A biomimetic modified bio-based wax and a method of making the same

Abstract

The application provides a kind of bionic modified bio-based wax, including the following components: bionic water-based polyurethane modifier, biological wax, leveling agent, deionized water and PH buffer, wherein the raw materials for preparing the bionic water-based polyurethane modifier include polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, organic solvent and tertiary amine. The preparation method of bionic modified bio-based wax includes the following steps: after mixing polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, organic solvent, reaction is carried out, after reaction, neutralize and stir dispersion into emulsion by adding tertiary amine, to obtain the bionic water-based polyurethane modifier with reactivity; after mixing bionic water-based polyurethane modifier, biological wax, leveling agent and deionized water, high-speed stirring emulsification is carried out, neutralize by adding PH buffer, then stand cooling to room temperature, take the obtained bionic modified emulsion, coat on leather substrate, and place in oven for curing.

Description

TECHNICAL FIELD

[0001] The application relates to the field of functional polymer leather surface protection technology, in particular to a biomimetic modified bio-based wax and a preparation method thereof. BACKGROUND

[0002] Leather has a long history of use, and is also widely used in daily life, but there are some problems in the use process. Most leathers will have problems such as wrinkles, peeling, discoloration, lack of gloss, deformation and the like to varying degrees after being used for a period of time.

[0003] At present, the adhesion of the wax to the substrate in the prior art is poor, and the leather cannot maintain a long-lasting luster, resulting in a general long-term stain resistance effect, which cannot meet the use requirements of the leather. SUMMARY

[0004] The application provides a biomimetic modified bio-based wax and a preparation method thereof, so as to solve the problems in the related art. The technical scheme is as follows:

[0005] In a first aspect, the application provides a biomimetic modified bio-based wax, which comprises the following components: a biomimetic water-based polyurethane modifier, a bio-based wax, a leveling agent, deionized water and a pH buffer, wherein the preparation raw material of the biomimetic water-based polyurethane modifier comprises polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, organic solvent and tertiary amine.

[0006] In an embodiment, the biomimetic water-based polyurethane modifier, the bio-based wax, the leveling agent, the deionized water and the pH buffer are used in a ratio of (5-10) g:(5-10) g:(0.05-1) g:(0.02-0.3) g:(40-80) g.

[0007] The polyester polyol, the diisocyanate, the functional monomer, the chain extender, the crosslinking agent, the initiator, the organic solvent and the tertiary amine are used in a ratio of 100 g:(20-36) g:(1-10) g:(1-5) g:(1-3) g:(0.02-0.1) mL:(10-20) mL:(2-5) g.

[0008] In an embodiment, the bio-based wax comprises at least one of sunflower seed wax, carnauba wax and beeswax.

[0009] The leveling agent is selected from DOSS-75E of HARCROS, USA.

[0010] The pH buffer is selected from Dow AMP-95.

[0011] In an embodiment, the diisocyanate comprises at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tetramethylxylylene diisocyanate;

[0012] The functional monomer is dopamine hydrochloride.

[0013] In an embodiment, the chain extender comprises at least one of 1,4-butanediol, ethylene glycol, propylene glycol, triethylenetetramine, adipic acid dihydrazide;

[0014] The crosslinking agent is dimethylol butanoic acid.

[0015] In an embodiment, the initiator comprises at least one of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate;

[0016] The organic solvent comprises at least one of acetone, N,N-dimethylacetamide, and N,N-dimethylformamide.

[0017] In a second aspect, the embodiments of the present application provide a preparation method of a biomimetic modified bio-based wax, for preparing the biomimetic modified bio-based wax described in any of the above, comprising the following steps:

[0018] After mixing the polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, and organic solvent, the mixture is reacted, and after the reaction, a tertiary amine is added for neutralization and stirring to disperse into an emulsion, to obtain a biomimetic waterborne polyurethane modifier with reactivity;

[0019] After mixing the biomimetic waterborne polyurethane modifier, bio-based wax, leveling agent, and deionized water, the mixture is high-speed stirred and emulsified, a PH buffer is added for neutralization, and then the mixture is left to cool to room temperature, and the obtained biomimetic modified emulsion is coated on a leather substrate and placed in an oven for curing, to obtain a biomimetic modified bio-based wax.

[0020] In an embodiment, after mixing the polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, and organic solvent, the mixture is reacted, and the reaction temperature is 70-95℃, and the reaction time is 4-6h.

[0021] In an embodiment, the stirring speed of the high-speed stirring is 2000-3000rpm, and the stirring time is 15-30min.

[0022] In an embodiment, the placing in the oven for curing is performed at a temperature of 40℃, and the curing time is 2h.

[0023] The above technical solution has at least the following advantages or beneficial effects:

[0024] The application prepares a functional polymer leather surface protective wax oil (i.e. biomimetic modified biological wax film). The wax oil is prepared by a simple modification and compounding process. First, a functional monomer is introduced by polyurethane to provide carboxyl groups to make the emulsion water-based and provide dopamine with catechol groups to tightly bind to the leather substrate. Second, the polyurethane modifier is self-crosslinked with biological wax at room temperature through intermolecular forces to make the film more dense. The method of the application can be simply prepared and applied. The prepared wax oil can reduce the number of times and time of applying the leather product, and does not stick at high temperature, thereby meeting the environment and needs of the use of leather.

[0025] The above summary is intended to illustrate, but not limit, the application in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features will be readily apparent to those skilled in the art by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0026] In the drawings, like reference numerals refer to like elements throughout the various drawings. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating certain principles of the application. It should be understood that the drawings are merely depictions of some embodiments in accordance with the disclosure and should not be construed as limiting the scope of the application.

[0027] Figure 1 The preparation method flowchart of the biomimetic modified biological wax of the application is shown.

[0028] Figure 2 The schematic diagram for testing the adhesion of the biomimetic modified biological wax to leather is shown.

[0029] Figure 3 The shear strength test result graph of Example 1-Example 4 is shown.

[0030] Figure 4 The water contact angle test result graph of Example 1-Example 4 is shown. DETAILED DESCRIPTION

[0031] In the following, only some exemplary embodiments are described in brief. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0032] The application is inspired by the fact that mussels can adhere to solid surfaces such as rocks, ship hulls, and cables under seawater without being eroded by pollutants and microorganisms in the ocean and can resist the erosion of wind and waves. A biomimetic strategy is proposed, which selects a safe and environmentally friendly biological wax as a wax film applied to the surface of leather, and crosslinks with a biomimetic waterborne polyurethane modifier to greatly improve the adhesion of the modified biological wax film to the substrate, so that a dense protective film can be formed on the surface of leather products. The film has excellent adhesion performance on the surface of the leather substrate, can maintain a long-lasting shine, and can also provide long-term stain and water resistance. In the field of leather surface protection technology, it is a challenging problem and has broad application prospects.

[0033] In a first aspect, the embodiments of the present application provide a biomimetic modified biological wax, comprising the following components: a biomimetic waterborne polyurethane modifier, a biological wax, a leveling agent, deionized water, and a PH buffer, wherein the raw materials for preparing the biomimetic waterborne polyurethane modifier include polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator, organic solvent, and tertiary amine.

[0034] In an embodiment, the biomimetic waterborne polyurethane modifier, the biological wax, the leveling agent, the deionized water, and the PH buffer are used in a ratio of (5-10) g:(5-10) g:(0.05-1) g:(0.02-0.3) g:(40-80) g.

[0035] In an embodiment, the polyester polyol, the diisocyanate, the functional monomer, the chain extender, the crosslinking agent, the initiator, the organic solvent, and the tertiary amine are used in a ratio of 100 g:(20-36) g:(1-10) g:(1-5) g:(1-3) g:(0.02-0.1) mL:(10-20) mL:(2-5) g.

[0036] In an embodiment, the biological wax includes at least one of sunflower seed wax, carnauba wax, and beeswax. These contain biological components and have excellent slip resistance, friction resistance, and film transparency, and can balance the advantages of sustainable development and reduce the environmental impact of the coating.

[0037] In an embodiment, the leveling agent is selected from DOSS-75E of HARCROS, USA.

[0038] In an embodiment, the PH buffer is selected from Dow AMP-95.

[0039] In an embodiment, the diisocyanate includes at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tetramethyl benzyl diisocyanate, and isophorone diisocyanate can be preferably selected.

[0040] In an embodiment, the functional monomer is dopamine hydrochloride, providing a catechol group.

[0041] In an embodiment, the chain extender comprises at least one of 1,4-butanediol, ethylene glycol, propylene glycol, triethylene tetramine, adipic acid dihydrazide.

[0042] In an embodiment, the crosslinking agent is dimethylol butanoic acid.

[0043] In an embodiment, the initiator comprises at least one of dibutyl tin dilaurate, stannous octoate and dibutyl tin diacetate.

[0044] In an embodiment, the organic solvent comprises at least one of acetone, N,N-dimethylacetamide and N,N-dimethylformamide.

[0045] In a second aspect, the embodiments of the present application provide a preparation method of the biomimetic modified bio-based wax, for preparing the biomimetic modified bio-based wax described in any of the above embodiments, comprising the following steps:

[0046] In step 101, the polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator and organic solvent are mixed and reacted, and then a tertiary amine is added for neutralization and stirring and dispersion into an emulsion to obtain a biomimetic waterborne polyurethane modifier with reactivity;

[0047] In step 102, the biomimetic waterborne polyurethane modifier, bio-based wax, leveling agent and deionized water are mixed and emulsified at high speed, a PH buffer is added for neutralization, and then the mixture is left to cool to room temperature, and the obtained biomimetic modified emulsion is coated on a leather substrate and placed in an oven for curing to obtain the biomimetic modified bio-based wax.

[0048] In an embodiment, the polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, initiator and organic solvent are mixed and reacted, and the reaction temperature is 70-95°C and the reaction time is 4-6h. The reaction temperature of 70-95°C is to react the alcohol hydroxyl group with the isocyanate group, and the reaction time of 4-6h enables more sufficient reaction.

[0049] In an embodiment, the stirring speed of the high-speed stirring is 2000-3000rpm and the stirring time is 15-30min. Such setting enables more sufficient reaction.

[0050] In an embodiment, the curing in the oven is at a temperature of 40°C and for a time of 2h.

[0051] In addition, the biomimetic modified emulsion prepared in step 2 can be perfumed by adding a fragrance and stirring, and the dosage ratio of the biomimetic modified emulsion to the fragrance is 100g:(0.5-2)g.

[0052] Example 1

[0053] The preparation method of the biomimetic modified bio-based wax of the present embodiment is as follows:

[0054] S1: Isophorone diisocyanate (IPDI) 22.3 g, polyester polyol (molecular weight 2000) 100 g, n(polyol):(isocyanate) = 1:2, dimethylol butyric acid 1.9 g, 1,4-butanediol 3.4 g, acetone 10 mL, dibutyltin dilaurate 50 ul are added to a four-necked flask, stirred uniformly and reacted at 75°C for 6 h, then neutralized by adding tertiary amine to obtain an aqueous polyurethane modifier;

[0055] S2: The above obtained aqueous polyurethane modifier 10 g, carnauba wax 10 g, deionized water 80 g are mixed and stirred, emulsified for 15 min, and cooled to room temperature, then emulsified for 30 min after adding leveling agent 0.05 g and PH buffer 0.02 g, adding essence 0.5 g, continuing to stir for 10 min, standing and cooling to room temperature, taking the obtained emulsion to coat on a leather substrate, and placing in a 40°C oven for curing for 24 h to obtain a biomimetic modified bio-based wax.

[0056] Example 2

[0057] Please refer to Figure 2 The preparation method of the biomimetic modified bio-based wax of the present embodiment is as follows:

[0058] S1: Isophorone diisocyanate (IPDI) 22.3 g, polyester polyol (molecular weight 2000) 100 g, dimethylol butyric acid 1.9 g, 1,4-butanediol 3.2 g, dopamine hydrochloride 1.9 g [n(-NCO):n(-NH2) = 0.1:0.01], acetone 10 mL, dibutyltin dilaurate 50 ul are added to a four-necked flask, stirred uniformly and reacted at 75°C for 6 h, then neutralized by adding tertiary amine to obtain a biomimetic aqueous polyurethane modifier.

[0059]

[0060] The above is the reaction formula of Example 2, wherein the alcohol hydroxyl group (-OH) in the polyester polyol reacts with the -NCO group of the diisocyanate under the action of a catalyst to synthesize a prepolymer, the dimethylol butyric acid and 1,4-butanediol are added, the dopamine hydrochloride is dissolved in an organic solvent, the -OH in the dimethylol butyric acid and the -OH in the 1,4-butanediol, and the -NH2 in the dopamine hydrochloride react with the -NCO and the remaining -NCO in the prepolymer to obtain a biomimetic aqueous polyurethane modifier. It should be understood that if other alternative raw materials are used, the reaction principle is similar, and will not be repeated here.

[0061] S2: Take the above obtained waterborne polyurethane modifier 10 g, carnauba wax 10 g, deionized water 80 g and mix stirring, emulsification 15 minutes, and cool to room temperature, then add leveling agent 0.05 g and PH buffer 0.02 g emulsification 30 minutes, add essence 0.5 g, continue stirring 10 minutes, stand cooling to room temperature, take the obtained emulsion coated on the leather substrate, and placed in 40°C oven curing 24 h, to get the biomimetic modified bio-based wax.

[0062] Example 3

[0063] The preparation method of the biomimetic modified bio-based wax of the present embodiment is as follows:

[0064] S1: Isophorone diisocyanate (IPDI) 22.3 g, polyester polyol (molecular weight 2000) 100 g, dimethylol butyric acid 1.9 g, 1,4-butanediol 2.25 g, dopamine hydrochloride 9.48 g [n(-NCO):n(-NH2)=0.1:0.05], acetone 10 mL, dibutyl tin dilaurate 50 ul are added to a four-necked flask, stirring uniformly at 75°C for 6 h, then adding tertiary amine neutralization, to get the biomimetic waterborne polyurethane modifier;

[0065] S2: Take the above obtained waterborne polyurethane modifier 10 g, carnauba wax 10 g, deionized water 80 g and mix stirring, emulsification 15 minutes, and cool to room temperature, then add leveling agent 0.05 g and PH buffer 0.02 g emulsification 30 minutes, add essence 0.5 g, continue stirring 10 minutes, stand cooling to room temperature, take the obtained emulsion coated on the leather substrate, and placed in 40°C oven curing 24 h, to get the biomimetic modified bio-based wax.

[0066] Example 4

[0067] The preparation method of the biomimetic modified bio-based wax of the present embodiment is as follows:

[0068] S1: Isophorone diisocyanate (IPDI) 22.3 g, polyester polyol (molecular weight 2000) 100 g, dimethylol butyric acid 1.9 g, 1,4-butanediol 2.25 g, dopamine hydrochloride 9.48 g [n(-NCO):n(-NH2)=0.1:0.05], acetone 10 mL, dibutyl tin dilaurate 50 ul are added to a four-necked flask, stirring uniformly at 75°C for 6 h, then adding tertiary amine neutralization, to get the biomimetic waterborne polyurethane modifier;

[0069] S2: Take the above obtained waterborne polyurethane modifier 5g, carnauba wax 15g, deionized water 20g and mix stirring, emulsification 15 minutes, and cool to room temperature, then add leveling agent 0.05g and PH buffer 0.02g emulsification 30 minutes, add essence 0.5g, continue stirring 10 minutes, stand cooling to room temperature, take the obtained emulsion coated on the leather substrate, and placed in 40℃ oven curing 24h, get the modified bio-based wax.

[0070] Please refer to Figure 2 and Figure 3 , the adhesion test is generally done with a mechanical tensile machine, and Figure 2 effect, the two ends of the substrate are clamped at the two ends of the tensile machine, and the adhesion can be obtained by stretching upward. Example 1 does not add dopamine hydrochloride, so the adhesion is poor, and the comparison of examples 2 and 3 is that the more dopamine hydrochloride is added, the better the adhesion is, and the adhesion is slightly decreased when the content of waterborne polyurethane modifier is reduced in example 4.

[0071] Please refer to Figure 4 , the contact angle is generally tested by optical contact angle instrument, 5μL distilled water is dropped on different positions of the coating respectively, and the average value is taken after 5 times of test, removing the maximum and minimum. The content of polyurethane modifier added in example 1, example 2 and example 3 is more, and the hydrophobicity is lower, the content of carnauba wax added in example 4 is more, and the hydrophobicity is stronger, so the surface energy is low, and the antifouling and waterproof effect is better.

[0072] On the basis of the existing invention patent: 201810711662.8 Antibacterial water-based shoe polish and its preparation method, the steps are optimized and improved. In this invention, acrylate polyurethane emulsion is synthesized to increase the adhesion of the material to the substrate, the resistance to strong acid and strong base, and the anti-aging performance. However, the synthesis process is complex, the polymerization efficiency is low, and the toxicity is large. In this application, dopamine hydrochloride is used to modify the polyurethane emulsion, replacing the acrylate polyurethane synthesized by polymerization. The catechol group in dopamine can form various non-covalent bonds with the substrate, including hydrogen bonds, hydrophobic interactions, Π-Π bonds and metal coordination bonds. It can react with the -NCO of diisocyanate and the amino group in dopamine to form a strong adhesion biomimetic waterborne polyurethane modifier with the substrate. Then the polyurethane segment is crosslinked to the biological wax by intermolecular forces such as hydrogen bonds. Because the isocyanate bond and the biological wax structure both have rich hydrogen bonds, this modification is more uniform and compact. A simple, strongly adhered, antifouling modified bio-based wax film is developed and applied to the field of leather surface protection technology.

[0073] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Also, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0074] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0075] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A biobased wax modified by biomimicry, characterized in that, It includes the following components: biomimetic waterborne polyurethane modifier, bio-wax, leveling agent, deionized water and pH buffer, wherein the raw materials for preparing the biomimetic waterborne polyurethane modifier include polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, catalyst, organic solvent and tertiary amine; The functional monomer is dopamine hydrochloride; The chain extender includes at least one of 1,4-butanediol, ethylene glycol, propylene glycol, triethylenetetramine, and adipate dihydrazide. The crosslinking agent is dimethylolbutyric acid; The preparation method includes the following steps: Polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, catalyst, and organic solvent are mixed and reacted. After the reaction, tertiary amine is added to neutralize and the mixture is stirred and dispersed into an emulsion to obtain a reactive biomimetic waterborne polyurethane modifier. The biomimetic waterborne polyurethane modifier, bio-wax, leveling agent and deionized water are mixed and emulsified by high-speed stirring. A pH buffer is added for neutralization, and then the mixture is allowed to stand and cool to room temperature. The resulting biomimetic modified emulsion is coated onto a leather substrate and placed in an oven to cure, thus obtaining a biomimetic modified bio-based wax.

2. The biologically modified bio-based wax of claim 1, wherein, The dosage ratio of biomimetic waterborne polyurethane modifier, bio-wax, leveling agent, deionized water and pH buffer is: (5-10)g : (5-10)g : (0.05-1)g : (0.02-0.3)g : (40-80)g; The ratio of polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, catalyst, organic solvent and tertiary amine is 100g: (20-36)g: (1-10)g: (1-5)g: (1-3)g: (0.02-0.1)mL: (10-20)mL: (2-5)g.

3. The biologically modified bio-based wax of claim 1 or 2, wherein, The biowax includes at least one of sunflower seed wax, carnauba wax and beeswax; The leveling agent is selected from DOSS-75E of HARCROS, USA; The pH buffer is selected from Dow AMP-95.

4. The biologically modified bio-based wax of claim 1 or 2, wherein, The diisocyanate includes at least one of L-lysine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tetramethylphenyl diisocyanate.

5. The biologically modified bio-based wax of claim 1 or 2, wherein, The catalyst includes at least one of dibutyltin dilaurate, stannous octanoate, and dibutyltin diacetate; The organic solvent includes at least one of acetone, N,N-dimethylacetamide, and N,N-dimethylformamide.

6. The method of preparing a biologically modified bio-based wax according to claim 1, wherein, Polyester polyol, diisocyanate, functional monomer, chain extender, crosslinking agent, catalyst, and organic solvent are mixed and reacted at a temperature of 70-95 ℃ for 4-6 h.

7. The method for preparing the biomimetic modified bio-based wax according to claim 1, characterized in that, The high-speed mixer operates at a speed of 2000-3000 rpm for 15-30 minutes.

8. The method for preparing the biomimetic modified bio-based wax according to claim 1, characterized in that, The mixture is placed in an oven for curing at a temperature of 40°C for 2 hours.

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