Polyurethane synthetic leather and preparation method thereof

Abstract

The invention belongs to the technical field of artificial leather, and particularly relates to polyurethane synthetic leather and a preparation method thereof. The bass layer of the synthetic leather provided by the invention comprises the calcium filler, the slow-release neutralizer and the polyurethane resin, and the slow-release neutralizer can neutralize alkaline substances in the calcium filler, so that a synthetic leather product which is soft in texture and relatively low in pH value can be directly obtained. In the long-term use process of the synthetic leather, the synthetic leather can make contact with water vapor in air for a long time, the calcium filler reacts to generate calcium hydroxide, the slow-release neutralizer can slowly release acidic substances to be subjected to a neutralization reaction with hydroxyl, alkali is neutralized, the polyurethane synthetic leather is in a non-alkaline state, the synthetic leather has the long-acting pH balancing function, and the service life of the synthetic leather is prolonged. Therefore, the service life is prolonged, for a wearer, the neutral environment is healthier, and irritation to the skin is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of artificial leather, and specifically relates to a polyurethane synthetic leather and a preparation method thereof. Background Art

[0002] Synthetic leather is a common material in everyday life, primarily simulating the composition and structure of natural leather and serving as a substitute. Generally speaking, the wet-fabric base of polyurethane synthetic leather is primarily produced by coating a wet-fabricated polyurethane resin slurry onto a base fabric. The wet-fabricated base is then pre-coagulated, washed, and dried. To adjust the base's pore structure, increase strength, enhance drape, and facilitate solvent displacement, synthetic leather factories often add large amounts of calcium fillers to the slurry used for wet-fabricated base coating. However, the calcium fillers commonly used in synthetic leather factories contain calcium hydroxide impurities, resulting in a pH range of 8.5 to 9.4 for the produced synthetic leather, with some even reaching pH values as high as 9 to 11. Synthetic leather products with a high pH value are highly irritating to the skin and can easily cause discomfort such as itching, redness, and swelling, which is not good for health. When the pH value of a synthetic leather product is above 10, the molecular chain of the polyurethane resin will break and hydrolysis will occur, resulting in a significant reduction in the storage and service life of the synthetic leather product. Ordinary synthetic leather usually cracks and peels only after 1-2 years of storage and use. Synthetic leather products with a high pH value have reduced anti-corrosion performance and are prone to mold growth, which significantly shortens their shelf life and service life.

[0003] In the prior art, synthetic leather products with a high pH (common synthetic leather is alkaline, with a pH mostly above 10) are generally neutralized with an acidic aqueous solution. However, during this process, a large amount of calcium salts are deposited on the inner walls of the leather's pores, causing the leather to become stiff and affecting the performance of the finished leather. Furthermore, this treatment method can only maintain a low pH level for a short period of time. After a period of storage or use, the pH of the finished leather will slowly rise again until it exceeds the standard. This is because, during the long-term use of synthetic leather, calcium carbonate will combine with water molecules to form calcium hydroxide. The specific process is as follows:

[0004] Dissolution process: When calcium carbonate comes into contact with water, the following process occurs: During the dissolution process, some calcium carbonate molecules will combine with water molecules to form corresponding ions, namely Ca 2+ and CO3 2- ; Discrete process. The Ca formed during the dissolution process 2+ and CO3 2- Ions will complex with water molecules to form discrete ionic substances. This process can be further refined as follows:

[0005] [Ca 2+ (aq) + 2H2O → [Ca(H2O)6] 2+ (aq)]

[0006] [CO3 2- (aq)+H2O→HCO3 - (aq)+OH - (aq)]

[0007] Crystallization process: When the Ca 2+ ions and OH - When the ions meet, calcium hydroxide is formed and precipitated. Therefore, over time, synthetic leather gradually becomes exposed to an alkaline environment, and polyurethane resins are prone to decomposition and aging in alkaline environments. The calcium ions in calcium carbonate accelerate the aging process of polyurethane resins in alkaline environments, significantly reducing the service life of synthetic leather. Summary of the Invention

[0008] Therefore, the technical problem to be solved by the present application is to overcome the defects of the synthetic leather in the prior art, such as the high pH value, the conventional acid treatment causing the synthetic leather to become stiff, accelerating aging and affecting the service life, and the pH only maintaining a low level for a short period of time, and the pH will slowly rise again after being stored or used for a period of time, thereby providing a polyurethane synthetic leather and a preparation method thereof.

[0009] To this end, this application provides the following technical solutions:

[0010] According to one aspect of the present application, there is provided a polyurethane synthetic leather comprising: a base fabric and a bass layer located on at least one side surface of the base fabric,

[0011] Wherein, the base layer comprises polyurethane resin, calcium filler, and slow-release neutralizer;

[0012] The slow-release neutralizer includes at least one of polyphosphates, metaphosphates, phosphates, metasilicate compounds, and sulfated aluminosilicate compounds.

[0013] In this application, the base layer includes a calcium filler, a slow-release neutralizer, and a polyurethane resin. The slow-release neutralizer can neutralize the alkaline substances in the calcium filler, directly producing a synthetic leather product with a soft texture and a low pH. During long-term use, the synthetic leather will be exposed to water vapor in the air for a long time, causing the calcium filler to react and produce calcium hydroxide. The slow-release neutralizer slowly releases acidic substances to react with hydroxide to neutralize the base, leaving the polyurethane synthetic leather in a non-alkaline state. The synthetic leather has the function of long-term pH balance, thereby extending its service life. For the wearer, the neutral environment is also healthier and reduces skin irritation.

[0014] In some optional embodiments, the base layer includes: 20-50 parts of polyurethane resin; 2-80 parts of calcium filler; 1-80 parts of slow-release neutralizer;

[0015] As an example, the content of the polyurethane resin can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, or within a range consisting of any of the above values; the content of the calcium filler can be 2 parts, 5 parts, 10 parts, 15 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, or within a range consisting of any of the above values; the content of the sustained-release neutralizer can be 1 part, 5 parts, 10 parts, 15 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, or within a range consisting of any of the above values.

[0016] In some optional embodiments, the bass layer further includes: 5-40 parts of fiber filler; 1-5 parts of color powder; and 0.1-3 parts of leveling agent.

[0017] In the present application, the fiber filler is conventional in the field, including but not limited to at least one of wood powder, paper fiber powder, animal leather powder, and herbal fiber powder; the color powder is conventional in the field, including but not limited to at least one of black powder, white powder, red powder, blue powder, green powder, purple powder, brown powder, yellow powder, and orange powder; the leveling agent is conventional in the field, including but not limited to at least one of silicone leveling agent and acrylic leveling agent.

[0018] In some optional embodiments, the polyphosphate includes at least one of calcium polyphosphate and aluminum polyphosphate;

[0019] And / or, the metaphosphate includes at least one of calcium metaphosphate and aluminum metaphosphate;

[0020] And / or, the phosphate includes at least one of calcium hydrogen phosphate, aluminum phosphate, aluminum dihydrogen phosphate, and aluminum monohydrogen phosphate;

[0021] And / or, the metasilicate compound includes at least one of acidified kaolin, acidified montmorillonite powder, acidified talc powder, and acidified mica powder;

[0022] And / or, the sulfated aluminosilicate compound comprises sulfated aluminosilicate.

[0023] In some optional embodiments, the acidified kaolin includes at least one of sulfated kaolin and phosphated kaolin;

[0024] And / or, the acidified montmorillonite powder includes at least one of sulfated montmorillonite and phosphated montmorillonite;

[0025] And / or, the acidified talc includes at least one of sulfated talc and phosphated talc;

[0026] And / or, the acidified mica powder includes at least one of sulfated mica powder and phosphated mica powder.

[0027] In some optional embodiments, the modulus of the polyurethane resin is 5-120 kgf / cm 2 As an example, the modulus of the polyurethane resin may be 5 kgf / cm 2 , 10kgf / cm 2 , 20kgf / cm 2 , 40kgf / cm 2 , 50kgf / cm 2 , 70kgf / cm 2 , 90kgf / cm 2 , 100kgf / cm 2 , 120kgf / cm 2 , or within a range consisting of any of the above values.

[0028] And / or, the calcium filler includes at least one of heavy calcium carbonate and light calcium carbonate.

[0029] In some optional embodiments, the base fabric includes at least one of nylon, polyester, spandex, viscose, cotton, linen, and silk.

[0030] In some optional embodiments, the thickness of the bass layer is 0.15-1 mm; as an example, the thickness of the bass layer can be 0.15 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, or within a range consisting of any of the above values.

[0031] And / or, the thickness of the base fabric is 0.15-2.8 mm; as an example, the thickness of the base fabric can be 0.15 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, or within a range consisting of any of the above values.

[0032] According to another aspect of the present application, there is provided a method for preparing the above-mentioned polyurethane synthetic leather, comprising the following steps:

[0033] S1, mixing the components with an organic solvent to obtain a slurry;

[0034] S2, coating the slurry on at least one side of the base fabric, pre-solidifying, washing, and drying to obtain the polyurethane synthetic leather.

[0035] In the present application, when the calcium filler, the slow-release neutralizer, the polyurethane resin and the organic solvent are stirred and mixed to form a coating slurry, the calcium hydroxide in the calcium filler and the soluble acidic substance of the slow-release neutralizer undergo an acid-base neutralization reaction to generate calcium salts. In the initial stage of making the synthetic leather wet-fabric base, the main components of the calcium filler, calcium carbonate, and the calcium salt can exist in a stable state. Since all the calcium salts produced are still in the mixing and stirring process of the slurry, the softness of the synthetic leather wet-fabric base made thereafter is relatively high, and the performance of the synthetic leather is relatively good. The acidic substance slowly released by the slow-release neutralizer can also exist stably and will not react. Moreover, the acidic substance slowly released by the slow-release neutralizer after the acid-base neutralization reaction in the coating slurry process is weakly acidic and will not affect the performance of the polyurethane resin. During long-term use, synthetic leather will be exposed to water vapor in the air for a long time, causing the calcium filler to react to produce calcium hydroxide. The slow-release neutralizer slowly releases acidic substances to react with hydroxide to neutralize the alkali, making the polyurethane synthetic leather in a non-alkaline state, thereby increasing its service life. The neutral environment is also healthier for the wearer.

[0036] At the same time, the preparation method of the present application omits the acidic aqueous solution treatment process, saves the energy consumption and waste liquid and waste gas emissions of one process, and also reduces the labor cost and material cost.

[0037] In some optional embodiments, in S1, the amount of the organic solvent is 60-250 parts; as an example, the amount of the organic solvent can be 60 parts, 80 parts, 100 parts, 120 parts, 150 parts, 180 parts, 200 parts, 220 parts, 240 parts, 250 parts, or within a range consisting of any of the above values.

[0038] In the present application, the polyurethane resin can be first mixed with part of the organic solvent to obtain a polyurethane slurry with a solid content of 20-40 wt %, or a polyurethane slurry with a solid content of 20-40 wt % can be directly purchased from the market for use.

[0039] And / or, it also includes adding 0.1-15 parts of water to the slurry; taking the example shown, the amount of water can be 0.1 part, 1 part, 3 parts, 5 parts, 7 parts, 9 parts, 10 parts, 12 parts, 14 parts, 15 parts, or within the range of any of the above values; the present application can reduce the sugar content of the slurry and adjust the pore structure formed during the solidification process of the polyurethane resin by adding a small amount of water to the slurry. Generally, the pores will be relatively larger after adding water.

[0040] And / or, the organic solvent includes at least one of N,N-dimethylformamide (DMF) and methyl acetate.

[0041] It should be noted that during the preparation process, the polyurethane resin is added in the form of a polyurethane resin slurry. The polyurethane resin can be first mixed with part of the organic solvent to obtain a polyurethane slurry with a solid content of 20 to 40 wt%, or a polyurethane slurry with a solid content of 20 to 40 wt% can be directly purchased from the market for use.

[0042] In this application, the steps of pre-coagulation, water washing, drying, etc. are conventional in the field and are not specifically limited in this application.

[0043] The technical solution of this application has the following advantages:

[0044] The polyurethane synthetic leather provided by the present application has the function of long-term pH balance, so that its pH meets health requirements. The synthetic leather provided by the present application has a longer service life and higher softness than ordinary synthetic leather, and has improved performance and tear strength of the synthetic leather. In addition, generally speaking, the pH of synthetic leather will be tested before it leaves the factory. If the pH is found to be too high, the existing technology will use an acidic aqueous solution for neutralization reaction. However, during this process, a large amount of calcium salt will be deposited on the inner wall of the pores of the leather, making the leather stiff, and requiring rubbing or a long time of rubbing to make the leather soft again, thus prolonging the rubbing process. In the solution of the present application, the acid-base neutralization reaction has already occurred in the wet-process leather mixed slurry and produced calcium salts. Since the calcium salts are produced before the slurry solidifies, the leather produced is relatively soft, and the synthetic leather product requires a shorter rubbing time or no rubbing is required. Therefore, compared with the existing technology, the present application reduces the workload of rubbing and can even eliminate the rubbing process, reducing the energy consumption and waste liquid and waste gas emissions of the rubbing process, and also reducing labor costs and material costs.

[0045] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. DETAILED DESCRIPTION

[0046] The following examples are provided to further better understand the present application, but are not limited to the best implementation mode described herein, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the scope of protection of the present application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application text are intended to cover non-exclusive inclusions.

[0048] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0049] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. In this application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just an abbreviation of these numerical combinations. In addition, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter can be, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0051] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0052] In the description of the embodiments of the present application, the term "at least one" refers to one or more than two (including two).

[0053] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0054] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0055] The present application is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present application in any way.

[0056] In the following examples and comparative examples, 1 part represents 1 g. The sources of some raw materials in the following examples and comparative examples are as follows:

[0057] Table 1

[0058] name factory 30% solid content wet-process polyurethane resin slurry Jining Huakai Resin Co., Ltd. Light calcium carbonate powder Changxing Qingsheng Calcium Industry Co., Ltd. Heavy calcium carbonate powder Changxing Qingsheng Calcium Industry Co., Ltd. Wood powder Shijiazhuang Tanxun New Material Technology Co., Ltd. Black powder Tianjin Huayuan Chemical Technology Co., Ltd. Leveling agent (RM-2020) Shandong Yousuo Chemical Technology Co., Ltd. Sulfated kaolin Guangzhou Rongyue Chemical Raw Materials Co., Ltd. Phosphated kaolin Guangzhou Rongyue Chemical Raw Materials Co., Ltd. calcium polyphosphate Anhui Datang Bioengineering Co., Ltd. Aluminum dihydrogen tripolyphosphate Jinan Yunuo Chemical Co., Ltd.

[0059] Example 1 (sulfated kaolin)

[0060] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0061] Step 1: Prepare the coating slurry of wet-fabricated bessa, which includes: weighing 30% solid content wet-fabricated polyurethane resin slurry (the organic solvent is DMF, the modulus of the polyurethane resin is 10kgf / cm 2 , the same below): 100 parts; light calcium carbonate powder 10 parts; sulfated kaolin (pH = 2.5): 10 parts; DMF: 120 parts; wood powder: 25 parts; black powder: 3 parts; water: 3 parts; leveling agent: 2 parts; then stir and mix to obtain a coating slurry;

[0062] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0063] Example 2

[0064] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0065] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of heavy calcium carbonate powder; 10 parts of sulfated kaolin; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0066] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0067] Example 3

[0068] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0069] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 5 parts of light calcium carbonate powder; 5 parts of heavy calcium carbonate powder; 10 parts of sulfated kaolin; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0070] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0071] Example 4 (Phosphorylated Kaolin)

[0072] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0073] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of phosphated kaolin; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0074] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0075] Example 5 (calcium polyphosphate)

[0076] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0077] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of calcium polyphosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0078] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0079] Example 6 (aluminum dihydrogen tripolyphosphate (aluminum polyphosphate))

[0080] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0081] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of dihydrogen aluminum tripolyphosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0082] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0083] Example 7 (Calcium metaphosphate)

[0084] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0085] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of calcium metaphosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0086] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0087] Example 8 (aluminum metaphosphate)

[0088] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0089] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of aluminum metaphosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0090] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0091] Example 9 (Calcium hydrogen phosphate)

[0092] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0093] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of heavy calcium carbonate powder; 10 parts of calcium hydrogen phosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0094] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0095] Example 10 (aluminum phosphate)

[0096] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0097] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of aluminum phosphate; 120 parts of DMF; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0098] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0099] Example 11 (aluminum dihydrogen phosphate)

[0100] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0101] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of aluminum dihydrogen phosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0102] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0103] Example 12 (aluminum monohydrogen phosphate)

[0104] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0105] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of aluminum monohydrogen phosphate; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0106] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0107] Example 13

[0108] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0109] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 20% solid content wet-process polyurethane resin slurry; 3 parts of light calcium carbonate powder; 3 parts of sulfated kaolin; 80 parts of DMF; 8 parts of wood powder; 3 parts of black powder; 3 parts of water; and 0.5 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0110] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0111] Example 14

[0112] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0113] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 125 parts of 40% solid content wet-process polyurethane resin slurry; 72 parts of light calcium carbonate powder; 68 parts of sulfated kaolin; 215 parts of DMF; 35 parts of wood powder; 3 parts of black powder; 13 parts of water; and 3 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0114] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0115] Example 15

[0116] This embodiment provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0117] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 10 parts of sulfated kaolin (pH = 2.5); 123 parts of DMF; 25 parts of wood powder; 3 parts of black powder; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0118] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0119] Comparative Example 1

[0120] This comparative example provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0121] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of heavy calcium carbonate powder; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0122] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0123] Comparative Example 2

[0124] This comparative example provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0125] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 10 parts of light calcium carbonate powder; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0126] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0127] Comparative Example 3

[0128] This comparative example provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0129] Step 1: preparing a coating slurry for wet-process base, the coating slurry for wet-process base comprising: weighing according to the following formula: 100 parts of 30% solid content wet-process polyurethane resin slurry; 5 parts of heavy calcium carbonate powder; 5 parts of light calcium carbonate powder; 120 parts of DMF; 25 parts of wood powder; 3 parts of black powder; 3 parts of water; and 2 parts of leveling agent; and then stirring and mixing to obtain a coating slurry;

[0130] Step 2: coating the wet-fabricated base leather coating slurry on a 0.32 mm thick warp-knitted suede-like base fabric, pre-solidifying, washing, and drying to obtain a polyurethane synthetic leather with a base leather layer thickness of 0.3 mm.

[0131] Comparative Example 4

[0132] This comparative example provides a polyurethane synthetic leather, the composition and specific preparation method of which are as follows:

[0133] The synthetic leather (pH=10.34) obtained in Comparative Example 3 was soaked in an acetic acid aqueous solution with a pH of 3.5 and then dried.

[0134] Test Case

[0135] The polyurethane synthetic leather provided in each embodiment and comparative example was tested, and the specific testing method is as follows:

[0136] 1. Jungle test: refer to standard QB / T 4671-2014, test temperature 70℃, relative humidity 95%;

[0137] 2. Synthetic leather pH test: refer to QB / T 2724-2018;

[0138] 3. Softness test: Test in accordance with standard GB / T 39371-2020.

[0139] The specific test results are shown in the table below:

[0140] Table 2

[0141]

[0142]

[0143] The above test results show that in Examples 1 through 12, a slow-release neutralizer was added during the preparation of the base layer, while Comparative Examples 1 through 3 did not. The experimental results also show that the jungle test duration for the Examples was significantly longer than that for the Comparative Examples. This is because the slow-release neutralizer slowly neutralizes alkaline substances, thereby ensuring the durability of the base layer. Adding a slow-release neutralizer does not significantly affect softness; the Examples even improve it to a certain extent. The pH of the polyurethane synthetic leathers provided by the Examples and Comparative Examples was tested after production. After 3 and 10 days of jungle testing, the pH was monitored again. The Examples, which added a slow-release neutralizer, maintained a pH of approximately 10, while Comparative Examples 1 through 3 remained alkaline, with a pH above 9. Comparative Examples 2 and 3 were unusable after the 3-day jungle test, so no pH data is available after 10 days of jungle testing. Comparative Example 4 was first subjected to acid washing. Although the pH value decreased after the acid washing, the pH value returned to above 9 after the 10-day jungle test, that is, the alkaline state, indicating that alkaline substances were slowly seeping out.

[0144] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A polyurethane synthetic leather, characterized in that: include: A base fabric and a bass layer located on at least one side of the base fabric. Wherein, the base layer comprises polyurethane resin, calcium filler, and slow-release neutralizer; The slow-release neutralizer includes at least one of polyphosphates, metaphosphates, phosphates, metasilicate compounds, and sulfated aluminosilicate compounds.

2. The polyurethane synthetic leather according to claim 1, characterized in that The bass layer includes: 20-50 parts of polyurethane resin; 2-80 parts of calcium filler; 1-80 parts of sustained-release neutralizer.

3. The polyurethane synthetic leather according to claim 2, characterized in that: The bass layer further comprises: 5-40 parts of fiber filler; 1-5 parts of color powder; and 0.1-3 parts of leveling agent.

4. The polyurethane synthetic leather according to any one of claims 1 to 3, characterized in that: The polyphosphate includes at least one of calcium polyphosphate and aluminum polyphosphate; And / or, the metaphosphate includes at least one of calcium metaphosphate and aluminum metaphosphate; And / or, the phosphate includes at least one of calcium hydrogen phosphate, aluminum phosphate, aluminum dihydrogen phosphate, and aluminum monohydrogen phosphate; And / or, the metasilicate compound includes at least one of acidified kaolin, acidified montmorillonite powder, acidified talc powder, and acidified mica powder; And / or, the sulfated aluminosilicate compound comprises sulfated aluminosilicate.

5. The polyurethane synthetic leather according to claim 4, characterized in that: The acidified kaolin includes at least one of sulfated kaolin and phosphated kaolin; And / or, the acidified montmorillonite powder includes at least one of sulfated montmorillonite and phosphated montmorillonite; And / or, the acidified talc includes at least one of sulfated talc and phosphated talc; And / or, the acidified mica powder includes at least one of sulfated mica powder and phosphated mica powder.

6. The polyurethane synthetic leather according to any one of claims 1 to 3 or 5, characterized in that: The modulus of the polyurethane resin is 5-120 kgf / cm 2 ; And / or, the calcium filler includes at least one of heavy calcium carbonate and light calcium carbonate.

7. The polyurethane synthetic leather according to any one of claims 1 to 3 or 5, characterized in that: The base fabric comprises at least one of nylon, polyester, spandex, viscose fiber, cotton, linen and silk.

8. The polyurethane synthetic leather according to any one of claims 1 to 3 or 5, characterized in that: The thickness of the bass layer is 0.15-1 mm; And / or, the base fabric has a thickness of 0.15-2.8 mm.

9. A method for preparing the polyurethane synthetic leather according to any one of claims 1 to 8, characterized in that: The steps include: S1, mixing the components with an organic solvent and water to obtain a slurry; S2, coating the slurry on at least one side of the base fabric, pre-solidifying, washing, and drying to obtain the polyurethane synthetic leather.

10. The method for preparing polyurethane synthetic leather according to claim 9, characterized in that: In S1, the amount of the organic solvent is 150-300 parts; and / or, water in an amount of 0.1-15 parts; And / or, the organic solvent includes at least one of N,N-dimethylformamide and methyl acetate.

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