A high glass transition temperature methacrylic acid resin based on isobornyl methacrylate derivatives and a method for its preparation

Abstract

The present application relates to the technical field of high polymer materials, and particularly discloses a high glass transition temperature acrylic resin based on isobornyl methacrylate derivative and a preparation method thereof. The acrylic resin is prepared by free radical polymerization of mixed monomers and an initiator, wherein the mixed monomers comprise: a) 20-80 wt% isobornyl methacrylate derivative MIBOMA as a rigid monomer for providing high Tg; b) 10-40 wt% other copolymerizable ethylenically unsaturated monomers for adjusting Tg and resin performance; and the initiator accounts for 0.1-3.0% of the total mass of the mixed monomers. The present application successfully prepares the acrylic resin with adjustable glass transition temperature Tg through the synergistic effect of isobornyl methacrylate derivative MIBOMA and other monomers. The acrylic resin has excellent thermal stability, mechanical strength, transparency and chemical resistance, and can be widely applied in the fields of high-performance coatings, optical adhesives, electronic packaging materials and inks.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high glass transition temperature acrylic resin based on isobornyl methacrylate derivative and its preparation method. Background Technology

[0002] Acrylic resins are widely used in coatings, adhesives, inks, and other fields due to their excellent weather resistance, transparency, film-forming properties, and mechanical properties. With technological advancements, especially in the electronics, aerospace, and automotive industries, higher demands are being placed on the heat resistance of acrylic resins. A high glass transition temperature (Tg) is a key indicator for ensuring that materials maintain their physical and mechanical properties at high temperatures.

[0003] Traditional high-Tg acrylic resins are typically obtained through the following methods: 1. Rigid monomers such as methyl methacrylate (MMA) are introduced, but the glass transition temperature (Tg) of its homopolymer is about 105℃, limiting the potential for further improvement.

[0004] 2. Introducing monomers containing benzene rings such as styrene (St), but styrene has the disadvantage of poor resistance to ultraviolet aging.

[0005] 3. Introducing polar monomers such as (meth)acrylamide and acrylonitrile may lead to problems such as high hygroscopicity and reduced toughness.

[0006] 4. The glass transition temperature (Tg) can be increased through cross-linking reactions, but this usually results in the resin becoming insoluble and infusible, making processing difficult.

[0007] Isobornyl methacrylate (IBOMA) and its derivatives are acrylate monomers with a large, rigid norbornene structure. Due to the strong steric hindrance effect and molecular chain segment movement restriction ability of its cyclic side chain structure, it is an ideal monomer for preparing acrylic resins with high glass transition temperatures (Tg). Therefore, developing an acrylic resin based on isobornyl methacrylate that can achieve precise adjustment of the Tg over a wide range while also possessing excellent comprehensive properties has significant industrial application value. Summary of the Invention

[0008] Objective of the Invention: To overcome the shortcomings of existing technologies, this invention provides a high glass transition temperature acrylic resin based on isobornyl methacrylate derivatives and its preparation method. Through the synergistic effect of isobornyl methacrylate derivatives and their derivative monomers with other monomers, an acrylic resin with an adjustable glass transition temperature (Tg) is successfully prepared. This resin exhibits excellent thermal stability, mechanical strength, transparency, and chemical resistance, and can be widely used in high-performance coatings, optical adhesives, electronic packaging materials, and inks.

[0009] The primary objective of this invention is to provide an acrylic resin with a high glass transition temperature (Tg) based on isobornyl methacrylate derivatives, wherein the glass transition temperature (Tg) of the acrylic resin can be controlled.

[0010] Another object of the present invention is to provide a method for preparing the above-mentioned acrylic resin, which is simple in process and easy to industrialize.

[0011] Another object of the present invention is to provide applications of the above-mentioned acrylic resin in the fields of high-performance coatings, adhesives, and electronic packaging materials.

[0012] Technical solution: To achieve the above objectives, the technical solution adopted by this invention is as follows: This invention provides an acrylic resin with a high glass transition temperature based on isobornyl methacrylate derivatives. The acrylic resin is prepared by free radical polymerization of mixed monomers and an initiator, wherein the mass of the initiator added is 0.1% to 3.0% of the mixed monomers. The mixed monomers comprise the following components by mass: Isoborneol methacrylate derivatives 20%~70%, Adjust monomer content to 10%~40%, The structural formula of the isoborneol methacrylate derivative is shown in formula (Ⅰ) below: Equation (I) The regulating monomer is selected from at least one of methyl methacrylate, acrylonitrile, n-butyl methacrylate, n-butyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, glycidyl methacrylate, and acrylic acid; The acrylic resin has a high glass transition temperature (Tg) of 50℃ to 150℃.

[0013] Optionally, in one embodiment of the present invention, the content of the isoborneol methacrylate derivative is 40% to 80%.

[0014] Further optionally, in one embodiment of the present invention, the content of the isoborneol methacrylate derivative is 40% to 70%. Even further, the content of the isoborneol methacrylate derivative is 50% to 70%. Even more further, the content of the isoborneol methacrylate derivative is 40% to 60%.

[0015] Optionally, in one embodiment of the present invention, the regulating monomer contains methyl methacrylate and n-butyl methacrylate in a mass ratio of 1:(2~3).

[0016] Optionally, in one embodiment of the present invention, the initiator is azobisisobutyronitrile and / or benzoyl peroxide.

[0017] Optionally, in one embodiment of the present invention, the high glass transition temperature Tg of the acrylic resin is 60°C to 150°C.

[0018] Further optionally, in one embodiment of the present invention, the high glass transition temperature Tg of the acrylic resin is 90°C to 140°C.

[0019] Optionally, in one embodiment of the present invention, the solid content of the acrylic resin is not less than 50%.

[0020] On the other hand, the present invention also proposes a method for preparing acrylic resin as described in any of the above, comprising the following steps: (1) Mix the formulated amount of isoborneol methacrylate derivative, adjusting monomer and part of organic solvent to obtain a mixed monomer solution; (2) Dissolve the amount of initiator in the formula in the remaining organic solvent to obtain an initiator solution; (3) Under an inert atmosphere, the mixed monomer liquid is heated to 100~150℃, and then the initiator solution is slowly added dropwise. After the addition is completed, the reaction is kept at the temperature for 0.5~2 hours. (4) After the reaction is complete, cool to obtain an acrylic resin solution.

[0021] Optionally, in one embodiment of the present invention, the organic solvent is at least one of toluene, ethyl acetate, butyl acetate, or propylene glycol methyl ether acetate.

[0022] Optionally, in one embodiment of the present invention, the organic solvent is used in an amount of 50-120 wt% of the mixed monomers.

[0023] Optionally, in one embodiment of the present invention, in step (1), the organic solvent accounts for 60-80 wt% of the organic solvent.

[0024] On the other hand, the present invention also provides the application of acrylic resins as described above in coatings, adhesives, inks or electronic packaging materials.

[0025] Beneficial effects: 1. High and adjustable glass transition temperature Tg: This invention fully utilizes the inherent high Tg characteristics of isobornyl methacrylate derivatives, enabling the glass transition temperature Tg of the resin to reach up to 160℃, meeting the heat resistance requirements of different application scenarios.

[0026] 2. Excellent comprehensive performance: After adding isobornyl methacrylate derivative, the resulting acrylic resin not only has good heat resistance, but also high hardness, excellent rigidity and dimensional stability.

[0027] 3. Good solubility and compatibility: The acrylic resin prepared by this invention is soluble in common organic solvents and is easy to process.

[0028] 4. Simple process, suitable for industrialization: It adopts the classic solution polymerization method, which has a simple process flow, mild conditions, and is easy to control and scale up production. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of MIBOMA, a derivative of isobornyl methacrylate.

[0031] Figure 2 The reaction equation for the preparation of isobornyl methacrylate derivative MIBOMA. Detailed Implementation

[0032] This invention relates to the field of polymer materials technology, specifically disclosing an acrylic resin with a high glass transition temperature based on isobornyl methacrylate derivatives and its preparation method. The acrylic resin is prepared by free radical polymerization from raw materials comprising the following components: a) 20-80 wt% of isobornyl methacrylate derivatives, as a rigid monomer providing high Tg; the structural formula is shown in formula (Ⅰ) below: Equation (I) b) 10–40 wt% of other copolymerizable olefinic unsaturated monomers, used to adjust the glass transition temperature (Tg) and resin properties; and c) An initiator comprising 0.1 to 3.0% of the total mass of the mixed monomers composed of a) and b).

[0033] This invention successfully prepared an acrylic resin with a controllable glass transition temperature (Tg) through copolymerization of isobornyl methacrylate derivatives with other copolymerizable olefinically unsaturated monomers. This acrylic resin exhibits excellent thermal stability, mechanical strength, transparency, and chemical resistance, and can be widely used in high-performance coatings, optical adhesives, electronic packaging materials, and inks.

[0034] Specifically, the following embodiments of the present invention provide an acrylic resin with a high glass transition temperature based on isobornyl methacrylate derivatives. The acrylic resin is prepared by solution free radical polymerization of a mixed monomer comprising the following components in the indicated mass percentages: (a) Methyl isoborneol methacrylate derivative (MIBOMA): 20%~80% The 2-methyl isobornyl methacrylate derivative (MIBOMA, 1,2,7,7-tetramethyl Bicyclo[2.2.1] heptan-2-yl (mathyl) acrylate) used in the embodiments of the present invention has the following structural formula: Figure 1 As shown, it is obtained by esterification of methacrylic acid with 1,2,7,7-tetramethyldicyclohexyl-2-ol, and the reaction equation is as follows. Figure 2 As shown. This monomer is the core component constituting the high glass transition temperature (Tg) characteristic of acrylic resins.

[0035] In this invention, the isobornyl methacrylate derivative has an additional methyl group on isobornyl methacrylate, which is beneficial for further increasing the glass transition temperature Tg.

[0036] (b) Adjustment of monomers: 10%~40% In this invention, the regulating monomer is selected from at least one of the following: Methyl methacrylate (MMA, homopolymer Tg ~105℃). Acrylonitrile (AN, homopolymer Tg ~125℃), and (Meth)acrylate C1-C8 alkyl esters, such as n-butyl methacrylate (BMA), n-butyl acrylate (BA, Tg ~-54℃), hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), glycidyl methacrylate (GMA), acrylic acid (AA), etc.

[0037] These monomers are used to appropriately increase the flexibility of the chain segments, adjust the brittle-toughness balance of the resin, and introduce functional groups such as hydroxyl, carboxyl, and epoxy groups to provide reaction sites for subsequent cross-linking and curing.

[0038] (c) Initiator: 0.1% to 3.0% of the total mass of the mixed monomers composed of (a) and (b).

[0039] In this invention, the initiator is selected from azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO).

[0040] Furthermore, the glass transition temperature (Tg) of the acrylic resin can be adjusted by modifying the isoborneol methacrylate derivative, the benzene ring-containing monomer, and the type and ratio of the monomers to design a resin formulation that meets the specific glass transition temperature (Tg) requirement.

[0041] On the other hand, embodiments of the present invention also provide a method for preparing the above-mentioned acrylic resin, comprising the following steps: 1. Ingredients: According to the above ratio, mix isobornyl methacrylate derivative, adjusting monomer and part (60~80wt%) of organic solvent (such as toluene, aromatic 100, butyl acetate, propylene glycol methyl ether acetate PMA) evenly to obtain mixed monomer solution.

[0042] It should be noted that the following embodiments of the present invention are all laboratory operations, so a four-necked flask is selected as the reaction vessel. In other embodiments of the present invention, if it is an actual production process, the raw materials can be added to a reaction vessel equipped with a stirrer, thermometer, condenser and constant pressure dropping funnel, and mixed evenly to obtain a mixed monomer liquid.

[0043] 2. Preparation of initiator solution: Dissolve the initiator in the remaining organic solvent to prepare an initiator solution, and place it in a constant pressure dropping funnel.

[0044] 3. Polymerization reaction: Under nitrogen protection, heat the mixed monomer solution in the four-necked flask / reactor to 100~150℃, and start slowly adding the initiator solution dropwise, controlling the dropwise addition time to 2~4 hours.

[0045] 4. Incubation and ripening: After the addition is complete, continue the reaction at 140℃ for 0.5 to 2 hours to allow the monomer to fully convert.

[0046] 5. Termination and Discharge: After the reaction is complete, cool the reaction system to below 40°C to obtain a transparent, viscous acrylic resin solution with a solid content of 50%~60%.

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the specific material ratios, process conditions, and results described in the embodiments are for illustrative purposes only and should not, and will not, limit the present invention as described in detail in the claims.

[0048] Example 1 Prepare acrylic resins according to the formulations shown in Table 1 below (the amount of each component is a percentage of the total mass of the mixed monomers).

[0049] Preparation process: 1. Ingredients: Add 100 g of mixed monomers (20 g MIBOMA, 10 g HEMA, 30 g MMA, 40 g BA) and 60 g of aromatics 100 to a four-necked flask, stir to dissolve, and mix evenly to obtain a mixed monomer solution.

[0050] 2. Preparation of initiator solution: Dissolve 2.5 g AIBN in the remaining 20 g aromatic hydrocarbon 100 to obtain an initiator solution, and place it in a constant pressure dropping funnel.

[0051] 3. Polymerization reaction: Under nitrogen protection, heat the mixed monomer solution in the four-necked flask to 140°C, and start adding the initiator solution dropwise to the mixed monomer solution at a uniform rate, which is completed within 3 hours.

[0052] 4. Incubation and ripening: After the addition is complete, continue the reaction at 140℃ for 1 hour to allow the monomer to fully convert.

[0053] 5. Termination and discharge: After the reaction is completed, the reaction system is cooled to below 40°C, filtered, and discharged to obtain a transparent acrylic resin solution.

[0054] Example 2 The preparation method in this embodiment is the same as in Example 1, except that the mixed monomers are 40 g MIBOMA, 10 g HEMA, 30 g MMA, and 20 g BA, totaling 100 g.

[0055] Example 3 The preparation method in this embodiment is the same as in Example 1, except that the mixed monomers are 60 g MIBOMA, 30 g MMA, and 10 g HEMA, totaling 100 g.

[0056] Example 4 The preparation method in this embodiment is the same as in Example 1, except that the mixed monomers are 80 g MIBOMA, 10 g MMA, and 10 g HEMA, totaling 100 g.

[0057] Comparative Example 1 The preparation method in this embodiment is the same as in Example 1, except that isobornyl methacrylate is not added, that is, the mixed monomers are 14g HEMA, 43g MMA, and 43g BA, totaling 100g.

[0058] Comparative Example 2 The preparation method in this embodiment is the same as in Example 1, except that only isobornyl methacrylate is added, and no adjusting monomer is added. That is, the mixed monomer is changed to only 100 g of MIBOMA, for a total of 100 g.

[0059] Testing and Characterization: Glass transition temperature (Tg) determination: The resin solution was cast into a film, dried, and then measured using a differential scanning calorimeter (DSC) at a heating rate of 10 °C / min. The results are shown in Table 1.

[0060] Table 1: Formulations and performance results of the examples and comparative examples (unit: wt%)

[0061] Results analysis: Table 1 shows the measured glass transition temperature (Tg) results, indicating that the amount of MIBOMA significantly affects the measured Tg of the prepared acrylic resin, demonstrating that MIBOMA plays a decisive role in increasing the Tg of the acrylic resin. Specifically, when the MIBOMA dosage is between 20% and 100%, the measured Tg of the resin can be effectively controlled within the range of 20-170℃ with increasing MIBOMA dosage, exhibiting a linear increasing trend. In particular, when the MIBOMA dosage reaches 80%, the measured Tg of the obtained acrylic resin reaches above 140℃; and when the MIBOMA dosage reaches 100%, the measured Tg of the obtained acrylic resin reaches above 160℃. This result demonstrates that MIBOMA has a significant positive linear promoting effect on the Tg of acrylic resin.

[0062] Furthermore, considering the high cost of MIBOMA, the desired glass transition temperature (Tg) of acrylic resin can be obtained by adjusting the ratio of MIBOMA to the adjusting monomer. This allows for the controllability of the glass transition temperature (Tg) of acrylic resin products, meeting the heat resistance requirements of different application scenarios.

[0063] Application Examples The acrylic resin solution obtained in Example 4 was mixed with a commercially available HDI trimer curing agent (NCO / OH molar ratio = 1.1), and appropriate amounts of leveling agent and solvent were added to prepare a varnish. It was sprayed onto a tinplate, surface-dried at room temperature, and then baked at 90°C for 30 minutes to cure. The resulting film was glossy and transparent, with a pencil hardness of 3H, and withstood more than 100 swipes with methyl ethyl ketone (MEK), exhibiting excellent high-temperature performance and chemical resistance, making it suitable for high-performance metal protective coatings.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An acrylic resin with a high glass transition temperature based on isobornyl methacrylate derivatives, characterized in that, Acrylic resin is prepared by free radical polymerization of mixed monomers and an initiator, wherein the initiator is added at a mass of 0.1% to 3.0% of the mixed monomers. The mixed monomers comprise the following components by mass: Isoborneol methacrylate derivatives 40%~80%, Adjust monomer content to 10%~40%, The structural formula of the isoborneol methacrylate derivative is shown in formula (Ⅰ) below: Equation (I) The regulating monomer contains hydroxyethyl methacrylate and methyl methacrylate in a mass ratio of 1:(2~3). The acrylic resin has a high glass transition temperature (Tg) of 50℃ to 150℃.

2. The acrylic resin according to claim 1, characterized in that, The regulating monomer also includes at least one of acrylonitrile, n-butyl methacrylate, n-butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, glycidyl methacrylate, and acrylic acid.

3. The acrylic resin according to claim 2, characterized in that, The regulating monomer also includes n-butyl acrylate.

4. The acrylic resin according to claim 1, characterized in that, The initiator is azobisisobutyronitrile and / or benzoyl peroxide.

5. The acrylic resin according to claim 1, characterized in that, The acrylic resin has a high glass transition temperature (Tg) of 60℃ to 150℃.

6. The acrylic resin according to claim 5, characterized in that, The acrylic resin has a high glass transition temperature (Tg) of 90℃ to 140℃.

7. A method for preparing the acrylic resin according to any one of claims 1-6, characterized in that, Includes the following steps: (1) The isobornyl methacrylate derivative, the adjusting monomer, and a portion of the organic solvent are mixed to obtain a mixed monomer solution; the amount of the organic solvent is 50-120 wt% of the mixed monomer; the portion of the organic solvent accounts for 60-80 wt% of the organic solvent. (2) Dissolve the amount of initiator in the formula in the remaining organic solvent to obtain an initiator solution; (3) Under an inert atmosphere, the mixed monomer liquid is heated to 100~150℃, and then the initiator solution is slowly added dropwise. After the addition is completed, the reaction is kept at the temperature for 0.5~2 hours. (4) After the reaction is complete, cool to obtain an acrylic resin solution.

8. The preparation method according to claim 7, characterized in that, The organic solvent is at least one of toluene, ethyl acetate, butyl acetate, or propylene glycol methyl ether acetate.

9. The use of an acrylic resin as described in any one of claims 1-6 in coatings, adhesives, inks or electronic packaging materials.

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