Fluorine-free sand streak agent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of powder coatings, particularly relates to a fluorine-free sand texture agent and a sand texture type powder coating, and further discloses a preparation method and application of the fluorine-free sand texture agent and the sand texture type powder coating. According to the fluorine-free sand texturing agent disclosed by the invention, the sand texturing agent is obtained by adopting n-butyl acrylate, methyl methacrylate, oleamide, 2-furan methacrylic acid, acrylic acid and triallyl cyanurate as monomers for copolymerization, the acid value of the product is 118-134mgKOH / g, and the glass transition temperature reaches 108-120 DEG C; therefore, when the powder coating is cured, matting and sand textures with excellent effects are generated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of powder coatings, and particularly relates to a fluorine-free sand-textured agent, and further discloses a preparation method and application thereof. BACKGROUND

[0002] Coating is a very important link in the surface processing technology of metal materials, and whether it is corrosion prevention, decoration, or functionality is the requirement of coating. With the improvement of national environmental emission standards, the limitation of VOC emission is gradually increasing, resulting in the gradual shift of many solvent-based coatings to environmentally friendly powder coatings with almost no VOC emission.

[0003] Powder coatings are currently widely used in various industries as environmentally friendly coatings for coating the surfaces of substrates or equipment. In recent years, they have developed rapidly due to their economic, efficient, environmentally friendly, and energy-saving advantages. Powder coatings, being 100% solid powders, have the characteristics of no solvent, no pollution, saving energy and resources, reducing labor intensity, and high mechanical strength of the coating film, and can be widely used in fields such as construction, automobiles, machinery, chemical industry, energy, and electronic and electrical equipment. TGIC system powder coatings are currently the main type of powder coatings used.

[0004] With the increasing demand for decorative coatings and changes in people's aesthetic tastes, the use of low-gloss powder coatings with sand-textured patterns has increased rapidly. Sand-textured powder coatings can scatter light and provide a comfortable viewing experience, and also have the advantages of high film hardness, smooth feel, resistance to scratching, and aging resistance, and are widely used in the field of architectural aluminum profiles. Traditional sand-textured powders (also known as textured powders) are achieved using polytetrafluoroethylene-based sand-textured agents (or textured agents). In order to reduce the harm to the environment and human body, the use of fluorine-containing products is restricted in regions such as the European Union. Therefore, how to develop a fluorine-free sand-textured agent to replace polytetrafluoroethylene-based sand-textured agents is the direction of industry development.

[0005] As disclosed in Chinese patent CN119431676A, a fluorine-free sand-textured agent is prepared by using PMMA micro-powder of a specific size as the main component of the sand-textured agent. However, due to insufficient dispersibility in powder coatings, the sand-textured stability of the final powder coating is not good, and the extinction is difficult to achieve below 10%. Therefore, it is desirable to develop a sand-textured agent product with better performance, which has a positive significance for improving the coating effect of powder coatings. SUMMARY

[0006] The first object of the present application is to provide a fluorine-free sand-textured agent that can produce extinction and excellent sand-textured pattern effects when curing powder coatings. The second object of the present application is to provide a preparation method and application of the above-mentioned fluorine-free sand-textured agent.

[0007] In order to solve the above technical problems, the present application provides a kind of fluorine-free sand agent, including polymer monomer and polymer additive;Wherein, The polymer monomer includes the following molar fraction components: N-butyl acrylate 3-5 moles; Methyl methacrylate 25-28 moles; Oleic acid amide 7-10 moles; 2-furfuryl methacrylate 5-10 moles; Acrylic acid 10-15 moles; Triallyl cyanurate 2-3 moles; The polymer additive includes initiator and molecular weight regulator;Wherein, The amount of initiator is 2-3wt% of the total mass of the polymer monomer; The amount of molecular weight regulator is 1-2wt% of the total mass of the polymer monomer.

[0008] Specifically, in the fluorine-free sand agent, the initiator includes dibenzoyl peroxide (BPO) and / or azobisisobutyronitrile (AIBN); Specifically, in the fluorine-free sand agent, the molecular weight regulator includes 2,4-diphenyl-4-methyl-1-pentene.

[0009] The present application also discloses a preparation method of the fluorine-free sand agent, comprising the following steps: (1) Take a selected amount of n-butyl acrylate, methyl methacrylate, acrylic acid, part of the reaction solvent, and part of the initiator to mix, to obtain a first mixture; (2) Take a selected amount of oleic acid amide and part of the reaction solvent to mix, to obtain a second mixture; (3) Take a selected amount of triallyl cyanurate, part of the reaction solvent, and the remaining amount of initiator to mix, to obtain a third mixture; (4) Take a selected amount of 2-furfuryl methacrylate, molecular weight regulator, and the remaining amount of reaction solvent to mix, to obtain a fourth mixture; (5) Add the first mixture and the second mixture into the fourth mixture respectively to mix, and carry out a heat preservation polymerization reaction; (6) Continue to add the third mixture to mix, and carry out a branching chain extension reaction; (7) After the reaction is completed, remove the reaction solvent by vacuum decompression, and discharge, to obtain the product.

[0010] Specifically, in the preparation method of the fluorine-free sand agent, the reaction solvent includes a mixture of xylene and propylene glycol methyl ether acetate; Preferably, the mass ratio of the xylene to propylene glycol methyl ether acetate is 1:1.5-2; Preferably, the amount of the reaction solvent is 1-2 times of the total mass of the polymerization monomers.

[0011] Specifically, in the preparation method of the fluorine-free sand agent, the amount of the reaction solvent in the step (1) is 20-30wt% of the total amount of the reaction solvent. Specifically, in the preparation method of the fluorine-free sand agent, the amount of the reaction solvent in the step (2) is 20-30wt% of the total amount of the reaction solvent. Specifically, in the preparation method of the fluorine-free sand agent, the amount of the reaction solvent in the step (3) is 20-30wt% of the total amount of the reaction solvent.

[0012] Specifically, in the preparation method of the fluorine-free sand agent, the amount of the reaction solvent in the step (4) is 20-30wt% of the total amount of the reaction solvent. Specifically, in the preparation method of the fluorine-free sand agent, the amount of the initiator in the step (1) is 1 / 2-2 / 3 of the total mass of the initiator.

[0013] Specifically, in the preparation method of the fluorine-free sand agent, the amount of the initiator in the step (3) is 1 / 3-1 / 2 of the total mass of the initiator. Specifically, in the preparation method of the fluorine-free sand agent, the temperature of the polymerization reaction in the step (5) is 120-125℃. Specifically, in the preparation method of the fluorine-free sand agent, the temperature of the branched chain extension reaction in the step (6) is 120-125℃.

[0014] Specifically, in the preparation method of the fluorine-free sand agent, when the first mixture is added to 40-60wt% of the total amount of the formulation, the second mixture is started to be added, and the first mixture is continuously added, and the addition of the first mixture and the second mixture is completed at the same time.

[0015] The application further discloses the use of the fluorine-free sand agent for preparing a powder coating, especially a sand type powder coating. Preferably, the powder coating comprises a TGIC type powder coating.

[0016] The application further discloses a sand type powder coating, which comprises the fluorine-free sand agent.

[0017] ​​​​Specifically, the sand-textured powder coating comprises the following components in parts by weight: polyester resin 480-550 parts by weight; TGIC 36-42 parts by weight; the fluorine-free sand-texturing agent 25-35 parts by weight; carbon black 7-10 parts by weight; barium sulfate 350-450 parts by weight; leveling agent 1-5 parts by weight.

[0018] Specifically, the sand-textured powder coating comprises the following components in parts by weight: polyester resin 510 parts by weight; TGIC 38 parts by weight; the fluorine-free sand-texturing agent 30 parts by weight; carbon black 7 parts by weight; barium sulfate 412 parts by weight; leveling agent 3 parts by weight.

[0019] The fluorine-free sand-texturing agent of the present application is obtained by copolymerization of n-butyl acrylate, methyl methacrylate, oleic acid amide, 2-furfuryl methacrylic acid, acrylic acid, and triallyl cyanurate as monomers. In the polymer, not only methyl methacrylate and acrylic acid, which are hard monomers, but also triallyl cyanurate, which is a trifunctional monomer, are introduced, so as to improve the glass transition temperature of the product. The product has an acid value of 100-150 mgKOH / g and a glass transition temperature of 108-120℃. Meanwhile, different functional groups such as methyl methacrylate, 2-furfuryl methacrylic acid, and oleic acid amide are introduced, so that the activity difference is obvious during curing, and the relatively poor flowability at 200℃ due to the high glass transition temperature brings about extinction and excellent sand-textured texture during curing of the powder coating.

[0020] The fluorine-free sand-texturing agent of the present application is suitable for TGIC system powder coating. The product is used in the TGIC powder coating system, and has the advantages of uniform and delicate sand-textured texture, low gloss, and high film hardness. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, in which, Figure 1 Glass transition temperature of the sand-texturing agent product prepared in Example 1. DETAILED DESCRIPTION

[0022] In order to obtain the powder coating with uniform and delicate sand texture, low glossiness, high film hardness and other advantages during coating, the application develops a suitable fluorine-free sanding agent, which comprises polymerized monomers and polymerized additives. The polymerized monomers comprise the following components in mole fraction: n-butyl acrylate 3-5 moles; methyl methacrylate 25-28 moles; oleic acid amide 7-10 moles; 2-furfuryl methacrylate 5-10 moles; acrylic acid 10-15 moles; triallyl cyanurate 2-3 moles; The polymerized additives comprise an initiator and a molecular weight regulator; wherein, The amount of the initiator is 2-3wt% of the total mass of the polymerized monomers; The amount of the molecular weight regulator is 1-2wt% of the total mass of the polymerized monomers.

[0023] In some specific embodiments, the initiator comprises benzoyl peroxide (BPO) and / or azobisisobutyronitrile (AIBN); In some specific embodiments, the molecular weight regulator comprises 2,4-diphenyl-4-methyl-1-pentene.

[0024] The application further discloses a preparation method of the fluorine-free sanding agent, comprising the following steps: (1) mixing selected amounts of n-butyl acrylate, methyl methacrylate, acrylic acid, part of a reaction solvent and part of an initiator to obtain a first mixture; (2) mixing selected amounts of oleic acid amide and part of a reaction solvent to obtain a second mixture; (3) mixing selected amounts of triallyl cyanurate, part of a reaction solvent and the remaining amount of an initiator to obtain a third mixture; (4) mixing selected amounts of 2-furfuryl methacrylate, a molecular weight regulator and the remaining amount of a reaction solvent to obtain a fourth mixture; (5) mixing the first mixture and the second mixture into the fourth mixture respectively and mixing, and then performing a polymerization reaction under insulation; (6) continuing to mix the third mixture and performing a branching and chain extension reaction; (7) after the reaction is completed, removing the reaction solvent by vacuum and pressure reduction, and discharging, to obtain the product.

[0025] Specifically, the preparation method of the fluorine-free sanding agent, the reaction solvent comprises a mixture of xylene and propylene glycol methyl ether acetate; Preferably, the mass ratio of the xylene to propylene glycol methyl ether acetate is 1:1.5-2; Preferably, the amount of the reaction solvent is 1-2 times of the total mass of the polymerization monomers.

[0026] In some specific embodiments, In the step (1), the amount of the reaction solvent accounts for 20-30wt% of the total amount of the reaction solvent; preferably 25wt%, i.e. 1 / 4 of the formula amount; In the step (2), the amount of the reaction solvent accounts for 20-30wt% of the total amount of the reaction solvent; preferably 25wt%, i.e. 1 / 4 of the formula amount; In the step (3), the amount of the reaction solvent accounts for 20-30wt% of the total amount of the reaction solvent; preferably 25wt%, i.e. 1 / 4 of the formula amount; In the step (4), the amount of the reaction solvent accounts for 20-30wt% of the total amount of the reaction solvent; preferably 25wt%, i.e. 1 / 4 of the formula amount; In the step (1), the amount of the initiator accounts for 1 / 2-2 / 3 of the total mass of the initiator, i.e. 1 / 2-2 / 3 of the formula amount; In the step (3), the amount of the initiator accounts for 1 / 3-1 / 2 of the total mass of the initiator, i.e. 1 / 2-2 / 3 of the formula amount.

[0027] Specifically, the preparation method of the fluorine-free sanding agent comprises the following steps: In the step (5), the temperature of the polymerization reaction is 120-125℃; In the step (6), the temperature of the branching and chain extension reaction is 120-125℃.

[0028] In the step (7), the temperature of the step of removing the reaction solvent under vacuum and reduced pressure is 220-225℃, and the vacuum degree is -0.095Mpa~-0.098Mpa.

[0029] Specifically, the preparation method of the fluorine-free sanding agent, in the step (5), when the first mixture is added dropwise to 40-60wt% of the total formula amount (preferably 1 / 2 of the total formula amount), the second mixture is started to be added dropwise, and the first mixture is continuously added dropwise, and the addition of the first mixture and the second mixture is controlled to be completed at the same time.

[0030] As an exemplary embodiment, the present application also provides a preparation method of a fluorine-free sanding agent, comprising the following steps: (1) The formula amount of the n-butyl acrylate, methyl methacrylate, acrylic acid, 1 / 4 formula amount of the reaction solvent and 1 / 2-2 / 3 formula amount of the initiator are mixed uniformly at room temperature, then pumped into the high tank 1 to obtain a first mixed material, ready for use; (2) The formula amount of the oleic acid amide, 1 / 4 formula amount of the reaction solvent are dissolved in a mixing kettle by heating to 70-75℃ and fully stirring, then pumped into the high tank 2 to obtain a second mixed material, ready for use; (3) The formula amount of the triallyl cyanurate, 1 / 4 formula amount of the reaction solvent and the remaining amount of the initiator are mixed and dissolved into a homogeneous phase at room temperature, then pumped into the high tank 3 to obtain a third mixed material, ready for use; (4) The remaining formula amount of the reaction solvent, the formula amount of the 2-furfuryl methacrylic acid and the molecular weight regulator are added into a polymerization reactor, the stirring is started and the temperature is raised to 120-125℃ to make them fully dissolved to obtain a fourth mixed material; (5) The temperature of the polymerization reactor is continuously maintained at 120-125℃, the heat preservation is continued and the first mixed material in the high tank 1 is started to be added dropwise, the dropwise adding time is controlled to be 4-4.5h; when the remaining amount of the first mixed material in the high tank 1 is 1 / 2 of the total amount, the bottom valve of the high tank 2 is opened, and the second mixed material in the high tank 2 is added dropwise to carry out the copolymerization reaction, which is used to introduce amide groups and different carboxyl groups into the polymer chain segment, the dropwise adding time is basically consistent with the dropwise adding time of the high tank 1; after the dropwise adding of the mixed solutions in the high tank 1 and the high tank 2 is completed, the polymerization reaction is continuously carried out under heat preservation; (6) After the reaction is completed, the content of the largest amount of raw material methyl methacrylate is detected by gas chromatography, when the conversion rate of the acrylic acid reaches more than 90%, the third mixed material in the high tank 3 is started to be added dropwise, the dropwise adding time is controlled to be 0.5-1h, and after the dropwise adding is completed, the branched chain polymerization reaction is continuously carried out at 120-125℃; (7) After the reaction is completed, the conversion rate of the triallyl cyanurate is detected by high performance liquid chromatography, when the conversion rate is greater than 99%, it is indicated that the branched chain polymerization reaction has been completed, at this time, the vacuum system is started, the mixed solvent is removed under reduced pressure, and the temperature is gradually raised to 220-225℃ to ensure that it is removed completely; the vacuum degree is controlled to be -0.095Mpa to -0.098Mpa; when the volatile matter of the polymer is less than 1%, the vacuum system is stopped, then the high temperature discharge is carried out, and the product is broken to obtain the required fluorine-free sand textured agent product.

[0031] The application further discloses the use of the fluorine-free sand textured agent for preparing a sand textured powder coating. Preferably, the powder coating comprises a TGIC type powder coating.

[0032] The present application also exemplarily discloses a sand-textured powder coating, i.e. a TGIC-cured powder coating, which comprises the fluorine-free sand-texturing agent.

[0033] In some specific embodiments, the sand-textured powder coating comprises the following components by weight: polyester resin 480-550 parts by weight; TGIC 36-42 parts by weight; the fluorine-free sand-texturing agent 25-35 parts by weight; carbon black 7-10 parts by weight; barium sulfate 350-450 parts by weight; leveling agent 1-5 parts by weight.

[0034] In some specific embodiments, the sand-textured powder coating comprises the following components by weight: polyester resin 510 parts by weight; TGIC 38 parts by weight; the fluorine-free sand-texturing agent 50 parts by weight; carbon black 7 parts by weight; barium sulfate 392 parts by weight; leveling agent 3 parts by weight.

[0035] In the following examples of the present application, the raw material components of the fluorine-free sand-texturing agent are all commercially available products in the prior art.

[0036] Example 1 In this example, the fluorine-free sand-texturing agent comprises polymerized monomers and polymerized additives; wherein, the polymerized monomers comprise the following components by mole fraction: n-butyl acrylate 4.5 mole parts; methyl methacrylate 26 mole parts; oleic acid amide 8 mole parts; 2-furfuryl methacrylate 9 mole parts; acrylic acid 12 mole parts; triallyl cyanurate 2.5 mole parts; the polymerized additives comprise an initiator, benzoyl peroxide (BPO), and a molecular weight regulator, 2,4-diphenyl-4-methyl-1-pentene; wherein, the amount of the initiator is 2.5wt% of the total mass of the polymerized monomers; the amount of the molecular weight regulator is 1.5wt% of the total mass of the polymerized monomers.

[0037] The preparation method of the fluorine-free sand-texturing agent in this example comprises the following steps: (1) The formula amount of the n-butyl acrylate, methyl methacrylate, acrylic acid, 1 / 4 formula amount of the reaction solvent and 3 / 5 formula amount of the initiator are mixed uniformly at room temperature, and then pumped into the high tank 1 to obtain a first mixed material, which is ready for use; (2) The formula amount of the oleic acid amide, 1 / 4 formula amount of the reaction solvent are dissolved in a mixing kettle by heating to 75℃ and fully stirring, and then pumped into the high tank 2 to obtain a second mixed material, which is ready for use; (3) The formula amount of the triallyl cyanurate, 1 / 4 formula amount of the reaction solvent and the remaining amount of the initiator are mixed and dissolved into a homogeneous phase at room temperature, and then pumped into the high tank 3 to obtain a third mixed material, which is ready for use; (4) The remaining formula amount of the reaction solvent, the formula amount of the 2-furfuryl methacrylic acid and the molecular weight regulator are added into a polymerization kettle, the stirring is started and the temperature is raised to 125℃ to fully dissolve them, and then a fourth mixed material is obtained; (5) The temperature (125℃) of the polymerization kettle is kept, the heat preservation is continued and the first mixed material in the high tank 1 is started to be added dropwise, and the dropwise adding time is controlled to be 4h; when the remaining amount of the first mixed material in the high tank 1 is 1 / 2 of the total amount, the bottom valve of the high tank 2 is opened, and the second mixed material in the high tank 2 is started to be added dropwise to carry out the copolymerization reaction, which is used to introduce amide groups and different carboxyl groups into the polymer chain segment, and the dropwise adding time is basically consistent with the dropwise adding time of the high tank 1; after the dropwise adding of the mixed solutions in the high tank 1 and the high tank 2 is completed, the polymerization reaction is continued under heat preservation; (6) After the reaction is completed, the content of the largest amount of raw material methyl methacrylate is detected by gas chromatography, when the conversion rate of the acrylic acid is more than 90%, the third mixed material in the high tank 3 is started to be added dropwise, and the dropwise adding time is controlled to be 1h; after the dropwise adding is completed, the branched chain polymerization reaction is continued at 125℃; (7) After the reaction is completed, the conversion rate of the triallyl cyanurate is detected by high performance liquid chromatography, when the conversion rate is greater than 99%, it is indicated that the branched chain polymerization reaction has been completed, at this time, the vacuum system is started, the mixed solvent is removed under reduced pressure, and the temperature is gradually raised to 225℃ to ensure that the removal is clean; the vacuum degree is controlled to be -0.095Mpa; when the volatile content of the polymer is less than 1%, the vacuum system is stopped, then the high temperature discharging is carried out, and the product is broken to obtain the required fluorine-free sand textured agent product.

[0038] In this embodiment, the prepared fluorine-free sand textured agent is a light yellow transparent resin particle, and the acid value is 125mgKOH / g and the glass transition temperature (Tg) is 113℃.

[0039] Example 2 In this embodiment, the fluorine-free sand textured agent comprises polymerized monomers and polymerized additives; wherein, The polymerization monomer includes the following molar fractions of components: n-butyl acrylate 3 moles; methyl methacrylate 28 moles; oleic acid amide 7 moles; 2-furfuryl methacrylate 10 moles; acrylic acid 10 moles; triallyl cyanurate 3 moles; The polymerization additive includes initiator benzoyl peroxide (BPO) and molecular weight regulator 2,4-diphenyl-4-methyl-1-pentene; wherein, The amount of the initiator is 3wt% of the total mass of the polymerization monomers; The amount of the molecular weight regulator is 2wt% of the total mass of the polymerization monomers.

[0040] The preparation method of the fluorine-free sand texturing agent described in this embodiment includes the following steps: (1) After the formula amount of the n-butyl acrylate, the methyl methacrylate, the acrylic acid, 1 / 4 of the formula amount of the reaction solvent, and 1 / 2 of the formula amount of the initiator are uniformly mixed at room temperature, they are pumped into a high tank 1 to obtain a first mixed material, which is ready for use; (2) After the formula amount of the oleic acid amide and 1 / 4 of the formula amount of the reaction solvent are fully stirred and dissolved in a mixing kettle when the temperature is raised to 70°C, they are pumped into a high tank 2 to obtain a second mixed material, which is ready for use; (3) After the formula amount of the triallyl cyanurate, 1 / 4 of the formula amount of the reaction solvent, and the remaining amount of the initiator are mixed and dissolved into a homogeneous phase at room temperature, they are pumped into a high tank 3 to obtain a third mixed material, which is ready for use; (4) The remaining formula amount of the reaction solvent, the formula amount of the 2-furfuryl methacrylate, and the molecular weight regulator are added into a polymerization reactor, stirring is started, and the temperature is raised to 120°C to fully dissolve them, thereby obtaining a fourth mixed material; (5) The temperature of the polymerization reactor is continuously maintained at 120°C, and the first mixed material in the high tank 1 is started to be added dropwise, with the dropwise adding time being controlled to be 4.5h; when the remaining amount of the first mixed material in the high tank 1 is 1 / 2 of the total amount, the bottom valve of the high tank 2 is opened, and the second mixed material in the high tank 2 is started to be added dropwise for copolymerization, which is used to introduce amide groups and different carboxyl groups into the polymer chain segment, and the dropwise adding time is basically consistent with the dropwise adding time of the high tank 1; after the mixed solutions in the high tank 1 and the high tank 2 are both added dropwise, the polymerization reaction is continuously carried out under temperature maintenance; (6) After the reaction is completed, sample is taken, and the content of the largest amount of raw material methyl methacrylate is detected by gas chromatography. When the conversion rate of acrylic acid reaches 90% or more, the third mixture in tank 3 is started to be added dropwise, and the dropwise adding time is controlled within 0.5 h. After the dropwise adding is completed, the branched chain extension polymerization reaction is continuously carried out at 120℃; (7) After the reaction is completed, sample is taken, and the conversion rate of triallyl cyanurate is detected by high performance liquid chromatography. When the conversion rate is greater than 99%, it is indicated that the branched chain extension reaction has been completed. At this time, the vacuum system is started, the mixed solvent is removed under reduced pressure, and the temperature is gradually increased to 220℃ to ensure that the removal is clean. The vacuum degree is controlled within -0.098 Mpa. When the volatile content of the polymer is less than 1%, the vacuum system is stopped, and then the product is discharged at high temperature and broken to obtain the required fluorine-free sanding agent product.

[0041] In this embodiment, the prepared fluorine-free sanding agent is a light yellow transparent resin particle, and the acid value data is 121 mgKOH / g, and the glass transition temperature (Tg) is 117℃.

[0042] Example 3 In this embodiment, the fluorine-free sanding agent includes polymerized monomers and polymerized additives; wherein, The polymerized monomers include the following components in mole fraction: 4 mole parts of n-butyl acrylate; 27 mole parts of methyl methacrylate; 9 mole parts of oleic acid amide; 8 mole parts of 2-furfuryl methacrylate; 13 mole parts of acrylic acid; 2.5 mole parts of triallyl cyanurate; The polymerized additives include an initiator of dibenzoyl peroxide (BPO) and a molecular weight regulator of 2,4-diphenyl-4-methyl-1-pentene; wherein, The amount of the initiator is 2.5wt% of the total mass of the polymerized monomers; The amount of the molecular weight regulator is 2.5wt% of the total mass of the polymerized monomers.

[0043] The preparation method of the fluorine-free sanding agent in this embodiment includes the following steps: (1) The formula amount of the n-butyl acrylate, the methyl methacrylate, the acrylic acid, 1 / 4 of the formula amount of the reaction solvent, and 3 / 5 of the formula amount of the initiator are uniformly mixed at room temperature, and then pumped into tank 1 to obtain the first mixture, which is ready for use; (2) The formula amount of the oleic acid amide and 1 / 4 of the formula amount of the reaction solvent are dissolved by being heated to 75℃ in a mixing kettle and then pumped into tank 2 to obtain the second mixture, which is ready for use; (3) Mix and dissolve the formulated amount of triallyl cyanurate, 1 / 4 of the formulated amount of reaction solvent and the remaining amount of initiator at room temperature to form a homogeneous phase, and then pump it into the high-level tank 3 to obtain the third mixture for later use. (4) Add the remaining amount of reaction solvent, the amount of the 2-furan methacrylic acid and molecular weight regulator to the polymerization reactor, start stirring and heat to 125°C to fully dissolve them, and obtain the fourth mixture. (5) Continue to maintain the temperature of the polymerization reactor (125°C), keep it warm and start adding the first mixture in the high-level tank 1, controlling the adding time to 4.5h; when the remaining first mixture in the high-level tank 1 is 1 / 2 of the total amount, open the bottom valve of the high-level tank 2, and simultaneously add the second mixture in the high-level tank 2 to carry out the copolymerization reaction, which is used to introduce amide groups and differentiated carboxyl groups into the polymer chain segments. The time for completing the adding is basically consistent with the time for completing the adding in the high-level tank 1; after the mixed solutions in the high-level tank 1 and the high-level tank 2 have been added, keep it warm and continue the polymerization reaction. (6) After the reaction is completed, take a sample and use gas chromatography to detect the content of the raw material methyl methacrylate with the largest amount. When the conversion rate of acrylic acid reaches more than 90%, start to add the third mixture in the high-level tank 3. The adding time is controlled at 1 hour. After the addition is completed, continue to carry out the branching chain extension polymerization reaction at 125℃. (7) After the reaction is completed, take a sample and use high performance liquid chromatography to detect the conversion rate of triallyl cyanurate. When the conversion rate is greater than 99%, it indicates that the branching and chain extension reaction has been completed. At this time, start the vacuum system, remove the mixed solvent under reduced pressure, and gradually raise the temperature to 225°C to ensure that the solvent is removed cleanly. The vacuum degree is controlled at -0.096 MPa. When the volatile content of the polymer is <1%, stop the vacuum system, then discharge the material at high temperature and crush it to obtain the desired fluorine-free sanding agent product.

[0044] In this embodiment, the prepared fluorine-free sanding agent is a light yellow transparent resin particle, and its acid value is measured to be 127 mg KOH / g.

[0045] In this experimental example, the glass transition temperature of the prepared fluorine-free sanding agent is shown in the attached figure. Figure 1 As shown, its glass transition temperature is 111℃.

[0046] Example 4 In this embodiment, the fluorine-free textured agent includes polymeric monomers and polymeric additives; wherein, The polymeric monomer comprises the following components in molar amounts: 5 moles of n-butyl acrylate; 25 moles of methyl methacrylate; 10 moles of oleamide; 5 moles of 2-furan methacrylic acid; 15 moles of acrylic acid; 2 moles of triallyl cyanurate; The polymerization additives include the initiator benzoyl peroxide (BPO) and the molecular weight regulator 2,4-diphenyl-4-methyl-1-pentene; wherein, The amount of the initiator is 2 wt% of the total mass of the polymeric monomers; The amount of the molecular weight regulator is 1 wt% of the total mass of the polymer monomers.

[0047] The preparation method of the fluorine-free textured agent described in this embodiment includes the following steps: (1) The n-butyl acrylate, methyl methacrylate, acrylic acid, 1 / 4 of the formulation amount of reaction solvent and 2 / 3 of the formulation amount of initiator are mixed evenly at room temperature and then pumped into high-level tank 1 to obtain the first mixture for later use. (2) The oleamide and 1 / 4 of the reaction solvent in the formula are heated to 70°C in a mixing vessel and stirred until fully dissolved. The mixture is then pumped to the high-level tank 2 to obtain the second mixture for later use. (3) Mix and dissolve the formulated amount of triallyl cyanurate, 1 / 4 of the formulated amount of reaction solvent and the remaining amount of initiator at room temperature to form a homogeneous phase, and then pump it into the high-level tank 3 to obtain the third mixture for later use. (4) Add the remaining amount of reaction solvent, the amount of the 2-furan methacrylic acid and molecular weight regulator to the polymerization reactor, start stirring and heat to 120°C to fully dissolve them, and obtain the fourth mixture. (5) Continue to maintain the temperature of the polymerization reactor (120°C), keep it warm and start adding the first mixture in the high-level tank 1, and control the adding time to 4 hours; when the remaining first mixture in the high-level tank 1 is 1 / 2 of the total amount, open the bottom valve of the high-level tank 2, and at the same time add the second mixture in the high-level tank 2 to carry out the copolymerization reaction, which is used to introduce amide groups and differentiated carboxyl groups into the polymer chain segments. The time for completing the adding is basically consistent with the time for completing the adding in the high-level tank 1; after the mixed solutions in the high-level tank 1 and the high-level tank 2 have been added, keep it warm and continue the polymerization reaction. (6) After the reaction is completed, take a sample and use gas chromatography to detect the content of the raw material methyl methacrylate with the largest amount. When the conversion rate of acrylic acid reaches more than 90%, start to add the third mixture in the high-level tank 3. The adding time is controlled at 0.5h. After the addition is completed, continue to carry out the branching chain extension polymerization reaction at 120℃. (7) After the reaction is completed, take a sample and use high performance liquid chromatography to detect the conversion rate of triallyl cyanurate. When the conversion rate is greater than 99%, it indicates that the branching and chain extension reaction has been completed. At this time, start the vacuum system, remove the mixed solvent under reduced pressure, and gradually raise the temperature to 220°C to ensure that the solvent is removed completely. The vacuum degree is controlled at -0.097 MPa. When the volatile content of the polymer is <1%, stop the vacuum system, then discharge the material at high temperature and crush it to obtain the desired fluorine-free sanding agent product.

[0048] In this embodiment, the prepared fluorine-free sanding agent is a light yellow transparent resin particle, and its acid value is 131 mg KOH / g, and its glass transition temperature (Tg) is 109℃.

[0049] Comparative Example 1 This comparative example uses a commercially available polytetrafluoroethylene (PTFE) textured agent as Comparative Example 1, model HA120, manufactured by Huangshan Huahui Technology Co., Ltd.

[0050] Comparative Example 2 The texture agent described in this comparative example is a product prepared with reference to the scheme in Example 1 of Chinese Patent CN119431676A.

[0051] Experimental Example 1. Coating performance In this experimental example, the textured agent prepared in Examples 1-4 and Comparative Example 2 was used to apply the powder coating according to the existing TGIC textured powder coating formulation. The powder coating system is formulated as follows by weight: 510 parts by weight of polyester resin; TGIC 38 parts by weight; 30 parts by weight of textured agent; 7 parts by weight of carbon black; 412 parts by weight of barium sulfate; 3 parts by weight of leveling agent.

[0052] In this experimental example, the texture agent from Comparative Example 1 was used to apply the powder coating according to the existing TGIC textured powder coating formulation. The powder coating system is formulated as follows by weight: 510 parts by weight of polyester resin; TGIC 38 parts by weight; Two parts by weight of textured agent; 7 parts by weight of carbon black; 440 parts by weight of barium sulfate; 3 parts by weight of leveling agent.

[0053] Among them, the polyester resin model SJ4ET, barium sulfate, TGIC, leveling agent and carbon black are all commercially available ordinary products.

[0054] In this experimental example, the powder coating was prepared as follows: The materials were physically mixed according to the powder coating formula, then extruded, pressed, and crushed using a twin-screw extruder. The sheets were then pulverized and sieved (160 mesh) to produce the powder coating. The powder coating was then sprayed onto a tinplate using an electrostatic spray gun, achieving a film thickness of 80 μm. After curing at 200℃ for 10 min, the coating was obtained.

[0055] In this experimental example, the coating index testing was conducted according to GB / T 21776-2008 "Guidelines for Testing Standards of Powder Coatings and Their Coatings", and the test results are shown in Table 1 below.

[0056] Table 1 Coating performance

[0057] As can be seen, the sand texture agent product of this invention is obtained by copolymerization of special raw materials containing different active carboxyl and amine groups. This product has a high glass transition temperature and insufficient compatibility with the system. When used in TGIC powder coating system, the cured coating film has the characteristics of uniform sand texture and good fineness, and the gloss is low, basically between 4-6.5%. The adhesion reaches level 0, and the impact resistance and water boiling resistance are also better. There is no change on the surface of the coating film after boiling in water for 2 hours.

[0058] The fluorinated sanding agent used in Comparative Example 1 has a uniform sanding texture, good fineness, a gloss of 5.5%, an adhesion of grade 0, and meets the requirements for impact resistance and boiling water test.

[0059] In contrast, Comparative Example 2 used surface-grafted modified PMMA resin micro powder as a texture agent. However, the texture of the coating film was not very fine, and the gloss was high, reaching 27.1%. The adhesion was only at level 1, and the water resistance was also relatively poor. After boiling in water for 2 hours, the coating film surface turned white.

[0060] It is evident that the fluorine-free sanding agent prepared by the method of this invention has fully achieved the performance of the fluorine-containing sanding agent, which has very important economic and environmental significance.

[0061] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A fluorine-free sanding agent, characterized in that, Includes polymeric monomers and polymeric additives; among which, The polymeric monomer comprises the following components in molar amounts: 3-5 moles of n-butyl acrylate; 25-28 moles of methyl methacrylate; 7-10 moles of oleamide; 5-10 moles of 2-furan methacrylic acid; 10-15 moles of acrylic acid; 2-3 moles of triallyl cyanurate; The polymerization additive includes an initiator and a molecular weight regulator; wherein... The amount of the initiator is 2-3 wt% of the total mass of the polymerized monomers; The amount of the molecular weight regulator is 1-2 wt% of the total mass of the polymeric monomers.

2. The fluorine-free textured agent according to claim 1, characterized in that, The initiator includes benzoyl peroxide (BPO) and / or azobisisobutyronitrile (AIBN).

3. The fluorine-free sanding agent according to claim 1 or 2, characterized in that, The molecular weight regulator includes 2,4-diphenyl-4-methyl-1-pentene.

4. A method for preparing a fluorine-free textured agent as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Take a selected amount of the n-butyl acrylate, methyl methacrylate, acrylic acid, and part of the reaction solvent and part of the initiator and mix them to obtain the first mixture; (2) Take a selected amount of the oleamide and part of the reaction solvent and mix them to obtain a second mixture; (3) Take a selected amount of the trimenyl cyanurate, part of the reaction solvent and the remaining amount of the initiator and mix them to obtain a third mixture; (4) Take a selected amount of the 2-furan methacrylic acid, the molecular weight regulator and the remaining amount of the reaction solvent and mix them to obtain a fourth mixture; (5) The first mixture and the second mixture are added to the fourth mixture respectively and mixed, and a heat-insulating polymerization reaction is carried out; (6) Continue to add the third mixture and mix, and carry out the branching and chain extension reaction; (7) After the reaction is completed, the reaction solvent is removed by vacuum decompression and the product is discharged.

5. The method for preparing the fluorine-free sanding agent according to claim 4, characterized in that, The reaction solvent includes a mixture of xylene and propylene glycol methyl ether acetate; Preferably, the mass ratio of xylene to propylene glycol methyl ether acetate is 1:1.5-2; Preferably, the amount of the reaction solvent is 1-2 times the total mass of the polymerized monomers.

6. The method for preparing the fluorine-free sanding agent according to claim 4 or 5, characterized in that: In step (1), the amount of the reaction solvent used accounts for 20-30 wt% of the total amount of the reaction solvent. In step (2), the amount of the reaction solvent used accounts for 20-30 wt% of the total amount of the reaction solvent. In step (3), the amount of the reaction solvent used accounts for 20-30 wt% of the total amount of the reaction solvent. In step (4), the amount of the reaction solvent is 20-30 wt% of the total amount of the reaction solvent.

7. The method for preparing the fluorine-free textured agent according to any one of claims 4-6, characterized in that: In step (1), the amount of the initiator is 1 / 2 to 2 / 3 of the total mass of the initiator; In step (3), the amount of the initiator is 1 / 3 to 1 / 2 of the total mass of the initiator.

8. The method for preparing the fluorine-free textured agent according to any one of claims 4-7, characterized in that, In step (5), the polymerization reaction is carried out at a temperature of 120-125°C; and / or, In step (6), the temperature of the branching chain extension reaction is 120-125℃; and / or, In step (7), the temperature of the vacuum decompression solvent removal step is 220-225℃, and the vacuum degree is -0.095Mpa~-0.098Mpa.

9. The method for preparing the fluorine-free textured agent according to any one of claims 4-8, characterized in that, In step (5), when the first mixture is added to 40-60 wt% of the total formula, the second mixture is added, while the first mixture is added continuously, and the first and second mixtures are added simultaneously.

10. Use of the fluorine-free textured agent according to any one of claims 1-3 in the preparation of powder coatings; Preferably, the powder coating includes a TGIC type powder coating.

Images