High-solid low-viscosity solid acrylic resin as well as preparation method and application thereof

Abstract

The invention provides high-solid low-viscosity solid acrylic resin as well as a preparation method and application thereof. The high-solid low-viscosity solid acrylic resin is prepared from the following raw materials: styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, a regulator, an initiator and a solvent. A specific preparation method comprises the following steps: uniformly mixing styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid and a regulator to obtain a premixed solution; adding a solvent into the reaction container, introducing inert gas into the reaction container to discharge air in the reaction container, heating the solvent to a set temperature, keeping the constant temperature, and starting stirring; adding the premixed liquid into the reaction container at a constant speed, synchronously adding part of the initiator, and after the addition is finished, preserving heat for a certain period of time; and adding the rest initiator into the reaction container after the heat preservation is finished, preserving the heat for a certain period of time after the addition is finished, and heating to a specific temperature after the heat preservation is finished, so as to remove the solvent and unreacted monomers, thereby obtaining the solid acrylic resin.

Description

Technical Field

[0001] This invention belongs to the field of polymer resin technology, specifically providing a high-solids, low-viscosity solid acrylic resin, its preparation method, and its application. Background Technology

[0002] Acrylic resins are widely used in the market due to their light color, good weather resistance, and excellent gloss and color retention. High-solids acrylic resins have excellent comprehensive properties, especially in terms of weather resistance, gloss, and film fullness, making them very popular in the market. However, due to the large molecular weight and high viscosity of acrylic resins, the viscosity will inevitably be high when the solid content is high, thus limiting their application performance.

[0003] To improve the application capabilities of solid acrylic resins, it is necessary to maximize the resin solid content while minimizing its viscosity. Common methods include reducing the resin molecular weight and lowering the resin glass transition temperature. However, these methods have the drawback of reducing coating performance. Alternatively, functional modification of the monomers can be performed, but this inevitably faces challenges such as difficult raw material preparation and high processing costs.

[0004] Therefore, it is of great significance to find an acrylic resin that can reduce viscosity without reducing solid content, while also maintaining a low glass transition temperature and high gloss, and reducing production costs. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in the prior art. Therefore, one object of this invention is to provide a high-solids, low-viscosity solid acrylic resin, its preparation method, and its applications, thereby achieving a simple process for preparing high-quality, high-solids, low-viscosity solid acrylic resin.

[0006] In a first aspect, the present invention provides a high-solids, low-viscosity solid acrylic resin, the raw materials for which are prepared, by weight, comprise the following components:

[0007] 5-15 parts styrene;

[0008] 10-30 parts of isobornyl methacrylate;

[0009] 10-30 parts of methyl methacrylate;

[0010] 20-35 parts of ethyl acrylate;

[0011] 8-15 parts acrylic acid;

[0012] 0.1-2 parts of regulator;

[0013] Initiator 0.1-2 parts;

[0014] Solvent 10-30 parts.

[0015] In some embodiments of the present invention, the modifier includes α-methylstyrene.

[0016] In some embodiments of the present invention, the initiator includes a peroxide radical initiator. Preferably, the peroxide radical initiator includes tert-butyl peroxide-2-ethylhexanoate.

[0017] In some embodiments of the present invention, the solvent includes ester and / or alcohol ether solvents. Preferably, the ester solvent includes at least one selected from butyl acetate, ethyl acetate, and isopropyl acetate; the alcohol ether solvent includes at least one selected from propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether, and dipropylene glycol butyl ether. Preferably, the solvent includes butyl acetate.

[0018] In a second aspect, the present invention also provides a method for preparing a high-solids, low-viscosity solid acrylic resin, characterized by comprising the following steps:

[0019] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and a modifier are mixed evenly to obtain a premixed solution;

[0020] S2: Add solvent to the reaction vessel, pass inert gas through the reaction vessel to remove air from the reaction vessel, heat the solvent to 100-120℃ and keep it at a constant temperature while starting the stirrer;

[0021] S3: Add the premixed liquid to the reaction vessel at a uniform rate, and simultaneously add 45-55% of the initiator. The rate of initiator addition should be less than or equal to the rate of initiator consumption. After the addition is complete, keep the temperature at 100-120℃ for at least 1 hour. After the temperature is complete, add the remaining initiator to the reaction vessel. The rate of initiator addition should be less than or equal to the rate of initiator consumption. After the addition is complete, keep the temperature at 100-120℃ for at least 2 hours. After the temperature is complete, raise the temperature to 170-190℃ to remove the solvent and unreacted monomers to obtain solid acrylic resin.

[0022] In some embodiments of the present invention, in step S2, the inert gas includes nitrogen.

[0023] In some embodiments of the present invention, in step S3, a premixed liquid is added to the reaction vessel at a uniform rate, and 50% of the initiator is added simultaneously.

[0024] In a third aspect, the present invention also provides an application of a high-solids, low-viscosity solid acrylic resin, wherein the above-mentioned acrylic resin is dissolved in ammonia water to obtain a resin liquid with a solid content of 40%.

[0025] In a fourth aspect, the present invention also provides an application of a high-solids, low-viscosity solid acrylic resin, which can be used to prepare coatings or inks.

[0026] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0027] This invention, through specific raw material combinations and controlled initiator addition steps and batch addition amounts, can effectively improve process performance, achieve the target low viscosity of acrylic resin, and ensure that the acrylic resin has excellent gloss and a low glass transition temperature. By selecting specific resin preparation raw materials and adjusting the process, this invention can achieve the preparation of high-performance acrylic resin, avoiding the use of high-cost raw materials or complex processes, and significantly reducing production costs. Detailed Implementation

[0028] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way.

[0029] In a first aspect, the present invention provides a high-solids, low-viscosity solid acrylic resin, the raw materials for which are prepared, by weight, comprise the following components:

[0030] 5-15 parts styrene;

[0031] 10-30 parts of isobornyl methacrylate;

[0032] 10-30 parts of methyl methacrylate;

[0033] 20-35 parts of ethyl acrylate;

[0034] 8-15 parts acrylic acid;

[0035] 0.1-2 parts of regulator;

[0036] Initiator 0.1-2 parts;

[0037] Solvent 10-30 parts.

[0038] In some embodiments of the present invention, the modifier includes α-methylstyrene.

[0039] In some embodiments of the present invention, the initiator includes a peroxide-based free radical initiator. Peroxide-based free radical initiators are more suitable for the reaction system and process of this application, ensuring the smooth and efficient progress of the reaction and improving the final performance of the product. Preferably, the peroxide-based free radical initiator includes tert-butyl peroxide-2-ethylhexanoate.

[0040] In some embodiments of the present invention, the solvent includes ester and / or alcohol ether solvents. Preferably, the ester solvent includes at least one selected from butyl acetate, ethyl acetate, and isopropyl acetate; the alcohol ether solvent includes at least one selected from propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether, and dipropylene glycol butyl ether. Preferably, the solvent includes butyl acetate.

[0041] In a second aspect, the present invention also provides a method for preparing a high-solids, low-viscosity solid acrylic resin, characterized by comprising the following steps:

[0042] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and a modifier are mixed evenly to obtain a premixed solution;

[0043] S2: Add solvent to the reaction vessel, purge the reaction vessel with inert gas to remove air, heat the solvent to 100-120℃ and keep it constant while stirring; the stirring speed is 200-500 rpm to ensure uniform mixing of the raw materials; the inert gas can be nitrogen, for example, purge nitrogen in the reaction vessel for 5 minutes to remove air and avoid heating causing the resin to yellow.

[0044] S3: Add the premixed liquid to the reaction vessel at a uniform rate, simultaneously adding 45-55% of the initiator. The initiator addition rate should be less than or equal to the initiator consumption rate. After the addition is complete, maintain the temperature at 100-120℃ for at least 1 hour. After the maintenance period, add the remaining initiator to the reaction vessel, again maintaining the initiator addition rate less than or equal to the initiator consumption rate. After the addition is complete, maintain the temperature at 100-120℃ for at least 2 hours. After the maintenance period, raise the temperature to 170-190℃ to remove the solvent and unreacted monomers, obtaining solid acrylic resin. Controlling the reaction temperature at 100-120℃ effectively ensures the smooth progress of the polymerization reaction. Preferably, simultaneously adding 50wt% of the initiator first can significantly improve the resin's performance.

[0045] In a third aspect, the present invention also provides an application of a high-solids, low-viscosity solid acrylic resin, wherein the above-mentioned acrylic resin is dissolved in ammonia water to obtain a resin solution with a solid content of 40%. The viscosity of the resin solution is 340-470 mPa·s, the gloss is 86-95 GU, and the glass transition temperature is 55-59 Tg / ℃.

[0046] In a fourth aspect, the present invention also provides an application of a high-solids, low-viscosity solid acrylic resin, which can be used to prepare coatings or inks.

[0047] The method for preparing high-solids, low-viscosity solid acrylic resin provided by this invention, on the one hand, can effectively improve the process effect by controlling the initiator addition steps and batch addition amounts, achieving the target low viscosity of the acrylic resin, while ensuring that the acrylic resin has excellent gloss and a low glass transition temperature. The inventors unexpectedly discovered that high-performance acrylic resin can be prepared through simple adjustments to the above process, avoiding the use of high-cost raw materials or complex processes, and significantly reducing production costs. On the other hand, this invention selects styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, and acrylic acid as reaction raw materials. Styrene can enhance the rigidity of high-solids, low-viscosity acrylic resin and reduce costs. Isobornyl methacrylate, with its cycloalkyl structure, significantly reduces viscosity while improving heat resistance and weather resistance. Isobornyl methacrylate (IBOMA), with its large, rigid, and hydrophobic isobornyl side chains, greatly increases the average distance between molecular chains, reducing viscosity through steric hindrance. The polarity of IBOMA is very close to that of common acrylic monomers, maintaining the high gloss of the paint film by promoting compatibility, reducing shrinkage, improving leveling, and hydrophobicity. The addition of methyl methacrylate ensures the high hardness and high light transmittance of the resin, which is the basis for gloss. Ethyl acrylate effectively regulates flexibility and leveling, while acrylic acid improves pigment wetting and adhesion. The reaction raw materials formed by mixing styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, and acrylic acid not only give full play to their respective advantages, but also have a significant synergistic effect. At the same time, under the above-mentioned stepwise addition of initiator process, a solid acrylic resin with excellent properties of high solid content and low viscosity is prepared.

[0048] Example 1

[0049] A high-solids, low-viscosity solid acrylic resin, the raw materials for its preparation include the following components in parts by weight:

[0050] 10 parts styrene;

[0051] 20 parts of isobornyl methacrylate;

[0052] 20 parts of methyl methacrylate;

[0053] 27 parts of ethyl acrylate;

[0054] 12 parts acrylic acid;

[0055] 1 part α-methylstyrene;

[0056] 1 part of tert-butyl peroxide-2-ethylhexanoate;

[0057] 20 parts of butyl acetate.

[0058] The preparation method of the above-mentioned high-solids, low-viscosity solid acrylic resin includes the following steps:

[0059] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and α-methylstyrene are mixed evenly to obtain a premixed solution;

[0060] S2: Add butyl acetate solvent to the reaction vessel, purge the reaction vessel with nitrogen for 5 minutes to purge the air in the reaction vessel, heat the solvent to 110°C and keep the temperature constant while starting the stirrer at 300 rpm.

[0061] S3: Add the premixed solution to the reaction vessel at a uniform rate, and simultaneously add 50% of tert-butyl peroxide-2-ethylhexanoate. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 1 hour. After the temperature is maintained, add the remaining 50% of tert-butyl peroxide-2-ethylhexanoate to the reaction vessel. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 2 hours. After the temperature is maintained, raise the temperature to 180℃ to remove the solvent and unreacted monomers, and obtain solid acrylic resin.

[0062] Example 2

[0063] The only difference between Example 2 and Example 1 is that 25 parts of isobornyl methacrylate were used, while the other components and preparation methods were the same as in Example 1.

[0064] Example 3

[0065] The only difference between Example 2 and Example 1 is that 15 parts of isobornyl methacrylate were used, while the other components and preparation methods were the same as in Example 1.

[0066] Comparative Example 1

[0067] The only difference between the raw materials for preparing the acrylic resin in Comparative Example 1 and Example 1 is that Comparative Example 1 did not add isobornyl methacrylate, while the other components and preparation methods were the same as in Example 1.

[0068] Comparative Example 2

[0069] An acrylic resin, by weight, comprises the following components in its preparation raw materials:

[0070] 10 parts styrene;

[0071] 20 parts of methyl methacrylate;

[0072] 27 parts of ethyl acrylate;

[0073] 12 parts acrylic acid;

[0074] 21 parts of α-methylstyrene;

[0075] 1 part of tert-butyl peroxide-2-ethylhexanoate;

[0076] 20 parts of butyl acetate.

[0077] The preparation steps of the acrylic resin in Comparative Example 2 were the same as those in Example 1.

[0078] Comparative Example 3

[0079] An acrylic resin, by weight, comprises the following components in its preparation raw materials:

[0080] 30 parts of isobornyl methacrylate;

[0081] 20 parts of methyl methacrylate;

[0082] 27 parts of ethyl acrylate;

[0083] 12 parts acrylic acid;

[0084] 1 part α-methylstyrene;

[0085] 1 part of tert-butyl peroxide-2-ethylhexanoate;

[0086] 20 parts of butyl acetate.

[0087] The preparation steps of the acrylic resin in Comparative Example 3 were the same as those in Example 1.

[0088] Comparative Example 4

[0089] The raw materials used to prepare the acrylic resin in Comparative Example 4 were the same as those in Example 1.

[0090] The preparation steps of the acrylic resin in Comparative Example 4 are as follows:

[0091] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and α-methylstyrene are mixed evenly to obtain a premixed solution;

[0092] S2: Add butyl acetate solvent to the reaction vessel, purge the reaction vessel with nitrogen for 5 minutes to purge the air in the reaction vessel, heat the solvent to 110°C and keep the temperature constant while starting the stirrer at 300 rpm.

[0093] S3: Add the premixed solution to the reaction vessel at a uniform rate, and simultaneously add 30% of tert-butyl peroxide-2-ethylhexanoate. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 1 hour. After the temperature is maintained, add the remaining 70% of tert-butyl peroxide-2-ethylhexanoate to the reaction vessel. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 2 hours. After the temperature is maintained, raise the temperature to 180℃ to remove the solvent and unreacted monomers, and obtain solid acrylic resin.

[0094] Comparative Example 5

[0095] The raw materials for preparing the acrylic resin in Comparative Example 5 were the same as those in Example 1.

[0096] The preparation steps of the acrylic resin in Comparative Example 5 are as follows:

[0097] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and α-methylstyrene are mixed evenly to obtain a premixed solution;

[0098] S2: Add butyl acetate solvent to the reaction vessel, purge the reaction vessel with nitrogen for 5 minutes to purge the air in the reaction vessel, heat the solvent to 110°C and keep the temperature constant while starting the stirrer at 300 rpm.

[0099] S3: Add the premixed solution to the reaction vessel at a uniform rate, and simultaneously add 70% of tert-butyl peroxide-2-ethylhexanoate. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 1 hour. After the temperature is maintained, add the remaining 30% of tert-butyl peroxide-2-ethylhexanoate to the reaction vessel. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 2 hours. After the temperature is maintained, raise the temperature to 180℃ to remove the solvent and unreacted monomers, and obtain solid acrylic resin.

[0100] Comparative Example 6

[0101] The raw materials used to prepare the acrylic resin in Comparative Example 6 were the same as those in Example 1.

[0102] The preparation steps of the acrylic resin in Comparative Example 6 are as follows:

[0103] S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and α-methylstyrene are mixed evenly to obtain a premixed solution;

[0104] S2: Add butyl acetate solvent to the reaction vessel, purge the reaction vessel with nitrogen for 5 minutes to purge the air in the reaction vessel, heat the solvent to 110°C and keep the temperature constant while starting the stirrer at 300 rpm.

[0105] S3: Add the premixed solution to the reaction vessel at a uniform rate, and simultaneously add tert-butyl peroxide-2-ethylhexanoate. The addition rate of tert-butyl peroxide-2-ethylhexanoate should be less than or equal to the consumption rate of tert-butyl peroxide-2-ethylhexanoate. After the addition is complete, keep the temperature at 110℃ for 3 hours. After the temperature is maintained, raise the temperature to 180℃ to remove the solvent and unreacted monomers to obtain solid acrylic resin.

[0106] The raw materials used in the above embodiments and comparative examples can be found in Table 1.

[0107] Table 1

[0108] The acrylic resins of the examples and comparative examples were dissolved in ammonia to form a resin solution with a solid content of 40%, and the performance of the resin solution was tested.

[0109] (1) Viscosity (40% solid content) / mPa.s (<500): Measured according to the rotation method in GB / T 10247-2008 Viscosity Measurement Method;

[0110] (2) Glass transition temperature Tg / ℃ (less than 60): Measured according to GB / T 19466.2-2004 Differential Scanning Calorimetry (DSC) for Plastics - Part 2: Determination of Glass Transition Temperature;

[0111] (3) Gloss (ASTM D523 60° angle) / GU (>85): The measurement is performed according to the measurement method of 60° geometric conditions in GB / T 9754-2025 Determination of gloss of paints and varnishes at 20°, 60° and 85°;

[0112] (4) Yield = Actual mass obtained / Theoretical mass obtained × 100%.

[0113] The specific test results are shown in Table 2.

[0114] Table 2

[0115] As shown in Table 2, the acrylic resin obtained using the raw materials and preparation process provided by this invention exhibits low viscosity, low glass transition temperature, and excellent gloss, with a yield greater than 95%. This demonstrates that the method of this invention achieves low-cost and simple preparation of high-solids, low-viscosity acrylic resin. Comparative Examples 1, 2, and 3, although using the same preparation process as this invention, suffer from unsuitable raw materials, resulting in poor viscosity, gloss, or glass transition temperature performance. Comparative Examples 4, 5, and 6, while using the same raw materials as this application, exhibit poor viscosity, gloss, or yield due to differences in the amount or timing of initiator addition. In conclusion, only by using the raw materials and process of this invention can the comprehensive properties of the resin be simultaneously improved.

[0116] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A high-solids, low-viscosity solid acrylic resin, characterized in that, The raw materials for its preparation include the following components in parts by weight: 5-15 parts styrene; 10-30 parts of isobornyl methacrylate; 10-30 parts of methyl methacrylate; 20-35 parts of ethyl acrylate; 8-15 parts acrylic acid; 0.1-2 parts of regulator; Initiator 0.1-2 parts; Solvent 10-30 parts.

2. The high-solids, low-viscosity solid acrylic resin according to claim 1, characterized in that, The regulator includes α-methylstyrene.

3. The high-solids, low-viscosity solid acrylic resin according to claim 1, characterized in that, The initiator includes peroxide-based free radical initiators.

4. The high-solids, low-viscosity solid acrylic resin according to claim 3, characterized in that, The peroxide-based free radical initiator includes tert-butyl peroxide-2-ethylhexanoate.

5. The high-solids, low-viscosity solid acrylic resin according to claim 1, characterized in that, The solvents include esters and / or alcohol ethers.

6. The high-solids, low-viscosity solid acrylic resin according to claim 5, characterized in that, The solvent includes butyl acetate.

7. The method for preparing high-solids, low-viscosity solid acrylic resin according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Styrene, isobornyl methacrylate, methyl methacrylate, ethyl acrylate, acrylic acid, and a modifier are mixed evenly to obtain a premixed solution; S2: Add solvent to the reaction vessel, pass inert gas through the reaction vessel to remove air from the reaction vessel, heat the solvent to 100-120℃ and keep it at a constant temperature while starting the stirrer; S3: Add the premixed liquid to the reaction vessel at a uniform rate, and simultaneously add 45-55% of the initiator. The rate of initiator addition should be less than or equal to the rate of initiator consumption. After the addition is complete, keep the temperature at 100-120℃ for at least 1 hour. After the temperature is complete, add the remaining initiator to the reaction vessel. The rate of initiator addition should be less than or equal to the rate of initiator consumption. After the addition is complete, keep the temperature at 100-120℃ for at least 2 hours. After the temperature is complete, raise the temperature to 170-190℃ to remove the solvent and unreacted monomers to obtain solid acrylic resin.

8. The application of the high-solids, low-viscosity acrylic resin according to any one of claims 1-6, characterized in that, The acrylic resin was dissolved in ammonia water to obtain a resin solution with a solid content of 40%.

9. The resin liquid according to claim 8, characterized in that, The resin solution has a viscosity of 340-470 mPa·s, a gloss of 86-95 GU, and a glass transition temperature of 55-59 Tg / ℃.

10. The application of the high-solids, low-viscosity acrylic resin according to any one of claims 1-5, characterized in that, The acrylic resin can be used to prepare coatings or inks.

Images