A bio-based hydroxy polyacrylate emulsion, its preparation method and application

Abstract

The present invention discloses a bio-based hydroxy polyacrylate emulsion, a preparation method and an application thereof. The raw materials for preparation include: a bio-based material and a polyacrylate polymer containing hydroxyl groups; the bio-based material includes a bio-based oil containing epoxy groups; the polymerization monomers of the polyacrylate polymer containing hydroxyl groups include a hydroxyacrylate monomer and an acrylamide monomer. The paint film of the waterborne two-component polyurethane coating prepared from the emulsion of the present invention reduces the use of petroleum-based materials and simultaneously has the characteristics of fast drying speed, high hardness and good chemical resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a bio-based hydroxy polyacrylate emulsion, a preparation method thereof, and an application thereof. Background Art

[0002] Coatings are substances coated on the surface of an object for protecting, decorating the coated object, and endowing it with certain properties. Most existing wood coatings are solvent-based coatings containing more than 50% organic solvents. These solvents will volatilize into the atmosphere during the construction process, polluting the environment, damaging human health, and the organic solvents themselves will bring safety hazards. Therefore, the water-based transformation of wood coatings is the development trend of coatings. Water-based wood coatings include one-component and two-component water-based wood coatings. Among them, the film properties such as water resistance, chemical resistance, and hardness of one-component water-based wood coatings are quite different from those of oil-based coatings, severely restricting the popularization and application of water-based wood coatings. The mechanical properties, water resistance, and chemical resistance of two-component water-based wood coatings are comparable to those of solvent-based wood coatings, overcoming the disadvantages of one-component water-based wood coatings, and thus becoming the first choice for high-grade water-based wood coatings.

[0003] Two-component water-based polyurethane coatings are composed of a water-based polymer polyol and a water-based polyisocyanate curing agent, which are packaged separately and mixed in proportion during use. Water-based polymer polyols include water-based polyacrylate polyols, water-based polyurethane polyols, water-based polyester polyols, polyether polyols, and mixed polyols. Among them, water-based polyacrylate polyols have excellent color retention, light retention, and weather resistance, are inexpensive, and have the advantages that the molecular weight, glass transition temperature, and hydroxyl content are easy to adjust, etc. They are currently the first choice for water-based polymer polyols in two-component water-based polyurethane coatings. Two types of polyacrylate polyols, namely emulsion and dispersion, can be prepared by different polymerization processes. The hydroxyl polyacrylate dispersion has a high hydroxyl content, and the prepared coating film has excellent water resistance and chemical resistance, but has disadvantages such as complex production processes, a product solid content of only 30%-40%, slow film drying speed, and high costs. Emulsion-type polyacrylate polyols are also called hydroxy polyacrylate emulsions, abbreviated as hydroxypropyl emulsions, but due to their disadvantages such as low hydroxyl content, poor water resistance and chemical resistance of the coating film, their application is limited. In addition, most existing two-component water-based polyurethane coatings are petroleum-based materials.

[0004] Therefore, there is an urgent need to develop a coating with a fast drying speed, high hardness, and good chemical resistance. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a bio-based hydroxy polyacrylate emulsion, and the paint film of the bio-based waterborne two-component polyurethane coating prepared therefrom has the characteristics of high gloss, high transparency, excellent water and chemical resistance, high crosslinking density, as well as high hardness, scratch resistance and wear resistance.

[0006] The second aspect of the present invention provides a preparation method of the bio-based hydroxy polyacrylate emulsion.

[0007] The third aspect of the present invention provides a coating, and the raw materials for preparing the coating include the bio-based hydroxy polyacrylate emulsion.

[0008] The fourth aspect of the present invention provides an application of a coating in the field of decoration.

[0009] A bio-based hydroxy polyacrylate emulsion according to an embodiment of the first aspect of the present invention, the raw materials for preparation include: bio-based materials and a polyacrylate polymer containing hydroxyl groups;

[0010] The bio-based materials include bio-based oils containing epoxy groups;

[0011] The polymerization monomers of the polyacrylate polymer containing hydroxyl groups include hydroxyacrylate monomers and acrylamide monomers.

[0012] A bio-based hydroxy polyacrylate emulsion according to an embodiment of the first aspect of the present invention has at least the following beneficial effects:

[0013] After adding the polyacrylate polymer containing hydroxyl groups to the bio-based materials, the epoxy groups of the bio-based materials and the amino groups of the acrylamide monomers in the polyacrylate polymer containing hydroxyl groups undergo a polycondensation reaction to regenerate a part of hydroxyl groups, and finally a bio-based hydroxy polyacrylate emulsion is obtained. The hydroxyl groups of the bio-based hydroxy polyacrylate emulsion of the present invention are respectively directly provided by the hydroxyacrylate monomers and generated after the reaction of the bio-based materials, ensuring the water and chemical resistance of the paint film.

[0014] The addition of the bio-based materials plays a role in chain extension, increasing the molecular weight of the polymer obtained in the reaction, and improving the polymer from a linear structure to a network structure. The paint film of the waterborne two-component polyurethane coating prepared therefrom has the characteristics of fast drying speed, high hardness and good chemical resistance. In addition, by introducing bio-based materials for reaction, the use of petroleum-based materials is reduced.

[0015] According to some embodiments of the present invention, the bio-based oil containing epoxy groups includes at least one of epoxy soybean oil and epoxy linseed oil.

[0016] According to some embodiments of the present invention, the epoxidized soybean oil includes at least one of GreenSoft D specialty epoxidized soybean oil and GreenSoft H specialty epoxidized soybean oil.

[0017] According to some embodiments of the present invention, the epoxidized linseed oil comprises epoxidized linseed oil ELO 9-5 TM .

[0018] According to some embodiments of the present invention, the acrylamide monomer is an acrylamide monomer containing one secondary amino group and no hydroxyl group.

[0019] In the present invention, if the acrylamide monomer contains hydroxyl groups, the original hydroxyl groups will form steric hindrance with the newly generated hydroxyl groups (generated by the reaction of epoxy and secondary amino groups), resulting in the inability of the hydroxyl groups to react completely with NCO, and the residual hydroxyl groups will significantly reduce the water resistance.

[0020] According to some embodiments of the present invention, the bio-based content of the bio-based hydroxy polyacrylate emulsion is 5% to 25%.

[0021] According to some embodiments of the present invention, the particle size of the bio-based hydroxy polyacrylate emulsion is 80 nm to 120 nm.

[0022] The particle size within the above range can ensure that the emulsion has a slightly transparent appearance.

[0023] According to some embodiments of the present invention, the solid content of the bio-based hydroxy polyacrylate emulsion is 47-52%.

[0024] According to some embodiments of the present invention, the mass content of hydroxyl groups in the bio-based hydroxy polyacrylate emulsion is 2.5% to 4.6%.

[0025] The hydroxyl content and solid content in the present invention are within the above ranges, which can ensure the versatility of the emulsion in subsequent use and the performance of the paint film.

[0026] According to some embodiments of the present invention, the raw materials for preparing the polyacrylate polymer containing hydroxyl groups further include acrylic acid monomers, acrylic acid ester monomers and vinyl monomers.

[0027] According to some embodiments of the present invention, the acrylic monomer includes at least one of an acrylic monomer and a methacrylic monomer.

[0028] According to some embodiments of the present invention, the acrylamide monomer includes at least one of N-tert-butylacrylamide, N-ethylacrylamide and N-methyl-2-acrylamide.

[0029] According to some embodiments of the present invention, the acrylate monomer includes at least one of methyl methacrylate, butyl acrylate, isobornyl acrylate, cyclohexyl methacrylate, and benzyl methacrylate.

[0030] According to some embodiments of the present invention, the vinyl monomer includes styrene.

[0031] According to some embodiments of the present invention, the hydroxyacrylate monomer includes at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0032] According to an embodiment of the second aspect of the present invention, a method for preparing a bio-based hydroxy polyacrylate emulsion is provided, including mixing and reacting the bio-based material and the hydroxy-containing polyacrylate polymer.

[0033] According to some embodiments of the present invention, in the mixing and reaction of the bio-based material and the hydroxy-containing polyacrylate polymer, the temperature of the mixing and reaction is 70-90°C.

[0034] According to some embodiments of the present invention, in the mixing and reaction of the bio-based material and the hydroxy-containing polyacrylate polymer, the time of the mixing and reaction is 45-80 minutes.

[0035] According to some preferred embodiments of the present invention, the method for preparing the bio-based hydroxy polyacrylate emulsion includes mixing and stirring the bio-based material and the hydroxy-containing polyacrylate polymer for 15-25 minutes, heating to 70-90°C, reacting for 45-80 minutes, stopping the reaction after measuring the epoxy value to be less than 0.005 by the hydrochloric acid-acetone method, cooling to 40°C, and filtering and discharging to obtain the bio-based hydroxy polyacrylate emulsion.

[0036] According to some embodiments of the present invention, the raw materials for preparing the polyacrylate polymer include: polyacrylate polymer, emulsifier, deionized water, and neutralizing agent 1.

[0037] According to some preferred embodiments of the present invention, the method for preparing the polyacrylate polymer includes:

[0038] S1: Mix the acrylic acid monomer, acrylamide monomer, acrylate monomer, vinyl monomer, and hydroxyacrylate monomer uniformly to form a mixed solution A for standby;

[0039] S2: Mix deionized water, emulsifier, and the monomer mixed solution A to obtain a pre-emulsion B for standby;

[0040] S3: Mix ionized water, initiator, and emulsifier to obtain a mixed solution C for standby;

[0041] S4: Mix deionized water and neutralizing agent 1 to form a mixed solution D for standby.

[0042] S5: Mix deionized water, emulsifier, buffer and initiator, stir and heat, then add part of the pre-emulsion B. After obtaining the seed emulsion, add the remaining pre-emulsion B, mixed solution C, mixed solution D and the bio-based material, and react to obtain the bio-based hydroxy polyacrylate emulsion.

[0043] According to some more preferred embodiments of the present invention, the preparation method of the polyacrylate polymer includes:

[0044] S1: Mix acrylic acid monomer, acrylamide monomer, acrylate monomer, vinyl monomer and hydroxyacrylate monomer evenly to form a mixed solution A for standby.

[0045] S2: Mix deionized water and emulsifier, then add the monomer mixed solution A. After adding, continue to disperse to obtain a pre-emulsion B for standby.

[0046] S3: Mix ionic water, initiator and emulsifier to form a mixed solution C for standby.

[0047] S4: Mix deionized water and neutralizing agent 1 to form a mixed solution D for standby.

[0048] S5: Mix deionized water, emulsifier, buffer and initiator, stir and heat, then add part of the pre-emulsion B. After obtaining the seed emulsion, add the remaining pre-emulsion B, mixed solution C, mixed solution D and the bio-based material, and react to obtain the bio-based hydroxy polyacrylate emulsion.

[0049] According to some embodiments of the present invention, in the mixed solution A of step S1, by weight, it includes 0.9 - 1.1 parts of acrylic acid monomer, 3.5 - 8.5 parts of acrylamide monomer, 15 - 31 parts of acrylate monomer, 5 - 9 parts of vinyl monomer and 5 - 15 parts of hydroxyacrylate monomer.

[0050] According to some embodiments of the present invention, in the pre-emulsion B of step S2, by weight, it includes 28 - 33 parts of deionized water, 0.45 - 2.1 parts of emulsifier, and 42.1 - 48.3 parts of monomer mixed solution A.

[0051] According to some preferred embodiments of the present invention, in step S2, it includes dissolving 0.45 - 2.1 parts of emulsifier in 28 - 33 parts of deionized water, stirring evenly, then adjusting the disperser to 700 revolutions per minute, dropping 42.1 - 48.3 parts of monomer mixed solution A, finishing dropping in 15 - 25 minutes, and continuing to disperse for 10 - 20 minutes after dropping to obtain a pre-emulsion B for standby.

[0052] According to some embodiments of the present invention, in the mixed solution C of step S3, by weight, it includes 5 to 7 parts of deionized water, 0.2 to 0.6 parts of initiator, and 0 to 1 part of emulsifier.

[0053] According to some embodiments of the present invention, in the mixed solution D of step S4, by weight, it includes 5 to 8.5 parts of deionized water and 0.5 to 0.7 parts of neutralizer 1.

[0054] According to some embodiments of the present invention, in the bio-based hydroxy polyacrylate emulsion of step S5, by weight, it includes 20 to 28 parts of deionized water, 0.3 to 0.8 parts of emulsifier, 0.1 to 0.25 parts of buffer, 0.1 to 0.2 parts of initiator, 71 to 84.5 parts of pre-emulsion B, 6.5 to 8.5 parts of mixed solution C, 5.5 to 9.5 parts of mixed solution D, and 9 to 15 parts of bio-based material.

[0055] According to some embodiments of the present invention, the initiator includes persulfate.

[0056] According to some embodiments of the present invention, the emulsifier includes at least one of non-reactive emulsifier and reactive emulsifier.

[0057] According to some embodiments of the present invention, the non-reactive emulsifier includes at least one of sodium dodecyl sulfate (SDS), isomeric alcohol polyoxyethylene ether (EH-9) of Dow Chemical Company, DOWFAX-2A1, and ammonium lauryl ether sulfate (KL-525).

[0058] According to some embodiments of the present invention, the reactive emulsifier includes at least one of sodium 3-allyloxy-1-hydroxypropanesulfonate (COPS-1), sodium 2-acrylamido-2-methylpropanesulfonate (COPS-2), SR-10, and ER-30.

[0059] According to some embodiments of the present invention, the neutralizer 1 includes a neutralizer containing tertiary amine.

[0060] According to some embodiments of the present invention, the neutralizer 1 includes at least one of triethylamine (TEA), N,N-dimethylethanolamine (DMEA), and N,N-dimethylcyclohexylamine (DMCHA).

[0061] According to some embodiments of the present invention, the buffer includes at least one of sodium bicarbonate (NaHCO3) and sodium carbonate (Na2CO3).

[0062] According to some embodiments of the present invention, the initiator includes at least one of potassium persulfate (KPS) and ammonium persulfate (APS).

[0063] According to an embodiment of the third aspect of the present invention, a coating is provided, and the raw materials for preparing the coating include the bio-based hydroxy polyacrylate emulsion described above.

[0064] According to some embodiments of the present invention, the method for preparing the coating includes a component A and a component B which are mixed at an NCO / OH molar ratio of 1.0 - 1.8:1 during construction;

[0065] By weight, the component A includes: 60 - 65 parts of bio-based hydroxy polyacrylate emulsion, 30 - 36 parts of water, 2 - 4 parts of film-forming aid, 0.05 - 0.2 part of defoamer, 0.5 - 0.8 part of thickener, 0.05 - 0.2 part of wetting agent, and 0.2 - 0.5 part of neutralizer;

[0066] By weight, the component B includes: 15 - 30 parts of aqueous polyisocyanate curing agent.

[0067] In the present invention, the NCO / OH molar ratio is 1.0 - 1.8:1. At this ratio, it avoids the problems of low hardness and poor resistance of the paint film caused by too low a ratio, and the appearance of defects such as "prickly heat" on the surface of the paint film caused by too high a ratio.

[0068] According to some embodiments of the present invention, the film-forming aid includes at least one of propylene glycol methyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, and dipropylene glycol butyl ether.

[0069] According to some embodiments of the present invention, the defoamer includes at least one of polyether silicone copolymer defoamer and modified polysiloxane copolymer solution.

[0070] According to some embodiments of the present invention, the polyether silicone copolymer defoamer includes at least one of TEGO-800, TEGO-805, TEGO-815, and TEGO-825.

[0071] According to some embodiments of the present invention, the modified polysiloxane copolymer solution includes at least one of BYK-019 and BYK-020.

[0072] According to some embodiments of the present invention, the thickener includes at least one of nonionic polyurethane associative thickener, hydrophobically modified alkali-swellable associative thickener, alkali-swellable non-associative thickener, and nonionic associative thickener.

[0073] According to some embodiments of the present invention, the nonionic polyurethane associative thickener includes RM-8W.

[0074] According to some embodiments of the present invention, the hydrophobically modified alkali-swellable associative thickener is TT-935.

[0075] According to some embodiments of the present invention, the alkali-swellable non-associative thickener includes ASE-60.

[0076] According to some embodiments of the present invention, the nonionic associative thickener includes at least one of TEGO ViscoPlus3000, TEGO ViscoPlus 3030, and TEGO ViscoPlus 3060.

[0077] According to some embodiments of the present invention, the wetting agent includes at least one of polyether silicone copolymer, nonionic organic surfactant, and polyether-modified polysiloxane solution.

[0078] According to some embodiments of the present invention, the polyether silicone copolymer includes TEGO-245.

[0079] According to some embodiments of the present invention, the nonionic organic surfactant includes TEGO-500.

[0080] According to some embodiments of the present invention, the polyether-modified polysiloxane solution includes BYK-346.

[0081] According to some embodiments of the present invention, the neutralizing agent 2 includes at least one of triethylamine and dimethylethanolamine.

[0082] According to some embodiments of the present invention, the polyisocyanate curing agent includes at least one of sulfonate, carboxylate, and alkoxy-hydrophilic modified hexamethylene diisocyanate (HDI).

[0083] According to some embodiments of the present invention, the polyisocyanate curing agent includes at least one of Bayhydur XP2487 / 1 and Bayhydur XP 2655.

[0084] According to some embodiments of the present invention, the preparation method of the bio-based waterborne two-component polyurethane coating includes the following steps:

[0085] Premix water and a film-forming aid and add them to the hydroxy polyacrylate emulsion, then sequentially add an antifoaming agent, a thickener, a wetting agent, and the neutralizing agent 2, disperse for 10-30 minutes, and filter to obtain Agent A;

[0086] During construction, add the waterborne polyisocyanate curing agent to Agent A according to an NCO / OH molar ratio of 1.0-1.8, and stir for 5-8 minutes to obtain the bio-based waterborne two-component polyurethane coating.

[0087] The A component of the bio-based two-component polyurethane coating prepared by the aforementioned method is used in combination with the B component of the bio-based two-component polyurethane coating of the present invention, and the obtained bio-based waterborne two-component polyurethane coating film has the advantages of high gloss, high transparency, excellent water and chemical resistance, high crosslinking density, high hardness, scratch resistance, abrasion resistance, and fast drying speed, and can be applied to high-grade wood coatings, automotive coatings, metal anti-corrosion coatings, and other industrial protective coatings.

[0088] According to an embodiment of the fourth aspect of the present invention, an application of a coating in the field of decoration is provided.

[0089] According to some embodiments of the present invention, the field of decoration of the coating includes wood.

[0090] According to some embodiments of the present invention, the field of decoration of the coating includes metal.

[0091] According to some embodiments of the present invention, the field of decoration of the coating includes automobiles.

[0092] According to some embodiments of the present invention, the field of decoration of the coating includes metal anti-corrosion. Detailed implementation manners

[0093] The concept of the present invention and the technical effects produced will be clearly and completely described below in conjunction with embodiments to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0094] (Meth)acrylic monomers are acrylic acid or methacrylic acid from Mitsuki Co., Ltd.

[0095] Acrylamide monomers are N-tert-butylacrylamide, N-ethylacrylamide, and N-methyl-2-acrylamide from Aladdin Co., Ltd.

[0096] (Meth)acrylate monomers are methyl methacrylate, butyl acrylate, isobornyl acrylate, cyclohexyl methacrylate, and benzyl methacrylate from Mitsuki Co., Ltd.

[0097] Vinyl monomers are styrene from Mitsuki Co., Ltd.

[0098] Hydroxyacrylate monomers are 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, or 2-hydroxypropyl methacrylate from Changxing Co., Ltd.

[0099] The non-reactive emulsifiers are sodium dodecyl sulfate (SDS) from BASF, isomeric alcohol polyoxyethylene ether (EH-9) from Dow Chemical Company, DOWFAX-2A1, and ammonium lauryl ether sulfate (KL-525) from Guangzhou Hangqin Company;

[0100] The reactive emulsifiers are sodium 3-allyloxy-1-hydroxypropylsulfonate (COPS-1), sodium 2-acrylamido-2-methylpropanesulfonate (COPS-2) from Solvay, SR-10 and ER-30 from ADEKA Corporation of Japan;

[0101] The buffers are sodium bicarbonate (NaHCO3) and sodium carbonate (Na2CO3) from Xilong Chemical;

[0102] The initiators are potassium persulfate (KPS) and ammonium persulfate (APS) from Xilong Chemical;

[0103] The bio-based materials are GreenSoft D special epoxy soybean oil, GreenSoft H special epoxy soybean oil, and epoxy linseed oil ELO from Xingbang High Polymer Materials Co., Ltd. 9-5 TM ;

[0104] The defoamers are polyether-polysiloxane copolymer defoamers TEGO-800, TEGO-805, TEGO-815, TEGO-825 from TEGO, and modified polysiloxane copolymer solutions BYK-019, BYK-020 from BYK;

[0105] The thickeners are nonionic polyurethane associative thickener RM-8W, hydrophobically modified alkali-swellable associative thickener TT-935, alkali-swellable non-associative thickener ASE-60 from DOW, and nonionic associative thickeners TEGOViscoPlus 3000, TEGO ViscoPlus 3030, TEGO ViscoPlus 3060 from TEGO; The wetting agents are polyether-polysiloxane copolymer TEGO-245, nonionic organic surfactant TEGO-500 from TEGO, and polyether-modified polysiloxane solution BYK-346 from BYK;

[0106] The neutralizers are triethylamine and dimethylethanolamine from Dow Chemical Company;

[0107] The polyisocyanate curing agents include sulfonate, carboxylate, and alkoxy hydrophilically modified hexamethylene diisocyanate (HDI);

[0108] The polyisocyanate curing agents are Bayhydur XP 2487 / 1 and Bayhydur XP 2655 from Covestro;

[0109] Example 1

[0110] A bio-based hydroxy polyacrylate emulsion 1 is prepared by the following steps:

[0111] S1. By mass, 0.9 parts of acrylic acid, 8.5 parts of N-tert-butylacrylamide, 5.5 parts of cyclohexyl methacrylate, 5.2 parts of methyl methacrylate, 5 parts of butyl acrylate, 7 parts of styrene, and 10 parts of 2-hydroxyethyl methacrylate are mixed evenly to form a mixed solution A1 for standby;

[0112] S2. Add 33 parts of deionized water to the dispersion tank, dissolve 0.5 part of SDS and 1 part of EH-9, stir evenly, adjust the disperser to 700 revolutions per minute, dropwise add 42.1 parts of the mixed solution A1, complete the dropping in 25 minutes, and continue to disperse for 10 minutes after the dropping to obtain a pre-emulsion B1 for standby;

[0113] S3. By mass, dissolve 0.45 part of APS and 1 part of COPS-1 in 7 parts of deionized water to form a mixed solution C1 for standby;

[0114] S4. By mass, 8.5 parts of deionized water and 0.6 part of DMEA are mixed evenly to form a mixed solution D1 for standby;

[0115] S5. Add 26.3 parts of deionized water, 0.25 part of SDS, 0.5 part of EH-9, 0.2 part of NaHCO3 and 0.15 part of APS to a four-necked flask equipped with a thermometer, a condenser, a stirring paddle and a constant pressure dropping funnel, mix and stir and heat. When the temperature reaches 77 °C, dropwise add 7.7 parts of the pre-emulsion B1 in 15 minutes. After the dropping, stabilize for 10 minutes to obtain a seed emulsion. Raise the temperature to 80 °C, and at the same time dropwise add 68.9 parts of the pre-emulsion B1 and 8.45 parts of the mixed solution C1, complete the dropping in 3.5 hours. After the dropping, raise the temperature to 85 °C, keep warm for 2 hours, cool down to 55 °C, add 9.1 parts of the mixed solution D1, stir for 10 minutes, then add 15 parts of epoxy soybean oil GreenSoft H, disperse at high speed for 15 minutes, then raise the temperature to 80 °C, react for 60 minutes, and stop the reaction when the epoxy value measured by the hydrochloric acid-acetone method is less than 0.005

[0116] S6. Cool down to 40 °C, filter and discharge to obtain the bio-based hydroxy polyacrylate emulsion 1.

[0117] Example 2

[0118] Example prepared a bio-based waterborne two-component polyurethane coating 1, and the bio-based hydroxy polyacrylate emulsion was prepared in Example 1. The specific steps are as follows:

[0119] During construction, Agent A1 and Agent B1 are mixed according to the NCO / OH molar ratio of 1.8:1;

[0120] Among them, the A1 agent is composed of the following components in parts by weight:

[0121]

[0122] The B1 agent is an aqueous polyisocyanate curing agent, and the aqueous polyisocyanate curing agent is Bayhydur XP2487 / 1, and the mass fraction of Bayhydur XP 2487 / 1 is 24.9 parts;

[0123] The preparation method of the A1 agent is as follows: Add the bio-based hydroxy polyacrylate emulsion 1 into a stirring kettle with a rotation speed of 700 rpm. Premix water, dipropylene glycol butyl ether and dipropylene glycol methyl ether and then add them into the stirring kettle. Sequentially add TEGO-800, RM-8W, TEGO-245 and TEA, disperse for 20 minutes, and then filter and discharge.

[0124] During construction, add the B1 agent into the A1 agent and stir for 6 minutes to obtain the bio-based aqueous two-component polyurethane coating 1, and its bio-based content is 12.2%.

[0125] Cure and dry the film made of the bio-based aqueous two-component polyurethane coating 1 at room temperature for 7 days, and its performance is shown in Table 1.

[0126] Example 3

[0127] A bio-based hydroxy polyacrylate emulsion 2, which is prepared by the following steps:

[0128] S1. In parts by mass, mix 1 part of methacrylic acid, 3.8 parts of N-ethyl acrylamide, 9.5 parts of isobornyl acrylate, 11 parts of methyl methacrylate, 10.45 parts of butyl acrylate, 5.5 parts of styrene, and 5.5 parts of 2-hydroxyethyl acrylate evenly to form a mixed solution A2 for standby;

[0129] S2. Add 28 parts of deionized water into a dispersion tank, dissolve 0.45 part of KL-525, stir evenly, then adjust the disperser to 700 rpm, and dropwise add 46.75 parts of the mixed solution A2. Finish dropping in 20 minutes, and continue to disperse for 8 minutes after dropping to obtain a pre-emulsion B2 for standby;

[0130] S3. In parts by mass, dissolve 0.2 part of KPS and 0.75 part of COPS-2 with 5 parts of deionized water to form a mixed solution C2 for standby;

[0131] S4. In parts by mass, mix 5.5 parts of deionized water and 0.5 part of TEA evenly to form a mixed solution D2 for standby;

[0132] S5. In a four-necked flask equipped with a thermometer, a condenser, a stirring paddle, and a constant-pressure dropping funnel, add 20 parts of deionized water, 0.3 part of KL-525, 0.15 part of NaHCO3, and 0.1 part of KPS. Mix and stir, and heat. When the temperature reaches 80 °C, add 6 parts of pre-emulsion B2 dropwise over 20 minutes. After dropping, stabilize for 15 minutes to obtain a seed emulsion. Maintain the temperature at 80 °C, and simultaneously add 69.2 parts of pre-emulsion B2 and 5.95 parts of mixture C2 dropwise. Finish dropping in 4 hours. After dropping, raise the temperature to 90 °C, hold for 1 hour, cool down to 50 °C, add 6 parts of mixture D2, stir for 8 minutes, then add 9 parts of epoxidized soybean oil GreenSoft D, disperse at high speed for 20 minutes, raise the temperature to 70 °C, react for 80 minutes, and stop the reaction when the epoxy value measured by the hydrochloric acid-acetone method is less than 0.005;

[0133] S6. Cool down to 40 °C, filter and discharge to obtain the bio-based hydroxy polyacrylate emulsion 2.

[0134] Example 4

[0135] In this example, a bio-based waterborne two-component polyurethane coating 2 is also prepared. The bio-based hydroxy polyacrylate emulsion is obtained from the preparation in Example 3. The specific steps are as follows:

[0136] During construction, mix Agent A2 and Agent B2 in an NCO / OH molar ratio of 1.8:1;

[0137] Among them, Agent A2 is composed of the following components in parts by weight:

[0138]

[0139] Agent B2 is an aqueous polyisocyanate curing agent. The aqueous polyisocyanate curing agent is Bayhydur XP 2655, and the mass fraction of Bayhydur XP 2655 is 17.4 parts;

[0140] The preparation method of Agent A2 of the above bio-based waterborne two-component polyurethane coating 2 is as follows: Add the bio-based hydroxy polyacrylate emulsion 2 to a stirring kettle with a rotation speed of 700 rpm. Premix water, dipropylene glycol butyl ether, and dipropylene glycol methyl ether and then add them to the stirring kettle. Add TEGO-805, TT-935, BYK-346, and DMEA in sequence, disperse for 10 minutes, filter and discharge.

[0141] During construction, add Agent B2 to Agent A2, stir for 5 minutes to obtain the bio-based waterborne two-component polyurethane coating 2, and its bio-based content is 9.4%.

[0142] Cure and dry the film made from the bio-based waterborne two-component polyurethane coating 2 at room temperature for 7 days, and its performance is shown in Table 1.

[0143] Example 5

[0144] A bio-based hydroxy polyacrylate emulsion 3 is prepared by the following steps:

[0145] S1. By mass, 1.1 parts of acrylic acid, 6.3 parts of N-methyl-2-acrylamide, 5 parts of benzyl methacrylate, 5 parts of methyl methacrylate, 7 parts of butyl acrylate, 8.9 parts of styrene, and 15 parts of hydroxypropyl methacrylate are mixed evenly to form a mixed solution A3 for standby;

[0146] S2. Add 30 parts of deionized water to the dispersion tank, dissolve 0.6 part of DOWFAX-2A1, 0.5 part of SR-10, and 1 part of ER-30. After stirring evenly, adjust the disperser to 700 revolutions per minute, and dropwise add 48.3 parts of the mixed solution A3. Finish dropping in 30 minutes. After dropping, continue to disperse for 12 minutes to obtain a pre-emulsion B3 for standby;

[0147] S3. By mass, dissolve 0.6 part of APS in 6 parts of deionized water to form a mixed solution C3 for standby;

[0148] S4. By mass, mix 7 parts of deionized water and 0.7 part of DMCHA evenly to form a mixed solution D3 for standby;

[0149] S5. Add 24.5 parts of deionized water, 0.5 part of DOWFAX-2A1, 0.2 part of SR-10, 0.25 part of NaHCO3, and 0.1 part of KPS to a four-necked flask equipped with a thermometer, a condenser, a stirring paddle, and a constant-pressure dropping funnel. Mix, stir, and heat. When the temperature reaches 83 °C, dropwise add 9.5 parts of the pre-emulsion B3 in 25 minutes. After dropping, stabilize for 20 minutes to obtain a seed emulsion. Raise the temperature to 85 °C, and at the same time, dropwise add 70.9 parts of the pre-emulsion B3 and 6.6 parts of the mixed solution C3. Finish dropping in 5 hours. After dropping, maintain at 85 °C and keep warm for 1.5 hours. Cool down to 60 °C, add 7.5 parts of the mixed solution D3, stir for 12 minutes, and then add 12.5 parts of epoxy linseed oil ELO 9-5 TM , tell to disperse for 25 minutes, raise the temperature to 90 °C, react for 45 minutes, and stop the reaction when the epoxy value measured by the hydrochloric acid-acetone method is less than 0.005;

[0150] S6. Cool down to 40 °C, filter and discharge to obtain the bio-based hydroxy polyacrylate emulsion 3.

[0151] Example 6

[0152] Example prepared a bio-based waterborne two-component polyurethane coating 3. The bio-based hydroxy polyacrylate emulsion was prepared in Example 5. The specific steps are as follows:

[0153] Agent A3 and Agent B3 mixed at an NCO / OH molar ratio of 1.8:1 during construction;

[0154] Among them, Agent A3 includes components in the following parts by weight:

[0155]

[0156] Agent B3 is an aqueous polyisocyanate curing agent, and the aqueous polyisocyanate curing agent is Bayhydur XP2487 / 1, and the mass fraction of Bayhydur XP 2487 / 1 is 29.9 parts;

[0157] The preparation method of Agent A3 of the above bio-based aqueous two-component polyurethane coating 3 is as follows: Add the bio-based hydroxy polyacrylate emulsion 3 to a stirring kettle at a rotation speed of 700 rpm. Premix water, dipropylene glycol butyl ether, and dipropylene glycol methyl ether and then add them to the stirring kettle. Sequentially add TEGO-805, TT-935, BYK-346, and DMEA, disperse for 30 minutes, and filter and discharge.

[0158] During construction, add Agent B3 to Agent A3 and stir for 8 minutes to obtain the bio-based aqueous two-component polyurethane coating 3, and its bio-based content is 8.9%.

[0159] The film formed from the bio-based aqueous two-component polyurethane coating 3 is cured and dried at room temperature for 7 days, and its performance is shown in Table 1.

[0160] Comparative Example 1

[0161] The difference between this comparative example and Example 1 is that the hydroxy polyacrylate emulsion synthesized without adding bio-based materials is not added. The specific steps are as follows:

[0162] S1. Take 0.9 part of acrylic acid, 8.5 parts of N-tert-butyl acrylamide, 5.5 parts of cyclohexyl methacrylate, 5.2 parts of methyl methacrylate, 5 parts of butyl acrylate, 7 parts of styrene, and 10 parts of 2-hydroxyethyl methacrylate, and mix them evenly to form a mixed solution A4 for standby;

[0163] S2. Add 33 parts of deionized water to a dispersion tank, dissolve 0.5 part of SDS and 1 part of EH-9, stir evenly, adjust the disperser to 700 rpm, and dropwise add 43.2 parts of the mixed solution A1. Finish dropping in 25 minutes. After dropping, continue to disperse for 10 minutes to obtain a pre-emulsion B4 for standby;

[0164] S3. Take 7 parts of deionized water to dissolve 0.45 part of APS and 1 part of COPS-1 to form a mixed solution C4 for standby;

[0165] S4. Take 8.5 parts of deionized water and 0.6 part of DMEA and mix them evenly to form a mixed solution D4 for standby;

[0166] S5. Add 26.3 parts of deionized water, 0.25 part of SDS, 0.5 part of EH-9, 0.2 part of NaHCO3 and 0.15 part of APS into a four-necked flask equipped with a thermometer, a condenser, a stirring paddle and a constant-pressure dropping funnel. Mix and stir, and heat. When the temperature reaches 77 °C, add 7.8 parts of pre-emulsion B4 dropwise within 15 minutes. After dropping, keep it stable for 10 minutes to obtain a seed emulsion. Raise the temperature to 80 °C, and at the same time, add 69.9 parts of pre-emulsion B4 and 8.45 parts of mixture C4 dropwise. Finish dropping within 3.5 hours. After dropping, raise the temperature to 85 °C, keep warm for 2 hours, cool down to 55 °C, add 9.1 parts of mixture D4, stir for 10 minutes, then disperse at high speed for 15 minutes, and then raise the temperature to 80 °C and react for 60 minutes. Stop the reaction after measuring the epoxy value to be less than 0.005 by the hydrochloric acid-acetone method;

[0167] S6. Cool down to 40 °C, filter and discharge to obtain hydroxy polyacrylate emulsion 4.

[0168] Comparative Example 2

[0169] A waterborne two-component polyurethane coating 4 was prepared in the comparative example. The emulsion was obtained from the preparation in Comparative Example 1. The specific steps are as follows:

[0170] During construction, agent A4 and agent B4 were mixed according to the NCO / OH molar ratio of 1.8:1;

[0171] Among them, agent A4 includes components in the following weight parts:

[0172]

[0173] Agent B4 is a waterborne polyisocyanate curing agent. The waterborne polyisocyanate curing agent is Bayhydur XP2487 / 1, and the mass part of Bayhydur XP 2487 / 1 is 28.4 parts;

[0174] The preparation method of agent A4 of the above waterborne two-component polyurethane coating 4 is as follows: Add hydroxy polyacrylate emulsion 4 into a stirring kettle with a rotation speed of 700 r / min. Premix water, dipropylene glycol butyl ether and dipropylene glycol methyl ether and then add them into the stirring kettle. Then add TEGO-800, RM-8W, TEGO-245 and TEA in sequence, disperse for 20 minutes, filter and discharge.

[0175] During construction, add agent B4 into agent A4 and stir for 6 minutes to obtain waterborne two-component polyurethane coating 4, and its bio-based content is 0%.

[0176] Cure and dry the film made from waterborne two-component polyurethane coating 4 at room temperature for 7 days, and its performance is shown in Table 1.

[0177] Comparative Example 3

[0178] This comparative example synthesizes a bio-based hydroxy polyacrylate emulsion without adding hydroxyacrylate monomers. The specific steps are as follows:

[0179] S1. By mass, 0.9 parts of acrylic acid, 18.3 parts of N-tert-butylacrylamide, 5.5 parts of cyclohexyl methacrylate, 5.2 parts of methyl methacrylate, 5 parts of butyl acrylate, and 7 parts of styrene are mixed evenly to form a mixed solution A5 for standby;

[0180] S2. Add 33 parts of deionized water to the dispersion tank, dissolve 0.5 part of SDS and 1 part of EH-9, stir evenly, adjust the disperser to 700 revolutions per minute, dropwise add 41.9 parts of the mixed solution A6, finish dropping in 25 minutes, and continue to disperse for 10 minutes after dropping to obtain a pre-emulsion B5 for standby;

[0181] S3. By mass, dissolve 0.45 part of APS and 1 part of COPS-1 in 7 parts of deionized water to form a mixed solution C5 for standby;

[0182] S4. By mass, mix 8.5 parts of deionized water and 0.6 part of DMEA evenly to form a mixed solution D5 for standby;

[0183] S5. Add 35.95 parts of deionized water, 0.25 part of SDS, 0.5 part of EH-9, 0.2 part of NaHCO3, and 0.15 part of APS to a four-necked flask equipped with a thermometer, a condenser, a stirring paddle, and a constant-pressure dropping funnel, mix and stir and heat. When the temperature reaches 77 °C, dropwise add 7.6 parts of the pre-emulsion B5 in 15 minutes. After dropping, stabilize for 10 minutes to obtain a seed emulsion. Raise the temperature to 80 °C, and at the same time dropwise add 68.8 parts of the pre-emulsion B5 and 8.45 parts of the mixed solution C5, finish dropping in 3.5 hours. After dropping, raise the temperature to 85 °C, keep warm for 2 hours, cool down to 55 °C, add 9.1 parts of the mixed solution D5, stir for 10 minutes, then add 32.3 parts of epoxidized soybean oil GreenSoft H, disperse at high speed for 15 minutes, then raise the temperature to 80 °C, react for 60 minutes, and stop the reaction when the epoxy value measured by the hydrochloric acid-acetone method is less than 0.005;

[0184] S6. Cool down to 40 °C, filter and discharge to obtain the bio-based hydroxy polyacrylate emulsion 5.

[0185] Comparative Example 4

[0186] In the comparative example, an aqueous two-component polyurethane coating 5 was prepared, and the emulsion was prepared in Comparative Example 3. The specific steps are as follows:

[0187] During construction, Agent A5 and Agent B5 are mixed according to an NCO / OH molar ratio of 1.8:1;

[0188] Among them, the A5 agent comprises components in the following parts by weight:

[0189]

[0190] The B5 agent is an aqueous polyisocyanate curing agent, and the aqueous polyisocyanate curing agent is Bayhydur XP2487 / 1, and the mass fraction of Bayhydur XP 2487 / 1 is 19.7 parts;

[0191] The preparation method of the A5 agent of the above bio-based aqueous two-component polyurethane coating 5 is as follows: Add the hydroxyl polyacrylate emulsion 5 into a stirring kettle with a rotation speed of 700 rpm. Premix water, dipropylene glycol butyl ether and dipropylene glycol methyl ether and then add them into the stirring kettle. Add TEGO-800, RM-8W, TEGO-245 and TEA in sequence, disperse for 20 minutes, and then filter and discharge.

[0192] During construction, add the B5 agent into the A5 agent and stir for 6 minutes to obtain the aqueous two-component polyurethane coating 5, and its bio-based content is 21.4%.

[0193] Cure and dry the film prepared from the bio-based aqueous two-component polyurethane coating 5 at room temperature for 7 days, and its performance is shown in Table 1.

[0194] Test Example 1

[0195] Cure and dry the aqueous two-component polyurethane coatings prepared in the examples and comparative examples at room temperature for 7 days, and their performance is shown in Table 1.

[0196] The test standards are as follows:

[0197] Appearance of the coating film: Visual inspection;

[0198] Surface drying time: GB / T1728-2020;

[0199] Actual drying time: GB / T1728-2020;

[0200] Pencil hardness: GB / T6739-2006;

[0201] Gloss of the coating film / (60°, %): GB / T9754-2007;

[0202] Water resistance (25°C, 24h): GB / T4893.1-2020;

[0203] Dry heat resistance (70±2°C, 15h): GB / T4893.3-2020;

[0204] Ethanol resistance (50%, 1h): GB / T4893.1-2020;

[0205] The detection method is as follows:

[0206] The basic performance tests include: The bio-based hydroxy polyacrylate emulsion is tested with reference to GB / T 11175-2002 "Test Methods for Synthetic Resin Emulsions" to test the appearance, pH, solid content, viscosity, and gel rate (coarse particles) of the emulsion. The performance of the paint film is tested with reference to GB / T 23999-2009 "Waterborne Wood Coatings for Interior Decoration and Refurbishment" to test the gloss, hardness, water resistance, dry heat resistance, and alcohol resistance. The average particle size of the emulsion is measured using a nano particle size analyzer (ZS Nano S).

[0207] Table 1 Comprehensive Performance of Bio-based Waterborne Two-component Polyurethane Coating 1

[0208]

[0209]

[0210] As can be seen from the above table, compared with the bio-based waterborne two-component polyurethane coating 1 in Example 2, the waterborne two-component polyurethane coating 4 in Comparative Example 2 has a longer surface drying time, which is not conducive to improving the construction efficiency, and is far inferior to the example in terms of the pencil hardness, water resistance, dry heat resistance, and ethanol resistance of the paint film; compared with the bio-based waterborne two-component polyurethane coating 1 in Example 2, the bio-based waterborne two-component polyurethane coating 5 in Comparative Example 4 has a relatively long surface drying time, which is not conducive to improving the construction efficiency, and is also inferior to the example in terms of the pencil hardness, water resistance, dry heat resistance, and ethanol resistance of the paint film. From Examples 2, 4, and 6, it can be seen that the present invention discloses a preparation method of a bio-based hydroxy polyacrylate emulsion. The bio-based hydroxy polyacrylate emulsion prepared by this preparation method has a high hydroxy content, good appearance and good stability; the paint film prepared from the prepared bio-based waterborne two-component polyurethane coating has the advantages of high hardness, excellent water and chemical resistance, high crosslinking density, scratch resistance, wear resistance, and fast drying speed, and can be applied to high-grade wood coatings, automotive coatings, metal anti-corrosion coatings, and other industrial protective coatings.

[0211] Test Example 2

[0212] The performance of the emulsions in Examples 1, 3, 5, Comparative Examples 1, and 3 was tested in this test example, and the data results are shown in Table 2.

[0213] Table 2: Performance Comparison Table of Emulsions

[0214]

[0215]

[0216] The difference between Comparative Example 1 and Example 1 lies in the non-addition of the hydroxy polyacrylate emulsion synthesized from bio-based materials. Compared with Example 1, the bio-based content of Comparative Example 1 is 0%, the solid content is slightly lower, and some hydroxyl groups are replaced by secondary amino groups, with a relatively high total content of hydroxyl and secondary amino groups. The reason for the above changes is the non-addition of epoxy soybean oil to react with the secondary amino groups of the hydroxy polyacrylate polymer. Comparative Example 3 does not add hydroxyacrylate monomers, and its hydroxyl groups are only generated after the reaction of hydrophilic modified epoxy soybean oil with secondary amino groups. Compared with Example 1, its solid content is slightly lower, the bio-based content is relatively high, at 41.0%, but the hydroxyl content is low, and the thermal storage stability is poor. In addition, the relatively high gel rate indicates relatively poor polymerization stability. The reason for the above problems is the excessive addition of epoxy soybean oil, resulting in too high a cross-linking density of the polymer.

[0217] The above has described the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A bio-based hydroxy polyacrylate emulsion, characterized in that, The preparation raw materials include: bio-based materials and polyacrylate polymers containing hydroxyl groups; The bio-based materials include bio-based oils containing epoxy groups; The polymerization monomers of the polyacrylate polymers containing hydroxyl groups include hydroxyacrylate monomers and acrylamide monomers; The acrylamide monomer is an acrylamide monomer containing one secondary amino group and no hydroxyl group; The hydroxyacrylate monomers include at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate; The preparation raw materials of the polyacrylate polymers containing hydroxyl groups further include acrylic acid monomers, acrylate monomers, and vinyl monomers; The preparation method of the bio-based hydroxy polyacrylate emulsion includes mixing and reacting the bio-based materials and the polyacrylate polymers containing hydroxyl groups; The acrylate monomers include at least one of methyl methacrylate, butyl acrylate, isobornyl acrylate, cyclohexyl methacrylate, and benzyl methacrylate; The vinyl monomer includes styrene.

2. The bio-based hydroxy polyacrylate emulsion according to claim 1, characterized in that, The bio-based content of the bio-based hydroxy polyacrylate emulsion is 5% - 25%.

3. The bio-based hydroxy polyacrylate emulsion according to claim 1, wherein The particle size of the bio-based hydroxy polyacrylate emulsion is 80nm - 120nm.

4. The bio-based hydroxy polyacrylate emulsion according to claim 1, wherein The solid content of the bio-based hydroxy polyacrylate emulsion is 47 - 52%.

5. The bio-based hydroxy polyacrylate emulsion according to claim 1, wherein The temperature of the mixing reaction is 70 - 90°C.

6. A coating, characterized in that, The preparation raw materials of the coating include the bio-based hydroxy polyacrylate emulsion according to any one of claims 1 - 5.

7. Use of a coating according to claim 6 in the field of decoration.

Images