2. The water-based mechanical foaming middle layer slurry is evenly coated on the water-based surface layer. The coating thickness of the water-based mechanical foaming middle layer slurry is 0.15 mm. After being air-dried at 90° C. for 3 minutes, a water-based mechanical foaming middle layer is formed on the surface layer.

[0048] The preparation process of the water-based mechanical foaming intermediate layer slurry is as follows: 100 parts of water-based polyurethane JF-846HY, 100 parts of inorganic filler calcium carbonate, 10 parts of pigment paste, 2 parts of wear-resistant additive 3238, 1 part of curing crosslinking agent 166. Mix and stir 1 part of leveling dispersant SY-8009 and 2 parts of thickener U-605 at a stirring speed of 5000 r / min for 10 min to obtain a water-based mechanical foaming intermediate layer slurry.

[0049] S3. The solvent-free composite adhesive layer slurry is evenly coated on the water-based mechanical foaming intermediate layer, and the coating thickness of the solvent-free composite adhesive layer slurry is 0.20mm. A solvent-free composite adhesive layer is formed on the water-based mechanical foaming intermediate layer, and the solvent-free composite adhesive layer is preheated at 85°C until the solvent-free composite adhesive layer is semi-dry, and a 1.00mm double-sided velvet base fabric is laminated to form a base fabric layer, and the lamination is 0.70mm. After aging and drying at 140°C for 4 minutes, the release paper is peeled off and rolled to obtain a polyurethane synthetic leather product.

[0050] The preparation process of the solvent-free composite adhesive layer slurry is as follows: 125 parts of polyol CC 6945 / 5315A (BASF), 44 parts of isocyanate CC 6945 / 100C-B, 0.1 parts of heat stabilizer Chisorb 234, and 0.2 parts of heat stabilizer Chisorb 944 are mixed and stirred evenly, and then evacuated to obtain the solvent-free composite adhesive layer slurry.

[0051] The double-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.0±0.05mm and a weight of 260±30g / cm 2 .

[0052] The prepared synthetic leather has a strong skin-friendly feel and excellent wear resistance and durability. It can withstand hydrolysis for 7-10 years, and has a wear resistance of ≥100,000 times by Valspar. The color fastness to friction is: dry rubbing (9N*500 times) ≥4 level, wet rubbing (9N*200 times) ≥3.5 level. The surface does not crack after 100,000 times of bending at room temperature, and the leather surface does not crack after 25℃*10% NaOH*48H.

[0053] Example 2

[0054] This embodiment proposes a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite adhesive layer and a base fabric layer arranged in sequence from top to bottom, and its preparation method includes the following three steps S1-S3.

[0055] S1. The aqueous surface layer slurry is evenly coated on the front side of the release paper. The coating thickness of the aqueous surface layer slurry is 0.10 mm. After air drying at 90° C. for 3 minutes, an aqueous surface layer is formed.

[0056] The preparation process of the water-based surface slurry is as follows: 50 parts of water-based polyurethane resin KTT728K, 50 parts of water-based silicone PUD resin dolphin-1088R, 6 parts of pigment paste, 2 parts of wear-resistant additive 3238, 2 parts of curing cross-linking agent 166. Dissolve 1 part of leveling dispersant SY-8009 and 1 part of thickener U-605 in 60 parts of water, stir thoroughly and evacuate to obtain a water-based surface slurry.

[0057] S2. The water-based mechanical foaming middle layer slurry is evenly coated on the water-based surface layer. The coating thickness of the water-based mechanical foaming middle layer slurry is 0.15 mm. After being air-dried at 90° C. for 3 minutes, a water-based mechanical foaming middle layer is formed on the surface layer.

[0058] The preparation process of the water-based mechanical foaming intermediate layer slurry is as follows: 150 parts of water-based polyurethane JF-846HY, 50 parts of inorganic filler calcium carbonate, 10 parts of pigment paste, 2 parts of wear-resistant additive 3238, 3 parts of curing crosslinking agent 166. Mix and stir 1 part of leveling dispersant SY-8009 and 2 parts of thickener U-605 at a stirring speed of 5000 r / min for 10 min to obtain a water-based mechanical foaming intermediate layer slurry.

[0059] S3. The solvent-free composite adhesive layer slurry is evenly coated on the water-based mechanical foaming intermediate layer, and the coating thickness of the solvent-free composite adhesive layer slurry is 0.20mm. A solvent-free composite adhesive layer is formed on the water-based mechanical foaming intermediate layer, and the solvent-free composite adhesive layer is preheated at 85°C until the solvent-free composite adhesive layer is semi-dry, and a 1.00mm double-sided velvet base fabric is laminated to form a base fabric layer, and the lamination is 0.70mm. After aging and drying at 140°C for 4 minutes, the release paper is peeled off and rolled to obtain a polyurethane synthetic leather product.

[0060] The preparation process of the solvent-free composite adhesive layer slurry is as follows: 125 parts of polyol CC 6945 / 5315A (BASF), 44 parts of isocyanate CC 6945 / 100C-B, 0.1 parts of heat stabilizer Chisorb 234, and 0.2 parts of heat stabilizer Chisorb 944 are mixed and stirred evenly, and then evacuated to obtain the solvent-free composite adhesive layer slurry.

[0061] The double-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.0±0.05mm and a weight of 260±30g / cm 2.

[0062] The prepared synthetic leather has a strong skin-friendly feel and excellent wear resistance and durability. It can withstand hydrolysis for 7-10 years, and has a wear resistance of ≥200,000 times by Valspar. The color fastness to friction is: dry rubbing (9N*500 times) ≥4 level, wet rubbing (9N*200 times) ≥4 level, and the surface does not crack after 200,000 times of bending at room temperature, and the leather surface does not crack after 25℃*10% NaOH*50H.

[0063] Example 3

[0064] This embodiment proposes a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, which includes a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite adhesive layer and a base fabric layer arranged in sequence from top to bottom, and its preparation method includes the following three steps S1-S3.

[0065] S1. The aqueous surface layer slurry is evenly coated on the front side of the release paper. The coating thickness of the aqueous surface layer slurry is 0.13 mm. After air drying at 90° C. for 3 minutes, an aqueous surface layer is formed.

[0066] The preparation process of the water-based surface slurry is as follows: 30 parts of water-based polyurethane resin KTT728K, 70 parts of water-based silicone PUD resin dolphin-1088R, 6 parts of pigment paste, 4 parts of wear-resistant additive 3238, 4 parts of curing cross-linking agent 166. Dissolve 1 part of leveling dispersant SY-8009 and 1 part of thickener U-605 in 30 parts of water, stir thoroughly and evacuate to obtain a water-based surface slurry.

[0067] S2. The water-based mechanical foaming middle layer slurry is evenly coated on the water-based surface layer. The coating thickness of the water-based mechanical foaming middle layer slurry is 0.20 mm. After being air-dried at 90° C. for 3 minutes, a water-based mechanical foaming middle layer is formed on the surface layer.

[0068] The preparation process of the water-based mechanical foaming intermediate layer slurry is as follows: 150 parts of water-based polyurethane JF-846HY, 50 parts of inorganic filler calcium carbonate, 10 parts of pigment paste, 6 parts of wear-resistant additive 3238, 3 parts of curing cross-linking agent 166. Mix and stir 1 part of leveling dispersant SY-8009 and 2 parts of thickener U-605 at a stirring speed of 5000 r / min for 10 min to obtain a water-based mechanical foaming intermediate layer slurry.

[0069] S3. The solvent-free composite adhesive layer slurry is evenly coated on the water-based mechanical foaming intermediate layer, and the coating thickness of the solvent-free composite adhesive layer slurry is 0.25mm. A solvent-free composite adhesive layer is formed on the water-based mechanical foaming intermediate layer. The solvent-free composite adhesive layer is preheated at 85°C until the solvent-free composite adhesive layer is semi-dry, and a 1.00mm double-sided velvet base fabric is laminated to form a base fabric layer, and the lamination is 0.80mm. After aging and drying at 140°C for 4 minutes, the release paper is peeled off and rolled to obtain a polyurethane synthetic leather product.

[0070] The preparation process of the solvent-free composite adhesive layer slurry is as follows: 125 parts of polyol CC 6945 / 5315A (BASF), 44 parts of isocyanate CC 6945 / 100C-B, 0.1 parts of heat stabilizer Chisorb 234, and 0.2 parts of heat stabilizer Chisorb 944 are mixed and stirred evenly, and then evacuated to obtain the solvent-free composite adhesive layer slurry.

[0071] The double-sided fleece base fabric is made of renewable polylactic acid fiber, with a thickness of 1.0±0.05mm and a weight of 260±30g / cm 2 .

[0072] The prepared synthetic leather has a strong skin-friendly feel and excellent wear resistance and durability. It can withstand hydrolysis for 7-10 years, and has a wear resistance of ≥400,000 times by Valspar. The color fastness to friction is: dry rubbing (9N*500 times) ≥4 level, wet rubbing (9N*200 times) ≥4 level, and the surface does not crack after 200,000 times of bending at room temperature, and the leather surface does not crack after 25℃*10% NaOH*72H.

[0073] Comparative Example 1

[0074] This comparative example provides a polyurethane synthetic leather, and its preparation method is the same as that of Example 1, and the only difference from Example 1 is that in this comparative example, the water-based silicone PUD resin dolphin-1088R is replaced by a water-based polyurethane resin DLC-F (Covestro). For specific preparation steps, refer to the corresponding content in Example 1 above.

[0075] Product performance of Comparative Example 1: The synthetic leather is not very skin-friendly, and is resistant to hydrolysis for 5 years, with a wear resistance of ≤100,000 times by Valspar, and color fastness to friction: dry rubbing (9N*500 times) ≥3 levels, wet rubbing (9N*200 times) ≥2 levels.

[0076] Comparative Example 2

[0077] This comparative example provides a polyurethane synthetic leather, and its preparation method is the same as that of Example 2, and the only difference from Example 2 is that in step S2 of this comparative example, the aqueous mechanical foaming process of the intermediate layer is replaced by a common aqueous preparation process, and the specific process of step S2 is as follows:

[0078] S2. 150 parts of waterborne polyurethane JF-846HY, 50 parts of inorganic filler calcium carbonate, 10 parts of pigment paste, 2 parts of wear-resistant additive 3238, 3 parts of curing crosslinking agent 166. Mix 1 part of leveling dispersant SY-8009 and 2 parts of thickener U-605 thoroughly and evacuate to obtain a water-based intermediate layer slurry.

[0079] For other preparation steps, see the corresponding contents in Example 2 above.

[0080] The polyurethane synthetic leather prepared in this comparative example has a stiff hand feel and a strong plastic feel. It can withstand hydrolysis for 7-10 years, and has a wear resistance of ≤200,000 times by Valspar. Its color fastness to friction is: dry rubbing (9N*500 times) ≥4, wet rubbing (9N*200 times) ≥4, and its surface cracks after 200,000 times of bending at room temperature, and cracks after 25℃*10%NaOH*50H.

[0081] Comparative Example 3

[0082] This comparative example provides a polyurethane synthetic leather, and its preparation method is the same as that of Example 3, and the difference from Example 3 is that in this comparative example, the waterborne polyurethane resin KTT728K is replaced by the waterborne polyurethane resin Leasys 3215 (Wanhua Chemical (Yantai) Sales Co., Ltd.). For specific preparation steps, refer to the corresponding content in Example 3 above.

[0083] The synthetic leather prepared in this comparative example only meets the requirements of hydrolysis resistance for 4 years, Valspar abrasion resistance ≤ 100,000 times, surface cracking after 200,000 flexures at room temperature, and leather surface cracking at 25°C*10%NaOH*48H.

[0084] Comparative Example 4

[0085] This comparative example provides a polyurethane synthetic leather, and its preparation method is the same as that of Example 1, and the only difference from Example 1 is that in step S1 of this comparative example, the addition amount of KTT728K resin is increased to 90 parts, and the addition amount of water-based silicone PUD resin dolphin-1088R is reduced to 10 parts. For the specific preparation steps, please refer to the corresponding content in Example 1 above.

[0086] The synthetic leather prepared in this comparative example has a weak skin-friendly feel, and is resistant to hydrolysis for 7-10 years, has a wear resistance of ≥100,000 times by Valspar, and has a friction color fastness of: dry rubbing (9N*500 times) ≥4 level, wet rubbing (9N*200 times) ≥2.5 level, and does not crack on the surface after 100,000 times of bending at room temperature, and does not crack on the leather surface after 25℃*10% NaOH*48H.

[0087] Comparative Example 5

[0088] This comparative example provides a polyurethane synthetic leather, and its preparation method is the same as that of Example 1. The only difference from Example 1 is that in step S1 of this comparative example, the addition amount of KTT728K resin is reduced to 10 parts, and the addition amount of water-based silicone PUD resin dolphin-1088R is increased to 90 parts. For the specific preparation steps, please refer to the corresponding content in Example 1 above.

[0089] The synthetic leather prepared in this comparative example has a strong skin-friendly feel, is resistant to hydrolysis for 5 years, has a wear resistance of ≤100,000 times by Valspar, and has a friction color fastness of: dry rubbing (9N*500 times) ≥4 level, wet rubbing (9N*200 times) ≥3.5 level. The surface cracks after 100,000 times of bending at room temperature, and the leather surface cracks after 25℃*10%NaOH*48H.

[0090] In summary, it can be seen that the present invention can obtain water-based solvent-free polyurethane synthetic leather for sofas and home furnishings with excellent comprehensive performance, skin-friendly wear resistance and durability by adopting a water-based surface resin with good wear resistance and skin-friendly touch, an intermediate layer of a water-based mechanical foaming process and a solvent-free composite adhesive layer with a soft feel.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0092] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings, characterized by: It includes a water-based surface layer, a water-based mechanical foaming middle layer, a solvent-free composite adhesive layer and a base fabric layer arranged in sequence from top to bottom; The aqueous surface layer is prepared from an aqueous surface layer slurry, and the aqueous surface layer slurry is prepared from the following components in parts by mass: 30-70 parts of aqueous anionic polyurethane resin, 30-70 parts of aqueous silicone PUD resin, 1-4 parts of curing cross-linking agent, 30-60 parts of water, 1-4 parts of wear-resistant additive, 0.3-1 parts of wetting dispersant, 1-2 parts of thickener, and 3-15 parts of pigment paste.

2. The skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings according to claim 1, characterized in that: The water-based anionic polyurethane resin is water-based anionic polycarbonate polyurethane dispersion KTT728K; the water-based silicone PUD resin is dolphin-1088R.

3. The skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and furniture according to claim 1, characterized in that: The water-based mechanical foaming middle layer is prepared from a water-based mechanical foaming middle layer slurry, and the water-based mechanical foaming middle layer slurry is prepared from the following components in parts by mass: 100-150 parts of water-based aliphatic polyurethane resin, 1-3 parts of curing cross-linking agent, 2-6 parts of wear-resistant additive, 50-100 parts of filler, 0.5-1.5 parts of wetting dispersant, 2-4 parts of thickener, and 3-15 parts of pigment paste.

4. The skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings according to claim 3, characterized in that: The aqueous anionic polyurethane resin is aqueous anionic polyurethane resin JF-846HY.

5. The skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings according to claim 1, characterized in that: The solvent-free composite adhesive layer is prepared from a solvent-free composite adhesive layer slurry, and the solvent-free composite adhesive layer slurry is prepared from the following components in parts by mass: 100-140 parts of polyol, 50-70 parts of isocyanate, and 0.4-1.5 parts of heat stabilizer.

6. The skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings according to claim 5, characterized in that: The polyol is a polyether polycarbonate copolymer oligomer diol.

7. A method for preparing a skin-friendly, wear-resistant, durable water-based solvent-free polyurethane synthetic leather for sofas and home furnishings as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Prepare an aqueous surface slurry, then apply the aqueous surface slurry on the front side of the release paper, and dry it to form an aqueous surface layer; S2. Prepare an aqueous mechanical foaming intermediate layer slurry, and then apply it on the aqueous surface layer, and after drying, form an aqueous mechanical foaming intermediate layer on the aqueous surface layer; S3. Prepare a solvent-free composite adhesive layer slurry, then apply it on the aqueous mechanical foaming intermediate layer, preheat it to a semi-dry state and then adhere it to the base fabric layer; after drying, peel off the release paper and roll it to obtain the final product.

8. The preparation method according to claim 7, characterized in that: The method for preparing the water-based mechanical foaming middle layer slurry is as follows: weighing 100-150 parts of water-based aliphatic polyurethane resin, 1-3 parts of curing cross-linking agent, 2-6 parts of wear-resistant additive, 50-100 parts of filler, 0.5-1.5 parts of wetting dispersant, 2-4 parts of thickener, 3-15 parts of pigment paste, and then mechanically stirring the same at a stirring speed of 4000-6000 r / min to obtain the water-based mechanical foaming middle layer slurry.

9. The preparation method according to claim 7, characterized in that: The coating thickness of the water-based surface layer slurry is 0.10-0.13 mm; the coating thickness of the water-based mechanically foamed intermediate layer slurry is 0.15-0.20 mm; and the coating thickness of the solvent-free composite adhesive layer slurry is 0.20-0.25 mm.

10. The preparation method according to claim 7, characterized in that: In step S3, the preheating temperature is 80-90°C.