Fluorine-free sand-texturing agent, preparation method and application thereof

Abstract

The present application belongs to the technical field of powder coating, and particularly relates to a fluorine-free sand-textured agent, a sand-textured powder coating, and further discloses a preparation method and application thereof. The fluorine-free sand-textured agent is obtained by copolymerization of n-butyl acrylate, methyl methacrylate, oleic acid amide, 2-furfuryl methacrylate, acrylic acid and triallyl cyanurate as monomers, and has an acid value of 118-134 mgKOH / g and a glass transition temperature of 108-120 DEG C, so that the powder coating has excellent extinction and sand-textured texture when cured.

Description

Technical Field

[0001] This invention belongs to the field of powder coating technology, specifically relating to a fluorine-free textured agent, and further discloses its preparation method and application. Background Technology

[0002] Coating is a crucial step in the surface processing of metal materials, encompassing requirements for corrosion resistance, decoration, and functionality. With increasingly stringent national environmental emission standards and stricter restrictions on VOC emissions, many solvent-based coatings are gradually shifting towards environmentally friendly powder coatings that emit virtually no VOCs.

[0003] Powder coatings are environmentally friendly coatings widely used in various industries for coating substrates or equipment surfaces. Their economic, efficient, environmentally friendly, and energy-saving advantages have led to rapid development in recent years. As 100% solid powder coatings, they are solvent-free, pollution-free, energy and resource-saving, reduce labor intensity, and offer high mechanical strength. They are widely used in construction, automotive, machinery, chemical, energy, and electronic equipment industries. TGIC system powder coatings are currently the most widely used type of powder coating.

[0004] With increasing demands for decorative coatings and evolving aesthetic preferences, the use of low-gloss powder coatings with sand-textured finishes is rapidly growing. Sand-textured powder coatings scatter light, providing a comfortable visual experience, and also offer advantages such as high film hardness, a smooth feel, scratch resistance, and aging resistance, making them widely used in the architectural aluminum profile industry. Traditional sand-textured powders (also known as textured powders) utilize polytetrafluoroethylene (PTFE)-based sand-texturing agents (or texture agents). However, to reduce environmental and health hazards, the EU and other regions restrict the use of fluorine-containing products. Therefore, developing fluorine-free sand-texturing agents to replace PTFE-based sand-texturing agents is a key direction for industry development.

[0005] For example, Chinese patent CN119431676A discloses a fluorine-free textured agent that uses PMMA micropowder of a specific size as the main component. However, due to insufficient dispersibility in powder coatings, the resulting textured surface of the powder coating is unstable, and the matte finish is difficult to achieve below 10%. Therefore, the art seeks to develop textured agents with superior performance, which would be of positive significance for improving the coating effect of powder coatings. Summary of the Invention

[0006] The first objective of this invention is to provide a fluorine-free sanding agent that, when used in powder coating curing, produces a matte finish and excellent sanding texture effect. The second objective of this invention is to provide a method for preparing and applying the above-mentioned fluorine-free sanding agent.

[0007] To address the aforementioned technical problems, this invention provides a fluorine-free textured agent, comprising polymeric monomers and polymeric additives; wherein... 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.

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

[0009] This invention also discloses a method for preparing the fluorine-free textured agent, comprising 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 aforementioned triallyl 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 the 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.

[0010] Specifically, in the preparation method of the fluorine-free sanding agent, 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.

[0011] Specifically, in the preparation method of the fluorine-free textured agent: 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.

[0012] Specifically, in the preparation method of the fluorine-free textured agent: 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.

[0013] Specifically, in the preparation method of the fluorine-free textured agent: In step (5), the polymerization reaction temperature is 120-125℃; In step (6), the temperature of the branching chain extension reaction is 120-125℃; In step (7), the temperature of the vacuum decompression solvent removal step is 220-225℃, and the vacuum degree is -0.095Mpa~-0.098Mpa.

[0014] Specifically, in the preparation method of the fluorine-free sanding agent, 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 mixture and the second mixture are added simultaneously.

[0015] The present invention also discloses the use of the fluorine-free textured agent in the preparation of powder coatings, especially textured powder coatings; Preferably, the powder coating includes a TGIC type powder coating.

[0016] The present invention also discloses a sand-textured powder coating, wherein the powder coating comprises the fluorine-free sand-texturing agent.

[0017] Specifically, the textured powder coating comprises the following components in parts by weight: 480-550 parts by weight of polyester resin; TGIC36-42 parts by weight; 25-35 parts by weight of the fluorine-free sanding agent; 7-10 parts by weight of carbon black; 350-450 parts by weight of barium sulfate; Leveling agent 1-5 parts by weight.

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

[0019] The fluorine-free sandblasting agent of this invention is obtained by copolymerizing n-butyl acrylate, methyl methacrylate, oleamide, 2-furanmethacrylic acid, acrylic acid, and triallyl cyanurate as monomers. This polymer not only introduces the hard monomers methyl methacrylate and acrylic acid, but also the trifunctional triallyl cyanurate, increasing 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℃. Simultaneously, it introduces functional groups with different end-group activities, such as methacrylic acid, 2-furanmethacrylic acid, and oleamide, resulting in significant differences in activity during curing. Furthermore, the high glass transition temperature leads to relatively poor fluidity at 200℃, thereby producing a matte finish and excellent sandblasted texture during powder coating curing.

[0020] The fluorine-free sand texture agent described in this invention is suitable for TGIC system powder coatings. When used in TGIC powder coating systems, this product has the advantages of uniform and delicate sand texture, low gloss, and high film hardness. Attached Figure Description

[0021] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 The glass transition temperature is the temperature of the textured agent product prepared in Example 1. Detailed Implementation

[0022] In the following embodiments of the present invention, in order to obtain powder coatings with advantages such as uniform and delicate sand texture, low gloss, and high film hardness during coating, an adaptive fluorine-free sand texture agent was specifically developed. The fluorine-free sand texture agent includes polymeric monomers and polymeric additives; wherein, 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 polymerizable monomers; The amount of the molecular weight regulator is 1-2 wt% of the total mass of the polymer monomers.

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

[0024] This invention also discloses a method for preparing the fluorine-free textured agent, comprising 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 aforementioned triallyl 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 the 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.

[0025] Specifically, in the preparation method of the fluorine-free sanding agent, 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.

[0026] In some specific implementations: In step (1), the amount of the reaction solvent is 20-30 wt% of the total amount of the reaction solvent; preferably 25 wt%, which is 1 / 4 of the formulation amount; In step (2), the amount of the reaction solvent is 20-30 wt% of the total amount of the reaction solvent; preferably 25 wt%, which is 1 / 4 of the formulation amount; In step (3), the amount of the reaction solvent accounts for 20-30 wt% of the total amount of the reaction solvent; preferably 25 wt%, which is 1 / 4 of the formulation amount; In step (4), the amount of the reaction solvent is 20-30 wt% of the total amount of the reaction solvent; preferably 25 wt%, which is 1 / 4 of the formulation amount; In step (1), the amount of the initiator is 1 / 2 to 2 / 3 of the total mass of the initiator, that is, 1 / 2 to 2 / 3 of the formulation amount; In step (3), the amount of the initiator is 1 / 3 to 1 / 2 of the total mass of the initiator, that is, 1 / 2 to 2 / 3 of the formulation amount.

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

[0028] In step (7), the temperature of the vacuum decompression solvent removal step is 220-225℃, and the vacuum degree is -0.095Mpa~-0.098Mpa.

[0029] Specifically, in the preparation method of the fluorine-free sanding agent, in step (5), when the first mixture is added to 40-60 wt% of the total formula (preferably 1 / 2 of the formula), the second mixture is added, while the first mixture is added continuously, and the first mixture and the second mixture are controlled to be added simultaneously.

[0030] As an exemplary embodiment, the present invention also provides a method for preparing a fluorine-free textured agent in the following embodiments, comprising the following steps: (1) The n-butyl acrylate, methyl methacrylate, acrylic acid, 1 / 4 of the formulation amount of reaction solvent and 1 / 2-2 / 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 70-75°C in a mixing vessel and stirred thoroughly to dissolve them. 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 120-125℃ to fully dissolve them, and obtain the fourth mixture. (5) Continue to maintain the temperature of the polymerization reactor (120-125℃), keep it warm and start adding the first mixture in the high-level tank 1, controlling the adding time to 4-4.5h; 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 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 0.5-1h. After the addition is completed, continue to carry out the branching chain extension polymerization reaction at 120-125℃. (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 220-225℃ to ensure that the solvent is removed cleanly. The vacuum degree is controlled between -0.095Mpa and -0.098Mpa. 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.

[0031] The present invention also discloses the use of the fluorine-free sanding agent in the preparation of sanding powder coatings; Preferably, the powder coating includes a TGIC type powder coating.

[0032] The present invention also discloses, by way of example, a sand-textured powder coating, namely a TGIC-cured powder coating, wherein the powder coating includes the fluorine-free sand-texturing agent.

[0033] In some specific embodiments, the textured powder coating comprises the following components in parts by weight: 480-550 parts by weight of polyester resin; TGIC36-42 parts by weight; 25-35 parts by weight of the fluorine-free sanding agent; 7-10 parts by weight of carbon black; 350-450 parts by weight of barium sulfate; Leveling agent 1-5 parts by weight.

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

[0035] In the following embodiments of the present invention, the raw materials used in the fluorine-free sanding agent are all commercially available products of the prior art.

[0036] Example 1 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: 4.5 moles of n-butyl acrylate; 26 moles of methyl methacrylate; 8 molars of oleamide; 9 moles of 2-furan methacrylic acid; 12 moles of acrylic acid; 2.5 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 2.5 wt% of the total mass of the polymerizable monomers; The amount of the molecular weight regulator is 1.5 wt% of the total mass of the polymeric monomers.

[0037] 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 3 / 5 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 75°C in a mixing vessel and stirred until fully dissolved. The mixture is then pumped to a high-level tank 2 to obtain a 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 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, 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 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 -0.095 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.

[0038] In this embodiment, the prepared fluorine-free sanding agent is a light yellow transparent resin particle with an acid value of 125 mg KOH / g and a glass transition temperature (Tg) of 113 °C.

[0039] Example 2 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: 3 moles of n-butyl acrylate; 28 moles of methyl methacrylate; 7 moles of oleamide; 10 moles of 2-furan methacrylic acid; 10 moles of acrylic acid; 3 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 3 wt% of the total mass of the polymeric monomers; The amount of the molecular weight regulator is 2 wt% of the total mass of the polymeric monomers.

[0040] The preparation method of the fluorine-free textured agent described in this embodiment includes the following steps: (1) The formula amounts of n-butyl acrylate, methyl methacrylate, acrylic acid, 1 / 4 of the formula amount of reaction solvent and 1 / 2 of the formula 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, 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 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 -0.098 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.

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

[0042] Example 3 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: 4 moles of n-butyl acrylate; 27 moles of methyl methacrylate; 9 moles of oleamide; 8 molar parts of 2-furan methacrylic acid; 13 moles of acrylic acid; 2.5 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 2.5 wt% of the total mass of the polymerizable monomers; The amount of the molecular weight regulator is 2.5 wt% of the total mass of the polymeric monomers.

[0043] 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 3 / 5 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 75°C in a mixing vessel and stirred until fully dissolved. The mixture is then pumped to a high-level tank 2 to obtain a 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 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; The preparation method of the fluorine-free textured agent 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.

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 textured agent according to claim 4, characterized in that, The reaction solvent includes a mixture of xylene and propylene glycol methyl ether acetate; The mass ratio of xylene to propylene glycol methyl ether acetate is 1:1.5-2; 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 claim 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 claim 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 sanding agent according to claim 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. The use of the fluorine-free textured agent according to any one of claims 1-3 in the preparation of powder coatings, The powder coating includes TGIC type powder coating.

Images