Biodegradable polyurethane synthetic leather as well as preparation method and application thereof

Abstract

The invention discloses biodegradable polyurethane synthetic leather as well as a preparation method and application thereof. The polyurethane synthetic leather sequentially comprises a bio-based polyurethane surface layer, a polyurethane bonding layer and a degradable base material layer from top to bottom, the bio-based polyurethane surface layer meets the requirement of biodegradation by using components such as polyurethane surface layer resin and lignocellulose; the polyurethane bonding layer is formed by reacting polylactic acid polyol and isocyanate which serve as main components, and degradability of the bonding layer is guaranteed through a polylactic acid structure in the polyurethane bonding layer; and the base material layer is made of polylactic acid or cotton fibers, so that the base material layer is degradable. Meanwhile, in order to guarantee the durability of the product and increase the thickness of the polyurethane surface layer, multiple curing agents are adopted, the surface layer structure is fully crosslinked, a compact structure is formed, a protective effect is achieved on a bonding layer in polyurethane, and rapid degradation is avoided. According to the invention, various biodegradable materials are reasonably utilized, so that the biodegradable polyurethane synthetic leather with certain durability is prepared.

Description

Technical Field

[0001] The invention relates to a preparation process of a functional polyurethane composite material, in particular to a biodegradable polyurethane synthetic leather and a preparation method and application thereof, belonging to the technical field of polyurethane synthetic leather. Background Art

[0002] Biodegradable materials are green, environmentally friendly, and resource-saving, and are the main focus of my country's strategic emerging industries. As an important new type of flexible bio-based composite material, biodegradable polyurethane synthetic leather has good application and development prospects.

[0003] As people's environmental awareness increases, biodegradable polyurethane synthetic leather is gradually expanding its application in sports and leisure shoes, sofa furniture, sporting goods, electronic packaging, interior and engineering decoration, automotive interior and other fields. Usually, in order to ensure the degradability of polyurethane synthetic leather, it is necessary to introduce biodegradable structures such as polylactic acid, polyhydroxyalkanoate polymers and butylene adipate into the polyurethane structure, but these structures usually lead to a decrease in the durability of polyurethane materials. The application scenarios of polyurethane synthetic leather determine that it requires certain durability and durability. Therefore, it is of great significance to ensure that the biodegradable polyurethane synthetic leather has certain hydrolysis resistance, wear resistance and folding resistance while ensuring the biodegradability of the degradable polyurethane synthetic leather. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the purpose of the invention is to provide a biodegradable polyurethane synthetic leather and a preparation method and application thereof. The present invention achieves a balance between the degradability and durability of the polyurethane synthetic leather through the comprehensive application of various additives in the polyurethane material and the design of the polyurethane layer structure, and realizes its application in the fields of electronic packaging, interior decoration and automobile roofs.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] The first aspect of the present invention is to provide a biodegradable polyurethane synthetic leather, which comprises, from top to bottom, a bio-based polyurethane surface layer, a bio-based polyurethane adhesive layer and a resolvable substrate layer, wherein:

[0007] The bio-based polyurethane surface layer is prepared from a polyurethane surface layer slurry composed of the following components in parts by weight: the mass fractions of each component in the polyurethane surface layer slurry are as follows: 100 parts of polyurethane surface layer resin, 5-10 parts of wood cellulose, 5-10 parts of montmorillonite, 4-6 parts of wear-resistant additives, 4-6 parts of curing agents and 1-5 parts of color paste. Preferably, the polyurethane surface layer resin is a polyester bio-based surface layer resin; the curing agent is a mixture of isocyanate curing agent and carboimide, and the mass ratio of HDI to carboimide is 3:1; the wear-resistant additive is at least one of molybdenum disulfide, polytetrafluoroethylene powder, high molecular weight polyethylene and polymer silicone.

[0008] The bio-based polyurethane adhesive layer is prepared from a solvent-free polyurethane adhesive layer slurry composed of the following components in parts by weight: 100 parts of polylactic acid polyol, 50-70 parts of isocyanate prepolymer, 10-20 parts of wood cellulose, 0.3-0.5 parts of organic bismuth catalyst and 0.5-0.8 parts of water.

[0009] The base material layer is made of polylactic acid or cotton fiber to achieve the degradability of the base material layer.

[0010] The second aspect of the present invention is to provide a method for preparing the biodegradable polyurethane synthetic leather as described in the first aspect, comprising the following steps:

[0011] Step 1: coating the polyurethane surface layer slurry on the release paper with a coating thickness of 0.4-0.5 mm, and drying to form a bio-based polyurethane surface layer; the drying temperature is 130-145° C., and the drying time is 3-5 min;

[0012] Step 2: Coat the polyurethane bonding layer slurry on the polyurethane surface layer with a coating thickness of 0.2-0.3 mm, and pre-react at a temperature of 130-135°C for 3-5 minutes to form a semi-dry polyurethane bonding layer;

[0013] Step 3: Lay the base fabric on the polyurethane adhesive layer, and obtain the final product after drying and peeling off the release paper; the drying temperature is 130-140° C., and the drying time is 3-5 minutes.

[0014] The third aspect of the present invention is to provide the use of the biodegradable polyurethane synthetic leather as described in the first aspect, wherein the biodegradable polyurethane synthetic leather can be used in engineering decoration, automobile roof or electronic packaging.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The bio-based polyurethane surface layer in the polyurethane synthetic leather provided by the present invention contains components such as polyurethane surface layer resin and lignocellulose, thereby achieving biodegradation of the polyurethane surface layer; the polyurethane bonding layer is formed by reacting polylactic acid polyol and isocyanate as main components, and the polylactic acid structure therein ensures the degradability of the bonding layer; the substrate layer adopts polylactic acid or cotton fiber to achieve the degradability of the substrate layer. At the same time, in order to ensure the durability of the product, the thickness of the polyurethane surface layer is increased, and multiple curing agents are used to fully cross-link the surface layer structure to form a dense structure, which protects the bonding layer inside the polyurethane and prevents rapid degradation, thereby ensuring a certain durability of the product and enabling it to be used in automobile roofs. At the same time, the montmorillonite component in the present invention can not only enhance the strength and wear resistance of the product, but also have a certain flame retardant effect. In addition, montmorillonite comes from natural soil and is discarded in the environment without pollution.

[0017] The product obtained by the present invention can be biodegraded in the environment after being discarded, and can meet the increasingly stringent requirements for product degradability. At the same time, the product can maintain a certain durability while being degradable. The product can meet the requirements of 2-year hydrolysis resistance (70℃*95%RH*2W leather surface without cracking or powdering); dry and wet rubbing color fastness 200 times ≥4 level; peel strength ≥20N / 3cm; Wisbo wear resistance 50,000 times without breaking; room temperature flexure, 50,000 times without cracking. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0019] In addition, unless otherwise specified, the preparation processes in the following embodiments are all conventional means in the prior art in the art, and therefore, they are not described in detail; the parts in the following embodiments are all parts by weight.

[0020] The raw material information used in the following examples is as follows:

[0021] The polyester bio-based surface resin was synthesized by Hefei Anli Polyurethane Materials Co., Ltd., with the brand name AL-7055;

[0022] The polyether bio-based surface resin in Comparative Example 2 was purchased from Hefei Anli Polyurethane New Materials Co., Ltd., with the brand name LT-8070BIO

[0023] The manufacturer of isocyanate curing agent is Yantai Wanhua Chemical, and the brand is WANNATE HT-100;

[0024] The manufacturer of carbodiimide curing agent is Starr Fine Coatings (Suzhou) Co., Ltd., brand XR-5580;

[0025] The wood cellulose is purchased from Yixing Shengdeli and is white wood cellulose;

[0026] The color paste adopts PU series color paste from Jiangxi Mitsukoshi Company.

[0027] Polylactic acid polyol is composed of 1,4-butanediol and lactide and is purchased from Hefei Anli Polyurethane New Materials Co., Ltd. with the brand name AL-2015;

[0028] In Comparative Example 6, the polyether polyol manufacturer is BASF Polyurethane (China) Co., Ltd., and the brand is polyol combination CC 6945 / 1100C-A;

[0029] The isocyanate prepolymers were all CC 6945 / 1100C-B from BASF Polyurethane (China) Co., Ltd.;

[0030] The organic bismuth catalyst was purchased from BASF Shanghai, with the brand name CC 6945 / 90C-CC.

[0031] The wear-resistant additive in the present invention is polymer silicone purchased from Changhui New Materials with a brand name of BNK-NSF898.

[0032] The above reagents are only for illustrating the sources and components of the reagents used in the experiments of the present invention so as to fully disclose the information, and do not mean that the present invention cannot be realized by using other similar reagents or reagents provided by other suppliers.

[0033] Example 1

[0034] A method for preparing biodegradable polyurethane synthetic leather comprises the following steps:

[0035] (1) coating a bio-based polyurethane surface layer slurry on a release paper with a coating thickness of 0.4 mm, and drying at 130° C. for 5 min to form a bio-based polyurethane surface layer;

[0036] The composition of the bio-based polyurethane surface slurry is: 100 parts of polyester polyurethane surface resin, 5 parts of wood cellulose, 5 parts of montmorillonite, 4 parts of BNK-NSF898, 3 parts of HT-100, 1 part of XR-5580 and 1 part of PU color paste;

[0037] (2) coating the polyurethane adhesive layer slurry on the polyurethane surface layer with a coating thickness of 0.2 mm; and drying at 130° C. for 5 minutes to form a semi-dried polyurethane adhesive layer;

[0038] The composition of the polyurethane bonding layer slurry is: 100 parts of polylactic acid polyol, 50 parts of isocyanate prepolymer, 5 parts of wood cellulose, 0.3 parts of CC 6945 / 90C-CC and 0.5 parts of water.

[0039] (3) Laminating a base fabric on the polyurethane adhesive layer, drying and peeling off the release paper to obtain the final product; the drying temperature is 130° C. and the drying time is 5 minutes; the base fabric is composed of polylactic acid and has a thickness of 0.8 mm.

[0040] Example 2

[0041] A method for preparing biodegradable polyurethane synthetic leather comprises the following steps:

[0042] (1) coating a bio-based polyurethane surface layer slurry on a release paper with a coating thickness of 0.45 mm, and drying at 140° C. for 4 minutes to form a bio-based polyurethane surface layer;

[0043] The composition of the polyurethane surface slurry is: 100 parts of polyester polyurethane surface resin, 8 parts of wood cellulose, 8 parts of montmorillonite, 5 parts of BNK-NSF898, 3.75 parts of HT-100, 1.25 parts of XR-5580 and 3 parts of PU color paste;

[0044] (2) coating the polyurethane adhesive layer slurry on the polyurethane surface layer with a coating thickness of 0.25 mm; and drying at 135° C. for 4 minutes to form a semi-dried polyurethane adhesive layer;

[0045] The composition of the polyurethane bonding layer slurry is: 100 parts of polylactic acid polyol, 60 parts of isocyanate prepolymer, 8 parts of wood cellulose, 0.4 parts of CC 6945 / 90C-CC and 0.6 parts of water.

[0046] (3) A base fabric is laminated on the polyurethane adhesive layer, and the final product is obtained after drying and peeling off the release paper; the drying temperature is 135° C. and the drying time is 4 minutes; the base fabric is composed of polylactic acid and has a thickness of 0.8 mm.

[0047] Example 3

[0048] A method for preparing biodegradable polyurethane synthetic leather comprises the following steps:

[0049] (1) coating a bio-based polyurethane surface layer slurry on a release paper with a coating thickness of 0.5 mm, and drying at 145° C. for 3 min to form a bio-based polyurethane surface layer;

[0050] The composition of the polyurethane surface slurry is: 100 parts of polyester polyurethane surface resin, 10 parts of wood cellulose, 10 parts of montmorillonite, 6 parts of BNK-NSF898, 4.5 parts of HT-100, 1.5 parts of XR-5580 and 5 parts of PU color paste;

[0051] (2) coating the polyurethane adhesive layer slurry on the polyurethane surface layer with a coating thickness of 0.3 mm; and drying at 135° C. for 4 minutes to form a semi-dried polyurethane adhesive layer;

[0052] The composition of the polyurethane bonding layer slurry is: 100 parts of polylactic acid polyol, 70 parts of isocyanate prepolymer, 10 parts of wood cellulose, 0.5 parts of CC 6945 / 90C-CC and 0.7 parts of water.

[0053] (3) Laminating a base fabric on the polyurethane adhesive layer, drying and peeling off the release paper to obtain a final product; the drying temperature is 140° C. and the drying time is 3 minutes; the base fabric is composed of cotton fibers and has a thickness of 0.8 mm.

[0054] Comparative Example 1:

[0055] The preparation method is the same as that in Example 1, except that the coating thickness of the bio-based polyurethane surface slurry is 0.3 mm.

[0056] Comparative Example 2:

[0057] The preparation method is the same as that of Example 1, the only difference being that the surface layer does not use a polyester-type bio-based polyurethane resin but uses a polyether-type bio-based surface layer resin.

[0058] Comparative Example 3:

[0059] The preparation method is the same as that of Example 1, the only difference being that no montmorillonite is used in the surface layer.

[0060] Comparative Example 4:

[0061] The preparation method is the same as in Example 1, except that no curing agent is used in the surface layer.

[0062] Comparative Example 5:

[0063] The preparation method is the same as that of Example 1, the only difference being that the surface layer uses only isocyanate curing agent, and the amount of isocyanate curing agent used is 4 parts.

[0064] Comparative Example 6: The preparation method is the same as that of Example 1, with the only difference being that only carbodiimide curing agent is used as the surface layer, and the amount of carbodiimide curing agent used is 4 parts.

[0065] Comparative Example 7: The preparation method is the same as that of Example 1, except that neither the bio-based polyurethane surface layer nor the adhesive layer uses wood cellulose.

[0066] Comparative Example 8:

[0067] The preparation method is the same as that of Example 1, except that: instead of using polylactic acid polyol as raw material, ordinary polyether polyol is used as raw material, and the polyol composition used is CC 6945 / 1100C-A of BASF Polyurethane (China) Co., Ltd.;

[0068] The polyurethane synthetic leathers prepared in the above Examples 1-3 and Comparative Examples 1-8 were subjected to relevant performance tests, and the test results are shown in Table 1 below.

[0069] Table 1

[0070]

[0071] From the comparison between comparative example 1 and example 1, it can be seen that only when the surface layer reaches a certain thickness, the hydrolysis resistance of the product can reach a certain time. This is because when the surface layer is thick enough, it can protect the inside of the product and increase its durability. From the comparison between comparative example 2 and example 1, it can be seen that the hydrolysis resistance of the polyether type resin is better than that of the polyester type, so that the product is not easy to degrade;

[0072] From the comparison between Comparative Example 3 and Example 1, it can be seen that montmorillonite has a certain wear resistance;

[0073] From the comparison between Comparative Examples 4, 5, 6 and Example 1, it can be seen that when a curing agent is used, the hydrolysis resistance and wear resistance of the product are significantly reduced.

[0074] From the comparison between Comparative Example 7 and Example 1, it can be seen that when lignin is not used, the biobased content of the product is significantly reduced.

[0075] From the comparison between Comparative Example 8 and Example 1, it can be seen that the hydrolysis resistance of the common polyol material is better than the durability of the polylactic acid bio-based polyol material, resulting in incomplete degradation of the product.

[0076] Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A biodegradable polyurethane synthetic leather, characterized in that: From top to bottom, it includes a bio-based polyurethane surface layer, a bio-based polyurethane adhesive layer and a degradable substrate layer, wherein: The bio-based polyurethane surface layer is prepared from a polyurethane surface layer slurry composed of the following components: polyurethane surface layer resin, wood cellulose, montmorillonite, wear-resistant additive, curing agent and color paste; The bio-based polyurethane adhesive layer is prepared from a polyurethane adhesive layer slurry consisting of the following components: polylactic acid polyol, isocyanate prepolymer, wood cellulose, a catalyst and water.

2. The biodegradable polyurethane synthetic leather according to claim 1, characterized in that: The polyurethane surface layer resin is a polyester-type bio-based surface layer resin.

3. The biodegradable polyurethane synthetic leather according to claim 1, characterized in that: The curing agent is a mixture of isocyanate curing agent and carboimide.

4. The biodegradable polyurethane synthetic leather according to claim 3, characterized in that: The isocyanate curing agent is HDI; the mass ratio of HDI to carboimide is 3:

1.

5. The biodegradable polyurethane synthetic leather according to claim 1, characterized in that: The wear-resistant additive is at least one of molybdenum disulfide, polytetrafluoroethylene powder, high molecular weight polyethylene and high molecular weight silicone.

6. The biodegradable polyurethane synthetic leather according to any one of claims 1 to 5, characterized in that: The mass fractions of the components in the polyurethane surface layer slurry are as follows: 100 parts of polyurethane surface layer resin, 5-10 parts of wood cellulose, 5-10 parts of montmorillonite, 4-6 parts of wear-resistant additives, 4-6 parts of curing agents and 1-5 parts of color paste.

7. The biodegradable polyurethane synthetic leather according to any one of claims 1 to 5, characterized in that: The mass fractions of the components in the polyurethane adhesive layer slurry are as follows: 100 parts of polylactic acid polyol, 50-70 parts of isocyanate prepolymer, 10-20 parts of wood cellulose, 0.3-0.5 parts of organic bismuth catalyst and 0.5-0.8 parts of water.

8. The method for preparing the biodegradable polyurethane synthetic leather according to any one of claims 1 to 7, characterized in that: The following steps are involved: Coating a polyurethane surface layer slurry on the release paper with a coating thickness of 0.4-0.5 mm, and drying to form a bio-based polyurethane surface layer; the drying temperature is 130-145° C., and the drying time is 3-5 minutes; Coating a polyurethane bonding layer slurry on the polyurethane surface layer with a coating thickness of 0.2-0.3 mm, pre-reacting at a temperature of 130-135° C. for 3-5 minutes to form a semi-dry bio-based polyurethane bonding layer; The base fabric is laminated on the bio-based polyurethane adhesive layer, and the final product is obtained after drying and peeling off the release paper; the drying temperature is 130-140° C., and the drying time is 3-5 minutes.

9. The use of the biodegradable polyurethane synthetic leather according to any one of claims 1 to 7, characterized in that: The biodegradable polyurethane synthetic leather is used in electronic packaging, interior engineering decorative materials or automobile roofs.

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