Bio-based sofa leather resin as well as preparation method and application thereof

Abstract

The invention discloses bio-based sofa leather resin as well as a preparation method and application thereof. The sofa leather resin is prepared from the following raw materials: a prepolymer, a first chain extender and first polyisocyanate, the prepolymer comprises the following raw materials: polyol A, polyol B, polyol C, polyol D, a second chain extender and second polyisocyanate; the polyol A is prepared from modified vegetable oil and alkylene oxide through a reaction, and the modified vegetable oil is generated from vegetable oil containing hydroxyl and propylene glycol through a reaction; the polyol B is generated by reaction of sebacic acid and 1, 3-propylene glycol; the polyol C is polytetrahydrofuran diol; the polyol D is generated by reacting adipic acid with ethylene glycol and / or 1, 4-butanediol; practices show that the bio-based sofa leather resin not only can obtain a product with stable performance, but also has excellent physical and chemical properties, especially has unexpected improvement in hydrolysis resistance, can still keep excellent peel strength in a high-temperature and high-humidity environment, and can be used for preparing sofas.

Description

Technical Field

[0001] The invention relates to the field of sofa leather, and in particular to a bio-based sofa leather resin and a preparation method and application thereof. Background Art

[0002] At present, most sofa leather resins use polyurethane systems. Since polyurethane synthetic leather itself is not biodegradable and not easy to rot, it brings a large amount of solid waste pollutants to the environment, causing serious impacts on the ecological environment and biological cycle. With the improvement of global environmental awareness and the growing demand for sustainable development, the application scope of bio-based materials continues to expand. As a kind of environmentally friendly material, bio-based sofa leather resin has gradually attracted market attention. However, there is still no bio-based sofa leather resin that is both biodegradable and has excellent physical and mechanical properties, especially the problem of low peel strength and a significant decrease in peel strength under high temperature and high humidity environments.

[0003] It should be noted that the information disclosed in the above background technology section is only used to understand the background of the present application, so the background technology section of the present invention may contain background information about the problem or environment of the present invention, but not necessarily describe the prior art. Therefore, the content contained in the background technology section is not an admission of the applicant to the prior art. Summary of the invention

[0004] The object of the present invention is to overcome one or more deficiencies in the prior art and to provide an improved bio-based sofa leather resin, which can solve at least one problem existing in the prior art.

[0005] The present invention also provides a method for preparing the bio-based sofa leather resin and application of the bio-based sofa leather resin in preparing sofas.

[0006] In order to achieve the above object, a technical solution adopted by the present invention is:

[0007] A bio-based sofa leather resin, wherein the raw materials of the sofa leather resin include a prepolymer, a first chain extender and a first polyisocyanate;

[0008] The raw materials of the prepolymer include polyol A, polyol B, polyol C, polyol D, a second chain extender and a second polyisocyanate, and the molar ratio of the polyol A, the polyol B, the polyol C and the polyol D is 0.2-0.3: 0.2-0.3: 0.2-0.4: 0.1-0.2;

[0009] The polyol A is prepared by reacting modified vegetable oil and alkylene oxide, wherein the modified vegetable oil is prepared by reacting vegetable oil containing hydroxyl groups and propylene glycol, and the number average molecular weight of the polyol A is 1800-3000;

[0010] The polyol B is produced by the reaction of sebacic acid and 1,3-propylene glycol, and has a number average molecular weight of 2000-2500;

[0011] The polyol C is polytetrahydrofuran diol, and the number average molecular weight of the polyol C is 1500-2500;

[0012] The polyol D is produced by the reaction of adipic acid with ethylene glycol and / or 1,4-butanediol, and the number average molecular weight of the polyol D is 3000-5000;

[0013] At least one of the sebacic acid, the 1,3-propylene glycol, the adipic acid, the ethylene glycol, and the 1,4-butanediol is 100% of plant origin.

[0014] According to some preferred aspects of the present invention, in the polyol A, the vegetable oil containing hydroxyl groups includes castor oil.

[0015] In some embodiments of the present invention, in the polyol A, the alkylene oxide is composed of ethylene oxide and propylene oxide, and in terms of molar percentage, the ethylene oxide accounts for 4mol%-8mol% of the alkylene oxide, and the propylene oxide accounts for 92mol%-96mol% of the alkylene oxide.

[0016] In some embodiments of the present invention, in the polyol A, the added amount of the alkylene oxide accounts for 200%-500% of the modified vegetable oil in terms of mass percentage.

[0017] In some embodiments of the present invention, in the polyol A, the added amount of the propylene glycol accounts for 25%-100% of the vegetable oil containing hydroxyl groups in terms of molar percentage.

[0018] In some embodiments of the present invention, the preparation method of the polyol A comprises: mixing a vegetable oil containing a hydroxyl group, propylene glycol and an alkaline catalyst, reacting at 160-170° C. to generate a modified vegetable oil, and then adding alkylene oxide under a protective atmosphere, at 100-130° C., and at 0.1-0.4 MPa, and reacting with a catalyst to generate the third polyol.

[0019] According to some specific aspects of the present invention, the number average molecular weight of the polyol A is 2000-2800.

[0020] In some embodiments of the present invention, in the polyol B, the molar ratio of the sebacic acid to the 1,3-propylene glycol is 1:1.15-1.25.

[0021] In some embodiments of the present invention, the preparation method of the polyol B comprises: mixing sebacic acid, 1,3-propylene glycol and a catalyst, heating the mixture to react, when the temperature rises to 130-150°C, evaporating water, and then raising the temperature to 210-230°C for reaction to generate the polyol B.

[0022] In some embodiments of the present invention, the hydroxyl value of the polyol B is 45-55 mgKOH / g.

[0023] According to some specific aspects of the present invention, the number average molecular weight of the polyol B is 2100-2300.

[0024] According to some specific aspects of the present invention, the number average molecular weight of the polyol C is 1800-2200.

[0025] In some embodiments of the present invention, in the polyol D, the molar ratio of the oxalic acid to the 1,4-butanediol is 1:1.05-1.1.

[0026] In some embodiments of the present invention, the preparation method of the polyol D comprises: mixing adipic acid, ethylene glycol and / or 1,4-butanediol, and a catalyst, heating the mixture for reaction, and when the temperature rises to 130-150° C., evaporating water, and then raising the temperature to 210-230° C. for reaction to generate the polyol D.

[0027] In some embodiments of the present invention, the hydroxyl value of the polyol D is 20-35 mgKOH / g.

[0028] According to some specific aspects of the present invention, the number average molecular weight of the polyol D is 3500-4500, further 3800-4200.

[0029] According to some preferred aspects of the present invention, the total molar amount of the polyol A, the polyol B, the polyol C, and the polyol D is recorded as M1, the total molar amount of the first chain extender and the second chain extender is recorded as M2, and the total molar amount of the first polyisocyanate and the second polyisocyanate is recorded as M3, M1:M2:M3=1:2.0-3.0:3.0-4.0.

[0030] In some embodiments of the present invention, the molar ratio of the first chain extender to the second chain extender is 3-5:1, further 3.5-4.5:1.

[0031] In some embodiments of the present invention, the molar ratio of the first polyisocyanate to the second polyisocyanate is 1-3:1, further 1.5-2.5:1.

[0032] In some embodiments of the present invention, the first polyisocyanate and the second polyisocyanate are diphenylmethane diisocyanate respectively.

[0033] According to some preferred aspects of the present invention, the first chain extender and the second chain extender are respectively diols with a functionality of 2.

[0034] In some embodiments of the present invention, the first chain extender and the second chain extender are independently selected from a combination of one or more of ethylene glycol, propylene glycol, and 1,4-butanediol.

[0035] According to some specific aspects of the present invention, at 65° C., the viscosity of the bio-based sofa leather resin is 60-70 Pa·s.

[0036] In some embodiments of the present invention, the raw material of the sofa leather resin further comprises a solvent (eg N,N-dimethylformamide) and an auxiliary agent, wherein the auxiliary agent comprises a terminator (eg methanol, ethylene glycol) and an antioxidant and the like.

[0037] Another technical solution provided by the present invention is a method for preparing the above-mentioned bio-based sofa leather resin, the preparation method comprising:

[0038] Preparing a prepolymer: mixing polyol A, polyol B, polyol C, polyol D, a second chain extender and a second polyisocyanate, and reacting them to form a prepolymer;

[0039] Preparation of bio-based sofa leather resin: mixing a prepolymer, a first chain extender and a first polyisocyanate, and reacting the mixture to a preset viscosity.

[0040] Furthermore, in the preparation process of the bio-based sofa leather resin, the reaction temperature is 75-85°C.

[0041] Another technical solution provided by the present invention is: use of the above-mentioned bio-based sofa leather resin in the preparation of sofas.

[0042] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0043] The present invention prepares a specific prepolymer by combining multiple specific polyols and reacting them with part of the chain extender and isocyanate in advance, and then reacting them with the remaining chain extenders and isocyanate. Practice shows that this bio-based sofa leather resin can not only obtain products with stable performance, but also has relatively excellent physical and chemical properties, especially unexpectedly improved in hydrolysis resistance, and can still maintain excellent peel strength under high temperature and high humidity environment. In addition, part of the raw materials of the present invention can be replaced by bio-based raw materials, which is highly environmentally friendly and can be used for the preparation of sofas. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a state diagram of the sofa leather resin obtained in Example 1 of the present invention after being tested by a high temperature and high pressure device;

[0045] Figure 2 This is a state diagram of the sofa leather sample after the sofa leather resin obtained in Example 2 of the present invention is tested by a high temperature and high pressure device;

[0046] Figure 3 This is a state diagram of the sofa leather resin obtained in Comparative Example 1 of the present invention after being tested by a high temperature and high pressure device;

[0047] Figure 4 This is a state diagram of the sofa leather resin obtained in Comparative Example 2 of the present invention after being tested by a high temperature and high pressure device;

[0048] Figure 5 This is a state diagram of the sofa leather sample after the sofa leather resin obtained in Comparative Example 3 of the present invention is tested by high temperature and high pressure equipment. DETAILED DESCRIPTION

[0049] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0050] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0051] Castor oil was purchased from Nanjing Jinghaojie.

[0052] Example 1

[0053] This example provides a bio-based sofa leather resin and a preparation method thereof. The raw materials of the bio-based sofa leather resin include a prepolymer, ethylene glycol: 10.58g and diphenylmethane diisocyanate: 49.04g;

[0054] The raw materials of the prepolymer include polyol A: 42.64 g, polyol B: 46.91 g, polyol C: 51.17 g, polyol D: 68.23 g, ethylene glycol: 2.64 g and diphenylmethane diisocyanate: 25.59 g;

[0055] The raw materials of the bio-based sofa leather resin also include 700 g of N,N-dimethylformamide, 1 g of a terminator: methanol, and 2.2 g of an auxiliary agent (specifically, an antioxidant 1010).

[0056] The preparation method of the bio-based sofa leather resin comprises:

[0057] 1. Polyol A: 42.64g, polyol B: 46.91g, polyol C: 51.17g, polyol D: 68.23g, ethylene glycol: 2.64g, diphenylmethane diisocyanate: 25.59g, and antioxidant 1010 2.2g were heated and mixed in 175g of N,N-dimethylformamide, and reacted at 75-80°C for 1.5 hours to prepare a prepolymer;

[0058] 2. Add 210 g of N,N-dimethylformamide, cool to 60°C and add 10.58 g of ethylene glycol and stir evenly, then add 49.04 g of diphenylmethane diisocyanate and continue the reaction;

[0059] 3. After reaching the predetermined high temperature viscosity (about 235±15Pa·s / 80℃), add 315g of N,N-dimethylformamide and 1g of methanol as a terminator;

[0060] 4. The viscosity is tested to be 65±5Pa·s / 65℃, and then packaged after cooling.

[0061] Among them, polyol A is prepared by the following method: 1000g castor oil, 60g 1,3-propylene glycol and 4g sodium hydroxide are added to the reactor, stirred evenly and heated to 170°C, reacted for 3 hours to obtain modified castor oil. Take 220g modified castor oil and add it to the autoclave, add 2.5g sodium hydroxide, control the temperature at 120°C and replace it with nitrogen, keep the pressure at 0.2MPa, add 800g EO ethylene oxide / PO propylene oxide (the molar ratio of ethylene oxide to propylene oxide is 0.4 / 9.6) to carry out polymerization reaction. After the reaction is completed, continue the internal pressure reaction for 3 hours to ensure that the reaction is complete. Then vacuum for 1 hour to remove the unreacted alkylene oxide monomer and small molecule by-products. Add phosphoric acid and water for neutralization, then adsorb with magnesium silicate, then decompress and dehydrate, and then filter to obtain crude polyether polyol. The crude polyether polyol is distilled to remove trace moisture and other impurities to obtain polyol A with a number average molecular weight of about 2000;

[0062] Polyol B is prepared by the following method: adding bio-based sebacic acid and bio-based 1,3-propylene glycol into a reactor at a molar ratio of 1:1.2, and adding tetrabutyl titanate (the addition amount of which is 1wt.% of the total amount of bio-based sebacic acid and bio-based 1,3-propylene glycol), heating the reaction, raising the temperature to 140°C, distilling off water at normal pressure, and then raising the temperature to 220°C for 2 hours. After the acid value reaches 0.5 mgKOH / g, vacuuming and gradually increasing the vacuum degree, reducing pressure to remove trace amounts of water and excess diol compounds, and finally obtaining polyol B with a number average molecular weight of about 2200;

[0063] Polyol C is polytetramethylene glycol PTMEG-2000 with a number average molecular weight of about 2000, purchased from Hangzhou Sanlong New Materials Co., Ltd.

[0064] Polyol D is prepared by the following method: 1,6-hexanediol and ethylene glycol / 1,4-butanediol (the molar ratio of ethylene glycol to 1,4-butanediol is 1:1) are added into a reactor in a molar ratio of 1:1.1, tetrabutyl titanate is added (the addition amount is 1wt.% of the total amount of 1,6-hexanediol and ethylene glycol / 1,4-butanediol), the temperature is increased to react, the temperature is increased to 140°C, the water is distilled off at normal pressure, and then the temperature is increased to 220°C and maintained for 2 hours. After the acid value reaches 0.5 mgKOH / g, vacuum is drawn and the vacuum degree is gradually increased, and the trace amount of water and excess diol compounds are removed under reduced pressure to finally obtain polyol D with a number average molecular weight of about 4000.

[0065] Example 2

[0066] This example provides a bio-based sofa leather resin and a preparation method thereof. The raw materials of the bio-based sofa leather resin include prepolymer, ethylene glycol: 9.07g and diphenylmethane diisocyanate: 42.04g

[0067] The raw materials of the prepolymer include polyol A: 65.15 g, polyol B: 44.24 g, polyol C: 40.22 g, polyol D: 64.35 g, ethylene glycol: 2.49 g and diphenylmethane diisocyanate: 21.93 g;

[0068] The raw materials of the bio-based sofa leather resin also include 700 g of N,N-dimethylformamide, 1 g of a terminator: methanol, and 2.2 g of an auxiliary agent (specifically, an antioxidant 1010).

[0069] The preparation method of the bio-based sofa leather resin comprises:

[0070] 1. 65.15 g of polyol A, 44.24 g of polyol B, 40.22 g of polyol C, 64.35 g of polyol D, 2.49 g of ethylene glycol, 21.93 g of diphenylmethane diisocyanate and 2.2 g of antioxidant 1010 were heated and mixed in 175 g of N,N-dimethylformamide, and reacted at 75-80° C. for 1.5 hours to prepare a prepolymer;

[0071] 2. Add 210 g of N,N-dimethylformamide, cool to 60°C and add 9.07 g of ethylene glycol and stir evenly, then add 42.04 g of diphenylmethane diisocyanate and continue the reaction;

[0072] 3. After reaching the predetermined high temperature viscosity (about 235±15Pa·s / 80℃), add 315g of N,N-dimethylformamide and 1g of methanol as a terminator;

[0073] 4. The viscosity is tested to be about 65±5Pa·s / 65℃, and it is packaged after cooling.

[0074] Polyol A, polyol B, polyol C and polyol D are the same as those in Example 1.

[0075] Comparative Example 1

[0076] This example provides a sofa leather resin and a preparation method thereof, which is basically the same as Example 1, except that polyol A is not added, and polyol A is replaced by an equal molar amount of polyol B, keeping the total added molar amount of polyol unchanged.

[0077] Comparative Example 2

[0078] This example provides a sofa leather resin and a preparation method thereof, which is basically the same as Example 1, except that polyol A is not added, and polyol A is replaced by an equimolar amount of polyol C, keeping the total added molar amount of the polyol unchanged.

[0079] Comparative Example 3

[0080] This example provides a sofa leather resin and a preparation method thereof, which is basically the same as Example 1, except that no polyol B is added, and polyol B is replaced by an equimolar amount of polyol D, keeping the total added molar amount of the polyol unchanged.

[0081] Performance Testing

[0082] The sofa leather resins obtained in the above-mentioned Examples 1-2 and Comparative Examples 1-3 were tested as follows. The testing method is as follows: the sofa leather resin is processed into leather samples, and the peel strength is tested after being placed in a high-temperature and high-pressure device at 0.1 MPa and 120 degrees Celsius for 48 hours. The test is also performed before being placed in the device. The specific results are shown in Table 1. The state of the leather samples after being tested by the high-temperature and high-pressure device is shown in Table 2.

[0083] Table 1

[0084]

[0085] The test standard for peel strength is: DIN53273.

[0086] Table 2

[0087] Status performance Whether it is cracked Example 1 good Uncracked Example 2 good Uncracked Comparative Example 1 Difference Cracking Comparative Example 2 middle About to crack Comparative Example 3 middle About to crack

[0088] See the state diagram of the leather sample after the sofa leather resin obtained in Example 1-2 and Comparative Example 1-3 was tested by high temperature and high pressure equipment. Figures 1 to 5As shown, no cracking was observed in Examples 1-2 ( Figure 1 and Figure 2 ), the state performance is good, while the comparative example 1 is the worst, and cracking has occurred ( Figure 3 ), Comparative Example 2-3 can be seen to be beginning to break, with slight cracks occurring at the edges, and is about to crack on a large scale.

[0089] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0090] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A bio-based sofa leather resin, characterized in that: The raw materials of the sofa leather resin include a prepolymer, a first chain extender and a first polyisocyanate; The raw materials of the prepolymer include polyol A, polyol B, polyol C, polyol D, a second chain extender and a second polyisocyanate, and the molar ratio of the polyol A, the polyol B, the polyol C and the polyol D is 0.2-0.3: 0.2-0.3: 0.2-0.4: 0.1-0.2; The polyol A is prepared by reacting modified vegetable oil and alkylene oxide, wherein the modified vegetable oil is prepared by reacting vegetable oil containing hydroxyl groups and propylene glycol, and the number average molecular weight of the polyol A is 1800-3000; The polyol B is produced by the reaction of sebacic acid and 1,3-propylene glycol, and has a number average molecular weight of 2000-2500; The polyol C is polytetrahydrofuran diol, and the number average molecular weight of the polyol C is 1500-2500; The polyol D is produced by the reaction of adipic acid with ethylene glycol and / or 1,4-butanediol, and the number average molecular weight of the polyol D is 3000-5000; At least one of the sebacic acid, the 1,3-propylene glycol, the adipic acid, the ethylene glycol, and the 1,4-butanediol is 100% of plant origin.

2. The bio-based sofa leather resin according to claim 1, characterized in that: In the polyol A, the vegetable oil containing hydroxyl groups includes castor oil; and / or, In the polyol A, the alkylene oxide is composed of ethylene oxide and propylene oxide, and in terms of molar percentage, the ethylene oxide accounts for 4mol%-8mol% of the alkylene oxide, and the propylene oxide accounts for 92mol%-96mol% of the alkylene oxide; and / or, In the polyol A, the amount of the alkylene oxide added accounts for 200%-500% of the modified vegetable oil in terms of mass percentage; and / or, In the polyol A, the added amount of the propylene glycol accounts for 25%-100% of the vegetable oil containing hydroxyl groups in terms of molar percentage.

3. The bio-based sofa leather resin according to claim 1, characterized in that The preparation method of the polyol A comprises: mixing a vegetable oil containing hydroxyl groups, propylene glycol and an alkaline catalyst, reacting at 160-170° C. to generate a modified vegetable oil, and then adding alkylene oxide under a protective atmosphere at 100-130° C. and 0.1-0.4 MPa, and reacting with a catalyst to generate the third polyol.

4. The bio-based sofa leather resin according to claim 1, characterized in that In the polyol B, the molar ratio of sebacic acid to 1,3-propylene glycol is 1:1.15-1.25; and / or, The preparation method of the polyol B comprises: mixing sebacic acid, 1,3-propylene glycol and a catalyst, heating to react, when the temperature is raised to 130-150° C., evaporating water, and then raising the temperature to 210-230° C., reacting to generate the polyol B; and / or, The hydroxyl value of the polyol B is 45-55 mgKOH / g.

5. The bio-based sofa leather resin according to claim 1, characterized in that: In the polyol D, the molar ratio of oxalic acid to 1,4-butanediol is 1:1.05-1.1; and / or, The preparation method of the polyol D comprises: mixing adipic acid, ethylene glycol and / or 1,4-butanediol and a catalyst, heating the mixture to react, when the temperature rises to 130-150° C., evaporating water, and then raising the temperature to 210-230° C., reacting to generate the polyol D; and / or, The hydroxyl value of the polyol D is 20-35 mgKOH / g.

6. The bio-based sofa leather resin according to claim 1, characterized in that: The total molar amount of the polyol A, the polyol B, the polyol C, and the polyol D is recorded as M1, the total molar amount of the first chain extender and the second chain extender is recorded as M2, and the total molar amount of the first polyisocyanate and the second polyisocyanate is recorded as M3, M1:M2:M3=1:2.0-3.0:3.0-4.0; and / or, The molar ratio of the first chain extender to the second chain extender is 3-5:1, further 3.5-4.5:1; and / or, The molar ratio of the first polyisocyanate to the second polyisocyanate is 1-3:1, further 1.5-2.5:

1.

7. The bio-based sofa leather resin according to claim 1, characterized in that: The first polyisocyanate and the second polyisocyanate are diphenylmethane diisocyanate respectively; and / or the first chain extender and the second chain extender are diols with a functionality of 2 respectively.

8. The bio-based sofa leather resin according to claim 1, characterized in that: The first chain extender and the second chain extender are independently selected from a combination of one or more of ethylene glycol, propylene glycol, and 1,4-butanediol; and / or, at 65° C., the viscosity of the bio-based sofa leather resin is 60-70 Pa·s.

9. A method for preparing a bio-based sofa leather resin according to any one of claims 1 to 8, characterized in that: The preparation method comprises: Preparing a prepolymer: mixing polyol A, polyol B, polyol C, polyol D, a second chain extender and a second polyisocyanate, and reacting them to form a prepolymer; Preparation of bio-based sofa leather resin: mixing a prepolymer, a first chain extender and a first polyisocyanate, and reacting the mixture to a preset viscosity.

10. Use of the bio-based sofa leather resin according to any one of claims 1 to 8 in the preparation of sofas.

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