A polyurethane resin, a polyurethane synthetic leather, and a preparation method and application thereof

Abstract

This invention belongs to the field of polyurethane resin technology, and provides a polyurethane resin, polyurethane synthetic leather, its preparation method, and applications. The raw materials for preparing the polyurethane resin, by mass fraction, include the following components: 11%-18% modified polyol, 3%-9% bio-based polyol A, 0.01%-0.02% antioxidant, 0.001%-0.003% catalyst, 5%-7% isocyanate, 0.5%-3% chain extender, 0.1%-0.4% terminator, 0.02%-0.04% anti-tack aid, 0.5%-3% polyether aid, and 68%-73% solvent. The raw materials for preparing the modified polyol include bio-based polyol, alkanolamine, and diacid; the bio-based polyol A includes bio-based polypropylene carbonate diol. The polyurethane synthetic leather prepared by this invention has good anti-slip properties, excellent color fastness to perspiration, and high blackness, making it suitable for yoga mats.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane resin technology, and particularly relates to a polyurethane resin, polyurethane synthetic leather, its preparation method and application. Background Technology

[0002] With the continuous improvement of people's living standards and health awareness, yoga has become a popular fitness method. This trend has led to a continuous increase in market demand for yoga mats, a core piece of equipment. At the same time, users are placing higher and more detailed demands on their overall performance. Early yoga mats only needed to provide basic cushioning and isolation functions, but today, the absorbency, resilience, anti-slip properties, and durability of yoga mats are increasingly becoming key factors influencing user experience and purchasing decisions.

[0003] Existing yoga mat materials include polyurethane, PVC, natural rubber, and TPE, with the main focus on properties such as abrasion and scratch resistance, interlayer delamination, antibacterial properties, and self-healing capabilities. CN115814328B discloses a wear-resistant and scratch-resistant yoga mat and its preparation method, comprising: coating a wear-resistant layer slurry onto a first mesh fabric, and after plasticization, obtaining a mesh-structured wear-resistant layer (the wear-resistant blocks are prepared from PVC resin powder, plasticizer, stabilizer, and filler). A foaming layer slurry is coated onto a second mesh fabric, and after curing and shaping, a preliminary blank layer is obtained. The wear-resistant layer is then laminated onto the preliminary blank layer, and after foaming, a wear-resistant and scratch-resistant yoga mat is obtained. This preparation method, by first preparing a mesh-structured wear-resistant layer and an unfoamed preliminary blank layer, then laminating the two together, and finally foaming, yields a yoga mat with good wear resistance, scratch resistance, and resilience. Furthermore, during the foaming process, the wear-resistant blocks in the wear-resistant layer can be partially embedded within it, thus eliminating the need for other adhesives for a stable bond. The preparation method of this invention is simple in steps and has low equipment requirements. It can be achieved using existing yoga mat production equipment, thus making it easy to promote and apply.

[0004] CN120347997A discloses a processing technology for a double-sided rubber yoga mat, comprising: preparing A-side natural rubber rolls and B-side natural rubber rolls respectively; plasticizing the natural rubber raw material at a temperature of 60-90℃ for 10-30 minutes; adding color masterbatch to the plasticized natural rubber for mixing, with different colors of color masterbatch used for A-side and B-side, the amount of color masterbatch added being 1-5% of the total weight of the rubber; feeding the mixed rubber compound and fine cloth simultaneously into a foaming furnace through a continuous lamination device, foaming and molding at 160-200℃ to form a roll of rubber layer with a porous surface composite with fine cloth; and continuously laminating the A-side roll and the B-side roll using hot press rollers at a hot pressing temperature of 120-150℃. This invention solves the problems of single function on both sides of traditional yoga mats, low efficiency of the lamination process, and risk of interlayer delamination.

[0005] CN119019836A discloses a wear-resistant and antibacterial TPE composite material and its application in yoga mats. This invention uses maleic acid, thionyl chloride, citronellol, furanylamine, and acidified carbon nanotubes as raw materials. Through acyl chloride reaction, esterification reaction, Diels-Alder reaction, and amidation reaction, citronellol-based carbon nanotubes are obtained. These nanotubes are then melt-blended with thermoplastic polyurethane elastomer, granulated, and injection molded to obtain the wear-resistant and antibacterial TPE composite material. The thermoplastic polyurethane elastomer prepared by this invention has been proven to have excellent antibacterial properties, wear resistance, and self-healing properties. The wear-resistant and antibacterial TPE composite material prepared by this invention has significant application value in yoga mats.

[0006] However, existing yoga mats have certain drawbacks. Their anti-slip properties are not good enough, and when made pure black, they tend to exhibit "white, red, or yellowish tinges," meaning the blackness is insufficient. Furthermore, yoga mats are prone to fading after repeated contact with sweat and friction. Compared to traditional PVC, TPE, and rubber materials, polyurethane has a porous, open structure. Through certain physical or chemical modifications, it can acquire anti-slip properties, making it particularly suitable for manufacturing yoga mats.

[0007] Therefore, developing a polyurethane synthetic leather with good anti-slip properties, excellent color fastness, and blackness is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a polyurethane resin, polyurethane synthetic leather, its preparation method, and its application. The polyurethane synthetic leather prepared by the present invention through the compounding of modified polyol, bio-based polyol A, and other substances has good anti-slip properties, excellent color fastness to perspiration, and high blackness, making it suitable for yoga mats.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a polyurethane resin, wherein the raw materials for preparing the polyurethane resin comprise the following components by mass fraction:

[0011] Modified polyols 11%-18%

[0012] Bio-based polyol A 3%-9%

[0013] Antioxidant 0.01%-0.02%

[0014] Catalyst 0.001%-0.003%

[0015] Isocyanates 5%-7%

[0016] Chain extender 0.5%-3%

[0017] Terminator 0.1%-0.4%

[0018] Anti-tack and anti-blocking agent: 0.02%-0.04%

[0019] Polyether additives 0.5%-3%

[0020] Solvent 68%-73%

[0021] The raw materials for preparing the modified polyol include bio-based polyols, alkanolamines, and diacids;

[0022] The bio-based polyol A includes bio-based polypropylene carbonate diol.

[0023] In this invention, both the modified polyol and the bio-based polyol A have good dyeing properties and sweat resistance. The terminator, due to its special structure, can significantly improve color fastness and sweat resistance. By compounding the modified polyol, the bio-based polyol A and other components, the polyurethane synthetic leather prepared in this invention has good anti-slip properties, excellent sweat fastness and high blackness.

[0024] The amount of the modified polyol can be 11%, 12%, 13%, 14%, 15%, 16%, 17%, or 18%, etc.

[0025] The amount of the bio-based polyol A can be 3%, 4%, 5%, 6%, 7%, 8%, or 9%, etc.

[0026] The amount of the antioxidant can be 0.01%, 0.015%, or 0.02%, etc.

[0027] The amount of catalyst used can be 0.001%, 0.002%, or 0.003%, etc.

[0028] The amount of isocyanate used can be 5%, 5.5%, 6%, 6.5%, or 7%, etc.

[0029] The amount of the chain extender can be 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, etc.

[0030] The amount of the terminator can be 0.1%, 0.2%, 0.3%, or 0.4%, etc.

[0031] The amount of the anti-tack and anti-blocking agent can be 0.02%, 0.025%, 0.03%, 0.035%, or 0.04%, etc.

[0032] The amount of the polyether additive can be 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, etc.

[0033] The amount of solvent used can be 68%, 69%, 70%, 71%, 72%, or 73%, etc.

[0034] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0035] Preferably, the alcoholamine includes monoethanolamine.

[0036] In this invention, monoethanolamine is selected to prepare bio-based polyols, which contain amino structures, thus giving polyurethane resins better dyeability and color fastness to perspiration. At the same time, monoethanolamine has high polarity, which enhances the crystallization properties of polyurethane resins. Furthermore, due to its high polarity, the van der Waals forces between it and the oxygen-containing functional groups on the carbon black surface in polyurethane synthetic leather are stronger, which can increase the blackness of polyurethane synthetic leather.

[0037] Preferably, the dicarboxylic acid includes adipic acid.

[0038] Preferably, the weight-average molecular weight of the bio-based polyol is 1500-2500, such as 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400 or 2500.

[0039] Preferably, the raw materials for preparing the bio-based polyol include bio-based dicarboxylic acid and bio-based diol.

[0040] Preferably, the bio-based dicarboxylic acid includes bio-based sebacic acid and / or bio-based succinic acid.

[0041] Preferably, the bio-based diol includes bio-based 1,3-propanediol and / or bio-based 1,4-butanediol.

[0042] Preferably, the molar ratio of the bio-based polyol, alkanolamine and diacid is 1:(0.06-0.1):(1.02-1.04).

[0043] Among them, 0.06-0.1 can be 0.06, 0.07, 0.08, 0.09 or 0.1, etc.

[0044] 1.02-1.04 can be 1.02, 1.03, or 1.04, etc.

[0045] Preferably, the bio-based polyol includes any one or a combination of at least two of Asahikawa Chemical XCP-B2000-J, Asahikawa Chemical XCP-B2000-S, Asahikawa Chemical XCP-B2000-JS, or Asahikawa Chemical XCP-B2000-BS.

[0046] Preferably, the terminating agent comprises tannic acid.

[0047] In this invention, the hydroxyl groups in tannic acid can combine with the oxygen-containing functional groups on the surface of carbon black in polyurethane synthetic leather to form hydrogen bonds, thereby enhancing the dyeing performance of polyurethane synthetic leather; tannic acid contains a large number of benzene ring structures, which helps to improve the color fastness of polyurethane synthetic leather to perspiration.

[0048] Preferably, the weight-average molecular weight of the modified polyol is 3000-5000, such as 3000, 3200, 3400, 3600, 3800, 4000, 4200, 4400, 4600, 4800 or 5000.

[0049] Preferably, the weight-average molecular weight of the bio-based polyol A is 1500-2500, such as 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400 or 2500.

[0050] Preferably, the solid content of the polyurethane resin is 29wt%-31wt%, such as 29wt%, 29.5wt%, 30wt%, 30.5wt%, or 31wt%.

[0051] Preferably, the viscosity of the polyurethane resin at 25°C is 220,000-280,000 cps, such as 220,000 cps, 225,000 cps, 230,000 cps, 235,000 cps, 240,000 cps, 245,000 cps, 250,000 cps, 255,000 cps, 260,000 cps, 265,000 cps, 270,000 cps, 275,000 cps, or 280,000 cps.

[0052] Preferably, the antioxidant comprises any one or a combination of at least two of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), 4,4'-thiobis(6-tert-butyl-3-methylphenol) (antioxidant 300), 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine (antioxidant 1024), N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide] (antioxidant 1098), or tris(2,4-di-tert-butylphenyl) phosphite (antioxidant B215).

[0053] Preferably, the catalyst comprises phosphoric acid.

[0054] Preferably, the isocyanate comprises 4,4-diphenylmethane diisocyanate.

[0055] Preferably, the chain extender comprises any one or a combination of at least two of ethylene glycol, 1,4-butanediol or neopentyl glycol.

[0056] Preferably, the anti-tack and anti-blocking agent includes malic acid.

[0057] Preferably, the solvent includes N,N-dimethylformamide.

[0058] Preferably, the method for preparing the modified polyol includes the following steps:

[0059] Bio-based polyols, alkanolamines, and diacids react under the action of catalyst A to obtain the modified polyol.

[0060] Preferably, the catalyst A comprises tetraisopropyl titanate and / or tetraisobutyl titanate.

[0061] Preferably, the preparation method of the modified polyol specifically includes the following steps:

[0062] (1) Add bio-based polyols, alkanolamines and dicarboxylic acids into a reaction flask, purge with nitrogen, heat to 140-170℃, keep at the temperature for 4-8 hours, continue heating to 210-230℃, keep at the temperature for 2-5 hours;

[0063] (2) Set the vacuum level to -0.05MPa and evacuate for 3-5 hours; set the vacuum level to -0.08MPa and evacuate for 6-8 hours.

[0064] (3) When the acid value of the system is between 20-30 mg KOH / g, catalyst A is added and the reaction is carried out at 210-230℃;

[0065] (4) Take samples every 1-1.2 hours. When the acid value is less than 0.5 mg KOH / g and the hydroxyl value is between 26-29 mg KOH / g, cool down and filter to obtain the modified polyol.

[0066] Preferably, based on the total amount of raw materials for preparing the modified polyol being 100%, the amount of catalyst A added is 40-70 ppm, such as 40 ppm, 50 ppm, 60 ppm, or 70 ppm.

[0067] Preferably, the flow rate of the nitrogen gas is 0.2-0.5 L / min, such as 0.2 L / min, 0.3 L / min, 0.4 L / min or 0.5 L / min.

[0068] Preferably, the 140-170℃ can be 140℃, 142℃, 144℃, 146℃, 148℃, 150℃, 152℃, 154℃, 156℃, 158℃, 160℃, 162℃, 164℃, 166℃, 168℃, or 170℃, etc.

[0069] Preferably, the 4-8h can be 4h, 5h, 6h, 7h, or 8h, etc.

[0070] Preferably, the 210-230℃ can be 210℃, 212℃, 214℃, 216℃, 218℃, 220℃, 222℃, 224℃, 226℃, 228℃ or 230℃, etc.

[0071] Preferably, the 2-5h can be 2h, 3h, 4h or 5h, etc.

[0072] Preferably, the 3-5h can be 3h, 3.5h, 4h, 4.5h or 5h, etc.

[0073] Preferably, the 6-8h can be 6h, 6.5h, 7h, 7.5h or 8h, etc.

[0074] Preferably, the acid value is 20-30 mg KOH / g, such as 20 mg KOH / g, 22 mg KOH / g, 24 mg KOH / g, 26 mg KOH / g, 28 mg KOH / g, or 30 mg KOH / g.

[0075] Preferably, the 1-1.2h can be 1h, 1.1h, or 1.2h, etc.

[0076] Preferably, the acid value is less than 0.5 mg KOH / g, such as 0.1 mg KOH / g, 0.2 mg KOH / g, 0.3 mg KOH / g, 0.4 mg KOH / g, or 0.5 mg KOH / g.

[0077] Preferably, the hydroxyl value is between 26 and 29 mg KOH / g, such as 26 mg KOH / g, 27 mg KOH / g, 28 mg KOH / g, or 29 mg KOH / g.

[0078] In a second aspect, the present invention provides a method for preparing a polyurethane resin as described in the first aspect, the method comprising the following steps:

[0079] (1) Mix the modified polyol, bio-based polyol, antioxidant, catalyst and isocyanate, and react;

[0080] (2) Add some solvent and chain extender, and continue the reaction;

[0081] (3) Add the remaining solvent for dilution during the process;

[0082] (4) Add a terminator, an anti-tack agent and a polyether agent to obtain the polyurethane resin.

[0083] Preferably, in step (1), the reaction time is 1-2 hours, such as 1 hour, 1.5 hours or 2 hours.

[0084] Preferably, in steps (1)-(3), the temperature of each reaction is independently 75-85℃, such as 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃ or 85℃.

[0085] Thirdly, the present invention provides a polyurethane synthetic leather, wherein the polyurethane synthetic leather comprises the polyurethane resin described in the first aspect.

[0086] Preferably, the raw materials for preparing the polyurethane synthetic leather include the following components by weight:

[0087] 100 parts of polyurethane resin

[0088] 15-20 parts of lignocellulose

[0089] 75-90 parts of N,N-dimethylformamide

[0090] 2-4 parts water

[0091] 3-7 parts colorant;

[0092] Preferably, the color paste includes a black color paste.

[0093] The amount of lignocellulose used can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts, etc.

[0094] The amount of N,N-dimethylformamide used can be 75 parts, 80 parts, 85 parts, or 90 parts, etc.

[0095] The amount of water used can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, or 4 parts, etc.

[0096] The amount of pigment used can be 3 parts, 4 parts, 5 parts, 6 parts, or 7 parts, etc.

[0097] The polyurethane synthetic leather in this invention is suitable for yoga mats.

[0098] Fourthly, the present invention provides a method for preparing polyurethane synthetic leather as described in the third aspect, the method comprising the following steps:

[0099] (1) Mix polyurethane resin, lignocellulose, N,N-dimethylformamide, water and color paste to obtain a mixed solution;

[0100] (2) The mixed solution is coated onto the substrate, solidified, and dried to obtain the polyurethane synthetic leather.

[0101] Preferably, the substrate comprises needle-punched nonwoven fabric.

[0102] Preferably, the thickness of the substrate is 3-4 mm, such as 3 mm, 3.5 mm or 4 mm.

[0103] Preferably, the coating thickness is 2-3 mm, such as 2 mm, 2.5 mm or 3 mm.

[0104] Preferably, the coating process further includes a settling period.

[0105] Preferably, the settling time is 20-30 seconds, such as 20 seconds, 22 seconds, 24 seconds, 26 seconds, 28 seconds, or 30 seconds.

[0106] Preferably, the solidification includes placing the substrate coated with the mixed solution into the mixed solvent.

[0107] Preferably, the mixed solvent comprises an aqueous solution of N,N-dimethylformamide.

[0108] Preferably, the mass percentage of N,N-dimethylformamide is 17%-23% based on the mass of the mixed solvent as 100%, for example, 17%, 18%, 19%, 20%, 21%, 22% or 23%.

[0109] Preferably, the solidification time is 15-20 minutes, such as 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, or 20 minutes.

[0110] Preferably, the solidification process further includes water washing.

[0111] Preferably, the drying temperature is 110-120℃, such as 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃, 119℃ or 120℃.

[0112] Preferably, the drying time is 20-30 minutes, such as 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes, or 30 minutes.

[0113] The preparation method specifically includes the following steps:

[0114] (1) Mix polyurethane resin, lignocellulose, N,N-dimethylformamide, water and color paste, centrifuge and degas to obtain a mixed solution;

[0115] (2) Coat the mixed solution onto the needle-punched nonwoven fabric and let it stand for 20-30 seconds;

[0116] (3) Place the needle-punched nonwoven fabric coated with the mixed solution into an aqueous solution of N,N-dimethylformamide and let it solidify for 15-20 minutes;

[0117] (4) Wash with water using extrusion rollers and dry at 110-120℃ for 20-30 minutes to obtain the polyurethane synthetic leather.

[0118] Compared with the prior art, the present invention has the following beneficial effects:

[0119] The polyurethane synthetic leather prepared by this invention through the compounding of modified polyol, bio-based polyol A and other substances has good anti-slip effect, with an anti-slip grade of 1, good dyeing effect, with high blackness, preferably grade 5, and excellent color fastness to perspiration, preferably grade 4-5. Detailed Implementation

[0120] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0121] The information sources for some raw materials in the preparation examples and embodiments of this invention are as follows:

[0122] Bio-based polyol I: Asahikawa Chemical XCP-B2000-J;

[0123] Bio-based polyols II: Asahikawa Chemical XCP-B2000-S;

[0124] Bio-based polyols III: Asahikawa Chemical XCP-B2000-JS;

[0125] Bio-based polyols IV: Asahikawa Chemical XCP-B2000-BS;

[0126] Bio-based polyol A: Shanghai Shuyu Chemical Co., Ltd. SYPC2000;

[0127] Polyether additive A: Ningbo Guodu Chemical KP-3351G;

[0128] Polyether additive B: Ningbo Guodu Chemical GY-5100;

[0129] Black paste: Jiangxi Sanyue New Materials PW-987E;

[0130] Lignocellulose: Lingshou County Zhihao Mineral Products Processing Plant, product name: wood flour, specification: 40 mesh;

[0131] PBA-4000: Asahikawa Chemical XCPP-40003;

[0132] PBA-2000: Asahikawa Chemical XCPP-20003.

[0133] Preparation Example 1

[0134] The preparation method of the modified polyol specifically includes the following steps:

[0135] (1) 2000 parts of bio-based polyol I, 4.275 parts of monoethanolamine and 149.1 parts of adipic acid were put into a reaction flask, nitrogen gas was bubbled in at a flow rate of 0.2 L / min, heated to 140℃ and kept at the temperature for 8 hours, and then heated to 210℃ and kept at the temperature for 5 hours.

[0136] (2) Set the vacuum level to -0.05MPa and evacuate for 5 hours; set the vacuum level to -0.08MPa and evacuate for 8 hours.

[0137] (3) When the acid value of the system is 25 mg KOH / g, add 0.14 parts of tetraisopropyl titanate and react at 210℃ and -0.08 MPa.

[0138] (4) Take samples every 1 hour. When the acid value is 0.48 mg KOH / g and the hydroxyl value is 27 mg KOH / g, cool down and filter to obtain modified polyol A.

[0139] Preparation Example 2

[0140] The preparation method of the modified polyol specifically includes the following steps:

[0141] (1) 2000 parts of bio-based polyol II, 4.89 parts of monoethanolamine and 150.5 parts of adipic acid were put into a reaction flask, nitrogen gas was bubbled in at a flow rate of 0.3 L / min, heated to 150°C and kept at a constant temperature for 7 h, and then heated to 220°C and kept at a constant temperature for 4 h.

[0142] (2) Set the vacuum level to -0.05MPa and evacuate for 4 hours; set the vacuum level to -0.08MPa and evacuate for 7 hours.

[0143] (3) When the acid value of the system is 28 mg KOH / g, add 0.129 parts of tetraisobutyl titanate and react at 220℃ and -0.08 MPa.

[0144] (4) Take a sample every 1 hour. When the acid value is 0.4 mg KOH / g and the hydroxyl value is 27 mg KOH / g, cool down and filter to obtain modified polyol B.

[0145] Preparation Example 3

[0146] The preparation method of the modified polyol specifically includes the following steps:

[0147] (1) 2000 parts of bio-based polyol III, 5.19 parts of monoethanolamine and 150.8 parts of adipic acid were put into a reaction flask, nitrogen gas was bubbled in at a flow rate of 0.35 L / min, heated to 160°C and kept at a constant temperature for 6 h, and then heated to 225°C and kept at a constant temperature for 3 h.

[0148] (2) Set the vacuum level to -0.05MPa and evacuate for 3.5h; set the vacuum level to -0.08MPa and evacuate for 6.5h.

[0149] (3) When the acid value of the system is 23 mg KOH / g, add 0.107 parts of tetraisobutyl titanate and react at 225℃ and -0.08 MPa.

[0150] (4) Take samples every 1 hour. When the acid value is 0.35 mg KOH / g and the hydroxyl value is 27.5 mg KOH / g, cool down and filter to obtain modified polyol C.

[0151] Preparation Example 4

[0152] The preparation method of the modified polyol specifically includes the following steps:

[0153] (1) 2000 parts of bio-based polyol IV, 5.49 parts of monoethanolamine and 151.2 parts of adipic acid were put into a reaction flask, nitrogen gas was bubbled in at a flow rate of 0.4 L / min, heated to 170°C and kept at a constant temperature for 5 h, and then heated to 230°C and kept at a constant temperature for 2 h.

[0154] (2) Set the vacuum level to -0.05MPa and evacuate for 3 hours; set the vacuum level to -0.08MPa and evacuate for 6 hours.

[0155] (3) When the acid value of the system is 27 mg KOH / g, add 0.097 parts of tetraisopropyl titanate and react at 230℃ and -0.08 MPa.

[0156] (4) Take samples every 1 hour. When the acid value is 0.3 mg KOH / g and the hydroxyl value is 27.7 mg KOH / g, cool down and filter to obtain modified polyol D.

[0157] Preparation Example 5

[0158] The only difference from Preparation Example 1 is that monoethanolamine is replaced with an equimolar amount of ethylene glycol, while the other components and preparation methods are the same as in Preparation Example 1, resulting in modified polyol E.

[0159] Example 1

[0160] This embodiment provides a polyurethane resin, polyurethane synthetic leather, and a method for preparing the same. The raw materials for preparing the polyurethane resin include the following components by weight:

[0161] 150 parts of modified polyol A;

[0162] 38 parts of bio-based polyol A;

[0163] Antioxidant 10100.1 parts;

[0164] 0.02 parts of phosphoric acid;

[0165] 56.8 servings of MDI;

[0166] 10.6 parts of ethylene glycol;

[0167] 1 part tannin;

[0168] 0.3 parts malic acid;

[0169] 9 parts of polyether additive A;

[0170] DMF 620.3 copies;

[0171] The method for preparing the polyurethane resin includes the following steps:

[0172] (1) Add modified polyol A, bio-based polyol A, antioxidant 1010 and phosphoric acid into a reaction flask, stir evenly, add MDI, and react at 75℃ for 1h.

[0173] (2) Add 260 parts of DMF to dilute, then add ethylene glycol and continue the reaction;

[0174] (3) Add 360.3 parts DMF for dilution;

[0175] (4) Add tannic acid to terminate the reaction, add malic acid and polyether additive A, control the viscosity of polyurethane resin at 25°C to be 250,000 cps and the solid content to be 30 wt%, cool to obtain polyurethane resin A.

[0176] The raw materials for preparing the polyurethane synthetic leather include the following components by weight:

[0177] 100 parts of polyurethane resin A;

[0178] 15 parts of lignocellulose;

[0179] 75 copies of DMF;

[0180] 4 parts water;

[0181] Five parts black paste;

[0182] The preparation method of the polyurethane synthetic leather specifically includes the following steps:

[0183] (1) Mix polyurethane resin A, lignocellulose, DMF, water and black paste evenly, centrifuge to remove bubbles, and obtain a mixed solution;

[0184] (2) Coat the mixed solution onto the surface of a 3mm thick needle-punched nonwoven fabric with a coating thickness of 2mm and let it stand for 20s;

[0185] (3) Place the needle-punched nonwoven fabric coated with the mixed solution into a 17% DMF aqueous solution and let it solidify for 15 minutes;

[0186] (4) Wash with water using a squeezing roller to remove DMF, and dry at 120°C for 20 min to obtain the polyurethane synthetic leather.

[0187] Example 2

[0188] This embodiment provides a polyurethane resin, polyurethane synthetic leather, and a method for preparing the same. The raw materials for preparing the polyurethane resin include the following components by weight:

[0189] 10 parts of modified polyol B1;

[0190] 71.5 parts of bio-based polyol A;

[0191] Antioxidant 3000.1 parts;

[0192] 0.02 parts of phosphoric acid;

[0193] 58.5 servings of MDI;

[0194] 1,4-Butanediol 15.4 parts;

[0195] 1 part tannin;

[0196] 0.3 parts malic acid;

[0197] 9 parts of polyether additive B;

[0198] DMF 620.3 copies;

[0199] The method for preparing the polyurethane resin includes the following steps:

[0200] (1) Add modified polyol B, bio-based polyol A, antioxidant 300 and phosphoric acid into a reaction flask and stir until homogeneous; add MDI and react at 80℃ for 1.5h.

[0201] (2) Add 260 parts of DMF to dilute, then add 1,4-butanediol and continue the reaction;

[0202] (3) Add 360.3 parts DMF for dilution;

[0203] (4) Add tannic acid to terminate the reaction, add malic acid and polyether additive B, control the viscosity of polyurethane resin at 25°C to be 250,000 cps and the solid content to be 30 wt%, cool to obtain polyurethane resin B.

[0204] The raw materials for preparing the polyurethane synthetic leather include the following components by weight:

[0205] 100 parts of polyurethane resin B;

[0206] 17 parts of lignocellulose;

[0207] 80 copies of DMF;

[0208] 3 parts water;

[0209] Five parts black paste;

[0210] The preparation method of the polyurethane synthetic leather specifically includes the following steps:

[0211] (1) Mix polyurethane resin B, lignocellulose, DMF, water and black paste evenly, centrifuge to remove bubbles, and obtain a mixed solution;

[0212] (2) Coat the mixed solution onto the surface of a 3mm thick needle-punched nonwoven fabric with a coating thickness of 2mm and let it stand for 25s;

[0213] (3) Place the needle-punched nonwoven fabric coated with the mixed solution into a 20% DMF aqueous solution and let it solidify for 20 minutes;

[0214] (4) Wash with water using a squeezing roller to remove DMF, and dry at 110°C for 30 min to obtain the polyurethane synthetic leather.

[0215] Example 3

[0216] This embodiment provides a polyurethane resin, polyurethane synthetic leather, and a method for preparing the same. The raw materials for preparing the polyurethane resin include the following components by weight:

[0217] Modified polyol C135 parts;

[0218] 38 parts of bio-based polyol A;

[0219] Antioxidant 10760.1 parts;

[0220] 0.02 parts of phosphoric acid;

[0221] 55.9 servings of MDI;

[0222] Neopentyl glycol 17.8 parts;

[0223] 1 part tannin;

[0224] 0.3 parts malic acid;

[0225] 18 parts of polyether additive A;

[0226] 621 copies of DMF;

[0227] The method for preparing the polyurethane resin includes the following steps:

[0228] (1) Add modified polyol C, bio-based polyol A, antioxidant 1076 and phosphoric acid into a reaction flask and stir until homogeneous; add MDI and react at 85℃ for 1.5h.

[0229] (2) Add 260 parts of DMF to dilute, then add neopentyl glycol and continue the reaction;

[0230] (3) Add 361 parts DMF for dilution;

[0231] (4) Add tannic acid to terminate the reaction, add malic acid and polyether additive A, control the viscosity of polyurethane resin at 25°C to be 250,000 cps and the solid content to be 30 wt%, cool, and obtain polyurethane resin C.

[0232] The raw materials for preparing the polyurethane synthetic leather include the following components by weight:

[0233] 100 parts of polyurethane resin C;

[0234] 20 parts of lignocellulose;

[0235] 90 copies of DMF;

[0236] 2 parts water;

[0237] Five parts black paste;

[0238] The preparation method of the polyurethane synthetic leather specifically includes the following steps:

[0239] (1) Mix polyurethane resin C, lignocellulose, DMF, water and black paste evenly, centrifuge to remove bubbles, and obtain a mixed solution;

[0240] (2) Coat the mixed solution onto the surface of a 3mm thick needle-punched nonwoven fabric, and let it stand for 30 seconds.

[0241] (3) Place the needle-punched nonwoven fabric coated with the mixed solution into a 23% DMF aqueous solution and let it solidify for 17 min;

[0242] (4) Wash with water using a squeezing roller to remove DMF, and dry at 115°C for 25 min to obtain the polyurethane synthetic leather.

[0243] Example 4

[0244] This embodiment provides a polyurethane resin, polyurethane synthetic leather, and a method for preparing the same. The raw materials for preparing the polyurethane resin include the following components by weight:

[0245] 35 parts of modified polyol D1;

[0246] 38 parts of bio-based polyol A;

[0247] Antioxidant 10100.1 parts;

[0248] 0.02 parts of phosphoric acid;

[0249] 55.9 servings of MDI;

[0250] Neopentyl glycol 17.8 parts;

[0251] Tannins 3 parts;

[0252] 0.3 parts malic acid;

[0253] 16 parts of polyether additive A;

[0254] 621 copies of DMF;

[0255] The method for preparing the polyurethane resin includes the following steps:

[0256] (1) Add modified polyol D, bio-based polyol A, antioxidant 1010 and phosphoric acid into a reaction flask and stir until homogeneous; add MDI and react at 85℃ for 1.5h.

[0257] (2) Add 260 parts of DMF to dilute, then add neopentyl glycol and continue the reaction;

[0258] (3) Add 361 parts DMF for dilution;

[0259] (4) Add tannic acid to terminate the reaction, add malic acid and polyether additive A, control the viscosity of polyurethane resin at 25°C to be 250,000 cps and the solid content to be 30 wt%, cool to obtain polyurethane resin D.

[0260] The raw materials for preparing the polyurethane synthetic leather include the following components by weight:

[0261] 100 parts of polyurethane resin D;

[0262] 20 parts of lignocellulose;

[0263] 90 copies of DMF;

[0264] 2 parts water;

[0265] 7 parts black paste;

[0266] The preparation method of the polyurethane synthetic leather specifically includes the following steps:

[0267] (1) Mix polyurethane resin D, lignocellulose, DMF, water and black paste evenly, centrifuge to remove bubbles, and obtain a mixed solution;

[0268] (2) Coat the mixed solution onto the surface of a 3mm thick needle-punched nonwoven fabric with a coating thickness of 2mm and let it stand for 30s;

[0269] (3) Place the needle-punched nonwoven fabric coated with the mixed solution into a 23% DMF aqueous solution and let it solidify for 15 minutes;

[0270] (4) Wash with water using a squeezing roller to remove DMF, and dry at 120°C for 20 min to obtain the polyurethane synthetic leather.

[0271] Example 5

[0272] The only difference from Example 1 is that tannic acid is replaced with an equimolar amount of ethylene glycol, while the other components and preparation methods are the same as in Example 1.

[0273] Comparative Example 1

[0274] The only difference from Example 1 is that the modified polyol E obtained in Preparation Example 5 is used to prepare polyurethane resin, and then polyurethane synthetic leather is prepared. The other components and preparation methods are the same as in Example 1.

[0275] Comparative Example 2

[0276] The only difference from Example 1 is that the modified polyol A is replaced with an equimolar amount of polybutylene adipate diol (PBA-4000), while the other components and preparation methods are the same as in Example 1.

[0277] Comparative Example 3

[0278] The only difference from Example 1 is that bio-based polyol A is replaced with an equimolar amount of polybutylene adipate diol (PBA-2000), while the other components and preparation methods are the same as in Example 1.

[0279] Comparative Example 4

[0280] The only difference from Example 1 is that the amount of modified polyol A is 179.7 parts (20.2%), the amount of bio-based polyol A is 10 parts (1.1%), and the amount of MDI is 55.22 parts (6.2%). The remaining components and preparation methods are the same as in Example 1.

[0281] Comparative Example 5

[0282] The only difference from Example 1 is that the amount of modified polyol A is 75 parts (8.5%), the amount of bio-based polyol A is 108.9 parts (12.3%), and the amount of MDI is 61.04 parts (6.9%). The remaining components and preparation methods are the same as in Example 1.

[0283] Comparative Example 6

[0284] The only difference from Example 1 is that the amount of tannic acid substitute is 5 parts (accounting for 0.56%), while the other components and preparation methods are the same as in Example 1.

[0285] Performance testing

[0286] (1) Slip rating: Tested according to QB / T 5352-2018 standard. The higher the slip rating, the worse the anti-slip effect.

[0287] (2) Color fastness to perspiration: Tested according to GB / T 3922-2013 standard. The higher the value, the better the color fastness to perspiration.

[0288] (3) Blackness: The blackness of the yoga mat is tested according to the QB / T 5160-2017 standard and the visual colorimetric method is used to detect the blackness of the yoga mat. In this invention, the higher the grade, the better the blackness.

[0289] Following the above testing methods, the performance of the polyurethane synthetic leather provided in the examples and comparative examples was tested, and the results are shown in Table 1:

[0290] Table 1

[0291]

[0292] As shown in Table 1, the polyurethane synthetic leather prepared by this invention has good anti-slip properties, with an anti-slip grade of 1, a color fastness to perspiration grade of 3-5, preferably 4-5, and high blackness, preferably grade 5, making it suitable for polyurethane yoga mats.

[0293] As can be seen from the comparison between Example 1 and Example 5, since the terminating agent tannic acid contains a large number of hydroxyl groups, it can combine with the oxygen-containing functional groups on the surface of carbon black to form hydrogen bonds, thereby enhancing the dyeing performance; the polybenzene ring structure of tannic acid helps to enhance the color fastness to perspiration, which is not available in ethylene glycol. Therefore, the color fastness to perspiration and blackness grade of the polyurethane synthetic leather in Example 5 decreased.

[0294] As can be seen from the comparison between Example 1 and Comparative Example 1, in Comparative Example 1, when the raw material for preparing the modified polyol, monoethanolamine, was replaced with ethylene glycol, the polyurethane resin prepared had poor crystallinity and a lower color fastness to perspiration due to the lower polarity of ethylene glycol compared to monoethanolamine. At the same time, the van der Waals forces between the less polar ethylene glycol and the oxygen-containing functional groups on the surface of carbon black in the polyurethane synthetic leather were weaker, resulting in poorer blackness of the prepared polyurethane synthetic leather.

[0295] As can be seen from the comparison of Example 1 and Comparative Examples 2-3, when conventional polyester polyols are used instead of the modified polyols or bio-based polyols A in this invention, the polyurethane synthetic leather has poor dyeability, color fastness to perspiration, and blackness because polyester polyols do not contain amino groups.

[0296] As can be seen from the comparison between Example 1 and Comparative Examples 4-5, the polyurethane synthetic leather exhibits the best overall performance when the amount of modified polyol and bio-based polyol A is within the limits defined by this invention. Exceeding this range will adversely affect its performance.

[0297] As can be seen from the comparison between Example 1 and Comparative Example 6, the amount of tannic acid added exceeds the scope specified in this invention. Even if too much tannic acid is added, the performance of polyurethane synthetic leather will not be enhanced, and further increasing the amount will only result in waste.

[0298] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A polyurethane resin, characterized by, The raw materials for preparing the polyurethane resin include the following components by mass fraction: Modified polyols 11%-18% Bio-based polyol A 3%-9% Antioxidant 0.01%-0.02% Catalyst 0.001%-0.003% Isocyanates 5%-7% Chain extender 0.5%-3% Terminator 0.1%-0.4% Anti-tack and anti-blocking agent: 0.02%-0.04% Polyether additives 0.5%-3% Solvent 68%-73% The raw materials for preparing the modified polyol include bio-based polyols, alkanolamines, and diacids; The bio-based polyol A includes a bio-based polypropylene carbonate diol; The terminating agent includes tannic acid.

2. The polyurethane resin according to claim 1, characterized in that, The alcoholamines include monoethanolamines; And / or, the dicarboxylic acid includes adipic acid; And / or, the weight-average molecular weight of the bio-based polyol is 1500-2500; And / or, the raw materials for preparing the bio-based polyol include bio-based dicarboxylic acids and bio-based diols; And / or, the bio-based dicarboxylic acid includes bio-based sebacic acid and / or bio-based succinic acid; And / or, the bio-based diols include bio-based 1,3-propanediol and / or bio-based 1,4-butanediol; And / or, the molar ratio of the bio-based polyol, alkanolamine and diacid is 1:(0.06-0.1):(1.02-1.04).

3. The polyurethane resin according to claim 1, characterized in that, The weight-average molecular weight of the modified polyol is 3000-5000; And / or, the weight-average molecular weight of the bio-based polyol A is 1500-2500; And / or, the solid content of the polyurethane resin is 29wt%-31wt%; And / or, the viscosity of the polyurethane resin at 25°C is 220,000-280,000 cps; And / or, the antioxidant comprises any one or a combination of at least two of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-thiobis(6-tert-butyl-3-methylphenol), 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], or tris(2,4-di-tert-butylphenyl) phosphite.

4. The polyurethane resin according to claim 1, characterized in that, The catalyst includes phosphoric acid; And / or, the isocyanate includes 4,4-diphenylmethane diisocyanate; And / or, the chain extender includes any one or a combination of at least two of ethylene glycol, 1,4-butanediol or neopentyl glycol; And / or, the anti-tack additive includes malic acid; And / or, the solvent includes N,N-dimethylformamide; And / or, the method for preparing the modified polyol includes the following steps: Bio-based polyols, alkanolamines, and diacids react under the action of catalyst A to obtain the modified polyol; And / or, the catalyst A comprises tetraisopropyl titanate and / or tetraisobutyl titanate.

5. The method for preparing polyurethane resin according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: (1) Mix the modified polyol, bio-based polyol A, antioxidant, catalyst and isocyanate, and react; (2) Add some solvent and chain extender, and continue the reaction; (3) Add the remaining solvent to dilute during the process; (4) Add a terminator, an anti-tack agent and a polyether agent to obtain the polyurethane resin.

6. The preparation method according to claim 5, characterized in that, In step (1), the reaction time is 1-2 hours; And / or, in steps (1)-(3), the temperature of the reaction is independently 75-85°C.

7. A polyurethane synthetic leather, characterized in that, The polyurethane synthetic leather comprises the polyurethane resin according to any one of claims 1-4.

8. The polyurethane synthetic leather according to claim 7, characterized in that, The raw materials for preparing the polyurethane synthetic leather include the following components by weight: 100 parts of polyurethane resin 15-20 parts of lignocellulose 75-90 parts of N,N-dimethylformamide 2-4 parts water 3-7 parts color paste; And / or, the pigment includes black pigment.

9. A method for preparing polyurethane synthetic leather as described in claim 7 or 8, characterized in that, The preparation method includes the following steps: (1) Mix polyurethane resin, lignocellulose, N,N-dimethylformamide, water and color paste to obtain a mixed solution; (2) The mixed solution is coated onto the substrate, solidified, and dried to obtain the polyurethane synthetic leather.

10. The preparation method according to claim 9, characterized in that, The substrate includes needle-punched nonwoven fabric; And / or, the thickness of the substrate is 3-4 mm; And / or, the coating thickness is 2-3 mm; And / or, the coating process further includes a settling period; And / or, the settling time is 20-30 seconds; And / or, the solidification includes immersing the substrate coated with the mixed solution in the mixed solvent; And / or, the mixed solvent comprises an aqueous solution of N,N-dimethylformamide; And / or, based on the mass percentage of the mixed solvent being 100%, the mass percentage of N,N-dimethylformamide is 17%-23%; And / or, the solidification time is 15-20 min; And / or, the solidification process further includes water washing; And / or, the drying temperature is 110-120°C; And / or, the drying time is 20-30 minutes.

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