1,5-diisocyanatopentane-polyurethane coating and method for its preparation

Abstract

The application discloses a kind of 1,5-diisocyanate pentane-polyurethane coating and preparation method thereof, belong to chemical technology field, the coating includes the following weight parts of raw materials: vegetable oil polyol 100 parts, isocyanate 40-75 parts, organic solvent 30-40 parts, ionic liquid catalyst 0.1-2 parts, flame retardant 10-20 parts, hydrophilic chain extender 10-30 parts, neutralizing agent 10-30 parts, deionized water 20-40 parts;Vegetable oil polyol, isocyanate, organic solvent and ionic liquid catalyst are mixed and reacted, to obtain prepolymer mixed solution, then hydrophilic chain extender is added to the prepolymer mixed solution to obtain polymer mixed solution, after polymer mixed solution cooling, neutralizing agent is added, then deionized water is emulsified to form polyurethane emulsion, after polyurethane emulsion is reduced pressure distillation to remove organic solvent, it is obtained.The formulation system and catalytic system provided by the application further increase the content of biological carbon in the coating, reduce environmental pollution, greatly improve the added value of vegetable oil product.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to a 1,5-diisocyanate pentane-polyurethane coating and its preparation method. Background Technology

[0002] Polyurethane is a polymer with repeating urethane segments, produced by the reaction of isocyanates and polyols. Traditional polyurethane systems primarily use petrochemical polyethers or polyester polyols and isocyanates as the two main raw materials. Polyurethane products are broadly classified into foamed and non-foamed products. Foamed products include flexible, rigid, and semi-rigid polyurethane foams; non-foamed products include coatings, adhesives, synthetic leather, elastomers, and elastic fibers. Polyurethane materials possess excellent properties, wide applications, and numerous product types, with polyurethane coatings being the most widely used.

[0003] In recent years, with increased environmental awareness and focus on personal health, coupled with stringent environmental regulations on volatile organic compound (VOC) emissions and harmful solvent content, the application of polyurethane coatings containing solvents and organic fillers has been severely limited. This has spurred the development of polyurethane coatings towards water-based, powder-based, and high-solids formulations. Water-based polyurethane coatings, using water as the dispersion medium, have gained significant attention in the coatings industry due to their safety, non-toxicity, solvent-free operation, environmental friendliness, and good water resistance. Developing water-based polyurethane coatings has become a hot topic in the polyurethane coatings field in recent years. However, existing water-based polyurethane coatings mostly use petroleum as a raw material to prepare polyols, requiring the consumption of large amounts of petroleum resources. Furthermore, the preparation of polyols from petroleum involves complex processes and severe pollution. Natural oils are currently recognized as the only renewable alternative to petroleum, and among natural oils, vegetable oils offer the most ideal performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to propose a 1,5-diisocyanate pentane-polyurethane coating and its preparation method. By introducing vegetable oil molecules into polyurethane materials using a ring-opening reagent with vegetable oil polyols, this invention can not only solve problems such as petroleum resource shortage and environmental pollution, but also increase the added value of vegetable oil products.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of this invention is to provide a 1,5-diisocyanate pentane-polyurethane coating, comprising the following raw materials in parts by weight: 100 parts of vegetable oil polyol, 40-75 parts of isocyanate, 30-40 parts of organic solvent, 0.1-2 parts of ionic liquid catalyst, 10-20 parts of flame retardant, 10-30 parts of hydrophilic chain extender, 10-30 parts of neutralizer, and 20-40 parts of deionized water.

[0007] In some embodiments, the vegetable oil polyol is selected from at least one of olive oil polyol, peanut oil polyol, rapeseed oil polyol, cottonseed oil polyol, soybean oil polyol, coconut oil polyol, palm oil polyol, sesame oil polyol, corn oil polyol, and sunflower seed oil polyol; the hydroxyl value of the vegetable oil polyol is 160-200 mg KOH / g.

[0008] Preferably, the vegetable oil polyol is soybean oil polyol.

[0009] It should be noted that the plant oil polyols can be FH-3170 and FHB-195 (manufacturer: Zhangjiagang Feihang Technology Co., Ltd.).

[0010] In some embodiments, the isocyanate is 1,5-diisocyanate pentane; the organic solvent is selected from at least one of acetone, ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, and carbon tetrachloride.

[0011] Preferably, the organic solvent is acetone.

[0012] In some embodiments, the ionic liquid catalyst is selected from at least one of pyridine-type ionic liquid catalysts, imidazole-type ionic liquid catalysts, and long-chain aliphatic amine-type ionic liquid catalysts; the ionic liquid catalyst includes anions and cations.

[0013] It should be noted that the present invention selected ionic liquid catalysts containing tertiary amine and quaternary ammonium salt structures because the tertiary amine structure in the catalyst can play a catalytic role in reducing spatial position and activating hydroxyl groups, but its catalytic effect on the activity of isocyanate molecules is low. The quaternary ammonium structure can play an activation role by reacting with oxygen in isocyanate, further overcoming the problems of poor activity of neutralizing agents, low reaction rate and poor material performance caused by system inhomogeneity in polymerization reaction. The 2 or 3 carbon linkage between the quaternary ammonium N cation and the tertiary amine N is better. Therefore, pyridine-type ionic liquid catalysts, imidazole-type ionic liquid catalysts or long-chain aliphatic amine-type ionic liquid catalysts are selected.

[0014] In some embodiments, the anion is selected from Brønsted bases, and is selected from at least one of dicyandiamide, hexafluorophosphate, boron tetrafluoride, and bis(trifluoromethanesulfonyl)imide.

[0015] Preferably, the Brønsted base is dicyandiamide.

[0016] In some embodiments, the cation is selected from at least one of the following structural formulas: CA-1, CA-2, CA-3, CA-4, CA-5, CA-6, CA-8, CA-9, CB-1, CB-2, CB-3, CB-4, CB-5, CB-6, CB-7, CB-8, CB-9, and CB-10.

[0017]

[0018] Preferably, the cation in the ionic liquid catalyst is CB-5.

[0019] In some embodiments, the flame retardant is selected from at least one of the following: tributyl phosphate, tris(2-ethylhexyl) phosphate, tris(2-chloroethyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, flame retardant Pyrol99, toluene-diphenyl phosphate, tricresyl phosphate, triphenyl phosphate, (2-ethylhexyl)-diphenyl phosphate, bis(4-hydroxyphenyl)phenylphosphine oxide, and casein.

[0020] Preferably, the flame retardant is Pyrol99.

[0021] The neutralizing agent is selected from at least one of triethylamine, dimethylethanolamine, and N,N-dimethylcyclohexylamine.

[0022] In some embodiments, the hydrophilic chain extender is a dihydroxy half ester; the dihydroxy half ester is prepared from a triol and a diacid anhydride; wherein the triol is glycerol, and the diacid anhydride is selected from at least one of phthalic anhydride, 1,2-cyclohexanediol, norbornenediic anhydride, and cyclopentane-1,2-dicarboxylic anhydride.

[0023] It should be noted that the present invention uses a dihydroxy half ester prepared from a triol and a dicarboxylic acid anhydride, which can introduce a cyclic structure into the polyurethane, thereby improving the mechanical properties of the material.

[0024] A second aspect of this invention provides a method for preparing a 1,5-diisocyanate pentane-polyurethane coating, comprising the following steps:

[0025] S1: Mix and react vegetable oil polyols, isocyanates, organic solvents, flame retardants and ionic liquid catalysts to obtain a prepolymer mixture;

[0026] S2: Add the hydrophilic chain extender to the prepolymer mixture and react to obtain the polymer mixture;

[0027] S3: After the polymer mixture cools down, add a neutralizing agent, then add deionized water to emulsify and form a polyurethane emulsion;

[0028] S4: The polyurethane emulsion is obtained by removing the organic solvent by vacuum distillation.

[0029] In some embodiments, the mixing reaction temperature in S1 is 40-70°C and the mixing reaction time is 1-3 hours; the reaction temperature in S2 is 40-70°C and the reaction time is 2-5 hours; and the temperature in S3 is cooled to 20-30°C.

[0030] The present invention has the following beneficial effects:

[0031] 1. This invention uses vegetable oil polyols with specific hydroxyl values ​​as raw materials, combined with isocyanates from biomass sources and ionic liquid catalysts. This formulation and catalytic system can increase the biochar content in coatings. High biochar content can reduce environmental pollution and solve the problem of petroleum resource shortage, greatly improving the added value of vegetable oil products.

[0032] 2. Compared with traditional polyurethane coatings, the 1,5-diisocyanate pentane-polyurethane coating prepared by this invention not only has good adhesion and mechanical properties, but also reduces the production cost of the coating by eliminating the need for non-renewable resources such as petroleum, making it suitable for industrial production. Detailed Implementation

[0033] The present invention will now be described in further detail. The embodiments described are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0034] Example 1

[0035] A method for preparing a 1,5-diisocyanate pentane-polyurethane coating:

[0036] 100 parts of vegetable oil polyol FH-3170, 49 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0037] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0038] After cooling the polymer mixture to 30°C, add 14 parts of triethylamine as a neutralizing agent to neutralize it to neutral. Then add 30 parts of deionized water and emulsify it under high-speed shearing to form a polyurethane emulsion. Remove acetone from the polyurethane emulsion by vacuum distillation to obtain a vegetable oil-based waterborne polyurethane coating.

[0039] Example 2

[0040] A method for preparing a 1,5-diisocyanate pentane-polyurethane coating:

[0041] 100 parts of vegetable oil polyol FHB-195, 49 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0042] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0043] After cooling the polymer mixture to 30°C, 17 parts of neutralizing agent N,N-dimethylcyclohexylamine were added to neutralize it to neutral. Then, 30 parts of deionized water were added and emulsified by high-speed shearing to form a polyurethane emulsion. The polyurethane emulsion was then distilled under reduced pressure to remove acetone, thus obtaining a vegetable oil-based waterborne polyurethane coating.

[0044] Example 3

[0045] A method for preparing a 1,5-diisocyanate pentane-polyurethane coating:

[0046] 100 parts of vegetable oil polyol FH-3170, 50 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0047] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0048] After cooling the polymer mixture to 30°C, 12 parts of neutralizing agent dimethylethanolamine were added to neutralize it to neutral. Then, 30 parts of deionized water were added and emulsified by high-speed shearing to form a polyurethane emulsion. The polyurethane emulsion was then distilled under reduced pressure to remove acetone, thus obtaining a vegetable oil-based waterborne polyurethane coating.

[0049] Example 4

[0050] A method for preparing a 1,5-diisocyanate pentane-polyurethane coating:

[0051] 100 parts of vegetable oil polyol FHB-195, 53 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0052] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0053] After cooling the polymer mixture to 30°C, 12 parts of neutralizing agent dimethylethanolamine were added to neutralize it to neutral. Then, 30 parts of deionized water were added and emulsified by high-speed shearing to form a polyurethane emulsion. The polyurethane emulsion was then distilled under reduced pressure to remove acetone, thus obtaining a vegetable oil-based waterborne polyurethane coating.

[0054] Comparative Example 1

[0055] A method for preparing a plant oil-based waterborne polyurethane coating:

[0056] 100 parts of vegetable oil polyol FH-3170, 79 parts of MDI (diphenylmethane diisocyanate), and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0057] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0058] After cooling the polymer mixture to 30°C, add 14 parts of triethylamine as a neutralizing agent to neutralize it to neutral. Then add 30 parts of deionized water and emulsify it under high-speed shearing to form a polyurethane emulsion. Remove acetone from the polyurethane emulsion by vacuum distillation to obtain a vegetable oil-based waterborne polyurethane coating.

[0059] Comparative Example 2

[0060] A method for preparing a plant oil-based waterborne polyurethane coating:

[0061] 100 parts of vegetable oil polyol FHB-195, 52 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0062] Add 15 parts of hydrophilic chain extender dihydroxypropionic acid to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0063] After cooling the polymer mixture to 30°C, add 16 parts of triethylamine as a neutralizing agent to neutralize it to neutral. Then add 30 parts of deionized water and emulsify it under high-speed shearing to form a polyurethane emulsion. Remove acetone from the polyurethane emulsion by vacuum distillation to obtain a vegetable oil-based waterborne polyurethane coating.

[0064] Comparative Example 3

[0065] A method for preparing a plant oil-based waterborne polyurethane coating:

[0066] 100 parts of vegetable oil polyol FH-3170, 49 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 were mixed in 30 parts of acetone and 0.5 parts of imidazole-type ionic liquid catalyst (anion is dicyandiamide and cation is CB-5) were added. The mixture was reacted at 50°C for 2 hours to obtain a prepolymer mixture.

[0067] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 3 hours to obtain the polymer mixture;

[0068] After cooling the polymer mixture to 30°C, add 8 parts of triethylamine as a neutralizing agent to neutralize it to neutral. Then add 30 parts of deionized water and emulsify it under high-speed shearing to form a polyurethane emulsion. Remove acetone from the polyurethane emulsion by vacuum distillation to obtain a vegetable oil-based waterborne polyurethane coating.

[0069] Comparative Example 4

[0070] A method for preparing a plant oil-based waterborne polyurethane coating:

[0071] Mix 100 parts of vegetable oil polyol FHB-195, 49 parts of 1,5-diisocyanate pentane, and 15 parts of flame retardant Pyrol99 in 30 parts of acetone and add 1 part of dibutyltin dilaurate. React at 50°C for 3 hours to obtain a prepolymer mixture.

[0072] Add 30 parts of hydrophilic chain extender dihydroxy half ester (synthesized from glycerol and phthalic anhydride) to the prepolymer mixture and react at 50°C for 5 h to obtain the polymer mixture;

[0073] After cooling the polymer mixture to 30°C, add 14 parts of triethylamine as a neutralizing agent to neutralize it to neutral. Then add 30 parts of deionized water and emulsify it under high-speed shearing to form a polyurethane emulsion. Remove acetone from the polyurethane emulsion by vacuum distillation to obtain a vegetable oil-based waterborne polyurethane coating.

[0074] Performance testing

[0075] The bio-based polyurethane coatings prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to performance characterization tests. Their drying time, pencil hardness, impact resistance, flexibility, and salt spray resistance were tested. The test data are shown in Table 1.

[0076] The coating was applied to a metal plate for testing, with the sample thickness controlled at approximately 240 μm.

[0077] The relevant testing methods for the prepared bio-based polyurethane coatings are as follows:

[0078] (1) The drying time of the coating was determined according to GB / T 1728-1979(1989);

[0079] (2) The pencil hardness of the coating was determined according to GB / T 6739-2006;

[0080] (3) The impact resistance of the coating was determined according to GB / T 1732-1993;

[0081] (4) The flexibility of the coating was determined according to GB / T 1731-1993;

[0082] (5) The salt spray resistance of the coating shall be determined according to GB / T 1771-2007.

[0083] Table 1 Performance Test Results

[0084]

[0085] Based on the data from the examples and comparative examples in Table 1, it can be seen that the bio-based polyurethane coating provided by this invention exhibits excellent mechanical properties and strong salt spray resistance. Referring to Comparative Example 1, the 1,5-diisocyanate pentane used in this invention achieves mechanical properties similar to MDI, and is environmentally friendly. Referring to Comparative Example 2, the use of short-chain chain extenders reduces the mechanical properties of the material. Referring to Comparative Example 3, adding less neutralizing agent leads to a decrease in the mechanical properties of the coating and an increase in drying time. Referring to Comparative Example 4, adding ordinary catalysts increases the reaction time and reduces the coating performance. Therefore, the appropriate proportions of isocyanate, hydrophilic chain extender, neutralizing agent, and ionic catalyst are indispensable in this invention.

[0086] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A 1,5-diisocyanate pentane-polyurethane coating, characterized in that, The product is prepared from the following raw materials in parts by weight: 100 parts of vegetable oil polyol, 40-75 parts of isocyanate, 30-40 parts of organic solvent, 0.1-2 parts of ionic liquid catalyst, 10-20 parts of flame retardant, 10-30 parts of hydrophilic chain extender, 10-30 parts of neutralizer, and 20-40 parts of deionized water; wherein the hydroxyl value of the vegetable oil polyol is 160-200 mgKOH / g, the isocyanate is 1,5-diisocyanate pentane, the ionic liquid catalyst is selected from at least one of pyridine-type ionic liquid catalysts, imidazole-type ionic liquid catalysts, and long-chain fatty amine-type ionic liquid catalysts, the hydrophilic chain extender is a dihydroxy half-ester, the dihydroxy half-ester is prepared from a triol and a diacid anhydride, the triol is glycerol, and the diacid anhydride is selected from at least one of phthalic anhydride, 1,2-cyclohexanediol, norbornene, and cyclopentane-1,2-dicarboxylic anhydride.

2. The 1,5-diisocyanate pentane-polyurethane coating according to claim 1, characterized in that, The plant oil polyols are selected from at least one of olive oil polyols, peanut oil polyols, rapeseed oil polyols, cottonseed oil polyols, soybean oil polyols, coconut oil polyols, palm oil polyols, sesame oil polyols, corn oil polyols, and sunflower seed oil polyols.

3. The 1,5-diisocyanate pentane-polyurethane coating according to claim 1, characterized in that, The organic solvent is selected from at least one of acetone, ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, and carbon tetrachloride.

4. The 1,5-diisocyanate pentane-polyurethane coating according to claim 1, characterized in that, The anion in the ionic liquid catalyst is selected from at least one of dicyandiamide, hexafluorophosphate, boron tetrafluoride, and bis(trifluoromethanesulfonyl)imide.

5. The 1,5-diisocyanate pentane-polyurethane coating according to claim 1, characterized in that, The cation in the ionic liquid catalyst is selected from at least one of the following structural formulas: CA-1, CA-2, CA-3, CA-4, CA-5, CA-6, CA-8, CA-9, CB-1, CB-2, CB-3, CB-4, CB-5, CB-6, CB-7, CB-8, CB-9, CB-10. 。 6. The 1,5-diisocyanate pentane-polyurethane coating according to claim 1, characterized in that, The flame retardant is selected from at least one of the following: tributyl phosphate, tris(2-ethylhexyl) phosphate, tris(2-chloroethyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, flame retardant Pyrol99, toluene-diphenyl phosphate, tricresyl phosphate, triphenyl phosphate, (2-ethylhexyl)-diphenyl phosphate, bis(4-hydroxyphenyl)phenylphosphine oxide, and casein. The neutralizing agent is selected from at least one of triethylamine, dimethylethanolamine, and N,N-dimethylcyclohexylamine.

7. A method for preparing the 1,5-diisocyanate pentane-polyurethane coating according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Mix and react vegetable oil polyols, isocyanates, organic solvents, flame retardants and ionic liquid catalysts to obtain a prepolymer mixture; S2: Add the hydrophilic chain extender to the prepolymer mixture and react to obtain the polymer mixture; S3: After the polymer mixture cools down, add a neutralizing agent, then add deionized water to emulsify and form a polyurethane emulsion; S4: The polyurethane emulsion is obtained by removing the organic solvent by vacuum distillation.

8. The method for preparing the 1,5-diisocyanate pentane-polyurethane coating according to claim 7, characterized in that, In step S1, the mixing reaction temperature is 40-70℃ and the mixing reaction time is 1-3h; in step S2, the reaction temperature is 40-70℃ and the reaction time is 2-5h; in step S3, the temperature is lowered to 20-30℃.

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